CN218601669U

CN218601669U - Projector radiating heat by using relay heat pipe

Info

Publication number: CN218601669U
Application number: CN202222394896.9U
Authority: CN
Inventors: 鲜善洪
Original assignee: Chengdu Jishen Creative Technology Co ltd
Current assignee: Chengdu Jishen Creative Technology Co ltd
Priority date: 2022-09-08
Filing date: 2022-09-08
Publication date: 2023-03-10
Anticipated expiration: 2032-09-08

Abstract

The embodiment provides a projector using a relay heat pipe for heat dissipation, and belongs to the technical field of projectors. The projector using the relay heat pipe to dissipate heat comprises an air duct member, a fan, an optical element and a heat pipe. The air duct member has a closed circulating air duct. The optical element which needs heat dissipation is arranged in the circulating air duct and is arranged in the light path of the projector. The fan is arranged in the circulating air duct, and the fan can enable air in the circulating air duct to flow circularly so as to dissipate heat of the optical element. The heat pipe is arranged on the air duct piece, part of the heat pipe extends into the circulating air duct, and part of the heat pipe extends to the outside of the air duct piece. When air circulates in the circulating air duct, the heat pipe can be used as relay heat dissipation to conduct and move heat in the circulating air duct to the outside of the circulating air duct, and therefore heat dissipation performance of the projector can be improved.

Description

Projector radiating heat by using relay heat pipe

Technical Field

The utility model relates to a projecting apparatus field particularly, relates to a with radiating projecting apparatus of relay heat pipe.

Background

In the LCD liquid crystal projector, since the liquid crystal light valve can only work under polarized light of one vibration direction, and polarized light of the other vibration direction will be blocked, and most of it will become heat and raise the temperature of the LCD, when the temperature reaches a certain value (e.g. 80 °), the liquid crystal light valve will lose its function and even be damaged. In order to enable optical devices such as LCDs to operate stably for a long period of time, it is necessary to perform convection heat dissipation on LCDs. However, the existing heat dissipation method has poor heat dissipation effect, and the use experience of the projector is affected.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a with radiating projecting apparatus of relay heat pipe, it can improve the not good problem of current projecting apparatus radiating effect to can promote user experience.

The embodiment of the utility model is realized like this:

the utility model provides a projector using relay heat pipe to dissipate heat, which comprises an air duct piece, a fan, an optical element and a heat pipe;

the air duct piece is provided with a closed circulating air duct;

the optical element needing heat dissipation is arranged in the circulating air duct and is arranged in the light path of the projector;

the fan is arranged in the circulating air duct, and the fan can operate to enable air in the circulating air duct to circularly flow so as to radiate the heat of the optical element;

the heat pipe is arranged on the air duct piece, part of the heat pipe extends into the circulating air duct, and part of the heat pipe extends to the outside of the air duct piece;

when the air in the circulating air duct circulates, the heat pipe can conduct and move the heat in the circulating air duct to the outside of the circulating air duct.

In an alternative embodiment, the projector using the relay heat pipe to dissipate heat further includes a first heat exchange fin group and a heat exchange member;

the first heat exchange fin group is arranged on the part of the heat pipe in the circulating air duct;

the heat exchange piece is arranged on the part of the heat pipe, which is positioned outside the air duct piece.

In an optional embodiment, the heat exchanging member includes a second heat exchanging fin group, and the second heat exchanging fin group is disposed at a portion of the heat pipe located outside the air duct member.

In an optional embodiment, the heat exchange member includes a semiconductor refrigeration assembly, and the semiconductor refrigeration assembly is disposed at a portion of the heat pipe located outside the air duct member.

In an optional embodiment, the projector using the relay heat pipe to dissipate heat further includes a heat dissipation fan, and the heat dissipation fan is disposed outside the air duct member and corresponds to the heat exchange member to dissipate heat from the heat exchange member.

