JP2007048509A - Fuel cell system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To stabilize a supply flow rate and supplied pressure to a fuel cell by suppressing oscillation in an ejector. <P>SOLUTION: The fuel cell system 1 is provided with the ejector 24 supplying reaction gas to the fuel cell 2 by converging the new reaction gas supplied to the fuel cell 2 and offgas for the reaction gas exhausted from the fuel cell 2. The ejector 24 is provided with a driving part 49 varying the supply flow rate of reaction gas to the fuel cell 2, and an oscillation suppressing means 50 for suppressing the oscillation produced in the driving part 49. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a fuel cell system including a variable flow rate ejector.

  In a fuel cell system including a fuel cell that generates power upon receiving a supply of a reaction gas (fuel gas, oxidizing gas), a reaction gas that has not contributed to power generation may be included in the off-gas discharged from the fuel cell. In the conventional fuel cell system, in order to reuse the unreacted reaction gas, the fuel cell may be circulated and supplied to the fuel cell by a variable flow rate ejector (see, for example, Patent Documents 1 and 2).

For example, the ejector described in Patent Document 1 has a configuration in which one of two concentrically arranged nozzles is moved in the axial direction to vary the flow rate of fuel gas injected from the gap between the nozzle and the other nozzle. The nozzle is moved when the flow rate is changed by driving a step motor.
JP 2002-56869 A JP 2002-227799 A JP 2004-134161 A

  However, in the ejector described in Patent Document 1, vibration is generated when the step motor is driven when the flow rate is variable, and this vibration may propagate to the fuel gas. For this reason, pressure fluctuations occur in the fuel gas supplied to the fuel cell, which may reduce the durability and power generation performance of the fuel cell. In particular, when a drive unit of another peripheral device such as a regulator provided in the same gas system as the ejector resonates with the drive unit of the ejector, the pressure fluctuation increases.

  An object of the present invention is to provide a fuel cell system capable of stabilizing the supply flow rate and supply pressure to the fuel cell by suppressing the vibration in the ejector.

  In order to solve the above problems, a fuel cell system of the present invention includes an ejector for supplying a reaction gas to a fuel cell by merging a new reaction gas supplied to the fuel cell and an off-gas of the reaction gas discharged from the fuel cell. The ejector includes a drive unit that varies the supply flow rate of the reaction gas to the fuel cell, and vibration suppression means that suppresses vibrations generated in the drive unit.

  According to this configuration, even if the supply flow rate of the reaction gas to the fuel cell is varied by the ejector, vibration in the drive unit that can occur at that time can be suppressed. Thereby, the supply flow rate and supply pressure to the fuel cell by the variable flow rate type ejector can be stabilized.

  Here, the “reactive gas” refers to a gas that is used for a power generation reaction in a fuel cell, and specifically refers to a fuel gas containing hydrogen or an oxidizing gas containing oxygen.

  Here, “variable supply flow rate of the reaction gas to the fuel cell” means that it is sufficient if the flow rate of the reaction gas after merging the off gas with the new reaction gas is finally variable. means. In other words, “to vary the supply flow rate of the reaction gas to the fuel cell” not only controls the flow rate of one of the new reaction gas and off gas, but also controls the flow rate of both the new reaction gas and off gas. Can be included.

  Here, the drive unit does not ask a drive system for varying the supply flow rate, and for example, a drive system based on a differential pressure of gas in a fuel cell system or a drive system using an actuator can be used. .

  According to one aspect of the fuel cell system of the present invention, it is preferable that the vibration suppressing means is composed of an oil damper.

  According to this configuration, the movement of oil becomes a damping force, and vibration that can be generated in the drive unit can be suppressed.

  According to one aspect of the fuel cell system of the present invention, it is preferable that temperature control means for controlling the temperature of oil in the oil damper is further provided.

  According to this configuration, it is possible to appropriately maintain the viscosity of the oil, and it is possible to maintain an optimum vibration damping effect with respect to a temperature change.

  According to one aspect of the fuel cell system of the present invention, the ejector is capable of moving forward and backward within the nozzle, which generates a negative pressure for injecting one of the new reaction gas and off gas and sucking the other. And a flow rate adjusting member configured to adjust the flow rate of the gas passing through the nozzle according to the advance / retreat position, and the drive unit applies an operating force for advancing / retreating to the flow rate adjusting member to react with the fuel cell. It is preferable to vary the supply flow rate.

