Hydrogen fuel power system thermal management system and control method thereof

Abstract

The invention discloses a hydrogen fuel power system thermal management system and a control method thereof, and relates to the technical field of fuel cell thermal management system integration. The hydrogen fuel power system thermal management system mainly includes a water pump, a particle filter, a first temperature sensor, a pressure sensor, a stack, a second temperature sensor, a first proportional three-way valve, a water heating PTC, a radiator, a water flow meter, an intercooler, a second proportional three-way valve, an air-cooled heat exchanger, a blower and a third proportional three-way valve. The implementation of the hydrogen fuel power system thermal management system and the control method thereof provided by the invention can improve the heat dissipation performance of the hydrogen fuel cell thermal management system.

Description

Technical Field

[0001] The present invention relates to the technical field of fuel cell thermal management system integration, and more specifically, to a hydrogen fuel power system thermal management system and a control method thereof. Background Art

[0002] In today's hydrogen fuel cell vehicle industry, due to limited space constraints and the low operating temperature of hydrogen fuel cells, and the rising ambient temperature in many areas in the summer (over 40°C), the heat dissipation of the hydrogen fuel cell system radiator is difficult to meet the needs of the hydrogen fuel cell system. At the same time, in the current vehicle energy management strategy, most of the vehicle's power requests for hydrogen fuel cell systems use power segmentation power requests, and according to the changes in the current power demand state of the power battery SOC, the basic required power of the fuel cell is determined, and then the requested power of the fuel cell is adjusted. However, the existing technology has problems such as insufficient heat dissipation performance of the hydrogen fuel cell thermal management system in hot environments or seasons, and frequent switching of related valves. Summary of the invention

[0003] The object of the present invention is to provide a hydrogen fuel power system thermal management system and a control method thereof, which can improve the heat dissipation performance of the hydrogen fuel cell thermal management system.

[0004] The present invention provides a hydrogen fuel power system thermal management system, which includes a water pump, a particulate filter, a first temperature sensor, a pressure sensor, a fuel cell stack, a second temperature sensor, a first proportional three-way valve, a water heating PTC, a radiator, a water flow meter, an intercooler, a second proportional three-way valve, an air-cooled heat exchanger, a blower and a third proportional three-way valve.

[0005] Furthermore, the liquid outlet of the water pump is respectively connected to the front end of the intercooler and the front end of the battery stack through a particle filter, the front end of the battery stack is provided with a first temperature sensor and a pressure sensor, the rear end of the battery stack is provided with a second temperature sensor, the rear end of the battery stack is connected to the input end of the first proportional three-way valve, the first output end of the first proportional three-way valve is connected to the front end of the radiator, the second output end of the first proportional three-way valve is connected to one end of the water heating PTC, the other end of the water heating PTC and the rear end of the radiator are connected to the liquid inlet end of the water pump, and the rear end of the radiator is provided with a water flow meter; the intercooler The rear end is connected to the input end of the second proportional three-way valve, the first output end of the second proportional three-way valve is connected to the rear end of the fuel cell stack, and the second output end of the second proportional three-way valve is connected to the coolant inlet of the air-cooled heat exchanger; the air outlet end of the blower is connected to the input end of the third proportional three-way valve via the evaporator of the vehicle air conditioner, the first output end of the third proportional three-way valve is connected to the cab, the second output end of the third proportional three-way valve is connected to the air inlet of the air-cooled heat exchanger, the air outlet of the air-cooled heat exchanger is connected to the outside world, and the coolant outlet of the air-cooled heat exchanger is connected to the liquid inlet of the water pump.

[0006] Furthermore, the water pump is used to drive the coolant circulation and adjust the coolant flow and pressure; the particle filter is used to filter particles in the coolant; the first temperature sensor is used to obtain the temperature of the coolant at the front end of the battery stack; the pressure sensor is used to measure the pressure of the coolant at the front end of the battery stack; the battery stack is used to provide electrical energy for the whole vehicle; the second temperature sensor is used to obtain the temperature of the coolant at the rear end of the battery stack; the first proportional three-way valve is used to select the coolant at the rear end of the battery stack to enter the water heating PTC or enter the radiator; the water heating PTC is used to heat the coolant; the radiator is used to cool the coolant; The water flow meter is used to measure the flow of coolant passing through the radiator; the intercooler is used to cool the air at the outlet end of the hydrogen fuel cell air compressor; the second proportional three-way valve is used to select the coolant at the rear end of the intercooler to enter the coolant inlet of the air-cooled heat exchanger or return to the rear end of the fuel cell stack; the air-cooled heat exchanger is used to pass cold air to cool the liquid; the blower is used to blow outside air into the evaporator of the vehicle air conditioner, and use the evaporator of the vehicle air conditioner to cool the outside air into cold air; the third proportional three-way valve is used to distribute the cold air flow to the air inlet of the cab and the air-cooled heat exchanger.

