CN113898724B

CN113898724B - Gear box

Info

Publication number: CN113898724B
Application number: CN202111077696.4A
Authority: CN
Inventors: 姚振环; 耿金富; 杨传龙; 宋银龙; 刘鑫; 刘岩
Original assignee: Huaneng Tongliao Wind Power Co Ltd
Current assignee: Huaneng Tongliao Wind Power Co Ltd
Priority date: 2021-09-14
Filing date: 2021-09-14
Publication date: 2023-07-28
Anticipated expiration: 2041-09-14
Also published as: DE202022103578U1; CN113898724A

Abstract

The invention relates to the technical field of wind power generation and discloses a gear box which comprises a box body, an oil pump, a compressor, a first heat exchanger, an evaporator and a second heat exchanger, wherein the first heat exchanger is connected with the oil pump; the box body is internally provided with a containing space for containing the transmission mechanism and lubricating oil; the transmission mechanism is provided with an input end used for being connected with a first rotating shaft of the impeller and an output end used for being connected with a second rotating shaft on the generator; the oil pump is provided with an inlet, a first outlet and a second outlet; the inlet of the oil pump is communicated with the accommodating space, and the inlet of the oil pump is communicated with the first outlet or the second outlet. According to the gear box provided by the embodiment of the invention, the refrigerating unit is formed by the compressor, the first heat exchanger, the evaporator and the second heat exchanger, the heat source and the cold source are provided at the same time, the temperature of the lubricating oil is adjusted according to the temperature of the lubricating oil, the heating and cooling effects are good, the energy utilization rate of the refrigeration cycle is higher, and the problems that the heat dissipation effect through air cooling is not high in summer and the energy utilization rate through electric heating in winter is not high are avoided.

Description

Gear box

Technical Field

The invention relates to the technical field of wind power generation, in particular to a gear box.

Background

Wind power generation is a way of generating electricity by using clean energy, wind energy.

The wind generating set generally includes an impeller, a first rotating shaft driven to rotate by the impeller, a second rotating shaft connected to the first rotating shaft, and a generator generating electricity by rotation of the second rotating shaft.

The rotating speed of the first rotating shaft is not high, and the generating capacity of the generator is increased along with the rising of the rotating speed of the second rotating shaft, so that part of wind generating sets can be provided with a gear box to speed up, and the second rotating shaft has a larger rotating speed.

In the using process of the gear box, the actual temperature and the expected temperature often do not accord with each other, so that the normal operation of the gear box is influenced, for example, the internal temperature of the gear box is higher in summer to influence the safety of internal components of the gear box, and the internal temperature of the gear box is lower in winter to cause high viscosity of lubricating oil.

In the prior art, the interior of the gear box is generally cooled by air cooling in summer and is heated by electric heating in winter. However, the outside temperature is also higher in summer, the efficiency of utilizing air cooling to dissipate heat is low, and the energy utilization rate is low; in winter, the electric heating method can achieve a good heating effect, but the energy utilization rate is also low.

Disclosure of Invention

The purpose of the invention is that: provided is a gear box which has both cooling efficiency and heating efficiency and has high energy utilization rate.

In order to achieve the above object, the present invention provides a gear box including a box body, an oil pump, a compressor, a first heat exchanger, an evaporator, and a second heat exchanger; the box body is internally provided with a containing space for containing the transmission mechanism and lubricating oil; the transmission mechanism is provided with an input end used for being connected with a first rotating shaft of the impeller and an output end used for being connected with a second rotating shaft on the generator; the oil pump is provided with an inlet, a first outlet and a second outlet; the oil pump inlet is communicated with the accommodating space, and the oil pump inlet is communicated with the first outlet or the second outlet; the compressor is internally provided with a refrigeration medium and is provided with a compression channel for compressing the refrigeration medium; the first heat exchanger is provided with a first medium channel, a first oil duct capable of exchanging heat with the first medium channel and a first air duct capable of exchanging heat with the first medium channel; the evaporator is provided with an evaporation channel for evaporating the liquid refrigeration medium; the second heat exchanger is provided with a second medium channel, a second oil duct capable of exchanging heat with the second medium channel and a second air duct capable of exchanging heat with the second medium channel; the compression channel, the first medium channel, the evaporation channel and the second medium channel are connected end to end; the first oil duct is provided with a first oil inlet communicated with the first outlet and a first oil outlet communicated with the accommodating space, and the first air duct is provided with a first air inlet and a first air outlet respectively communicated with the outside; the second oil duct is provided with a second oil inlet communicated with the second outlet and a second oil outlet communicated with the accommodating space, and the second air duct is provided with a second air inlet and a second air outlet respectively communicated with the outside; and valve bodies are respectively arranged in the first oil duct, the second oil duct, the first air duct and the second air duct.

