JP2008120678A - Combine system of carbon monoxide selective oxidizer and steam generator and fuel reformer system - Google Patents

Abstract

A carbon monoxide selective oxidizer that quickly obtains a sufficient amount of water vapor at start-up and oxidizes carbon monoxide in preference to hydrogen is maintained at an appropriate temperature.
As a system for cooling a CO selective oxidation unit of a fuel reformer system, a first cooling system connected to a first cooling passage of the CO selective oxidation unit and capable of taking out cooling water as water vapor is provided. And a second cooling system 50 that circulates a cooling medium in a circulation line including the second cooling passage 36 and cools it. When the system is started, the flow of the hydrogen-rich gas is changed by the flap 38 so that the cooling water in the first cooling passage 34 can receive a large amount of heat, and the cooling water is quickly heated to quickly take out a necessary amount of water vapor. When the steady operation state is reached, the CO selective oxidation unit 30 is cooled by the second cooling system 50, and the water in the steam generator 60 is heated by heat at that time to stably obtain a necessary amount of steam.
[Selection] Figure 1

Description

  The present invention relates to a carbon monoxide selective oxidizer, a combine system of the same and a steam generator, and a fuel reformer system, and more specifically, carbon monoxide selection that oxidizes carbon monoxide in a hydrogen-rich gas in preference to hydrogen. Combined system of oxidizer and carbon monoxide selective oxidizer that oxidizes carbon monoxide in hydrogen-rich gas with priority over hydrogen and steam generator that generates steam, and hydrogen rich gas by steam reforming hydrocarbon fuel The present invention relates to a fuel reformer system including a reformer and a carbon monoxide selective oxidizer.

  Conventionally, as this type of carbon monoxide selective oxidizer, a reaction tank holding a catalyst that selectively oxidizes carbon monoxide in a hydrogen-rich gas is supplied with cooling water through a flow path provided inside the reaction tank. The thing which cools by this is proposed (for example, Unexamined-Japanese-Patent No. 7-185303 etc.). In this device, a cooling water flow path is provided near the entrance of the reaction tank where carbon monoxide in the hydrogen-rich gas is mainly oxidized, and the catalyst is activated in the reaction tank mainly by cooling near this entrance. Trying to keep in the temperature range.

  Further, as a conventional fuel reformer, an apparatus for humidifying air or hydrocarbon fuel supplied to a reformer by contact with warmed water has been proposed (for example, JP-A-10-330101). Issue gazette). In this apparatus, the steam supplied to the reformer is performed by bringing the air into contact with the hot water used for cooling the fuel cell that generates electricity using the hydrogen-rich gas obtained by reforming as fuel, and humidifying it.

  However, such a carbon monoxide selective oxidation apparatus has a problem that it is difficult to maintain the reaction vessel at a uniform temperature. The site that contributes to the selective oxidation reaction of carbon monoxide in the reaction vessel changes with the change in the flow rate of the hydrogen-rich gas, but this change is due to the fact that the cooling water flow path is mainly provided near the entrance of the reaction vessel. Can not cope with.

  Further, the above-described fuel reforming apparatus has a problem in that there may be a case where sufficient steam necessary for reforming the hydrocarbon fuel cannot be supplied to the reformer. For example, in the case of a polymer electrolyte fuel cell, the warm water used for cooling the fuel cell has a fuel cell operating temperature of about 80 ° C., so that the humidified air is humidified only up to the saturated water vapor pressure at 80 ° C. I can't. At the saturated water vapor pressure at 80 ° C., assuming that methane is used as the hydrocarbon fuel, the molar ratio of water vapor to methane (number of moles of water vapor / number of moles of methane) is only about 1.5. It does not reach the necessary and sufficient amount.

  In order to solve at least a part of these problems, the applicant holds the cooling water in a state in which heat can be exchanged with the reaction tank, and takes out the cooling water as steam and supplies it to the reformer. An apparatus has been proposed (Japanese Patent Application No. 8-355381).

  One object of the carbon monoxide selective oxidation apparatus of the present invention is to appropriately control the temperature of the reaction vessel. One object of the carbon monoxide selective oxidizer of the present invention is to quickly reach an appropriate temperature at the start.

  One object of the fuel reformer system of the present invention is to supply sufficient steam to the reformer. Another object of the fuel reformer system of the present invention is to quickly start up at the time of starting. Furthermore, the fuel reformer system of the present invention has an object of improving energy efficiency.

  A combined system of a carbon monoxide selective oxidizer and a steam generator of the present invention has an object of obtaining steam efficiently. Another object of the combined system of the carbon monoxide selective oxidizer and the steam generator of the present invention is to quickly obtain steam at the start. Furthermore, the combined system of the carbon monoxide selective oxidizer and the steam generator of the present invention has an object of setting the temperature of the reaction tank for oxidizing carbon monoxide to an appropriate temperature.

  The carbon monoxide selective oxidizer, the combine system of this and the steam generator, and the fuel reformer system of the present invention employ the following means in order to achieve at least a part of the above object.

  The carbon monoxide selective oxidizer according to the present invention is a carbon monoxide selective oxidizer that oxidizes carbon monoxide in a hydrogen-rich gas in preference to hydrogen, and cools a reaction tank filled with a catalyst that performs the oxidation. The gist is to include a plurality of cooling systems and cooling control means for controlling cooling by the plurality of cooling systems.

