Refrigerant state control method based on thermal management system

Abstract

The invention discloses a refrigerant state control method based on a thermal management system, which is characterized in that the thermal management system comprises a pressure sensor I and a pressure sensor II, and the pressure of the pressure sensor I is higher than that of the pressure sensor II; the refrigerant state at least comprises a balance state, a pre-starting state, a stable state, a switching state and a stopping state; when the pressure difference value of the first pressure sensor and the second pressure sensor is smaller than a pressure difference value threshold value, the refrigerant state is a balanced state; control target switching of related electric appliance loads is achieved through the refrigerant state, cooperative operation of all components is achieved through refrigerant state migration, and after the refrigerant states are integrated, repeated judgment conditions based on temperature and pressure are reduced, and calibration parameter and software complexity are reduced.

Description

Technical Field

[0001] The present invention relates to the field of refrigerants, and in particular to a control method for refrigerant status based on a thermal management system. Background Art

[0002] With the continuous development of the automotive industry, automotive thermal management systems have received widespread attention as an important component for improving driving comfort and energy efficiency. However, traditional thermal management systems have obvious shortcomings in refrigerant management, mainly manifested in the following points: Refrigerant status monitoring is insufficient. The existing system does not monitor the refrigerant status (such as temperature, pressure, flow, etc.) comprehensively and accurately enough, lacks real-time classification management, and it is difficult to accurately grasp the specific status changes of the refrigerant in different components and under different working conditions.

[0003] The control strategy is not sophisticated enough. The control strategy for refrigerant is relatively simple and is mostly based on fixed logic. It is impossible to formulate differentiated control plans according to the specific status of the refrigerant, making it difficult to achieve refined management of the refrigerant.

[0004] The software solution is highly complex. When executing electrical loads related to thermal management, the specific action sequence needs to be determined based on the state of the refrigerant, usually based on pressure and temperature. This will increase a large number of calibration processes. At the same time, the complex judgment conditions also bring difficulties to software development. Summary of the Invention

[0005] The purpose of the present invention is to provide a control method for the refrigerant state based on a thermal management system to solve the problems raised in the above background technology, such as insufficient refrigerant state monitoring, insufficiently sophisticated refrigerant control strategy and high complexity of software solutions.

[0006] To achieve the above object, the present invention provides the following technical solutions: A control method based on the refrigerant state of a thermal management system. The thermal management system includes a first pressure sensor and a second pressure sensor, wherein the pressure of the first pressure sensor is higher than the pressure of the second pressure sensor; The refrigerant state includes at least a balanced state, a pre-start state, a stable state, a switching state and a stopped state; when the pressure difference between the pressure sensor 1 and the pressure sensor 2 is less than the pressure difference threshold, the refrigerant state is a balanced state; The control method based on the refrigerant state of the thermal management system has the following steps: S1. When the system refrigerant state is in the equilibrium state, if the electric compressor speed reaches the pre-start speed threshold and the rotation duration reaches the pre-start time threshold, the system enters the pre-start state. If not, the system returns to the equilibrium state. S2. When the system refrigerant state is in the pre-start state, if the speed change of the electric compressor is less than the steady state speed change threshold and the rotation duration reaches the steady time threshold, the system enters the steady state. If not, it returns to the equilibrium state. S3. When the system refrigerant state is in the stable state, if the system receives a control target change instruction, the system refrigerant state enters a switching state; if the system does not receive a target change instruction, it returns to the stable state; S4. When the system refrigerant state is in the switching state, if the system receives a shutdown command, it enters the operating stop state until the end. If no system shutdown command is received, it returns to the switching state. The refrigerant state is defined based on the actual pressure parameters, compressor operation, and changes in the control target. The refrigerant state is determined by the conditions included in the determination of the refrigerant state. The refrigerant state is defined based on the conditions of the specific determination parameters, and the system state is no longer determined based on specific parameters. This reduces the complexity of calibration parameters and software while ensuring the consistency of state transitions.

