Pure electric heavy truck and integrated thermal management control method thereof

Abstract

The invention relates to a pure electric heavy truck and an integrated thermal management control method thereof, and belongs to the technical field of new energy automobile thermal management. The opening degrees of expansion valves on the battery side and the air conditioner side are optimized according to the temperature in the cab, the set temperature of an air conditioner panel of the cab and the battery temperature, all refrigerating capacity is prior to the cab under the condition that the temperature of the cab does not meet the set temperature, and cooling is provided for the battery at a small opening degree after the temperature of the cab is close to the set temperature. Reasonable distribution of refrigerating capacity of the battery side and the air conditioner side of the heavy duty vehicle is achieved, accurate control over the battery temperature and improvement of the refrigerating effect of a cab are achieved, and the satisfaction degree of customers to products is improved.

Description

Technical Field

[0001] The present invention relates to a pure electric heavy truck and an integrated thermal management control method thereof, belonging to the technical field of new energy vehicle thermal management. Background Technique

[0002] For pure electric new energy vehicles, the integrated thermal management system has been widely promoted and applied in large quantities. The integrated thermal management system adopts one compressor and one condenser to simultaneously meet the cooling requirements of the passenger compartment and the power battery. After the refrigerant circulation pipeline comes out of the condenser, it is divided into two paths. One path leads to the in-vehicle evaporator to cool the compartment; the other path is connected to the battery heat exchanger to cool the battery coolant by refrigerant evaporation, thereby realizing battery cooling.

[0003] For example, the published text of the Chinese patent application with the publication number CN109383229A discloses an integrated thermal management system as described above. The integrated thermal management system respectively sets expansion valves on the pipelines leading to the in-vehicle evaporator and the battery heat exchanger, and controls the distribution of the refrigerant by controlling the opening and closing of the two expansion valves. This integrated thermal management realizes the use of a set of air conditioning systems to be able to refrigerate the compartment and the battery, reducing the vehicle cost.

[0004] Currently, the control strategies for integrated thermal management mainly target passenger cars and buses. In order to improve the user experience, the strategies need to ensure the refrigeration demand of the passenger compartment, that is, the compartment. At the same time, passenger cars and buses have good working conditions and high speeds, and the natural air cooling brought by the vehicle speed can also bring a certain battery heat dissipation effect. However, compared with passenger cars and buses, the cab of a heavy truck is smaller and the refrigeration capacity demand is lower; while the battery power of heavy trucks is generally higher, the battery has a large volume and large weight, and the battery has a higher demand for refrigeration capacity.

[0005] When integrated thermal management is applied to heavy-duty trucks, especially when the thermal management system of a bus with a large passenger capacity and a large passenger compartment is applied to a truck, considering the differences between heavy-duty trucks and buses, only by changing the specifications of the expansion valve and modifying the control parameters, the refrigerant (i.e., refrigerant) flow rate to the cab is reduced, and the refrigerant flow rate for battery cooling is significantly increased to meet the characteristics of heavy-duty trucks. However, due to the "dual evaporation operation" of cooling the battery while using the cab air conditioner, the mutual influence between the cab refrigeration branch and the battery cooling branch of the refrigerant is very large. Under the air conditioning system with the same refrigeration capacity, after optimizing the integrated thermal management system in favor of the power battery, since the refrigeration branch power that can meet the cooling of the power battery after optimization is much greater than that of the cab air conditioning branch (for example, the refrigeration power of the heavy-duty truck power battery reaches 10 kW, while the cab air conditioning power is only 3 kW), the cab refrigeration effect will be greatly reduced during simultaneous operation. In severe cases, the temperature may rise by more than 10 degrees compared to when the expansion valve of the power battery is not opened, resulting in unreasonable distribution of the cab refrigeration capacity and the battery refrigeration capacity. Eventually, in actual vehicle applications, there are problems such as poor cab refrigeration effect and inability to meet the battery temperature control requirements. Especially when both the battery side and the cab side are turned on and the integrated thermal management system is in "dual evaporation operation", customers report poor cab refrigeration effect, affecting product satisfaction.

