JP7243279B2 - Fluid heating device and cogeneration system using the heating device - Google Patents

Description

The present invention relates to a fluid heating device and a cogeneration system using the heating device.

For the purpose of securing power supply and saving energy in the event of a system power loss in the event of a disaster, etc., it is equipped with a power generation unit that includes a generator driven by an internal combustion engine, etc., or a fuel cell, etc., and utilizes exhaust heat from the power generation unit. Various cogeneration systems (combined heat and power systems) are widely used to achieve overall high energy efficiency. In such a system, for example, the heat medium is used for the purpose of consuming the surplus power generated by the power generation unit and controlling the temperature of the heat medium (for example, fluid such as water) that receives the exhaust heat from the power generation unit. A heating means (for example, a heater, etc.) for heating and a cooling means (for example, a radiator, a fan, etc.) for cooling the heat medium are arranged in the heat medium circulation path or the like. Then, the heating means and the cooling means are controlled so that the temperature of the heat medium detected by the detection means such as the temperature sensor falls within a desired range (see, for example, Patent Document 1).

That is, in the cogeneration system or the like according to the prior art, temperature detection means for detecting the temperature of the heat medium flowing through the flow path such as the circulation path is separately provided, and based on the temperature of the heat medium detected by the detection means, to control the heating means and/or cooling means of the heat medium. However, from the viewpoint of reducing the complication of the system configuration and the increase in cost, it is desirable to detect the temperature of the heat medium flowing through the flow path such as the circulation path without separately providing the temperature detection means as described above. It is desirable to be able to

From this point of view, in a heating device equipped with a resistance heating type heater that generates heat by Joule heat generated by energization, the temperature of the heater is calculated based on the electrical resistance value of the heater when the object to be heated is being heated. There is known a technique for doing so (see, for example, Patent Document 2). According to this technology, the temperature of the heater can be calculated without separately providing a temperature detection means. However, what is calculated by this technique is the temperature of the heater as the heating element that heats the object to be heated, not the temperature of the object that is heated by the heater.

As described above, in the technical field, no technology has yet been established that can detect the temperature of a fluid as an object to be heated without separately providing a detection means for detecting the temperature of the fluid.

WO2014/002801 JP-A-10-116885

As described above, in the technical field, there is a demand for a technique capable of detecting the temperature of a fluid as an object to be heated without separately providing a detection means for detecting the temperature of the fluid. That is, one object of the present invention is to provide a fluid heating apparatus capable of detecting the temperature of a fluid without separately providing a detection means for detecting the temperature of the fluid as an object to be heated. .

Therefore, as a result of intensive research, the inventors of the present invention have found that, in a fluid heating device comprising a plurality of resistance heaters arranged in a single flow path through which a fluid flows, resistance heating that does not contribute to the heating of the fluid We have found that the temperature of the fluid can be determined based on the electrical resistance of the mold heater.

In view of the above, a fluid heating device according to the present invention (hereinafter sometimes referred to as the "apparatus of the present invention") includes a single flow path through which a fluid flows, and a module disposed in the flow path. A fluid heating apparatus comprising: a plurality of heaters (resistance heating type heaters) capable of heating the fluid with heat; and a controller controlling power supply to the plurality of heaters. In the apparatus of the present invention, for each heater of the plurality of heaters, a first power, which is a predetermined power for measuring the electrical resistance value of the heater, is supplied to the heater to measure the electrical resistance value of the heater. It further comprises a measurement unit configured to be able to measure.

Furthermore, the control unit is configured to execute the processes listed in (1) to (3) below when measuring the temperature of the fluid.

(1) Selecting, as the first heater, a heater to which second electric power for heating the fluid is not supplied from among the plurality of heaters.
(2) supplying the first electric power to the first heater;
(3) Identifying the temperature of the fluid based on the first resistance value R1, which is the electrical resistance value of the first heater measured by the measuring unit.

Further, a cogeneration system according to the present invention (hereinafter sometimes referred to as "the system of the present invention") includes a power generation unit and a storage container for storing the fluid heated by exhaust heat from the power generation unit. and a circulation path for circulating the fluid between the power generation unit and the storage container. The system of the present invention further comprises the apparatus of the present invention described above, and the flow path of the apparatus of the present invention is interposed in the circulation path so as to communicate with the circulation path.

In the device of the present invention, as described above, a plurality of resistance heating heaters are arranged in a single flow path through which the fluid flows, and the electric resistance value of the resistance heating heater that does not contribute to heating the fluid is The temperature of the fluid can be determined based on Therefore, according to the device of the present invention, it is possible to detect the temperature of the fluid without separately providing a detection means for detecting the temperature of the fluid.

Also, the system of the present invention uses the device of the present invention as a heating means for heating the fluid circulating between the power generating section and the storage container. In the apparatus of the present invention, as described above, a plurality of resistance heaters are arranged in a single flow path through which the fluid flows, and the electric resistance value of the resistance heater that does not contribute to heating the fluid is The temperature of the fluid can be determined based on Therefore, according to the system of the present invention, it is possible to detect the temperature of the fluid without separately providing a detection means (for example, a temperature sensor, etc.) for detecting the temperature of the fluid. Then, based on the temperature of the fluid detected in this way, for example, heating means for heating the fluid and/or cooling means for cooling the fluid are controlled to keep the temperature of the fluid within a predetermined range. can be accommodated. That is, according to the system of the present invention, it is possible to keep the temperature of the fluid in the cogeneration system within a suitable range while reducing problems such as complication of configuration and increase in cost.

Other objects, features and attendant advantages of the present invention will be readily understood from the description of each embodiment of the present invention described with reference to the following drawings.

1 is a schematic diagram illustrating the configuration of a fluid heating device (first device) according to a first embodiment of the present invention; FIG. It is a flowchart which shows an example of the fluid temperature measurement routine performed in the control part with which a 1st apparatus is provided. FIG. 2 is a schematic block diagram showing an example of the configuration of a cogeneration system (first system) according to a second embodiment of the present invention; FIG. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram showing an example of the configuration of a fluid heating device (embodiment device) according to one embodiment of the present invention; 1 is a schematic block diagram showing an example of a configuration of a cogeneration system (embodiment system) according to one embodiment of the present invention; FIG. It is a typical graph showing the 1st relationship which is the corresponding relationship of the electrical resistance value of a 1st heater when a 1st state is materialized, and the temperature of a fluid. 1 is a schematic diagram showing an example of a configuration of a conventional fluid heating device (conventional device); FIG. 1 is a schematic block diagram showing an example of a configuration of a conventional cogeneration system (conventional system); FIG.

