JP6870409B2 - Fuel cell system - Google Patents

Description

The invention of the present disclosure relates to a fuel cell system including a fuel cell that generates electricity by an electrochemical reaction between an anode gas and a cathode gas.

Conventionally, as a fuel cell system of this type, a reformer for reforming a hydrocarbon gas and a desulfurizer for removing a sulfur compound in the hydrocarbon gas at the stage before the reformer are known. (See, for example, Patent Document 1). In this fuel cell system, an adsorbent with an indicator function is arranged in the desulfurizer, and the life of the adsorbent is detected based on the hue change of the adsorbent. Further, as this type of fuel cell system, the air supply unit that supplies air to the gas flow path connecting the desulfurizer and the reformer and the position downstream from the position where the air from the air supply unit is mixed. It is also known to include a single-chamber solid electrolyte fuel cell interposed in a gas flow path on the side and upstream of the reformer (see, for example, Patent Document 2). In this fuel cell system, the life of the desulfurizer is determined by mixing air by an air supply unit and detecting the power generation output of the single-chamber solid electrolyte fuel cell.

Japanese Unexamined Patent Publication No. 2002-358992 Japanese Unexamined Patent Publication No. 2011-113726

In the fuel cell system described in Patent Document 1, the life of the adsorbent is determined by visually observing or photographing the hue change of the adsorbent with a camera. However, it is not easy to properly grasp the hue change of the adsorbent by visual inspection or camera photography, and the fuel cell system described in Patent Document 1 still has room for improvement in terms of the life determination accuracy of the adsorbent. doing. In addition, if a camera for photographing the adsorbent is installed in the fuel cell system, the cost of the entire system will increase. Further, in the fuel cell system described in Patent Document 2, the cost of the entire system is increased due to the addition of the single-chamber type solid electrolyte fuel cell.

Therefore, the main object of the present disclosure is to make it possible to accurately determine the deterioration of the removing agent for removing the component to be removed in the raw material and fuel while suppressing the cost increase of the fuel cell system.

The fuel cell system of the present disclosure is a fuel cell system including a fuel cell that generates power by an electrochemical reaction between an anode gas and a cathode gas, and a reformer that reforms raw fuel to generate the anode gas. It has a remover that is arranged on the upstream side of the reformer and generates heat by reacting with oxygen, and in the presence of the remover, the component to be removed in the raw material and fuel is chemically reacted to obtain the component to be removed. From the removing device adsorbed on the removing agent, the oxygen supply device that supplies oxygen to the gas inlet of the removing device, the temperature sensor that detects the temperature of the removing agent on the gas outlet side of the removing device, and the oxygen supply device. It is provided with a deterioration determining device for determining deterioration of the removing agent of the removing device based on a value detected by the temperature sensor when oxygen is supplied to the gas inlet of the removing device.

In this fuel cell system, the remover of the remover deteriorates from the gas inlet side due to the adsorption of the component to be removed, and as the operating time of the fuel cell system becomes longer, the position of the remover that has not deteriorated becomes It moves from the gas inlet side to the gas outlet side. Then, when oxygen is supplied from the oxygen supply device to the removal device, the component to be removed is not adsorbed, and the undeteriorated remover reacts with oxygen to generate heat. Therefore, by acquiring the temperature of the removing agent on the gas outlet side with the temperature sensor in a state where the removing agent generates heat due to the supply of oxygen from the oxygen supply device to the removing device, the degree of deterioration of the removing agent is based on the temperature. Can be properly grasped. Further, the cost increase due to the installation of the temperature sensor can be tolerated, and the oxygen supply device can also be provided for other purposes. As a result, in this fuel cell system, it is possible to accurately determine the deterioration of the removing agent for removing the removal target component in the raw material fuel while suppressing the cost increase of the entire system.

Further, the deterioration determination device may determine that the removal agent of the removal device has reached the end of its life when the detection value of the temperature sensor becomes equal to or higher than a predetermined threshold value. That is, by installing the temperature sensor on the gas outlet side of the removing device having the removing agent having the above-mentioned characteristics, it is possible to accurately detect the life of the removing agent.

Further, the deterioration determining device may determine that the life of the removing agent of the removing device is near when the detected value of the temperature sensor becomes equal to or higher than the low temperature side threshold value lower than the threshold value. This makes it possible to more appropriately grasp the degree of deterioration of the removing agent.

Further, the fuel cell system may further include a notification device for notifying the determination result of the deterioration determination device. This makes it possible to notify the user of the fuel cell system of the degree of deterioration of the removing agent of the removing device and provide it to the user's stool.