  In this carbon monoxide selective oxidation apparatus of the present invention, a reaction tank filled with a catalyst that oxidizes carbon monoxide in a hydrogen-rich gas with priority over hydrogen is cooled by a plurality of cooling systems. Therefore, the cooling of the reaction tank can be diversified, and accurate cooling can be performed according to the state of the reaction tank.

  In such a carbon monoxide selective oxidation apparatus of the present invention, the plurality of cooling systems may be cooling systems that cool the reaction vessel using different cooling media. In the carbon monoxide selective oxidizer according to this aspect of the present invention, the cooling control means is configured such that the reaction tank is cooled by the first cooling system of the plurality of cooling systems when the carbon monoxide selective oxidizer is started. And a second control unit that is different from the first cooling system of the plurality of cooling systems after the start of the carbon monoxide selective oxidizer is completed. The cooling tank may be a means for controlling the plurality of cooling systems so that the reaction tank is cooled. By appropriately designing the first cooling system and the second cooling system, the reaction tank can be brought to an appropriate temperature both at the start and after the start.

  In the carbon monoxide selective oxidizer according to the present invention that cools the reaction tank by the first cooling system and the second cooling system, the first cooling system and the second cooling system are heated in the reaction tank. It can also be an interchangeable system. In the carbon monoxide selective oxidation apparatus of the present invention of this aspect, the reaction tank is in close contact with one surface so that heat exchange with the hydrogen-rich gas is possible and the other surface is heat-exchangeable with each other. The first cooling system and the second cooling system are systems capable of cooling the reaction vessel by flowing each cooling medium through the two-layer cooling medium path. It can also be. If it carries out like this, a reaction tank can be cooled also in a 1st cooling system or a 2nd cooling system, and heat exchange can also be carried out mutually.

  In the carbon monoxide selective oxidation apparatus of the present invention that cools the reaction tank by the first cooling system at the start-up, the flow path changing means capable of changing the flow path of the hydrogen-rich gas in the reaction tank, and the flow path changing means And a flow path change control means for controlling the change of the flow path in the reaction tank. In the carbon monoxide selective oxidizer according to this aspect of the present invention, the flow path change control unit is capable of exchanging heat with the cooling medium of the first cooling system when starting the carbon monoxide selective oxidizer. It is assumed that the flow path changing means is controlled so that the hydrogen rich gas flows into the flow path in the tank, or the flow path changing control means is configured to start the first carbon monoxide selective oxidizer when the first gas oxidizing device is started. The cooling medium of the cooling system may be a means for controlling the flow path changing means so as to obtain a large amount of heat from the hydrogen-rich gas. If it carries out like this, while starting, the temperature of a reaction tank can be raised rapidly, and the heat exchange in a 1st cooling system can be validated.

  In the carbon monoxide selective oxidizer of the present invention that changes the flow path of the hydrogen-rich gas at the start-up, when the start of the carbon monoxide selective oxidizer is completed, the flow path change control means It is also possible to control the flow path changing means so that the hydrogen-rich gas flows through all the flow paths. If it carries out like this, the selective oxidation reaction of carbon monoxide can be performed in the whole reaction tank.

  A fuel reformer system according to the present invention is a fuel reformer system including a reformer that generates a hydrogen-rich gas by steam reforming a hydrocarbon-based fuel, and the hydrogen-rich gas generated by the reformer The carbon monoxide selective oxidizer of the present invention including all the above-described embodiments that oxidize carbon monoxide in preference to hydrogen, and steam generated using heat generated by the reaction tank provided in the carbon monoxide selective oxidizer And a steam supply means for supplying the generated steam to the reformer.

  In the fuel reformer system of the present invention, steam is generated using heat generated in the reaction tank of the carbon monoxide selective oxidizer of the present invention, and the generated steam is supplied to the reformer. Since the carbon monoxide selective oxidizer of the present invention starts quickly and is controlled at an appropriate temperature, steam can be quickly obtained and supplied to the reformer at the time of starting. Can be supplied to the reformer and the thermal efficiency can be improved.

  In the fuel reformer system of the present invention, the carbon monoxide selective oxidizer is a device that cools the reaction tank by a first cooling system at the start, and the cooling medium of the first cooling system is water, The steam supply means may be means for supplying water, which is a cooling medium of the first cooling system, to the reformer as steam. In this way, loss of heat due to heat exchange can be reduced, and steam can be quickly obtained and supplied to the reformer. In the fuel reformer system of the present invention of this aspect, a gas cooling means disposed between the reformer and the carbon monoxide selective oxidizer and capable of cooling a hydrogen-rich gas from the reformer, and the fuel When the reformer system is started, a start-time control means for controlling the gas cooling means so as not to cool the hydrogen rich gas from the reformer may be provided. If it carries out like this, high temperature hydrogen rich gas can be supplied to a carbon monoxide selective oxidation apparatus. As a result, the carbon monoxide selective oxidizer can be quickly heated and steam can be quickly obtained and supplied to the reformer.

  Further, in the fuel reformer system of the present invention, the carbon monoxide selective oxidizer is a device that cools the reaction tank by a second cooling system after startup, and the steam supply means is the second cooling device. A steam generation unit that generates steam by heat exchange with the system may be provided, and the generated steam may be supplied to the reformer. If it carries out like this, after start-up, water vapor | steam can be obtained by heat exchange with the 2nd cooling system of a carbon monoxide selective oxidation apparatus, and it can supply to a reformer. Since the steam generating means exchanges heat with the second cooling system, any cooling medium can be used for the second cooling system.

