JP2006216283A - Town gas supply device for solid polymer electrolyte fuel cell power generation device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To stably supply town gas to a fuel treatment device by suppressing pressure variation and flow rate variation without using a buffer tank when the town gas is supplied to the fuel treatment device with a fuel pump in a power generation device using a solid polymer electrolyte fuel cell. <P>SOLUTION: The fuel pump 22 for compressing town gas TG to required pressure, a check valve 35 for giving required resistance to the flow of the town gas, and a flow meter 23 for controlling the flow of the fuel pump 22 are installed in order from the upstream part in a town gas supply line 11 for supplying the town gas TG to the fuel treatment device 5 of a solid polymer electrolyte fuel cell power generation device, and by giving the required resistance to the flow of the town gas TG supplied from the fuel gas supply line 11 by crack pressure characteristics of the check valve 35, the amplitude of pulsation of the town gas caused by the fuel pump 11 is suppressed and the pressure variation and the flow rate variation are suppressed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to a city gas supply device for a polymer electrolyte fuel cell power generator used when city gas is supplied as a fuel gas to a fuel processor in a stationary polymer electrolyte fuel cell power generator.

The fuel cell is expected to be an effective power generation device because it has higher thermal efficiency than other power generations using fuel and less environmental pollution. In particular, the polymer electrolyte fuel cell (PEFC)
Power generation is performed at a low temperature of 100 ° C. or lower, power density is high, and operation is performed at a low temperature. Therefore, it is possible to reduce the size as compared with other types of fuel cells, and there is little deterioration of battery constituent materials, and startup is easy. In recent years, it has come to be used as a power generator for small-scale business use or home use.

A power generation device (PEFC power generation device) using the polymer electrolyte fuel cell is generally shown in FIG.
The configuration is as outlined below. That is, the cathode (air electrode) 2 and the anode (fuel electrode) 3 are disposed on both sides of a solid polymer electrolyte membrane in which a fluorine-based ion exchange membrane is used as an electrolyte.
The solid polymer fuel cell 1 has a configuration in which cells sandwiched between the gas diffusion electrodes are stacked via a separator to form a stack, and one cooling unit 4 is provided for several cells. . Further, on the inlet side of the anode 3 in the polymer electrolyte fuel cell 1, a fuel processor 5 including a reformer 6, a shift converter 7, and a CO remover 8 in order from the upstream side, and a humidifier 9.
After desulfurizing a raw material such as natural gas or methanol as a fuel gas 12 supplied from a fuel supply source (not shown) in the desulfurization reactor 10, the fuel processing apparatus 5 together with water vapor is supplied through a fuel gas supply line 11. The reformer 6 is supplied with steam reforming, and the resulting reformed gas (fuel gas) 12a is guided to the shift converter 7 for a shift reaction, and the CO remover 8 further performs CO removal treatment. Thereafter, the anode 3 of the polymer electrolyte fuel cell 1 is passed through a humidifier 9.
To supply. On the other hand, a compressor (air blower) 13 is connected to the humidifier 9 on the inlet side of the cathode 2 via an oxidizing gas supply line 14, and air 1 is used as the oxidizing gas.
5 is supplied to the cathode 2 of the polymer electrolyte fuel cell 1 through the humidifier 9 after being compressed by the compressor 13.

With such a configuration, in the polymer electrolyte fuel cell 1, hydrogen in the reformed gas 12a supplied to the anode 3 side and oxygen in the air 15 supplied to the cathode 2 side undergo an electrochemical reaction (
Battery reaction), and the electromotive force generated at this time is taken out.

Reference numeral 16 denotes an anode offgas line for introducing the anode offgas 17 discharged from the outlet side of the anode 3 to the combustion chamber of the reformer, and 18 denotes a part of the fuel gas 12 to the combustion chamber of the reformer 6. A fuel gas line 19 for supplying a part of the air 15 to the combustion chamber of the reformer 6, and a gas line 20 for the flue gas 21 discharged from the combustion chamber of the reformer 6. is there.

By the way, when city gas is used as the fuel gas 12 supplied to the reformer 6 of the fuel processor 5 in the power generation apparatus using the polymer electrolyte fuel cell 1, the reforming chamber in the reformer 6 is used. Due to the dense packing of the catalyst, the city gas itself has 2.0 ± 0.5k.
It is difficult to supply a sufficient amount of city gas to the fuel processor 5 with only a supply pressure of about Pa. Therefore, the city gas is pressurized to a required pressure with a fuel pump and then sent to the fuel processor 5.

When the city gas pressurized by the fuel pump is supplied to the fuel processing device 5, the flow rate of the supplied city gas is controlled so that a predetermined amount of city gas is supplied to the fuel processing device 5. A flow meter is generally used, and the flow rate is controlled based on the measured value of the flow meter.

FIG. 20 shows an outline of the fuel gas supply when the city gas TG is supplied as the fuel gas to the fuel processing device 5 in the same configuration as the polymer electrolyte fuel cell power generator shown in FIG. A fuel pump 22 is provided in the line 11, and the city gas TG is generated by the fuel pump 22.
Is pressurized and discharged, and the city gas TG discharged from the fuel pump 22
The flow meter 23 is provided as a configuration for controlling the flow rate. That is, a fuel pump 22 for pressurizing the city gas TG is provided in the middle of the fuel gas supply line 11 for supplying the city gas TG to the reformer 6 of the fuel processing device 5, and downstream of the fuel pump 22. A flow meter 23 for detecting the flow rate of the discharged city gas TG is provided, and the city gas T
When G is pressurized to a required pressure by the fuel pump 22 and discharged, the flow rate of the discharged city gas TG is detected by the flow meter 23, and the fuel pump 22's flow rate is detected based on the measured value of the detected flow rate. Operation control is performed to control the flow rate of the city gas TG supplied to the fuel processor 5. As the fuel pump 22 for pressurizing the city gas TG, there is a turbo type pump. However, there is a possibility that pressurization to a desired pressure is insufficient with this pump, and the pulsation is excessive with the reciprocating pump. There is a problem that there is a concern that the apparatus is enlarged. Therefore, in general, a positive displacement pump for compressive fluid such as a diaphragm pump or a bellows pump is used.

