Heat exchange system and engineering machinery

Abstract

The utility model belongs to the technical field of engineering machinery, and discloses a heat exchange system and engineering machinery. The heat exchange system comprises a power system, a gearbox system, a hydraulic system, a radiator and a heat exchanger. Wherein the heat exchanger comprises a first cavity, a second cavity and a third cavity, the power system can convey liquid (such as cooling liquid) in the power system into the first cavity, and the gearbox system can convey liquid (such as gearbox oil) in the gearbox system into the second cavity; the hydraulic system can convey liquid (such as hydraulic oil) in the hydraulic system into the third cavity, and cooling liquid in the first cavity, gearbox oil in the second cavity and the hydraulic oil in the third cavity can exchange heat. According to the heat exchange system, temperature rise preheating and heat preservation of a gearbox system and a hydraulic system are achieved; and the gearbox system can be cooled and radiated through the hydraulic system, so that the gearbox system does not need to be provided with a radiator, and the occupied space and the manufacturing cost are reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of engineering machinery, in particular to a heat exchange system and engineering machinery. Background Art

[0002] When construction machinery such as loaders are working, the temperature of the coolant in the power system, the hydraulic oil in the hydraulic system, and the transmission oil in the transmission system will increase. Therefore, a cooling system is required to dissipate the heat of each system so that each system can operate within the appropriate temperature range.

[0003] In existing technology, each system is equipped with a radiator to dissipate heat. During actual operation, such as shoveling, the transmission system generates relatively little heat, so no heat dissipation is required. During driving, the hydraulic system also generates relatively little heat, so no heat dissipation is required. This configuration results in redundant radiators, consuming space within the entire machine, and wasting resources. Utility Model Content

[0004] The purpose of the utility model is to provide a heat exchange system and engineering machinery, which optimize the space of the entire machine, avoid resource waste and reduce the cost of the heat exchange system.

[0005] To achieve this purpose, the present invention adopts the following technical solutions:

[0006] A heat exchange system comprising a power system, a transmission system, a hydraulic system, a radiator, and a heat exchanger, wherein the heat exchanger is provided with a first cavity, a second cavity, and a third cavity, and liquid in the first cavity, liquid in the second cavity, and liquid in the third cavity can exchange heat with each other;

[0007] The liquid outlet of the power system is connected to the liquid inlet of the first cavity through a first pipeline, the liquid outlet of the first cavity is connected to the radiator through a second pipeline, and the radiator is connected to the liquid inlet of the power system through a third pipeline;

[0008] The liquid outlet of the transmission system is connected to the liquid inlet of the second cavity through a fourth pipeline, and the liquid outlet of the second cavity is connected to the liquid inlet of the transmission system through a fifth pipeline;

[0009] The liquid outlet of the hydraulic system is connected to the liquid inlet of the third cavity through the sixth pipeline, the liquid outlet of the third cavity is connected to the radiator through the seventh pipeline, and the radiator is connected to the liquid inlet of the hydraulic system through the eighth pipeline.

[0010] As an optional solution, the liquid outlet of the power system is further connected to the radiator through a first branch pipeline;

[0011] The liquid outlet of the transmission system is also connected to the liquid inlet of the transmission system through a second branch pipeline;

[0012] The liquid outlet of the hydraulic system is also connected to the radiator through a third branch pipeline.

[0013] As an optional solution, the first pipeline, the fourth pipeline and the sixth pipeline are all provided with flow control valves;

[0014] The inlet of the flow control valve of the first pipeline is connected to the liquid outlet of the power system, the first outlet of the flow control valve of the first pipeline is connected to the liquid inlet of the first cavity, and the second outlet of the flow control valve of the first pipeline is connected to the radiator through the first branch pipeline;

[0015] The inlet of the flow control valve of the fourth pipeline is connected to the liquid outlet of the transmission system, the first outlet of the flow control valve of the fourth pipeline is connected to the liquid inlet of the second cavity, and the second outlet of the flow control valve of the fourth pipeline is connected to the liquid inlet of the transmission system through the second branch pipeline;

[0016] The inlet of the flow control valve of the sixth pipeline is connected to the liquid outlet of the hydraulic system, the first outlet of the flow control valve of the sixth pipeline is connected to the liquid inlet of the third cavity, and the second outlet of the flow control valve of the sixth pipeline is connected to the radiator through the third branch pipeline.

