Integrated fuel cell air supply system and fuel cell system

Abstract

The present invention discloses an integrated fuel cell air supply system, comprising a controller unit, an air filter, an air compressor, an intercooler, an integrated valve group, a humidifier, a water separator and a muffler; the air compressor comprises an air supply inlet, an air supply outlet, an air recovery inlet and an air recovery outlet, the air supply inlet is connected to the air filter, and the air supply outlet is connected to the intercooler; the humidifier comprises a dry side inlet, a dry side outlet, a wet side inlet and a wet side outlet, the integrated valve group comprises an intake three-way valve and an exhaust three-way valve, the intake three-way valve comprises an intake inlet and a first intake outlet, the intake inlet is connected to the intercooler, the intake outlet is connected to the dry side inlet, the exhaust three-way valve comprises a first exhaust inlet and an exhaust outlet, and the first exhaust inlet is connected to the wet side outlet; the water separator comprises a wet air inlet, a separated water outlet and a dry air outlet, the wet air inlet is connected to the exhaust outlet, and the dry air outlet is connected to the air recovery inlet.

Description

Technical Field

[0001] The present invention relates to the field of fuel cells, and in particular to an integrated fuel cell air supply system and a fuel cell system. Background Art

[0002] A fuel cell is a device that converts the chemical energy of a fuel directly into electrical energy. Its principle is to conduct fuel protons through a proton exchange membrane and generate electricity by outputting current in an external path. The product is composed only of water. This is an efficient and environmentally friendly way of energy conversion. Its energy conversion efficiency is very high, and the conversion method is not limited by the Carnot cycle. Fuel cells are widely used in new energy vehicles, ships, drones, and combined heat and power generation.

[0003] In the fuel cell system, the air system provides the required oxidant. During the operation of the fuel cell system, the influences from the air system mainly include factors such as air pressure, flow, temperature, humidity, cathode water production and water delivery capacity inside the stack, and the response speed and stability of the air supply. When the above conditions are met, the reliability of the system must be considered, including the number of air compressor starts and stops, air compressor durability, air filter replacement cycle, and humidifier service life.

[0004] Patent document with patent publication number CN110957507A discloses a fuel cell air supply device and a control method thereof. The air system air compressor anti-surge bypass flow scheme provided by the method is without energy recovery. The scheme also provides that the air humidity is adjusted by multiple proportional valves at the inlet end of the fuel cell stack. This cannot guarantee the air flow entering the fuel cell stack when adjusting the air humidity, and there is no cut-off function at the air inlet and outlet of the fuel cell stack. Summary of the invention

[0005] The main purpose of the present invention is to provide an integrated fuel cell air supply system, aiming to solve the technical problems raised in the above background technology.

[0006] To achieve the above-mentioned purpose, the present invention proposes an integrated fuel cell air supply system, which includes a controller unit, an air filter, an air compressor, an intercooler, an integrated valve group, a humidifier, a water separator and a muffler, wherein the integrated valve group and the air compressor are respectively connected to the controller unit; wherein: the air compressor includes an air supply inlet, an air supply outlet, an air recovery inlet and an air recovery outlet, the air supply inlet is connected to the air filter, and the air supply outlet is connected to the intercooler; the humidifier includes a dry side inlet, a dry side outlet, a wet side inlet and a wet side outlet, and the dry side outlet It can be connected to the inlet of the fuel cell stack, and the wet side inlet can be connected to the outlet of the fuel cell stack. The integrated valve group includes an intake three-way valve and an exhaust three-way valve. The intake three-way valve includes an intake inlet and a first intake outlet. The intake inlet is connected to the intercooler, and the intake outlet is connected to the dry side inlet. The exhaust three-way valve includes a first exhaust inlet and an exhaust outlet, and the first exhaust inlet is connected to the wet side outlet. The water separator includes a wet air inlet, a separated water outlet and a dry air outlet. The wet air inlet is connected to the exhaust outlet, and the dry air outlet is connected to the air recovery inlet, and the air recovery outlet is connected to the muffler.

