JP5262638B2 - Fuel cell power generation system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cell power generation system including a reforming part for stably supplying optimum hydrogen-containing gas for operation. <P>SOLUTION: The fuel cell power generation system 100 includes the reforming part 30 for producing hydrogen-containing gas, a reforming temperature detecting part 21, a combustion air supply part 18, an air flow amount measuring part 31, a fuel cell 8, a combustion part 2 for supplying heat required for reforming reaction, a steam generating part 23 for generating steam, a detecting part for determining whether the measuring operation of the air flow amount measuring part 31 is adequate or not, and an operation control part 16. The operation control part 16 controls the operation of the combustion air supply part 18 in accordance with at least a flow amount measured by the air flow amount-measuring part 31, and determines whether the measuring operation of the air flow amount-measuring part 31 is adequate or not in accordance with a value detected by the detecting part. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a fuel cell power generation system including a reforming unit that generates a hydrogen-containing gas having a low carbon monoxide concentration from a fossil raw material.

  In recent years, development of a fuel cell power generation system using a fuel cell stack (hereinafter simply referred to as “fuel cell”) capable of generating power with a small size and high efficiency as a distributed energy supply source has been promoted. The fuel cell power generation system supplies a hydrogen-containing gas and an oxygen-containing gas to a fuel cell, which is a main body of a power generation unit, and electrically generates chemical energy generated by an electrochemical reaction between hydrogen and oxygen. It is a system that generates electricity by taking it out as valuable energy.

  However, at present, an infrastructure for supplying the hydrogen-containing gas necessary for the fuel cell has not been established.

  Therefore, the conventional fuel cell power generation system uses a gas containing hydrogen via a steam reforming section that uses city gas or LPG as a raw material and reforms with steam at a temperature of 600 to 700 ° C. using a Ru catalyst or Ni catalyst. A hydrogen generator for generating

  However, the hydrogen-containing gas obtained by the reforming reaction usually contains carbon monoxide derived from the raw material, and when the concentration thereof is high, the power generation characteristics of the fuel cell deteriorate.

  Therefore, in addition to the steam reforming unit, the hydrogen generator is provided with a reaction unit such as a shift unit and a selective oxidation unit in order to reduce carbon monoxide.

  The fuel cell power generation system is a method for improving efficiency by reforming reaction by returning a hydrogen-containing gas (hereinafter referred to as “anode off-gas”) discharged from the anode of the fuel cell to the hydrogen generator and burning it. Is common.

  In general, since a fuel cell power generation system is composed of many devices such as the fuel cell and the hydrogen generator as described above, each device can be operated under appropriate conditions in order to operate with high efficiency. Necessary. In particular, in order to stably supply the hydrogen-containing gas optimal for operation, it is important to perform the reforming reaction by stabilizing the combustion of the anode off gas in the hydrogen generator.

  Therefore, in order to stabilize the combustion of the anode off gas, the load current of the fuel cell is temporarily increased or decreased according to the reforming catalyst temperature of the steam reforming section to control the anode off gas flow rate and the combustion air flow rate. An example of proper combustion is disclosed (for example, see Patent Document 1).

  In addition, an example is disclosed in which the combustion state of the anode off gas is detected to appropriately control the flow rate of combustion air in the combustion air supply device (see, for example, Patent Document 2).

Also, if the combustion air flow rate is not supplied in the set amount due to, for example, clogging of the filter, the temperature change of the reforming catalyst temperature is detected to correct the combustion air flow rate, and even during long-term operation An example in which each device is operated under appropriate conditions is disclosed (for example, see Patent Document 3).
JP 63-146367 A JP-A-2004-178862 JP 2007-200777 A

  According to the fuel cell power generation systems disclosed in Patent Documents 1 and 2, the combustion of the anode off gas in the hydrogen generator is stabilized by controlling it through a detector or the like that measures the flow rate of the combustion air. Can do. However, in the conventional configuration described above, the operation of the detector is not appropriate, for example, if the detected value is not accurate, the combustion of the anode off gas in the hydrogen generator cannot be stabilized.

  Further, according to the fuel cell power generation system disclosed in Patent Document 3, a detector for measuring the flow rate of combustion air is not required, but a short-term change in the flow rate of combustion air generated during power generation operation cannot be detected. There is a problem.

  The present invention solves the above-described conventional problems, and an object thereof is to provide a fuel cell power generation system including a reforming unit that stably supplies a hydrogen-containing gas optimum for operation.

  In order to solve the above-described conventional problems, in the fuel cell power generation system of the present invention, a reforming unit that generates a hydrogen-containing gas by a reforming reaction between a raw material and steam, and a reforming that detects a reaction temperature in the reforming reaction A temperature detection unit; a combustion air supply unit that supplies combustion air; an air flow rate measurement unit that measures the flow rate of combustion air; a fuel cell that is supplied with a hydrogen-containing gas and an oxygen-containing gas to generate power; and a fuel cell Combustion unit that burns the hydrogen-containing gas returned from the reactor and supplies heat necessary for the reforming reaction, a steam generation unit that generates steam by the heat supplied from the combustion unit, and the measurement operation of the air flow measurement unit are appropriate At least a detection unit for determining whether or not the operation control unit controls the operation of the combustion air supply unit based on at least the flow rate measured by the air flow rate measurement unit. Detection value measurement operation of the air flow measuring unit based on the parts having a configuration to determine whether proper.

  With this configuration, the flow rate of the combustion air is controlled by the measurement value of the air flow rate measurement unit, and whether or not the measurement value is correct is determined by the detection value of the detection unit and can be optimally controlled. As a result, it is possible to realize a safe and highly reliable fuel cell power generation system by controlling the flow rate of combustion air in two stages of an air flow rate measurement unit and a detection unit.

