JP2003035612A - Combustion heat flow rate measuring instrument, combustion heat flow rate measuring method, gas meter and gas use quantity inspection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a combustion heat flow rate measuring instrument simple in constitution capable of accurately measuring the use flow rate as fuel of a fluid on the basis of the dimension of a combustion heat flow rate, even if one or more different variations are present in the compositional component ratio of the fluid, a gas meter and a gas use quantity inspection device. SOLUTION: The change in quantity of heat or in temperature caused by the flow of the fluid in a flow passage is detected by a flow rate measuring sensor (flow rate measuring means) 100 to be outputted as an electric signal. The electric signal is subjected to linear corresponding processing (processing linearly corresponding to a combustion heat flow rate per a unit time) in an linearization arithmetic part (linearization arithemetic means) 201, to more directly obtain the data of the accurate combustion heat flow rate value wherein tolerance is received in a predetermined allowable range.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention regards a flow of combustion heat obtained when a fluid used as a fuel is burned at a predetermined air-fuel ratio, and measures the flow rate of the combustion heat per unit time. The present invention relates to a combustion heat flow rate measuring device, a combustion heat flow rate measuring method, a gas meter, and a gas usage meter reading device.

[0002]

2. Description of the Related Art Conventionally, a gas meter for measuring the amount of city gas or natural gas used is installed in individual general houses, shops, factories, etc. that are consumers (users) of city gas or LNG (liquefied natural gas). Set to calculate the integrated value of volume flow rate for each user, display it as the integrated value of gas usage, and calculate the monthly gas usage charge based on the output usage of gas. Has been done. Conventionally, in such a gas meter, a volume flow rate is generally used as a unit of measurement. Further, as a flow rate measuring device which is arranged at each of so-called take-off bases further upstream than a gas meter installed in an individual consumer, a device which measures a volume flow rate like a gas meter is used. .

More specifically, for example, in a gas meter called a membrane type, a blower-shaped volumetric flow rate measuring device is built in, and the change in the volume of the blower corresponding to the flow of gas is utilized to
The volumetric flow rate of the gas flow is measured and integrated, and the integrated value of the volumetric flow rate of the gas is output as the usage amount (display output by a counter or data output by a telegram, etc.). Also,
In a gas meter called an ultrasonic wave propagation method, the time taken to propagate the ultrasonic wave from the upstream side to the downstream side in the gas and the time taken to propagate the ultrasonic wave from the downstream side to the upstream side are measured, and the time difference is the flow velocity of the gas. Based on the corresponding change, the gas flow rate value is indirectly obtained, and the gas flow rate value is calculated by multiplying it by the cross-sectional area of the gas conduit, and the flow rate value is further integrated. , Output the integrated volumetric flow rate of gas as a display or as a data message. In addition, a method using a turbine flow meter and a method using a heat ray flow rate measurement method have been proposed. In any case, conventional gas meters generally measure the volume flow value directly or indirectly,
The volume flow rate values were integrated and displayed.

[0004]

However, in the gas meter for directly or indirectly measuring the volumetric flow rate value as described above, from the viewpoint of measuring gas as an energy resource or a fuel, it is necessary to use it in an environment where the gas is used. There is a problem that an error is likely to occur in the substantial amount of gas used depending on various conditions such as temperature and pressure. That is, generally, the lower the temperature and the higher the pressure of the fuel gas, the higher the density per unit volume, so the energy amount per unit volume (when the gas is burned at a predetermined air-fuel ratio, The combustion heat quantity per unit volume obtained) tends to increase. Therefore, even if the gas of the same volume flow rate is consumed, the amount of heat obtained by the combustion of the gas changes depending on the temperature and pressure (atmospheric pressure and supply pressure) in the gas use environment at that time. There is an error in terms of the amount of energy consumed. In other words, as an index of energy consumption, the volume flow rate value is not always a strict unit of measurement value (dimension).

In the conventional gas meter, the integrated value of the volumetric flow rate is displayed on a screen of a mechanical counter or a liquid crystal display panel. However, even if the amount of gas used is displayed as the integrated value of the volumetric flow rate, it is regarded as an energy resource. It cannot be denied that it is difficult to accurately grasp the actual amount of gas used. For example, it is possible to obtain the value of energy consumption by multiplying the volumetric flow rate value by a predetermined coefficient, but as described above, the combustion heat quantity of gas in the same volume depends on temperature and pressure. Since it changes with the change in density, it is difficult for a gas meter of the volume flow rate measurement method that an error is likely to be mixed due to such a factor, to accurately grasp the energy consumption.

Further, in order to more accurately measure the amount of gas used as an energy resource, it is desirable to fundamentally change the unit of measurement from the volume flow rate to the mass flow rate.
That is, a mass flow sensor is used as a sensor for measuring the flow rate of gas, and the mass flow rate has a heat generation amount per unit mass (combustion heat amount per unit mass obtained when gas is burned at a predetermined air-fuel ratio). By multiplying by
It has been proposed to understand energy consumption. In order to measure such a mass flow rate, for example, a thermal mass flow rate sensor called a flow sensor is used, and the mass flow rate measured by the flow sensor is multiplied by the combustion heat quantity per unit mass to burn gas. It is considered that the flow rate of the combustion heat quantity per unit time (hereinafter referred to as the combustion heat flow rate) can be calculated by considering it as the flow of thermal energy. In this case, theoretically, there is an advantage that the mass flow rate does not depend on conditions such as temperature and pressure of the gas to be measured.

However, in the above flow sensor, generally, if one kind of gas is measured, there is no problem, but if the gas type (gas type) is different, the constant pressure specific heat and composition component ratio of the gas are different for each gas type. An error occurs due to the difference between the values, and the measured value of the mass flow rate deviates from the true value. Therefore, in order to accurately measure different gas types, it is necessary to make corrections corresponding to the constant pressure specific heat and composition component ratio for each gas type, or change the conversion rate from the mass flow rate to the combustion heat flow rate. It is considered. Moreover, it is not enough to accurately measure the mass flow rate and the combustion heat flow rate value based on the measured value just by performing the correction corresponding to the difference in the constant pressure specific heat for each gas type. Since it has also been reported that an accurate combustion heat flow rate value is not always obtained based on the measured value of the mass flow rate.

Further, in order to obtain the value of the combustion heat flow rate based on the measured mass flow rate value, the calculation of multiplying the mass flow rate by the combustion heat quantity per unit mass must be performed as described above. If the combination of components or the value of the composition component ratio is different, the combustion heat quantity per unit mass will also be different, so it is necessary to correct the combustion heat quantity per unit mass corresponding to the difference in the gas composition composition. Become. In order to correct the combustion heat quantity per unit mass according to such gas type, a sensor for discriminating the gas type currently being measured and a calculation means for performing the correction according to the gas type are required. However, there is an inconvenience that the configuration of the entire flow rate measuring device becomes more complicated. Moreover, even if the combustion heat quantity per unit mass could be corrected in that way,
If the error in the measurement value of the mass flow rate is insufficiently corrected as described above, it is still impossible to obtain an accurate combustion heat flow rate.

Here, for example, a gas used as a city gas is prepared so as to correspond to a prescribed compositional component ratio, but in reality, various variations within the range and errors within an allowable range are included. Since, etc. are included,
There is a high possibility that an error will occur in the mass flow rate due to this.
In addition to the gas that is ultimately supplied to consumers as so-called city gas, it also measures the combustion heat flow rate for measuring the combustion heat flow rate of natural gas that is sent from the place of origin and gas that passes through each takeoff site. Since there are various composition component variations in the device, in order to accurately measure the combustion heat flow rate of such a gas by the product of the mass flow rate and the combustion amount as described above, the gas type is determined. It is necessary to provide a sensor and a calculation means for performing the correction, and the configuration of the measuring device to which the correction means is added is further complicated.

In addition to the flow rate measuring device for measuring the value of the combustion heat flow rate based on the measured value of the mass flow rate as described above,
As a device capable of measuring the value of the combustion heat flow rate with high accuracy, a flow rate measuring device using a so-called gas chromatography is known. For example, an application for measuring the combustion heat flow rate of industrial fuel gas or measurement or combustion heat In some applications such as a flow rate standard, it may be put to practical use in a foreign country such as the United Kingdom.

However, the combustion heat flow measuring device using gas chromatography is generally very complicated in its measuring means and data processing device, and due to the complexity of such device, the combustion heat flow measuring device is Maintenance and operation become extremely complicated, and further, manufacturing costs and operation costs are incomparably expensive, so such gas chromatography is used for general consumers such as gas meters. It is not realistic to use for. Further, it is extremely difficult or practically impossible to realize such simplification and cost reduction of gas chromatography.

