A gas supply and exhaust device for fuel cell testing

Abstract

The application relates to a gas supply and discharge device for fuel cell testing, and relates to the technical field of fuel cells. The device is mainly composed of a gas flow control unit, a gas humidifying unit, a gas heating unit and a gas pressure control and discharge unit. The gas flow control unit is composed of a flow control device and a three-way proportional valve, and is used for making fuel cell reaction gas reach a set flow value. The gas humidifying unit is composed of a humidifying tank body and a matched circulating temperature control system, and is used for making fuel cell reaction gas reach a set humidity value. The gas heating unit is composed of a heat exchanger body matched with a temperature control system, and is used for making fuel cell reaction gas reach a set temperature value. The gas pressure control and discharge unit is composed of a back pressure control valve and a tail end condensing device, and is used for making fuel cell reaction gas reach a set pressure value. Reaction gas enters a fuel cell to participate in reaction after sequentially passing through the above units to obtain required flow, temperature, humidity and pressure values, so that the testing requirement of a fuel cell stack is met.

Description

Technical Field

[0001] This invention relates to the field of fuel cell technology, and more specifically to a gas supply and exhaust device for fuel cell testing. Background Technology

[0002] The technological background of this fuel cell testing device stems from the urgent global demand for clean energy and sustainable development. With the rise of the hydrogen economy, fuel cell technology, due to its high efficiency and zero emissions, has been widely applied in transportation, stationary power generation, and portable devices. The fuel cell is the core component of a fuel cell engine, a power source that converts the chemical energy of air and hydrogen into electrical energy. Therefore, the performance of the fuel cell has a crucial impact on the fuel cell engine. The performance of the fuel cell can be directly evaluated by conducting polarization curve tests, dynamic response tests, and durability tests on the fuel cell stack. Based on this background, this invention designs a gas supply and exhaust device that can accurately and reliably provide a certain flow rate, temperature, pressure, and humidity, which can be used to conduct various tests on the fuel cell to evaluate its performance.

[0003] The existing technical solution uses multiple sets of flow controllers in parallel to obtain different dry and wet gas flow rates, uses a heating core rod to heat the gas to control the gas temperature, uses a back pressure valve to control the gas inlet pressure, and uses a humidification tank to control the gas inlet humidity (CN118970103A).

[0004] Existing technical solutions for accurately obtaining dry and wet reaction gases across the entire flow range typically require multiple flow controllers connected in parallel in the dry and wet circuits. This is especially true on high-power fuel cell test benches with capacities of 300kW or more, where six or more flow controllers are usually required in parallel. However, high-precision gas flow controllers are usually imported brands and are expensive, resulting in high overall equipment costs when using existing technical solutions.

[0005] Existing technologies typically use electrically heated mandrels to heat air and hydrogen at a certain temperature. However, heat exchange between a high-temperature mandrel and the gas is inefficient, especially at low flow rates where laminar flow further reduces efficiency, failing to meet actual testing requirements. Furthermore, the inability to remove heat generated by the mandrel in time can cause the heater to trip and burn out. Additionally, since hydrogen is a flammable and explosive medium, an explosion-proof heater is required at the hydrogen end, which is costly.

[0006] The existing technical solution does not preheat the dry gas when mixing dry gas and wet gas in a certain ratio. This causes the wet gas to condense when the relatively cold dry gas is mixed with the high humidity and high heat. Therefore, the set humidity cannot be achieved after mixing. At the same time, the condensate entering the fuel cell stack will affect the performance of the fuel cell stack.

[0007] The purpose of this invention: First, reduce the number of flow controllers used, simplify the internal structure of the equipment, and reduce the hardware cost of the equipment; Second: Improve gas temperature control performance and enhance equipment safety; Third: Reduce moisture condensation during dry-wet gas mixing and improve the equipment's humidity control capability. Summary of the Invention

