Electric pile waterway drainage structure for fuel cell electric pile test bench
By introducing a nitrogen source and sensor monitoring piping system into the fuel cell stack test bench, the problem of residual cooling water in the stack water circuit was solved, achieving efficient and thorough drainage and improving the performance and lifespan of the stack.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- CHINA AUTOMOTIVE IND INST (JIANGSU) NEW ENERGY TECH CO LTD
- Filing Date
- 2025-05-30
- Publication Date
- 2026-05-15
AI Technical Summary
In existing fuel cell stack testing, incomplete drainage can easily leave residual cooling water, leading to corrosion, icing expansion, and increased conductivity, which affects stack performance and lifespan. Furthermore, traditional drainage operations are cumbersome and difficult to monitor and manage.
The pipeline system, consisting of a nitrogen source, water tank, centrifugal pump, heater, sensors, and solenoid valves, achieves efficient and thorough drainage of the fuel cell stack water circuit through nitrogen purging and deionized water circulation, combined with temperature, pressure, and dew point sensor monitoring.
It achieves complete drainage of cooling water, prevents corrosion and icing expansion, ensures stack performance and lifespan, simplifies operation procedures, and improves drainage efficiency and quality.
Smart Images
Figure CN224248618U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to a fuel cell stack testing method, and more particularly to a fuel cell stack water drainage structure for a fuel cell stack test bench. Background Technology
[0002] Currently, fuel cells are devices that directly convert the chemical energy of fuel and oxidant into electrical energy through an electrochemical reaction. They offer advantages such as high energy conversion efficiency, cleanliness, and low noise, with the main byproduct being water and virtually no pollutants. Fuel cells are widely used in new energy vehicles, distributed power generation, and backup power supplies, and are one of the key technologies for achieving low-carbon energy transition and sustainable development.
[0003] After the fuel cell stack is tested offline, the stack's water circuit needs to be drained. Existing drainage methods mostly use conventional gravity drainage or simple manual purging. While these methods are feasible, they have many drawbacks:
[0004] 1. Incomplete drainage can leave some cooling water in the fuel cell stack's water circuit. This residual cooling water can cause various problems during subsequent fuel cell stack maintenance, transportation, and reinstallation, such as corrosion of metal parts within the system, freezing and expansion at low temperatures leading to structural damage, and increased conductivity due to prolonged storage of deionized water, all of which affect fuel cell stack performance and lifespan.
[0005] 2. Traditional drainage operations are cumbersome, time-consuming, and labor-intensive, and it is difficult to effectively monitor and manage the drainage process, which cannot ensure the quality and efficiency of the drainage work and poses potential risks to the subsequent use of the fuel cell stack. Utility Model Content
[0006] The purpose of this invention is to provide a fuel cell stack water circuit drainage structure for a fuel cell stack test bench that can efficiently, thoroughly and conveniently drain the cooling water in the fuel cell stack water circuit.
[0007] The purpose of this utility model is achieved through the following technical solution: a fuel cell stack water drainage structure for a fuel cell stack test bench, comprising a nitrogen source, a water tank with an inlet and an outlet, and a fuel cell stack with a cooling water inlet and a cooling water outlet. The outlet is connected to the cooling water inlet via pipe A, and the inlet is connected to the cooling water outlet via pipe B. A centrifugal pump A, a heater, and a three-way valve A are sequentially arranged on pipe A. The nitrogen source is connected to the three-way valve A via pipe C.
[0008] Furthermore, on the pipeline A, between the three-way valve A and the cooling water inlet, a temperature sensor A, a pressure sensor A, and a conductivity sensor are sequentially installed; on the pipeline B, between the inlet and the cooling water outlet, a back pressure valve, a pressure sensor B, a dew point sensor, and a temperature sensor B are sequentially installed.
[0009] Further description: A three-way valve B is installed on pipe B between temperature sensor B and cooling water outlet; a three-way valve C is installed on pipe A between conductivity sensor and cooling water inlet; a centrifugal pump B is installed between pipe A and pipe B; the centrifugal pump B is connected to both three-way valve B and three-way valve C.
[0010] To facilitate drainage, a three-way valve D is installed on the pipe B between the inlet and the back pressure valve. The three-way valve D is connected to the external drain outlet A.
