Gas-water separator for fuel cell expansion machine and fuel cell system

Abstract

The utility model discloses a gas-water separator for a fuel cell expansion machine and a fuel cell system, and the gas-water separator comprises a gas-water separator body which is provided with an inner cavity; the gas-water separator body is provided with an inlet used for being connected with a stack air exhaust port, an exhaust port used for discharging separated air to an expansion machine, and a water outlet used for discharging water, and is characterized in that the inlet is formed in the upper part of the side surface of the gas-water separator body; the part, connected with the inlet, of the inner cavity is provided with a flow guide area in an involute mode. According to the gas-water separator disclosed by the utility model, the structure of the part, connected with the inlet, of the inner cavity is designed into the flow guide area in an involute form, so that gas introduced into the gas-water separator at a high speed rotates, centrifugal force is generated, and the gas-water separation effect is achieved. Gas rotation is ensured under the condition that energy consumption is not increased, and the gas-water separation effect is improved. Meanwhile, the structural design of the inner cavity of the gas-water separator is simple, complex structural design is not needed, and the manufacturing difficulty is relatively low.

Description

Technical Field

[0001] The utility model belongs to the technical field of fuel cells, and particularly relates to a gas-water separator for a fuel cell expander and a fuel cell system. Background Art

[0002] In a fuel cell system, the stack has a hydrogen end and an air end. There is still a large amount of hydrogen in the anode tail gas mixture at the hydrogen end. Therefore, generally, hydrogen is separated and then recycled into the stack. The cathode tail gas mixture at the air end is mainly air after part of the oxygen is consumed, and the components themselves have little recycling value. Therefore, it is generally directly discharged into the atmosphere. However, the exhaust gas discharged from the tail pipe at the air end contains heat energy and kinetic energy. At present, some technologies have begun to recycle the cathode exhaust gas, but a large amount of water and impurities in the exhaust gas prevent the normal recovery of energy.

[0003] For example, the invention application with the publication number of CN118336023A discloses a hydrogen fuel cell air supply system with an exhaust gas energy recovery structure. The air flow meter is connected to the expander through an air flow meter connection pipe; the expander outlet is connected to the air intercooler inlet through an expander outlet pipe; the air intercooler outlet is connected to the air humidifier inlet through an intercooler outlet joint; the air main throttle is installed at the right outlet of the air humidifier; the bypass throttle is installed at the left outlet of the air humidifier through a bypass throttle adapter. In this prior art, the internal structure of the gas-water separator itself is not improved.

[0004] For another example, the invention application with the publication number of CN115463482A discloses a gas-water separator for a fuel cell, including a housing. The housing is sequentially communicated with a gas-water inlet, a shunt chamber, a shunt device, and an air outlet along the flow direction. At least two identical water separation devices are arranged in the shunt chamber. The end of each water separation device along the flow direction is communicated with the shunt device, and the end of the shunt device along the flow direction is communicated with the air outlet to weaken the impact of the fluid at the gas-water inlet; this design increases or decreases the number of cavity parts to match the usage scenarios of different flow conditions, and is applicable to high and low power conditions, thereby avoiding the limitation of the gas-water separation effect of a single-structured gas-water separator and the reduction of the service life of the downstream expander. In this prior art, the gas-liquid separation efficiency is increased by improving the internal structure of the gas-water separator, but the structure in the internal cavity of the gas-water separator is too complex, increasing the manufacturing difficulty and cost. Summary of the Utility Model

[0005] In view of the above deficiencies in the prior art, the utility model provides a gas-water separator for a fuel cell expander and a fuel cell system.

[0006] The present utility model first provides a gas-water separator for a fuel cell expander, which includes a gas-water separator body. The gas-water separator body has an inner cavity, and the gas-water separator body has an inlet for connecting to the air exhaust port of the fuel cell stack, an exhaust port for discharging the separated air to the expander, and a drain port for draining water. The inlet is provided at the upper part of the side surface of the gas-water separator body, and the inner cavity has an involute-shaped diversion area at the part connecting the inlet.