[0007] The present invention also provides a control method for the thermal management system of the above-mentioned hydrogen fuel power system, comprising the following steps: S1: obtaining the water pump speed of each power point of the hydrogen fuel power system according to the heat dissipation power of each power point of the hydrogen fuel power system, and controlling the operation of the water pump according to the water pump speed of each power point of the hydrogen fuel power system; S2: controlling the water heating PTC, the first proportional three-way valve and the radiator according to the feedback temperature of the first temperature sensor; S3: obtaining the target opening of the second proportional three-way valve according to the maximum heat dissipation demand of the hydrogen fuel cell system, the maximum heat dissipation of the radiator, the heat dissipation power of each power point of the hydrogen fuel power system and the calibration parameters; controlling the operation of the second proportional three-way valve according to the target opening of the second proportional three-way valve; S4: controlling the blower and the third proportional three-way valve according to the feedback temperature of the first temperature sensor.

[0008] Furthermore, step S1 specifically includes: S11: obtaining the coolant flow rate of each power point of the hydrogen fuel power system according to the heat dissipation power of each power point of the hydrogen fuel power system; S12: obtaining the preliminary required water pump speed of each power point according to the coolant flow rate of each power point of the hydrogen fuel power system, the pressure drop of each part of the system and the water pump head curve; S13: obtaining the water pump speed of each power point of the hydrogen fuel power system according to the preliminary required water pump speed and control coefficient of each power point; S14: controlling the water pump operation according to the water pump speed of each power point of the hydrogen fuel power system.

[0009] Further, step S13 specifically includes: according to the preliminary required water pump speed and control coefficient of each power point, the water pump speed of each power point of the hydrogen fuel power system is obtained, such as the formula:

[0010] in, Hydrogen fuel power system The pump speed at each power point, Hydrogen fuel power system The control coefficient of each power point is Hydrogen fuel power system The initial required pump speed for each power point.

[0011] Furthermore, step S2 specifically includes: obtaining the feedback temperature of the first temperature sensor, and when the feedback temperature of the first temperature sensor is lower than the preset first liquid inlet temperature, setting the water heating PTC to a working state; when the feedback temperature of the first temperature sensor is not lower than the preset first liquid inlet temperature and lower than the preset second liquid inlet temperature, setting the water heating PTC to a closed state; when the feedback temperature of the first temperature sensor is higher than the preset third liquid inlet temperature, setting the first proportional three-way valve to an open state, and setting the radiator to a pre-start state; when the feedback temperature of the first temperature sensor is higher than the preset fourth liquid inlet temperature, setting the radiator to a working state.

[0012] Further, step S3 specifically includes: S31: obtaining the heat dissipation rating of the air-cooled heat exchanger according to the maximum heat dissipation demand of the hydrogen fuel cell system and the maximum heat dissipation of the radiator; S32: obtaining the rated coolant flow through the air-cooled heat exchanger according to the heat dissipation rating of the air-cooled heat exchanger; S33: obtaining the power demand point of the whole vehicle according to the heat dissipation rating of the air-cooled heat exchanger, and setting the second proportional three-way valve to an open state when the operating power of the hydrogen fuel cell system is not lower than the power demand point of the whole vehicle; S34: obtaining the auxiliary heat dissipation power point according to the heat dissipation power of each power point of the hydrogen fuel power system; according to the operating conditions of the stack and the auxiliary heat dissipation power point, The theoretical heat dissipation required by each assisting heat dissipation power point is obtained, and the actual heat dissipation required by each power point is obtained according to the theoretical heat dissipation required by each assisting heat dissipation power point; the heat required to be removed by the air-cooling heat exchanger at each power point and the coolant flow rate passing through the air-cooling heat exchanger are obtained according to the actual heat dissipation required by each power point, and the theoretical opening of the second proportional three-way valve is obtained according to the heat required to be removed by the air-cooling heat exchanger at each power point and the coolant flow rate passing through the air-cooling heat exchanger; S35: according to the theoretical opening and calibration parameters of the second proportional three-way valve, the target opening of the second proportional three-way valve is obtained; S36: according to the target opening of the second proportional three-way valve, the operation of the second proportional three-way valve is controlled.

