JP5022592B2 - Gas-liquid separator and fuel cell power generation system equipped with gas-liquid separator - Google Patents

Description

  The present invention relates to a gas-liquid separation device using a porous capillary force and a fuel cell power generation system including such a gas-liquid separation device.

  In recent years, fuel cells have attracted attention as highly efficient energy conversion devices. In particular, solid polymer fuel cells that use proton-conducting solid polymer membranes as electrolytes have a compact structure and high power density, and can be operated with a simple system. It is attracting attention not only as a power source but also as a power source for space and mobile use.

  The outline of the prior art known as such a polymer electrolyte fuel cell power generation system will be described below with reference to FIG. This system includes a fuel cell main body 1, a reaction gas supply system 2 for supplying a reaction gas to the fuel cell main body 1, and a water recovery for recovering water contained in the existing reaction gas discharged from the fuel cell main body 1. The system 3 and the battery body cooling system 4 for removing heat generated in the battery body are configured as main modules. The main modules are described in detail below.

  The fuel cell main body 1 supplies a membrane electrode complex in which gas diffusion electrodes (fuel electrode 1a and oxidant electrode 1b) are arranged on both sides of a solid polymer membrane, and fuel gas and oxidant gas to the gas diffusion electrode, respectively. In this configuration, a plurality of unit cells each including a reaction gas supply separator provided with reaction gas supply grooves are stacked through a cooling plate 1c that removes heat generated during power generation. In addition, a reaction gas supply manifold and a reaction gas discharge manifold for supplying a reaction gas to each reaction gas supply separator or discharging a reaction gas from each reaction gas supply separator are provided on the side surface of the laminate. As the solid polymer membrane, perfluorocarbon sulfonic acid (Nafion R: DuPont, USA), which is a proton exchange membrane, is generally known. As the gas diffusion electrode, a carbon porous plate having a catalyst layer using platinum or the like as a catalyst is generally used.

  When a fuel gas containing hydrogen as a main component and an oxidant gas (air) are supplied to the fuel cell main body 1, the following electrochemical reaction proceeds in each unit cell, and about 1V is generated between the electrodes of each unit cell. An electromotive force is generated.

Fuel electrode: 2H ₂ → 4H ⁺ + 4e ⁻ (Formula 1)
Oxidant electrode: O ₂ + 4H ⁺ + 4e ⁻ → 2H ₂ O (Formula 2)

  At the fuel electrode, as shown in (Formula 1), the supplied hydrogen is dissociated into hydrogen ions and electrons. Hydrogen ions move through the solid polymer film, and electrons move through the external circuit to the oxidant electrode. On the other hand, at the oxidizer electrode, as shown in (Formula 2), oxygen in the supplied air reacts with the hydrogen ions and electrons to generate water. At this time, electrons passing through the external circuit become current and can supply power. Since the gas that has been supplied to the fuel cell body 1 and was not used for the reaction and the humidified water vapor and the water generated by the cell reaction are discharged from the fuel cell body 1 as the already reacted gas, a large amount of moisture is present in the already reacted gas. included.

  The reactive gas supply system 2 includes an air supply system 2a and a fuel gas supply system 2b. In the polymer electrolyte fuel cell, the solid polymer membrane that is an electrolyte is proton-conductive in a wet state, so that the reaction gas supply system 2 is generally provided with a humidifier 2c. However, when a hydrocarbon such as methane is used as a raw fuel, a fuel reformer 2d and a heating burner 2e are required for reacting the fuel with water vapor to reform it into a hydrogen-rich gas. Since the reformed fuel gas contains water vapor, the fuel gas supply system 2b may not be humidified.

  In FIG. 10, the steam supply line to the fuel reformer 2d required for steam reforming is omitted. Further, 2f is a heat exchanger provided in the exhaust system of the burner 2e, and 2g is a supply pipe for reaction gas sent from the fuel reformer 2d and the humidifier 2c to the fuel cell main body 1.

  The moisture recovery system 3 is a system for removing moisture contained in the already-reacted gas after the cell reaction discharged from the fuel cell body 1, and is generally composed of a heat exchanger 3a and a gas-liquid separator 3b. It is. The water recovered in the gas-liquid separator 3b on the oxidizer electrode side is water that is pre-humidified in the reaction gas and water generated by the reaction of (Equation 2) in the fuel cell body 1, and generally the amount of water to be recovered Therefore, the recovered water is recovered in the cooling water tank 4a by the pump 3c and used as cooling water or humidified water. In addition, the already reacted air after moisture recovery is discharged out of the system system.

