CN220106598U

CN220106598U - Fuel cell gas circulation system

Info

Publication number: CN220106598U
Application number: CN202321523613.4U
Authority: CN
Inventors: 宋维龙; 沈雪松; 祝银海; 姜培学; 黄玉磊
Original assignee: Shandong Guochuang Fuel Cell Technology Innovation Center Co ltd
Current assignee: Shandong Guochuang Fuel Cell Technology Innovation Center Co ltd
Priority date: 2023-06-15
Filing date: 2023-06-15
Publication date: 2023-11-28
Anticipated expiration: 2033-06-15

Abstract

The utility model belongs to the technical field of fuel cells, and discloses a fuel cell gas circulation system which comprises a working fluid source, a fuel cell, a condenser and an ejector, wherein the condenser is communicated with an anode outlet of the fuel cell and can condense part of anode exhaust gas at the anode outlet to generate condensed water, and an outlet of the ejector is communicated with an anode inlet of the fuel cell. The ejector comprises a suction chamber, the working fluid source, the condenser and the anode outlet are respectively communicated with the suction chamber, and the working fluid can be sprayed to the suction chamber so as to eject condensed water in the condenser and the other part of anode exhaust gas at the anode outlet to enter the suction chamber. The gas circulation system of the fuel cell can effectively improve the water content in the mixed gas, meet the required water-carbon ratio requirement and prolong the service life of the fuel cell.

Description

Fuel cell gas circulation system

Technical Field

The utility model relates to the technical field of fuel cells, in particular to a fuel cell gas circulation system.

Background

Solid Oxide Fuel Cells (SOFCs) are high temperature fuel cells in which the anode exhaust gas has the characteristics of high temperature, high water content, and a portion of unreacted fuel, and therefore, the recycling of heat, moisture, and fuel is often accomplished by the anode exhaust gas cycle. The anode exhaust contains unreacted fuel as well as anode exhaust products such as water and carbon dioxide.

The ejector is a pressurizing, vacuum and mixing device and can transfer energy by means of shock waves generated by fluid transonic flow and a mixing process between two fluids. The two fluids are respectively working fluid and induced fluid. The working fluid is fluid flowing through a nozzle part in the ejector, generally has higher energy (pressure), and is an energy source for ejecting circulation. The jet flow is fluid which is jetted and circulated by the ejector in the jet circulation system. Because the ejector has no moving parts, is simple to maintain and long in service life, the ejector is often adopted to complete the gas circulation, pressurization and mixing processes in the anode gas circulation loop of the SOFC. SOFCs are capable of utilizing a mixture of fuel and steam to produce hydrogen in a reformer by reforming reactions.

However, if the water content in the mixed gas is insufficient, carbon is deposited inside the reformer and the SOFC, which seriously affects the performance and the service life of the SOFC. The water vapor recovered by the existing ejector is difficult to meet the water-carbon ratio requirement of the SOFC.

Therefore, a fuel cell gas circulation system is needed to solve the above problems.

Disclosure of Invention

The utility model aims to provide a fuel cell gas circulation system which can effectively improve the water content in mixed gas, meet the required water-carbon ratio requirement and prolong the service life of a fuel cell.

To achieve the purpose, the utility model adopts the following technical scheme:

a fuel cell gas circulation system comprising:

the device comprises a working fluid source, a fuel cell, a condenser and an ejector, wherein the condenser is communicated with an anode outlet of the fuel cell and can condense part of anode exhaust gas at the anode outlet to generate condensed water, and an outlet of the ejector is communicated with an anode inlet of the fuel cell;

the ejector comprises a suction chamber, the working fluid source, the condenser and the anode outlet are respectively communicated with the suction chamber, and the working fluid can be sprayed to the suction chamber so as to eject condensed water in the condenser and the other part of anode exhaust gas at the anode outlet to enter the suction chamber.

As the preferable scheme of the fuel cell gas circulation system provided by the utility model, the suction chamber is provided with a working flow inlet pipe, a first injection flow inlet and a second injection flow inlet, the working flow inlet pipe is communicated with the working flow source, the first injection flow inlet is communicated with the anode outlet, and the second injection flow inlet is communicated with the condenser outlet.