Further, the device also comprises a return pipe; the first oil outlet and the second oil outlet are respectively communicated to the accommodating space through the return pipe.

Further, the electric heater is arranged in the second oil duct.

Further, the first heat exchanger comprises a first pipe body which is linear and surrounds the first medium channel, a first oil pipe which is arranged in the first pipe body in a penetrating manner and surrounds the first oil channel, and a first air channel pipe which surrounds the first air channel; the first pipe body is positioned in the first air duct pipe.

Further, the second heat exchanger comprises a second pipe body which is linear and surrounds the second medium channel, a second oil pipe which is arranged in the second pipe body in a penetrating manner and surrounds the second oil channel, and a second air channel pipe which surrounds the second air channel; the second pipe body is positioned in the second air duct pipe.

Further, the device also comprises a first medium pipe, a second medium pipe and a bypass pipe arranged on the outer surface of the box body; the outlet of the compression channel is communicated with the inlet of the first medium channel through the first medium pipe, and the outlet of the first medium channel is communicated with the inlet of the evaporation channel through the second medium pipe; the first medium pipe is provided with a first branch which is communicated with the inlet of the bypass pipe; the second medium pipe is provided with a second branch which is communicated with the outlet of the bypass pipe; the junction of the first branch and the first medium pipe is provided with a first flow dividing valve, and the junction of the second branch and the second medium pipe is provided with a first stop valve.

Further, the bypass pipe is spirally wound around the outer surface of the tank body.

Further, the device also comprises a third medium pipe and a fourth medium pipe; the outlet of the evaporation channel is communicated with the inlet of the second medium channel through the third medium pipe, and the outlet of the second medium channel is communicated with the inlet of the compression channel through the fourth medium channel; a third branch is arranged on the third medium pipe and is communicated with the inlet of the bypass pipe; a fourth branch is arranged on the fourth medium pipe and is communicated with the outlet of the bypass pipe; the junction of the third branch and the third medium pipe is provided with a second flow dividing valve, and the junction of the fourth branch and the fourth medium pipe is provided with a second stop valve.

Further, the evaporator comprises a capillary tube.

Further, the oil pump is a gear pump.

Compared with the prior art, the gearbox provided by the embodiment of the invention has the beneficial effects that:

according to the gear box provided by the embodiment of the invention, the refrigerating unit is formed by the compressor, the first heat exchanger, the evaporator and the second heat exchanger, the heat source and the cold source are provided at the same time, the temperature of the lubricating oil is adjusted according to the temperature of the lubricating oil, the heating and cooling effects are good, the energy utilization rate of the refrigeration cycle is higher, and the problems that the heat dissipation effect through air cooling is not high in summer and the energy utilization rate through electric heating in winter is not high are avoided.

Drawings

FIG. 1 is an overall block diagram of a gearbox according to an embodiment of the present invention.

FIG. 2 is a block diagram of a first heat exchanger of a gearbox of an embodiment of the present invention.

FIG. 3 is a block diagram of a second heat exchanger of a gearbox of an embodiment of the present invention.

In the figure, 1, a box body; 2. an oil pump; 3. a compressor;

4. a first heat exchanger; 41. a first media channel; 42. a first oil passage; 43. a first air duct;

5. an evaporator;

6. a second heat exchanger; 61. a second media channel; 62. a second oil passage; 63. a second air duct;

7. a return pipe;

8. a first media tube; 81. a first branch; 82. a first diverter valve;

9. a second medium pipe; 91. a second branch; 92. a first stop valve;

10. a bypass pipe;

11. a third medium pipe; 111. a third branch; 112. a second shunt valve;

12. a fourth medium pipe; 121. a fourth branch; 122. and a second shut-off valve.

Detailed Description

The following describes in further detail the embodiments of the present invention with reference to the drawings and examples. The following examples are illustrative of the invention and are not intended to limit the scope of the invention.

In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present invention.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present invention, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.