  The water recovered by the gas-liquid separator 3a on the fuel electrode side is mostly water previously humidified in the reaction gas or water contained in the fuel reforming and may be discharged outside the system. When performing a self-supporting operation (operation without supplying water to the system from the outside), the water may be collected in the cooling water tank 4a by the pump 3c. When a hydrocarbon such as methane is used as a raw fuel, the remaining fuel gas after moisture recovery is supplied to the fuel reformer 2d by the remaining fuel gas recovery line 3d in order to supply heat necessary for fuel reforming. Is supplied to the burner 2e provided for combustion and burned.

  The battery main body cooling system 4 is a system for discharging reaction heat generated when power is generated by the fuel cell main body 1 to the outside of the system. The coolant stored in the coolant tank 4a by the pump 4b is circulated to the cooling plate 1c of the fuel cell main body 1 through the coolant circulation pipe 4c. The exhaust heat recovered in the cooling water tank 4a is recovered by the heat exchanger 4d and used as heat. It can be used directly as hot water. Further, when the coolant is water, a part of the coolant can be supplied to the humidifier 2c as reaction gas humidified water and used.

  In the polymer electrolyte fuel cell power generation system described above, a large amount of water vapor is contained in the residual fuel gas recovery line 3d that supplies the reaction gas supply pipe 2g or the residual fuel gas after gas-liquid separation to the combustion burner 2e for the fuel reformer. Gas containing it circulates. For this reason, when the temperature of the pipe is lowered even partly, the water vapor condenses in that part and becomes a gas-liquid two-phase fluid, causing various problems. In particular, since the gas pipe is cold when the system is started, water vapor tends to condense in the gas pipe, which often causes a problem.

  For example, when water vapor condenses in the reaction gas supply pipe 2g, a large amount of water contained in the reaction gas supplied to the reaction gas supply manifold of the fuel cell main body 1 is supplied to the unit cell near the reaction gas supply unit. The reaction gas distribution in the battery body is deteriorated. As a result, the battery performance of each unit battery varies, and the battery performance of the battery body becomes extremely unstable. Note that the same phenomenon occurs when water vapor condenses in the reaction gas supply manifold of the fuel cell main body 1. Further, if the water vapor is condensed in the remaining fuel gas recovery line for supplying the remaining fuel gas after the gas-liquid separation to the fuel reformer combustion burner 2e, the fuel reformer combustion burner 2e may misfire.

  As these countermeasures, Patent Document 1 discloses a method of keeping the temperature of the gas pipe in order to prevent condensation of water vapor. Patent Document 2 discloses a method of providing a water absorber filled with a water absorbing agent as means for removing water.

  In addition, as a countermeasure when it becomes a gas-liquid two-phase fluid, in general, a pipe is branched and a U-shaped tube is provided, so that the gas-liquid two-phase fluid is sealed with water and only the liquid phase is separated and discharged. Although a method etc. can be considered, when the pressure of a gas-liquid two-phase fluid becomes high, a water seal may be broken. The sealing pressure resistance is equal to the water head pressure of the U-shaped tube, and a high sealing pressure resistance cannot be expected. In addition, a method may be considered in which a valve is provided at the discharge port of the liquid phase fluid, and the valve is opened when a certain amount of the liquid phase fluid has accumulated, and the liquid phase fluid is discharged. Necessary.

  Furthermore, the already reacted gas discharged from the fuel cell main body 1 is a gas-liquid two-phase fluid containing a large amount of moisture. For this reason, the existing reaction gas piping is likely to be clogged with water, the pressure loss becomes high, and the reaction gas supply becomes unstable, so that the battery performance may be lowered.

  From the above, it is necessary to quickly gas-liquid separate the existing reaction gas. As a countermeasure against this, Patent Document 3 discloses a method of performing gas-liquid separation using water vapor in the reaction gas as condensed water. In addition, a condensate discharge port may be provided, and when a certain amount of condensate has accumulated, the valve may be opened to discharge the condensate, but a discharge valve, water pump, and devices for controlling them Is required.