The present invention has been made in view of the above problems, and its object is to provide a plurality of different variations in the composition ratio of the fuel fluid such as natural gas or city gas to be measured. However, the flow rate of the fluid used as a fuel can be accurately measured by the dimension of the combustion heat flow rate, which is a substantial index as an energy resource. Provided are a combustion heat flow rate measuring device, a combustion heat flow rate measuring method, a gas meter, a gas usage meter reading apparatus, and a gas usage meter reading system, which are capable of outputting or storing the integrated value or data thereof and having extremely simple configurations and operations. Especially.

[0013]

A combustion heat flow rate measuring apparatus according to the present invention is provided with a conduction path for conducting a fluid, and a change in the amount of heat radiation or an amount of heat transfer caused by heating or cooling of the flow of the fluid in the conduction path. Flow rate measuring means for detecting a change or a change in the amount of heat received and outputting a first signal carrying information on the value of the change, and a change carried by the first signal outputted from the flow rate measuring means. And linearly correlate the correlation between the flow rate of the fluid and the value of the flow rate of the combustion heat per unit time obtained when the fluid flow is burned at a predetermined air-fuel ratio. And a linearization calculation means for performing another type of calculation processing and outputting a second signal carrying information on the value of the flow rate of the combustion heat per unit time.

Further, in the combustion heat flow rate measuring method according to the present invention, a fluid is made to pass through a conduction path, and the amount of heat radiation or the amount of heat transfer or change caused by heating or cooling of the flow of the fluid in the conduction path is changed. Detects a change in heat quantity and outputs a first signal carrying information on the value of the change,
A change value carried by the output first signal,
One kind of predetermined one for plural kinds of gas, which linearly correlates the correlation with the value of the flow rate of combustion heat per unit time obtained when the flow of the fluid is burned at a predetermined air-fuel ratio By performing arithmetic processing, a second signal carrying information on the value of the flow rate of the combustion heat per unit time is output.

The gas meter according to the present invention detects a conduction path through which a gas is conducted, and a change in the amount of heat radiation, a change in the amount of heat transfer, or a change in the amount of heat received, which occurs due to heating or cooling of the flow of the gas in the conduction path. A flow rate measuring means for outputting a first signal carrying information on a change value, a change value carried by the first signal output from the flow rate measuring means, and a flow of the gas are predetermined. The linear correlation of the correlation with the flow rate value per unit time of the combustion heat obtained when burning at the air-fuel ratio of, by performing one kind of predetermined arithmetic processing for a plurality of kinds of gas, A second information carrying value of the flow rate of the combustion heat per unit time
And a linearization calculation means for outputting the signal of.

The gas meter according to the present invention further comprises, in addition to the above combustion heat flow rate measuring device or gas meter,
A flow rate value integrating means for integrating the data of the flow rate value of the combustion heat per unit time may be provided. Alternatively, an integrated value storage means for storing the data integrated by the flow rate value integration means may be provided. Here, the above-mentioned “outputting a first signal carrying information on the value of the flow rate of combustion heat per unit time” means
The flow rate measuring means corresponds to the value of the amount of heat (change in the amount of heat) taken from the heating means such as an electric heater or the value of the temperature difference (change in temperature) before and after the flow of the gas in the conducting path, This means outputting a signal such as an electric signal or an optical signal having a waveform obtained by modulating any one or a plurality of elements of amplitude, frequency, duty, voltage level and the like.

In the combustion heat flow rate measuring device or gas meter according to the present invention, a temperature sensor or the like detects a calorific value change or a temperature change generated in the fluid due to heating or cooling in the flow of the fluid or gas due to the flow in the conducting path, The first signal, which carries information on the value of the amount of heat change or the value of the temperature change output from the flow rate measuring means equipped with a temperature sensor, etc., linearly correlates the correlation with the value of the flow rate of combustion heat per unit time. Information on the flow rate value of the combustion heat per unit time in a fluid such as the fuel gas to be measured is calculated by performing one kind of predetermined arithmetic processing on a plurality of gases (combustion heat flow rate). ) Is output as a signal.

That is, in a combustion heat flow rate measuring device or gas meter using a conventional mass flow rate sensor, the mass flow rate is measured by the mass flow rate sensor, and the measured mass flow rate is expressed in units of the fluid to be measured at that time. The combustion heat flow rate was calculated by multiplying the combustion heat quantity per mass. Alternatively, a method is known in which the volumetric flow rate is measured, the temperature and pressure are corrected, converted to a standard state, and the converted volumetric flow rate is multiplied by the combustion heat quantity per volume to measure the combustion heat flow rate. However, in any case, the combustion heat quantity per unit mass or unit standard volume is known, or it is necessary to separately measure the combustion heat quantity by gas chromatography or the like. Moreover, an error occurs in each of the measurement of the mass flow rate or the volumetric flow rate in the standard state and the measurement of the combustion heat quantity, and these errors are multiplied when calculating the heat quantity flow rate, resulting in an error in the finally obtained measurement value. It was supposed to be expanded. In such a conventional measuring method or measuring apparatus, in order to accurately measure the mass flow rate, it was necessary to perform mass flow rate correction corresponding to each fluid type. Also, if the type of fluid to be measured (in other words, the composition ratio of the components that affect the combustion heat quantity per unit standard volume) is unknown (not accurately grasped), it is impossible to measure. It was However, in the combustion heat flow rate measuring device or the gas meter according to the present invention, a plurality of types of electric signals output from the flow rate measuring means can be used without correcting the constant pressure specific heat and the combustion heat amount according to the type of fluid as in the conventional art. Only one kind of predetermined linear correspondence processing (processing to linearly correspond to the combustion heat flow rate per unit time) is applied to the gas of, and a plurality of intermediate parameters and their corrections are performed. Can be obtained more directly (and thus concisely) without any need for accurate combustion heat flow data with tolerances within a predetermined tolerance. The inventors of the present invention perform the linear correspondence calculation processing on the output from the thermal flow rate measuring means in this way, and perform combustion without correcting the constant pressure specific heat and the combustion heat quantity according to the type of fluid. We thought that it is possible to measure the heat flow rate accurately, and confirmed it through experiments and theoretical consideration based on the results.

Here, the change in the amount of heat radiation, the change in the amount of heat transfer, or the change in the amount of heat received that occurs due to the heating or cooling of the flow of the gas in the conducting path is detected, and information on the value of the change is carried. As a method of "outputting the first signal", for example, an electric heating wire (electric heating heater) heated by passing an electric current is arranged in the fluid flow (in the conduction path), and is caused by the flow. There is a method of detecting a change in heat radiation amount based on a change in electric resistance of a heating wire. Alternatively, the fluid is set to be heated by a heat source such as a heating wire arranged in the flow of the fluid, and temperature measuring means is provided on the upstream side or the downstream side near the heating wire to measure the temperature. There is a method in which the temperature of the fluid is measured by a measuring means and the change in heat transfer amount of the fluid is measured based on the temperature. The method of measuring the change in the amount of heat transfer further includes a method of measuring the heat mainly conducted through the conduction path wall between the heat source and the temperature measuring means, and a method of measuring the heat mainly in the fluid between the heat source and the temperature measuring means. There is one that measures the heat conducted, but especially the latter is called a change in the amount of heat received (measures a change in the amount of heat received).