In the present invention, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.

In the present invention, unless expressly stated or limited otherwise, a first feature "above" or "below" a second feature may include both the first and second features being in direct contact, as well as the first and second features not being in direct contact but being in contact with each other through additional features therebetween. Moreover, a first feature being "above," "over" and "on" a second feature includes the first feature being directly above and obliquely above the second feature, or simply indicating that the first feature is higher in level than the second feature. The first feature being "under", "below" and "beneath" the second feature includes the first feature being directly under and obliquely below the second feature, or simply means that the first feature is less level than the second feature.

Referring to fig. 1 to 3, a gear box according to a preferred embodiment of the present invention includes a box body 1, an oil pump 2, a compressor 3, a first heat exchanger 4, an evaporator 5, and a second heat exchanger 6; the box body 1 is internally provided with a containing space for containing a transmission mechanism and lubricating oil; the transmission mechanism is provided with an input end used for being connected with a first rotating shaft of the impeller and an output end used for being connected with a second rotating shaft on the generator; the oil pump 2 has an inlet, a first outlet, and a second outlet; the inlet of the oil pump 2 is communicated with the accommodating space, and the inlet of the oil pump 2 is communicated with the first outlet or the second outlet; the compressor 3 has a refrigerant medium built therein and has a compression passage for compressing the refrigerant medium; the first heat exchanger 4 has a first medium passage 41, a first oil passage 42 capable of exchanging heat with the first medium passage 41, and a first air passage 43 capable of exchanging heat with the first medium passage 41; the evaporator 5 is provided with an evaporation channel for evaporating the liquid refrigeration medium; the second heat exchanger 6 has a second medium passage 61, a second oil passage 62 capable of exchanging heat with the second medium passage 61, and a second air passage 63 capable of exchanging heat with the second medium passage 61; wherein the compression channel, the first medium channel 41, the evaporation channel and the second medium channel 61 are connected end to end; the first oil duct 42 has a first oil inlet communicating with the first outlet and a first oil outlet communicating with the accommodating space, and the first air duct 43 has a first air inlet and a first air outlet communicating with the outside, respectively; the second oil duct 62 has a second oil inlet communicating with the second outlet and a second oil outlet communicating with the accommodating space, and the second air duct 63 has a second air inlet and a second air outlet communicating with the outside, respectively; the first oil passage 42, the second oil passage 62, the first air passage 43, and the second air passage 63 are respectively provided with valve bodies.

When the gearbox of the embodiment works, the first rotating shaft of the impeller is accelerated through the transmission mechanism of the gearbox and then transmits power to the second rotating shaft of the generator, and the mechanical energy is converted into electric energy to generate electricity.

In this embodiment, the gearbox may cool or heat the oil based on the internal oil temperature.

When the lubricating oil needs to be cooled, for example, when the wind driven generator set runs for a long time in summer, the whole temperature in the gear box is increased, the compressor 3 is started, the compressor 3, the first heat exchanger 4, the evaporator 5 and the second heat exchanger 6 form a refrigerating unit, a refrigerating medium generates refrigeration circulation, the first medium channel 41 in the first heat exchanger 4 releases heat, and the second medium channel 61 in the second heat exchanger 6 absorbs heat.

The oil pump 2 is started, the lubricating oil in the accommodating space enters the oil pump 2 from the inlet of the oil pump 2, flows out from the second outlet under the action of the oil pump 2, enters the second oil duct 62, exchanges heat with the refrigerating medium in the second medium channel 61 in the second heat exchanger 6, and reduces the temperature of the lubricating oil because the temperature of the lubricating oil is higher than that of the refrigerating medium in the second medium channel 61; after the heat exchange is completed, the lubricating oil flows back into the box body 1 from the second oil outlet, exchanges heat with the lubricating oil in the box body 1, reduces the temperature in the box body 1, and further reduces the temperature of the transmission mechanism. Meanwhile, the cooling air flows in the first air duct 43 to exchange heat with the refrigerating medium in the first medium channel 41, so that the temperature of the refrigerating medium in the first medium channel 41 is reduced, and the refrigerating cycle is promoted.

When it is necessary to heat the lubricating oil, for example, when the temperature of the whole wind generating set is reduced in winter, the temperature inside the gear box is reduced, and the compressor 3 is started to generate refrigeration circulation for the refrigeration medium.