  According to the present invention, it is possible to realize a highly reliable fuel cell power generation system by determining whether the measurement operation of the air flow rate measurement unit is appropriate based on the detection value of the detector and controlling the operation by the operation control unit.

  The first invention includes a reforming unit that generates a hydrogen-containing gas by a reforming reaction between a raw material and steam, a reforming temperature detecting unit that detects a reaction temperature in the reforming reaction, and combustion air that supplies combustion air A supply unit, an air flow rate measurement unit for measuring the flow rate of combustion air, a fuel cell that is supplied with hydrogen-containing gas and an oxygen-containing gas to generate power, and a hydrogen-containing gas returned from the fuel cell is burned to perform a reforming reaction A combustion section that supplies heat necessary for the operation, a steam generation section that generates steam by heat supplied from the combustion section, a detection section that determines whether the measurement operation of the air flow measurement section is appropriate, and an operation control section, The operation control unit controls the operation of the combustion air supply unit based on at least the flow rate measured by the air flow rate measurement unit, and the measurement operation of the air flow rate measurement unit is performed based on the detection value of the detection unit. Appropriate It is a fuel cell power generation system to determine whether.

  With this configuration, the flow rate of the combustion air is controlled by the measurement value of the air flow rate measurement unit, and whether or not the measurement value is correct is determined by the detection value of the detection unit and can be optimally controlled. As a result, it is possible to realize a safe and highly reliable fuel cell power generation system by controlling the flow rate of combustion air in two stages of an air flow rate measurement unit and a detection unit.

  According to a second invention, in the first invention, the combustion unit is provided with a combustion detection unit for detecting an ionic current value in the flame, and the operation control unit is detected by the reforming temperature detection unit which is a detection value of the detection unit. On the basis of the reaction temperature to be detected and the ion current value detected by the combustion detection unit, it is determined whether or not the measurement operation of the air flow rate measurement unit is appropriate.

  Thereby, it can be controlled by determining whether the measurement operation of the air flow rate measurement unit is appropriate using the reaction temperature and the ion current value as the detection value of the detection unit.

  According to a third invention, in the second invention, the operation control unit is configured such that the reaction temperature decreases and the ion current value decreases, or the reaction temperature increases and the ion current value increases. Control is performed by determining that the measurement operation of the air flow rate measurement unit is outside the range of the appropriate measurement operation set in advance.

  Accordingly, it is possible to control the fuel cell power generation system by judging the malfunction of the air flow rate measurement unit in a short period of time.

  According to a fourth aspect, in the second aspect, the reaction temperature is set to a predetermined reaction temperature threshold value and the ion current value is set to a predetermined current value threshold value. When the current value falls below the current value threshold value, or when the reaction temperature exceeds the reaction temperature threshold value and the ion current value exceeds the current value threshold value, the measurement operation of the air flow rate measurement unit is set to a proper measurement operation. Control outside the range.

  According to a fifth invention, in the first invention, the water vapor generation unit is provided with a water vapor temperature detection unit for detecting a water vapor atmosphere temperature, and the operation control unit is detected by the reforming temperature detection unit, which is a detection value of the detection unit. On the basis of the reaction temperature and the water vapor atmosphere temperature detected by the water vapor temperature detector, it is determined whether or not the measurement operation of the air flow rate measurement unit is appropriate.

  Thereby, it can be controlled by determining whether the measurement operation of the air flow rate measurement unit is appropriate using the reaction temperature and the water vapor atmosphere temperature as the detection values of the detection unit.

  In a sixth aspect based on the fifth aspect, the operation control unit, when the reaction temperature decreases and the water vapor atmosphere temperature increases, or when the reaction temperature increases and the water vapor atmosphere temperature decreases, Control is performed by determining that the measurement operation of the air flow rate measurement unit is outside the range of the appropriate measurement operation set in advance.

  In a fifth aspect based on the fifth aspect, the reaction temperature threshold is set in advance in the reaction temperature, and the water vapor temperature threshold is set in advance in the water vapor atmosphere temperature, and the operation control unit is configured so that the reaction temperature exceeds the reaction temperature threshold, and the water vapor atmosphere temperature. Is below the water vapor temperature threshold, or when the reaction temperature falls below the reaction temperature threshold, and the water vapor atmosphere temperature exceeds the water vapor temperature threshold, the measurement operation of the air flow measurement unit is outside the range of the appropriate measurement operation set in advance. Judge.

  According to the invention of the younger brother 8, in the first invention, the fuel cell is provided with a voltage detection unit for detecting the generated voltage, and the operation control unit is a reaction temperature detected by the reforming temperature detection unit, which is a detection value of the detection unit. Then, based on the generated voltage detected by the voltage detector, it is determined whether or not the measurement operation of the air flow rate measurement unit is appropriate.

  Thereby, it can be controlled by determining whether the measurement operation of the air flow rate measurement unit is appropriate using the reaction temperature and the generated voltage as detection values of the detection unit.

  In a ninth aspect based on the eighth aspect, the operation control unit determines whether the air flow rate when the reaction temperature decreases and the generated voltage decreases, or when the reaction temperature increases and the generated voltage increases. Control is performed by determining that the measurement operation of the measurement unit is abnormal.

  According to a tenth aspect, in the eighth aspect, a reaction temperature threshold is set in advance for the reaction temperature and a voltage threshold is set for the generated voltage in advance, and the operation control unit exceeds the reaction temperature threshold for the reaction temperature and the voltage threshold for the generated voltage. In the case, or when the reaction temperature falls below the reaction temperature threshold of the reaction temperature and the voltage threshold of the generated voltage, the measurement operation of the air flow rate measurement unit is determined to be abnormal and is controlled.

  Accordingly, it is possible to control the fuel cell power generation system by judging the malfunction of the air flow rate measurement unit in a short period of time.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the same components as those of the above-described embodiments will be denoted by the same reference numerals, and detailed description thereof will be omitted. The present invention is not limited to the embodiments.