  In order to solve the problems caused by the gas-liquid two-phase fluid in such a fuel cell power generation system, it is conceivable to provide gas-liquid separators at various points in the system. For example, in Patent Document 4, a liquid branch pipe is branched in the middle of a pipe through which a gas-liquid two-phase fluid flows, and a porous body is arranged at the branch portion, so that the liquid branches through the porous body. A gas-liquid separation device is shown in which the gas flows to the piping side, and the gas is blocked by the capillary force of the liquid that has entered the pores of the porous body and does not flow out to the branch piping side.

  Certainly, the gas-liquid separation device of Patent Document 4 has an advantage that gas-liquid can be effectively separated with a simple configuration in which a porous body using capillary force is provided at a branching portion of a pipe. However, this type of gas-liquid separation device cannot be used in various parts of the fuel cell power generation system as described above, because the gas blocking effect is lost if no liquid is always present in the porous body. That is, the gas flowing in the fuel cell power generation system is not necessarily a gas-liquid two-phase body. For example, the gas flowing through the reaction gas supply pipes 2a and 2b for supplying the reaction gas to the fuel cell main body basically has a relative humidity of 100% or less, and does not always contain liquid.

  Therefore, even if there is a gas sealing effect in a state where the liquid is trapped in the porous body, the liquid present in the porous body is evaporated and removed while the gas flows in the pipe, and the wet due to capillary force Since the sealing function is lost, there arises a problem that gas leaks from the portion to the branch pipe side. In addition, when power generation is stopped, gas does not circulate in the piping or purge gas with low humidity circulates, so that the liquid present in the porous body is evaporated and removed, and the wet seal function due to capillary force is lost. Therefore, there arises a problem that the reaction gas leaks at the time of startup.

JP 2000-12057 A JP 2002-100385 A JP 2000-357529 A JP-A-5-137933

  As described above, in the polymer electrolyte fuel cell power generation system, there are places where a gas-liquid two-phase fluid consisting of a gas phase fluid and a liquid phase fluid circulates inside, such as a reaction gas pipe and a cooling water tank. There are many places where the internal fluid becomes a gas-liquid two-phase fluid due to external conditions such as environmental temperature, such as the reaction gas supply pipe and the residual fuel gas recovery line. On the other hand, since the gas-liquid two-phase fluid in the system makes the battery performance unstable or significantly deteriorates, it is necessary to quickly separate and discharge the liquid-phase fluid from the gas-liquid two-phase fluid.

  In order to meet these requirements, when a gas-liquid separator having a simple structure using capillary force as described in Patent Document 4 is used in a fuel cell power generation system, a gas having a relative humidity of 100% or less flowing in the pipe is used. If the liquid trapped in the porous material is lost, the sealing function due to the capillary force is lost and gas leakage occurs.

  The present invention provides a gas-liquid separator capable of reliably and quickly separating and discharging only a liquid phase fluid from a gas-liquid two-phase fluid without requiring special control such as valve operation, and a fuel cell power generation system using the same. The purpose is to do.

  More specifically, with respect to the reaction gas supply pipe and the residual fuel gas recovery line of the reaction gas supply system, a gas containing water vapor with a relative humidity close to 100% normally circulates in the pipe. When the outside air temperature decreases, the water vapor may condense in the pipe and become a gas-liquid two-phase fluid. Even in this case, a technique is proposed that does not require special control such as valve operation, and can reliably and quickly separate and discharge only the liquid phase fluid without leaking the gas phase fluid even when the pressure in the pipe rises.

  The moisture recovery system does not require special control such as valve operation, and only liquid phase fluid is reliably and promptly extracted from the gas-liquid two-phase fluid flowing in the existing reaction gas piping without leaking the gas phase fluid. Propose technologies that can be separated and discharged.

  In addition, as a gas-liquid separator used in each system of the fuel cell power generation system, a liquid that exists in a porous body can be obtained even if no liquid is supplied from a fluid flowing in a pipe such as a gas having a relative humidity of 100% or less. We propose a technology that can reliably prevent the leakage of gas flowing in the piping without causing the air to dry and the sealing function by capillary force to be exerted reliably.