Further, the fuel cell system may further include an oxidizer that produces hydrogen by reacting hydrocarbons in the raw material and fuel with oxygen from the oxygen supply device, and the removal device may be provided from the oxidizer. A desulfurizer may be used which removes the sulfur component by reacting hydrogen with the sulfur component in the raw material and fuel. When the removing device is a so-called hydrogenated desulfurizer, the deterioration of the desulfurizing agent of the desulfurizer can be determined by using the oxygen supply device provided for the desulfurizer. This makes it possible to accurately determine the deterioration of the desulfurizing agent in the desulfurizer while suppressing the cost increase of the entire system.

Further, when the temperature of the fuel cell drops due to the stop of the operation of the fuel cell system, the deterioration determination device supplies oxygen from the oxygen supply device to the removal device to deteriorate the removal agent. You may judge. This makes it possible to suppress deterioration due to oxidation of the fuel cell due to execution of deterioration determination of the removing agent.

It is a schematic block diagram which shows the fuel cell system of this disclosure. It is explanatory drawing which shows the structure of the desulfurizer in the fuel cell system of this disclosure, and the progress state of deterioration of the desulfurizing agent contained in the desulfurizer. It is a flowchart which shows an example of the desulfurization agent deterioration determination routine executed in the fuel cell system of this disclosure.

Next, a mode for carrying out the invention of the present disclosure will be described with reference to the drawings.

FIG. 1 is a schematic configuration diagram showing the fuel cell system 10 of the present disclosure. The fuel cell system 10 shown in the figure comprises a power generation unit 20 having a fuel cell FC that generates power by an electrochemical reaction between hydrogen in an anode gas (fuel gas) and oxygen in a cathode gas (oxidizer gas), and hot water. It includes a hot water supply unit 100 having a hot water storage tank 101 for storing, and a control device 80 for controlling the entire system. Further, the power generation unit 20 is a power generation module 30 including a fuel cell FC, a box-shaped module case 31 formed of a heat insulating material, a vaporizer 32, a reformer 33, and the like, and a vaporizer 32 of the power generation module 30. For example, the raw fuel gas supply system 40 for supplying raw fuel gas (raw fuel) such as natural gas and LP gas, and the air supply for supplying air (air) as cathode gas to the fuel cell FC of the power generation module 30. The system 50, the reformed water supply system 55 for supplying the reformed water to the vaporizer 32 of the power generation module 30, the exhaust heat recovery system 60 for recovering the exhaust heat generated in the power generation module 30, and the fuel cell. It has a power conditioner 71 connected to an output terminal of the FC, and a housing 22 for accommodating the power conditioner 71.

The fuel cell FC of the power generation module 30 is a solid oxide fuel cell, and a plurality of single cells including an electrolyte such as zirconium oxide and an anode electrode and a cathode electrode sandwiching the electrolyte are laminated in the left-right direction in FIG. A plurality of (two in this embodiment) cell stack CS configured by the above are included. On the anode electrode side of each cell, an anode gas passage (not shown) through which the anode gas flows is formed so as to extend in a direction orthogonal to the cell stacking direction (vertical direction in the figure). Further, on the cathode electrode side of each cell, an air passage (not shown) for circulating air is formed so as to extend in a direction orthogonal to the stacking direction of the cells (vertical direction in the drawing). The two cell stack CSs constituting the fuel cell FC are arranged side by side on a manifold installed in the module case 31 via a heat insulating material, and the anode gas passage of each cell is an anode gas passage formed in the manifold. Be connected. Further, the air passage of each cell is connected to an air supply passage (not shown) in the module case 31.

The vaporizer 32 and the reformer 33 of the power generation module 30 are arranged above the plurality of cell stacks CS in the module case 31 at intervals from each other. Between the two cell stacks CS and the carburetor 32 and the reformer 33, there is a combustion unit 34 that generates heat required for the operation of the fuel cell FC and the reaction in the carburetor 32 and the reformer 33. It is made. An ignition heater 35 is installed in the combustion unit 34, and a temperature sensor 36 is installed so as to be close to one of the two cell stacks CS.

The vaporizer 32 heats the raw fuel gas from the raw material fuel gas supply system 40 and the reformed water from the reformed water supply system 55 by the heat from the combustion unit 34 to preheat the raw material fuel gas and reformed water. To generate water vapor. The raw material fuel gas preheated by the vaporizer 32 is mixed with water vapor, and the mixed gas of the preheated raw material fuel gas and water vapor is introduced from the vaporizer 32 into the reformer 33.