(Embodiment 1)
First, the configuration of the fuel cell power generation system according to Embodiment 1 of the present invention will be described in detail below.

  FIG. 1 is a schematic configuration diagram showing a fuel cell power generation system according to Embodiment 1 of the present invention.

  As shown in FIG. 1, a fuel cell power generation system 100 includes a hydrogen generator 1 that generates a hydrogen-containing gas, a fuel cell 8 that generates power using the hydrogen-containing gas supplied from the hydrogen generator 1, and a hydrogen generator. A hydrogen gas supply path 12 for supplying a hydrogen-containing gas from the apparatus 1 to the fuel cell 8; an off-gas path 14 for supplying a hydrogen-containing gas (anode offgas) discharged from the fuel cell 8 to the combustion unit 2 of the hydrogen generator 1; And a combustion gas supply path 15.

  The off-gas path 14 is provided with a sealing portion 9 that seals the supply of the hydrogen-containing gas from the hydrogen generator 1, and the sealing portion 9 is connected to the hydrogen generator bypass path 11 and the fuel cell bypass path 13. ing. The hydrogen gas supply path 12 is provided with a sealing portion 9A that seals the supply of the hydrogen-containing gas from the hydrogen generator 1, and the sealing portion 9A is connected to the fuel cell bypass path 13. Here, the sealing portions 9 and 9A are configured by combining a plurality of solenoid valves (detailed explanation is omitted), and are supplied from the hydrogen gas supply path 12, the hydrogen generator bypass path 11, and the fuel cell bypass path 13. It also has a switching function to switch the distribution of gas.

  Further, the fuel cell 8 includes a fuel cell air blower 17 that supplies air as an oxygen-containing gas, and a voltage detection unit 28 that detects a power generation voltage of the fuel cell 8. Since the other configuration of the fuel cell 8 is the same as that of a general solid polymer fuel cell, detailed description thereof is omitted.

  The hydrogen generator 1 also uses a water supply unit 3 that supplies water, a desulfurization unit 5 that adsorbs and removes sulfur components contained in hydrocarbon-based raw materials, and a hydrogen-containing gas using the raw materials and water. A reforming unit 30 to be generated, a raw material supply unit 4 that controls the flow rate of raw material (raw material flow rate), and an operation control unit 16 that controls at least the operations of the raw material supply unit 4 and the water supply unit 3 are provided. The hydrocarbon-based raw material supplied to the desulfurization section 5 may be a raw material containing an organic compound composed of at least carbon and hydrogen elements such as hydrocarbons. For example, city gas mainly composed of methane, natural gas Gas, LPG, etc.

  As shown in FIG. 1, in the present embodiment, for example, a gas infrastructure line 6 of city gas is used as a raw material supply source, and the gas infrastructure line 6 is connected to the desulfurization section 5. In addition, the desulfurization part 5 has a shape that can be attached to and detached from the desulfurization connection part 7 disposed on the upstream side and the downstream side, and when the adsorption amount for the sulfur component of the desulfurization part 5 is saturated and the adsorption characteristics are reduced, It can be replaced with a new desulfurization section 5. At this time, the desulfurization section 5 is filled with a zeolite-based adsorption / removal agent that adsorbs a sulfur compound that is an odorant component in the city gas.

  Moreover, the desulfurization connection part 7 also has the valve function comprised, for example with a solenoid valve which controls the distribution | circulation of a raw material. In addition, the desulfurization part 5 is good also as a structure using hydrodesulfurization (hydrodesulfurization).

  Moreover, the water supply part 3 has a pump having a flow rate adjusting function.

  The raw material supply unit 4 is disposed in the raw material supply path 10 that connects the desulfurization unit 5 and the reforming unit 30, and controls the flow rate of the raw material supplied to the reforming unit 30, so that the gas infrastructure line 6 The flow rate of the raw material supplied to the desulfurization part 5 is controlled. In addition, the raw material supply part 4 should just be able to control the flow volume of the raw material supplied to the desulfurization part 5, and may be arrange | positioned upstream of the desulfurization part 5. FIG. In this Embodiment, the raw material supply part 4 has a booster pump, and can control the flow volume of the raw material supplied to the desulfurization part 5 by controlling the input current pulse, input electric power, etc., for example.

  The operation control unit 16 is a control unit that controls the operation of the reforming unit 30, and the amount of raw material supplied from the raw material supply unit 4 to the reforming unit 30, and the water supply unit 3 to the reforming unit 30. Control of the amount of supplied water and the operation of the desulfurization connecting part 7 and the sealing parts 9 and 9A are performed. Further, as will be described in detail below, the measurement of the air flow measurement unit is performed based on the detection value of the detection unit such as the reaction temperature detected by the reforming temperature detector and the ion current value detected by the combustion detection unit. Judging whether the operation is appropriate, the flow rate of combustion air is optimally controlled.

  Further, the operation control unit 16 determines the combustion state in the combustion unit 2 based on the ion current value measured by the combustion detection unit 22. For example, when the detected ion current value is equal to or less than a preset value, it is determined that the fire is extinguished, and control is performed so as to stop the combustion of the combustion unit 2. This is based on the fact that there is a proportional relationship between the ionic current value caused by the organic compound ions in the flame and the organic compound concentration detected by the combustion detector 22. Specifically, for example, when the ionic current value is decreased, it can be determined that the concentration of the organic compound in the flame of the combustion unit 2 is decreased.

  The operation control unit 16 also controls the operation of the fuel cell 8, but detailed description thereof is omitted.

  The operation control unit 16 is configured by, for example, a semiconductor memory or a CPU. Then, the operation information such as the operation sequence of the reforming unit 30 and the raw material integrated flow rate is stored, the appropriate operation conditions according to the situation are calculated, and necessary for the operation of the water supply unit 3 and the raw material supply unit 4 Specific operating conditions.

