JP4872760B2 - Operation control method and apparatus for fuel processor - Google Patents

Description

  The present invention relates to an operation control method and apparatus for a fuel processor that performs reforming of a raw material to generate hydrogen-rich reformed gas to be supplied to a fuel cell.

  A fuel cell is expected to be an effective power generation device because it has higher thermal efficiency and less environmental pollution than other power generation methods using fuel. In particular, the polymer electrolyte fuel cell (PEFC) generates power at a low temperature of 100 ° C. or less, and has a high output density. Therefore, the polymer electrolyte fuel cell (PEFC) can be downsized as compared with other types of fuel cells and can be easily started. In recent years, it has come to be used as a power generator for small-scale business use or home use.

A general configuration of a power generation device (PEFC power generation device) using the polymer electrolyte fuel cell is as follows. That is, as shown in FIG. 2, both surfaces of a solid polymer electrolyte membrane in which a fluorine ion exchange membrane is used as an electrolyte are sandwiched between both gas diffusion electrodes of a cathode (air electrode) 2 and an anode (fuel electrode) 3. The solid polymer fuel cell 1 is formed by stacking the cells formed through a separator (not shown) as a stack. On the inlet side of the anode 3 in the polymer electrolyte fuel cell 1, a fuel processor 4 comprising a reformer 5, a low temperature shift converter 6, a CO selective oxidation reactor (CO remover) 7 in this order, and a humidification A vessel 8 is provided. Thereby, after desulfurizing the raw material (raw fuel) 9 such as city gas (natural gas), LPG, and kerosene supplied from the fuel supply unit by the desulfurizer 10, the raw material preheater (raw fuel vaporizer) 11 is used. Then, it is supplied to the fuel processor 4 together with the steam 13 guided from the water evaporator 12 and heated to about 700 ° C. in the reformer 5 of the fuel processor 4 to perform steam reforming. It is supposed to be done. The resulting reformed gas (fuel gas) 14 is guided to the low-temperature shift converter 6 to be lowered to about 250 ° C. for a shift reaction, and further to about 150 ° C. in the CO selective oxidation reactor 7. To remove CO.
Thereafter, the reformed gas 14 delivered from the fuel processor 4 is humidified by the humidifier 8 and then supplied to the anode 3 of the polymer electrolyte fuel cell 1. On the other hand, air 15 as an oxidizing gas is supplied to the inlet side of the cathode 2 through the humidifier 8 after being pressurized by the air blower 16.

  With this configuration, in the polymer electrolyte fuel cell 1, hydrogen in the reformed gas 14 supplied to the anode 3 side and oxygen in the air 15 supplied to the cathode 2 side are electrochemically converted. Reaction (fuel cell reaction) is performed, and the electromotive force generated at this time is taken out.

  After the fuel cell reaction by the polymer electrolyte fuel cell 1, unreacted hydrogen remains in the anode offgas 17 discharged from the outlet of the anode 3. For this purpose, the anode off-gas 17 is introduced into a burner (not shown) attached to the reformer 5 of the fuel processor 4 and burned, and steam reforming which is an endothermic reaction in the reforming chamber of the reformer 5. It is used as a heat source for advancing the quality reaction.

  Furthermore, in view of the small calorific value of the anode off-gas 17, the burner of the fuel processing device 4 is made up of a part of the raw material 9 such as city gas, LPG, kerosene supplied from the fuel supply unit. When the fuel processor 4 is operated and the steam reforming of the raw material 9 is performed in the reformer 5 by supplying the fuel 9a and burning it, the amount of heat that is insufficient with only the calorific value of the anode offgas 17 is reduced. I make up for it. Reference numeral 18 denotes a cooling unit in the polymer electrolyte fuel cell 1.

  By the way, as shown in FIG. 3, the fuel processor 4 including the reformer 5, the shift converter 6, and the CO selective oxidation reactor 7 includes the anode off-gas 17 and the additional gas in one heat insulating container 19. A burner (combustor) 20 is provided so that the fuel 9a can be burned as a fuel for combustion, and a combustion gas flow path 22 is formed to circulate the combustion gas 21 generated by the burner 20, In the combustion gas flow path 22, the reformer 5, the water evaporator 12 related to the reformer 5, the low-temperature shift converter 6, and the CO selective oxidation reactor 7 are sequentially provided from the upstream side. Conventionally, a type in which these are combined into one unit has been proposed.

  That is, the unit-type fuel processing device 4 has a heat insulation provided with a vacuum heat insulation layer 19c as a heat insulation layer between a container inner cylinder 19a and a container outer cylinder 19b having a required height and closed at the upper end. A base plate (fuel processing apparatus bottom plate) 23 is airtightly attached to the lower end side of the container (vacuum heat insulating container) 19 via a base outer cylinder 24. A base inner cylinder 25 is provided at the center of the base plate 23 so as to rise up to the vicinity of the intermediate portion in the vertical direction of the heat insulating container 19. The burner 20 is disposed inside the upper end of the base inner cylinder 25.