[0007] Preferably, the pressure difference threshold is 0.3 bar. This is because equilibrium indicates a relatively stable initial state for the system, allowing the compressor to start and provide power for the thermal system. This association allows compressor startup to be based on the refrigerant's stable state, avoiding system shocks caused by startup during unstable refrigerant conditions.

[0008] Preferably, the pre-start speed threshold is 1500 rpm-2000 rpm, so that the compressor can quickly reach the required speed and the control parameters of the system can follow more quickly.

[0009] Preferably, the pre-start time threshold is 5S-10S, which provides sufficient time at the required speed.

[0010] Preferably, the stable time threshold is 20 seconds, and the stable state speed change threshold is 300 rpm. In this state, the compressor basically reaches the control target stable range, the speed adjustment is small, and the system enters a stable operation state.

[0011] Preferably, the electric compressor is controlled as follows: When the system refrigerant is in the balanced state, the electric compressor is not restricted and operates normally; When the system refrigerant state is in the pre-start state, the electric compressor speed is controlled to reach the pre-start speed threshold and the rotation duration reaches the pre-start time threshold; When the system refrigerant state is in the stable operation state, controlling the electric compressor to gradually increase the speed so that the electric compressor achieves the control target; When the system refrigerant state is in the switching state, when the user operates the air conditioner to set the temperature, the electric compressor adjusts the control target because the user switches the control target, and the speed of the electric compressor is adjusted according to the preset ratio within the preset interval; When the system refrigerant state is in the stopped state, the electric compressor system is turned off, and the electric compressor is turned on again until the refrigerant state enters a balanced state.

[0012] Preferably, the preset interval time is 5 seconds, and the preset ratio is 5%-10%. By controlling the rising or falling rate, the system can achieve the control target more stably and avoid overshoot.

[0013] Preferably, the thermal management system further includes an electronic expansion valve, which is controlled as follows: When the system refrigerant state is in the stable state, the electronic expansion valve is confirmed to start working and is at the initial default valve opening; When the system refrigerant state is in the pre-start state, the electronic expansion valve executes the opening instruction and runs to the initial valve opening; When the system refrigerant state is in the stable operation state, the expansion valve adjusts the valve opening according to the control target requirement, and controls the target through closed-loop subcooling; When the system refrigerant state is in the switching state, since the control target switches when the user operates the air conditioner to set the temperature, the electronic expansion valve adjusts the control target at a preset rate based on system stability considerations; When the system refrigerant state is in the stopped state, the refrigerant state is adjusted to the running stopped state. At this time, the electronic expansion valve is closed to the valve opening of the initial default position. If it is opened again, it is necessary to ensure that the refrigerant enters a balanced state.

[0014] Preferably, the initial default valve opening is 50%-100%, and the initial valve opening is 10%-30%. Ensure that the valve body has a certain opening so that the circuits in the system are connected and the refrigerant can enter a balanced state.

[0015] Preferably, the preset rate is 1% / S-2% / S. By controlling the rising or falling rate, the system can achieve the control target more stably and avoid overshoot.

[0016] Beneficial effects of the present invention: 1. While traditional thermal management systems monitor and manage refrigerant status in a crude manner, this new system clearly defines refrigerant states, such as balance and pre-startup, and uses quantitative indicators such as a pressure differential threshold (0.3 bar) to accurately identify refrigerant status. Based on dynamic state transitions, components such as the electric compressor and electronic expansion valve operate collaboratively, with differentiated control logic corresponding to different states. This addresses the difficulties traditional systems face in accurately monitoring refrigerant status and poor component coordination, allowing refrigerant circulation and state transitions within the system to better meet actual needs and lay a solid foundation for the refined operation of the thermal management system.

[0017] 2. To address the shortcomings of traditional control strategies, which are simple and complex, this invention customizes control solutions for different refrigerant states. The electric compressor utilizes precise logic for speed control and target adaptation in various states, such as balancing and pre-start. The electronic expansion valve adjusts its opening and speed based on its state. Furthermore, refrigerant state migration replaces traditional multi-parameter load determination, reducing redundant calibration and development complexity, enabling refined control strategy upgrades, and reducing software complexity, making thermal management system development and operation more efficient.