As a preferable scheme of the fuel cell gas circulation system provided by the utility model, the ejector further comprises a mixing chamber, the mixing chamber is communicated with the suction chamber and is positioned at the downstream of the suction chamber, and the working flow, the condensed water in the second ejection flow inlet and the anode exhaust in the first ejection flow inlet can be mixed in the mixing chamber.

As a preferable scheme of the fuel cell gas circulation system provided by the utility model, the ejector further comprises a diffusion chamber, wherein the diffusion chamber is communicated with the mixing chamber and is positioned at the downstream of the mixing chamber, and the inner diameter of the diffusion chamber is gradually increased along the direction away from the inlet of the diffusion chamber and close to the outlet of the diffusion chamber.

As a preferable mode of the fuel cell gas circulation system provided by the utility model, the working flow inlet pipe is inserted into the suction chamber, a working flow nozzle is arranged at the outlet of the working flow inlet pipe, and the working flow is sprayed to the suction chamber through the working flow nozzle.

As a preferred scheme of the fuel cell gas circulation system provided by the utility model, the fuel cell gas circulation system further comprises a heat exchanger, wherein the heat exchanger is arranged between the ejector and the working fluid source, the first ejection flow inlet is communicated with the heat exchanger, and the working fluid can exchange heat in the heat exchanger with anode exhaust gas which is about to enter the first ejection flow inlet for heating.

As a preferred scheme of the fuel cell gas circulation system provided by the utility model, the fuel cell gas circulation system further comprises a regulating valve assembly, wherein the regulating valve assembly is arranged at the anode outlet and can regulate the flow of anode exhaust gas entering the first injection inflow port; and, the regulator valve assembly is capable of regulating the flow of anode exhaust gas into the condenser.

As a preferred scheme of the fuel cell gas circulation system provided by the utility model, the fuel cell gas circulation system further comprises a reformer, wherein the reformer is arranged between an anode inlet of the fuel cell and an outlet of the ejector and is used for reforming and producing hydrogen by mixing the working flow, condensed water in the condenser and part of anode exhaust gas at the anode outlet.

As a preferable scheme of the fuel cell gas circulation system provided by the utility model, the fuel cell gas circulation system further comprises a gas-liquid separator, wherein the gas-liquid separator is arranged between the condenser and the ejector, and is used for separating the condensed water and the anode gas discharged from the outlet of the condenser.

As a preferable mode of the fuel cell gas circulation system provided by the utility model, the fuel cell gas circulation system further comprises a working flow regulating valve, wherein the working flow regulating valve is arranged between the suction chamber and the working flow source and can regulate the flow rate of the working flow entering the suction chamber.

The utility model has the beneficial effects that:

the utility model provides a fuel cell gas circulation system which comprises a working fluid source, a fuel cell, a condenser and an ejector, wherein the condenser is communicated with an anode outlet of the fuel cell and can condense part of anode exhaust gas at the anode outlet to generate condensed water, and an outlet of the ejector is communicated with an anode inlet of the fuel cell. That is, a part of the anode off-gas discharged from the anode outlet of the fuel cell enters the condenser to generate condensed water. The ejector comprises a suction chamber, the working fluid source, the condenser and the anode outlet are respectively communicated with the suction chamber, and the working fluid can be sprayed into the suction chamber to guide condensed water in the condenser and the other part of anode exhaust gas of the anode outlet to enter the suction chamber. That is, a part of unreacted fuel at the anode outlet can directly enter the ejector, and condensed water can also enter the ejector, so that the water content in the ejector is increased, the water-carbon ratio requirement of mixed fluid sprayed from the ejector outlet is met, carbon deposition of the fuel cell is avoided, and the service life of the fuel cell is prolonged.

Drawings

FIG. 1 is a schematic diagram of a fuel cell gas circulation system provided by an embodiment of the present utility model;

fig. 2 is a schematic structural view of an ejector according to an embodiment of the present utility model.