The oil pump 2 is started, the lubricating oil in the accommodating space enters the oil pump 2 from the inlet of the oil pump 2, flows out from the first outlet under the action of the oil pump 2, enters the first oil duct 42, exchanges heat with the refrigerating medium in the first medium channel 41 in the first heat exchanger 4, and increases the temperature of the lubricating oil because the temperature of the lubricating oil is lower than that of the refrigerating medium in the first medium channel 41; after heat exchange is completed, lubricating oil flows back into the box body 1 from the first oil outlet, exchanges heat with the lubricating oil in the box body 1, and enables the temperature in the box body 1 to rise, so that the temperature of the transmission mechanism is improved. Meanwhile, heating air flows in the second air duct 63 to exchange heat with the refrigerating medium in the second medium channel 61, so that the temperature of the refrigerating medium in the second medium channel 61 is increased, and the refrigerating cycle is promoted.

In this embodiment, the refrigerating unit is formed by the compressor 3, the first heat exchanger 4, the evaporator 5 and the second heat exchanger 6, and a heat source and a cold source are provided at the same time, the temperature of the lubricating oil is adjusted according to the temperature of the lubricating oil, the heating and cooling effects are good, the energy utilization rate of the refrigeration cycle is high, and the problems that the heat dissipation effect through air cooling is not high in summer and the energy utilization rate through electric heating in winter is not high are avoided.

When the temperature difference between the lubricating oil and the refrigerant in the second medium channel 61 is smaller during cooling the lubricating oil, the second air duct 63 may be opened to perform auxiliary heating on the refrigerant in the second medium channel 61 to ensure the refrigeration cycle; similarly, the first air duct 43 may be opened to perform auxiliary heat dissipation on the refrigerant medium in the first medium channel 41, so as to ensure the refrigeration cycle.

In addition, the oil pump 2 is provided to extract and supply lubricating oil, so that the transmission mechanism in the box body 1 can be forced to be lubricated, and the transmission efficiency of the transmission mechanism can be improved.

Further, in one embodiment, referring to fig. 1 to 3, the device further comprises a return pipe 7; the first oil outlet and the second oil outlet are respectively communicated to the accommodating space through the return pipe 7.

In this embodiment, after the lubricating oil passes through the first oil duct 42 or the second oil duct 62, the lubricating oil flows back into the accommodating space through the return pipe 7, so that a plurality of openings are prevented from being formed in the tank body 1, and the structural complexity of the tank body 1 is reduced.

Further, in an embodiment, referring to fig. 1 to 3, an electric heater is further included in the second oil passage 62, so as to avoid the problem of insufficient temperature rise when the lubricating oil exchanges heat with the refrigeration medium in the first medium passage 41, and ensure that the lubricating oil can be heated to a temperature in accordance with the expected temperature.

Further, in one embodiment, referring to fig. 1 to 3, the first heat exchanger 4 includes a first tube body that is linear and encloses the first medium channel 41, a first oil pipe that is inserted into the first tube body and encloses the first oil channel 42, and a first air channel 43 pipe that encloses the first air channel 43; the first pipe body is located in the first air duct 43.

In the present embodiment, on the one hand, since the flow rate of the lubricating oil is small, a good cooling effect for the lubricating oil can be obtained by disposing the first oil pipe in the first medium passage 41; on the other hand, when the first oil pipe is provided in the first medium passage 41 and the first air duct 43 needs to be opened to perform auxiliary heat radiation on the refrigerant medium in the first medium passage 41, the cooling air for auxiliary heat radiation does not affect the temperature of the lubricating oil in the first oil pipe.

Further, in one embodiment, referring to fig. 1 to 3, the second heat exchanger 6 includes a second pipe body that is linear and encloses the second medium channel 61, a second oil pipe that is inserted into the second pipe body and encloses the second oil channel 62, and a second air channel 63 pipe that encloses the second air channel 63; the second pipe body is positioned in the second air duct 63.

Similarly, in this embodiment, on the one hand, the heating effect on the lubricating oil can be ensured; on the other hand, when the refrigerant in the second medium passage 61 is subjected to auxiliary heating, the temperature of the lubricating oil in the second oil pipe is not affected by the auxiliary heating air.

