JP2010019574A - Fluid supply estimation apparatus and fuel cell system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To simply and accurately estimate a flow rate of a fluid transmitted in all operation modes in a fuel cell system. <P>SOLUTION: The fuel cell system includes: a discharge pressure detecting means for detecting a discharge pressure of the fluid discharged from a fluid transmitting apparatus; a drive quantity detecting means for detecting the drive quantity of the fluid transmitting apparatus; and an estimated transmission quantity deriving means for storing a flow rate estimation map M representing a relationship among the discharge pressure of the fluid discharged from the fluid transmitting apparatus, the drive quantity of the fluid transmitting apparatus and a discharge flow rate of the fluid discharged from the fluid transmitting apparatus in response to the discharge pressure and the drive quantity in a storage section, and obtaining an estimated transmission flow rate estflux1 of the fluid discharged from the fluid transmitting apparatus based on the discharge flow rate of the fluid obtained from the flow rate estimation map M in response to the detected drive quantity and the detected discharge pressure. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

The present invention relates to flow measurement of a fuel cell system.

Conventionally, what is shown by patent document 1 as a fuel cell system is known. As shown in FIG. 3, the fuel cell system of Patent Document 1 is capable of accurately measuring the flow rate of the fluid to be delivered without providing a large and expensive flow meter in the control device for fluid delivery. Temperature detection means (temperature sensor) for detecting the temperature around the fluid for flow rate measurement, pressure detection means (pressure sensor) for detecting the pressure of the fluid, and drive for detecting the drive amount of the pump for delivering the fluid An amount detection means (rotation speed sensor) is provided, and the detected ambient temperature, discharge pressure, and drive amount are input to the flow rate estimation logic unit 32, and the flow rate stored in advance using the ambient temperature, discharge pressure, and drive amount as variables. The flow rate is calculated by the calculation formula so that the flow rate value can be estimated with high accuracy. At this time, the flow rate calculation formula of the flow rate estimation logic unit 32 is prepared in two types for the warm-up mode and the power generation mode in consideration of the difference in passage resistance in order to obtain the flow rate value with higher accuracy. Switching between types of flow rate calculation formulas is performed based on the measured values of the temperature detection means (temperature sensors) provided in the fuel cell stack and the reformed gas flow path, respectively.
Japanese Patent Laid-Open No. 2008-4414

  In the fuel cell system described in Patent Document 1 described above, two types of flow rate calculation formulas are switched depending on the operation mode of the fuel cell system, and the detection results detected by the temperature detection means, the pressure detection means, and the drive amount detection means are selected. By inputting into the calculated flow rate calculation formula, the flow rate can be calculated with high accuracy. However, if any one of the temperature detection means provided in the fuel cell stack and reformed gas flow path used for determining the operation mode fails, the operation mode cannot be determined and an appropriate flow rate calculation is performed. Since it becomes difficult to select an expression, there is a possibility that the flow rate cannot be calculated with high accuracy.

  The present invention has been made to solve the above-described problems, and in the fuel cell system, even without each temperature detection means provided in each of the fuel cell stack for operation mode determination and the reformed gas flow path, The purpose is to accurately estimate the flow rate of the fluid to be delivered in all operation modes of the fuel cell system.

  In order to solve the above problem, the structural feature of the invention according to claim 1 is supplied to the apparatus from a fluid delivery apparatus connected to an apparatus in which the flow path resistance of the fluid is changed according to the operating state. In the fluid supply amount estimation device for estimating the flow rate of the fluid, discharge pressure detection means for detecting a discharge pressure of the fluid discharged from the fluid delivery device, and drive amount detection means for detecting the drive amount of the fluid delivery device; The relationship between the discharge pressure of the fluid discharged from the fluid delivery device, the drive amount of the fluid delivery device, and the discharge flow rate of the fluid discharged from the fluid delivery device according to the discharge pressure and the drive amount A flow rate estimation map is stored in the storage unit and discharged from the fluid delivery device based on the fluid discharge flow rate obtained from the flow rate estimation map in accordance with the detected drive amount and the detected discharge pressure. And estimated transmission amount deriving means for obtaining an estimated delivery rate of fluid, is that with the.

  According to a second aspect of the present invention, there is provided a structural feature of the invention according to the first aspect, further comprising discharge temperature detection means for detecting a discharge temperature of the fluid discharged from the fluid delivery device, wherein the estimated delivery amount deriving means is the flow rate. The fluid discharge flow rate obtained from the estimated map is corrected by the detected discharge temperature to obtain the estimated delivery flow rate of the fluid discharged from the fluid delivery device.

  A structural feature of the invention according to claim 3 is that a fluid that estimates the flow rate of the fluid supplied to the device from a fluid delivery device connected to the device in which the flow path resistance of the fluid is changed according to the operating state. In the supply amount estimation device, the discharge pressure detection means for detecting the discharge pressure of the fluid discharged from the fluid delivery device, the drive amount detection means for detecting the drive amount of the fluid delivery device, and a change according to the operating state A limit pressure loss map representing the relationship between the limit discharge pressure of the fluid discharged from the fluid delivery device and the drive amount of the fluid delivery device when the pressure loss value due to the flow path resistance of the fluid is a limit value. And storing a limit discharge pressure corresponding to the detected drive amount from the limit pressure loss map, and sending a consumable replacement signal when the detected discharge pressure exceeds the limit discharge pressure.

  The constitutional feature of the invention according to claim 4 is that a fuel cell for generating electricity with fuel gas and oxidant gas respectively supplied to the fuel electrode and the oxidant electrode, a reforming fuel and reforming water are supplied, A reformer that generates the fuel gas containing hydrogen by reforming the supplied reforming fuel, and is supplied from the fluid delivery device according to warm-up operation and steady operation In the fuel cell system in which the flow path resistance of the fluid to be changed is changed, the discharge pressure detecting means for detecting the discharge pressure of the fluid discharged from the fluid delivery device, and the drive amount detection for detecting the drive amount of the fluid delivery device Means, a discharge pressure of the fluid discharged from the fluid delivery device, a drive amount of the fluid delivery device, and a discharge flow rate of the fluid discharged from the fluid delivery device according to the discharge pressure and the drive amount Is stored in the storage unit, and the fluid delivery device is based on the discharge flow rate of the fluid obtained from the flow rate estimation map in accordance with the detected drive amount and the detected discharge pressure. And an estimated delivery amount deriving unit for obtaining an estimated delivery flow rate of the fluid discharged from the fluid.

  According to a fifth aspect of the present invention, there is provided a structural feature of the invention according to the fourth aspect, further comprising discharge temperature detection means for detecting a discharge temperature of the fluid discharged from the fluid delivery device, wherein the estimated delivery amount deriving means is the flow rate. The fluid discharge flow rate obtained from the estimated map is corrected by the detected discharge temperature to obtain the estimated delivery flow rate of the fluid discharged from the fluid delivery device.

  The structural feature of the invention according to claim 6 is that the discharge flow rate obtained from the flow rate estimation map in claim 5, the discharge temperature detected by the discharge temperature detection means, and creation of the flow rate estimation map The temperature correction function that is configured with the environmental temperature A at the time as a variable and calculates the estimated delivery flow rate after the temperature correction is expressed by the following equation (1).

