CN114883608A - Single-chip waterway temperature control system of fuel cell stack - Google Patents

Abstract

The invention relates to a single-chip waterway temperature control system of a fuel cell stack, which comprises a galvanic pile, a water tank, a circulating waterway and a bypass pipe, wherein the circulating waterway comprises a water inlet pipe and a water outlet pipe; the water in the water tank flows into the galvanic pile through the water inlet pipe and then flows back to the water tank through the water outlet pipe, the two ends of the bypass pipe are respectively communicated with the water inlet pipe and the water outlet pipe, and when the bypass needle valve is opened, the water in the water inlet pipe flows into the water outlet pipe through the bypass pipe and flows back to the water tank. Compared with the prior art, the invention adds the bypass pipe in the main path, the bypass needle valve is arranged on the bypass pipe, the water flow entering the electric pile can be ensured to be smaller, the temperature transfer performance is good, the temperature control precision is greatly improved, and the temperature fluctuation is small.

Description

A fuel cell stack monolithic water circuit temperature control system

technical field

The invention relates to the technical field of fuel cell testing, in particular to a fuel cell stack monolithic water circuit temperature control system.

Background technique

A fuel cell is an electrochemical device that directly converts stored chemical energy into electrical energy, heat energy and water through a reaction. As a new type of green power source, fuel cell engines are gradually becoming one of the research and development priorities of on-board engines due to their excellent characteristics such as high efficiency and low emissions. The output of the fuel cell engine is based on the load, which has good controllability for the whole vehicle; at the same time, the energy output of the fuel cell engine is electrical energy, which simplifies the transmission and speed regulation structure of traditional vehicles. Although the fuel cell engine has many advantages compared with the internal combustion engine, there are still many problems to be solved for the fuel cell engine to replace the internal combustion engine as the mainstream of the automobile engine.

In low-power fuel cell stack or single-chip testing, in order to ensure the temperature difference between the inlet and outlet of the fuel cell stack, the overall flow rate of the water circuit is small, generally 0.1-1LPM. , Slow flow rate, poor temperature transfer performance, resulting in poor overall temperature control accuracy, and large temperature fluctuations when the flow rate changes, affecting the test results.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a fuel cell stack monolithic water circuit temperature control system in order to overcome the above-mentioned defects of the prior art. A bypass pipe is added to the main circuit, and a bypass needle valve is arranged on the bypass pipe to ensure that the The water flow into the stack is small, and the temperature transfer performance is good, which greatly improves the temperature control accuracy and the temperature fluctuation is small.

The object of the present invention can be realized through the following technical solutions:

A single-chip water circuit temperature control system for a fuel cell stack, comprising an electric stack, a water tank, a circulating water circuit and a bypass pipe, the circulating water circuit includes a water inlet pipe and a water outlet pipe, and a water pump, a temperature control module, a liquid A level monitoring module, a water replenishing module, a drainage module and a pressure regulating module, and a bypass needle valve is arranged on the bypass pipe;

The water in the water tank flows into the stack through the water inlet pipe, and then flows back to the water tank through the water outlet pipe. The two ends of the bypass pipe are respectively connected to the water inlet pipe and the water outlet pipe. When the bypass needle valve is opened, the water in the water inlet pipe The bypass pipe flows into the water outlet pipe and flows back to the water tank. The opening of the bypass needle valve controls the flow of the bypass pipe. Controlling the bypass needle valve can adjust the flow distribution into the bypass pipe and the stack.

Further, the temperature control module includes a heater and a plate heat exchanger. The heater is a heating rod, which is used for heating the water circuit, and the plate heat exchanger is used for cooling the water circuit. The heater is arranged in a water tank, and the water tank is provided with a first A temperature sensor, which can control the power of the heater and accurately adjust the temperature rise. The plate heat exchanger is arranged on the water inlet pipe, the bypass pipe is connected to the hot side outlet of the plate heat exchanger, and the cold side of the plate heat exchanger is provided with The cooling water flow proportional valve can precisely adjust the cooling water flow on the cold side of the plate heat exchanger, so as to accurately control the cooling capacity of the plate heat exchanger. A second temperature sensor is arranged between, a third temperature sensor is arranged between the bypass tube and the stack inlet, and a fourth temperature sensor is arranged between the bypass tube and the stack outlet.