[0013] Further, step S31 specifically includes: obtaining the heat dissipation rating of the air-cooled heat exchanger according to the maximum heat dissipation demand of the hydrogen fuel cell system and the maximum heat dissipation of the radiator, such as the formula: , in, is the heat dissipation rating of the air-cooled heat exchanger, The maximum heat dissipation requirement for hydrogen fuel cell systems. is the maximum heat dissipation of the radiator.

[0014] Further, step S35 specifically includes: obtaining a target opening of the second proportional three-way valve according to the theoretical opening of the second proportional three-way valve and the calibration parameters, such as the formula: , in, For the The target opening of the second proportional three-way valve at each power point is For the The theoretical opening of the second proportional three-way valve at each power point, No. Calibration parameters for each power point.

[0015] The implementation of the hydrogen fuel power system thermal management system and the control method thereof provided by the present invention has the following beneficial effects: The present invention adds a three-way proportional valve and an air-cooled heat exchanger, and in combination with the energy management strategy of the whole vehicle, controls the flow distribution by adjusting the opening of the three-way valve to meet the coolant flow demand of the air-cooled heat exchanger, fixes the opening of the three-way valve to several points, reduces the number of switching times of the three-way valve, and extends its service life; combines the control of the air conditioner with the three-way valve, integrates the whole vehicle air conditioner with the thermal management system under the hydrogen fuel cell, and controls the cooling air volume and air volume distribution to meet the heat dissipation requirements of the cab and the heat dissipation requirements of the hydrogen fuel cell system. The whole vehicle air conditioner is used to compensate for the insufficient heat dissipation performance of the hydrogen fuel cell system. When the radiator performance cannot meet the heat dissipation requirements of the stack, the whole vehicle air conditioner is used to assist the hydrogen fuel cell system in heat dissipation, thereby solving the problem of insufficient heat dissipation performance of the hydrogen fuel cell thermal management system in hot environments or seasons. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which: Figure 1 is a block diagram of a thermal management system for a hydrogen fuel power system provided by the present invention; Figure 2 It is a flow chart of a control method for a thermal management system of a hydrogen fuel power system provided by the present invention. DETAILED DESCRIPTION

[0017] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, specific embodiments of the present invention are now described in detail with reference to the accompanying drawings.

[0018] Figure 1The block diagram of the thermal management system of the hydrogen fuel power system of this embodiment is shown. In this embodiment, the thermal management system of the hydrogen fuel power system includes a water pump, a particulate filter, a first temperature sensor, a pressure sensor, a stack, a second temperature sensor, a first proportional three-way valve, a water heating PTC, a radiator, a water flow meter, an intercooler, a second proportional three-way valve, an air-cooled heat exchanger, a blower and a third proportional three-way valve.

[0019] In an exemplary embodiment, the liquid outlet of the water pump is connected to the front end of the intercooler and the front end of the battery stack respectively through a particle filter, the front end of the battery stack is provided with a first temperature sensor and a pressure sensor, the rear end of the battery stack is provided with a second temperature sensor, the rear end of the battery stack is connected to the input end of the first proportional three-way valve, the first output end of the first proportional three-way valve is connected to the front end of the radiator, the second output end of the first proportional three-way valve is connected to one end of the water heating PTC, the other end of the water heating PTC and the rear end of the radiator are connected to the liquid inlet end of the water pump, and the rear end of the radiator is provided with a water flow meter; The rear end of the air cooler is connected to the input end of the second proportional three-way valve, the first output end of the second proportional three-way valve is connected to the rear end of the fuel cell stack, and the second output end of the second proportional three-way valve is connected to the coolant inlet of the air-cooled heat exchanger; the air outlet of the blower is connected to the input end of the third proportional three-way valve via the evaporator of the vehicle air conditioner, the first output end of the third proportional three-way valve is connected to the cab, the second output end of the third proportional three-way valve is connected to the air inlet of the air-cooled heat exchanger, the air outlet of the air-cooled heat exchanger is connected to the outside world, and the coolant outlet of the air-cooled heat exchanger is connected to the liquid inlet of the water pump.