Further, in one embodiment, referring to fig. 1 to 3, the tank further comprises a first medium pipe 8, a second medium pipe 9, and a bypass pipe 10 provided on the outer surface of the tank body 1; the outlet of the compression channel is communicated with the inlet of the first medium channel 41 through the first medium pipe 8, and the outlet of the first medium channel 41 is communicated with the inlet of the evaporation channel through the second medium pipe 9; the first medium pipe 8 is provided with a first branch 81, and the first branch 81 is communicated with the inlet of the bypass pipe 10; a second branch 91 is arranged on the second medium pipe 9, and the second branch 91 is communicated with the outlet of the bypass pipe 10; the junction of the first branch 81 and the first medium pipe 8 is provided with a first diverter valve 82, and the junction of the second branch 91 and the second medium pipe 9 is provided with a first stop valve 92.

In the actual use process, the lubricating oil needs to ensure the lubricating effect in two modes of forced lubrication and temperature adjustment.

In the foregoing embodiment, when forced lubrication is required, the oil pump 2 may be independently turned on to pump and supply the lubricating oil; however, when the temperature of the lubricating oil is adjusted, the oil pump 2 and the compressor 3 need to be turned on at the same time, and the lubricating oil needs to be forced to be lubricated at the same time to adjust the temperature. Therefore, when the above-described embodiment is applied to a scene where only the temperature adjustment of the lubricating oil is required, the energy utilization efficiency thereof is low.

In contrast, in the present embodiment, when the lubricant oil is only heated, the compressor 3 is started to form a refrigeration cycle; the first diverter valve 82 makes part of the refrigerant medium in the first medium pipe 8 flow to the bypass pipe 10 in the accommodating space via the first branch 81, exchange heat with the lubricating oil in the accommodating space, heat the lubricating oil in the accommodating space, and then flow to the second medium pipe 9 via the second branch 91, so as to complete other processes of the refrigeration cycle.

In this embodiment, when the lubricating oil is heated only, the oil pump 2 is not required to be started, so that energy is saved and the energy utilization efficiency is improved.

The opening of the first diverter valve 82 is adjusted according to the actual heat dissipation requirement, the greater the heat requirement of the lubricating oil in the accommodating space, the greater the flow of the bypass pipe 10, otherwise, the smaller the flow of the bypass pipe 10.

At this time, if the refrigerant flows through the first medium passage 41, the first air duct 43 is also activated to radiate heat from the refrigerant in the first medium passage 41.

Further, in one embodiment, referring to fig. 1 to 3, the bypass pipe 10 is spirally wound around the outer surface of the tank body 1, so as to increase the contact area between the bypass pipe 10 and the tank body 1, thereby improving the heat exchange efficiency.

Further, in one embodiment, referring to fig. 1 to 3, the medium pipe further includes a third medium pipe 11 and a fourth medium pipe 12; the outlet of the evaporation channel is communicated with the inlet of the second medium channel 61 through the third medium pipe 11, and the outlet of the second medium channel 61 is communicated with the inlet of the compression channel through the fourth medium channel; a third branch 111 is arranged on the third medium pipe 11, and the third branch 111 is communicated with the inlet of the bypass pipe 10; a fourth branch 121 is arranged on the fourth medium pipe 12, and the fourth branch 121 is communicated with the outlet of the bypass pipe 10; the junction of the third branch 111 and the third medium pipe 11 is provided with a second diverter valve 112, and the junction of the fourth branch 121 and the fourth medium pipe 12 is provided with a second stop valve 122.

In the present embodiment, similarly, when the lubricating oil only needs to be cooled, the compressor 3 is started to form a refrigeration cycle; the second diverter valve 112 makes part of the refrigerant in the third medium pipe 11 flow to the bypass pipe 10 in the accommodating space via the third branch 111, exchange heat with the lubricant in the accommodating space, cool the lubricant in the accommodating space, and then flow to the second medium pipe 9 via the fourth branch 121, so as to complete other processes of the refrigeration cycle.

In this embodiment, when the lubricating oil is only required to be cooled, the oil pump 2 is not required to be started, so that energy is saved, and the energy utilization efficiency is improved. In addition, the bypass pipe 10 of the present embodiment can be used to cool and heat the lubricating oil, reducing the structural complexity of the gearbox.

The opening of the two-way valve is adjusted according to the actual cooling requirement, the greater the cooling requirement of the lubricating oil in the accommodating space is, the greater the flow of the bypass pipe 10 is, and otherwise, the smaller the flow of the bypass pipe 10 is.