The reformer 33 has, for example, a Ru-based or Ni-based reforming catalyst filled therein, and the reaction of the mixed gas from the vaporizer 32 by the reforming catalyst in the presence of heat from the combustion unit 34. (Steam reforming reaction) produces hydrogen gas and carbon monoxide. Further, the reformer 33 produces hydrogen gas and carbon dioxide by the reaction between carbon monoxide generated by the steam reforming reaction and steam (carbon monoxide shift reaction). As a result, the reformer 33 produces an anode gas containing hydrogen, carbon monoxide, carbon dioxide, steam, unreformed raw material fuel gas, and the like.

The anode gas generated by the reformer 33 is supplied to the anode electrodes of each cell via the manifold, the anode gas passage of each cell of the cell stack CS, and the like. Further, air as a cathode gas containing oxygen is supplied to the cathode electrodes of each cell of the cell stack CS via an air passage or the like of each cell. The cathode electrode, oxide ions (O ₂ ^-) is generated, electric energy is obtained by the oxide ions react with the hydrogen and carbon monoxide at the anode electrode through the electrolyte. In addition, the anode gas (hereinafter referred to as "anode off gas") and air (hereinafter referred to as "cathode off gas") that were not used for the electrochemical reaction (power generation) in each cell stack CS are the anode gas passage and air of each cell. It flows out from the passage to the upper combustion part 34.

The anode off gas flowing into the combustion section 34 from the anode gas passage of each cell is a flammable gas containing fuel components such as hydrogen and carbon monoxide, and the cathode containing oxygen flowing into the combustion section 34 from the air passage of each cell. Mixes with off-gas. Hereinafter, the mixed gas of the anode off gas and the cathode off gas is referred to as "off gas". Then, when the ignition heater 35 ignites and the off gas (anode off gas) is ignited in the combustion unit 34, the combustion of the off gas causes the operation of the fuel cell FC, the preheating of the raw fuel gas in the vaporizer 32, and the generation of steam. , The heat required for the steam reforming reaction in the reformer 33 will be generated. Further, with the combustion of off-gas, the combustion unit 34 generates combustion exhaust gas containing water vapor.

As shown in FIG. 1, the raw material fuel gas supply system 40 for supplying the raw material fuel gas to the vaporizer 32 is a raw material fuel gas connecting the raw material fuel supply source 1 for supplying natural gas or LP gas and the vaporizer 32. It is located between the supply pipe 41, the raw fuel gas supply valves (electromagnetic on-off valves) 42, 43 and the raw fuel gas pump 44 incorporated in the raw material fuel gas supply pipe 41, and the vaporizer 32 and the raw fuel gas pump 44. The first desulfurizer 45A incorporated in the raw fuel gas supply pipe 41 and the second desulfurizer incorporated in the raw fuel gas supply pipe 41 so as to be located between the vaporizer 32 and the first desulfurizer 45A. (Removal device) 45B and an oxidizer 46 incorporated in a raw material fuel gas supply pipe 41 so as to be located between the first desulfurizer 45A and the second desulfurizer 45B. Further, the raw material fuel gas supply pipe 41 includes a pressure sensor 48 that detects the pressure of the raw material fuel gas in the raw material fuel gas supply pipe 41, and a raw material fuel gas flowing through the raw material fuel gas supply pipe 41 per unit time. A flow rate sensor 49 that detects the flow rate is installed.

The first desulfurizer 45A removes a sulfur component (sulfur compound) from a raw material fuel gas by using an adsorbent such as zeolite. Further, when the supply of the raw material fuel gas to the first desulfurizer 45A is started, the fuel component (hydrocarbon such as methane) in the raw material fuel gas is physically adsorbed on the adsorbent together with the sulfur component. The desulfurization method of the first desulfurization device 45A is not limited to the so-called room temperature desulfurization method. As shown in FIG. 2, the second desulfurizer 45B has a housing 45c having a gas inlet 45i and a gas outlet 45o, and a hydrogenated desulfurizing agent (removing agent) 45ds filled inside the housing 45c. , A so-called hydrogenated desulfurizer. In this embodiment, a CuZn-based catalyst is used as the hydrogenated desulfurizing agent 45ds. The second desulfurizer 45B reacts the sulfur compound (SR) of the raw material fuel gas with hydrogen (H ₂ ) in the presence of the hydrogenated desulfurizing agent 45ds to convert it into hydrogen sulfide (H ₂ S), and uses it as a component to be removed. Hydrogen sulfide containing sulfur is adsorbed on the hydrogenated desulfurizing agent 45ds.

