Integrated thermal management system, thermal management control method, and electric excavator

Abstract

This invention discloses an integrated thermal management system, a thermal management control method, and an electric excavator. The integrated thermal management system includes a hydraulic cooling system, a first heat exchanger, a battery thermal management system, and a switching device. The hydraulic cooling system forms a hydraulic cooling circuit, on which a phase change heat storage device is installed. The phase change heat storage device has a first heat storage channel and a second heat storage channel, and contains phase change heat storage material for heat exchange with the first and second heat storage channels. The battery thermal management system forms a battery heat exchange circuit, including a battery heat exchange main circuit, and heating pipes and connecting pipes connected to the battery heat exchange main circuit and arranged in parallel. The heating pipes are connected to the second heat storage channel for heat exchange with the phase change heat storage device. The switching device switches the connection of the heating pipes or the connecting pipes to the battery heat exchange main circuit. Heat from the hydraulic cooling system is recovered through the phase change heat storage device.

Description

Technical Field

[0001] This invention relates to the field of engineering machinery technology, and in particular to an integrated thermal management system, a thermal management control method, and an electric excavator. Background Technology

[0002] With the country's strong promotion of clean energy, major construction machinery manufacturers have successively deployed electric products. At present, the air conditioning system, cooling system and battery thermal management system of electric excavators are relatively independent and have a relatively complex structure. The thermal management subsystems of electric excavators are independent of each other, resulting in high costs. A single excavator needs to be equipped with multiple thermal management solutions, leading to high energy consumption of the entire vehicle and affecting its driving range.

[0003] In existing technologies, the air conditioning system is used to heat or cool the battery pack and the excavator hydraulic system separately. Only when the cab needs to be heated can some of the heat in the battery and the excavator hydraulic system be recovered. The effect of recovering and redistributing the waste heat of the electric drive system and the excavator hydraulic system of electric construction machinery is poor. Summary of the Invention

[0004] The main objective of this invention is to provide an integrated thermal management system, a thermal management control method, and an electric excavator, aiming to solve the problem of poor waste heat recovery in electric excavators.

[0005] To achieve the above objectives, the present invention provides an integrated thermal management system, comprising:

[0006] A hydraulic cooling system is provided, forming a hydraulic cooling circuit. A phase change heat storage device is provided on the hydraulic cooling circuit. The phase change heat storage device has a first heat storage channel and a second heat storage channel. A phase change heat storage material is provided in the phase change heat storage device for heat exchange with the first heat storage channel and the second heat storage channel.

[0007] The first heat exchanger has two first heat exchange channels that can exchange heat with each other. One of the first heat exchange channels is located on the hydraulic cooling circuit and its outlet end is connected to the first heat storage channel. The other is located on the flow path of the excavator hydraulic system.

[0008] A battery thermal management system includes a battery heat exchange circuit. The battery heat exchange circuit includes a battery heat exchange main circuit, and heating pipes and connecting pipes connected to the battery heat exchange main circuit and arranged in parallel. The heating pipes are connected to the second heat storage channel for heat exchange with the phase change heat storage device.

[0009] A switching device is used to switch the heating pipeline or the connecting pipeline to the battery heat exchange trunk line.

[0010] Optionally, the switching device includes two three-way valves, and the three ports of the two three-way valves are respectively connected to the heating pipeline, the connecting pipeline and the battery heat exchange trunk line.

[0011] Optionally, the integrated thermal management system further includes an air conditioning thermal management system, on which an air conditioning refrigerant circuit is formed;

[0012] The integrated thermal management system further includes a second heat exchanger, on which two second heat exchange channels capable of exchanging heat with each other are formed. One of the second heat exchange channels is located on the air conditioning refrigerant circuit, and the other is located on the battery heat exchange trunk line.

[0013] Optionally, the air conditioning refrigerant circuit includes a refrigerant main circuit, and a first refrigerant branch circuit and a second refrigerant branch circuit, both connected to and arranged in parallel with the refrigerant main circuit, wherein a first throttling device is provided on the first refrigerant branch circuit.