<<1st Embodiment>>
Hereinafter, a fluid heating device (hereinafter sometimes referred to as "first device") according to a first embodiment of the present invention will be described.

<composition>
A first device controls a single flow path through which a fluid flows, a plurality of heaters arranged in the flow path and capable of heating the fluid by Joule heat, and power supply to the plurality of heaters. and a controller for heating a fluid.

Although the fluid is not particularly limited, it is typically a fluid that is used as a heat medium in a device or facility in which the first device is incorporated (hereinafter sometimes collectively referred to as a "parent device"). Specific examples of such fluids include water and oil.

A specific configuration of the flow path is not particularly limited as long as the fluid, which is the object to be heated by the first device, can flow. Typically, the channel may be constructed by a tubular or grooved member formed of a material that can withstand the chemistry, pressure, temperature, etc. of the fluid used in the parent device described above.

The plurality of heaters arranged in the flow path are so-called "resistance heaters" that heat an object to be heated by Joule heat generated by energization. The controller is configured to control power supply to the plurality of heaters.

A specific control mode of power supply to the plurality of heaters by the control unit is appropriately determined according to a heating mode of the fluid by the first device required in the parent device. For example, the control unit is configured to control a power source for supplying power to the plurality of heaters, and switch between supply and cutoff of predetermined power supplied to each of the plurality of heaters. good too. Alternatively, the control unit may be configured to control a power supply for supplying power to the plurality of heaters and change the magnitude of the predetermined power supplied to each of the plurality of heaters. good.

A first device supplies a first electric power, which is a predetermined electric power for measuring an electric resistance value of each heater of the plurality of heaters, to the heater to measure an electric resistance value of the heater. It further comprises a measurement unit configured to be able to measure.

A specific configuration of the measurement unit is not particularly limited as long as it can measure the electric resistance value of the heater. For example, the measuring unit calculates the electrical resistance value R of the heater based on the voltage V applied to the heater when a predetermined power P is supplied to the heater and the current I flowing through the first heater due to the voltage. (R=V/I). Such arithmetic processing can be executed by, for example, the control unit. Further, as described above, since the control unit is originally configured to control the electric power (that is, current and voltage) supplied to the plurality of heaters, this can be achieved without adding a special detection device or the like. Such functions of the measurement section can be easily achieved by the control section.

Furthermore, the control unit is configured to execute the processes listed in (1) to (3) below when measuring the temperature of the fluid.

(1) Selecting, as the first heater, a heater to which second electric power for heating the fluid is not supplied from among the plurality of heaters.
INDUSTRIAL APPLICABILITY As described above, the apparatus of the present invention is a fluid heating apparatus comprising a plurality of resistance heaters arranged in a single flow path through which a fluid flows. determines the temperature of the fluid based on the electrical resistance of Therefore, when the temperature of the fluid is to be measured, the controller selects a heater that does not contribute to heating the fluid from among the plurality of heaters. A heater selected in this manner is referred to as a "first heater" in the present invention.

The first heater may be any one of the plurality of heaters. However, as will be described in detail later, in the application of the parent device, a period during which it does not contribute to the heating of the fluid is set at least temporarily. A heater that does not cause any substantial trouble even if it is provided can be selected as the first heater. Alternatively, a heater can be selected as the first heater that is configured not to contribute to heating the fluid when the temperature of the fluid is to be measured in the mode of operation of the parent device. In any case, a specific (fixed) heater of the plurality of heaters is not selected as the first heater, and heating of the fluid when measuring the temperature of the fluid among the plurality of heaters. is selected as the first heater.

(2) supplying the first electric power to the first heater;
The control unit supplies the first electric power to the first heater selected by the process described in (1) above. The first power is, for example, power that does not substantially contribute to the heating of the fluid although the electrical resistance value of the first heater can be measured by the measuring unit.

The state in which one of the plurality of heaters is selected as the first heater and the first power is supplied to the first heater as described above is a state that can occur in the normal operating mode of the parent device. may be achieved only for measuring electrical resistance values of different first heaters. Alternatively, the condition may be any condition included in the conditions that can occur in the normal mode of operation of the parent device.

For example, in the operating mode of the parent device, the fluid is heated only by the heater A and the fluid is heated by both the heater A and the heater B depending on the amount of heat to be supplied to the fluid. It is assumed that the . In this case, since the heater B does not heat the fluid in the former state, the heater B is selected as the first heater, the first electric power is supplied, and the electrical resistance value thereof is measured by the measuring unit. can be done. On the other hand, in the latter state, both heater A and heater B heat the fluid. Therefore, if there is no other heater that does not contribute to the heating of the fluid, either one of the heater A and the heater B is selected as the first heater, and the power supplied to that heater is the second power. to the first power (heating of the fluid by the heater is stopped), and the electrical resistance value thereof needs to be measured by the measuring unit.

Alternatively, it is assumed that the heater C and the heater D are switched and used so that only one of the heater C and the heater D heats the fluid according to the operation mode of the parent device. In this case, it is not necessary to achieve a special state only for measuring the electrical resistance value of the first heater as described above, and the one that is not heating the fluid at the time of measuring the temperature of the fluid (that is, , to which the second power is not supplied) may be selected as the first heater.

(3) Identifying the temperature of the fluid based on the first resistance value R1, which is the electrical resistance value of the first heater measured by the measuring unit.
As described above, the control unit performs the measurement when a state is established in which one of the plurality of heaters is selected as the first heater and the first power is supplied to the first heater. The temperature of the fluid is specified based on the first resistance value R1, which is the electrical resistance value of the first heater measured by the unit. A specific method for determining the temperature of the fluid based on the first resistance value R1 is not particularly limited. Specific examples of such methods include method A and method B listed below.