[0008] This invention aims to solve the problems of the prior art mentioned above. It proposes a gas supply and exhaust device for fuel cell testing. The technical solution of this invention is as follows: A gas supply and exhaust device for fuel cell testing includes: a gas flow control unit; a gas humidification unit; a gas heating unit; and a gas pressure-controlled exhaust unit. The gas flow control unit is sequentially connected to the humidification unit, the heating unit, and the pressure-controlled exhaust unit. The gas humidification unit is connected in parallel in the main pipeline, and the other units are sequentially connected in series in the main pipeline. The gas flow control unit is used to ensure that the fuel cell reaction gas reaches a set flow rate value, the gas humidification unit is used to ensure that the fuel cell reaction gas reaches a set humidity value, the gas heating unit is used to ensure that the fuel cell reaction gas reaches a set temperature value, and the gas pressure-controlled exhaust unit is used to ensure that the fuel cell reaction gas reaches a set pressure value. The reaction gas, after obtaining the required flow rate, temperature, humidity, and pressure values, enters the fuel cell to participate in the reaction, meeting the testing requirements of the fuel cell stack.

[0009] Furthermore, the gas flow control unit includes a first pressure sensor, a filter, a first shut-off valve, a flow control device, and a three-way proportional regulating valve connected in sequence. The flow rate of the reaction gas is achieved by the action of the flow control device, and the proportion of gas entering the humidification unit is controlled by the three-way proportional regulating valve.

[0010] Furthermore, the gas humidification unit consists of a humidification tank body and a humidification circulating water system. The humidification circulating water system includes a humidification water pump, a first heat exchanger, a second heat exchanger, a first proportional regulating valve, a first heater, a first drain switch valve, a first water supply switch valve, a first liquid level sensor, a second shut-off valve, and a manual regulating valve. Gas is introduced from the bottom of the humidification tank to achieve gas humidification. The circulating water system is responsible for controlling the water temperature inside the humidification tank, thereby achieving gas humidity control.

[0011] Furthermore, the gas heating unit consists of a third heat exchanger and its heating circulating water system. The heating circulating water system includes a heating water pump, a second heater, a fourth heat exchanger, a second proportional regulating valve, a first temperature sensor, a first liquid level sensor, a second drain switch valve, and a second water supply switch valve. Hot water circulates in one channel of the third heat exchanger, and gas circulates in the other channel of the third heat exchanger. The gas temperature is controlled by controlling the water temperature of the heating circulating water system.

[0012] Furthermore, the gas pressure control and discharge unit includes a back pressure valve, a fifth heat exchanger, a cooling switch valve, a fourth temperature sensor, a third liquid level sensor, and a third drain switch valve. The pressure control of the reaction gas is achieved through the back pressure valve, and the cooling of the exhaust gas discharged from the fuel cell and the discharge of condensate are achieved through the fifth heat exchanger and the third drain switch valve.

[0013] Furthermore, it also includes a control unit, which controls the above four units. All sensors, water pumps, heaters, flow control devices, and valves in the four units are connected to the control unit for signal acquisition and control.

[0014] The advantages and beneficial effects of this invention are as follows: This invention abandons the strategy of setting separate flow controllers for dry and wet branches. Instead, it merges the flow controllers of the dry and wet branches into the main branch and sets a three-way proportional regulating valve at the branch. This can realize the separate supply of dry and wet air, or the proportional supply of dry and wet air to achieve rapid mixing of dry and wet air. This can maximize the utilization rate of flow controllers and reduce the number of parallel flow controller groups, thereby maximizing cost reduction without affecting the function of the equipment.

[0015] Second: Abandoning the traditional method of directly heating gas with a heater, the deionized water is first heated and cooled using a heater and heat exchanger. Then, the heat exchanger is used to achieve indirect heat exchange between the deionized water and the gas, thereby improving the heat exchange efficiency and the heating and cooling rate of the gas. At the same time, it can avoid the power outage and dry burning phenomena when heating gas with a traditional heater, making it safer and more efficient.

[0016] Thirdly, this invention adds a heat exchanger to the dry gas path before mixing dry gas and wet gas to preheat the dry gas, thereby avoiding the problem of condensation of wet gas. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of a gas supply and exhaust device for fuel cell testing according to a preferred embodiment of the present invention.

[0018] Figure 2 This is a block diagram showing the connection between the gas flow control unit and the humidification unit, heating unit, and pressure control and discharge unit.

