JP2001335303A - Fuel reformer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel reformer cooling a reformed gas at a proper temperature and preventing generation of condensed water in both a shift reaction section to which a cooled reformed gas is supplied and a CO concentration reduction section. SOLUTION: The reformed gas discharged from the reforming reaction section 32 is cooled through the heat exchange section 36 comprising the first heat exchange section 40, the second heat exchange section 50 and the third heat exchange section 60 and is supplied to the shift reaction section 70. While causing the third heat exchange section 60 to function as a condenser to condense the water contained in the reformed gas, the condensed water is stored in the sump section 62 and is recovered into the water tank 22 through the drain port 63. Thus, this process can definitely prevent the condensed water from being transferred to the shift reaction section 70 or to the CO reduction section 74, thereby keeping dry the shift catalyst and the preferential oxide catalyst whose functions may not be deteriorated. Since the recovered water can be reutilized as a reforming material, the economic effect of resources can be further enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel reformer, and more particularly, to a fuel reformer for reforming a hydrocarbon-based fuel into a hydrogen-rich fuel gas.

[0002]

2. Description of the Related Art Conventionally, as a fuel reformer of this type,
A system in which a reformed gas from a reforming section is cooled by heat exchange with a reforming raw material supplied to the reforming section and supplied to a shift reaction section has been proposed (for example, Japanese Patent Application Laid-Open No. 9-227103). . In this apparatus, the reformed gas from the reforming section is cooled by the reforming material supplied to the reforming section and supplied to the reforming section by a heat exchanger provided between the reforming section and the shift reaction section. The reforming raw material is being heated. Through such heat exchange, the thermal efficiency of the device is improved.

[0003]

However, in such a fuel reformer, the shift reaction section and the carbon monoxide concentration reduction section provided at the subsequent stage may not function as desired. The reformed gas may generate condensed water downstream of the heat exchanger, that is, in the shift reaction unit or the carbon monoxide concentration reduction unit, as the heat is cooled by the heat exchanger. The condensed water is
Since the catalytic activity in the shift reaction section and the carbon monoxide concentration reduction section is reduced, it is impossible to obtain a desired fuel gas.

[0004] It is an object of the fuel reformer of the present invention to prevent condensed water from being generated in the shift reaction section and the carbon monoxide concentration reduction section. Another object of the fuel reformer of the present invention is to improve the efficiency of the device.

[0005]

Means for Solving the Problems and Their Functions and Effects The fuel reforming apparatus of the present invention employs the following means to achieve at least a part of the above objects.

[0006] A fuel reforming apparatus according to the present invention is a fuel reforming apparatus for reforming a hydrocarbon-based fuel into a hydrogen-rich fuel gas, wherein the hydrocarbon-based fuel includes hydrogen and carbon monoxide. A reforming section for reforming the reformed gas; heat exchange means for cooling the reformed gas by heat exchange and recovering condensed water generated by the cooling; The gist of the present invention is to provide a shift reaction unit that shifts carbon oxide to hydrogen and carbon dioxide using water vapor.

In the fuel reformer of the present invention, the heat exchange means cools the reformed gas and collects the condensed water generated by the cooling, so that the condensed water due to the cooling is generated in the shift reaction section. Can be suppressed. As a result, it is possible to prevent a decrease in the catalytic activity of the shift reaction section due to the condensed water.

[0008] In such a fuel reformer of the present invention,
The heat exchange means includes a first heat exchange means for evaporating water by heat exchange between a combustion gas obtained by burning a fuel and water, and steam and the reformed gas from the first heat exchange means. Second heat exchange means for cooling the reformed gas by heat exchange with the third heat exchange means for cooling the reformed gas by heat exchange between the reformed gas and the cooling medium from the second heat exchange means. It is also possible to adopt a means having: In this case, the reformed gas can be more appropriately cooled. In the fuel reforming apparatus according to the aspect of the present invention, the heat exchange unit includes a first condensed water recovery unit that recovers condensed water from fuel gas generated by heat exchange in the first heat exchange unit;
A second condensed water recovery unit for recovering condensed water from the reformed gas generated by heat exchange in the second heat exchange unit; and a condensed water from the reformed gas generated by heat exchange in the third heat exchange unit. It may be a means provided with a third condensed water recovery means. This makes it possible to more reliably recover the condensed water. The first condensed water collecting means, the second condensed water collecting means, and the third condensed water collecting means may all be means provided with a drain port. In this way, the condensed water can be recovered from the drain port.

In the fuel reforming apparatus according to the aspect of the present invention, wherein the heat exchange means includes first to third condensed water recovery means.
At least one of the condensed water collecting means, the second condensed water collecting means, and the third condensed water collecting means is a water reservoir for storing condensed water, and a drain means for draining water from the water storing part. And a water level detecting means for detecting the water level of the water reservoir, and a drain control means for controlling the discharge of water by the discharging means based on the water level detected by the water level detecting means. In this case, the condensed water can be more appropriately recovered.

In the fuel reforming apparatus according to the present invention, wherein the heat exchanging means includes first to third heat exchanging means, a shift temperature detecting means for detecting a temperature of the shift reaction section; Cooling medium flow rate control means for controlling the flow rate of the cooling medium supplied to the flow path of the cooling medium of the third heat exchange means based on the temperature of the third heat exchange means. In this case, the temperature of the shift reaction section can be maintained at a more appropriate temperature.

