WO2025102277A1

WO2025102277A1 - Loop heat pipe

Info

Publication number: WO2025102277A1
Application number: PCT/CN2023/131877
Authority: WO
Inventors: Yuqing Zhang; Shuaijun Li
Original assignee: Telefonaktiebolaget LM Ericsson AB
Current assignee: Telefonaktiebolaget LM Ericsson AB
Priority date: 2023-11-15
Filing date: 2023-11-15
Publication date: 2025-05-22
Anticipated expiration: 2026-05-15

Abstract

Embodiments of the present disclosure provide a loop heat pipe. The loop heat pipe comprises: an evaporator comprising a first internal space and configured to change at least a part of a refrigerant in the first internal space from a liquid phase into a gas phase upon absorbing heat from a heat source; a condensing conduit comprising an inlet in communication with the first internal space and an outlet and configured to change the refrigerant from the gas phase into the liquid phase; and a liquid returning cavity comprising a second internal space in communication with the first internal space and the outlet of the condensing conduit and configured to receive the refrigerant in the liquid phase from condensing conduit and return the refrigerant into the first internal space, wherein in a case that the loop heat pipe is placed on a horizontal surface, the liquid returning cavity is arranged alongside the evaporator in a horizontal direction, and the inlet of the condensing conduit is arranged at a position higher than the outlet of the condensing conduit.

Description

LOOP HEAT PIPE

FIELD

Embodiments of the present disclosure generally relate to loop heat pipes.

BACKGROUND

A loop heat pipe (LHP) may also be referred to as a thermosiphon. A traditional LHP includes a closed loop formed by an evaporator, a condenser, and conduits connecting between the evaporator and the condenser. The conduits include a vapor conduit leading from the evaporator to the condenser and a liquid conduit leading from the condenser to the evaporator. The LHP uses a phase-change working fluid charged in the closed loop to transfer high-density heat generated by a heat source, such as an electronic device or home electric appliance. In the evaporator, the working fluid in a liquid phase absorbs heat from the heat source, such that a part of the working fluid changes into a gas phase. The mixed working fluid containing the gas phase and the liquid phase moves in the vapor conduit under the action of pressure difference and buoyancy and reaches the condenser. In the condenser, the mixed fluid is cooled into the liquid phase. The condensed working fluid returns to the evaporator under the action of capillary force or gravity.

In telecom industry, the LHP is mainly applied to vertically installed products, not horizontally installed products, due to limitation of its working principle. The horizontally installed products, such as baseband products, are typically cooled by heat dissipating solutions other than the LHP, for example, heat pipes (HP) and vapor chambers (VC) . Such heat dissipating solutions have a lower cooling capacity than the loop heat pipe.

SUMMARY

Example embodiments of the present disclosure provide a loop heat pipe suitable for cooling the horizontally installed products.

In an aspect of the present disclosure, it is provided a loop heat pipe. The loop heat pipe comprises: an evaporator comprising a first internal space and configured to change at least a part of a refrigerant in the first internal space from a liquid phase into a gas phase upon absorbing heat from a heat source; a condensing conduit comprising an inlet in communication with the first internal space and an outlet and configured to change the refrigerant from the gas phase into the liquid phase; and a liquid returning cavity comprising a second internal space in communication with the first internal space and the outlet of the condensing conduit and configured to receive the refrigerant in the liquid phase from condensing conduit and return the refrigerant into the first internal space, wherein in a case that the loop heat pipe is placed on a horizontal surface, the liquid returning cavity is arranged alongside the evaporator in a horizontal direction, and the inlet of the condensing conduit is arranged at a position higher than the outlet of the condensing conduit.

In some embodiments, the condensing conduit comprises a single conduit or a plurality of sub-conduits connected in parallel between the evaporator and the liquid returning cavity.

In some embodiments, in a case that the loop heat pipe is placed on the horizontal surface, each of a bottom of the first internal space and a bottom of the second internal space extends in the horizontal direction.

In some embodiments, the bottom of the first internal space is in flush with the bottom of the second internal space, or the bottom of the first internal space is higher or lower than the bottom of the second internal space.

In some embodiments, in a case that the loop heat pipe is placed on the horizontal surface, the bottom of the first internal space extends in the horizontal direction, the bottom of the second internal space is inclined relative to the horizontal direction, and an end of the bottom of the second internal space adjacent to the first internal space is lower than the other end of the bottom of the second internal space away from the first internal space.