  Below, the modification part of Embodiment 1 of this invention is demonstrated in detail using drawing. FIG. 2 is a cross-sectional view showing a main part of the reforming unit 30 in the fuel cell power generation system according to Embodiment 1 of the present invention.

  As shown in FIG. 2, the reforming unit 30 includes at least a steam generating unit 23, a steam reforming unit 20, and a metamorphic unit 25. Here, the water vapor generation unit 23 evaporates the water supplied from the water supply unit 3 to generate water vapor, and preheats a mixed gas of the raw material and water vapor. And the steam reforming part 20 advances the reforming reaction of a raw material and water vapor | steam. Further, the shift unit 25 shifts the carbon monoxide in the hydrogen-containing gas generated in the steam reforming unit 20 and water vapor to reduce the carbon monoxide concentration of the hydrogen-containing gas. The carbon monoxide remaining in the hydrogen-containing gas after passing through the shift unit 25 is mainly oxidized using air supplied from the air supply unit 19 to the hydrogen-containing gas after passing through the shift unit 25. Alternatively, the selective oxidation unit 26 to be removed may be provided.

  At this time, the steam reforming unit 20 includes, for example, a Ru-based reforming catalyst, the shift unit 25 includes, for example, a Cu—Zn-based shift catalyst, and the selective oxidation unit 26 includes, for example, a Ru-based selective oxidation catalyst. doing.

  In addition, the reforming unit 30 includes a reforming temperature detecting unit 21 that detects the temperature (reaction temperature) of the reforming catalyst (or hydrogen-containing gas) in the steam reforming unit 20 and a steam atmosphere (or a raw material) in the steam generating unit 23. A water vapor temperature detector 24 for detecting the temperature of the water vapor mixed gas) is provided. At this time, the exhaust gas generated by the combustion unit 2 is supplied to the steam reforming unit 20 and the steam generation unit 23 via the wall surface of the reforming unit 30 with the combustion unit 2.

  Further, the reforming unit 30 includes a combustion unit 2 made of, for example, a burner for burning combustion gas for supplying reaction heat necessary for the reforming reaction in the steam reforming unit 20. At this time, the combustion gas burned in the combustion unit 2 is supplied to the combustion unit 2 via the combustion gas supply path 15. Further, the combustion unit 2 detects the combustion state of the combustion unit 2, for example, a combustion detection unit 22 such as a frame rod, and supplies combustion air to the combustion unit 2, for example, a combustion air supply unit 18 such as a combustion fan An air flow rate measurement unit 31 that measures the flow rate of combustion air is provided. The flame rod is a device that applies a voltage to ions generated when a flame is formed and measures the value of the ionic current that flows at that time.

  Then, the hydrogen-containing gas generated in the reforming unit 30 is supplied to the fuel cell 8 via the hydrogen gas supply path 12 shown in FIG.

  The general configuration of the steam reforming unit 20, the shift unit 25, and the selective oxidation unit 26 is not illustrated or described in detail.

  Next, the operation of the fuel cell power generation system will be specifically described.

  Hereinafter, the operation of the fuel cell power generation system at the time of start-up, normal power generation, and stop will be described focusing on the operation of the hydrogen generator 1.

  First, the operation of the hydrogen generator 1 from the start of the fuel cell power generation system to the normal power generation will be described.

  That is, when the hydrogen generator 1 is started from a stopped state, according to a command from the operation controller 16, the raw material supplier 4 passes through the hydrogen generator bypass path 11, the sealing part 9, and the combustion gas supply path 15, The raw material is supplied to the combustion unit 2. Then, when the raw material is combusted in the combustion unit 2, heating of the reforming unit 30 is started.

  Next, after the start of heating, raw material is supplied to the reforming unit 30 via the raw material supply path 10, and water is supplied from the water supply unit 3, and the reforming reaction between water and the raw material starts. In the present embodiment, city gas (13A) mainly composed of methane will be described as an example of a raw material. At this time, water from the water supply unit 3 is controlled so that water vapor is about 3 mol (3 in terms of steam carbon ratio (S / C)) with respect to 1 mol of carbon atoms in the average molecular formula of city gas. Supplied. As a result, in the reforming unit 30, the steam reforming reaction is performed in the steam reforming unit 20, the modification reaction is performed in the modification unit 25, and the selective oxidation reaction of carbon monoxide is performed in the selective oxidation unit 26, thereby generating a hydrogen-containing gas.

  Then, until the carbon monoxide concentration of the generated hydrogen-containing gas decreases to a predetermined concentration (for example, 20 ppm or less on a dry gas basis), it circulates via the sealing portions 9 and 9A and the fuel cell bypass path 13. And supplied to the combustion section 2. At this time, based on the reaction temperature detected by the reforming temperature detection unit 21, the operation control unit 16 causes the steam reforming unit 20, the shift unit 25, and the selective oxidation unit 26 to have temperatures suitable for each reaction. The combustion of the combustion unit 2 is controlled.

  Next, after the raw material supplied to the reforming unit 30 is supplied to the combustion unit 2 and the combustion state in the heating unit is stabilized, the supply of the raw material from the hydrogen generator bypass path 11 is stopped.

  Next, after reducing the carbon monoxide concentration of the hydrogen-containing gas generated in the reforming unit 30 to a predetermined concentration, the sealing unit 9 is operated and is optimal for operation via the hydrogen gas supply path 12. A hydrogen-containing gas is supplied to the fuel cell 8. At this time, the operation control unit 16 controls the operation of the raw material supply unit 4 to adjust the supply amount of the raw material and supply it to the fuel cell 8. As a result, hydrogen in the hydrogen-containing gas and oxygen in the oxygen-containing gas react in the fuel cell 8 to start a steady power generation operation.

