CN114658882A

CN114658882A - Heat dissipation control valve and heat dissipation system

Info

Publication number: CN114658882A
Application number: CN202210258637.5A
Authority: CN
Inventors: 王新慧; 高利; 胡新科; 文小凤
Original assignee: Zhejiang Haihong Hydraulic Technology Co ltd
Current assignee: Zhejiang Haihong Hydraulic Technology Co ltd
Priority date: 2022-03-16
Filing date: 2022-03-16
Publication date: 2022-06-24

Abstract

The application relates to a heat dissipation control valve and cooling system, heat dissipation control valve include valve body and valve rod, and the valve body is equipped with valve pocket, main oil feed passageway, first working channel, second working channel and oil return passage, and the valve rod is mobilizable to be located in the valve pocket to main oil feed passageway of control passes through first working channel of valve pocket intercommunication or second working channel. When main oil feed passageway intercommunication first working channel, the heat dissipation control valve can drive hydraulic motor and drive the fan along clockwise rotation, and when main oil feed passageway intercommunication second working channel, the heat dissipation control valve can drive hydraulic motor and drive the fan along anticlockwise rotation. The valve body is further provided with an overflow channel capable of communicating the main oil inlet channel and the oil return channel, the heat dissipation control valve further comprises an overflow valve, and the overflow channel is arranged on the overflow valve so as to control the on-off of the overflow channel. The application provides a heat dissipation control valve and cooling system has solved the long-time work of fan and has leaded to the blade of fan or even the problem of the other positions of cooling system to gather a large amount of dusts.

Description

Heat dissipation control valve and heat dissipation system

Technical Field

The application relates to the technical field of engineering machinery, in particular to a heat dissipation control valve and a heat dissipation system.

Background

Generally, engineering mechanical equipment generates a large amount of heat in the working process, and therefore a heat dissipation system is required to dissipate heat of the engineering mechanical equipment, wherein the heat dissipation system comprises a fan, a hydraulic motor and a heat dissipation control valve, the fan is installed on an output shaft of the hydraulic motor, and the heat dissipation control valve is connected with the hydraulic motor to drive the hydraulic motor to rotate. However, the long-term operation of the fan causes the blades of the fan and even other parts of the heat dissipation system to accumulate a large amount of dust, which in turn causes the heat dissipation control valve and the heat dissipation system to have poor heat dissipation effects.

Disclosure of Invention

Therefore, a heat dissipation control valve and a heat dissipation system are needed to solve the problem that the long-time operation of the fan causes the accumulation of a large amount of dust on the blades of the fan and even on other parts of the heat dissipation system.

The application provides a heat dissipation control valve includes valve body and valve rod, and the valve body is equipped with valve pocket, main oil feed passageway, first working channel, second working channel and oil return passageway, and the valve rod movably is located in the valve pocket to main oil feed passageway of control passes through first working channel of valve pocket intercommunication or second working channel. When main oil feed passageway intercommunication first working channel, the heat dissipation control valve can drive hydraulic motor and drive the fan along clockwise rotation, and when main oil feed passageway intercommunication second working channel, the heat dissipation control valve can drive hydraulic motor and drive the fan along anticlockwise rotation. The valve body is further provided with an overflow channel capable of communicating the main oil inlet channel and the oil return channel, the heat dissipation control valve further comprises an overflow valve, and the overflow channel is arranged on the overflow valve so as to control the on-off of the overflow channel.

In one embodiment, the overflow valve is a proportional control valve, and the opening and closing pressure of the overflow valve is proportional to the magnitude of the current of the overflow valve. It can be understood that so set up, be favorable to controlling the biggest hydraulic pressure in the main oil feed passageway, and be favorable to improving the control accuracy of overflow valve.

In one embodiment, the heat dissipation control valve further comprises an electric control assembly connected with the valve rod and used for controlling the valve rod to move in the valve cavity. It can be understood that the arrangement is favorable for improving the control convenience of the valve rod.