[0018] 3. Orderly refrigerant state switching and component control avoid pressure fluctuations and abnormal component starts and stops associated with traditional control, improving system stability and component lifespan. Adjusting refrigerant circulation on demand and precisely matching the heat load achieves energy savings and consumption reductions, meeting the need for improved energy efficiency. During refrigerant switching, components quickly and collaboratively respond to user operations (such as thermostat adjustment), ensuring smooth restarts through standardized starts and stops. This significantly enhances user comfort and system convenience, comprehensively optimizing thermal management system performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is the flow chart of refrigerant state mode operation; Figure 2 It is based on the operating logic of the electronic expansion valve and electric compressor in the refrigerant status mode. DETAILED DESCRIPTION

[0020] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0021] Example 1 See Figure 1-Figure 2 The present invention provides a control method based on the refrigerant state of a thermal management system. The thermal management system includes a first pressure sensor and a second pressure sensor, wherein the pressure of the first pressure sensor is higher than the pressure of the second pressure sensor; The refrigerant state includes at least a balanced state, a pre-start state, a stable state, a switching state and a stopped state; when the pressure difference between the pressure sensor 1 and the pressure sensor 2 is less than 0.3 bar, the refrigerant state is a balanced state; when the pressure difference is less than 0.3 bar, it indicates that the system is in a balanced state, providing a stable initial condition for subsequent operations such as compressor startup.

[0022] The control method based on the refrigerant state of the thermal management system has the following steps: S1. When the system refrigerant is in the equilibrium state, if the electric compressor speed reaches 1500-2000 rpm and the rotation duration is 5-10 seconds, it enters the pre-start state. If it does not meet the requirements, it returns to the equilibrium state. When the system refrigerant is in the equilibrium state, the electric compressor first runs at 1500-2000 rpm for 5-10 seconds before entering the pre-start state. This significantly reduces the mechanical stress impact at the startup moment and allows the system control parameters to follow more quickly. If the speed or duration does not meet the requirements, the system automatically returns to the equilibrium state and waits for the start conditions again.

[0023] S2. When the system refrigerant state is in the pre-start state, if the speed change of the electric compressor is less than 300rpm and the rotation duration is 20S, the system enters a stable state. If it is not satisfied, it returns to a balanced state. This step strictly controls the transition from the pre-start state to the stable state. The speed change is small and continuous and stable, indicating that the compressor has adapted to the current operating rhythm and the system refrigerant circulation has gradually become stable, laying the foundation for subsequent precise regulation.

[0024] S3. When the system refrigerant state is in the stable state, if the system receives a control target change instruction, the system refrigerant state enters a switching state; if the system does not receive a target change instruction, it returns to a stable state; this step allows the system to flexibly respond to external demands and reasonably switch between stable operation and dynamic adjustment.

[0025] S4. When the system refrigerant state is in the switching state, if the system receives a shutdown command, it enters the operation stop state until the end. If it does not receive a system shutdown command, it returns to the switching state. This ensures that the system completes state transitions in an orderly manner under different commands to avoid confusion.

[0026] See Figure 1-Figure 2 , the control method of the electric compressor is as follows: When the system refrigerant is in the balanced state, the electric compressor is not restricted and operates normally, ensuring the basic circulation of the refrigerant.

[0027] When the system refrigerant state is in the pre-start state, the electric compressor speed is controlled to reach 1500rpm-2000rpm and the rotation duration is 5s-10s; at this time, the electric compressor first runs continuously at 1500rpm-2000rpm for 5s-10s before entering the pre-start state, which greatly reduces the mechanical stress impact at the startup moment and allows the system control parameters to follow more quickly.

[0028] When the system refrigerant state is in the stable operation state, the electric compressor is controlled to gradually increase the speed so that the electric compressor reaches the control target; and sudden changes in speed are avoided to impact the system.

