Fuel cell vehicle and control method for integrated cooling and heating thermal management system thereof

Abstract

The application provides a fuel cell vehicle and a refrigeration and heating integrated thermal management system and control method thereof, and belongs to the field of fuel cell vehicles. A passage one of a first heat exchanger is connected in series in a motor and motor controller cooling liquid circulation branch, and a passage one of a second heat exchanger is connected in series in a fuel cell cooling liquid circulation branch. A waste heat utilization circulation branch comprises a refrigeration branch and a heating branch connected in parallel, the refrigeration branch is composed of a first two-way valve and an absorption refrigeration air conditioner connected in series, and the heating branch is composed of a second two-way valve and an indoor water heating radiator module connected in series. Cooling liquid passing through the absorption refrigeration air conditioner and the indoor water heating radiator module flows through a passage two of the first heat exchanger and / or a passage two of the second heat exchanger under the action of a water pump and then enters the refrigeration branch or the heating branch. The system can fully utilize various waste heat of the vehicle and simultaneously has refrigeration and heating functions.

Description

Technical Field

[0001] This invention relates to a fuel cell vehicle and its integrated thermal management system and control method for cooling and heating, belonging to the field of fuel cell vehicle technology. Background Technology

[0002] The fuel cell system / engine on a fuel cell vehicle includes a fuel cell stack and a fuel cell auxiliary system. It can operate normally when connected to an external hydrogen source. The fuel cell auxiliary system mainly includes: a cooling system, a hydrogen system, an air system, an electrical system, and a control system.

[0003] Fuel cell vehicles generate a large amount of waste heat during operation, including fuel cell waste heat, motor and motor controller waste heat, and other waste heat from the vehicle. Among these, (1) fuel cell waste heat is the largest source of waste heat in fuel cell vehicles. Fuel cells generate a large amount of heat, i.e., waste heat, during the process of generating electricity through electrochemical reactions. For hydrogen fuel cells, the electrical efficiency is about 50%, meaning that for every 1kW of electricity generated by the fuel cell, 1kW of waste heat is also generated. For fuel cell vehicles, if the average electrical power of the fuel cell is 30kW, then the waste heat is also 30kW. The waste heat temperature of fuel cells is mostly between 60-80℃. Currently, most of the waste heat generated by fuel cells is transferred to the environment through two pathways: a) carried out of the fuel cell by the coolant and dissipated by the radiator; b) directly discharged into the atmosphere through exhaust gas. The exhaust gas of fuel cells contains a large amount of water vapor, which contains a lot of latent heat. (2) Waste heat from the motor and motor controller is the second largest source of waste heat in fuel cell vehicles. When the motor and motor controller are working, the electrical efficiency cannot reach 100%, and the remaining electrical energy is converted into heat energy. For fuel cell buses, the waste heat from the commonly used motor and motor controller is about 15kW, and the temperature of the waste heat from the motor and controller is mostly between 60-100℃. (3) Other waste heat of the whole vehicle. Fuel cell vehicles also have other sources of waste heat, such as waste heat from the fuel cell air compressor + DC / DC, waste heat from the power battery, etc. Compared with the waste heat from the fuel cell and the waste heat from the motor and motor controller, the other waste heat of the whole vehicle is less.

[0004] Current fuel cell vehicles achieve summer cooling and winter heating through the following methods: (1) Summer cooling is achieved through onboard air conditioning, specifically using traditional compression refrigeration; (2) Winter heating is achieved through onboard air conditioning or electric heaters. The heating principle of onboard air conditioning is the heat pump principle, which is the reverse process of compression refrigeration; electric heaters are PTC electric heaters, which directly heat the air. This cooling and heating method has the following drawbacks: both summer cooling and winter heating of the passenger compartment consume a large amount of electricity, which will significantly increase the energy consumption of the entire vehicle and shorten the vehicle's driving range. Moreover, the waste heat from components such as fuel cells, motors, and motor controllers is not utilized and is directly emitted into the ambient air, resulting in energy waste.

[0005] Currently, there are also methods for achieving refrigeration using waste heat, such as using absorption refrigeration systems. Absorption refrigeration systems have the following main characteristics: (1) They mainly use waste heat, exhaust gas, and other thermal energy as energy sources, which can greatly reduce energy consumption; (2) They use water as a refrigerant, which is more environmentally friendly; (3) The system power can be adjusted within the range of 30% to 100%, and the refrigeration power adjustment range is relatively wide, which can adapt to various heat sources. In the Chinese invention patent application document with publication number CN109458750A, a lithium bromide absorption refrigeration system that utilizes the waste heat of motor control and fuel cell is disclosed. This system introduces the waste heat of motor control and fuel cell into the heat exchanger in parallel, and transfers the heat to the absorption refrigeration air conditioner to achieve refrigeration. Because there is a temperature difference between the waste heat from the motor and the waste heat from the fuel cell, this patent introduces these two types of waste heat into the same heat exchanger in parallel, which leads to insufficient utilization of vehicle waste heat and low waste heat utilization efficiency. Moreover, this patent can only achieve waste heat cooling, not waste heat heating. In addition, this patent cannot achieve waste heat utilization from fuel cell exhaust gas, nor does it have integrated cooling and heating control, and it does not have refined management and control of the waste heat utilization process. Summary of the Invention

[0006] The purpose of this invention is to provide a fuel cell vehicle and its integrated thermal management system and control method for cooling and heating, which can make full use of various waste heats of the vehicle, improve the waste heat utilization rate, and realize both waste heat cooling and waste heat heating.