(Equation 1)

  The structural feature of the invention according to claim 7 is that a fuel cell for generating electricity by using fuel gas and oxidant gas respectively supplied to the fuel electrode and the oxidant electrode, a reforming fuel and reforming water are supplied, A reformer that generates the fuel gas containing hydrogen by reforming the supplied reforming fuel, and is supplied from the fluid delivery device according to warm-up operation and steady operation In the fuel cell system in which the flow path resistance of the fluid to be changed is changed, the discharge pressure detecting means for detecting the discharge pressure of the fluid discharged from the fluid delivery device, and the drive amount detection for detecting the drive amount of the fluid delivery device And the limit discharge of the fluid discharged from the fluid delivery device when the pressure loss value due to the flow path resistance of the fluid changed according to the warm-up operation state and the steady operation state becomes a limit value A limit pressure loss map representing the relationship between the force and the drive amount of the fluid delivery device is stored in the storage unit, a limit discharge pressure corresponding to the detected drive amount is obtained from the limit pressure loss map, and the detected discharge When the pressure exceeds the limit discharge pressure, a consumable replacement signal is sent.

  In the invention according to claim 1 configured as described above, the estimation of the discharge flow rate delivered by the fluid delivery device is based on the discharge pressure of the fluid delivery device, the drive amount of the fluid delivery device, and the measurement unit previously measured. It is accurately derived based on the stored flow rate estimation map representing the relationship between the discharge pressure of the fluid delivery device and the drive amount. As a result, it is not necessary to provide an expensive and large flow meter, cost can be reduced, and space can be saved.

  In the invention according to claim 2 configured as described above, in claim 1, it is provided with discharge temperature detecting means for detecting the discharge temperature of the fluid discharged from the fluid delivery device, and the estimated delivery amount deriving means is flow rate estimation. The fluid discharge flow rate obtained from the map is corrected by the detected discharge temperature, and the estimated delivery flow rate of the fluid discharged from the fluid delivery device is obtained. Thereby, in addition to the effect in claim 1, the estimated flow rate is derived with higher accuracy.

  In the invention according to claim 3 configured as described above, the limit discharge pressure of the fluid discharged from the fluid delivery device when the pressure loss value due to the flow path resistance of the fluid changed according to the operation state becomes the limit value A limit pressure loss map representing the relationship between the drive amount of the fluid delivery device and the fluid delivery device is stored in the storage unit, a limit discharge pressure corresponding to the detected drive amount is obtained from the limit pressure loss map, and the detected discharge pressure indicates the limit discharge pressure. If it exceeds, a consumable replacement signal is sent out. This saves time because the driver does not need to carry out an overhaul to check for deterioration. Further, since the driver can visually confirm the deterioration, the possibility of continuing to drive while the route is deteriorated is reduced, and the driving can be performed with high reliability and efficiency.

  In the invention according to claim 4 configured as described above, in the fuel cell system, the discharge pressure detecting means for detecting the discharge pressure of the fluid discharged from the fluid delivery device, and the drive for detecting the drive amount of the fluid delivery device Relationship between the amount detection means, the discharge pressure of the fluid discharged from the fluid delivery device, the drive amount of the fluid delivery device, and the discharge pressure and the discharge flow rate of the fluid discharged from the fluid delivery device according to the drive amount Is stored in the storage unit, and the flow rate of the fluid discharged from the fluid delivery device is determined based on the flow rate of the fluid obtained from the flow rate estimation map according to the detected drive amount and the detected discharge pressure. And an estimated delivery amount deriving unit for obtaining an estimated delivery flow rate. As a result, it is not necessary to provide an expensive and large flow meter, cost can be reduced, and space can be saved. In addition, the flow rate calculation formula prepared for each operating state required in the prior art to accurately estimate the discharge flow rate regardless of the operating state (operating mode) by using the flow rate estimation map There is no need to select. Therefore, the temperature detection means (sensor) for the stack and the reformed fuel used for selecting the corresponding flow rate calculation formula becomes unnecessary, and the reliability is improved. Further, since each temperature detecting means for determining the operation mode is not used, the memory capacity for storing data can be reduced, and the cost can be reduced.

  In the invention according to claim 5 configured as described above, in claim 4, there is provided discharge temperature detection means for detecting the discharge temperature of the fluid discharged from the fluid delivery device, and the estimated delivery amount deriving means is flow rate estimation. The fluid discharge flow rate obtained from the map is corrected by the detected discharge temperature to obtain the estimated delivery flow rate of the fluid discharged from the fluid delivery device. Therefore, the discharge flow rate can be estimated more accurately regardless of the operation state (operation mode), and there is no need to select a flow rate calculation formula prepared for each operation state, which was necessary in the prior art. Therefore, the temperature detecting means (sensors) for the stack and the reformed fuel that have been used for selecting the flow rate calculation formula corresponding to each operation mode are not required, and the reliability is improved. Further, since each temperature detection means for determining the operation mode is not used, the memory capacity for storing data can be reduced, and thus the cost can be reduced.

  In the invention according to Claim 6 configured as described above, in Claim 5, the discharge flow rate obtained from the flow rate estimation map, the discharge temperature detected by the discharge temperature detecting means, and the environmental temperature at the time of creating the flow rate estimation map A temperature correction function that is configured with A as a variable and calculates the estimated delivery flow rate is expressed by the following equation (1). It has been confirmed that the temperature correction can be accurately converted by the equation (1). This makes it possible to perform the temperature correction with high accuracy in a short time and to reduce the control load.

(Equation 1)

  In the invention according to claim 7 configured as described above, in the fuel cell system, the fluid when the pressure loss value due to the flow path resistance of the fluid changed according to the warm-up operation state and the steady operation state becomes a limit value A limit pressure loss map representing the relationship between the limit discharge pressure of the fluid discharged from the delivery device and the drive amount of the fluid delivery device is stored in the storage unit, and the limit discharge pressure corresponding to the detected drive amount is obtained from the limit pressure loss map. When the detected discharge pressure exceeds the limit discharge pressure, a consumable replacement signal is sent out. This saves time because the driver does not need to carry out an overhaul to check for deterioration. Further, since the driver can visually confirm the deterioration, the possibility of continuing to drive while the route is deteriorated is reduced, and the driving can be performed with high reliability and efficiency.

  Hereinafter, a first embodiment of a fuel cell system according to the present invention will be described. FIG. 1 is a schematic diagram showing an outline of this fuel cell system. The fuel cell system includes a fuel cell 10 and a reformer 20 that generates a reformed gas that is a fuel gas containing hydrogen gas necessary for the fuel cell 10.

  The fuel cell 10 includes a fuel electrode 11, an air electrode 12 that is an oxidant electrode, and an electrolyte 13 interposed between the electrodes 11 and 12, and supplies the reformed gas supplied to the fuel electrode 11 and the air electrode 12. Electric power is generated using air (cathode air), which is the oxidant gas. In addition, you may make it supply oxidant gas the gas which enriched oxygen of air instead of air.

  The reformer 20 steam reforms the reforming fuel and supplies a hydrogen-rich reformed gas to the fuel cell 10. The reformer 20 includes a reforming unit 21, a cooling unit 22, a carbon monoxide shift reaction unit (hereinafter referred to as a “carbon monoxide shift reaction unit”). , A CO shift unit) 23, a carbon monoxide selective oxidation reaction unit (hereinafter referred to as a CO selective oxidation unit) 24, a combustion unit 25, and an evaporation unit 26. The reforming fuel includes natural gas, LPG, and the like. In this embodiment, natural gas will be described.

  The reforming unit 21 generates and derives a reformed gas from a mixed gas that is a reforming raw material in which steam is mixed with the reforming fuel. The reforming portion 21 is formed in a bottomed cylindrical shape, and includes an annular folded channel 21a extending along the axis in the annular cylindrical portion.