  The burner 20 is supplied with the anode off gas 17 guided to the lower position of the base plate 23 through an anode off gas pipe (not shown) through an anode off gas supply path 26 inserted into the base inner cylinder 25. I can do it. Further, the additional fuel 9a supplied from the outside can be supplied from a concentric position at the tip (upper end) of the anode off-gas supply path 26 through a required path as shown in FIG. As a result, the burner 20 supplies the anode offgas 17 supplied from the fuel cell (not shown) via the anode offgas pipe, the anode offgas supply path 26, or the additional fuel 9a supplied via the required path, to the above-mentioned burner 20. Combustion can be performed using air 15 supplied from below to the burner 20 through the inside of the base inner cylinder 25.

  Further, a furnace cylinder 27 extending in the vertical direction to the vicinity of the ceiling portion of the heat insulating container 19 is connected to the upper side of the base inner cylinder 25, and the inner surface of the container inner cylinder 19a in the heat insulating container 19 and the furnace cylinder 27 are connected. A cylindrical space extending in the vertical direction is provided between the outer peripheral surface of the base inner cylinder 25 and the combustion gas flow path 22 is formed in the space. Thereby, the high-temperature (about 1000 ° C.) combustion gas 21 generated by the combustion of the anode off-gas 17 and the additional fuel 9a in the burner 20 is once led to the vicinity of the ceiling of the heat insulating container 19 through the furnace tube 27. Thereafter, the gas flow direction is reversed downward, and the combustion gas passage 22 is circulated downward from the upper end side toward the exhaust port 28 provided in the side wall of the base outer cylinder 24 which is the lower end side of the heat insulating container 19. I can do it.

  In the upper region of the combustion gas passage 22 located on the outer periphery of the furnace tube 27, a plurality of reformers 5 are arranged at a required interval in the circumferential direction, and supplied to the respective reformers 5 at the lower positions thereof. A water evaporator 12 for generating water vapor 13 is provided. Further, in the lower region of the combustion gas passage 22 located on the outer periphery of the base inner cylinder 25, a low temperature shift converter 6 connected to the downstream side of each reformer 5, and a CO selective oxidation reactor (selective oxidation reactor). CO remover) 7 is arranged in order from above.

  The raw material preheater (partial vaporizer) 11 is disposed in the combustion gas flow path 22 on the outer peripheral side of the low temperature shift converter 6 and supplies a raw material for reforming (raw fuel) 9 supplied from the outside. The heat remaining in the combustion gas 21 after passing through the water evaporator 12 can be used for preheating. The raw material 9 preheated by the raw material preheater 11 is supplied to a mixer (mixing header) 29 disposed between the water evaporator 12 and the low temperature shift converter 6 in the combustion gas flow path 22. The water vapor 13 introduced from the water evaporator 12 is mixed with the water vapor 13 and supplied to the reformers 5.

  With the above configuration, when the high-temperature combustion gas 21 generated by the burner 20 rises in the furnace tube 27 and then flows downward through the combustion gas flow path 22, each reformer 5 is heated to about 700 ° C., and in this state, the mixed gas of the preheated raw material 9 and water vapor 13 is supplied from the mixer 29 to each reformer 5. The reforming reaction is advanced to generate the reformed gas 14. The generated reformed gas 14 is guided to the low temperature shift converter 6 and subjected to a shift reaction, and then the CO selective oxidation reactor 7 performs a CO removal treatment, and the resulting reformed gas 14 is converted into the CO selective oxidation reaction. It can be sent through the reformed gas pipe 30 connected to the outlet side of the vessel 7.

  The combustion gas 21 that has been supplied as a heat source for the steam reforming reaction in each reformer 5 and whose temperature has been lowered heats the remaining heat from the water 35 supplied from the outside by the water evaporator 12. Then, after being used as a heat source for generating the steam 13 to be supplied to each reformer 5, it is led to the exhaust port 28 at the lower end of the heat insulating container 19 and exhausted to the outside.

In the above, the shift reaction of the reformed gas 14 in the low-temperature shift converter 6 and the reaction that causes the CO selective oxidation reactor 7 to perform the CO removal treatment of the reformed gas 14 are both exothermic reactions.
For this purpose, both the CO selective oxidation reactor 7 and the low temperature shift converter 6 are equipped with cooling water pipes 31 and 32, and the cooling water pipes 31 and 32 are connected in series to the cooling water line 33. is there. Thereby, the cooling water 34 supplied from the outside to the cooling water line 33 is circulated through the cooling water pipe 31 of the CO selective oxidation reactor 7 and the cooling water pipe 32 of the low temperature shift converter 6 in this order, and the CO selection is performed. The oxidation reactor 7 can be maintained in a temperature range of approximately 150 ° C., and the low temperature shift converter 6 can be maintained in a temperature range of approximately 250 ° C., respectively. As described above, the cooling water 34 after passing through the cooling water piping of the low-temperature shift converter 6 that is designed to be maintained in a temperature range of about 250 ° C. is heated to generate water vapor. Therefore, the water vapor is mixed with the raw material 9 and can be used for distributing and supplying to each reformer 5 like the water vapor 13 generated in the water evaporator 12 (for example, Patent Document 1). reference).