In an optional embodiment, the heat exchange member includes a second heat exchange fin group, a semiconductor refrigeration assembly and a cooling fan;

the second heat exchange fin group is arranged on the part of the heat pipe, which is positioned outside the air duct piece;

the semiconductor refrigeration assembly is arranged on the part of the heat pipe, which is positioned outside the air duct piece;

the heat radiation fan is arranged outside the air duct piece and corresponds to the second heat exchange fin group and/or the semiconductor refrigeration assembly to radiate heat for the second heat exchange fin group and/or the semiconductor refrigeration assembly.

In an optional implementation mode, the semiconductor refrigeration assembly comprises a heat transfer element, a semiconductor refrigeration piece and a heat dissipation element, the heat transfer element is arranged on the refrigeration side of the semiconductor refrigeration piece and attached to the heat pipe, and the heat dissipation element is arranged on the heat dissipation side of the semiconductor refrigeration piece.

In an optional embodiment, the projector using the relay heat pipe to dissipate heat further includes an air deflector, the air deflector is movably disposed at an outer side of the air duct member, and corresponds to the fan;

when the semiconductor refrigeration piece operates, the air deflector can movably guide the air of the heat radiation fan so as to blow the air on the heat radiation piece;

when the semiconductor refrigerating fins stop operating, the air guide plate moves to enable the air of the cooling fan to blow on the second heat exchange fin group.

In an optional embodiment, the heat dissipating member is disposed in parallel with the second heat exchanging fin group, and the heat dissipating fan may dissipate heat to the heat dissipating member and the second heat exchanging fin group at the same time.

In an optional embodiment, the number of the heat dissipation fans includes two, one of the two heat dissipation fans is opposite to the heat dissipation member and is used for dissipating heat of the heat dissipation member, and the other heat dissipation fan is opposite to the second heat exchange fin group and is used for dissipating heat of the second heat exchange fin group.

In optional embodiment, semiconductor refrigeration subassembly still includes temperature sensor and temperature controller, temperature sensor set up in the circulation wind channel, and with the temperature controller is connected, the semiconductor refrigeration piece with the temperature controller electricity is connected, the temperature controller can reach according to presetting the temperature the actual measurement temperature control of temperature sensor the semiconductor refrigeration piece is closed or is opened.

The embodiment of the utility model provides a with radiating projecting apparatus of relay heat pipe's beneficial effect includes:

this embodiment is through setting up the wind channel subassembly to set up the circulation wind channel at the wind channel subassembly, and set up the optical element of projecting apparatus in the circulation wind channel, utilize the fan that sets up in the circulation wind channel just can realize that the air just can realize just can realizing the cooling to optical element at circulation wind channel inner loop, and can play the dustproof protection to optical element. The heat pipe can be used as a relay to transfer the heat in the circulating air duct to the outside, so that the heat can be prevented from being accumulated in the circulating air duct, and the heat dissipation of the optical element of the projector can be better realized.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are required to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention, and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

Fig. 1 is a schematic structural diagram of a first embodiment of a projector for dissipating heat by using a relay heat pipe according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram of a projector for dissipating heat by using a relay heat pipe according to an embodiment of the present invention;

fig. 3 is a schematic structural diagram of a projector for dissipating heat by using a relay heat pipe according to an embodiment of the present invention;

fig. 4 is a schematic structural diagram of a fourth embodiment of a projector for dissipating heat by using a relay heat pipe according to an embodiment of the present invention;

fig. 5 is a schematic structural diagram of a fifth implementation manner of a projector using a relay heat pipe to dissipate heat according to an embodiment of the present invention.

100-projector using relay heat pipe to dissipate heat; 110-an air duct member; 111-circulating air duct; a 115-fresnel lens; 120-a fan; 130-an optical element; 131-LCD elements; 133-an illumination source; 135-an imaging lens; 140-a heat pipe; 160-a first set of heat exchange fins; 170-heat exchange member; 171-a second set of heat exchange fins; 180-a heat dissipation fan; 183-semiconductor refrigeration components; 185-a heat transfer element; 187-conductor cooling fins; 189-a heat sink; 191-a wind deflector; 193-temperature sensor; 195-temperature controller.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. The components of embodiments of the present invention, as generally described and illustrated in the figures herein, may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the present invention, presented in the accompanying drawings, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate the position or positional relationship based on the position or positional relationship shown in the drawings, or the position or positional relationship which is usually placed when the product of the present invention is used, and are only for convenience of description and simplification of the description, but do not indicate or imply that the device or element referred to must have a specific position, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," "third," and the like are used solely to distinguish one from another and are not to be construed as indicating or implying relative importance.