(Method A)
For each heater of the plurality of heaters, data representing a first relationship, which is a correspondence relationship between the electrical resistance value of the heater when the first power is supplied and the temperature of the fluid, is stored in advance in a data storage device. Then, the controller specifies the temperature of the fluid based on the first resistance value from the first relationship for the heater selected as the first heater.

The data storage device may be included in the control unit, may be a component of the first device other than the control unit, or may be included in a device other than the first device, such as a parent device. A specific configuration of the data storage device is not particularly limited as long as it can hold the data representing the first relationship in a referable state. Specific examples of such data storage devices include non-volatile memories such as ROMs (Read Only Memories) and HDDs (Hard Disk Drives).

The first relationship is obtained, for example, by an experiment in which fluids of various temperatures are flowed through the flow path while the first electric power is being supplied, and the electrical resistance values of the heaters are recorded for each of the plurality of heaters. can be requested in advance. The format of the data representing the first relationship is not particularly limited as long as it can represent the correspondence relationship between the electrical resistance value of each heater and the temperature of the fluid when the first power is supplied. Specific examples of such data include a table such as a lookup table, a data map, and a function representing the corresponding relationship.

(Method B)
When the voltage applied to the resistance heater is constant, the electrical resistance values Rx and Ry of the heater when the heater temperatures are Tx and Ty include the temperature coefficient α of the electrical resistance value of the heater. It can be represented by the following formula.

Therefore, the electric resistance value Rr of the first heater when the first electric power is supplied and the temperature of the fluid is the predetermined reference temperature Tr, the first resistance value R1, and the electric resistance value of the first heater The controller calculates the temperature T of the fluid according to the following equation (1) based on the temperature coefficient α.

The configuration of the control unit is not particularly limited as long as it can execute the above control. For example, the control unit may be implemented as an electronic control unit (ECU) having a microcomputer as a main part. In this case, the control unit includes, for example, an input port for receiving the detection signal from the above-described measurement unit, etc., and an instruction signal for controlling the power supply for supplying power to the above-described plurality of heaters (resistance heating type heaters). It has an output port and the like for transmitting In this specification, a microcomputer includes a CPU, a ROM, a RAM (Random Access Memory), and a data storage device such as an HDD, and the CPU receives a detection signal based on instructions (programs) stored in the ROM, It is configured to implement various functions by executing various arithmetic processes and transmitting instruction signals.

The above-described various functions achieved by the control unit may be achieved by the control unit provided in the first device, or may be achieved by the control unit provided in the parent device. Further, the above-described various functions achieved by the control unit may be achieved by distributed processing by a plurality of control units out of the control unit provided in the first device and the control unit provided in the parent device.

Here, the configuration of the first device will be described in more detail with reference to the drawings and in comparison with the configuration of a conventional fluid heating device.

FIG. 7 is a schematic diagram showing an example of the configuration of a conventional fluid heating device (hereinafter sometimes referred to as a “conventional device”). A conventional device 901 illustrated in (a) of FIG. and a controller (not shown) for controlling power supply to the fluid heating device. A conventional device 902 illustrated in (b) differs from the conventional device 901 described above only in that two resistance heaters 21 and 22 are arranged in series in the flow path 10 . In the conventional device 903 illustrated in (c), instead of the two resistance heaters 21 and 22 arranged in series in the flow channel 10, two resistance heaters arranged at the same position in the flow channel 10 are used. 23 and 24 is the only difference from the conventional device 902 described above.

In any of the conventional devices 901 to 903 described above, a temperature detection means (for example, a temperature sensor such as a thermocouple) 30 for detecting the temperature of the fluid flowing through the flow path 10 is provided separately from each heater. . A control unit (not shown) included in the conventional device is configured to control power supply to each heater so that the temperature of the fluid detected by the temperature detection means 30 falls within a desired range. there is As described above, in the conventional apparatus, it is necessary to separately provide temperature detection means, which causes problems such as complication of the configuration and increase in cost.

On the other hand, in the first device, as described above, a plurality of resistance heaters are arranged in a single flow path through which the fluid flows, and the electric resistance of the resistance heaters that do not contribute to the heating of the fluid is The temperature of the fluid can be determined based on the resistance value.

For example, FIG. 1 is a schematic diagram illustrating the configuration of the first device. A first device 101 illustrated in FIG. 1A includes a single flow path 10 through which a fluid (white arrow) flows, two resistance heaters 21 arranged in series in the flow path 10, and 22 and a controller (not shown) for controlling power supply to the heaters 21 and 22 . Moreover, the first device 101 further includes a measuring unit 40 that measures the electrical resistance values of the heaters 21 and 22 .

When measuring the temperature of the fluid, the control section selects the heater that does not contribute to the heating of the fluid at that time as the first heater from among the heaters 21 and 22 . If both the heaters 21 and 22 contribute to the heating of the fluid and there is no substantial problem even if both or one of the heaters 21 and 22 does not contribute to the heating of the fluid, the heaters 21 and 22 contribute to the heating of the fluid. A heater that does not cause any substantial trouble even if a non-heating period is provided is selected as the first heater. Then, the heater selected as the first heater is supplied with the first power (power for measuring the electrical resistance value), and the electrical resistance value (first resistance value R1) of the first heater measured by the measuring unit 40 is Determine the temperature of the fluid based on

In the first device 102 illustrated in (b), instead of the two resistance heaters 21 and 22 arranged in series in the channel 10, two resistance heaters arranged at the same position in the channel 10 It differs from the first device 101 described above only in that heaters 23 and 24 are provided. In the first device 102, similarly to the above-described first device 101, the heater that does not contribute to the heating of the fluid is selected as the first heater from the heaters 23 and 24 from time to time, and the electrical resistance value ( The temperature of the fluid can be determined based on the first resistance value R1).