[0017] As an optional solution, the first pipeline, the fourth pipeline and the sixth pipeline are all further provided with a temperature detector;

[0018] The temperature detector of the first pipeline is used to detect the temperature of the liquid in the power system, and the controller controls the opening of the first outlet and the second outlet of the flow control valve of the first pipeline according to the temperature in the power system;

[0019] The temperature detector of the fourth pipeline is used to detect the temperature of the liquid in the transmission system, and the controller controls the opening of the first outlet and the second outlet of the flow control valve of the fourth pipeline according to the temperature in the transmission system;

[0020] The temperature detector of the sixth pipeline is used to detect the temperature of the liquid in the hydraulic system, and the controller controls the opening of the first outlet and the second outlet of the flow control valve of the sixth pipeline according to the temperature in the hydraulic system.

[0021] As an optional solution, the temperature detector is a temperature thermistor.

[0022] As an optional solution, the flow control valve is an electromagnetic proportional control valve.

[0023] As an optional solution, the power system is an engine system or a motor system.

[0024] As an optional solution, the radiator is a cooling fan.

[0025] Engineering machinery, comprising the heat exchange system described in any of the above solutions.

[0026] Beneficial effects of the utility model:

[0027] The heat exchange system provided by the present invention realizes preheating and heat preservation of the transmission system and the hydraulic system in a low-temperature environment; and can also cool and dissipate heat from the transmission system through the hydraulic system, so that the transmission system does not need to be equipped with a radiator, reducing occupied space and manufacturing costs, and optimizing the overall spatial layout. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a structural diagram of the heat exchange system provided by an embodiment of the present utility model.

[0029] In the picture:

[0030] 1. Power system; 11. First pipeline; 12. Second pipeline; 13. Third pipeline;

[0031] 2. Transmission system; 21. Fourth pipeline; 22. Fifth pipeline;

[0032] 3. Hydraulic system; 31. Sixth pipeline; 32. Seventh pipeline; 33. Eighth pipeline;

[0033] 4. Radiator;

[0034] 5. Heat exchanger;

[0035] 6. Flow control valve;

[0036] 7. Temperature detector. DETAILED DESCRIPTION

[0037] The following describes in detail embodiments of the present invention. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar components or components having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to explain the present invention, and should not be construed as limiting the present invention.

[0038] In the description of this utility model, unless otherwise expressly specified or limited, the terms "connected," "connect," and "fixed" should be understood in a broad sense. For example, they may refer to fixed or detachable connections, mechanical or electrical connections, direct or indirect connections through an intermediate medium, and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on specific circumstances.

[0039] In the description of the present utility model, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first feature and the second feature being in direct contact, or may include the first feature and the second feature being in contact not directly but through another feature between them. Moreover, a first feature being "above," "above," and "above" a second feature includes the first feature being directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature includes the first feature being directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0040] The technical solution of the present invention will be further described below with reference to the accompanying drawings and through specific implementation methods.

[0041] like Figure 1 As shown, an embodiment of the present invention provides a heat exchange system applicable to engineering machinery, comprising a power system 1, a transmission system 2, a hydraulic system 3, a radiator 4, and a heat exchanger 5. The heat exchanger 5 comprises a first cavity, a second cavity, and a third cavity. The power system 1 can transport liquid (such as coolant) in the power system 1 to the first cavity, the transmission system 2 can transport liquid (such as transmission oil) in the transmission system 2 to the second cavity, and the hydraulic system 3 can transport liquid (such as hydraulic oil) in the hydraulic system 3 to the third cavity. The coolant in the first cavity, the transmission oil in the second cavity, and the hydraulic oil in the third cavity can perform heat exchange.

[0042] Specifically, the liquid outlet of the power system 1 is connected to the liquid inlet of the first cavity through the first pipeline 11, the liquid outlet of the first cavity is connected to the radiator 4 through the second pipeline 12, and the radiator 4 is connected to the liquid inlet of the power system 1 through the third pipeline 13; the liquid outlet of the transmission system 2 is connected to the liquid inlet of the second cavity through the fourth pipeline 21, and the liquid outlet of the second cavity is connected to the liquid inlet of the transmission system 2 through the fifth pipeline 22; the liquid outlet of the hydraulic system 3 is connected to the liquid inlet of the third cavity through the sixth pipeline 31, the liquid outlet of the third cavity is connected to the radiator 4 through the seventh pipeline 32, and the radiator 4 is connected to the liquid inlet of the hydraulic system 3 through the eighth pipeline 33.