In the figure:

100. a working fluid source;

200. a fuel cell; 210. an anode outlet; 211. a first anode outlet leg; 212. a second anode outlet leg; 220. a cathode outlet;

300. a condenser;

400. an ejector; 410. a suction chamber; 420. a working fluid inlet pipe; 421. a workflow nozzle; 430. a first jet inlet; 440. a second jet inlet; 450. a mixing chamber; 460. a diffusion chamber;

500. a reformer;

600. a gas-liquid separator; 610. a gas outlet;

700. a heat exchanger;

810. a first regulating valve; 820. a second regulating valve; 830. a workflow regulating valve;

900. an air source.

Detailed Description

The utility model is described in further detail below with reference to the drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the utility model and are not limiting thereof. It should be further noted that, for convenience of description, only some, but not all of the structures related to the present utility model are shown in the drawings.

In the description of the present utility model, unless explicitly stated and limited otherwise, the terms "connected," "connected," and "fixed" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the present utility model will be understood in specific cases by those of ordinary skill in the art.

In the present utility model, unless expressly stated or limited otherwise, a first feature "above" or "below" a second feature may include both the first and second features being in direct contact, as well as the first and second features not being in direct contact but being in contact with each other through additional features therebetween. Moreover, a first feature being "above," "over" and "on" a second feature includes the first feature being directly above and obliquely above the second feature, or simply indicating that the first feature is higher in level than the second feature. The first feature being "under", "below" and "beneath" the second feature includes the first feature being directly under and obliquely below the second feature, or simply means that the first feature is less level than the second feature.

In the description of the present embodiment, the terms "upper", "lower", "right", "left", and the like are orientation or positional relationships based on those shown in the drawings, merely for convenience of description and simplicity of operation, and do not indicate or imply that the apparatus or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the utility model. Furthermore, the terms "first," "second," and the like, are used merely for distinguishing between descriptions and not for distinguishing between them.

Fig. 1 shows a schematic diagram of a fuel cell gas circulation system according to an embodiment of the present utility model. Referring to fig. 1, the present embodiment provides a fuel cell gas circulation system including a working fluid source 100, a fuel cell 200, a condenser 300, and an ejector 400. The ejector 400 is disposed between the working fluid source 100 and the anode inlet of the fuel cell 200; the condenser 300 is disposed between the anode outlet 210 of the fuel cell 200 and the ejector 400.

Specifically, fig. 2 shows a schematic structural diagram of an ejector according to an embodiment of the present utility model. Referring to fig. 2, the ejector 400 includes a suction chamber 410, and the working fluid source 100, the condenser 300, and the anode outlet 210 are respectively connected to the suction chamber 410. The working fluid, condensed water in the condenser 300, and a portion of the anode exhaust gas of the anode outlet 210 can enter the suction chamber 410. The condensed water in the condenser 300 and a portion of the anode exhaust gas from the anode outlet 210 are two pilot streams from the ejector 400. The addition of the condensed water can increase the water content in the mixed gas sprayed out of the outlet of the ejector 400, meet the required water-carbon ratio requirement, effectively meet the high water-carbon ratio requirement of the fuel cell 200, prevent carbon deposition and prolong the service life of the fuel cell.

More specifically, the intake chamber 410 is provided with a working fluid inlet duct 420, a first jet inlet 430, and a second jet inlet 440. The working fluid inlet pipe 420 communicates with the working fluid source 100, is coaxially disposed in the suction chamber 410, and is inserted from the head end of the suction chamber 410. The first jet stream inlet 430 communicates with the anode outlet 210 and the second jet stream inlet 440 communicates with the condenser 300 outlet. Preferably, the first injection inflow port 430 and the second injection inflow port 440 are respectively provided at the upper and lower sides of the suction chamber 410 and are disposed opposite to each other, so that the condensed water and a part of the anode exhaust gas are mixed at the moment of entering the suction chamber 410, and the efficiency of fluid mixing is improved.

