Cold start control method, new energy automobile thermal management system and new energy automobile

Abstract

The invention provides a cold start control method, a new energy automobile thermal management system and a new energy automobile. In the cold start control method, when the new energy automobile is subjected to cold start in an ultralow temperature environment, if an electronic expansion valve is locked, the rotating speed of a compressor is controlled to reach a preset rotating speed; by means of the method, it can be guaranteed that a refrigerant loop is heated and blocked to the maximum extent, the heating performance is guaranteed, and therefore refrigerants in the loop are heated, the oil temperature of a compressor is increased, the oil viscosity is reduced, the locked-rotor problem of an electronic expansion valve is rapidly solved, rapid cold start of a new energy automobile is guaranteed, and the service life of the new energy automobile is prolonged. The new energy automobile experience degree of the user is ensured; and the performance of the compressor in an ultralow-temperature environment is guaranteed, and the compressor is prevented from being damaged.

Description

Technical Field

[0001] This invention relates to the field of new energy vehicle technology, and in particular to a cold start control method, a new energy vehicle thermal management system, and a new energy vehicle. Background Technology

[0002] As a core technology for new energy vehicles, the thermal management system not only solves the cooling problems of electric drive and battery, but also ensures the overall performance of the vehicle, including thermal comfort. In particular, the power consumption of new energy vehicles increases in winter, especially in ultra-low temperature environments, where battery performance is affected, causing the battery to become less responsive and increasing energy consumption. Therefore, to prevent reduced battery activity and ensure vehicle performance and range, new energy vehicles will activate a battery heating system.

[0003] Traditional battery heating and passenger compartment heating solutions primarily utilize PTC (Positive Temperature Coefficient) heaters, but these consume a relatively high amount of energy. Another approach uses tetrafluoroethane (R134a) as a coolant and employs heat pump heating in ultra-low temperature environments, such as around -10°C. While this reduces energy consumption, the heat pump cannot function properly in ultra-low temperatures. Furthermore, when using R290 refrigerant for cold starts in ultra-low temperatures, the sudden increase in compressor oil viscosity can cause the electronic expansion valve to become blocked, preventing proper cold starts and reducing the user experience of new energy vehicles. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a cold start control method, a thermal management system for new energy vehicles, and a new energy vehicle, so as to alleviate the above-mentioned problems.

[0005] In a first aspect, embodiments of the present invention provide a cold start control method applied to a thermal management system for new energy vehicles, the thermal management system for new energy vehicles including a compressor and an electronic expansion valve; the method includes: when a new energy vehicle is cold started in an ultra-low temperature environment, determining whether the electronic expansion valve is stalled; if so, controlling the speed of the compressor to reach a preset speed.

[0006] Optionally, the method further includes: controlling the electronic expansion valve to operate at a given opening degree, and determining whether the electronic expansion valve continues to be blocked; if so, initializing the electronic expansion valve so that the opening degree of the electronic expansion valve reaches a preset opening degree; and adjusting the opening degree of the electronic expansion valve to a given opening degree, and continuing to determine whether the electronic expansion valve continues to be blocked until the electronic expansion valve returns to normal.

[0007] Optionally, the method further includes: when the electronic expansion valve returns to normal, controlling the opening degree of the electronic expansion valve to reach the target opening degree, and using a superheat control strategy to control the opening degree of the electronic expansion valve.

[0008] Optionally, the method further includes: when the new energy vehicle is powered off, controlling the opening degree of the electronic expansion valve to a preset opening degree.

[0009] Optionally, the method further includes: when the electronic expansion valve stalls, controlling the drive current of the electronic expansion valve to be increased from a first current to a second current.

[0010] Optionally, the method further includes: when the electronic expansion valve returns to normal, controlling the drive current of the electronic expansion valve to a first current.

[0011] Optionally, the thermal management system for new energy vehicles also includes a water pump located on the side of the water-cooled condenser, and the method further includes controlling the water pump to operate at a target speed.

[0012] Optionally, the preset speed is 7000 rpm.

[0013] In a second aspect, embodiments of the present invention also provide a thermal management system for a new energy vehicle, including a controller, a compressor, an electronic expansion valve, and a water pump disposed on the side of a water-cooled condenser; the controller is used to control the thermal management system for the new energy vehicle using the method described in the first aspect.

