Cathode tail gas water-ice separation device for fuel cell

Abstract

The invention provides a water-ice separation device for cathode tail exhaust for a fuel cell, which comprises a device body, the device body is provided with an inner cavity, the inner cavity is provided with a cathode tail exhaust mixed gas inlet and a mixed gas outlet at two opposite sides of the device body respectively, and the inner cavity is provided with a water / ice outlet at the bottom of the device body; the inner cavity is provided with a spiral separation rotating rod which extends from the cathode tail gas mixed gas inlet to the mixed gas outlet, and the spiral separation rotating rod is provided with a spiral separation blocking piece. Water and / or ice in the cathode tail gas are / is better separated by arranging multi-stage rotational flow, the water and / or ice in the cathode tail gas under the gravity action and the centrifugal action are / is collected and separated by arranging a scattering control filter screen and a flow accumulation filter screen, only gas enters the expansion machine, blades of a rotational flow turbine of the expansion machine are not impacted by the water and / or the ice, and the water and / or the ice in the cathode tail gas are / is separated. The efficiency of the expander is increased and power consumption is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of fuel cells, and in particular to a cathode tail exhaust water-ice separation device for a fuel cell. Background Art

[0002] A fuel cell is a device that converts chemical energy into electrical energy. It has the advantages of high efficiency and low emissions and is widely used in many fields such as automobiles, aviation, and portable power sources. In a fuel cell system, especially a proton exchange membrane fuel cell (PEMFC), hydrogen is decomposed into electrons and protons at the anode. The protons pass through the proton exchange membrane to the cathode and react with oxygen to form water. This water usually appears in the form of water vapor and liquid water and is discharged in the cathode tail gas.

[0003] If the water vapor and liquid water in the tail gas are not effectively treated, it will cause a variety of problems. For example, water will condense in the fuel cell exhaust system, affecting system efficiency, increasing maintenance difficulties, and may even cause early failure of the system. Therefore, a gas-water separator is often used to separate the gas and water from the cathode reaction mixed gas, supply the separated water to the humidification device, and discharge the separated gas.

[0004] The patent with the authorization announcement number CN219186189U discloses a gas-water separator for a fuel cell, including: a shell, one end of which is provided with an air inlet and the other end is provided with an air outlet; and a plurality of partitions arranged in the shell. The application separates liquid water by multiple baffles, and sets drainage grooves on the partitions to quickly drain the separated liquid water, thereby reducing the liquid water carried away by the gas, improving the gas-water separation efficiency, and being able to meet the needs of gas-water separation for the continuous recycling of reaction gas during the normal operation of the fuel cell system; the interior adopts a pure partition separation method, and the partitions are staggered at a low height, so that the volume of the gas-water separator is reduced, which can save space and the total height of the system when the fuel cell system is arranged.

[0005] The patent with authorization announcement number CN218687300U discloses a steam-water separation device and a fuel cell system. The steam-water separation device includes a shell provided with an air inlet and an air outlet, a first partition and a separator assembly. The separator assembly is formed by adopting a first separator and a second separator. The airflow enters the interior of the shell through the air inlet, and after the first steam-water separation is performed in the first separator, it enters the second separator for the second steam-water separation, and the airflow after the steam-water separation is output to improve the steam-water separation effect.

[0006] In order to increase the efficiency of the system and reduce the parasitic power consumption of the system, the existing high-power fuel cell system is matched with an expander on the system. The mixed gas coming out of the fuel cell stack is connected to the expander cyclone gas inlet interface, which drives the expander worm to rotate and improve the efficiency of the expander. However, the water in the mixed gas (ice will be produced under low temperature conditions) will collide with the expander turbine blades, causing damage to the turbine blades and reducing the performance of the expander. Therefore, there is an urgent need for a new type of cathode tail exhaust water-ice separation device that can more efficiently separate gas, water and ice from the fuel cell tail gas, improve the output efficiency of the expander, and ensure the stable operation of the fuel cell under various environments. Summary of the invention

[0007] In order to solve the above problems, the present application provides a cathode tail exhaust water-ice separation device for a fuel cell.