  The combined system of a carbon monoxide selective oxidizer and a steam generator of the present invention is a combined system of a carbon monoxide selective oxidizer that oxidizes carbon monoxide in a hydrogen-rich gas in preference to hydrogen and a steam generator that generates steam. The first cooling means capable of cooling the reaction tank filled with the catalyst for performing the oxidation using cooling water, and the second cooling means capable of cooling the reaction tank using a cooling medium different from water. The gist of the invention is that it comprises a cooling means, and a water vapor take-out means capable of taking out the reaction water of the first cooling means and the heat-exchanged cooling water as water vapor from the first cooling means.

  In the combined system of the carbon monoxide selective oxidizer and the steam generator of the present invention, a reaction tank filled with a catalyst that oxidizes carbon monoxide in a hydrogen-rich gas with priority over hydrogen is used as a first tank that uses cooling water. Cooling is performed by the cooling means and the second cooling means using a cooling medium different from water. The water vapor take-out means takes out the cooling water after heat exchange with the reaction tank from the first cooling means as water vapor. Since the two cooling means are provided, the selective oxidation reaction of carbon monoxide can be performed efficiently by setting the reaction vessel to an appropriate temperature. Moreover, since the cooling water after heat exchange with the reaction vessel is taken out as water vapor, the water vapor can be obtained without a special device.

  The combined system of the carbon monoxide selective oxidizer and the steam generator according to the present invention may include a steam generator that exchanges heat with the cooling medium of the second cooling means to generate steam. In this way, water vapor can be obtained not only when the reaction tank is cooled by the first cooling means, but also when the reaction tank is cooled by the second cooling means.

  In the combined system of the carbon monoxide selective oxidation apparatus and the steam generation apparatus of the present invention having such a steam generation means, a state detection means for detecting the state of the steam generation means, and the first based on the detected state. One cooling means, the second cooling means, the water vapor extraction means, and a control means for controlling the water vapor generation means may be provided. If it carries out like this, while being able to hold | maintain a reaction tank at more suitable temperature, water vapor | steam can be obtained.

  In the combined system of the carbon monoxide selective oxidizer and the steam generator of the present invention having the control means, the control means is in a state where the state of the steam generator detected by the state detector is in an unsteady state. When the first cooling means cools the reaction tank and the water vapor take-out means takes out water vapor from the first cooling means, the first cooling means and the water vapor take-out means are controlled. It can also be. If it carries out like this, the temperature of a reaction tank can be raised rapidly at the time of start-up, and water vapor | steam can be obtained rapidly. In the combined system of the carbon monoxide selective oxidizer and the steam generator of this aspect of the present invention, when the flow path changing means capable of changing the flow path of the hydrogen-rich gas in the reaction tank, and starting the combine system, The cooling water of the first cooling means may include flow path change control means for controlling the flow path changing means so as to obtain a large amount of heat from the hydrogen rich gas. If it carries out like this, water vapor | steam can be obtained more rapidly.

  Further, in the combined system of the carbon monoxide selective oxidizer and the steam generator of the present invention having the control means, the control means is in a steady state in the state of the steam generating means detected by the state detecting means. The second cooling means may be a means for controlling the second cooling means and the water vapor generating means so that the reaction tank is cooled by the second cooling means and water vapor is generated by the water vapor generating means. . If it carries out like this, while being able to hold | maintain a reaction tank in an appropriate state, water vapor | steam can be obtained.

  Next, embodiments of the present invention will be described using examples. FIG. 1 is a configuration diagram showing an outline of a configuration of a fuel reformer system 20 according to an embodiment of the present invention. As shown in the figure, the fuel reformer system 20 of the embodiment includes a reformer 22 that reforms a hydrocarbon-based fuel into a hydrogen-rich gas containing hydrogen, and heat exchange that cools the hydrogen-rich gas from the reformer 22. , A CO selective oxidation unit 30 that preferentially oxidizes carbon monoxide in the hydrogen rich gas over hydrogen, a first cooling system 40 that cools the CO selective oxidation unit 30, and a CO selective oxidation unit 30 that is also cooled. A second cooling system 50, a steam generator 60 that generates steam by heat exchange with the second cooling system 50, and an electronic control unit 80 that controls the entire system are provided.

The reformer 22 receives supply of air and water vapor as an oxygen-containing gas containing methane and oxygen as a hydrocarbon-based fuel, and generates a hydrogen-rich gas by the reaction of the following formulas (1) to (3) The heating part 24 which heats the mixed gas of the supplied methane, air, and water vapor | steam, and the modification | reformation part 26 which performs reaction of Formula (1) thru | or Formula (3) are provided. The mixing ratio of methane, air, and water vapor is, for example, such that air is supplied so that the molar ratio [O ₂ / CH ₄ ] of oxygen to methane is 0.5, and the water vapor is a molar ratio of water to methane [H ₂ O / CH ₄ ] is adjusted to be 2.0. The supply amount of each gas and the temperature of the reforming unit 26 are controlled by the electronic control unit 80.