Further, in the fuel reforming apparatus according to the present invention, wherein the heat exchange means includes first to third heat exchange means, the combustion gas from the first heat exchange means is reformed by the third heat exchange means. A first combustion gas supply unit capable of supplying the gas to the gas flow path;
A first start-up control means for controlling the combustion gas supply means so as to be supplied to the flow path of the reformed gas of the heat exchange means may be provided. In this case, warm-up at the time of starting can be performed quickly.

Further, in the fuel reforming apparatus according to the present invention, wherein the heat exchanging means includes first to third heat exchanging means, a fuel supply for supplying fuel to a reformed gas flow path of the second heat exchanging means. Means, an ignition means mounted near the inlet of the reformed gas flow path of the second heat exchange means,
A second start-up control unit that controls the fuel supply unit so that fuel is supplied to the reformed gas flow path of the heat exchange unit and controls the ignition unit so that the supplied fuel is burned. It can also be. In this case, warm-up at the time of starting can be performed quickly. In this aspect of the fuel reforming apparatus of the present invention, the fuel supply means may be a means for supplying the hydrocarbon-based fuel. In this way, there is no need to prepare another fuel.

Alternatively, in the fuel reforming apparatus according to the present invention in which the heat exchange means includes first to third heat exchange means, the fuel burned by the first heat exchange means is the hydrocarbon-based fuel. It can also be. In this way, there is no need to prepare another fuel.

In the fuel reforming apparatus according to the present invention, wherein the heat exchanging means includes first to third heat exchanging means, the shift reaction section can exchange heat with a flow path of the reformed gas undergoing the shift reaction. The fuel cell system may further include a second combustion gas supply unit having a shift reaction unit heat exchange flow passage, and capable of supplying the combustion gas from the first heat exchange unit to the shift reaction unit heat exchange flow passage. In this case, the shift reaction section can be heated using the combustion gas from the first heat exchange means. In the fuel reforming apparatus according to the aspect of the present invention, the fuel reforming apparatus further includes first temperature detecting means for detecting a temperature of the shift reaction section,
The combustion gas supply means may be a means for controlling a supply amount of the combustion gas to the shift reaction part heat exchange flow path based on the temperature detected by the first temperature detection means. In this case, the temperature of the shift reaction section can be adjusted. Therefore, the temperature of the shift reaction section can be adjusted to a more appropriate temperature.

In the fuel reformer according to the present invention, wherein the heat exchanging means comprises first to third heat exchanging means, the fuel reforming apparatus is disposed downstream of the shift reaction section, and carbon monoxide contained in gas from the shift reaction section is provided. A carbon monoxide concentration reduction unit having a heat exchange flow passage for reducing the concentration and heat exchange with the gas reducing the carbon monoxide concentration, and reducing the combustion gas from the first heat exchange means. And a third combustion gas supply unit capable of supplying the partial heat exchange flow path. With this configuration, the carbon monoxide concentration reducing section can be heated using the combustion gas from the first heat exchange unit. In the fuel reforming apparatus according to the aspect of the present invention, the fuel reforming apparatus further includes a second temperature detecting unit that detects a temperature of the carbon monoxide concentration reducing unit, and the third combustion gas supply unit detects the temperature by the second temperature detecting unit. It may be a means for controlling the supply amount of the combustion gas to the reduction section heat exchange flow path based on the temperature thus set. In this case, the temperature of the carbon monoxide concentration reducing section can be adjusted. Accordingly, the temperature of the carbon monoxide concentration reducing section can be adjusted to a more appropriate temperature.

In the fuel reformer of the present invention, the heat exchanging means is means for cooling the reformed gas using steam, and the steam heated by the heat exchanging means is combined with the hydrocarbon fuel. A mixing section may be provided for mixing and supplying the mixed section to the reforming section. In this case, the steam heated by the heat exchange means can be used for the reforming reaction and the shift reaction, and the efficiency of the apparatus can be improved. In the fuel reforming apparatus according to the aspect of the present invention, the heat exchange unit may be a unit that uses water recovered from the heat exchange unit as the steam.
In this case, the efficiency of resource utilization can be improved.

Further, in the fuel reformer of the present invention, the hydrocarbon-based fuel may be natural gas or gasoline.

[0018]

Next, embodiments of the present invention will be described with reference to examples. FIG. 1 is a configuration diagram schematically showing the configuration of a fuel reforming apparatus 20 according to one embodiment of the present invention. As shown in the figure, a fuel reforming apparatus 20 of the embodiment includes a mixing section 30 that mixes a hydrocarbon-based fuel such as gasoline, steam, and air to form a reforming raw material, and a reforming raw material from the mixing section 30. And a heat exchanger for cooling the reformed gas from the reforming reaction unit 32 and evaporating water supplied to the mixing unit 30. Part 3
6, a shift reaction unit 70 that shifts carbon monoxide in the reformed gas cooled by the heat exchange unit 36 to hydrogen and carbon dioxide using steam to produce a hydrogen-rich gas, and a blower 76.
A CO reduction unit 74 that reduces the concentration of carbon monoxide in the hydrogen-rich gas from the shift reaction unit 70 using the air introduced by the control unit, and an electronic control unit 80 that controls the entire apparatus.