According to the present invention, when a certain type of fluid α is flowing at a calorific flow rate A by using the above-described detection method, the calorific value change or temperature change due to the flow of the fluid α to be measured is caused. When the first signal A1 corresponding to the value of the enthalpy change relating to the fluid is obtained, the second signal A2 is calculated by one predetermined conversion table or conversion formula F.
Converted to and output. Also, when another type of fluid β is flowing at the calorific flow rate A, the first signal A1 corresponding to the value of the calorific value change or the temperature change caused by the flow of the fluid β to be measured.
Is obtained, and is converted into the second signal B2 by one predetermined conversion table or conversion formula F and output. Similarly, when a certain type of fluid α is flowing at the calorific flow rate B, the fluid α
When the first signal B1 corresponding to the value of the change in the amount of heat or the change in the temperature due to is obtained, it is converted into the second signal B2 by one predetermined conversion table or conversion formula F and output.
Also, when another type of fluid β is flowing at the calorific flow rate B, the first signal B1 corresponding to the value of the calorific value change or the temperature change caused by the fluid β is obtained and converted into a predetermined one conversion value. It is converted into the second signal B2 by the table or the conversion formula F and output. As described above, in the combustion heat flow rate measuring device or the combustion heat flow rate measuring method according to the present invention, even if the types of fluids to be measured are different, the same heat quantity flow rate is provided in the conducting path in which the flow rate measuring means is installed. , The same first signal is output for that heat flow rate, so even if the fluid type is different, or even if the fluid type is unknown, The same second signal is output only by performing a calculation using one fixed conversion table or conversion formula. The fact that the second signals are the same means that the calorific value measurement values obtained based on them are the same. The first signal above,
The second signals may be digital signals in addition to analog signals such as amplitude, frequency, duty, voltage / current level. The degree of "same" that the same second signal is obtained for the same heat quantity flow rate as described above varies depending on the type and flow rate of the fluid to be measured, In the case of a fluid generally called natural gas, it is possible to set it within an instrumental error range such as ± 1.5% or ± 4.0% (a range such as a verification tolerance or a usage tolerance). However, it is needless to say that the above numerical values are an example, and the measurement accuracy by the device or method according to the present invention is not limited to the above numerical values, and can be made even higher.

The gas consumption meter reading device according to the present invention comprises the above-mentioned flow rate measuring means and flow rate value integrating means to obtain the integrated value of the combustion heat flow rate from the gas meter according to the present invention. Combustion heat integrated value reading means for reading out the value data via wireless communication or wired communication, and the integrated value of the combustion heat flow rate read by the combustion heat integrated value reading means for display output, print output, or externally as data. And output means for outputting.

Alternatively, a storage means for storing the integrated value of the combustion heat flow rate read by the combustion heat integrated value reading means for each gas meter together with the identification information of the consumer of the gas meter is provided instead of the output means. Alternatively, it may be provided separately from (additionally to) the output means.

Alternatively, based on the unit price of the gas per unit combustion heat flow rate, a charge conversion means for converting the integrated value of the combustion heat flow rate into a usage charge amount value, and displaying or printing the use charge amount value. It may be further provided with an output means for outputting to the outside as output or data.

Alternatively, a storage means for storing the value of the usage fee amount together with the identification information of the customer of the gas meter for each gas meter may be further provided.

Alternatively, a usage charge amount display means for displaying the value of the usage charge amount may be further provided.

In the gas usage meter reading apparatus according to the present invention, for example, when a gas meter reading person inputs a predetermined command, the combustion heat from the gas meter according to the present invention as described above can be obtained without the gas meter reading person visually checking the meter. The integrated value of the flow rate is read out by the combustion heat integrated value reading means via wireless communication or wired communication, and the numerical value data is output to the display, printed out, or output as data to the outside. Alternatively, the storage means stores the data of the integrated value of the combustion heat flow rate and the data of the value of the usage charge amount together with the identification information of the customer of the gas meter whose data was measured.

For example, in a gas meter, conventionally, the mass flow rate is measured by each customer in response to the measurement needs of the heat flow rate, the calorific value is measured at the district branch, and the heat flow rate is measured by multiplying these measured values. A method of obtaining a value has been proposed. However, as described above, the mass flow rate measurement itself needs to be corrected according to the type of fluid, and in reality, there is nothing but to allow a relatively large error. Further, in the method of measuring the volumetric flow rate, measuring the temperature and the absolute pressure separately, and converting to the standard state by using Boyle-Charles' law, the temperature measurement using a thermometer and the absolute pressure gauge are used. Absolute pressure measurement is required. For this reason, commercialization of the calorific flow measurement device has a track record in large-scale transaction gas meters, but in small gas meters for general households and business use, it is not possible to incorporate a thermometer or absolute pressure gauge in the gas meter. It is fatal that practical application is difficult or impossible due to the fact that the device configuration becomes too complicated and costly, and that a device with a simple configuration cannot provide sufficient measurement accuracy. There was an inconvenience. Furthermore, in order to maintain sufficient measurement accuracy, it is necessary to correct for the long-term transition of the absolute pressure gauge, so there is the inconvenience that the possibility of practical application is low in terms of maintenance. On the other hand, in the gas meter according to the present invention, since the calorific flow rate can be accurately measured without using a thermometer or an absolute pressure gauge, which are the main factors that complicate the device configuration and increase the cost, it is possible to use the fuel or raw material As the charge according to the usage amount of the gas for use, the usage amount according to the heat quantity of the gas can be charged with high accuracy instead of the usage amount according to the conventional volume of gas. The charge conversion means may convert the metered charge portion into a usage charge based on the unit price per unit combustion heat flow rate, and in the case of a charge system including the basic charge portion, the basic charge or the like may be added separately. When the pay-as-you-go rate changes depending on the time or season, it may be converted according to the pay-as-you-go rate or the like predetermined corresponding to each time or season.

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows a schematic configuration of a gas meter 1 according to an embodiment of the present invention. The gas meter 1 includes a flow rate measurement sensor (flow rate measurement means) 100, a linearization calculation unit (linearization calculation means) 201, a combustion heat flow rate numerical calculation unit (combustion heat flow rate numerical conversion means) 202, and a flow rate value integration unit (flow rate). Combustion heat flow calculation circuit 200 having a value integration means) 203, and an integrated value storage unit (storage means) 300
An integrated value display section (output means) 400 and a flow rate monitoring section 5
00 and the meter-side communication unit 600 are provided as main parts.

As schematically shown in FIG. 1, the flow rate measuring sensor 100 includes a conducting path 101 for conducting gas and a hot wire heater (heating means) 102 for giving a predetermined heat to the gas passing through the conducting path 101. The upstream side temperature sensor 103 and the downstream side temperature sensor 1 which are respectively arranged before and after the heat ray heater 102 and measure the temperature at that position.
04, and the main part thereof is constituted, and the temperature of the gas on the upstream side before heat is applied (this is referred to as T1) is measured by the upstream temperature sensor 103, and the heat ray heater 1
The temperature of the gas after being heated by 02 (T
2) is measured by the downstream temperature sensor 104,
An electric signal having a waveform modulated corresponding to the temperature difference (ΔT = T2 -T1) is output. The upstream temperature sensor 103 and the downstream temperature sensor 104 may be, for example, a modulation type sensor using a temperature measuring resistance element made of Pt (platinum) or a Pt-based alloy, or a direct output type sensor using a thermocouple element. A (self-excited) sensor may be used.
The hot wire heater 102 is controlled so as to keep the amount of heat applied to the gas constant in order to make the measurement conditions uniform. In addition,
Although not shown, in addition to measuring the temperature difference between the upstream side and the downstream side of the heat ray heater 102 as described above, the temperature and the heat ray measured by the temperature sensor provided on the downstream side of the heat ray heater 102 are not shown. A flow rate measurement sensor or the like that measures the amount of heat taken from the hot wire heater 102 by the flow of gas based on the amount of heat output from the heater 102 and outputs an electric signal that is modulated according to the value of the amount of heat is also applicable. Is.

The electromechanical structure of the flow rate measuring sensor 100 is the same as that of a thermal type flow meter used for measuring a mass flow rate called a so-called flow sensor, but in the present embodiment, it is directly or indirectly. Not to measure the mass flow rate, but to regard the flow of gas as the flow of energy (combustion heat) with the possibility of combustion, and to measure the flow of combustion heat (combustion heat flow) more directly. It is used to measure. Therefore, in the flow rate measurement sensor 100 of the present embodiment, the same electromechanical structure as that of a general flow sensor can be used, but its function or specification is that of the gas to be measured. It is desirable to set the specifications (main specifications such as sensitivity, gain, output voltage waveform and voltage level) suitable for accurately measuring the combustion heat flow rate rather than the mass flow rate. It is desirable to focus on measuring the flow rate accurately.

The combustion heat flow rate calculation circuit 200 includes a linearization calculation section 201, a combustion heat flow rate numerical conversion section 202, and a flow rate value integration section 2
03 is provided as a main part thereof, but as a more specific hardware configuration, these may be embodied using a general-purpose arithmetic circuit such as a so-called microcomputer (not shown), Alternatively, it may be realized by combining discrete elements and circuits (not shown).