The fuel cell power generation system of the present invention includes a fuel cell main body, a reaction gas supply system for supplying a reaction gas to the fuel cell main body, and a water for recovering water contained in the existing reaction gas discharged from the fuel cell main body. In a fuel cell power generation system including a recovery system and a battery main body cooling system for removing heat generated in the battery main body, a liquid branch branched from the pipe is formed in a part of the pipe constituting the moisture recovery system A pipe is provided, a U-shaped liquid reservoir is formed in a part of the branch pipe, and a porous body is disposed in the liquid stored in the liquid reservoir to prevent gas flow by capillary force. A gas-liquid separation device is provided, and the gas-liquid separation device includes a vertical portion in which a gas-liquid two-phase fluid flows in a pipe of a water recovery system and a horizontal portion in which a gas after separating the liquid extending to the side flows. Glyph Disposed the bending portion, the branch pipes from the lower portion of the vertical portion of the L-shaped, characterized in that it is branched vertically.

  According to the fuel cell power generation system of the present invention having the above-described configuration, the liquid can be easily and surely removed from the gas-liquid two-phase fluid flowing through the reaction gas supply system, the water recovery system, or the pipe constituting the fuel cell main body. Therefore, excellent battery performance can be ensured. In addition, since a liquid reservoir is formed as a gas-liquid separator, and a porous body is disposed in the liquid stored in the liquid reservoir, only a gas having a relative humidity of 100% or less circulates in the pipe. Even in such a case, since the porous body is always held in the liquid, the sealing function by the capillary force can be surely exerted, and the gas leaks through the liquid branch pipe. There is no fear.

  Hereinafter, some of the best modes for carrying out the present invention will be sequentially described. In addition, the same code | symbol is attached | subjected about the part which is common in the conventional fuel cell power generation system shown in the said FIG. 10, and description is abbreviate | omitted.

(1) First Embodiment In the present embodiment, the gas-liquid separator 10 of the present invention is attached to the reaction gas supply system 2 and the remaining fuel gas recovery line 3d in the fuel cell power generation system. In the reaction gas supply system 2, the fuel gas pipe supplied from the fuel reformer 2d and the oxidant gas pipe supplied from the humidifier 2c are located near the fuel cell main body 1 and the fuel. In the gas recovery line 3d, the gas-liquid separator 10 is disposed at a location near the combustion burner 2e of the fuel reformer 2d. The liquid-phase fluid separated and discharged from the gas-liquid two-phase fluid by these gas-liquid separators 10 was collected in the cooling water tank 4a.

  The structure of the gas-liquid separation apparatus 10 used for this embodiment is shown in FIG. A branch pipe 12 is provided from the main pipe 11 through which the gas-liquid two-phase fluid flows, and a U-shaped liquid reservoir 13 having a length of 20 mm is formed in order to retain the liquid phase fluid in the branch pipe 12. Further, a porous body 14 having a thickness of 5 mm and an average pore radius of 15 μm was disposed at a position where the liquid phase fluid stays. The porous body 14 used in the present embodiment is a foam metal, but any material having corrosion resistance such as a carbon material or a resin may be used. Further, a porous membrane such as filter paper may be used.

  In the present embodiment having such a configuration, when the fuel cell power generation system is started, the temperature of each main pipe 11 is low, and water vapor in the gas flowing through the main pipe 11 aggregates to generate water. Further, when the outside air temperature decreases, the heat radiation from each main pipe 11 increases, and water vapor in the gas flowing through the main pipe 11 aggregates to generate water. As described above, the water generated in the main pipe 11 is quickly discharged from the main pipe 11 through the branch pipe 12 by the gas-liquid separator 10 of FIG.

  In addition, the pressure of the gas-liquid two-phase fluid in the main pipe 11 increases, the liquid level of the water accumulated in the U-shaped liquid reservoir 13 of the branch pipe 12 decreases, and the gas phase fluid contacts the porous body 14. Even so, since the porous body 14 containing water has a wet seal function, the gas phase fluid is not discharged.

Generally, the wet seal function of the porous body 14 is determined by the capillary force of water in the porous body 14, and the capillary force ΔP of the porous body 14 can be calculated by the following equation.
ΔP = 2σCOSθ / r
σ: Surface tension of water θ: Contact angle of water r: Pore radius

  For example, the capillary force ΔP of the porous body 14 containing water and having a pore radius of 20 μm is about 5 kPa from the above formula. In this case, a pressure of 5 kPa or more is required to pass the gas phase fluid through the porous body 14. When the fuel cell main body 1 generates power in an atmospheric pressure atmosphere, the reaction gas supply pressure is about 3 kPa, and a wet seal function of 5 kPa or more is necessary. Therefore, the pore radius of the porous body 14 should be 20 μm or less. Is preferred.