[0019] in: First pressure sensor -071, second pressure sensor -073, third pressure sensor -074; First temperature sensor -083, second temperature sensor -084, third temperature sensor -085. Fourth temperature sensor - 086; First liquid level sensor-101, second liquid level sensor-102, third liquid level sensor-103; First shut-off valve-011, second shut-off valve-012; First water supply switch valve -013, second water supply switch valve -015; First drain switch valve -014, second drain switch valve -016, third drain switch valve -018; First proportional control valve -112, second proportional control valve -113; First heater-041, second heater-042; First heat exchanger - 031, second heat exchanger - 032, third heat exchanger - 033, fourth heat exchanger - 034, fifth heat exchanger - 035; First manual switch valve -131, second manual switch valve -132; Filter-061, Flow control device-021, Three-way proportional regulating valve-111, Humidifying water pump-051, Heating water pump-052, Manual regulating valve-141, Humidity sensor-091, Back pressure valve-121, Cooling switch valve-017. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and thoroughly described below with reference to the accompanying drawings. The described embodiments are merely some embodiments of the present invention.

[0021] The technical solution of the present invention to solve the above-mentioned technical problems is: The gas supply and exhaust device of the present invention comprises the following units: a gas flow control unit; a gas humidification unit; a gas heating unit; and a gas pressure control and exhaust unit; the above four units are connected in sequence, as detailed in the appendix. Figure 2 The reaction gases pass through the above units in sequence, and after obtaining the required flow rate, temperature, humidity and pressure values, they enter the fuel cell to participate in the reaction, thus meeting the testing requirements of the fuel cell stack.

[0022] The gas flow control unit enables the reaction gas to reach the set flow rate. The first pressure sensor 071 at the front end is used to monitor the gas source pressure. The filter 061 is used to filter impurities in the gas. The first shut-off valve 011 is used to control the supply of reaction gas. 021 is a flow control device used to control the flow rate of reaction gas. 111 is a three-way proportional regulating valve used to control the ratio of reaction gas flowing into the dry and wet paths, so as to achieve the ratio of dry and wet gases, thereby enabling the reaction gas to quickly reach the set humidity.

[0023] The gas humidification unit consists of a humidification tank and a humidification circulating water system, which can bring the fuel cell reaction gas to a set humidity value. 051 is a humidification water pump that enables water flow in the circulating water system. 032 is a second heat exchanger. 112 is a first proportional regulating valve. The action of the first proportional regulating valve 112 allows external cold water to be introduced into the second heat exchanger 032, thereby cooling the circulating water system. 041 is a first heater that can heat the circulating water system. The combined action of the first proportional regulating valve 112 and the first heater 041 can achieve precise control of the water temperature in the humidification tank, thereby controlling the gas dew point temperature. 031, the first heat exchanger, preheats the dry gas by introducing hot water from the humidification unit, preventing condensation when the cold dry gas mixes with the hot humid gas. 141 is a manual regulating valve. By adjusting the opening of the manual regulating valve, sufficient hot water is ensured to enter the first heat exchanger 031. The first water supply switch valve 013 and the first water drain switch valve 014 can realize the replenishment and drainage of the circulating water system. The first liquid level sensor 101 is used to monitor the liquid level.

[0024] The gas heating unit consists of a third heat exchanger 033 and a heating circulating water system, which can bring the fuel cell reaction gas to a set temperature value. 052 is a heating water pump that enables the water flow in the heating circulating water system. 042, 034, and 113 are the second heater, the fourth heat exchanger, and the second proportional regulating valve, respectively. The combined action of the second heater 042 and the second proportional regulating valve 113 can achieve precise control of the water temperature in the heating circulating water system. Thus, the third heat exchanger 033 enables heat exchange between the gas and hot water, thereby indirectly controlling the temperature of the reaction gas. 083 is a temperature sensor used to monitor and provide feedback on the water temperature. The second liquid level sensor 102 is used to detect the water level height to prevent water shortage and over-filling of the water system. The second water replenishment switch valve 015 and the second water drain switch valve 016 can realize the replenishment and drainage of the circulating water system.

[0025] In the gas pressure control and emission unit, the back pressure valve 121 is used to control the pressure of the reaction gas. The fifth heat exchanger introduces external cold water through the action of the cooling switch valve 017, thereby reducing the temperature and humidity of the fuel cell exhaust gas and allowing it to be safely discharged into the external environment. The fourth temperature sensor 086 monitors the temperature of the exhaust gas, the third liquid level sensor 103 monitors the water level of the condensate in the exhaust gas, and the third switch valve 018, in conjunction with the third liquid level sensor 103, discharges the condensate in a timely manner.