Preferably, the working fluid inflow pipe 420 is provided with a working fluid nozzle 421 at one end inserted into the suction chamber 410. The working fluid nozzle 421 is designed to be variable in diameter, and the inner diameter of the working fluid nozzle 421 is gradually decreased and then gradually increased in a direction away from the inlet end of the working fluid inlet pipe 420. By the above arrangement, when the working fluid is sprayed from the working fluid nozzle 421 to the suction chamber 410, supersonic flow can be formed, and suction effect is formed on the anode exhaust gas of the first injection inlet 430 and the condensed water in the second injection inlet 440, so that mixing efficiency of the working fluid, the condensed water and the anode exhaust gas in the suction chamber 410 is increased, and suction speed of the anode exhaust gas in the first injection inlet 430 and the condensed water in the second injection inlet 440 is increased.

More specifically, the eductor 400 also includes a mixing chamber 450. The mixing chamber 450 communicates with the suction chamber 410 and has a smaller inner diameter relative to the suction chamber 410, downstream of the suction chamber 410. The working stream, the condensed water in the second jet stream inlet 440, and the anode exhaust in the first jet stream inlet 430 can be mixed in the mixing chamber 450 to form a mixed fluid.

More specifically, the ejector 400 also includes a diffuser chamber 460. The diffuser 460 is in communication with the mixing chamber 450 and downstream of the mixing chamber 450, with the diffuser 460 having an inner diameter that gradually increases in a direction away from the inlet of the diffuser 460 and toward the outlet of the diffuser 460. That is, the mixed fluid mixed in the mixing chamber 450 can complete the pressurizing and decelerating process in the diffuser chamber 460 and then be discharged from the outlet of the diffuser chamber 460.

With continued reference to fig. 1, a reformer 500 is disposed between the outlet of the diffusion chamber 460 and the anode inlet of the fuel cell 200. The reformer 500 is used for performing a reforming reaction on the mixed fluid to produce hydrogen, which is the anode gas of the fuel cell 200, and enters the fuel cell 200 from the anode inlet thereof to participate in an electrochemical reaction. The reformer 500 is a prior art, and the structure and principle of this embodiment are not described herein.

Specifically, the fuel cell 200 is a solid oxide fuel cell in which an anode gas and a cathode gas can electrochemically react to generate electric power. The anode gas is hydrogen and the cathode gas is air. The fuel cell gas circulation system further comprises an air source 900, the air source 900 being in communication with the cathode inlet of the fuel cell 200, the air source 900 being adapted to provide a cathode oxidant, i.e. oxygen, to the fuel cell 200.

More specifically, the fuel cell 200 is further provided with a cathode outlet 220. The cathode outlet 220 is used to discharge cathode exhaust gas after electrochemical reaction of the fuel cell 200. The anode outlet 210 is used to discharge anode off-gas after electrochemical reaction of the fuel cell 200.

More specifically, the anode outlet 210 is for discharging anode exhaust gas in the reaction of the fuel cell 200, and is provided with two branches, a first anode outlet branch 211 and a second anode outlet branch 212, respectively. The anode off-gas discharged from the anode outlet 210 flows partially to the first anode outlet branch pipe 211 and partially to the second anode outlet branch pipe 212.

With continued reference to fig. 1, the condenser 300 is disposed in the second anode outlet manifold 212 and is capable of condensing a portion of the anode exhaust gas from the anode outlet 210 to produce condensed water. A gas-liquid separator 600 is disposed between the outlet of the condenser 300 and the second jet stream inlet 440. The gas-liquid separator 600 serves to separate the condensed water and the anode gas discharged from the outlet of the condenser 300. The gas-liquid separator 600 is provided with a liquid outlet communicating with the second ejector inflow port 440 and a gas outlet 610 communicating with the external environment for discharging gaseous substances in the fluid discharged from the outlet of the condenser 300.

Specifically, the working fluid source 100 is a fuel tank capable of providing high pressure fuel as a working fluid to the ejector 400 according to the requirements of the fuel cell gas circulation system. A heat exchanger 700 is provided in a communication line between the working fluid inlet pipe 420 and the working fluid source 100. And the first injection flow inlet 430 is in communication with the heat exchanger 700, the working stream being capable of exchanging heat in the heat exchanger 700 with the anode exhaust gas that is about to enter the first injection flow inlet 430. Since the anode exhaust gas exiting through the anode outlet 210 itself has some heat, the working stream is able to achieve a temperature rise in the heat exchanger 700, facilitating subsequent mixing of the working stream with the two induced streams.