JP 2005-108753 A

  However, as shown in FIG. 3, a combustion gas passage 22 through which the combustion gas 21 generated by the burner 20 is circulated is formed in the heat insulating container 19, and the reformer is placed in the combustion gas passage 22. 5, the water evaporator 12, the low-temperature shift converter 6, and the CO selective oxidation reactor 7 in order from the upstream side, the reformer 5 has a temperature of about 700 ° C. and the low-temperature shift. Optimal reaction temperature conditions are determined for the converter 6 at about 250 ° C. and the CO selective oxidation reactor 7 at about 150 ° C., respectively. Therefore, in order to optimize the operation of the fuel processing device 4, it is required to comprehensively control the temperature of each device. However, a specific control method for performing such temperature control has not been proposed in the past. That is the case.

  Accordingly, the present invention is provided with a combustion gas passage for allowing the combustion gas of the burner to flow in the heat insulation container, and a reformer, a water evaporator, a low temperature shift converter, a CO selective oxidation reactor in the combustion gas passage. In order to optimize the operation of the fuel processing apparatus of the type that is provided in order from the upstream side, so that the temperature control of the reformer, the low-temperature shift converter, and the CO selective oxidation reactor can be comprehensively performed. It is an object of the present invention to provide an operation control method and apparatus for a processing apparatus.

  In order to solve the above problems, the present invention provides a heat insulating container with a burner and a flow path of combustion gas generated by the burner, and a reformer, a water evaporator, and a low temperature shift in the combustion gas flow path. The temperature of the combustion gas generated in the burner in the fuel processing apparatus comprising the converter and the CO selective oxidation reactor in order from the upstream side is detected, and the detected temperature of the combustion gas is maintained at the required temperature. The amount of combustion fuel supplied to the burner is determined, and the temperature at which the combustion gas generated by the burner reaches a position near the upstream side of the reformer through the combustion gas flow path is defined as a reformer. The upstream gas temperature is detected, and the detected upstream gas temperature of the reformer is supplied to the burner so that the temperature range corresponds to the temperature range desired for the steam reforming reaction of the reformer. Compensate the amount of fuel supplied for combustion The operation control method of the material processing apparatus, and a burner and a flow path of combustion gas generated by the burner are provided in the heat insulation container, and a reformer, a water evaporator, and a low temperature shift converter are provided in the combustion gas flow path. A combustion gas temperature sensor capable of detecting the temperature of the combustion gas generated by the burner is provided at a position in the vicinity of the burner in a fuel processing apparatus comprising a CO selective oxidation reactor in order from the upstream side, and the combustion gas flow path The reformer upstream gas temperature that enables the temperature of the combustion gas immediately before reaching the reformer via the combustion gas passage to be detected as the reformer upstream gas temperature at a position near the upstream side of the reformer in A sensor is provided, and an amount of combustion fuel to be supplied to the burner is set based on a detection signal of the temperature of the combustion gas input from the combustion gas temperature sensor, and the reformer upstream gas temperature is further set. SE Operation of a fuel processor having a configuration having a controller having a function of correcting the supply amount of combustion fuel to the burner based on a detection signal of the gas temperature upstream of the reformer input from the compressor Control device.

  Further, in the above, the temperature of the combustion gas flowing downstream of the water evaporator in the combustion gas flow path and upstream of the low temperature shift converter is detected as the water evaporator downstream gas temperature, and the water evaporation is performed. A method of controlling the amount of water supplied to the vessel so that the detected gas temperature downstream of the water evaporator is in a temperature range corresponding to the temperature range desired for the shift reaction in the low temperature shift converter, and A water evaporator downstream gas temperature sensor is provided downstream of the water evaporator in the combustion gas flow path and upstream of the low temperature shift converter, and the water evaporator downstream gas temperature sensor is provided in the controller. The apparatus has a function of controlling the amount of water supplied to the water evaporator on the basis of the temperature detection signal input more.

  Further, in the above, the low temperature shift converter in the cooling water line in which the cooling water piping of the CO selective oxidation reactor and the cooling water piping of the low temperature shift converter are connected in series so that the cooling water can be circulated. The temperature of the cooling water flowing in the vicinity of the outlet side is detected as the shift converter outlet cooling water temperature, the amount of cooling water supplied to the cooling water line is controlled, and the detected shift converter outlet cooling water temperature is A method for achieving a temperature range corresponding to a temperature range desired for a shift reaction in a low temperature shift converter, and a cooling water pipe of a CO selective oxidation reactor and a cooling water pipe of a low temperature shift converter are connected in series. In the vicinity of the outlet side of the low temperature shift converter in the cooling water line in which the cooling water can be circulated, A shift converter outlet cooling water temperature sensor that detects the temperature of the cooling water immediately after passing through the shift converter is provided, and the cooling is performed based on the temperature detection signal input from the shift converter outlet cooling water temperature sensor in the controller. A device having a function of controlling the amount of cooling water supplied to the water line.