[0006] However, selecting a high-power compressor to improve the refrigeration capacity of the air conditioner will lead to the problem of increasing vehicle costs only to cope with the limited-duration hot summer. Summary of the Invention

[0007] The purpose of the present invention is to provide a pure electric heavy-duty truck and its integrated thermal management control method to solve the problem that the existing integrated thermal management system is difficult to adapt to and balance the refrigeration requirements of the cab and the power battery when applied to heavy-duty trucks.

[0008] To achieve the above purpose, the solution of the present invention includes:

[0009] In the technical solution of an integrated thermal management control method for a pure electric heavy-duty truck of the present invention, first, the cab temperature, the cab set temperature, and the battery temperature are obtained; when the cab temperature is higher than the cab set temperature and the excess part exceeds the first threshold, the expansion valve on the cab air conditioning branch in the refrigerant cycle is opened, and the expansion valve on the power battery cooling branch parallel to the cab air conditioning branch in the refrigerant cycle is closed; when the cab temperature is higher than the cab set temperature and the excess part does not reach the first threshold, and the power battery temperature is higher than the refrigeration start temperature threshold, the expansion valves on both the cab air conditioning branch and the power battery cooling branch are opened simultaneously.

[0010] Further, when the cab temperature is higher than the cab set temperature, and the exceeding part does not reach the first threshold, and the power battery temperature is higher than the refrigeration start temperature threshold, the expansion valve of the cab air-conditioning branch is normally opened, and the expansion valve on the power battery cooling branch is opened with a preset small opening degree.

[0011] Further, when the cab temperature is higher than the cab set temperature, and the exceeding part does not reach the first threshold, and the power battery temperature is lower than the refrigeration start temperature threshold, the expansion valve of the cab air-conditioning branch is opened, and the expansion valve on the power battery cooling branch is closed.

[0012] Further, when the cab temperature is lower than the cab set temperature, and the falling short part does not reach the second threshold, and the power battery temperature is higher than the refrigeration start temperature threshold, the expansion valves of both the cab air-conditioning branch and the power battery cooling branch are opened simultaneously.

[0013] Further, when the cab temperature is lower than the cab set temperature, and the falling short part does not reach the second threshold, and the power battery temperature is higher than the refrigeration start temperature threshold, the expansion valve of the power battery cooling branch is normally opened, and the expansion valve of the cab air-conditioning branch is opened with a preset small opening degree.

[0014] Further, when the cab temperature is lower than the cab set temperature, and the falling short part does not reach the second threshold, and the power battery temperature is lower than the refrigeration start temperature threshold, the expansion valve of the cab air-conditioning branch is opened, and the expansion valve on the power battery cooling branch is closed.

[0015] Further, when the cab temperature is lower than the cab set temperature, and the falling short part exceeds the second threshold, and the power battery temperature is higher than the refrigeration start temperature threshold, the expansion valve of the power battery cooling branch is opened, and the expansion valve of the cab air-conditioning branch is closed.

[0016] Further, when the cab temperature is lower than the cab set temperature, and the falling short part exceeds the second threshold, and the power battery temperature is lower than the refrigeration start temperature threshold, the refrigeration cycle is closed.

[0017] Further, when the cab air-conditioning is turned off, and the power battery temperature is higher than the refrigeration start temperature threshold, the expansion valve of the power battery cooling branch is opened, and the expansion valve of the cab air-conditioning branch is closed.

[0018] The technical solution of a pure - electric heavy - duty truck of the present invention includes an integrated thermal management system. In the refrigerant cycle of the integrated thermal management system, the cab air - conditioner branch and the power - battery cooling branch are in parallel, and expansion valves are respectively arranged on the cab air - conditioner branch and the power - battery cooling branch. Wherein, the controller of the integrated thermal management system is used to execute and implement the integrated thermal management control method of the pure - electric heavy - duty truck as described above.

[0019] The beneficial effects of the present invention are as follows:

[0020] The present invention provides a targeted and brand - new thermal management control method for pure - electric heavy - duty trucks. According to the temperature inside the cab, the set temperature on the cab air - conditioner panel, and the battery temperature, the opening degrees of the expansion valves on the battery side and the air - conditioner side are optimized. When the cab temperature does not meet the set temperature, all the cooling capacity is preferentially provided to the cab first. After the cab temperature is close to the set temperature, cooling is then provided to the battery. In this way, a reasonable distribution of the cooling capacity between the battery side and the air - conditioner side of the heavy - duty truck is achieved, precise control of the battery temperature and improvement of the cab cooling effect are realized, and the customer satisfaction with the product is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is the flow chart of the integrated thermal management control method for the pure - electric heavy - duty truck in the method embodiment. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] To make the purpose, technical solution and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to the drawings and embodiments.