  The return channel 21a of the reforming unit 21 is filled with a catalyst 21b (for example, a Ru or Ni-based catalyst). The catalyst 21b is pressed by the mesh members 15 and 16 which are consumables provided at the bottom of the folded flow path 21a, so that it does not fall downward. Then, a mixed gas of the reforming fuel introduced from the cooling unit 22 via the mesh member 15 and the steam introduced from the steam supply pipe 51 reacts and is reformed by the catalyst 21b, so that hydrogen gas and carbon monoxide gas are converted. (So-called steam reforming reaction). At the same time, a so-called carbon monoxide shift reaction occurs in which carbon monoxide generated in the steam reforming reaction reacts with steam to transform into hydrogen gas and carbon dioxide. These generated gases (so-called reformed gas) are led out to the cooling unit (heat exchange unit) 22 through the net member 16.

  The cooling unit 22 is a heat exchanger (heat exchange unit) in which heat exchange is performed between the reformed gas derived from the reforming unit 21 and a mixed gas of reforming fuel and reformed water (steam). The temperature of the reformed gas having a high temperature is lowered by the mixed gas having a low temperature and led to the CO shift unit 23, and the temperature of the mixed gas is raised by the reformed gas and led to the reforming unit 21. Yes.

  A fuel supply pipe 41 connected to a fuel supply source Sf (for example, a city gas pipe) is connected to the cooling unit 22. The fuel supply pipe 41 is provided with a first fuel valve 42, a reforming fuel pump 43, and a second fuel valve 45 in order from the upstream. The first and second fuel valves 42 and 45 open and close the fuel supply pipe 41 according to commands from the control device 30.

  The reforming fuel pump 43 supplies reforming fuel to the reforming unit 21 in accordance with an instruction from the control device 30 and adjusts the supply amount. The reforming fuel pump 43 includes a rotation speed sensor 43a that is a drive amount detection means for detecting the rotation speed (drive amount) of the pump. A detection signal detected by the rotation speed sensor 43 a is output to the control device 30. The discharge port of the reforming fuel pump 43 is provided with a pressure sensor 43b as discharge pressure detection means and a temperature sensor 43c as discharge temperature detection means. The pressure sensor 43 b is discharge pressure detection means for detecting the pressure of the fluid on the outlet side of the reforming fuel pump 43, and outputs a detection signal to the control device 30. The temperature sensor 43 c (for example, a thermocouple) is discharge temperature detection means for detecting the temperature of the fluid on the outlet side of the reforming fuel pump 43, and outputs a detection signal to the control device 30. These sensors 43a, 43b, 43c are provided integrally with the reforming fuel pump 43.

  The rotation speed sensor 43a uses a magnetic rotary encoder and converts the rotation speed into a voltage and outputs it as a waveform having a predetermined shape. A DC tachometer generator that attaches a DC generator to the rotating shaft and measures the rotational speed from the generated voltage, and a resolver that measures the rotational speed from a sinusoidal voltage generated by using two sets of coils and an iron core. Can also be used.

  The pressure sensor 43b receives pressure by the diaphragm, converts the distortion of the diaphragm into a voltage, and outputs the voltage. The material is a semiconductor (Si), and is detected from a change in capacitance to detect strain. A resistance wire type using an alloy of Ni or Cu can also be used.

  Further, a steam supply pipe 51 connected to the evaporation section 26 is connected between the second fuel valve 45 of the fuel supply pipe 41 and the cooling section 22. The steam supplied from the evaporation unit 26 is mixed with the reforming fuel, and the mixed gas is supplied to the reforming unit 21 through the cooling unit 22.

  The CO shift unit 23 is a carbon monoxide reduction unit that reduces carbon monoxide in the reformed gas (fuel gas) supplied from the reforming unit 21 through the cooling unit 22. Carbon monoxide contained in the supplied reformed gas reacts with water vapor by a catalyst 23a (for example, a Cu—Zn-based catalyst) filled in the CO shift unit 23 to be converted into hydrogen gas and carbon dioxide gas. A so-called carbon monoxide shift reaction occurs. As a result, the reformed gas is derived with a reduced carbon monoxide concentration.

  The CO selective oxidation unit 24 is a carbon monoxide reduction unit that further reduces the carbon monoxide in the reformed gas supplied from the CO shift unit 23 and supplies it to the fuel cell 10. The CO selective oxidation unit 24 is formed in a cylindrical shape, and is provided so as to cover the outer peripheral wall of the evaporation unit 26. The CO selective oxidation unit 24 is filled with a catalyst 24a (for example, a Ru or Pt catalyst).

  A connecting pipe 93 connected to the CO shift unit 23 and a reformed gas supply pipe 71 connected to the fuel electrode 11 of the fuel cell 10 are connected to the lower side wall surface and the upper side wall surface of the CO selective oxidation unit 24, respectively. ing. An oxidation air supply pipe 61 that supplies oxidation air is connected to the connection pipe 93. As a result, the reformed gas and the oxidizing air from the CO shift unit 23 are introduced into the CO selective oxidation unit 24. The oxidation air supply pipe 61 is provided with an oxidation air blower 63 and an oxidation air valve 64 in order from the upstream. The oxidizing air blower 63 supplies oxidizing air and adjusts the supply amount. The oxidation air valve 64 opens and closes the oxidation air supply pipe 61. Therefore, carbon monoxide in the reformed gas introduced into the CO selective oxidation unit 24 reacts (oxidizes) with oxygen in the oxidizing air to become carbon dioxide. Thereby, the reformed gas is derived by further reducing the carbon monoxide concentration (10 ppm or less) by the oxidation reaction, and is supplied to the fuel electrode 11 of the fuel cell 10.

  In the CO selective oxidation unit 24, a temperature sensor 24b for detecting the temperature of the catalyst 24a is provided. The detection signal of the temperature sensor 24 b is output to the control device 30.

  The combustion unit 25 burns combustible gas such as combustion fuel, reformed gas and anode off-gas with combustion oxidant gas, heats the reforming unit 21 with the combustion gas, and generates heat necessary for the steam reforming reaction. The lower end portion is inserted into the inner peripheral wall of the reforming portion 21 and arranged with a space.

  A combustion fuel supply pipe 47 branched from the fuel supply pipe 41 upstream of the reforming fuel pump 43 is connected to the combustion section 25, and one end is connected to the outlet of the fuel electrode 11. The other end of the pipe 72 is connected. At the start of the fuel cell 10 (warm-up operation state), combustion fuel is supplied to the combustion unit 25, and during the warm-up operation of the fuel cell 10 (warm-up operation state), the reformed gas from the CO selective oxidation unit 24 is The anode off-gas that is supplied to the combustion unit 25 without going through the fuel cell 10 and is discharged from the fuel cell 10 during the power generation operation (steady operation state) of the fuel cell 10 Quality gas) is supplied to the combustion section 25. In addition, the shortage of reformed gas and off-gas is supplemented with combustion fuel.

  The combustion unit 25 is connected to a combustion air supply pipe 65 for supplying combustion air, and combusts (oxidizes) the combustion fuel, combustible gas such as anode off-gas and reformed gas, and combustible gas. For this purpose, an oxidant gas such as combustion air is supplied.

  The combustion fuel supply pipe 47 is provided with a combustion fuel pump 48. The combustion fuel pump 48 supplies combustion fuel and adjusts the supply amount. Further, the combustion air supply pipe 65 is provided with a filter 17 and a combustion air blower 66 which are consumables for preventing dust in the air from entering in order from the upstream.