[0008] The present application provides a cathode tail exhaust water-ice separation device for a fuel cell, comprising a device body, the device body having an inner cavity, the inner cavity being provided with a cathode tail exhaust mixed gas inlet and a mixed gas outlet on opposite sides of the device body, respectively, and the inner cavity being provided with a drain / ice outlet at the bottom of the device body; the inner cavity being provided with a spiral separation device, the spiral separation device comprising a spiral separation rotary rod extending from the cathode tail exhaust mixed gas inlet to the mixed gas outlet, and the spiral separation rotary rod being provided with a spiral separation baffle.

[0009] The spiral separation baffle will rotate together with the spiral separation rotating rod under the push of the cathode tail exhaust mixed gas entering the device, thereby forming centrifugal force on the attachments on the surface of the spiral separation baffle. When the cathode tail exhaust gas flows forward and contacts the spiral separation baffle, the water and / or ice (indicating three situations: only water, only ice, and both water and ice) in the cathode tail exhaust gas will collide and adhere to the spiral separation baffle and the spiral separation rotating rod, and disperse to the surroundings under the action of centrifugal force. In other words, the main function of the spiral separation baffle is that the gas from the cathode tail exhaust will cause the spiral separation baffle and the spiral separation rotating rod to rotate at high speed, forming centrifugal force, and achieving the effect of gas-water separation.

[0010] Furthermore, the outer ring of the spiral separation baffle is also spaced apart with spiral separation comb teeth. The function of the spiral separation comb teeth is to separate gas, water and ice, because the ice coming from the cathode tail discharge will first collide with the spiral separation baffle after entering the device, and then spread to the surroundings, and when it reaches the position of the spiral separation comb teeth, the spiral separation comb teeth will block the ice; the function of the spiral separation comb teeth is also to reduce the flow resistance of the gas and ensure the gas pressure at the outlet of the mixed gas (that is, the gas pressure at the inlet of the expander). The spiral separation comb teeth can increase the attachment area of ​​water in the cathode tail discharge gas, thereby improving the gas-water-ice separation efficiency. The interval between adjacent spiral separation comb teeth can reduce the loss of cathode tail discharge gas pressure, and ensure that the pressure difference between the front and rear ends of the device is within the allowable range.

[0011] Furthermore, the inner cavity of the device body is divided into a first separation zone located at the top and a second separation zone located at the bottom, the spiral separation device is arranged in the first separation zone, the cathode tail exhaust mixed gas inlet and the mixed gas outlet are arranged at two ends of the first separation zone respectively; a dispersion control filter is arranged between the first separation zone and the second separation zone, and the dispersion control filter is provided with a first filter hole. The dispersion control filter collects water and / or ice that jumps around after impacting the spiral separation baffle and the spiral separation comb teeth, and then flows downward through the first filter hole.

[0012] Furthermore, the first separation zone is a shape that gradually increases from one end of the cathode tail exhaust mixed gas inlet to one end of the mixed gas outlet, and the length of the spiral separation baffle extending from the spiral separation rotary rod gradually increases from one end of the cathode tail exhaust mixed gas inlet to one end of the mixed gas outlet to prevent water and / or ice in the cathode tail exhaust gas from entering the mixed gas outlet under the inlet gas pressure; the mixed gas outlet is arranged higher than the cathode tail exhaust mixed gas inlet, and this height difference can make the water and / or ice in the cathode tail exhaust gas separated by the spiral separation baffle and the spiral separation comb teeth, and will not be discharged from the mixed gas outlet due to the action of gravity and centrifugal force. These two structural designs work together to make it more difficult for water and ice in the cathode tail exhaust mixed gas to be discharged from the mixed gas outlet.

[0013] Furthermore, the first separation zone is narrowed at both ends to form the cathode tail exhaust mixed gas inlet and mixed gas outlet, so that a small portion of water and ice is blocked from entering the mixed gas outlet due to the narrowing when it reaches the vicinity of the mixed gas outlet through the airflow. The second separation zone gradually shrinks from top to bottom, and the drain / ice outlet is located at the bottom of the second separation zone. An accumulation flow filter is provided in the middle of the second separation zone, and a second filter hole is provided on the accumulation flow filter. The accumulation flow filter can allow water and / or ice to flow to the drain / ice outlet in time, and can also prevent water and / or ice that has already flowed to the drain / ice outlet from forming backflow during system vibration or turbulence.