[0007] Preferably, the gas-water separator body includes an upper shell and a lower shell. The inlet is located at the upper part of the side surface of the upper shell, the exhaust port is located on the top surface of the upper shell, and the drain port is located on the bottom surface of the lower shell. Designing the gas-water separator body as a structure assembled by the upper shell and the lower shell makes the preparation of the upper shell and the lower shell relatively simple. The two parts of the upper shell and the lower shell can be fixed by bolts, and the installation and disassembly are relatively convenient, allowing for customized design with high flexibility.

[0008] More preferably, a connector is provided at the inlet. The connector is fixed to the upper shell by bolts, and the outer end of the connector is used to connect to the air exhaust port of the fuel cell stack.

[0009] More preferably, the main body of the inner cavity is cylindrical, and the upper side wall of the inner cavity at the upper shell forms the involute-shaped diversion area by expanding outward; the inlet end of the diversion area extends outward to form a diversion channel protruding from the side wall of the inner cavity, and the inlet is provided at the end of the diversion channel.

[0010] Preferably, a filter screen for filtering the discharged air is provided at the exhaust port. More preferably, the diameter of the filter holes in the filter screen is 0.05 - 0.2 mm. Most preferably, the diameter of the filter holes in the filter screen is 0.1 mm. By filtering the exhaust port and adding a filter screen, impurities and ice slag can be effectively prevented from entering the expander, improving the service life of the expander, and the system can reduce the use of a back pressure valve. The diameter of the filter screen is relatively small, with a large flow resistance, which can filter ice slag and impurities. At low temperatures, if there is no filter screen, there will be ice slag inside the water. At this time, a back pressure valve (throttle valve) needs to be added at the back end of the water to break the ice. With the filter screen, the ice slag cannot enter the expander, and thus there is no need to add a back pressure valve (throttle valve).

[0011] Preferably, a drain valve is provided at the drain port. More preferably, the drain valve is a heating drain valve with a heating function. The drain valve is used to open and drain the water after a certain amount of separated water has accumulated. Adding a heating function is for use at low temperatures, which can effectively prevent ice formation inside the cavity at low temperatures.

[0012] Preferably, an exhaust pipe extends inwardly at the exhaust port. The bottom surface of the exhaust pipe has a gas inlet, and the gas inlet extends below the diversion area. By extending the gas inlet on the bottom surface of the exhaust pipe below the diversion area, the gas entering the inner cavity of the gas-liquid separator body needs to first undergo gas-liquid separation in the diversion area before the gas can reach the gas inlet and be discharged from the inner cavity of the gas-liquid separator body through the exhaust pipe from the exhaust port, avoiding the discharge of unseparated gas from the exhaust port.

[0013] More preferably, the exhaust port is located in the middle area at the top of the gas-liquid separator body. More preferably, the gas inlet has a flared shape with an inner diameter gradually increasing from top to bottom. The design of the flared shape can effectively increase the air intake and improve the recovery efficiency.

[0014] The present invention also provides a fuel cell system, including a fuel cell stack. The fuel cell stack has an air inlet and an air tail exhaust port. The air inlet has an air inlet pipeline, and an expander is provided on the air inlet pipeline. The expander has a compression end and an expansion end, and the impellers at the compression end and the expansion end are coaxially arranged. The fuel cell system also includes the gas-liquid separator. The inlet of the gas-liquid separator is connected to the air tail exhaust port, and the exhaust port of the gas-liquid separator is connected to the expansion end of the expander.

[0015] In the gas-liquid separator of the present invention, by specially designing the structure at the part where the inner cavity connects the inlet, it is designed as a diversion area with an involute form, allowing the gas flowing into the gas-liquid separator at high speed to rotate and generate centrifugal force to achieve the effect of gas-liquid separation. Ensure gas rotation without increasing energy consumption and improve the gas-liquid separation effect. At the same time, the structure design of the inner cavity of the gas-liquid separator is simple, without the need for complex structure design, and the manufacturing difficulty is relatively low. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a three-dimensional structural schematic diagram of the gas-liquid separator of the present invention.

[0017] Figure 2 is a three-dimensional structural schematic diagram of the lower housing.

[0018] Figure 3 is a side view structural schematic diagram of the upper housing.