In the mixing section 30, hydrocarbon fuel is supplied from a fuel tank 24 by a fuel pump 25, water is supplied as water vapor from a water tank 22 by a water pump 23 through a heat exchange section 36, and Air is supplied.

The reforming reaction section 32 reforms a hydrocarbon-based fuel in the reforming raw material into a reformed gas containing carbon monoxide and hydrogen by a reforming reaction represented by the following formula (1). (For example, platinum), and is controlled by the electronic control unit 80 to be maintained at a temperature of about 600 ° C. at which the reforming catalyst is activated.

CnH _{2n + 2} + (n / 2) O ₂ → nCO + (n + 1) H ₂ (1)

The heat exchange section 36 exchanges water supplied from the water tank 22 by the water pump 23 with a combustion gas obtained by burning hydrocarbon fuel from the fuel tank 24 using air from the blower 41. First heat exchange section 4 for converting to steam
0, a second heat exchange section 50 for cooling the reformed gas from the reforming reaction section 32 and heating the steam by heat exchange between the reformed gas from the reforming reaction section 32 and steam. A third heat exchange unit 60 that functions as a condenser that further cools the reformed gas by heat exchange between the reformed gas from the unit 50 and air from the blower 61 and condenses water in the reformed gas.

The flow path of the combustion gas of the first heat exchange section 40 and the second
Water reservoirs 42, 52, 62 for storing condensed water are provided vertically below the reformed gas flow path of the heat exchange section 50 and the reformed gas flow path of the third heat exchange section 60, respectively. . Drain valves 44, 54, 64 are attached to the drain ports 43, 53, 63 of the water reservoirs 42, 52, 62, and condensed water is collected in the water tank 22 through a collection pipe 68. ing.

An ignition device 45 for burning the supplied hydrocarbon-based fuel is attached to the inlet of the combustion gas flow path of the first heat exchange section 40. In the embodiment, a catalytic combustion device (for example, EHC) is used as the ignition device 45. In addition, the exhaust gas of the combustion gas of the first heat exchange section 40 is supplied to the flow path of the reformed gas of the third heat exchange section 60 and the heat exchange flow paths provided in the shift reaction section 70 and the CO reduction section 74 by the exhaust gas pipe 46. Can be supplied.

In the flow path of the reformed gas in the second heat exchange section 50,
A hydrocarbon fuel from the fuel tank 24 and air from the blower 51 can be introduced, and an ignition device 55 is attached to the inlet. In the embodiment, the ignition device 55 is also a catalytic combustion device (for example, EHC).
Was used.

The shift reaction unit 70 is provided with a shift catalyst (for example, copper catalyst) for shifting carbon monoxide in the reformed gas cooled in the heat exchange unit 36 to carbon dioxide and hydrogen by a shift reaction of the following formula (2). The electronic control unit 80 controls the shift catalyst to be maintained at a temperature of about 250 ° C. at which the shift catalyst is activated. Here, the reason why the temperature of the shift reaction section 70 is controlled to be lower than that of the reforming reaction section 32 is to advance the shift reaction, which is an equilibrium reaction, to the right.

CO + H ₂ O → CO ₂ + H ₂ (2)

The CO reduction unit 74 includes a preferential oxidation catalyst (eg, platinum or ruthenium) that preferentially oxidizes carbon monoxide to hydrogen in the presence of hydrogen. The temperature is controlled to be maintained at a temperature of about 140 ° C. for activation.

The electronic control unit 80 is configured as a microprocessor mainly including a CPU 82, and includes a ROM 84 storing a processing program, a RAM 86 temporarily storing data, and an input / output port (not shown). Prepare. The electronic control unit 80 includes the temperature of the reforming section reaction section from the temperature sensor 34 provided in the reforming reaction section 32 and the temperature of the first heat exchange section 40, the second heat exchange section 50, and the third heat exchange section 60. The water level signals from the level sensors 49, 59, 69 attached to the water reservoirs 42, 52, 62, the shift reaction section temperature Ts from the temperature sensor 72 provided in the shift reaction section 70, and the CO reduction section 74 are provided. The temperature Tc of the CO reduction unit from the temperature sensor 78 is input via the input port. Further, the electronic control unit 80 outputs a drive signal to the water pump 23 and the fuel pump 25, a drive signal to the blower 26 that supplies air to the mixing unit 30, a mixing unit 30, the first heat exchange unit 40, and a second heat exchange unit. Fuel supply valves 27 and 2 for restricting the supply of hydrocarbon fuel to the exchange section 50
8 and 29, drive signals to the actuators 27a, 28a and 29a, drive signals to the blowers 41 and 51 for supplying air to the first heat exchange section 40 and the second heat exchange section 50, and the first heat exchange section 40 and the (2) Ignition signals to the ignition devices 45 and 55 of the heat exchange unit 50, and drain valves attached to the drain ports 43, 53 and 63 of the first heat exchange unit 40, the second heat exchange unit 50 and the third heat exchange unit 60 44, 54, 64 actuators 4
4a, 54a, 64a, drive signal to the first heat exchange unit 40
An exhaust gas valve 66 that regulates the supply of exhaust gas from the fuel to the third heat exchange unit 60, the shift reaction unit 70, and the CO reduction unit 74.
Drive signals to the actuators 66a, 73a, 79a of 73, 79 and the actuator 47 of the exhaust gas release valve 47 for regulating the release of exhaust gas from the first heat exchange unit 40 to the atmosphere.
a, a drive signal to the blower 61 that supplies air to the third heat exchange unit 60, a drive signal to the blower 76 that introduces air to the CO reduction unit 74, and the like are output via the output port. .