[0014] Furthermore, the side walls of the inner cavity are provided with mounting brackets near the cathode tail exhaust mixed gas inlet and the mixed gas outlet, respectively, and both ends of the spiral separation rotary rod are rotatably connected to the mounting brackets at both ends through bearings.

[0015] The present application also provides a fuel cell system, including a fuel cell stack and an expander, wherein the fuel cell stack has an air inlet and an air outlet, and the expander is used to introduce air into the fuel cell stack. The fuel cell system also includes a cathode tail exhaust water-ice separation device for the fuel cell, and the cathode tail exhaust water-ice separation device for the fuel cell passes the remaining mixed gas from the cathode tail exhaust mixed gas of the fuel cell stack after gas-water and / or ice separation into the expander.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] The present invention provides a cathode tail gas water-ice separation device for a fuel cell. The gas from the cathode tail gas causes the spiral separation baffle and the spiral separation rotary rod to rotate at high speed, forming centrifugal force to achieve the effect of gas-water separation. The water and / or ice in the cathode tail gas are better separated by setting a multi-stage swirl. The water and / or ice in the cathode tail gas under gravity and centrifugal action are collected and separated by setting a dispersion control filter and an accumulation flow filter, so that only gas enters the expander, and the blades of the expander swirl turbine are not impacted by water and / or ice, thereby increasing the efficiency of the expander and reducing power consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a front view structural schematic diagram of the cathode tail exhaust water-ice separation device for the fuel cell of the present invention.

[0019] Figure 2 It is a schematic diagram of the top view of the structure of the cathode tail exhaust water-ice separation device for the fuel cell of the present invention.

[0020] Figure 3 for Figure 2 Cross-sectional view along AA direction.

[0021] Figure 4 It is a schematic diagram of the three-dimensional structure of the cathode tail exhaust water-ice separation device for the fuel cell of the present invention.

[0022] Figure 5 It is a structural schematic diagram of the dispersion control filter.

[0023] Figure 6 It is a structural schematic diagram of the spiral separation device.

[0024] Figure 7 It is a schematic diagram of the structure of the accumulation flow filter.

[0025] Figure markings: device body 1, cathode tail exhaust mixed gas inlet 101, mixed gas outlet 102, drain / ice outlet 103, spiral separation rotary rod 104, spiral separation baffle 1041, spiral separation comb teeth 1042, first separation area 105, second separation area 106, dispersion control filter 107, first filter hole 1071, accumulation flow filter 108, second filter hole 1081, mounting bracket 109. DETAILED DESCRIPTION

[0026] like Figure 1-7As shown, the present application provides a cathode tail exhaust water-ice separation device for a fuel cell, wherein the device body 1 has an inner cavity, and the inner cavity is provided with a cathode tail exhaust mixed gas inlet 101 and a mixed gas outlet 102 on opposite sides of the device body 1, respectively, and a drain / ice outlet 103 is provided at the bottom of the device body 1. The inner cavity of the device body 1 is divided into a first separation zone 105 located at the top and a second separation zone 106 located at the bottom. The cathode tail exhaust mixed gas inlet 101 and the mixed gas outlet 102 are respectively provided at the two ends of the first separation zone 105; the drain / ice outlet 103 is located at the bottom of the second separation zone 106.

[0027] like Figure 3 As shown, the first separation zone 105 is provided with a spiral separation device, which includes a spiral separation rotary rod 104 extending from the cathode tail exhaust mixed gas inlet 101 to the mixed gas outlet 102, and a spiral separation baffle 1041 is provided on the spiral separation rotary rod 104. The outer ring of the spiral separation baffle 1041 is also provided with spiral separation comb teeth 1042 at intervals, and the spiral separation comb teeth 1042 can increase the attachment area of ​​water in the cathode tail exhaust gas, thereby improving the gas-water-ice separation efficiency, and the interval between adjacent spiral separation comb teeth 1042 can reduce the loss of cathode tail exhaust gas pressure, ensuring that the pressure difference between the front and rear ends of the device is within the allowable range.

[0028] The first separation zone 105 is a shape that gradually increases from one end of the cathode tail exhaust mixed gas inlet 101 to one end of the mixed gas outlet 102. The length of the spiral separation baffle 1041 extending from the spiral separation rotor 104 gradually increases from one end of the cathode tail exhaust mixed gas inlet 101 to one end of the mixed gas outlet 102 to prevent water and / or ice in the cathode tail exhaust gas from entering the mixed gas outlet 102 under the inlet gas pressure.