[0023] The concept of the present invention is that considering the characteristics of "small cab, large battery" of heavy - duty trucks (hereinafter referred to as heavy trucks or heavy - duty trucks for short), when there is a cooling demand for both the cab and the battery at the same time, the integrated thermal management system focuses on cooling the cab first. After the temperature of the small cab quickly drops to meet the set temperature, then the battery with a certain heat capacity is cooled. At the same time, when there is no cooling demand for the power battery, based on the set temperature, the temperature of the cab is additionally reduced by a certain amount, leaving a certain margin. When the cab temperature reaches the set temperature and the power battery has a cooling demand, then the power battery is preferentially cooled. When the cab temperature is lower than the set temperature and there is enough margin, all efforts are made to cool the power battery with a cooling demand.

[0024] The present invention designs a jump logic. After meeting the corresponding conditions, it jumps to the corresponding working mode, and dynamically switches the adjustment strategy according to the conditions in the time dimension, ensuring that each point of the current cooling capacity and cooling quantity is reasonably utilized to the place where it is most needed in combination with the characteristics of heavy - duty trucks. By adjusting, on the premise that the total cooling capacity remains unchanged, the integrated thermal management system tries its best to balance the needs of the cab and the power battery.

[0025] Truck Embodiment:

[0026] This embodiment provides a pure - electric heavy - duty truck equipped with an integrated thermal management system to balance and meet the cooling requirements of the truck cab and the truck power battery.

[0027] The integrated thermal management system in this embodiment includes a main refrigeration system path formed by an electric compressor and a condenser, a cab air - conditioning branch including a cab expansion valve and a cab evaporator, and a power - battery cooling branch including a power - battery expansion valve and a power - battery heat exchanger. The power - battery heat exchanger is a coolant - refrigerant heat exchanger. One end of the refrigerant of this heat exchanger constitutes the evaporation side of the power - battery cooling branch. A liquid - cooling cycle is formed between the power - battery heat exchanger and the power - battery water jacket to cool down the power battery.

[0028] Both the above - mentioned power - battery expansion valve and cab expansion valve adopt expansion valves with adjustable opening degrees to implement the thermal management control method of the present invention.

[0029] In this embodiment, the refrigeration system is realized by the refrigerant cycle of air - conditioning refrigeration in the prior art. For example, it can be realized by using the HVAC (Heating, Ventilation and Air Conditioning) assembly equipped on existing - technology vehicles. The specific structure and principle are not described in this embodiment.

[0030] Specifically, it can achieve the following functions:

[0031] 1. Through the coolant - refrigerant heat exchanger, realize the heat exchange between the battery coolant and the refrigerant to cool the battery.

[0032] 2. Through the HVAC assembly, realize the heat exchange between the cab air and the refrigerant to cool the cab.

[0033] 3. By adjusting the opening degrees of the expansion valves of the power - battery cooling branch and the cab air - conditioning branch respectively, realize the proportional distribution and adjustment of the cooling capacity of the cab and the battery.

[0034] The controller of the integrated thermal management system executes computer - readable instructions to implement an integrated thermal management control method for a pure - electric heavy - duty truck of the present invention. This method is clearly and completely introduced in the following method embodiment and is not described in this embodiment.

[0035] Method Embodiment:

[0036] This embodiment provides an integrated thermal management control method for a pure - electric heavy - duty truck. This control method can control the working mode of the in - vehicle thermal management system, so as to reasonably distribute the cooling capacity of the cab and the power battery for the heavy - duty truck.

[0037] The method of this embodiment is as follows Figure 1 shown, including the following steps. First, collect the temperature of the power battery and the air-conditioning switch control status of the air-conditioning control panel in the cab, and determine whether the power battery and the cab need refrigeration. When the temperature of the power battery is higher than the power battery's refrigeration start temperature threshold, or the cab air-conditioning is turned on, it means refrigeration is required.