However, a positive displacement pump for a compressive fluid such as a diaphragm pump used as the fuel pump 22 is not as reciprocating as a reciprocating pump, but pulsation occurs and pressure fluctuations change in units of seconds. City gas TG will be sent. In addition, the positive displacement pump such as the diaphragm pump does not change the discharge amount in one stroke, and adjusts the discharge amount by changing the number of strokes. There is a characteristic that the flow rate fluctuation increases as the value increases.

Thus, when the fluctuation of the flow rate of the city gas TG supplied from the fuel pump 22 to the fuel processing device 5 becomes large, a reaction failure occurs in the reforming reaction of the city gas TG in the fuel processing device 5.
When a reaction failure occurs, the concentration of carbon monoxide in the reformed gas supplied from the fuel processor 5 to the fuel cell 1 increases, and the catalyst used for the electrode of the polymer electrolyte fuel cell 1 is poisoned. And
There is a possibility that the power generation voltage of the polymer electrolyte fuel cell 1 is lowered. Further, when an excessive amount of city gas TG is supplied to the fuel processing apparatus 5 due to a control error with respect to the amount of steam supplied for steam reforming, the fuel processing apparatus 5 There is also a concern that the vapor / carbon balance may be lost and carbon deposition may occur.

Further, as the flow meter 23, since the measurement object is city gas TG, there are restrictions on the types of flow meters that can be used, and only the pressure type can be used at present. On the other hand, if the city gas TG supplied from the fuel pump 22 pulsates and a pressure fluctuation occurs, an error occurs in the flow meter side value of the flow meter 23, and the flow rate measurement value with the error is the fuel pump 2.
2, the operation control of the fuel pump 22 is performed. Therefore, the control error further increases, and there is a problem that the fluctuation of the flow rate becomes large.

Therefore, in order to suppress the pressure fluctuation and the flow fluctuation of the city gas TG supplied from the fuel pump 22, the flow rate regulator for adjusting the flow of the city gas TG discharged from the fuel pump 22 is used as a fuel. Conventionally proposed is the one provided on the downstream side of the pump 22.

In the above fuel cell power generator, a flow rate regulator is used on the downstream side of the fuel pump, as shown in FIG.

That is, in the polymer electrolyte fuel cell power generator including the reformer 24, the shift converter (carbon monoxide converter) 30, the CO remover (carbon monoxide remover) 31, and the fuel cell 32, the above reforming is performed. Supply pipe 25 for supplying city gas TG as fuel gas to the vessel 24
In addition, from the upstream side, for example, a pressure pump 26 as a fuel pump using a bellows pump or the like and a flow rate regulator 27 are connected and provided. This
The city gas TG is pressurized by the pressurizing pump 26 before being supplied to the reformer 24 through the supply pipe 25, and after the pressure and flow rate are controlled by the flow rate regulator 27, the city gas TG is led from the steam generator 28. What has been proposed to be supplied to the reformer 24 together with the steam 29 (
For example, see Patent Document 1). In FIG. 21, reference numeral 33 denotes a fan for supplying oxygen in the air.

In general, a buffer tank (receiver tank) is used as the flow rate regulator 27 provided on the downstream side of the pressurizing pump 26.

21 is not provided with a flow meter downstream of the pressurizing pump 26, but in order to suppress a control error caused by the flow meter due to the pressure fluctuation of the city gas TG, the flow meter And a flow rate regulator can be used in combination.

FIG. 22 shows a configuration similar to that of the polymer electrolyte fuel cell power generator shown in FIG. 19, and a fuel pump 22 is provided in the fuel gas supply line 11 that supplies the city gas TG to the fuel processor 5. At the same time, a buffer tank 34 and a flow meter 23 are sequentially provided on the downstream side from the upstream side. According to this, the pressure fluctuation of the city gas TG discharged from the fuel pump 22 can be suppressed by the buffer tank 34, and then the flow rate of the city gas TG is detected by the flow meter 23. Therefore, the operation control error of the fuel pump 22 in the flow meter 23 is suppressed, and the city gas TG can be stably supplied to the fuel processing device 5.

JP 2000-299120 A

However, in order to use the fixed polymer fuel cell power generation device as a power generation device for small-scale business use or home use, it is desired to further reduce the size of the entire power generation device. On the other hand, since the buffer tank 34 has a volume of several liters, there is a problem that it becomes an obstacle to such downsizing.