[0007] Preferably, the integrated valve group also includes a humidity proportional valve for adjusting the air humidity at the inlet of the fuel cell stack, one end of the humidity proportional valve can be connected to the outlet of the fuel cell stack, and the other end of the humidity proportional valve is connected to the second exhaust inlet of the exhaust three-way valve.

[0008] Preferably, a dew point sensor for monitoring air humidity is provided at the dry-side outlet of the humidifier, and the dew point sensor is connected to the controller unit.

[0009] Preferably, the integrated valve group further comprises a back pressure valve for regulating the air flow and pressure entering the fuel cell stack, the inlet end of the back pressure valve is connected to the exhaust outlet, and the outlet end of the back pressure valve is connected to the muffler.

[0010] Preferably, the integrated valve group further comprises a bypass proportional valve for preventing the air compressor from surging, one end of the bypass proportional valve is connected to the second air intake outlet of the air intake three-way valve, and the other end of the bypass proportional valve is connected to the air supply inlet of the air compressor.

[0011] Preferably, a bypass flowmeter is provided at the outlet end of the bypass proportional valve, and a main flowmeter is provided at the air supply inlet end of the air compressor, and the main flowmeter and the bypass flowmeter are respectively connected to the controller unit.

[0012] The present invention also proposes a fuel cell system, which includes the integrated fuel cell air supply system described in the aforementioned embodiments, wherein the integrated fuel cell air supply system includes a controller unit, an air filter, an air compressor, an intercooler, an integrated valve group, a humidifier, a water separator and a muffler, wherein the integrated valve group and the air compressor are respectively connected to the controller unit; wherein: the air compressor includes an air supply inlet, an air supply outlet, an air recovery inlet and an air recovery outlet, the air supply inlet is connected to the air filter, and the air supply outlet is connected to the intercooler; the humidifier includes a dry side inlet, a dry side outlet, a wet side inlet and a wet side outlet outlet, the dry side outlet can be connected to the inlet of the fuel cell stack, the wet side inlet can be connected to the outlet of the fuel cell stack, the integrated valve group includes an intake three-way valve and an exhaust three-way valve, the intake three-way valve includes an intake inlet and a first intake outlet, the intake inlet is connected to the intercooler, the intake outlet is connected to the dry side inlet, the exhaust three-way valve includes a first exhaust inlet and an exhaust outlet, the first exhaust inlet is connected to the wet side outlet; the water separator includes a wet air inlet, a separated water outlet and a dry air outlet, the wet air inlet is connected to the exhaust outlet, the dry air outlet is connected to the air recovery inlet, and the air recovery outlet is connected to the muffler.

[0013] Compared with the prior art, the beneficial technical effects of the embodiments of the present invention are:

[0014] The air supply system proposed in the embodiment of the present invention can recover the energy of the waste air discharged by the fuel cell stack, so as to use this energy to assist in driving the motor of the air compressor to rotate, thereby realizing energy recovery for the fuel cell air supply system. Specifically, the waste air discharged by the fuel cell stack contains a large amount of nitrogen, unreacted oxygen, water vapor and other gases, and because the waste air also contains liquid water, the waste air needs to be separated from the liquid water contained therein by a water separator after passing through the three-way valve, and then the waste air is introduced into the air recovery inlet of the air compressor to use the energy contained in the waste air to drive the motor of the air compressor to rotate, and the air after the energy is exhausted is discharged through the air recovery outlet. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural schematic diagram of an embodiment of an integrated fuel cell air supply system of the present invention;

[0016] Figure 2 It is a performance diagram of the air compressor of the integrated fuel cell air supply system of the present invention. DETAILED DESCRIPTION

[0017] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, but are not to be construed as limiting the present invention. All other embodiments obtained by ordinary technicians in the field without creative work based on the embodiments of the present invention are within the scope of protection of the present invention.