Next, the operation of the fuel reformer 20 of the embodiment configured as described above will be described. FIG. 2 shows the electronic control unit 8 when the fuel reformer 20 of the embodiment is started.
9 is a flowchart illustrating an example of a start-time processing routine executed by a routine 0;

When the startup processing routine is executed, the CPU 82 of the electronic control unit 80 first executes startup valve operation processing (step S100). The starting valve operation is an operation of closing the fuel supply valve 27, opening the fuel supply valves 28 and 29, opening the exhaust gas valve 66, closing the exhaust gas valves 73 and 79, and closing the exhaust gas opening valve 47. Then, the warm-up process by the first heat exchange unit 40 and the second heat exchange unit 50 of the heat exchange unit 36 is started (step S102). In the warm-up process, the fuel pump 25 is driven to supply the hydrocarbon fuel in the fuel tank 24 to the combustion gas flow path of the first heat exchange unit 40 and the reformed gas flow path of the second heat exchange unit 50. And blowers 41 and 51 are driven to generate air.
The fuel is supplied to the combustion gas flow path of the heat exchange section 40 and the reformed gas flow path of the second heat exchange section 50, and is ignited by the ignition devices 45 and 55 so that the supplied hydrocarbon fuel is burned. It is performed by The combustion gas from the first heat exchange unit 40 and the combustion gas from the second heat exchange unit 50
Is supplied to the shift reaction unit 70 and the CO reduction unit 74 at the subsequent stage to warm up the third heat exchange unit 60, the shift reaction unit 70, and the CO reduction unit 74. FIG. 3 schematically shows the configuration of the fuel reforming apparatus 20 of the embodiment centering on a portion that functions during a warm-up process. In FIG. 3, the display of signals input / output to the input / output port of the electronic control unit 80 is omitted. As described above, the hydrocarbon-based fuel is burned in the first heat exchange unit 40 and the second heat exchange unit 50, and the combustion gas is transferred to the third heat exchange unit 60, the shift reaction unit 70,
By supplying the heat to the CO reduction unit 74, the first heat exchange unit 40, the second heat exchange unit 50, and the third heat exchange unit 6 having a large heat capacity are provided.
0, the shift reaction unit 70 and the CO reduction unit 74 can be quickly warmed up.

When the warm-up process is started, the shift reaction section temperature Ts and the CO reduction section temperature Tc from the temperature sensor 72 and the temperature sensor 78 are read (step S104), and the shift reaction section temperature Ts is set to the threshold value Tsr. It waits for the temperature to increase and the CO reduction unit temperature Tc to exceed the threshold value Tcr (step S106). Here, the threshold value Tsr and the threshold value Tcr are used to determine the end of the warm-up process, and the threshold value Tsr is set as a value larger than the lower limit value of the temperature range in which the shift catalyst of the shift reaction unit 70 is activated. Then, the threshold value Tcr is set as a value larger than the lower limit value of the temperature range in which the preferential oxidation catalyst of the CO reduction unit 74 is activated.

While waiting for the warm-up process to be completed, the fuel reformer 20 of the embodiment uses the first water exchange unit 40 and the second heat exchange unit according to the first water recovery process routine illustrated in FIG. The process of collecting the condensed water generated in the third heat exchange unit 60 is performed by the process of collecting the condensed water generated in 50 and the second water recovery process routine illustrated in FIG. The following briefly describes these water recovery processes. Note that the first water recovery processing routine and the second water recovery processing routine are repeatedly executed at predetermined time intervals (for example, every 100 msec).

When the first water recovery processing routine of FIG. 4 is executed, the CPU 82 of the electronic control unit 80 first inputs signals from the level sensors 49 and 59 (step S2).
00), and determines whether it is an ON signal (step S20).
2). When both are OFF signals, it is determined that no condensed water is stored in the water reservoirs 42 and 52, and this routine ends. When the signal from any one of the level sensors 49 and 59 is an ON signal, the supply of the hydrocarbon fuel and the supply of the air to the corresponding heat exchange unit is stopped (step S204), and the corresponding drainage is performed. The valve is opened (Step S206). That is, when the signal from the level sensor 49 is an ON signal, the fuel supply valve 28 is closed, and the blowers 41 and 51 are stopped to stop the supply of fuel and air to the first heat exchange unit 40. 44 is opened. By such processing, the condensed water is removed from the water tank 22.
Will be collected.

Then, after the signal from the corresponding level sensor is turned off (steps S208, S21)
0), and close the opened drain valve (step S21).
2) At the same time, the supply of the hydrocarbon fuel and the air is started again (step S214), the ignition is performed by the ignition device (step S216), and this routine ends. The reason why the supply of hydrocarbon fuel and air is stopped while the drain valve is opened is that the hydrocarbon fuel and air are vigorously discharged through the drain ports 43 and 53. This is to prevent it.