In one embodiment, the electric control assembly comprises an electromagnet and a return spring assembly, the electromagnet is arranged at one end of the valve rod, when the electromagnet is powered on, the electromagnet can push the valve rod to move towards the direction away from the electromagnet, when the electromagnet is powered off, the return spring assembly is connected with the valve rod and the valve body and used for applying acting force to the valve rod in the direction close to the electromagnet, and the return spring assembly can push the valve rod to move towards the direction close to the electromagnet.

In one embodiment, an oil supplementing channel is further arranged between the main oil inlet channel and the oil return channel, and a one-way oil supplementing valve is arranged in the oil supplementing channel, so that pressure oil can flow in a one-way mode from the oil return channel to the main oil inlet channel through the oil supplementing channel. It can be understood that, so set up, be favorable to avoiding appearing the condition of negative pressure in the main oil feed passageway, and then avoid cooling system cavitation to appear.

In one embodiment, the one-way oil supplementing valve comprises a valve seat, a compression spring and a movable plug, wherein the valve seat is fixedly connected with the valve body, one end of the compression spring is connected with the valve seat, the other end of the compression spring is connected with the movable plug, and the compression spring can push the movable plug to plug the oil supplementing channel.

In one embodiment, the valve body is further provided with a first overload protection channel which can communicate the first working channel and the oil return channel, the first overload protection channel is provided with a first overload valve, and when the hydraulic value of the pressure oil in the first working channel exceeds a first preset pressure value, the first overload valve can open the first overload protection channel. It will be appreciated that such an arrangement is advantageous in absorbing the impact of the pressurized oil on the heat dissipation system.

In one embodiment, the valve body is further provided with a second overload protection channel which can communicate the second working channel and the oil return channel, the second overload protection channel is provided with a second overload valve, and when the hydraulic value of the pressure oil in the second working channel exceeds a second preset pressure value, the second overload valve can open the second overload protection channel. It will be appreciated that such an arrangement is advantageous in absorbing the impact of the pressurized oil on the heat dissipation system.

In one embodiment, the valve body is provided with an insertion hole, and the overflow valve is inserted into the insertion hole and is detachably connected with the valve body. It can be appreciated that such an arrangement is beneficial to reducing the difficulty of assembly of the overflow valve.

The application also provides a heat dissipation system, this heat dissipation system include fan, hydraulic motor and above arbitrary one embodiment the heat dissipation control valve, the fan is installed in hydraulic motor's output shaft, the heat dissipation control valve is connected hydraulic motor through first working channel or second working channel respectively to be used for driving hydraulic motor and drive fan clockwise turning or anticlockwise rotation.

Compared with the prior art, the application provides a heat dissipation control valve and cooling system, when the valve rod removed to the primary importance, pressure fluid got into first working channel through main oil feed passageway, later, pressure fluid got into hydraulic motor's output shaft along clockwise rotation from first working channel, and at this moment, hydraulic motor drove the fan along clockwise rotation to, pressure fluid gets into oil return channel and then accomplishes the oil return through second working channel. After the fan works for a period of time, the valve rod moves to the second position, the pressure oil enters the second working channel through the main oil inlet channel, then the pressure oil enters the hydraulic motor from the second working channel to push the output shaft of the hydraulic motor to rotate anticlockwise, at the moment, the hydraulic motor drives the fan to rotate anticlockwise, and the pressure oil enters the oil return channel through the first working channel and then completes oil return. Through constantly changing the direction of rotation of fan, the dust is difficult to gather at fan and other positions of cooling system, has effectively solved the fan and has been worked for a long time and can lead to the blade of fan and the problem of a large amount of dust of other positions of cooling system accumulation even. From the above, the rotation direction of the fan is changed depending on the change of the flow direction of the pressure oil, for example, when the first working channel is fed with oil and the second working channel is fed with oil, the fan rotates clockwise, and when the second working channel is fed with oil and the first working channel is fed with oil, the fan rotates counterclockwise.