[0007] To achieve the above objectives, the present invention provides an integrated cooling and heating thermal management system, which includes: a controller, a first heat exchanger, a second heat exchanger, a waste heat generation circulation branch and a waste heat utilization circulation branch, wherein the waste heat generation circulation branch includes at least a motor and a motor controller coolant circulation branch and a fuel cell coolant circulation branch.

[0008] Among them, the first heat exchanger channel is connected in series in the motor and motor controller coolant circulation branch, and the second heat exchanger channel is connected in series in the fuel cell coolant circulation branch.

[0009] The waste heat recovery circulation branch includes a parallel refrigeration branch and a heating branch. The refrigeration branch is composed of a first two-way valve and an absorption refrigeration air conditioner connected in series, and the heating branch is composed of a second two-way valve and an in-vehicle water heating radiator module connected in series. The coolant passing through the absorption refrigeration air conditioner and the in-vehicle water heating radiator module flows through channel two of the first heat exchanger and / or channel two of the second heat exchanger under the action of the water pump before entering the refrigeration branch or the heating branch. A first temperature sensor is installed on the water pump outlet pipe, and a second temperature sensor is installed on the inlet pipe of the refrigeration branch and the heating branch.

[0010] The controller controls the absorption refrigeration air conditioner, the in-vehicle water heating radiator module, the water pump, and various temperature sensors.

[0011] The present invention also provides a fuel cell vehicle, including a vehicle body and an integrated cooling and heating thermal management system, wherein the integrated cooling and heating thermal management system is the aforementioned integrated cooling and heating thermal management system.

[0012] The beneficial effects of this fuel cell vehicle and its integrated cooling and heating thermal management system are as follows: The integrated cooling and heating thermal management system utilizes two heat exchangers to realize waste heat utilization. One heat exchanger is used to utilize the waste heat of the motor and motor controller, and the other heat exchanger is used to utilize the waste heat of the fuel cell. This can make full use of various waste heat sources in the vehicle and improve the waste heat utilization rate. At the same time, the waste heat utilization circulation branch includes parallel cooling and heating branches. By controlling the flow direction of the coolant in the waste heat utilization circulation branch, the switching between waste heat cooling and waste heat heating can be realized, so that the integrated cooling and heating thermal management system can realize both waste heat cooling and waste heat heating.

[0013] In order to utilize the waste heat from the exhaust gas of the fuel cell engine and further improve the waste heat utilization rate, in the above-mentioned fuel cell vehicle and its integrated cooling and heating thermal management system, the second heat exchanger is a three-channel heat exchanger. The third channel of the second heat exchanger is connected to the exhaust gas discharge pipeline of the fuel cell engine, and the exhaust gas discharge direction is opposite to the coolant flow direction in the waste heat utilization circulation branch.

[0014] Furthermore, in the aforementioned fuel cell vehicle and its integrated cooling and heating thermal management system, channel two of the first heat exchanger is connected in series with channel two of the second heat exchanger; wherein, the outlets of the cooling branch and the heating branch are connected to the inlet of the water pump, the outlet of the water pump is connected to the inlet of channel two of the second heat exchanger, the outlet of channel two of the second heat exchanger is connected to the inlet of channel two of the first heat exchanger, and the outlet of channel two of the first heat exchanger is connected to the inlet of the cooling branch and the heating branch.

[0015] The beneficial effects of this approach are: by connecting the second channel of the first heat exchanger with the second channel of the second heat exchanger in series, it is possible to fully utilize the characteristic that the waste heat temperature of the motor and motor controller is higher than that of the fuel cell. By having the coolant in the waste heat utilization circulation branch first exchange heat with the fuel cell coolant through the second heat exchanger, and then exchange heat with the motor and motor controller coolant through the first heat exchanger, it is ensured that there is a temperature difference to exchange heat, thus making full use of various types of waste heat and improving the waste heat utilization rate.

[0016] Furthermore, in the aforementioned fuel cell vehicle and its integrated cooling and heating thermal management system, the waste heat utilization circulation branch further includes a first three-way valve, a second three-way valve, a first coolant pipeline, and a second coolant pipeline; wherein, the outlet of the water pump is connected to the inlet of the second heat exchanger channel two, the outlet of the second heat exchanger channel two is connected to the first inlet of the second three-way valve, the outlet of the second three-way valve is connected to the inlet of the first heat exchanger channel two, the outlet of the first heat exchanger channel two is connected to the first inlet of the first three-way valve, and the outlet of the first three-way valve is connected to the inlet of the cooling branch and the heating branch; the outlet of the water pump is also connected to the second inlet of the second three-way valve through the second coolant pipeline, and the outlet of the second three-way valve is also connected to the second inlet of the first three-way valve through the first coolant pipeline; a third temperature sensor is installed on the outlet pipeline of the second three-way valve, and the controller also controls the connection to the third temperature sensor.

[0017] The beneficial effects of this approach are: by setting up a first three-way valve, a second three-way valve, a first coolant pipeline, and a second coolant pipeline, the flow direction and flow rate of coolant in the waste heat utilization circulation branch can be precisely controlled, enabling refined management and control of the waste heat utilization process.

[0018] Furthermore, in the aforementioned fuel cell vehicle and its integrated cooling and heating thermal management system, channel two of the first heat exchanger and channel two of the second heat exchanger are connected in parallel; wherein, the outlet of channel two of the first heat exchanger and the outlet of channel two of the second heat exchanger are connected in parallel to the inlet of the cooling branch and the heating branch, the inlet of channel two of the first heat exchanger and the inlet of channel two of the second heat exchanger are connected in parallel to the outlet of the water pump, and the inlet of the water pump is connected to the outlet of the cooling branch and the heating branch.