Furthermore, the terms "horizontal", "vertical" and the like do not imply that the components are required to be absolutely horizontal or pendant, but rather may be slightly inclined. For example, "horizontal" merely means that the direction is more horizontal than "vertical" and does not mean that the structure must be perfectly horizontal, but may be slightly inclined.

In the description of the present invention, it should also be noted that, unless otherwise explicitly specified or limited, the terms "disposed," "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Referring to fig. 1 to 5, the present embodiment provides a projector 100 for dissipating heat by using a relay heat pipe, where the projector 100 for dissipating heat by using a relay heat pipe includes an air duct member 110, a fan 120, an optical element 130, and a heat pipe 140. The air duct member 110 has a closed circulating air duct 111. An optical element 130 that requires heat dissipation is provided in the circulation duct 111 and in the optical path of the projector. The fan 120 is disposed in the circulating air duct 111, and the fan 120 is operated to circulate air in the circulating air duct 111 to dissipate heat from the optical element 130. The heat pipe 140 is disposed on the air duct member 110, and the heat pipe 140 extends partially into the circulating air duct 111 and partially out of the air duct member 110. The heat pipe 140 may conduct heat in the circulating air duct 111 to the outside of the circulating air duct 111 when air circulates in the circulating air duct 111.

In this embodiment, by providing the air duct assembly, providing the circulating air duct 111 in the air duct assembly, and disposing the optical element 130 of the projector in the circulating air duct 111, the fan 120 disposed in the circulating air duct 111 can circulate air in the circulating air duct 111 to cool the optical element 130, and can protect the optical element 130 from dust. The heat pipe 140 can serve as a heat dissipation relay to transfer heat in the circulating air duct 111 to the outside, so that heat accumulation in the circulating air duct 111 can be avoided, and heat dissipation of the projector optical element 130 can be better achieved.

It should be noted that the heat pipe 140 generally comprises a pipe shell, a wick and an end cover, one end of the heat pipe 140 is an evaporation section, and the other end is a condensation section, when one end of the heat pipe 140 is heated, the liquid is evaporated and vaporized, the vapor flows to the other end under a slight pressure difference to release heat and condense into liquid, the liquid flows back to the evaporation section along the porous material by the action of capillary force, and thus the circulation is not performed, and the heat is transferred from one end of the heat pipe 140 to the other end. Disposed inside the circulating air duct 111 is an evaporation section of the heat pipe 140, and disposed outside the air duct member 110 is a condensation section of the heat pipe 140.

In the present embodiment, the air duct member 110 has an elliptical ring shape. Generally comprises a base and a top cover, wherein the circulating air duct 111 is arranged on the base, and the circulating air duct 111 is in a ring groove shape. The optical element 130 and the fan 120, which need to dissipate heat, are disposed behind the circulating air duct 111, and the top cover is mounted on the base, so that the circulating air duct 111 can be sealed.

In a typical LCD projector, the optical elements 130 typically include an illumination source 133, a set of collimating mirrors, an LCD element 131, a shaped lens, and the like. In this embodiment, the optical element 130 disposed in the circulating air duct 111 is an LCD element 131, both sides of the base circulating air duct 111 are disposed with notches, a planar lens is disposed in the notch, and the LCD element 131 is disposed between the two planar lenses and spaced from the two planar lenses for air flowing. The planar lens allows the illumination light from the projector to enter the circulating air duct 111 to the LCD device 131 and then exit through the LCD device 131. The planar lens may be a fresnel lens 115. The illumination light source 133 is disposed in the hollow region of the base and corresponds to the inner fresnel lens 115, and the imaging lens 135 is disposed on the outer side of the base and corresponds to the outer fresnel lens 115. Further, other optical elements 130 such as the illumination light source 133 and the imaging lens 135 are also hermetically mounted.