[0019] Figure 4 is Figure 3 a cross-sectional view taken along the A-A direction in

[0020] Figure 5 is Figure 3 a cross-sectional view taken along the B-B direction in

[0021] Figure 6Schematic top view of the upper housing after removing the connector at the inlet.

[0022] Figure 7 Schematic structural diagram of the fuel cell system of the present utility model.

[0023] Reference numerals:

[0024] Gas-water separator 1, inner cavity 101, upper housing 102, lower housing 103, inlet 104, exhaust port 105, drain port 106, diversion area 107, diversion channel 108, connector 109, filter screen 110, drain valve 111, exhaust pipe 112, gas inlet 113

[0025] Stack 2, expander 3, air filter 4, flow meter 5, intercooler 6, humidifier 7, pressure sensor 8, temperature sensor 9, switching valve 10, silencer 11. Detailed implementation manners

[0026] As Figures 1 to 6 shown, a gas-water separator 1 for a fuel cell expander includes a gas-water separator body. The gas-water separator body has an inner cavity 101, and the gas-water separator body has an inlet 104 for connecting to the air tail discharge port of the stack, an exhaust port 105 for discharging the separated air to the expander, and a drain port 106 for draining water. The inlet 104 is provided at the upper side of the gas-water separator body, and the inner cavity 101 has an involute-shaped diversion area 107 at the part connecting to the inlet 104.

[0027] The gas-water separator body includes an upper housing 102 and a lower housing 103. The inlet 104 is located at the upper side of the upper housing 102, the exhaust port 105 is located on the top surface of the upper housing 102, and the drain port 106 is located on the bottom surface of the lower housing 103. The gas-water separator body is designed as a structure assembled by the upper housing 102 and the lower housing 103, so that the preparation of the upper housing 102 and the lower housing 103 is relatively simple. The upper housing 102 and the lower housing 103 can be fixed by bolts, and the installation and disassembly are both relatively convenient, allowing for customized design with high flexibility.

[0028] A connector 109 is provided at the inlet 104. The connector 109 is fixed to the upper housing 102 by bolts, and the outer end of the connector 109 is used to connect to the air tail discharge port of the stack. The outer end of the connector 109 is a plug-in connection structure, which is directly plugged and connected to the air tail discharge port of the stack, and the installation and disassembly are both relatively convenient.

[0029] The main body of the inner cavity 101 is cylindrical, and the upper side wall of the inner cavity at the upper shell 102 forms a diversion area 107 with an involute form by expanding outwards. The inlet end of the diversion area 107 extends outwards to form a diversion channel 108 protruding from the side wall of the inner cavity, and the inlet 104 is arranged at the end of the diversion channel 108. The diversion area 107 is arranged horizontally around the inner cavity 101, and the degree of outward expansion of the diversion area 107 gradually decreases from one end of the diversion channel 108 to the other end until it is smoothly connected to the cylindrical part of the inner cavity 102. The total area spanned by the diversion area 107 can be adjusted according to actual needs. Figure 4 As can be seen from the structure shown in Figure 4 , the diversion area 107 approximately spans half of the cross-section of the inner cavity 101.

[0030] The cathode tail gas mixture coming out of the air tail exhaust port of the stack enters the diversion channel 108 through the inlet 104, and then enters the diversion area 107. Under the diversion of the diversion area 107, the gas rotates, and the high-speed rotating gas generates centrifugal force. At this time, the water carried in the gas is thrown to the inner wall of the inner cavity 101 of the gas-water separator body and flows along the inner wall to the bottom of the inner cavity 101, that is, the inner bottom surface of the lower shell 103, and then is discharged from the drain port 106.

[0031] The drain port 106 is arranged on one side of the bottom surface of the inner cavity 101, and the bottom surface of the inner cavity 101 is inclined towards the position where the drain port 106 is located, which is convenient for the separated water to be diverted to the drain port 106 for discharge. A drain valve 111 is arranged at the drain port 106. The drain valve 111 is preferably a heated drain valve with a heating function. The drain valve 111 is used to open to discharge water after a certain amount of separated water accumulates. The heating function is added for use at low temperatures, which can effectively prevent icing in the cavity at low temperatures.