[0043] When the construction machinery is started and preheated, the coolant in the power system 1 can be heated up in a relatively short time. The coolant in the power system 1 enters the first cavity, the second cavity and the third cavity respectively through the first pipeline 11, the transmission oil in the transmission system 2 enters the fourth pipeline 21 and the hydraulic oil in the hydraulic system 3 enters the sixth pipeline 31, so that the higher temperature coolant can perform heat exchange with the transmission oil and the hydraulic oil, so as to preheat the transmission oil and the hydraulic oil, which is beneficial to the performance of the transmission system 2 and the hydraulic system 3. It can be understood that after the preheating of the transmission oil and the hydraulic oil is completed, the first pipeline 11, the fourth pipeline 21 and the sixth pipeline 31 can be disconnected.

[0044] When the temperature of the transmission oil in the transmission system 2 or the temperature of the hydraulic oil in the hydraulic system 3 drops, the first pipeline 11 can be opened again, and the fourth pipeline 21 or the sixth pipeline 31 corresponding to the transmission oil or hydraulic oil with a dropped temperature can be opened to keep the transmission oil or hydraulic oil warm.

[0045] When the construction machinery is in the moving condition, the temperature of the coolant of the power system 1 and the temperature of the transmission oil of the transmission system 2 are high, while the temperature of the hydraulic oil of the hydraulic system 3 is low. Therefore, the fourth pipeline 21 and the sixth pipeline 31 can be controlled to be connected respectively, so that the transmission oil in the transmission system 2 enters the second cavity through the fourth pipeline 21, and the hydraulic oil in the hydraulic system 3 enters the third cavity through the sixth pipeline 31, thereby realizing heat exchange between the transmission oil in the second cavity and the hydraulic oil in the third cavity, so as to achieve cooling and heat dissipation of the transmission system 2 through the hydraulic system 3, avoiding the need for a radiator 4 for the transmission system 2 and saving space.

[0046] The heat exchange system realizes preheating and heat preservation of the transmission system 2 and the hydraulic system 3 in a low-temperature environment; and can also cool and dissipate heat of the transmission system 2 through the hydraulic system 3, so that the transmission system 2 does not need to be equipped with a radiator 4, reducing the occupied space and manufacturing costs, and optimizing the overall spatial layout.

[0047] Furthermore, the liquid outlet of the power system 1 is also connected to the radiator 4 through the first branch pipeline, that is, the coolant in the power system 1 can enter the radiator 4 directly through the first branch pipeline without passing through the heat exchanger 5, and return to the power system 1 through the third pipeline 13 after dissipating heat in the radiator 4; the liquid outlet of the transmission system 2 is also connected to the liquid inlet of the transmission system 2 through the second branch pipeline, that is, the transmission oil in the transmission system 2 can return directly through the second branch pipeline without passing through the heat exchanger 5, thereby realizing self-circulation; the liquid outlet of the hydraulic system 3 is also connected to the radiator 4 through the third branch pipeline, that is, the hydraulic oil in the hydraulic system 3 can enter the radiator 4 directly through the third branch pipeline without passing through the heat exchanger 5, and return to the hydraulic system 3 through the eighth pipeline 33 after passing through the radiator 4.

[0048] In order to facilitate the control of the heat exchange system, the first pipeline 11 , the fourth pipeline 21 and the sixth pipeline 31 are all provided with flow control valves 6 .

[0049] Among them, the inlet of the flow control valve 6 of the first pipeline 11 is connected to the liquid outlet of the power system 1, the first outlet of the flow control valve 6 of the first pipeline 11 is connected to the liquid inlet of the first cavity, and the second outlet of the flow control valve 6 of the first pipeline 11 is connected to the radiator 4 through the first branch pipeline. In this embodiment, the end of the first branch pipeline away from the flow control valve 6 can be connected to the second pipeline 12 to reduce the length of the first branch pipeline. By arranging the flow control valve 6 on the first pipeline 11, the flow of coolant passing through the first pipeline 11 and the first branch pipeline can be controlled by controlling the opening of the first outlet and the second outlet of the flow control valve 6 on the first pipeline 11.