[0020] In an exemplary embodiment, a water pump is used to drive the coolant circulation and adjust the coolant flow and pressure; a particle filter is used to filter particles in the coolant; a first temperature sensor is used to obtain the temperature of the coolant at the front end of the battery stack; a pressure sensor is used to measure the pressure of the coolant at the front end of the battery stack; the battery stack is used to provide electrical energy to the entire vehicle; a second temperature sensor is used to obtain the temperature of the coolant at the rear end of the battery stack; a first proportional three-way valve is used to select the coolant at the rear end of the battery stack to enter the water-heating PTC or the radiator; the water-heating PTC is used to heat the coolant; and the radiator is used to supply the coolant Cooling; the water flow meter is used to measure the flow of coolant passing through the radiator; the intercooler is used to cool the air at the outlet end of the hydrogen fuel cell air compressor; the second proportional three-way valve is used to select the coolant at the rear end of the intercooler to enter the coolant inlet of the air-cooled heat exchanger or return to the rear end of the fuel cell stack; the air-cooled heat exchanger is used to pass cold air to cool the liquid; the blower is used to blow outside air into the evaporator of the vehicle air conditioner, and use the evaporator of the vehicle air conditioner to cool the outside air into cold air; the third proportional three-way valve is used to distribute the cold air flow to the air inlet of the cab and the air-cooled heat exchanger.

[0021] This embodiment provides a control method for the thermal management system of the hydrogen fuel power system, comprising the following steps: S1: according to the heat dissipation power of each power point of the hydrogen fuel power system, the water pump speed of each power point of the hydrogen fuel power system is obtained, and according to the water pump speed of each power point of the hydrogen fuel power system, the water pump operation is controlled; In an exemplary embodiment, step S1 specifically includes: S11: obtaining the coolant flow rate of each power point of the hydrogen fuel power system according to the heat dissipation power of each power point of the hydrogen fuel power system; S12: according to the coolant flow rate at each power point of the hydrogen fuel power system, the pressure drop of each system component and the water pump head curve, the preliminary required water pump speed at each power point is obtained; S13: obtaining the water pump speed at each power point of the hydrogen fuel power system according to the preliminary required water pump speed and control coefficient at each power point; In an exemplary embodiment, step S13 specifically includes: obtaining the water pump speed of each power point of the hydrogen fuel power system according to the preliminary required water pump speed and control coefficient of each power point, such as the formula:

[0022] in, Hydrogen fuel power system The pump speed at each power point, Hydrogen fuel power system The control coefficient of each power point is Hydrogen fuel power system The initial required pump speed for each power point; S14: controlling the operation of the water pump according to the water pump speed at each power point of the hydrogen fuel power system; S2: Control the water heating PTC, the first proportional three-way valve and the radiator according to the feedback temperature of the first temperature sensor; In an exemplary embodiment, step S2 specifically includes: obtaining the feedback temperature of the first temperature sensor, and when the feedback temperature of the first temperature sensor is lower than the preset first liquid inlet temperature, setting the water heating PTC to a working state; when the feedback temperature of the first temperature sensor is not lower than the preset first liquid inlet temperature and lower than the preset second liquid inlet temperature, setting the water heating PTC to a closed state; when the feedback temperature of the first temperature sensor is higher than the preset third liquid inlet temperature, setting the first proportional three-way valve to an open state, and setting the radiator to a pre-start state; when the feedback temperature of the first temperature sensor is higher than the preset fourth liquid inlet temperature, setting the radiator to a working state; In an exemplary embodiment, the first liquid inlet temperature is preset to 20° C., the second liquid inlet temperature is preset to 50° C., the third liquid inlet temperature is preset to 60° C., and the fourth liquid inlet temperature is preset to 68° C.; S3: obtaining a target opening of the second proportional three-way valve according to the maximum heat dissipation demand of the hydrogen fuel cell system, the maximum heat dissipation of the radiator, the heat dissipation power of each power point of the hydrogen fuel power system and calibration parameters; controlling the operation of the second proportional three-way valve according to the target opening of the second proportional three-way valve; In an exemplary embodiment, step S3 specifically includes: S31: obtaining a heat dissipation rating of the air-cooled heat exchanger according to a maximum heat dissipation requirement of the hydrogen fuel cell system and a maximum heat dissipation of the radiator; In an exemplary embodiment, step S31 specifically includes: obtaining a heat dissipation rating of the air-cooled heat exchanger according to a maximum heat dissipation requirement of the hydrogen fuel cell system and a maximum heat dissipation of the radiator, such as the formula: , in, is the heat dissipation rating of the air-cooled heat exchanger, The maximum heat dissipation requirement for hydrogen fuel cell systems. is the maximum heat dissipation of the radiator; S32: obtaining a rated coolant flow rate through the air-cooling heat exchanger according to a rated value of heat dissipation of the air-cooling heat exchanger; S33: according to the rated value of the heat dissipation of the air-cooled heat exchanger, the power demand point of the whole vehicle is obtained, and when the operating power of the hydrogen fuel cell system is not lower than the power demand point of the whole vehicle, the second proportional three-way valve is set to an open state; S34: according to the heat dissipation power of each power point of the hydrogen fuel power system, the assisting heat dissipation power point is obtained; according to the operation conditions of the fuel cell stack and the assisting heat dissipation power point, the theoretical heat dissipation required for each assisting heat dissipation power point is obtained, and according to the theoretical heat dissipation required for each assisting heat dissipation power point, the actual heat dissipation required for each power point is obtained; according to the actual heat dissipation required for each power point, the heat required to be removed by the air-cooling heat exchanger at each power point and the coolant flow rate passing through the air-cooling heat exchanger are obtained, and according to the heat required to be removed by the air-cooling heat exchanger at each power point and the coolant flow rate passing through the air-cooling heat exchanger, the theoretical opening of the second proportional three-way valve is obtained; S35: Obtaining a target opening of the second proportional three-way valve according to the theoretical opening of the second proportional three-way valve and the calibration parameters; In an exemplary embodiment, step S35 specifically includes: obtaining a target opening of the second proportional three-way valve according to the theoretical opening of the second proportional three-way valve and the calibration parameters, such as the formula: , in, For the The target opening of the second proportional three-way valve at each power point is For the The theoretical opening of the second proportional three-way valve at each power point, No. Calibration parameters for each power point; S36: Controlling the operation of the second proportional three-way valve according to the target opening of the second proportional three-way valve; S4: Control the blower and the third proportional three-way valve according to the feedback temperature of the first temperature sensor.