Further, the city gas T to be supplied to the fuel processing device 5 due to the heavy load of the polymer electrolyte fuel cell
When the amount of G is large, it is conceivable to operate a plurality of fuel pumps in parallel. In this case, for example, the fuel gas supply line 11 is branched into a plurality of parts from the supply system of the city gas TG to the fuel processing device 5 shown in FIG. It can be considered that the fuel pumps 22 are operated in parallel to supply the city gas TG to the fuel processing device 5. In such a case, when the operation control of each fuel pump 22 is performed using the flow meter 23, for example, as shown in FIG. 23, the fuel pump 22 is provided in each branch line 11a, 11b, 11c. In such a configuration, the flow meter 23 is provided on the downstream side of each fuel pump 22 in each of the branch lines 11a, 11b, and 11c, and the city gas TG supplied by being pressurized by a plurality of fuel pumps 22 is provided. Is detected by each flow meter 23 to control the operation of each fuel pump 22 or, as shown in FIG. 24, the fuel gas supply lines 11a, 11b are the same as shown in FIG. , 11c, the fuel pump 22 is provided, and a flow meter is provided downstream of the junction A of the branch lines 11a, 11b, 11c. 3 is provided so that the total flow rate of the city gas TG supplied by a plurality of fuel pumps 22 is detected by a single flow meter 23, and the operation control of each fuel pump 22 is performed collectively. It is possible to do. When a plurality of fuel pumps 22 are operated in parallel as described above, pulsations generated for each fuel pump 22 interfere with each other, which may further increase the pulsations, and may further increase the fluctuation in flow rate. . In particular, in the case of the configuration shown in FIG. 23, since the pulsation generated in each fuel pump 22 has a phase shift, each branch line 11a, 11b, 11c at the junction A of the branch lines 11a, 11b, 11c. As a result, a difference in elevation occurs in the supply pressure of the city gas TG flowing through the city gas, and the city gas TG in the branch line with the lower supply pressure may flow backward for a short time until the supply pressure recovers. In such a case, since the flow meter 23 is provided on the upstream side of the junction A of the branch line, there is a concern that the city gas TG may flow backward through the flow meter 23 and the flow rate fluctuation may further increase. The Therefore, in the configuration shown in FIG. 23, as shown in FIG. 25, the buffer tank 34 is installed between the fuel pump 22 and the flow meter 23 in each branch line 11a, 11b, 11c. It is possible to do. Also, for the configuration shown in FIG. 24, as shown in FIG.
In a, 11b, and 11c, a buffer tank 34 is provided between each fuel pump 22 and the junction A of the branch lines, or as shown in FIG. The buffer tank 34 is located between the confluence A and the flow meter 23.
It is conceivable to provide a single number. However, if this is done, the flow rate fluctuation and pressure fluctuation of the city gas TG can be suppressed. However, in the configuration shown in FIGS. 25 and 26, a plurality of buffer tanks 34 must be provided, In the configuration shown in FIG. 27 as well, since the city gas TG supplied by the plurality of fuel pumps 22 is processed by a single buffer tank 34, the buffer tank 34 must be provided with a larger size. However, there is a problem that the entire power generation device is enlarged.

Therefore, the present invention uses a buffer tank as a flow regulator when supplying city gas as a fuel gas to a fuel processing apparatus in a power generation apparatus using a polymer electrolyte fuel cell using a fuel pump such as a diaphragm pump. It is an object of the present invention to provide a city gas supply device for a polymer electrolyte fuel cell power generator that can suppress a pressure fluctuation and a flow rate fluctuation and can stably supply a city gas to a fuel processing apparatus.

In order to solve the above-mentioned problems, the present invention provides the above-described fuel processing in a polymer electrolyte fuel cell power generator having a configuration in which fuel gas is processed by the fuel processor and then supplied to the polymer electrolyte fuel cell. A fuel pump or a fuel pump and a flow meter are provided on a fuel gas supply line designed to supply the fuel gas to the apparatus, and are required for the circulation of city gas pressurized and discharged by the fuel pump. It is set as the structure which provided the voltage regulator which gives resistance.

Further, the fuel gas is supplied to the fuel processing device in the polymer electrolyte fuel cell power generator having a configuration in which the fuel gas is processed by the fuel processing device and then supplied to the polymer electrolyte fuel cell. On a certain fuel gas supply line, a plurality of branch lines that once branch and then merge again are provided, and each branch line is provided with a fuel pump or a fuel pump and a flow meter, respectively, Each of the pressure regulators is provided with a pressure regulator that gives a necessary resistance to the circulation of the city gas pressurized and discharged by each fuel pump.

Furthermore, in the same configuration as the above configuration, each branch line is provided with a fuel pump,
In addition, a configuration is provided in which a pressure regulator is provided on the fuel gas supply line obtained by joining the branch lines to give a required resistance to the circulation of the city gas pressurized and discharged by the fuel pumps. Or each branch line is provided with a fuel pump, a flow meter is provided on the downstream side of each fuel pump or on the fuel gas supply line where the branch lines are joined, and the branch lines are provided. A pressure regulator is provided on the combined fuel gas supply line so as to give a required resistance to the circulation of the city gas pressurized and discharged by the fuel pumps.

In the above configuration, the most upstream position on the fuel pump discharge side on the fuel gas supply line, the fuel pump discharge side on each branch line, or the fuel gas supply line that joins each branch line, A small container for suppressing gas pressure fluctuations is provided.

Further, in the above configuration, the pressure regulator is a check valve having a required crack pressure characteristic, and the check valve is a supply pressure required for supplying city gas to the downstream fuel processor. A configuration having a lower crack pressure characteristic is adopted.

According to the city gas supply device for a polymer electrolyte fuel cell power generator of the present invention, the following excellent effects are exhibited.
(1) A fuel pump is provided on the fuel gas supply line for supplying fuel gas to the fuel processing apparatus so that the city gas is pressurized and supplied, and the city gas pressurized and discharged by the fuel pump is supplied. Since it is supplied to the fuel processing device through a pressure regulator such as a check valve having crack pressure characteristics, the pulsation of city gas on the discharge side of the fuel pump can be suppressed by the pressure regulator. Thus, it is possible to supply the fuel processing apparatus with city gas having a stable pressure and flow rate.
(2) In the configuration in which the fuel pump and the flow meter are provided on the fuel gas supply line, the above (1
In addition to obtaining the same effect as the above (1), the pulsation of the city gas is reduced by the pressure regulator on the discharge side of the fuel pump. Display error and flow measurement failure are not caused, and flow control using a flow meter becomes easy.
(3) Provide a plurality of branch lines that once split the fuel supply line and then merge again,
A fuel pump is provided in each branch line so that a plurality of fuel pumps are operated in parallel, and a check valve such as a check valve having crack pressure characteristics is provided on the discharge side of the fuel pump on each branch line. In addition to the effect of (1) above, a plurality of pressure devices are provided corresponding to each fuel pump, or a single unit is provided on the fuel supply line where each branch line is joined. Thus, the phenomenon that other fuel pumps cause instability due to the pulsation of the fuel pump can be avoided, and a stable supply system can be made in parallel operation of a plurality of fuel pumps.
(4) Due to the effects of (1), (2), and (3) above, the pressure and flow rate of the city gas supplied to the downstream fuel processor is stabilized, so that carbon deposition and reaction failure in the fuel processor are prevented. Accordingly, it is possible to extend the life of the fuel processor.
(5) Further, a small container is provided on the fuel supply line or each branch line for supplying the city gas pressurized and discharged by the fuel pump to the fuel processor, and a check valve having a crack pressure characteristic or the like. By using together with the pressure regulator, the pressure fluctuation and flow rate fluctuation due to the pressure regulator can be suppressed in addition to the pressure fluctuation caused by the small container, so that the city gas can be stabilized more effectively.
(6) By using a check valve having crack pressure characteristics as the pressure regulator, a large-capacity buffer tank can be omitted, and the power generator can be made compact.
(7) Further, by using the check valve as described in (6) above, a small container used in combination with the check valve can be made small, and even a small container can be downsized. .
(8) Since a check valve having a check function is used, the problem of city gas supplied to the fuel processor and reformed gas from the fuel processor flowing back to the fuel pump can be eliminated. Because it is a check valve with crack pressure characteristics, when the fuel pump is started,
The problem of city gas flowing downstream can also be solved.