It will be appreciated that the flow rate of the pressure oil is relatively fast, and for example, when the first working passage is changed from the oil-in state to the oil-return state, it is difficult for the pressure oil to change the flow direction in a short time due to inertia. Therefore, through setting up the overflow valve for part pressure fluid can pass through overflow channel entering oil return passage from main oil feed passageway, so, has reduced the oil inlet capacity of pressure fluid in the first working channel, also, has reduced the velocity of flow of hydraulic pressure and pressure fluid in the first working channel, and under the condition that the runoff and the velocity of flow of pressure fluid all descend, the flow direction of pressure fluid changes relatively more easily, can not lead to the heat dissipation control valve to appear damaging yet.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments or the conventional technologies of the present application, the drawings used in the descriptions of the embodiments or the conventional technologies will be briefly introduced below, it is obvious that the drawings in the following descriptions are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a cross-sectional view of a heat sink control valve provided herein;

FIG. 2 is a schematic structural diagram of a heat dissipation control valve provided herein;

FIG. 3 is a cross-sectional view taken at A-A of FIG. 2;

fig. 4 is a piping diagram of a heat dissipation control valve provided herein.

Reference numerals: 100. a valve body; 110. a valve cavity; 120. a main oil inlet channel; 130. a first working channel; 140. a second working channel; 150. an oil return passage; 160. an overflow channel; 170. an oil supplementing channel; 180. a first overload protection channel; 190. a second overload protection channel; 200. inserting holes; 300. a valve stem; 400. an overflow valve; 500. an electronic control assembly; 510. an electromagnet; 520. a return spring assembly; 600. a one-way oil replenishing valve; 610. a valve seat; 620. a compression spring; 630. a movable plug; 700. a first overload valve; 800. a second overload valve.

Detailed Description

In the description of the present application, it is to 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," "axial," "radial," "circumferential," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the present application and for simplicity in description, and are not intended to indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and are therefore not to be considered limiting of the present application.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present application, "plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In this application, unless expressly stated or limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can include, for example, fixed connections, removable connections, or integral parts; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art as appropriate.

In this application, unless expressly stated or limited otherwise, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through intervening media. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

It will be understood that when an element is referred to as being "secured to" or "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. As used herein, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and the like are for purposes of illustration only and do not denote a single embodiment.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the description of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Generally, engineering mechanical equipment generates a large amount of heat in the working process, and therefore a heat dissipation system is required to dissipate heat of the engineering mechanical equipment, wherein the heat dissipation system comprises a fan, a hydraulic motor and a heat dissipation control valve, the fan is installed on an output shaft of the hydraulic motor, and the heat dissipation control valve is connected with the hydraulic motor and used for driving the hydraulic motor to rotate. However, the long-term operation of the fan causes the blades of the fan and even other parts of the heat dissipation system to accumulate a large amount of dust, which in turn causes the heat dissipation control valve and the heat dissipation system to have poor heat dissipation effects.

Referring to fig. 1 and 4, in order to solve the problem that the long-term operation of the fan causes the blade of the fan and even other parts of the heat dissipation system to accumulate a large amount of dust, the present application provides a heat dissipation control valve, which includes a valve body 100 and a valve rod 300, the valve body 100 is provided with a valve cavity 110, a main oil inlet passage 120, a first working passage 130, a second working passage 140 and an oil return passage 150, and the valve rod 300 is movably disposed in the valve cavity 110 to control the main oil inlet passage 120 to communicate with the first working passage 130 or the second working passage 140 through the valve cavity 110. When main oil feed passageway 120 communicates first working channel 130, the heat dissipation control valve can drive hydraulic motor and drive the fan along clockwise rotation, and when main oil feed passageway 120 communicates second working channel 140, the heat dissipation control valve can drive hydraulic motor and drive the fan along anticlockwise rotation. The valve body 100 is further provided with an overflow passage 160 capable of communicating the main oil inlet passage 120 and the oil return passage 150, the heat dissipation control valve further comprises an overflow valve 400, and the overflow valve 400 is arranged on the overflow passage 160 to control the on-off of the overflow passage 160.