[0023] In an exemplary embodiment, the above-mentioned hydrogen fuel power system thermal management system includes a water pump, a particulate filter, a temperature sensor 1, a pressure sensor, a fuel cell, a temperature sensor 2, a three-way valve 1, a water heating PTC (Positive Temperature Coefficient), a main radiator, a water flow meter, an intercooler, a three-way valve 2, an air conditioning blower, a three-way valve 3, and an air-cooled heat exchanger; wherein, the liquid outlet of the water pump is connected to the intercooler and the fuel cell respectively through the particulate filter, and the intercooler is used to cool the air at the outlet end of the hydrogen fuel cell air compressor; a temperature sensor 1 and a pressure sensor are provided at the front end of the fuel cell, and a temperature sensor 2 is provided at the rear end; the rear end of the fuel cell is connected to the three-way valve 1, and it is selected to enter the PTC or the main radiator through the three-way valve 1; a water flow meter is provided at the rear end of the main radiator, and the water flow meter is used to measure the flow of coolant through the main radiator; the outside air is blown at The outside air is cooled to cold air inside and outside the vehicle air-conditioning evaporator. The rear end of the vehicle air-conditioning evaporator is connected to a three-way valve 3. One port of the three-way valve 3 is connected to the air-cooling heat exchanger, and the other port is connected to the cab. Under the action of the three-way valve 3, the cold air flow is distributed; the rear end of the intercooler is connected to a three-way valve 2, and the coolant passes through the three-way valve 2 to choose to enter the air-cooling heat exchanger or return to the rear end of the fuel cell stack; the air-cooling heat exchanger has 4 interfaces, namely the air inlet and outlet and the coolant inlet and outlet. Its main function is to allow cold air to cool the liquid. The heat dissipation is related to the temperature and flow of the cold air and coolant.

[0024] In an exemplary embodiment, the control method applied to the thermal management system of the hydrogen fuel power system may be implemented in the following manner.

[0025] The coolant starts to circulate under the action of the water pump; in the initial state, the proportional three-way valve 1 and the proportional three-way valve 2 are closed, the rear end of the intercooler is connected to the rear end of the stack, and the main water circuit coolant passes through the three-way valve 1 through the PTC (small cycle); when the temperature sensor 1 feedback temperature is less than 20°C, the PTC is turned on to heat the coolant; when the temperature sensor 1 feedback temperature is greater than 20°C and less than 50°C, the PTC is closed and the coolant is allowed to go through the small cycle; when the temperature sensor 1 feedback temperature is greater than 60°C, the proportional three-way valve 1 is opened, the coolant enters the radiator, and the fan enters the pre-start state, the temperature sensor 1 feedback temperature is greater than 68°C, and the radiator starts working; the coolant inlet temperature requirement is guaranteed by controlling the fan speed; as the speed of all fans of the radiator reaches the maximum (rated value), the temperature feedback temperature of the temperature sensor 1 continues to rise; at this time, the three-way valve 2 is opened, and the coolant returns to the main water circuit after dissipating heat through the air-cooled heat exchanger.

