JP2007292730A - Apparatus and method for identifying fluid - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fluid identifying apparatus and a fluid identifying method using the same for identifying the type of fluid on fluids to be identified through the use of thermal characteristics of fluid, and to provide a long-life fluid identifying apparatus. <P>SOLUTION: At least two liquid type detection parts provide with both a temperature sensing element and a heater are used. Either heater is selected to be energized. On the basis of fluid temperature detection signals of the temperature sensing element provided for the fluid detection part not containing the heater selected to be energized according to this and output of a fluid type detection circuit, fluids to be identified are identified. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to fluid properties of fluids such as hydrocarbon liquids such as gasoline, naphtha, kerosene, light oil, and heavy oil, alcoholic liquids such as ethanol and methanol, urea aqueous solution liquids, gases, and granular materials. Fluid identification device that identifies fluid type identification, concentration identification, fluid presence / absence identification, fluid temperature identification, flow rate identification, fluid leakage identification, fluid level identification, ammonia generation amount, etc. And a fluid identification method using a fluid identification device.

  The fluid identification device and the fluid identification method using the fluid identification device according to the present invention are, for example, exhaust gas for decomposing nitrogen oxide (NOx) in a system for purifying exhaust gas discharged from an internal combustion engine of an automobile. It can be used to identify whether or not the liquid sprayed as the urea aqueous solution having the predetermined concentration with respect to the purification catalyst is really the urea aqueous solution having the predetermined concentration.

  An automobile internal combustion engine burns fossil fuels such as gasoline and light oil. In the exhaust gas generated along with this, together with water, carbon dioxide, etc., unburned carbon monoxide (CO) and hydrocarbons (HC), sulfur oxide (SOx), nitrogen oxide (NOx), etc. Of environmental pollutants. In recent years, various measures have been taken to purify the exhaust gas of these automobiles, particularly in order to protect the environment and prevent pollution of the living environment.

  One such measure is the use of an exhaust gas purification catalyst device. In this method, a three-way catalyst for exhaust gas purification is disposed in the middle of the exhaust system, and CO, HC, NOx, etc. are decomposed by an oxidation-reduction reaction to make them harmless. In order to continuously maintain the decomposition of NOx in the catalyst device, an aqueous urea solution is sprayed onto the catalyst from the upstream side of the exhaust catalyst device. This urea aqueous solution needs to be in a specific urea concentration range in order to enhance the effect of NOx decomposition, and the urea concentration of 32.5% is particularly optimal.

  The urea aqueous solution is stored in the urea aqueous solution tank loaded on the automobile, but the concentration may change over time, and the concentration distribution may be locally uneven in the tank. . Since the urea aqueous solution supplied from the tank to the spray nozzle through the supply pipe by the pump is generally collected from the outlet near the bottom of the tank, the efficiency of the catalyst device is that the concentration in this region is a predetermined urea concentration. It is important to increase

  In addition, it is actually possible that a liquid other than the urea aqueous solution is erroneously stored in the urea aqueous solution tank. In such a case, it is necessary to quickly detect that the liquid is other than a urea aqueous solution having a predetermined urea concentration and issue a warning in order to exhibit the function of the catalyst device.

  By the way, the present inventors have already made a heating element generate heat by energization in Japanese Patent Application Laid-Open No. 11-153561 (Patent Document 1) (in particular, see paragraphs [0042] to [0049]). Heating the temperature element, the heat transfer from the heating element to the temperature sensing element has a thermal effect on the identified fluid, and the type of the identified fluid is determined based on the electrical output corresponding to the electrical resistance of the temperature sensing element. And a method for periodically energizing a heating element.

However, in this fluid identification method, since it is necessary to periodically energize the heating element (multiple pulses), identification takes time, and it is difficult to identify the fluid instantaneously. In addition, this method can perform fluid identification by using representative values for substances having considerably different properties such as water, air, and oil. For example, the urea concentration of the urea solution can be identified as described above. It is difficult to do accurately and quickly.

For this purpose, Japanese Patent Application Laid-Open No. 2005-337969 (Patent Document 2) discloses a heating element and a temperature sensing device as a liquid type identification device for identifying whether or not a liquid to be measured is a predetermined one. What has an identification sensor unit that has an indirectly heated liquid type detection unit that includes a body and a liquid temperature detection unit that detects the temperature of the liquid to be measured, and is arranged facing the flow path of the liquid to be measured Are listed. In this liquid type identification device, a single pulse voltage is applied to the heating element of the indirectly heated liquid type detection unit to generate heat, and the temperature sensing element and the liquid temperature detection unit of the indirectly heated liquid type detection unit And an identification calculation unit that identifies the liquid to be measured based on the output of the liquid type detection circuit including
JP-A-11-153561 JP 2005-337969 A JP-A-11-118566 JP 2003-185522 A

  However, in the liquid type identification device described in Patent Document 2, the liquid temperature detection unit detects the temperature by operating only the temperature sensing element without acting the heating element. That is, the liquid temperature detection part and the liquid type detection part are clearly divided in function. Therefore, since the heating element of the liquid type detection unit is always used for detecting the liquid type, there is a problem in that the deterioration of the heating element progresses with time and the life of the liquid type identification device is short.

In view of the present situation as described above, the present invention is to provide a long-life liquid type identification device.
On the other hand, various types of flowmeters [flow sensors] (or flowmeters [flow velocity sensors]) that measure the flow (or flow velocity) of various fluids, particularly liquids, have been used in the past. Therefore, a so-called thermal type (particularly side-heat type) flow meter is used.

  This indirectly heated flow meter uses a thin film technology on a substrate to transfer heat between a thin film heating element and a thin film temperature sensor through an insulating layer between the fluid in the pipe. The one arranged as possible is used.

  By energizing the heating element, the temperature sensing element is heated, and the electrical characteristics of the temperature sensing element, for example, the value of electric resistance are changed. This change in electrical resistance value (based on the temperature rise of the temperature sensing element) changes according to the flow rate (flow velocity) of the fluid flowing in the pipe.

  This is because part of the calorific value of the heating element is transmitted into the fluid, and the amount of heat that diffuses into the fluid changes according to the flow rate (flow velocity) of the fluid, and in response to this, the heat sensing element This is because the amount of heat supplied changes and the electric resistance value of the temperature sensing element changes.

  The change in the electric resistance value of the temperature sensing element also varies depending on the temperature of the fluid. Therefore, a temperature sensing element for temperature compensation should be incorporated in the electric circuit for measuring the change in the electric resistance value of the temperature sensing element. The change of the flow rate measurement value due to the temperature of the fluid is also minimized.

  Such an indirectly heated flow meter using a thin film element is described in, for example, Japanese Patent Application Laid-Open No. 11-118656 (Patent Document 3). In this flow meter, an electric circuit (detection circuit) including a bridge circuit is used to obtain an electrical output corresponding to the flow rate of the fluid.

In the flowmeters as described above, if the thermal properties of the fluid are different, the output of the detection circuit is different even if the actual flow rate is the same. Therefore, it is generally assumed that the type of fluid whose flow rate is measured is known. The output of the detection circuit is converted into a fluid flow rate value using a calibration curve for the fluid.

  However, in recent years, a subdivided supply source obtained by subdividing a fluid is used as a supply source of a fluid whose flow rate is measured, and a plurality of subdivided supply sources are sequentially replaced for the same type of fluid to measure a flow rate.

  For example, in high-purity reagent synthesis, pharmaceutical synthesis, chemical analysis, etc., a small portable container containing a raw material fluid or reagent fluid is connected to a reaction device or an analyzer by a measurement unit, and the measurement unit In some cases, the raw material fluid and the reagent fluid are supplied into the reaction apparatus while the flow rate is being measured.

When the raw material fluid or reagent fluid is replenished, a new portable container filled with the raw material fluid or reagent fluid is connected to the reaction apparatus or analyzer in place of the empty portable container.
In addition, when injecting a medical drug solution into a living body, the medical drug solution is divided into packs for each amount that can be carried, and the drug solution pack and a living body, for example, a blood vessel are connected by a measurement unit, A chemical solution is injected into the living body while measuring the flow rate in the measurement unit. When the chemical solution is replenished, a new pack filled with the chemical solution is connected to the living body instead of the empty pack.

  In addition, in the case of injecting medical medicinal solution into such a living body, the use of a subdivided supply source has a great practical advantage, but on the other hand, it is necessary to replace the fluid supply source with other than the required fluid. There is a possibility of connecting to a source containing fluid.

  In such a case, if the fluid is supplied without noticing that, not only the flow rate cannot be accurately measured based on the difference in thermal properties between the required fluid and the actually supplied fluid, Supplying a fluid can cause manufacturing and analysis defects, accidents, and medical accidents.

  Accordingly, the present invention provides a fluid identification device that can be used as a thermal flow meter with a simple configuration and a function of determining whether or not a fluid is necessary in order to avoid such excessive fluid flow. It is intended to provide.

  On the other hand, fuel oil and various liquid chemicals are stored in the tank. For example, in recent years, a central fueling system in an apartment house has been proposed. In this system, fuel kerosene is supplied to each dwelling unit from a central kerosene tank through a pipe.

  The tank may crack due to deterioration with time, and in this case, the liquid in the tank leaks out of the tank. It is important to detect such a situation as soon as possible and to prevent the occurrence of a flammable explosion, environmental pollution, or generation of toxic gas.

  As an apparatus for detecting leakage of liquid in a tank as soon as possible, Japanese Patent Application Laid-Open No. 2003-185522 (Patent Document 4) discloses a measurement tube into which liquid in a tank is introduced, and a measurement thin tube positioned below the measurement tube. And measuring a flow rate of the liquid in the measurement capillary using a sensor unit attached to the measurement capillary, thereby detecting a minute liquid level fluctuation of the liquid in the tank, that is, a change in the liquid level. ing.

In this leak detection device, an indirectly heated flow meter is used as a sensor attached to the measurement thin tube. In this flow meter, a heating element is heated by energization, a part of the generated heat is absorbed by the liquid, and the effect of this endotherm is taken advantage of the fact that the endothermic amount of the liquid varies depending on the flow rate of the liquid. It is detected by a change in electrical characteristic value, for example, a resistance value due to a temperature change of the temperature sensing element.

  However, in the indirectly heated flow meter used in the leak detection device described in Patent Document 4, the change in the electric circuit output with respect to the change in the flow rate is small in a very small region where the flow rate value is, for example, 1 milliliter / h or less. Therefore, the error of the flow rate measurement value tends to increase. For this reason, there has been a limit to improving the accuracy of leak detection.

  By the way, in the above-described leakage detection, if an external commercial power source is used as a power source for energizing the heating element, it is necessary to lay a power supply wiring from the outside to the sensor of the leakage detection device. Such power supply wiring may cause electric leakage in a long-term use, particularly in a portion taken into the structure of the leakage detection device. When the liquid is flammable or has electrical conductivity, the liquid adhering to the structure of the leak detection device may cause ignition or short circuit due to electric leakage.

  From this point of view, it is preferable to use a battery built in the structure of the leak detection device as a power source for the sensor heating element, particularly when the liquid is flammable or electrically conductive. In that case, it is desirable to reduce the power consumption of the leak detection device in order to perform leak detection without replacing the battery for as long as possible.

  Furthermore, leakage of the liquid in the tank can be detected based on the magnitude of the liquid level fluctuation. A pressure sensor can be used for measuring the liquid level fluctuation. By the way, since the liquid level detection by the pressure sensor converts the detected liquid pressure into the depth from the liquid surface to the pressure sensor, the specific gravity of the liquid to be measured is involved in the conversion.

  Therefore, when leak detection is performed only for a fluid to be measured (for example, water) having a constant specific gravity, the liquid level is immediately calculated based on the output of the pressure sensor by inputting the specific gravity value of the liquid into the conversion program in advance. A value can be obtained, and leak detection can be performed accurately based on this value.

  However, when the liquid to be measured is a mixed composition of many organic compounds such as fuel oil (gasoline, naphtha, kerosene, light oil or heavy oil), even if it is the same kind of fuel oil, for example kerosene, There are many kerosenes that have different compound compositions depending on kerosene distilling conditions, and therefore have different specific gravities (for example, a specific gravity difference of 0.05).

  Therefore, for example, when leak detection is performed for kerosene contained in a tank, the standard specific gravity value of kerosene is used as the liquid specific gravity value in the conversion program from the hydraulic pressure to the liquid level in the leak detection device. However, when the kerosene actually stored in the tank has a specific gravity different from that of standard kerosene, an error due to conversion occurs.

  When the remaining amount of kerosene in the tank decreases, the kerosene is newly replenished, but the supplementary kerosene at that time varies, and therefore the specific gravity of the kerosene in the tank may change each time kerosene is replenished. Thus, in the case of leak detection of a mixed composition such as kerosene, the liquid level is often measured including the conversion error as described above, and the accuracy of leak detection tends to decrease.

  Accordingly, it is an object of the present invention to provide a tank liquid leak detection device with improved detection accuracy when detecting liquid leak in the tank based on fluctuations in the liquid level measured by the pressure sensor.

Another object of the present invention is to provide a fluid identification device that can be used as a leak detection device for liquid in a tank that can detect an extremely small amount of leakage.
Furthermore, an object of the present invention is to provide a fluid identification device that can be used as a leakage detection device capable of continuously detecting leakage and reducing power consumption.

  On the other hand, according to the fluid identification method described in Patent Document 1 (Japanese Patent Laid-Open No. 11-153561), for example, fluids having considerably different properties such as water, air, and oil can be identified by representative values. However, it cannot be said that it is sufficient for accurate and quick identification by applying to the identification of different types of gasoline as described above.

In addition, when this method is applied to gasoline type identification mounted on a moving body such as an automobile, another technical problem arises.
That is, in this case, the inclination angle (inclination angle) of the vehicle with respect to the vertical direction (the direction of gravity) is not always maintained constant. For example, when the vehicle is stopped on an inclined ground, it is compared with the case where the vehicle is stopped on a flat ground. As the tilt angle increases and the discriminator tilts at various angles accordingly, the thermal effect exerted by the gasoline as the fluid to be discriminated on the heat transfer from the heating element to the temperature sensing element changes, and the accuracy of discrimination is changed. May decrease.

  Furthermore, forced flow may occur in the gasoline around the heat transfer member during the movement of the vehicle based on external factors, and the heat provided by the identified fluid for heat transfer from the heating element to the temperature sensing element. The accuracy of identification may be reduced due to a change in the influence of the image.

  Therefore, the present invention provides a fluid identification device that can be used as a gasoline type identification device capable of accurately and quickly identifying a gasoline type even when it is inclined at various angles or during movement. Objective.

  In addition, in order to keep the fuel material composition constant and the optimum combustion conditions do not change, individual hydrocarbons that are components of fossil fuels such as pentane, cyclohexane, octane, etc., or individual alcohols such as methanol, It has been considered to use ethanol or the like as a fuel either alone or in combination of at most about two kinds. This type of fuel is roughly classified into hydrocarbon fuel and alcohol fuel.

  However, when such various fuels are used in parallel in the city, there is a risk that fuel other than a predetermined fuel may be accidentally replenished when refueling the fuel tank. When the fuel supplied to the internal combustion engine is different from a predetermined one, the output efficiency of the engine may be extremely lowered, and such a situation must be avoided.

For this reason, it is desirable that the automobile side also actually detects the type of fuel supplied from the fuel tank to the internal combustion engine and confirms that the type is predetermined.
Further, when the detected fuel type is similar to a predetermined type, it is desirable to optimize the combustion conditions of the internal combustion engine in accordance with the detected fuel type.

  That is, by identifying the type of fuel that is actually supplied to the internal combustion engine and appropriately setting the combustion conditions of the internal combustion engine according to the identification result, it is possible to select a suitable type according to the type of fuel that is actually provided for combustion It is desirable to achieve a combustion state (ie, a combustion state that increases the output torque of the internal combustion engine and reduces the amount of incomplete combustion products in the exhaust gas).

  As described above, since the combustion characteristics and physical properties of the hydrocarbon fuel and the alcohol fuel are greatly different from each other, it is necessary to first determine which of the liquids (fuels) to be measured belongs to. Moreover, it is preferable to identify what kind of hydrocarbon fuel or alcohol fuel is the liquid to be measured (fuel).

  However, the fluid identification method described in Patent Document 1 (Japanese Patent Application Laid-Open No. 11-153561) can identify, for example, fluids having considerably different properties such as water, air, and oil using representative values. Therefore, it is impossible to sufficiently and accurately discriminate the hydrocarbon liquid and the alcohol liquid as described above.

  Accordingly, an object of the present invention is to provide an identification device capable of accurately, quickly and easily identifying a hydrocarbon liquid and an alcohol liquid that can be used as fuel.

  Another object of the present invention is to provide an identification device capable of accurately, quickly and easily identifying what kind of liquid a hydrocarbon liquid or an alcohol liquid is to be measured. To do.

  On the other hand, in the indirectly heated thermal sensor described in Patent Document 1 (Japanese Patent Application Laid-Open No. 11-153561), when the fluid to be measured is a liquid, the dissolved air is caused by a temperature rise or the like. Vaporizes to form bubbles that may adhere to the outer surface of the sensor.

  Similarly, when the fluid to be measured is a liquid, for example, if the liquid is contained in a tank and there is a free surface of the liquid in the tank, the liquid in the tank is swung to The surface undulates and a gas such as air in contact with the liquid surface is entrained in the liquid and remains as bubbles in the liquid, and the bubbles may adhere to the outer surface of the sensor.

In particular, in the case of the urea aqueous solution in the tank mounted on the automobile, the violent rocking based on the external force is repeated during the running of the automobile, so that bubbles adhere to the outer surface of the sensor.
If bubbles are attached to the sensor, the heat generated from the heating element of the sensor will not be transferred to the liquid through the heat transfer member, and the heat will not be transferred from the liquid to the temperature sensing member through the heat transfer member. . As described above, when the heat transfer between the sensor and the liquid to be measured is not normally performed, there is a possibility that a large error occurs in the concentration measurement value of the liquid to be measured and the reliability of the measurement is significantly lowered.

  Accordingly, the present invention provides a fluid identification device identification sensor module that can be used as a thermal sensor that can reduce the adhesion of bubbles to the outer surface of the sensor and improve measurement accuracy, particularly when the object to be measured is an aqueous liquid. It is an object of the present invention to provide a fluid identification device that can be used as a measuring device using the same.

  Furthermore, the present invention provides a fluid identification that can be used as a liquid level detection method that is intended to detect a liquid level with high accuracy by performing correction based on the density of the liquid when detecting the liquid level using a pressure sensor. It is an object to provide a method and a fluid identification device that can be used as a liquid level detection device.

  On the other hand, as described above, in the exhaust gas purification catalyst device, in order to continuously maintain the decomposition of NOx in the catalyst device, the urea aqueous solution is sprayed on the catalyst from immediately upstream of the exhaust system catalyst device. In particular, a urea concentration of 32.5% is said to be optimal.

  However, in this case, the aqueous urea solution has a relatively high freezing point, and in the case of an aqueous urea solution having a urea concentration of 32.5%, it freezes at −11 ° C. Therefore, for example, in Japan, around Wakkanai, Alaska, and the Great Lakes In extremely cold regions such as Canada and Russia, the above exhaust gas purifying catalyst device cannot continuously maintain NOx decomposition in the catalyst device.

For this reason, in the US and the like, a mixed solution in which an ammonium formate solution is mixed with an aqueous urea solution is
In the exhaust gas purifying catalyst device, the freezing point, that is, the freezing temperature is lowered by using it instead of the urea aqueous solution.

By the way, in the case of such a mixed solution, for example, 20% by weight of urea, 26% by weight of ammonium formate, in order to efficiently generate a reduction reaction on the upstream side of the catalyst device without solidifying the mixed solution, H ₂ O is preferably 54% by weight, but no actual method for determining such a suitable mixing ratio has been provided.

  Therefore, in the present invention, when a mixed solution obtained by mixing an aqueous ammonium formate solution with an aqueous urea solution is used instead of the aqueous urea solution in an exhaust gas purification catalyst device, the concentration of the mixed solution in the urea tank and the amount of ammonia generated are accurately determined. And, as a result, the mixed solution can be kept at a predetermined concentration. As a result, the ammonia generation amount measuring device and the ammonia generation amount measuring method can be reduced extremely by reducing NOx in the exhaust gas. The purpose is to provide.

  The present invention has been invented in order to achieve the above-described problems and objects in the prior art, and the sensor module of the present invention includes a temperature sensing element and heat generated in the vicinity of the temperature sensing element. It is characterized in that at least two fluid detectors having a body are accommodated in a container.

The identification sensor module of the present invention includes a fluid detection circuit connected to the at least two fluid detection units,
And an identification calculation unit for identifying the fluid to be identified based on the output of the fluid detection circuit.

  Further, in the identification sensor module of the present invention, the identification calculation unit selects energization of the heating element provided in any one of the at least two fluid detection units, and the heat generation selected to be energized accordingly. A fluid temperature detection signal by a temperature sensing body provided in any one of the fluid detection units not including the body is selected, and the identification target is performed based on the selected fluid temperature detection signal and the output of the fluid detection circuit. Fluid identification is performed.

Further, in the identification sensor module of the present invention, a switch exists in each energization path for the heating element provided in the at least two fluid detection units,
The identification calculation unit selects one of the switches included in the at least two fluid detection units, and thereby selects one of the heating elements included in the at least two fluid detection units. It is characterized by selecting energization.

  In the identification sensor module of the present invention, the identification calculation unit selects energization of the heating element provided in any one of the at least two fluid detection units, and the heating element selected to be energized is selected. Select a fluid temperature detection signal by a temperature sensing element provided in any one of the fluid detection units not included, identify the fluid to be measured, sequentially select the energization to a plurality of heating elements It is characterized by performing.

In the identification sensor module of the present invention, the identification calculation unit selects energization of the heating element provided in any one of the at least two fluid detection units, and the heating element selected to be energized is selected. A characteristic value group calculated based on the output of the liquid type detection circuit when a liquid temperature detection signal by a temperature sensing element provided in any one of the fluid detection units not included is selected for a plurality of heating elements. Obtained in combination with the selection of energization and the selection of the liquid temperature detection signal by the temperature sensor,
The liquid to be measured is identified using an average characteristic value group obtained by averaging corresponding ones.