[0026] In addition to the four units mentioned above, the components also include a first manual switch valve 131 and a second manual switch valve 132, which are used to manually disconnect the fuel cell stack from the four units when the equipment is shut down to prevent accidental safety incidents. The second pressure sensor 073 and the third pressure sensor 074 monitor the pressure of the gas entering and exiting the fuel cell, the second temperature sensor 084 and the third temperature sensor 085 monitor the temperature of the gas entering and exiting the fuel cell, and the humidity sensor 091 monitors the humidity of the gas entering the fuel cell.

[0027] In addition to the four units described in the above embodiments, this embodiment also includes an additional control unit. The control unit can control the above four units through, but is not limited to, a PLC and a host computer. All the sensing signals of the pressure sensor, temperature sensor, humidity sensor and liquid level sensor of this device are collected by the control unit. All the heaters, flow control devices, valves and water pumps of this device are controlled by the control unit.

[0028] Working principle: such as Figure 1As shown, the reactant gas first enters the flow control unit, where it is filtered by the front-end filter 061 to remove impurities and moisture. When a gas supply signal is received from the host computer and PLC, and the pressure value read by the first pressure sensor 071 is within the normal range, the shut-off valve 011 opens to allow gas to flow into the flow control device 021. After receiving the required flow rate value from the host computer, the flow control device 021 adjusts the flow to allow the specified flow rate of gas to enter the three-way proportional valve 111. The three-way proportional valve then controls the proportion of gas entering the humidification unit through PID regulation, so that the gas can quickly reach the preset humidity. The humidification unit consists of a humidification tank body and a humidification circulating water system. The gas is humidified by the humidification tank body. The humidification circulating water system uses the humidification water pump 051 to draw pure water from the bottom of the humidification tank, which then passes through the second heat exchanger 032 and the first heater 041 before returning to the humidification tank to maintain a constant water temperature inside the humidification tank, thus ensuring continuous humidification of the gas. Dry and humid gases converge above the humidification tank. Before converging, the dry gas is heated by the first heat exchanger 031. Since the heat medium of the first heat exchanger 031 comes from the humidification unit, the temperatures of the dry and humid gases are kept close, thus preventing condensation of the humid gas. After obtaining the gas with the specified flow rate and humidity, the reaction gas enters the heating unit. The heating unit consists of the third heat exchanger 033 and a heating circulating water system. The reaction gas exchanges heat with the hot water through the third heat exchanger 033. The fourth heat exchanger 034 in the heating circulating water system, together with the second heater 042 and the second proportional valve 113, forms a temperature control module. The heating power of the second heater 042 and the opening of the proportional valve 113 are controlled by PID regulation, and the water temperature is monitored by the first temperature sensor 083. The gas temperature is controlled by controlling the water temperature. The back pressure valve 121 in the pressure control and discharge unit adjusts the valve opening through PID control, thereby regulating the pressure of the reactant gas to reach the set pressure value. Since the exhaust gas discharged from the fuel cell stack is in a high temperature and high humidity state, the fifth heat exchanger 035 at the end is used to reduce the temperature and humidity of the exhaust gas. The third drain switch valve 018, in conjunction with the third liquid level sensor 103, realizes the automatic discharge of condensate, so that the exhaust gas discharged from the fuel cell can be safely discharged into the atmosphere, and finally realizes the power generation test of the fuel cell stack.

[0029] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0030] The above embodiments should be understood as illustrative only and not as limiting the scope of protection of the present invention. After reading the description of the present invention, those skilled in the art can make various alterations or modifications to the present invention, and these equivalent changes and modifications also fall within the scope defined by the claims of the present invention.

Claims

1. A gas supply and exhaust device for fuel cell testing, characterized in that, include: The system includes a gas flow control unit, a gas humidification unit, a gas heating unit, and a gas pressure control and discharge unit. The gas flow control unit is connected in sequence with the humidification unit, heating unit, and pressure control and discharge unit. The gas humidification unit is connected in parallel with the main pipeline, while the other units are connected in series with the main pipeline. The gas flow control unit is used to ensure that the fuel cell reaction gas reaches a set flow rate value, the gas humidification unit is used to ensure that the fuel cell reaction gas reaches a set humidity value, the gas heating unit is used to ensure that the fuel cell reaction gas reaches a set temperature value, and the gas pressure control and discharge unit is used to ensure that the fuel cell reaction gas reaches a set pressure value. After the reaction gas obtains the required flow rate, temperature, humidity, and pressure values, it enters the fuel cell to participate in the reaction, thus meeting the testing requirements of the fuel cell stack.