  The combustion air blower 66 supplies combustion air and adjusts the supply amount. The combustion air blower 66 includes a rotation speed sensor 66a that is a drive amount detection means for detecting the rotation speed (drive amount) of the blower. A detection signal detected by the rotation speed sensor 66 a is output to the control device 30. A pressure sensor 66 b and a temperature sensor 66 c are provided at the discharge port of the combustion air blower 66. The pressure sensor 66 b is discharge pressure detection means for detecting the pressure of the fluid (air) on the outlet side of the combustion air blower 66, and the detection signal is output to the control device 30.

  The temperature sensor 66 c is discharge temperature detection means for detecting the temperature of the fluid (air) on the outlet side of the combustion air blower 66, and the detection signal is output to the control device 30.

  When the above-described combustion section 25 is ignited, the supplied combustion fuel, reformed gas or anode off-gas is combusted by the combustion air to generate high-temperature combustion gas. The combustion gas flows through the combustion gas passage 27 and is exhausted as combustion exhaust gas through the exhaust pipe 91. As a result, the combustion gas heats the reforming unit 21 and the evaporation unit 26. The combustion gas flow path 27 is disposed in contact with the inner peripheral wall of the reforming section 21 and is folded and disposed between the outer peripheral wall of the reforming section 21 and the heat insulating section 28 and folded. In other words, the flow path is disposed in contact between the heat insulating portion 28 and the evaporation portion 26.

  The evaporation unit 26 heats and boiles the reformed water to generate water vapor, and supplies the steam to the reforming unit 21 via the cooling unit 22. The evaporation part 26 is formed in a cylindrical shape and is provided so as to cover the outer peripheral wall of the outermost channel of the combustion gas channel 27.

  A water supply pipe 52 connected to the reforming water tank Sw is connected to the lower part (for example, the lower part of the side wall surface and the bottom surface) of the evaporation unit 26. A water vapor supply pipe 51 is connected to the upper part (for example, the upper part of the side wall surface) of the evaporation unit 26. The reformed water introduced from the reformed water tank Sw is heated by the heat from the combustion gas and the heat from the CO selective oxidation unit 24 in the course of flowing through the evaporation unit 26 to become water vapor and the steam supply pipe 51 and the cooling unit 22 are led out to the reforming unit 22. The water supply pipe 52 is provided with a reforming water pump 53 and a reforming water valve 54 in order from the upstream. The reforming water pump 53 supplies reforming water to the evaporation unit 26 and adjusts the reforming water supply amount. The reforming water valve 54 opens and closes the water supply pipe 52.

  A CO selective oxidation unit 24 is connected to the inlet of the fuel electrode 11 of the fuel cell 10 via a reformed gas supply pipe 71, and the combustion unit 25 is connected to the outlet of the fuel electrode 11 via an offgas supply pipe 72. Is connected. The bypass pipe 73 bypasses the fuel cell 10 and directly connects the reformed gas supply pipe 71 and the offgas supply pipe 72. The reformed gas supply pipe 71 is provided with a first reformed gas valve 74 between the branch point of the bypass pipe 73 and the fuel cell 10. The off gas supply pipe 72 is provided with an off gas valve 75 between the junction with the bypass pipe 73 and the fuel cell 10. A second reformed gas valve 76 is provided in the bypass pipe 73.

  Further, a cathode air supply pipe 67 that supplies cathode air is connected to the inlet of the air electrode 12 of the fuel cell 10, and an exhaust pipe 92 is connected to the outlet of the air electrode 12, so that off-gas is supplied. Will be exhausted. The cathode air supply pipe 67 is provided with a cathode air blower 68 and a cathode air valve 69 in order from the upstream.

  The cathode air blower 68 supplies cathode air and adjusts the supply amount. The cathode air valve 69 opens and closes the cathode air supply pipe 67.

  The reforming fuel pump 43, the combustion fuel pump 48, the oxidizing air blower 63, and the combustion air blower 66 described above are fluid delivery devices that send fuel and air as fluid to the reformer 20. The reforming water pump 53 is a fluid delivery device that delivers a fluid that is water to the evaporation unit 26. Further, the cathode air blower 68 is a fluid delivery device that delivers a fluid, which is air, to the fuel cell 10.

  The fuel cell system includes a control device 30, and the control device 30 includes a microcomputer (not shown). The microcomputer includes an input / output interface, a CPU, a RAM, and a ROM (all of which are connected via a bus). (Not shown). The CPU, based on the input signals from the temperature sensors 24b, 43c, 66c, the rotational speed sensors 43a, 66a, and the pressure sensors 43b, 66b, each pump 43, 48, 53 and each blower 63, 66, 68. The valves 42, 45, 54, 64, 69, 74, 75, 76 and the combustion unit 25 are controlled. Thus, the fuel for reforming is performed so that the warm-up operation (warm-up mode) and the power generation operation (power-generation mode) of the fuel cell system are performed and the desired output current (current / power consumed by the load device) is obtained. Each supply amount of combustion fuel, combustion air, reforming water and cathode air is controlled. The RAM temporarily stores variables necessary for executing the program. The ROM stores the program.

  The control device 30 controls, for example, the flow rate (delivery amount) of the fluid of the reforming fuel pump 43 that is a fluid delivery device, or estimates the flow rate (delivery amount) delivered from the reforming fuel pump 43. Yes, as shown in FIG. 3, a control logic unit 31 and a flow rate estimation logic unit 32 which is a fluid supply amount estimation device are provided.

  The control logic unit 31 operates the operation amount deriving means for calculating the duty ratio duty of the motor 43d of the reforming fuel pump 43 based on the set flow rate rflux, and outputs the calculation result to the driver circuit 43e of the motor 43d to drive the motor 43d. Control means for controlling the amount (number of rotations).

  The control logic unit 31 derives the operation amount by the operation amount deriving unit based on the difference between the estimated delivery flow rate estflux2 that is the estimated flow rate estimated by the flow rate estimation logic unit 32 and the set flow rate rflux that is the target flow rate. The driving amount (rotation speed) of the motor 43d of the reforming fuel pump 43 is feedback-controlled by the control means that receives the duty ratio duty that is the derived operation amount. The motor 43d is PWM-controlled with a duty ratio based on the calculation result (the pulse size is constant and the pulse width is controlled according to the duty ratio). The set flow rate rflux is derived based on the current / power consumed by the load device installed at the power supply destination of the fuel cell system and the fuel supply map stored in advance. The fuel supply map shows a correlation between current / power consumed by the load device and supply amounts (supply instruction values) of reforming fuel, combustion fuel, combustion air, reforming water, and cathode air. Is.

  As shown in FIG. 4, the flow rate estimation logic unit 32 includes two estimated transmission amount derivation means. The first estimated delivery amount deriving means calculates the rotation speed rpm of the reforming fuel pump 43 detected by the rotation speed sensor 43a and the discharge pressure press of the reforming fuel pump 43 detected by the discharge pressure sensor 43b. The estimated delivery flow rate estflux1 is derived from the flow rate estimation map M stored in the ROM.

  The flow rate estimation map M is detected by the rotation speed rpm detected by the rotation speed sensor 43a that is the drive amount detection means of the reforming fuel pump 43 and by the pressure sensor 43b that is the discharge pressure detection means of the reforming fuel pump 43. This represents the correlation between the discharge pressure pressed and the flow rate value measured by a flow meter provided for the experiment, and is measured in advance and stored in the storage unit 30a.

  In addition, the flow rate estimation map M is measured corresponding to each other at predetermined intervals in the entire operation mode region of the fuel cell system, and a portion that is not measured is a predetermined value of a quadratic function or more based on the measured data. The data is interpolated by the polynomial.