[0014] One of the second heat exchange channels is located on the first refrigerant branch.

[0015] Optionally, the integrated thermal management system further includes an air conditioning thermal management system, on which an air conditioning refrigerant circuit is formed, and a condenser is provided on the air conditioning refrigerant circuit, with a cooling fan corresponding to the condenser.

[0016] The hydraulic cooling circuit is equipped with a cooling pipe, which is connected to the liquid outlet of the first heat storage channel. The cooling pipe is configured to correspond to the heat dissipation fan.

[0017] Optionally, the integrated thermal management system further includes a liquid replenishment device, which is connected to the battery heat exchange circuit and the hydraulic cooling circuit to replenish coolant to the battery heat exchange circuit and the hydraulic cooling circuit.

[0018] The present invention also provides a thermal management control method, based on the integrated thermal management system described in any one of the above claims, the thermal management control method comprising:

[0019] Obtain the actual operating temperature at the battery pack outlet side of the battery heat exchange dry circuit;

[0020] The switching device is controlled to operate according to the actual operating temperature, so as to select one of the heating pipeline and the connecting pipeline to connect with the battery heat exchange trunk line.

[0021] Optionally, controlling the switching device to operate based on the actual operating temperature to select one of the heating pipe and the connecting pipe to connect with the battery heat exchange main circuit includes:

[0022] When the actual operating temperature is lower than the first preset temperature, the switching device is controlled to switch the heating pipeline to the battery heat exchange trunk line.

[0023] When the actual operating temperature is greater than the first preset temperature, a cooling strategy is determined, and the liquid flowing through the battery heat exchange trunk line is cooled according to the cooling strategy.

[0024] Optionally, the integrated thermal management system includes an air conditioning thermal management system, on which an air conditioning refrigerant circuit is formed, and the air conditioning refrigerant circuit includes a first refrigerant branch, on which a first throttling device is provided;

[0025] When the actual operating temperature is greater than the first preset temperature, a cooling strategy is determined, and the liquid flowing through the battery heat exchange trunk line is cooled according to the cooling strategy, including:

[0026] When the actual operating temperature is greater than the first preset temperature and less than the second preset temperature, the switching device is controlled to switch the connecting pipeline to the battery heat exchange trunk.

[0027] When the actual operating temperature is greater than the second preset temperature, the switching device is controlled to switch the connecting pipe to the battery heat exchange trunk, and the compressor on the air conditioning thermal management system is turned on, and the first throttling device is controlled to open the first refrigerant branch.

[0028] The second preset temperature is greater than the first preset temperature.

[0029] Optionally, the integrated thermal management system further includes an air conditioning thermal management system, which is equipped with a cooling fan and the hydraulic cooling circuit is equipped with cooling pipes;

[0030] The thermal management control method further includes:

[0031] Obtain the temperature of the coolant inside the cooling pipe;

[0032] When the temperature of the coolant is greater than the third preset temperature, the cooling fan is started.

[0033] The present invention also provides an electric excavator including the integrated thermal management system described in any one of the above-mentioned methods.

[0034] In the integrated thermal management system provided by this invention, the hydraulic cooling system forms a hydraulic cooling circuit, and a first heat exchanger is disposed on the hydraulic cooling circuit. The heat generated by the excavator hydraulic system is transferred to the hydraulic cooling circuit through the first heat exchanger to cool the excavator hydraulic system. The hydraulic cooling circuit is provided with a phase change heat storage device, and the heat in the hydraulic cooling circuit is transferred and stored in the phase change heat storage device, thereby cooling the hydraulic cooling circuit. The battery thermal management system forms a battery heat exchange circuit, including a heating pipe and a connecting pipe arranged in parallel. When the battery pack needs to be heated, the switching device is controlled to switch the heating pipe to the battery heat exchange main line to heat the battery heat exchange circuit, thereby heating the battery pack. When the battery pack does not need to be heated, the connecting pipe is controlled to be connected to the battery heat exchange main line. The phase change heat storage device recovers the heat in the hydraulic cooling system to heat the battery pack, eliminating the need for an additional heating system and avoiding energy waste. Attached Figure Description

[0035] Figure 1 This is a structural block diagram of the integrated thermal management system provided in the embodiments of the present invention;

[0036] Figure 2 This is a flowchart of the thermal management control method provided in the embodiments of the present invention.