When the valve rod 300 moves to the first position, the pressure oil enters the first working channel 130 through the main oil inlet channel 120, and then the pressure oil enters the hydraulic motor from the first working channel 130 to push the output shaft of the hydraulic motor to rotate clockwise, at this time, the hydraulic motor drives the fan to rotate clockwise, and the pressure oil enters the oil return channel 150 through the second working channel 140 to complete oil return. After the fan works for a period of time, the valve rod 300 moves to the second position, the pressure oil enters the second working channel 140 through the main oil inlet channel 120, and then the pressure oil enters the hydraulic motor from the second working channel 140 to push the output shaft of the hydraulic motor to rotate counterclockwise, at this time, the hydraulic motor drives the fan to rotate counterclockwise, and the pressure oil enters the oil return channel 150 through the first working channel 130 to complete oil return. Through constantly changing the direction of rotation of fan, the dust is difficult to gather at fan and other positions of cooling system, has effectively solved the fan and has been worked for a long time and can lead to the blade of fan and the problem of a large amount of dust of other positions of cooling system accumulation even. As can be seen from the above, the rotation direction of the fan changes depending on the change of the flow direction of the pressure oil, for example, when the first working channel 130 is filled with oil and the second working channel 140 is returned with oil, the fan rotates clockwise, and when the second working channel 140 is filled with oil and the first working channel 130 is returned with oil, the fan rotates counterclockwise.

It will be appreciated that the fan and hydraulic motor rotate at a faster rate and the flow rate of the pressurized oil is also faster, for example, when the first working passage 130 changes from the oil-in state to the oil-out state, it is difficult for the fan and hydraulic motor to change the direction of rotation in a short time due to inertia, and it is also difficult for the pressurized oil to change the direction of flow in a short time. Therefore, by providing the overflow valve 400, the partial pressure oil can enter the oil return passage 150 from the main oil inlet passage 120 through the overflow passage 160, so that the oil inlet amount of the pressure oil in the first working passage 130 is reduced, that is, the flow rate of the hydraulic pressure and the pressure oil in the first working passage 130 is reduced, and under the condition that the radial flow amount and the flow rate of the pressure oil are both reduced, the flow direction of the pressure oil is relatively easier to change, and the heat dissipation control valve is not damaged. In conclusion, the heat dissipation electromagnetic valve provided by the application effectively solves the problem that the long-time work of the fan can cause the blades of the fan and even other parts of the heat dissipation system to accumulate a large amount of dust.

In order to improve the control accuracy of the overflow valve 400, in one embodiment, the overflow valve 400 is a proportional control valve, and the opening and closing pressure of the overflow valve 400 is proportional to the current of the overflow valve 400. For example, when the opening/closing pressure of the relief valve 400 is proportional to the magnitude of the current for controlling the relief valve 400, the greater the current passing through the relief valve 400, the greater the opening/closing pressure of the relief valve 400. When the opening and closing pressure of the relief valve 400 is inversely proportional to the magnitude of the current controlling the relief valve 400, the larger the current passing through the relief valve 400 is, the smaller the opening of the opening and closing pressure of the relief valve 400 is.

Further, in order to reduce the difficulty in assembling the relief valve 400, in one embodiment, as shown in fig. 1 and 4, the valve body 100 is provided with an insertion hole 200, and the relief valve 400 is inserted into the insertion hole 200 and detachably connected to the valve body 100.