  The second estimated delivery amount derivation means includes an estimated delivery flow rate estflux1 that is the discharge flow rate derived by the first estimated delivery amount derivation means, and a reforming fuel pump 43 that is detected by the temperature sensor 43c that is a discharge temperature detection means. The estimated delivery flow rate estflux2 is derived from the temperature correction function shown in the following (Equation 1) configured with the discharge temperature temp of the fluid and the environmental temperature A when the flow rate estimation map M is created as variables. The estimated delivery flow rate estflux2 is output to the control logic unit 31. The environmental temperature A when the flow rate estimation map M is created is for correcting the temperature of the flow rate estimation map M, and is 20 ° C. in the present embodiment. As a result of the inventor's verification, it has been confirmed that the equation (1) can accurately derive the estimated delivery flow rate by correcting the temperature.

(Equation 1)

  Next, the operation of the above-described fuel cell system will be described. When a start switch (not shown) is turned on at time t0, control device 30 starts the warm-up operation of the fuel cell system. That is, the fuel cell system enters a warm-up operation state. The control device 30 closes the first reformed gas valve 74 and the off-gas valve 75, opens the second reformed gas valve 76, connects the CO selective oxidation unit 24 to the combustion unit 25, opens the first fuel valve 42, and opens the second fuel valve. 45 is closed and the combustion fuel pump 48 and the combustion air blower 66 are driven to supply combustion fuel and combustion air to the combustion unit 25 to ignite the combustion unit 25. Thereby, the fuel for combustion is combusted, and the reforming part 21 and the evaporation part 26 are heated by the combustion gas.

  When the temperature reaches a temperature sufficient for the evaporation unit 26 to generate water vapor, the control device 30 opens the water valve 54 and drives the reforming water pump 53 to supply water in the water tank Sw by a predetermined flow rate (predetermined supply amount). Supply to the reforming unit 21 is started via the evaporation unit 26. Thereafter, the control device 30 opens the second fuel valve 45 to drive the reforming fuel pump 43 to supply the fuel from the fuel supply source Sf to the reforming unit 21 by a predetermined flow rate (predetermined supply amount) and The air valve 64 is opened to drive the oxidizing air blower 63 to supply the oxidizing air to the CO selective oxidation unit 24 by a predetermined flow rate (predetermined supply amount). Thus, the reformed fuel and steam mixed gas are supplied to the reforming unit 21, and the reforming unit 21 generates the reformed gas by causing the steam reforming reaction and the carbon monoxide shift reaction described above. The reformed gas derived from the reforming unit 21 is derived from the CO selective oxidizing unit 24 after the carbon monoxide gas is reduced by the CO shift unit 23 and the CO selective oxidizing unit 24, supplied to the combustion unit 25 and burned. The

  During the generation of the reformed gas, the control device 30 detects the temperature of the catalyst 24a of the CO selective oxidation unit 24 by the temperature sensor 24b, and if the detected temperature is equal to or higher than a predetermined temperature, As a result, the first reformed gas valve 74 and the offgas valve 75 are opened, the second reformed gas valve 76 is closed, and the CO selective oxidizer 24 is connected to the fuel electrode 11 of the fuel cell 10. And the outlet of the fuel electrode 11 is connected to the combustion section 25. Thereby, after the warm-up operation state for warming up the fuel cell system is completed, the flow path is changed and the steady operation state is started. That is, the fuel cell system enters the power generation mode.

  In the power generation mode, the control device 30 performs reforming fuel, combustion fuel, combustion air, oxidation air, cathode air, and a desired output current (current / power consumed by the load device). The reformed water is supplied. The control device 30 calculates the supply amount of the reforming fuel so as to obtain a desired output current, outputs it as a set flow rate, drives the reforming fuel pump 43 so as to obtain the supply amount, and performs the calculated reforming. Based on the set fuel flow rate and S / C (steam carbon ratio), the supply amount of reforming water is calculated and output as the set flow rate, and the reforming water pump 53 is driven so as to obtain the supply amount.

  Further, the control device 30 determines the supply amount of the fuel for combustion supplied to the combustion unit 25 when the thermal energy necessary for the combustion unit 25 is insufficient by the combustion heat of the anode off gas, or when the start-up operation is being performed. Calculate and output as a set flow rate, drive the combustion fuel pump 48 so as to achieve the supply amount, calculate the supply amount of combustion air based on the reforming fuel supply amount, etc., and output it as the set flow rate, The combustion air blower 66 is driven so as to obtain a supply amount.

  In addition, the control device 30 calculates the supply amount of the oxidation air so that the carbon monoxide is less than or equal to a predetermined amount, outputs it as a set flow rate, and drives the oxidation air blower 63 so as to achieve the supply amount. . Then, the control device 30 calculates a supply amount of cathode air sufficient to react with the reformed gas supplied from the reformer 20, outputs it as a set flow rate, and supplies the cathode air blower so as to obtain the supply amount. 68 is driven. When the stop switch is pushed, the fuel cell system performs a stop operation and stops.

  Next, calculation of the estimated delivery flow rate estflux2 of the reforming fuel pump 43 and feedback control of the reforming fuel pump 43 based on the calculated estimated delivery flow rate estflux2 will be described with reference to the flowchart 1 shown in FIG. Note that the flowchart 1 is applied to an operation state in which the flow path resistance of the fluid delivered by the fluid delivery device is different, that is, both a warm-up operation state and a power generation operation state.

  When the start switch (not shown) is turned on and the warm-up operation is started, the control device 30 drives the reforming fuel pump 43 and supplies the fuel from the fuel supply source Sf to the reforming unit 21 by a predetermined flow rate (predetermined supply amount). The execution of the program corresponding to the flow chart 1 shown in FIG. 6 is started (step S10).

  Thereafter, the control device 30 detects the rotation speed rpm detected by the rotation speed sensor 43a of the reforming fuel pump 43, the discharge pressure press detected by the pressure sensor 43b of the reforming fuel pump 43, and the temperature sensor 43c. The discharge temperature temp of the reforming fuel pump 43 is received (step S11).

  The control device 30 reads and derives the estimated delivery flow rate estflux1 by the estimated delivery amount deriving means M (rpm, press) from the received rotation speed rpm, the discharge pressure press, and the flow rate estimation map M previously stored in the ROM. (Step S12).

  Next, the control device 30 calculates the estimated delivery flow rate estflux1 derived, the received discharge temperature temp, and the ambient temperature A (20 ° C. in the present embodiment) when the flow rate estimation map M is created. It inputs into the temperature correction function (Formula 1) which is a derivation means, and presumes sending flow rate estflux2 (Step S13).

  As a precaution, in step S14, it is confirmed from the data up to step S13 whether or not the reforming fuel pump 43 has been operated based on the magnitude of the number of revolutions of the reforming fuel pump 43. It is confirmed whether or not the rotational speed rpm is greater than 0. If the rotational speed rpm is greater than 0, it is assumed that the reforming fuel pump 43 has not been operated, and the estimated delivery flow rate estflux2 is set to 0. Assuming that the fuel pump 43 is operating normally, the value derived in step S13 is set as the estimated delivery flow rate estflux2.

  Next, the control device 30 receives the set flow rate rflux of the reforming fuel pump 43 in order to perform feedback control (step S15), and the set flow rate rflux and the estimated delivery flow rate estflux2 derived in step S13. Calculate the difference. Then, the control device 30 calculates the duty ratio duty of the motor 43d, which is the operation amount following the set flow rate rflux, by the operation amount deriving unit from the difference between the calculated set flow rate rflux and the estimated delivery flow rate estflux2 (step S16). ).