Preferably, the fuel cell gas circulation system further comprises a regulating valve assembly provided at the anode outlet 210, capable of regulating the flow rate of the anode exhaust gas entering the first ejector inflow port 430; and, the regulator valve assembly is also capable of regulating the flow of anode exhaust gas into the condenser 300.

Specifically, the regulator valve assembly includes a first regulator valve 810, the first regulator valve 810 disposed between the anode outlet 210 and the first jet stream inlet 430, capable of regulating the flow of anode exhaust gas into the first jet stream inlet 430. Likewise, the fuel cell gas circulation system further includes a second regulating valve 820, the second regulating valve 820 being disposed between the anode outlet 210 and the condenser 300, capable of regulating the flow rate of anode off-gas entering the condenser 300. Through the first regulating valve 810 and the second regulating valve 820, component regulation of the mixed fluid can be realized, so that decoupling of injection ratio and water-carbon ratio can be realized, and wider working condition operation can be satisfied. Alternatively, the regulator valve assembly may be a three-way valve of the prior art, and the present embodiment is not limited in the type of regulator valve assembly.

Preferably, the fuel cell gas circulation system further includes a workflow regulating valve 830, the workflow regulating valve 830 being disposed between the workflow inflow pipe 420 and the outlet of the workflow source 100, and being capable of regulating the flow rate of the workflow entering the suction chamber 410 according to the need.

The working process of the fuel cell gas circulation system provided in this embodiment is as follows:

the high-pressure fuel in the working fluid source 100 passes through the working fluid regulating valve 830, enters the heat exchanger 700, exchanges heat with the high-temperature anode exhaust gas of the fuel cell 200 to raise temperature, then enters the suction chamber 410 through the working fluid inlet pipe 420, forms supersonic flow at the outlet of the working fluid nozzle 421, and sucks two diversion flows. The two pilot streams and the working stream mix in the mixing chamber 450 and complete the pressurization and deceleration process in the diffuser chamber 460. The mixed fluid enters the reformer 500 to undergo a reforming reaction, and the reaction product enters the fuel cell 200 to undergo an electrochemical reaction with a cathode oxidant from the air source 900 to generate electric power. The cathode exhaust of the fuel cell 200 exits through the cathode outlet 220 and the anode exhaust enters the two diversion flow loops, namely the first anode outlet leg 211 and the second anode outlet leg 212, through the anode outlet 210.

Downstream of the first anode outlet leg 211, a portion of the anode exhaust gas enters the heat exchanger 700 through the first regulator valve 810 to exchange heat with the working stream and is then drawn into the suction chamber 410 through the first jet stream inlet 430. Downstream of the second anode outlet leg 212, another portion of the anode exhaust gas passes through a second regulator valve 820 to the condenser 300 to condense water vapor in this portion of the anode exhaust gas to liquid water before entering the gas-liquid separator 600. The gaseous materials in the portion of the anode exhaust are discharged through the gas outlet 610, and the condensed water flows into the suction chamber 410 through the second injection flow inlet 440. The anode exhaust and condensed water entering the suction chamber 410 through the first jet inlet 430 are thoroughly mixed with the supersonic working stream in the mixing chamber 450, completing the jet process.

The control strategy of the fuel cell gas circulation system is as follows:

the flow rate of the workflow is first determined according to the required power of the fuel cell 200, and is adjusted to meet the demand by the workflow adjusting valve 830. For example, when the actual flow rate of the working fluid is higher than the demand of the fuel cell 200, the opening degree of the working fluid regulating valve 830 is decreased; conversely, when the actual flow rate of the working fluid is lower than the demand of the fuel cell 200, the opening degree of the working fluid regulating valve 830 needs to be increased.

Then, calculating the corresponding water-carbon ratio requirement, and if the water-carbon ratio is higher than the required water-carbon ratio, adjusting the opening of the second regulating valve 820 or increasing the opening of the first regulating valve 810 to reduce the water content of the induced flow; if the water to carbon ratio is lower than the desired water to carbon ratio, the opening of the second regulator valve 820 may be increased or the opening of the first regulator valve 810 may be decreased to increase the draw stream water content.