[0038] If refrigeration is required, then collect the set temperature of the cab air-conditioning panel, the current temperature in the cab, and the temperature of the power battery, and select the working mode of the integrated thermal management system according to the switching conditions. Subsequently, continuously collect the above information to determine whether mode switching is required.

[0039] The air-conditioning switch of the above-mentioned air-conditioning control panel in the cab refers to the air-conditioning control switch for the driver to operate in the cab, and its control status is whether the driver controls to turn on or turn off the cab air-conditioning; the cab air-conditioning panel allows the driver to select the temperature that the driver hopes the cab to reach according to needs, and the set temperature is the temperature that the driver controls and selects for the cab to reach.

[0040] The power battery's refrigeration start temperature threshold is pre-set, for example, a temperature threshold set based on experimental calibration combined with industry knowledge, so that when the power battery works at this temperature threshold for a long time, it can achieve an overall optimum considering the available battery capacity, battery life, discharge capacity, battery safety, and temperature control energy consumption, etc.

[0041] After the integrated thermal management system is turned on, the working modes and control contents of the system are shown in the following table:

[0042] Table 1 Working Modes of the Thermal Management System

[0043] Working mode Description of control content Mode 1 The expansion valve of the power battery is closed, and the cooling capacity is prioritized for the cab air conditioner. Mode 2 The expansion valve of the power battery is slightly opened, and the cooling capacity is prioritized for the cab air conditioner. Mode 3 The cooling capacity is prioritized for the power battery side, and the expansion valve of the cab air conditioner is slightly opened. Mode 4 The cooling capacity is prioritized for the power battery side, and the expansion valve of the cab air conditioner is closed.

[0044] The switching conditions corresponding to the above working modes are composed of the control logic shown in the following table:

[0045] Table 2 Integrated Thermal Management Control Logic

[0046]

[0047] Next, the control logic of this embodiment will be described in the order from top to bottom in Table 2.

[0048] 1) The current cab temperature (i.e., the in-vehicle temperature in Table 2, the same below) t1 is greater than the set temperature t2 and exceeds the set temperature t2 by a preset threshold (i.e., the difference between the two is greater than the preset threshold, which is used to evaluate the degree to which the cab temperature is higher than the set temperature. In Table 2 of this embodiment, the preset threshold is 2°C. As other embodiments, other thresholds can also be set according to the in-vehicle calibration). At the same time, the power battery temperature (i.e., the battery temperature in Table 2, the same below) T1 is less than the power battery cooling start temperature threshold (i.e., the battery cooling start temperature in Table 2, the same below) T2. Then the integrated thermal management system is turned on, that is, the main compressor condenser of the refrigeration system starts to work, and at the same time, it jumps and switches to Mode 1. If the integrated thermal management system has already been turned on and the main road of the refrigeration system is working, but the working mode is not Mode 1, then it directly jumps and switches to Mode 1.

[0049] In Mode 1, since the power battery temperature T1 has not reached the power battery cooling start temperature threshold T2, the power battery expansion valve is closed and does not cool the power battery. At the same time, the current cab temperature is greater than the set temperature set by the driver and greater than a certain degree, that is, the current cab temperature has a large gap compared with the driver's expectation. Therefore, the cab expansion valve is opened, and all the refrigerant flows to the cab air-conditioning branch to meet the driver's demand for cooling the cab.

[0050] 2) The current cab temperature t1 is greater than the set temperature t2 and exceeds the set temperature t2 by a preset threshold. At the same time, the power battery temperature T1 is greater than the power battery cooling start temperature threshold T2. Then the integrated thermal management system is turned on, and at the same time, it jumps and switches to Mode 1. If the integrated thermal management system has already been turned on, but the working mode is not Mode 1, then it directly jumps and switches to Mode 1.

[0051] At this time, in Mode 1, the power battery temperature T1 has reached the power battery cooling start temperature threshold T2. However, considering the characteristics of the power battery of heavy trucks, the large capacity and the current output generally account for a relatively small proportion compared with its discharge capacity. Moreover, the power battery has a large volume and a large mass, and has a certain heat storage capacity, and the battery temperature changes slowly. At the same time, to avoid affecting the refrigeration effect of the cab air conditioner when the current cab temperature has a large gap compared with the driver's expectation, the power battery expansion valve is closed at this time, and the cab expansion valve is normally opened (the normal opening in this embodiment is that the expansion valve is fully opened, or opened with a preset maximum opening when working normally). The refrigeration capacity of the system is given priority to the cab air conditioner to meet the driver's demand for cooling the cab.