  Furthermore, in the above, when the flow rate of the combustion gas generated in the burner and flowing through the combustion gas flow path decreases, the temperature of the low-temperature shift converter is supplied to the burner when the temperature falls below a required temperature. A method for increasing the amount of air, and a controller, the temperature of the low-temperature shift converter is lower than the required temperature as the flow rate of the combustion gas generated in the burner and flowing through the combustion gas passage decreases. The apparatus is provided with a function of increasing the amount of air supplied to the burner when the pressure drops to the above.

  In the above configuration, while the temperature of the low temperature shift converter is raised to the temperature range desired for the shift reaction and the temperature of the CO selective oxidation reactor is raised to the temperature range desired for the CO removal treatment, A method for stopping the supply of water to the evaporator, the supply of cooling water to the cooling water line connected to the CO selective oxidation reactor and the low-temperature shift converter, and a low-temperature shift to the controller When the temperature of the converter is lower than the temperature range desired for the shift reaction in the low temperature shift converter and the temperature of the CO selective oxidation reactor is lower than the temperature range desired for the CO removal process, The apparatus has a function of stopping water supply and cooling water supply to the cooling water line connected to the CO selective oxidation reactor and the low-temperature shift converter.

According to the present invention, the following excellent effects are exhibited.
(1) A burner and a flow path of combustion gas generated by the burner are provided in the heat insulating container, and a reformer, a water evaporator, a low temperature shift converter, and a CO selective oxidation reactor are provided in the combustion gas flow path. Combustion fuel supplied to the burner by detecting the temperature of the combustion gas generated by the burner in the fuel processing apparatus provided in order from the upstream side and maintaining the detected temperature of the combustion gas at a required temperature And the temperature at which the combustion gas generated by the burner reaches the position near the upstream side of the reformer through the combustion gas flow path is detected as the reformer upstream gas temperature, The amount of fuel supplied to the burner is corrected so that the detected upstream gas temperature of the reformer falls within a temperature range corresponding to the temperature range desired for the steam reforming reaction of the reformer. Operation control method for fuel processing device and Because are the location, it is possible to heat the reformer, the temperature range suitable for the steam reforming process of the raw material.
(2) The temperature of the combustion gas flowing downstream of the water evaporator in the combustion gas flow path and upstream of the low-temperature shift converter is detected as the water evaporator downstream gas temperature, and sent to the water evaporator. A method and apparatus for controlling the amount of water to be supplied so that the detected gas temperature downstream of the water evaporator falls within a temperature range corresponding to a temperature range desired for the shift reaction in the low-temperature shift converter. Thus, when the combustion gas flowing through the combustion gas flow path passes through the water evaporator, the temperature of the combustion gas can be lowered to a temperature suitable for the shift reaction in the low temperature shift converter. The possibility that the low temperature shift converter is excessively heated by the combustion gas reaching the low temperature shift converter can be eliminated.
(3) The outlet side of the low-temperature shift converter in the cooling water line in which the cooling water piping of the CO selective oxidation reactor and the cooling water piping of the low-temperature shift converter are connected in series so that the cooling water can be circulated. The temperature of the cooling water flowing in the vicinity position is detected as the shift converter outlet cooling water temperature, the amount of the cooling water supplied to the cooling water line is controlled, and the detected shift converter outlet cooling water temperature is the low temperature shift. By adopting a method and apparatus for setting the temperature range corresponding to the temperature range desired for the shift reaction in the converter, the low-temperature shift converter is set to a temperature suitable for the shift reaction, and the CO selective oxidation reactor is provided. It can be kept at a temperature suitable for CO removal treatment.
(4) The above (1), (2), and (3) can establish an optimal temperature distribution in the reformer, the low-temperature shift converter, and the CO selective oxidation reactor. The reformed gas can be generated by satisfactorily performing the steam reforming reaction, shift reaction, and CO removal treatment of the raw material.
(5) The amount of air supplied to the burner when the temperature of the low temperature shift converter decreases below the required temperature as the flow rate of the combustion gas generated in the burner and flowing through the combustion gas flow path decreases. By using the method and apparatus for increasing the temperature, it becomes possible to prevent the temperature of the low-temperature shift converter from decreasing even when the flow rate of the combustion gas tends to decrease.
(6) While the temperature of the low temperature shift converter is raised to the temperature range desired for the shift reaction and the temperature of the CO selective oxidation reactor is raised to the temperature range desired for the CO removal treatment, the water evaporator And a method and apparatus for stopping the supply of cooling water to the cooling water line connected to the CO selective oxidation reactor and the low-temperature shift converter. And the CO selective oxidation reactor can be quickly heated to quickly start the fuel processing apparatus.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  1 (a) and 1 (b) show an embodiment of an operation control method and apparatus for a fuel processing apparatus according to the present invention. Similarly to the case shown in FIG. A burner 20 that burns the anode off-gas 17 and the additional fuel 9a (see FIG. 3) guided from the fuel cell as the combustion fuel 36, and a combustion gas flow path 22 for circulating the combustion gas 21 generated by the burner 20. The reformer 5, the water evaporator 12, the low-temperature shift converter 6, and the CO selective oxidation reactor 7 are sequentially provided in the combustion gas flow path 22 from the upstream side to form a unit. A combustion gas temperature sensor 37 for detecting the combustion gas temperature T <b> 1 of the combustion gas 21 generated by the burner 20 is provided in the vicinity of the burner 20 in the fuel processor 4.