[0050] The inlet of the flow control valve 6 of the fourth pipeline 21 is connected to the liquid outlet of the transmission system 2, the first outlet of the flow control valve 6 of the fourth pipeline 21 is connected to the liquid inlet of the second cavity, and the second outlet of the flow control valve 6 of the fourth pipeline 21 is connected to the liquid inlet of the transmission system 2 through the second branch pipeline. In this embodiment, the end of the second branch pipeline away from the flow control valve 6 can be connected to the fifth pipeline 22 to reduce the length of the second branch pipeline. By arranging the flow control valve 6 on the fourth pipeline 21, the flow of the transmission oil passing through the fourth pipeline 21 and the second branch pipeline can be controlled by controlling the opening of the first outlet and the second outlet of the flow control valve 6 on the fourth pipeline 21.

[0051] The inlet of the flow control valve 6 of the sixth pipeline 31 is connected to the liquid outlet of the hydraulic system 3, the first outlet of the flow control valve 6 of the sixth pipeline 31 is connected to the liquid inlet of the third cavity, and the second outlet of the flow control valve 6 of the sixth pipeline 31 is connected to the radiator 4 through the third branch pipeline. In this embodiment, the end of the third branch pipeline away from the flow control valve 6 can be connected to the seventh pipeline 32 to reduce the length of the third branch pipeline. By arranging the flow control valve 6 on the sixth pipeline 31, the flow of hydraulic oil passing through the sixth pipeline 31 and the third branch pipeline can be controlled by controlling the opening of the first outlet and the second outlet of the flow control valve 6 on the sixth pipeline 31.

[0052] Optionally, in order to be able to detect the temperature of the liquid in the power system 1 , the transmission system 2 and the hydraulic system 3 in real time, the first pipeline 11 , the fourth pipeline 21 and the sixth pipeline 31 are also provided with a temperature detector 7 .

[0053] Among them, the temperature detector 7 of the first pipeline 11 is used to detect the temperature of the coolant in the power system 1, and the controller can control the opening of the first outlet and the second outlet of the flow control valve 6 of the first pipeline 11 according to the temperature of the coolant in the power system 1 to achieve temperature control of the power system 1.

[0054] The temperature detector 7 of the fourth pipeline 21 is used to detect the temperature of the transmission oil in the transmission system 2. The controller can control the opening of the first outlet and the second outlet of the flow control valve 6 of the fourth pipeline 21 according to the temperature of the transmission oil in the transmission system 2 to achieve temperature control of the transmission system 2.

[0055] The temperature detector 7 of the sixth pipeline 31 is used to detect the temperature of the hydraulic oil in the hydraulic system 3. The controller can control the opening of the first outlet and the second outlet of the flow control valve 6 of the sixth pipeline 31 according to the temperature of the hydraulic oil in the hydraulic system 3 to achieve temperature control of the hydraulic system 3.

[0056] Optionally, the radiator 4 may be a cooling fan.

[0057] Optionally, the flow control valve 6 may be an electromagnetic proportional control valve.

[0058] Optionally, the temperature detector 7 may be a temperature thermistor sensor.

[0059] Optionally, the power system 1 can be selected as an engine system or a motor system.

[0060] In this embodiment, when the power system 1 is an engine system, the maximum temperature of the power system 1 cannot exceed 105°C; when the power system 1 is a motor system, the maximum temperature of the power system 1 cannot exceed 65°C; the maximum temperature of the transmission system 2 cannot exceed 120°C; the maximum temperature of the hydraulic system 3 cannot exceed 85°C.

[0061] In this embodiment, the control method of the heat exchange system includes:

[0062] Real-time detection of the temperature of the power system 1, transmission system 2 and hydraulic system 3;

[0063] When the temperature of the power system 1 reaches a first high temperature threshold, and the temperatures of the transmission system 2 and the hydraulic system 3 are both lower than a low temperature threshold, the first pipeline 11, the fourth pipeline 21, and the sixth pipeline 31 are controlled to be conductive, so that the power system 1 preheats or keeps the transmission system 2 and the hydraulic system 3 warm.

[0064] When the temperature of the power system 1 reaches a first high temperature threshold, and the temperature of the transmission system 2 is lower than a low temperature threshold, and the temperature of the hydraulic system 3 is higher than a low temperature threshold, the first pipeline 11 and the fourth pipeline 21 are controlled to be connected, so that the power system 1 preheats or keeps the transmission system 2 warm;

[0065] When the temperature of the power system 1 reaches a first high temperature threshold, the temperature of the hydraulic system 3 is lower than a low temperature threshold, and the temperature of the transmission system 2 is higher than the low temperature threshold and lower than a second high temperature threshold, the first pipeline 11 and the sixth pipeline 31 are controlled to be connected, so that the power system 1 preheats or keeps the hydraulic system 3 warm.