  Hereinafter, the operation of the hydrogen generator 1 when the operation of the fuel cell power generation system is stopped will be described.

  That is, when the operation of the fuel cell power generation system 100 is stopped, the operation control unit 16 operates the sealing units 9 and 9A to stop the supply of the hydrogen-containing gas to the fuel cell 8, and the fuel cell bypass path 13 is instructed to be supplied to the combustion section 2 via the control 13.

  Next, the operation of the hydrogen generator 1 is stopped by instructing the water supply unit 3 and the raw material supply unit 4 to stop the supply of water and the raw material. At this time, it is preferable to perform an operation for preventing contamination of outside air as much as possible in the reforming unit 30 when the hydrogen generator 1 is stopped. In addition, the operation | movement which prevents mixing of external air is the quantity corresponded to the operation | movement which operates the sealing parts 9 and 9A, for example, seals the modification | reformation part 30, and the quantity by which the modification | reformation part 30 cools down and volume decreases. Operation of supplying the raw material.

  Hereinafter, the operation of the detection unit that determines whether the measurement operation of the flow rate measurement unit for combustion air, which is the point of the present invention, is appropriate will be described in detail.

  That is, there is no problem when the measurement value of the air flow rate measurement unit is correct and the flow rate of the combustion air is accurately controlled. However, if for some reason the measured value of the air flow rate measurement unit returns a value different from the actual value to the operation control unit and the reforming unit is controlled based on that value, the safety, reliability, and power generation efficiency This causes problems such as degradation. Therefore, it is important to determine whether the measurement operation of the air flow rate measurement unit is appropriate.

  In the hydrogen generator 1 of the present embodiment, the reforming temperature detector 21 and the combustion detector 22 are used as detectors, the reaction temperature detected by the reforming temperature detector 21 and the ionic current detected by the combustion detector 22. Based on the detected value, it is determined whether or not the measurement operation of the air flow rate measurement unit with respect to the flow rate of the combustion air supplied to the combustion unit 2 is appropriate.

  Hereinafter, a specific operation of the detection unit will be described.

  First, when the flow rate of combustion air supplied from the combustion air supply unit 18 decreases, the amount of combustion exhaust gas decreases. As a result, the amount of heat taken out from the hydrogen generator 1 by the combustion exhaust gas decreases, so that the reaction temperature detected by the reforming temperature detector 21 increases. In addition, when the flow rate of the combustion air decreases while the amount of the combustion gas supplied to the combustion unit 2 does not change, the concentration of the organic compound in the flame increases, so that the ionic current value detected by the combustion detection unit 22 Will increase.

  On the other hand, when the flow rate of the combustion air supplied from the combustion air supply unit 18 increases, the amount of combustion exhaust gas increases. As a result, the amount of heat taken out from the hydrogen generator 1 by the combustion exhaust gas increases, so that the reaction temperature detected by the reforming temperature detector 21 decreases. In addition, when the flow rate of combustion air increases while the amount of combustion gas supplied to the combustion unit 2 does not change, the concentration of the organic compound in the flame decreases, so the ionic current value detected by the combustion detection unit 22 Decrease.

  That is, the air for measuring the flow rate of the combustion air is determined by the operation control unit 16 determining the change in the reaction temperature of the reforming temperature detection unit 21 and the ionic current value of the combustion detection unit 22 as the detection value of the detection unit. It can be determined whether or not the measurement operation (measurement value) of the flow rate measurement unit 31 is appropriate.

  When it is determined that the flow rate of the combustion air has decreased, the reaction temperature detected by the reforming temperature detection unit 21 and the ion current value detected by the combustion detection unit 22 are reduced. Control the behavior. If it is determined that the flow rate of the combustion air has increased, control is performed by the reverse operation.

  Furthermore, when it is determined that the measurement operation of the air flow rate measurement unit 31 is not appropriate and is outside the range of the appropriate measurement operation, control is performed to stop the operation of the fuel cell power generation system 100.

  In the present embodiment, whether or not the measurement operation (measurement value) of the air flow rate measurement unit 31 is appropriate is determined by changing the reaction temperature of the reforming temperature detection unit 21 and the ionic current value of the combustion detection unit 22. Although the example of determining and controlling in 16 has been described, the present invention is not limited to this. For example, according to the measurement operation of the air flow rate measuring unit 31, a reaction temperature threshold is set for the reaction temperature detected in advance by the reforming temperature detection unit 21, and a current value threshold is set for the ion current value detected by the combustion detection unit 22. May be. Specifically, when the operation control unit 16 falls below the reaction temperature threshold and the current value threshold or exceeds the reaction temperature threshold and the current value threshold, the measurement operation of the air flow rate measurement unit 31 is set in advance. It is determined that the fuel cell power generation system 100 is out of the range, and the operation of the fuel cell power generation system 100 is stopped. Here, the reaction temperature threshold value and the ionic current value threshold value indicate the relationship between the flow rate of combustion air, the reaction temperature, and the ionic current value at which the combustion state in the combustion unit 2 becomes unstable in the hydrogen generator 1. It is set by measuring in advance. For example, for combustion where the flow rate of combustion air increases and lean combustion increases the amount of carbon monoxide in the combustion exhaust gas, or the flow rate of combustion air decreases and the amount of carbon monoxide in the combustion exhaust gas increases. The air flow rate.

(Embodiment 2)
Hereinafter, a fuel cell power generation system according to Embodiment 2 of the present invention will be described. In the fuel cell power generation system, the detection unit that determines whether the measurement operation of the air flow rate measurement unit is appropriate is different from the first embodiment. Other configurations and operations are substantially the same as those of the fuel cell power generation system 100 of the first embodiment, and thus description thereof may be omitted. That is, as the detection unit, the reforming temperature detection unit and the steam temperature detection unit are used, and the reaction temperature of the reforming temperature detection unit and the steam atmosphere temperature of the steam temperature detection unit are used as detection values. Different.