In the identification sensor module of the present invention, the identification calculation unit selects energization of the heating element provided in any one of the at least two fluid detection units, and the heating element selected to be energized is selected. When a liquid temperature detection signal by a temperature sensing element provided in any one of the fluid detection units not included is selected, a characteristic value group calculated based on the output of the liquid type detection circuit is applied to a plurality of heating elements. In combination with the selection of the liquid temperature detection signal by the temperature sensor,
The liquid to be measured is identified using a sum characteristic value group obtained by taking the sum of the corresponding ones.

In the identification sensor module of the present invention, the identification calculation unit selects energization of the heating element provided in any one of the at least two fluid detection units, and the heating element selected to be energized is selected. When a liquid temperature detection signal by a temperature sensing element provided in any one of the fluid detection units not included is selected, a characteristic value group calculated based on the output of the liquid type detection circuit is applied to a plurality of heating elements. In combination with the selection of the liquid temperature detection signal by the temperature sensor,
The presence or absence of at least one defect of the at least two fluid detection units is determined based on at least one of the difference characteristic value groups obtained by taking the difference between corresponding ones.

The identification sensor module of the present invention is characterized in that the fluid detection unit is disposed in contact with the identified fluid side of the container so as not to be exposed from the container to the identified fluid side.
Further, the identification sensor module of the present invention is arranged such that at least a part of the fluid detection unit is exposed from the container to the identified fluid side.

In the identification sensor module according to the present invention, the exposed portion of the fluid detection unit is covered with a hydrophilic film or a filter.
In the identification sensor module of the present invention, the container includes a container body located on the identified fluid side and a lid portion located on the opposite side to the identified fluid side.

In the identification sensor module of the present invention, the container body is made of metal.
Further, the identification sensor module of the present invention is characterized in that a part of the fluid detection circuit and the identification calculation unit are constituted by an IC.

Further, in the identification sensor module of the present invention, the fluid detection unit has a thin film chip for fluid detection in which a fluid detection temperature sensing element is formed on a chip substrate with a thin film formed on a synthetic resin mold so that one surface thereof is exposed. It is composed by embedding,
One surface of the thin film chip for fluid detection is arranged so as to be positioned on the identified fluid side of the container.

In the identification sensor module of the present invention, the at least two fluid detection units are
A first fluid detection unit including a first temperature sensing element and a first heating element disposed in the vicinity of the first temperature sensing element;
It is comprised by the 2nd fluid detection part provided with the 2nd heat sensing element and the 2nd heat generating body arrange | positioned in the vicinity of this 2nd temperature sensing element.

  In the identification sensor module of the present invention, the identification calculation unit selects the energization to the first heating element and selects the liquid temperature detection signal by the second temperature sensing element to identify the fluid to be measured. The second fluid type for selecting the fluid to be measured by selecting the first fluid identification to be performed and energizing the second heating element and selecting the liquid temperature detection signal by the first temperature sensing element Identification is performed alternately.

  In the identification sensor module of the present invention, when the identification calculation unit selects energization to the first heating element and selects a liquid temperature detection signal by the second temperature sensing element, the fluid detection circuit includes: The first characteristic value group calculated based on the output and the output of the fluid detection circuit when the energization to the second heating element is selected and the liquid temperature detection signal by the first temperature sensing element is selected. The fluid to be measured is identified using an average characteristic value group obtained by averaging the corresponding ones with the second characteristic value group calculated based on the second characteristic value group.

  In the identification sensor module of the present invention, when the identification calculation unit selects energization to the first heating element and selects a liquid temperature detection signal by the second temperature sensing element, the fluid detection circuit includes: The first characteristic value group calculated based on the output and the output of the fluid detection circuit when the energization to the second heating element is selected and the liquid temperature detection signal by the first temperature sensing element is selected. The fluid to be measured is identified using a sum characteristic value group obtained by taking the sum of the corresponding ones with the second characteristic value group calculated on the basis of the second characteristic value group.

  In the identification sensor module of the present invention, when the identification calculation unit selects energization to the first heating element and selects a liquid temperature detection signal by the second temperature sensing element, the fluid detection circuit includes: The first characteristic value group calculated based on the output and the output of the fluid detection circuit when the energization to the second heating element is selected and the liquid temperature detection signal by the first temperature sensing element is selected. Based on at least one of the difference characteristic value groups obtained by taking a difference between corresponding ones with the second characteristic value group calculated based on which of the first and second fluid detection units It is characterized by determining the presence or absence of defects in the mosquito.

In addition, a fluid identification device of the present invention includes any one of the identification sensor modules described above.
In the fluid identification device of the present invention, the identification sensor module is attached to a waterproof case,
It is arrange | positioned so that the fluid detection part side of a container may be exposed to the to-be-identified fluid side from the said waterproof case.

Further, the fluid identification device of the present invention is characterized in that the fluid detection unit side of the container projects from the waterproof case to the identified fluid side.
In the fluid identification device of the present invention, the container is composed of a container main body located on the identified fluid side and a lid located on the opposite side to the identified fluid side,
The junction part of the said container main body and a cover part is arrange | positioned in the waterproof case, It is characterized by the above-mentioned. In the fluid identification device of the present invention, the waterproof case includes a cover member that covers the identified fluid side of the container,
A flow path for the fluid to be identified is formed inside the cover member.

In the fluid identification device of the present invention, a fluid level sensor module for detecting a fluid level of the fluid to be identified is attached to the waterproof case.
The fluid identification device of the present invention is characterized in that a power circuit section is accommodated in the waterproof case.

In the fluid identification device of the present invention, a waterproof wiring extends from the waterproof case.
In the fluid identification device of the present invention, the identification of the fluid to be identified is at least one of fluid type identification, concentration identification, fluid presence / absence identification, fluid temperature identification, flow rate identification, fluid leakage identification, and fluid level identification. It is characterized by one identification.

In the fluid identification apparatus of the present invention, the fluid to be identified is any one of a hydrocarbon liquid, an alcohol liquid, and a urea aqueous solution.
Further, the fluid identification device of the present invention is based on the respective electrical characteristic values of the temperature sensing elements provided in the at least two fluid detection units.
In addition to detecting the flow rate of the fluid, the fluid type is determined by measuring the conductivity between each of the at least two fluid detectors.

In the fluid identification device of the present invention, the fluid identification device is disposed in a fluid type identification chamber,
A pulse voltage is applied to the heating element of the fluid detection unit for a predetermined time, and the identification fluid temporarily retained in the fluid type identification chamber is heated by the heating element of the fluid detection unit,
The fluid type of the fluid to be identified is identified by a voltage output difference corresponding to a temperature difference between an initial temperature and a peak temperature of the temperature sensing element of the fluid detection unit.

In addition, the fluid identification device of the present invention includes a main channel through which the fluid to be identified flows,
A sub-channel branched from the main channel;
The fluid identification device provided in the sub-flow path;
A sub-channel opening / closing valve provided in the sub-channel and controlling the flow of the fluid to be identified to the fluid identification device;
A control device for controlling the fluid identification device and the sub-channel opening / closing valve;
The control device is
When identifying the fluid to be identified, close the sub-channel opening / closing valve and temporarily retain the fluid to be identified in the fluid identification device to identify the fluid to be identified,
When detecting the flow rate of the fluid to be identified, control is performed to detect the flow rate of the fluid to be identified by opening the sub-channel opening / closing valve and causing the fluid to be identified to flow through the fluid identification device. It is comprised by these.

Further, the fluid identification device of the present invention includes a fluid identification detection chamber for temporarily retaining the identification target fluid,
An identification sensor module of the fluid identification device disposed in the fluid identification detection chamber;
And a flow control plate disposed in the fluid identification detection chamber and surrounding the identification sensor module.

In the fluid identification device of the present invention, the fluid identification device is disposed in a fluid type identification chamber,
A pulse voltage is applied to the heating element of the fluid detection unit for a predetermined time, and the identification fluid temporarily retained in the fluid type identification chamber is heated by the heating element of the fluid detection unit,
The fluid detection unit is configured to identify the concentration of the fluid to be identified based on a voltage output difference corresponding to a temperature difference between an initial temperature and a peak temperature of the temperature sensing element.

Further, in the fluid identification device of the present invention, the fluid identification device is disposed in a measurement thin tube into which the fluid to be identified in the tank is introduced from the lower end.
Obtaining an output corresponding to a difference in temperature sensed by the temperature sensing body of the at least two fluid detection units;
Based on the flow-corresponding value corresponding to the flow rate of the identified fluid calculated using the output, the specific gravity of the identified fluid in the tank is detected,
Using the obtained specific gravity value, the fluid level of the fluid to be identified is measured by the fluid level sensor module, and the leakage of the fluid to be identified in the tank is detected based on the magnitude of the temporal change rate of the fluid level. It is characterized by that.

In the fluid identification device of the present invention, the fluid level sensor module detects the fluid pressure of the fluid to be identified, and the provisional fluid level value when the fluid to be identified is a fluid of a predetermined density based on the fluid pressure. To calculate
A pulse voltage is applied to the heating element of the fluid detection unit for a predetermined time, and the fluid to be identified is heated by the heating element of the fluid detection unit,
The concentration of the fluid to be identified is identified by the voltage output difference corresponding to the temperature difference between the initial temperature and the peak temperature of the temperature sensing element of the fluid detector,
Based on the relationship between the density and density of the identified fluid to be identified, the density value of the identified fluid is obtained,
The fluid level of the identification target fluid is calculated based on the temporary fluid level value and the density value.

Further, an ammonia generation amount measuring apparatus according to the present invention includes the fluid identification device according to any one of the foregoing, and the amount of ammonia generated from a liquid to be identified consisting of urea water, ammonium formate water, or a mixed water thereof. A device for measuring the amount of ammonia generated,
Using a sensor comprising a heating element and a temperature sensing element disposed in the vicinity of the heating element,
A pulse voltage is applied to the heating element for a predetermined time, the liquid to be measured is heated by the heating element, and an electric output corresponding to the electric resistance of the temperature sensing element is used.
While measuring the output value corresponding to the thermal conductivity which is the electrical output of the temperature sensing element depending on the thermal conductivity of the liquid to be measured,
Using a differential pressure sensor, measure the density-corresponding output value, which is an electrical output that depends on the density of the liquid to be measured,
From the relationship between the thermal conductivity-corresponding output value and the density-corresponding output value, the urea concentration X wt% and the ammonium formate concentration Y wt% contained in the liquid to be measured are calculated,
Calculate the urea amount A and ammonium formate amount B contained in the liquid to be measured from the concentration and the amount of the liquid to be measured,
The following formula:
Ammonia generation amount = X × A + Y × B
The amount of ammonia generated is measured from

Further, an ammonia generation amount measuring apparatus according to the present invention includes the fluid identification device according to any one of the foregoing, and the amount of ammonia generated from a liquid to be identified consisting of urea water, ammonium formate water, or a mixed water thereof. A device for measuring the amount of ammonia generated,
Using a sensor comprising a heating element and a temperature sensing element disposed in the vicinity of the heating element,
A pulse voltage is applied to the heating element for a predetermined time, the liquid to be measured is heated by the heating element, and an electric output corresponding to the electric resistance of the temperature sensing element is used.
While measuring the output value corresponding to the thermal conductivity which is the electrical output of the temperature sensing element depending on the thermal conductivity of the liquid to be measured,
Using a differential pressure sensor, measure the density-corresponding output value, which is an electrical output that depends on the density of the liquid to be measured,
From the relationship between the thermal conductivity-corresponding output value and the density-corresponding output value, the urea concentration X wt% and the ammonium formate concentration Y wt% contained in the liquid to be measured are calculated,
Calculate the urea amount A and ammonium formate amount B contained in the liquid to be measured from the concentration and the amount of the liquid to be measured,
The following formula:
Ammonia generation amount = X × A + Y × B
The method for measuring the amount of ammonia generated according to the present invention is characterized in that urea water, ammonium formate water, or their aqueous solution can be obtained using any of the fluid identification devices described above. A method for measuring the amount of ammonia generated by measuring the amount of ammonia generated from a liquid to be identified comprising mixed water,
Using a sensor comprising a heating element and a temperature sensing element disposed in the vicinity of the heating element,
A pulse voltage is applied to the heating element for a predetermined time, the liquid to be measured is heated by the heating element, and an electric output corresponding to the electric resistance of the temperature sensing element is used.
The output corresponding to the thermal conductivity, which is the electrical output of the temperature sensor depending on the thermal conductivity of the liquid to be measured, is measured, and the dynamic output which is the electrical output of the temperature sensor depending on the kinematic viscosity of the liquid to be measured. Measure the viscosity corresponding output value,
From the relationship between the thermal conductivity corresponding output value and the kinematic viscosity corresponding output value, the urea concentration X weight% and the ammonium formate concentration Y weight% contained in the liquid to be measured are respectively calculated,
Calculate the urea amount A and ammonium formate amount B contained in the liquid to be measured from the concentration and the amount of the liquid to be measured,
The following formula:
Ammonia generation amount = X × A + Y × B
The amount of ammonia generated is measured from

In addition, the method for measuring the amount of ammonia generated according to the present invention uses the fluid identification device according to any one of the foregoing, and uses the fluid identification device described above to determine the amount of ammonia generated from the liquid to be identified consisting of urea water, ammonium formate water, or a mixture thereof. A method for measuring the amount of ammonia generated to measure the amount,
Using a sensor comprising a heating element and a temperature sensing element disposed in the vicinity of the heating element,
A pulse voltage is applied to the heating element for a predetermined time, the liquid to be measured is heated by the heating element, and an electric output corresponding to the electric resistance of the temperature sensing element is used.
While measuring the output value corresponding to the thermal conductivity which is the electrical output of the temperature sensing element depending on the thermal conductivity of the liquid to be measured,
Using a differential pressure sensor, measure the density-corresponding output value, which is an electrical output that depends on the density of the liquid to be measured,
From the relationship between the thermal conductivity-corresponding output value and the density-corresponding output value, the urea concentration X wt% and the ammonium formate concentration Y wt% contained in the liquid to be measured are calculated,
Calculate the urea amount A and ammonium formate amount B contained in the liquid to be measured from the concentration and the amount of the liquid to be measured,
The following formula:
Ammonia generation amount = X × A + Y × B
The amount of ammonia generated is measured from

  In addition, the fluid identification method of the present invention is characterized in that the fluid to be identified is identified using any of the fluid identification devices described above.

  According to the present invention, at least two liquid type detection units each including both a temperature sensing element and a heating element are used, electrification to any one of the heating elements is selected, and a heating element that has been electrified accordingly is selected. Since the fluid to be identified is identified based on the fluid temperature detection signal from the temperature sensing element provided in the fluid detection unit not included and the output of the fluid type detection circuit, a plurality of heating elements can be used in order, Since the progress of aging of the body is slowed down, a long-life fluid identification device can be provided.

  Further, according to the present invention, since the exposed part of the fluid detection unit and the exposed part of the fluid temperature detection unit are covered with the hydrophilic film or the filter, the identification is performed particularly when the measurement object is an aqueous liquid. Since the adhesion of bubbles to the outer surface of the sensor module is reduced and the sensor module is covered with a filter, the identification sensor module and the identification sensor module capable of improving measurement accuracy are less likely to cause forced flow based on external factors. It is possible to provide a fluid identification device using the.

Further, according to the present invention, the waterproof case includes the cover member that covers the identified fluid side of the container, and the flow passage of the identified fluid is formed inside the cover member. Forcible flow based on external factors is unlikely to occur in the fluid to be identified such as gasoline, and the fluid to be identified such as gasoline with respect to heat transfer from the heating element to the temperature sensing element, regardless of the inclination of the identification device. Therefore, the accuracy of identification such as the type of fluid to be identified such as gasoline can be improved.

  In addition, according to the present invention, the fluid type is determined by measuring the conductivity of the fluid between the fluid sensing temperature sensor used for flow rate detection and the fluid temperature sensing temperature sensor. Therefore, it is possible to prevent a fluid having a clearly different conductivity from passing through a fluid to be identified as a required measurement target with a simple configuration.

  In addition, according to the present invention, a pulse voltage is applied to the heating element of the fluid detection unit for a predetermined time, and the identification fluid temporarily retained in the fluid type identification chamber is heated by the heating element of the fluid detection unit to detect the fluid. Since it is configured to identify the fluid type of the fluid to be identified by the voltage output difference corresponding to the temperature difference between the initial temperature and the peak temperature of the temperature sensor, it is only necessary to apply a pulse voltage for a predetermined time. It is possible to identify the type and distillation properties of the fluid to be identified accurately and quickly by heating in a short time and without heating the fluid to be identified such as light oil to a temperature that ignites. That is, the correlation between the kinematic viscosity of the identified fluid and the sensor output is used, natural convection is used, and the applied voltage of one pulse is used. Can be identified.

  In addition, according to the present invention, for example, when performing fluid type detection, concentration detection, etc. of the identified fluid, when identifying the identified fluid, the sub-channel opening / closing valve is closed, The fluid to be identified can be temporarily retained in the fluid identification device, and the fluid to be identified can be identified accurately and quickly.

  On the other hand, when detecting the flow rate of the fluid to be identified, the sub-channel opening / closing valve is opened, and when detecting the flow rate of the fluid to be identified, the sub-channel opening / closing valve is opened to identify the fluid to be identified. The fluid can be circulated through the fluid identification device, and the flow rate of the fluid to be identified can be detected.

  Therefore, it is possible to accurately and quickly detect the fluid flow rate, for example, fluid type detection, concentration detection, etc. at the same time, and the fluid flow rate can be detected with one fluid identification device. Since it is possible to detect the fluid type, concentration, etc. of the fluid at the same time as the detection, it is compact. For example, when applied to an automobile system, the entire system can be made compact.

  According to the present invention, when the fluid to be identified is temporarily retained in the fluid identification detection chamber, the flow of the identification fluid in the fluid identification detection chamber is suppressed by the flow control plate and surrounded by the flow control plate. The flow of the identification target fluid around the identification sensor module located inside the flow control plate stops instantaneously.

  Accordingly, when the fluid is identified by the identification sensor module, the flow of the fluid to be identified does not occur, and the fluid to be identified is not disturbed due to vibration. For example, the fluid type and concentration of the fluid to be identified are detected. Can be prevented, and the fluid to be identified can be accurately identified.

  In addition, since the fluid identification detection chamber is provided, the amount of the fluid to be identified stays larger, and therefore, when detecting the liquid type, concentration, etc. of the fluid to be identified, it is affected by ambient influences such as external temperature. Therefore, accurate detection can be performed.

  Therefore, for example, when applied to fluids such as gasoline and light oil for automobiles, when the automobile is stopped due to a signal or the like, the pump for gasoline or the like is stopped and the liquid type and concentration of the fluid to be identified are instantly changed. It can be detected, and after the detection is completed, the pump can be started and the automobile can be started again, so that the running of the automobile is not hindered.

  In addition, according to the present invention, a pulse voltage is applied to the heating element of the fluid detection unit for a predetermined time, and the identification fluid temporarily retained in the fluid type identification chamber is heated by the heating element of the fluid detection unit to detect the fluid. Since the configuration is such that the concentration of the fluid to be identified is identified by the voltage output difference corresponding to the temperature difference between the initial temperature and the peak temperature of the temperature sensor, it is only necessary to apply a pulse voltage for a predetermined time, so It is possible to identify the concentration of the fluid to be identified, for example, the urea concentration of the urea solution, accurately and quickly by heating for a period of time.

  That is, the correlation between the kinematic viscosity of the fluid to be identified and the sensor output is used, natural convection is used, and the applied voltage of one pulse is used. Can be identified.

  Further, according to the present invention, the voltage output difference can be accurately obtained based on the average value of the predetermined number of samplings with respect to the applied voltage of one pulse, so the concentration of the fluid to be identified can be accurately and quickly determined. It is possible to identify.

  Further, according to the present invention, the fluid identification device is disposed in the measurement capillary into which the fluid to be identified in the tank is introduced from the lower end, and the fluid temperature sensing body of the fluid detection unit and the fluid temperature of the fluid temperature detection unit The specific gravity of the identified fluid in the tank is obtained based on the flow rate corresponding value corresponding to the flow rate of the identified fluid calculated using the output by obtaining an output corresponding to the difference in temperature sensed by the sensing temperature sensor. Using the obtained specific gravity value, the fluid level sensor module measures the fluid level of the fluid to be identified, and the leakage of the fluid to be identified in the tank is determined based on the magnitude of the time change rate of the fluid level. Therefore, regardless of the specific gravity of the liquid in the tank, it is possible to improve the detection accuracy when detecting leakage of the fluid in the tank due to the fluctuation of the fluid level measured by the fluid level sensor module.

  According to the present invention, the fluid level sensor module detects the fluid pressure of the fluid to be identified, and calculates a temporary fluid level value when the fluid to be identified is a fluid having a predetermined density based on the fluid pressure. The pulse voltage is applied to the heating element of the fluid detection unit for a predetermined time, the fluid to be identified is heated by the heating element of the fluid detection unit, and the temperature between the initial temperature and the peak temperature of the fluid detection temperature sensor Based on the voltage output difference corresponding to the difference, the concentration of the identified fluid is identified, the density value of the identified fluid is obtained based on the relationship between the concentration and density of the identified identified fluid, and a temporary fluid level value is obtained. Since the fluid level of the fluid to be identified is calculated based on the density value and the density value, it is possible to detect the fluid level with high accuracy while preventing the detection error due to the fluid density.

Further, according to the present invention, using a sensor provided with a heating element and a temperature sensing element arranged in the vicinity of the heating element,
A pulse voltage is applied to the heating element for a predetermined time, the liquid to be measured is heated by the heating element, and an electric output corresponding to the electric resistance of the temperature sensing element is used.
The output corresponding to the thermal conductivity, which is the electrical output of the temperature sensor depending on the thermal conductivity of the liquid to be measured, is measured, and the dynamic output which is the electrical output of the temperature sensor depending on the kinematic viscosity of the liquid to be measured. Measure the viscosity corresponding output value,
From the relationship between the thermal conductivity corresponding output value and the kinematic viscosity corresponding output value, the urea concentration X weight% and the ammonium formate concentration Y weight% contained in the liquid to be measured are respectively calculated,
Calculate the urea amount A and ammonium formate amount B contained in the liquid to be measured from the concentration and the amount of the liquid to be measured,
The following formula:
Ammonia generation amount = X × A + Y × B
Therefore, when a mixed solution in which an ammonium formate solution is mixed with an aqueous urea solution is used instead of the aqueous urea solution in an exhaust gas purification catalyst device, the mixture in the urea tank is measured. The concentration of ammonia and the amount of ammonia generated can be accurately and quickly grasped. As a result, the mixed solution can be maintained at a predetermined concentration, and the amount of ammonia generated can be reduced significantly by reducing NOx in the exhaust gas. A measuring device and a method for measuring the amount of ammonia generated can be provided.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic sectional view showing an embodiment used in a liquid type identification device as an example of a fluid identification device according to the present invention, FIG. 2 is a schematic sectional view of the identification sensor module, and FIG. It is typical sectional drawing which shows a liquid type detection part. FIG. 4 is a schematic cross-sectional view showing a usage state of the liquid type identification device of the present embodiment. In the present embodiment, a urea aqueous solution having a urea concentration within a predetermined range is assumed as the predetermined liquid.