In some embodiments, the loop heat pipe further comprises a boiling enhancement material layer arranged at a bottom of the first internal space.

In some embodiments, the evaporator comprises a first portion connected to the liquid returning cavity and a second portion above the first portion, the first internal space is surrounded by the first portion and the second portion, the inlet of the condensing conduit is connected to a side of the second portion of the evaporator, and the outlet of the condensing conduit is connected to a top of the liquid returning cavity.

In some embodiments, the loop heat pipe further comprises a separating wall arranged between the first internal space and the second internal space and configured to allow the refrigerant in the liquid phase to flow from the second internal space into the first internal space and prevent the refrigerant in the gas phase from flowing from the first internal space into the second internal space.

In some embodiments, the loop heat pipe further comprises an injection port arranged on a top of the liquid returning cavity for injection of the refrigerant.

In some embodiments, the loop heat pipe further comprises fins arranged around the condensing conduit.

In some embodiments, the loop heat pipe further comprises a fan arranged close to the fins and configured to drive a gas flow to pass through the fins.

According to embodiments of the present disclosure, the loop heat pipe is suitable for the horizontally installed products such as the baseband products to improve the heat transfer performance and phase-change capacity. In addition, the loop heat pipe can achieve higher and more reliable thermal performance. Furthermore, the size and weight of the loop heat pipe can be decreased due to its larger cooling capacity.

DESCRIPTION OF DRAWINGS

Through the following detailed descriptions with reference to the accompanying drawings, the above and other objectives, features and advantages of the example embodiments disclosed herein will become more comprehensible. In the drawings, several example embodiments disclosed herein will be illustrated in an example and in a non-limiting manner, wherein:

Fig. 1 is a perspective view of a loop heat pipe according to an embodiment of the present disclosure;

Fig. 2 is a cross-sectional view of the loop heat pipe as shown in Fig. 1;

Fig. 3 is a perspective view of a loop heat pipe according to an embodiment of the present disclosure;

Fig. 4 is a perspective view of a loop heat pipe according to an embodiment of the present disclosure;

Fig. 5 is a perspective view of a loop heat pipe according to an embodiment of the present disclosure;

Fig. 6 is a top view of the loop heat pipe as shown in Fig. 5; and

Fig. 7 is a graph illustrating a comparison between heat transfer coefficients when a heating surface is implemented as Cu foam or Cu plate.

Throughout the drawings, the same or similar reference symbols are used to indicate the same or similar elements.

DETAILED DESCRIPTION OF EMBODIMETNS

Principles of the present disclosure will now be described with reference to several example embodiments shown in the drawings. Though example embodiments of the present disclosure are illustrated in the drawings, it is to be understood that the embodiments are described only to facilitate those skilled in the art in better understanding and thereby achieving the present disclosure, rather than to limit the scope of the disclosure in any manner.

The term “comprises” or “includes” and its variants are to be read as open terms that mean “includes, but is not limited to. ” The term “or” is to be read as “and/or” unless the context clearly indicates otherwise. The term “based on” is to be read as “based at least in part on. ” The term “being operable to” is to mean a function, an action, a motion or a state can be achieved by an operation induced by a user or an external mechanism. The term “one embodiment” and “an embodiment” are to be read as “at least one embodiment. ” The term “another embodiment” is to be read as “at least one other embodiment. ” The terms “first, ” “second, ” and the like may refer to different or same objects. Other definitions, explicit and implicit, may be included below. A definition of a term is consistent throughout the description unless the context clearly indicates otherwise.

As described above, the LHP is mainly applied to vertically installed products, but not suitable for horizontally installed products, due to limitation of its working principle. For example, in the telecom industry, phase-change cooling solutions such as rolling bond cards (RBC) and thermosiphons have been applied due to their larger cooling capacity than traditional heatsinks. However, most of such high-performance cooling solutions are mainly applied to the vertically installed products, while the horizontally installed products such as baseband products mainly rely on traditional heat pipes and vapor chambers which have a relatively lower cooling capacity.

Embodiments of the present disclosure aim to provide a loop heat pipe suitable for the horizontally installed products such as the baseband products to improve the heat transfer performance and phase-change capacity. Hereafter, principles of example embodiments of the present disclosure will be described with reference to Figs. 1-7.