[0032] The exhaust port 105 is provided with a filter net 110 for filtering the discharged air. The diameter of the filter holes in the filter net 110 is 0.05 - 0.2 mm. By filtering the exhaust port 105 and adding the filter net 110, impurities and ice slag can be effectively prevented from entering the expander, the life of the expander can be improved, and one back pressure valve can be reduced in the system.

[0033] The exhaust port 105 has an exhaust pipe 112 extending inwards, and the bottom surface of the exhaust pipe 112 has a gas inlet 113, and the gas inlet 113 extends into the lower part of the diversion area 107. By extending the gas inlet 113 on the bottom surface of the exhaust pipe 112 into the lower part of the diversion area 107, the gas entering the inner cavity 101 of the gas-water separator body needs to pass through the gas-liquid separation of the diversion area 107 before the gas can reach the gas inlet 113 and be discharged from the inner cavity 101 of the gas-water separator body through the exhaust pipe 112 from the exhaust port 105, avoiding the discharge of unseparated gas from the exhaust port 105.

[0034] The exhaust port 105 is located in the middle area at the top of the gas-water separator body, so that the exhaust pipe 112 is also located in the middle area. The exhaust pipe 112 is equivalent to being arranged on the central axis of the inner cavity 101. Since the water is rotated and thrown towards the side wall of the inner cavity 101 during gas-water separation, the gas at the center of the inner cavity 101 is the separated gas with less moisture, and then enters the exhaust pipe 112. The gas inlet 113 of the exhaust pipe 112 needs to have a certain distance from the bottom surface of the inner cavity 101 to leave a space for water accumulation at the bottom of the inner cavity 101.

[0035] The gas inlet 113 is in the shape of a flared opening with an inner diameter gradually increasing from top to bottom. The design of the flared opening shape can effectively increase the air intake and improve the recovery efficiency.

[0036] During installation, the gas-water separator 1 is directly plugged and connected to the air tail exhaust port of the fuel cell stack through the outer end of the connector 109. During use, the cathode tail exhaust mixture coming out of the air tail exhaust port of the fuel cell stack enters the diversion channel 108 through the inlet 104, and then enters the diversion area 107. Under the diversion of the diversion area 107, the gas rotates, and the high-speed rotating gas generates centrifugal force. At this time, the water carried in the gas is thrown onto the inner wall of the inner cavity 101 of the gas-water separator body and flows along the inner wall to the bottom of the inner cavity 101, that is, the inner bottom surface of the lower housing 103, and then is discharged from the drain port 106. Regular drainage is realized by regularly opening the drain valve 111; while the separated gas enters the exhaust pipe 112 from the gas inlet 113 and is filtered by the filter net 110, and then is discharged from the exhaust port 105 from the inner cavity 101 of the gas-water separator body. The gas discharged from the exhaust port 105 enters the expander.

[0037] As Figure 7 shown, a fuel cell system includes a fuel cell stack 2. The fuel cell stack 2 has an air inlet and an air tail exhaust port. The air inlet has an air inlet pipeline, and an expander 3 is provided on the air inlet pipeline. The expander 3 has a compression end and an expansion end, and the impellers of the compression end and the expansion end are coaxially arranged.

[0038] The fuel cell system further includes a gas-water separator 1. The inlet 104 of the gas-water separator 1 is connected to the air tail exhaust port of the fuel cell stack 2, and the exhaust port 105 of the gas-water separator 1 is connected to the expansion end of the expander 3.

[0039] An air filter 4 and a flow meter 5 are successively provided upstream of the air inlet pipeline. The air enters the expander 3 after being filtered by the air filter 4, and the flow meter 5 measures the flow rate of the passing air. A pressure sensor 8 and a temperature sensor 9 are further provided upstream of the air filter 4. The pressure sensor 8 is used to detect the intake pressure, and the temperature sensor 9 is used to detect the temperature.