[0026] In another exemplary embodiment, the control method applied to the thermal management system of the hydrogen fuel power system may be implemented in the following manner.

[0027] According to the power request of the whole vehicle to the hydrogen fuel cell system, the power response of the hydrogen fuel cell system when each power point is requested is now assumed to be Pw1, Pw2, Pw3, ..., Pwi. The required heat dissipation power of each power point can be calculated according to the system operating conditions; 1. Water pump control: 1.1 The required coolant flow rate can be calculated based on the heat dissipation power of each power point. Combined with the pressure drop of each part of the system, the required pump speed for each power point can be calculated through the pump head curve. The corresponding speed calculation values ​​of each power point are ; 1.2 Introduction of control coefficient , that is, the speeds corresponding to each power point are , through bench experiments, observe the outlet temperature of the battery stack, that is, the feedback temperature of temperature sensor 2 to calibrate the Kt value; 2. Air-cooled heat exchanger selection and proportional three-way valve 2 control: The heat dissipation components of the hydrogen fuel cell system mainly include the main radiator and the air-cooled heat exchanger; the maximum heat dissipation requirement of the hydrogen fuel cell system is , the maximum heat dissipation of the main radiator is , then the theoretical value of heat dissipation of air-cooled heat exchanger is Should be Considering the reduced efficiency of the hydrogen fuel cell system and each radiator during actual use, the heat dissipation rating of the air-cooled heat exchanger is ; The rated coolant flow through the air-cooled heat exchanger can be calculated based on the rated heat dissipation power value of the air-cooled heat exchanger; After determining the performance of the air-cooled heat exchanger, the flow distribution through the air-cooled heat exchanger and the main radiator at each power point is determined next; First, it is considered that Corresponding system power The rated speed of the lower main radiator fan just takes away the heat generated by the battery stack. Theoretically, at this power point, the three-way valve 2 begins to open; in actual use of the vehicle, It is not necessarily the power demand point of the whole vehicle, so Previous vehicle power demand point As the opening point of the three-way valve 2; secondly, the hydrogen fuel cell system at the power point , ,… The vehicle air conditioner is required to assist in heat dissipation during operation; the theoretical heat dissipation required for each power point above is obtained based on the operating conditions of the battery stack, and 10% is added to the theoretical heat dissipation as the actual required heat dissipation; the heat required to be removed by the air-cooled heat exchanger at each power point and the coolant flow through the air-cooled heat exchanger are calculated, and then the flow control through the air-cooled heat exchanger at each power point is achieved by controlling the opening of the proportional three-way valve 2; 3. Proportional three-way valve 2 calibration: 3.1 According to the factory test pressure drop data of the three-way valve, roughly determine the valve opening after the flow rate changes at each power point. Assume that the stack is , ,… During power operation, the theoretical opening of the proportional three-way valve 2 is , ,… ;Introduce calibration parameters , the target opening of the valve is , ,……, ; 3.2 On the test bench The value is calibrated, and the accuracy is generally required to be 20% higher than the target value. Power operation, the target flow rate through the air-cooled heat exchanger is , the actual flow rate should be , the total flow rate of the actual flow value of the air-cooled heat exchanger minus the flow rate shown by the flow meter at the rear end of the radiator; 4. Vehicle air conditioning and proportional three-way valve 3 control: The vehicle air conditioning is affected by the cockpit air conditioning request and the heat dissipation demand of the hydrogen fuel cell system. First, close the proportional three-way valve 3. When the system main radiator performance cannot be met, that is, the main radiator fan speed reaches the rated value, and the feedback temperature of the stack temperature sensor (temperature sensor 1) exceeds the target temperature of 68°C, the vehicle air conditioning starts to start, and the air conditioning cold air all enters the air-cooled intercooler to dissipate heat for the hydrogen fuel cell system. At this time, the air conditioning blower speed is controlled by the feedback temperature of the temperature sensor 1, and the method is as follows: The temperature sensor feedback temperature T in As the target temperature for fan control; Temperature vs. Time The first derivative of is recorded as: , About Time The first derivative of is recorded as: , that is: ,Right now for The first-order derivative with respect to time is the problem of how the reaction temperature changes with time; that is, for The second-order derivative of time reflects the rate at which the temperature changes with time; the coolant temperature belongs to a second-order linear large delay system, so not only the change situation (first-order derivative) but also the rate of change (second-order derivative problem) should be considered; the calibration shown in Table 1 is completed with the stability index and accuracy index of the target temperature; Table 1: Calibration table of stability index and accuracy index of target temperature

[0028] By querying the blower map, the air volume at each target speed can be obtained; similarly, the required air volume of the cab air conditioning can be obtained through the cab air conditioning request, and the sum of the two is the total air volume; then the actual blower speed can be obtained by corresponding to the total blower air volume; and then the air volume is distributed by controlling the opening of the three-way valve 3 to meet the heat dissipation of the cab and the hydrogen fuel cell system.