CH ₄ + (1/2) O ₂ → 2H ₂ + CO + 35.7 kJ (1)
CH ₄ + H ₂ O → 3H ₂ + CO−206.2 kJ (2)
CO + H ₂ O → H ₂ + CO ₂ +41.2 kJ (3)

  The heat exchanger 28 efficiently converts the hydrogen-rich gas from the reformer 22 operated at a temperature of 600 ° C. to 800 ° C. at which the above-described reaction is efficiently performed, with selective oxidation of carbon monoxide by the CO selective oxidation unit 30. Cool to a temperature of 120-170 ° C. performed. The heat exchanger 28 cools such a high-temperature hydrogen-rich gas by heat exchange, but can change the flow path of the hydrogen-rich gas and supply it to the subsequent stage without performing heat exchange. In this case, a high-temperature hydrogen-rich gas is supplied to the CO selective oxidation unit 30. The presence or absence of heat exchange by the heat exchanger 28 is controlled by a drive signal from the electronic control unit 80.

  FIG. 2 shows a partial configuration of the inside of the CO selective oxidation unit 30. As shown in the figure, the CO selective oxidation unit 30 includes a plurality of catalyst filling units filled with a catalyst that preferentially oxidizes carbon monoxide in a hydrogen-rich gas over hydrogen in the presence of oxygen, for example, a catalyst such as ruthenium or rhodium. 32a, 32b, a pair of first and second cooling passages 34 and 36 laminated with the plurality of catalyst filling portions 32a, 32b, and the vicinity of the hydrogen rich gas inlet of the catalyst filling portion 32b. And a plurality of flaps 38. The catalyst filling portions 32a and the catalyst filling portions 32b are alternately stacked, the first cooling passages 34 are disposed on both the stacked surfaces of the catalyst filling portion 32a, and the second cooling surfaces are disposed on both the stacked surfaces of the catalyst filling portion 32b. A cooling passage 36 is disposed. Therefore, the catalyst filling portion 32 a is cooled via the first cooling passage 34, and the catalyst filling portion 32 b is cooled via the second cooling passage 36. The plurality of flaps 38 controls the supply of the hydrogen rich gas to the catalyst filling unit 32b by opening and closing thereof. That is, when the flap 38 is opened, the state shown in FIG. 2 is obtained and the introduction of the hydrogen-rich gas into the catalyst filling portion 32b is inhibited. When the flap 38 is closed, the state shown by the wavy line in FIG. Releases the inhibition of introduction of hydrogen-rich gas into Note that oxygen necessary for the oxidation of carbon monoxide in the CO selective oxidation unit 30 is introduced into the hydrogen rich gas supplied to the CO selective oxidation unit 30 by the blower 29 as shown in FIG. .

  The first cooling system 40 includes a first cooling pipe 42 connected to the first cooling passage 34 of the CO selective oxidation unit 30, and water is supplied to the first cooling pipe 42 from a water tank 66 through a water supply pipe 68. Is to be supplied. An electromagnetic valve 44 that controls the supply of water to the first cooling pipe 42 is attached in the vicinity of the connection portion of the water supply pipe 68 of the first cooling pipe 42. The connection pipe 43 connected to the other end of the first cooling passage 34 is connected to a water vapor supply pipe 72, and the connection pipe 43 is provided with a pressure reducing on / off valve 46 that serves as a pressure reducing valve and an on / off valve. Yes. The steam supply pipe 72 exchanges heat with the heat exchanger 28 and is connected to the heating unit 24 of the reformer 22. Therefore, the water supplied from the water tank 66 is heated by heat exchange with the hydrogen-rich gas in the first cooling passage 34 of the CO selective oxidation unit 30, depressurized by the electromagnetic valve 46 to become water vapor, and passes through the water vapor supply pipe 72. And supplied to the heating unit 24.

  The second cooling system 50 is connected to the second cooling passage 36 of the CO selective oxidation unit 30 to form a circulation conduit 52 that circulates oil as a heat exchange medium in the circulation formation conduit 52. A circulation pump 54 to be connected, a water superheater pipe 56 connected to the circulation forming pipe 52 to heat the water in the water vapor generator 60 by heat exchange and cool the oil, and oil to compensate for the shortage of oil in the circulation pipe is stored. The oil tank 58 is provided. Therefore, the second cooling system 50 cools the CO selective oxidation unit 30 by exchanging heat between the oil as the heat exchange medium cooled by the steam generator 60 and the hydrogen rich gas in the second cooling passage 36. In other words, it can be said that the second cooling system 50 heats the water in the steam generator 60 with oil as a heat exchange medium heated by heat exchange with the hydrogen-rich gas in the second cooling passage 36. . As the heat exchange medium used in the second cooling system 50, oil whose composition does not change even at a relatively high temperature, such as gas turbine oil, is used.

  The steam generator 60 is configured as a pressurized tank that stores pressurized water, and the water stored inside is heated by the water superheater pipe 56 as described above. The steam generator 60 is connected to a water tank 66 by a connecting pipe 61 and a water supply pipe 68. The connecting pipe 61 is provided with an electromagnetic valve 62 that controls the supply of water from the water tank 66 to the water vapor generator 60. The water vapor generated in the water vapor generator 60 is reduced in pressure by a pressure reducing on / off valve 74 serving as a pressure reducing valve and an on / off valve attached to the water vapor supply pipe 72 and supplied to the heating unit 24 of the reformer 22. . In order to supply water from the water tank 66 to the steam generator 60 and the first cooling passage 34, a pressure pump 70 is attached to the water supply pipe 68.