  The fuel cell power generation system provided with the gas-liquid separation device 10 of the present embodiment was started and continuously operated, and the effect of separating and discharging the liquid phase body was examined. In the conventional system, it is considered that the condensate of water vapor in the reaction gas supply pipe at start-up is caused by the performance degradation of the fuel cell main body 1 and the condensate of steam in the residual fuel gas recovery line 3d pipe. The combustion burner 2e of the fuel reformer 2d was extinguished. On the other hand, in the system of this embodiment, the condensed water generated at the time of start-up or pipe heat dissipation can be quickly discharged out of the main pipe 11, and the performance degradation of the fuel cell main body 1 at the time of start-up and the extinction of the combustion burner 2e Did not occur.

  Moreover, although the pressure of 2 g of reaction gas supply piping was 5 kPa, it was confirmed that the wet seal | sticker of the porous body 14 is functioning without discharge | release of a gaseous-phase fluid being seen. If the porous body 14 is not disposed, a 500 mm long U-shaped tube is required.

  As described above, according to the present embodiment, even if the pressure in the main pipe 11 rises, only the liquid phase fluid can be separated and discharged reliably and quickly without leaking the gas phase fluid. It is possible to prevent performance degradation of the fuel cell main body 1 due to condensation of water vapor and fire extinguishing of the combustion burner of the fuel reformer. Moreover, even if the gas in the main pipe 11 is only a gas having a relative humidity of 100% or less, the porous body 14 is disposed in the liquid stored in the U-shaped portion 12 and is always in the pores. Since the liquid is present, the capillary force is not lost and the wet seal function is maintained, so that the gas in the main pipe 11 is not leaked from the branch pipe 12 to the outside.

(2) Second Embodiment FIG. 3 shows a second embodiment of the present invention. This embodiment is provided at the bottom of the reaction gas supply manifold 1d and the already reacted gas discharge manifold 1e in the fuel cell main body 1. 2 is provided with the gas-liquid separation device 10 of FIG.

  In the second embodiment having such a configuration, in the reaction gas supplied from the reaction gas supply pipe 2g to the fuel cell main body 1 via the reaction gas supply manifold 1d and from the fuel cell main body 1 to the already reacted gas discharge manifold 1e. And the liquid in the already reacted gas exhausted through the already reacted gas discharge pipe 2h is separated by the gas-liquid separator 10. In particular, the remaining fuel gas from the fuel electrode 1a among the already reacted gases is effectively removed by the gas-liquid separation device 10, so that this is supplied to the fuel reformer combustion burner 2e. In addition, inconveniences such as burner misfire due to liquid in the remaining fuel gas are eliminated.

(3) Third Embodiment FIG. 4 shows a third embodiment of the present invention. In the third embodiment, the gas-liquid separator 10 is arranged in the water recovery system 3 in the fuel cell power generation system. It is. That is, as shown in FIG. 10, in the prior art, the moisture recovery system 3 is provided with a gas-liquid separation device including a heat exchanger 3a and a gas-liquid separator 3b. The gas-liquid separator 10 shown in FIG. 5 is provided in place of the gas-liquid separator 3b.

  The gas-liquid separation device 10 of the present embodiment is attached to the already-reacted gas discharge pipe 2h of the fuel electrode 1a and the oxidant electrode 1b in the moisture recovery system 3. That is, the already-reacted gas discharge pipe 2h is provided with an L-shaped bent portion 15 including a vertical portion in which the gas-liquid two-phase fluid flows and a horizontal portion in which the gas after separating the liquid extending to the side flows. A branch pipe 12 of the gas-liquid separator 10 is vertically branched from a lower part of the vertical portion of the character shape, and a U-shaped portion 13 containing a porous body 14 is continuously formed in the branch pipe 12. Also, a heat exchanger for condensing a part of the gas-phase fluid (mainly water vapor) contained in the gas-liquid two-phase fluid into a liquid-phase fluid in a vertical portion of the pipe through which the gas-liquid two-phase fluid flows 16 is housed.

  In the present embodiment having such a configuration, the gas-liquid two-phase fluid flowing in the already-reacted gas discharge pipe 2h is condensed by the heat exchanger 16, and the branch pipe 12 disposed below the vertical portion. Drip inside. The liquid stored in the branch pipe 12 passes through the porous body 14 and is discharged to the outside of the gas-liquid separator 10, and the gas from which the liquid has been removed is exhausted from the L-shaped horizontal portion or the reformer burner as residual fuel gas. 2e. That is, the already reacted gas on the oxidizer electrode 1b side after separating and discharging water is directly discharged to the atmosphere, while the already reacted gas on the fuel electrode 1a side after separating and discharging water is passed through the residual fuel gas recovery line 3d. The fuel is supplied to the combustion burner 2e for the fuel reformer.