  Further, a reformer upstream gas temperature sensor 38 is provided in the combustion gas flow path 22 in the vicinity of the upstream side of the reformer 5, so that the temperature of the combustion gas 21 immediately before reaching the reformer 5, that is, The temperature T2 of the combustion gas 21 used as a heat source for heating the reformer 5 (hereinafter referred to as the reformer upstream gas temperature) T2 can be detected.

  Further, a water evaporator downstream gas temperature sensor 39 is provided in the combustion gas flow path 22 in the vicinity of the downstream side of the water evaporator 12 and is provided as a heat source for generating water vapor in the water evaporator 12. The temperature remaining in the combustion gas 21, that is, the temperature of the combustion gas 21 that will be guided to the low-temperature shift converter 6 provided downstream of the combustion gas passage 22 after passing through the water evaporator 12 (hereinafter referred to as the temperature of the combustion gas 21. T3) (referred to as water evaporator downstream gas temperature).

  Further, the low temperature shift in the cooling water line 33 in which the cooling water pipe 31 of the CO selective oxidation reactor 7 and the cooling water pipe 32 of the low temperature shift converter 6 are connected in series to allow the cooling water 34 to flow therethrough. A shift converter outlet cooling water temperature sensor 40 is provided in the vicinity of the outlet side of the converter 6 and the temperature of the cooling water 34 immediately after passing through the cooling water pipe 32 of the low temperature shift converter 6 (hereinafter referred to as shift converter outlet cooling water temperature). T4 can be detected.

  Further, as shown in FIG. 1 (b), a burner fuel blower 41 for supplying the combustion fuel 36 to the burner 20 based on temperature detection signals inputted from the temperature sensors 37, 38, 39, 40, and An air blower 42 for supplying combustion air 15 to the burner 20, a raw material blower 43 for supplying reforming raw material 9 to the reformer 5, and water 35 for generating steam to the water evaporator 12. And a controller 46 that gives commands to the CO selective oxidation reactor 7 and the cooling water pump 45 that supplies the cooling water 34 to the cooling water line 33 of the low-temperature shift converter 6.

  More specifically, the controller 46 gives a command to the burner fuel blower 41 based on the combustion gas temperature T1 input from the combustion gas temperature sensor 37, and determines the supply amount of the combustion fuel 36 supplied to the burner. With the function of feedback control, the temperature of the combustion gas 21 generated by burning the combustion fuel 36 with the burner 20 can be maintained at about 1000 ° C.

  Further, in order to optimally perform the steam reforming process of the raw material 9 in the reformer 5, it is preferable that the reformer 5 is heated to about 700 ° C. Due to the fact that complicated heat exchange is performed and that the reformer 5 has a large heat capacity, the temperature change rate is slow at the time of startup or the like. Therefore, as described above, the controller 46 gives a command to the burner fuel blower 41 based on the combustion gas temperature T1 input from the combustion gas temperature sensor 37 and supplies the combustion fuel 36 to the burner 20. In order to control the temperature of the combustion gas 21 reaching the reformer 5 in the combustion gas flow path 22 at about 700 ° C., the reformer upstream side gas sensor 38 is used. A function for correcting a command given to the burner fuel blower 41 based on the input reformer upstream gas temperature T2 is provided. As a result, the reformer 5 causes the combustion gas 21 generated by the combustion of the combustion fuel 36 in the burner 20 and flowing through the combustion gas passage 22 to reach the reformer 5 at about 700 ° C. Thus, the reformer 5 is reliably heated to about 700 ° C. In the above, the controller 15 is configured so that the amount of the air 15 supplied from the air blower 42 to the burner 20 is increased or decreased according to the increase or decrease in the supply amount of the combustion fuel 36 supplied from the burner fuel blower 41 to the burner 20. The air blower 42 is controlled by 46.