Of course, in other embodiments of the present application, all the optical elements 130 of the projector may be disposed in the circulating air duct 111.

Referring to fig. 1 to 5, in the present embodiment, the projector 100 using the relay heat pipe to dissipate heat further includes a first heat exchanging fin set 160 and a heat exchanging element 170. The first heat exchange fin set 160 is disposed at a portion of the heat pipe 140 located in the circulating air duct 111. The heat exchange member 170 is disposed at a portion of the heat pipe 140 outside the air duct member 110.

In this embodiment, the first heat exchange fin set 160 is disposed at a portion of the heat pipe 140 located in the circulating air duct 111, so that a heat exchange area of air in the circulating air duct 111 can be increased, and heat in the circulating air duct 111 can be more quickly led out.

It should be noted that the first heat exchanging fin set 160 is formed by a plurality of metal sheets arranged at intervals, and is disposed on the heat pipe 140 in a penetrating manner, when air passes through a gap between two adjacent metal sheets, the air can exchange heat with the first heat exchanging fin, and then the heat is conducted to the heat pipe 140, and the heat pipe 140 then conducts the heat to the heat exchanging element 170, so that the heat is transferred out of the circulating air duct 111.

Referring to fig. 1, in some embodiments of the present application, the heat exchanging member 170 includes a second heat exchanging fin set 171, and the second heat exchanging fin set 171 is disposed on a portion of the heat pipe 140 located outside the air duct member 110. The heat exchange member 170 is disposed as the second heat exchange fin group 171 in this embodiment, so that heat dissipation can be better achieved. The second heat exchanging fin group 171 is also formed of a plurality of spaced metal sheets so as to exchange heat with the external air to dissipate heat.

Further, the external heat dissipation is improved, and the projector 100 using the relay heat pipe for heat dissipation further includes a heat dissipation fan 180, the heat dissipation fan 180 is disposed outside the air duct member 110 and is disposed corresponding to the second heat exchange fin set 171, and the heat dissipation fan 180 operates to dissipate heat from the second heat exchange fin set 171.

Referring to fig. 2, in some embodiments of the present disclosure, the heat exchanging element 170 includes a semiconductor cooling element 183, and the semiconductor cooling element 183 is disposed on a portion of the heat pipe 140 located outside the air duct element 110. The semiconductor refrigeration component 183 is arranged in the embodiment, so that the heat pipe 140 can be actively cooled, and heat dissipation can be better realized.

Further, the semiconductor cooling module 183 includes a heat transfer element 185, a semiconductor cooling plate 187 and a heat dissipation element 189, the heat transfer element 185 is disposed on the cooling side of the semiconductor cooling plate 187 and attached to the heat pipe 140, and the heat dissipation element 189 is disposed on the heat dissipation side of the semiconductor cooling plate 187. The heat radiating fan 180 blows air to the heat radiating member 189, so that the cooling efficiency of the semiconductor cooling sheet 187 can be improved.

Referring to fig. 3-5, in some embodiments of the present application, the heat exchange member 170 includes a second heat exchange fin set 171, a semiconductor cooling assembly 183, and a heat dissipation fan 180. The second heat exchanging fin set 171 is disposed on a portion of the heat pipe 140 outside the air duct member 110. The semiconductor refrigeration assembly 183 is disposed at a portion of the heat pipe 140 outside the air duct member 110. The heat dissipation fan 180 is disposed outside the air duct member 110, and is disposed corresponding to the second heat exchange fin set 171 and the semiconductor cooling assembly 183, so as to dissipate heat from the second heat exchange fin set 171 and the semiconductor cooling assembly 183.