The first temperature sensor is a thermal resistance temperature sensor, which is used to detect the water temperature in the water tank, the second temperature sensor is used to detect the water temperature at the outlet of the hot side of the plate heat exchanger, and the third temperature sensor and the fourth temperature sensor are respectively used to detect electricity. Water temperature at stack inlet and outlet.

Further, the water pump is arranged between the water tank and the plate heat exchanger, and the flow rate of the circulating water circuit can be roughly regulated by adjusting the power of the pump. The main circuit filter further filters impurities, and the main circuit flow proportional valve can precisely control the flow of the circulating water circuit.

Further, the liquid level monitoring module includes a plurality of liquid level sensors, which are respectively arranged at different heights of the water tank for monitoring the water level in the water tank.

Further, the number of the liquid level sensors is three, which are a low liquid level sensor, a medium liquid level sensor and a high liquid level sensor, which are installed in the water tank from low to high.

Further, the water replenishment module includes an inlet water source, and the pipeline between the inlet water source and the water tank is sequentially provided with a ball valve, an inlet filter, a pressure reducing valve, an inlet pressure sensor and an inlet solenoid valve, and the inlet water source provides deionized water, and the ball valve is The manual switch can manually control the on-off between the water supply source and the water tank, the inlet filter is used to filter impurities in the water, the pressure reducing valve is used to control the water inlet pressure of the water tank, and the inlet pressure sensor is used to detect the water inlet pressure of the water tank inlet. The inlet solenoid valve is electronically controlled by software, which can be automatically opened and closed to control the on-off between the inlet water source and the water tank.

Further, the drainage module includes a tail row, the tail row and the water tank are connected by two parallel branches, and the two branches are respectively provided with a drainage solenoid valve and a drainage ball valve, which can be automatically controlled by the drainage solenoid valve to drain the water. , can also be drained by manual control through the drain ball valve.

Further, the pressure regulating module includes an air supply source, and the air supply source leads to the upper part of the water tank through a pipeline, the pipeline is provided with an electric proportional valve and a pressure regulating valve, a safety valve is installed on the water tank, and the air supply is provided. The source can provide inert gas such as nitrogen, and the pressure is controlled by the electric proportional valve and the pressure regulating valve, so as to control the pressure of the whole circuit, and the safety valve is used to realize overpressure protection.

Further, a flow meter and a first pressure sensor are arranged between the bypass pipe and the stack inlet, and a second pressure sensor is arranged between the bypass pipe and the stack outlet. The pressure sensor and the second pressure sensor detect stack inlet and outlet pressures, respectively.

Further, a conductivity transmitter is provided in the circulating water circuit to detect the conductivity of the entire circuit. When the conductivity is too high, the conductivity will be reduced by replenishing water and draining the water.

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

(1) By adding a bypass pipe to the main circuit of large flow, it can ensure that the water flow into the stack is small, and the temperature transfer performance is good, which greatly improves the temperature control accuracy and the temperature fluctuation is small.

(2) Monitor the water level in the water tank through the liquid level monitoring module, and conduct drainage and replenishment through the water replenishment module and the drainage module to ensure that the water volume in the water tank is within an appropriate range.

(3) Accurate temperature control of the circuit is achieved through heaters, plate heat exchangers and multiple temperature sensors, and the overpressure module and multiple pressure sensors realize precise pressure control. The main circuit can be controlled by the water pump and the main circuit flow proportional valve. The water flow into the stack can be precisely controlled by controlling the bypass needle valve, and the control accuracy is high.

Description of drawings

Fig. 1 is the structural representation of the present invention;

Reference numerals, 1, ball valve, 2, inlet filter, 3, pressure reducing valve, 4, inlet pressure sensor, 5, inlet solenoid valve, 6, water tank, 7, heater, 8, first temperature sensor, 9, Low level sensor, 10, medium level sensor, 11, high level sensor, 12, electric proportional valve, 13, pressure regulating valve, 14, conductivity transmitter, 15, water pump, 16, main flow proportional valve , 17, main filter, 18, plate heat exchanger, 19, cooling water flow proportional valve, 20, second temperature sensor, 21, flow meter, 22, first pressure sensor, 23, third temperature sensor, 24 , Fourth temperature sensor, 25, second pressure sensor, 26, safety valve, 27, drain solenoid valve, 28, drain ball valve, 29, bypass needle valve, 30, electric stack.