In the present embodiment, the second desulfurizer 45B is arranged near or inside the module case 31 in order to bring the hydrogenated desulfurizing agent 45ds to a temperature suitable for the desulfurization reaction. Further, the second desulfurizer 45B is provided with a temperature sensor 45t that detects the temperature of the hydrogenated desulfurizing agent 45ds on the gas outlet 45o side of the housing 45c. The temperature sensor 45t is installed near the gas outlet 45o, that is, at a position close to the gas outlet 45o between the center of the housing 45c (see the alternate long and short dash line in FIG. 2) and the gas outlet 45o in the flow direction of the raw material fuel gas. Will be done. The hydrogenated desulfurizing agent 45ds may be, for example, a ZnO-based catalyst as long as it contains a component that generates heat by reacting with oxygen. Further, the temperature sensor 45t may be installed at the gas outlet 45o.

The oxidizer 46 has, for example, a carrier such as alumina carrying a deoxidizing catalyst such as rhodium, platinum, or palladium, or a porous body made of Cu, Zn, or the like as a deoxidizing catalyst, and the presence of the deoxidizing catalyst. Below, the hydrocarbons in the raw material and fuel gas are burned to remove oxygen in the raw material and fuel gas by a deoxidizing reaction (hydrogenation deoxidizing reaction) and generate hydrogen. Further, an air blower (oxygen supply device) 47 is connected to a portion of the raw material fuel gas supply pipe 41 between the gas outlet of the first desulfurizer 45A and the gas inlet of the oxidizer 46 via an air supply pipe. .. By operating the air blower 47, the air sucked through the air filter is pressure-fed (supplied) to the gas inlet of the oxidizer 46 by the air blower 47, and oxygen for combustion is supplied to the oxidizer 46. .. Thereby, by operating the air blower 47 during the operation of the fuel cell system 10, hydrogen to be reacted with the sulfur compound can be supplied from the oxidizing device 46 to the second desulfurizing device 45B. Further, the oxidizer 46 is also arranged near or inside the module case 31 in order to bring the deoxidizing catalyst to a temperature suitable for the hydrogenation deoxygenation reaction.

The air supply system 50 includes an air supply pipe 51 connected to an air supply passage in the module case 31, an air filter 52 installed at the air inlet of the air supply pipe 51, and an air blower 53 incorporated in the air supply pipe 51. And include. By operating the air blower 53, the air sucked through the air filter 52 is pressure-fed (supplied) to the fuel cell FC by the air blower 53. Further, the air supply pipe 51 is provided with a flow rate switch 54 that turns on when the flow rate of air flowing through the air supply pipe 51 per unit time reaches a predetermined value.

The reformed water supply system 55 includes a reformed water supply pipe 56 connected to the vaporizer 32, a reformed water tank 57 connected to the reformed water supply pipe 56 and storing the reformed water, and the reformed water. It includes a reforming water pump 58 incorporated in the supply pipe 56. By operating the reforming water pump 58, the reforming water in the reforming water tank 57 is pumped (supplied) to the vaporizer 32 by the reforming water pump 58. Further, in the reformed water tank 57, a water purifier (not shown) for purifying the stored reformed water is installed.

The exhaust heat recovery system 60 is a heat exchanger that exchanges heat between the circulation pipe 61 connected to the hot water storage tank 101 of the hot water supply unit 100, the hot water flowing through the circulation pipe 61, and the combustion exhaust gas from the combustion unit 34 of the power generation module 30. 62 and a circulation pump 63 incorporated in the circulation pipe 61. By operating the circulation pump 63, the hot water stored in the hot water storage tank 101 by the circulation pump 63 is introduced into the heat exchanger 62, and the heat exchanger 62 removes heat from the combustion exhaust gas to heat the hot water. It can be returned to the hot water storage tank 101.

Further, the heat exchanger 62 (combustion exhaust gas passage) of the exhaust heat recovery system 60 is connected to the reforming water tank 57 via the condensed water supply pipe 66, and the steam in the combustion exhaust gas is discharged from the hot water storage tank 101. The condensed water obtained by condensing by heat exchange with hot water is introduced into the reformed water tank 57 via the condensed water supply pipe 66. Further, the passage of the combustion exhaust gas of the heat exchanger 62 is connected to the exhaust pipe 67. As a result, the exhaust gas discharged from the combustion unit 34 (fuel cell FC) of the power generation module 30 and from which the water has been removed by the heat exchanger 62 is discharged to the atmosphere through the exhaust pipe 67.