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

FIG. 1 shows an embodiment of a city gas supply device for a polymer electrolyte fuel cell power generator of the present invention, which has the following configuration.

That is, the city gas as the fuel gas supplied to the fuel processing device 5 is supplied to the fuel gas supply line 11 on the upstream side of the fuel processing device 5 in the polymer electrolyte fuel cell power generation device, as shown in FIG. A fuel pump 22 for pressurizing the TG, and a flow meter for detecting the flow rate of the city gas TG pressurized and discharged by the fuel pump 22 and controlling the discharge flow rate of the fuel pump 22 based on the detected value 23, in the downstream side of the flow meter 23,
A pressure regulator, for example, a check valve 35 is provided so as to give a required resistance to the circulation of the city gas TG supplied under pressure from the fuel pump 22, and the city gas TG is supplied to the fuel processing device 5. It is designed to flow only in the direction.

Further, as the fuel pump 22, for example, a positive displacement pump for compressive fluid such as a diaphragm pump or a bellows pump is used, and as the flow meter 23, a pressure type is used. Further, as the check valve 35, a valve having a check action and crack pressure characteristics and having a crack pressure and a pressure loss when passing through the city gas TG are equal to or less than a pressure loss in the subsequent fuel processing device 5 is used. Like that. For example, when the discharge pressure of the fuel pump 22 is 100%, the crack pressure of the check valve 35 is 25%.
To be about.

Due to the above configuration, the city gas TG as fuel gas is pressurized to a desired pressure by the fuel pump 22 and then supplied to the fuel processing device 5 via the flow meter 23 and the check valve 35. At this time, the check valve 35 provided on the downstream side of the flow meter 23 functions as a pressure damper for the circulation of the city gas TG. Therefore, even if the pulsation of the city gas TG after passing through the flow meter 23 is generated, the pulsation is reduced by passing through the check valve 35. That is, the check valve 35 gives a constant load (resistance) to the circulation of the city gas TG to such an extent that the flow is not stopped due to the crack pressure characteristic, and the pressure fluctuation and the flow fluctuation due to the pulsation of the city gas TG are reduced. Can be suppressed. As a result, the pressure and flow rate of the city gas TG supplied to the reformer 6 of the downstream fuel processing device 5 can be stabilized, and accordingly, the fuel processing device 5
The problem of carbon deposition and reaction failure can be eliminated. Further, since the flow rate and pulsation of the city gas TG can be stabilized by the check valve 35, even if the pulsation is large on the upstream side of the check valve 35, the flow rate fluctuation of the city gas TG measured by the flow meter 23 is changed. Even if there are, the fluctuations are gradually suppressed. As a result, it is possible to eliminate a situation where the pulsation of the fuel pump 22 becomes large and the flow rate control using the flow meter 23 becomes impossible. That is, the error of the flow rate measurement value detected by the flow meter 23 can be reduced, and the operation control of the fuel pump 22 can be performed based on a more accurate measurement value.

Further, the use of the check valve 35 as described above eliminates the need to use a buffer tank having a volume of several liters, thereby reducing the size of the entire power generation device. The check action can prevent the backflow of city gas TG and reformed gas to the fuel pump 22 side, and since the check valve 35 having crack pressure characteristics is used, when the fuel pump 22 is started. The city gas TG can be prevented from flowing out downstream.

FIG. 2 shows another embodiment of the present invention, which is a modification of the embodiment shown in FIG. That is, in the same configuration as shown in FIG. 1, the check valve 35 is provided between the fuel pump 22 and the flow meter 23 in place of the check valve 35 provided on the downstream side of the flow meter 23. Is.

Other configurations are the same as those shown in FIG. 1, and the same components are denoted by the same reference numerals.

According to this embodiment, the city gas TG as fuel gas is pressurized to the desired pressure by the fuel pump 22 and then supplied to the fuel processing device 5 via the check valve 35 and the flow meter 23. At this time, since the check valve 35 provided on the upstream side of the flow meter 23 functions as a pressure damper, the pressure fluctuation and the flow fluctuation of the city gas TG discharged from the fuel pump 22 are checked. It can be suppressed by the valve 35, and stable city gas TG can be supplied to the reformer 6 of the fuel processing device 5, and the same effect as in the embodiment shown in FIG. 1 can be obtained. it can.
In addition, in this embodiment, there is a check valve 35 on the discharge side of the fuel pump 22, and the pulsation of the city gas TG discharged from the fuel pump 22 can be reduced by the check valve 35. ,
Since the city gas TG with reduced pulsation is guided to the flow meter 23, the display error of the flow meter 23 and the problem of poor flow measurement can be solved more effectively and the flow rate can be reduced. There is an advantage that the control can be easily performed.

Next, FIG. 3 shows another embodiment of the present invention. The fuel pump 22 having a plurality of units (showing the case of three units) is arranged in parallel with the configuration shown in FIG. Are operated in parallel.