[0011] To control the water intake, an inlet pipe is installed on the upper part of the water tank. The inlet pipe is connected to an external deionized water source, and a solenoid valve A is installed on the inlet pipe.
[0012] To control drainage, a water outlet pipe is provided at the outlet, which is connected to an external drain outlet B, and a solenoid valve B is installed on the water outlet pipe.
[0013] To control the entry of nitrogen gas, a solenoid valve C is installed on the pipeline C.
[0014] To facilitate venting, an venting valve is installed on the top of the water tank.
[0015] Due to the adoption of the above technical solution, this utility model has the advantages of convenient operation and reliable use. It can efficiently, thoroughly and conveniently drain the cooling water in the fuel cell stack water circuit, making the cooling water drain more thoroughly. This not only prevents the cooling water from corroding the metal parts in the system, but also prevents the fuel cell stack structure from being damaged by the expansion of the cooling water when it freezes at low temperatures, as well as prevents the increase in conductivity caused by long-term storage of deionized water, which would affect the performance and lifespan of the fuel cell stack. Attached Figure Description
[0016] The accompanying drawings of this utility model are described below:
[0017] Figure 1 This is a schematic diagram of the structure of this utility model. Detailed Implementation
[0018] The specific embodiments of this utility model will be further described in detail below with reference to the accompanying drawings. However, this utility model is not limited to these embodiments. Any improvements or substitutions based on the basic spirit of these embodiments shall still fall within the scope of protection claimed by the claims of this utility model.
[0019] Example 1: As Figure 1 As shown, a fuel cell stack water drainage structure for a fuel cell stack test bench includes a nitrogen source 1, a water tank 2 with an inlet and an outlet, and a fuel cell stack 5 with a cooling water inlet 3 and a cooling water outlet 4. The outlet is connected to the cooling water inlet 3 via a pipe A6, and the inlet is connected to the cooling water outlet 4 via a pipe B7. A centrifugal pump A8, a heater 9, and a three-way valve A10 are sequentially arranged on the pipe A6. The nitrogen source 1 is connected to the three-way valve A10 via a pipe C11.
[0020] Specifically, a temperature sensor A12, a pressure sensor A13, and a conductivity sensor 14 are sequentially installed on the pipe A6 between the three-way valve A10 and the cooling water inlet 3; a back pressure valve 15, a pressure sensor B16, a dew point sensor 17, and a temperature sensor B18 are sequentially installed on the pipe B7 between the inlet and the cooling water outlet 4.
[0021] Furthermore, a three-way valve B19 is installed on the pipe B7 between the temperature sensor B18 and the cooling water outlet 4; a three-way valve C20 is installed on the pipe A6 between the conductivity sensor 14 and the cooling water inlet 3; a centrifugal pump B21 is installed between the pipe A6 and the pipe B7; the centrifugal pump B21 is connected to the three-way valves B19 and C20 respectively.
[0022] To facilitate drainage, a three-way valve D22 is installed on the pipe B7 between the inlet and the back pressure valve 15. The three-way valve D22 is connected to the external drain port A23.
[0023] In order to control the replenishment of deionized water, an inlet pipe 24 is provided on the upper part of the water tank 2. The inlet pipe 24 is connected to the external deionized water source 25, and a solenoid valve A26 is provided on the inlet pipe 24.
[0024] To facilitate drainage control, a water outlet pipe 27 is provided at the outlet, which is connected to an external drain outlet B28. A solenoid valve B29 is provided on the water outlet pipe 27.
[0025] To control the entry of nitrogen gas, a solenoid valve C30 is installed on the pipeline C11.
[0026] To facilitate venting, an venting valve 31 is provided on the top of the water tank 2.
[0027] This invention works as follows:
[0028] Large cycle test of fuel cell stack
[0029] Step 1. Piping Control
[0030] In this configuration, the piping control during the large-cycle test of the fuel cell stack is as follows: Three-way valve A10 establishes a connection between heater 9 and temperature sensor A12, while ensuring that the nitrogen source 1 end-side piping is closed. Three-way valve B19 connects the cooling water outlet 4 of fuel cell stack 5 to the temperature sensor B18 side piping, and closes the centrifugal pump B21 side piping; three-way valve C20 connects the cooling water inlet 3 of fuel cell stack 5 to the pressure sensor A13 side piping, and closes the centrifugal pump B21 side piping.