[0052] At this time, there is no need to worry about the overheating problem of the power battery. Firstly, as mentioned above, the power battery has a large specific heat capacity, and the temperature rise caused by heat generation is much smaller than that of a passenger car. Moreover, under normal driving conditions of a heavy truck, the output current accounts for a much smaller proportion of the output capacity, so the heat generation is also small. The stored electrical energy of the heavy truck power battery is generally between 400 and 500 degrees. A large number of experiments have confirmed that the power consumption caused by discharging for a short time (such as half an hour) will not cause a large temperature change. At the same time, the cab of a heavy truck is even smaller than that of a passenger car, and the space is transparent without obstructions such as the front seat backrests, so that the air blown by the air conditioner can reach every corner. At the same time, for every one-degree Celsius decrease in the temperature of the heavy truck battery with a large specific heat capacity, a large amount of heat needs to be absorbed from it. To meet the cooling requirements of the large-capacity power battery of the heavy truck, the heavy truck is often equipped with a refrigeration system compressor with a higher power, which is much higher than the cooling requirement of the smaller cab of the heavy truck. Therefore, when the cooling capacity is prioritized for the cab, the cab temperature will drop rapidly and quickly reach the expected temperature of the driver. At this time, by switching to other working modes with the power battery prioritized, the power battery can be cooled. That is, after giving priority to quickly meeting the cab cooling requirements, then control the battery temperature to avoid the influence on the cab air-conditioning branch caused by the opening of the power battery expansion valve in the prior art. Due to the suction effect of the power battery evaporator, the refrigerant tends to flow to the power battery cooling branch, resulting in a significant reduction in the cab air-conditioning effect. And the power battery with a large heat storage capacity has a slow temperature change even when the cooling capacity is prioritized, resulting in the cab temperature being unable to be reduced all the time, affecting the use experience.

[0053] 3) When the current cab temperature t1 is greater than the set temperature t2 and the difference is within the preset threshold, and at the same time the power battery temperature T1 is greater than the power battery cooling start temperature threshold T2; then the integrated thermal management system is turned on, and at the same time it jumps and switches to Mode 2; if the integrated thermal management system has already been turned on, but the working mode is not Mode 2, then directly jump and switch to Mode 2.

[0054] In Mode 2, the power battery temperature T1 has reached the power battery cooling start temperature threshold T2, but at this time the cab temperature has approached the expected temperature set by the driver. Some of the cooling capacity can be transferred to the power battery. If the cooling capacity is still prioritized for the cab when the power battery temperature is higher than the corresponding threshold, it will cause waste of the cooling capacity and the limited cooling capacity will not be optimally distributed. At the same time, considering the influence of the power battery evaporation on the cab air-conditioning branch, the power battery expansion valve is opened slightly, and the cab expansion valve is opened normally. The additional cooling capacity when the cab is about to reach the set temperature is used to control the battery temperature. At this time, the power battery expansion valve starts to operate with a small opening and outputs a certain amount of cooling capacity to the battery. At this time, the cab expansion valve is still opened normally, and the system cooling capacity is still prioritized for the cab air conditioner to meet the driver's demand for cab cooling and temperature reduction.

[0055] 4) If the current cab temperature t1 is greater than the set temperature t2 and the difference is within the preset threshold, and at the same time the power battery temperature T1 is less than the power battery cooling start temperature threshold T2, then the integrated thermal management system is turned on and switches to Mode 1 at the same time; if the integrated thermal management system is already on but the working mode is not Mode 1, then directly switch to Mode 1.

[0056] At this time, in Mode 1, the power battery temperature T1 has dropped below the power battery cooling start temperature threshold T2, and the temperature rise of the power battery is slow, so there is no need to continue cooling it. Although the cab temperature is already close to the expected temperature set by the driver at this time, it still has not reached it. At this time, the power battery has no cooling requirement, and the cooling capacity can be prioritized for the cab to make the cab temperature reach the driver's set temperature as soon as possible. Therefore, the cab air-conditioning expansion valve is normally opened and the power battery expansion valve is closed at this time to make the cab reach the set temperature as soon as possible.