[0014] Thirdly, embodiments of the present invention also provide a new energy vehicle, including the new energy vehicle thermal management system described in the second aspect above.

[0015] The embodiments of the present invention bring the following beneficial effects:

[0016] This invention provides a cold start control method, a thermal management system for new energy vehicles, and a new energy vehicle. In the cold start control method, when a new energy vehicle is cold-started in an ultra-low temperature environment, if the electronic expansion valve becomes blocked, controlling the compressor speed to reach a preset speed not only ensures maximum heating and unblocking of the refrigerant circuit, guaranteeing heating performance, but also heats the refrigerant in the circuit, increasing the compressor oil temperature and reducing oil viscosity. This quickly resolves the electronic expansion valve blockage problem, thereby ensuring rapid cold start of the new energy vehicle and enhancing the user's new energy vehicle experience. Furthermore, it ensures the compressor's performance in ultra-low temperature environments, preventing compressor damage.

[0017] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention are realized and obtained through the structures particularly pointed out in the description and the drawings.

[0018] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0019] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0020] Figure 1 A flowchart of a cold start control method provided in an embodiment of the present invention. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] To facilitate understanding of this embodiment, the embodiments of the present invention will be described in detail below.

[0023] This invention provides a cold start control method applied to the thermal management system of a new energy vehicle. The thermal management system includes, but is not limited to, a compressor, an electronic expansion valve, an electronic shut-off valve, a water-cooled condenser, a liquid receiver, a gas-injection enthalpy-enhancing plate heat exchanger, and an evaporator, all connected via pipelines to achieve thermal management of the new energy vehicle. Specific new energy vehicle thermal management systems can be found in existing technologies; details are not elaborated upon here.

[0024] Based on the aforementioned new energy vehicle thermal management system, such as Figure 1 As shown, the cold start control method provided in this embodiment of the invention includes the following steps:

[0025] Step S102: When a new energy vehicle is cold-started in an ultra-low temperature environment, determine whether the electronic expansion valve is stuck.

[0026] Specifically, when a new energy vehicle is cold-started again after a certain period of time following its last power-off in an ultra-low temperature environment, the controller first determines whether the electronic expansion valve is stalled. Stalling refers to the phenomenon that the electronic expansion valve cannot open normally after power-on. Due to the sudden increase in the viscosity of the compressor oil in an ultra-low temperature environment, the electronic expansion valve may stall during cold start. In this case, the electronic expansion valve does not operate, which affects the normal operation of the new energy vehicle. Therefore, solving the problem of electronic expansion valve stalling is of great significance to ensure rapid cold start of new energy vehicles.

[0027] It should be noted that the above-mentioned ultra-low temperature environment refers to an environment where the ambient temperature is lower than the preset temperature. For example, if the preset temperature is -15℃, then when the ambient temperature is -35℃, it is considered an ultra-low temperature environment. The specific preset temperature can be set according to the actual situation.

[0028] Step S104: If yes, control the compressor speed to reach the preset speed.

[0029] When the electronic expansion valve becomes blocked, controlling the compressor speed to reach the preset speed not only ensures maximum heating of the refrigerant circuit to clear the blockage and maintain heating performance, but also heats the refrigerant in the circuit, raising the compressor oil temperature and reducing oil viscosity. This quickly resolves the electronic expansion valve blockage problem, ensuring rapid cold starts for new energy vehicles and guaranteeing a better user experience. Furthermore, it ensures compressor performance in ultra-low temperature environments, preventing compressor damage. The preferred preset speed is 7000 rpm, but can be adjusted adaptively for certain scenarios.

[0030] The cold start control method provided in this invention addresses the issue of electronic expansion valve blockage in new energy vehicles operating in ultra-low temperature environments. By controlling the compressor speed to a preset speed, it ensures maximum heating and unblocking of the refrigerant circuit, maintaining heating performance and heating the refrigerant in the circuit. This raises the compressor oil temperature, reduces oil viscosity, and quickly resolves the electronic expansion valve blockage problem, thereby ensuring rapid cold start of the new energy vehicle and enhancing the user's experience. Furthermore, it guarantees compressor performance in ultra-low temperature environments, preventing compressor damage.