Fig. 1 is a perspective view of a loop heat pipe according to an embodiment of the present disclosure, and Fig. 2 is a cross-sectional view of the loop heat pipe as shown in Fig. 1. As shown in Figs. 1 and 2, the loop heat pipe 100 described herein generally includes an evaporator 11, a condensing conduit 12, and a liquid returning cavity 13.

The evaporator 11 includes a first internal space 110 filled with a refrigerant 14. The refrigerant 14 at least covers a bottom of the first internal space 110. The evaporator 11 may change at least a part of the refrigerant 14 in the first internal space 110 from a liquid phase into a gas phase upon absorbing heat from a heat source 200 thermally connected to the evaporator 11. The heat source 200 may be attached to a bottom of the evaporator 11 via a thermal interface material 201. The thermal interface material 201 may transfer heat generated by the heat source 200 to the evaporator 11, such that at least a part of the refrigerant 14 in the first internal space 110 changes from the liquid phase into the gas phase.

The condensing conduit 12 includes an inlet 121 in communication with the first internal space 110 and an outlet 122 connected to the liquid returning cavity 13. The condensing conduit 12 may change the refrigerant 14 from the gas phase into the liquid phase. The refrigerant 14 in the gas phase may flow from the first internal space 110 into the condensing conduit 12 via the inlet 121. Since the condensing conduit 12 is at a relatively low temperature, the refrigerant 14 may condense into the liquid phase in the condensing conduit 12. The refrigerant 14 in the liquid phase may flow from the condensing conduit 12 into the liquid returning cavity 13 via the outlet 122.

In the traditional loop heat pipe, the evaporator and the condenser are separated from each other and connected via extra tubes or conduits, such that the structure of the loop heat pipe is complicated and the loop heat pipe occupies a large volume for installation. According to embodiments of the present disclosure, the condensing conduit 12 is directly connected to the evaporator 11, thus there is no need to separate the evaporator and condenser. Integration of the condensing conduit 12 and the evaporator 11 may decrease a volume of the loop heat pipe 100, such that the loop heat pipe 100 can be applied in space-limited conditions.

The liquid returning cavity 13 includes a second internal space 130. The second internal space 130 is in communication with the first internal space 110 and the outlet 122 of the condensing conduit 12. The liquid returning cavity 13 may receive the refrigerant 14 changed into the liquid phase from condensing conduit 12 and return the refrigerant 14 into the first internal space 110.

As shown in Figs. 1 and 2, in a case that the loop heat pipe 100 is placed on a horizontal surface, the liquid returning cavity 13 is arranged alongside the evaporator 11 in a horizontal direction X, and the inlet 121 of the condensing conduit 12 is arranged at a position higher than the outlet 122 of the condensing conduit 12.

During a working process of the heat source 200, the heat generated by the heat source 200 may be transferred to the evaporator 11 via the thermal interface material 201, such that at least a part of the refrigerant 14 in the first internal space 110 changes from the liquid phase into the gas phase. The refrigerant 14 in the gas phase may rise in the first internal space 110 and flow from the first internal space 110 into the condensing conduit 12 via the inlet 121. The refrigerant 14 may condense into the liquid phase in the condensing conduit 12. Since the inlet 121 of the condensing conduit 12 is arranged at a position higher than the outlet 122 of the condensing conduit 12, the refrigerant 14 changed into the liquid phase may flow from the condensing conduit 12 into the liquid returning cavity 13 via the outlet 122. Further, since the liquid returning cavity 13 is arranged alongside the evaporator 11 in the horizontal direction X, the refrigerant 14 in the liquid returning cavity 13 may return into the first internal space 110. In this manner, the loop heat pipe 100 allows the refrigerant 14 to circulate in a closed loop formed by the evaporator 11, the condensing conduit 12, and the liquid returning cavity 13 so as to cool the heat source 200.

According to embodiments of the present disclosure, the loop heat pipe 100 is suitable for the horizontally installed products such as the baseband products to improve the heat transfer performance and phase-change capacity. In addition, the loop heat pipe 100 can achieve higher and more reliable thermal performance. Furthermore, the size and weight of the loop heat pipe 100 can be decreased due to its larger cooling capacity.