  Then, the control device 30 outputs the duty ratio duty of the motor 43d of the reforming fuel pump 43 calculated by the control means in step S16 to the driver circuit 43e of the motor 43d to drive the reforming fuel pump 43. (Step S17), and then the program ends (Step S18). This program is operated with the same contents even in the power generation operation state.

  The flow rate of the reforming fuel pump 43 estimated in this way is verified. FIG. 5 shows an actual flow rate measured using a mass flow meter provided for verification in the warm-up operation state and the power generation operation state of the reforming fuel pump 43 according to the present embodiment, and the reforming fuel pump 43. The comparison with the estimated delivery flow rate estflux2 estimated by the flow rate estimation logic 32 using the detected values of the rotation speed sensor 43a, the pressure sensor 43b, and the temperature sensor 43c is shown.

  As shown in FIG. 5, the actual flow rate measured for a predetermined time using a mass flow meter is represented by dots. Simultaneously with the actual flow rate measurement and based on the detected values of the sensors 43a, 43b and 43c detected for the same predetermined time, the first estimated delivery amount deriving means and the second estimated delivery amount deriving means. The estimated delivery flow rate estflux2 derived in two stages is represented by a solid line La1.

  As is apparent from FIG. 5, it can be confirmed that the second estimated delivery flow rate estflux2 is in good agreement with the actual flow rate in both the warm-up operation state and the power generation operation state.

  As is apparent from the above description, in the present embodiment, the detection means of the discharge pressure detection means, the drive amount detection means, and the discharge temperature detection means provided in the fluid delivery device (for example, the reforming fuel pump 43) are used. Using only the detected discharge pressure, rotation speed rpm, and discharge temperature temp, the fluid delivery amount can be estimated with high accuracy. Therefore, it is not necessary to provide a large and expensive flow meter, and the cost can be reduced.

  Further, as described above, the path along which each fluid delivered from each fluid delivery device (for example, the reforming fuel pump 43) moves greatly differs between the warm-up operation state immediately after startup and the steady operation state in which power generation is performed. This indicates that the flow resistance is different depending on each operation state, that is, the flow rate characteristic is different. However, in the present embodiment, the flow rate estimation map M related to the warm-up operation state and the steady operation state obtained in advance by experiments is stored in advance in the ROM, and the first estimated delivery flow rate estflux1 based on the flow rate estimation map M. Is derived, and the second estimated delivery flow rate estflux2 is derived based on the derived first estimated delivery flow rate estflux1. As a result, the flow rate estimation for the warm-up operation state and the steady operation state can be performed by one program, and the flow rate calculation formula provided for each mode of the warm-up operation state and the steady operation state as in the past. The operation for switching is unnecessary. Therefore, it is not necessary to depend on the stack thermometer and reformed gas thermometer used to switch the flow rate calculation formula in the prior art, so the stack thermometer and reformed gas thermometer should fail. Even in this case, the fluid delivery amount can be estimated with high accuracy, and the reliability is improved. Furthermore, since it is not necessary to store the data of the stack thermometer and the reformed gas thermometer for estimating the fluid delivery flow rate, the memory capacity can be reduced and the cost can be reduced.

  Further, in the present embodiment, the estimated delivery flow rate estflux1 and the reforming fuel pump 43 are used as estimated delivery amount derivation means for correcting the temperature of the estimated delivery flow rate estflux1 derived as the discharge flow rate in the flow rate estimation logic 32. The following equation (1), which is a temperature correction function configured with the fluid discharge temperature temp and the environmental temperature A (in this embodiment, A is 20 ° C.) when the flow rate estimation map M is created as variables. Is provided. It has been confirmed by the inventor that the equation (Equation 1) can be temperature-corrected with high accuracy. Thereby, temperature correction can be performed accurately in a short time, and the control load can be reduced.

(Equation 1)

  Next, a second embodiment will be described (FIGS. 10 and 11). Only the changes will be described below, and the other configurations are the same as those of the first embodiment. Therefore, the same components are denoted by the same reference numerals, and the description of the same configurations and the same operations is omitted.

  In the second embodiment, as shown in FIG. 10, the path of the fluid delivered by the fluid delivery device (reforming fuel pump 43, combustion air blower 66, etc.) relative to the first embodiment is blocked. The difference is that a pressure loss fluctuation calculation logic 33 having a function of detecting deterioration and displaying the deterioration is provided. In the second embodiment, the combustion air blower 66 will be described.

  The pressure loss fluctuation calculation logic 33 is provided in the control device 30. As shown in FIG. 11, the pressure loss fluctuation calculation logic 33 sends a consumable replacement signal when it is determined that the limit pressure loss map Mmpre, the deterioration determining means for determining the deterioration of the route, and the deterioration determining means. And a component replacement display means for informing the outside of replacement of deteriorated consumables.

  The consumable item to be used herein refers to a component that changes the discharge pressure of the fluid delivery device by clogging. For example, as shown in FIG. 1, there is a filter 17 provided upstream of the combustion air blower 66 and having a function of preventing dust from entering the air. Other consumables to be targeted are the mixed members sent by the reforming fuel pump 43 and the net members 15 and 16 provided in the reformed gas passage. As described above, the net members 15 and 16 are provided at the inlet of the mixed gas and the outlet of the reformed gas at the bottom of the reforming unit 21 and are interposed between the cooling unit 22 and press the catalyst 21b of the reforming unit 21, It has a function of preventing the catalyst 21b from falling downward. Although the net members 15 and 16 are separate bodies, they may be integrally formed.

  The limit pressure loss map Mmpre is the limit discharge pressure mpress of the fluid discharged from the combustion air blower 66 in which the pressure loss value due to the flow path resistance of the fluid becomes a limit value in operating the fuel cell system, and the combustion air at that time The correlation with the rotation speed rpm which is the drive amount of the blower 66 is represented.

  The limit pressure loss map Mmpre is obtained by artificially reproducing a flow path in a state where the fluid flow path is clogged in advance by the actual machine, that is, when the limit state is deteriorated. Correlation between the rotational speed rpm of the combustion air blower 66, the discharge pressure, and the actual flow rate value measured by the flow meter provided for the experiment is derived for each flow path changed according to the steady operation state. And stored in the storage unit 30a.

  Next, verification is performed based on FIGS. FIG. 7 is a graph in which the relationship between the rotational speed rpm of the combustion air blower 66 and the elapsed time and the discharge pressure press and the elapsed time in the initial state in which there is no deterioration in the fluid path is acquired on the same time scale. FIG. 8 is a graph in which data is acquired under the same conditions as in FIG. 7 by reproducing the clogging of the limit state where the pressure loss value of the system operation limit occurs in the fluid flow path, that is, the state where the deterioration of the limit state has occurred. . 7 and 8, the horizontal axis (X-axis) is a predetermined elapsed time (for example, 1 minute to 10 hours, preferably 3 to 20 minutes), and the vertical axis (Y-axis) is the rotation speed rpm or the discharge pressure press. The rotational speed rpm (broken line) detected by the rotational speed sensor 66a of the combustion air blower 66 and the discharge pressure press (point) detected by the pressure sensor 66b of the combustion air blower 66 are associated with each other at the same time and obtained. It is a thing. Although FIG. 7 and FIG. 8 do not show actually measured flow rate data for each measured point, actually measured flow rate data corresponding to all measured points are measured, and the respective measurement data are measured. Exists in correspondence with the marked points. The predetermined elapsed time required for the above-described measurement may be a length that allows the obtained data to be regressed to obtain a straight line. However, the longer the data acquisition time, the more reliable the regression line, and the more reliable the judgment of deterioration.