[0057] 5) If the current cab temperature t1 is lower than the set temperature t2 and the difference is within the preset threshold (this preset threshold is the threshold used to evaluate the degree of temperature below the set temperature after the temperature drops below the set temperature. It can be the same as the preset threshold value used to evaluate the degree of temperature above the set temperature in the previous four cases, or it can be set separately; in Table 2 of this embodiment, these two preset thresholds are the same, both 2°C), and at the same time the power battery temperature T1 is less than the power battery cooling start temperature threshold T2, then the integrated thermal management system is turned on and switches to Mode 1 at the same time; if the integrated thermal management system is already on but the working mode is not Mode 1, then directly switch to Mode 1.

[0058] Although the cab temperature is already lower than the driver's set temperature at this time, it is only just lower. Considering the heat insulation of the heavy truck cab and the fact that the power battery has no cooling need at this time, the cooling capacity for the cab can still be prioritized. A certain amount of cooling redundancy is added on the basis of the driver's set temperature to prevent the cab temperature from rising out of the comfortable range quickly when the cooling capacity needs to be tilted towards the power battery after the battery temperature rises subsequently. Therefore, in this case, switch to Mode 1, still prioritize cab cooling, and make the cab temperature lower than the set temperature to a certain extent to reserve a certain amount of "cooling capacity".

[0059] 6) If the current cab temperature t1 is lower than the set temperature t2 and the difference is within the preset threshold, and at the same time the power battery temperature T1 is greater than the power battery cooling start temperature threshold T2, then the integrated thermal management system is turned on and switches to Mode 3 at the same time; if the integrated thermal management system is already on but the working mode is not Mode 3, then directly switch to Mode 3.

[0060] At this time, the cab temperature has dropped below the driver's set temperature. Although the "cooling capacity" is still insufficiently reserved, the power battery starts to require cooling at this time. Therefore, the cooling capacity is prioritized for the battery side. Combining the above situation 5, that is, after the cab temperature reaches the set temperature, if the battery has a cooling requirement, the cooling capacity is prioritized for the battery; if the battery has no cooling requirement, a certain amount of redundant "cooling capacity" is reserved for the cab.

[0061] 7) When the current cab temperature t1 is lower than the set temperature t2 and exceeds the preset threshold, it indicates that the cab has reserved a certain amount of cooling margin, meeting the cab temperature comfort requirements within a certain period of time. At the same time, the power battery temperature T1 is greater than the power battery cooling start temperature threshold T2, and there is a cooling requirement. Then the integrated thermal management system is turned on, and at the same time, it jumps and switches to Mode Four; if the integrated thermal management system has already been turned on, but the working mode is not Mode Four, it directly jumps and switches to Mode Four. In Mode Four, the cab air-conditioning expansion valve is closed, and the power battery expansion valve is normally opened. The cooling capacity is prioritized for the battery side; at this time, the cab temperature is already low enough, which also prevents the cab temperature from further decreasing and causing a decline in comfort.

[0062] 8) When the current cab temperature t1 is lower than the set temperature t2 and exceeds the preset threshold, the cab has reserved a certain amount of cooling margin. At the same time, the power battery temperature T1 is less than the power battery cooling start temperature threshold T2, and there is no cooling requirement. Then the integrated thermal management system is turned off to save electrical energy.

[0063] 9) When the driver actively closes the cab through the cab air-conditioning control panel, the integrated thermal management system no longer collects the cab temperature t1 and no longer performs the corresponding comparison and judgment. When the power battery temperature T1 is greater than the power battery cooling start temperature threshold T2 and there is a cooling requirement, the integrated thermal management system is turned on, and at the same time, it jumps and switches to Mode Four; if the integrated thermal management system has already been turned on, but the working mode is not Mode Four, it directly jumps and switches to Mode Four. In Mode Four, the cab air-conditioning expansion valve is closed, and the power battery expansion valve is normally opened.

[0064] 10) When the driver actively closes the cab through the cab air-conditioning control panel, and at the same time the power battery temperature T1 is less than the power battery cooling start temperature threshold T2, the integrated thermal management system is turned off to save electrical energy.