[0019] The beneficial effect of doing this is that by connecting channel two of the first heat exchanger and channel two of the second heat exchanger in parallel, another way to realize waste heat utilization can be provided.

[0020] Furthermore, in the aforementioned fuel cell vehicle and its integrated cooling and heating thermal management system, the waste heat utilization circulation branch further includes a third three-way valve, a fourth three-way valve, a third coolant pipeline, and a fourth coolant pipeline; wherein, the outlet of the third three-way valve and the outlet of the fourth three-way valve are connected in parallel to the inlets of the cooling branch and the heating branch, the first inlet of the third three-way valve is connected to the outlet of the second channel of the first heat exchanger, and the second inlet of the third three-way valve is connected to the outlet of the water pump through the third coolant pipeline; the first inlet of the fourth three-way valve is connected to the outlet of the second channel of the second heat exchanger, and the second inlet of the fourth three-way valve is connected to the outlet of the water pump through the fourth coolant pipeline; a fourth temperature sensor is installed on the outlet pipeline of the third three-way valve, and a fifth temperature sensor is installed on the outlet pipeline of the fourth three-way valve, and the controller also controls the connection of the fourth and fifth temperature sensors.

[0021] The beneficial effects of this approach are that by setting up a third three-way valve, a fourth three-way valve, a third coolant pipeline, and a fourth coolant pipeline, the flow direction and flow rate of coolant in the waste heat utilization circulation branch can be precisely controlled, enabling refined management and control of the waste heat utilization process.

[0022] The present invention also provides a control method for an integrated refrigeration and heating thermal management system, the method comprising the following steps:

[0023] (1) Obtain the target control temperature of the vehicle and determine whether the current control mode of the integrated cooling and heating thermal management system is cooling mode or heating mode based on the target control temperature.

[0024] (2) When in cooling mode, control the cooling branch to be turned on and the heating branch to be turned off, and calculate in real time the current required waste heat for cooling, the current available waste heat of the fuel cell, the current available waste heat of the motor and motor controller, the current actual utilization of waste heat of the fuel cell and the current actual utilization of waste heat of the motor and motor controller. The current required waste heat for cooling is used as the control target, and waste heat cooling is achieved by controlling the flow direction of coolant in the waste heat utilization circulation branch.

[0025] (3) When in heating mode, control the heating branch to be turned on and the cooling branch to be turned off, and calculate in real time the current required waste heat, the current available waste heat of the fuel cell, the current available waste heat of the motor and motor controller, the current actual utilization of waste heat of the fuel cell and the current actual utilization of waste heat of the motor and motor controller. Using the current required waste heat as the control target, waste heat heating is achieved by controlling the flow direction of coolant in the waste heat utilization circulation branch.

[0026] The beneficial effect of this integrated refrigeration and heating thermal management system control method is that it enables integrated control of the aforementioned integrated refrigeration and heating thermal management system.

[0027] Furthermore, in the above-mentioned integrated cooling and heating thermal management system control method, the process of realizing waste heat cooling includes: if the current required waste heat for cooling is less than or equal to the current available waste heat of the fuel cell, then only the waste heat of the fuel cell is used for waste heat cooling, and the flow direction of the coolant in the waste heat utilization circulation branch is controlled according to the deviation between the current required waste heat for cooling and the current actual utilization of the fuel cell waste heat to achieve waste heat cooling; if the current available waste heat of the fuel cell is less than the current required waste heat for cooling and less than or equal to the current available waste heat of the fuel cell plus the current available waste heat of the motor and motor controller, then both the waste heat of the fuel cell and the waste heat of the motor and motor controller are used for waste heat cooling, wherein all the waste heat of the fuel cell is used, and the flow direction of the coolant in the waste heat utilization circulation branch is controlled according to the deviation between the current required waste heat for cooling and the current actual utilization of the waste heat to achieve waste heat cooling, wherein the current actual utilization of waste heat = the current actual utilization of the fuel cell waste heat + the current actual utilization of the motor and motor controller waste heat;

[0028] The process of achieving waste heat heating includes: if the current required waste heat is less than or equal to the current available waste heat of the fuel cell, then only the waste heat of the fuel cell is used for waste heat heating, and the flow direction of the coolant in the waste heat utilization circulation branch is controlled according to the deviation between the current required waste heat and the current actual utilization of the fuel cell waste heat to achieve waste heat heating; if the current available waste heat of the fuel cell is less than the current required waste heat and less than or equal to the current available waste heat of the fuel cell plus the current available waste heat of the motor and motor controller, then both the waste heat of the fuel cell and the waste heat of the motor and motor controller are used simultaneously, wherein all the waste heat of the fuel cell is used, and the flow direction of the coolant in the waste heat utilization circulation branch is controlled according to the deviation between the current required waste heat and the current actual utilization of the waste heat to achieve waste heat heating.