Further, semiconductor refrigeration assembly 183 includes heat transfer element 185, semiconductor refrigeration sheet 187 and heat dissipation element 189, heat transfer element 185 is disposed on the refrigeration side of semiconductor refrigeration sheet 187 and attached to heat pipe 140, and heat dissipation element 189 is disposed on the heat dissipation side of semiconductor refrigeration sheet 187. Referring to fig. 3, the projector 100 using the relay heat pipe to dissipate heat further includes an air guiding plate 191, and the air guiding plate 191 is movably disposed outside the air duct 110 and corresponds to the fan 120. When the semiconductor cooling fins 187 are operated, the air guide plate 191 is movable to guide the air of the heat dissipation fan 180 to be blown onto the heat dissipation member 189. When the semiconductor cooling fins 187 stop operating, the air deflector 191 moves to blow the air of the heat dissipation fan 180 onto the second heat exchange fin set 171.

The air deflector 191 is rotatably disposed in the housing of the projector and is controlled in conjunction with the semiconductor cooling sheet 187. Thus, the number of the heat dissipation fans 180 can be reduced, the cost can be lowered, and the volume can be reduced.

Referring to fig. 4, it is understood that the heat dissipation member 189 may be partially disposed in parallel with the second heat exchange fin set 171, and the heat dissipation fan 180 may simultaneously dissipate heat from the heat dissipation member 189 and the second heat exchange fin set 171. Referring to fig. 5, two heat dissipation fans 180 may be provided, one of the two heat dissipation fans 180 is opposite to the heat dissipation member 189 for dissipating heat from the heat dissipation member 189, and the other is opposite to the second heat exchange fin group 171 for dissipating heat from the second heat exchange fin group 171.

Referring to fig. 2-5, in the present embodiment, the semiconductor cooling assembly 183 further includes a temperature sensor 193 and a temperature controller 195, the temperature sensor 193 is disposed in the circulating air duct 111 and connected to the temperature controller 195, the semiconductor cooling sheet 187 is electrically connected to the temperature controller 195, and the temperature controller 195 can control the semiconductor cooling sheet 187 to be turned off or on according to a preset temperature and a measured temperature of the temperature sensor 193.

For example, the preset temperatures of the temperature controller 195 are 40 ℃ and 60 ℃. When the temperature actually measured by the temperature sensor 193 is higher than 60 ℃, the semiconductor refrigeration sheet 187 is opened, and when the temperature is lower than 40 ℃, the semiconductor refrigeration sheet 187 is closed, so that the energy consumption can be reduced, and dew condensation in the circulating air duct 111 can be avoided.

It should be noted that the temperature controller 195 is an existing electronic module, and can be automatically controlled only by inputting a preset temperature threshold value according to the requirement.

The working principle and the beneficial effects of the projector 100 using the relay heat pipe for heat dissipation provided by the embodiment include:

in this embodiment, by providing the air duct assembly, providing the circulating air duct 111 in the air duct assembly, and disposing the optical element 130 of the projector in the circulating air duct 111, the fan 120 disposed in the circulating air duct 111 can circulate air in the circulating air duct 111 to cool the optical element 130, and can protect the optical element 130 from dust. The heat pipe 140 can transfer heat in the circulating air duct 111 to the outside, so that heat accumulation in the circulating air duct 111 can be avoided, and heat dissipation of the projector optical element 130 can be better achieved.

The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes will occur to those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A projector using a relay heat pipe to dissipate heat is characterized by comprising an air duct member (110), a fan (120), an optical element (130) and a heat pipe (140);

the air duct piece (110) is provided with a closed circulating air duct (111);

the optical element (130) is arranged in the circulating air duct (111) and is arranged in an optical path of the projector;

the fan (120) is arranged in the circulating air duct (111), and the fan (120) operates to enable air in the circulating air duct (111) to circularly flow so as to dissipate heat of the optical element (130);

the heat pipe (140) is arranged on the air duct piece (110), and the heat pipe (140) extends partially into the circulating air duct (111) and partially out of the air duct piece (110);

when air in the circulating air duct (111) circulates, the heat pipe (140) can conduct heat in the circulating air duct (111) to the outside of the circulating air duct (111).