[0029] When the system refrigerant state is in the switching state, when the user operates the air conditioner to set the temperature, the electric compressor adjusts the control target because the user switches the control target. The speed of the electric compressor is adjusted by 5%-10% within an interval of 5S; by adjusting the speed by 5%-10% within an interval of 5S and controlling the rise or fall rate, the system can achieve the control target more stably and avoid overshoot.

[0030] When the system refrigerant state is in the above-mentioned stopped state, the electric compressor system is turned off and then turned on again until the refrigerant state reaches a balanced state, creating conditions for the next stable start.

[0031] See Figure 1-Figure 2 , the thermal management system also includes an electronic expansion valve, which is controlled as follows: When the system refrigerant state is in the stable state, the electronic expansion valve is confirmed to start working, and the initial default valve opening is 50%-100%; by setting the initial default valve opening of the electronic expansion valve to 50%-100%, a basic channel is provided for the stable circulation of the system refrigerant and the efficient heat exchange of the system.

[0032] When the system refrigerant state is in the pre-start state, the electronic expansion valve executes the opening instruction and runs to an initial valve opening of 10%-30%; for the electronic expansion valve to receive the instruction, the initial valve opening of the valve body is 10%-30%, ensuring that the valve body has a certain opening, so that the circuit in the system is connected and the refrigerant can enter a balanced state.

[0033] When the system refrigerant state is in the stable operating state, the expansion valve adjusts the valve opening according to the requirements of the control target, and controls the target through closed-loop subcooling; accurately regulates the refrigerant flow and state to ensure the system heat exchange efficiency and stability.

[0034] When the system refrigerant state is in the switching state, since the control target switches when the user operates the air conditioner to set the temperature, the electronic expansion valve adjusts the control target at a rate of 1% / S-2% / S based on system stability considerations; by controlling the rise or fall rate, the system can reach the control target more stably and avoid overshoot.

[0035] When the system refrigerant is in the stopped state, the refrigerant state is adjusted to the stopped state. At this time, the electronic expansion valve is closed to the initial default valve opening. If it is reopened, it is necessary to ensure that the refrigerant is in a balanced state. If it is reopened, it is necessary to ensure that the refrigerant is in a balanced state to provide a prerequisite for the stable operation of the electronic expansion valve and the reliable restart of the system.

[0036] Example 2 See Figure 1-Figure 2 The present invention provides a control method based on the refrigerant state of a thermal management system. The thermal management system includes a first pressure sensor and a second pressure sensor, wherein the pressure of the first pressure sensor is higher than the pressure of the second pressure sensor; The refrigerant state includes at least a balanced state, a pre-start state, a stable state, a switching state, and a stopped state; when the pressure difference between the pressure sensor 1 and the pressure sensor 2 is less than 0.3 bar, the refrigerant state is a balanced state; The control method based on the refrigerant state of the thermal management system has the following steps: S1. When the system refrigerant state is in the equilibrium state, if the speed of the electric compressor reaches 1500 rpm and the rotation duration is 5 seconds, it enters the pre-start state. If it is not satisfied, it returns to the equilibrium state; S2. When the system refrigerant state is in the pre-start state, if the speed change of the electric compressor is less than 200 rpm and the rotation duration is 20 seconds, the system enters a stable state. If not, it returns to a balanced state. S3. When the system refrigerant state is in the stable state, if the system receives a control target change instruction, the system refrigerant state enters a switching state; if the system does not receive a target change instruction, it returns to the stable state; S4. When the system refrigerant state is in the switching state, if the system receives a shutdown command, it enters the operation stop state until the end; if no system shutdown command is received, it returns to the switching state.