  As shown in FIG. 4, the liquid type identification device 1 constitutes a dosing pipe unit portion disposed inside a urea aqueous solution tank 100 for NOx decomposition that constitutes an exhaust gas purification system mounted on an automobile, for example. It is attached to the wall member 101. This attachment can be performed by screwing or band fastening. As shown in FIGS. 1 and 4, the liquid type identification device 1 includes an identification sensor module 2, a liquid level sensor module 3, a waterproof case 4, and a waterproof wiring 5.

  As shown in FIG. 2, the identification sensor module 2 includes a first liquid type liquid temperature detection unit (fluid detection unit) 21, a second liquid type liquid temperature detection unit 22, and a liquid type in a container 20. A detection circuit board (liquid type detection circuit board) 25 and a custom IC (ASIC) 26 are accommodated. The container 20 is made of, for example, an integral body portion 20A made of a corrosion-resistant material such as a metal such as stainless steel and an integral lid portion 20B made of a metal such as stainless steel. This adaptation can be performed by caulking, for example. As shown in FIG. 1, the conforming portion between the main body 20 </ b> A and the lid 20 </ b> B of the container is in the waterproof case 4.

  As shown in FIG. 2, two bulging portions 20A1 and 20A2 are formed on the bottom of the container body 20A (the right portion in FIGS. 1 and 2; the lower portion in FIG. 3). In addition, the first liquid type liquid temperature detection unit 21 and the second liquid type liquid temperature detection unit 22 are disposed in the recesses inside the container corresponding to the bulging parts. The first liquid type liquid temperature detection unit 21 and the second liquid type liquid temperature detection unit 22 are arranged at a certain distance in the vertical direction. As shown in FIG. 3, the first liquid type liquid temperature detection unit 21 detects the first liquid type liquid temperature by forming a first temperature sensing element with a thin film on the chip substrate as described later. A chip (liquid type liquid temperature detecting thin film chip) 21a is embedded in a synthetic resin mold 23 so that one surface thereof is exposed. The synthetic resin mold 23 is made of, for example, an epoxy resin. The exposed one surface (the right surface in FIG. 2; the lower surface in FIG. 3) of the thin film chip 21a of the first liquid type liquid temperature detection unit is in contact with the inner surface of the recessed portion of the container body 20A.

FIG. 5 is an exploded perspective view of the first liquid seed / liquid temperature detecting thin film chip 21a of the first liquid seed / liquid temperature detecting unit 21. FIG. The first liquid type liquid temperature detection thin film chip 21a is, for example a chip substrate 21a1 made of Al ₂ O _3, and the first temperature sensing element 21a2 made of Pt, an interlayer insulating film 2 made of SiO ₂
1a3, a first heating element 21a4 made of TaSiO ₂ and a heating element electrode 21 made of Ni
and a5, and a protective film 21a6 made of SiO _2, and an electrode pad 21a7 made of Ti / Au, consists that sequentially appropriately stacked. Although not shown, the first temperature sensing element 21a2 is formed in a meandering pattern.

As shown in FIG. 3, the electrode pad 21a7 connected to the first temperature sensing element 21a2 and the heating element electrode 21a5 is connected to the external electrode terminal (lead) 21 via the bonding wire 21d.
connected to e. As shown in FIG. 3, one end of the lead 21e (the lower end in FIG. 3) is connected to the synthetic resin mold 23, that is, enters the synthetic resin mold 23, and It is electrically connected to the first liquid type liquid temperature detecting chip 21a through the bonding wire 21d. The other end (the upper end in FIG. 3) of the lead 21e is connected to the liquid type detection circuit board 25 as shown in FIG. 2, that is, fixed to the liquid type detection circuit board 25. . This connection is made by, for example, soldering and has a necessary electrical connection to the circuit formed on the liquid type detection circuit board 25 together with the mechanical connection.

  The second liquid type liquid temperature detection unit 22 can also have the same configuration as the first liquid type liquid temperature detection unit 21. That is, in the second liquid type liquid temperature detection unit 22, a second heating element and a second temperature sensing element similar to the first heating element and the first temperature sensing element, respectively, are used. In FIG. 2, the second liquid seed liquid temperature detecting thin film chip and the external electrode terminals (leads) of the second liquid seed liquid temperature detecting section 22 are indicated by reference numerals 22a and 22e, respectively.

  As shown in FIG. 2, the external electrode terminal 21 e of the liquid type liquid temperature detection unit 21 and the external electrode terminal 22 e of the liquid type liquid temperature detection unit 22 are connected to the circuit of the liquid type detection circuit board 25. . Terminal pins 27 are attached to the liquid type detection circuit board 25. The terminal pin 27 extends out of the container through the container lid 20B. As will be described later, the custom IC 26 includes a part of the liquid type detection circuit and an identification calculation unit.

The liquid level sensor module 3 includes a conventionally known pressure sensor, detects the water pressure received from the liquid in the tank, and outputs a detection signal (corresponding to the liquid level) from the terminal pin 31.
As shown in FIG. 1, a power supply circuit unit 41 is disposed in the waterproof case 4, and the power supply circuit unit 41 is supported by support means (not shown). The power supply circuit unit 41 is formed by mounting required circuit elements on the circuit board 41a, and is suitable for driving each circuit portion of the liquid type identification device 1 based on, for example, DC 24V supplied from an external power supply. It creates DC 5V. The terminal pin 27 of the identification sensor module 2 and the terminal pin 31 of the liquid level sensor module 3 are connected to the circuit of the circuit board 41a.

  As shown in FIGS. 1 and 4, a cover member 2 d is attached to the waterproof case 4 so as to surround the container main body portion 20 </ b> A that protrudes from the waterproof case and is exposed. By this cover member 2d, the upper and lower ends are opened in the vertical direction (vertical direction) through the region adjacent to the liquid seed liquid temperature detection unit 21 and the liquid seed liquid temperature detection unit 22 and located outside the container main body 20A. A measured liquid introduction path 24 is formed.

  The waterproof wiring 5 extends upward from the waterproof case 4, penetrates the top plate of the tank 100 and has an end located outside the tank. A connector 51 for connection to an external circuit is attached to the end of the waterproof wiring 5. The waterproof wiring 5 includes power supply lines to the power supply circuit unit 41 and output signal lines from the identification sensor module 2 and the liquid level sensor module 3 via the circuit board 41a.

FIG. 6 shows a configuration of a circuit for identifying a liquid type in the present embodiment. A bridge circuit is formed by the first temperature sensor 21a2 of the first seed liquid temperature detector 21, the second temperature sensor 22a2 of the second liquid seed liquid temperature detector 22, and the two resistors 64 and 66. (Liquid type detection circuit) 68 is formed. The output of the bridge circuit 68 is input to a differential amplifier 70, and the output of the differential amplifier (also referred to as a liquid type detection circuit output or a sensor output) constitutes an identification calculation unit via an A / D converter (not shown). Is input to a microcomputer 72. The microcomputer 72 also detects the liquid temperature from the first temperature sensing body 21a2 of the first liquid type liquid temperature detection unit 21 and the second temperature sensing body 22a2 of the second liquid type liquid temperature detection unit 22, respectively. The first and second liquid temperature corresponding output values corresponding to the temperature of the liquid to be measured are input through the amplifier 71. On the other hand, the microcomputer 72 outputs a heater control signal for controlling opening and closing of the first switch 74a located in the energization path to the first heating element 21a4 of the first liquid type liquid temperature detection unit 21. Further, a heater control signal for controlling opening and closing of the second switch 74b located in the energization path to the second heating element 22a4 of the second liquid seed liquid temperature detection unit 22 is output.

In the present embodiment, the portion surrounded by the alternate long and short dash line in FIG.
In FIG. 6, for the sake of simplicity, each of the switches 74a and 74b is described as simply opening and closing, but a plurality of voltage application paths that can apply different voltages to each other when built in the custom IC 26. May be formed so that one of the voltage application paths can be selected during heater control. By doing in this way, the selection range of the characteristics of the heating elements 21a4 and 22a4 of the liquid seed liquid temperature detectors 21 and 22 is greatly expanded. That is, it is possible to apply a voltage optimum for identification according to the characteristics of the heating elements 21a4 and 22a4. That is, even if the heating elements 21a4 and 22a4 have a difference in characteristics based on manufacturing errors, the heating elements 21a4 and 22a4 can generate the same amount of heat. In addition, since a plurality of different voltages can be applied during heater control, the types of identification target liquids can be expanded.

  Further, in FIG. 6, for the sake of simplicity, the resistors 64 and 66 are described as having a constant resistance value. However, when the resistors 64 and 66 are built in the custom IC 26, the resistance values of the resistors 64 and 66 are variable. For example, the resistance values of the resistors 64 and 66 may be appropriately changed for identification. Similarly, the characteristics of the differential amplifier 70 and the liquid temperature detection amplifier 71 may be adjusted when being built in the custom IC 26, and the amplifier characteristics may be changed as appropriate for identification. By doing so, it becomes easy to set the characteristics of the liquid type detection circuit to an optimum one, and in manufacturing the first liquid type liquid temperature detection unit 21 and the second liquid type liquid temperature detection unit 22 Variation in identification characteristics generated based on the individual variation of the custom IC 26 and the individual variation in manufacturing the custom IC 26 can be reduced, and the manufacturing yield can be improved.

Hereinafter, the liquid type identification operation in the present embodiment will be described.
When the liquid to be measured US is stored in the tank 100, the liquid to be measured US is also filled in the liquid to be measured introduction path 24 formed by the cover member 2d that covers the identification sensor module 2. The liquid US to be measured in the tank 100 including the inside of the urea aqueous solution introduction path 24 does not substantially flow.

  In the present embodiment, the first liquid type identification for selecting the current to be measured US by selecting the energization to the first heating element 21a4 and selecting the liquid temperature detection signal by the second temperature sensing element 22a2. The second liquid type identification is performed in which the energization of the second heating element 22a4 is selected and the liquid temperature detection signal by the first temperature sensing element 21a2 is selected to identify the liquid US to be measured. Hereinafter, first, the first liquid type identification will be described.

  By closing the switch 74a for a predetermined time (for example, 8 seconds) by a heater control signal (switch closing signal) output from the microcomputer 72 to the first switch 74a, the heating element 21a4 has a predetermined height (for example, for example). A single pulse voltage P of 10 V) is applied to generate heat. At this time, the output voltage (sensor output) Q of the differential amplifier 70 gradually increases during the voltage application to the heating element 21a4 and gradually decreases after the voltage application to the heating element 21a4 is completed, as shown in FIG. To do.

During this operation, the heater control signal (switch closing signal) is not output from the microcomputer 72 to the second switch 74b. That is, the microcomputer 72 selects energization to one of the first and second heating elements 21a4 and 22a4 by selecting the closed state of either the first or second switch 74a or 74b.

  In the microcomputer 72, as shown in FIG. 7, the sensor output is sampled a predetermined number of times (for example, 256 times) for a predetermined time (for example, 0.1 second) before the voltage application to the heating element 21a4 is started, and the average value is obtained. To obtain the average initial voltage value V1. This average initial voltage value V1 corresponds to the initial temperature of the temperature sensing element 21a2.

  In addition, as shown in FIG. 7, the first time which is a relatively short time from the start of voltage application to the heating element (for example, 0.5 or less of the application time of a single pulse and 0.5 ~ 3 seconds; 2 seconds in FIG. 7 (specifically immediately before the passage of the first time), the sensor output is sampled a predetermined number of times (for example, 256 times), and the average value is calculated and averaged. A first voltage value V2 is obtained. This average first voltage value V2 corresponds to the first temperature when the first time elapses from the start of the single pulse application of the temperature sensing element 21a2. Then, a difference V01 (= V2−V1) between the average initial voltage value V1 and the average first voltage value V2 is obtained as the liquid type corresponding first voltage value.

  Further, as shown in FIG. 7, when a second time (for example, the application time of a single pulse; 8 seconds in FIG. 7), which is a relatively long time from the start of voltage application to the heating element has elapsed (specifically Specifically, the sensor output is sampled a predetermined number of times (for example, 256 times) immediately before the second time elapses, and an average is obtained to obtain an average second voltage value V3. This average second voltage value V3 corresponds to the second temperature when the second time elapses from the start of single pulse application of the temperature sensing element 21a2. Then, a difference V02 (= V3−V1) between the average initial voltage value V1 and the average second voltage value V3 is obtained as the liquid type-corresponding second voltage value.

  By the way, a part of the heat generated in the heating element 21a4 based on the voltage application of the single pulse as described above is transmitted to the temperature sensing element 21a2 through the liquid to be measured. There are mainly two forms of this heat transfer that differ depending on the time from the start of pulse application. That is, in the first stage within a relatively short time (for example, 3 seconds, especially 2 seconds) from the start of pulse application, the heat transfer is mainly dominated by conduction (for this reason, the first voltage value V01 corresponding to the liquid type is mainly liquid. Affected by the thermal conductivity of On the other hand, in the second stage after the first stage, heat transfer is mainly dominated by natural convection (for this reason, the liquid type-corresponding second voltage value V02 is mainly influenced by the kinematic viscosity of the liquid). This is because in the second stage, natural convection occurs due to the liquid to be measured heated in the first stage, and the ratio of heat transfer due to this increases.

  As described above, the optimum concentration (weight percent: the same applies hereinafter) of the urea aqueous solution used in the exhaust gas purification system is 32.5%. Therefore, the allowable range of the urea concentration of the urea aqueous solution to be accommodated in the urea aqueous solution tank 100 can be set to 32.5% ± 5%, for example. The width ± 5% of the allowable range can be appropriately changed as desired. That is, in this embodiment, a urea aqueous solution having a urea concentration in the range of 32.5% ± 5% is determined as the predetermined liquid.

  The liquid type corresponding first voltage value V01 and the liquid type corresponding second voltage value V02 change as the urea concentration of the urea aqueous solution changes. Therefore, the range (predetermined range) of the liquid type-corresponding first voltage value V01 and the range (predetermined range) of the liquid type-corresponding second voltage value V02 corresponding to the urea aqueous solution within the urea concentration range of 32.5% ± 5% are obtained. Exists.

By the way, even if it is liquid other than urea aqueous solution, depending on the density | concentration, the output in the predetermined range of said liquid type corresponding | compatible 1st voltage value V01 and the predetermined range of liquid type corresponding | compatible 2nd voltage value V02 is obtained. There is. That is, even if the liquid type corresponding first voltage value V01 or the liquid type corresponding second voltage value V02 is within the predetermined range, the liquid is not necessarily a predetermined urea aqueous solution. For example, as shown in FIG. 8, the urea concentration falls within a predetermined range within the range of the first voltage value V01 corresponding to the liquid type obtained with the urea aqueous solution of 32.5% ± 5% (ie, the sensor display concentration value). Within the range of 32.5% ± 5% in terms of conversion, there is a first voltage value corresponding to the liquid type of the sugar aqueous solution having a sugar concentration of about 25% ± 3%.

  However, the value of the liquid type corresponding second voltage value V02 obtained from the sugar aqueous solution within the sugar concentration range is far from the range of the liquid type corresponding second voltage value V02 obtained with the urea aqueous solution within the predetermined urea concentration range. It will be. That is, as shown in FIG. 9, in the sugar aqueous solution within the sugar concentration range of 15% to 35% including the sugar concentration range of about 25% ± 3%, the liquid type corresponding first voltage value V01 is predetermined. However, the liquid type-corresponding second voltage value V02 is significantly different from the urea aqueous solution within the predetermined urea concentration range. In FIG. 9, both the liquid type-corresponding first voltage value V01 and the liquid type-corresponding second voltage value V02 are shown as relative values with 1.000 being a urea aqueous solution having a urea concentration of 30%. Thus, the sugar aqueous solution can be determined by determining whether or not the liquid is in a predetermined range with respect to both the liquid type corresponding first voltage value V01 and the liquid type corresponding second voltage value V02. Can be reliably identified as not being a predetermined liquid.

  In addition, the liquid type corresponding second voltage value V02 may overlap with that of the predetermined liquid. However, in this case, since the liquid type-corresponding first voltage value V01 is different from that of the predetermined liquid, it is possible to reliably identify that the liquid is not the predetermined one based on the determination criterion.

  In the present invention, the liquid type is identified by utilizing the fact that the relationship between the liquid type-corresponding first voltage value V01 and the liquid type-corresponding second voltage value V02 varies depending on the type of solution as described above. That is, the first voltage value V01 corresponding to the liquid type and the second voltage value V02 corresponding to the liquid type are affected by different physical properties of the liquid, that is, thermal conductivity and kinematic viscosity, and these relations differ depending on the type of the solution. Thus, liquid type identification as described above becomes possible. By narrowing the predetermined range of the urea concentration, the identification accuracy can be further increased.

  That is, in the embodiment of the present invention, the first calibration curve indicating the relationship between the temperature and the liquid type-corresponding first voltage value V01 and the temperature and the liquid type corresponding to some urea aqueous solutions (reference urea aqueous solution) having a known urea concentration. A second calibration curve showing the relationship with the second voltage value V02 is obtained in advance, and these calibration curves are stored in the storage means of the microcomputer 72. Examples of the first and second calibration curves are shown in FIGS. 10 and 11, respectively. In these examples, calibration curves are created for reference urea aqueous solutions having urea concentrations c1 (for example, 27.5%) and c2 (for example, 37.5%).

  As shown in FIGS. 10 and 11, since the liquid type corresponding first voltage value V01 and the liquid type corresponding second voltage value V02 depend on the temperature, the liquid to be measured is identified using these calibration curves. In this case, the liquid temperature corresponding output value T input from the second temperature sensing element 22a2 of the second liquid type liquid temperature detection unit 22 via the liquid temperature detection amplifier 71 is also used. An example of the liquid temperature corresponding output value T is shown in FIG. Such a calibration curve is also stored in the storage means of the microcomputer 72.

When measuring the liquid type-corresponding first voltage value V01, first, a temperature value is obtained from the liquid temperature-corresponding output value T obtained for the liquid to be measured, using the calibration curve of FIG. Assuming that the obtained temperature value is t, then, in the first calibration curve of FIG. 10, the liquid type corresponding first voltage values V01 (c1; t), V01 (c2; c) of each calibration curve corresponding to the temperature value t. t). Then, cx of the liquid type corresponding first voltage value V01 (cx; t) obtained for the liquid to be measured to be measured is used as the liquid type corresponding first voltage value V01 (c1; t), V01 (c2; c) of each calibration curve. Determine by performing a proportional operation using t). That is, cx is based on V01 (cx; t), V01 (c1; t), V01 (c2; t), and the following formula (1)
cx = c1 +
(C2-c1) [V01 (cx; t) -V01 (c1; t)]
/ [V01 (c2; t) -V01 (c1; t)] (1)
Ask from.

Similarly, when measuring the liquid type corresponding second voltage value V02, the liquid type of each calibration curve corresponding to the temperature value t obtained for the liquid to be measured in the second calibration curve of FIG. 11 as described above. Corresponding second voltage values V02 (c1; t), V02 (c2; t) are obtained. Then, the cy of the liquid type corresponding second voltage value V02 (cy; t) obtained for the liquid to be measured is set as the liquid type corresponding second voltage value V02 (c1; t), V02 (c2; t) of each calibration curve. Determine by performing the proportional calculation used. That is, cy is based on V01 (cy; t), V01 (c1; t), V01 (c2; t), and the following formula (2)
cy = c1 +
(C2-c1) [V02 (cy; t) -V02 (c1; t)]
/ [V02 (c2; t) -V02 (c1; t)] (2)
Ask from.

  In addition, by using the first and second calibration curves in FIGS. 10 and 11 that use the liquid temperature corresponding output value T instead of the temperature, the calibration curve in FIG. 12 is stored and converted using this. Can be omitted.

  As described above, for each of the liquid type-corresponding first voltage value V01 and the liquid type-corresponding second voltage value V02, it is possible to set a predetermined range that varies depending on the temperature. By setting c1 to 27.5% and c2 to 37.5% as described above, the region surrounded by the two calibration curves in each of FIGS. 10 and 11 is a predetermined liquid (that is, urea concentration). 32.5% ± 5% urea aqueous solution).

  FIG. 13 is a graph schematically showing that a predetermined liquid identification criterion based on the combination of the liquid type-corresponding first voltage value V01 and the liquid type-corresponding second voltage value V02 changes according to the temperature. As the temperature rises to t1, t2, and t3, the areas AR (t1), AR (t2), and AR (t3) that are determined as the predetermined liquid move.

FIG. 14 is a flowchart showing a liquid type identification process in the microcomputer 72.
First, before applying a pulse voltage to the heating element 21a4 by heater control, N = 1 is stored in the microcomputer (S1), and then the sensor output is sampled to obtain an average initial voltage value V1 (S2). Next, heater control is executed, and the sensor output is sampled when the first time has elapsed from the start of voltage application to the heating element 21a4 to obtain an average first voltage value V2 (S3). Next, the calculation of V2-V1 is performed to obtain a liquid type corresponding first voltage value V01 (S4). Next, the sensor output is sampled when the second time has elapsed from the start of voltage application to the heating element 21a4 to obtain an average second voltage value V3 (S5). Next, calculation of V3-V1 is performed to obtain a liquid type corresponding second voltage value V02 (S6).

Next, referring to the temperature value t obtained for the liquid to be measured, the liquid type-corresponding first voltage value V01 is within a predetermined range at the temperature and the liquid type-corresponding second voltage value V02 is a predetermined value at the temperature. It is determined whether or not the condition of being within the range is satisfied (S7). If it is determined in S7 that at least one of the liquid type-corresponding first voltage value V01 and the liquid type-corresponding second voltage value V02 is not within the predetermined range (NO), the stored value N is 3. It is determined whether or not there is (S8). If it is determined in S8 that N is not 3 [that is, the current measurement routine is not the third time (specifically, the first or second time)] (NO), then the stored value N is set to 1 only. Increase (S9) and return to S2. On the other hand, when it is determined in S8 that N is 3 [that is, the current measurement routine is the third time] (YES), it is determined that the fluid to be measured is not a predetermined one (S10).