  The combustion gas 21 whose temperature has been lowered by serving as a heat source for steam reforming of the raw material 9 in the reformer 5 then remains in the combustion gas 21 when it reaches the water evaporator 12. Heat is used as a heat source for evaporating the water 35 supplied from the water pump 44 to the water evaporator 12 to form the water vapor 13, and is used as a heat source for generating water vapor to further reduce the temperature of the combustion gas 21 is led to the low temperature shift converter 6 provided on the downstream side of the combustion gas flow path 22. At this time, as described above, the low temperature shift converter 6 is such that the reformed gas 14 obtained from the reformer 5 is temperature-reduced to about 250 ° C. to cause a shift reaction. When the combustion gas 21 reaches the low temperature shift converter 6, it is required that the temperature of the combustion gas 21 is lowered to about 250 ° C.

  Therefore, the controller 46 uses the water evaporator downstream side gas temperature sensor 39 to provide the water evaporator downstream side gas, which is the temperature of the combustion gas 21 after being supplied to the heat source for generating water vapor in the water evaporator 12. When the temperature T3 is input, a command is given to the water pump 44 based on the gas temperature T3 on the downstream side of the water evaporator, and the amount of water 35 supplied from the water pump 44 to the water evaporator 12 is feedback controlled. It has a function to do. As a result, the amount of heat provided as a heat source for generating the water vapor 13 when the combustion gas 21 passes through the water evaporator 12 is adjusted, so that the water evaporator downstream gas temperature T3 is approximately about 250 ° C. It can be kept constant.

  Further, the low-temperature shift converter 6 reliably performs the shift reaction of the reformed gas 14 at about 250 ° C., and the CO selective oxidation reactor 7 reliably performs the CO removal processing at about 150 ° C. In order to be able to carry out, the said controller 46 is based on the shift converter exit cooling water temperature T4 input from the said shift converter exit cooling water temperature sensor 40 in which the temperature of the said shift converter 6 is reflected. Cooling supplied to the cooling water pipe 31 of the CO selective oxidation reactor 7 and the cooling water pipe 32 of the low temperature shift converter 6 from the cooling water pump 45 through the cooling water line 33. A function for feedback control of the amount of water 34 is provided. Accordingly, the temperature of the CO selective oxidation reactor 6 and the low temperature shift converter 7 is set to about 150 ° C., respectively, by keeping the shift converter outlet cooling water temperature T4 approximately constant at about 250 ° C. And about 250 ° C.

  As described above, the burner fuel blower is based on the combustion gas temperature T1 input from the combustion gas temperature sensor 37 and the reformer upstream gas temperature T2 input from the reformer upstream gas sensor 38. The temperature of the combustion gas 21 reaching the reformer 5 becomes approximately 700 ° C. by giving a command to 41 and controlling the supply amount of the combustion fuel 36 supplied from the burner fuel blower 41 to the burner 20. Even in the controlled state, if the flow rate of the combustion gas 21 in the combustion gas passage 22 is small, the temperatures of the low-temperature shift converter 6 and the CO selective oxidation reactor 7 are gradually lowered. In this case, the supply amount of water 35 supplied from the water pump 44 to the water evaporator 12, the cooling water pipe 31 of the CO selective oxidation reactor 7 and the low temperature from the cooling water pump 45 through the cooling water line 33. Both supply amounts of the cooling water 34 supplied to the cooling water pipe 32 of the shift converter 6 are reduced. However, it is necessary to supply a certain amount of steam 13 to the reformer 5 in order to steam reform the raw material 9. Therefore, the controller 46 supplies the water 35 supplied from the water pump 44 to the water evaporator 12 when the flow rate of the combustion gas 21 flowing through the combustion gas passage 22 is small as described above. The supply amount of the cooling water 34 supplied from the cooling water pump 45 to the cooling water pipe 31 of the CO selective oxidation reactor 7 and the cooling water pipe 32 of the low temperature shift converter 6 through the cooling water line 33 is predetermined. When the minimum amount is reached, a command is given to the air blower 42 to perform a control to increase the amount of air 15 supplied to the burner 20. Thus, the supply amount of water 35 supplied from the water pump 44 to the water evaporator 12 and the cooling water can be increased so that the flow rate of the combustion gas 21 flowing through the combustion gas passage 22 can be increased. The supply amount of the cooling water 34 supplied from the pump 45 to the cooling water pipe 31 of the CO selective oxidation reactor 7 and the cooling water pipe 32 of the low temperature shift converter 6 through the cooling water line 33 is ensured to be a certain fixed amount or more. It is supposed to be.

  Further, as an option for starting the fuel processing device 4, the controller 46 has a period until the low temperature shift converter 6 and the CO selective oxidation reactor 7 reach a desired temperature when the fuel processing device 4 is started. The water pump 44 and the cooling water pump 45 are both provided with a function of stopping. As a result, when the fuel processor 4 is started up, the combustion gas is generated by the combustion of the burner 20 and then guided to the reformer 5 through the combustion gas flow path 22 to exchange heat with the reformer 5. 21 is led to the low temperature shift converter 6 and the CO selective oxidation reactor 7 without heat exchange in the water evaporator 12, and the cooling water pipe 32 in the low temperature shift converter 6 and the CO selective oxidation reactor 7 and The low temperature shift converter 6 and the CO selective oxidation reactor 7 can be quickly heated by stopping the flow of the cooling water to 31.