The linearization calculation unit 201 includes a flow rate measurement sensor 1
The electric signal output from 00 is carried as a modulated waveform or an output voltage level (the electric signal is given as information by modulating the electric signal or corresponding the voltage level). The value of ΔT and the value of the flow rate of combustion heat per unit time obtained when the flow of the gas to be measured is burned at a predetermined air-fuel ratio (hereinafter referred to as the combustion heat flow rate value W. The unit is, for example, [ MJ / h]), the arithmetic processing for linearizing the correlation is performed. this is,
Assuming that the flow rate measuring sensor 100 outputs a voltage level (this is referred to as VT) proportional to the value of ΔT, the voltage level (VT = kΔT, k is the flow rate measuring sensor 10).
The proportional relationship between 0 and the combustion heat flow rate value W corresponding to the gas flow at that time is often non-linear as shown in FIG. The correlation calculation unit 201 linearly correlates the correlation over the entire measurable range as shown in FIG. For example, in the example of FIG. 2A, the correlation in the lower part of W (low flow range) is relatively linear, but the correlation in the middle to upper part (middle to high flow range) is non-linear. Therefore, linearization processing according to the degree of such non-linearity
Over the entire measurable range of the combustion heat flow rate value W,
The voltage level VT and the combustion heat flow rate value W are processed so as to linearly (proportionally) correspond to each other as shown in FIG.

The combustion heat flow rate digitizing section 202 digitizes the electric signal output after being subjected to the linearization processing in the linearization computing section 201 into data of the flow rate value of the combustion heat per unit time. Output. Here, VT = kΔT which has been linearized at a conversion rate fixedly determined in advance.
Convert the value of to the value of W. The conversion rate used at this time is set in advance so that the combustion heat flow rate value obtained as the measured value is within the predetermined tolerance even if the type or composition of the gas to be measured changes within the expected range. The fixed value is fixed, and in the gas meter 1 of the present embodiment, a conversion value based on a heat generation correlation or a constant pressure specific heat value that differs for each gas type as in a general mass flow meter. Will not be changed at all. Although details such as specific examples will be described later, in the case of a device or method for measuring the combustion heat flow rate based on the conventional measurement value of the mass flow rate, the mass flow rate is used as an indirect parameter for measuring the combustion heat flow rate. The measurement is performed and the mass flow rate is converted into a combustion heat flow rate at a conversion rate different for each gas type, but at the time of the conversion, a different conversion rate is used for each gas type. However, such a measuring device or measuring method always identifies (determines) the gas species currently being measured.
However, the conversion rate must be changed according to the gas type, which makes the measuring device and the measuring method extremely complicated.
Moreover, as will be described later, the measured value of the combustion heat flow rate finally obtained by the conventional method in this way may have a larger error than the case where the converted value is not changed. However, as in the present embodiment, a fixed conversion rate that does not change regardless of the gas type is used without interposing the value of the mass flow rate and the coefficient for calculating it as parameters. By more directly converting the output signal of the flow rate measurement sensor 100 into the combustion heat flow rate value, it is possible to measure the combustion heat flow rate value more accurately than in the case of a general mass flow meter, and its device configuration. Also, the arithmetic circuit can be simplified.

The flow rate value integrating section 203 integrates the combustion heat flow rate value W output from the combustion heat flow rate digitizing section 202. As an integration method performed by the flow rate value integration unit 203, for example, a new measurement value is added to the integration value up to that point every predetermined period, and the data is incremented (the value is rewritten while sequentially integrating the values). It is possible to do). Integrated value of the combustion heat flow rate value W integrated in this way (combustion heat flow rate integrated value, which is referred to as ΣW)
Is stored in the integrated value storage unit 300. The integrated value storage unit 300 may be, for example, a D-RAM or S-R.
A memory circuit element such as AM or other information recording medium can be preferably used.

The integrated value display section 400 is provided with an electronically driven flat panel display device (plate-shaped display element) such as a segment type or dot matrix type liquid crystal display panel (not shown). The data of the combustion heat flow integrated value ΣW output from the flow value integration unit 203 is displayed together with the unit of the value. For example, as shown in an example in FIG. 3, the combustion heat flow integrated value ΣW
Is displayed as the work equivalent, the unit [MJ]
((A) of FIG. 3) or [kWh] ((B) of FIG. 3)
Is displayed together with the numerical value of the combustion heat flow integrated value ΣW. Alternatively, when displaying in heat quantity, the unit [kca
1] ((C) of FIG. 3), the value is displayed together with the numerical value of the combustion heat flow integrated value ΣW. Alternatively, although not shown,
Change the number of digits in the numerical notation according to the number of the gas meter,
For example, [100 kWh] or [0.1 Mcal] may be displayed as a basic unit.

The flow rate monitoring unit 500 includes a linearization calculation unit 201.
The combustion heat flow rate W carried by the electric signal output from the motor is constantly monitored. For example, when the combustion heat flow rate W exceeds a voltage level corresponding to a predetermined flow rate value, it is detected to be excessive. An alarm indicating that the combustion heat flow is flowing is output. Alternatively, the flow rate monitoring unit 500 may include the combustion heat flow rate digitizing unit 2
The numerical value of the combustion heat flow rate W output from No. 02 is monitored, and when the data exceeds a predetermined combustion heat flow rate value, it is detected and an excessive combustion heat flow rate is flowing. The alarm may be output. More specifically, for example, when the electric signal output from the linearization calculation unit 201 is modulated to a voltage level that is linearly proportional to the combustion heat flow rate W as described above, combustion determined to be an excessive flow rate The threshold value of the voltage level corresponding to the heat flow rate is compared with the voltage level of the electric signal output from the linearization operation unit 201, and if the threshold value is exceeded, the combustion heat flow rate is excessive. It is possible to output an alarm indicating that is flowing.

The meter-side communication section 600 receives a data read command sent from an external gas management system 700, a meter reading terminal device 800, or the like via the wired communication means 901 or the wireless communication means 902, for example. Then, the data of the combustion heat flow rate value W output from the combustion heat flow rate digitizing unit 202 or the data of the combustion heat flow rate integrated value ΣW stored in the integrated value storage unit 300 is read out, and the data is transmitted by wire communication. Means 901 or wireless communication means 90
It transmits to the external gas management system 700 via the 2 or the terminal device 800 for meter-reading etc. which a meter-reader carries. Alternatively, as shown by the dotted line in FIG.
The analog electric signal output from the device 1 is read out as it is, transmitted to the external gas management system 700 or the meter-reading terminal device 800 as an electric signal that is not converted to data, and the gas management system 700 that receives it Alternatively, the meter-reading terminal device 800 may digitize (numerical data).

Terminal device for meter reading (gas meter reading device) 8
00 is, as shown in FIG. 4, a terminal side communication unit 801 and
The integrated value reading unit 802, the gas usage amount storage unit 803, and the output unit 804 constitute the main part. The integrated value reading unit 802 allows a gas meter reading person, such as a gas supply company or a gas management company, to read the meter via the wired communication unit 901 or the wireless communication unit 902 when, for example, the gas meter operator performs a predetermined command input operation. The data of the integrated value of combustion heat flow rate is read out from the gas meter 1 of the customer who desires. In this meter-reading terminal device 800, the integrated value of the combustion heat flow rate measured by the gas meter 1 is converted into a gas usage charge based on the unit price per unit combustion heat flow rate of the gas to be measured by the gas meter 1, and the amount is calculated. The output unit 804 outputs the display, for example. Here, this meter-reading terminal device 800
May be a portable device such as a handheld terminal so that the meter reader can read the meter for each user as described above, or can be attached to the outside of the body of the gas meter 1 or built in the inside thereof. Good. Alternatively, this meter-reading terminal device 800 is installed in a gas supply company or a gas management company, and a so-called automatic meter-reading system is used, for example, via a communication means such as a telephone line, a dedicated communication line, the Internet, or a wireless communication network. Gas meter 1
It is also possible to read the data or signal of the integrated value of the combustion heat flow rate from and to convert the integrated value of the combustion heat flow rate into a gas usage charge at a gas supply company or a gas management company.
That is, this meter-reading terminal device 800 includes the gas meter 1
Applicable to any of the following purposes: converting gas usage charges with a mobile terminal, converting gas usage charges as a mobile terminal, and centrally managing gas usage charges with a management center of a gas management company. It is possible.

The terminal side communication section 801 has a function of transmitting the command input of the above-mentioned read operation to the gas meter 1 via the wired communication means 901 or the wireless communication means 902, and read from the gas meter 1 according to the function. It has a function of receiving the data of the combustion heat flow integrated value ΣW via the wired communication unit 901 or the wireless communication unit 902.