As described above, in the first device, a specific (fixed) heater out of the plurality of heaters (heaters 21 and 22 or heaters 23 and 24) is not selected as the first heater. , which heater does not contribute to heating the fluid when measuring the temperature of the fluid is selected as the first heater. Specifically, a heater configured not to contribute to the heating of the fluid due to the operation mode of the parent device when the temperature of the fluid is to be measured can be selected as the first heater. Alternatively, in the application of the parent device, a heater that does not cause substantial problems even if a period of time during which it does not contribute to the heating of the fluid is provided at least temporarily may be designated in advance as the first heater.

In FIG. 1, the measurement unit 40 is drawn as one block for the purpose of facilitating understanding of the configuration of the first device, but the measurement unit 40 does not necessarily have to be another configuration of the first device. It need not be constructed as a separate device from the elements. As previously mentioned, the controller is primarily configured to control the power (ie, current and voltage) supplied to the plurality of resistive heaters. Therefore, without adding a special detection device or the like, the function of the measurement unit 40 as described above can be easily achieved by the control unit, and the electric resistance of the heater (first heater) that does not contribute to the heating of the fluid can be calculated. A value (first resistance value R1) can be measured. Then, the temperature of the fluid can be specified based on the electrical resistance value.

<Operation>
The operation of the first device 102 will now be described in detail with reference to the drawings. FIG. 2 is a flow chart showing an example of a fluid temperature measurement routine that is executed by the control unit provided in the first device 102. As shown in FIG. Such a fluid temperature measurement routine is repeatedly executed at predetermined intervals by a CPU provided in an ECU that functions as a control section.

When the fluid temperature measurement routine is started, the CPU determines in step S101 whether the heater 23 is heating the fluid. In other words, the CPU determines in step S101 whether or not the second power, which is power for heating the fluid, is continuously or intermittently supplied to the heater 23 . When the heater 23 is heating the fluid, the CPU determines "Yes" in step S101, and advances the process to the next step S102.

In step S102, the CPU now determines whether the heater 24 is heating the fluid. In other words, the CPU determines in step S102 whether or not the second power, which is power for heating the fluid, is continuously or intermittently supplied to the heater 24 .

If the heater 24 is heating the fluid, the CPU determines "Yes" in step S102. In this case, both the heater 23 and the heater 24 are heating the fluid and are not in a state (first state) in which the first power can be supplied and the electrical resistance value can be measured. Therefore, in this case, the CPU once terminates the routine.

On the other hand, if the heater 24 is not heating the fluid, the CPU determines "No" in step S102, proceeds to the next step S103, selects the heater 24 as the first heater, and A first power, which is power for measuring the resistance value, is supplied to the heater 24 as the first heater. Further, the CPU proceeds to the next step S104, and calculates the temperature of the fluid from the electric resistance value (first resistance value R1) of the heater 24 as the first heater.

On the other hand, if the heater 23 is not heating the fluid, the CPU determines "No" in step S101, proceeds to the next step S105, selects the heater 23 as the first heater, and A first power, which is power for measuring the resistance value, is supplied to the heater 23 as the first heater. Then, the CPU proceeds to the next step S104 and calculates the temperature of the fluid from the electric resistance value of the heater 23 as the first heater.

By the way, FIG. 1 illustrates the first device provided with two resistance heaters as described above. A plurality of heaters can be provided that can heat the fluid with heat. That is, the number of resistance heaters provided in the first device is not limited to two, and may be three or more.

Further, in the flowchart shown in FIG. 2, as described above, it is determined whether the heater 24 is heating the fluid after determining whether the heater 23 is heating the fluid. Conversely, however, it may be determined whether the heater 23 is heating the fluid after determining whether the heater 24 is heating the fluid.

Furthermore, in the flowchart shown in FIG. 2, when both the heater 23 and the heater 24 are heating the fluid, the CPU determines "Yes" in step S102, and terminates the routine. However, as described above, if there is no substantial problem in providing both or one of the heaters 23 and 24 with a period that does not contribute to heating of the fluid, even if a period that does not contribute to heating of the fluid is provided, there is no substantial problem. The heater that does not cause any trouble may be selected as the first heater. In this case, the process proceeds to the next step S104, and the temperature of the fluid can be calculated from the electric resistance value (first resistance value R1) of the heater selected as the first heater out of the heaters 23 and 24. can.

<effect>
As described above, in the first device, a plurality of resistance heaters are arranged in a single flow path through which the fluid flows, and the electric resistance value of the resistance heater that does not contribute to heating the fluid is The temperature of the fluid can be determined based on Therefore, according to the first device, it is possible to detect the temperature of the fluid without separately providing a detection means (for example, a temperature sensor or the like) for detecting the temperature of the fluid.

The temperature of the fluid detected as described above can be used, for example, as an index for various controls executed in the application of the parent device. For example, control of heating means (e.g., heaters, etc.) for heating fluid and/or cooling means (e.g., radiators and fans, etc.) for cooling fluid (e.g., switching between operation and non-operation, etc.) The temperature of the fluid can be used as an indicator for the temperature of the fluid to fall within a predetermined range.

<<Second embodiment>>
A fluid cogeneration system (hereinafter sometimes referred to as "first system") according to a second embodiment of the present invention will be described below.

<composition>
The first system includes a power generation unit, a storage container for storing the fluid warmed by exhaust heat from the power generation unit, and a circulation path for circulating the fluid between the power generation unit and the storage container. It is a cogeneration system.

The power generation unit may be, for example, an internal combustion engine, a fuel supply device that supplies fuel to the internal combustion engine, and a power generation device that includes a generator driven by the internal combustion engine, or a fuel cell and a fuel cell that supplies fuel to the fuel cell. It may be a power generation device or the like including a fuel supply device for supplying fuel. The specific configuration of the storage container is not particularly limited as long as it can store the fluid warmed by the exhaust heat from the power generation unit. For example, a container such as a tank can be used as the fluid storage container. . Typically, the fluid is water and the storage container is a hot water tank.

The means and/or technique for warming the fluid with exhaust heat from the power generation section is not particularly limited. For example, the heat medium itself for cooling the internal combustion engine that constitutes the power generation section may be used as the fluid. Alternatively, a heat exchanger or the like may be provided so that the fluid receives heat from the heat medium for cooling the internal combustion engine and/or the exhaust gas discharged from the internal combustion engine via the heat exchanger. Further, when the power generation unit is configured by a fuel cell, a heat exchanger or the like may be provided so that the fluid receives heat from the exhaust gas discharged from the fuel cell via the heat exchanger.