Detailed ways

The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. This embodiment is implemented on the premise of the technical solution of the present invention, and provides a detailed implementation manner and a specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

In the drawings, structurally identical components are denoted by the same numerals, and structurally or functionally similar components are denoted by like numerals throughout. The size and thickness of each component shown in the drawings are arbitrarily shown, and the present invention does not limit the size and thickness of each component. Parts in the drawings have been appropriately exaggerated in some places for clarity of illustration.

Example 1:

A single-chip water circuit temperature control system for a fuel cell stack, comprising a stack 30, a water tank 6, a circulating water circuit and a bypass pipe, where the stack 30 is the tested piece, and the circulating water circuit includes a water inlet pipe, a water outlet pipe, and the water tank 6 and the circulating water circuit. It is provided with a water pump 15, a temperature control module, a liquid level monitoring module, a water replenishing module, a drainage module and a pressure regulating module, and a bypass needle valve 29 is arranged on the bypass pipe;

The water in the water tank 6 flows into the stack 30 through the water inlet pipe, and then flows back to the water tank 6 through the water outlet pipe. The two ends of the bypass pipe are respectively connected to the water inlet pipe and the water outlet pipe. When the bypass needle valve 29 is opened, the water in the water inlet pipe The bypass pipe flows into the water outlet pipe and flows back to the water tank 6 . The opening of the bypass needle valve 29 controls the flow of the bypass pipe. Controlling the bypass needle valve 29 can adjust the flow distribution into the bypass pipe and the stack 30 .

When testing low-power fuel cell stacks or monolithic cells, in order to ensure the temperature difference between the inlet and outlet of the fuel cell stack, the overall flow rate is small, generally 0.1-1LPM. When the overall loop flow rate of the test equipment is small, the flow rate is slow and the temperature transfer performance is low. poor, resulting in poor overall temperature control accuracy and large temperature fluctuations when the flow rate changes. The present invention designs a large-flow circulating water circuit, adds a bypass pipe, and a bypass needle valve 29 is arranged on the bypass pipe, which is the key improvement point of the present invention. The large-flow circulating water circuit can realize precise and stable temperature control, The bypass pipe can make a small part of the water in the large-flow circulating water flow through the stack 30, so that the stack 30 can still be tested with a small-flow loop, while meeting the small-flow requirements for single-cell battery testing, as well as accurate temperature control and temperature fluctuations Require.

The water replenishment module includes an inlet water source. The pipeline between the inlet water source and the water tank 6 is sequentially provided with a ball valve 1, an inlet filter 2, a pressure reducing valve 3, an inlet pressure sensor 4 and an inlet solenoid valve 5. The water tank 6 is about 5L, and the inlet water source provides Deionized water, the ball valve 1 is a manual switch, which can manually control the on-off between the water inlet source and the water tank 6, the inlet filter 2 is used to filter impurities in the water, the pressure reducing valve 3 is used to control the water inlet pressure of the water tank 6, the inlet The pressure sensor 4 is used to detect the water inlet pressure at the inlet of the water tank 6 . The inlet solenoid valve 5 is electrically controlled by software and can be automatically opened and closed to control the connection between the inlet water source and the water tank 6 .

The liquid level monitoring module includes a plurality of liquid level sensors, which are respectively arranged at different heights of the water tank 6 for monitoring the water level in the water tank 6 . In this embodiment, there are three liquid level sensors, which are a low liquid level sensor 9 , a middle liquid level sensor 10 and a high liquid level sensor 11 , which are installed in the water tank 6 from low to high.