[0029] Furthermore, in the above-mentioned integrated cooling and heating thermal management system control method, the available amount of waste heat from the fuel cell is equal to the available amount of waste heat from the fuel cell coolant, or the available amount of waste heat from the fuel cell is equal to the available amount of waste heat from the fuel cell coolant plus the available amount of waste heat from the fuel cell engine exhaust. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the integrated cooling and heating thermal management system in the vehicle embodiment of the present invention;

[0031] Figure 2 This is a flowchart of the control method for the integrated cooling and heating thermal management system in the vehicle embodiment of the present invention;

[0032] In the diagram, 1 is the fuel cell engine, 2 is the motor and motor controller, 3 is the two-channel heat exchanger, 4 is the three-channel heat exchanger, 5 is the absorption refrigeration air conditioner, 6 is the in-vehicle water heating radiator module, 7 is the first electrically controlled three-way valve, 8 is the second electrically controlled three-way valve, 9 is the first electrically controlled two-way valve, 10 is the second electrically controlled two-way valve, 11 is the fuel cell radiator, 12 is the motor and motor controller radiator, 13 is the motor and motor controller circulating water pump, 14 is the fuel cell circulating water pump, 15 is the waste heat recovery circulating water pump, 16 is the exhaust gas emission line connecting the fuel cell engine and the three-channel heat exchanger, 17 is the exhaust gas emission line connecting to the atmosphere, 18 is the air conditioning controller, 19 is the bypass line of the two-channel heat exchanger 3, 20 is the bypass line of the three-channel heat exchanger 4, and 21, 22, and 23 are all temperature sensors. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0034] Vehicle Example:

[0035] The fuel cell vehicle of this embodiment includes a vehicle body and an integrated cooling and heating thermal management system, wherein the integrated cooling and heating thermal management system is as follows: Figure 1 As shown, the system includes an air conditioning controller 18 (i.e., the controller), a two-channel heat exchanger 3 (i.e., the first heat exchanger), a three-channel heat exchanger 4 (i.e., the second heat exchanger), a waste heat generation circulation branch, and a waste heat utilization circulation branch. The waste heat generation circulation branch includes: a motor and motor controller coolant circulation branch, a fuel cell coolant circulation branch, and a fuel cell engine exhaust branch (although the exhaust branch does not constitute a circulation, since exhaust gas is continuously generated during the operation of the fuel cell engine, the exhaust branch can be regarded as a circulation branch).

[0036] The motor and motor controller coolant circulation branch includes a motor and motor controller 2, a motor and motor controller circulating water pump 13, a two-channel heat exchanger 3, and a motor and motor controller radiator 12 connected in series.

[0037] The fuel cell coolant circulation branch includes a fuel cell engine 1, a fuel cell circulating water pump 14, a three-channel heat exchanger 4, and a fuel cell radiator 11 connected in series.

[0038] The fuel cell engine exhaust branch includes an exhaust pipe 16 for connecting the fuel cell engine to the three-channel heat exchanger and an exhaust pipe 17 for connecting to the atmosphere.

[0039] The first channel of the two-channel heat exchanger 3 is connected in series in the coolant circulation branch of the motor and motor controller, the first channel of the three-channel heat exchanger 4 is connected in series in the coolant circulation branch of the fuel cell, and the third channel of the three-channel heat exchanger 4 is connected to the exhaust gas discharge pipe 16 and the exhaust gas discharge pipe 17 (i.e. connected to the exhaust gas discharge pipe of the fuel cell engine).

[0040] The waste heat utilization circulation branch includes a parallel refrigeration branch and a heating branch. The refrigeration branch is composed of a first electrically controlled two-way valve 9 (i.e., the first two-way valve) and an absorption refrigeration air conditioner 5 connected in series. The heating branch is composed of a second electrically controlled two-way valve 10 (i.e., the second two-way valve) and an in-vehicle water heating radiator module 6 connected in series. The coolant passing through the absorption refrigeration air conditioner 5 and the in-vehicle water heating radiator module 6 flows through the second channel of the first heat exchanger and / or the second channel of the second heat exchanger under the action of the waste heat utilization circulation water pump 15 (hereinafter referred to as the third water pump) and then enters the refrigeration branch or the heating branch. (When in refrigeration mode, all the coolant in the waste heat utilization circulation branch flows out from the absorption refrigeration air conditioner and then into the refrigeration branch. When in heating mode, all the coolant in the waste heat utilization circulation branch flows out from the in-vehicle water heating radiator module and then into the heating branch.)

[0041] The waste heat recovery circulation branch also includes a first electrically controlled three-way valve 7 (i.e., the first three-way valve), a second electrically controlled three-way valve 8 (i.e., the second three-way valve), a bypass pipe 19 (i.e., the first coolant pipe) for the two-channel heat exchanger 3, and a bypass pipe 20 (i.e., the second coolant pipe) for the three-channel heat exchanger 4; wherein, the outlets of the refrigeration branch and the heating branch are connected to the inlet of the third water pump, the outlet of the third water pump is connected to the inlet of the second heat exchanger channel two, the outlet of the second heat exchanger channel two is connected to the first inlet of the second three-way valve, the outlet of the second three-way valve is connected to the inlet of the first heat exchanger channel two, the outlet of the first heat exchanger channel two is connected to the first inlet of the first three-way valve, and the outlet of the first three-way valve is connected to the inlet of the refrigeration branch and the heating branch; the outlet of the water pump is also connected to the second inlet of the second three-way valve through the second coolant pipe, and the outlet of the second three-way valve is also connected to the second inlet of the first three-way valve through the first coolant pipe;

[0042] The outlet pipe of the third water pump is equipped with a first temperature sensor (i.e., temperature sensor 21), the inlet pipes of the cooling branch and the heating branch are equipped with a second temperature sensor (i.e., temperature sensor 23), and the outlet pipe of the second three-way valve is equipped with a third temperature sensor (i.e., temperature sensor 22).

[0043] The air conditioning controller 18 controls and connects to the absorption refrigeration air conditioner 5, the in-vehicle water heating radiator module 6, the third water pump, various valves, and various temperature sensors.

[0044] The functions of each device in the integrated refrigeration and heating thermal management system will be described in detail below. For the sake of simplicity, the names of each device in the system will be replaced with corresponding numbers.