[0037] Explanation of icon numbers:

[0038] label name label name 100 Integrated thermal management system 4 Switching device 1 Hydraulic cooling system 5 Air conditioning thermal management system 11 Phase change heat storage device 51 First refrigerant branch 12 Cooling pipes 52 Second refrigerant branch 2 First heat exchanger 53 Cooling fan 3 Battery thermal management system 6 Second heat exchanger 31 heating pipes 7 Liquid replenishment device 32 Connecting pipes

[0039] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0040] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0041] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0042] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the meaning of "and / or" throughout the text includes three parallel solutions; for example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0043] With the country's strong promotion of clean energy, major construction machinery manufacturers have successively deployed electric products. At present, the air conditioning system, cooling system and battery thermal management system of electric excavators are relatively independent and have a relatively complex structure. The thermal management subsystems of electric excavators are independent of each other, resulting in high costs. A single excavator needs to be equipped with multiple thermal management solutions, leading to high energy consumption of the entire vehicle and affecting its driving range.

[0044] In existing technologies, the air conditioning system is used to heat or cool the battery pack and the excavator hydraulic system separately. Only when the cab needs to be heated can some of the heat in the battery and the excavator hydraulic system be recovered. The effect of recovering and redistributing the waste heat of the electric drive system and the excavator hydraulic system of electric construction machinery is poor.

[0045] Please see Figure 1This invention provides an integrated thermal management system 100, including a hydraulic cooling system 1, a first heat exchanger 2, a battery thermal management system 3, and a switching device 4. The hydraulic cooling system 1 forms a hydraulic cooling circuit, and a phase change heat storage device 11 is provided on the hydraulic cooling circuit. The phase change heat storage device 11 has a first heat storage channel and a second heat storage channel, and a phase change heat storage material is disposed in the phase change heat storage device 11 for heat exchange with the first heat storage channel and the second heat storage channel, respectively. The first heat exchanger 2 forms two first heat exchange channels capable of mutual heat exchange, one of which is a first heat exchange channel. The channel is located on the hydraulic cooling circuit, and its outlet end is connected to the first heat storage channel. Another first heat exchange channel is used to be located on the flow path of the excavator hydraulic system. The battery thermal management system 3 forms a battery heat exchange circuit, which includes a battery heat exchange main circuit, and heating pipes 31 and connecting pipes 32, which are connected to the battery heat exchange main circuit and arranged in parallel. The heating pipes 31 are connected to the second heat storage channel for heat exchange with the phase change heat storage device 11. The switching device 4 switches the heating pipes 31 or the connecting pipes 32 to be connected to the battery heat exchange main circuit.

[0046] In the integrated thermal management system 100 provided by the present invention, the hydraulic cooling system 1 forms a hydraulic cooling circuit, and the first heat exchanger 2 is disposed on the hydraulic cooling circuit. When the excavator hydraulic system is working, it will frequently pressurize and depressurize the working device components such as the excavator arm, causing the hydraulic oil in the excavator hydraulic system to continuously heat up. The heat generated in the excavator hydraulic system is transferred to the hydraulic cooling circuit through the first heat exchanger 2. The low-temperature liquid in the hydraulic cooling circuit absorbs the heat in the excavator hydraulic system, thereby reducing the temperature in the excavator hydraulic system and cooling the excavator hydraulic system.

[0047] The hydraulic cooling circuit is equipped with the phase change heat storage device 11. The heat transferred from the excavator hydraulic system to the hydraulic cooling circuit is further transferred and stored in the phase change heat storage device 11. The phase change heat storage device 11 forms a low temperature environment relative to the hydraulic cooling circuit. The heat in the hydraulic cooling circuit is absorbed and the temperature in the hydraulic cooling circuit is reduced, thereby achieving cooling of the hydraulic cooling circuit.