  On the other hand, if it is determined in S7 that both the liquid type-corresponding first voltage value V01 and the liquid type-corresponding second voltage value V02 are within the respective predetermined ranges (YES), the fluid to be measured is the predetermined one. It is determined that there is (S11).

  In this embodiment, following S11, the urea concentration of the urea aqueous solution is calculated (S12). This concentration calculation is based on the output of the liquid temperature detector 22, that is, the temperature value t obtained for the liquid to be measured, the liquid type corresponding first voltage value V01, and the first calibration curve in FIG. ) Can be used. Alternatively, the concentration is calculated based on the output of the liquid temperature detection unit 22, that is, the temperature value t obtained for the liquid to be measured, the liquid type corresponding second voltage value V02, and the second calibration curve in FIG. 2).

  On the other hand, the second liquid type identification is performed by the operation of the first liquid type liquid temperature detection unit 21 and the first switch 74a and the second liquid type liquid temperature detection unit 22 and the second liquid type in the first liquid type identification. This is done in the same way by changing the operation of the switch 74b.

  The first liquid type identification and the second liquid type identification as described above can be executed alternately. As a result, the heating element 21a4 of the first liquid type and liquid temperature detection unit 21 and the heating element 22a4 of the second liquid type and liquid temperature detection unit 22 each have half the frequency of heat generation. Significantly extended.

In the present invention, as another method, the following liquid type identification operation can be performed in the microcomputer 72.
(1) The energization of the first heating element 21a4 is selected and the liquid temperature detection signal by the second temperature sensing element 22a2 is selected. At that time, the first characteristic value group (the above-mentioned liquid type correspondence number is selected based on the sensor output). 1 voltage value V01 ₋₁ and liquid type corresponding second voltage value V02 ₋₁ ) are calculated. Next, energization of the second heating element 22a4 is selected, and a liquid temperature detection signal by the first temperature sensing element 21a2 is selected, and at that time, the second characteristic value group (the first corresponding to the liquid type described above) is selected based on the sensor output. Voltage value V01 _-2 and liquid type corresponding second voltage value V02 _-2 ) are calculated. Based on this, the average characteristic is obtained by averaging the corresponding ones of the first characteristic value group and the second characteristic value group (liquid type-corresponding first voltage values and liquid type-corresponding second voltage values). Value group (averaged liquid type corresponding first voltage value V01A = (V01 ₋₁ −V01 ₋₂ ) / 2 and averaged liquid type corresponding second voltage value V02A = (V02 ₋₁ −V02 ₋₂ ) / 2) is obtained. Then, using the averaged liquid type corresponding first voltage value V01A and the averaged liquid type corresponding second voltage value V02A as the liquid type corresponding first voltage value V01 and the liquid type corresponding second voltage value V02, The liquid US to be measured is identified as described above.

(2) The energization of the first heating element 21a4 is selected and the liquid temperature detection signal by the second temperature sensing element 22a2 is selected. At that time, the first characteristic value group (the above-mentioned liquid type corresponding 1 voltage value V01 ₋₁ and liquid type corresponding second voltage value V02 ₋₁ ) are calculated. Next, energization of the second heating element 22a4 is selected, and a liquid temperature detection signal by the first temperature sensing element 21a2 is selected, and at that time, the second characteristic value group (the first corresponding to the liquid type described above) is selected based on the sensor output. Voltage value V01 _-2 and liquid type corresponding second voltage value V02 _-2 ) are calculated. Based on this, by taking the sum of the corresponding ones of the first characteristic value group and the second characteristic value group (liquid type corresponding first voltage values and liquid type corresponding second voltage values), Characteristic value groups (sum of liquid type corresponding first voltage values V01S = (V01 ₋₁ + V01 ₋₂ ) and sum of liquid type corresponding second voltage values V02S = (V02 ₋₁ + V02 ₋₂ )) are obtained. Then, instead of the liquid type corresponding first voltage value V01 and the liquid type corresponding second voltage value V02, the sum V01S of the liquid type corresponding first voltage value and the sum V02S of the liquid type corresponding second voltage value are used. In this way, the liquid US to be measured is identified. However, in this identification, instead of the calibration curves in FIGS. 10 and 11, the one corresponding to the sum V01S of the liquid type corresponding first voltage value and the sum V02S of the liquid type corresponding second voltage value is used. .

  As described above, the liquid type can be identified accurately and quickly. This liquid type identification routine can be appropriately executed when the engine of the vehicle is started, periodically, when requested by the driver or the vehicle (ECU described later), or when the key of the vehicle is turned off. In a desired manner, it is possible to monitor whether or not the liquid in the urea tank is a urea aqueous solution having a predetermined urea concentration. A signal indicating whether or not the liquid type is obtained in this way (whether or not it is a predetermined one, and further a signal indicating a urea concentration in the case of a predetermined [urea aqueous solution having a predetermined urea concentration]) is not shown. 6 is output to the output buffer circuit 76 shown in FIG. 6 through the D / A converter, and from here through the terminal pins 27, the power supply circuit board 41a and the waterproof wiring 5, an automobile engine (not shown) is provided as an analog output. Is output to a main computer (ECU) that performs combustion control and the like. The analog output voltage value corresponding to the liquid temperature is also output to the main computer (ECU) through a similar route. On the other hand, the signal indicating the liquid type can be taken out as a digital output as necessary, and can be input to a device that performs a display, an alarm, and other operations through a similar route.

  Further, a warning is given when it is detected that the temperature of the urea aqueous solution has dropped to near the temperature (about -13 ° C.) based on the liquid temperature corresponding output value T input from the liquid type liquid temperature detectors 22 and 21. Can be issued.

Moreover, the presence or absence of a defect in either of the first and second liquid type liquid temperature detection units 21 and 22 can be determined as follows. That is, first, energization to the first heating element 21a4 is selected, and a liquid temperature detection signal by the second temperature sensing element 22a2 is selected, and at that time, the first characteristic value group (corresponding to the above liquid type) is selected based on the sensor output. First voltage value V01 ₋₁ and liquid type corresponding second voltage value V02 ₋₁ ) are calculated. Next, energization of the second heating element 22a4 is selected, and a liquid temperature detection signal by the first temperature sensing element 21a2 is selected, and at that time, the second characteristic value group (the first corresponding to the liquid type described above) is selected based on the sensor output. Voltage value V01 _-2 and liquid type corresponding second voltage value V02 _-2 ) are calculated. Based on this, by taking the difference between the corresponding ones of the first characteristic value group and the second characteristic value group (liquid type corresponding first voltage values and liquid type corresponding second voltage values), a difference is obtained. A characteristic value group (difference in first voltage value corresponding to liquid type V01R = (V01 ₋₁ −V01 ₋₂ ) and difference in second voltage value corresponding to liquid type V02S = (V02 ₋₁ −V02 ₋₂ )) is obtained. Then, at least one of these difference characteristic value groups, for example, the difference V02R of the liquid type-corresponding second voltage value is compared with the preset allowable limit value REF, and if V02R ≦ REF, the first value is compared. And the second liquid type liquid temperature detectors 21 and 22 are determined to be free of defects, and if V02R> REF, one of the first and second liquid type liquid temperature detectors 21 and 22 is determined. It is determined that there is a defect. If it is determined that there is a defect in this determination, it is possible to instruct a display means (not shown) to display a warning. This determination can be performed periodically or every time a liquid type identification is performed a preset number of times.

  Note that the above liquid type identification uses natural convection and uses the principle that the kinematic viscosity of the liquid to be measured such as urea aqueous solution and the sensor output have a correlation. In order to increase the accuracy of such liquid type identification, the container body in which heat is transferred between the first liquid type liquid temperature detection unit 21 and the second liquid type liquid temperature detection unit 22 and the liquid to be measured. It is preferable that forced flow based on external factors be made as difficult as possible in the liquid to be measured around the portion 20A. From this point, the cover member 2d, in particular, the liquid to be measured in the vertical direction (vertical direction) is formed. The use of things is preferred. Note that the cover member 2d also functions as a protective member that prevents contact of foreign matter.

  In the above embodiment, a urea aqueous solution having a predetermined urea concentration is used as the predetermined fluid. However, in the present invention, the predetermined liquid may be an aqueous solution or other liquid using other than urea as a solute.

In the above embodiment, the liquid to be measured is used as the fluid to be identified. However, as described later, for example, hydrocarbon liquids such as gasoline, naphtha, kerosene, light oil, and heavy oil, alcohols such as ethanol and methanol For fluids such as system liquids, urea aqueous solution liquids, gases, and particulates, fluid type identification, concentration identification, fluid presence / absence identification, fluid temperature identification, flow rate, using the thermal properties of the fluid Identification such as identification, fluid leakage identification, fluid level identification, and ammonia generation amount can be performed.

The embodiment shown in FIG. 15 shows an embodiment applied to a gasoline identification device as a fluid identification device to which the cover member 2d is applied.
In this case, as in the above-described embodiment, the principle of gasoline type identification may be based on the principle that the dynamic viscosity of gasoline and the sensor output have a correlation using natural convection. In order to increase the accuracy of such gasoline type identification, it is preferable that forced flow based on external factors be made as difficult as possible in the gasoline around the gasoline type detection unit fin 21c and the liquid temperature detection unit fin 22c. From this point of view, it is preferable to use the cover member 2d, particularly one that forms a gasoline introduction path in the vertical direction. Note that the cover member 2d also functions as a protective member that prevents contact of foreign matter.

  The cover member 2d also exhibits a function of improving the accuracy of gasoline type identification as compared with the case where the cover member is not present when the tilt angle of the measurement unit 40, particularly the identification sensor module 2, with respect to the vertical direction changes. . That is, when there is no cover member, the change in the form in which the heat generated from the heating element is transmitted to the temperature sensing element by the natural convection is large with respect to the change in the inclination angle. The change in the corresponding voltage value V0 is large, and therefore the inclination range where the confusion with the output value in the case of other types of gasoline does not occur is relatively narrow.

  On the other hand, when the cover member 2d is present, the change in the form in which the heat generated from the heating element is transmitted to the temperature sensing element by the natural convection is small with respect to the change in the tilt angle (that is, Natural convection is always performed mainly along the gasoline introduction path in the cover member 2d). Therefore, the change in the voltage value V0 corresponding to the gasoline type of the same gasoline is small, and therefore the output value in the case of other types of gasoline. The tilt range that does not cause confusion is relatively wide.

FIG. 16 shows the change in the gasoline type-corresponding voltage value V0 obtained when the tilt angle of the measurement unit is changed in the fluid identification device of the embodiment of FIG. 15 (with the cover member 2d), and FIG. The change of the gasoline type corresponding voltage value V0 obtained when the inclination angle of the measurement unit is changed is the same as that of the above-described embodiment of the present invention (comparative form) except for the removal.
Two types of gasoline having different T50s (sample 1 [T50 = 99 ° C.] and sample 2 [T50 = 87 ° C.]) are used, and the direction of inclination is the X direction shown in FIG. 15 (a) and FIG. Two types in the Y direction shown in FIG.

  In the comparative form, as shown in FIG. 17, the gasoline type-corresponding voltage value V0 may overlap between the sample 1 and the sample 2 within the range of the inclination angle θ of ± 30 °. As shown in FIG. 16, the gasoline type corresponding voltage value V0 does not overlap between the sample 1 and the sample 2 in the range where the inclination angle θ is ± 30 °. Thus, it can be seen that by attaching the cover member 2d, it is possible to identify the gasoline type with high accuracy in a wide inclination range.

  FIG. 18 is a schematic configuration diagram of an embodiment using a series circuit instead of the parallel circuit of FIG. The same components as those in the circuit diagram of FIG. 6 are denoted by the same reference numerals, and detailed description thereof is omitted.

In FIG. 18, reference numeral 13 is a resistor, and 14 is a changeover switch for detecting a liquid temperature. As shown in the figure, the voltage at both ends of the liquid temperature detector 22 is output as the output A.

In this embodiment, when the changeover switch 14 is set to the a side, an output A of liquid temperature detection is obtained. On the other hand, at the time of identification such as liquid type identification, the output A for liquid type identification can be obtained by setting the changeover switch 14 to the b side. The liquid type identification and the liquid temperature can be detected based on the same principle as in the above embodiment.
Yeah.

  FIG. 19 is a graph showing an example of an output A (that is, a liquid temperature detection result) obtained in a state where the changeover switch 14 shown in FIG. 18 is connected to the a side. There is a 1: 1 correspondence between the liquid temperature and the output A. Since this characteristic can be measured in advance, the liquid temperature can be detected from the value of the output A obtained.

  20 is a cross-sectional view of an identification sensor module according to another embodiment of the present invention, FIG. 21A is a schematic view showing the inside of FIG. 20, and FIG. 21B is viewed from the direction A of FIG. It is a partial expanded sectional view.

  As shown in FIGS. 20 and 21, a part of the metal fins 21c and 22c is exposed from the resin mold 23 to form an exposed surface portion, and a hydrophilic film 50 is attached to the exposed surface portion. Has been. More preferably, a hydrophilic film 50 is also applied to the surface portion of the resin mold 23 located around the exposed surface portions of the metal fins 21c and 22c. That is, the hydrophilic film 50 is formed over the exposed surface portions of the metal fins 21 c and 22 c and the surface portion of the resin mold 23 around the exposed surface portions.

  The hydrophilic film 50 is, for example, a silicon oxide film. The thickness of the silicon oxide film 50 is, for example, 0.01 μm to 1 μm. The silicon oxide film 50 has good adhesion to both the metal fins 21c and 22c and the resin mold 23, and has high film strength. Further, the surface of the silicon oxide film 50 has a higher degree of hydrophilicity than any of the surfaces of the metal fins 21 c and 22 c and the resin mold 23.

  The degree of hydrophilicity can be expressed by a water contact angle, and generally a water contact angle of about 40 ° or less is regarded as hydrophilic. The water contact angle of the silicon oxide film 50 can be set to 40 ° or less, and the silicon oxide film 50 exhibits hydrophilicity. In the present invention, the water contact angle of the hydrophilic membrane 50 is preferably 35 ° or less, more preferably 30 ° or less, still more preferably 25 ° or less, and particularly preferably 20 ° or less. .

  The silicon oxide film 50 can be formed, for example, by sputtering, CVD (chemical vapor deposition), or coating with a coating agent. Among these, sputtering and CVD require a long actual processing time, and it is difficult to form a film having a large thickness, and the apparatus configuration for film formation becomes large. On the other hand, the application of the coating agent has many practical advantages such as simple processing and a relatively short actual processing time apart from the standing time. As the coating agent, an organic silicon compound containing a silicon oxide film by a reaction after coating can be used.

Examples of such a coating agent include polysilazane such as perhydropolysilazane, a silane coupling agent added as necessary, an organic solvent, and a palladium catalyst or an amine catalyst used as necessary (for example, Clariant Japan). An example is Aquamica [registered trademark] available from a corporation. An example of the specific steps of coating application and related pre- and post-treatments is as follows:
(1) Ethanol cleaning process (to remove stains on the surface where the coating agent should be applied)
(2) Xylene cleaning process (for degreasing the surface part)
(3) Drying step (for removing water from the surface portion: about 100 ° C., about 1 hour)
(4) Coating agent coating process (performed by spray coating, brush or waste coating, flow coating, dip coating, etc.)
(5) Heating step (for solvent removal and silicon oxide conversion: 125 to 200 ° C., about 1 hour)
(6) Heating and humidifying step (for silicon oxide conversion: 50 to 90 ° C., 80 to 95%, about 3 hours)
(7) Cooling step The cleaning step is exemplified by using an organic solvent such as acetone, isopropyl alcohol or hexane as the cleaning solvent in addition to the above-described ethanol or xylene as the cleaning solvent. The

In the heating step and the heating and humidifying step, a silicon oxide film is formed by causing the following conversion reaction with water in the surrounding air (naturally occurring or due to humidification):
-(-SiH ₂ NH-)-+ 2H ₂ O →-(-SiO ₂ -)-+ NH ₃ + 2H ₂
By using the heating and humidifying process, the heating temperature of the heating process can be lowered. For example, when the heating and humidifying process is not used, the heating temperature in the heating process is about 250 ° C.

  The thickness of the silicon oxide film to be formed is, for example, 0.01 μm to 1 μm as described above, but if it is too thick, peeling tends to occur, while if it is too thin, it may be difficult to maintain hydrophilicity for a long time. Therefore, it is more preferably 0.05 μm to 0.8 μm.

  FIG. 22A is a perspective view of an identification sensor module according to another embodiment of the present invention, FIG. 22B is a schematic view showing a mounting state of the identification sensor module of FIG. 22A, and FIG. It is the longitudinal cross-sectional view which looked at the identification sensor module of FIG. 22 from the B direction.

  As shown in FIGS. 22 and 23, the identification sensor module 2 of this embodiment includes a container 20 that is configured in a sealed state and in which the identification target fluid 212 does not enter the inside. A sensor holder 6 is disposed on the identified fluid side in the container 20 and is attached so as to keep the container 20 in a sealed state.

  Then, as shown in FIG. 23, the liquid type liquid temperature detecting thin film chip 21a is embedded in the sensor mounting hole 6a in the center of the sensor holder 6 with the synthetic resin mold 23 in the same manner as the embodiment of FIG. It has become.

  The liquid type detecting thin film chip 21a is in a state of protruding from the protruding end side of the synthetic resin mold 23 toward the identified fluid 212 side, and the portion protruding toward the identified fluid 212 side is the synthetic resin 23a. It is configured to be covered.

  Further, as shown in FIG. 22B, the identification sensor module 2 of this embodiment is fixed by fastening a fixing screw 208 to the waterproof case 4 via a fixing member 206. . In FIG. 22B, reference numeral 210 denotes packing.

  A filter holder 8 is fixed to the sensor holder 6 via a fixing screw 7. A filter 9 having a substantially U-shaped cross section is fixed to the filter holder 8 so as to surround the metal fin 21c. In the figure, reference numeral 200 denotes an ASIC board, 202 denotes packing, and 204 denotes a connector.

Such a filter is not particularly limited. For example, filter materials include resins such as polyethylene and polyester, ceramics such as zirconia and alumina, and those porous materials can be used as a filter. Is possible. Since the exposed part of the identification sensor module 2 is covered with a hydrophilic film or a filter, the adhesion of bubbles to the outer surface of the identification sensor module 2 is reduced particularly when the object to be measured is an aqueous liquid. At the same time, forced flow based on external factors is unlikely to occur in the fluid to be identified, and measurement accuracy can be improved.

24 and 25 are graphs for explaining another embodiment using the fluid identification device of the present invention.
By the way, in order to keep the material composition of the fuel constant so that the optimum combustion conditions do not change, individual hydrocarbons such as pentane, cyclohexane, octane, etc., or individual alcohols such as methanol, ethanol, etc., which are components of the fossil fuel, are added. These are considered to be used alone or in combination of at most about two kinds as fuel. This type of fuel is roughly classified into hydrocarbon fuel and alcohol fuel.

A fluid identification method using these hydrocarbon fuel and alcohol fuel will be described below.
As in the embodiment of FIG. 7 described above, the microcomputer 72 outputs the sensor output for a predetermined time (for example, 0.1 second) before the start of voltage application to the heating element 21a4, as shown in FIG. The number of times (for example, 256 times) is sampled, and an operation for obtaining the average value is performed to obtain the average initial voltage value V1. This average initial voltage value V1 corresponds to the initial temperature of the temperature sensing element 21a2.

In addition, as shown in FIG. 7, the first time which is a relatively short time from the start of voltage application to the heating element (for example, 0.5 or less of the application time of a single pulse and 0.5 -1.5 seconds; 1 second in FIG. 7 (specifically immediately before the first time), the sensor output is sampled a predetermined number of times (for example, 256 times), and the average value is calculated. Thus, the average first voltage value V2 is obtained. This average first voltage value V2 corresponds to the first temperature when the first time elapses from the start of the single pulse application of the temperature sensing element 21a2.
Then, a difference V01 (= V2−V1) between the average initial voltage value V1 and the average first voltage value V2 is obtained as the liquid type corresponding first voltage value.

  Further, as shown in FIG. 7, when a second time (for example, a single pulse application time; 4 seconds in FIG. 7), which is a relatively long time from the start of voltage application to the heating element has elapsed (specifically Specifically, the sensor output is sampled a predetermined number of times (for example, 256 times) immediately before the second time elapses, and an average is obtained to obtain an average second voltage value V3. This average second voltage value V3 corresponds to the second temperature when the second time elapses from the start of single pulse application of the temperature sensing element 21a2. Then, a difference V02 (= V3−V1) between the average initial voltage value V1 and the average second voltage value V3 is obtained as the liquid type-corresponding second voltage value.

  By the way, a part of the heat generated in the heating element 21a4 based on the voltage application of the single pulse as described above is transmitted to the temperature sensing element 21a2 through the liquid to be measured. There are mainly two forms of this heat transfer that differ depending on the time from the start of pulse application. That is, in the first stage within a relatively short time (for example, 1.5 seconds) from the start of pulse application, conduction is mainly dominant in heat transfer.

  On the other hand, in the second stage after the first stage, heat transfer is mainly governed by natural convection. This is because in the second stage, natural convection occurs due to the liquid to be measured heated in the first stage, and the ratio of heat transfer due to this increases.

The heat transfer due to conduction in the first stage is greatly related to the thermal conductivity of the liquid to be measured, and the heat transfer due to natural convection in the second stage is largely related to the kinematic viscosity of the liquid to be measured. For some known liquids belonging to hydrocarbon liquids and alcohol liquids (cyclohexane, pentane, octane, toluene, o-xylene as hydrocarbon liquids, and methanol, ethanol, propanol as alcohol liquids) FIG. 24 shows the relationship between the liquid type-corresponding first voltage value V01 (= V2−V1) obtained by the apparatus of this example with the first time being 1.5 seconds and the thermal conductivity of the liquid to be measured. Show. Further, for the same liquid to be measured, the liquid type corresponding second voltage value V02 (= V3-V1) obtained by the apparatus of this example with the second time being 5 seconds and the kinematic viscosity of the liquid to be measured The relationship is shown in FIG.