  According to this configuration, when the driving unit applies an operating force to the flow rate adjusting member, the advance / retreat position of the flow rate adjusting member inside the nozzle is changed, and the gas (new reaction gas or off gas) passing through the nozzle is changed. The flow rate is adjusted.

  According to one aspect of the fuel cell system of the present invention, the drive unit has a movable unit connected to the flow rate adjusting member, and the movable unit is moved together with the flow rate adjusting member when the operating force is directly applied thereto, and the vibration suppressing means is It is preferable that it is connected to the movable part.

  According to this configuration, since the vibration suppressing means is connected to the movable part, it is possible to suitably suppress the vibration that can be generated by the movement of the movable part. In addition, a movable part can be comprised with a piston or a diaphragm, for example.

  According to one aspect of the fuel cell system of the present invention, the fuel cell system includes a supply flow path for supplying a new reaction gas to the fuel cell, and a circulation flow path for circulating off-gas to the supply flow path. It is preferable that a pressure regulating valve is provided in at least one of the supply flow path and the circulation flow path.

  According to this configuration, even if resonance occurs between the drive unit of the ejector and the pressure regulating valve, the vibration can be suppressed by the vibration suppressing means of the ejector. For example, when the reaction gas is a fuel gas, a pressure regulating valve may be provided in the supply flow path. On the other hand, when the reaction gas is an oxidizing gas, a pressure regulating valve is provided in the circulation flow path. Good.

  According to the fuel cell system of the present invention, the vibration in the ejector can be suppressed by the vibration suppressing means, and the supply flow rate and supply pressure to the fuel cell by the ejector can be stabilized.

  Hereinafter, a fuel cell system according to a preferred embodiment of the present invention will be described with reference to the accompanying drawings. This fuel cell system stabilizes the supply flow rate and supply pressure of the reaction gas to the fuel cell by suppressing the vibration in the ejector that circulates and supplies the off gas. Below, the example which has arranged the ejector in the piping system of fuel gas is explained. As a fuel cell system, a fuel cell vehicle represented by a device equipped with the fuel cell system will be described as an example.

<First Embodiment>
FIG. 1 is a diagram showing a main part of a fuel cell system.
The fuel cell system 1 includes a fuel cell 2 that generates electric power upon receiving supply of oxidizing gas (air) and fuel gas (hydrogen). The fuel cell 2 is made of, for example, a solid polymer electrolyte type, and is configured as a stack structure in which a large number of cells are stacked. The fuel cell system 1 supervises the entire system, an oxidizing gas piping system 3 for supplying an oxidizing gas as a reactive gas to the fuel cell 2, a hydrogen gas piping system 4 for supplying a hydrogen gas as a reactive gas to the fuel cell 2. And a control device (ECU) 5 to be controlled.

  The oxidizing gas piping system 3 includes a supply channel 12 that supplies the oxidizing gas humidified by the humidifier 11 to the fuel cell 2, a discharge channel 13 that guides the oxidizing off-gas discharged from the fuel cell 2 to the humidifier 11, and An exhaust passage 14 is provided for leading the oxidizing off gas from the humidifier 11 to the combustor. The supply flow path 12 is provided with a compressor 15 that takes in oxygen gas in the atmosphere and pumps it to the humidifier 11. The discharge flow path 13 is provided with a pressure regulating valve 16 that adjusts the pressure of the oxidizing gas (oxidizing gas supply pressure) supplied to the fuel cell 2.

  The hydrogen gas piping system 4 is discharged from the fuel cell 2, a hydrogen tank 21 that is a hydrogen supply source storing high-pressure hydrogen gas, a supply passage 22 that supplies the hydrogen gas in the hydrogen tank 21 to the fuel cell 2, and Hydrogen gas in the circulation flow path 23 is provided in a circulation flow path 23 for returning hydrogen gas off-gas (hereinafter referred to as hydrogen off gas) to the supply flow path 22 and a connection portion between the supply flow path 22 and the circulation flow path 23. An ejector 24 that recirculates the off gas to the supply flow path 22 and an introduction passage 25 that introduces the pressure of the hydrogen off gas into the ejector 24 as a pilot pressure are provided.