A specific configuration of the circulation path can circulate the exhaust heat from the power generation unit and the fluid as the object to be heated by the first device between the heat receiving unit from the power generation unit and the storage container. It is not particularly limited as long as Typically, the circulation path can be constructed by a tubular or groove-shaped member made of a material that can withstand the chemical properties, pressure, temperature, etc. of the fluid.

The first system further comprises any of the fluid heating apparatus (inventive apparatus) according to various embodiments of the present invention, including the first apparatus described above. Since the specific configuration of the device of the present invention has already been described in the description of the first device, it will not be repeated here. Furthermore, the flow path provided in the fluid heating device is interposed in the circulation path so as to communicate with the circulation path.

With the above configuration, in the first system, the fluid as the object to be heated by exhaust heat from the power generation unit is circulated between the heat receiving unit from the power generation unit and the storage container via the device of the present invention. However, if necessary, the fluid can be heated by the device of the present invention, or the temperature of the fluid can be detected by the device of the present invention.

Here, the configuration of the first system will be described in more detail with reference to the drawings, but the configuration of a conventional cogeneration system (hereinafter sometimes referred to as a "conventional system") for comparison will be described. I will explain first. FIG. 8 is a schematic block diagram showing an example of the configuration of a conventional system.

A conventional system 9000 shown in FIG. The cogeneration system includes a circulation path 140 and a pump 150 for circulating the fluid between the heat exchanger 120 and the storage container 130 . For the purpose of facilitating the explanation, the example shown in FIG. 8 will be described assuming that the fluid is water.

In the conventional system 9000, the heat medium warmed by the exhaust heat from the power generation unit (for example, the heat medium for cooling the internal combustion engine constituting the power generation unit and/or the exhaust discharged from the internal combustion engine, or the fuel cell ) is sent to the heat exchanger 120, where heat exchange between the heat medium and the water W takes place. Specifically, the water W is circulated by the pump 150 between the heat exchanger 120 and the storage container 130 via the circulation path 140, and the water W is warmed by the heat received from the heat medium in the heat exchanger 120. It becomes hot water Wh and is stored in the storage container 130 . The hot water Wh stored in the storage container 130 in this manner can be supplied to an external facility (not shown) such as a water heater.

In addition to the above, the conventional system 9000 further includes a conventional device 900 that is any of the conventional fluid heating devices (conventional devices), including the conventional devices 901 to 903 described above. In FIG. 8, the term "conventional device 900" is used as a generic term for the conventional devices as described above, and the generic term "heater 20" is used as a generic term for heaters for heating the fluid. A fluid flow path included in the conventional device 900 is interposed in the circulation path 140 so as to communicate with the circulation path 140 . Further, the conventional system 9000 also comprises cooling means 200 for cooling the fluid. The cooling means 200 comprises a radiator 210 and a fan 220 for supplying airflow to the radiator 210 .

As described above with reference to FIG. 7, the conventional device 900 includes temperature detection means (for example, a thermocouple or the like) for detecting the temperature of the fluid separately from the heater 20 for heating the fluid flowing through the flow path. temperature sensor) 30. As a result, a control unit (not shown) included in the conventional apparatus 900 controls power supply to the heater 20 based on the temperature of the fluid detected by the temperature detection means 30, or controls the power supply to the heater 20, By controlling the flow rate of the airflow supplied to the radiator 210, the temperature of the fluid can be kept within the desired range. However, the conventional system 9000 using the conventional device 900 including the temperature detection means 30 provided separately from the heater 20 as a device for heating the fluid has, as described above, a complicated configuration and an increased cost. etc.

On the other hand, FIG. 3 is a schematic block diagram showing an example of the configuration of the first system. A first system 1000 shown in FIG. 3 includes any one of the fluid heating devices (apparatus of the present invention) according to various embodiments of the present invention, including the first device described above, in place of the conventional device 900 described above. It has a configuration different from that of the above-described conventional system 9000 in terms of provision. In FIG. 3, the term "present invention device 100" is used as a generic term for the present invention devices. As described above, the device 100 of the present invention does not include the temperature detection means 30, and has a plurality of heaters (for example, the heaters 21, 22, 23 and 24). However, unlike the conventional device 900 described above, the device 100 of the present invention does not include temperature detection means separate from the plurality of heaters.

<effect>
As described above, the first system uses the device of the present invention as heating means for heating the fluid circulating between the power generation section and the storage container. In the apparatus of the present invention, as described above, a plurality of resistance heaters are arranged in a single flow path through which the fluid flows, and the electric resistance value of the resistance heater that does not contribute to heating the fluid is The temperature of the fluid can be determined based on Therefore, according to the first system, it is possible to detect the temperature of the fluid without separately providing a detection means (for example, a temperature sensor or the like) for detecting the temperature of the fluid. Then, for example, control of heating means (e.g., heater, etc.) for heating fluid and/or cooling means (e.g., radiator and fan, etc.) for cooling fluid (e.g., switching between operation and non-operation, etc.) Using the temperature of the fluid as an indicator for, etc., the temperature of the fluid can be kept within a predetermined range. That is, according to the first system, it is possible to keep the temperature of the fluid in the cogeneration system within a suitable range while reducing problems such as complication of configuration and increase in cost.

<<Third embodiment>>
A fluid cogeneration system (hereinafter sometimes referred to as a "second system") according to a third embodiment of the present invention will be described below.

By the way, in this technical field, there are a stand-alone heater that is a heater for converting surplus power into heat during self-sustained operation of the cogeneration system, and a commercial power source that heats the fluid when the cogeneration system is not in operation. A cogeneration system is known that includes an antifreeze heater that is a heater for preventing freezing of a fluid circulation path. In such a cogeneration system, only the self-sustaining heater is used to heat the fluid during self-sustained operation, and only the antifreeze heater is used during non-operation.