[0066] When the temperature of the transmission system 2 is higher than the second high temperature threshold, the fourth pipeline 21 and the sixth pipeline 31 are controlled to be connected, so that the hydraulic system 3 can cool and dissipate heat for the transmission system 2;

[0067] The first high temperature threshold is greater than the low temperature threshold, and the second high temperature threshold is greater than the low temperature threshold.

[0068] It can be understood that when applying the control method of the heat exchange system, the temperatures of the power system 1, the transmission system 2 and the hydraulic system 3 do not exceed their respective corresponding maximum temperatures; the first high temperature threshold is the optimal temperature when the power system 1 is working, the low temperature threshold is the preheating value, which can be selected between 0-10°C, and the second high temperature threshold is the optimal temperature when the transmission system 2 is working.

[0069] For example, under extremely cold conditions, when the construction machinery is starting to preheat, the temperature of the power system 1 reaches the first high temperature threshold. At this time, the temperatures of the transmission system 2 and the hydraulic system 3 are lower than the low temperature threshold. Then, the first outlet of the flow control valve 6 of the first pipeline 11, the first outlet of the flow control valve 6 of the fourth pipeline 21, and the first outlet of the flow control valve 6 of the sixth pipeline 31 are all opened, and the transmission system 2 and the hydraulic system 3 can be preheated through the power system 1.

[0070] In extremely cold conditions, when the construction machinery is preheated and in operation, such as during driving or shoveling, the temperatures of both the transmission system 2 and the hydraulic system 3 may fall below the low-temperature threshold due to the extremely low ambient temperature. In this case, the power system 1 can be used to keep the transmission system 2 and the hydraulic system 3 warm. It is understood that the insulation temperature and the preheating temperature are the same.

[0071] Under normal conditions (i.e., non-extremely cold conditions), when the engineering machinery completes preheating and is driving, the heat generated by the power system 1 and the transmission system 2 is large, while the heat generated by the hydraulic system 3 is small (the hydraulic system 3 does not work during driving), then the first outlet of the flow control valve 6 of the first pipeline 11 is closed and the second outlet is opened, the first outlet of the flow control valve 6 of the fourth pipeline 21 is opened, and the first outlet of the flow control valve 6 of the sixth pipeline 31 is opened. The coolant in the power system 1 can enter the radiator 4 through the second outlet of the flow control valve 6 of the first pipeline 11 for heat dissipation and then flow back through the third pipeline 13. The transmission oil in the transmission system 2 enters the second cavity through the first outlet of the flow control valve 6 of the fourth pipeline 21, and then flows back to the transmission system 2 through the fifth pipeline 22. The hydraulic oil in the hydraulic system 3 enters the third cavity through the first outlet of the flow control valve 6 of the sixth pipeline 31, and then enters the radiator 4 through the seventh pipeline 32 for heat dissipation and then flows back to the hydraulic system 3 through the eighth pipeline 33. The transmission oil in the second cavity and the hydraulic oil in the third cavity achieve heat exchange, so that the hydraulic system 3 cools and dissipates heat from the transmission system 2 .

[0072] Under normal conditions (i.e., not extreme cold conditions), when the construction machinery completes preheating and begins shoveling operations, the power system 1 and hydraulic system 3 generate a large amount of heat, while the transmission system 2 generates a small amount of heat (no heat dissipation is required). The first outlet of the flow control valve 6 in the first pipeline 11 is closed and the second outlet is opened. The first outlet of the flow control valve 6 in the fourth pipeline 21 is closed and the second outlet is opened. The first outlet of the flow control valve 6 in the sixth pipeline 31 is closed and the second outlet is opened. The coolant in the power system 1 enters the radiator 4 through the second outlet of the flow control valve 6 in the first pipeline 11 for heat dissipation and then flows back through the third pipeline 13. The transmission oil in the transmission system 2 flows back through the second outlet of the flow control valve 6 in the fourth pipeline 21. The hydraulic oil in the hydraulic system 3 enters the radiator 4 through the second outlet of the flow control valve 6 in the sixth pipeline 31 for heat dissipation and then flows back to the hydraulic system 3 through the eighth pipeline 33. This achieves heat dissipation and cooling of the power system 1 and the hydraulic system 3.

[0073] This embodiment also provides an engineering machine, comprising the above-mentioned heat exchange system.