[0031] In one embodiment, the method further includes: controlling the electronic expansion valve to operate at a given opening degree, and determining whether the electronic expansion valve continues to be blocked; if so, initializing the electronic expansion valve to make the opening degree of the electronic expansion valve reach a preset opening degree; and adjusting the opening degree of the electronic expansion valve to the given opening degree, and continuing to determine whether the electronic expansion valve continues to be blocked until the electronic expansion valve returns to normal.

[0032] Specifically, during ultra-low temperature cold start, if the electronic expansion valve becomes stalled, the system first controls the electronic expansion valve to operate at a given opening degree. This given opening degree is determined based on the low pressure downstream of the electronic expansion valve. For example, the given opening degree requires maintaining the voltage downstream of the electronic expansion valve at 0.1 MPa or higher. The system then checks whether the electronic expansion valve continues to stall. If it does, the system initializes the electronic expansion valve to achieve a preset opening degree, which is the opening degree before the electronic expansion valve is powered off. Next, the opening degree of the electronic expansion valve is adjusted to the given opening degree, and the system continues to check whether the electronic expansion valve continues to stall. If it still stalls, the system initializes the electronic expansion valve again, then adjusts the opening degree back to the given opening degree, and continues to check whether the electronic expansion valve continues to stall until the electronic expansion valve returns to normal. This resolves the stalling issue of the electronic expansion valve, ensuring rapid cold start for new energy vehicles and thus guaranteeing the user's new energy vehicle experience.

[0033] In one embodiment, the method further includes: when the electronic expansion valve returns to normal, controlling the opening degree of the electronic expansion valve to reach the target opening degree, and using a superheat control strategy to control the opening degree of the electronic expansion valve.

[0034] The target opening degree is the number of steps required for the electronic expansion valve to fully open. Here, the target opening degree is preferably 576 to avoid step loss. That is, when the electronic expansion valve returns to normal, the opening degree of the electronic expansion valve is controlled to reach the target opening degree. An overheat control strategy, such as PID (Proportional Integral Derivative), is used to control the opening degree of the electronic expansion valve to ensure the normal operation of the new energy vehicle. It should be noted that the overheat control strategy can refer to existing technologies, such as controlling the difference between the overheat degree and the target value within 5°C. This embodiment of the invention will not be described in detail here.

[0035] In one embodiment, the method further includes: when the new energy vehicle is powered off, controlling the opening degree of the electronic expansion valve to a preset opening degree.

[0036] Specifically, in order to prevent the electronic expansion valve from stalling during cold starts at ultra-low temperatures due to increased oil viscosity in the compressor, which may even approach the pour point, the opening of the electronic expansion valve needs to be controlled to a preset opening each time the new energy vehicle is powered off. This preset opening can be determined based on the ambient temperature and the corresponding pressure curve at the time of power-off.

[0037] In one embodiment, the method further includes: when the electronic expansion valve is stalled, controlling the drive current of the electronic expansion valve to increase from a first current to a second current.

[0038] The second current is greater than the first current. For example, in an ultra-low temperature environment of -35℃, if the electronic expansion valve stalls when a new energy vehicle is cold-started, the driving current of the electronic expansion valve is increased from the first current (e.g., 200mA) to the second current (e.g., 450mA) so as to quickly alleviate the stalling problem of the electronic expansion valve by increasing the driving current, thereby ensuring the rapid cold start of the new energy vehicle and ensuring the user's new energy vehicle experience.

[0039] Furthermore, when the electronic expansion valve returns to normal operation, the drive current of the electronic expansion valve is controlled to be the first current to ensure the durability of the electronic expansion valve coil, thereby extending the service life of the electronic expansion valve. The specific values ​​of the first and second currents can be adaptively adjusted according to actual conditions, and this embodiment of the invention does not impose any limitations on this.

[0040] In one embodiment, the thermal management system for new energy vehicles further includes a water pump installed on the side of the water-cooled condenser. The method further includes controlling the water pump to operate at a target speed. The target speed is a speed value lower than a preset speed threshold. Thus, during cold starts in ultra-low temperature environments, by controlling the water pump to operate at a low speed, not only can the minimum requirement of water flow be guaranteed, but also the heat loss caused by the refrigerant side temperature drop can be avoided. This not only heats the refrigerant side circuit but also quickly solves the problem of electronic expansion valve blockage, ensuring rapid cold starts for new energy vehicles and guaranteeing the user's new energy vehicle experience.