The gas usage storage unit 803 is used for the gas meter 1
The data of the combustion heat flow integrated value ΣW read from is stored in association with the data of the identification number that identifies the consumer of the gas meter 1 from which it was read. The data stored in the gas usage amount storage unit 803 is, for example, when a gas meter reader performs a predetermined command input operation on the integrated value reading unit 802, the gas meter user's desired consumer is requested according to the command. Is read out together with the identification number. The read data is printed out or displayed, for example, from the output unit 804. Alternatively, the data may be output as it is to the outside. Here, this meter-reading terminal device 800
Although not shown in the figure, in addition to the above, the integrated value reading unit 8
A charge conversion unit (circuit) that converts the integrated value of the combustion heat flow rate read by 02 into the usage charge based on the unit price per unit combustion heat flow of gas, and a liquid crystal display for displaying the amount of the usage charge A display device such as a panel may be provided. As a more specific method of charge conversion in that case, for example, in the case where the gas usage fee system is set to consist of a basic charge part and a metered charge part, the amount of the metered charge part per unit combustion heat flow rate is set. The total charge may be calculated by converting the usage charge based on the unit price and adding the basic charge and various service charges such as the gas monitoring information service. Also, if the unit price per unit combustion heat flow rate for calculating the meter-rate charge is set to be changed depending on the gas usage time, season, etc., the unit combustion heat flow rate will be correspondingly set. The unit price data should be changeable. By doing so, not only the combustion heat flow integrated value can be read by the meter-reading terminal device 800, but also a gas use charge corresponding to the combustion heat flow integrated value is calculated and output. It becomes possible to record.

Next, the operation of measuring the combustion heat flow rate value executed by the gas meter 1 will be described. Conduction path 1
While applying a predetermined heat from the hot wire heater 102 to the gas flowing through 01, the upstream temperature sensor 103 arranged upstream of the hot wire heater 102 determines the temperature (T1) of the gas at that position at predetermined intervals. To the heat wire heater 102
The downstream temperature sensor 104 arranged on the downstream side of
The temperature (T2) of the gas at that position is measured every predetermined period. And the temperature difference between them (ΔT = T2-T1)
The flow rate measuring sensor 100 outputs an electric signal whose voltage level (VT = kΔT) is modulated corresponding to At this time, the correlation between the temperature difference ΔT and the voltage level VT is merely a proportional relation determined by the proportional constant k unique to the flow rate measurement sensor 100. Here, the constant pressure specific heat and density of the gas, or per unit mass. No conversions or corrections have been made to the amount of combustion.

The electric signal output from the flow rate measuring sensor 100 carries the information of the temperature difference ΔT as the voltage level VT (the voltage level VT is modulated corresponding to the temperature difference ΔT), but it is generally as it is. In the form of voltage level V
The correlation of the combustion heat flow rate value W with respect to T is non-linear. Therefore, the linearization calculation unit 201 performs linearization processing on the electric signal output from the flow rate measurement sensor 100 so as to linearly correspond to this. The processing performed at this time is
The correlation is only linearized so that the voltage level VT (or the temperature difference ΔT) linearly corresponds to the combustion heat flow rate value W, and the correction of the numerical value regarding the dimension of the mass flow rate and the different gas type. The method of linear correspondence processing is not changed according to the above. In other words, in the linear correspondence process performed at this time, the output characteristic peculiar to the flow rate measurement sensor 100 is the combustion heat flow rate value W.
Since it is generally not necessarily linear (non-linear) in terms of the correlation of the voltage level VT with respect to, the non-linear output characteristic peculiar to such a flow rate measuring sensor 100 is fixed. It is only linearly corrected by the kind of linear correspondence processing.

The information carried by the electric signal output from the linearization operation unit 201 is processed so as to linearly correspond to the combustion heat flow rate value W, but the dimension is the voltage level VT [V]. And the combustion heat flow rate value W
It has not been converted to [MJ / h] (or [kcal / h], etc.). Therefore, the linearization calculation unit 201 digitizes the voltage level VT [V] into the combustion heat flow rate value W [MJ / h] and outputs it. At this time, VT [V] is changed to W [MJ /
Since the dimension conversion (unit conversion) is performed on [h], W [MJ / h] is converted to VT [V] by the conversion.
A conversion rate (conversion rule) for making

More specifically, in this conversion, even if the composition component ratio is variously changed within the range assumed in the fuel gas such as city gas such as 13A gas to be measured or natural gas, One kind of conversion rate fixedly determined in advance so that the combustion heat flow rate value obtained as a measured value is kept within a predetermined tolerance range such as within ± 1.5% of the tolerance of a domestic gas meter. Is used. This conversion rate is not changed at all in accordance with the gas type as in the case of combustion heat flow measurement using a mass flow meter. That is, in the linearization calculation unit 201,
Even if the composition ratio (or gas type) of the gas is different (changed), one kind of conversion rate predetermined as described above can be fixedly used. Therefore, before and after this conversion, correction of the conversion value based on the heat generation correlation (combustion heat quantity per unit volume or constant pressure specific heat value) that differs for each gas type, as in the case of a general mass flowmeter, etc. Does not have to be done.

As described above, in the gas meter 1 of the present embodiment, the voltage level VT [V] output from the flow rate measuring sensor 100 and subjected to the linear correspondence processing is changed in the conversion rate according to the gas type. Is not performed at all, and is directly converted to the combustion heat flow rate value W [MJ / h].
Even if the type or composition of the gas to be measured changes variously within the expected range, it is possible to measure an accurate combustion heat flow rate value within a predetermined tolerance range. Then, an accurate combustion heat flow rate integrated value can be obtained by integrating the accurate combustion heat flow rate values thus measured. Also, since it is not necessary to change the constant pressure specific heat or density value or the conversion value of the combustion heat quantity per unit volume according to the type or composition of the gas to be measured, the gas type or composition to change the conversion value. It is not necessary to add an extremely complicated sensor for detecting the value, a circuit for changing the converted value, or the like, and thus it is possible to achieve simplification of the device. Further, since this gas meter 1 uses a flow rate measuring sensor 100 having a simple structure such as a thermal type flow sensor, it is compared with a calorific value measuring device using gas chromatography (described as a gas chromatographic measuring system in the described embodiment). Then, the structure becomes extremely simple, and as a result, manufacturing cost and operation cost can be reduced. In addition, it is possible to dramatically simplify the trouble of maintenance and calibration.

[Example] As an example, the gas meter 1 as described above was produced, and as typical examples of hydrocarbon-based gas for fuel, nine kinds of gases having various composition component ratios were prepared. An experiment was conducted to confirm the accuracy (tolerance) of the combustion heat flow value measured in each case.

As the flow rate measuring sensor 100, one Si (silicon) microchip 10 as shown in FIG. 5 is used.
5, the upstream temperature sensor 103 and the downstream temperature sensor 1
A μF sensor (trade name), which is a flow sensor manufactured by Yamatake Co., having a structure in which 04, a heat ray heater 102, and a driving circuit are incorporated. This sensor uses Pt for each of the upstream temperature sensor 103 and the downstream temperature sensor 104.
And a heat ray heater 10
2 uses an electrothermal resistance wire made of Pt,
The main specification is that the flow velocity resolution is 1 [mm
/ S] and the responsiveness is 2000 [μs].

A combustion heat flow rate calculation circuit which uses such a flow rate measurement sensor 100 and at least includes a linearization calculation section 201 and a combustion heat flow rate numerical conversion section 202 which perform the functions described in the above embodiments. A gas meter 1 used in the experiment of the present example was manufactured by constructing 200 with a microcomputer.

On the other hand, a typical example of hydrocarbon gas for fuel and
9 kinds of gas prepared by _Four With C as the subject
₂ H_Four , C₂H₆, C₃H₈ , H₂ , CO₂ , N₂ , I
-C_FourH_Ten, N-C_Four H_Ten, I-C_FiveH₁₂, N-C_FiveH
₁₂The so-called 13A moth
In city gas and natural gas like
It is assumed that it will fluctuate (change) depending on the gas species.
Combination of composition components according to the variation of composition components
13 for experimental use
9 as a typical example of city gas such as A gas and natural gas
A variety of fuel gases were made.

More specifically, the above composition ratios are
Each was set to any value within the range from the minimum content rate to the maximum content rate as described below, and each composition component was synthesized according to the composition component to prepare nine kinds of gases having different compositions. .