In the second water recovery processing routine of FIG. 5, when the signal from the level sensor is turned on, the supply of hydrocarbon fuel or air is stopped, and the signal from the level sensor is turned off. The first water recovery processing routine is the same as the first water recovery processing routine except that the supply start processing of the hydrocarbon fuel or air is not performed. Therefore, further description of the second water recovery processing routine will be omitted. In the embodiment, the first heat exchange unit 40 and the second heat exchange unit 50
Although the condensed water recovery processing in the above is performed according to the first water recovery processing routine, the condensed water recovery may be performed according to the second water recovery processing routine. Thus, during the warm-up process, the first heat exchange unit 40 and the second heat exchange unit 50
And the condensed water generated in the third heat exchange unit 60 is recovered,
The adverse effect caused by the condensed water being sent to the shift reaction section 70 and the CO reduction section 74 to wet the shift catalyst and the preferential oxidation catalyst, that is, a decrease in the catalytic function can be prevented.

Returning to the start-time processing routine of FIG. 2, if it is determined in step S106 that the shift reaction section temperature Ts is larger than the threshold value Tsr and the CO reduction section temperature Tc is larger than the threshold value Tcr, the warm-up is terminated. Judgment is performed and valve operation processing for steady operation is performed (step S10
8) Start the steady operation process (step S110),
This routine ends. The valve operation for the steady operation is performed by closing the fuel supply valve 29 that supplies the hydrocarbon-based fuel to the second heat exchange unit 50 and connecting the first heat exchange unit 40 to the third heat exchange unit 60.
The exhaust gas valve 66 for supplying the combustion gas from the fuel tank is closed, and the fuel supply valve 2 for supplying the hydrocarbon fuel to the mixing section 30
7 is an operation for opening the exhaust gas release valve 47 for opening the combustion gas from the first heat exchange unit 40 to the atmosphere. In addition,
In the steady operation, the fuel supply valve 28 that supplies the hydrocarbon-based fuel to the first heat exchange unit 40 is also open. However, since the fuel supply valve 28 has already been opened during the warm-up process, it need not be opened here. In the steady operation process, the water pump 23, the fuel pump 25, the blowers 26, 61, and 7 are stopped while the blower 51 is stopped.
6 is a process for driving as necessary. In steady operation,
The blower 41 that supplies air to the first heat exchange unit 40 is also driven, but since it has already been driven during the warm-up process, it is not necessary to drive it again in this process. The fuel reforming apparatus 20 according to the embodiment centering on a portion that functions during a steady operation.
FIG. 6 shows an outline of the configuration. In FIG. 6, the display of signals input to and output from the input / output ports of the electronic control unit 80 is omitted.

When the steady operation process is started, the water tank 2
The second water is supplied to the first heat exchange unit 40 by the water pump 23 to be vaporized, heated by the second heat exchange unit 50, and supplied to the mixing unit 30. In the mixing section 30, the fuel tank 24 is operated by the supplied steam and the fuel pump 25.
And the air supplied by the blower 26 are mixed and supplied to the reforming reaction section 32 as a reforming raw material. Since the reforming reaction in the reforming reaction section 32 progresses relatively quickly due to the exothermic reaction, the reforming reaction section 32
Becomes a steady operation state in a short time even if it is not warmed up in advance. Then, the reformed gas from the reforming reaction section 32 is cooled by the second heat exchange section 50 and the third heat exchange section 60 and supplied to the shift reaction section 70. Water vapor in the reformed gas may be condensed by such cooling, but this condensed water is stored in the water reservoirs 52 and 62 and recovered through the drain ports 53 and 63, so that the shift reaction unit 70 and CO reduction No condensed water is sent to the section 74. As a result, it is possible to prevent the shift catalyst of the shift reaction unit 70 and the preferential oxidation catalyst of the CO reduction unit 74 from getting wet and reducing their functions. The control of collecting condensed water in the second heat exchange unit 50 and the third heat exchange unit 60 and the control of the amount of air supplied to the third heat exchange unit 60 by the blower 61 will be described later.

Next, control of the fuel reformer 20 of the embodiment in a steady operation state, in particular, control of the amount of supplied air in the third heat exchange unit 60, the first heat exchange unit 40 and the second heat exchange unit 5
The control of the condensed water recovery process in the 0th and third heat exchange units 60 and the temperature control of the shift reaction unit 70 and the CO reduction unit 74 will be described.

The control of the supply air amount in the third heat exchange section 60 is performed by a supply air amount control routine illustrated in FIG. This routine is executed at predetermined time intervals (for example, 10
(Every second). When this routine is executed, the CPU 82 of the electronic control unit 80 first reads the shift reaction section temperature Ts detected by the temperature sensor 72 (step S400), and the read shift reaction section temperature Ts is set to the threshold T1 and the threshold T2. (Step S40).
2). Here, the range set by the threshold value T1 and the threshold value T2 is used to control the temperature of the reformed gas supplied to the shift reaction unit 70, and is set within the temperature range in which the shift catalyst is activated. . The shift reaction section temperature Ts is equal to the threshold T
When the temperature is within the temperature range set by 1 and the threshold value T2, it is determined that the reformed gas is within the appropriate temperature range, and this routine ends. When the shift reaction section temperature Ts is lower than the threshold value T1, it is determined that the temperature of the reformed gas is low, and the blower 61 is drive-controlled to supply the cooling air supplied to the third heat exchange section 60 by a predetermined amount. (Step S40)
4), end this routine. When the temperature Ts of the shift reaction section is higher than the threshold value T2, it is determined that the temperature of the reformed gas is high, and the blower 61 is driven to control the supply amount of the cooling air supplied to the third heat exchange section 60. The amount is increased by the fixed amount (step S406), and this routine ends. By controlling the amount of air supplied to the third heat exchange unit 60 by such a blower 61, it is possible to supply the shift reaction unit 70 with a reformed gas in an appropriate temperature range. In addition,
In the embodiment, the blower 6 is operated based on the shift reaction section temperature Ts.
1, the amount of air supplied to the third heat exchange unit 60 is controlled. However, the temperature of the reformed gas supplied to the shift reaction unit 70 is directly detected, and the air is supplied based on the temperature of the reformed gas. The amount may be controlled.