[0018] Embodiment 1

[0019] The embodiment of the present invention provides an integrated fuel cell air supply system, see Figure 1 The integrated fuel cell air supply system includes a controller unit 10, an air filter 20, an air compressor 30, an intercooler 40, an integrated valve group 50, a humidifier 60, a water separator 70 and a muffler 80. The integrated valve group 50 and the air compressor 30 are respectively connected to the controller unit 10; wherein: the air compressor 30 includes an air supply inlet, an air supply outlet, an air recovery inlet and an air recovery outlet, the air supply inlet is connected to the air filter 20, and the air supply outlet is connected to the intercooler 40; the humidifier 60 includes a dry side inlet, a dry side outlet, a wet side inlet and a wet side outlet, and the dry side outlet can be connected to the fuel The inlet of the fuel cell stack 300 is connected, and the wet side inlet can be connected to the outlet of the fuel cell stack 300. The integrated valve group 50 includes an intake three-way valve 51 and an exhaust three-way valve 52. The intake three-way valve 51 includes an intake inlet and a first intake outlet. The intake inlet is connected to the intercooler 40, and the intake outlet is connected to the dry side inlet. The exhaust three-way valve 52 includes a first exhaust inlet and an exhaust outlet. The first exhaust inlet is connected to the wet side outlet; the water separator 70 includes a wet air inlet, a separated water outlet and a dry air outlet. The wet air inlet is connected to the exhaust outlet, the dry air outlet is connected to the air recovery inlet, and the air recovery outlet is connected to the muffler 80.

[0020] The controller unit 10 proposed in the embodiment of the present invention is electrically connected to the air compressor 30 and the integrated valve group 50 respectively, so as to realize the electrical control of the air compressor 30 and the integrated valve group 50 through the controller unit 10, that is, the controller unit 10 can control the motor speed of the air compressor 30 and control the on and off of each valve in the integrated valve group 50 according to actual conditions. The air compressor 30 has an air supply inlet and an air supply outlet. The air supply inlet is connected to the air filter 20 through a pipeline. The air filter 20 is used to filter the air supplied from the outside. It mainly captures dust from the gas-solid two-phase flow through a porous filter material to ensure the cleanliness of the air supplied to the fuel cell stack 300, thereby preventing the dust mixed in the air from damaging the fuel cell stack 300. The air supply outlet is connected to the intercooler 40 through a pipeline. Because the temperature of the air compressed by the air compressor 30 is high, it is necessary to cool the compressed air through the intercooler 40 so that the temperature of the compressed air can adapt to the fuel cell stack 300.

[0021] The intercooler 40 cools down the compressed air, and the cooled compressed air will flow through the intake three-way valve 51, and then flow through the humidifier 60, so as to humidify the air to be entered into the fuel cell stack 300 through the humidifier 60, so as to meet the air humidity requirement of the fuel cell stack 300. The humidifier 60 has a dry side inlet, a dry side outlet, a wet side inlet and a wet side outlet, the dry side inlet is connected to the intake three-way valve 51 through a pipeline, the dry side outlet is connected to the inlet of the fuel cell stack 300 through a pipeline, the wet side inlet is connected to the outlet of the fuel cell stack 300 through a pipeline, and the wet side outlet is connected to the exhaust three-way valve 52 through a pipeline. The fuel cell stack 300 will generate water vapor during the reaction process, and the exhaust gas discharged will also contain water vapor. Therefore, the water vapor can be used to exchange the humidity of the air entering from the dry side inlet, so that the air humidity to be entered into the fuel cell stack 300 meets the requirement. After humidity exchange, the waste air exhausted from the fuel cell stack 300 will be discharged to the water separator 70 through the exhaust three-way valve 52, so that the liquid water contained in the waste air is separated by the water separator 70, and the separated liquid water will be discharged to the outside through the separation water outlet of the humidifier 60, so as to obtain relatively dry waste air, and the dry air will be discharged through the dry air outlet of the humidifier 60. The dry air outlet of the humidifier 60 is connected to the air recovery inlet of the air compressor 30 through a pipeline, and the air exhausted from the dry air outlet will flow into the air compressor 30 through the air recovery inlet, so that the motor of the air compressor 30 is driven to rotate by the dry air, thereby realizing energy recovery of the waste air.