[0045] In this embodiment of the integrated cooling and heating thermal management system, lines 5, 6, 7, 8, 9, 10, 15, 21, 22, 23, and 18 are control line connections; lines 16 and 17 are fuel cell engine exhaust pipes; and all other connection lines (including lines 19 and 20) are coolant pipes. Specifically, the coolant flow direction in the fuel cell coolant circulation branch is: 1→14→4→11→1; the coolant flow direction in the motor and motor controller coolant circulation branch is: 2→13→3→12→2; the exhaust gas flow direction in the fuel cell engine exhaust branch is: 1→16→4→17; and the coolant flow direction in the waste heat recovery circulation branch varies depending on the actual situation. When in cooling mode, the coolant flow direction in the waste heat recovery circulation branch includes: 15→4 and 20→19→9→5→15 (coolant partially flows through line 4, not through line 3), and 15→4. →19→9→5→15 (coolant flows entirely through 4, not through 3), 15→4→3 and 19→9→5→15 (coolant first flows entirely through 4, then partially through 3), 15→4→3→9→5→15 (coolant first flows entirely through 4, then entirely through 3); when in heating mode, the coolant flow direction in the waste heat utilization circulation branch includes: 15→4 and 20→19→10→6→15, 15→4→19→10→6→15, 15→4→3 and 19→10→6→15, 15→4→3→10→6→15.

[0046] By connecting the motor and motor controller coolant to the two-channel heat exchanger 3, the waste heat of the motor and motor controller can be transferred to the waste heat utilization circulation branch; by connecting the fuel cell coolant and fuel cell exhaust gas to the three-channel heat exchanger 4, the waste heat in the fuel cell coolant and exhaust gas can be transferred to the waste heat utilization circulation branch. Because the fuel cell coolant and exhaust gas have similar temperatures, there is little heat exchange between them, and the heat is mainly transferred to the lower-temperature waste heat utilization circulation.

[0047] In this embodiment, 3 and 4 are connected in series. According to the temperature characteristics of the components, since the temperature of the coolant in the motor and motor controller is higher than that of the fuel cell coolant, the coolant in the waste heat utilization circulation branch first passes through 4 and then through 3. This ensures that there is a temperature difference to exchange for heat, making full use of various waste heat sources and improving waste heat utilization efficiency.

[0048] The absorption cooling air conditioner 5 can use waste heat for cooling, and the produced cold air is transferred to the passenger compartment through the air duct. The in-vehicle water heating radiator module 6 can use waste heat for heating. When the waste heat flows through the in-vehicle water heating radiator module using the coolant in the circulation branch, the cooling fan directly transfers the heat to the passenger compartment.

[0049] 7 and 8 are electrically controlled three-way valves, with two inlets and one outlet. The sum of the flow rates of the two inlets is the outlet flow rate. If the flow rate of one inlet increases, the flow rate of the other inlet decreases proportionally. Bypass lines 19 and 20 can bypass 3 and 4 respectively. Through 7 and 8, the flow rate of coolant entering 3 and 4 in the waste heat recovery circulation branch can be controlled, thereby enabling refined management and control of the waste heat recovery process. For example, if it is necessary to reduce the amount of waste heat recovery, controlling 7 and 8 will allow more flow to pass through bypass lines 19 and 20.

[0050] 9 and 10 are electrically controlled two-way valves, which are shut-off valves with only two states: open and closed.

[0051] 15 is a waste heat recovery circulating water pump, which provides power for waste heat recovery circulation. This water pump is a fixed frequency water pump and operates at a constant speed after being powered on.

[0052] 18 represents the air conditioning controller. In this embodiment, the vehicle's cooling and heating needs are uniformly managed by the air conditioning controller. The air conditioning controller receives driver commands through the air conditioning control panel and then automatically executes and manages the heating or cooling process according to its built-in program. This embodiment achieves integrated management of cooling and heating through the air conditioning controller. In other implementations, a dedicated controller can also be used to achieve these functions.

[0053] 21, 22, and 23 collect the coolant temperature at the corresponding locations in real time. The collected temperature values ​​are represented by T3, T4, and T5, respectively, and the temperature values ​​are transmitted to the controller 18.

[0054] Based on the above-mentioned integrated cooling and heating thermal management system, the control method of the integrated cooling and heating thermal management system in this embodiment is as follows: Figure 2As shown, this method controls the opening or closing of the refrigeration and heating branches, allowing the coolant in the waste heat utilization circulation branch to flow only in the refrigeration branch or only in the heating branch, thus achieving the switching between waste heat refrigeration and waste heat heating. It calculates the required heat / cooling capacity in real time based on the actual temperature inside the vehicle and the target control temperature, and converts the required heat / cooling capacity into the required waste heat (target value) according to the energy efficiency ratio. It calculates the actual waste heat (actual value) obtained from the fuel cell, motor, and motor controller in real time based on the coolant temperature and flow rate on the waste heat utilization side. Based on the comparison between the target and actual waste heat values, it performs PID control on the electronically controlled three-way valve, adjusting the coolant flow rate into the heat exchanger to control the actual waste heat utilization amount in real time. It monitors the available waste heat from the fuel cell, motor, and motor controller in real time, and intelligently controls the gradual input of the two waste heat sources according to vehicle needs, maximizing the utilization of vehicle waste heat.

[0055] The water pumps and radiators of the fuel cell coolant circulation branch, motor and motor controller coolant circulation branch are controlled by each system and operate according to their existing strategies. They only need to upload their operating status and related parameters to the vehicle CAN network, and then the 18 will read and parse them automatically.