The pressure regulating module includes an air supply source, which leads to the upper part of the water tank 6 through a pipeline. The pipeline is provided with an electric proportional valve 12 and a pressure regulating valve 13, and a safety valve 26 is installed on the water tank 6. The air supply source can provide nitrogen and other inert gas, the pressure is controlled by the electric proportional valve 12 and the pressure regulating valve 13, so as to control the pressure of the whole circuit, and the safety valve 26 is used to realize overpressure protection.

A conductivity transmitter 14 is arranged in the circulating water circuit to detect the conductivity of the entire circuit. When the conductivity is too high, the conductivity will be reduced by replenishing water and draining the water.

The temperature control module includes a heater 7 and a plate heat exchanger 18. The heater 7 is a heating rod and is used for heating the water circuit. The plate heat exchanger 18 is used for cooling the water circuit. The heater 7 is arranged in the water tank 6, and the water tank 6 has a The first temperature sensor 8 can control the power of the heater 7 to accurately adjust the temperature increase. The plate heat exchanger 18 is arranged on the water inlet pipe, and the bypass pipe is connected to the hot side outlet of the plate heat exchanger 18. The cold side is provided with a cooling water flow proportional valve 19, through which the cooling water flow rate of the cold side of the plate heat exchanger 18 can be precisely adjusted, thereby accurately controlling the cooling capacity of the plate heat exchanger 18. The plate heat exchanger 18 A second temperature sensor 20 is arranged between the hot side outlet and the bypass tube, a third temperature sensor 23 is arranged between the bypass tube and the inlet of the stack 30, and a fourth temperature sensor 23 is arranged between the bypass tube and the outlet of the stack 30. temperature sensor 24 .

The first temperature sensor 8 is a thermal resistance temperature sensor, which is used to detect the water temperature in the water tank 6, the second temperature sensor 20 is used to detect the water temperature at the outlet of the hot side of the plate heat exchanger 18, the third temperature sensor 23 and the fourth temperature sensor. 24 is used to detect the water temperature at the inlet and outlet of the stack 30, respectively.

The water pump 15 is arranged between the water tank 6 and the plate heat exchanger 18, and the flow rate of the circulating water circuit can be roughly regulated by the power adjustment of the water pump 15. Between the water pump 15 and the plate heat exchanger 18, there is also a main circuit filter 17 and a main circuit flow rate. The proportional valve 16 and the main circuit filter 17 further filter impurities, and the main circuit flow proportional valve 16 can precisely control the flow of the circulating water circuit.

A flow meter 21 and a first pressure sensor 22 are arranged between the bypass pipe and the inlet of the stack 30, and a second pressure sensor 25 is arranged between the bypass pipe and the outlet of the stack 30. The flow meter 21 detects the water entering the stack 30. Flow, the first pressure sensor 22 and the second pressure sensor 25 detect the inlet and outlet pressures of the stack 30, respectively.

The drainage module includes a tail row. The tail row and the water tank 6 are connected by two parallel branches. The two branches are respectively provided with a drainage solenoid valve 27 and a drainage ball valve 28, which can be automatically controlled by the drainage solenoid valve 27 to drain water. Drainage can also be manually controlled through the drain ball valve 28 .

The working process of the present invention is as follows:

The water replenishment module replenishes water in the water tank 6 and the circulating water circuit, the water in the water tank 6 and the circulating water circuit is discharged by the drainage module, the pressure regulating module controls the pressure of the entire circuit, and the liquid level monitoring module monitors the water level in real time. When the liquid level is too high ( The high liquid level sensor 11 detects that there is water), and the drain solenoid valve is automatically opened to drain water. When the liquid level is low (the middle liquid level sensor 10 detects that there is no water), the inlet solenoid valve is opened to replenish water. When the liquid level is too low (low The liquid level sensor 9 detects that there is no water), and the inlet solenoid valve is opened to replenish water. At the same time, the entire system cannot be started, and the test is stopped.

The heater 7 is used for initial temperature rise, and the temperature of the water in the water tank 6 and the circulating water circuit reaches the operating temperature of the overall stack 30. The first temperature sensor 8 (thermal resistance temperature sensor) is used to detect the temperature in the water tank 6, and perform temperature compensation. Heat exchanger 18 and cooling water flow proportional valve 19 are used for precise cooling of the overall circuit.