[0022] The intake three-way valve 51 and the exhaust three-way valve 52 proposed in the embodiment of the present invention have intake cut-off function and exhaust cut-off function respectively. The intake cut-off function refers to disconnecting the air supply pipeline of the fuel cell stack 300 through the intake three-way valve 51, and the exhaust cut-off function refers to disconnecting the air exhaust pipeline of the fuel cell stack 300 through the exhaust three-way valve 52, that is, the air supply pipeline and the air exhaust pipeline of the fuel cell stack 300 are disconnected by the intake three-way valve 51 and the exhaust three-way valve 52 at the same time, so that part of the air is sealed inside the fuel cell stack 300. Because part of the air is sealed inside the fuel cell stack 300, the hydrogen remaining inside the fuel cell stack 300 can be consumed by this part of the air. After the reaction on the air side, the remaining nitrogen will penetrate into the hydrogen side, and the proton exchange membrane of the fuel cell stack 300 is protected by increasing the nitrogen content, and the rate of oxidation of the cathode of the fuel cell stack 300 by air after shutdown is reduced (nitrogen is an inert gas and will not react with the proton exchange membrane).

[0023] Embodiment 2

[0024] The integrated valve group 50 proposed in the embodiment of the present invention also includes a humidity proportional valve 53 for adjusting the air humidity at the inlet of the fuel cell stack 300. One end of the humidity proportional valve 53 can be connected to the outlet of the fuel cell stack 300, and the other end of the humidity proportional valve 53 is connected to the second exhaust inlet of the exhaust three-way valve 52. When the fuel cell system is running at high load, the reaction rate of the fuel and the oxidant increases, resulting in an accelerated rate of production of byproduct water. At this time, the output rate of the water generated by the cathode should be increased, and the air demand and the air humidity at the inlet of the fuel cell stack 300 need to be guaranteed. In order to achieve the above requirements, the embodiment of the present invention bypasses part of the humid air at the outlet of the fuel cell stack 300 through the humidity proportional valve 53 to adjust the inlet air humidity when the fuel cell system is running at high load. Specifically, a part of the waste air discharged at the outlet of the fuel cell stack 300 flows into the first exhaust inlet of the exhaust three-way valve 52 through the humidifier 60, and the other part flows into the second exhaust inlet of the exhaust three-way valve 52 after passing through the humidity proportional valve 53. The flow rate of the waste air flowing into the humidifier 60 is adjusted by controlling the opening of the humidity proportional valve 53. That is, the waste air discharged from the fuel cell stack 300 will pass through two paths, namely, the path where the humidifier 60 is located and the path where the humidity proportional valve 53 is located. If the opening of the humidity proportional valve 53 increases, the waste air flow through the path where the humidity proportional valve 53 is located will increase, and the corresponding waste air flow flowing into the humidifier 60 will decrease. It can be understood that if the waste air flow flowing into the humidifier 60 decreases, the humidity that can be achieved when the waste air and the air flowing in from the dry side inlet of the humidifier 60 are exchanged is lower, and vice versa. The humidity is higher. In this embodiment, the humidity of the air at the inlet of the fuel cell stack 300 can be adjusted by the humidity proportional valve 53 to prevent the excessive humidity of the air entering the fuel cell stack 300 from causing "flooding" inside the fuel cell stack.