[0048] Unlike traditional construction machinery, electric excavators also have a battery system, which includes a battery pack. Temperature control is required during operation. Therefore, the battery thermal management system 3 forms a battery heat exchange circuit, including a parallel heating pipe 31 and a connecting pipe 32. When the excavator is initially started, especially when the outside temperature is low, the temperature inside the battery pack is too low to output effective voltage. Therefore, the battery pack needs to be preheated to reach its optimal operating temperature. At this time, the switching device switches the heating pipe 31 to the battery heat exchange main line. The heating pipe 31 is connected to the second heat storage channel. The low-temperature liquid passing through the heating pipe 31 exchanges heat with the phase change heat storage material in the phase change heat storage device 11 as it passes through the second heat storage channel, thus heating up. The heated liquid then enters the battery heat exchange main line and subsequently enters the battery pack to preheat it.

[0049] When the battery pack is at its normal operating temperature, or when the battery pack reaches its normal operating temperature after being heated for a period of time, there is no need to heat the battery pack. At this time, the connecting pipe 32 is connected to the battery heat exchange trunk line, so that the liquid in the battery heat exchange circuit does not exchange heat with the phase change heat storage device 11, thereby preventing the phase change heat storage device 11 from further heating the liquid in the battery heat exchange circuit, cutting off the heat exchange path between the battery heat exchange circuit and the hydraulic cooling circuit, and preventing the high-temperature circuit from heating the low-temperature circuit.

[0050] The phase change heat storage device 11 is equipped with a phase change heat storage material, which can exchange heat with the first heat storage channel and the second heat storage channel. After the hydraulic cooling system 1 absorbs the heat generated in the excavator hydraulic system, it flows through the first heat storage channel and recovers the heat in the hydraulic cooling system 1 through the phase change heat storage material. The heating pipe 31 can be connected to the second heat storage channel according to actual needs to release the heat in the phase change heat storage device 11 and heat the battery pack. This eliminates the need for an additional heating system to heat the battery pack and avoids energy waste.

[0051] It should be noted that the phase change heat storage device 11 is based on phase change energy storage material for heat storage, and can be applied to working conditions where heat supply is discontinuous or supply and demand are not coordinated, solving the problem of contradiction between energy supply time and space. This is especially useful for electric excavators in construction machinery, where the working conditions are complex, variable, and harsh, often operating in extreme temperature regions such as Xinjiang and Tibet with large temperature differences. At the same time, the phase change heat storage device 11 can achieve passive heat storage without the need for active activation and additional energy consumption. In this embodiment, the phase change heat storage device 11 also forms a heat storage cavity, with the first heat storage channel and the second heat storage channel passing through the heat storage cavity. The phase change heat storage material fills the heat storage cavity and is arranged to fit against the outer walls of the first heat storage channel and the second heat storage channel for heat exchange with the first heat storage channel and the second heat storage channel.

[0052] In the embodiments provided by the present invention, the phase change heat storage material in the phase change heat storage device 11 can be implemented in various ways, such as composite ceramic materials or composite metal materials, etc., and no specific limitation is made here.

[0053] The switching device 4 can be implemented in various ways, as long as it can achieve the switching of the heating pipe 31 and the connecting pipe 32. For example, a three-way valve can be used to control the conduction of the heating pipe 31 and the connecting pipe 32.

[0054] Furthermore, in this embodiment, the switching device 4 includes two three-way valves, each with its three ports connected to the heating pipe, the connecting pipe, and the battery heat exchange main circuit, respectively. In this embodiment, the two three-way valves enable switching between the heating pipe 31 and the connecting pipe 32. By controlling the opening and closing of both ends of the heating pipe 31 and the connecting pipe 32, backflow and turbulence of the liquid in the circuit caused by unilateral control can be effectively avoided, resulting in better heating or stopping of heating.