That is, the ratio of each composition component (23 ° C./1
the minimum value to the maximum value of the volume ratio in atm)_Four 
Is about 77% to about 99.5%, C₂ H_Four0 to about 0.2
%, C ₂ H₆0 to about 15.5%, C₃H₈Is 0 to about
5.4%, i-C_FourH_Ten0 to about 3.0%, nC_FourH
_Ten0 to about 2.1%, i-C_Five H₁₂0 to about 0.2%,
n-C_FiveH₁₂Is 0 to about 0.3%, H is 0 to 5.2%, C
O₂Is 0 to 0.7%, N₂0 to 2.8%, and
Any value within the range between the minimum content and the maximum content
, Set the ratio of each composition component, and
Combining each composition component in composition ratio, like 13A gas
A total of 9 types assumed as city gas or natural gas
Gas was prepared. For example, one of the gases
In this case, CH is assumed as natural gas._Four
About 95%, C₂H_Four Is 0% ...
Set the composition ratio to a value within the above range, and calculate the composition composition ratio
For experiment by combining (mixing) each component according to
As a gas for each gas
Each bottle was stored separately.

As an experimental method, a test apparatus having a schematic structure as schematically shown in FIG. 6 was prepared, and the above-mentioned experimental gases were made to flow from the gas cylinder one by one and measured by a standard device. The tolerance of the measured value by the gas meter 1 of the present embodiment when the combustion heat flow rate value was used as a reference (which was regarded as the true value) was obtained.

More specifically, in this test apparatus, a heat exchanger 11, a gas meter 1 which is the subject of this experiment, and a reference unit 12 are arranged in series in a temperature-controlled room 10 in the gas flow direction. Then, the same gas flow from the gas cylinder 13 was set to be measured by the gas meter 1 and the reference unit 12 of this embodiment. The standard device 12 has a measurement error of ±
A gas chromatography type combustion heat flow meter with an extremely high accuracy of less than 0.1% was used. More specifically, the reference unit 12 includes a pressure gauge (represented by P in FIG. 6) 121, a thermometer (represented by T in FIG. 6) 122, a wet meter 123 of a volume flow rate measurement method, and a gas. The chromatography 124 is provided, and the volume flow rate measured by the wet meter 123 is
Value of pressure measured by pressure gauge 121 and thermometer 122
It is said that the value of the combustion heat flow rate is obtained by correcting to the standard state with the value of the temperature measured by, and further multiplying the volume flow rate value by the combustion heat quantity per unit volume in the standard state measured by the gas chromatography 124. However, the structure is extremely complicated, but in terms of the accuracy of measured values, the error is ± 0.5%.
And, it is of sufficient accuracy to be used as a reference device here. It should be noted that the reference device 12 means a reference device for checking the tolerance of the gas meter of this embodiment, and it goes without saying that the reference device 12 is different from the “reference device” in the Measurement Law. Further, the heat exchanger 11 is provided on the upstream side of the gas meter 1 in order to measure the nine kinds of gases under conditions as uniform as possible (23 ° C. · 1 atm). In addition, the gas that had been measured by the standard device was incinerated and diffused on the downstream side.

As a result of carrying out such an experiment, as shown in FIG. 7, nine kinds of gases A, B, 9 having different compositional component ratios were used.
The tolerance of the combustion heat flow rate value measured by the gas meter 1 of the present embodiment in all types of C ... I gas is within ± 2% at the maximum in the low flow rate region, and the average of all flow rate ranges is about ±. It was confirmed to fall within the range of 1.5%.

The gases A, B, C used in this experiment ...
23 ℃ ・ 1at theoretically calculated from the compositional ratio of I
As for the minimum value and the maximum value of the combustion heat quantity at m, the minimum value is 39.5 [MJ / m ³ ] of gas I, and the maximum value is 46.
The difference is 5 [MJ / m ³ ], which is about 17% of the minimum value, which is a combination in which the combustion heat amount is relatively varied.

More specifically, the experimental results of this example are as follows.
First, in the case of gas E and gas F, which are examples of typical city gas (13A gas), the tolerance is within the range of 0 to less than ± 1%. Among the city gas systems, the gas H containing a few% of H ₂ and the gas G containing a few% of H ₂ and having a lower CH ₄ compositional component ratio (content ratio) than other gas species. In this case, the tolerance was more markedly negative than that of Gas E or Gas F.
The tolerance is within the range of 0 to -2%, and is about -1.5% on average over the entire flow range.
Further, in the case of the gas C, which is a 13A gas having a composition of composition components (combination of components and its composition ratio) close to 12A gas, a maximum tolerance of + 2% occurs, but +1 when averaged over the entire flow range. It is about 5%.

Further, in the case of gas A produced as an extreme example of natural gas having the highest composition ratio of CH ₄ ,
The tolerance in the entire flow rate range is about -1.5 to -2.0, but the tolerance is -2.0 even when the maximum swing range is reached.
Never exceeds. Further, in the case of gas B having a composition ratio of CH ₄ lower than that of gas A but 90% or more, 3
0000 [kcal / h] (125.7 [MJ / h])
The maximum deviation in the vicinity is about -2%,
This is also within + 1.5% on average over the entire flow range. Further, the composition ratio of CH ₄ is 90% or more and the composition is close to that of the gas A, but in the case of the gas I containing a relatively large amount of CO ₂ , the tolerance is within the range of -1.0 to -0.5. It fits in. Further, when it is relatively close composition city gas of the gas D which is produced as an example of a natural gas composition component ratio of CH ₄ contains CH ₄ at a higher rate than the 90% and city gas, The tolerance is within the range of 0 to less than ± 1%.

As described above, the composition components are variously different, and as a result, the theoretical heat of combustion is 39.
The unit mass of various kinds of gas differed between 5 [MJ / m ³ ] and 46.5 [MJ / m ³ ] and the constant pressure specific heat and density were also different. Even if parameters such as the combustion heat conversion rate per unit and constant pressure specific heat and density are not changed or corrected for each gas type, the tolerance of the measured values by the gas meter 1 of the present embodiment is ± 1 for all nine types of gas. It is within the range of 0.5%. From such experimental results, it was confirmed that the gas meter 1 is sufficiently compatible with the conditions as the combustion heat flow meter.

On the other hand, as a comparative example, when the volume flow rate value was measured by a gas meter of the volume flow rate measurement method which has been generally used conventionally, the maximum tolerance is as shown in the experimental result of FIG. It became about -18%. In addition, the tolerance varies greatly from 0% to -18%, and when measuring the combustion heat flow rate with a gas meter of volume flow rate measurement method, a fundamental correction or conversion rate according to each gas type is required. It was confirmed that the change of is essential.

By the way, based on the above experimental results, the reason why the combustion heat quantity conversion rate, constant pressure specific heat, density, etc. as in the conventional case of measuring the mass flow rate and multiplying it by the combustion heat quantity to calculate the combustion heat flow rate, etc. Whether the gas meter 1 according to the present embodiment can accurately measure gases having different compositions as described above without changing or correcting the parameters of the above, and as a result of examining its operation, the operation of the gas meter is decisive. Although it has not been clarified, it is thought that the following interpretation is influential.

That is, first, for example, gas G and gas H
Due to the inclusion of H ₂ , the tolerances appear to be relatively significantly negative in both cases, but the proportion of H _{2 in} the composition of gas H is higher than that of gas G. Nevertheless, both tolerances are within the same range. This is because, when the content ratio of N ₂ is high, theoretically the tolerance tends to appear on the plus side, but due to the tolerance appearing on the plus side due to N ₂ existing in the composition of the gas H, It is considered that the tolerance appearing on the negative side due to H ₂ existing in the composition of the gas H was offset. Due to the offsetting effect of the tolerance between the compositions, the combustion heat flow rates of the nine types of gases having different compositions as described above can be obtained without changing or correcting the combustion heat conversion rate for each gas type. The analysis that the tolerance of the measured value is within ± 1.5% is considered to be one of the most effective.

Secondly, the temperature difference measured by the flow rate measuring sensor 100 is ΔT, the constant pressure specific heat of the gas to be measured is CP, and the mass flow rate of the gas is M '(= dM / dt, the unit is, for example, [ g / s] or [kg / h])
The relationship of ΔT = k · CP · M ′ holds between T and M ′. This can be written as M '= ΔT / {k · CP} (Equation 1). Here, k is a constant peculiar to the flow rate measurement sensor 100, which is determined by the amount of heat supplied from the hot wire heater 102, the output characteristics of the flow rate measurement sensor 100, and the like. By the way, since the constant pressure specific heat CP in the above equation has different values depending on the gas species, when the gas species is gty, CP is a function of the gas species gty. Therefore, if the function is F, it can be written as CP = F (gty) (Equation 2). Therefore, the above equation 1 is M ′ = ΔT / {k ·
It can be written as F (gty)} (Equation 3).