  From FIG. 24, there is a considerable correlation between the liquid type-corresponding first voltage value V01 and the thermal conductivity of the liquid to be measured, and the alcohol-based liquid is located in a region where the liquid type-corresponding first voltage value V01 is smaller than the boundary value Vs. In addition, it can be seen that the hydrocarbon-based liquid is located in a region larger than the boundary value Vs. Further, it can be seen from FIG. 25 that the liquid type-corresponding second voltage value V02, the kinematic viscosity of the hydrocarbon-based liquid, and the kinematic viscosity of the alcohol-based liquid have a considerable correlation independently.

FIG. 26 is a circuit configuration diagram of an embodiment in which the fluid identification device of the present invention is used as a flow meter.
The stabilized direct current supplied from the power supply circuit 90 is supplied to the bridge circuit (detection circuit) 73. The bridge circuit 73 includes a flow rate detection temperature sensor 32a, a temperature compensation temperature sensor 32b, a resistor 92, and a variable resistor 94. Potentials Va and Vb at points a and b of the bridge circuit 73 are input to a differential amplification circuit 75 having a variable amplification factor. The output of the differential amplifier circuit 75 is input to the integrating circuit 77.

  On the other hand, the output of the power supply circuit 90 is supplied to the thin film heating element 33 through the field effect transistor 81 for controlling the current supplied to the thin film heating element 33. That is, in the flow rate detection unit 42, the temperature sensing by the thin film temperature sensing element 32a is executed under the influence of heat absorption by the fluid to be sensed via the fin plate 44 based on the heat generated by the thin film heating element 33.

As a result of the temperature sensitivity, a difference between potentials Va and Vb at points a and b of the bridge circuit 73 shown in FIG. 26 is obtained.
The value of (Va−Vb) changes as the temperature of the flow rate detecting temperature sensing element 32a changes according to the flow rate of the fluid. By appropriately setting the resistance value of the variable resistor 94 in advance, the value of (Va−Vb) can be set to zero in the case of a desired fluid flow rate serving as a reference. At this reference flow rate, the output of the differential amplifier circuit 75 is zero, and the output of the integration circuit 77 is constant (a value corresponding to the reference flow rate). The level of the output of the integrating circuit 77 is adjusted so that the minimum value becomes 0V.

The output of the integration circuit 77 is input to the V / F conversion circuit 78, where a pulse signal having a frequency (for example, a maximum of 5 × 10 ⁻⁵ ) corresponding to the voltage signal is formed. This pulse signal has a constant pulse width (time width) (for example, a desired value of 1 to 10 microseconds). For example, a pulse signal with a frequency of 0.5 kHz is output when the output of the integrating circuit 77 is 1V, and a pulse signal with a frequency of 2 kHz is output when the output of the integrating circuit 77 is 4V.

  The output of the V / F conversion circuit 78 is supplied to the gate of the transistor 81. As described above, a current flows through the thin film heating element 33 through the transistor 81 in which the pulse signal is input to the gate.

  Therefore, the divided voltage of the output voltage of the power supply circuit 90 is applied to the thin film heating element 33 in a pulsed manner at a frequency corresponding to the output value of the integrating circuit 77 via the transistor. Flows intermittently. Thereby, the thin film heating element 33 generates heat. The frequency of the V / F conversion circuit 78 is set based on a high-precision clock that is set by the reference frequency generation circuit 80 based on the oscillation of the temperature-compensated crystal resonator 79.

  The pulse signal output from the V / F conversion circuit 78 is counted by the pulse counter 82. The microcomputer 83 converts the pulse generated with the frequency generated by the reference frequency generation circuit 80 as a reference (pulse frequency), converts the flow rate into a corresponding flow rate (instantaneous flow rate), and integrates the flow rate with respect to time. Calculate the flow rate.

  The conversion to the flow rate is performed using a required calibration curve for fluid flow that is stored in the memory 84 in advance. That is, a data table obtained by measuring the pulse frequency output from the pulse counter 82 for each flow rate of the fluid is stored in the memory 84 as a calibration curve. The microcomputer 83 specifies the flow value on the calibration curve corresponding to the pulse frequency output from the pulse counter 82 when measuring the flow rate as the measurement value.

  The instantaneous flow rate and integrated flow rate values obtained as described above are displayed on the display unit 85 and transmitted to the outside through a communication line including a telephone line and other networks. In addition, instantaneous flow rate and integrated flow rate data can be stored in the memory 84 as desired.

  When the fluid flow rate increases or decreases, the output of the differential amplifier circuit 75 changes in polarity (depending on the sign of the resistance-temperature characteristic of the flow rate detection temperature sensor 32a) and the magnitude according to the value of (Va−Vb), In response to this, the output of the integrating circuit 77 changes. The speed of change of the output of the integrating circuit 77 can be adjusted by setting the amplification factor of the differential amplifier circuit 75. These integrating circuit 77 and differential amplifier circuit 75 set the response characteristic of the control system.

  When the fluid flow rate increases, the temperature of the flow rate detecting temperature sensing element 32a decreases, so that the output of the integrating circuit 77 that increases the amount of heat generated by the thin film heating element 33 (that is, increases the pulse frequency) (more (High voltage value) is obtained, and the bridge circuit 73 is in an equilibrium state when the output of the integration circuit becomes a voltage corresponding to the fluid flow rate.

  On the other hand, when the fluid flow rate decreases, the temperature of the flow rate detecting temperature sensing element 32a increases, so that the output of the integration circuit 77 that reduces the amount of heat generated by the thin film heating element 33 (that is, reduces the pulse frequency). (Lower voltage value) is obtained, and the bridge circuit 73 is in an equilibrium state when this integration circuit output becomes a voltage corresponding to the fluid flow rate.

  That is, in the control system of the present embodiment, the frequency (corresponding to the amount of heat) of the pulsed current supplied to the thin film heating element 33 is set so that the bridge circuit 73 is in an equilibrium state, and such an equilibrium state is realized. (Control system response) can be, for example, within 0.1 seconds.

  On the other hand, the output of the power supply circuit 90 is supplied to the fluid temperature detection fin plate 44a through the resistor 62 having a high resistance value (for example, about 10 kΩ) and the electrode terminal 49a. The terminal 49 is grounded. A voltmeter 63 is connected to both ends of the resistor 62.

  The voltage measured by the voltmeter 63 corresponds to the magnitude of the current flowing through the fluid between the two fin plates 44 and 44a when the fluid is introduced into the measuring section, which is between the fin plates 44 and 44a. It corresponds to the resistance value of the fluid. Including these, a circuit for measuring conductivity between the fin plate 44 for detecting the flow rate and the fluid temperature detecting 44a is configured.

The output of the voltmeter 63 is input to the microcomputer 83 via the A / D converter 65. The memory 84 stores data of an output value range (hereinafter referred to as “corresponding range”) of the voltmeter 63 to be measured by the conductivity measuring circuit for a required measurement target fluid.

This applicable range can be appropriately set in advance by introducing a required fluid to be measured into the measuring unit, actually measuring the output value of the voltmeter 63 of the conductivity measuring circuit, and taking into account the required detection error range.
For example, in the case where the required fluid to be measured is physiological saline, the conductivity measuring circuit capable of setting 3.2 to 3.6 V as the corresponding range, the voltmeter 63 for city water The output value is 0.8 to 1.2 V, the output value of the voltmeter 63 for alcohol or acetone is 0.05 V or less, and when a fluid that is not the required fluid to be measured is introduced excessively, It is possible to discriminate from the required fluid to be measured.

  In this embodiment, prior to the detection of the fluid flow rate, first, the fluid is introduced into the measurement unit of the flow meter, and then the conductivity of the fluid in the measurement unit (specifically, the flow of fluid is stopped) The output voltage value of the voltmeter 63 is measured.

  In the microcomputer 83, whether or not the voltage value input from the A / D converter 65 belongs to the corresponding range stored in the memory 84 (that is, whether the voltage value is within the corresponding range or outside the corresponding range). Make a decision.

  If it is determined in this determination that the output voltage value of the voltmeter 63 is within the corresponding range, the fluid introduced into the measurement unit is regarded as a predetermined measurement target fluid, and then the fluid is supplied into the measurement unit. The fluid is supplied from the source, and the fluid is circulated while detecting the flow rate as described above.

  Conversely, if it is determined in the above determination that the output voltage value of the voltmeter 63 is outside the corresponding range, the display unit 85 is warned without supplying the fluid from the fluid supply source into the measurement unit. It is possible to display or generate an alarm sound by an alarm means (not shown).

  Therefore, in this embodiment, the above-mentioned fluid discrimination is performed every time the fluid supply source is replaced, so that the fluid having a conductivity clearly different from that of the required fluid to be measured (this is clearly required) It is possible to prevent the flow of the fluid that is not measured fluid).

  Further, according to the above embodiment, the pulse signal created by the V / F conversion circuit 78 is used for flow rate measurement, and this pulse signal can easily reduce an error due to temperature change sufficiently. Therefore, it is possible to reduce the error between the flow rate value obtained based on the pulse frequency and the integrated flow rate value. In this embodiment, the energization of the thin-film heating element 33 is controlled by ON / OFF using the pulse signal created by the V / F conversion circuit 78, so that the occurrence of a control error based on the temperature change is extremely small. .

  Further, in this embodiment, since a microchip-shaped device including a thin film heating element and a thin film temperature sensing element is used as the flow rate detection unit, the above high-speed response is realized, and the flow rate measurement accuracy is good. Can be.

  Further, in this embodiment, the temperature of the flow sensing temperature sensing element 32a around the thin film heating element 33 is maintained almost constant regardless of the flow rate of the fluid to be sensed. It is possible to prevent the occurrence of ignition and explosion of the flammable fluid to be detected.

As described above, according to the flowmeter of the present invention, the fluid conductivity is measured by measuring the fluid conductivity between the flow rate detection heat transfer member and the fluid temperature detection heat transfer member used for flow rate detection. Therefore, it is possible to prevent a fluid having a conductivity clearly different from that of a required fluid to be measured from passing through with a simple configuration.

  As shown in FIG. 27, the light oil type identification device 1 of the present invention includes a liquid type identification device main body 12, a first flow path 436 formed in the liquid type identification device main body 12, and a second The flow path 438 is provided.

  As shown by the arrows in FIG. 27, the gas oil is temporarily retained in the gas oil liquid type identification chamber 400 from the gas oil inlet 18 through the first flow path 436. The light oil liquid type identification chamber 400 is formed with a substantially track-shaped liquid type identification sensor opening 402 at the top thereof.

As shown in FIG. 27, a liquid type identification sensor 404 is attached to the liquid type identification sensor opening 402.
In FIG. 27, 36 is a fin, 54 is a light oil discharge port, 408 is a lead electrode, 410 is a liquid temperature sensor, and 412 is a mold resin.

  As a preferred embodiment, the heater of the liquid type identification sensor heater 405 generates heat at 50 to 400 mW, preferably 250 mW, and after 1 to 50 seconds, preferably 10 seconds, By measuring the temperature change with the voltage output difference V0, it is possible to identify the difference in the properties of the light oil.

That is, as apparent from the graph of FIG. 28, the voltage output difference V0 after 10 seconds is
Honshu diesel oil A ... 1.20V
European standard diesel oil B ... 1.21V
US standard diesel oil C ... 1.20V
Swedish standard diesel oil D ... 1.18V
Each is different as described above.

Therefore, it is possible to recognize the light oil type identification and distillation properties based on data stored in advance in a computer constituting the identification control unit.
The above light oil type identification method utilizes the principle that the kinematic viscosity of light oil and the sensor output have a correlation using natural convection.

  That is, as shown in FIG. 29, there is a correlation between kinematic viscosity and sensor output, and as shown in FIG. 30, there is also a correlation between kinematic viscosity and distillation temperature. As a result, as shown in FIG. 31, there is a correlation between the sensor output and the distillation temperature. In the liquid type identification device of the present invention, by using such a relationship, the liquid type identification of light oil and the distillation property of light oil can be recognized as described above.

Furthermore, in order to perform such liquid type identification of light oil and distillation characteristics of light oil more accurately and quickly, the following method may be used.
That is, as shown in FIG. 32, for a predetermined reference light oil, for example, in this embodiment, light oil A in Honshu, which is the heaviest (evaporation is difficult), and Swedish standard, which is the lightest (evaporation is easy) For light oil D, calibration curve data, which is a correlation of voltage output difference with respect to temperature, is obtained and stored in a computer constituting the identification control unit.

  Based on the calibration curve data, proportional calculation is performed in the computer, and the type of light oil is identified by the voltage output difference V0 obtained for the identified light oil.

Specifically, although not shown, the liquid type voltage output Vout for the voltage output difference V0 at the measured temperature T of the light oil to be identified is set to a predetermined threshold reference light oil (in this example, Correction is made in correlation with the output voltage of the voltage output difference at the measured temperature for the diesel oil A in Honshu and the standard diesel oil D in Sweden.

  That is, although not shown, based on the calibration curve data, at the temperature T, the voltage output difference V0-A of the diesel oil A in Honshu, the voltage output difference V0-D of the standard diesel oil D in Sweden, and the voltage output difference V0 of the identified diesel oil D -S is obtained.

  Then, the liquid type output of the threshold reference light oil at this time is set to a predetermined voltage, that is, in this embodiment, the liquid type output of light oil A in Honshu is 3.5 V, and the liquid type of Swedish standard light oil D is used. By setting the output to 0.5 V and obtaining the liquid type voltage output Vout of the identified light oil, it is possible to correlate with the properties of the light oil.

  By comparing the liquid type voltage output Vout of the identified light oil with the data stored in the computer based on the calibration curve data in advance, the liquid type identification of the light oil can be performed accurately and quickly (instantly). It becomes possible.

  In addition, in such a light oil liquid type identification method, it is known that there is a more correlation between the light oil distillation properties shown in FIG. 33 and the distillation properties T30 to T70, which is desirable.

Although not shown, the light oil liquid type identification device 1 configured in this way can be applied to an automobile system.
In this automobile system, the light oil liquid type identification device 10 may be disposed in the light oil tank or upstream of the light oil pump.

  The light oil liquid type identification device 1 identifies the light oil type in the light oil tank or upstream or downstream of the light oil pump, and according to the type of light oil, by the control of the control device, by the ignition timing control device, The ignition timing can be adjusted.

  That is, for example, when a light (easy to evaporate) Swedish standard light oil D is identified, the ignition timing is advanced, and conversely, when a heavy (hard to evaporate) Honshu light oil A is identified. Is controlled to delay the ignition timing.

  This makes it possible to reduce the amount of HC in the exhaust gas and to improve fuel efficiency, even when the engine is not warmed, particularly when the engine is not warmed.

  The light oil liquid type identification device 1 identifies the light oil type in the light oil tank or upstream or downstream of the light oil pump, and controls the light oil compression control device by controlling the control device according to the type of light oil. Therefore, it can be configured to adjust the compression ratio of the light oil.

  That is, for example, when a light (easy to evaporate) Swedish standard diesel oil D is identified, the compression rate is lowered, and conversely, a heavy (hard to evaporate) Honshu diesel oil A is identified. Is controlled to increase the compression rate.

  This makes it possible to reduce the amount of HC in the exhaust gas and to improve fuel efficiency, even when the engine is not warmed, particularly when the engine is not warmed.

  FIG. 34 is a schematic diagram of another embodiment when the fluid identification device of the present invention is used as a flow rate / liquid type detection device, and FIG. 35 is a flow rate detection method using the flow rate / liquid type detection device of FIG. It is a graph which shows the analytical curve which shows.

  In FIG. 34, 420 indicates the flow rate / liquid type detection device of the present invention as a whole. The flow rate / liquid type detection device 420 includes a main flow path 422 through which a fluid to be detected such as gasoline, light oil, or urea solution flows. Further, a sub-channel 424 is provided branching from the main channel 422.

  The sub-flow path 424 is provided with the flow rate / liquid type detection sensor device 11, and on the upstream side thereof, the sub-flow path opening / closing valve 426 that controls the flow of the fluid to be detected to the flow rate / liquid type detection sensor apparatus 11. Is provided. Further, a reverse branch valve 416 is disposed in the sub flow path 424 on the downstream side of the flow rate / liquid type detection sensor device 11.

On the other hand, the main flow path 422 is provided with a main flow path opening / closing valve 417 for controlling the flow of the fluid to be detected to the main flow path, and an orifice 418 is disposed downstream thereof.
Further, a sensor control device 419 including a communication device for controlling the flow rate / liquid type detection sensor device 11, the auxiliary flow path opening / closing valve 426, and the main flow path opening / closing valve 417 is provided. When applied to an automobile, an ECU (Electronic Circuit Unit) 428 is connected to the sensor control device 419.

In this case, the auxiliary flow path opening / closing valve 426 and the main flow path opening / closing valve 417 are not particularly limited. For example, an electromagnetic valve or the like can be employed.
The orifice 418 is not particularly limited, and for example, a flange tap orifice, a variable orifice, an orifice having a plurality of thin tubes, and the like can be employed.

The thus configured flow rate / liquid type detection device 420 is operated as follows.
When performing either or both of liquid type detection and concentration detection of the fluid to be detected, the sub-channel opening / closing valve 426 is opened under the control of the sensor control device 419 (or ECU 428), and then the sub-channel The on-off valve 426 is closed so that the fluid to be detected is temporarily retained in the flow rate / liquid type detection sensor device 11 so as to perform either liquid type detection or concentration detection, or both. It has become.

  On the other hand, when detecting the flow rate of the fluid to be detected, the sub-channel opening / closing valve 426 is opened under the control of the sensor control device 419 (or ECU 428), and the flow rate / liquid type detection sensor device 11 is detected. The flow is controlled so that the flow rate is detected in this state.

  In this case, the sensor control device 419 (or ECU 428) closes the main flow path opening / closing valve 417 when the flow rate of the detected fluid is small, and conversely, when the flow rate of the detected fluid is large, 417 is configured to control to open the valve.

  That is, when the flow rate of the fluid to be detected is small as described above, the fluid to be detected is caused to flow through the sub flow channel 424 by closing the main flow path opening / closing valve 417, so that the flow rate / liquid type detection sensor device 11 can detect the flow rate. The necessary fluid flow rate can be secured.

On the other hand, when the flow rate of the fluid to be detected is large, the flow rate of the fluid flowing through the sub-flow channel 424 is decreased by opening the main flow channel opening / closing valve 417 and causing the fluid to flow through the main flow channel 422. -The fluid flow rate required for detection in the liquid type detection sensor device 11 can be secured.

Therefore, it is possible to cope with a wide flow rate dynamic range, and the sensitivity range is widened.
In addition, by disposing the reverse branch valve 416 on the downstream side of the flow rate / liquid type detection sensor device 11 of the sub flow path 424, for example, depending on the type of pump that is a liquid feeding device that circulates fluid, the type of drive system, When a pulsating flow is generated and a backflow is generated, this backflow can be suppressed.

  Therefore, since the back flow of the fluid in the flow rate / liquid type detection sensor device 11 can be prevented, these detections are not affected by the back flow of the fluid at the time of liquid type detection, concentration detection, and flow rate detection. It can be done accurately and quickly.

  Further, since the orifice 418 is disposed in the main flow path 422, the pressure loss in the main flow path 422 is increased by the orifice 418 when the pressure loss in the main flow path 422 is small and the fluid hardly flows in the sub flow path 424. As a result, a fluid having a constant flow rate necessary for detection can be caused to flow in the sub-channel 424, and detection can be performed reliably.

  In this state, the voltage output Vout of the fluid to be detected is obtained in the same manner as the liquid type detection described above, and stored in the computer based on the calibration curve data relating to the flow rate measured in advance as shown in FIG. By comparing with the obtained data, it becomes possible to detect the flow rate of gasoline accurately and quickly (instantly).

  FIG. 36 is an exploded perspective view of the whole of another embodiment when the fluid identification device of the present invention is used as a liquid type detection device, and FIG. 37 is an exploded perspective view of a liquid type detection chamber of the liquid type detection device of FIG. 38 and 38 are schematic diagrams for explaining the detection state of the liquid type detection chamber of the liquid type detection device of FIG.

  In FIG. 36, reference numeral 430 denotes the liquid type detection device of the present invention as a whole. The liquid type detection device 430 includes a substantially box-shaped liquid type detection device main body 432 through which a fluid to be detected such as gasoline, light oil, or urea solution flows.

  As shown in FIG. 36, the liquid type detection device main body 432 is provided with a liquid type detection chamber 434 having a substantially circular tube shape therein. In addition, the liquid type detection device main body 432 includes a first channel 436 and a second channel 438.

  The first flow path 436 is connected to a fluid inlet 440 provided in the liquid type detection chamber 434. The second flow path 438 is connected to a fluid discharge port 442 provided in the liquid type detection chamber 434.

  37, the fluid to be detected introduced into the liquid type detection device main body 432 temporarily stays in the liquid type detection chamber 434 through the fluid introduction port 440 from the first flow path 436. It is configured as follows.

  The liquid type detection chamber 434 is provided with a liquid type detection chamber lid member 444 at the upper portion thereof. The liquid type detection chamber lid member 444 has a substantially track-shaped liquid type detection sensor opening 446. Is formed.

A liquid type detection sensor 448 is attached to the liquid type detection sensor opening 446.
In FIG. 37, reference numeral 472 is a liquid temperature sensor, 473 is a liquid temperature sensor heater,
Reference numeral 474 denotes a lead electrode.

  As shown in FIG. 36, the liquid type detection sensor 448 includes a circuit board member 450 and an outer lid member 452 that covers the circuit board member 450. In FIG. 37, the circuit board member 450 and the outer lid member 452 are omitted for convenience of explanation.

In FIG. 36, reference numerals 454a and 454b denote attachment flanges for attaching the liquid type detection device 430 provided in the liquid type detection device main body 432 to, for example, an automobile.
On the other hand, in the liquid type detection chamber 434, as shown in FIG. 37, a flow control plate 456 is provided for the liquid type detection chamber so as to surround the liquid type detection sensor 448 protruding from the liquid type detection chamber 434. It is formed inside the lid member 444.

  The flow control plate 456 includes a plate member 458 having a substantially U-shaped cross section. The plate member 458 surrounds the liquid type detection sensor 448 from both sides, and fluid flows from the fluid introduction port 440 of the liquid type detection chamber 434. A pair of side plate members 460 and 462 extending toward the discharge port 442 and a covering plate member 464 connected to the side plate members 460 and 462 are provided.

  The flow control plate 456 is provided with a fluid inlet 466 that faces the fluid inlet 440 of the liquid type detection chamber 434 and a fluid outlet 468 that faces the fluid outlet 442 of the liquid type detection chamber 434. Yes.

