Heat exchange system, heat exchange method and engineering machinery

Abstract

The invention belongs to the technical field of engineering machinery, and discloses a heat exchange system, a heat exchange method 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 present invention relates to the technical field of engineering machinery, and in particular to a heat exchange system, a heat exchange method and engineering machinery. Background Art

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

[0003] In the prior art, each system is equipped with a radiator for heat dissipation. When the loader is actually working, such as in shoveling operation, the heat generated by the gearbox system is small, so the gearbox system does not need to be radiated; in driving operation, the heat generated by the hydraulic system is small, so the hydraulic system does not need to be radiated. This structure causes the radiator structure to be redundant, occupies the space of the entire machine, and causes a waste of resources. Summary of the invention

[0004] The object of the present invention is to provide a heat exchange system, a heat exchange method and engineering machinery, which optimize the space of the whole machine, avoid waste of resources and reduce the cost of the heat exchange system.

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

[0006] A heat exchange system, comprising a power system, a gearbox 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 gearbox 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 gearbox 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 also connected to the radiator through a first branch pipeline;

[0011] The liquid outlet of the gearbox system is also connected to the liquid inlet of the gearbox 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 communicated with the liquid outlet of the power system, the first outlet of the flow control valve of the first pipeline is communicated with the liquid inlet of the first cavity, and the second outlet of the flow control valve of the first pipeline is communicated with the radiator through the first branch pipeline;

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

[0016] The inlet of the flow control valve of the sixth pipeline is connected to the outlet of the hydraulic system, the first outlet of the flow control valve of the sixth pipeline is connected to the 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 sensor.

[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] A heat exchange method, applied to the heat exchange system described in any of the above schemes, comprising:

[0026] Real-time detection of the temperature of the power system, transmission system and hydraulic system;

[0027] When it is detected that the temperature of the power system reaches a first high temperature threshold, and the temperature of the hydraulic system and the temperature of the transmission system are both lower than the low temperature threshold, the first pipeline, the fourth pipeline and the sixth pipeline are controlled to be connected;

[0028] When it is detected that the temperature of the power system reaches the first high temperature threshold, the temperature of the transmission system is lower than the low temperature threshold, and the temperature of the hydraulic system is higher than the low temperature threshold, the first pipeline and the fourth pipeline are controlled to be connected;

[0029] When it is detected that the temperature of the power system reaches the first high temperature threshold, the temperature of the hydraulic system is lower than the low temperature threshold, and the temperature of the transmission system is higher than the low temperature threshold and lower than the second high temperature threshold, the first pipeline and the sixth pipeline are controlled to be connected;

[0030] When it is detected that the temperature of the transmission system is higher than the second high temperature threshold, the fourth pipeline and the sixth pipeline are controlled to be connected;

[0031] The first high temperature threshold is greater than the low temperature threshold; the second high temperature threshold is greater than the low temperature threshold.

[0032] Engineering machinery, including the heat exchange system described in any of the above schemes or adopting the above heat exchange method.

[0033] Beneficial effects of the present invention:

[0034] The heat exchange system provided by the present invention realizes preheating of the transmission system and the hydraulic system in a low-temperature environment, as well as heat preservation of the transmission system and the hydraulic system; and can also cool and dissipate heat of the transmission system through the hydraulic system, so that the transmission system does not need to be equipped with a radiator, thereby reducing the occupied space and manufacturing costs, and optimizing the overall spatial layout. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1is a schematic structural diagram of a heat exchange system provided by an embodiment of the present invention;

[0036] Figure 2 It is a flow chart of the heat exchange method provided by an embodiment of the present invention.

[0037] In the figure:

[0038] 1. Power system; 11. First pipeline; 12. Second pipeline; 13. Third pipeline;

[0039] 2. Transmission system; 21. Fourth pipeline; 22. Fifth pipeline;

[0040] 3. Hydraulic system; 31. Sixth pipeline; 32. Seventh pipeline; 33. Eighth pipeline;

[0041] 4. Radiator;

[0042] 5. Heat exchanger;

[0043] 6. Flow control valve;

[0044] 7. Temperature detector. DETAILED DESCRIPTION

[0045] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar parts or parts having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0046] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection, it can be a mechanical connection or an electrical connection, it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0047] In the description of the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include the first feature being in direct contact with the second feature, or may include the first feature being in contact with the second feature through another feature between them instead of being in direct contact. 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.

[0048] The technical solution of the present invention is further described below with reference to the accompanying drawings and through specific implementation methods.