  According to the present embodiment having such a configuration, the conventional gas-liquid separator, pump, valve, and the like are not required, and therefore, in the already-reacted gas from the fuel cell main body, the configuration is simple compared with the prior art. It is possible to remove the water and supply it to the atmosphere or to the combustion burner. In particular, by providing the heat exchanger 16 in the pipe, there is also an advantage that the liquid contained in the gas-liquid two-phase fluid can be condensed and the liquid can be separated more efficiently.

  In addition, it is not a requirement for the gas-liquid separation device 10 to provide the heat exchanger 16 therein, and liquefaction is promoted by means such as lowering the temperature of the piping provided with the gas-liquid separation device 10. If it is possible, it is possible to use one without the heat exchanger 16 as shown in FIG.

(4) Fourth Embodiment FIG. 7 shows a fourth embodiment of the present invention. This embodiment is arranged on the fuel electrode side and the oxidant electrode side in the conventional fuel cell power generation system shown in FIG. The separated and discharged water is stored in the gas-liquid separators 3b and 3b, respectively, and when the amount of water becomes constant, the pump 3c and the valve 3e are operated to discharge the water to the cooling water tank 4a. The liquid separator 3b, pump 3c, valve 3e and the like are not required, and the separated and discharged water is directly discharged to the cooling water tank 4a.

  That is, in this embodiment, as shown in the enlarged view of FIG. 8, the heat exchange in which the inlet of the U-shaped branch pipe 11 in the gas-liquid separator 10 is provided on the pipe of the already reacted gas from the fuel electrode 1a. The outlet of the branch pipe 11 is connected to the side of the heat exchanger container 18 provided on the pipe of the already-reacted gas from the oxidant electrode 1b, and the heat exchanger container 19 A drain pipe 19 provided at the bottom is connected to the cooling water tank 4a.

  In the present embodiment having such a configuration, moisture in the already reacted gas from the fuel electrode 1a condensed in the heat exchanger vessel 17 passes through the gas-liquid separation device 10 at the bottom of the heat exchanger vessel 17 and is oxidized. Already reacted gas from the agent electrode 1b is collected in the heat exchanger vessel 18 into which it is introduced. In this case, the residual fuel gas from the fuel electrode 1a is reliably prevented from leaking to the heat exchanger vessel 18 side by the porous body 14 of the gas-liquid separator 10. On the other hand, the already-reacted gas from the oxidizer electrode 1 b is condensed in the liquid (water) contained in the heat exchanger in the heat exchanger vessel 18 and collected at the bottom of the heat exchanger vessel 18. In this way, the liquid removed from the already-reacted gas of both systems accumulated at the bottom of the heat exchanger vessel 18 is collected in the coolant tank 4a via the drain pipe 19.

  In this case, in this embodiment, it is possible to provide the gas-liquid separator 10 on the drain pipe 19 of the heat exchanger vessel 18, but the liquid contained in the already-reacted gas from the oxidizer electrode 1b is mainly water. In addition, since the gas from which moisture has been removed is exhausted to the atmosphere, the degree of moisture removal is gentle compared to the case of the already reacted gas from the fuel electrode 1a. The separation device 10 may not be provided.

  As described above, according to the present embodiment, the liquid phase from the gas-liquid two-phase fluid that circulates in the existing reaction gas pipe without leaking the gas-phase fluid without requiring special control such as a water pump or valve operation. Since the fluid alone is reliably and promptly separated and discharged, stable system operation is possible.

(5) Fifth Embodiment In the fourth embodiment, the gas-liquid separation device 10 having a U-shaped pipe is provided at the bottom of the heat exchanger vessel 17 provided on the pipe of the already reacted gas from the fuel electrode 1a. Are connected to the side surface of the heat exchanger vessel 18 provided on the pipe of the already-reacted gas from the oxidant electrode 1b. In the fifth embodiment, the heat exchanger vessels 17 and 18 are separated from the gas-liquid separator. The apparatus 10 forms a U-shaped water seal portion as a whole. That is, in this embodiment, the inlet of the branch pipe 11 of the gas-liquid separator 10 is connected to the bottom of the heat exchanger container 17, the outlet is connected to the bottom of the heat exchanger container 18, and the drain pipe 19 is connected to the heat exchanger container 18. It is provided at a position higher than the connecting portion of the branch pipe 11 on the side surface.