[0041] Based on the above method embodiments, this invention also provides a new energy vehicle thermal management system, including a controller, a compressor, an electronic expansion valve, and a water pump disposed on the water-cooled condenser side; the controller is used to control the new energy vehicle thermal management system using the above method embodiments.

[0042] Furthermore, embodiments of the present invention also provide a new energy vehicle, including the aforementioned new energy vehicle thermal management system. Specific new energy vehicles and new energy vehicle thermal management systems can be found in existing technologies, and will not be described in detail here.

[0043] The new energy vehicle thermal management system provided in this embodiment of the invention has the same technical features as the cold start control method provided in the above embodiment, so it can also solve the same technical problems and achieve the same technical effects.

[0044] This embodiment also provides a machine-readable storage medium storing machine-executable instructions. When the machine-executable instructions are called and executed by the processor, the machine-executable instructions cause the processor to implement the above-described cold start control method.

[0045] The cold start control method, new energy vehicle thermal management system, and new energy vehicle computer program product provided in the embodiments of the present invention include a computer-readable storage medium storing program code. The instructions included in the program code can be used to execute the methods described in the preceding method embodiments. For specific implementation, please refer to the method embodiments, which will not be repeated here.

[0046] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working process of the system and apparatus described above can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0047] Furthermore, in the description of the embodiments of the present invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention based on the specific circumstances.

[0048] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a processor-executable, non-volatile, computer-readable storage medium. Based on this understanding, the technical solution of this invention, essentially, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0049] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0050] Finally, it should be noted that the above-described embodiments are merely specific implementations of the present invention, used to illustrate the technical solutions of the present invention, and not to limit it. The scope of protection of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments within the technical scope disclosed in the present invention, or make equivalent substitutions for some of the technical features; and these modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A cold start control method applied to a new energy vehicle thermal management system, the new energy vehicle thermal management system comprising a compressor and an electronic expansion valve; characterized in that, The method comprises: When the new energy vehicle is cold started in an ultra-low temperature environment, it is determined whether the electronic expansion valve is stalled; If yes, the rotation speed of the compressor is controlled to reach a preset rotation speed.

2. The method of claim 1, wherein, The method further comprises: The electronic expansion valve is controlled to operate at a given opening degree, and it is determined whether the electronic expansion valve continues to be stalled; if yes, the electronic expansion valve is initialized so that the opening degree of the electronic expansion valve reaches a preset opening degree; and the opening degree of the electronic expansion valve is adjusted to the given opening degree, and it is continuously determined whether the electronic expansion valve continues to be stalled until the electronic expansion valve returns to normal.

3. The method of claim 2, wherein, The method further comprises: When the electronic expansion valve returns to normal, the opening degree of the electronic expansion valve is controlled to reach a target opening degree, and a superheat degree control strategy is adopted to control the opening degree of the electronic expansion valve.

4. The method of claim 2, wherein, The method further comprises: When the new energy vehicle is powered off, the opening degree of the electronic expansion valve is controlled to be the preset opening degree.

5. The method of claim 1, wherein, The method further comprises: When the electronic expansion valve is stalled, the drive current of the electronic expansion valve is controlled to be raised from a first current to a second current.

6. The method of claim 5, wherein, The method further comprises: When the electronic expansion valve returns to normal, the drive current of the electronic expansion valve is controlled to be the first current.

7. The method of claim 1, wherein, The new energy vehicle thermal management system further comprises a water pump arranged at the side of a water-cooled condenser, and the method further comprises: The water pump is controlled to operate at a target rotation speed.

8. The method of claim 1, wherein, The preset rotation speed is 7000 rpm.

9. A new energy vehicle thermal management system, characterized in that, The new energy vehicle thermal management system comprises a controller, a compressor, an electronic expansion valve, and a water pump arranged at the side of a water-cooled condenser. The controller is configured to control the new energy vehicle thermal management system by using the method of any one of claims 1-8.

10. A new energy vehicle, characterized in that, The new energy vehicle thermal management system of claim 9.

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