On the other hand, the theoretical combustion heat quantity for one type of gas (the theoretical combustion heat quantity assumed to be obtained when the gas per unit volume is completely burned, the unit is [cal
/ G] or [J / g] etc. is Bty, the combustion heat flow rate W (unit is [cal / h] or [J] which is the flow rate of combustion heat per unit time when the mass flow rate is M '. /
h]) is W = Bty · M ′ (Equation 4). Here, since the theoretical combustion heat quantity Bty has different values depending on the composition of the gas, if the gas species is gty as in the above case, Bty
Is a function of the gas species gty. Therefore, if the function is G, Bty = G (gty) can be written (Equation 5). Therefore, the above equation 4 of the combustion heat flow rate W is W = G (gty) ·
It can be written as M ′ (Equation 6). By the way, M ′ in this equation 6 is M ′ as shown in the above equation 3.
= ΔT / {kF (gty)}, substituting this equation 3 into the equation 6, the combustion heat flow W is eventually W = G (gt
y) · ΔT / {k · F (gty)} = {1 / k} · {G
(Gty) / F (gty)} · ΔT (Equation 7). This Expression 7 is a function of the gas species gty {G (gty) /
It is shown that W is obtained by multiplying F (gty)} by a constant k that does not depend on the type of gas.

Here, since the nine kinds of gases used in the above experimental results were prepared so that their compositions were intentionally different from each other, the theoretical heat of combustion (Bty = G (gty))
Are also different from each other. Therefore, the numerator G (gty) in {G (gty) / F (gty)} of equation 7
Should be different. Also,
The denominator F (gty) should also be different. However, as confirmed by the above experimental results, the results measured by the gas meter 1 of the present embodiment show that although the theoretical combustion heat quantity is not corrected at all, the combustion heat flow rates of the nine types of gas are Since the tolerance of the true value is within ± 1.5%,
Due to the difference in gas species, the tolerance generated in the numerator G (gty) of {G (gty) / F (gty)} and the tolerance generated in the denominator F (gty) are in a substantially proportional relationship, and the tolerance of the two Is the denominator
It is possible that the molecules canceled each other.

Assuming that such an operation is actually functioning, the theoretical combustion heat quantity used for conversion from the mass flow rate value measured by using the conventional mass flowmeter to the combustion heat flow rate value is corrected. (That is, the correction of G (gty) of the numerator of formula 7)
In the measurement method of performing, the numerator G (gty) of Equation 7 is corrected, but the denominator F (gty) is not corrected.
The cancellation balance in the denominator / numerator of the tolerance as described above may be upset, and the tolerance may rather increase.

FIG. 9 shows a typical hydrocarbon, methane,
6 is a graph showing the relationship between the output (first signal) from the flow rate measurement sensor 100 and the mass flow rate when four types of gases, ethane, propane, and butane, are flowed through the conduit. In this graph, the horizontal axis plots the mass flow rate, and the vertical axis plots the magnitude of the output from the flow rate measurement sensor 100. According to FIG. 9, as the molecular weight of hydrocarbon increases from methane to butane, the output from the flow rate measurement sensor 100 per the same mass flow rate tends to increase. Therefore, in a conventional mass flow meter using a thermal type flow sensor, in order to accurately measure the mass flow rate, it is necessary to accurately determine the gas type and make a correction suitable for the gas type. It was On the other hand, as shown in FIG. 10, the relationship between the calorific value per unit molecular weight of hydrocarbon and the molecular weight tends to decrease as the molecular weight increases. Therefore, according to the present invention, even if the same mass flow rate flows, the larger the molecular weight of the hydrocarbon that is the fluid to be measured, the higher the flow rate measurement sensor 1
When a different type of hydrocarbon is flown as a measurement target, the tendency that the output from 00 becomes large and the tendency that the larger the molecular weight becomes, the smaller the calorific value per unit molecular weight becomes (cancelling each other) However, it is possible to obtain the output of the same magnitude (for example, the output of the instrumental error range ± 1.5% to ± 4.0% or less) for the flow of the same heat generation amount (combustion heat flow rate). Further, even if different corrections or conversion formulas are not used according to the type of hydrocarbon (without changing the corrections or conversion formulas), based on the output from the same flow rate measurement sensor 100 (flow rate measurement sensor). Of the combustion heat flow rate by, for example, only one fixed conversion formula that is set in advance, without changing the output characteristics of the corresponding to the type of hydrocarbon to be measured.
It is possible to measure with a usage tolerance of ± 4.0% or better.

In any case, the combustion heat flow rates of gases having different compositions, such as the gas meter 1 according to the present invention, are set by the thermal type flow rate measuring sensor 100 and one type preset for measuring the combustion heat flow rate. From the fundamental idea itself that it can be measured using a fixed conversion rate, the theoretical combustion heat quantity is corrected to the mass flow rate value measured using a mass flow meter, and the combustion heat flow rate is corrected. It was not even noticed by the conventional measurement method of calculating the value or its extension. Therefore, the success or failure of the accurate measurement of the combustion heat flow rate value by the gas meter 1 according to the present invention should be confirmed by the above-mentioned experiment. Even the prior art has never attempted it. However, the present inventors have conceived that it is possible to accurately measure the combustion heat flow rate value by the gas meter 1 according to the present embodiment and the present embodiment, as has been clearly shown in the above embodiment, and We were able to confirm it by experiments.

In the above embodiments and examples, the case where the present invention is applied to a household gas meter has been described, but the present invention is also applicable to other commercial gas meters, for example. . Alternatively, the fuel fluid to be measured is not only a gas meter that measures the combustion heat flow rate of city gas or natural gas, but also a fuel meter that measures the combustion heat flow rate of multiple types of liquid fuels with different compositions. Applicable.

[0070]

As described above, the first to seventh aspects are as follows.
9. The combustion heat flow rate measuring device according to any one of claims 1 to 8.
According to the combustion heat flow measuring method according to any one of claims 1 to 14 or the gas meter according to any one of claims 15 to 21, a fixed conversion rate that does not change regardless of gas type is used, By directly applying the process of linear correspondence to the combustion heat flow rate per unit time to the electrical signal output from the flow rate measuring means, the combustion heat per unit time of the fluid such as the fuel gas to be measured is measured. Since an electric signal or information carrying the flow rate information is output, it is possible to intervene with the mass flow rate as a parameter as in the conventional technology and to apply a constant pressure specific heat according to the type of fluid for fuel such as gas. It is a pole that one conversion rate is used for gases (of multiple types) with different composition component ratios without performing complicated processing such as correction of combustion heat quantity and combustion. By a simple method Te, it is possible to obtain an integrated value of the measured value of the correct combustion heat flow and combustion heat flow.

Further, according to the gas usage meter reading apparatus of any one of claims 22 to 26, the combustion heat integrated value reading means obtains the data of the integrated value of the combustion heat flow rate from the gas meter according to the present invention. Since the numerical value is read out via the wireless communication or the wired communication and is displayed or printed out by the output means, the integrated value of the combustion heat flow rate accurately measured by the gas meter according to the present invention, for example, the gas meter reading Since it is possible to automatically read and output as display output, print output, or data without the need for a person to visually inspect the meter, the meter reading operation can be simplified.

[Brief description of drawings]

FIG. 1 is a diagram showing a schematic configuration of a gas meter according to an embodiment of the present invention.

FIG. 2 is a diagram showing a correlation between a voltage level VT and a combustion heat flow rate value W corresponding to a gas flow at that time.

FIG. 3 is a diagram showing an example of integrated values and units displayed on an integrated value display unit.

FIG. 4 is a diagram showing a configuration of a main part of a terminal device for meter reading.

FIG. 5 is a diagram showing a schematic configuration of a flow rate measurement sensor used in an example.

FIG. 6 is a diagram showing a schematic configuration of a test apparatus used in an experiment of an example.

FIG. 7 is a diagram showing an experimental result of an example.

FIG. 8 is a diagram showing an experimental result when a volume flow rate value is measured by a gas meter of a volume flow rate measurement method which has been generally used conventionally as a comparative example.

FIG. 9 is a diagram showing four types of typical hydrocarbon gases such as methane, ethane, propane, and butane, which are flowed in a conduit.
It is a graph showing the relationship between the output from the flow rate measurement sensor and the mass flow rate.