That is, the flow meter 23 is provided on the discharge side of the fuel pump 22 and the check valve 35 is provided on the downstream side thereof, so that the pressure and flow rate of the city gas TG are stabilized and supplied to the fuel processing device 5. In the configuration, the fuel pumps 22 are arranged in parallel and connected to the branch lines 11a, 11b, and 11c of the fuel gas supply line 11, respectively, and on the downstream side of the fuel pumps 22, opposite to the flowmeters 23, respectively. A stop valve 35 is provided in order from the upstream side, and the city gas TG is supplied to the fuel processing device 5 on the downstream side through each check valve 35.

According to this embodiment, a check valve 35 similar to that shown in FIG. 1 is provided on the downstream side of the flow meter 23 for each branch line 11a, 11b, 11c, and the city gas discharged from the fuel pump 22 is provided. The TG pressure fluctuation and flow fluctuation are stabilized by the check valve 35 and the downstream fuel processing device 5
Since the stable city gas TG can be supplied to each of the reformers 6, the same effects as those shown in FIG. 1 can be obtained. In addition, since the load of the polymer electrolyte fuel cell is large and the amount of city gas TG to be supplied to the fuel processing device 5 is large, a plurality of fuel pumps 22 are operated in parallel and the city gas TG is supplied to the fuel processing device 5. Since each check valve 35 provided on the downstream side of each flow meter 23 can function as a pressure damper for the circulation of the city gas TG, each fuel pump City gas TG discharged from 22
The pulsation of can be reduced. As a result, the pressure fluctuation and the flow fluctuation caused by the pulsation of the city gas TG on the discharge side of the fuel pump 22 can be reduced for each branch line 11a, 11b, and 11c, so that the fuel processing device 5 has a stable pressure and flow. City gas TG can be supplied.

Further, when a plurality of fuel pumps 22 are operated in parallel, the pulsations generated for each fuel pump 22 interfere with each other and the pulsations increase, and the other fuel pumps 22 may become unstable. Even in such a case, the check valve 3 is provided in each branch line 11a, 11b, 11c.
5 is provided, even if the pulsations of the city gas TG flowing through the branch lines 11a, 11b, and 11c interfere with each other, the pulsations can be suppressed by passing through the check valve 35. Therefore, the phenomenon that the instability of the other fuel pumps 22 is caused by the pulsation of each fuel pump 22 can be avoided, and it is possible to prevent the flow rate control from becoming difficult. Therefore, stable city gas TG can be supplied to the reformer 6 of the fuel processor 5 when a plurality of fuel pumps 22 are operated in parallel.

Furthermore, in the case of parallel operation of a plurality of fuel pumps 22, there is a phase shift in the pulsation generated in each fuel pump 22, so that each branch line 11 a, 11 b, 11 c is connected at the junction A of the branch lines. There is a risk that a difference in height occurs in the supply pressure of the flowing city gas TG, and the city gas TG in the branch line with the lower supply pressure may flow backward for a short time until the supply pressure recovers. In each branch line 11a, 11b, 11c, a check valve 3 is provided.
5 is provided, the backflow can be prevented by the check action of each check valve 35. As a result, the city gas TG is supplied to each flow meter 23 provided upstream from the junction A of the branch line.
Can be prevented from flowing back and the flow rate fluctuation can be prevented from being increased.

FIG. 4 shows still another embodiment of the present invention, in which the one shown in FIG. 2 is arranged in parallel and a plurality of fuel pumps 22 are operated in parallel.

That is, a check valve 35 is provided on the discharge side of the fuel pump 22, and a flow meter 23 is provided on the downstream side thereof, so that the pulsation of the city gas TG discharged from the fuel pump 22 is suppressed by the check valve 35. In the configuration in which the city gas TG having a stabilized flow rate is supplied to the downstream fuel processing device 5 via the flow meter 23, the fuel pumps 22 are arranged in parallel, As shown in FIG. 2, a check valve 35 and a flow meter 23 are provided in order from the upstream side in the same manner as shown in FIG. 2 on the downstream side of each fuel pump 22 and are connected to the branch lines 11a, 11b, and 11c. 23, the city gas TG is supplied to the fuel processing device 5.

In the configuration as described above, the same operational effects as in the case of FIG. 2 described above can be obtained, and similarly to the case shown in FIG. 3, a plurality of fuel pumps 22 are operated in parallel to the fuel processing device 5. When the city gas TG is supplied, the city gas TG discharged from each fuel pump 22 can be reduced in pulsation by each check valve 35 and supplied to the reformer 6 of the fuel processing device 5. The pressure fluctuation and flow rate fluctuation of the city gas TG can be suppressed and stabilized, and carbon deposition and reaction failure in the fuel processing device 5 can be eliminated. As in the embodiment of FIG.
Even if the pulsations generated for each fuel pump 22 interfere with each other, the problem that the pulsations increase can be solved.

FIG. 5 shows an application example of the embodiment shown in FIG. 3 as another embodiment of the present invention. In the same configuration as that shown in FIG. Each branch line 1
Instead of the configuration in which check valves 35 are respectively provided in 1a, 11b, and 11c, each branch line 11a
, 11b, 11c, a single check valve 35 is provided in the fuel gas supply line 11 downstream of the junction A.

Other configurations are the same as those shown in FIG. 3, and the same components are denoted by the same reference numerals.

According to this embodiment, when a plurality of fuel pumps 22 are operated in parallel and the city gas TG is supplied to the fuel processor 5 as shown in FIG. The check valve 35 can suppress the pressure fluctuation and the flow fluctuation of the city gas TG supplied to the fuel processing device 5, and the city gas TG having a stable pressure and flow rate to the reformer 6 of the fuel processing device 5. Can be supplied.

In this way, when the flow rate of the city gas TG discharged from each fuel pump 22 is detected by each flow meter 23, even if pressure fluctuations and flow rate fluctuations occur due to the pulsation of each fuel pump 22, the most downstream Since it is once stabilized by the one check valve 35 on the side, the pressure fluctuation and flow fluctuation of the city gas TG discharged from each fuel pump 22 are gradually suppressed to prevent a large fluctuation. It becomes possible. As a result, it is possible to prevent the pulsation of the fuel pump 22 from being large, causing an error in display on the flow meter 23 and a flow rate measurement failure, and avoiding a situation in which the operation control of the fuel pump 22 cannot be performed. Further, in this embodiment, since only one check valve 35 is required, the number of check valves 35 can be reduced as compared with the case where the check valves 35 are provided in each line, and a plurality of fuel pumps 22 are provided. The power generator for parallel operation can be made compact.