[0055] It should be noted that the design of the two three-way valves makes the overall structure of the switching device 4 highly controllable. During operation, the heating pipe 31 and the connecting pipe 32 can be completely connected to or completely disconnected from the heat exchange main, which facilitates subsequent maintenance and replacement.

[0056] On the other hand, the integrated thermal management system 100 also includes an air conditioning thermal management system 5, on which an air conditioning refrigerant circuit is formed; the integrated thermal management system 100 also includes a second heat exchanger 6, on which two second heat exchange channels capable of exchanging heat with each other are formed, one of which is located on the air conditioning refrigerant circuit, and the other is located on the battery heat exchange trunk line. In this embodiment, in addition to heating, the battery pack also needs to ensure heat dissipation during normal operation. By combining the air conditioning refrigerant circuit with the battery heat exchange circuit, if the liquid temperature in the battery heat exchange circuit is too high, it can be cooled by the air conditioning thermal management system 5.

[0057] Furthermore, the air conditioning refrigerant circuit includes a refrigerant main circuit, and a first refrigerant branch circuit 51 and a second refrigerant branch circuit 52, both connected to and arranged in parallel with the refrigerant main circuit. The first refrigerant branch circuit 51 is equipped with a first throttling device; one of the second heat exchange channels is located on the first refrigerant branch circuit 51. In this embodiment, by connecting the first refrigerant branch circuit 51 with the second heat exchanger, the cooling capacity of the air conditioning refrigerant circuit is transferred to the second heat exchanger 6, thereby achieving cooling of the battery heat exchange circuit.

[0058] It should be noted that both the first heat exchanger 2 and the second heat exchanger 6 have multiple implementations. In the embodiment provided by the present invention, both the first heat exchanger 2 and the second heat exchanger 6 are plate heat exchangers to improve the heat exchange rate.

[0059] In addition, during the heat exchange process, the liquid flow direction between the two heat exchange tubes of the plate heat exchanger is set in opposite directions, which further improves the heat exchange rate.

[0060] On the other hand, the integrated thermal management system 100 also includes an air conditioning thermal management system 5, on which an air conditioning refrigerant circuit is formed. A condenser is provided on the air conditioning refrigerant circuit, and a cooling fan 53 is provided corresponding to the condenser. A cooling pipe 12 is provided on the hydraulic cooling circuit, and the cooling pipe 12 is connected to the liquid outlet of the first heat storage channel. The cooling pipe 12 is positioned corresponding to the cooling fan 53. In this embodiment, the phase change heat storage device 11 absorbs heat from the hydraulic cooling circuit. However, the heat absorption capacity of the phase change heat storage device 11 is limited, and the liquid temperature in the hydraulic cooling circuit may still rise slowly. Through the cooling pipe 12 and the cooling fan 53, when the liquid temperature in the hydraulic cooling circuit reaches a certain level, heat dissipation is controlled to prevent the temperature in the hydraulic cooling circuit from becoming too high, which would prevent the excavator's hydraulic system from being properly cooled.

[0061] It should be noted that the hydraulic cooling circuit is also connected to the motor of the excavator's hydraulic system to directly cool the motor, achieving dual cooling and ensuring the normal operation of the motor and the excavator's hydraulic system.

[0062] It should be noted that both the hydraulic cooling system 1 and the battery thermal management system 3 require cooling through some components of the air conditioning system. In the embodiment provided by the present invention, the battery thermal management system 3 is linked with the air conditioning refrigerant circuit in the air conditioning thermal management system 5, and the battery thermal management system 3 is linked with the cooling fan 53 in the air conditioning thermal management system 5. Therefore, the hydraulic cooling system 1 and the battery thermal management system 3 can share a set of air conditioning thermal management system 5.

[0063] On the other hand, the integrated thermal management system 100 also includes a coolant replenishment device 7, which is connected to the battery heat exchange circuit and the hydraulic cooling circuit to replenish coolant in the battery heat exchange circuit and the hydraulic cooling circuit. In this embodiment, since various factors may cause the coolant in the battery heat exchange circuit and the hydraulic cooling circuit to decrease, replenishing coolant through the coolant replenishment device 7 can enable the integrated thermal management system 100 to operate for extended periods.