[0031] Step 2. Cooling water circulation
[0032] Centrifugal pump A8 is turned on, and deionized water is drawn from water tank 2 by centrifugal pump A8. After being heated by heater 9, it passes through temperature sensor A12 to monitor the infeed temperature and pressure sensor A13 to monitor the infeed pressure. Then, it enters the fuel cell stack through the stack cooling water inlet for circulating cooling. After completing heat exchange inside the fuel cell stack, the cooled deionized water flows out from the stack cooling water outlet, passes through temperature sensor 2 to monitor the outfeed temperature and pressure sensor 2 to monitor the outfeed pressure, and finally returns to water tank 2 after the pressure is regulated by back pressure valve 15, completing a complete circulation loop.
[0033] Small cycle test of fuel cell stack
[0034] Step 1. Add coolant
[0035] Coolant or deionized water is added to fuel cell stack 5 via external filling or large-circulation testing.
[0036] Step 2. Piping Control
[0037] In this configuration, the piping control during the small-cycle test of fuel cell stack 5 is as follows: Three-way valve B19 connects the cooling water outlet 4 of the fuel cell stack to the centrifugal pump B21 side piping, and closes the temperature sensor B18 side piping. Three-way valve C20 connects the cooling water inlet 3 of the fuel cell stack 5 to the centrifugal pump B21 side piping, and closes the pressure sensor A13 side piping.
[0038] Step 3. Cooling water circulation
[0039] When centrifugal pump B21 is turned on, the coolant is drawn out from the cooling water outlet 4 of the fuel cell stack 5 and enters the cooling water inlet 3 of the fuel cell stack 5 under the action of centrifugal pump B21.
[0040] II. Fuel Cell Water System Drainage
[0041] Step 1. Stop the water circulation.
[0042] Shut down all centrifugal pumps and stop water circulation in the pipeline.
[0043] Step 2. Piping Control
[0044] In this structure, the pipeline control for the fuel cell stack water drainage process is as follows:
[0045] When using non-deionized water as coolant, three-way valve A10 establishes a connection between nitrogen source 1 and temperature sensor A12, while ensuring the centrifugal pump A8 side line is closed. Three-way valve B19 connects the cooling water outlet 4 of fuel cell stack 5 to the temperature sensor B18 side line, closing the centrifugal pump B21 side line. Three-way valve C20 connects the cooling water inlet 3 of fuel cell stack 5 to the pressure sensor A13 side line, closing the centrifugal pump B21 side line. Three-way valve D22 connects the back pressure valve 15 to the drain outlet A23 side line, disconnecting the water tank 2 side line to prevent coolant from entering water tank 2, and allowing for dedicated collection of the discharged coolant.
[0046] When using deionized water as the coolant, three-way valve A10 establishes a connection between the nitrogen source 1 and temperature sensor A12, while ensuring the centrifugal pump A8 side connection is closed. Three-way valve B19 connects the cooling water outlet 4 of fuel cell stack 5 to the temperature sensor B18 side connection, closing the centrifugal pump B21 side connection. Three-way valve C20 connects the cooling water inlet 3 of fuel cell stack 5 to the pressure sensor A13 side connection, closing the centrifugal pump B21 side connection. Three-way valve D22 connects the back pressure valve 15 to the water tank 2 side connection, disconnecting the drain outlet A23 side connection.
[0047] Step 3. Nitrogen purging and drainage
[0048] When solenoid valve C30 is opened, nitrogen gas flows out from nitrogen source 1, passing sequentially through solenoid valve C30, three-way valve A10, temperature sensor A12, pressure sensor A13, and conductivity sensor 14. Finally, it enters the cooling water inlet 3 of fuel cell stack 5 through three-way valve C20, and then into the interior of fuel cell stack 5. After completing its flow inside fuel cell stack 5, the coolant inside fuel cell stack 5 flows out from cooling water outlet 4 along with the nitrogen gas, passing sequentially through three-way valve B19, temperature sensor B18 (for temperature monitoring), dew point sensor 17 (for dew point monitoring), pressure sensor B16, and back pressure valve 15. It then either exits directly through three-way valve D22 or enters water tank 2. If it enters water tank 2, the deionized water pushed out by the nitrogen gas is stored in water tank 2, while the nitrogen gas is discharged through vent valve 31 at the top of water tank 2 to prevent excessive pressure inside the tank.