FIG. 6 shows an application example of the embodiment shown in FIG. 4 as another embodiment of the present invention. In the same configuration as that shown in FIG. Instead of the configuration in which the flow meter 23 is provided on the downstream side of each check valve 35 provided, each branch line 11a, 11 is provided.
A single flow meter 23 is provided in the fuel gas supply line 11 on the downstream side of the junction A of b and 11c. Other configurations are the same as those shown in FIG.

According to this embodiment, when a plurality of fuel pumps 22 are operated in parallel and the city gas TG is supplied to the fuel processing device 5 as shown in FIG. Since the flow rate fluctuations are suppressed by the check valves 35, a stable city gas TG can be supplied to the fuel processing apparatus 5 as in the case of FIG.
Therefore, the flow meter 23 does not become defective in flow measurement.
In addition, since the number of flow meters 23 can be reduced, the power generation apparatus when a plurality of fuel pumps 22 are operated in parallel can be made compact.

Next, FIG. 7 shows still another embodiment of the present invention. As shown in FIG. 3, when a plurality of fuel pumps 22 are operated in parallel, both the flow meter 23 and the check valve 35 are singular. As mentioned above, the city gas TG is supplied to the fuel processor 5.

That is, the branch lines 11a, 11b, and 11c on the discharge side of the fuel pumps 22 provided in the branch lines 11a, 11b, and 11c are merged at the merge point A so that the fuel gas supply line 1
1 and a single flow meter 23 and a check valve 3 in order from the upstream side to the fuel gas supply line 11.
5 is provided. Other configurations are the same as those shown in FIG.

According to this embodiment, after the city gas TG discharged from each fuel pump 22 is merged, the flow rate is measured by one flow meter 23, and the pressure fluctuation of the city gas TG is detected by the check valve 35 on the downstream side. Since the flow rate fluctuation can be suppressed, the stable city gas TG can be supplied to the reformer 6 of the fuel processor 5 as in the embodiment of FIG. By suppressing the pulsation of the city gas TG on the upstream side of the check valve 35, the flow rate control by the flow meter 23 cannot be prevented. Further, when a plurality of fuel pumps 22 are operated in parallel, the flow meter 23 and the check valve 35 are used.
Therefore, the power generation device can be made compact.

FIG. 8 shows still another embodiment of the present invention. As shown in FIG. 4, when a plurality of fuel pumps 22 are operated in parallel, both the check valve 35 and the flow meter 23 are singular. TG is supplied to the fuel processor 5.

That is, the branch lines 11a, 11b, and 11c on the discharge side of the fuel pump 22 provided in the branch lines 11a, 11b, and 11c are merged at the merge point A and the fuel gas supply line 11 is joined.
And a single check valve 35 and a flow meter 23 in order from the upstream side to the fuel gas supply line 11.
It is set as the structure which provided. Other configurations are the same as those shown in FIG.

According to this embodiment, the city gas TG discharged from each fuel pump 22 is merged and then passed through one check valve 35. Thereby, the pressure fluctuation and the flow fluctuation of the city gas TG discharged from each fuel pump 22 can be suppressed by the check valve 35, and FIG.
As in the case of the embodiment, stable city gas TG can be supplied to the fuel processor 5. Further, as in the case of the embodiment of FIG. 7, it is possible to reduce the size of the power generation apparatus when a plurality of fuel pumps 22 are operated in parallel.

FIGS. 9 and 10 show application examples of the embodiments shown in FIGS. 1 and 2, respectively.
1 and FIG. 2, the pressure of the city gas TG that once receives the discharged city gas TG and flows it to the downstream side at the most upstream side of the discharge side of the fuel pump 22 in both configurations. A small container 36 that suppresses fluctuations and flow fluctuations is installed as a flow regulator, and a combination of the small container 36 and a check valve 35 is used to reform the city gas TG having a stable pressure and flow rate into the fuel processor 5. It can be supplied to the vessel 6. Other configurations are shown in FIG.
The same components as those shown in FIG. 2 are denoted by the same reference numerals.

The small container 36 is about 25 to 50 ml, and has the same function as a conventional buffer tank.

With such a configuration, the pulsation of the city gas TG discharged from the fuel pump 22 can be reduced by the function of the small container 36 as a buffer tank. Therefore, in the case of the embodiment shown in FIGS. As compared with the above, the stability of the city gas TG supplied to the reformer 6 of the fuel processor 5 can be further improved. At this time, by using the small container 36 and the check valve 35 in combination, the small container 36 can be configured such that the capacity of the buffer tank of the large container is reduced to 1/300 to 1/150. It can be downsized. In addition, by installing such a small container 36, the stability of the measurement value of the flow meter 23 can be further increased as compared with the cases of FIGS. Thereby, the flow volume of city gas TG can be stabilized more and it can become still more effective in prevention of the fall of the performance of the fuel processing apparatus 5 in the downstream.

Next, FIG. 11, FIG. 12, FIG. 13, FIG. 14, FIG. 15 and FIG.
Similarly to the explanation about 0, each of the embodiments shown in FIG. 3, FIG. 4, FIG. 5, FIG. 6, FIG. A small container 36 having the above-described configuration is installed for each fuel pump 22 on the discharge side of each fuel pump 22, and the other configurations are the same as those shown in FIGS. The same reference numerals are given to the objects.

With such a configuration, in the parallel operation of the plurality of fuel pumps 22, the pulsation on the discharge side of each fuel pump 22 can be suppressed by the small containers 36 by the function of the small containers 36. Advantage of being able to further stabilize the pressure and flow rate of the city gas TG supplied to the reformer 6 of the fuel processing device 5 for each form, and to further increase the stability of the measured value of the flow meter 23 There is.