[0049] like Figure 1 As shown, an embodiment of the present invention provides a heat exchange system applicable to engineering machinery, including a power system 1, a gearbox system 2, a hydraulic system 3, a radiator 4 and a heat exchanger 5. The heat exchanger 5 includes a first cavity, a second cavity and a third cavity. The power system 1 can transport the liquid (such as coolant) in the power system 1 to the first cavity, the gearbox system 2 can transport the liquid (such as gearbox oil) in the gearbox system 2 to the second cavity, and the hydraulic system 3 can transport the liquid (such as hydraulic oil) in the hydraulic system 3 to the third cavity. The coolant in the first cavity, the gearbox oil in the second cavity and the hydraulic oil in the third cavity can perform heat exchange.

[0050] 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.

[0051] When the construction machinery is started and preheated, the coolant in the power system 1 can be heated up in a relatively short time, by respectively entering the first cavity, the second cavity and the third cavity through the first pipeline 11, the gearbox oil in the gearbox system 2 through the fourth pipeline 21 and the hydraulic oil in the hydraulic system 3 through the sixth pipeline 31, so as to achieve heat exchange between the gearbox oil and the hydraulic oil by the coolant with a higher temperature, so as to preheat the gearbox oil and the hydraulic oil, thereby facilitating the performance of the gearbox system 2 and the hydraulic system 3; it can be understood that after the preheating of the gearbox oil and the hydraulic oil is completed, the first pipeline 11, the fourth pipeline 21 and the sixth pipeline 31 can be disconnected.

[0052] And 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 whose temperature has dropped can be opened to keep the transmission oil or hydraulic oil warm.

[0053] 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, so that the transmission oil in the second cavity and the hydraulic oil in the third cavity are heat exchanged, so as to realize cooling and heat dissipation of the transmission system 2 through the hydraulic system 3, avoiding the need to configure the radiator 4 for the transmission system 2 and saving space.

[0054] The heat exchange system realizes preheating of the transmission system 2 and the hydraulic system 3 in a low-temperature environment, as well as heat preservation of the transmission system 2 and the hydraulic system 3; 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, thereby reducing the occupied space and manufacturing costs and optimizing the overall spatial layout.

[0055] 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 flow back to the power system 1 through the third pipeline 13 after the heat is dissipated by 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 flow back directly through the second branch pipeline without passing through the heat exchanger 5, so as to realize 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 flow back to the hydraulic system 3 through the eighth pipeline 33 after passing through the radiator 4.

[0056] 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 .

[0057] Among them, the inlet of the flow control valve 6 of the first pipeline 11 is connected to the outlet of the power system 1, the first outlet of the flow control valve 6 of the first pipeline 11 is connected to the 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 setting the flow control valve 6 on the first pipeline 11, it is possible to control the flow of coolant through the first pipeline 11 and the first branch pipeline by controlling the opening of the first outlet and the second outlet of the flow control valve 6 on the first pipeline 11.

[0058] 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.

[0059] The inlet of the flow control valve 6 of the sixth pipeline 31 is connected to the outlet of the hydraulic system 3, the first outlet of the flow control valve 6 of the sixth pipeline 31 is connected to the 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, it is possible to control the flow of hydraulic oil through the sixth pipeline 31 and the third branch pipeline by controlling the opening of the first outlet and the second outlet of the flow control valve 6 on the sixth pipeline 31.

[0060] Optionally, in order 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 .

[0061] 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.

[0062] The temperature detector 7 of the fourth pipeline 21 is used to detect the temperature of the transmission oil of 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.

[0063] 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.

[0064] Optionally, the radiator 4 may be a cooling fan.

[0065] Optionally, the flow control valve 6 may be an electromagnetic proportional control valve.

[0066] Optionally, the temperature detector 7 may be a temperature thermistor sensor.

[0067] Optionally, the power system 1 can be selected as an engine system or a motor system.

[0068] 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.

[0069] like Figure 2 Combined with Figure 1 As shown, this embodiment also provides a heat exchange method, which is applied to the above-mentioned heat exchange system. The heat exchange method includes:

[0070] Real-time detection of the temperature of the power system 1, the transmission system 2 and the hydraulic system 3;

[0071] When the temperature of the power system 1 reaches the first high temperature threshold, and the temperature of the transmission system 2 and the temperature of the hydraulic system 3 are both lower than the low temperature threshold, the first pipeline 11, the fourth pipeline 21 and the sixth pipeline 31 are controlled to be connected, so that the power system 1 preheats or keeps the transmission system 2 and the hydraulic system 3 warm;

[0072] When the temperature of the power system 1 reaches the first high temperature threshold, and the temperature of the transmission system 2 is lower than the low temperature threshold, and the temperature of the hydraulic system 3 is higher than the 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;

[0073] When the temperature of the power system 1 reaches the first high temperature threshold, the temperature of the hydraulic system 3 is lower than the low temperature threshold, and the temperature of the transmission system 2 is higher than the low temperature threshold and lower than the 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;

[0074] 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 cools and dissipates the heat of the transmission system 2;

[0075] 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.