[0025] Embodiment 3

[0026] The dry side outlet of the humidifier 60 proposed in the embodiment of the present invention is provided with a dew point sensor 90 for monitoring the air humidity, and the dew point sensor 90 is connected to the controller unit 10. In this embodiment, the air humidity to be entered into the fuel cell stack 300 can be monitored in real time by the dew point sensor 90, and the dew point data monitored by the dew point sensor 90 can be collected by the controller unit 10, and the controller unit 10 then determines whether the air humidity reaches the upper threshold of the air humidity entering the stack. If it exceeds the set threshold, the opening of the humidity proportional valve 53 is adjusted to reduce the amount of waste air entering the humidifier 60, reduce the amount of water exchange between the air at the inlet of the fuel cell stack and the humid air, and thus control the air humidity at the inlet of the fuel cell stack.

[0027] Embodiment 4

[0028] The integrated valve group 50 proposed in the embodiment of the present invention also includes a back pressure valve 54 for adjusting the air flow and pressure entering the fuel cell stack 300. One end of the back pressure valve 54 is connected to the exhaust outlet, and the other end of the back pressure valve 54 is connected to the muffler 80. In this embodiment, the air pressure entering the fuel cell stack 300 can be adjusted by the back pressure valve 54, so as to achieve full working condition control that meets the power demand. Specifically, when the fuel cell system is running at a high load, the air flow is very large. If the back pressure valve 54 is closed, although the energy recovery efficiency is high, this will cause the pressure at the inlet of the fuel cell stack 300 to be too high. Therefore, in this embodiment, a back pressure valve 54 is provided at the exhaust outlet end of the exhaust three-way valve 52 to release the pressure through the back pressure valve 54, so as to achieve the purpose of adjusting the air pressure at the inlet of the fuel cell stack 300.

[0029] Embodiment 5

[0030] The integrated valve group 50 proposed in the embodiment of the present invention also includes a bypass proportional valve 55 for preventing the air compressor 30 from surging. One end of the bypass proportional valve 55 is connected to the second air inlet outlet of the air inlet three-way valve 51, and the other end of the bypass proportional valve 55 is connected to the air supply inlet of the air compressor 30. When the fuel cell system is running at low load, the air compressor 30 will operate under a condition of a small flow rate and a large pressure ratio (air supply outlet / air supply inlet), and under this condition, the air compressor may operate near the surge line, so it is necessary to increase the pressure at the air supply inlet. Air compressor surge is: when the air compressor 30 is at a constant speed, when the flow rate of the air compressor 30 is reduced to a certain value due to the increase in the pressure ratio, its outlet pressure and speed will fluctuate violently. In order to achieve the pressure at the air supply inlet required when the fuel cell system is running, the speed of the air compressor 30 should be increased. While increasing the speed of the air compressor 30, the air flow rate will increase accordingly and exceed the required value when the fuel cell stack 300 is running. To this end, the present embodiment provides a bypass proportional valve 55 at the second air intake outlet end of the air intake three-way valve 51, so as to adjust the opening of the bypass proportional valve 55 to flow excess air to the air supply inlet of the air compressor 30, thereby preventing surge and realizing secondary recovery of air energy.

[0031] Embodiment 6

[0032] The bypass proportional valve 55 provided in the embodiment of the present invention is provided with a bypass flow meter 100 at its outlet, and the air supply inlet of the air compressor 30 is provided with a main flow meter 200, which are respectively connected to the controller unit 10. In this embodiment, the main flow meter 200 can monitor the external air flow in real time, and the bypass flow meter 100 can monitor the air flow recovered by the bypass proportional valve in real time. The controller unit 10 can calculate the air flow and air pressure entering the fuel cell stack 300 based on the monitoring data of the bypass flow meter 100 and the main flow meter 200. Figure 2 In order to detect whether the pressure ratio corresponding to the output flow of the air compressor 30 is near the surge line, the present embodiment calculates the air pressure ratio at the air supply inlet and the air supply outlet of the air compressor 30 through the controller unit 10, and compares the total amount of air collected in real time with the air flow required by the working condition of the fuel cell stack 300 to determine whether the working condition operation value of the air compressor 30 is near the surge line of the air compressor performance diagram. If the air compressor operates within the controllable flow area, the bypass proportional valve 55 can be closed; if the air compressor operates outside the controllable flow area, the speed of the air compressor 30 needs to be increased to make it operate within the controllable flow area, and the opening of the bypass proportional valve 55 is adjusted to bypass the excess air and recover it into the air compressor 30.