Therefore, in the cogeneration system as described above, when attempting to detect the temperature of the fluid, the one of the self-supporting heater and the anti-freezing heater that is not used for heating the fluid is selected as the above-described first heater. and can be used. Accordingly, the temperature of the fluid can be detected without separately providing a detection means for detecting the temperature of the fluid. That is, the part including the self-supporting heater and the anti-freezing heater in the fluid flow path of the cogeneration system as described above can function as the device of the present invention described above.

<composition>
Thus, the second system is any of the cogeneration systems according to various embodiments of the invention, including the first system described above, and includes a self-supporting heater and an anti-freeze heater. The self-sustaining heater is a heater for heating the fluid and converting surplus electric power into heat during the self-sustaining operation of the cogeneration system. The anti-freezing heater is a heater for heating the fluid to prevent freezing of the circulation path when the cogeneration system is not in operation.

As noted above, the self-sustaining heater is used during self-sustaining operation of the second system and the freeze protection heater is used during non-operation of the second system. Therefore, these two heaters are not used at the same time, but are used alternatively depending on the operating conditions of the second system. Therefore, in the second system, the heater that does not contribute to the heating of the fluid at any given time is selected as the above-described first heater, and the temperature of the fluid can be specified based on the electrical resistance value of the heater. .

Therefore, in the second system, the anti-freezing heater is selected as the first heater when the cogeneration system is self-sustaining, and the self-sustaining heater is selected as the first heater when the cogeneration system is not in operation. part is constructed.

<effect>
As described above, the second system includes the self-sustaining heater and the anti-freezing heater. Of these heaters, the heater that does not contribute to the heating of the fluid at any given time is selected as the first heater. A controller is configured to determine the temperature of the fluid based on the electrical resistance value. Therefore, according to the second system, it is possible to reliably detect the temperature of the fluid without separately providing a detection means for detecting the temperature of the fluid. Then, for example, the temperature of the fluid can be kept within a predetermined range by using the temperature of the fluid as an index for controlling the heating means for heating the fluid and/or the cooling means for cooling the fluid. can. Thus, according to the second system, the temperature of the fluid in the cogeneration system can be reliably kept within a suitable range while easily reducing problems such as complication of configuration and increase in cost.

Here, a fluid heating device according to one embodiment of the present invention (hereinafter sometimes referred to as "embodiment device") and one embodiment of the present invention using the device of the present invention A specific example of a cogeneration system (hereinafter, sometimes referred to as an "embodiment system") will be described in detail below with reference to the drawings.

<composition>
FIG. 4 is a schematic diagram showing an example of the configuration of the embodiment apparatus. An example device 104 illustrated in FIG. 24 and. Specifically, the heaters 23 and 24 are integrally formed as a sheet-like member 25 as shown in FIG. A sheet member 25 is wound around the outer circumference of the member 11 . That is, FIG. 4(b) is a development view showing a state in which the sheet-like member 25 is developed in a plane.

Next, FIG. 5 is a schematic block diagram showing an example of the configuration of the embodiment system. The embodiment system 1001 includes a power generation unit 110, a heat exchanger 120 for warming a fluid with exhaust heat from the power generation unit 110, a storage container 130 for storing the fluid, and a heat exchanger included in the power generation unit 110. A cogeneration system comprising a circulation path 140 and a pump 150 for circulating the fluid between 120 and a storage container 130 . For the purpose of facilitating the explanation, the example shown in FIG. 5 will also be explained assuming that the fluid is water.

The power generation unit 110 included in the embodiment system 1001 is composed of a fuel cell 110 that extracts power (generates power) from the chemical energy of the fuel F through an electrochemical reaction of the fuel F, air A, and water (reformed water Wp). It is This electric power is supplied to loads (eg, storage battery, substation equipment, electrical equipment, etc.) not shown.

Hot exhaust Ge is generated as a result of the electrochemical reactions in the fuel cell. This exhaust Ge is sent to the heat exchanger 120, where heat is exchanged between the exhaust Ge and the water W as the fluid (the water W is warmed by the heat received from the exhaust Ge to become hot water Wh). . Specifically, the water W is circulated by the pump 150 through the circulation path 140 between the heat exchanger 120 and the storage container (hot water storage tank) 130, and the water W receives heat from the exhaust Ge in the heat exchanger 120. , is stored in the storage container 130 as hot water Wh. The hot water Wh stored in the storage container 130 in this manner can be supplied to external equipment such as the water heater 300, for example. Further, the exhaust Ge that has undergone heat exchange in the heat exchanger 120 as described above is discharged from the exhaust port 121 .

Further, when the amount of the reformed water Wp stored in the reformed water tank 123 exceeds a predetermined upper limit, it is discharged from the reformed water tank 123 as drain water Wd1. Further, when the internal pressure of the storage container (hot water storage tank) 130 exceeds a predetermined upper limit, the pressure relief valve 131 is opened to discharge surplus hot water Wh as drain water Wd2, thereby lowering the internal pressure of the storage container 130. . Furthermore, for example, when the amount of hot water Wh stored in the storage container 130 exceeds a predetermined upper limit, the drain plug 132 is opened to discharge excess hot water Wh from the storage container 130 .

Furthermore, as a result of heat exchange in the heat exchanger 120, water contained in the exhaust Ge is condensed to produce condensed water Wc. This condensed water Wc is sent to the water purifier 122 to be reformed (refined), stored in the reformed water tank 123 as reformed water Wp, and supplied again to the fuel cell of the power generation unit 110 to undergo the electrochemical reaction. consumed by In this way, a circulation cycle is established in which moisture contained in the exhaust Ge from the fuel cell is recovered and returned to the fuel cell again.

However, if the temperature of the water W supplied from the storage container (hot water storage tank) 130 to the heat exchanger 120 is excessively high, the heat exchanger 120 cannot obtain a sufficient amount of condensed water Wc from the exhaust Ge. Therefore, a cooling means (radiating device) 200 including a radiator 210 and a fan 220 is provided in the portion of the circulation path 140 that supplies the water W from the storage container 130 to the heat exchanger 120 .