[0074] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention, and are not intended to limit the implementation methods of the present invention. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all implementation methods here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. A heat exchange system, characterized in that: The invention comprises a power system (1), a transmission system (2), a hydraulic system (3), a radiator (4) and a heat exchanger (5), wherein the heat exchanger (5) is provided with a first cavity, a second cavity and a third cavity, and liquid in the first cavity, liquid in the second cavity and liquid in the third cavity can exchange heat with each other; The liquid outlet of the power system (1) is connected to the liquid inlet of the first cavity through a first pipeline (11), the liquid outlet of the first cavity is connected to the radiator (4) through a second pipeline (12), and the radiator (4) is connected to the liquid inlet of the power system (1) through a third pipeline (13); The liquid outlet of the transmission system (2) is communicated with the liquid inlet of the second cavity via a fourth pipeline (21), and the liquid outlet of the second cavity is communicated with the liquid inlet of the transmission system (2) via a fifth pipeline (22); The liquid outlet of the hydraulic system (3) is connected to the liquid inlet of the third cavity through a sixth pipeline (31), the liquid outlet of the third cavity is connected to the radiator (4) through a seventh pipeline (32), and the radiator (4) is connected to the liquid inlet of the hydraulic system (3) through an eighth pipeline (33).

2. The heat exchange system according to claim 1, characterized in that: The liquid outlet of the power system (1) is also connected to the radiator (4) through a first branch pipeline; The liquid outlet of the transmission system (2) is also connected to the liquid inlet of the transmission system (2) via a second branch pipeline; The liquid outlet of the hydraulic system (3) is also connected to the radiator (4) via a third branch pipeline.

3. The heat exchange system according to claim 2, characterized in that: The first pipeline (11), the fourth pipeline (21) and the sixth pipeline (31) are all provided with flow control valves (6); The inlet of the flow control valve (6) of the first pipeline (11) is in communication with the liquid outlet of the power system (1), the first outlet of the flow control valve (6) of the first pipeline (11) is in communication with the liquid inlet of the first cavity, and the second outlet of the flow control valve (6) of the first pipeline (11) is in communication with the radiator (4) via the first branch pipeline; The inlet of the flow control valve (6) of the fourth pipeline (21) is communicated with the liquid outlet of the transmission system (2), the first outlet of the flow control valve (6) of the fourth pipeline (21) is communicated with the liquid inlet of the second cavity, and the second outlet of the flow control valve (6) of the fourth pipeline (21) is communicated with the liquid inlet of the transmission system (2) through the second branch pipeline; The inlet of the flow control valve (6) of the sixth pipeline (31) is connected to the liquid outlet of the hydraulic system (3), the first outlet of the flow control valve (6) of the sixth pipeline (31) is connected to the liquid inlet of the third cavity, and the second outlet of the flow control valve (6) of the sixth pipeline (31) is connected to the radiator (4) through the third branch pipeline.

4. The heat exchange system according to claim 3, characterized in that: The first pipeline (11), the fourth pipeline (21) and the sixth pipeline (31) are all further provided with a temperature detector (7); The temperature detector (7) of the first pipeline (11) is used to detect the temperature of the liquid in the power system (1), and the controller controls the opening of the first outlet and the second outlet of the flow control valve (6) of the first pipeline (11) according to the temperature in the power system (1); The temperature detector (7) of the fourth pipeline (21) is used to detect the temperature of the liquid in the transmission system (2), and the controller controls the opening of the first outlet and the second outlet of the flow control valve (6) of the fourth pipeline (21) according to the temperature in the transmission system (2); The temperature detector (7) of the sixth pipeline (31) is used to detect the temperature of the liquid in the hydraulic system (3), and the controller controls the opening of the first outlet and the second outlet of the flow control valve (6) of the sixth pipeline (31) according to the temperature in the hydraulic system (3).

5. The heat exchange system according to claim 4, characterized in that: The temperature detector (7) is a temperature-sensitive sensor.

6. The heat exchange system according to claim 3, characterized in that: The flow control valve (6) is an electromagnetic proportional control valve.

7. The heat exchange system according to claim 1, characterized in that: The power system (1) is an engine system or a motor system.

8. The heat exchange system according to claim 1, characterized in that: The radiator (4) is a cooling fan.

9. Construction machinery, characterized in that: A heat exchange system comprising the heat exchange system according to any one of claims 1 to 8.

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