  The fluid inlet 440 of the liquid type detection chamber 434 and the fluid inlet 466 of the flow control plate 456 are separated by a predetermined distance L1, and the fluid discharge port 442 of the liquid type detection chamber 434 and the flow control plate 456 are separated from each other. The fluid outlet 468 is separated by a predetermined distance L2.

  With this configuration, when the introduction of the fluid to be detected into the liquid type detection device main body 432 is stopped and the fluid to be detected is temporarily retained in the liquid type detection chamber 434, the liquid type detection chamber 434 is used. The flow of the detected fluid around the liquid type detection sensor 448 positioned inside the flow control plate 456 surrounded by the flow control plate 456 is suppressed by the flow control plate 456. However, it will stop instantly.

  That is, the fluid to be detected flows from the fluid inlet 440 of the liquid type detection chamber 434 to the inside of the flow control plate 456 surrounded by the flow control plate 456 through the fluid inlet 466 of the flow control plate 456. The liquid type detection sensor 448 can reliably enter the periphery of the liquid type detection sensor 448 located inside the plate 456, and the liquid type and concentration of the fluid to be detected can be detected.

  Then, after detecting the liquid type and concentration of the fluid to be detected by the liquid type detection sensor 448, after detection from the fluid discharge port 442 of the liquid type detection chamber 434 via the fluid outlet 468 of the flow control plate 456. Since the detected fluid can be reliably discharged, the detected fluid can be accurately detected sequentially.

  Therefore, when the liquid type and concentration are detected by the liquid type detection sensor 448, the flow of the detected fluid does not occur, and the disturbance of the detected fluid due to vibration does not occur. The influence on the detection of the concentration can be prevented, and the liquid type and concentration of the fluid to be detected can be accurately measured.

  In addition, since the liquid type detection chamber 434 is provided, the amount of the fluid to be detected is increased, and therefore, when detecting the liquid type and concentration of the liquid to be detected, it is affected by ambient influences such as external temperature. Therefore, accurate detection can be performed.

  Therefore, for example, when applied to a fluid such as gasoline or light oil in an automobile, when the automobile is stopped due to a signal or the like, the pump of gasoline or the like is stopped and the liquid type and concentration of the fluid to be detected are instantly changed. It can be detected, and after the detection is completed, the pump can be started and the automobile can be started again, so that the running of the automobile is not hindered.

  Further, as indicated by an arrow B in FIG. 38, the air mixed into the fluid to be detected at the time of this detection is discharged from the fluid type detection chamber 434 through the fluid outlet 468 of the flow control plate 456. Since this air can be reliably discharged from 442, air does not stay around the liquid type detection sensor 448, so that the influence on the detection can be prevented and accurate detection can be performed. it can.

  Furthermore, since the fluid inlet 440 of the liquid type detection chamber 434 and the fluid inlet 466 of the flow control plate 456 are separated from each other by a predetermined distance L1, as shown by an arrow A in FIG. From the gap, the air mixed in the fluid to be detected moves to the outside of the flow control plate 456 and is discharged to the outside from the fluid discharge port 442 of the liquid type detection chamber 434.

  Therefore, since air does not enter the flow control plate 456, air does not stay around the liquid type detection sensor 448, so that the influence on the detection can be prevented and accurate detection can be performed. It can be carried out.

  Moreover, even if air enters the inside of the flow control plate 456, the fluid in the liquid type detection chamber 434 passes through the fluid outlet 468 of the flow control plate 456 as shown by the arrow C in FIG. Since this air can be reliably discharged from the discharge port 442, the air does not stay around the liquid type detection sensor 448, so that the influence on the detection can be prevented and accurate detection is performed. be able to.

  Further, as shown by an arrow B in FIG. 38, the side wall of the liquid type detection chamber 434 in the vicinity of the fluid discharge port 442 has a substantially circular tube shape and is formed in a substantially arc shape. Along the side wall 470 of the liquid type detection chamber 434, the air mixed in the fluid to be detected is guided to the fluid discharge port 442 of the liquid type detection chamber 434 and discharged.

  Accordingly, air does not collect in the vicinity of the fluid discharge port 442 of the liquid type detection chamber 434, and air does not stay around the liquid type detection sensor 448, so that the influence on detection can be prevented. Accurate detection can be performed.

  In order to achieve such effects, as shown in FIG. 38, the predetermined distances L1 and L2 are 1.5 mm to 5 mm, preferably 2 mm to 3.5 mm. . The distance L3 between the pair of side plate members 460 and 462 of the flow control plate 456 and the liquid type detection sensor 448 is 5 mm to 10 mm, preferably 6 mm to 8 mm.

Further, the size of the liquid type detection chamber 434 is not particularly limited.
Furthermore, the material constituting the liquid type detection chamber 434 is not particularly limited, but a metal such as stainless steel such as SUS304, a synthetic resin such as polyacetal (POM), or a fiber reinforced resin such as FRP can be used. It is.

  Further, the material constituting the flow control plate 456 is not particularly limited, but a metal such as stainless steel such as SUS304, a synthetic resin such as polyacetal (POM), a fiber reinforced resin such as FRP, or a ceramic is used. Is possible.

Furthermore, the liquid type detection device 430 of the present invention has a circuit configuration similar to that shown in the embodiment of FIG. 6 described above.
In this embodiment, although not shown, in the circuit configuration of FIG. 6 described above, the liquid type detection liquid temperature sensor of the liquid type detection sensor heater 406 of the liquid type detection sensor 448 and the liquid temperature sensor 472 have two resistances. To form a bridge circuit. The output of the bridge circuit is connected to the input of the amplifier, and the output of the amplifier is connected to the input of the computer that constitutes the detection control unit.

Further, the voltage applied to the heater of the liquid type detection sensor heater 406 is controlled by a computer.
In the liquid type detection device 430 configured as described above, for example, liquid type detection of gasoline is performed as follows.

  First, the fluid to be detected is introduced from the first flow path 436 through the fluid inlet 440 into the liquid type detection chamber 434 by introducing the fluid to be detected into the liquid type detection device main body 432 under the control of a control device (not shown). After the inflow, the inflow of the fluid to be detected is stopped, and the liquid type detection chamber 434 is temporarily retained.

  In this state, when the introduction of the fluid to be detected into the liquid type detection device main body 432 is stopped and the fluid to be detected is temporarily retained in the liquid type detection chamber 434, the liquid to be detected in the liquid type detection chamber 434 is stopped. The flow of the detection fluid is suppressed by the flow control plate 456, and the flow of the detection fluid around the liquid type detection sensor 448 located inside the flow control plate 456 surrounded by the flow control plate 456 is instantaneously Will stop.

  The fluid identification device of the present invention can be used in a urea concentration identification method for a urea solution. In this case as well, the principle that the kinematic viscosity of urea and the sensor output have a correlation may be used using natural convection in the same manner as in the above embodiment.

FIG. 39 is a schematic diagram of an embodiment in which the urea concentration identification device 482 for urea solution configured as described above is applied to an automobile system 480.
In FIG. 39, reference numeral 130 is a urea solution supply mechanism, and 140 and 142 are NOx sensors.

In this automobile system 480, a urea solution urea concentration identification device 482 is disposed in the urea solution tank 132 or upstream of the urea pump.
The urea concentration of the urea solution is identified by the urea concentration identification device 482 of the urea solution in the urea solution tank 132 or upstream or downstream of the urea pump (in this embodiment, the upstream side is shown for convenience of explanation). The concentration of the urea sprayed on the upstream side of the catalyst device 116 is determined based on the concentration discrimination, so that the urea solution does not solidify and the reduction reaction efficiently occurs on the upstream side of the catalyst device 116. For example, urea 32 .5 wt% and H ₂ O are set to a constant state of 67.5 wt%.

Therefore, since the urea concentration of the urea solution in the urea tank can be maintained at a predetermined concentration, NOx in the exhaust gas can be reduced and extremely reduced.
Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 40 is a partially broken perspective view for explaining an embodiment in which the fluid identification device of the present invention is used in a tank liquid leak detection device, and FIG. 41 is a view of one example of the leak detection device of this embodiment. FIG.

  The tank 490 includes a top plate 496 in which a liquid injection port 494 used for injecting liquid into the metering port 492 and the tank, and a supply used for supplying liquid from the inside of the tank to the outside of the tank. It has a side plate 500 in which a liquid port 498 is formed and a bottom plate 502. As shown in FIG. 40, the tank 490 contains a liquid L (for example, gasoline, light oil, kerosene, or other combustible liquid made of a mixed composition of many organic compounds). LS indicates the liquid level.

  The leak detection device 504 is partially inserted into the tank 490 through the measuring port 492 formed in the top plate 496 of the tank 490, and is arranged in the vertical direction as a whole. The leak detection device 504 includes a liquid introduction / extraction part 506, a flow rate measurement part 508, a liquid reservoir part 510, a cap 16, and a circuit housing part 15. The liquid introduction / extraction part 506, the flow rate measurement part 508, and the liquid reservoir 510 are located inside the tank 490, and the liquid level LS is located within the height range of the liquid reservoir 510. The flow rate measuring unit 508 and the liquid reservoir 510 include a sheath tube 512 extending in the vertical direction across these.

  In the flow rate measurement unit 508, as shown in FIG. 41, a sensor holder 13a is disposed in the sheath tube 512, and the vertical measurement capillary 13b is fixedly held by the sensor holder. A first temperature sensor 133, a heater 135, and a second temperature sensor 134 are arranged and attached to the measurement thin tube 13b in this order from the upper side. The heater 135 is disposed at an equal distance from the first temperature sensor 133 and the second temperature sensor 134.

  Since the outer side of the sensor holder 13 a is covered with the sheath tube 512, the first temperature sensor 133, the heater 135, and the second temperature sensor 134 are protected from corrosion by the liquid L. The measurement thin tube 13b functions as a liquid flow path between the liquid reservoir 510 and the liquid inlet / outlet 506. The first temperature sensor 133, the heater 135, and the second temperature sensor 134 constitute a flow rate sensor unit for measuring the flow rate of the liquid in the measurement thin tube 13b.

  The flow rate measurement unit 508 is provided with a pressure sensor 137 attached to the sensor holder 13a in the vicinity of the lower end of the measurement thin tube 13b. The pressure sensor 137 is for measuring the liquid level of the liquid L in the tank. For example, a piezo element or a capacitor-type pressure detection element can be used, and an electric signal corresponding to the liquid level of the liquid, for example, a voltage Output a signal.

  In the liquid introduction / extraction part 506, as shown in FIG. 41, the filter cover 12b fixes the filter 12a to the lower part of the sensor holder 13a. The filter 12a has a function of removing foreign matters such as sludge that floats or settles in the liquid in the tank and introduces only the liquid to the liquid reservoir 510 through the measurement thin tube 13b. In addition, an opening is provided in the side wall of the filter cover 12b, and the liquid L in the tank 490 is introduced into the measurement capillary 13b through the filter 12a of the liquid introduction / extraction part 506.

  The liquid reservoir 510 is located above the flow rate measuring unit 508, has a space G surrounded by the sheath tube 512, and is configured to store the liquid introduced from the measurement capillary 13b in this space G. ing. A third temperature sensor 136 for measuring the temperature of the liquid in the space G is attached to the sensor holder 13a.

A cap 16 is fixed to the upper portion of the sheath tube 512, and an air passage 16a is formed in the cap for communicating the inside of the liquid reservoir portion 510 with the space in the tank outside the detection device. The cap 16 is provided with an on-off valve 138 for opening and closing the air passage 16a.
The valve body 138a of the on-off valve is movable up and down, and the ventilation path 16a is closed (opening of the on-off valve) at the lowest position, and the ventilation path 16a is open (opening / closing valve) at a position higher than that. Is closed).

  A circuit housing portion 15 is attached to the cap 16, and a leak detection control portion 15a is housed in the circuit housing portion. A guide tube Pg extending so as to connect the upper portion of the sensor holder 13a and the cap 16 is disposed in the sheath tube 512, and the first temperature sensor 133, the heater 135, and the second temperature sensor 508 of the flow rate measurement unit 508 are disposed. A wiring 17 that connects the temperature sensor 134, the pressure sensor 137, the third temperature sensor 136, and the leakage detection control unit 15a extends through the guide tube Pg. The on-off valve 138 is connected to the leak detection control unit 15a.

  The sheath tube 512 in the liquid reservoir 510 constitutes the measurement tube of the present invention. The cross-sectional area of the measuring thin tube 13b is sufficiently smaller than the cross-sectional area of the sheath tube 512 (excluding the cross-sectional area of the guide tube Pg) (for example, 1/50 or more, 1/100 or less, and further 1/300 times or less). ) By setting it, it is possible to generate a liquid flow that can measure the flow rate in the measurement thin tube 13b even with a slight change in liquid level when a slight liquid leaks.

  The sheath tube 512, the sensor holder 13a, the filter cover 12b, the cap 16 and the guide tube Pg are preferably made of a metal having a thermal expansion coefficient close to that of the material constituting the tank 490, such as cast iron or stainless steel. More preferably, it is made of the same metal as the material.

  When the leak detection device 504 as described above is attached to the measuring port 492 of the tank 490 with the open / close state of the ventilation passage 16a by the open / close valve 138 being open, the liquid level LS of the liquid L in the tank is as described above. It is located within the height range of the reservoir 510. Therefore, the pressure sensor 137 is immersed in the in-tank liquid L filtered by the filter 12a of the liquid introduction / extraction part 506, and the in-tank liquid L rises through the measurement thin tube 13b of the flow rate measurement part 508, and stores the liquid. It is introduced into the space G of the part 510, and finally the liquid level in the liquid reservoir 510 becomes the same height as the liquid level LS of the liquid in the tank outside the leak detection device. When the liquid level LS of the liquid in the tank fluctuates, the liquid level of the liquid in the liquid reservoir 510 also fluctuates. Will occur.

Hereinafter, the leak detection operation in this embodiment, that is, the operation of the CPU will be described. In this embodiment, kerosene is used as the liquid in the tank.
FIG. 42 is a timing chart showing the relationship between the voltage Q applied from the pulse voltage generation circuit to the thin film heating element and the voltage output S of the leak detection circuit.
From the CPU, a single pulse voltage having a width t1 is applied at a predetermined time interval t2 based on a clock. This single pulse voltage has, for example, a pulse width t1 of 2 to 10 seconds and a pulse height Vh of 1.5 to 4V.

  As a result, the heat generated by the thin film heating element heats the measuring thin tube 13b and the liquid inside thereof and is transmitted to the surroundings. The influence of this heating reaches the thin film temperature sensors, and the temperature of these thin film temperature sensors changes. Here, when the flow rate of the liquid in the measurement narrow tube 13b is zero, the temperature change in the two temperature sensing elements is the same if the contribution of temperature transfer by convection is ignored.

However, when the liquid level of the liquid in the tank decreases as when the liquid in the tank leaks from the tank, the liquid is introduced from the liquid reservoir 510 into the tank outside the detection device through the measuring thin tube 13b. Since it is derived from 506, the liquid in the measurement capillary 13b flows from top to bottom.
As a result, more heat from the thin film heating element is transferred to the thin film temperature sensing element of the lower temperature sensor 134 than to the thin film temperature sensing element of the upper temperature sensor.

  Thus, there is a difference between the temperatures detected by the two thin film temperature sensors, and the resistance value changes of these thin film temperature sensors are different from each other. FIG. 42 shows changes in the voltage VT1 applied to the thin film temperature sensor of the temperature sensor 133 and the voltage VT2 applied to the thin film temperature sensor of the temperature sensor 134. As described above, the output of the differential amplifier, that is, the voltage output S of the leakage detection circuit changes as shown in FIG.

  FIG. 43 shows a specific example of the relationship between the voltage Q applied to the thin film heating element from the pulse voltage generation circuit and the voltage output S of the leak detection circuit. In this example, the single pulse voltage has a pulse height Vh of 2 V, a pulse width t1 of 5 seconds, and the liquid level change rate F [mm / h] is changed to obtain a voltage output S [F].

In the CPU, in response to the application of the single pulse voltage to the thin film heating element of the heater 135 by the pulse voltage generation circuit, the voltage output S of the leak detection circuit and its initial value at a predetermined time t3 after the start of the single pulse voltage application. The difference (S0−S) from the value (ie, at the start of applying a single pulse voltage) S0 is integrated. This integral value ∫ (S0−S) dt corresponds to the hatched area in FIG. 42 and is a flow rate corresponding value corresponding to the flow rate of the liquid in the measurement capillary 13b. The predetermined time t3 is, for example, 20 to 150 seconds.

FIG. 44 shows a specific example of the relationship between the liquid level change rate corresponding to the flow rate F of the liquid in the measurement capillary 13b and the integral value ∫ (S0−S) dt.
In this example, the predetermined time t3 for obtaining the integral value is 30 seconds, and relationships at three different temperatures are obtained. It can be seen that there is a good linear relationship between the liquid level change rate and the integral value ∫ (S0−S) dt in the region where the liquid level change rate is 1.5 mm / h or less.

  In this example, a good linear relationship was shown in the region where the liquid level change rate was 1.5 mm / h or less. By doing so, it is possible to obtain a good linear relationship in a region where the liquid level change rate is 20 mm / h or less.

Such a typical relationship between the integral value ∫ (S0−S) dt and the liquid level change speed can be stored in advance as a calibration curve in the memory. Therefore, based on the integral value ∫ (S0−S) dt, which is a flow-corresponding value calculated using the output of the leak detection circuit, conversion is performed by referring to the stored contents of the memory, thereby reducing the liquid leak in the tank. It can be obtained as the position change speed. However, when a liquid level change rate smaller than a certain value (for example, 0.01 mm / h) is obtained, it can be determined that there is no leakage, considering that it is within the measurement error range.

Strictly speaking, the relationship between the integral value） (S0−S) dt and the liquid level change speed varies depending on the temperature of the liquid as shown in FIG. Therefore, a calibration curve indicating the relationship between the integral value ∫ (S0−S) dt and the liquid level change rate is stored in the memory for each of a plurality of temperatures, and the temperature (actual measurement) measured by the third temperature sensor 136 is stored. Integral value ∫ (S0−S) dt using a calibration curve of the temperature closest to the actually measured temperature stored in the memory, or by interpolation or extrapolation using calibration curves of a plurality of temperatures. To a liquid level change rate can be performed. This makes it possible to detect leaks with higher accuracy.

This leak detection (micro leak detection) is repeatedly executed at an appropriate time interval t2. The time t2 is, for example, 40 seconds to 5 minutes (however, a time longer than the integration time t3).
Further, the CPU can immediately convert the liquid level corresponding output P input from the pressure sensor 137 via the A / D converter into the liquid level p. This conversion is related to the specific gravity ρ of the liquid. The pressure value measured by the pressure sensor 137 is P, the liquid level based on the height position of the pressure sensor 137 is p, and the acceleration of gravity is g. ,
Formula (1)
p = P / (ρg) (1)
Can be used. The value of the liquid level p is based on the height of the pressure sensor 137. The height of the measurement port 492 of the tank 490 and the distance from the attachment portion of the leak detection device to the measurement port to the pressure sensor 137 Can be converted into a liquid level value for the tank itself. A liquid level detection signal indicating the result of the liquid level detection is output from the CPU.

The specific gravity ρ of the liquid is detected as follows. A flow of this specific gravity detection is shown in FIG.
The specific gravity of the liquid is detected every time the liquid is injected into the tank for replenishment, and is started by external input or the like after an appropriate time for the liquid surface to settle after the liquid injection. At this time, the above-described pulse energization is started for the heater 135 of the flow rate sensor unit (if pulse energization has already been performed, it is continued).

Then, the air passage 16a is closed by the on-off valve 138 (S1), and is kept stationary (S2) for an appropriate period (for example, 2 to 5 minutes) during which the liquid level is stabilized, and then the integral value ∫ ( S0−
S) Measurement of dt is performed a plurality of times (for example, 5 times) (S3), and a plurality of obtained integral values ∫ (S0
-S) The average value of dt is calculated (S4), and the specific gravity ρ is calculated from the average value obtained by using the specific gravity calibration curve (S5).

The specific gravity calibration curve can be obtained by measuring the integral value ∫ (S0−S) dt in the same way for liquids of the same kind of specific gravity whose specific gravity is known in advance (for example, fuel oil including kerosene). Remember it. In S3, the integral value ∫ (S0−S) dt may be measured only once, S4 may be omitted, and the value obtained by the above one measurement may be used as an average value in S5.

  Next, it is determined whether or not the specific gravity ρ obtained as described above is within a range of 0.7 or more and 0.95 or less (S6). This determination is to determine whether or not the liquid is fuel oil. When it is determined that 0.7 ≦ ρ ≦ 0.95, it is assumed that the liquid is fuel oil. The value of ρ is stored in the memory as the current specific gravity of the liquid in the tank (S7).

  On the other hand, if it is determined in S6 that other than 0.7 ≦ ρ ≦ 0.95, it is determined whether or not S3 to S5 have been executed for 3 consecutive cycles (S8) and executed for 3 consecutive cycles. If it is determined that the liquid is not fuel oil, an error process for final confirmation is performed (S9). Based on this, the CPU can issue an appropriate warning signal to the outside. On the other hand, if it is determined in S8 that the three cycles are not continuously executed, S3 and the subsequent steps are executed. Note that S8 may be omitted, and the process may proceed from S6 to S9 immediately.

Next, after S7 or S9, the air passage 16a is opened by the on-off valve 138 (S10), and the specific gravity detection is terminated.
Further, the CPU stores the value of the liquid level p obtained as described above in the memory every certain time tt, for example, every 2 to 10 seconds, and calculates the difference from the previous stored value every time this storage is performed. This is stored in the memory as the value of the time change rate p ′ of the liquid level.

  FIG. 45 shows a specific example of the relationship between the liquid level change rate and the time change rate P ′ of the liquid level corresponding output P. In the region where the liquid level change rate is 150 mm / h or less, there is a good linear relationship between the liquid level change speed and the time change rate P ′ of the liquid level corresponding output, and therefore the liquid level change rate and the liquid level time change rate. It can be seen that p ′ corresponds well. In this example, a good linear relationship was shown in the region where the liquid level change rate was 150 mm / h or less. However, a good linear relationship was obtained in the region up to the liquid level change rate of 200 mm / h. It is possible.

Therefore, the leakage of the liquid in the tank can be obtained as the magnitude of the time change rate p ′ of the liquid level p measured by the pressure sensor 137.
By the way, the specific gravity ρ of the liquid differs strictly according to the temperature of the liquid. Accordingly, in response to the specific gravity detection described above, the following processing can be performed.