  In FIG. 1, the downstream end of the cooling water line 33 in which the cooling water pipe 31 of the CO selective oxidation reactor 7 and the cooling water pipe 32 of the low temperature shift converter 6 are connected in series is The steam generated by the cooling of the CO selective oxidation reactor 7 and the low temperature shift converter 6 can be directly led to the mixer 29. For convenience of illustration, among the various devices installed in the heat insulating container 19, the burner 20, the reformer 5, the water evaporator 12, the low temperature shift converter 6, the CO selective oxidation reactor 7, and the mixer 29 described above. Description of equipment other than the above is omitted, but it is assumed that it is provided in the same manner as the unitized type fuel processing apparatus 4 proposed in the prior art shown in FIG.

  Thus, according to the operation control method and apparatus of the fuel processing apparatus of the present invention, the reformer 5, the low temperature shift converter 6 and the CO selection in the combustion gas flow path 22 through which the combustion gas 21 generated by the burner 20 is circulated. Optimum temperature distributions corresponding to desired temperatures can be established in the reformer 5, the low temperature shift converter 6 and the CO selective oxidation reactor 7 for the respective locations of the oxidation reactor 7.

  Therefore, the steam reforming reaction of the raw material 9 in the reformer 5, the shift reaction of the reformed gas 14 in the CO selective oxidation reactor 7, and the CO removal processing of the reformed gas 14 in the CO selective oxidation reactor 7 are performed. Both can be performed satisfactorily.

  Further, when the flow rate of the combustion gas 21 in the combustion gas flow path 22 decreases, the amount of air 15 supplied from the air blower 42 to the burner 20 is increased, and the flow rate of the combustion gas 21 is increased, whereby the water evaporation. The supply amount of water 35 supplied to the reactor 12 and the supply amount of the cooling water 34 supplied to the CO selective oxidation reactor 7 and the low temperature shift converter 6 are ensured to be a certain fixed amount or more. Therefore, the amount of water vapor 12 supplied to the reformer 5 can be maintained above a certain required level.

  Furthermore, since the temperature of the low temperature shift converter 6 and the CO selective oxidation reactor 7 can be quickly raised when the fuel processor 4 is started, the fuel processor 4 can be started quickly.

  The present invention is not limited to the above-described embodiment. For example, the water evaporator downstream gas temperature sensor 39 is downstream of the water evaporator 12 in the combustion gas flow path 22 and is subjected to a low temperature shift. If the temperature of the combustion gas 21 guided to the low temperature shift converter 6 after passing through the water evaporator 12 at a position upstream of the converter 6 can be detected as the water evaporator downstream gas temperature T3, two points in FIG. As indicated by a chain line, the combustion gas passage 21 may be disposed at a position downstream of the mixer 29.

  In a required heat insulating container 19, a combustion gas flow path 22 for flowing a combustion gas 21 generated by the burner 20 is provided, and in the combustion gas flow path 22, the reformer 5, the water evaporator 12, and the low temperature shift converter. 6 and the CO selective oxidation reactor 7 in order from the upstream side, the shape and the heat insulating structure of the heat insulating container 19 and the arrangement path of the combustion gas flow path 22 in the heat insulating container 19 The shape, shape, and size of the reformer 5, the water evaporator 12, the low temperature shift converter 6, and the CO selective oxidation reactor 7 disposed in the combustion gas passage 22 are appropriately changed. The present invention can be applied to operation control of any type of fuel processor. Of course, various modifications can be made without departing from the scope of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows an embodiment of an operation control method and apparatus for a fuel processor according to the present invention, where (A) is a schematic diagram of the apparatus configuration, and (B) is a schematic diagram of a control system. It is a figure which shows the outline | summary of a general polymer electrolyte fuel cell power generator. Outline of a conventional fuel processing system of a type in which a reformer, a water evaporator, a low-temperature shift converter, and a CO selective oxidation reactor are arranged as a unit in a combustion gas flow path of a burner proposed in the past. It is a side view.

Explanation of symbols

DESCRIPTION OF SYMBOLS 5 Reformer 6 Low temperature shift converter 7 CO selective oxidation reactor 12 Water evaporator 15 Air 19 Heat insulation container 20 Burner 21 Combustion gas 22 Combustion gas flow path 31 Cooling water piping 32 Cooling water piping 33 Cooling water line 34 Cooling water 35 Water 37 Combustion gas temperature sensor 38 Reformer upstream gas temperature sensor 39 Water evaporator downstream gas temperature sensor 40 Shift converter outlet cooling water temperature sensor 46 Controller T1 Combustion gas temperature T2 Reformer upstream gas temperature T3 Water evaporator Downstream gas temperature T4 Shift converter outlet coolant temperature

Claims (10)