In some embodiments, as shown in Figs. 1 and 2, the condensing conduit 12 includes a single conduit. The single conduit may have a relatively large internal space in communication with the first internal space 110 and the second internal space 130, such that the refrigerant 14 in the gas phase may efficiently flow from the first internal space 110 into the condensing conduit 12 and rapidly condense into the liquid phase in the condensing conduit 12. In an embodiment, as shown in Figs. 1 and 2, a width of the single conduit in a direction normal to the horizontal direction X may be much larger than a thickness of the single conduit. In an embodiment, as shown in Figs. 1 and 2, a cross-section of the single conduit along the width direction may be rectangular. It is to be understood that the single conduit may have any appropriate size or shape. The scope of the present disclosure is not intended to be limited in this respect.

In some embodiments, as shown in Fig. 2, in a case that the loop heat pipe 100 is placed on the horizontal surface, each of a bottom of the first internal space 110 and a bottom of the second internal space 130 extends in the horizontal direction X. The bottom of both the first internal space 110 and the second internal space 130 may be substantially flat. Since the second internal space 130 is in communication with the first internal space 110, a liquid level of the refrigerant 14 in the second internal space 130 tends to be identical to that in the first internal space 110. Therefore, in a case that the refrigerant 14 changed into the liquid phase flows from the condensing conduit 12 into the liquid returning cavity 13, the liquid level of the refrigerant 14 in the liquid returning cavity 13 will rise, such that the refrigerant 14 in the liquid returning cavity 13 flows into the first internal space 110. In this manner, the refrigerant 14 may be circulated in the loop heat pipe 100.

In an embodiment, as shown in Fig. 2, the liquid level of the refrigerant 14 in the liquid returning cavity 13 may be below a top of the first internal space 130. In other words, a gap may be provided between the liquid level of the refrigerant 14 in the liquid returning cavity 13 and the top of the first internal space 130. In an embodiment, the liquid level of the refrigerant 14 in the liquid returning cavity 13 may be substantially in flush with the top of the first internal space 130.

In some embodiments, as shown in Fig. 2, the bottom of the first internal space 110 may be in flush with the bottom of the second internal space 130. In other embodiments, the bottom of the first internal space 110 may be higher or lower than the bottom of the second internal space 130.

In some embodiments, in a case that the loop heat pipe 100 is placed on the horizontal surface, the bottom of the first internal space 110 may extend in the horizontal direction X, and the bottom of the second internal space 130 may be inclined relative to the horizontal direction. An end of the bottom of the second internal space 130 adjacent to the first internal space 110 may be lower than the other end of the bottom of the second internal space 130 away from the first internal space 110. With such an arrangement, if the refrigerant 14 changed into the liquid phase flows from the condensing conduit 12 into the liquid returning cavity 13, the refrigerant 14 in the liquid returning cavity 13 may flow at a relatively higher speed at the inclined bottom of the second internal space 130, increasing a circulating efficiency of the refrigerant 14 in the loop heat pipe 100.

It is to be understood that the bottom of the first internal space 110 may be in any appropriate position relationship with respect to the bottom of the second internal space 130, as long as the liquid level of the refrigerant 14 in the second internal space 130 can be in flush with the liquid level of the refrigerant 14 in the first internal space 110.

In some embodiments, as shown in Fig. 2, the loop heat pipe 100 further includes a boiling enhancement material layer 16 arranged at the bottom of the first internal space 110. The boiling enhancement material layer 16 is applied on a heating surface of the evaporator 11 and immersed in the refrigerant 14 to improve the nucleate boiling process. Traditional phase-change heatsinks without a boiling enhancement material can easily achieve a film boiling regime, such that such phase-change heatsinks cannot work properly at a high heat flux.

Since boiling in the evaporator 11 is a main physical factor that determines the performance of the loop heat pipe 100, enhancement of the boiling process by modifying morphology of a heating surface of the evaporator 11 is an effective way to improve heat transfer performance of the loop heat pipe 100. Porous structures of the heating surface may be used to enhance the heat transfer performance. In an embodiment, the boiling enhancement material layer 16 includes a Cu foam formed at the bottom of the first internal space 110. Interconnected pores in the porous surface structures may increase a wetted area and a nucleation site density. Additionally, a proper liquid level above the heating surface can further improve the heat transfer coefficient, obviously enhancing the boiling process at certain conditions. Although the traditional heat pipes (HP) and vapor chambers (VC) also apply porous structures, they mainly focus on a capillary behavior to transport liquid from the condenser to the evaporator, rather than enhancing the boiling process.

Main parameters of the boiling enhancement material layer 16 include types of material, thickness, pores per linear Inch (PPI) and pore diameter. These parameters may be determined according to the working property of the refrigerant 14, bubble dynamics, desired heat load, and position of the heat source 200.