  The electronic control unit 80 is configured as a one-chip microprocessor mainly composed of a CPU 82, and includes a ROM 84 that stores a processing program, a RAM 86 that temporarily stores data, and an input / output that inputs and outputs various signals. Port 88. The electronic control unit 80 includes a detection signal such as a temperature indicating the operation state of the reformer 22 and a gas flow rate, and a temperature Tco of the CO selective oxidation unit 30 from a temperature sensor 39 attached to the CO selective oxidation unit 30. The water temperature Tw detected by the temperature sensor 64 attached to the steam generator 60, the internal water level Hw detected by the water level meter 65 attached to the steam generator 60, and the like are input via the input / output port 88. ing. Further, from the electronic control unit 80, a drive signal to the reformer 22, a drive signal to the heat exchanger 28, a drive signal to the blower 29, a drive signal to the actuators 47 and 75 of the pressure reducing on / off valves 46 and 74, A drive signal to the actuators 45 and 63 of the electromagnetic valves 44 and 62, a drive signal to the circulation pump 54 and the pressurizing pump 70, and the like are output via the input / output port 80.

  Next, the operation of the fuel reformer system 20 of the embodiment thus configured, particularly the operation at the start of the fuel reformer system 20 will be described. FIG. 3 is a flowchart illustrating an example of a start time processing routine executed by the electronic control unit 80 of the embodiment. This routine is executed when the fuel reformer system 20 of the embodiment is started.

  When this routine is executed, the CPU 82 first stops the heat exchange by the heat exchanger 28 (step S100) and opens the flap 38 to the catalyst filling section 32b that is cooled through the second cooling passage 36. A process for inhibiting the introduction of the hydrogen rich gas is executed (step S102). Specifically, the heat exchange of the heat exchanger 28 is stopped by outputting a drive signal from the input / output port 88 of the electronic control unit 80 to the heat exchanger 28. By such a process, the high-temperature hydrogen rich gas from the reformer 22 is introduced into the catalyst filling unit 32a of the CO selective oxidation unit 30.

  Then, the temperature Tco of the CO selective oxidation unit 30 detected by the temperature sensor 64 is read (step S104), and the process waits for the read temperature Tco to be equal to or higher than the threshold Tr1 (step S106). Here, the threshold value Tr1 is set as a threshold value for starting the cooling of the CO selective oxidation unit 30, and is set to a steady operation temperature of the CO selective oxidation unit 30, a temperature slightly lower than this, or a temperature slightly higher than this. Is done.

  When the temperature Tco of the CO selective oxidation unit 30 becomes equal to or higher than the threshold value Tr1, a process for starting cooling by the first cooling system 40 is executed (step S108), and a process for starting heating of the water in the steam generator 60 is executed. (Step S110). Specifically, the cooling of the first cooling system 40 is started by opening the electromagnetic valve 44 and driving the pressurizing pump 70 to pressurize the water in the first cooling pipe 42 and in the first cooling passage 34. This is done by adjusting the pressure reducing on / off valve 46 so that the water heated in step 1 becomes water vapor at a predetermined pressure. Since the water in the first cooling passage 34 is pressurized by the pressurizing pump 70, it does not evaporate even when the temperature of the CO selective oxidation unit 30 reaches the temperature Tco (steady operation temperature of 120 ° C. to 170 ° C.). Although the state is maintained, the pressure is reduced by the pressure reducing on / off valve 46 and the steam is ejected to the steam supply pipe 72 as steam. Heating of the water in the first cooling passage 34 is performed very quickly because the heat exchange by the heat exchanger 28 is stopped and the flap 38 is opened so that the high-temperature hydrogen-rich gas flows only to the catalyst filling portion 32a. It is. As a result, water vapor can be supplied by the first cooling system 40 immediately after the temperature Tco of the CO selective oxidation unit 30 reaches the threshold value Tr1. On the other hand, the heating of the water in the steam generator 60 is started by specifically driving the circulation pump 54 to circulate the oil in the circulation line. At this time, since the high-temperature hydrogen-rich gas is not introduced into the catalyst filling portion 32b that exchanges heat through the second cooling passage 36, the heat exchange of the oil in the second cooling passage 36 is performed in the first cooling passage 34. Performed with cooling water. That is, the oil in the second cooling passage 36 is heated by heat exchange with the cooling water in the first cooling passage 34. Therefore, in order to reduce the amount of circulating oil so as not to lower the temperature of the cooling water in the first cooling passage 34, the rotational speed of the circulation pump 54 is kept low. The heating of the water in the steam generator 60 is started simultaneously with the opening / closing control by a routine (not shown) of the electromagnetic valve 62 provided in the connecting pipe 61 so that the water level Hw in the steam generator 60 becomes the predetermined water level Hr. Is done.

  Next, the water temperature Tw of the water vapor generator 60 detected by the temperature sensor 64 and the water level Hw of the water vapor generator 60 detected by the water level meter 65 are read (step S112), and the water level becomes higher than the threshold value Tr2 and the water level. Wait until Hw reaches the predetermined water level Hr (steps S114 and S116). Here, the threshold value Tr2 is set as the temperature of the water in the steam generator 60 that is normally operated or a temperature slightly lower than this.

  When the water temperature Tw becomes equal to or higher than the threshold value Tr2 and the water level Hw becomes the predetermined water level Hr, the flap 38 is closed so that the hydrogen rich gas is introduced into the catalyst filling portion 32b (step S118), and the hydrogen generated by the heat exchanger 28 is increased. Cooling of rich gas is started (step S120), and processing for starting cooling by the second cooling system 50 is executed (step S122). Specifically, the start of cooling by the second cooling system 50 is performed by operating the circulation pump 54 that has been driven at a low rotation speed at the rotation speed during steady operation.