  FIG. 9 is a graph in which the time axis is excluded from the data in FIGS. 7 and 8, the horizontal axis is the discharge pressure press, and the vertical axis is the rotation speed rpm. The limit pressure loss map Mmpre is stored in the storage unit 30a. Also, FIG. 9 does not show the actual flow data measured for each measured point, but actually there is actual measured flow data corresponding to all the measurement points, and the flow data is also In addition, a limit pressure loss map Mmpre is configured.

  In addition, not only the deterioration limit data group indicated by circles but also the initial data group indicated by diamonds and the data filling the middle between the initial data and the deterioration limit data group are obtained in advance and combined to obtain the limit pressure loss map Mmpre. It is good. By doing so, it is possible to obtain an effect that the transition of the deterioration state can be grasped.

  As can be seen from FIG. 9, the deterioration limit data (circle points) when the path deterioration is in the limit state is in the direction in which the discharge pressure increases in parallel while maintaining substantially the same inclination as the initial data (diamond points). You can see that it is moving in the direction). That is, after the deterioration, it can be seen that the discharge pressure press is increased with respect to the same rotation speed rpm. This indicates that the fluid delivery path is deteriorated, that is, the pressure loss is increased due to clogging, and the magnitude of each discharge pressure press corresponding to the same rotation speed rpm is an index for determining deterioration. I understand that.

  The deterioration determination means obtains a limit discharge pressure mpress corresponding to the rotation speed rpm detected by the rotation speed sensor 66a, which is a drive amount detection means of the combustion air blower 66, when the deterioration detection is performed, from the limit pressure loss map Mmpre, When the discharge pressure press detected by the pressure sensor 66b, which is the discharge pressure detection means of the combustion air blower 66, exceeds the limit discharge pressure mpless, it is determined that the fluid path is deteriorated. For example, in FIG. 9, the limit discharge pressure mpress when the rotation speed rpm is Prpm is QkPa, and when the deterioration detection is performed, the rotation speed rpm detected by the rotation speed sensor 66a is detected by the pressure sensor 66b when Prpm. When the discharged pressure pressure exceeds QkPa, it is determined that the fluid path is deteriorated.

  The consumables replacement signal is sent out when the fluid path is determined to be deteriorated by the deterioration determining means, and a parts replacement display for notifying the outside of replacement of the deteriorated consumables is made.

  Next, the control of the pressure loss fluctuation calculation logic 33 will be described with reference to the flowchart 2 shown in FIG. Flowchart 2 is activated when determining the deterioration of the fluid path, and compares the limit discharge pressure mpress read from the limit pressure loss map Mmpre previously stored in the storage unit 30a with the discharge pressure press detected at the time of deterioration determination to determine deterioration. To do.

  When a deterioration determination switch (not shown) is turned on while the fuel cell system is in operation, the control device 30 starts executing a program corresponding to the flowchart 2 (step S20).

  Thereafter, the control device 30 correlates the rotation speed rpm detected by the rotation speed sensor 66a of the combustion air blower 66 and the discharge pressure press detected by the pressure sensor 66b of the combustion air blower 66 at the same time. The data is received for a predetermined time (for example, 1 minute to 10 hours, preferably 3 to 20 minutes) (step S21).

  Next, the control device 30 derives the limit discharge pressure mpress at an arbitrary rotation speed rpm read from the limit pressure loss map Mmpre stored in the storage unit 30a (step S22).

  Next, the control device 30 compares the discharge pressure press received in step S21 corresponding to the same rotation speed rpm with the derived limit discharge pressure mpress with the limit discharge pressure mpress and compares the discharge pressure with the discharge pressure. When the pressure exceeds the limit discharge pressure mppress, it is determined that the deterioration has been deteriorated by the deterioration determining means, and the consumables replacement signal change_flag is changed from 0 to 1 (step S23).

  Then, it is confirmed whether change_flag is 0 or 1 (step S24). If it is 0, it is determined to be normal (step S25), and the process ends (step S26). If change_flag is 1, it is determined that replacement of consumables is necessary due to deterioration, and a consumables replacement display signal is sent to turn on a light emitting object such as an LED (not shown) by the component replacement display means ( Step S27) is ended (Step S28).

  It should be noted that the value of each discharge pressure press corresponding to the rotation speed rpm received in step S21 and the value of each limit discharge pressure press corresponding to the rotation speed rpm when the limit pressure loss map Mmpre is created are accurately obtained. The regression lines La2 and La3 for calculating the rotation speed rpm obtained by regressing as a linear function composed of the discharge pressure press as a variable are calculated based on the acquired data groups, and the same based on the regression lines La2 and La3. What is necessary is just to calculate each discharge pressure press with respect to the rotation speed rpm (FIG. 9). At this time, as the time for data acquisition is longer, the reliability of the regression lines La2 and La3 is improved, and the reliability of determination for deterioration is also improved as described above.

  As is apparent from the above description, in the second embodiment, the rotational speed rpm and the discharge detected by the rotational speed sensor 66a and the pressure sensor 66b provided in the fluid delivery device (for example, the combustion air blower 66). By using the pressure press, it is possible to easily detect the deterioration of the fluid path and display the result when it is determined that the fluid path is deteriorated. As a result, the deterioration can be appropriately checked visually, and the possibility of continuing the operation while the route is deteriorated is reduced, so that a highly reliable and efficient operation can be performed. Moreover, since it is not necessary to carry out an overhaul to confirm the deterioration, time can be saved.

  In the first and second embodiments described above, the flow rate estimation logic 32 and the pressure loss calculation logic 33 have been described separately, but of course, they may be provided simultaneously.

  In the first embodiment described above, the reforming fuel pump 43 has been described as a fluid delivery device that estimates the delivery flow rate of the fluid. However, the present invention is not limited to this, and other fluid delivery devices may be used. In the fuel cell system shown in FIG. 1, a gas fluid delivery device such as a cathode air blower 68, a combustion air blower 66, an oxidation air blower 63, a combustion fuel pump 48, and a liquid fluid delivery device such as a reforming water pump 53. It can also be applied to. In a different fuel cell system, if there is a fluid delivery device provided in addition to the above, it can be applied to that. It can also be applied to fluid delivery devices of systems other than the fuel cell system. In any case, the discharge pressure detection means, the drive amount detection means, and the temperature detection means are provided in the same manner as the reforming fuel pump 43 and can be applied by performing the same control.

  In the second embodiment described above, the path of the combustion air blower 66 has been described as detecting the deterioration of the path of the fluid. However, the path is not limited to this, and may be a path of another fluid delivery device. If the pressure detection means and the drive amount detection means are provided in the same manner as the combustion air blower 66 and the limit pressure loss map Mmpre is prepared for each flow path of each fluid, it can be applied by performing the same control. It is.

  Further, in the first and second embodiments described above, the blower is adopted as the fluid delivery device that sends out air (for example, the devices 63 and 66 that send out oxidation air and combustion air, respectively). Any device that delivers a fluid may be used, and for example, a pump may be employed. In this case as well, control may be performed in the same manner as the blower.

  In the first and second embodiments described above, the pump is employed as the fluid delivery device for delivering the fuel (for example, the devices 43 and 48 for delivering the reforming fuel and the combustion fuel, respectively). Any device that delivers a fluid may be used, and for example, a blower may be employed. In this case as well, control may be performed in the same manner as the pump.