[0049] Step 4. Determining the degree of drainage
[0050] When deionized water is used as the coolant, the degree of drainage of the cooling water inside the fuel cell stack 5 can be accurately determined based on the values monitored by the dew point sensor 17 and the temperature sensor B18. The dew point sensor 17 can accurately measure the dew point temperature of the gas inside the pipe, which is the temperature at which water vapor in the gas reaches saturation and begins to condense under a specific pressure. The temperature sensor B18 monitors the actual temperature inside the pipe in real time. By comparing these two temperature values, the difference between the temperature and the dew point can be calculated to assess the dryness of the pipe and the residual amount of cooling water. If the temperature-dew point difference is large (e.g., >15℃), it indicates that the pipe is very dry with almost no residual moisture; if the temperature-dew point difference is small (e.g., <2℃), it indicates that there may be a lot of residual moisture in the pipe.
[0051] III. Deionized water replacement
[0052] During the test, the conductivity sensor 14 can monitor the conductivity of deionized water in real time. When it exceeds the requirements of the tested stack, the deionized water in the water tank 2 needs to be replaced.
[0053] Step 1. Drain the water tank
[0054] Open solenoid valve B29 to drain the deionized water from water tank 2. After the deionized water in water tank 2 is drained, close solenoid valve B29. Drainage is complete.
[0055] Step 2. Refill the water tank
[0056] Open solenoid valve A26, and deionized water enters water tank 2 from the source through solenoid valve A26. When the water level in water tank 2 reaches 2 / 3, close solenoid valve A26; water replenishment is complete.
Claims
1. A fuel cell stack water drainage structure for a fuel cell stack test bench, comprising a nitrogen source (1), a water tank (2) with an inlet and an outlet, and a fuel cell stack (5) with a cooling water inlet (3) and a cooling water outlet (4), characterized in that: The outlet is connected to the cooling water inlet (3) via pipe A (6), and the inlet is connected to the cooling water outlet (4) via pipe B (7); a centrifugal pump A (8), a heater (9) and a three-way valve A (10) are sequentially installed on pipe A (6); the nitrogen source (1) is connected to the three-way valve A (10) via pipe C (11).
2. The fuel cell stack water drainage structure for a fuel cell stack test bench as described in claim 1, characterized in that: in Temperature sensor A (12), pressure sensor A (13), and conductivity sensor (14) are sequentially installed on pipe A (6) between three-way valve A (10) and cooling water inlet (3); back pressure valve (15), pressure sensor B (16), dew point sensor (17), and temperature sensor B (18) are sequentially installed on pipe B (7) between inlet and cooling water outlet (4).
3. The fuel cell stack water drainage structure for a fuel cell stack test bench as described in claim 2, characterized in that: in A three-way valve B (19) is installed on pipe B (7) between temperature sensor B (18) and cooling water outlet (4); a three-way valve C (20) is installed on pipe A (6) between conductivity sensor (14) and cooling water inlet (3); a centrifugal pump B (21) is installed between pipe A (6) and pipe B (7); the centrifugal pump B (21) is connected to the three-way valve B (19) and the three-way valve C (20) respectively.
4. The fuel cell stack water drainage structure for a fuel cell stack test bench as described in claim 3, characterized in that: in A three-way valve D (22) is installed on the pipe B (7) between the inlet and the back pressure valve (15), and the three-way valve D (22) is connected to the external drain outlet A (23).
5. The fuel cell stack water drainage structure for a fuel cell stack test bench as described in claim 4, characterized in that: in The water tank (2) is provided with an inlet pipe (24) at the top, which is connected to an external deionized water source (25). A solenoid valve A (26) is provided on the inlet pipe (24).
6. The fuel cell stack water drainage structure for a fuel cell stack test bench as described in claim 5, characterized in that: in The outlet is provided with a water outlet pipe (27), which is connected to an external drain outlet B (28). A solenoid valve B (29) is provided on the water outlet pipe (27).
7. The fuel cell stack water drainage structure for a fuel cell stack test bench as described in claim 6, characterized in that: in A solenoid valve C(30) is installed on the pipe C(11).
8. The fuel cell stack water drainage structure for a fuel cell stack test bench as described in claim 7, characterized in that: An air vent valve (31) is provided on the top of the water tank (2).