[0029] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation modes, which are merely illustrative rather than restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the present invention and the claims, all of which are within the protection of the present invention.

Claims

1. A thermal management system for a hydrogen fuel power system, characterized in that: The hydrogen fuel power system thermal management system includes a water pump, a particulate filter, a first temperature sensor, a pressure sensor, a fuel cell stack, a second temperature sensor, a first proportional three-way valve, a water heating PTC, a radiator, a water flow meter, an intercooler, a second proportional three-way valve, an air-cooled heat exchanger, a blower and a third proportional three-way valve.

2. The hydrogen fuel power system thermal management system according to claim 1, characterized in that: The liquid outlet of the water pump is connected to the front end of the intercooler and the front end of the battery stack respectively through the particle filter, the front end of the battery stack is provided with a first temperature sensor and a pressure sensor, the rear end of the battery stack is provided with a second temperature sensor, the rear end of the battery stack is connected to the input end of the first proportional three-way valve, the first output end of the first proportional three-way valve is connected to the front end of the radiator, the second output end of the first proportional three-way valve is connected to one end of the water heating PTC, the other end of the water heating PTC and the rear end of the radiator are connected to the liquid inlet of the water pump, and the rear end of the radiator is provided with a water flow meter; the intercooler The rear end of the blower is connected to the input end of the second proportional three-way valve, the first output end of the second proportional three-way valve is connected to the rear end of the fuel cell stack, and the second output end of the second proportional three-way valve is connected to the coolant inlet of the air-cooling heat exchanger; the air outlet end of the blower is connected to the input end of the third proportional three-way valve via the evaporator of the vehicle air conditioner, the first output end of the third proportional three-way valve is connected to the cab, the second output end of the third proportional three-way valve is connected to the air inlet of the air-cooling heat exchanger, the air outlet of the air-cooling heat exchanger is connected to the outside world, and the coolant outlet of the air-cooling heat exchanger is connected to the liquid inlet of the water pump.

3. The hydrogen fuel power system thermal management system according to claim 1, characterized in that: The water pump is used to drive the coolant circulation and adjust the coolant flow and pressure; the particle filter is used to filter particles in the coolant; the first temperature sensor is used to obtain the temperature of the coolant at the front end of the battery stack; the pressure sensor is used to measure the pressure of the coolant at the front end of the battery stack; the battery stack is used to provide electrical energy for the entire vehicle; The second temperature sensor is used to obtain the temperature of the coolant at the rear end of the fuel cell stack; The first proportional three-way valve is used to select the coolant at the rear end of the battery stack to enter the water-heating PTC or the radiator; the water-heating PTC is used to heat the coolant; the radiator is used to cool the coolant; the water flow meter is used to measure the flow of the coolant through the radiator; the intercooler is used to cool the air at the outlet end of the hydrogen fuel cell air compressor; the second proportional three-way valve is used to select the coolant at the rear end of the intercooler to enter the coolant inlet of the air-cooled heat exchanger or return to the rear end of the battery stack; the air-cooled heat exchanger is used to pass cold air to cool the liquid passed in; the blower is used to blow outside air into the evaporator of the vehicle air conditioner, and use the evaporator of the vehicle air conditioner to cool the outside air into cold air; the third proportional three-way valve is used to distribute the cold air flow to the air inlet of the cab and the air inlet of the air-cooled heat exchanger.

4. A control method for a thermal management system of a hydrogen fuel power system as claimed in any one of claims 1 to 3, characterized in that: The control method comprises: S1: obtaining a water pump speed at each power point of the hydrogen fuel power system according to the heat dissipation power of each power point of the hydrogen fuel power system, and controlling the operation of the water pump according to the water pump speed at each power point of the hydrogen fuel power system; S2: Controlling the water heating PTC, the first proportional three-way valve and the radiator according to the feedback temperature of the first temperature sensor; S3: obtaining a target opening of the second proportional three-way valve according to the maximum heat dissipation demand of the hydrogen fuel cell system, the maximum heat dissipation of the radiator, the heat dissipation power of each power point of the hydrogen fuel power system and calibration parameters; controlling the operation of the second proportional three-way valve according to the target opening of the second proportional three-way valve; S4: Controlling the blower and the third proportional three-way valve according to the feedback temperature of the first temperature sensor.