[0033] The present invention further proposes a fuel cell system including an integrated fuel cell air supply system. The specific structure of the integrated fuel cell air supply system refers to the above-mentioned embodiments. Since the fuel cell system adopts all the technical solutions of all the above-mentioned embodiments, it has at least all the technical effects brought by the technical solutions of the above-mentioned embodiments, which will not be described one by one here.

[0034] The above are only partial or preferred embodiments of the present invention. Neither the text nor the drawings can limit the scope of protection of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the overall concept of the present invention, or direct / indirect application in other related technical fields are included in the scope of protection of the present invention.

Claims

1. An integrated fuel cell air supply system, characterized in that: It includes a controller unit, an air filter, an air compressor, an intercooler, an integrated valve group, a humidifier, a water separator and a muffler, wherein the integrated valve group and the air compressor are respectively connected to the controller unit; wherein: The air compressor comprises an air supply inlet, an air supply outlet, an air recovery inlet and an air recovery outlet, the air supply inlet is connected to the air filter, and the air supply outlet is connected to the intercooler; The humidifier includes a dry side inlet, a dry side outlet, a wet side inlet and a wet side outlet, the dry side outlet can be connected to the inlet of the fuel cell stack, the wet side inlet can be connected to the outlet of the fuel cell stack, the integrated valve group includes an intake three-way valve and an exhaust three-way valve, the intake three-way valve includes an intake inlet and a first intake outlet, the intake inlet is connected to the intercooler, the intake outlet is connected to the dry side inlet, the exhaust three-way valve includes a first exhaust inlet and an exhaust outlet, the first exhaust inlet is connected to the wet side outlet; The water separator comprises a wet air inlet, a separated water outlet and a dry air outlet, the wet air inlet is connected to the exhaust outlet, the dry air outlet is connected to the air recovery inlet, and the air recovery outlet is connected to the muffler.

2. The integrated fuel cell air supply system according to claim 1, characterized in that: The integrated valve group also includes a humidity proportional valve for adjusting the air humidity at the inlet of the fuel cell stack. One end of the humidity proportional valve can be connected to the outlet of the fuel cell stack, and the other end of the humidity proportional valve is connected to the second exhaust inlet of the exhaust three-way valve.

3. The integrated fuel cell air supply system according to claim 2, characterized in that: A dew point sensor for monitoring air humidity is provided at the dry side outlet of the humidifier, and the dew point sensor is connected to the controller unit.

4. The integrated fuel cell air supply system according to claim 1, characterized in that: The integrated valve group further includes a back pressure valve for regulating the air flow and pressure entering the fuel cell stack, wherein the inlet end of the back pressure valve is connected to the exhaust outlet, and the outlet end of the back pressure valve is connected to the muffler.

5. The integrated fuel cell air supply system according to claim 1, characterized in that: The integrated valve group also includes a bypass proportional valve for preventing the air compressor from surging, one end of the bypass proportional valve is connected to the second air intake outlet of the air intake three-way valve, and the other end of the bypass proportional valve is connected to the air supply inlet of the air compressor.

6. The integrated fuel cell air supply system according to claim 5, characterized in that: A bypass flowmeter is provided at the outlet end of the bypass proportional valve, and a main flowmeter is provided at the air supply inlet end of the air compressor. The main flowmeter and the bypass flowmeter are respectively connected to the controller unit.

7. A fuel cell system, characterized in that: The invention comprises a fuel cell stack and the integrated fuel cell air supply system according to any one of claims 1 to 6, wherein the integrated fuel cell air supply system is used to supply air to the fuel cell stack.

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