The power conditioner 71 includes a DC / DC converter that is connected to the output terminal of the fuel cell FC to boost the DC power from the fuel cell FC, and an inverter that converts the DC power from the DC / DC converter into AC power. Has (all not shown). The output terminal of the power conditioner 71 (inverter) is connected to the power line 3 connected to the system power supply 2. As a result, the DC power from the fuel cell FC can be converted into AC power and supplied to the load 4 of the home electric appliance or the like. Further, the fuel cell system 10 includes a power supply board 72 connected to the power line 3. The power supply board 72 has an AC / DC converter that converts AC power from the system power supply 2 into DC power, and includes raw fuel gas supply valves 42 and 43, raw fuel gas pumps 44, air blowers 47 and 53, and reformed water. DC power is supplied to auxiliary equipment such as the pump 58 and the circulation pump 63, sensors such as the temperature sensors 36 and 45t, and the control device 80 and the like.

Further, in the auxiliary equipment room where the power conditioner 71, the power supply board 72, etc. are arranged, a cooling fan (not shown) for cooling the power conditioner 71, the power supply board 72, etc., and a ventilation fan 24 are arranged. Has been done. A cooling fan (not shown) sends air to the heat generating portion of the power conditioner 71 or the power supply board 72, and the air heated by cooling the heat generating portion is discharged to the atmosphere by the ventilation fan 24.

The control device 80 is a computer including a CPU 81, a ROM 82 for storing various programs, a RAM 83 for temporarily storing data, a timer 84, and an input port and an output port (not shown). The control device 80 inputs the temperature sensors 36, 45t, the pressure sensor 48, the detected values of the flow rate sensor 49, the signal from the flow rate switch 54, and the like via the input port. Further, the control device 80 includes a ventilation fan 24, an ignition heater 35, a solenoid of raw fuel gas supply valves 42 and 43, a raw fuel gas pump 44, an air blower 47 and 53, a reforming water pump 58, a circulation pump 63, and a power conditioner. Control signals to 71 (DC / DC converter and inverter), display panel 90, etc. are output via the output port to control these devices. Further, the remote control 85 is connected to the control device 80 via a wireless or wired communication line, and the control device 80 is based on a signal from the remote control 85 operated by the user of the fuel cell system 10. To execute various controls. Further, in the present embodiment, the remote controller 85 has a display unit 85a capable of displaying various information.

Here, in the above-mentioned fuel cell system 10, the hydrogenated desulfurizing agent 45ds of the second desulfurizer 45B deteriorates from the gas inlet 45i side due to the adsorption of hydrogen sulfide, and the operating time of the fuel cell system 10 becomes longer. As a result, the position of the hydrogenated desulfurizing agent 45ds that has not deteriorated moves from the gas inlet 45i side to the gas outlet 45o side, as can be seen from FIG. Further, during the operation of the fuel cell system 10, the hydrogenated desulfurizing agent 45ds of the second desulfurizer 45B becomes a state containing reduced Cu, and becomes the hydrogenated desulfurizing agent 45ds during the operation of the fuel cell system 10 or after the operation is stopped. On the other hand, when oxygen is supplied, Cu is oxidized (2Cu + O ₂ → 2CuO) to generate heat. At this time, the hydrogenated desulfurization agent 45ds deteriorated by the adsorption of hydrogen sulfide located in the range shown by the broken line in FIG. 2 does not generate heat, and the undeteriorated hydrogenated desulfurization adjacent to the deteriorated portion without adsorbing hydrogen sulfide. The agent 45ds (Cu) reacts with oxygen to generate heat. Therefore, when oxygen is supplied to the second desulfurizer 45B, the temperature of the hydrogenated desulfurizing agent 45ds rises at the heat generating portion that has reacted with oxygen. Based on this, in the fuel cell system 10 of the present embodiment, deterioration of the hydrogenated desulfurizing agent 45ds of the second desulfurizing device 45B is determined as described below.

FIG. 3 is a flowchart showing an example of a desulfurizing agent deterioration determination routine executed by the control device 80 of the fuel cell system 10.

The CPU 81 of the control device 80 starts the routine of FIG. 3 after the operation of the fuel cell system 10 is stopped and when the temperature of the fuel cell FC (cell stack CS) detected by the temperature sensor 36 becomes equal to or lower than a predetermined temperature. .. The predetermined temperature is determined so that the hydrogenated desulfurizing agent 45ds of the second desulfurizer 45B contains reduced Cu when the temperature of the fuel cell FC becomes equal to or lower than the predetermined temperature. At the start of the routine of FIG. 3, the CPU 81 first operates the air blower 47 to start supplying air (oxygen) to the gas inlet 45i of the second desulfurizer 45B via the oxidizing device 46 (step S100).