[0029] The mixed gas outlet 102 is arranged higher than the cathode tail exhaust mixed gas inlet 101. This height difference can prevent the water and / or ice in the cathode tail exhaust gas from being discharged from the mixed gas outlet 102 due to the effects of gravity and centrifugal force after being separated by the spiral separation baffle 1041 and the spiral separation comb teeth 1042.

[0030] The first separation zone 105 is narrowed at both ends to form a cathode tail exhaust mixed gas inlet 101 and a mixed gas outlet 102, so that a small portion of water and / or ice is blocked from entering the mixed gas outlet 102 due to the narrowing when it passes through the airflow to the vicinity of the mixed gas outlet 102.

[0031] A dispersion control filter 107 is provided between the first separation zone 105 and the second separation zone 106. The dispersion control filter 107 is a sheet structure that semi-surrounds the spiral separation rod 104, the spiral separation baffle 1041, and the spiral separation comb teeth 1042 from below. The dispersion control filter 107 cooperates with the top wall of the first separation zone 105 to roughly form a conical cylinder shape.

[0032] The control filter 107 is provided with a first filter hole 1071, such as Figure 5 As shown, there are a plurality of first filter holes 1071 arranged at intervals along the axial direction, and each first filter hole 1071 is a waist-shaped hole extending circumferentially along the dispersion control filter 107. The dispersion control filter 107 collects water and / or ice that jumps around after impacting the spiral separation baffle 1041 and the spiral separation comb teeth 1042, and then flows downward through the first filter holes 1071.

[0033] The second separation area 106 gradually shrinks from top to bottom, specifically, it can be gradually shrunk from top to bottom along the axial direction of the spiral separation rod 104, so that it can play a convergence role and guide the separated water and / or ice to the bottom drain / ice outlet 103. The middle part of the second separation area 106 is provided with an accumulation filter 108, and the accumulation filter 108 is provided with a second filter hole 1081, such as Figure 7 As shown, the accumulation flow filter 108 is bent to form two parts, one part is a horizontal part located above the drain / ice outlet 103, and the other part is an inclined part, the inclined part is inclined downward to one side of the horizontal part, and plays a guiding role to a certain extent, and the second filter holes 1081 are evenly and densely distributed on the accumulation flow filter 108. The accumulation flow filter 108 can make water and / or ice flow to the drain / ice outlet 103 in time, and can also prevent the water and / or ice that has flowed to the drain / ice outlet 103 from forming backflow during system vibration or bumping.

[0034] The side wall of the inner cavity is provided with mounting brackets 109 near the cathode tail exhaust mixed gas inlet 101 and the mixed gas outlet 102, and the two ends of the spiral separation rotating rod 104 are rotatably connected to the mounting brackets 109 at both ends through bearings (the detailed structure of the bearings is not shown in the figure). Figure 4 and Figure 6 shown.

[0035] The present application also provides a fuel cell system, including a fuel cell stack and an expander, the fuel cell stack having an air inlet and an air outlet, the expander being used to introduce air into the fuel cell stack, the fuel cell system also including a cathode tail exhaust water-ice separation device for the fuel cell, the cathode tail exhaust water-ice separation device for the fuel cell passes the remaining mixed gas from the cathode tail exhaust of the fuel cell stack after gas-water-ice separation into the expander.

[0036] The cathode tail gas from the fuel cell stack enters the cathode tail mixed gas inlet 101 of the gas-water-ice separation device through the silicone tube. After entering the device, the cathode tail gas will first impact the spiral separation baffle 1041 and the spiral separation comb teeth 1042. The cathode tail gas forms a thrust on the spiral separation baffle 1041 to rotate the spiral separation baffle 1041 together with the spiral separation rotary rod 104. At this time, the cathode tail gas contacts the spiral separation baffle 1041 and the spiral separation comb teeth 1042 during the forward flow, and the water in the cathode tail gas will adhere to the spiral separation rotary rod 104, the spiral separation baffle 1041 and the spiral separation comb teeth 1042, and the rotation of the spiral separation rotary rod 104, the spiral separation baffle 1041 and the spiral separation comb teeth 1042 will form a centrifugal force on the water attached thereto. As the pressure of the incoming cathode tail gas increases, the spiral separation rotary rod 104 rotates faster, the centrifugal force is greater, and the gas-water separation capability of the incoming cathode tail gas is stronger.