[0037] See Figure 1-Figure 2 , the control method of the electric compressor is as follows: When the system refrigerant is in the balanced state, the electric compressor is not restricted and operates normally; When the system refrigerant state is in the pre-start state, the electric compressor speed is controlled to reach 1500 rpm and the rotation duration is 5 seconds; When the system refrigerant state is in the stable operation state, controlling the electric compressor to gradually increase the speed so that the electric compressor achieves the control target; When the system refrigerant state is in the switching state, when the user operates the air conditioner to set the temperature, the electric compressor adjusts the control target because the user switches the control target. The speed of the electric compressor is adjusted by 5% within an interval of 5 seconds. When the system refrigerant state is in the stopped state, the electric compressor system is turned off, and the electric compressor is turned on again until the refrigerant state enters a balanced state.

[0038] See Figure 1-Figure 2 , the thermal management system also includes an electronic expansion valve, which is controlled as follows: When the system refrigerant state is in the above-mentioned stable state, the electronic expansion valve is confirmed to start working, and the initial default valve opening is 50%; When the system refrigerant state is in the pre-start state, the electronic expansion valve executes the opening instruction and operates until the initial valve opening is 10%; When the system refrigerant state is in the stable operation state, the expansion valve adjusts the valve opening according to the control target requirement, and controls the target through closed-loop subcooling; When the system refrigerant state is in the switching state, since the control target switches when the user operates the air conditioner to set the temperature, the electronic expansion valve adjusts the control target at a rate of 1% / S based on system stability considerations; When the system refrigerant state is in the stopped state, the refrigerant state is adjusted to the running stopped state. At this time, the electronic expansion valve is closed to the valve opening of the initial default position. If it is opened again, it is necessary to ensure that the refrigerant enters a balanced state.

[0039] Example 3 See Figure 1-Figure 2 The present invention provides a control method based on the refrigerant state of a thermal management system. The thermal management system includes a first pressure sensor and a second pressure sensor, wherein the pressure of the first pressure sensor is higher than the pressure of the second pressure sensor; The refrigerant state includes at least a balanced state, a pre-start state, a stable state, a switching state, and a stopped state; when the pressure difference between the pressure sensor 1 and the pressure sensor 2 is less than 0.3 bar, the refrigerant state is a balanced state; The control method based on the refrigerant state of the thermal management system has the following steps: S1. When the system refrigerant state is in the equilibrium state, if the speed of the electric compressor reaches 2000 rpm and the rotation duration is 10 seconds, it enters the pre-start state. If it is not satisfied, it returns to the equilibrium state; S2. When the system refrigerant state is in the pre-start state, if the speed change of the electric compressor is less than 300 rpm and the rotation duration reaches 20 seconds, the system enters a stable state. If not, it returns to a balanced state; S3. When the system refrigerant state is in the stable state, if the system receives a control target change instruction, the system refrigerant state enters a switching state; if the system does not receive a target change instruction, it returns to the stable state; S4. When the system refrigerant state is in the switching state, if the system receives a shutdown command, it enters the operation stop state until the end; if no system shutdown command is received, it returns to the switching state.

[0040] See Figure 1-Figure 2 , the control method of the electric compressor is as follows: When the system refrigerant is in the balanced state, the electric compressor is not restricted and operates normally; When the system refrigerant state is in the pre-start state, the electric compressor speed is controlled to reach 2000 rpm and the rotation duration is 10 seconds; When the system refrigerant state is in the stable operation state, controlling the electric compressor to gradually increase the speed so that the electric compressor achieves the control target; When the system refrigerant state is in the switching state, when the user operates the air conditioner to set the temperature, the electric compressor adjusts the control target because the user switches the control target. The speed of the electric compressor is adjusted by 10% within an interval of 5 seconds. When the system refrigerant state is in the stopped state, the electric compressor system is turned off, and the electric compressor is turned on again until the refrigerant state enters a balanced state.