  In the first and second embodiments described above, the rotational speed of the fluid delivery device may be either the rotational speed of a pump (or blower) or the rotational speed of a drive source (for example, a motor) that drives the pump.

1 is a schematic diagram of an embodiment of a fuel cell system according to the present invention. It is a block diagram which shows the fuel cell system shown in FIG. FIG. 3 is a block diagram according to a first embodiment of the control device shown in FIG. 2. It is a block diagram of the flow volume estimation logic part shown in FIG. It is the graph which showed the comparison with the actual flow volume of the fuel pump for a reforming measured with the actual machine which concerns on 1st Embodiment, and an estimated flow volume. It is a flowchart of the control program which concerns on 1st Embodiment performed with the control apparatus shown in FIG. It is a graph which shows the time series data of the initial discharge pressure and rotation speed of the combustion air blower measured with the actual machine concerning a 2nd embodiment. It is a graph which shows the time series data of the discharge pressure and rotation speed after deterioration of the combustion air blower measured with the actual machine which concerns on 2nd Embodiment. It is a graph which shows the limit pressure loss map which concerns on 2nd Embodiment. FIG. 3 is a block diagram according to a second embodiment of the control device shown in FIG. 2. It is a block diagram of the pressure loss fluctuation | variation calculation part shown in FIG. It is a flowchart of the control program which concerns on 2nd Embodiment of the control apparatus shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Fuel cell, 11 ... Fuel electrode, 12 ... Air electrode, 15 ... Net member, 16 ... Net member, 17 ... Filter, 20 ... Reformer, 21 ... Reformer, 22 ... Cooling unit, 23 ... CO shift , 24 ... CO selective oxidation unit, 25 ... combustion unit, 30 ... control device, 30a ... storage unit (storage unit), 31 ... control logic unit (operation amount derivation unit, control unit), 32 ... flow rate estimation logic unit ( Estimated delivery amount deriving means), 33... Pressure loss fluctuation calculation logic (pressure loss coefficient deriving means, deterioration determining means, parts replacement display means), 43... Reforming fuel pump (fluid delivery device), 43 a. Quantity detection means), 43b ... pressure sensor (discharge pressure detection means), 43c ... temperature sensor (discharge temperature detection means), 66 ... combustion air blower (fluid delivery device), 66a ... rotational speed sensor (drive quantity detection means) 66b ... Pressure sensor (Discharge pressure detection means), 66c ... temperature sensor (discharge temperature detection means), M ... flow rate estimation map, Mmpre ... limits pressure loss map.

Claims (7)

In a fluid supply amount estimation device for estimating a flow rate of the fluid supplied to a device from a fluid delivery device connected to a device whose flow path resistance of the fluid is changed according to an operation state,
A discharge pressure detecting means for detecting a discharge pressure of the fluid discharged from the fluid delivery device;
Drive amount detection means for detecting the drive amount of the fluid delivery device;
The relationship between the discharge pressure of the fluid discharged from the fluid delivery device, the drive amount of the fluid delivery device, and the discharge flow rate of the fluid discharged from the fluid delivery device according to the discharge pressure and the drive amount is represented. A flow rate estimation map is stored in the storage unit, and discharged from the fluid delivery device based on the fluid discharge flow rate obtained from the flow rate estimation map in accordance with the detected drive amount and the detected discharge pressure. An estimated delivery amount deriving means for obtaining an estimated delivery flow rate of the fluid;
A fluid supply amount estimation device comprising: In Claim 1, it comprises a discharge temperature detection means for detecting the discharge temperature of the fluid discharged from the fluid delivery device,
The estimated delivery amount deriving means corrects the discharge flow rate of the fluid obtained from the flow rate estimation map by the detected discharge temperature to obtain an estimated delivery flow rate of the fluid discharged from the fluid delivery device. A fluid supply amount estimation device. In a fluid supply amount estimation device for estimating a flow rate of the fluid supplied to a device from a fluid delivery device connected to a device whose flow path resistance of the fluid is changed according to an operation state,
A discharge pressure detecting means for detecting a discharge pressure of the fluid discharged from the fluid delivery device;
Drive amount detection means for detecting the drive amount of the fluid delivery device;
A limit representing the relationship between the limit discharge pressure of the fluid discharged from the fluid delivery device and the drive amount of the fluid delivery device when the pressure loss value due to the flow path resistance of the fluid changed according to the operating state becomes the limit value A pressure loss map is stored in the storage unit, a limit discharge pressure corresponding to the detected drive amount is obtained from the limit pressure loss map, and a consumable replacement signal is sent when the detected discharge pressure exceeds the limit discharge pressure A fluid supply amount estimation device. A fuel cell that generates electric power using the fuel gas and the oxidant gas respectively supplied to the fuel electrode and the oxidant electrode;
And a reformer that is supplied with reforming fuel and reforming water and generates the fuel gas containing hydrogen by reforming the supplied reforming fuel. In the fuel cell system in which the flow path resistance of the fluid supplied from the fluid delivery device is changed according to the machine operation and the steady operation,
A discharge pressure detecting means for detecting a discharge pressure of the fluid discharged from the fluid delivery device;
Drive amount detection means for detecting the drive amount of the fluid delivery device;
The relationship between the discharge pressure of the fluid discharged from the fluid delivery device, the drive amount of the fluid delivery device, and the discharge flow rate of the fluid discharged from the fluid delivery device according to the discharge pressure and the drive amount is represented. A flow rate estimation map is stored in the storage unit, and discharged from the fluid delivery device based on the fluid discharge flow rate obtained from the flow rate estimation map in accordance with the detected drive amount and the detected discharge pressure. An estimated delivery amount deriving means for obtaining an estimated delivery flow rate of the fluid;
A fuel cell system comprising: The discharge temperature detecting means according to claim 4, further comprising a discharge temperature detecting means for detecting a discharge temperature of the fluid discharged from the fluid delivery device,
The estimated delivery amount deriving means corrects the discharge flow rate of the fluid obtained from the flow rate estimation map by the detected discharge temperature to obtain an estimated delivery flow rate of the fluid discharged from the fluid delivery device. A fuel cell system. 6. The discharge flow rate obtained from the flow rate estimation map, the discharge temperature detected by the discharge temperature detection means, and the environmental temperature A when the flow rate estimation map is created are configured as variables in claim 5. The fuel cell system is characterized in that the temperature correction function for calculating the estimated delivery flow rate after temperature correction is expressed by the following equation (1).
(Equation 1)

A fuel cell that generates electric power using the fuel gas and the oxidant gas respectively supplied to the fuel electrode and the oxidant electrode;
And a reformer that is supplied with reforming fuel and reforming water and generates the fuel gas containing hydrogen by reforming the supplied reforming fuel. In the fuel cell system in which the flow path resistance of the fluid supplied from the fluid delivery device is changed according to the machine operation and the steady operation,
A discharge pressure detecting means for detecting a discharge pressure of the fluid discharged from the fluid delivery device;
Drive amount detection means for detecting the drive amount of the fluid delivery device;
The limit discharge pressure of the fluid discharged from the fluid delivery device when the pressure loss value due to the flow path resistance of the fluid changed according to the warm-up operation state and the steady operation state becomes a limit value, and the fluid delivery device A limit pressure loss map representing the relationship with the drive amount is stored in the storage unit, a limit discharge pressure corresponding to the detected drive amount is obtained from the limit pressure loss map, and the detected discharge pressure is calculated as the limit discharge pressure. A fuel cell system that sends a consumable replacement signal when exceeded.

Images