On the other hand, for example, when the embodiment system 1001 is not in operation in a cold region or the like, the temperature of the water W supplied from the storage container (hot water storage tank) 130 to the heat exchanger 120 drops too much, causing the water W to freeze. This may lead to problems such as damage to the circulation path 140 . Therefore, when it is determined that the possibility of freezing the water W is high, it is necessary to heat the water W flowing through the circulation path 140 to prevent freezing. In this case, since the embodiment system 1001 is not in operation, AC power is supplied from the commercial power supply to the anti-freezing heater for heating the water W. FIG.

Furthermore, in the same way as a general fuel cell cogeneration system, the system 1001 according to the embodiment, at the start of self-sustaining operation, for example, during a power failure of the commercial power supply, generates a predetermined amount of power that is larger than the power consumption by the assumed load. is configured to generate electricity by Therefore, by heating the fluid with a resistance heater, it is necessary to convert the surplus power, which is the difference between the power generated by the fuel cell and the power consumed by the load, into heat. In this case, a self-supporting heater for converting surplus power into heat is supplied with DC power generated by the fuel cell.

However, if the heater generates excessive heat and, for example, boiling of the water W causes bubbles to adhere to the periphery of the heater, it may lead to problems such as breakage of the heater. In particular, in the case of a ceramic heater, excessive heat generation tends to lead to problems such as cracking of the heater. Therefore, from the viewpoint of reducing such problems, it is necessary to control the temperature of the heater so that the temperature of the heater does not become excessively high, for example, using the temperature of the water W as a guideline.

As described above, in the embodiment system 1001, it is necessary to control the operation of the heating means (heater) and cooling means for the water W as the fluid based on the temperature of the water W. FIG. In such a case, in the conventional fluid heating device (conventional device), as described above, temperature detection means such as a thermocouple is provided separately from the heater in order to detect the temperature of the water W. Therefore, problems such as complication of the configuration and an increase in cost are caused.

However, the embodiment system 1001 includes the above-described embodiment apparatus 104 as heating means for heating the fluid. The flow path 10 provided in the embodiment apparatus 104 is interposed in the circulation path 140 and is configured to communicate with the circulation path 140 . Further, in the embodiment system 1001, among the two heaters 23 and 24 provided in the embodiment apparatus 104, the self-sustaining heater for heating the fluid (water W) and converting the surplus power into heat during self-sustained operation of the system. A heater 23 is used as a heater, and a heater 24 is used as an antifreeze heater for heating the fluid to prevent freezing of the circulation path 140 when the system is not in operation. That is, as shown in FIG. 4B, a heater 23 (thick solid line), which is a self-sustaining heater, is supplied with direct current power (DC), and a heater 24 (thin solid line), which is an anti-freezing heater, is supplied with DC power. is supplied with alternating current power (AC).

As described above, the heater 23, which is a self-supporting heater, is used when the embodiment system 1001 is self-sustaining, and the heater 24, which is an anti-freezing heater, is used when the system 1001 is not in operation. Therefore, these two heaters are not used at the same time, and are used alternatively according to the operating conditions of the system 1001 of the embodiment. Therefore, in the system 1001 of the embodiment, the heater which does not contribute to heating the fluid is selected as the above-described first heater from among the heaters 23 and 24, and the fluid (water W ) can be specified.

In the system 1001 of the embodiment, the electric resistance value of the heater and the fluid Data representing the first relationship, which is the correspondence relationship between the temperature and the temperature, is stored in advance in a data storage device (ROM) included in the control unit 500 . As described above, the first power is a level of power that does not substantially contribute to the heating of the fluid (water W) although the electrical resistance value of the first heater can be measured by the measuring unit.

The first relationship is, for example, for each of the heaters 23 and 24, the electrical resistance values of the heaters when fluids (water W) at various temperatures are caused to flow through the flow path 10 while the first power is being supplied. It can be obtained in advance by recording experiments or the like. FIG. 6 is a schematic graph showing a first relationship, which is a correspondence relationship between the electrical resistance value of the heater and the temperature of the fluid when the first state is established. As shown in FIG. 6, in the resistance heater, the higher the temperature T of the heater, the higher the electrical resistance value R of the heater.

Therefore, based on the electrical resistance value R of the first heater when the first power is being supplied, the temperature T of the first heater at that time can be specified. When the first power is supplied, the first heater does not substantially contribute to heating the fluid (water W). In other words, the temperature T of the first heater at that time corresponds to the temperature of the fluid. In this manner, the control unit 500 can specify the temperature of the fluid based on the electrical resistance value R of the first heater when the first electric power is being supplied.

Note that the control unit 500 constituting the embodiment system 1001 stores in advance a function representing the first relationship as represented by the graph shown in FIG. , the temperature of the fluid is calculated based on the function from the electric resistance value of the first heater when the first electric power is supplied.

Note that the fluid temperature measurement routine executed by the control unit 500 provided in the system 1001 of the embodiment is the fluid temperature measurement routine executed by the control unit provided in the first device 102 described with reference to the flowchart shown in FIG. is similar to

Therefore, although a detailed description of the flow of processing up to the determination of the temperature of the fluid (water W) is omitted, during the self-sustained operation of the embodiment system 1001, the power generated by the power generation unit 110 (fuel cell) is The surplus (surplus electric power) is supplied as the second electric power to the heater 23, which is a self-supporting heater, to heat the fluid, while electric power is not supplied to the heater 24, which is an anti-freezing heater. Therefore, in this case, the heater 24 is used as the above-described first heater (the first electric power is supplied to the heater 24), the electrical resistance value of the heater 24 is measured, and the fluid flow rate is determined based on the electrical resistance value. Temperature can be specified.

On the other hand, when the embodiment system 1001 is not in operation, electric power for preventing freezing of the fluid is supplied as second electric power to the heater 24, which is an anti-freezing heater, to heat the fluid, while the system is not in operation. Therefore, power is not supplied to the heater 23, which is a self-sustaining heater. Therefore, in this case, the heater 23 is used as the above-described first heater (the first electric power is supplied to the heater 23), the electrical resistance value of the heater 23 is measured, and the fluid flow rate is determined based on the electrical resistance value. Temperature can be specified.

In the embodiment system 1001, the heater (and , other heaters, if present, etc.) and/or the cooling means 200 may be controlled to bring the temperature of the fluid within a predetermined range.