The condensed water recovery processing in the first heat exchange section 40, the second heat exchange section 50, and the third heat exchange section 60 is performed by a second water recovery processing routine illustrated in FIG.
Since this processing has been described above, further description is omitted. As described above, since the condensed water that can be generated in the first heat exchange unit 40, the second heat exchange unit 50, and the third heat exchange unit 60 is collected, the condensed water is sent to the shift reaction unit 70 and the CO reduction unit 74. It is possible to prevent an adverse effect caused by wetting the shift catalyst and the preferential oxidation catalyst, that is, a decrease in the catalytic function.

The temperature control of the shift reaction section 70 and the CO reduction section 74 is performed by a shift reaction section temperature control routine illustrated in FIG. 8 and a CO reduction section temperature control routine illustrated in FIG. These routines are executed at predetermined time intervals (for example,
(Every 10 seconds).

When the shift reaction section temperature control routine of FIG. 8 is executed, the CPU 82 of the electronic control unit 80 first reads the shift reaction section temperature Ts detected by the temperature sensor 72 (step S500), and reads the read shift reaction temperature. A process for determining whether or not the reaction section temperature Ts is less than the threshold Tr1 is executed (Step S502). Here, the threshold T
r1 is set as a value higher than the lower limit of the temperature range in which the shift catalyst of the shift reaction section 70 is activated. When the shift reaction section temperature Ts is equal to or higher than the threshold Tr1, it is determined that the shift reaction section 70 does not need to be heated, and this routine ends. On the other hand, when the shift reaction section temperature Ts is lower than the threshold value Tr1, it is determined that the shift reaction section 70 needs to be heated, and the combustion gas from the first heat exchange section 40 is supplied for a predetermined time (step S504). To end. The supply of the combustion gas from the first heat exchange section 40 for a predetermined time is performed by closing the exhaust gas opening valve 47 and opening the exhaust gas valve 73, and after the lapse of the predetermined time, opening the exhaust gas opening valve 47 and closing the exhaust gas valve 73. This is done by performing As a result, the combustion gas as the exhaust gas from the first heat exchange unit 40 is supplied to the heat exchange channel of the shift reaction unit 70, and the shift reaction unit 70 can be heated.

The CO reduction unit temperature control routine of FIG. 9 uses the CO reduction unit temperature Tc instead of the shift reaction unit temperature Ts, and the temperature at which the preferential oxidation catalyst of the CO reduction unit 74 is activated instead of the threshold value Tr1. 8 is the same as the shift reaction unit temperature control routine of FIG. 8 except that a threshold Tr2 set to a value larger than the lower limit of the range is used. Therefore, the description will be duplicated, and further description will be omitted.

According to the fuel reforming apparatus 20 of the embodiment described above, the heat exchange section 36 for cooling the reformed gas from the reforming reaction section 32 is connected to the first heat exchange section 40 and the second heat exchange section 50. Third
The condensed water is formed by the heat exchange unit 60 and the condensed water that can be generated in each unit is recovered.
It is possible to prevent an adverse effect caused by being sent to the reduction unit 74 to wet the shift catalyst or the preferential oxidation catalyst, that is, a decrease in the catalytic function. In addition, since the reformed gas supplied to the shift reaction unit 70 is cooled by the second heat exchange unit 50 and the third heat exchange unit 60, the reformed gas in an appropriate temperature range is supplied to the shift reaction unit 70. be able to. Further, since the recovered water is used as a reforming raw material, resources can be used efficiently.

Further, according to the fuel reforming apparatus 20 of the embodiment, the hydrocarbon-based fuel and air are supplied to the reformed gas flow path of the second heat exchange section 50 and burned at the time of startup, and the combustion is performed. Since the gas is supplied to the third heat exchange unit 60, the shift reaction unit 70, and the CO reduction unit 74, the second heat exchange unit 50, the third heat exchange unit 60, and the shift reaction unit 70 can be quickly warmed up. . In addition, the combustion gas from the first heat exchange section 40
Since the reformed gas is supplied to the flow path of the reformed gas in the heat exchange unit 60, it is possible to warm up more quickly. Also, the first heat exchange unit 40
Since the fuel supplied to the second heat exchange unit 50 is a hydrocarbon-based fuel used as a reforming raw material, it is not necessary to separately store the fuel, and the apparatus can be simplified.

Further, according to the fuel reformer 20 of the embodiment, the exhaust gas of the first heat exchange section 40 is
Since it is used for controlling the temperature of the O reduction unit 74, the thermal efficiency of the entire apparatus can be improved.

Due to the effects of the fuel reforming apparatus 20 of the embodiment, the fuel reforming apparatus 20 of the embodiment efficiently reforms the hydrocarbon-based fuel and has a hydrogen-rich composition having a very low carbon monoxide concentration. Fuel gas can be obtained.