[0037] Under low temperature conditions, the cathode tail gas from the battery stack will contain ice debris. When the cathode tail gas containing ice debris enters the gas-water-ice separation device, the ice debris first impacts the spiral separation baffle 1041 and jumps around. Under the action of gravity and the centrifugal action of the spiral separation rod 104, the spiral separation baffle 1041 and the spiral separation comb teeth 1042, the ice debris and water will be gathered on the dispersion control filter 107, and flow from the first filter hole 1071 of the dispersion control filter 107 to the accumulation flow filter 108 under the action of gravity. The second filter hole 1081 on the accumulation flow filter 108 allows the ice debris and water to flow out of the drain / ice outlet 103 in time, thereby achieving the gas-water and / or ice separation of the cathode tail gas.

Claims

1. A cathode tail exhaust water-ice separation device for a fuel cell, characterized in that: The device comprises a device body, the device body has an inner cavity, the inner cavity is provided with a cathode tail exhaust mixed gas inlet and a mixed gas outlet on two opposite sides of the device body, and the inner cavity is provided with a drainage / ice outlet at the bottom of the device body; The inner cavity is provided with a spiral separation device, which includes a spiral separation rotary rod extending from the cathode tail exhaust mixed gas inlet to the mixed gas outlet, and a spiral separation baffle is provided on the spiral separation rotary rod.

2. The cathode tail exhaust water-ice separation device for a fuel cell according to claim 1, characterized in that: The outer circle of the spiral separation baffle is provided with spiral separation comb teeth.

3. The cathode tail exhaust water-ice separation device for a fuel cell according to claim 1, characterized in that: The inner cavity of the device body is divided into a first separation zone located at the top and a second separation zone located at the bottom, the spiral separation device is arranged in the first separation zone, and the cathode tail exhaust mixed gas inlet and the mixed gas outlet are respectively arranged at two ends of the first separation zone; A dispersion control filter is provided between the first separation zone and the second separation zone, and a first filter hole is provided on the dispersion control filter.

4. The cathode tail exhaust water-ice separation device for a fuel cell according to claim 3, characterized in that: The first separation zone is a shape that gradually increases from one end of the cathode tail exhaust mixed gas inlet to one end of the mixed gas outlet, and the length of the spiral separation baffle extending from the spiral separation rotor gradually increases from one end of the cathode tail exhaust mixed gas inlet to one end of the mixed gas outlet.

5. The cathode tail exhaust water-ice separation device for a fuel cell according to claim 3, characterized in that: The first separation zone is narrowed at both ends to form the cathode tail exhaust mixed gas inlet and the mixed gas outlet.

6. The cathode tail exhaust water-ice separation device for fuel cells according to claim 3, characterized in that: The height of the mixed gas outlet is higher than the height of the cathode tail exhaust mixed gas inlet.

7. The cathode tail exhaust water-ice separation device for a fuel cell according to claim 3, characterized in that: The second separation zone is gradually reduced in size from top to bottom, the drainage / ice outlet is located at the bottom of the second separation zone, an accumulation filter screen is provided in the middle of the second separation zone, and a second filter hole is provided on the accumulation filter screen.

8. The cathode tail exhaust water-ice separation device for a fuel cell according to claim 1, characterized in that: The side walls of the inner cavity are provided with mounting brackets near the cathode tail exhaust mixed gas inlet and the mixed gas outlet, respectively. The two ends of the spiral separation rotating rod are rotatably connected to the mounting brackets at both ends through bearings.

9. A fuel cell system, comprising a fuel cell stack and an expander, wherein the fuel cell stack has an air inlet and an air outlet, and the expander is used to introduce air into the fuel cell stack, characterized in that: The fuel cell system also includes the fuel cell cathode tail exhaust water-ice separation device as described in any one of claims 1 to 8, and the fuel cell cathode tail exhaust water-ice separation device passes the remaining mixed gas after gas-water-ice separation of the cathode tail exhaust gas from the fuel cell stack into the expander.

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