After operating the air blower 47, the CPU 81 waits for a predetermined time until the undegraded hydrogenated desulfurizing agent 45ds on which the sulfur component is not adsorbed sufficiently generates heat, and then the temperature sensor of the second desulfurizer 45B. The temperature T (detection value) detected by 45t is acquired (step S110). Further, the CPU 81 determines whether or not the temperature T acquired in step S110 is equal to or higher than the predetermined first threshold value (low temperature side threshold value) Tref1 (step S120). In the present embodiment, the first threshold Tref1 is, for example, higher than the temperature of the hydrogenated desulfurizing agent 45ds when it reacts with oxygen and does not generate heat, and the hydrogenated desulfurizing agent 45ds when it reacts with oxygen and generates heat. It is a temperature set lower than the maximum temperature of.

When the temperature T detected by the temperature sensor 45t is less than the first threshold Tref1, the hydrogenated desulfurizing agent 45ds located in the vicinity of the temperature sensor 45t does not generate heat due to the reaction with oxygen, and the second desulfurizer 45B It can be considered that a sufficient amount of undeteriorated hydrogenated desulfurizing agent 45ds is left inside the housing 45c. Therefore, when it is determined in step S120 that the temperature T is less than the first threshold value Tref1 (step S120: NO), the CPU 81 stops the operation of the air blower 47 (step S160) and ends this routine.

On the other hand, when it is determined in step S120 that the temperature T is equal to or higher than the first threshold value Tref1 (step S120: YES), the CPU 81 has a second threshold value Tref2 in which the temperature T acquired in step S110 is higher than the first threshold value Tref1. It is determined whether or not the temperature is less than (step S130). In the present embodiment, the second threshold value Tref2 is set to be slightly lower than the maximum temperature of the hydrogenated desulfurizing agent 45ds when the temperature is generated by reacting with oxygen, for example. It is the temperature.

When the temperature T detected by the temperature sensor 45t is less than the second threshold Tref1, the hydrogenated desulfurizing agent 45ds located in the vicinity of the temperature sensor 45t does not generate heat due to the reaction with oxygen, but is relatively relatively different from the temperature sensor 45t. It can be considered that the hydrogenated desulfurizing agent 45ds located in a close position generates heat due to the reaction with oxygen. Therefore, when it is determined in step S130 that the temperature T is less than the second threshold value Tref2 (step S130: YES), the CPU 81 displays a warning display indicating that the life of the hydrogenated desulfurizing agent 45ds is approaching. Along with displaying on 90, a display command signal is transmitted to the remote controller 85 so that the same warning display is displayed on the display unit 85a (step S140). Then, the CPU 81 stops the operation of the air blower 47 (step S160), and ends this routine.

When it is determined in step S130 that the temperature T is equal to or higher than the second threshold value Tref2 (step S130: NO), the CPU 81 indicates that the hydrogenated desulfurizing agent 45ds has reached the end of its useful life (replacement request display). ) Is displayed on the display panel 90, and a display command signal is transmitted to the remote controller 85 so that the display unit 85a displays the same display of the end of life (step S150). Then, the CPU 81 stops the operation of the air blower 47 (step S160), and ends this routine.

As described above, the fuel cell system 10 has a hydrogenated desulfurizing agent 45ds having a property of reacting with oxygen to generate heat, and is not deteriorated as the operating time of the fuel cell system 10 is extended. A temperature sensor 45t is installed on the gas outlet 45o side of the second desulfurizer 45B in which the position of the desulfurizing agent 45ds moves from the gas inlet 45i side to the gas outlet 45o side. Then, in the fuel cell system 10, by executing the desulfurizing agent deterioration determination routine of FIG. 3, the hydrogenated desulfurizing agent 45ds generates heat due to the supply of oxygen from the air blower 47 to the second desulfurizer 45B, and the gas outlet is operated by the temperature sensor 45t. The temperature T of the hydrogenated desulfurizing agent 45ds on the 45o side is acquired, and the temperature T is compared with the first and second thresholds Tref1 and Tref2 (steps S110, S120, S130). This makes it possible to appropriately and accurately grasp the degree of deterioration and the life of the hydrogenated desulfurizing agent 45ds that removes the sulfur component, which is the component to be removed in the raw material fuel gas. Further, the cost increase due to the installation of the temperature sensor 45t can be tolerated, and the air blower 47 used for supplying oxygen to the oxidizing device 46 can also be used as the oxygen supply device for supplying oxygen to the second desulfurization device 45B. it can. As a result, in the fuel cell system 10, it is possible to satisfactorily suppress the cost increase of the entire system.