  The ejector 24 joins hydrogen gas from the hydrogen gas outlet of the fuel cell 2 to hydrogen gas from the hydrogen tank 21 (hereinafter referred to as new hydrogen gas), and this combined hydrogen gas (hereinafter referred to as mixed hydrogen gas). May be supplied to the fuel cell 2. Note that the gas supplied to the anode of the fuel cell 2 may be a fuel gas containing hydrogen.

  The supply flow path 22 is located on the upstream side of the ejector 24, is located on the downstream side of the ejector 24, and the main flow flow path 22 a is a flow path for introducing new hydrogen gas to the ejector 24. And a mixing channel 22b which is a channel leading to A shut valve 31 that opens and closes the main flow path 22a and a pressure regulating valve 32 that adjusts the pressure of the hydrogen gas are provided in this order from the upstream side.

  A check valve 34 is interposed in the circulation flow path 23, and an introduction passage 25 is branched on the upstream side of the check valve 34. Hydrogen off-gas in the circulation channel 23 is sucked into the ejector 24 through the check valve 34. Further, the hydrogen off-gas pressure in the circulation passage 23 is introduced as a pilot pressure into the ejector 24 through the introduction passage 25.

  In addition, an exhaust passage 26 is provided in the circulation passage 23 for branching out impurities contained in the hydrogen off gas together with the hydrogen off gas to the outside of the system. The exhaust passage 26 is provided with a purge valve 27 that is periodically opened. When the purge valve 27 is opened, the hydrogen off gas is guided to the gas processing device 28 through the exhaust passage 26, and the hydrogen concentration of the hydrogen off gas is reduced in the gas processing device 28.

  Although not shown, a pressure sensor for detecting a hydrogen supply pressure (inlet pressure) to the fuel cell 2 is provided in the main flow channel 22a near the hydrogen gas inlet of the fuel cell 2. A circulation sensor 23 near the hydrogen gas outlet of the fuel cell 2 is provided with a pressure sensor that detects a hydrogen discharge pressure (outlet pressure) from the fuel cell 2.

FIG. 2 is a diagram showing a configuration of the ejector 24.
The ejector 24 is configured such that the supply flow rate of hydrogen gas (mixed hydrogen gas) supplied to the fuel cell 2 can be varied. The ejector 24 has a housing 41 that forms the outline thereof. The casing 41 has a primary supply port 42 connected to the downstream side of the main flow channel 22a, a secondary discharge port 43 connected to the upstream side of the mixing channel 22b, and the circulation channel 23. A suction port 44 on the negative pressure acting side connected to the downstream side of the suction passage and a pressure introduction port 45 connected to the downstream side of the introduction passage 25 are formed.

  Inside the housing 41, a nozzle 46 that injects new hydrogen gas from the supply port 42 toward the downstream side, and a new hydrogen gas and hydrogen off-gas that are provided on the downstream side of the nozzle 46 and pass through the nozzle 46. A diffuser 47 that joins the (substream), a needle 48 (flow rate adjusting member) that adjusts the supply flow rate of hydrogen gas to the fuel cell 2 by moving forward and backward in the nozzle 46, and the needle 48 in its axial direction A drive unit 49 that moves forward and backward, and a vibration suppression unit 50 that suppresses vibration generated in the drive unit 49 are provided.

  The nozzle 46 is a so-called tapered nozzle, and is formed so as to taper as a whole in the flow direction of hydrogen gas. The expanded upstream side of the nozzle 46 is connected to the supply port 42, and the downstream side of the nozzle 46 and the diffuser 47 are connected to the suction port 44. In addition, although the nozzle 46 was integrally formed with the component of the housing | casing 41, these are good also as another body.

  The diffuser 47 is formed coaxially with the nozzle 46, and its downstream side is connected to the discharge port 43. When new hydrogen gas is injected from the nozzle 46 toward the diffuser 47, a negative pressure for sucking the hydrogen off gas is generated, and the hydrogen off gas in the circulation passage 23 is sucked into the diffuser 47. As a result, new hydrogen gas and hydrogen off-gas are merged and mixed in the diffuser 47, and this mixed hydrogen gas is discharged from the discharge port 43 to the mixing flow path 22b.