[0064] It should be noted that the liquid replenishment device 7 includes a liquid replenishment vessel, which is connected to the battery heat exchange circuit and the hydraulic cooling circuit through a valve structure.

[0065] Based on the above-mentioned integrated thermal management system 100, the present invention also provides an electric excavator, which includes all the technical features of the above-mentioned integrated thermal management system 100, and therefore also has the technical effects brought about by all the above-mentioned technical features, which will not be described in detail here.

[0066] The integrated thermal management system 100 further includes a control device, which includes a memory, a processor, and a thermal management control method stored in the memory. The thermal management control program implements the following thermal management control method:

[0067] Obtain the actual operating temperature at the battery pack outlet side of the battery heat exchange dry circuit;

[0068] The switching device is controlled to operate according to the actual operating temperature, so as to select one of the heating pipeline and the connecting pipeline to connect with the battery heat exchange trunk line.

[0069] Optionally, controlling the switching device to operate based on the actual operating temperature to select one of the heating pipe and the connecting pipe to connect with the battery heat exchange main circuit includes:

[0070] When the actual operating temperature is lower than the first preset temperature, the switching device is controlled to switch the heating pipeline to the battery heat exchange trunk line.

[0071] When the actual operating temperature is greater than the first preset temperature, a cooling strategy is determined, and the liquid flowing through the battery heat exchange trunk line is cooled according to the cooling strategy.

[0072] Optionally, when the actual operating temperature is greater than a first preset temperature, determining a cooling strategy and cooling the liquid flowing through the battery heat exchange dryer according to the cooling strategy includes:

[0073] When the actual operating temperature is greater than the first preset temperature and less than the second preset temperature, the switching device is controlled to switch the connecting pipeline to the battery heat exchange trunk.

[0074] When the actual operating temperature is greater than the second preset temperature, the switching device is controlled to switch the connecting pipe to the battery heat exchange trunk, and the compressor on the air conditioning thermal management system is turned on, and the first throttling device is controlled to open the first refrigerant branch.

[0075] The second preset temperature is greater than the first preset temperature.

[0076] Optionally, the thermal management control method further includes:

[0077] Obtain the temperature of the coolant inside the cooling pipe;

[0078] When the coolant temperature is higher than the third preset temperature, the cooling fan is activated.

[0079] Please see Figure 2 Based on the aforementioned integrated thermal management system 100, the present invention also provides a thermal management control method, the thermal management control method comprising:

[0080] S10. Obtain the actual operating temperature at the battery pack outlet side of the battery heat exchange dry circuit;

[0081] The battery heat exchange trunk line is used to exchange heat with the battery pack and detect the actual operating temperature at the battery pack outlet side. The actual operating temperature obtained by measuring at the battery pack outlet side is more accurate. Based on this, it is determined whether the battery pack needs to be heated.

[0082] It should be noted that, in this embodiment, a temperature detection device is provided on the battery pack outlet side to detect the actual operating temperature of the battery pack outlet side. The temperature detection device can be implemented in various ways, such as an infrared thermometer, a water thermometer, etc., as long as the temperature of the battery pack outlet side can be obtained, no specific limitation is made here.

[0083] S20. Control the switching device to operate according to the actual working temperature, so as to select one of the heating pipeline and the connecting pipeline to connect with the battery heat exchange trunk line.

[0084] After obtaining the actual operating temperature, the heating pipe 31 and the connecting pipe 32 are connected according to the actual operating temperature, so as to heat the battery heat exchange circuit through the phase change heat storage device 11, realize the waste heat utilization and exchange between the hydraulic cooling system and the battery thermal management system, and avoid the need to heat the battery pack through an additional heating system, thus avoiding energy waste.

[0085] Specifically, step S20 includes:

[0086] S21. When the actual working temperature is less than the first preset temperature, control the switching device to switch the heating pipeline to the battery heat exchange trunk line.