Further, in the fuel cell system 10, the determination result of the control device 80 as the deterioration determination device is displayed on the display unit 85a or the display panel 90 of the remote controller 85 as the notification device (steps S140 and S150). This makes it possible to notify the user of the fuel cell system 10 of the degree of deterioration of the hydrogenated desulfurizing agent 45ds of the second desulfurizer 45B and provide it to the user's stool.

Further, when the temperature of the fuel cell FC drops due to the stop of the operation of the fuel cell system 10, the control device 80 supplies oxygen from the air blower 47 to the second desulfurizer 45B to deteriorate the hydrogenated desulfurizing agent 45ds. To judge. This makes it possible to suppress deterioration due to oxidation of the fuel cell FC due to execution of deterioration determination of the hydrogenated desulfurizing agent 45ds.

As described above, the fuel cell system 10 of the present disclosure has a hydrogenated desulfurizing agent 45ds that is arranged on the upstream side of the reformer 33 and generates heat by reacting with oxygen, and the hydrogenated desulfurizing agent 45ds. A second desulfurizer 45B that chemically reacts sulfur components in the raw material fuel gas in the presence and adsorbs it on the hydrogenated desulfurizer 45ds, an air blower 47 that supplies oxygen to the gas inlet 45i of the second desulfurizer 45B, and a first 2 Detection of the temperature sensor 45t that detects the temperature of the hydrogenated desulfurizing agent 45ds on the gas outlet 45o side of the desulfurizer 45B and the temperature sensor 45t when oxygen is supplied from the air blower 47 to the gas inlet 45i of the second desulfurizer 45B. It includes a control device 80 for determining deterioration of the hydrogenated desulfurizing agent 45ds based on the value. As a result, in the fuel cell system 10, it is possible to accurately determine the deterioration of the hydrogenated desulfurizing agent 45ds for removing the sulfur component in the raw material fuel gas while suppressing the cost increase of the entire system.

In the fuel cell system 10, the air blower 47 that supplies oxygen to the oxidizing device 46 is also used as an oxygen supply device that supplies oxygen to the second desulfurizing device 45B when determining the deterioration of the hydrogenated desulfurizing agent 45ds, but this is limited to this. It is not something that can be done. That is, the air blower 53 of the air supply system 50 that supplies air as the cathode gas to the fuel cell FC may also be used as an oxygen supply device that supplies oxygen to the second desulfurizer 45B. In this case, the branch pipe including the switching valve is branched from the air supply pipe 51 connected to the air blower 53 in the middle, and the branch pipe is divided into the gas outlet of the first desulfurizer 45A of the raw material fuel gas supply pipe 41 and the oxidizer 46. It may be connected to the part between the gas inlet. Further, when the oxidizer 46 is omitted or the like, a dedicated oxygen supply device for supplying oxygen to the second desulfurization device 45B may be provided for the fuel cell system 10.

Further, in the fuel cell system 10, when the oxidizer 46 has a deoxidizing catalyst having a characteristic of reacting with oxygen to generate heat, as shown by a two-point chain line in FIG. 1, the oxidizer 46 is on the gas outlet side. A temperature sensor 46t for detecting the temperature of the deoxidizing catalyst may be installed in the above, and deterioration of the deoxidizing catalyst may be determined based on the detected value of the temperature sensor 46t. Also in this case, the temperature of the oxygen scavenger on the gas outlet side of the oxidizer 46 is acquired by the temperature sensor 46t in a state where the oxygen scavenger is generated by the supply of oxygen from the air blower 47 to the oxidizer 46, and the acquired temperature is used. It may be compared with the predetermined thresholds (first and second thresholds).

Further, in the above fuel cell system 10, when the first desulfurizer 45A has a desulfurizing agent (for example, a desulfurizing agent other than the hydrogenated desulfurizing agent) having a characteristic of reacting with oxygen to generate heat, the two-point chain wire is shown in FIG. As shown in the above, a temperature sensor 45t'that detects the temperature of the desulfurizing agent on the gas outlet side is installed in the first desulfurizing device 45A, and the desulfurizing agent of the first desulfurizing device 45A is installed based on the detected value of the temperature sensor 45t'. Deterioration may be determined. In this case, as shown by the alternate long and short dash line in FIG. 2, a branch pipe including a switching valve may be installed in the middle between the air blower 47 and the gas inlet of the first desulfurizer 45A. In this case as well, the temperature of the desulfurizing agent on the gas outlet side of the first desulfurizing device 45A is acquired by the temperature sensor 45t'in a state where the desulfurizing agent generates heat due to the supply of oxygen from the air blower 47 to the first desulfurizing device 45A. , The acquired temperature may be compared with the predetermined first and second thresholds.