  A burner and a flow path of combustion gas generated by the burner are provided in the heat insulation container, and a reformer, a water evaporator, a low temperature shift converter, and a CO selective oxidation reactor are provided in the combustion gas flow path from the upstream side. The supply amount of combustion fuel supplied to the burner by detecting the temperature of the combustion gas generated by the burner in the fuel processing apparatus provided in order and maintaining the detected temperature of the combustion gas at a required temperature And the temperature at which the combustion gas generated by the burner reaches the position near the upstream side of the reformer through the combustion gas flow path is detected as the upstream gas temperature of the reformer and is detected. The amount of combustion fuel supplied to the burner is corrected so that the gas temperature on the upstream side of the reformer falls within a temperature range corresponding to a temperature range desired for the steam reforming reaction of the reformer. Operating system of fuel processing equipment Method.   Water supplied to the water evaporator by detecting the temperature of the combustion gas flowing downstream of the water evaporator in the combustion gas flow path and upstream of the low-temperature shift converter as the water evaporator downstream gas temperature. 2. The fuel processing apparatus according to claim 1, wherein the amount of the gas is controlled so that the detected gas temperature downstream of the water evaporator falls within a temperature range corresponding to a temperature range desired for a shift reaction in the low-temperature shift converter. Operation control method.   The position near the outlet side of the low-temperature shift converter in the cooling water line in which the cooling water piping of the CO selective oxidation reactor and the cooling water piping of the low-temperature shift converter are connected in series so that the cooling water can be circulated. The temperature of the circulating cooling water is detected as the shift converter outlet cooling water temperature, the amount of cooling water supplied to the cooling water line is controlled, and the detected shift converter outlet cooling water temperature is shifted in the low temperature shift converter. The operation control method for a fuel processor according to claim 2, wherein the temperature range corresponds to a temperature range desired for the reaction.   When the flow rate of the combustion gas generated in the burner and flowing through the combustion gas flow path decreases, the amount of air supplied to the burner is increased when the temperature of the low temperature shift converter falls below the required temperature. The operation control method for the fuel processor according to claim 2.   While the temperature of the low temperature shift converter is raised to the temperature range desired for the shift reaction and the temperature of the CO selective oxidation reactor is raised to the temperature range desired for the CO removal process, the water to the water evaporator is And the cooling water supply to the cooling water line connected to the CO selective oxidation reactor and the low temperature shift converter is stopped.   A burner and a flow path of combustion gas generated by the burner are provided in the heat insulation container, and a reformer, a water evaporator, a low temperature shift converter, and a CO selective oxidation reactor are provided in the combustion gas flow path from the upstream side. A combustion gas temperature sensor capable of detecting the temperature of the combustion gas generated by the burner is provided at a position in the vicinity of the burner in the fuel processing apparatus provided in order, and at a position near the upstream side of the reformer in the combustion gas flow path. Providing a reformer upstream side gas temperature sensor for detecting the temperature of the combustion gas immediately before reaching the reformer via the combustion gas flow path as the reformer upstream side gas temperature, and the combustion gas temperature A combustion fuel supply amount to be supplied to the burner is set based on a combustion gas temperature detection signal input from a sensor, and further, a reformer upstream side input from the reformer upstream side gas temperature sensor gas Based on the detection signal of the time, the operation control device of the fuel processing apparatus characterized by having provided comprising constituting a controller provided with the function for correcting the supply amount of combustion fuel to the burner.   A water evaporator downstream gas temperature sensor is provided downstream of the water evaporator in the combustion gas flow path and upstream of the low temperature shift converter, and the controller is provided with a gas temperature sensor downstream of the water evaporator. The operation control apparatus of the fuel processor according to claim 6, comprising a function of controlling the amount of water supplied to the water evaporator based on the input temperature detection signal.   The cooling water pipe of the CO selective oxidation reactor and the cooling water pipe of the low temperature shift converter are connected in series so that the cooling water can be circulated at a position near the outlet side of the low temperature shift converter in the cooling water line. A shift converter outlet cooling water temperature sensor for detecting the temperature of the cooling water immediately after passing through the low temperature shift converter is provided, and the controller is based on the temperature detection signal input from the shift converter outlet cooling water temperature sensor. The operation control device for a fuel processor according to claim 7, further comprising a function of controlling an amount of cooling water supplied to the cooling water line.   When the temperature of the low-temperature shift converter drops below a required temperature as the flow rate of the combustion gas generated in the burner and flowing through the combustion gas flow path decreases, the controller supplies air to the burner. The operation control device for a fuel processor according to claim 7, wherein the operation controller is provided with a function of increasing the amount.   When the temperature of the low temperature shift converter is lower than the temperature range desired for the shift reaction in the low temperature shift converter and the temperature of the CO selective oxidation reactor is lower than the temperature range desired for the CO removal process The fuel processing according to claim 8, further comprising a function of stopping water supply to the water evaporator and supply of cooling water to a cooling water line connected to the CO selective oxidation reactor and the low temperature shift converter. Operation control device of the device.

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