The combination of the water pump 15, the main flow proportional valve 16 and the bypass needle valve 29 precisely controls the water flow into the stack 30. The circuit between the water tank 6 and the bypass pipe is used as the main circuit. By adjusting the opening of the bypass needle valve 29, The flow rate of the main circuit can be controlled to be much larger than the flow rate of the incoming reactor water. Increasing the flow rate of the main circuit (which can be increased by 4-5 times by design) can greatly improve the overall temperature transfer and ensure the accuracy of temperature control.

The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make many modifications and changes according to the concept of the present invention without creative efforts. Therefore, any technical solutions that can be obtained by those skilled in the art through logical analysis, reasoning or limited experiments on the basis of the prior art according to the concept of the present invention shall fall within the protection scope determined by the claims.

Claims (10)

1. A single-chip water path temperature control system of a fuel cell stack is characterized by comprising a stack, a water tank, a circulating water path and a bypass pipe, wherein the circulating water path comprises a water inlet pipe and a water outlet pipe, a water pump, a temperature control module, a liquid level monitoring module, a water supplementing module, a water discharging module and a pressure regulating module are arranged in the water tank and the circulating water path, and a bypass needle valve is arranged on the bypass pipe;

the water in the water tank flows into the galvanic pile through the water inlet pipe and then flows back to the water tank through the water outlet pipe, the two ends of the bypass pipe are respectively communicated with the water inlet pipe and the water outlet pipe, and when the bypass needle valve is opened, the water in the water inlet pipe flows into the water outlet pipe through the bypass pipe and flows back to the water tank.

2. The single water path temperature control system of the fuel cell stack according to claim 1, wherein the temperature control module comprises a heater and a plate heat exchanger, the heater is arranged in the water tank, a first temperature sensor is arranged in the water tank, the plate heat exchanger is arranged on the water inlet pipe, the bypass pipe is connected to a hot side outlet of the plate heat exchanger, a cooling water flow proportional valve is arranged on a cold side of the plate heat exchanger, a second temperature sensor is arranged between the hot side outlet of the plate heat exchanger and the bypass pipe, a third temperature sensor is arranged between the bypass pipe and the electric stack inlet, and a fourth temperature sensor is arranged between the bypass pipe and the electric stack outlet.

3. The single-chip waterway temperature control system of the fuel cell stack of claim 2, wherein the water pump is arranged between the water tank and the plate heat exchanger, and a main path filter and a main path flow proportional valve are further arranged between the water pump and the plate heat exchanger.

4. The single-chip waterway temperature control system of the fuel cell stack of claim 1, wherein the liquid level monitoring module comprises a plurality of liquid level sensors respectively disposed at different height positions of the water tank for monitoring the height of the water level in the water tank.

5. The single-chip waterway temperature control system of claim 4, wherein the number of the liquid level sensors is three, and the liquid level sensors are respectively a low liquid level sensor, a medium liquid level sensor and a high liquid level sensor, and are arranged in the water tank from low to high.

6. The single-chip waterway temperature control system of the fuel cell stack of claim 1, wherein the water replenishing module comprises a water inlet source, and a pipeline between the water inlet source and the water tank is sequentially provided with a ball valve, an inlet filter, a pressure reducing valve, an inlet pressure sensor and an inlet electromagnetic valve.

7. The single-chip waterway temperature control system of the fuel cell stack of claim 1, wherein the drain module comprises a tail row, the tail row is connected with the water tank through two parallel branches, and a drain solenoid valve and a drain ball valve are respectively arranged on the two branches.

8. The single-chip waterway temperature control system of claim 1, wherein the pressure regulating module comprises an air supply source, the air supply source is introduced into the upper part of the water tank through a pipeline, the pipeline is provided with an electric proportional valve and a pressure regulating valve, and the water tank is provided with a safety valve.

9. The single-chip waterway temperature control system of the fuel cell stack of claim 1, wherein a flow meter and a first pressure sensor are arranged between the bypass pipe and the inlet of the stack, and a second pressure sensor is arranged between the bypass pipe and the outlet of the stack.

10. The monolithic waterway temperature control system of claim 1, wherein the circulating waterway is provided with a conductivity transmitter.

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