2. The gas supply and exhaust device for fuel cell testing according to claim 1, characterized in that, The gas flow control unit includes a first pressure sensor (071), a filter (061), a first shut-off valve (011), a flow control device (021), and a three-way proportional regulating valve (111) connected in sequence. The first pressure sensor (071) is used to monitor the gas source pressure, the filter (061) is used to filter impurities in the gas, the first shut-off valve (011) is used to control the supply of the reaction gas, the flow control device (021) is used to control the flow rate of the reaction gas, and the three-way proportional regulating valve (111) is used to control the ratio of the reaction gas flowing into the dry and wet paths, so as to realize the ratio of dry and wet gas flow rates, thereby enabling the reaction gas to quickly reach the set humidity.

3. A gas supply and exhaust device for fuel cell testing according to claim 1, characterized in that, The gas humidification unit includes a humidification water pump (051), a second heat exchanger (032), a first heater (041), a manual regulating valve (141), a first drain switch valve (014), a first water replenishment switch valve (013), a first proportional regulating valve (112), a first liquid level sensor (101), a first heat exchanger (031), a second shut-off valve (012), a humidification water pump (051) to realize the water flow of the humidification circulating water system, a first proportional regulating valve (112) to introduce external cold water into the second heat exchanger (032) to realize the cooling of the circulating water system, a first heater (041) to realize the heating of the circulating water system, and the precise control of gas humidity can be realized through the combined action of the first proportional regulating valve (112) and the first heater (041), a first drain switch valve (014) and a first water replenishment switch valve (013) to realize the drainage and replenishment of water in the circulating water system, and a first liquid level sensor (101) to realize the monitoring of the water level in the humidification tank.

4. A gas supply and exhaust device for fuel cell testing according to claim 1, characterized in that, The gas heating unit includes a heating water pump (052), a second heater (042), a third heat exchanger (033), a fourth heat exchanger (034), a second proportional regulating valve (113), a first temperature sensor (083), a second liquid level sensor (102), a second drain switch valve (016), and a second water supply switch valve (015). The heating water pump (052) is used to realize the water flow of the heating circulating water system. The linkage between the second heater (042) and the second proportional regulating valve (113) realizes the precise control of the water temperature in the heating circulating water system, thereby indirectly realizing the control of the temperature of the reaction gas through the third heat exchanger (033). The first temperature sensor (083) is used to monitor and feedback the water temperature, and the second liquid level sensor (102) is used to detect the water level height.

5. A gas supply and exhaust device for fuel cell testing according to claim 1, characterized in that, The gas pressure control and discharge unit includes a back pressure valve (121), a fifth heat exchanger (035), a cooling switch valve (017), a fourth temperature sensor (086), a third liquid level sensor (103), and a third drain switch valve (018). The back pressure valve (121) is used to control the pressure of the reaction gas. The fifth heat exchanger (035) is used to reduce the temperature of the fuel cell exhaust gas by the action of the cooling switch valve (017) so that it is discharged to the outside environment at room temperature. The fourth temperature sensor (086) is used to monitor the temperature of the exhaust gas. The third liquid level sensor (103) is used to monitor the water level of the condensate. The third drain switch valve (018) is linked with the third liquid level sensor 103 to discharge the condensate in a timely manner.

6. A gas supply and exhaust device for fuel cell testing according to claim 1, characterized in that, In addition to the above four units, there are also a first manual switch valve (131), a second manual switch valve (132), a second pressure sensor (073), a third pressure sensor (074), a second temperature sensor (084), a third temperature sensor (085), and a humidity sensor (091) that are directly connected to the fuel cell stack.

7. A gas supply and exhaust device for fuel cell testing according to claim 1, characterized in that, It also includes a control unit to control the above four units. All the sensing signals of the pressure sensor, temperature sensor, humidity sensor and liquid level sensor in this device are collected by the control unit. All the heaters, flow control devices, valves and water pumps in this device are controlled by the control unit.

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