In the fuel reformer 20 of the embodiment, the heat exchanging section 36 is constituted by the first heat exchanging section 40, the second heat exchanging section 50, and the third heat exchanging section 60. And the third
The second heat exchange unit 50 may be configured to directly supply water from the water tank 22 to the second heat exchange unit 50. Further, the heat exchanging unit 36 is connected to the first heat exchanging unit 40 and the second heat exchanging unit 5.
0 may be used.

In the fuel reforming apparatus 20 of the embodiment, at the time of start-up, the hydrocarbon-based fuel and air are supplied to the first heat exchange section 40 and the second heat exchange section 50, and the fuel is burned. Was supplied to the third heat exchange section 60, the shift reaction section 70, and the CO reduction section 74 to warm up. However, only the second heat exchange section 50 was supplied with hydrocarbon fuel and air, and was burned. The gas may be supplied to the third heat exchange unit 60 and thereafter to warm it up. Further, the combustion gas from the first heat exchange unit 40 is supplied to the reformed gas flow path of the second heat exchange unit 50, and the second heat exchange unit 50, the third heat exchange unit 60, the shift reaction unit 70, The CO reduction unit 74 may be warmed up.

In the fuel reformer 20 of the embodiment, the first heat exchange section 40, the second heat exchange section 50, and the third heat exchange section 60 are provided with water reservoirs 42, 52, 62 and drain ports 43, 53, 63. Although provided, the water reservoir and the drain port may be provided only in the third heat exchange unit 60.

In the fuel reformer 20 of the embodiment, the exhaust gas from the first heat exchange section 40 is used for controlling the temperature of the shift reaction section 70 and the CO reduction section 74.
Exhaust gas from 0 may not be used for temperature control of the shift reaction unit 70 or the CO reduction unit 74.

In the fuel reforming apparatus 20 of the embodiment, the fuel supplied to the first heat exchange section 40 and the second heat exchange section 50 is a hydrocarbon fuel used as a reforming material, but a different fuel is supplied. It does not matter.

In the fuel reformer 20 of the embodiment, natural gas or gasoline is used as the hydrocarbon fuel. However, various other fuels such as saturated hydrocarbons, unsaturated hydrocarbons, alcohols such as methanol, etc. A hydrocarbon fuel may be used.

Although the fuel reforming apparatus 20 of the embodiment is provided with the CO reducing unit 74, when supplying the hydrogen-rich gas to the equipment in which the concentration of carbon monoxide does not matter so much, the CO reducing unit 74 is provided. It does not matter if you do not have it.

The embodiments of the present invention have been described with reference to the embodiments. However, the present invention is not limited to these embodiments, and various embodiments may be made without departing from the gist of the present invention. Of course, it can be carried out.

[Brief description of the drawings]

FIG. 1 is a configuration diagram schematically showing the configuration of a fuel reforming apparatus 20 according to one embodiment of the present invention.

FIG. 2 is a flowchart illustrating an example of a start-time processing routine executed by an electronic control unit 80 of the fuel reforming apparatus 20 according to the embodiment.

FIG. 3 is a configuration diagram schematically illustrating a configuration of a fuel reforming apparatus 20 according to an embodiment, mainly focusing on a portion that functions during a warm-up process;

FIG. 4 is a flowchart illustrating an example of a first water recovery processing routine executed by the electronic control unit 80 of the fuel reformer 20 of the embodiment during the warm-up processing.

FIG. 5 is a flowchart illustrating an example of a second water recovery processing routine executed by the electronic control unit 80 of the fuel reformer 20 of the embodiment during the warm-up processing.

FIG. 6 is a configuration diagram schematically showing a configuration of a fuel reforming apparatus 20 according to an embodiment centering on a portion that functions during a steady operation.

FIG. 7 is a flowchart illustrating an example of an air amount control routine executed by the electronic control unit 80 of the fuel reforming apparatus 20 of the embodiment during a steady operation.

FIG. 8 is a flowchart illustrating an example of a shift reaction unit temperature control routine executed by the electronic control unit 80 of the fuel reformer 20 of the embodiment during a steady operation.

FIG. 9 is a flowchart illustrating an example of a CO reduction unit temperature control routine executed by the electronic control unit 80 of the fuel reformer 20 according to the embodiment during a steady operation.

[Explanation of symbols]

Reference Signs List 20 fuel reformer, 22 water tank, 23 water pump, 24 fuel tank, 25 fuel pump, 26 blower, 30 mixing section, 32 reforming reaction section, 34 temperature sensor, 36 heat exchange section, 40 first heat exchange section , 41,5
1,61 blower, 42,52,62 pool, 43,
53, 63 drain port, 44, 54, 64 drain valve, 44a, 54a, 64a actuator, 4
5,55 ignition device, 46 exhaust gas pipe, 47 exhaust gas release valve, 47a actuator, 49, 59, 69
Level sensor, 50 second heat exchange section, 60 third heat exchange section, 66, 73, 79 exhaust gas valve, 66 a, 73
a, 79a actuator, 68 recovery pipe, 70 shift reaction section, 72, 78 temperature sensor, 74 CO reduction section, 76 blower, 80 electronic control unit, 82 C
PU, 84 ROM, 86 RAM.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4G040 EA03 EB03 EB13 EB31 EB32 EB43 EB44 4H013 AA04 4H060 BB08 BB11 BB12 BB24 CC18 DD05 FF02