It is to be understood that the above examples of the present utility model are provided for clarity of illustration only and are not limiting of the embodiments of the present utility model. Various obvious changes, rearrangements and substitutions can be made by those skilled in the art without departing from the scope of the utility model. It is not necessary here nor is it exhaustive of all embodiments. Any modification, equivalent replacement, improvement, etc. which come within the spirit and principles of the utility model are desired to be protected by the following claims.

Claims

1. A fuel cell gas circulation system, characterized by comprising:

a working fluid source (100), a fuel cell (200), a condenser (300) and an ejector (400), wherein the condenser (300) is communicated with an anode outlet (210) of the fuel cell (200) and can condense part of anode exhaust gas at the anode outlet (210) to generate condensed water, and an outlet of the ejector (400) is communicated with an anode inlet of the fuel cell (200);

the ejector (400) comprises a suction chamber (410), the working fluid source (100), the condenser (300) and the anode outlet (210) are respectively communicated with the suction chamber (410), and the working fluid can be sprayed to the suction chamber (410) so as to eject condensed water in the condenser (300) and the other part of anode exhaust gas of the anode outlet (210) to enter the suction chamber (410).

2. The fuel cell gas circulation system according to claim 1, wherein the suction chamber (410) is provided with a working flow inlet pipe (420), a first injection flow inlet (430) and a second injection flow inlet (440), the working flow inlet pipe (420) being in communication with the working flow source (100), the first injection flow inlet (430) being in communication with the anode outlet (210), the second injection flow inlet (440) being in communication with the condenser (300) outlet.

3. The fuel cell gas circulation system according to claim 2, wherein the ejector (400) further comprises a mixing chamber (450), the mixing chamber (450) being in communication with the suction chamber (410) downstream of the suction chamber (410), the working stream, the condensed water in the second ejector inflow (440) and the anode exhaust in the first ejector inflow (430) being mixable in the mixing chamber (450).

4. A fuel cell gas circulation system according to claim 3, wherein the ejector (400) further comprises a diffuser chamber (460), the diffuser chamber (460) being in communication with the mixing chamber (450) and downstream of the mixing chamber (450), the diffuser chamber (460) having an inner diameter that gradually increases in a direction away from an inlet of the diffuser chamber (460) and toward an outlet of the diffuser chamber (460).

5. A fuel cell gas circulation system according to claim 3, wherein the working flow inlet pipe (420) is inserted in the suction chamber (410), a working flow nozzle (421) is provided at an outlet of the working flow inlet pipe (420), and the working flow is sprayed from the working flow nozzle (421) to the suction chamber (410).

6. The fuel cell gas circulation system according to claim 2, further comprising a heat exchanger (700), the heat exchanger (700) being arranged between the ejector (400) and the working fluid source (100), and the first ejector inflow port (430) being in communication with the heat exchanger (700), the working fluid being capable of heat exchanging and temperature rising in the heat exchanger (700) with the anode exhaust gas to be introduced into the first ejector inflow port (430).

7. The fuel cell gas circulation system according to claim 2, further comprising a regulating valve assembly disposed at the anode outlet (210) capable of regulating the flow rate of anode exhaust gas entering the first ejector flow inlet (430); and, the regulator valve assembly is also capable of regulating the flow of anode exhaust gas into the condenser (300).

8. The fuel cell gas circulation system according to claim 1, further comprising a reformer (500), the reformer (500) being arranged between an anode inlet of the fuel cell (200) and an outlet of the ejector (400) for reforming the mixed working stream, condensed water in the condenser (300) and a part of anode exhaust gas of the anode outlet (210) to produce hydrogen.

9. The fuel cell gas circulation system according to claim 1, further comprising a gas-liquid separator (600), the gas-liquid separator (600) being disposed between the condenser (300) and the ejector (400), the gas-liquid separator (600) being configured to separate the condensed water and the anode gas discharged from an outlet of the condenser (300).

10. The fuel cell gas circulation system according to any one of claims 1 to 9, further comprising a workflow adjustment valve (830), the workflow adjustment valve (830) being arranged between the suction chamber (410) and the workflow source (100) capable of adjusting the flow of workflow into the suction chamber (410).