[0040] The air coming out of the expander 3 is humidified by the humidifier 7 after passing through the intercooler 6, and then enters the fuel cell stack 2 through the air inlet. The exhaust gas coming out of the air exhaust port of the fuel cell stack 2 first passes through the humidifier 7 for humidifying the air entering the fuel cell stack 2, and then the exhaust gas enters the gas-water separator 1. A switching valve 10 and a temperature sensor 9 are also provided on a section of the air inlet pipeline between the humidifier 7 and the fuel cell stack 2. A switching valve 10 is also provided on a section of the air exhaust pipeline between the humidifier 7 and the gas-water separator 1.

[0041] The fuel cell system further includes a muffler 11. A branch pipe connecting the muffler 11 is provided in the air inlet pipeline between the intercooler 6 and the humidifier 7. A switching valve 10 is provided on the branch pipe. By opening and closing the switching valve 10, the air flow rate entering the fuel cell stack 2 can be controlled. The exhaust gas coming out of the air exhaust port of the fuel cell stack 2 is separated from moisture by the gas-water separator 1 and then introduced into the expander 3, and then exhausted to the muffler 11.

[0042] Fresh air sequentially passes through the air filter 4, the flow meter 5, the compression end of the expander 3, the intercooler 6, the humidifier 7, the throttle valve 10 and reaches the fuel cell stack 2. The high-temperature exhaust air coming out of the air exhaust port of the fuel cell stack 2 enters the gas-water separator 1. The air after separating the moisture in the exhaust air enters the expansion end of the expander 3 from the exhaust port 105 and drives the impeller of the expansion end to rotate. The rotation of the impeller of the expansion end drives the impeller of the compression end arranged coaxially to rotate, reducing the motor power in the expander 3 and realizing the recovery of the energy of the exhaust air.

Claims

1. A gas-water separator for a fuel cell expander, comprising a gas-water separator body. The gas-water separator body has an inner cavity, and the gas-water separator body has an inlet for connecting to the air exhaust port of the fuel cell stack, an exhaust port for discharging the separated air to the expander, and a drain port for draining water. It is characterized in that, The inlet is provided at the upper side of the gas-water separator body, and the inner cavity has a diversion area in the form of an involute at the part connecting the inlet.

2. The gas-water separator for a fuel cell expander according to claim 1, characterized in that, The gas-water separator body includes an upper shell and a lower shell. The inlet is located at the upper side of the upper shell, the exhaust port is located at the top surface of the upper shell, and the drain port is located at the bottom surface of the lower shell.

3. The gas-water separator for a fuel cell expander according to claim 2, wherein, A connector is provided at the inlet, and the connector is fixed to the upper shell by bolts. The outer end of the connector is used to connect the air tail exhaust port of the fuel cell stack.

4. The gas-water separator for a fuel cell expander according to claim 2, wherein The main body of the inner cavity is cylindrical, and the upper side wall of the inner cavity at the upper shell forms the diversion area in the form of an involute by expanding outwards; the inlet end of the diversion area extends outwards to form a diversion channel protruding from the side wall of the inner cavity, and the inlet is provided at the end of the diversion channel.

5. The gas-water separator for a fuel cell expander according to claim 1, wherein A filter screen for filtering the discharged air is provided at the exhaust port.

6. The gas-water separator for a fuel cell expander according to claim 5, characterized in that, The diameter of the filter holes in the filter screen is 0.05 - 0.2 mm.

7. The gas-water separator for a fuel cell expander according to claim 1, wherein, A drain valve is provided at the drain port; the drain valve is a heated drain valve with a heating function.

8. The gas-water separator for a fuel cell expander according to claim 1, characterized in that The exhaust port has an exhaust pipe extending inwards, and the bottom surface of the exhaust pipe has a gas inlet, and the gas inlet extends into the lower part of the diversion area.

9. A fuel cell system includes a stack, the stack having an air inlet and an air exhaust port. The air inlet has an air inlet pipeline, and an expander is provided on the air inlet pipeline. The expander has a compression end and an expansion end, and the impellers of the compression end and the expansion end are coaxially arranged. It is characterized in that, The fuel cell system further includes the gas-water separator according to any one of claims 1 - 8. The inlet of the gas-water separator is connected to the air tail exhaust port, and the exhaust port of the gas-water separator is connected to the expansion end of the expander.

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