  Then, after a predetermined time has elapsed (step S124), the supply of water vapor from the water vapor generator 60 is started by adjusting the pressure reducing on / off valve 74 (step S126), and cooling by the first cooling system 40 is performed. Stop (step S128) and end this routine. Here, the predetermined time is set as a time necessary for the steam generator 60 to be in a steady operation state in which sufficient steam can be generated. The cooling of the first cooling system 40 is stopped by closing the pressure reducing on-off valve 46 and the electromagnetic valve 44. Even if the cooling by the first cooling system 40 is stopped, the pressure in the first cooling passage 34 is maintained, so that no bubbles are generated inside. Further, the catalyst filling portion 32a is cooled by the second cooling passage 36 through the first cooling passage 34 by heat conduction. That is, the cooling water convection to the first cooling passage 34 transfers the heat of the catalyst filling portion 32a to the oil in the second cooling passage 36 by heat conduction, thereby cooling the catalyst filling portion 32a.

  FIG. 4 is a time chart illustrating the state of each part in a time series when the start time processing routine of FIG. 3 is executed to start the fuel reformer system 20 of the embodiment. As shown in the figure, when the start of the fuel reformer system 20 of the embodiment is started at time t1, the high-temperature hydrogen rich gas from the reformer 22 is directly introduced into the catalyst filling unit 32a of the CO selective oxidation unit 30. As a result, the temperature Tco of the CO selective oxidation unit 30 rapidly increases. At time t2 when the temperature Tco of the CO selective oxidation unit 30 reaches the threshold value Tr1, cooling by the first cooling system 40 is started and heating of the steam generator 60 is also started. At this time, since the cooling water in the first cooling passage 34 has already reached the threshold value Tr1 which is the steady operation temperature of the CO selective oxidation unit 30, the water vapor is immediately supplied from the pressure reducing on-off valve 46 via the water vapor supply pipe 72. 24. Further, the water temperature Tw and the water level Hw of the steam generator 60 also start to rise. At time t3 when the water temperature Tw of the water vapor generator 60 reaches the threshold value Tr2 and the water level Hw becomes the predetermined water level Hr, cooling by the second cooling system 50 is started and the flap 38 is closed and the catalyst filling unit 32b is also heated to a high temperature. The hydrogen rich gas is introduced. Then, at time t4 when a predetermined time has elapsed, the cooling by the first cooling system 40 is stopped, and the supply of the steam generated by the steam generator 60 to the heating unit 24 is started, and the steady operation is performed.

  According to the fuel reformer system 20 of the embodiment described above, the CO selective oxidation unit 30 includes two cooling systems including the first cooling system 40 and the second cooling system 50, and only the first cooling system 40 is started at the time of starting. By cooling the CO selective oxidation unit 30 by this, it is possible to quickly obtain sufficient steam to be supplied to the reformer 22. Moreover, since heat exchange by the heat exchanger 28 is stopped or the flow path of the hydrogen-rich gas is changed by the flap 38 to increase the efficiency of heat exchange in the first cooling system 40, water vapor can be obtained more quickly. . Further, according to the fuel reformer system 20 of the embodiment, when the start-up is completed and a steady operation state is reached, the CO selective oxidation unit 30 is cooled by the second cooling system 50 and heat exchange with the second cooling system 50 is performed. Since sufficient steam is generated by the steam generator 60, a sufficient amount of steam can be supplied to the reformer 22 in an energy efficient manner. Furthermore, since the first cooling system 40 and the second cooling system 50 are configured as a two-layered heat exchange path in close contact with each other, the CO selective oxidation unit can be smoothly performed even after starting the system and after reaching steady operation. 30 can be cooled. Naturally, since the flap 38 is closed and the hydrogen-rich gas is introduced also into the catalyst filling portion 32b, carbon monoxide in the hydrogen-rich gas can be oxidized with priority over hydrogen. In addition, heat exchange is performed by the heat exchanger 28 and an appropriate-temperature hydrogen-rich gas is supplied to the CO selective oxidation unit 30, so that the CO selective oxidation unit 30 can be operated more efficiently. Furthermore, since steam is heated by the heat exchanger 28 and supplied to the reformer 22, energy efficiency can be improved.

  In the fuel reformer system 20 of the embodiment, the CO selective oxidation unit 30 is cooled by the two cooling systems of the first cooling system 40 and the second cooling system 50, but the CO selection is performed by three or more cooling systems. The oxidation unit 30 may be cooled. Further, in the fuel reformer system 20 of the embodiment, the first cooling system 40 and the second cooling system 50 are configured to be able to exchange heat with the first cooling passage 34 and the second cooling passage 36, but heat exchange is not performed. You may comprise. Furthermore, the fuel reformer system 20 of the embodiment includes the flap 38 that can change the introduction of the hydrogen rich gas into the catalyst filling portion by opening and closing, but if the introduction of the hydrogen rich gas into the catalyst filling portion can be changed, It may be performed by any mechanism. Further, in the fuel reformer system 20 of the embodiment, the flap 38 is provided, and the hydrogen rich gas is introduced only into the catalyst filling portion 32a at the time of starting. However, the flap 38 is not provided, and the startup is also performed during steady operation. Similarly, hydrogen rich gas may be introduced into all catalyst filling portions. In the fuel reformer system 20 of the embodiment, methane is used as the hydrocarbon-based fuel. However, hydrocarbon-based fuels other than methane, for example, other hydrocarbons such as ethane and ethylene, alcohol, and the like are used. Also good.