2. The projector using the relay heat pipe for heat dissipation according to claim 1, further comprising a first heat exchanging fin set (160) and a heat exchanging member (170);

the first heat exchange fin group (160) is arranged at the part of the heat pipe (140) positioned in the circulating air duct (111);

the heat exchange piece (170) is arranged at the part of the heat pipe (140) outside the air duct piece (110).

3. The projector using the relay heat pipe for heat dissipation as defined in claim 2, wherein the heat exchanging member (170) comprises a second set of heat exchanging fins (171), and the second set of heat exchanging fins (171) is disposed on a portion of the heat pipe (140) outside the air duct member (110).

4. The projector using a relay heat pipe for dissipating heat according to claim 2, wherein the heat exchanging member (170) includes a semiconductor cooling unit (183), and the semiconductor cooling unit (183) is disposed at a portion of the heat pipe (140) located outside the air duct member (110).

5. The projector using the relay heat pipe for heat dissipation according to any one of claims 2-4, further comprising a heat dissipation fan (180), wherein the heat dissipation fan (180) is disposed outside the air channel member (110) and is disposed corresponding to the heat exchange member (170) for dissipating heat from the heat exchange member (170).

6. The projector using a relay heat pipe for heat dissipation according to claim 2, wherein the heat exchanger (170) includes a second heat exchanging fin group (171), a semiconductor cooling unit (183), and a heat dissipating fan (180);

the second heat exchange fin group (171) is arranged on the part of the heat pipe (140) outside the air duct piece (110);

the semiconductor refrigeration component (183) is arranged at the part of the heat pipe (140) outside the air duct piece (110);

the heat dissipation fan (180) is disposed outside the air duct member (110), and is disposed corresponding to the second heat exchange fin group (171) and/or the semiconductor cooling assembly (183) to dissipate heat of the second heat exchange fin group (171) and/or the semiconductor cooling assembly (183).

7. The projector using the relay heat pipe for heat dissipation according to claim 6, wherein the semiconductor cooling module (183) includes a heat transfer member (185), a semiconductor cooling plate (187), and a heat dissipation member (189), the heat transfer member (185) is disposed on a cooling side of the semiconductor cooling plate (187) and attached to the heat pipe (140), and the heat dissipation member (189) is disposed on a heat dissipation side of the semiconductor cooling plate (187).

8. The projector using the relay heat pipe to dissipate heat according to claim 7, further comprising an air deflector (191), wherein the air deflector (191) is movably disposed outside the air duct member (110) and corresponds to the fan (120);

when the semiconductor refrigeration piece (187) operates, the air deflector (191) can guide the wind of the heat dissipation fan (180) to blow on the heat dissipation piece (189);

when the semiconductor refrigeration piece (187) stops operating, the air guide plate (191) moves to enable the air of the heat radiation fan (180) to blow on the second heat exchange fin group (171).

9. The projector using a relay heat pipe for heat dissipation according to claim 7, wherein the heat dissipation member (189) is partially disposed in parallel with the second heat exchange fin group (171), and the heat dissipation fan (180) can simultaneously dissipate heat from the heat dissipation member (189) and the second heat exchange fin group (171); or the like, or, alternatively,

the number of the heat radiation fans (180) comprises two, one of the two heat radiation fans (180) is opposite to the heat radiation piece (189) and used for radiating the heat radiation piece (189), and the other one is opposite to the second heat exchange fin group (171) and used for radiating the second heat exchange fin group (171).

10. The projector using the relay heat pipe to dissipate heat according to any one of claims 7 to 9, wherein the semiconductor cooling module (183) further comprises a temperature sensor (193) and a temperature controller (195), the temperature sensor (193) is disposed in the circulating air duct (111) and connected to the temperature controller (195), the semiconductor cooling plate (187) is electrically connected to the temperature controller (195), and the temperature controller (195) controls the semiconductor cooling plate (187) to be turned off or on according to a preset temperature and a measured temperature of the temperature sensor (193).