  The needle 48 is formed of a cone or a pyramid having a pyramid shape, and is tapered toward the distal end. For example, the distal end is formed with a parabolic surface. The opening area of the gap between the needle 48 and the inner peripheral wall of the nozzle 46 (hereinafter referred to as the opening area of the nozzle 46) is varied according to the axial advance / retreat position of the needle 48. As a result, the flow rate of new hydrogen gas passing through the nozzle 46 is controlled, and the supply flow rate of hydrogen gas to the fuel cell 2 is controlled.

  The drive unit 49 applies an operating force for advancing and retreating to the needle 48 to advance and retract the needle 48. The drive unit 49 includes a piston 62 (movable unit) in which the proximal end side of the needle 48 is connected to the center of the surface 62a, and a spring 63 (biasing member) in which one end is connected to the back surface 62b of the piston 62 or the vibration suppressing means 50. ) And. The needle 48, the piston 62, and the spring 63 are disposed coaxially with the nozzle 46. The needle 48 and the piston 62 are integrally formed, but of course, they may be formed separately.

  The spring 63 has a predetermined spring constant and urges the back surface 62 b of the piston 62 toward the distal end side of the needle 48. One end of the spring 63 is connected to the back surface 62 b of the piston 62 or the vibration suppressing means 50, and the other end is connected to the bottom of the inner wall surface of the housing 41. The spring 63 is constituted by the inner wall surface of the housing 41 and the back surface 62 b of the piston 62 and is accommodated in the pressure chamber 65. A pressure introducing port 45 communicates with the pressure chamber 65, and the hydrogen off-gas in the circulation channel 23 is guided as a signal pressure through the introducing passage 25 and the pressure introducing port 45.

  The piston 62 is configured so that its outer peripheral surface can slide along the inner wall surface of the housing 41 and slides in the axial direction thereof. A new hydrogen gas pressure P <b> 1 from the main flow path 22 a directly acts on the surface 62 a of the piston 62. On the other hand, the urging force from the spring 63 acts on the back surface 62b of the piston 62, and the hydrogen off-gas pressure P2 from the circulation flow path 23 acts directly.

  With such a configuration, the piston 62 applies (transmits) the differential pressure between the pressure P1 and the pressure P2 to the needle 48 as an operating force for forward and backward movement. Based on the balance between the differential pressure of the hydrogen gas and the biasing force of the spring 63, the needle 48 moves forward and backward in the axial direction together with the piston 62. Thereby, the opening area of the nozzle 46 is varied, and the supply flow rate of the hydrogen gas to the fuel cell 2 is varied.

  Instead of the piston 62, a diaphragm may be used as the movable member. In this case, the peripheral edge of the diaphragm may be fixed to the inner wall of the housing 41. By doing so, the differential pressure of the hydrogen gas acting on both the front and back surfaces of the diaphragm causes the diaphragm to be displaced (vibrates) so as to bend, whereby the needle 48 moves forward and backward together with the diaphragm.

  The vibration suppressing means 50 suppresses vibration generated in the drive unit 49 when the needle 48 moves forward and backward. Specifically, when the drive unit 49 moves during the forward / backward movement of the needle 48, particularly vibration due to expansion / contraction of the spring 63 or vibration of the piston 62 related thereto is generated, this vibration is suppressed by the vibration suppressing means 50. It is like that.

  The vibration suppressing means 50 can be constituted by, for example, an air damper, an oil damper, a friction damper, and an inertial force damper, and is constituted by an oil damper in this embodiment. The oil damper 50 is configured as a twin tube type or a single tube type, and is accommodated in the pressure chamber 65.

  For example, the twin tube type oil damper 50 has a double cylinder filled with oil, and a piston with an orifice is slidable inside an inner cylinder. The rod connected to the piston is coupled to the back surface 62a of the piston 62. When the piston 62 vibrates, the piston in the oil damper 50 causes the oil to flow. This flow becomes a damping force and absorbs the vibration of the piston 62 and hence the vibration of the drive unit 49.

  When the oil damper 50 is located inside the spring 63, one end of the spring 63 is connected to the back surface 62b of the piston 62, and the oil damper 50 is located between the spring 63 and the back surface 62b of the piston 62. In other words, one end of the spring 63 is connected to the oil damper 50.

  Here, the control of the supply flow rate of the ejector 24 will be described in relation to the load of the fuel cell 2.