[0041] See Figure 1-Figure 2 , the thermal management system also includes an electronic expansion valve, which is controlled as follows: When the system refrigerant state is in the above-mentioned stable state, the electronic expansion valve is confirmed to start working, and the initial default valve opening is 100%; When the system refrigerant state is in the pre-start state, the electronic expansion valve executes the opening instruction and operates until the initial valve opening is 30%; When the system refrigerant state is in the stable operation state, the expansion valve adjusts the valve opening according to the control target requirement, and controls the target through closed-loop subcooling; When the system refrigerant state is in the switching state, because the control target switches when the user operates the air conditioner to set the temperature, the electronic expansion valve adjusts the control target at a preset rate of 2% / S based on system stability considerations; When the system refrigerant state is in the stopped state, the refrigerant state is adjusted to the running stopped state. At this time, the electronic expansion valve is closed to the valve opening of the initial default position. If it is opened again, it is necessary to ensure that the refrigerant enters a balanced state.

[0042] Example 4 See Figure 1-Figure 2 The present invention provides a control method based on the refrigerant state of a thermal management system. The thermal management system includes a first pressure sensor and a second pressure sensor, wherein the pressure of the first pressure sensor is higher than the pressure of the second pressure sensor; The refrigerant state includes at least a balanced state, a pre-start state, a stable state, a switching state, and a stopped state; when the pressure difference between the pressure sensor 1 and the pressure sensor 2 is less than 0.3 bar, the refrigerant state is a balanced state; The control method based on the refrigerant state of the thermal management system has the following steps: S1. When the system refrigerant state is in the equilibrium state, if the speed of the electric compressor reaches 1750 rpm and the rotation duration is 7.5 seconds, it enters the pre-start state. If it is not satisfied, it returns to the equilibrium state; S2. When the system refrigerant state is in the pre-start state, if the speed change of the electric compressor is less than 250 rpm and the rotation duration is 20 seconds, the system enters a stable state. If not, it returns to a balanced state. S3. When the system refrigerant state is in the stable state, if the system receives a control target change instruction, the system refrigerant state enters a switching state; if the system does not receive a target change instruction, it returns to the stable state; S4. When the system refrigerant state is in the switching state, if the system receives a shutdown command, it enters the operation stop state until the end; if no system shutdown command is received, it returns to the switching state.

[0043] See Figure 1-Figure 2 , the control method of the electric compressor is as follows: When the system refrigerant is in the balanced state, the electric compressor is not restricted and operates normally; When the system refrigerant state is in the pre-start state, the electric compressor speed is controlled to reach 1750 rpm and the rotation duration is 7.5 seconds; When the system refrigerant state is in the stable operation state, controlling the electric compressor to gradually increase the speed so that the electric compressor achieves the control target; When the system refrigerant state is in the switching state, when the user operates the air conditioner to set the temperature, the electric compressor adjusts the control target because the user switches the control target. The speed of the electric compressor is adjusted at a ratio of 7.5% within an interval of 5 seconds. When the system refrigerant state is in the stopped state, the electric compressor system is turned off, and the electric compressor is turned on again until the refrigerant state enters a balanced state.

[0044] See Figure 1-Figure 2 , the thermal management system also includes an electronic expansion valve, which is controlled as follows: When the system refrigerant state is in the above-mentioned stable state, the electronic expansion valve is confirmed to start working, and the initial default valve opening is 75%; When the system refrigerant state is in the pre-start state, the electronic expansion valve executes the opening instruction and operates until the initial valve opening is 20%; When the system refrigerant state is in the stable operation state, the expansion valve adjusts the valve opening according to the control target requirement, and controls the target through closed-loop subcooling; When the system refrigerant state is in the switching state, since the control target switches when the user operates the air conditioner to set the temperature, the electronic expansion valve adjusts the control target at a rate of 1.5% / S based on system stability considerations; When the system refrigerant state is in the stopped state, the refrigerant state is adjusted to the running stopped state. At this time, the electronic expansion valve is closed to the valve opening of the initial default position. If it is opened again, it is necessary to ensure that the refrigerant enters a balanced state.