FIG. 10 shows a correlation between a molecular weight and a calorific value per unit volume (linear graph) and a correlation between a molecular weight and a calorific value per unit mass of methane (curve graph) for a typical hydrocarbon. FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Gas meter, 100 ... Flow rate measuring sensor, 200 ... Combustion heat flow rate arithmetic circuit, 201 ... Linearization arithmetic circuit, 202 ...
Combustion heat flow rate digitizing unit, 203 ... Flow rate value integrating unit, 300 ...
Integrated value storage unit, 400 ... Integrated value display unit, 500 ... Flow rate monitoring unit, 600 ... Meter side communication unit

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G08C 17/00 G08C 17/00 Z (72) Inventor Mitsunori Komaki 1-5-20 Kaigan, Minato-ku, Tokyo Tokyo Gas Co., Ltd. (72) Inventor Kenchi Kobayashi 1-5-20 Kaigan, Minato-ku, Tokyo Tokyo Gas Co., Ltd. (72) Inventor Ken Tashiro 1-5-20 Kaigan, Minato-ku, Tokyo Tokyo Gas Co., Ltd. Internal F-term (reference) 2F030 CC13 CD20 CE01 CE09 2F073 AA08 AA40 BB01 BB20 CC01 CC12 FG07 GG01 GG09 2F075 GG04 GG09 GG15 GG16 2G040 AB08 AB12 BA04 BA23 CB02 CB04 DA02 DA12 EA02 EB02 GA01 GA07 HA08

Claims (26)

[Claims] 1. A conduction path for conducting a fluid, and a change in the amount of heat radiation, a change in the amount of heat transfer, or a change in the amount of heat received, which occurs due to heating or cooling of the flow of the fluid in the conduction path, and the value of the change is detected. A flow rate measuring means for outputting a first signal carrying information, a change value carried by the first signal output from the flow rate measuring means, and a flow of the fluid at a predetermined air-fuel ratio. One kind of predetermined arithmetic processing is performed on a plurality of types of gas, which linearly correlates the correlation with the value of the flow rate of combustion heat per unit time obtained when burning, and A combustion heat flow rate measurement device, comprising: a linearization calculation means for outputting a second signal carrying information on the value of the flow rate per unit time. 2. The combustion heat flow rate measuring device according to claim 1, further comprising a flow rate value accumulating means for accumulating the data of the value of the flow rate of the combustion heat per unit time. 3. The combustion heat flow rate measuring device according to claim 1, wherein the fluid is natural gas. 4. The combustion heat flow measuring device according to claim 1, wherein the fluid is a hydrocarbon gas. 5. The combustion heat flow measuring device according to claim 1, wherein the fluid is a chain hydrocarbon-based gas. 6. The verification tolerance of the fluid as a combustion heat flow rate measuring device in the value of the flow rate of the combustion heat per unit time output from the linearization calculation means is ± 1.5.
The combustion heat flow rate measuring device according to any one of claims 1 to 5, wherein the combustion heat flow rate measuring device comprises a component that is within the range of%. 7. The use tolerance of the fluid as a combustion heat flow rate measuring device in the value of the flow rate of the combustion heat per unit time output from the linearization calculation means is ± 4.0.
The combustion heat flow rate measuring device according to any one of claims 1 to 5, wherein the combustion heat flow rate measuring device comprises a component that is within the range of%. 8. A fluid is caused to flow through a conduction path, and a change in the amount of heat radiation, a change in the amount of heat transfer, or a change in the amount of heat received caused by heating or cooling of the flow of the fluid in the conduction path is detected, and the change is detected. Outputting a first signal carrying value information, the change value carried by the output first signal, and
One kind of predetermined one for plural kinds of gas, which linearly correlates the correlation with the value of the flow rate of combustion heat per unit time obtained when the flow of the fluid is burned at a predetermined air-fuel ratio A combustion heat flow rate measuring method comprising: performing a calculation process to output a second signal carrying information on the value of the flow rate of the combustion heat per unit time. 9. The combustion heat flow rate measuring method according to claim 8, wherein the data of the value of the flow rate of the combustion heat per unit time is integrated. 10. The combustion heat flow measuring method according to claim 8, wherein the fluid is natural gas. 11. The combustion heat flow rate measuring method according to claim 8, wherein the fluid is a hydrocarbon-based gas. 12. The combustion heat flow rate measuring method according to claim 8, wherein the fluid is a chain hydrocarbon gas. 13. The fluid comprises a component having a verification tolerance of ± 1.5% or less in the value of the flow rate of the combustion heat output per unit time as the combustion heat flow rate measuring method. 13. The combustion heat flow rate measuring method according to any one of claims 8 to 12. 14. The fluid comprises a component having a usage tolerance of ± 4.0% as a method for measuring the combustion heat flow rate in the value of the flow rate of the output combustion heat per unit time. 13. The combustion heat flow rate measuring method according to any one of claims 8 to 12. 15. A conduction path for conducting gas, and a change in the amount of heat radiation, a change in the amount of heat transfer, or a change in the amount of heat received, which is caused by heating or cooling of the flow of the gas in the conduction path, are detected, and the value of the change is detected. A flow rate measuring means for outputting a first signal carrying information, a change value carried by the first signal outputted from the flow rate measuring means, and a flow of the gas at a predetermined air-fuel ratio. One kind of predetermined arithmetic processing is performed on a plurality of types of gas, which linearly correlates the correlation with the value of the flow rate of combustion heat per unit time obtained when burning, and A gas meter, comprising: a linearization calculation means for outputting a second signal carrying information on the value of the flow rate per unit time. 16. The gas meter according to claim 15, further comprising flow rate value integrating means for integrating data on a value of a flow rate of the combustion heat per unit time. 17. The gas meter according to claim 15, wherein the gas is natural gas. 18. The gas meter according to claim 15, wherein the gas is a hydrocarbon-based gas. 19. The gas meter according to claim 15, wherein the gas is a chain hydrocarbon gas. 20. The gas comprises a component having a verification tolerance of ± 1.5% as the gas meter in the value of the flow rate of the combustion heat per unit time output from the linearization calculation means. The gas meter according to any one of claims 15 to 19, wherein the gas meter is provided. 21. The gas comprises a component having a usage tolerance of ± 4.0% or less in the value of the flow rate of the combustion heat per unit time output from the linearization calculation means. The gas meter according to any one of claims 15 to 19, wherein the gas meter is provided. 22. A conduction path for conducting a gas for fuel or a raw material, and a change in heat radiation amount, a change in heat transfer amount, or a change in heat receiving amount caused by heating or cooling of the flow of the gas in the conduction path are detected. A flow rate measuring means for outputting a first signal carrying information on the value of the change, a change value carried by the first signal outputted from the flow rate measuring means, and a flow of the gas. One kind of predetermined arithmetic processing is performed for a plurality of kinds of gas, which linearly correlates the correlation with the value of the flow rate of combustion heat per unit time obtained when the fuel is burned at a predetermined air-fuel ratio. Then, the linearization calculation means for outputting a second signal carrying information on the value of the flow rate of the combustion heat per unit time, and the value of the flow rate of the combustion heat per unit time are integrated to perform the combustion. Flow rate for obtaining integrated heat flow rate data In a gas meter provided with a value integrating means, the integrated value of the combustion heat flow rate is read by the integrated combustion heat integrated value reading means for reading out the integrated data of the combustion heat flow rate via wireless communication or wired communication, and the integrated integrated combustion heat value reading means. A gas usage meter reading device comprising: an output unit that outputs the integrated value of the combustion heat flow rate to the outside as a display output, a print output, or data. 23. Instead of the output means, a storage means for storing the integrated value of the combustion heat flow rate read by the combustion heat integrated value reading means for each gas meter together with the customer identification information of the gas meter. 23. The gas usage meter reading device according to claim 22, wherein the device is provided at or in addition to the above. 24. Charge conversion means for converting an integrated value of the combustion heat flow into a value of a usage charge based on a unit price per unit combustion heat flow of the gas, and displaying or printing the value of the usage charge. The gas usage meter reading device according to claim 22 or 23, further comprising an output means for outputting to the outside as output or data. 25. A storage means is further provided for storing, for each gas meter, the value of the usage fee amount together with the identification information of the customer of the gas meter.
4. The gas consumption meter reading device according to 4. 26. The gas usage meter reading device according to claim 25, further comprising usage charge amount display means for displaying the value of the usage charge amount.