[0065] The method of this embodiment is targeted at the characteristics of heavy trucks, and combines the air-conditioning state, battery temperature, vehicle interior temperature, and set temperature to select a reasonable working mode of the thermal management system, realizing the optimized distribution of the cooling capacity of the integrated thermal management system, improving the cab cooling effect and ensuring the effective control of the battery temperature. It effectively solves the problem of unreasonable distribution of the cooling capacity between the cab and the battery side when the integrated thermal management system is used for heavy trucks, ensures the rapid reduction of the cab temperature, improves product satisfaction, and at the same time effectively controls the battery within the efficient working temperature range.

Claims

1. An integrated thermal management control method for a pure electric heavy truck, characterized in that, Obtain the cab temperature, the cab set temperature, and the battery temperature; when the cab temperature is higher than the cab set temperature and the exceeded part exceeds the first threshold, open the expansion valve on the cab air-conditioning branch in the refrigerant cycle and close the expansion valve on the power battery cooling branch in parallel with the cab air-conditioning branch in the refrigerant cycle; when the cab temperature is higher than the cab set temperature and the exceeded part does not reach the first threshold and the power battery temperature is higher than the refrigeration start temperature threshold, open the expansion valves on both the cab air-conditioning branch and the power battery cooling branch simultaneously.

2. The integrated thermal management control method for a pure electric heavy-duty truck according to claim 1, characterized in that When the cab temperature is higher than the cab set temperature and the exceeded part does not reach the first threshold and the power battery temperature is higher than the refrigeration start temperature threshold, normally open the expansion valve on the cab air-conditioning branch and open the expansion valve on the power battery cooling branch with a preset small opening degree.

3. The integrated thermal management control method for a pure electric heavy-duty truck according to claim 1, wherein, When the cab temperature is higher than the cab set temperature and the exceeded part does not reach the first threshold and the power battery temperature is lower than the refrigeration start temperature threshold, open the expansion valve on the cab air-conditioning branch and close the expansion valve on the power battery cooling branch.

4. The integrated thermal management control method for a pure electric heavy-duty truck according to claim 1, wherein When the cab temperature is lower than the cab set temperature and the lower part does not reach the second threshold and the power battery temperature is higher than the refrigeration start temperature threshold, open the expansion valves on both the cab air-conditioning branch and the power battery cooling branch simultaneously.

5. The integrated thermal management control method for a pure electric heavy-duty truck according to claim 4, wherein When the cab temperature is lower than the cab set temperature and the lower part does not reach the second threshold and the power battery temperature is higher than the refrigeration start temperature threshold, normally open the expansion valve on the power battery cooling branch and open the expansion valve on the cab air-conditioning branch with a preset small opening degree.

6. The integrated thermal management control method for a pure electric heavy-duty truck according to claim 1, wherein When the cab temperature is lower than the cab set temperature and the lower part does not reach the second threshold and the power battery temperature is lower than the refrigeration start temperature threshold, open the expansion valve on the cab air-conditioning branch and close the expansion valve on the power battery cooling branch.

7. The integrated thermal management control method for a pure electric heavy-duty truck according to claim 1, characterized in that, When the cab temperature is lower than the cab set temperature and the lower part exceeds the second threshold and the power battery temperature is higher than the refrigeration start temperature threshold, open the expansion valve on the power battery cooling branch and close the expansion valve on the cab air-conditioning branch.

8. The integrated thermal management control method for a pure electric heavy-duty truck according to claim 1, wherein When the cab temperature is lower than the cab set temperature and the lower part exceeds the second threshold and the power battery temperature is lower than the refrigeration start temperature threshold, shut down the refrigeration cycle.

9. The integrated thermal management control method for a pure electric heavy-duty truck according to claim 1, characterized in that When the cab air-conditioning is turned off and the power battery temperature is higher than the refrigeration start temperature threshold, open the expansion valve on the power battery cooling branch and close the expansion valve on the cab air-conditioning branch.

10. A pure electric heavy-duty truck includes an integrated thermal management system. In the refrigerant cycle of the integrated thermal management system, the cab air-conditioning branch and the power battery cooling branch are in parallel, and expansion valves are respectively arranged on the cab air-conditioning branch and the power battery cooling branch; it is characterized in that, The controller of the integrated thermal management system is used to execute and implement the integrated thermal management control method for the pure electric heavy truck as described in any one of claims 1 to 9.

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