  The CO selective oxidation unit 30, the first cooling system 40, and the second cooling system 50 included in the fuel reformer system 20 of this embodiment constitute an embodiment of the carbon monoxide selective oxidation apparatus of the present invention. According to this embodiment, by providing two cooling systems, the temperature can be quickly raised when the CO selective oxidation unit 30 is started, and the catalyst is stably activated after reaching a steady operation state. Temperature can be maintained. As a result, the CO selective oxidation unit 30 can be quickly started to efficiently oxidize carbon monoxide with priority over hydrogen. In addition, since the flap 38 is opened at the time of start-up and the high-temperature hydrogen-rich gas is introduced only into the catalyst filling portion 32a, the temperature of the CO selective oxidation portion 30 can be raised more rapidly. Further, after the start is completed, the flap 38 is closed and the hydrogen rich gas is introduced into the catalyst filling portion 32b to oxidize carbon monoxide, so that the concentration of carbon monoxide in the hydrogen rich gas can be further reduced.

  In the embodiment, the CO selective oxidation unit 30, the first cooling system 40, and the second cooling system 50 are used as the configuration of the fuel reformer system 20, but may be used for systems other than the fuel reformer system. In this case, the first cooling system 40 may use a cooling medium other than the cooling water, such as alcohol or oil. Furthermore, in the embodiment, the first cooling system 40 is configured to extract steam, but when not configured as one configuration of the fuel reformer system, it may be configured not to extract steam. In this case, similarly to the second cooling system 50, a cooling water circulation line may be formed. Further, in the embodiment, the cooling system is configured to include two cooling systems. However, the cooling system may include three or more cooling systems.

  In addition, the CO selective oxidation unit 30, the first cooling system 40, the second cooling system 50, and the steam generator 60 included in the fuel reformer system 20 of the embodiment are the carbon monoxide selective oxidizer and the steam generator of the present invention. An embodiment of the combine system is constructed. According to the combine system of this embodiment, a sufficient amount of water vapor can be quickly obtained by the first cooling system 40 at the time of start-up, and after the start is completed, the second cooling system 50 allows the CO selective oxidation unit 30 to A sufficient amount of water vapor can be obtained from the water vapor generator 60 while maintaining the temperature at an appropriate temperature. Moreover, since the high-temperature hydrogen rich gas is introduced only into the catalyst filling portion 32a at the time of start-up, the steam can be obtained from the first cooling system 40 more quickly. Further, when the start is completed, the flap 38 is closed and the hydrogen rich gas is introduced into the catalyst filling portion 32b to oxidize the carbon monoxide, so that the concentration of carbon monoxide in the hydrogen rich gas can be further reduced. A sufficient amount of water vapor can be stably obtained from the water vapor generator 60.

  In the combine system of the embodiment, the CO selective oxidation unit 30, the first cooling system 40, the second cooling system 50, and the steam generator 60 are used as the configuration of the fuel reformer system 20, but other than the fuel reformer system It may be used for the system. Moreover, in the combine system of an Example, although two cooling systems were provided, it is good also as a thing provided with three or more cooling systems.

  The embodiments of the present invention have been described using the embodiments. However, the present invention is not limited to these embodiments, and can be implemented in various forms without departing from the gist of the present invention. Of course you get.

It is a block diagram which shows the outline of a structure of the fuel reformer system 20 which is one Example of this invention. 2 is a configuration diagram illustrating a configuration of a part inside a CO selective oxidation unit 30. FIG. It is a flowchart which shows an example of the process routine at the time of starting performed by the electronic control unit 80 of an Example. It is a time chart which illustrates the mode of each part when the fuel reformer system 20 of an Example is started in time series.

Explanation of symbols

  20 Fuel reformer system, 22 reformer, 24 heating unit, 26 reforming unit, 28 heat exchanger, 30 CO selective oxidation unit, 34 first cooling passage, 36 second cooling passage, 38 flap, 39 temperature sensor , 40 1st cooling system, 42 1st cooling pipe, 43 Connection pipe, 44, 62 Solenoid valve, 45, 47, 63, 75 Actuator, 46, 74 Pressure reducing on-off valve, 50 2nd cooling system, 52 Circulation formation pipeline , 54 Circulation pump, 56 Water superheat pipe, 58 Oil tank, 60 Steam generator, 61 Connection pipe, 64 Temperature sensor, 65 Water level gauge, 66 Water tank, 68 Water supply pipe, 70 Pressure pump, 72 Steam supply pipe, 80 Electronic control unit, 82 CPU, 84 ROM, 86 RAM, 88 I / O ports.