FIGS. 17 and 18 show application examples of the embodiment shown in FIGS. 7 and 8, respectively.
7 is a small container 36 similar to that described above on the upstream side of the flow meter 23 on the fuel gas supply line 11, and FIG. 18 is described above on the upstream side of the check valve 35 on the fuel gas line 11. A single small container 36 is installed. Other configurations are the same as those shown in FIGS. 7 and 8, and the same components are denoted by the same reference numerals.

By adopting such a configuration, a plurality of fuel pumps 2 in each embodiment of FIGS.
In the case of performing two parallel operations, the pulsation of the city gas TG discharged from each fuel pump 22 can be suppressed by one small container 36 functioning as a buffer tank, FIG.
In each of the embodiments of FIG. 8, the pressure and flow rate of the city gas TG supplied to the reformer 6 of the fuel processor 5 can be further stabilized, and the stability of the measurement value of the flow meter 23 is further increased. Can be made.

In addition, this invention is not limited only to said each embodiment, The fuel pump 22 is
The case of a positive displacement pump for compressible fluid such as a diaphragm pump or a bellows type pump has been shown. However, any type may be used as long as it can be supplied to the fuel processing device 5 while being pressurized to a desired pressure. In addition, the case where the check valve 35 having crack pressure characteristics is used as the pressure regulator has been exemplified. The flow meter 23 may be a pressure type because the fuel gas is a city gas TG. However, the flow meter 23 can measure the flow rate of the city gas TG supplied to the fuel processing device 5. It goes without saying that any type may be used, and various modifications can be made without departing from the scope of the present invention.

その結果、表１より明らかなように、流量計２３の表示値と実流量の値との差が、逆止
弁３５有りの場合の方が逆止弁３５無しの場合よりも小さくなっており、逆止弁３５を用
いた場合には、流量計２３の表示をより実流量に近い値とすることができることが判明し
た。 (1) The results of experiments conducted by the present inventors will be described below.
Using the city gas supply device for a polymer electrolyte fuel cell power generator of the present invention, the value of the flow meter used for the flow control of the fuel pump and the actual gas flow rate were measured. In this experiment, FIG.
In the same manner as described above, a fuel pump 22 having a single unit was used. As an experimental method, the secondary pressure of the pump is set so as to correspond to the desired supply pressure of the fuel processing device 5, and under these conditions, the pump output is 25%, 50%, 75% and 100%. The measured value displayed on the flow meter 23 and the actual flow rate of the city gas TG were measured. For comparison, the measurement value displayed on the flow meter 23 and the actual flow rate of the city gas TG were also measured when the check valve 35 having the same configuration as described above was not provided. The results are shown in the table below.
In Table 1, the measured values are shown as relative values when the actual flow rate is 1.00 when the pump output is 100% in the presence of the check valve.

As a result, as is clear from Table 1, the difference between the displayed value of the flow meter 23 and the actual flow rate is smaller when the check valve 35 is provided than when the check valve 35 is not provided. When the check valve 35 is used, it has been found that the display of the flow meter 23 can be a value closer to the actual flow rate.

その結果、表２より明らかなように、流量計２３の表示値と実流量の値との差が、逆止
弁３５有りの方が逆止弁３５無しの場合よりも小さい値となっていることが判明した。更
に、逆止弁３５が無しの場合には、流量計２３の表示にぶれが生じるようになった。これ
に対し、逆止弁３５が有る場合には、燃料ポンプ２２の流量制御に使っている流量計２３
の表示値を安定化させることができ、燃料ポンプ２２による流量制御が行い易くなること
が判明した。 (2) Next, the effect of the city gas supply device for a polymer electrolyte fuel cell power generator of the present invention is shown in FIG.
In the same manner as described above, the fuel pump 22 is operated in parallel with a plurality of fuel pumps 22.
The value of the flow meter 23 used for the flow rate control and the actual gas flow rate were measured. In this experiment, the results are shown when four fuel pumps 22 are operated in parallel. The experimental method is the same as in Example (1).
Also, in Table 2, the measured values are shown as relative values when the actual flow rate is 1.00 when the pump output is 100% in the case of having a check valve as in Table 1.

As a result, as is apparent from Table 2, the difference between the display value of the flow meter 23 and the actual flow rate is smaller when the check valve 35 is present than when the check valve 35 is absent. It has been found. Further, when the check valve 35 is not provided, the display on the flow meter 23 is blurred. On the other hand, when the check valve 35 is provided, the flow meter 23 used for the flow control of the fuel pump 22 is used.
It has been found that the display value can be stabilized and the flow rate control by the fuel pump 22 can be easily performed.