5. The control method according to claim 4, characterized in that: Step S1 specifically includes: S11: obtaining the coolant flow rate of each power point of the hydrogen fuel power system according to the heat dissipation power of each power point of the hydrogen fuel power system; S12: obtaining a preliminary required water pump speed for each power point according to the coolant flow rate at each power point of the hydrogen fuel power system, the pressure drop of each system component, and the water pump head curve; S13: obtaining the water pump speed at each power point of the hydrogen fuel power system according to the water pump speed and control coefficient initially required for each power point; S14: Controlling the operation of the water pump according to the water pump speed at each power point of the hydrogen fuel power system.

6. The control method according to claim 5, characterized in that: Step S13 specifically includes: obtaining the water pump speed of each power point of the hydrogen fuel power system according to the water pump speed and control coefficient initially required for each power point, such as the formula: in, Hydrogen fuel power system The pump speed at each power point, Hydrogen fuel power system The control coefficient of each power point is Hydrogen fuel power system The initial required pump speed for each power point.

7. The control method according to claim 4, characterized in that: Step S2 specifically includes: obtaining the feedback temperature of the first temperature sensor, and when the feedback temperature of the first temperature sensor is lower than the preset first liquid inlet temperature, setting the water heating PTC to a working state; when the feedback temperature of the first temperature sensor is not lower than the preset first liquid inlet temperature and lower than the preset second liquid inlet temperature, setting the water heating PTC to a closed state; when the feedback temperature of the first temperature sensor is higher than the preset third liquid inlet temperature, setting the first proportional three-way valve to an open state, and setting the radiator to a pre-start state; when the feedback temperature of the first temperature sensor is higher than the preset fourth liquid inlet temperature, setting the radiator to a working state.

8. The control method according to claim 4, characterized in that: Step S3 specifically includes: S31: obtaining a heat dissipation rating of the air-cooled heat exchanger according to a maximum heat dissipation requirement of the hydrogen fuel cell system and a maximum heat dissipation of the radiator; S32: obtaining a rated coolant flow rate through the air-cooling heat exchanger according to the heat dissipation rating of the air-cooling heat exchanger; S33: obtaining a vehicle power demand point according to the heat dissipation rating of the air-cooled heat exchanger, and setting the second proportional three-way valve to an open state when the operating power of the hydrogen fuel cell system is not lower than the vehicle power demand point; S34: according to the heat dissipation power of each power point of the hydrogen fuel power system, the assisting heat dissipation power point is obtained; according to the operation conditions of the fuel cell stack and the assisting heat dissipation power point, the theoretical heat dissipation required for each assisting heat dissipation power point is obtained, and according to the theoretical heat dissipation required for each assisting heat dissipation power point, the actual heat dissipation required for each power point is obtained; according to the actual heat dissipation required for each power point, the heat required to be removed by the air-cooling heat exchanger at each power point and the coolant flow rate passing through the air-cooling heat exchanger are obtained, and according to the heat required to be removed by the air-cooling heat exchanger at each power point and the coolant flow rate passing through the air-cooling heat exchanger, the theoretical opening of the second proportional three-way valve is obtained; S35: Obtaining a target opening of the second proportional three-way valve according to the theoretical opening of the second proportional three-way valve and the calibration parameters; S36: Controlling the operation of the second proportional three-way valve according to the target opening of the second proportional three-way valve.

9. The control method according to claim 8, characterized in that: Step S31 specifically includes: obtaining the heat dissipation rating of the air-cooled heat exchanger according to the maximum heat dissipation requirement of the hydrogen fuel cell system and the maximum heat dissipation of the radiator, such as the formula: ， in, is the heat dissipation rating of the air-cooled heat exchanger, The maximum heat dissipation requirement for hydrogen fuel cell systems. is the maximum heat dissipation of the radiator.

10. The control method according to claim 8, characterized in that: Step S35 specifically includes: obtaining the target opening of the second proportional three-way valve according to the theoretical opening of the second proportional three-way valve and the calibration parameters, such as the formula: ， in, For the The target opening of the second proportional three-way valve at each power point is For the The theoretical opening of the second proportional three-way valve at each power point, No. Calibration parameters for each power point.

Images