Further, the desulfurizing agent deterioration determination routine of FIG. 3 may be modified so as to operate the air blower 47 for a predetermined time in step S100, and in this case, step S160 may be omitted. Further, in the desulfurizing agent deterioration determination routine of FIG. 3, the processes of steps S120 and S140 may be omitted.

It goes without saying that the invention of the present disclosure is not limited to the above-described embodiment, and various changes can be made within the scope of the extension of the present disclosure. Furthermore, the above-described embodiment is merely a specific embodiment of the invention described in the column of the outline of the invention, and does not limit the elements of the invention described in the column of the outline of the invention.

The invention of the present disclosure can be used in the manufacturing industry of fuel cell systems and the like.

1 Raw fuel supply source, 2 system power supply, 3 power line, 4 load, 10 fuel cell system, 20 power generation unit, 22 housing, 24 ventilation fan, 30 power generation module, 31 module case, 32 vaporizer, 33 reformer , 34 Combustion unit, 35 Ignition heater, 36 Temperature sensor, 40 Raw fuel gas supply system, 41 Raw fuel gas supply pipe, 42, 43 Raw fuel gas supply valve, 44 Raw fuel gas pump, 45A 1st desulfurizer, 45B 2nd Desulfurizer, 45c housing, 45ds hydrogenated desulfurizing agent, 45i gas inlet, 45o gas outlet, 45t, 45t', 46t temperature sensor, 46 oxidizer, 47 air blower, 48 pressure sensor, 49 flow sensor, 50 air supply system, 51 air supply pipe, 52 air filter, 53 air blower, 54 flow switch, 55 reformed water supply system, 56 reformed water supply pipe, 57 reformed water tank, 58 reformed water pump, 60 exhaust heat recovery system, 61 circulation Piping, 62 Heat exchanger, 63 Circulation pump, 66 Condensed water supply pipe, 67 Exhaust pipe, 71 Power conditioner, 72 Power supply board, 80 Control device, 81 CPU, 82 ROM, 83 RAM, 84 Timer, 85 Remote control, 85a Display, 90 display panel, 100 hot water supply unit, 101 hot water storage tank, CS cell stack, FC fuel cell.

Claims (6)

In a fuel cell system including a fuel cell that generates power by an electrochemical reaction between an anode gas and a cathode gas, and a reformer that reforms raw fuel to generate the anode gas.
The first desulfurizer that removes the sulfur component in the raw material and fuel,
It has a remover that is arranged on the downstream side of the first desulfurizer and upstream of the reformer and generates heat by reacting with oxygen, and in the presence of the remover, the sulfur component in the raw material fuel is removed. a second desulfurizer adsorbing the sulfur component in the removing agent by chemical reaction,
An oxygen supply device that supplies oxygen to the gas inlet of the second desulfurizer, and
A temperature sensor that detects the temperature of the remover on the gas outlet side of the second desulfurizer, and
And determining deterioration determination device deterioration of the removal agent of the second desulfurizer based on the detection value of the temperature sensor when the oxygen gas inlet of the second desulfurizer is supplied from the oxygen supply device,
Fuel cell system with. In the fuel cell system according to claim 1,
The deterioration determination device is a fuel cell system that determines that the remover of the second desulfurizer has reached the end of its life when the detection value of the temperature sensor exceeds a predetermined threshold value. In the fuel cell system according to claim 2.
The deterioration determination device is a fuel cell system that determines that the life of the remover of the second desulfurizer is near when the detection value of the temperature sensor becomes equal to or higher than the low temperature side threshold value lower than the threshold value. In the fuel treatment system according to any one of claims 1 to 3,
A fuel cell system further comprising a notification device for notifying the determination result of the deterioration determination device. In the fuel cell system according to any one of claims 1 to 4.
Further provided with an oxidizer that produces hydrogen by reacting hydrocarbons in the raw material and fuel with oxygen from the oxygen supply device.
The second desulfurizer, a fuel cell system for removing hydrogen and the sulfur component by reacting a sulfur component of the raw fuel from the oxidizer. In the fuel cell system according to any one of claims 1 to 5.
When the temperature of the fuel cell drops due to the stop of the operation of the fuel cell system, the deterioration determination device supplies oxygen from the oxygen supply device to the second desulfurizer to deteriorate the removing agent. Fuel cell system to judge.

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