It is a schematic diagram showing one embodiment of a city gas supply device for a polymer electrolyte fuel cell power generator of the present invention. It is a schematic diagram which shows the other form of implementation of this invention. It is a schematic diagram which shows another form of implementation of this invention. It is a schematic diagram which shows another form of implementation of this invention. It is a schematic diagram which shows the example of application of embodiment shown in FIG. 3 as another form of implementation of this invention. It is a schematic diagram which shows the example of application of embodiment shown in FIG. 4 as another form of implementation of this invention. It is a schematic diagram which shows the modification of embodiment shown in FIG. 3 as another form of implementation of this invention. It is a schematic diagram which shows the modification of embodiment shown in FIG. 4 as another form of implementation of this invention. It is a schematic diagram which shows the application example of embodiment shown in FIG. 1 as another form of implementation of this invention. It is a schematic diagram which shows the example of application of embodiment shown in FIG. 2 as another form of implementation of this invention. It is a schematic diagram which shows the application example of embodiment shown in FIG. 3 as another form of implementation of this invention. It is a schematic diagram which shows the application example of embodiment shown in FIG. 4 as another form of implementation of this invention. It is a schematic diagram which shows the application example of embodiment shown in FIG. 5 as another form of implementation of this invention. It is a schematic diagram which shows the application example of embodiment shown in FIG. 6 as another form of implementation of this invention. It is a schematic diagram which shows the example of application of embodiment shown in FIG. 7 as another form of implementation of this invention. It is a schematic diagram which shows the application example of embodiment shown in FIG. 8 as another form of this invention. It is a schematic diagram which shows the other application example of embodiment shown in FIG. 7 as another form of implementation of this invention. It is a schematic diagram which shows the other application example of embodiment shown in FIG. 8 as another form of implementation of this invention. It is a schematic diagram showing an example of a conventional general polymer electrolyte fuel cell power generator. It is a schematic diagram which shows an example at the time of providing a flowmeter in the discharge side of a fuel pump in the case of using city gas as fuel gas of the conventional polymer electrolyte fuel cell power generator. It is a schematic diagram which shows an example of the conventionally proposed polymer electrolyte fuel cell power generator. It is a schematic diagram showing an example in which pulsation on the discharge side of the fuel pump is suppressed when city gas is used as fuel gas of a conventional polymer electrolyte fuel cell power generator. It is a schematic diagram showing an example in which pulsation is suppressed when a plurality of fuel pumps are operated in parallel when city gas is used as fuel gas of a conventional polymer electrolyte fuel cell power generator. It is a schematic diagram which shows the modification of FIG. It is a schematic diagram showing another example in which pulsation is suppressed when a plurality of fuel pumps are operated in parallel when city gas is used as fuel gas of a conventional polymer electrolyte fuel cell power generator. It is a schematic diagram which shows the modification of FIG. FIG. 26 is a schematic diagram showing still another modified example of FIG. 25.

Explanation of symbols

TG City gas 5 Fuel treatment device 6 Reformer 11 Fuel gas supply line 11a, 11b, 11c Branch line 12 Fuel gas 22 Fuel pump 23 Flow meter 35 Check valve (pressure regulator)
36 small containers

Claims (11)

Fuel in which fuel gas is supplied to the fuel processing device in the polymer electrolyte fuel cell power generator having a configuration in which the fuel gas is processed by the fuel processing device and then supplied to the polymer electrolyte fuel cell. A fuel pump is provided on the gas supply line, and a pressure regulator is provided to give a required resistance to the circulation of city gas pressurized and discharged by the fuel pump. A city gas supply device for a polymer electrolyte fuel cell power generator. Fuel in which fuel gas is supplied to the fuel processing device in the polymer electrolyte fuel cell power generator having a configuration in which the fuel gas is processed by the fuel processing device and then supplied to the polymer electrolyte fuel cell. A fuel pump and a flow meter are provided on the gas supply line, and a pressure regulator is provided to give a required resistance to the circulation of the city gas pressurized and discharged by the fuel pump. A city gas supply device for a polymer electrolyte fuel cell power generator. Fuel in which fuel gas is supplied to the fuel processing device in the polymer electrolyte fuel cell power generator having a configuration in which the fuel gas is processed by the fuel processing device and then supplied to the polymer electrolyte fuel cell. The gas supply line is provided with a plurality of branch lines that once branch and then merge again, and each branch line is provided with a fuel pump, and the city gas pressurized and discharged by each fuel pump is provided. A city gas supply device for a polymer electrolyte fuel cell power generator, characterized in that it has a configuration in which a pressure regulator is provided to give a required resistance to distribution. Fuel in which fuel gas is supplied to the fuel processing device in the polymer electrolyte fuel cell power generator having a configuration in which the fuel gas is processed by the fuel processing device and then supplied to the polymer electrolyte fuel cell. The gas supply line is provided with a plurality of branch lines that once branch and then merge again, and each branch line is provided with a fuel pump and a flow meter, respectively, and pressurized and discharged by each fuel pump. A city gas supply device for a polymer electrolyte fuel cell power generator, characterized by having a configuration in which a pressure regulator is provided to give a required resistance to the distribution of city gas. Fuel in which fuel gas is supplied to the fuel processing device in the polymer electrolyte fuel cell power generator having a configuration in which the fuel gas is processed by the fuel processing device and then supplied to the polymer electrolyte fuel cell. The gas supply line is provided with a plurality of branch lines that are once branched and then merged again, a fuel pump is provided for each branch line, and the fuel gas supply line is formed by joining the branch lines. For a polymer electrolyte fuel cell power generator having a pressure regulator that provides a required resistance to the circulation of city gas pressurized and discharged by each of the fuel pumps City gas supply device. Fuel in which fuel gas is supplied to the fuel processing device in the polymer electrolyte fuel cell power generator having a configuration in which the fuel gas is processed by the fuel processing device and then supplied to the polymer electrolyte fuel cell. The gas supply line is provided with a plurality of branch lines that are once branched and then joined again, and each branch line is provided with a fuel pump, and the downstream side of each fuel pump or each branch line is joined. A flow meter is provided on the fuel gas supply line, and the fuel gas supply line obtained by joining the branch lines is required for the circulation of city gas pressurized and discharged by the fuel pumps. A city gas supply device for a polymer electrolyte fuel cell power generator, comprising a pressure regulator that provides resistance. The city gas supply device for a polymer electrolyte fuel cell power generator according to claim 1 or 2, wherein a small container that suppresses pressure fluctuation of the city gas is provided at the most upstream position on the fuel pump discharge side on the fuel gas supply line. The city gas supply device for a polymer electrolyte fuel cell power generator according to claim 3, 4, 5, or 6, wherein a small container for suppressing pressure fluctuation of the city gas is provided on each fuel pump discharge side on each branch line. 7. The polymer electrolyte fuel cell according to claim 5, wherein a small container is provided on the fuel gas supply line obtained by joining the branch lines on the discharge side of each fuel pump on each branch line to suppress the pressure fluctuation of the city gas. City gas supply device for power generators. The pressure regulator is a check valve having required crack pressure characteristics.
The city gas supply device for a polymer electrolyte fuel cell power generator according to claim 7, 8, or 9. The city for a polymer electrolyte fuel cell power generator according to claim 10, wherein the check valve has a crack pressure characteristic lower than a supply pressure required for supplying city gas to the downstream fuel processor. Gas supply device.

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