In general, the valve stem 300 is manually controlled by an operator, but the manual control method is difficult to conveniently control the valve stem 300, and in order to improve the control convenience of the valve stem 300, in one embodiment, as shown in fig. 1 and 4, the heat dissipation control valve further comprises an electronic control assembly 500, and the electronic control assembly 500 is connected with the valve stem 300 and is used for controlling the valve stem 300 to move in the valve cavity 110. Specifically, in one embodiment, the electrical control assembly 500 includes an electromagnet 510 and a return spring assembly 520, the electromagnet 510 is disposed at one end of the valve stem 300, and when the electromagnet 510 is energized, the electromagnet 510 is capable of pushing the valve stem 300 to move away from the electromagnet 510. When the electromagnet 510 is de-energized, a return spring assembly 520 connects the valve stem 300 and the valve body 100 for applying a force to the valve stem 300 in a direction adjacent to the electromagnet 510, the return spring assembly 520 being capable of urging the valve stem 300 to move in a direction adjacent to the electromagnet 510. It should be noted that in other embodiments, the electromagnet 510 may also generate an attraction force on the valve stem 300, when the electromagnet 510 is powered, the electromagnet 510 may attract the valve stem 300 to move towards the electromagnet 510, and the return spring assembly 520 may connect the valve stem 300 and the valve body 100 for applying a force on the valve stem 300 in a direction away from the electromagnet 510.

When the radial flow of the pressure oil in the main oil inlet passage 120 suddenly decreases, a negative pressure state occurs in the main oil inlet passage 120, and thus cavitation is generated in the heat dissipation system. In order to solve the above technical problem, in one embodiment, as shown in fig. 2 and 3, an oil compensating passage 170 is further disposed between the main oil inlet passage 120 and the oil return passage 150, and a one-way oil compensating valve 600 is disposed in the oil compensating passage 170, so that pressure oil can flow in one direction from the oil return passage 150 to the main oil inlet passage 120 through the oil compensating passage 170. Thus, when the hydraulic value in the main oil inlet passage 120 is smaller than the hydraulic value in the oil return passage 150, the pressure oil in the oil return passage 150 can flow back to the main oil inlet passage 120 from the oil return passage 150 under the pushing of the pressure difference, so that the negative pressure in the main oil inlet passage 120 is avoided, and further the cavitation of the heat dissipation system is avoided.

Specifically, in one embodiment, as shown in fig. 3, the one-way oil recharging valve 600 includes a valve seat 610, a compression spring 620 and a movable plug 630, the valve seat 610 is fixedly connected to the valve body 100, one end of the compression spring 620 is connected to the valve seat 610, the other end of the compression spring 620 is connected to the movable plug 630, and the compression spring 620 can push the movable plug 630 to plug the oil recharging channel 170.

In order to absorb the impact of the pressure oil on the heat dissipation system, in one embodiment, as shown in fig. 1 and 4, the valve body 100 is further provided with a first overload protection passage 180 capable of communicating the first working passage 130 with the oil return passage 150, and the first overload protection passage 180 is provided with a first overload valve 700, and when the hydraulic pressure of the pressure oil in the first working passage 130 exceeds a first preset pressure value, the first overload valve 700 is capable of opening the first overload protection passage 180.

Also, in order to absorb the impact of the pressure oil on the heat dissipation system, in one embodiment, as shown in fig. 1 and 4, the valve body 100 is further provided with a second overload protection passage 190 capable of communicating the second working passage 140 and the oil return passage 150, and the second overload protection passage 190 is provided with a second overload valve 800, and when the hydraulic pressure of the pressure oil in the second working passage 140 exceeds a second preset pressure value, the second overload valve 800 is capable of opening the second overload protection passage 190.

The present application further provides a heat dissipation system, which includes a fan (not shown), a hydraulic motor (not shown) and the heat dissipation control valve described in any of the above embodiments, wherein the fan is installed on an output shaft of the hydraulic motor, and the heat dissipation control valve is connected to the hydraulic motor through the first working channel 130 or the second working channel 140 respectively, so as to drive the hydraulic motor to drive the fan to rotate clockwise or counterclockwise.

All possible combinations of the technical features of the above embodiments may not be described for the sake of brevity, but should be considered as within the scope of the present disclosure as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the claims. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present application shall be subject to the appended claims.