  Generally, when the amount of power generated by the fuel cell 2 increases, for example, when the fuel cell vehicle is accelerated, the amount of hydrogen gas consumed by the fuel cell 2 increases. When this consumption increases and the flow rate of the mixing channel 22b increases, the pressure loss in the fuel cell 2 increases and the hydrogen off-gas pressure P2 decreases (the mixed hydrogen gas pressure P3 in the mixing channel 22b also decreases). .)

  Then, the piston 62 and the needle 48 are retracted from the equilibrium state against the spring 63 by the balance of the urging forces of P1, P2 and the spring 63. When the needle 48 is retracted, the opening area of the nozzle 46 is increased, and the flow rate of new hydrogen gas passing through the nozzle 46 is increased. Further, when the needle 48 is retracted, vibration generated in the drive unit 49 is suppressed by the oil damper.

  Therefore, when the load of the fuel cell 2 increases, the ejector 24 can be driven autonomously and without causing pressure fluctuations, and the supply flow rate to the fuel cell 2 can be varied in the increasing direction. Since the pressure P3 increases due to the increase in the flow rate of the new hydrogen gas, the hydrogen supply pressure to the fuel cell 2 is ensured to an appropriate value, and the flow rate of the hydrogen off gas is increased to increase the flow rate of the new hydrogen gas. Therefore, it is ensured to an appropriate value.

  On the other hand, when the amount of power generated by the fuel cell 2 decreases, such as when the fuel cell vehicle decelerates, the amount of hydrogen gas consumed by the fuel cell 2 decreases. When this consumption amount decreases and the flow rate of the mixing flow path 22b decreases, the pressure loss in the fuel cell 2 decreases, and the hydrogen off-gas pressure P2 increases (the mixed hydrogen gas pressure P3 also increases).

  Then, the piston 62 and the needle 48 advance from the equilibrium state by the balance of the urging forces of P1, P2 and the spring 63. When the needle 48 advances, the opening area of the nozzle 46 becomes small, and the flow rate of new hydrogen gas passing through the nozzle 46 decreases. Further, when the needle 48 advances, vibration generated in the drive unit 49 is suppressed by the oil damper.

  Therefore, when the load of the fuel cell 2 becomes small, the ejector 24 can be driven autonomously and without causing a pressure fluctuation to vary the supply flow rate to the fuel cell 2 in the decreasing direction. Since the pressure P3 decreases due to the decrease in the flow rate of the new hydrogen gas, the hydrogen supply pressure to the fuel cell 2 is ensured to an appropriate value, and the flow rate of the hydrogen off-gas decreases to reduce the flow rate of the new hydrogen gas. Therefore, it is ensured to an appropriate value.

  As described above, according to the fuel cell system 1 of the present embodiment, since the vibration suppressing means 50 is provided corresponding to the drive unit 49 of the ejector 24, the hydrogen gas supplied to the fuel cell 2 is changed when the flow rate is variable. It is possible to suppress the occurrence of pressure fluctuation. Further, even when resonance occurs between the drive unit 49 of the ejector 24 and the peripheral device, the vibration can be suppressed by the vibration suppressing means 50.

  For example, even if resonance occurs between the spring 63 and the pressure regulating valve 32 or resonance occurs between the spring 63 and the purge valve 27, the vibration suppressing means 50 can cause pressure fluctuations in the hydrogen gas. Can be suppressed. Therefore, according to the fuel cell system 1 including the ejector 24 of the present embodiment, the supply flow rate and supply pressure of the hydrogen gas to the fuel cell 2 can be stabilized, and the durability of the fuel cell 2 is reduced and power generation is performed. A decrease in performance can be appropriately suppressed.

  As a modification, the pressure P3 of the mixed hydrogen gas may be introduced into the pressure chamber 65. Further, the pressure of the oxidizing gas in the oxidizing gas piping system 3 may be introduced into the pressure chamber 65, and in that case, it may be a new oxidizing gas in the supply flow path 12, The oxidizing off gas in the flow path 14 may be used. Further, the gas guided to the pressure chamber 65 may be a gas not involved in the gas piping system (3, 4) of the fuel cell system 1 or may be a dedicated gas guided to the pressure chamber 65.