<effect>
As described above, the embodiment system 1001 includes, as heating means, an embodiment device capable of specifying the temperature of the fluid based on the electrical resistance value of the resistance heater that does not contribute to heating the fluid. Therefore, according to the embodiment system 1001, it is possible to detect the temperature of the fluid without separately providing a detection means (for example, a temperature sensor, etc.) for detecting the temperature of the fluid. The temperature of the fluid detected in this manner can be used, for example, as an index for various controls executed in the application of the system 1001 of the embodiment. For example, control of heating means (e.g., heaters, etc.) for heating fluid and/or cooling means (e.g., radiators and fans, etc.) for cooling fluid (e.g., switching between operation and non-operation, etc.) The temperature of the fluid can be used as an indicator for the temperature of the fluid to fall within a predetermined range.

By the way, in the above description of the embodiment system 1001, the non-operating time of the system (the period during which the control for preventing freezing of the fluid (anti-freezing control) is being executed) and the self-sustained operation were described. However, the present invention is also applicable to interconnected operation of various cogeneration systems. Specifically, during the interconnected operation of the cogeneration system, the power generated by the power generation unit and the power supplied from the commercial power supply are used together according to the amount of power consumed by the load. Therefore, it is not necessary to supply power to the anti-freezing heater to prevent freezing of the fluid, and basically it is necessary to convert the surplus power (surplus power) generated by the power generation unit into heat by the self-supporting heater. neither.

That is, during the interconnected operation of the cogeneration system, a situation may arise in which the second electric power for heating the fluid is not supplied to either the self-sustaining heater or the anti-freezing heater. Even in such a situation, when the temperature of the fluid rises excessively due to exhaust heat from the power generation unit, it is necessary to operate cooling means (such as radiators and fans) to lower the temperature of the fluid. Temperature should be monitored. Also in this case, at least one of the self-sustaining heater and the anti-freezing heater to which power is not supplied is used as the first heater (the first power is supplied), and the temperature of the fluid is adjusted based on the electrical resistance value thereof. can be detected.

The present invention can also be applied during a period before antifreeze control is started when the cogeneration system is not in operation. Specifically, during this period, the cogeneration system is not in operation, so power generation by the power generation unit is not being performed. Therefore, there is no need to supply surplus power to the self-contained heater and convert it to heat. In addition, the anti-freeze heater has not yet been powered because the anti-freeze control has not yet started. That is, power is not supplied to either the self-supporting heater or the antifreeze heater. However, even during this period, it is necessary to monitor the temperature of the fluid from the viewpoint of avoiding problems such as damage to the circulation path due to freezing of the fluid. Also in this case, at least one of the self-sustaining heater and the anti-freezing heater to which power is not supplied is used as the first heater (the first power is supplied), and the temperature of the fluid is adjusted based on the electrical resistance value thereof. can be detected.

Although several embodiments and examples having specific configurations have been described above for the purpose of illustrating the present invention, sometimes with reference to the accompanying drawings, the scope of the present invention is not limited to these exemplary embodiments. It should not be construed as being limited to the embodiments and examples, and it goes without saying that modifications can be made as appropriate within the scope of the claims and the matters described in the specification.

DESCRIPTION OF SYMBOLS 10... Flow path 11... Tubular member 20, 21, 22, 23, 24... Heater 25... Sheet-like member 30... Temperature detection means 40... Measurement unit 100, 101, 102... Fluid heating device ( 104 Fluid heating device (embodiment of the present invention) 110 Power generation unit 120 Heat exchanger 121 Exhaust port 122 Water purifier 123 Reforming water tank 130 Storage Container 131 Pressure relief valve 132 Drain valve 140 Circulation path 150 Pump 200 Cooling means 210 Radiator 220 Fan 300 Water heater 500 Control unit 900 , 901, 902, 903 Fluid heating device (prior art) 1000 Cogeneration system (present invention) 1001 Cogeneration system (embodiment of the present invention) 9000 Cogeneration system (prior art) W Water, Wh: Hot water, Wc: Condensed water, Wp: Reforming water, F: Fuel, A: Air, and Ge: Exhaust gas.

Claims (4)

a single flow path through which a fluid flows, a plurality of heaters arranged in the flow path and capable of heating the fluid by Joule heat, a control unit for controlling power supply to the plurality of heaters; A fluid heating device comprising:
For each heater among the plurality of heaters, the electric resistance value of the heater can be measured by supplying the heater with a first electric power that is a predetermined electric power for measuring the electric resistance value of the heater. Further comprising a measuring unit configured to
When the control unit measures the temperature of the fluid,
selecting, as the first heater, a heater other than the second heater supplied with the second power, which is the power for heating the fluid, from among the plurality of heaters;
supplying the first electric power to the first heater;
specifying the temperature of the fluid based on a first resistance value R1, which is the electrical resistance value of the first heater measured by the measuring unit;
configured as
a fluid heating device;
a power generation unit;
a storage container for storing the fluid warmed by exhaust heat from the power generation unit;
a circulation path for circulating the fluid between the power generation unit and the storage container;
A cogeneration system comprising
The flow path is interposed in the circulation path so as to communicate with the circulation path,
A self-sustaining heater, which is a heater for heating the fluid with DC power as the second heater during self-sustained operation of the cogeneration system and converting surplus power into heat, and the second heater during non-operation of the cogeneration system. An anti-freeze heater is provided as a heater for heating the fluid with AC power to prevent freezing of the circulation path,
The control unit is configured so that the self-supporting heater and the anti-freezing heater do not simultaneously heat the fluid as the second heater.
cogeneration system. A cogeneration system according to claim 1 ,
The control unit
selecting the anti-freezing heater as the first heater during self-sustained operation of the cogeneration system;
selecting the self-supporting heater as the first heater when the cogeneration system is not in operation;
configured as
cogeneration system. A cogeneration system according to claim 1 or claim 2 ,
The power generation unit includes a fuel cell,
cogeneration system. A cogeneration system according to claim 1 or claim 2 ,
The power generation unit includes a generator and an internal combustion engine that drives the generator,
cogeneration system.

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