JPH0526589A - Cooling device equipped with spiral heat pipe - Google Patents

Abstract

PURPOSE:To make the speed of the flow of steam, which is the flow of blocks of bubbles, quicker than the speed of the flow of liquid, which is the flow of the blocks of liquid, and divide the flow of the steam and liquid so as to be different. CONSTITUTION:In a cooling device, in which a heat receiving section 1 is connected to a heat dissipating section 5 through a heat pipe so as to form a loop, the heat pipe between the outlet port of the heat receiving section 1 and the inlet port of the heat dissipating section 5 is constituted of a spiral tube 3-4, whose inner wall is provided with a spiral groove. The liquid flows through the spiral groove on the inner wall of the spiral tube while the steam flows through the central part of the spiral tube. According to this method, the flow of the steam arrives at the heat dissipating section 5 sooner than the flow of liquid and, therefore, cooling efficiency is improved.

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling device having a spiral heat pipe for efficiently transporting heat generated by a heating element through a refrigerant. FIG. 2 shows a cross-sectional view of a structural example of a conventional loop heat pipe used for cooling a heating element. FIG. 2 shows a loop type thin pipe heat pipe in which the heat receiving portion 1 and the heat radiating portion 5 are installed in contact with the outer wall of the thin pipe 3-1. Inside the thin pipe 3-1 is a condensable fluid such as water or Freon. , Ammonia, etc. are enclosed, and a check valve 4 for controlling the flow of fluid is arranged in the thin tube 3-1. The heat generated from the heat receiving unit 1 is the thin tube 3 which is in contact with the heat receiving unit 1.
1, the fluid inside is rapidly vaporized and the boiling liquid 2-1
And the heat receiving part is cooled by the latent heat of vaporization. The bubble lump 6-1 containing latent heat of vaporization becomes a slag flow existing between the liquid lumps (fluid excluding the bubble lump 6-1) 6-2, moves to the heat radiating unit 5, and is a thin tube in contact with the heat radiating unit 5. In the part 3-2, the bubbles are gradually condensed and turned into liquid. At this time, the heat is exhausted from the heat radiating portion 5 to the outside. As the operating principle of the fluid recirculation, the pressure difference caused by the temperature difference between the heat receiving part 1 and the heat radiating part 5 and the interaction of the check valve 4 and the thin tube 3-1 in contact with the heat receiving part 1
The fluid in the thin tube 3-1 circulates in the direction regulated by the check valve 4 by the propagating action of the pressure wave generated by the boiling of the two-phase fluid in the inside. At this time, the heat generated from the heat receiving section 1 is transported to the heat radiating section 5 to cool the heat receiving section 1. In the loop type thin pipe heat pipe of FIG. 2, a bubble mass 6-1 between the heat receiving part 1 and the heat radiating part 5 when the working fluid circulates is a liquid mass 6-. 2 flow alternately with each other, so that the flow of the bubble mass 6-1, that is, the vapor flow (meaning velocity and direction) 2-2, is the liquid mass 6
-2 liquid flow (meaning flow velocity and direction) 2-3
It flows at the same speed as. However, when the length of the thin tube 3-1 is long or when the air diameter is large, the liquid mass 6-2 increases the frictional force due to the viscosity between the liquid mass 6-2 and the wall of the thin capillary 3-1 and the liquid mass 6- The flow phenomenon of 2 does not occur, so that the bubble lump 6-1 cannot be refluxed,
There is a drawback that the heat input from the heat receiving unit 1 cannot be transported. The present invention provides at least one of the following:
One or more pipes are connected in an annular shape to form a closed space, a predetermined amount of condensable gas-liquid two-phase fluid is enclosed in the closed space, and a heat receiving portion is provided in a predetermined portion of the connected annular pipes. In a cooling device provided with a loop-type heat pipe configured by disposing a heat radiating portion in the other portion, a spiral is formed on the inner wall of the heat pipe tube between the outlet of the co-heat receiving portion and the heat radiating portion of the annular pipe. It is characterized by forming a groove. According to the present invention, by disposing a pipe having an inner wall having a spiral shape in a section from the heat receiving section to the heat radiating section, the gas-liquid two-phase fluid in this section flows along the tube wall and vapor. Flows in the central part of the tube, and the gas-liquid flows by forming an independent phase.Therefore, regardless of the slow flow velocity of the liquid, the vapor flow containing latent heat of vaporization is quickly transferred to the heat radiating part, and the heat receiving part Can be cooled. In addition, the pressure wave caused by the boiling of the hydraulic fluid in the heat receiving portion and the pressure fluctuation caused by the uneven state of the pipe wall become the propulsive force of the hydraulic fluid. FIG. 1 shows an embodiment of a cooling device having a spiral heat pipe according to the present invention. 1, the same reference numerals as those in FIG. 2 indicate parts having the same functions. In FIG. 1, 3-2 is a thin tube portion of the heat dissipation section, 3-3 is a straight tube, and 3-4 is a spiral tube. The configuration of the cooling device of the present invention will be described. An annular closed space is formed by the two pipes of the straight pipe 3-3 and the spiral pipe 3-4, and the heat receiving portion 1, the heat radiating portion 5 and the circulation direction of the fluid are controlled in a predetermined annular portion. A check valve 4 is provided for this purpose, and a condensable hydraulic fluid is sealed inside the pipe. The operation of the cooling device of the present invention will be described. The gas-liquid two-phase fluid containing bubbles generated by boiling in the heat receiving section 1 reaches the heat radiating section 5 via the spiral tube 3-4, is condensed and changes into a liquid, and passes through the straight tube 3-3. And returns to the heat receiving unit 1. At this time, in the state of the two-phase fluid, the liquid flows along the wall of the spiral pipe, and the vapor passes through the central portion of the pipe, and flows independently of the liquid. Most of the boiling hydraulic fluid is condensed into a liquid at the heat radiating portion, so the straight pipe 3-3 is used in the section from the heat radiating portion 5 to the heat receiving portion 1 so as to reduce the pressure loss due to the viscosity of the liquid. If the flow velocity of the liquid is high, the spiral tube 3-4 may be used. The flow of the fluid occurs due to the pressure wave generated by the instantaneous expansion and contraction of the heat receiving portion 1 at the time of boiling, and the pressure fluctuation due to the unevenness in the spiral pipe 3-4 when the fluid flows. Since the present invention operates as described above with the configuration of the embodiment, the vapor flow generated in the heat receiving portion flows to the heat radiating portion independently of the liquid, so the two-phase flow is stagnant due to the viscosity of the liquid. Flows without Therefore, the heat given from the heat receiving portion can be transported at high speed to the heat radiating portion in a large amount, so that the cooling efficiency can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows an embodiment of a cooling device including a spiral heat pipe of the present invention. FIG. 2 shows a cooling device including a conventional loop heat pipe. [Explanation of Codes] 1 Heat receiving part 2-1 Boiling liquid 2-2 Vapor flow 2-3 Liquid flow 3-2 Heat dissipation thin tube part 3-3 Straight pipe 3-4 Spiral pipe 4 Check valve 5 Heat dissipation part 6- 1 Bubble mass 6-2 Liquid mass

Claims (1)

Claim: What is claimed is: 1. A closed space is formed by annularly connecting at least one or more pipes, and a predetermined amount of condensable gas-liquid two-phase fluid is enclosed in the closed space. In a cooling device provided with a loop-type heat pipe in which a heat receiving part is provided in a predetermined part of the connected annular pipes and a heat radiating part is provided in the other part, the heat receiving part and the heat receiving part of the annular pipe A cooling device comprising a spiral heat pipe, characterized in that a spiral groove is formed on the inner wall of the heat pipe tube between the parts.