In some embodiments, as shown in Figs. 1 and 2, the evaporator 11 may include a first portion 111 connected to the liquid returning cavity 13 and a second portion 112 above the first portion 111. The first internal space 110 is surrounded by the first portion 111 and the second portion 112. The refrigerant 14 is accommodated in the first portion 111. The inlet 111 of the condensing conduit 12 is connected to a side of the second portion 112 of the evaporator 11. The outlet 112 of the condensing conduit 12 is connected to a top of the liquid returning cavity 13. During the working process of the heat source 200, the heat generated by the heat source 200 may be transferred to the evaporator 11, such that at least a part of the refrigerant 14 in the first portion 111 changes from the liquid phase into the gas phase. The refrigerant 14 in the gas phase may rise into the second portion 112 and flow into the condensing conduit 12 via the inlet 121.

In some embodiments, as shown in Fig. 2, the loop heat pipe 100 further includes a separating wall 17 arranged between the first internal space 110 and the second internal space 130. A gap is provided between the separating wall 17 and the bottom of the first internal space 110 and the second internal space 30. The liquid level may be above the gap. The separating wall 17 may allow the refrigerant 14 in the liquid phase to flow from the second internal space 130 into the first internal space 110 and prevent the refrigerant 14 in the gas phase from flowing from the first internal space 110 into the second internal space 130. The separating wall 17 can maintain a pressure difference between the evaporator 11 and the liquid returning cavity 13 and ensure that the vapor flows into the condensing conduit 12 in a desired circulating direction.

In some embodiments, as shown in Figs. 1 and 2, the loop heat pipe 100 further includes an injection port 15 arranged on a top of the liquid returning cavity 13 for injection of the refrigerant 14. The refrigerant 14 may be injected or added into the liquid returning cavity 13.

Fig. 3 is a perspective view of a loop heat pipe according to an embodiment of the present disclosure. In an embodiment, as shown in Fig. 3, the loop heat pipe 100 further includes fins 18 arranged around the condensing conduit 12. The fins 100 may enhance the heat dissipating performance of the condensing conduit 12.

Fig. 4 is a perspective view of a loop heat pipe according to an embodiment of the present disclosure. In an embodiment, as shown in Fig. 4, the condensing conduit 12 includes a plurality of sub-conduits connected in parallel between the evaporator 11 and the liquid returning cavity 13. The inlet 121 of each of the sub-conduits is connected to the evaporator 11 and the outlet 122 of each of the sub-conduits is connected to the liquid returning cavity 13. In an embodiment, as shown in Fig. 4, the plurality of sub-conduits may extend in the same orientation. In an embodiment, according to an actual requirement, the plurality of sub-conduits may extend in different orientations.

In addition, as shown in Fig. 4, the fins 18 may be arranged around the plurality of sub-conduits, so as to enhance the heat dissipating performance of the plurality of sub-conduits.

Fig. 5 is a perspective view of a loop heat pipe according to an embodiment of the present disclosure, and Fig. 6 is a top view of the loop heat pipe as shown in Fig. 5. In an embodiment, as shown in Figs. 5 and 6, the loop heat pipe 100 further includes a fan 31 arranged close to the fins 18. The fan 31 may drive a gas flow to pass through the fins 18 along a direction indicated arrows in Figs. 5 and 6, so as to bring the heat away from the fins 18. In an embodiment, the fan 31 may blow air towards the fins 18. In another embodiment, the fan 31 may draw air from the fins 18.

In an embodiment, as shown in Figs. 5 and 6, the heat source 200 such as an electronic device or home electric appliance may be arranged on a base 32, and the evaporator 11 of the loop heat pipe 100 covers the heat source 200.

Fig. 7 is a graph illustrating a comparison between heat transfer coefficients when a heating surface is implemented as Cu foam or Cu plate. As shown in Fig. 7, the heat transfer coefficient of the evaporator 11 is significantly increased in a case that the heating surface is implemented as Cu foam. Thus, the boiling enhancement material layer 16 may significantly improve the boiling heat transfer coefficient and provide higher cooling capacity.