At this time, if the refrigerant flows through the second medium passage 61, the second air duct 63 is also activated to cool the refrigerant in the second medium passage 61.

Further, in one embodiment, referring to fig. 1 to 3, the evaporator 5 includes a capillary tube.

Further, in one embodiment, referring to fig. 1 to 3, the oil pump 2 is a gear pump.

In the description of the present specification, reference to the terms "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

While embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that: many changes, modifications, substitutions and variations may be made to the embodiments without departing from the spirit and principles of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A gearbox, comprising:

the box body is internally provided with a containing space for containing the transmission mechanism and lubricating oil; the transmission mechanism is provided with an input end used for being connected with a first rotating shaft of the impeller and an output end used for being connected with a second rotating shaft on the generator;

an oil pump having an inlet, a first outlet, and a second outlet; an inlet of the oil pump is communicated with the accommodating space, and the inlet of the oil pump is communicated with the first outlet or the second outlet;

a compressor having a refrigerant medium built therein and having a compression passage for compressing the refrigerant medium;

the first heat exchanger is provided with a first medium channel, a first oil duct capable of exchanging heat with the first medium channel and a first air duct capable of exchanging heat with the first medium channel;

an evaporator having an evaporation channel for evaporating the liquid refrigerant medium; and

the second heat exchanger is provided with a second medium channel, a second oil duct capable of exchanging heat with the second medium channel and a second air duct capable of exchanging heat with the second medium channel;

the compression channel, the first medium channel, the evaporation channel and the second medium channel are connected end to end;

the first oil duct is provided with a first oil inlet communicated with the first outlet and a first oil outlet communicated with the accommodating space, and the first air duct is provided with a first air inlet and a first air outlet respectively communicated with the outside;

the second oil duct is provided with a second oil inlet communicated with the second outlet and a second oil outlet communicated with the accommodating space, and the second air duct is provided with a second air inlet and a second air outlet respectively communicated with the outside;

the first oil duct, the second oil duct, the first air duct and the second air duct are respectively internally provided with a valve body;

the first heat exchanger comprises a first pipe body which is linear and surrounds the first medium channel, a first oil pipe which is arranged in the first pipe body in a penetrating manner and surrounds the first oil channel, and a first air channel pipe which surrounds the first air channel; the first pipe body is positioned in the first air duct pipe;

the second heat exchanger comprises a second pipe body which is linear and surrounds the second medium channel, a second oil pipe which is arranged in the second pipe body in a penetrating manner and surrounds the second oil channel, and a second air channel pipe which surrounds the second air channel; the second pipe body is positioned in the second air duct pipe;

the device also comprises a first medium pipe, a second medium pipe and a bypass pipe arranged on the outer surface of the box body;

the outlet of the compression channel is communicated with the inlet of the first medium channel through the first medium pipe, and the outlet of the first medium channel is communicated with the inlet of the evaporation channel through the second medium pipe;

the first medium pipe is provided with a first branch which is communicated with the inlet of the bypass pipe; the second medium pipe is provided with a second branch which is communicated with the outlet of the bypass pipe; a first diverter valve is arranged at the joint of the first branch and the first medium pipe, and a first stop valve is arranged at the joint of the second branch and the second medium pipe;

the device also comprises a third medium pipe and a fourth medium pipe;

the outlet of the evaporation channel is communicated with the inlet of the second medium channel through the third medium pipe, and the outlet of the second medium channel is communicated with the inlet of the compression channel through the fourth medium channel;

a third branch is arranged on the third medium pipe and is communicated with the inlet of the bypass pipe; a fourth branch is arranged on the fourth medium pipe and is communicated with the outlet of the bypass pipe; the junction of the third branch and the third medium pipe is provided with a second flow dividing valve, and the junction of the fourth branch and the fourth medium pipe is provided with a second stop valve.

2. The gearbox of claim 1, further comprising a return line; the first oil outlet and the second oil outlet are respectively communicated to the accommodating space through the return pipe.

3. The gearbox of claim 1, further comprising an electric heater disposed within the second oil gallery.

4. The gearbox as recited in claim 1, wherein the bypass tube is helical and wrapped around an outer surface of the box body.

5. The gearbox of claim 1, wherein the evaporator comprises a capillary tube.

6. The gearbox of claim 1, wherein the oil pump is a gear pump.