  Therefore, in the following, operations of the reforming temperature detection unit and the water vapor temperature detection unit, which are detection units that determine whether the measurement operation of the air flow rate measurement unit is appropriate, will be mainly described in detail.

  In the hydrogen generator 1 of the present embodiment, the reforming temperature detector 21 and the steam temperature detector 24 are used as detectors. Then, based on the reaction temperature detected by the reforming temperature detector 21 and the detected value of the steam atmosphere temperature detected by the steam temperature detector 24, the air flow rate is measured with respect to the flow rate of the combustion air supplied to the combustion unit 2. This is to determine whether the measurement operation of the part is appropriate.

  Hereinafter, a specific operation of the detection unit will be described.

  First, when the flow rate of combustion air supplied from the combustion air supply unit 18 decreases, the amount of combustion exhaust gas decreases. As a result, the amount of heat taken out from the hydrogen generator 1 by the combustion exhaust gas decreases, so that the reaction temperature detected by the reforming temperature detector 21 increases. Further, since the amount of combustion exhaust gas is reduced, the heat exchange performance between the combustion exhaust gas in the steam generation unit 23, water (including steam) and the raw material is lowered, and the steam atmosphere temperature detected by the steam temperature detection unit 24 is reduced. Decrease.

  On the other hand, when the flow rate of combustion air supplied from the combustion air supply unit 18 increases, the amount of combustion exhaust gas increases. As a result, the amount of heat taken out from the hydrogen generator 1 by the combustion exhaust gas increases, so that the reaction temperature detected by the reforming temperature detector 21 decreases. Further, since the amount of combustion exhaust gas increases, the heat exchange performance between the combustion exhaust gas in the steam generation unit 23, water (including steam) and the raw material is improved, and the steam atmosphere temperature detected by the steam temperature detection unit 24 is increased. To increase.

  In other words, the operation control unit 16 determines changes in the reaction temperature of the reforming temperature detection unit 21 and the water vapor atmosphere temperature in the water vapor temperature detection unit 24, which are detection values of the detection unit, thereby measuring the air flow rate measurement unit 31. It is possible to determine whether the operation (measurement value) is appropriate.

  When it is determined that the flow rate of the combustion air has decreased, the combustion air is such that the reaction temperature detected by the reforming temperature detector 21 decreases and the steam atmosphere temperature detected by the steam temperature detector 24 increases. The operation of the supply unit 18 is controlled. If it is determined that the flow rate of the combustion air has increased, control is performed by the reverse operation.

  Furthermore, when it is determined that the measurement operation of the air flow rate measurement unit 31 is not appropriate and is outside the range of the appropriate measurement operation, control is performed to stop the operation of the fuel cell power generation system 100.

  In the present embodiment, whether or not the measurement operation (measured value) of the air flow rate measurement unit 31 is appropriate is controlled by changing the reaction temperature of the reforming temperature detection unit 21 and the change in the steam atmosphere temperature of the steam temperature detection unit 24. Although the example which judges and controls by the part 16 was demonstrated, it is not restricted to this. For example, in accordance with the measurement operation of the air flow rate measurement unit 31, the reaction temperature threshold is set in advance to the reaction temperature detected by the reforming temperature detection unit 21, and the water vapor atmosphere temperature detected by the water vapor temperature detection unit 24 is controlled. May be. Specifically, when the operation control unit 16 falls below the reaction temperature threshold and exceeds the water vapor temperature threshold, or exceeds the reaction temperature threshold and falls below the water vapor temperature threshold, the measurement operation of the air flow rate measurement unit 31 is performed in advance. Control is performed to stop the operation of the fuel cell power generation system 100 by determining that it is outside the range of the proper measurement operation to be set. Here, the reaction temperature threshold value and the water vapor temperature threshold value indicate the relationship between the flow rate of combustion air, the reaction temperature, and the steam atmosphere temperature at which the combustion state in the combustion unit 2 becomes unstable in the hydrogen generator 1. It is set by measurement. For example, for combustion where the flow rate of combustion air increases and lean combustion increases the amount of carbon monoxide in the combustion exhaust gas, or the flow rate of combustion air decreases and the amount of carbon monoxide in the combustion exhaust gas increases. The air flow rate.

(Embodiment 3)
Hereinafter, a fuel cell power generation system according to Embodiment 3 of the present invention will be described. In the fuel cell power generation system, the detection unit that determines whether the measurement operation of the air flow rate measurement unit is appropriate is different from the first embodiment. Other configurations and operations are substantially the same as those of the fuel cell power generation system 100 of the first embodiment, and a description thereof may be omitted. That is, as the detection unit, the reforming temperature detection unit and the voltage detection unit are used, and the reaction temperature of the reforming temperature detection unit and the generated voltage detected by the voltage detection unit are used as detection values. Different.

  Therefore, in the following, operations of the reforming temperature detection unit and the voltage detection unit, which are detection units that determine whether the measurement operation of the air flow rate measurement unit is appropriate, will be mainly described in detail.

  In the hydrogen generator 1 according to the present embodiment, the reforming temperature detector 21 and the voltage detector 28 are used as detectors. Then, based on the reaction temperature detected by the reforming temperature detector 21 and the detected value of the generated voltage detected by the voltage detector 28, the air flow rate measurement unit measures the flow rate of combustion air supplied to the combustion unit 2. This is to determine whether the operation is appropriate.

  Hereinafter, a specific operation of the detection unit will be described.