Claims (17)

[Claims] 1. A fuel reformer for reforming a hydrocarbon fuel into a hydrogen-rich fuel gas, wherein the hydrocarbon fuel is reformed into a reformed gas containing hydrogen and carbon monoxide. A reforming section, a heat exchange means for cooling the reformed gas by heat exchange and recovering condensed water generated by the cooling, and using carbon monoxide in the cooled reformed gas using steam. A fuel reformer comprising: a shift reaction unit that shifts to hydrogen and carbon dioxide. 2. The heat exchange means comprises: first heat exchange means for evaporating water by heat exchange between water and a combustion gas obtained by burning fuel; and water vapor from the first heat exchange means. A second step of cooling the reformed gas by heat exchange with the reformed gas;
2. The fuel reformer according to claim 1, further comprising a heat exchange unit, and a third heat exchange unit that cools the reformed gas by exchanging heat between the reformed gas from the second heat exchange unit and a cooling medium. apparatus. 3. The heat exchange means includes: first condensed water recovery means for recovering condensed water from fuel gas generated by heat exchange in the first heat exchange means; and heat exchange generated by the second heat exchange means. A second condensed water collecting means for collecting condensed water from the reformed gas; and a third condensed water collecting means for collecting condensed water from the reformed gas generated by heat exchange in the third heat exchanging means. The fuel reformer according to claim 2. 4. The fuel reformer according to claim 3, wherein each of the first condensed water collecting means, the second condensed water collecting means, and the third condensed water collecting means has a drain port. 5. A condensed water collecting means for collecting at least one of the first condensed water collecting means, the second condensed water collecting means, and the third condensed water collecting means,
Drainage means for draining water from the water reservoir, water level detection means for detecting the water level of the water reservoir, and drainage control means for controlling water discharge by the water discharge means based on the water level detected by the water level detection means 5. The fuel reformer according to claim 3, further comprising: 6. The fuel reforming apparatus according to claim 2, wherein a shift temperature detecting means for detecting a temperature of the shift reaction section, and wherein the shift temperature detecting section detects a temperature of the shift reaction section based on the detected temperature of the shift reaction section. A cooling medium flow control means for controlling a flow rate of the cooling medium supplied to the flow path of the cooling medium of the third heat exchange means. 7. The fuel reformer according to claim 2, wherein the combustion gas from the first heat exchange unit can be supplied to a reformed gas flow path of the third heat exchange unit. A first combustion gas supply means, and a first start-up means for controlling the combustion gas supply means to supply the combustion gas from the first heat exchange means to the reformed gas flow path of the third heat exchange means at the time of starting. A fuel reformer comprising: a time control unit. 8. The fuel reforming apparatus according to claim 2, wherein a fuel supply unit that supplies a fuel to a reformed gas flow path of the second heat exchange unit, and the second heat exchange unit. Igniting means attached near the inlet of the reformed gas flow path of the means; and controlling the fuel supply means so that fuel is supplied to the reformed gas flow path of the second heat exchange means at startup. A second start-time control means for controlling the ignition means so that the supplied fuel is burned. 9. The fuel reformer according to claim 8, wherein the fuel supply means is a means for supplying the hydrocarbon-based fuel. 10. The fuel reformer according to claim 2, wherein the fuel burned by the first heat exchange means is the hydrocarbon-based fuel. 11. The fuel reformer according to claim 2, wherein the shift reaction unit is capable of performing heat exchange with a flow path of the reformed gas undergoing the shift reaction. A fuel reformer, comprising: a flow passage; and a second combustion gas supply means capable of supplying combustion gas from the first heat exchange means to the shift reaction part heat exchange flow path. 12. The fuel reforming apparatus according to claim 11, further comprising: first temperature detecting means for detecting a temperature of the shift reaction section, wherein the second combustion gas supplying means is configured to detect the first temperature. A fuel reformer that controls a supply amount of the combustion gas to the shift reaction unit heat exchange flow path based on the temperature detected by the means. 13. The fuel reformer according to claim 2, wherein the fuel reformer is disposed downstream of the shift reaction unit, and reduces a concentration of carbon monoxide in gas from the shift reaction unit. A carbon monoxide concentration reducing section having a reducing section heat exchange channel capable of exchanging heat with a gas having a reduced carbon monoxide concentration; and a combustion gas from the first heat exchanging means being supplied to the reducing section heat exchange channel. And a third combustion gas supply unit capable of supplying the fuel. 14. The fuel reforming apparatus according to claim 13, further comprising: a second temperature detecting unit that detects a temperature of the carbon monoxide concentration reducing unit, wherein the third combustion gas supplying unit includes the third combustion gas supplying unit. (2) A fuel reformer which is a means for controlling a supply amount of a combustion gas to the heat exchange flow path of the reducing section based on a temperature detected by a temperature detecting means. 15. The fuel reforming apparatus according to claim 1, wherein the heat exchange unit is a unit that cools the reformed gas using steam, and is heated by the heat exchange unit. A fuel reforming apparatus comprising: a mixing section that mixes the steam with the hydrocarbon-based fuel and supplies the mixture to the reforming section. 16. The fuel reformer according to claim 15, wherein said heat exchange means is means for using water recovered from said heat exchange means as said steam. 17. The fuel reformer according to claim 1, wherein the hydrocarbon-based fuel is natural gas or gasoline.