  In 5th Embodiment which has such a structure, the container of two heat exchangers and the gas-liquid separation apparatus 10 form the U-shaped part as a whole by the transfer, and in the liquid always stored in the inside The porous body 14 can be disposed. As a result, the phenomenon that the porous body 14 is dried and the gas passes does not occur, and the existing reaction gas does not leak to the coolant tank 4a side. Thus, even if the piping itself is not U-shaped, the liquid reservoir can be formed, and the porous body 14 can be disposed in such a liquid reservoir.

The piping diagram which shows 1st Embodiment of the fuel cell power generation system of this invention. Sectional drawing which shows an example of the gas-liquid separator used for 1st Embodiment of this invention. The piping diagram which shows 2nd Embodiment of the fuel cell power generation system of this invention. The piping diagram which shows 3rd Embodiment of the fuel cell power generation system of this invention. Sectional drawing which shows an example of the gas-liquid separation apparatus used for 3rd Embodiment of this invention. Sectional drawing which shows the other example of the gas-liquid separation apparatus used for 3rd Embodiment of this invention. The piping diagram which shows 4th Embodiment of the fuel cell power generation system of this invention. Sectional drawing which shows an example of the gas-liquid separation apparatus used for 4th Embodiment of this invention. Sectional drawing which shows the other example of the gas-liquid separator used for 5th Embodiment of this invention. The piping diagram which shows the conventional fuel cell power generation system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Fuel cell main body 2 ... Reaction gas supply system 3 ... Water | moisture-content recovery system 4 ... Battery main body cooling system 10 ... Gas-liquid separation apparatus 11 ... Main piping 12 ... Branch piping 13 ... U-shaped liquid storage part 14 ... Porous body 14
15 ... L-shaped bent part 16 ... Heat exchanger 17, 18 ... Heat exchanger container 19 ... Drain piping

Claims (2)

Generated in the battery main body, a reaction gas supply system for supplying a reaction gas to the fuel cell main body, a water recovery system for recovering water contained in the existing reaction gas discharged from the fuel cell main body, and the battery main body In a fuel cell power generation system equipped with a battery main body cooling system for removing heat,
A branch pipe of the liquid branched from this pipe is provided in a part of the pipe constituting the moisture recovery system, and a U-shaped liquid storage part is formed in a part of the branch pipe, and is stored in this liquid storage part. A gas-liquid separation device is provided in which a porous body that prevents gas flow by capillary force is disposed in the liquid being
The gas-liquid separation device is disposed in an L-shaped bent portion composed of a vertical portion in which a gas-liquid two-phase fluid flows in a pipe of a water recovery system and a horizontal portion in which a gas after separating the liquid extending to the side flows. The fuel cell power generation system, wherein the branch pipe is branched vertically from a lower portion of the L-shaped vertical portion. Generated in the battery main body, a reaction gas supply system for supplying a reaction gas to the fuel cell main body, a water recovery system for recovering water contained in the existing reaction gas discharged from the fuel cell main body, and the battery main body In a fuel cell power generation system equipped with a battery main body cooling system for removing heat,
A branch pipe of the liquid branched from this pipe is provided in a part of the pipe constituting the moisture recovery system, and a U-shaped liquid storage part is formed in a part of the branch pipe, and is stored in this liquid storage part. A gas-liquid separation device is provided in which a porous body that prevents gas flow by capillary force is disposed in the liquid being
The gas-liquid separator is a heat exchanger provided on a pipe of a previously reacted gas from the fuel electrode of the fuel cell main body, and a heat provided on a pipe of the already reacted gas from the oxidant electrode of the fuel cell main body. Provided between the exchange and
The inlet of the branch pipe in the gas-liquid separator is connected to the bottom of a heat exchanger vessel provided on the pipe of the already reacted gas from the fuel electrode, and the outlet of the branch pipe is the outlet of the already reacted gas from the oxidant electrode. Connected to the side of the heat exchanger vessel provided on the pipe, drain pipe provided on the bottom of the heat exchanger vessel provided on the pipe of the existing reaction gas from the oxidizer electrode is connected to the cooling water tank. A fuel cell power generation system.

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