  First, when the flow rate of combustion air supplied from the combustion air supply unit 18 decreases, the amount of combustion exhaust gas decreases. As a result, the amount of heat taken out from the hydrogen generator 1 by the combustion exhaust gas decreases, so that the reaction temperature detected by the reforming temperature detector 21 increases. Note that an increase in the reaction temperature of the reforming temperature detection unit 21 is synonymous with an increase in the temperature (reaction temperature) of the reforming catalyst (or hydrogen-containing gas) in the steam reforming unit 20, and thus the reforming reaction between the raw material and water. As a result, the hydrogen concentration of the hydrogen-containing gas at the outlet of the reforming unit 30 also increases. As a result, the power generation voltage detected by the voltage detector 28 of the fuel cell 8 increases.

  On the other hand, when the flow rate of combustion air supplied from the combustion air supply unit 18 increases, the amount of combustion exhaust gas increases. As a result, the amount of heat taken out from the hydrogen generator 1 by the combustion exhaust gas increases, so that the reaction temperature detected by the reforming temperature detector 21 decreases. Note that the reduction in the reaction temperature of the reforming temperature detection unit 21 is synonymous with the reduction in the temperature (reaction temperature) of the reforming catalyst (or hydrogen-containing gas) in the steam reforming unit 20, and thus the reforming reaction between the raw material and water. Is suppressed, and the hydrogen concentration of the hydrogen-containing gas at the outlet of the reforming unit 30 decreases. As a result, the generated voltage detected by the voltage detection unit 28 of the fuel cell 8 decreases.

  That is, the operation control unit 16 determines changes in the reaction temperature of the reforming temperature detection unit 21 and the generated voltage detected by the voltage detection unit 28, which are detection values of the detection unit, thereby reducing the flow rate of combustion air. It can be determined whether the measurement operation (measurement value) of the air flow rate measurement unit 31 to be measured is appropriate.

  When it is determined that the flow rate of the combustion air has decreased, the combustion air supply unit is configured so that the reaction temperature detected by the reforming temperature detection unit 21 decreases and the power generation voltage detected by the voltage detection unit 28 decreases. 18 operations are controlled. If it is determined that the flow rate of the combustion air has increased, control is performed by the reverse operation.

  Furthermore, when it is determined that the measurement operation of the air flow rate measurement unit 31 is not appropriate and is outside the range of the appropriate measurement operation, control is performed to stop the operation of the fuel cell power generation system 100.

  In the present embodiment, whether or not the measurement operation (measured value) of the air flow rate measurement unit 31 is appropriate is determined based on the change in the reaction temperature of the reforming temperature detection unit 21 and the generated voltage of the voltage detection unit 28. However, the present invention is not limited to this. For example, according to the measurement operation of the air flow rate measuring unit 31, the reaction temperature detected by the reforming temperature detection unit 21 may be controlled in advance by setting the reaction temperature threshold and the generated voltage detected by the voltage detection unit 28 by controlling the voltage threshold. Good. Specifically, when the operation control unit 16 exceeds the reaction temperature threshold and the voltage threshold, or falls below the reaction temperature threshold and the water vapor temperature threshold, the operation control unit 16 performs an appropriate measurement operation in which the measurement operation of the air flow rate measurement unit 31 is set in advance. It is determined that the fuel cell power generation system 100 is out of the range and the operation of the fuel cell power generation system 100 is stopped. Here, the reaction temperature threshold and the voltage threshold are obtained by measuring in advance the relationship between the flow rate of combustion air at which the combustion state in the combustion unit 2 becomes unstable, the reaction temperature, and the power generation voltage in the hydrogen generator 1. Is set. For example, for combustion where the flow rate of combustion air increases and lean combustion increases the amount of carbon monoxide in the combustion exhaust gas, or the flow rate of combustion air decreases and the amount of carbon monoxide in the combustion exhaust gas increases. The air flow rate.

  In each of the above embodiments, the fuel cell power generation system having a configuration including all of the reforming temperature detection unit, the combustion detection unit, the water vapor temperature detection unit, and the voltage detection unit has been described as an example. Needless to say, a configuration having a detection unit that determines whether the measurement operation (measurement value) of the air flow rate measurement unit is appropriate may be selected as appropriate.

  In each of the above embodiments, the example in which the selective oxidation unit is provided in the reforming unit has been described. However, when the concentration of the raw material carbon monoxide can be reduced to a level that does not hinder the operation of the fuel cell in the transformation unit. Need not be provided. This simplifies the configuration of the reforming unit and the operation control unit.

  The present invention is useful in the technical field of fuel cell power generation systems that require high safety and reliability.

1 is a schematic configuration diagram of a fuel cell power generation system according to Embodiment 1 of the present invention. Sectional drawing of the principal part of the modification | reformation part in the fuel cell power generation system of Embodiment 1 of this invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hydrogen generator 2 Combustion part 3 Water supply part 4 Raw material supply part 5 Desulfurization part 6 Gas infrastructure line 7 Desulfurization connection part 8 Fuel cell 9, 9A Sealing part 10 Raw material supply path 11 Hydrogen generator bypass path 12 Hydrogen gas supply path DESCRIPTION OF SYMBOLS 13 Fuel cell bypass path 14 Off gas path 15 Combustion gas supply path 16 Operation control part 17 Fuel cell air blower 18 Combustion air supply part 19 Air supply part 20 Steam reforming part 21 Reforming temperature detection part 22 Combustion detection part 23 Steam generation part 23 24 Steam Temperature Detection Unit 25 Transformer 26 Selective Oxidation Unit 28 Voltage Detection Unit 30 Reformation Unit 31 Air Flow Measurement Unit 100 Fuel Cell Power Generation System

Claims (10)