Claims (20)

A carbon monoxide selective oxidizer that oxidizes carbon monoxide in a hydrogen-rich gas in preference to hydrogen,
A plurality of cooling systems for cooling the reaction tank filled with the catalyst for performing the oxidation;
A carbon monoxide selective oxidation apparatus comprising: cooling control means for controlling cooling by the plurality of cooling systems.   The carbon monoxide selective oxidizer according to claim 1, wherein the plurality of cooling systems are cooling systems that cool the reaction vessel using different cooling media.   The cooling control means is means for controlling the plurality of cooling systems so that the reaction tank is cooled by a first cooling system of the plurality of cooling systems when the carbon monoxide selective oxidizer is started. Item 3. A carbon monoxide selective oxidation apparatus according to Item 2.   The cooling control means is configured so that the reaction tank is cooled by a second cooling system different from the first cooling system of the plurality of cooling systems after the start of the carbon monoxide selective oxidizer is completed. The carbon monoxide selective oxidation apparatus according to claim 3, which is means for controlling a plurality of cooling systems.   The carbon monoxide selective oxidation apparatus according to claim 4, wherein the first cooling system and the second cooling system are systems capable of exchanging heat in the reaction vessel. A carbon monoxide selective oxidation apparatus according to claim 5,
The reaction vessel includes a two-layer coolant passage in which one surface is in contact with the flow of the hydrogen-rich gas so as to be able to exchange heat with the hydrogen-rich gas, and the other surface is in close contact so as to be able to exchange heat with each other.
The first cooling system and the second cooling system are systems capable of cooling the reaction tank by flowing each cooling medium through the two-layer cooling medium passages. It is a carbon monoxide selective oxidation apparatus in any one of Claim 3 thru | or 6, Comprising:
A flow path changing means capable of changing a flow path in the reaction tank of the hydrogen-rich gas;
A carbon monoxide selective oxidation apparatus comprising: a channel change control unit that controls a change of the channel in the reaction tank by the channel change unit.   When the carbon monoxide selective oxidizer is started, the flow path change control means is configured to cause the hydrogen-rich gas to flow through the flow path in the reaction tank that can exchange heat with the cooling medium of the first cooling system. The carbon monoxide selective oxidation apparatus according to claim 7, which is means for controlling the path changing means.   The flow path change control means is means for controlling the flow path change means so that the cooling medium of the first cooling system obtains a large amount of heat from the hydrogen-rich gas when the carbon monoxide selective oxidizer is started. The carbon monoxide selective oxidizer according to claim 7.   The flow path change control means is a means for controlling the flow path change means so that the hydrogen-rich gas flows in all flow paths in the reaction tank when the start of the carbon monoxide selective oxidizer is completed. Item 10. A carbon monoxide selective oxidizer according to Item 8 or 9. A fuel reformer system comprising a reformer that generates a hydrogen-rich gas by steam reforming a hydrocarbon-based fuel,
The carbon monoxide selective oxidation apparatus according to any one of claims 1 to 10, wherein carbon monoxide in the hydrogen-rich gas generated by the reformer is preferentially oxidized over hydrogen.
A fuel reformer system comprising: a steam supply unit that generates steam using heat generated by a reaction tank provided in the carbon monoxide selective oxidizer, and supplies the generated steam to the reformer. The fuel reformer system according to claim 11, wherein
The carbon monoxide selective oxidizer is any one of the carbon monoxide selective oxidizers dependent on claim 3 or claim 3,
The cooling medium of the first cooling system is water;
The water vapor supply means is means for supplying water, which is a cooling medium of the first cooling system, to the reformer as water vapor. A fuel reformer system. The fuel reformer system according to claim 12, wherein
A gas cooling means disposed between the reformer and the carbon monoxide selective oxidizer and capable of cooling the hydrogen-rich gas from the reformer;
A fuel reformer system comprising: a start time control unit that controls the gas cooling unit so as not to cool the hydrogen-rich gas from the reformer when the fuel reformer system is started. The fuel reformer system according to any one of claims 11 to 13,
The carbon monoxide selective oxidizer is any one of carbon monoxide selectors dependent on claim 4 or claim 4,
The fuel reformer system, wherein the steam supply means includes means for generating steam by heat exchange with the second cooling system, and supplies the generated steam to the reformer. A combined system of a carbon monoxide selective oxidizer that oxidizes carbon monoxide in a hydrogen-rich gas in preference to hydrogen and a steam generator that generates steam,
First cooling means capable of cooling the reaction tank filled with the catalyst for performing oxidation using cooling water;
A second cooling means capable of cooling the reaction vessel using a cooling medium different from water;
A combine system comprising: a water vapor take-out means that can be taken out from the first cooling means as the water after the heat exchange with the reaction tank of the first cooling means.   The combine system of Claim 15 provided with the water vapor | steam production | generation means which heat-exchanges with the cooling medium of a said 2nd cooling means, and produces | generates water vapor | steam. The combine system according to claim 16, comprising:
State detecting means for detecting the state of the water vapor generating means;
A combine system comprising: control means for controlling the first cooling means, the second cooling means, the water vapor extraction means, and the water vapor generation means based on the detected state.   When the state of the water vapor generating means detected by the state detecting means is in an unsteady state, the control means cools the reaction tank by the first cooling means, and the first means by the water vapor take-out means. The combine system according to claim 17, wherein the combine system is means for controlling the first cooling means and the water vapor extraction means so as to take out water vapor from the cooling means. The combine system according to claim 18, wherein
A flow path changing means capable of changing a flow path in the reaction tank of the hydrogen-rich gas;
A combine system comprising: a flow path change control means that controls the flow path change means so that the cooling water of the first cooling means obtains a large amount of heat from the hydrogen-rich gas when the combine system is started.   When the state of the water vapor generating unit detected by the state detecting unit is a steady state, the control unit cools the reaction tank by the second cooling unit and generates water vapor by the water vapor generating unit. The combine system according to any one of claims 17 to 19, which is means for controlling the second cooling means and the water vapor generating means.

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