[0045] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions or improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A control method based on the refrigerant state of a thermal management system, characterized in that: The thermal management system includes a first pressure sensor and a second pressure sensor, wherein the pressure of the first pressure sensor is higher than the pressure of the second pressure sensor; The refrigerant state includes at least a balanced state, a pre-start state, a stable state, a switching state and a stopped state; when the pressure difference between the pressure sensor 1 and the pressure sensor 2 is less than the pressure difference threshold, the refrigerant state is a balanced state; The control method based on the refrigerant state of the thermal management system has the following steps: S1. When the system refrigerant state is in the equilibrium state, if the electric compressor speed reaches the pre-start speed threshold and the rotation duration reaches the pre-start time threshold, the system enters the pre-start state. If not, the system returns to the equilibrium state. S2. When the system refrigerant state is in the pre-start state, if the speed change of the electric compressor is less than the steady state speed change threshold and the rotation duration reaches the steady time threshold, the system enters the steady state. If not, it returns to the equilibrium state. S3. When the system refrigerant state is in the stable state, if the system receives a control target change instruction, the system refrigerant state enters a switching state; if the system does not receive a target change instruction, it returns to the stable state; S4. When the system refrigerant state is in the switching state, if the system receives a shutdown command, it enters the operation stop state until the end; if no system shutdown command is received, it returns to the switching state.

2. The method for controlling the operation of a thermal system based on the refrigerant state according to claim 1, characterized in that: The pressure difference threshold is 0.3 bar.

3. The method for controlling the operation of a thermal system based on refrigerant status according to claim 1, characterized in that: The pre-start speed threshold is 1500 rpm-2000 rpm.

4. The method for controlling the operation of a thermal system based on refrigerant status according to claim 1, characterized in that: The pre-start time threshold is 5S-10S.

5. The method for controlling the operation of a thermal system based on refrigerant status according to claim 1, characterized in that: The stable time threshold is 20S, and the stable state speed change threshold is 300rpm.

6. The method for controlling the operation of a thermal system based on refrigerant status according to claim 1, characterized in that: The control method of the electric compressor is as follows: When the system refrigerant is in the balanced state, the electric compressor is not restricted and operates normally; When the system refrigerant state is in the pre-start state, the electric compressor speed is controlled to reach the pre-start speed threshold and the rotation duration reaches the pre-start time threshold; When the system refrigerant state is in the stable operation state, controlling the electric compressor to gradually increase the speed so that the electric compressor achieves the control target; When the system refrigerant state is in the switching state, when the user operates the air conditioner to set the temperature, the electric compressor adjusts the control target because the user switches the control target, and the speed of the electric compressor is adjusted according to the preset ratio within the preset interval; When the system refrigerant state is in the stopped state, the electric compressor system is turned off, and the electric compressor is turned on again until the refrigerant state enters a balanced state.

7. The method for controlling the operation of a thermal system based on the refrigerant state according to claim 6, characterized in that: The preset interval time is 5S, and the preset ratio is 5%-10%.

8. The method for controlling the operation of a thermal system based on refrigerant status according to claim 1, characterized in that: The thermal management system also includes an electronic expansion valve, which is controlled as follows: When the system refrigerant state is in the stable state, the electronic expansion valve is confirmed to start working and is at the initial default valve opening; When the system refrigerant state is in the pre-start state, the electronic expansion valve executes the opening instruction and runs to the initial valve opening; When the system refrigerant state is in the stable operation state, the expansion valve adjusts the valve opening according to the control target requirement, and controls the target through closed-loop subcooling; When the system refrigerant state is in the switching state, since the control target switches when the user operates the air conditioner to set the temperature, the electronic expansion valve adjusts the control target at a preset rate based on system stability considerations; When the system refrigerant state is in the stopped state, the refrigerant state is adjusted to the running stopped state. At this time, the electronic expansion valve is closed to the valve opening of the initial default position. If it is opened again, it is necessary to ensure that the refrigerant enters a balanced state.

9. The method for controlling the operation of a thermal system based on the refrigerant state according to claim 8, characterized in that: The initial default valve opening is 50%-100%, and the initial valve opening is 10%-30%.

10. The method for controlling the operation of a thermal system based on the refrigerant state according to claim 8, characterized in that: The preset rate is 1% / S-2% / S.

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