[0056] The following is combined Figure 2 The heating and cooling modes will be described in detail below:

[0057] I. Heating Mode

[0058] (1) When the waste heat utilization circulating water pump 15 is turned on, the coolant begins to circulate and flows through the vehicle water heating radiator module 6 to supply heat to the vehicle compartment.

[0059] (2) The air conditioning controller 18 calculates in real time the available amount of waste heat of fuel cell Q1, the available amount of waste heat of motor and motor controller Q2, the required heating capacity Q4 (equal to the required waste heat), the actual amount of waste heat of fuel cell Q6 and the actual amount of waste heat of motor and motor controller Q7.

[0060] (3) If Q4≤Q1, it means that the fuel cell has sufficient available waste heat. When heating, only the waste heat of the fuel cell can be used (the specific amount used is achieved by PID control of 8). The waste heat of the motor and motor controller is not used (control 7 to make the coolant flow through 19 and not through 3).

[0061] If Q1 < Q4 ≤ Q1 + Q2, then during heating, the waste heat of the fuel cell and the waste heat of the motor and motor controller must be used simultaneously. All the available waste heat of the fuel cell is used (control 8, so that all the coolant flows through 4), and a portion of the waste heat of the motor and motor controller is used (the specific amount used is achieved through PID control of 7).

[0062] If Q1 + Q2 < Q4, it means that the waste heat required for heating is greater than the waste heat available from the fuel cell plus the waste heat available from the motor and motor controller. In this case, both of them need to be put into use and combined with other heating modules in the vehicle to heat the vehicle (e.g., using heating modules such as electric heaters in the vehicle).

[0063] Regarding PID control, let's take PID control of 8 as an example (PID control of 7 is similar): Q4 is the target value controlled by 8 (to prevent frequent changes, it is updated / changed once every t1 time interval, and the size of t1 is set according to actual needs), and Q6 is the actual value calculated in real time. 8 needs to be controlled so that Q6 is close to or equal to Q4. If Q6≤Q4, and the difference between the two is large (P), increasingly large (I), and increasing at a faster rate (D), then more coolant is controlled to flow through 4, increasing the actual waste heat utilization Q6; if Q6>Q4, and the difference between the two is large (P), increasingly large (I), and increasing at a faster rate (D), then more coolant flow is controlled to flow through the bypass pipe 19 of 4, reducing the actual waste heat utilization Q6.

[0064] II. Cooling Mode

[0065] (1) The waste heat utilization circulating water pump 15 is turned on, the coolant starts to circulate, and all of it flows through the absorption refrigeration air conditioner 5 to cool the car compartment.

[0066] (2) The air conditioning controller 18 calculates in real time the available amount of waste heat of fuel cell Q1, the available amount of waste heat of motor and motor controller Q2, the waste heat required for cooling Q5, the actual amount of waste heat utilized by fuel cell Q6 and the actual amount of waste heat utilized by motor and motor controller Q7.

[0067] (3) If Q5≤Q1, it means that the fuel cell has sufficient available waste heat. When cooling, only the waste heat of the fuel cell can be used (the specific amount used is achieved by PID control of 8). The waste heat of the motor and motor controller is not used (control 7 to make the coolant flow through 19 and not through 3).

[0068] If Q1 < Q5 ≤ Q1 + Q2, then during cooling, the waste heat of the fuel cell and the waste heat of the motor and motor controller must be used simultaneously. All the waste heat of the fuel cell is used (control 8, so that all the coolant flows through 4), and a portion of the waste heat of the motor and motor controller is used (the specific amount used is achieved through PID control of 7).

[0069] If Q1 + Q2 < Q5, it means that the waste heat required for cooling is greater than the waste heat available from the fuel cell plus the waste heat available from the motor and motor controller. In this case, both of them need to be put into use and combined with other cooling modules in the vehicle to cool the vehicle (e.g., using cooling modules such as fans in the vehicle).

[0070] The PID control principle for 7 and 8 is the same as above.

[0071] The relevant parameters and calculation explanations involved in the control method of the integrated refrigeration and heating thermal management system in this embodiment are detailed in Table 1:

[0072] Table 1 Parameter Description and Calculation Table

[0073]

[0074]

[0075]

[0076]

[0077] In this embodiment, the second heat exchanger is a three-channel heat exchanger, which can simultaneously provide waste heat from the fuel cell coolant and waste heat from the fuel cell engine exhaust. Therefore, when calculating the available amount of waste heat from the fuel cell, the available amount of waste heat from the fuel cell = available amount of waste heat from the fuel cell coolant + available amount of waste heat from the fuel cell engine exhaust. As another implementation, the hardware related to the utilization of exhaust waste heat in the system can be removed, and the second heat exchanger can be replaced with a two-channel heat exchanger. In this case, only waste heat from the fuel cell coolant is provided, and when calculating the available amount of waste heat from the fuel cell, the available amount of waste heat from the fuel cell = available amount of waste heat from the fuel cell coolant.