[0087] When the actual operating temperature is lower than the first preset temperature, the temperature inside the battery pack cannot achieve normal operation. Therefore, switching the heating pipe 31 to heat the battery heat exchange circuit can realize the utilization of waste heat across time and space.

[0088] S22. When the actual operating temperature is greater than the first preset temperature, a cooling strategy is determined, and the liquid flowing through the battery heat exchange dry circuit is cooled according to the cooling strategy.

[0089] When the actual operating temperature is greater than the first preset temperature, it indicates that the battery pack has completed preheating. At this time, it is necessary to reconfirm the operating status of the battery pack and establish different cooling strategies based on the actual operating temperature to ensure the normal operation of the battery pack.

[0090] Furthermore, step S22 includes:

[0091] S221. When the actual working temperature is greater than the first preset temperature and less than the second preset temperature, control the switching device to switch the connection pipeline to the battery heat exchange trunk.

[0092] When the actual operating temperature is between the first preset temperature and the second preset temperature, the battery pack can operate normally on its own without heating or cooling. Therefore, the connection pipe 32 is connected to allow the battery heat exchange circuit to circulate internally.

[0093] S222. When the actual operating temperature is greater than the second preset temperature, the switching device is controlled to switch the connecting pipe to the battery heat exchange main circuit, and the compressor on the air conditioning thermal management system is turned on, and the first throttling device is controlled to open the first refrigerant branch; wherein, the second preset temperature is greater than the first preset temperature.

[0094] When the actual operating temperature is greater than the second preset temperature, the temperature inside the battery pack rises, requiring cooling to ensure its normal operation. Therefore, in addition to controlling the connection of the connecting pipe 32, it is also necessary to control the air conditioning thermal management system to start and operate, and to cool the battery heat exchange circuit through the air conditioning refrigerant circuit to cool the battery pack.

[0095] It should be noted that in this embodiment, the first refrigerant branch is used to exchange heat with the battery heat exchange circuit, and the second refrigerant branch is used to exchange heat with the cab of the electric excavator. The two refrigerant branches can operate independently to form a complete air conditioning operation path.

[0096] On the other hand, the thermal management control method also includes:

[0097] S30. Obtain the temperature of the coolant in the cooling pipe;

[0098] S40. When the temperature of the coolant is greater than the third preset temperature, control the cooling fan to start.

[0099] In the embodiments provided by the present invention, the hydraulic cooling circuit is used to exchange heat in the excavator hydraulic system. The hydraulic cooling circuit undergoes heat exchange treatment through the phase change heat storage device 11, which can achieve a certain degree of cooling. However, during long-term operation, the temperature of the hydraulic cooling circuit will still rise slowly. In order to avoid the continuous rise in temperature from affecting other components of the hydraulic cooling circuit, such as the connected motor, the cooling fan 53 is turned on when the coolant temperature is too high to cool the hydraulic cooling circuit.

[0100] The above are merely preferred embodiments of the present invention and do not limit the scope of the patent. Any equivalent structural or procedural transformations made based on the description and drawings of the present invention, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of the present invention.

Claims

1. An integrated thermal management system, characterized in that, include: A hydraulic cooling system is provided, forming a hydraulic cooling circuit. A phase change heat storage device is provided on the hydraulic cooling circuit. The phase change heat storage device has a first heat storage channel and a second heat storage channel. A phase change heat storage material is provided in the phase change heat storage device for heat exchange with the first heat storage channel and the second heat storage channel. The first heat exchanger has two first heat exchange channels that can exchange heat with each other. One of the first heat exchange channels is located on the hydraulic cooling circuit and its outlet end is connected to the first heat storage channel. The other first heat exchange channel is located on the hydraulic oil circuit of the excavator hydraulic system to transfer the heat generated by the excavator hydraulic system to the hydraulic cooling circuit. A battery thermal management system includes a battery heat exchange circuit. The battery heat exchange circuit includes a battery heat exchange main circuit, and heating pipes and connecting pipes connected to the battery heat exchange main circuit and arranged in parallel. The heating pipes are connected to the second heat storage channel for heat exchange with the phase change heat storage device. A switching device to switch the heating pipeline or to connect the connecting pipeline to the battery heat exchange trunk line.