Claims

1. The heat dissipation control valve is characterized by comprising a valve body (100) and a valve rod (300), wherein the valve body (100) is provided with a valve cavity (110), a main oil inlet passage (120), a first working passage (130), a second working passage (140) and an oil return passage (150), the valve rod (300) is movably arranged in the valve cavity (110) to control the main oil inlet passage (120) to be communicated with the first working passage (130) or the second working passage (140) through the valve cavity (110), when the main oil inlet passage (120) is communicated with the first working passage (130), the heat dissipation control valve can drive a hydraulic motor to drive a fan to rotate clockwise, and when the main oil inlet passage (120) is communicated with the second working passage (140), the heat dissipation control valve can drive the hydraulic motor to drive the fan to rotate anticlockwise; the valve body (100) is further provided with an overflow channel (160) which can be communicated with the main oil inlet channel (120) and the oil return channel (150), the heat dissipation control valve further comprises an overflow valve (400), and the overflow valve (400) is arranged on the overflow channel (160) to control the on-off of the overflow channel (160).

2. The heat dissipation control valve according to claim 1, wherein the overflow valve (400) is a proportional control valve, and the opening/closing pressure of the overflow valve (400) is proportional to the magnitude of the current controlling the overflow valve (400).

3. The heat dissipation control valve of claim 1, further comprising an electronic control assembly (500), the electronic control assembly (500) being connected to the valve stem (300) for controlling movement of the valve stem (300) within the valve cavity (110).

4. The heat dissipation control valve of claim 3, wherein the electronic control assembly (500) comprises an electromagnet (510) and a return spring assembly (520), the electromagnet (510) is disposed at one end of the valve rod (300), when the electromagnet (510) is powered on, the electromagnet (510) can push the valve rod (300) to move in a direction away from the electromagnet (510), when the electromagnet (510) is powered off, the return spring assembly (520) connects the valve rod (300) and the valve body (100) for applying an acting force to the valve rod (300) in a direction close to the electromagnet (510), and the return spring assembly (520) can push the valve rod (300) to move in a direction close to the electromagnet (510).

5. The heat dissipation control valve of claim 1, wherein an oil compensating passage (170) is further disposed between the main oil inlet passage (120) and the oil return passage (150), and a one-way oil compensating valve (600) is disposed in the oil compensating passage (170) so that pressure oil can flow from the oil return passage (150) to the main oil inlet passage (120) through the oil compensating passage (170) in a one-way manner.

6. The heat dissipation control valve of claim 5, wherein the one-way oil compensation valve (600) comprises a valve seat (610), a compression spring (620) and a movable plug (630), the valve seat (610) is fixedly connected with the valve body (100), one end of the compression spring (620) is connected with the valve seat (610), the other end of the compression spring is connected with the movable plug (630), and the compression spring (620) can push the movable plug (630) to plug the oil compensation channel (170).

7. The thermal dissipation control valve according to claim 1, wherein the valve body (100) is further provided with a first overload protection passage (180) capable of communicating the first working passage (130) and the oil return passage (150), the first overload protection passage (180) is provided with a first overload valve (700), and the first overload valve (700) is capable of opening the first overload protection passage (180) when a hydraulic pressure value of the pressure oil in the first working passage (130) exceeds a first preset pressure value.

8. The thermal dissipation control valve according to claim 1, wherein the valve body (100) is further provided with a second overload protection passage (190) capable of communicating the second working passage (140) and the oil return passage (150), the second overload protection passage (190) is provided with a second overload valve (800), and the second overload valve (800) is capable of opening the second overload protection passage (190) when a hydraulic pressure value of the pressure oil in the second working passage (140) exceeds a second preset pressure value.

9. The heat dissipation control valve according to claim 1, wherein the valve body (100) is provided with a cartridge hole (200), and the overflow valve (400) is inserted into the cartridge hole (200) and detachably connected to the valve body (100).

10. A heat dissipation system, comprising a fan, a hydraulic motor, and the heat dissipation control valve as claimed in any one of claims 1 to 9, wherein the fan is mounted on an output shaft of the hydraulic motor, and the heat dissipation control valve is connected to the hydraulic motor through the first working channel (130) or the second working channel (140), respectively, for driving the hydraulic motor to rotate the fan clockwise or counterclockwise.