[0078] In this embodiment, the two-way heat exchanger 3 and the three-way heat exchanger 4 are connected in series, and the coolant in the waste heat utilization circulation branch first passes through the three-way heat exchanger 4 and then through the two-way heat exchanger 3, which can first utilize the waste heat of the fuel cell and then the waste heat of the motor and motor controller, thereby improving the waste heat utilization rate of the vehicle; as another implementation, the two-way heat exchanger 3 and the three-way heat exchanger 4 can also be changed to a parallel connection. There are two connection methods: (1) the outlet of the second channel of the two-way heat exchanger 3 and the outlet of the second channel of the three-way heat exchanger 4 are connected in parallel and then connected to the inlet of the refrigeration branch and the heating branch. The inlet of the second channel of the two-way heat exchanger 3 and the inlet of the second channel of the three-way heat exchanger 4 are connected in parallel and then connected to the outlet of the third water pump. (1) The pump inlet is connected to the outlet of the refrigeration branch and the heating branch; (2) The outlet of the third three-way valve and the outlet of the fourth three-way valve are connected in parallel to the inlet of the refrigeration branch and the heating branch. The first inlet of the third three-way valve is connected to the outlet of the second channel of the two-way heat exchanger 3. The second inlet of the third three-way valve is connected to the outlet of the third water pump through the third coolant pipeline. The first inlet of the fourth three-way valve is connected to the outlet of the second channel of the three-way heat exchanger 4. The second inlet of the fourth three-way valve is connected to the outlet of the third water pump through the fourth coolant pipeline. A fourth temperature sensor is installed on the outlet pipeline of the third three-way valve. A fifth temperature sensor is installed on the outlet pipeline of the fourth three-way valve. The controller also controls the connection of the fourth and fifth temperature sensors.

[0079] In summary, the integrated refrigeration and heating thermal management system and its control method of this embodiment have the following advantages:

[0080] (1) Real-time monitoring of the available waste heat of fuel cell, motor and motor controller, and intelligent control of the gradual input of the two waste heat sources according to vehicle demand; real-time calculation and monitoring of the actual waste heat utilization, feeding the value back to fuel cell, motor and motor controller, thereby formulating corresponding measures, which can minimize the impact of waste heat utilization on the thermal management of the two waste heat sources themselves, and can maximize the utilization of waste heat according to demand, reduce the heating energy consumption of the whole vehicle, and increase the driving range of the vehicle.

[0081] (2) To achieve precise control of waste heat utilization, the entire integrated thermal management system can operate in an orderly and stable manner. Specifically, by setting multiple three-way valves and two-way valves in combination, the switching between waste heat cooling and heating can be achieved. Through the PID regulation of the three-way valve, the amount of waste heat utilization can be adjusted in real time and accurately.

[0082] System Implementation Example:

[0083] The integrated cooling and heating thermal management system in this embodiment is the same as the integrated cooling and heating thermal management system in the vehicle embodiment, and will not be described again here.

[0084] Method Implementation Examples:

[0085] The control method of the integrated cooling and heating thermal management system in this embodiment is the same as that in the vehicle embodiment, and will not be described again here.

Claims

1. An integrated cooling and heating thermal management system, characterized in that, The system comprises: a controller, a first heat exchanger, a second heat exchanger, a waste heat generation circulation branch and a waste heat utilization circulation branch, wherein the waste heat generation circulation branch at least comprises a motor and motor controller coolant circulation branch and a fuel cell coolant circulation branch; wherein, a first channel of the first heat exchanger and a motor and motor controller radiator are connected in series in the motor and motor controller coolant circulation branch, and a first channel of the second heat exchanger and a fuel cell radiator are connected in series in the fuel cell coolant circulation branch; the waste heat utilization circulation branch comprises a refrigeration branch and a heating branch which are connected in parallel, a first three-way valve, a second three-way valve, a first coolant pipeline which is a bypass pipeline of a second channel of the first heat exchanger, and a second coolant pipeline which is a bypass pipeline of a second channel of the second heat exchanger, the refrigeration branch is formed by connecting a first two-way valve and an absorption refrigeration air conditioner in series, the heating branch is formed by connecting a second two-way valve and an in-vehicle water heating radiator module in series, and the second channel of the first heat exchanger and the second channel of the second heat exchanger are connected in series; wherein, under the action of a water pump, the coolant passing through the absorption refrigeration air conditioner and the in-vehicle water heating radiator module first flows through the second channel of the second heat exchanger, then flows through the second channel of the first heat exchanger, and then enters the refrigeration branch or the heating branch; outlets of the second channel of the second heat exchanger and the second coolant pipeline are respectively connected to two inlets of the second three-way valve, and an outlet of the second three-way valve is respectively connected to inlets of the second channel of the first heat exchanger and the first coolant pipeline; outlets of the second channel of the first heat exchanger and the first coolant pipeline are respectively connected to two inlets of the first three-way valve, and an outlet of the first three-way valve is respectively connected to inlets of the refrigeration branch and the heating branch; a first temperature sensor is arranged on an outlet pipeline of the water pump, and a second temperature sensor is arranged on inlet pipelines of the refrigeration branch and the heating branch; the controller is in control connection with the absorption refrigeration air conditioner, the in-vehicle water heating radiator module, the water pump, each temperature sensor, each three-way valve and each two-way valve, the controller is used for calculating heat / cold required for heating / refrigeration in real time according to the actual in-vehicle temperature and the vehicle target control temperature, converting the heat / cold required in the vehicle into required waste heat Q4 / Q5 according to the energy efficiency ratio; calculating available waste heat Q1 of the fuel cell and available waste heat Q2 of the motor and the motor controller in real time; if Q4 ≤ Q1 or Q5 ≤ Q1, only the waste heat of the fuel cell is utilized, and PID adjustment is performed on the second three-way valve according to the required waste heat Q4 / Q5; if Q1 < Q4 ≤ Q1+Q2 or Q1 < Q5 ≤ Q1+Q2, the second three-way valve is controlled to enable all coolant to flow through the second channel of the second heat exchanger, and PID adjustment is performed on the first three-way valve to enable part of the coolant to flow through the second channel of the first heat exchanger; if Q1+Q2 < Q4 or Q1+Q2 < Q5, all waste heat of the fuel cell and the motor and the motor controller is put into use.