2. The integrated thermal management system according to claim 1, characterized in that, The switching device includes two three-way valves, and the three ports of the two three-way valves are respectively connected to the heating pipeline, the connecting pipeline and the battery heat exchange trunk line.

3. The integrated thermal management system according to claim 1, characterized in that, The integrated thermal management system also includes an air conditioning thermal management system, on which an air conditioning refrigerant circuit is formed; The integrated thermal management system further includes a second heat exchanger, on which two second heat exchange channels capable of exchanging heat with each other are formed. One of the second heat exchange channels is located on the air conditioning refrigerant circuit, and the other second heat exchange channel is located on the battery heat exchange trunk line.

4. The integrated thermal management system according to claim 3, characterized in that, The air conditioning refrigerant circuit includes a refrigerant main circuit, and a first refrigerant branch circuit and a second refrigerant branch circuit, both connected to and arranged in parallel with the refrigerant main circuit. A first throttling device is provided on the first refrigerant branch circuit. One of the second heat exchange channels is located on the first refrigerant branch.

5. The integrated thermal management system according to claim 1, characterized in that, The integrated thermal management system also includes an air conditioning thermal management system, on which an air conditioning refrigerant circuit is formed, and a condenser is provided on the air conditioning refrigerant circuit, with a cooling fan corresponding to the condenser. The hydraulic cooling circuit is equipped with a cooling pipe, which is connected to the liquid outlet of the first heat storage channel. The cooling pipe is configured to correspond to the heat dissipation fan.

6. A thermal management control method, based on an integrated thermal management system as described in any one of claims 1 to 5, characterized in that, The thermal management control method includes: Obtain the actual operating temperature at the battery pack outlet side on the battery heat exchange dry circuit; The switching device is controlled to operate according to the actual operating temperature, so as to select one of the heating pipeline and the connecting pipeline to connect to the battery heat exchange trunk line.

7. The thermal management control method according to claim 6, characterized in that, The step of controlling the switching device to operate based on the actual operating temperature, to select one of the heating pipe and the connecting pipe to connect to the battery heat exchange main circuit, includes: When the actual operating temperature is lower than the first preset temperature, the switching device is controlled to switch the heating pipeline to the battery heat exchange trunk line. When the actual operating temperature is greater than the first preset temperature, a cooling strategy is determined, and the liquid flowing through the battery heat exchange trunk line is cooled according to the cooling strategy.

8. The thermal management control method according to claim 7, characterized in that, The integrated thermal management system includes an air conditioning thermal management system, on which an air conditioning refrigerant circuit is formed. The air conditioning refrigerant circuit includes a first refrigerant branch, and a first throttling device is provided on the first refrigerant branch. When the actual operating temperature is greater than the first preset temperature, a cooling strategy is determined, and the liquid flowing through the battery heat exchange trunk line is cooled according to the cooling strategy, including: When the actual operating temperature is greater than the first preset temperature and less than the second preset temperature, the switching device is controlled to switch the connecting pipeline to the battery heat exchange trunk. When the actual operating temperature is greater than the second preset temperature, the switching device is controlled to switch the connecting pipe to the battery heat exchange trunk, and the compressor on the air conditioning thermal management system is turned on, and the first throttling device is controlled to open the first refrigerant branch. The second preset temperature is greater than the first preset temperature.

9. The thermal management control method according to claim 6, characterized in that, The integrated thermal management system also includes an air conditioning thermal management system, which is equipped with a cooling fan and a cooling pipe on the hydraulic cooling circuit. The thermal management control method further includes: Obtain the temperature of the coolant inside the cooling pipe; When the temperature of the coolant is greater than the third preset temperature, the cooling fan is started.

10. An electric excavator, characterized in that, Includes the integrated thermal management system according to any one of claims 1 to 5.

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