Second Embodiment
Next, with reference to FIG. 3, the ejector 24 according to the second embodiment will be described focusing on the differences. The difference from the first embodiment is that the configuration of the drive system of the drive unit 49 is changed to an electrical operating force instead of the operating force due to the differential pressure of the gas.

  The drive unit 49 includes an actuator 72 that is electrically controlled by the control device 71 and a piston 62 to which an output unit of the actuator 72 is coupled.

  The control device 71 includes a CPU (not shown), a ROM storing a control program and control data processed by the CPU, and a RAM mainly used as various work areas for control processing. The control device 71 detects, for example, detection signals from pressure sensors of the supply flow path or the circulation flow path 22b and the circulation flow path 23, other detection signals from pressure sensors (not shown) provided in the piping systems (3, 4), and fuel. Based on various signals from outside the battery system 1, the actuator 71 is driven to control the hydrogen gas supply flow rate and the hydrogen supply pressure by the ejector 24.

  The actuator 72 includes, for example, a motor, a cylinder device, or a solenoid, and is electrically connected to the control device 71. By driving the actuator 72, the needle 61 is applied with an advancing / retreating operating force via the piston 62 and moves forward and backward in the axial direction together with the piston 62, whereby the supply flow rate of hydrogen gas to the fuel cell 2 is variable. To do.

  When the actuator 72 is driven and the output unit moves when the needle 48 moves forward and backward, vibration can be generated in the drive unit 49. However, since the vibration suppressing means 50 made of, for example, an oil damper is provided in association with the drive unit 49, the vibration of the drive unit 49 can be absorbed. Therefore, also according to the present embodiment, the supply flow rate and supply pressure of hydrogen gas to the fuel cell 2 can be stabilized, and a decrease in durability and a decrease in power generation performance of the fuel cell 2 can be appropriately suppressed. .

  The vibration suppressing means 50 can be configured and arranged in the same manner as in the first embodiment. For example, an oil damper may be used as the vibration suppressing means 50 and the rod of the oil damper may be connected to the back surface 62 a of the piston 62. Alternatively, when the actuator 72 is composed of a solenoid, an oil damper rod may be coupled to the solenoid armature (movable member). Note that the vibration suppressing means 50 may be housed inside the housing 41. Moreover, since the actuator 72, the damper as the vibration suppressing means 50, and the needle 48 are connected in series, vibration transmission to the actuator 72 can be further blocked or suppressed.

  Note that the control device 71 generates the power generation state of the fuel cell 2 such as the power generation command and power generation amount of the fuel cell 2, the consumption amount of hydrogen gas or the oxidation gas in the fuel cell 2, the supply amount of the oxidation gas by the compressor 15, Alternatively, the actuator 72 may be driven based on the oxidizing gas supply pressure to the fuel cell 2.

  In addition, the ejector 24 includes a drive unit (for example, the drive unit 49 of the first embodiment) that applies an actuation force due to a differential pressure of gas to the needle 61, and a drive unit that applies an electrical actuation force by the actuator to the needle 61. (For example, the drive unit 49 of the second embodiment) may be included. By doing so, the ejector 24 can vary the supply flow rate by hybrid control using the differential pressure of gas and electricity. In this case, the vibration suppression means 50 may be provided individually corresponding to the two drive sections, or vibration generated in the two drive sections may be suppressed by one vibration suppression means 50.

<Third Embodiment>
Next, with reference to FIG. 4, the ejector 24 according to the third embodiment will be described focusing on the differences. The difference from the second embodiment is that a temperature control means 80 for controlling the temperature of the oil of the oil damper, which is the vibration suppressing means 50, is added.

  In the case of the twin tube type oil damper 50, for example, the temperature control means 80 is configured by a heater provided in the inner cylinder or the outer cylinder filled with oil. The heater 80 is connected to the control device 71 and adjusts the oil to a predetermined temperature according to the external environment of the fuel cell 2, for example, the outside air temperature of the vehicle on which the fuel cell system 1 is mounted.

  The advantage of this embodiment compared to the above embodiment is that the viscosity of the oil in the oil damper 50 can be appropriately maintained by the heater 80. Therefore, since the oil temperature can be set so as to maintain the optimum vibration damping effect against the temperature change of the external environment of the fuel cell 2, the vibration suppressing effect is stable in a wide temperature environment from low temperature to high temperature. Can be played. Of course, the temperature suppressing means 80 can also be provided in the ejector 24 having the configuration of the first embodiment.