2. The integrated cooling and heating thermal management system according to claim 1, characterized in that, the second heat exchanger is a three-channel heat exchanger, a third channel of the second heat exchanger is connected to an exhaust emission pipeline of a fuel cell engine, and the flow direction of exhaust emission is opposite to the flow direction of the coolant in the waste heat utilization circulation branch.

3. The integrated cooling and heating thermal management system according to claim 1 or 2, characterized in that, wherein, The outlets of the cooling branch and the heating branch are connected to the inlet of the water pump. The outlet of the water pump is connected to the inlet of the second heat exchanger channel 2. The outlet of the second heat exchanger channel 2 is connected to the inlet of the first heat exchanger channel 2. The outlet of the first heat exchanger channel 2 is connected to the inlet of the cooling branch and the heating branch.

4. The integrated cooling and heating thermal management system according to claim 3, characterized in that, The outlet of the water pump is connected to the inlet of the second heat exchanger channel 2, the outlet of the second three-way valve is connected to the inlet of the first heat exchanger channel 2, and the outlet of the second three-way valve is also connected to the second inlet of the first three-way valve through the first coolant pipeline; a third temperature sensor is installed on the outlet pipeline of the second three-way valve, and the controller also controls the connection to the third temperature sensor.

5. The integrated cooling and heating thermal management system according to claim 1 or 2, characterized in that, The formula for calculating the usable waste heat of a fuel cell, Q1, is: Q1 = I × N × (ε0 - ε cell )×b%, where I is the fuel cell current, N is the number of individual fuel cell cells, ε0 is a constant determined by the fuel cell characteristics, and ε cell denoted as the average voltage of a single fuel cell, and b% as the heat exchange efficiency of the second heat exchanger.

6. The integrated cooling and heating thermal management system according to claim 1 or 2, characterized in that, The formula for calculating the usable waste heat of the motor and motor controller, Q2, is: Q2 = c × m × Δt × a%, where c is the specific heat capacity of the coolant, m is the flow rate of the coolant, Δt is the temperature difference, and a% is the heat exchange efficiency of the first heat exchanger.

7. A control method for the integrated refrigeration and heating thermal management system according to any one of claims 1-6, characterized in that, The method includes the following steps: (1) Obtain the target control temperature of the vehicle and determine whether the current control mode of the integrated cooling and heating thermal management system is cooling mode or heating mode based on the target control temperature; (2) When in cooling mode, control the cooling branch to be turned on and the heating branch to be turned off, and calculate in real time the current required waste heat for cooling, the current available waste heat of the fuel cell, the current available waste heat of the motor and motor controller, the current actual utilization of waste heat of the fuel cell and the current actual utilization of waste heat of the motor and motor controller. The current required waste heat for cooling is used as the control target, and waste heat cooling is achieved by controlling the flow direction of coolant in the waste heat utilization circulation branch. (3) When in heating mode, control the heating branch to be turned on and the cooling branch to be turned off, and calculate in real time the current required heat, the current available heat of the fuel cell, the current available heat of the motor and motor controller, the current actual utilization of the fuel cell and the current actual utilization of the motor and motor controller. Using the current required heat as the control target, the heat is generated by controlling the flow direction of the coolant in the heat utilization circulation branch.

8. The control method for the integrated refrigeration and heating thermal management system according to claim 7, characterized in that, The process of achieving waste heat cooling includes: if the waste heat required for current cooling is less than or equal to the available waste heat of the current fuel cell, then only the waste heat of the fuel cell is used for waste heat cooling, and the flow direction of the coolant in the waste heat utilization circulation branch is controlled according to the deviation between the waste heat required for current cooling and the actual waste heat utilization of the current fuel cell to achieve waste heat cooling; if the available waste heat of the current fuel cell is less than the waste heat required for current cooling and less than or equal to the available waste heat of the current fuel cell plus the available waste heat of the current motor and motor controller, then both the waste heat of the fuel cell and the waste heat of the motor and motor controller are used for waste heat cooling, wherein all the waste heat of the fuel cell is used, and the flow direction of the coolant in the waste heat utilization circulation branch is controlled according to the deviation between the waste heat required for current cooling and the actual waste heat utilization to achieve waste heat cooling, wherein the actual waste heat utilization is equal to the actual waste heat utilization of the current fuel cell plus the actual waste heat utilization of the current motor and motor controller. The process of achieving waste heat heating includes: if the current required waste heat is less than or equal to the current available waste heat of the fuel cell, then only the waste heat of the fuel cell is used for waste heat heating, and the flow direction of the coolant in the waste heat utilization circulation branch is controlled according to the deviation between the current required waste heat and the current actual utilization of the fuel cell waste heat to achieve waste heat heating; if the current available waste heat of the fuel cell is less than the current required waste heat and less than or equal to the current available waste heat of the fuel cell plus the current available waste heat of the motor and motor controller, then both the waste heat of the fuel cell and the waste heat of the motor and motor controller are used simultaneously, wherein all the waste heat of the fuel cell is used, and the flow direction of the coolant in the waste heat utilization circulation branch is controlled according to the deviation between the current required waste heat and the current actual utilization of the waste heat to achieve waste heat heating.

9. The control method for the integrated refrigeration and heating thermal management system according to claim 8, characterized in that, The available waste heat of the fuel cell is equal to the available waste heat of the fuel cell coolant, or the available waste heat of the fuel cell is equal to the available waste heat of the fuel cell coolant plus the available waste heat of the fuel cell engine exhaust.

10. A fuel cell vehicle, comprising a vehicle body and an integrated cooling and heating thermal management system, characterized in that, The integrated cooling and heating management system is the integrated cooling and heating management system as described in any one of claims 1-6.

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