According to embodiments of the present disclosure, the evaporator 11 and the condensing conduit 12 in the loop heat pipe 100 are integrated so as to be suitable for the horizontally installed baseband products. The loop heat pipe 100 can save more volume with larger cooling capacity compared to the traditional loop heat pipe or thermosiphon and therefore reduce the weight and size of the products. Such a new structure design ensures the working pressure difference and vapor flow direction from the evaporator 11 to the condensing conduit. The surface enhancement to nucleate boiling of the refrigerant 14 and matched liquid level inside the loop heat pipe 100 can also improve the heat transfer performance. In addition, the loop heat pipe 100 can be installed as a separate part via screw and thermal interface material, without need for welding, thus improving reliability of the loop heat pipe 100.

It should be appreciated that the above detailed embodiments of the present disclosure are only to exemplify or explain principles of the present disclosure and not to limit the present disclosure. Therefore, any modifications, equivalent alternatives and improvement, etc. without departing from the spirit and scope of the present disclosure shall be included in the scope of protection of the present disclosure. Meanwhile, appended claims of the present disclosure aim to cover all the variations and modifications falling under the scope and boundary of the claims or equivalents of the scope and boundary.

Claims

A loop heat pipe (100) comprising:

an evaporator (11) comprising a first internal space (110) and configured to change at least a part of a refrigerant (14) in the first internal space (110) from a liquid phase into a gas phase upon absorbing heat from a heat source (200) ;

a condensing conduit (12) comprising an inlet (121) in communication with the first internal space (110) and an outlet (122) and configured to change the refrigerant (14) from the gas phase into the liquid phase; and

a liquid returning cavity (13) comprising a second internal space (130) in communication with the first internal space (110) and the outlet (122) of the condensing conduit (12) and configured to receive the refrigerant (14) in the liquid phase from condensing conduit (12) and return the refrigerant (14) into the first internal space (110) ,

wherein in a case that the loop heat pipe (100) is placed on a horizontal surface, the liquid returning cavity (13) is arranged alongside the evaporator (11) in a horizontal direction, and the inlet (121) of the condensing conduit (12) is arranged at a position higher than the outlet (122) of the condensing conduit (12) .
The loop heat pipe (100) according to claim 1, wherein the condensing conduit (12) comprises a single conduit or a plurality of sub-conduits connected in parallel between the evaporator (11) and the liquid returning cavity (13) .
The loop heat pipe (100) according to claim 1, wherein in a case that the loop heat pipe (100) is placed on the horizontal surface, each of a bottom of the first internal space (110) and a bottom of the second internal space (130) extends in the horizontal direction.
The loop heat pipe (100) according to claim 3, wherein the bottom of the first internal space (110) is in flush with the bottom of the second internal space (130) , or

the bottom of the first internal space (110) is higher or lower than the bottom of the second internal space (130) .
The loop heat pipe (100) according to claim 1, wherein in a case that the loop heat pipe (100) is placed on the horizontal surface, the bottom of the first internal space (110) extends in the horizontal direction, the bottom of the second internal space (130) is inclined relative to the horizontal direction, and an end of the bottom of the second internal space (130) adjacent to the first internal space (110) is lower than the other end of the bottom of the second internal space (130) away from the first internal space (110) .
The loop heat pipe (100) according to claim 1, further comprising a boiling enhancement material layer (16) arranged at a bottom of the first internal space (110) .
The loop heat pipe (100) according to claim 1, wherein the evaporator (11) comprises a first portion (111) connected to the liquid returning cavity (13) and a second portion (112) above the first portion (111) , the first internal space (110) is surrounded by the first portion (111) and the second portion (112) , the inlet (111) of the condensing conduit (12) is connected to a side of the second portion (112) of the evaporator (11) , and the outlet (112) of the condensing conduit (12) is connected to a top of the liquid returning cavity (13) .
The loop heat pipe (100) according to any of claims 1-7, further comprising a separating wall (17) arranged between the first internal space (110) and the second internal space (130) and configured to allow the refrigerant (14) in the liquid phase to flow from the second internal space (130) into the first internal space (110) and prevent the refrigerant (14) in the gas phase from flowing from the first internal space (110) into the second internal space (130) .
The loop heat pipe (100) according to any of claims 1-7, further comprising an injection port (15) arranged on a top of the liquid returning cavity (13) for injection of the refrigerant (14) .
The loop heat pipe (100) according to any of claims 1-7, further comprising fins (18) arranged around the condensing conduit (12) .
The loop heat pipe (100) according to claim 10, further comprising a fan (31) arranged close to the fins (18) and configured to drive a gas flow to pass through the fins (18) .