That is, a specific gravity standard curve (standard temperature specific gravity standard curve) at a standard temperature TR (for example, 15 ° C.) is used. In creating this standard temperature specific gravity calibration curve, assuming that the specific gravity detected at the liquid temperature TA is ρ [TA], based on this, the specific gravity value ρ [TR] at the standard temperature TR is expressed by the equation (2).
ρ [TR] = ρ [TA] +0.00071 (TA−TR) (2)
Can be used to calculate. The coefficient 0.00071 in the equation (2) is for the case where the liquid is fuel oil.

Then, when the specific gravity detection described with reference to FIG. 46 was performed on the liquid to be detected, the temperature measured by the third temperature sensor 136 was TX and converted using the standard temperature specific gravity calibration curve. Assuming that the specific gravity value is ρ [TX], the corrected specific gravity value ρ ′ [TX] at the current temperature TX is expressed by Equation (3).
ρ ′ [TX] = ρ [TX] −0.00071 (TX-TR) (3)
Can be used to calculate. The coefficient 0.00071 in the equation (3) is for the case where the liquid is fuel oil.

By using the corrected specific gravity value ρ ′ [TX] obtained as described above as the specific gravity value ρ in the above formula (1) and converting it to the liquid level, it is possible to detect leaks with higher accuracy. Become.
The leak detection using the pressure sensor as described above can cover a wider liquid level change speed range than the above-described minute leak detection. On the other hand, the minute leak detection can measure a minute liquid level change speed region with higher accuracy than the leak detection using the pressure sensor.

  By the way, the liquid level change in the tank 490 also occurs when liquid is injected from the liquid injection port 494 into the tank or when liquid is supplied from the liquid supply port 498 to the outside. However, the speed of the rise or fall of the liquid level in the tank 490 in these cases is generally much larger than the liquid level change rate or the liquid level time change rate in the case of a leak.

Therefore, the CPU performs the following processing regarding leakage.
(1) In the leak detection using the pressure sensor, when the level of the liquid level time change rate p ′ is within a predetermined range (for example, 10 to 100 mm / h), the result of the leak detection using the pressure sensor is used as the leak detection signal. Output as.
(2) When the level of the liquid level time change rate p ′ is smaller than the lower limit of the predetermined range (for example, smaller than 10 mm / h) in leak detection using a pressure sensor, the result of minute leak detection is output as a leak detection signal. To do.
(3) When the level of the liquid level time change rate p ′ exceeds the upper limit of the predetermined range (for example, greater than 100 mm / h) in leak detection using a pressure sensor, it may be caused by causes other than leak, such as liquid injection or liquid supply. It is determined that the leak is detected and the leak detection signal is not output.
Further, in this embodiment, when the state (3) is reached, that is, when the level of the liquid level time change rate p ′ exceeds the upper limit of the predetermined range in the leak detection using the pressure sensor, the CPU The first leak detection can be stopped for a predetermined time tm thereafter.

  The predetermined time tm for stopping the leakage detection is preferably a time slightly longer than the settling time of the liquid level LS after the liquid is injected from the outside into the tank or the liquid is supplied from the inside to the outside. It can be 10 to 60 minutes. In particular, during the predetermined time tm, the CPU can stop the operations of the pulse voltage generation circuit and the leak detection circuit. According to this, power consumption is reduced.

  The liquid level change rate or the liquid level time change rate is related to the leak amount (leak amount per unit time). That is, the liquid level change rate or the liquid level time change rate multiplied by the horizontal sectional area inside the tank at the liquid level corresponds to the liquid leakage amount. Therefore, the shape of the tank (that is, the relationship between the height position and the horizontal cross-sectional area inside the tank) is stored in advance in the memory, and the liquid level detected as described above with reference to the stored contents of the memory. And the amount of leakage of the liquid in the tank can be calculated based on the leakage (liquid level change rate or liquid level time change rate).

  When the tank has a constant horizontal cross-sectional area regardless of its height, such as the vertical cylindrical shape shown in FIG. 40, the liquid level change rate or the liquid level time change rate The amount of leakage is simply proportional, so it is easy to multiply the liquid level change rate or liquid level time change rate by the proportional constant according to the horizontal cross-sectional area inside the tank regardless of the liquid level value itself. The amount of leakage can be calculated. That is, in this case, the leak detected by the apparatus of this embodiment is substantially equivalent to that based on the leak rate.

  47 is an exploded perspective view showing another embodiment in which the fluid identification device of the present invention is used as a liquid level detection device, FIG. 48 is a partially omitted sectional view, and FIG. 49 is an attachment to the tank. It is a figure which shows a state. In this embodiment, a urea aqueous solution is assumed as the liquid.

  As shown in FIG. 49, for example, an opening 522 is provided in an upper part of a urea aqueous solution tank 520 for decomposing NOx constituting an exhaust gas purification system mounted on an automobile, and the opening is provided in the opening according to the present invention. A liquid level detection device 523 is attached. The urea aqueous solution tank 520 is provided with an inlet pipe 524 for injecting the urea aqueous solution and an outlet pipe 526 for taking out the urea aqueous solution.

  The outlet pipe 526 is connected to the tank at a height position close to the bottom of the urea aqueous solution tank 520, and is connected to a urea aqueous solution sprayer (not shown) via the urea aqueous solution supply pump 110. In the exhaust system, the urea aqueous solution sprayer disposed immediately before the exhaust gas purifying catalyst device sprays the urea aqueous solution onto the catalyst device.

  The liquid level detection device includes an identification sensor unit 528, a pressure sensor 530, and a support unit 532. An identification sensor portion 528 is attached to one end (lower end) of the support portion 532, and an attachment portion 4 a for attaching to the tank opening 522 is provided at the other end (upper end portion) of the support portion 532. It has been.

  47 and 48, reference numeral 2a is a base, 2b and 2c are O-rings, 4a is a mounting portion, 21 is an indirectly heated concentration detector, 21c and 22c are metal fins, and 21e and 22e are external electrode terminals. , 24 is a liquid introduction path to be measured, 540 is a circuit board, 542 is a lid member, 544, 546 and 548 are wires, 550 is a connector, and 532 is a support portion.

FIG. 50 is a flowchart showing a liquid level detection process in the microcomputer.
The pressure sensor 530 detects the hydraulic pressure P of the urea aqueous solution, and the detected hydraulic pressure value is input to the microcomputer. On the basis of the detected hydraulic pressure value, the microcomputer uses the urea aqueous solution having a predetermined density, for example, water having a urea concentration of zero and a density of 1. A provisional liquid level H is calculated when there is (ST1).

In this calculation, the following relationship obtained from the relationship (shown in FIG. 13) between the hydraulic pressure P [kPa] of water measured in advance by the pressure sensor 530 and the liquid level (provisional liquid level value) H [cm]. Formula (3)
H = 0.0041 · P2 + 10.181 · P (3)
Can be used.

On the other hand, the urea concentration value C obtained using the identification sensor unit 528 as described above is input to the microcomputer. Based on this, the microcomputer calculates the density value ρ of the urea aqueous solution having the urea concentration value C (ST2). The relation of the change in the density ρ [g / cm ³ ] of the urea aqueous solution to the change in the urea concentration C [wt%] is expressed by the following relational expression (4)
ρ = 7.450E (−6) · C2 + 2.482E (−3) · C + 1.000 (4)
Can be used to calculate the density ρ.

Next, from the temporary liquid level H obtained as described above and the density ρ of the urea aqueous solution, the liquid level H ′ [cm] is expressed by the following relational expression (5).
H '= ρ · H (5)
(ST3).

  As described above, it is possible to accurately and quickly detect the liquid pressure, identify the concentration, and calculate the liquid level based on these. This liquid level detection routine based on the concentration identification is appropriately executed when the engine of the automobile is started, periodically, when requested by the driver or the automobile (ECU described later), or when the key of the automobile is turned off. The level of the aqueous urea solution in the urea tank can be monitored in a desired manner.

  The signal indicating the concentration and the liquid level obtained in this way is output to an output buffer circuit through a D / A converter (not shown) as shown in the embodiment of FIG. Is output to a main computer (ECU) that performs combustion control of an automobile engine (not shown). An analog output voltage value corresponding to the liquid temperature is also output to the main computer (ECU). On the other hand, the signal indicating the concentration and the liquid level can be taken out as a digital output if necessary and input to a device that performs display, alarm, and other operations.

  Further, based on the liquid temperature corresponding output value T input from the liquid temperature detection unit 534, a warning is issued when it is detected that the temperature of the urea aqueous solution has dropped to near the freezing temperature (about −13 ° C.). can do.

FIG. 51 is a schematic cross-sectional view showing an example in which the fluid identification device according to the present invention is used in an ammonia generation amount measuring device.
Note that the ammonia generation amount measuring apparatus 1 shown in FIG. 51 has basically the same configuration as the liquid type identification apparatus 1 in the embodiment shown in FIG. 1 to FIG. Reference numerals are assigned and detailed descriptions thereof are omitted. Reference numeral 301 denotes a terminal pin.

  As described above, the liquid type-corresponding first voltage value V01 is mainly influenced by the thermal conductivity of the liquid, and the liquid type-corresponding second voltage value V02 is mainly influenced by the kinematic viscosity of the liquid. Therefore, hereinafter, the liquid type-corresponding first voltage value is referred to as thermal conductivity-corresponding voltage value V01, and the liquid type-corresponding second voltage value is referred to as kinematic viscosity-corresponding voltage value V02.

The thermal conductivity corresponding voltage value V01 and the kinematic viscosity corresponding voltage value V02 change as the urea concentration and the ammonium formate concentration of the liquid US to be measured change.
The present embodiment measures the urea concentration and the ammonium formate concentration by utilizing the fact that the relationship between the thermal conductivity corresponding voltage value V01 and the kinematic viscosity corresponding voltage value V02 varies depending on the urea concentration and ammonium formate concentration of the mixed solution. Thus, the amount of ammonia generated from the mixed solution is measured. That is, the voltage value V01 corresponding to the thermal conductivity and the voltage value V02 corresponding to the kinematic viscosity are affected by different physical properties of the liquid, that is, the thermal conductivity and the kinematic viscosity, and these relations are the urea concentration and ammonium formate concentration of the mixed solution. Therefore, it is possible to detect the density as described above.

  That is, in the example of the present invention, the ratio Y / X = 0 of the ammonium formate concentration Y wt% and the urea concentration X wt%, that is, several urea aqueous solutions (reference urea) having an ammonium formate concentration of 0% and a known urea concentration. The first calibration curve showing the relationship between the thermal conductivity-corresponding voltage value V01 and the kinematic viscosity-corresponding voltage value V02, and the ratio of ammonium formate concentration Y wt% and urea concentration X wt% Y / X = c0 (constant) ), A second calibration curve showing the relationship between the thermal conductivity corresponding voltage value V01 and the kinematic viscosity corresponding voltage value V02 is obtained in advance, and these calibration curves are stored in the storage means of the microcomputer 72. Remember. An example of the first and second calibration curves is shown in FIG.

  Here, it is assumed that a thermal conductivity-corresponding voltage value V01a and a kinematic viscosity-corresponding voltage value V02a are obtained for the liquid US to be measured which is a mixed solution of urea concentration Xa% and ammonium formate concentration Ya%.

If the solution contains only urea (urea aqueous solution), the kinematic viscosity corresponding voltage value should be V02b when the thermal conductivity corresponding voltage value is V01a as shown in FIG. Thus, the fact that the combination of the thermal conductivity corresponding voltage value V01 and the kinematic viscosity corresponding voltage value V02 does not match the first calibration curve indicates that not only urea but also ammonium formate is mixed in the solution. ing.

  From the first and second calibration curves obtained in advance, when the thermal conductivity corresponding voltage value is V01a, the temporary first kinematic viscosity corresponding voltage value in the case of Y / X = 0 is V02b, Y / X = c0 It can be seen that the provisional second kinematic viscosity corresponding voltage value in this case is V02c.

Then, a value of Y / X = c is calculated by using a proportional calculation so that the thermal conductivity corresponding voltage value is V01a and the kinematic viscosity corresponding voltage value is V02a. That is,
c = c0 (V02a-V02b) / V02c
Ask from.

  52. The first and second calibration curves in FIG. 52 vary depending on the liquid temperature. Therefore, calibration curves corresponding to a plurality of liquid temperatures are obtained in advance, stored in the storage means of the microcomputer 72, and used. It is necessary to change the calibration curve appropriately according to the liquid temperature.

  When it is determined that Y / X = c, the heat conductivity corresponding voltage value V01 and the calibration curve (comparison curve) of urea concentration X in the case of Y / X = c stored in advance are used. The value of X at which the conductivity corresponding voltage value V01 becomes V01a can be determined. Furthermore, the value of Y is also determined according to the determined X.

  Note that the calibration curve (comparison curve) for the thermal conductivity corresponding voltage value V01 and urea concentration X at Y / X = c is set by performing interpolation calculation from the calibration curves for some values of c stored in advance. May be.

  Then, from the calculated urea concentration X wt%, ammonium formate concentration Y wt% and the amount Q of the mixed solution, the urea amount A = Q × X / 100 and the ammonium formate amount B = Q × Y / 100 in the mixed solution are obtained. calculate. The amount Q of the mixed solution may be a mass (unit: kg, g, etc.) or a volume (unit: cc, l, etc.).

And, from the four parameters of urea concentration X wt%, ammonium formate concentration Y wt%, urea amount A, ammonium formate amount B, the following equation:
Ammonia generation amount G = X × A + Y × B
Thus, the ammonia generation amount can be calculated.

  FIG. 53 is a schematic cross-sectional view showing another embodiment in which the fluid identification device according to the present invention is used in a device for measuring the amount of ammonia generated, and includes a differential pressure sensor 300 in addition to the identification sensor module 2. Here, the differential pressure sensor 300 may be a differential pressure sensor that has been conventionally used.

  Note that the ammonia generation amount measuring apparatus 1 shown in FIG. 53 has basically the same configuration as the liquid type identifying apparatus 1 in the embodiment shown in FIGS. Reference numerals are assigned and detailed descriptions thereof are omitted.

As shown in FIG. 53, the terminal pin 31 of the differential pressure sensor 300 is connected to the circuit of the circuit board 41a.
The hydraulic pressure at the first inlet 300a of the differential pressure sensor 300 is p1, the hydraulic pressure at the second inlet 300b is p2, the height difference between the first inlet 300a and the second inlet 300b is L, When the density of the identification liquid is ρ, there is a relationship of p1−p2 = ρ × L. Therefore, the differential pressure sensor 300 can measure the density-corresponding voltage value V03 that is an electrical output depending on ρ.

  Here, in the same manner as described above, using the identification sensor module 2, the ratio Y / X = 0 of the ammonium formate concentration Y wt% and the urea concentration X wt%, that is, the ammonium formate concentration 0% and the urea concentration is known. A third calibration curve showing the relationship between the thermal conductivity-corresponding voltage value V01 and the density-corresponding voltage value V03, and ammonium formate. The thermal conductivity corresponding voltage value V01 is measured for several mixed solutions in which the ratio Y / X = c0 (constant) of the concentration Y weight% and the urea concentration X weight%, and the density corresponding to the thermal conductivity corresponding voltage value V01. A fourth calibration curve showing the relationship with the voltage value V03 is obtained in advance, and these calibration curves are stored in the storage means of the microcomputer 72. Examples of the third and fourth calibration curves are shown in FIG.

  In this embodiment, since it is not necessary to obtain the kinematic viscosity-corresponding voltage value V02, the application of the pulse voltage is terminated when the first time, which is a relatively short time from the start of the voltage application to the heating element, has elapsed. May be. That is, the first time may be the pulse voltage application time. Thereby, the measurement time can be shortened.

  Here, it is assumed that a thermal conductivity-corresponding voltage value V01a and a density-corresponding voltage value V03a are obtained for the liquid US to be measured which is a mixed solution of urea concentration Xa% and ammonium formate concentration Ya%.

If it is a solution containing only urea (urea aqueous solution), as shown in FIG. 54, when the voltage value corresponding to thermal conductivity is V01a, the voltage value corresponding to density should be V03b. in this way,
The fact that the combination of the thermal conductivity corresponding voltage value V01 and the density corresponding voltage value V03 is not compatible with the third calibration curve indicates that not only urea but also ammonium formate are mixed in the solution.

  From the third and fourth calibration curves obtained in advance, when the thermal conductivity corresponding voltage value is V01a, the density corresponding voltage value is V03b when Y / X = 0, and the density corresponding when Y / X = c0. It can be seen that the voltage value is V03c.

Then, the value of Y / X = c, where the thermal conductivity corresponding voltage value is V01a and the density corresponding voltage value is V03a, is calculated using a proportional calculation. That is,
c = c0 (V03a-V03b) / V03c
Ask from.

54. The third and fourth calibration curves in FIG. 54 vary depending on the liquid temperature. Therefore, a calibration curve corresponding to a plurality of liquid temperatures is obtained in advance, and the calibration curve to be used is appropriately changed according to the liquid temperature. There is a need.
Then, from the value of Y / X = c, the value of X and the value of Y at which the thermal conductivity corresponding voltage value V01 becomes V01a is determined, so that the amount of ammonia generated can be calculated as described above. it can.

The preferred embodiment of the present invention has been described above, but the present invention is not limited to this. For example, the pulse voltage P, the number of samplings, etc. can be changed as appropriate, and the scope of the present invention is not deviated. Various changes can be made.