<Modification>
Next, various modifications of the fuel cell system 1 of the present embodiment will be described.
In the above description, the main flow gas (injection gas) of the ejector 24 is a new hydrogen gas, and the side flow gas (suction gas) is a hydrogen off gas. That is, the ejector 24 may suck new hydrogen gas from the hydrogen tank 21 when injecting hydrogen off-gas from the nozzle 46.

  Further, the ejector 24 may be disposed in the oxidizing gas piping system 3. For example, the ejector 24 may join the new oxidizing gas from the compressor 15 with the oxidizing off-gas in the discharge flow path 13 and supply the mixed oxidizing gas after the joining to the fuel cell 2. In this case, even if resonance occurs between the pressure regulating valve 16 and the drive unit 49 of the ejector 24, vibration can be appropriately suppressed by the vibration suppressing means 50 of the ejector 24, and at a stable supply flow rate and supply pressure. Oxidizing gas can be supplied to the fuel cell 2.

  The above-described fuel cell system 1 of the present invention can be mounted on a train, an aircraft, a ship, a self-propelled robot, or other mobile body other than a two-wheel or four-wheel automobile. Further, the fuel cell system 1 can be used for stationary use and can be incorporated into a cogeneration system.

  Further, the ejector 24 mounted on the fuel cell system 1 of the present invention can be applied not only to the fuel cell system 1 but also to other systems that need to join and supply fluids. Particularly, the supply destination device that is the fluid supply destination of the ejector 24 is a fluid consuming device that consumes fluid (a gas consuming device in the case of gas), and is suitable for a system in which the amount of fluid consumed by the fluid consuming device varies. It is. A more preferred system is a system in which the fluid discharged from the fluid consuming device is circulated again to the fluid consuming device by the ejector 24.

It is a lineblock diagram showing the fuel cell system concerning a 1st embodiment. It is sectional drawing which shows typically the ejector which concerns on 1st Embodiment. It is sectional drawing which shows typically the ejector which concerns on 2nd Embodiment. It is sectional drawing which shows typically the ejector which concerns on 3rd Embodiment.

Explanation of symbols

  1: fuel cell system, 2: fuel cell, 3: oxidizing gas piping system, 4: hydrogen gas piping system, 22: supply channel, 23: circulation channel, 24: ejector, 46: nozzle, 48: needle (flow rate) Adjustment member), 49: drive unit, 50: vibration suppression means, 62: piston (movable part), 63: spring, 72: actuator, 80: temperature control means

Claims (6)

In a fuel cell system provided with an ejector that combines a new reaction gas supplied to the fuel cell and an off-gas of the reaction gas discharged from the fuel cell to supply the reaction gas to the fuel cell,
The ejector is
A drive unit that varies a supply flow rate of the reaction gas to the fuel cell;
Vibration suppressing means for suppressing vibration generated in the drive unit;
A fuel cell system comprising:   The fuel cell system according to claim 1, wherein the vibration suppression unit is configured by an oil damper.   The fuel cell system according to claim 2, further comprising temperature control means for controlling the temperature of oil in the oil damper. The ejector is
A nozzle that generates a negative pressure for injecting one of the new reaction gas and the off-gas and sucking the other;
A flow rate adjusting member configured to be capable of moving forward and backward within the nozzle, and adjusting the flow rate of gas passing through the nozzle according to the forward and backward position,
4. The fuel cell system according to claim 1, wherein the drive unit applies an advancing / retreating operating force to the flow rate adjusting member to vary a supply flow rate of the reactive gas to the fuel cell. 5. . The drive unit is connected to the flow rate adjusting member, and has a movable unit that is directly actuated by the operating force to move together with the flow rate adjusting member.
The fuel cell system according to claim 4, wherein the vibration suppression unit is connected to the movable part. A supply flow path for supplying the new reaction gas to the fuel cell;
A circulation flow path for circulating the off gas to the supply flow path,
The ejector is provided at a connection portion between the supply flow path and the circulation flow path,
The fuel cell system according to any one of claims 1 to 5, wherein a pressure regulating valve is provided in at least one of the supply channel and the circulation channel.

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