A reforming section for generating a hydrogen-containing gas by a reforming reaction between the raw material and steam;
A reforming temperature detector for detecting a reaction temperature in the reforming reaction;
A combustion air supply unit for supplying combustion air;
An air flow rate measurement unit for measuring the flow rate of the combustion air;
A fuel cell that is supplied with the hydrogen-containing gas and the oxygen-containing gas to generate electricity;
A combustion section for burning the hydrogen-containing gas returned from the fuel cell and supplying heat necessary for the reforming reaction;
A water vapor generating unit that generates the water vapor by heat supplied from the combustion unit;
A combustion detection unit for detecting an ion current value in a flame provided in the combustion unit;
An operation control unit,
The operation control unit controls the operation of the combustion air supply unit based on at least the flow rate measured by the air flow rate measurement unit,
A fuel cell that determines and controls whether the measurement operation of the air flow rate measurement unit is appropriate based on the reaction temperature detected by the reforming temperature detection unit and the ion current value detected by the combustion detection unit Power generation system. When the flow rate of the combustion air is decreased, the reaction temperature is decreased, and the ion current value is decreased, or the flow rate of the combustion air is increased, and the reaction temperature is increased. and, and wherein when the ion current value increases, the fuel cell power generation system of claim 1, measuring operation of the air flow measuring unit controls is determined that abnormality. A predetermined reaction temperature threshold is set for the reaction temperature, and a predetermined current value threshold is set for the ion current value,
The operation control unit, when the flow rate measured by the air flow rate measurement unit is in an appropriate range, the reaction temperature is below the reaction temperature threshold, and the ion current value is below the current value threshold Or, when the reaction temperature exceeds the reaction temperature threshold value and the ion current value exceeds the current value threshold value, it is determined that the measurement operation of the air flow rate measurement unit is outside the range of the appropriate measurement operation set in advance. The fuel cell power generation system according to claim 1 , which is controlled as described above. A reforming section for generating a hydrogen-containing gas by a reforming reaction between the raw material and steam;
A reforming temperature detector for detecting a reaction temperature in the reforming reaction;
A combustion air supply unit for supplying combustion air;
An air flow rate measurement unit for measuring the flow rate of the combustion air;
A fuel cell that is supplied with the hydrogen-containing gas and the oxygen-containing gas to generate electricity;
A combustion section for burning the hydrogen-containing gas returned from the fuel cell and supplying heat necessary for the reforming reaction;
A water vapor generating unit that generates the water vapor by heat supplied from the combustion unit;
A water vapor temperature detection unit for detecting a water vapor atmosphere temperature provided in the water vapor generation unit ;
An operation control unit,
The operation control unit controls the operation of the combustion air supply unit based on at least the flow rate measured by the air flow rate measurement unit,
Based on the reaction temperature detected by the reforming temperature detection unit and the water vapor atmosphere temperature detected by the water vapor temperature detection unit, whether or not the measurement operation of the air flow rate measurement unit is appropriate is controlled. fuel cell power generation system that. The operation control unit increases the reaction temperature when the flow rate of the combustion air decreases, the reaction temperature decreases, and the water vapor atmosphere temperature increases, or the flow rate of the combustion air increases. The fuel cell power generation system according to claim 4 , wherein when the water vapor atmosphere temperature decreases, the measurement operation of the air flow rate measurement unit is determined to be abnormal and controlled. A reaction temperature threshold is set in advance for the reaction temperature, and a water vapor temperature threshold is set in advance for the water vapor atmosphere temperature;
The operation control unit, when the flow rate measured by the air flow rate measurement unit is in an appropriate range, the reaction temperature exceeds the reaction temperature threshold, and the water vapor atmosphere temperature is lower than the water vapor temperature threshold Or, when the reaction temperature is lower than the reaction temperature threshold value and the water vapor atmosphere temperature is higher than the water vapor temperature threshold value, it is determined that the measurement operation of the air flow rate measurement unit is outside the range of the appropriate measurement operation set in advance. The fuel cell power generation system according to claim 4 , wherein the fuel cell power generation system is controlled as described above. A reforming section for generating a hydrogen-containing gas by a reforming reaction between the raw material and steam;
A reforming temperature detector for detecting a reaction temperature in the reforming reaction;
A combustion air supply unit for supplying combustion air;
An air flow rate measurement unit for measuring the flow rate of the combustion air;
A fuel cell that is supplied with the hydrogen-containing gas and the oxygen-containing gas to generate electricity;
A combustion section for burning the hydrogen-containing gas returned from the fuel cell and supplying heat necessary for the reforming reaction;
A water vapor generating unit that generates the water vapor by heat supplied from the combustion unit;
A voltage detector for detecting a power generation voltage provided in the fuel cell ;
An operation control unit,
The operation control unit controls the operation of the combustion air supply unit based on at least the flow rate measured by the air flow rate measurement unit,
Wherein a reaction temperature detected by the reforming temperature detection section, based on said generated voltage detected by the voltage detection unit, the measurement operation of the air flow measuring unit that controls to determine whether the proper retardant Battery power generation system. When the flow rate of the combustion air decreases, the reaction temperature decreases, and the power generation voltage decreases, or the operation control unit increases the flow rate of the combustion air, the reaction temperature increases. The fuel cell power generation system according to claim 7 , wherein when the power generation voltage increases, the measurement operation of the air flow rate measurement unit is determined to be abnormal and controlled. A reaction temperature threshold is set in advance for the reaction temperature, and a voltage threshold is set in advance for the generated voltage;
The operation control unit, even though the flow rate measured by the air flow measuring section is appropriate range, the reaction temperature is higher than the reaction temperature threshold value, and when said generated voltage exceeds the voltage threshold, or When the reaction temperature is lower than the reaction temperature threshold value and the generated voltage is lower than the voltage threshold value, it is determined that the measurement operation of the air flow rate measurement unit is outside the range of the preset proper measurement operation. The fuel cell power generation system according to claim 7 . The fuel cell power generation system according to any one of claims 1 to 9, wherein the operation control unit controls the operation to be stopped when it is determined that the measurement operation of the air flow rate measurement unit is not appropriate .

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