FIG. 1 is a schematic sectional view showing an embodiment in which a fluid identification device according to the present invention is used as an example in a liquid type identification device. It is typical sectional drawing of the identification sensor module of the liquid type identification device of FIG. It is typical sectional drawing which shows the liquid type detection part of the liquid type identification apparatus of FIG. It is typical sectional drawing which shows the use condition of the liquid type identification device of FIG. It is a disassembled perspective view of the thin film chip | tip of an indirectly heated liquid type detection part. It is a block diagram of the circuit for liquid type identification. It is a figure which shows the relationship between the single pulse voltage P applied to a heat generating body, and the sensor output Q. FIG. The figure which shows that the liquid type corresponding | compatible 1st voltage value of the sugar aqueous solution in a certain sugar concentration range exists in the range of the liquid type corresponding | compatible 1st voltage value V01 obtained with the urea aqueous solution in which urea concentration is a predetermined range. It is. It is a figure which shows the liquid type corresponding | compatible 1st voltage value V01 and liquid type corresponding | compatible 2nd voltage value V02 about urea aqueous solution of 30% of urea concentration with respect to 1.00 regarding urea aqueous solution, sugar aqueous solution, and water. . It is a figure which shows the example of a 1st calibration curve. It is a figure which shows the example of a 2nd calibration curve. It is a figure which shows an example of the liquid temperature corresponding | compatible output value T. FIG. It is a graph which shows typically that the judgment standard of predetermined liquid discernment by the combination of liquid type correspondence 1st voltage value V01 and liquid type correspondence 2nd voltage value V02 changes according to temperature. It is a flowchart which shows a liquid type identification process. FIG. 15 is a cross-sectional view showing an embodiment applied to a gasoline identification device as a fluid identification device to which the cover member 2d is applied. FIG. 16 is a graph showing a change in the gasoline type-corresponding voltage value V0 obtained when the inclination angle of the measurement unit is changed in the fluid identification device of the embodiment of FIG. 15 (with the cover member 2d). FIG. 17 is a graph showing a change in the gasoline type corresponding voltage value V0 obtained when the inclination angle is changed in the comparative form. FIG. 18 is a schematic diagram of a circuit configuration of an embodiment using a series circuit instead of the parallel circuit of FIG. FIG. 19 is a graph showing an example of an output A (that is, a liquid temperature detection result) obtained in a state where the changeover switch 14 shown in FIG. 18 is connected to the a side. FIG. 20 is a cross-sectional view of an identification sensor module according to another embodiment of the present invention. FIG. 21 shows the identification sensor module of the embodiment of FIG. 20, FIG. 21 (A) is a schematic view showing the inside of FIG. 20, and FIG. 21 (B) is a portion seen from the direction A of FIG. It is an expanded sectional view. FIG. 22 shows an identification sensor module according to another embodiment of the present invention. FIG. 22A is a perspective view of an identification sensor module according to another embodiment of the present invention, and FIG. It is the schematic which shows the attachment state of the identification sensor module of 22 (A). FIG. 23 is a longitudinal sectional view of the identification sensor module of FIG. 22 viewed from the B direction. FIG. 24 is a graph for explaining another embodiment using the fluid identification device of the present invention. FIG. 25 is a graph for explaining another embodiment using the fluid identification device of the present invention. FIG. 26 is a circuit configuration diagram of an embodiment in which the fluid identification device of the present invention is used as a flow meter. FIG. 27 is a schematic cross-sectional view of an embodiment of the light oil type identification device of the present invention. FIG. 28 is a graph showing a time-voltage relationship showing a liquid type identification method using the light oil type identification device of the present invention. FIG. 29 is a graph showing the relationship between kinematic viscosity and sensor output. FIG. 30 is a graph showing the relationship between kinematic viscosity and distillation temperature. FIG. 31 is a graph showing the relationship between sensor output and distillation temperature. FIG. 32 is a graph showing a calibration curve showing a liquid type identification method using the light oil type identification device of the present invention. FIG. 33 is a graph showing the distillation properties of light oil. FIG. 34 is a schematic view of another embodiment when the fluid identification device of the present invention is used as a flow rate / liquid type detection device. FIG. 35 is a graph showing a calibration curve showing a flow rate detection method using the flow rate / liquid type detection device of FIG. FIG. 36 is an exploded perspective view of the whole of another embodiment when the fluid identification device of the present invention is used as a liquid type detection device. FIG. 37 is an exploded perspective view of the liquid type detection chamber of the liquid type detection apparatus of FIG. FIG. 38 is a schematic diagram for explaining the detection state of the liquid type detection chamber of the liquid type detection apparatus of FIG. FIG. 39 is a schematic diagram of an embodiment in which the urea concentration identification device for urea solution of the present invention is applied to an automobile system. FIG. 40 is a partially broken perspective view for explaining an embodiment in which the fluid identification device of the present invention is used in a tank liquid leakage detection device. FIG. 41 is a partially omitted cross-sectional view of the leak detection apparatus of this embodiment. FIG. 42 is a timing chart showing the relationship between the voltage Q applied from the pulse voltage generation circuit to the thin film heating element and the voltage output S of the leak detection circuit. FIG. 43 is a diagram showing a specific example of the relationship between the voltage Q applied to the thin film heating element and the voltage output S of the leak detection circuit. FIG. 44 is a diagram showing a specific example of the relationship between the liquid level change rate and the integral value ∫ (S0−S) dt. FIG. 45 is a diagram showing a specific example of the relationship between the liquid level change rate and the time change rate P ′ of the liquid level corresponding output. FIG. 46 is a flowchart of specific gravity detection. FIG. 47 is an exploded perspective view showing another embodiment in which the fluid identification device of the present invention is used as a liquid level detection device. 48 is a partially omitted cross-sectional view of FIG. FIG. 49 is a diagram showing a state in which the fluid identification device of the present invention is attached to the tank. FIG. 50 is a flowchart showing a liquid level detection process in the microcomputer. FIG. 51 is a schematic cross-sectional view showing an example in which the fluid identification device according to the present invention is used in an ammonia generation amount measuring device. FIG. 52 is a diagram showing examples of first and second calibration curves. FIG. 53 is a schematic cross-sectional view showing another embodiment in which the fluid identification device according to the present invention is used in an apparatus for measuring the amount of ammonia generated, and in the case where a differential pressure sensor 300 is provided in addition to the identification sensor module 2. It is typical sectional drawing which shows the measuring apparatus of ammonia generation amount. FIG. 54 is a diagram showing examples of third and fourth calibration curves.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Liquid type identification device 2 Identification sensor module 2a Base | substrate 2b O ring 2c O ring 2d Cover member 3 Liquid level sensor module 4 Waterproof case 4a Mounting part 5 Waterproof wiring 6 Sensor holder 6a Sensor mounting hole 7 Fixing screw 8 Filter holder 9 Filter 11 Flow rate / liquid type detection sensor device 12 Liquid type identification device main body 12a Filter 12b Filter cover 13 Resistor 13a Sensor holder 13b Measurement capillary 14 Changeover switch 15 Circuit housing part 15a Leakage detection control part 16 Cap 16a Ventilation path 17 Wiring 18 Light oil inflow path 20 container 20A container main body 20A1 bulging part 20A2 bulging part 20B container lid part 21 first liquid type liquid temperature detection part 21a first liquid type liquid temperature detection thin film chip 21a1 chip substrate 21a2 first temperature sensitive Body 21a3 interlayer insulating film 21 4 First Heating Element 21a5 Heating Element Electrode 21a6 Protective Film 21a7 Electrode Pad 21c Metal Fin 21d Bonding Wire 21e External Electrode Terminal 22 Second Liquid Type Liquid Temperature Detection Unit 22a Second Liquid Type Liquid Temperature Detection Thin Film Chip 22a2 Second temperature sensing element 22a4 Second heating element 22c Metal fin 22e External electrode terminal 23 Synthetic resin mold 23a Synthetic resin 24 Liquid to be measured 25 Liquid type detection circuit board 26 Custom IC
27 Terminal Pin 31 Terminal Pin 32 Flow Sensing Temperature Sensor 32a Temperature Compensation Sensing Body 33 Thin Film Heating Element 36 Fin 40 Measuring Unit 41 Power Supply Circuit Unit 41a Circuit Board 42 Flow Rate Detection Unit 44 Flow Detection Fin Plate 44a Fluid Temperature Detection Fin plate 49 Electrode terminal 49a Electrode terminal 50 Hydrophilic film 51 Connector 54 Light oil outlet 62 Resistor 63 Voltmeter 64 Resistor 65 A / D converter 66 Resistor 68 Bridge circuit 70 Differential amplifier circuit 71 Liquid temperature detection amplifier 72 Microcomputer 73 Bridge circuit 74a First switch 74b Second switch 75 Differential amplification circuit 76 Output buffer circuit 77 Integration circuit 78 V / F conversion circuit 79 Temperature compensated crystal resonator 80 Reference frequency generation circuit 81 Transistor 82 Pulse counter 83 Microcomputer 84 Memory 85 Display unit 90 power supply circuit 92 resistor 94 variable resistor 100 tank 101 wall member 110 urea solution supply pump 116 catalyst device 130 urea solution supply mechanism 132 urea solution tank 133 first temperature sensor 134 second temperature sensor 135 heater 136 first 3 temperature sensor 137 pressure sensor 138 on-off valve 138a valve element 140 NOx sensor 142 NOx sensor 200 ASIC board 202 packing 204 connector 206 fixing member 208 fixing screw 210 packing 212 fluid to be identified 300 differential pressure sensor 300a first introduction path 300b Second introduction path 301 Terminal pin 400 Light oil liquid type identification chamber 402 Liquid type identification sensor opening 404 Liquid type identification sensor 405 Liquid type identification sensor heater 406 Liquid type detection sensor heater 408 Lead electrode 41 Liquid temperature sensor 412 molding resin 416 check valve 417 main passage on-off valve 418 orifice 419 sensor controller 420 flow rate and fluid type detection device 422 the main channel 424 sub-passage 426 sub-passage opening and closing valve 428 ECU
430 Liquid type detection device 432 Liquid type detection device main body 434 Liquid type detection chamber 436 First flow path 438 Second flow path 440 Fluid introduction path 442 Fluid discharge port 444 Liquid type detection chamber lid member 446 For liquid type detection sensor Opening 448 Liquid type detection sensor 450 Circuit board member 452 Outer cover member 454a Mounting flange 454b Mounting flange 456 Flow control plate 458 Plate member 460 Side plate member 462 Side plate member 464 Cover plate member 466 Fluid inlet 468 Fluid outlet 470 Side wall 472 Liquid Temperature sensor 473 Liquid temperature sensor heater 474 Lead electrode 480 Automobile system 482 Urea concentration identification device 490 Tank 492 Metering port 494 Injection port 496 Top plate 498 Liquid supply port 500 Side plate 502 Bottom plate 504 Leakage detection device 506 Liquid introduction / extraction part 508 Part 510 Liquid reservoir 512 Tube 520 aqueous urea solution for the tank 522 openings 523 liquid level detection device 524 inlet pipe 526 outlet pipe 528 identifying sensor section 530 pressure sensor 532 support part 540 circuit board 542 lid member 544 wires 546 interconnect 548 wires 550 connector

Claims (42)

  An identification sensor module characterized in that at least two fluid detection units each including a temperature sensing element and a heating element arranged in the vicinity of the temperature sensing element are accommodated in a container. A fluid detection circuit connected to the at least two fluid detection units;
The identification sensor module according to claim 1, further comprising: an identification calculation unit configured to identify a fluid to be identified based on an output of the fluid detection circuit.   The identification calculation unit selects energization of the heating element provided in any one of the at least two fluid detection units, and accordingly, any of the fluid detection units not including the heating element selected to be energized A fluid temperature detection signal by a temperature sensor provided in one is selected, and the identified fluid is identified based on the selected fluid temperature detection signal and the output of the fluid detection circuit. The identification sensor module according to claim 2. A switch exists in each energization path for the heating element provided in the at least two fluid detection units,
The identification calculation unit selects one of the switches included in the at least two fluid detection units, and thereby selects one of the heating elements included in the at least two fluid detection units. 4. The identification sensor module according to claim 2, wherein energization is selected.   The identification calculation unit selects energization of the heating element provided in any one of the at least two fluid detection units, and any one of the fluid detection units not including the heating element selected to be energized 3. A fluid temperature detection signal is selected by a temperature sensing element provided in the sensor, and fluid identification for identifying the fluid to be measured is performed in order of selecting energization to a plurality of heating elements. 4. The identification sensor module according to any one of 4 above. The identification calculation unit selects energization of the heating element provided in any one of the at least two fluid detection units, and any one of the fluid detection units not including the heating element selected to be energized The characteristic value group calculated based on the output of the liquid type detection circuit when the liquid temperature detection signal by the temperature sensor provided in is selected, the selection of energization to the plurality of heating elements and the liquid temperature by the temperature sensor. In combination with detection signal selection,
The identification sensor module according to any one of claims 2 to 4, wherein the liquid to be measured is identified using an average characteristic value group obtained by averaging corresponding ones. The identification calculation unit selects energization of the heating element provided in any one of the at least two fluid detection units, and any one of the fluid detection units not including the heating element selected to be energized When selecting a liquid temperature detection signal by the temperature sensing element provided in the sensor, the characteristic value group calculated based on the output of the liquid type detection circuit is selected from the electrification to the plurality of heating elements and the liquid temperature detection by the temperature sensing element. Obtained in combination with signal selection,
5. The identification sensor module according to claim 2, wherein the liquid to be measured is identified using a sum characteristic value group obtained by taking the sum of the corresponding ones. The identification calculation unit selects energization of the heating element provided in any one of the at least two fluid detection units, and any one of the fluid detection units not including the heating element selected to be energized When selecting a liquid temperature detection signal by the temperature sensing element provided in the sensor, the characteristic value group calculated based on the output of the liquid type detection circuit is selected from the electrification to the plurality of heating elements and the liquid temperature detection by the temperature sensing element. Obtained in combination with signal selection,
2. The presence / absence of at least one defect among the at least two fluid detection units is determined based on at least one of a difference characteristic value group obtained by taking a difference between corresponding ones. The identification sensor module according to any one of 7 to 7.   9. The identification sensor module according to claim 1, wherein the fluid detection unit is disposed in contact with the identified fluid side of the container so as not to be exposed from the container to the identified fluid side. .   The identification sensor module according to any one of claims 1 to 8, wherein at least a part of the fluid detection unit is arranged to be exposed from the container to the identified fluid side.   The identification sensor module according to claim 10, wherein an exposed portion of the fluid detection unit is covered with a hydrophilic film or a filter.   The said container is comprised from the container main body located in the to-be-identified fluid side, and the cover part located in the opposite side to the to-be-identified fluid side, The identification in any one of Claim 1 to 11 characterized by the above-mentioned. Sensor module.   The identification sensor module according to claim 12, wherein the container body is made of metal.   14. The identification sensor module according to claim 1, wherein the identification sensor module is incorporated in a part of the fluid detection circuit, an identification calculation unit, or an IC. The fluid detection unit is configured by embedding a fluid detection thin film chip in which a fluid detection temperature sensing element is formed as a thin film on a chip substrate and embedded in a synthetic resin mold such that one surface thereof is exposed,
15. The identification sensor module according to claim 1, wherein one surface of the fluid detection thin film chip is disposed so as to be positioned on the identified fluid side of the container. The at least two fluid detectors are
A first fluid detection unit including a first temperature sensing element and a first heating element disposed in the vicinity of the first temperature sensing element;
The second fluid sensing part is provided with a second temperature sensing element and a second heating element disposed in the vicinity of the second temperature sensing element. The identification sensor module according to any one of the above.   The identification calculation unit selects first energization to the first heating element and selects a liquid temperature detection signal by the second temperature sensing element to identify the fluid to be measured, A second liquid type identification for identifying the fluid to be measured is performed alternately by selecting energization to the second heating element and selecting a liquid temperature detection signal by the first temperature sensing element. The identification sensor module according to claim 16.   The identification calculation unit selects a first characteristic calculated based on an output of the fluid detection circuit when the energization to the first heating element is selected and a liquid temperature detection signal by the second temperature sensing element is selected. A second characteristic value group calculated based on an output of the fluid detection circuit when a value group and energization to the second heating element are selected and a liquid temperature detection signal by the first temperature sensing element is selected The identification sensor module according to claim 16, wherein the fluid to be measured is identified using an average characteristic value group obtained by averaging the corresponding ones.   The identification calculation unit selects a first characteristic calculated based on an output of the fluid detection circuit when the energization to the first heating element is selected and a liquid temperature detection signal by the second temperature sensing element is selected. A second characteristic value group calculated based on an output of the fluid detection circuit when a value group and energization to the second heating element are selected and a liquid temperature detection signal by the first temperature sensing element is selected The identification sensor module according to claim 16, wherein the fluid to be measured is identified using a sum characteristic value group obtained by taking the sum of the corresponding ones.   The identification calculation unit selects a first characteristic calculated based on an output of the fluid detection circuit when the energization to the first heating element is selected and a liquid temperature detection signal by the second temperature sensing element is selected. A second characteristic value group calculated based on an output of the fluid detection circuit when a value group and energization to the second heating element are selected and a liquid temperature detection signal by the first temperature sensing element is selected And determining whether or not there is a defect in one of the first and second fluid detection units based on at least one of the difference characteristic value groups obtained by taking the difference between corresponding ones. The identification sensor module according to any one of claims 16 to 19,   A fluid identification apparatus comprising the identification sensor module according to claim 1. The identification sensor module is attached to a waterproof case;
The fluid identification device according to claim 21, wherein the fluid identification device is arranged so that the fluid detection unit side of the container is exposed to the identified fluid side from the waterproof case.   23. The fluid identification device according to claim 22, wherein the fluid identification device is arranged so that the fluid detection unit side of the container protrudes from the waterproof case to the identification target fluid side. The container is composed of a container body located on the identified fluid side and a lid portion located on the opposite side of the identified fluid side,
The fluid identification device according to any one of claims 22 to 23, wherein a joint portion between the container main body and the lid portion is disposed in a waterproof case. The waterproof case includes a cover member that covers the identified fluid side of the container,
The fluid identification device according to any one of claims 22 to 24, wherein a flow path of a fluid to be identified is formed inside the cover member.   The fluid identification device according to any one of claims 22 to 25, wherein a fluid level sensor module for detecting a fluid level of a fluid to be identified is attached to the waterproof case.   27. The fluid identification device according to claim 22, wherein a power supply circuit unit is accommodated in the waterproof case.   28. The fluid identification device according to claim 22, wherein a waterproof wiring extends from the waterproof case.   The identification of the fluid to be identified is at least one of fluid type identification, concentration identification, fluid presence / absence identification, fluid temperature identification, flow rate identification, fluid leakage identification, and fluid level identification. The fluid identification device according to any one of claims 21 to 28.   30. The fluid identification device according to any one of claims 21 to 29, wherein the identification target fluid is any one of a hydrocarbon-based liquid, an alcohol-based liquid, and an aqueous urea solution. Based on the electrical characteristic values of the temperature sensing elements provided in the at least two fluid detection units,
30. The apparatus according to claim 29, wherein the fluid type is determined by detecting the flow rate of the fluid and measuring conductivity between each of the at least two fluid detectors. The fluid identification apparatus according to the description. The fluid identification device is disposed in a fluid type identification chamber,
A pulse voltage is applied to the heating element of the fluid detection unit for a predetermined time, and the identification fluid temporarily retained in the fluid type identification chamber is heated by the heating element of the fluid detection unit,
30. The fluid type of the identified fluid is identified by a voltage output difference corresponding to a temperature difference between an initial temperature and a peak temperature of the temperature sensing element of the fluid detection unit. The fluid identification apparatus according to the description. A main channel through which the fluid to be identified flows;
A sub-channel branched from the main channel;
The fluid identification device provided in the sub-flow path;
A sub-channel opening / closing valve provided in the sub-channel and controlling the flow of the fluid to be identified to the fluid identification device;
A control device for controlling the fluid identification device and the sub-channel opening / closing valve;
The control device is
When identifying the fluid to be identified, close the sub-channel opening / closing valve and temporarily retain the fluid to be identified in the fluid identification device to identify the fluid to be identified,
When detecting the flow rate of the fluid to be identified, control is performed to detect the flow rate of the fluid to be identified by opening the sub-channel opening / closing valve and causing the fluid to be identified to flow through the fluid identification device. The fluid identification device according to claim 29, wherein the fluid identification device is configured as follows. A fluid identification detection chamber for temporarily retaining a fluid to be identified;
An identification sensor module of the fluid identification device disposed in the fluid identification detection chamber;
30. The fluid identification device according to claim 29, further comprising a flow control plate disposed in the fluid identification detection chamber and surrounding the identification sensor module. The fluid identification device is disposed in a fluid type identification chamber,
A pulse voltage is applied to the heating element of the fluid detection unit for a predetermined time, and the identification fluid temporarily retained in the fluid type identification chamber is heated by the heating element of the fluid detection unit,
30. The configuration of claim 29, wherein the concentration of the fluid to be identified is identified by a voltage output difference corresponding to a temperature difference between an initial temperature and a peak temperature of the temperature sensing element of the fluid detection unit. Fluid identification device. The fluid identification device is disposed in a measurement capillary into which the fluid to be identified in the tank is introduced from the lower end,
Obtaining an output corresponding to a difference in temperature sensed by the temperature sensing body of the at least two fluid detection units;
Based on the flow-corresponding value corresponding to the flow rate of the identified fluid calculated using the output, the specific gravity of the identified fluid in the tank is detected,
Using the obtained specific gravity value, the fluid level of the fluid to be identified is measured by the fluid level sensor module, and the leakage of the fluid to be identified in the tank is detected based on the magnitude of the temporal change rate of the fluid level. 30. The fluid identification device according to claim 29. The fluid level sensor module detects the fluid pressure of the fluid to be identified, and calculates a temporary fluid level value when the fluid to be identified is a fluid of a predetermined density based on the fluid pressure.
A pulse voltage is applied to the heating element of the fluid detection unit for a predetermined time, and the fluid to be identified is heated by the heating element of the fluid detection unit,
The concentration of the fluid to be identified is identified by the voltage output difference corresponding to the temperature difference between the initial temperature and the peak temperature of the temperature sensing element of the fluid detector,
Based on the relationship between the density and density of the identified fluid to be identified, the density value of the identified fluid is obtained,
30. The fluid identification device according to claim 29, wherein the fluid level of the identification target fluid is calculated based on the temporary fluid level value and the density value. An apparatus for measuring the amount of ammonia generated, comprising the fluid identification device according to any one of claims 21 to 28, for measuring the amount of ammonia generated from a liquid to be identified comprising urea water, ammonium formate water, or a mixed water thereof. Because
Using a sensor comprising a heating element and a temperature sensing element disposed in the vicinity of the heating element,
A pulse voltage is applied to the heating element for a predetermined time, the liquid to be measured is heated by the heating element, and an electric output corresponding to the electric resistance of the temperature sensing element is used.
While measuring the output value corresponding to the thermal conductivity which is the electrical output of the temperature sensing element depending on the thermal conductivity of the liquid to be measured,
Using a differential pressure sensor, measure the density-corresponding output value, which is an electrical output that depends on the density of the liquid to be measured,
From the relationship between the thermal conductivity-corresponding output value and the density-corresponding output value, the urea concentration X wt% and the ammonium formate concentration Y wt% contained in the liquid to be measured are calculated,
Calculate the urea amount A and ammonium formate amount B contained in the liquid to be measured from the concentration and the amount of the liquid to be measured,
The following formula:
Ammonia generation amount = X × A + Y × B
A device for measuring the amount of ammonia generated, characterized in that the amount of ammonia generated is measured from the above. An apparatus for measuring the amount of ammonia generated, comprising the fluid identification device according to any one of claims 21 to 28, for measuring the amount of ammonia generated from a liquid to be identified comprising urea water, ammonium formate water, or a mixed water thereof. Because
Using a sensor comprising a heating element and a temperature sensing element disposed in the vicinity of the heating element,
A pulse voltage is applied to the heating element for a predetermined time, the liquid to be measured is heated by the heating element, and an electric output corresponding to the electric resistance of the temperature sensing element is used.
While measuring the output value corresponding to the thermal conductivity which is the electrical output of the temperature sensing element depending on the thermal conductivity of the liquid to be measured,
Using a differential pressure sensor, measure the density-corresponding output value, which is an electrical output that depends on the density of the liquid to be measured,
From the relationship between the thermal conductivity-corresponding output value and the density-corresponding output value, the urea concentration X wt% and the ammonium formate concentration Y wt% contained in the liquid to be measured are calculated,
Calculate the urea amount A and ammonium formate amount B contained in the liquid to be measured from the concentration and the amount of the liquid to be measured,
The following formula:
Ammonia generation amount = X × A + Y × B
A device for measuring the amount of ammonia generated, characterized in that the amount of ammonia generated is measured from the above. Measurement of the amount of ammonia generated by measuring the amount of ammonia generated from a liquid to be identified comprising urea water, ammonium formate water, or a mixed water thereof using the fluid identification device according to any one of claims 21 to 28. A method,
Using a sensor comprising a heating element and a temperature sensing element disposed in the vicinity of the heating element,
A pulse voltage is applied to the heating element for a predetermined time, the liquid to be measured is heated by the heating element, and an electric output corresponding to the electric resistance of the temperature sensing element is used.
The output corresponding to the thermal conductivity, which is the electrical output of the temperature sensor depending on the thermal conductivity of the liquid to be measured, is measured, and the dynamic output which is the electrical output of the temperature sensor depending on the kinematic viscosity of the liquid to be measured. Measure the viscosity corresponding output value,
From the relationship between the thermal conductivity corresponding output value and the kinematic viscosity corresponding output value, the urea concentration X weight% and the ammonium formate concentration Y weight% contained in the liquid to be measured are respectively calculated,
Calculate the urea amount A and ammonium formate amount B contained in the liquid to be measured from the concentration and the amount of the liquid to be measured,
The following formula:
Ammonia generation amount = X × A + Y × B
A method for measuring the amount of ammonia generated, characterized in that the amount of ammonia generated is measured. Ammonia generation amount for measuring the amount of ammonia generated from a liquid to be measured comprising urea water urea water, ammonium formate water, or a mixed water thereof using the fluid identification device according to any one of claims 21 to 28. Measuring method,
Using a sensor comprising a heating element and a temperature sensing element disposed in the vicinity of the heating element,
A pulse voltage is applied to the heating element for a predetermined time, the liquid to be measured is heated by the heating element, and an electric output corresponding to the electric resistance of the temperature sensing element is used.
While measuring the output value corresponding to the thermal conductivity which is the electrical output of the temperature sensing element depending on the thermal conductivity of the liquid to be measured,
Using a differential pressure sensor, measure the density-corresponding output value, which is an electrical output that depends on the density of the liquid to be measured,
From the relationship between the thermal conductivity-corresponding output value and the density-corresponding output value, the urea concentration X wt% and the ammonium formate concentration Y wt% contained in the liquid to be measured are calculated,
Calculate the urea amount A and ammonium formate amount B contained in the liquid to be measured from the concentration and the amount of the liquid to be measured,
The following formula:
Ammonia generation amount = X × A + Y × B
A method for measuring the amount of ammonia generated, characterized in that the amount of ammonia generated is measured.   29. A fluid identification method comprising identifying a fluid to be identified using the fluid identification device according to claim 21.

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