[0076] It can be understood that when applying this heat exchange method, 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.

[0077] For example, under extremely cold conditions, when the construction machinery is started and preheated, the temperature of the power system 1 reaches a 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. 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.

[0078] In extremely cold conditions, when the construction machinery is preheated and in driving or shoveling operation, the temperature of the transmission system 2 and the hydraulic system 3 may be lower than the low temperature threshold due to the extremely low external environment. The transmission system 2 and the hydraulic system 3 can be kept warm by the power system 1. It can be understood that the temperature of the insulation and the temperature of the preheating are the same temperature value.

[0079] Under normal conditions (i.e. non-extremely cold conditions), when the engineering machinery completes preheating and starts driving, at this time, 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, and 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, and 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 gearbox 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 for the gearbox system 2 .

[0080] Under normal conditions (i.e., non-extremely cold conditions), when the construction machinery completes preheating and shoveling operations, at this time, the heat generated by the power system 1 and the hydraulic system 3 is large, while the heat generated by the transmission system 2 is small (no heat dissipation is required), then the first outlet of the flow control valve 6 of the first pipeline 11 is controlled to be closed and the second outlet is opened, the first outlet of the flow control valve 6 of the fourth pipeline 21 is closed and the second outlet is opened, the first outlet of the flow control valve 6 of the sixth pipeline 31 is closed and the second outlet 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 gearbox oil in the transmission system 2 flows back through the second outlet of the flow control valve 6 of the fourth pipeline 21, and the hydraulic oil in the hydraulic system 3 enters the radiator 4 through the second outlet of the flow control valve 6 of the sixth pipeline 31 for heat dissipation and then flows back to the hydraulic system 3 through the eighth pipeline 33. Heat dissipation and cooling of the power system 1 and the hydraulic system 3 are achieved.

[0081] This embodiment also provides an engineering machinery, including the above-mentioned heat exchange system, or adopting the above-mentioned heat exchange method.

[0082] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope 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 gearbox system (2) is connected to the liquid inlet of the second cavity through a fourth pipeline (21), and the liquid outlet of the second cavity is connected to the liquid inlet of the gearbox system (2) through a fifth pipeline (22); The liquid outlet of the hydraulic system (3) is connected to the liquid inlet of the third cavity via a sixth pipeline (31), the liquid outlet of the third cavity is connected to the radiator (4) via a seventh pipeline (32), and the radiator (4) is connected to the liquid inlet of the hydraulic system (3) via 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) via a first branch pipeline; The liquid outlet of the gearbox system (2) is also connected to the liquid inlet of the gearbox 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 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; The inlet of the flow control valve (6) of the fourth pipeline (21) is communicated with the liquid outlet of the gearbox 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 gearbox 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 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 gearbox 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 gearbox 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 thermistor 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. A heat exchange method, characterized in that: Applicable to the heat exchange system according to any one of claims 1 to 8, the heat exchange method comprising: Real-time detection of the temperature of the power system (1), the transmission system (2) and the hydraulic system (3); When it is detected that the temperature of the power system (1) reaches a first high temperature threshold, and the temperature of the hydraulic system (3) and the temperature of the transmission system (2) 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 connected; When it is detected that the temperature of the power system (1) reaches the first high temperature threshold, the temperature of the transmission system (2) is lower than the low temperature threshold, and the temperature of the hydraulic system (3) is higher than the low temperature threshold, the first pipeline (11) and the fourth pipeline (21) are controlled to be connected; When it is detected that the temperature of the power system (1) reaches the first high temperature threshold, and the temperature of the hydraulic system (3) is lower than the low temperature threshold, and the temperature of the transmission system (2) is higher than the low temperature threshold and lower than the second high temperature threshold, the first pipeline (11) and the sixth pipeline (31) are controlled to be connected; When it is detected that 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; The first high temperature threshold is greater than the low temperature threshold; the second high temperature threshold is greater than the low temperature threshold.

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

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