JPH04366391A - Loop type heat pipe - Google Patents

Abstract

PURPOSE:To effectively supply operation liquid to an evaporator even when flowing speed of vapor is fast. CONSTITUTION:A liquid return tube 14 in which many nozzle holes 16 for injecting operation liquid F to an inner periphery of an evaporating tube 12, are formed, is so provided near the inner periphery as to generate a vapor passage along an axial direction at the center of the tube 12 thereby to form a structure in which a jet flow (f) of the liquid F to be injected from the nozzles 16 is scarcely blown off by the evaporated vapor flow (v) of the liquid F. Thus, even if the flowing speed of the vapor is fast, the liquid F can be effectively supplied to an evaporator 12.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a loop-type heat pipe in which a vapor flow path and a liquid flow path are separated.

0002

2. Description of the Related Art As is well known, in a loop heat pipe in which a vapor flow path and a liquid flow path are separated, for example, as shown in FIGS. 3 and 4, a liquid return pipe is provided with a heat insulating coating 2 on its outer circumference 3 is arranged along the central axis of the evaporation tube 1, and the evaporation section 1a in the evaporation tube 1 is located at the lower part of the liquid return tube 3.
A large number of nozzle holes 4 are formed in the radial direction in a portion facing the radial direction, penetrating the heat insulating coating 2 on the outer periphery.

The portion of the liquid return pipe 3 where the many nozzle holes 4 are formed is heated by being removed from the condensation section (not shown) at the top of the loop heat pipe and returns to the liquid phase. The hydraulic fluid F flowing down inside the return pipe 3 forms a liquid pool,
The head pressure of this liquid pool causes the evaporator 1 to flow from each nozzle hole 4.
The hydraulic fluid F is spouted toward the inner circumferential surface of a.

[0004] Therefore, in this conventional loop-type heat pipe, the working fluid F that has been refluxed in the liquid return pipe 3 becomes a jet flow f from the nozzle hole 4 and is constantly supplied to the inner circumferential surface of the evaporating section 1a. Ru.

[0005]Then, the working fluid F heated in the evaporator section 1a evaporates, becomes a vapor flow v of the working fluid F, moves to the condensing section at the upper part of the evaporating tube 1, radiates heat in the condensing section, and condenses. The working fluid F becomes a liquid phase again, flows down inside the fluid return pipe 3, and returns to the evaporation section 1a through the nozzle hole 4 formed at its lower end. At this time, since the liquid return pipe 3 is coated with heat insulation, the working liquid F flows down to the lower part where the nozzle hole 4 is formed without evaporating on the way.

[0006]Then, the heat thus inputted into the evaporation section 1a is transferred by the vapor of the working fluid F to the condensation section in the form of latent heat of vaporization.

[0007]

[Problems to be Solved by the Invention] In the conventional loop heat pipe described above, the liquid return pipe 3 is provided along the central axis of the evaporation pipe 1. The hydraulic fluid F supplied to the inner peripheral surface of 1a is
The liquid is ejected in the radial direction from each nozzle hole 4 formed in the liquid return pipe 3.

[0008] Therefore, when the flow velocity of the vapor of the working fluid F heated and evaporated in the evaporator 1a increases, the jet flow f of the working fluid F from the nozzle hole 4 is scattered by the vapor flow v, resulting in evaporation. There was a problem in that the working fluid F was not sufficiently refluxed to the portion 1a, resulting in a decrease in heat transport efficiency.

In particular, in a large-diameter, large-capacity loop-type heat pipe, the distance from the nozzle hole 4 to the inner circumferential surface of the evaporator section 1a is long, so the jet flow f is easily influenced by the vapor flow v, and the evaporation There has been a problem in that the amount of hydraulic fluid 4 supplied to section 1a tends to be insufficient.

The present invention was made in view of the above-mentioned circumstances, and is a loop-type device that can sufficiently reflux the working fluid to the evaporator and efficiently transport heat even when the flow rate of the vapor of the working fluid is high. The purpose is to provide a heat pipe.

[0011]

[Means for Solving the Problems] As a means for solving the above-mentioned problems, the present invention provides a loop-type liquid return pipe having a large number of nozzle holes for ejecting working liquid onto the inner surface of the evaporation pipe. The heat pipe is characterized in that the plurality of liquid return tubes are disposed close to the inner surface of the evaporation tube so that a vapor flow path along the axial direction is formed in the center of the evaporation tube.

0012

[Operation] The loop-type heat pipe of the present invention has a liquid return pipe formed with a number of nozzle holes for ejecting working fluid against the inner surface of the evaporation pipe, so that a vapor flow path along the axial direction is created at the center of the evaporation pipe. Since each nozzle is disposed close to the inner peripheral surface, the working fluid is ejected from each nozzle hole toward the nearby evaporation section, and is prevented from being blown away by the vapor flow toward the condensation section. Since the scattering of the working fluid can be greatly reduced, a sufficient amount of the working fluid can be constantly supplied to the entire evaporation section.

Furthermore, by adjusting the circulating flow rate of the working fluid in each liquid return pipe, the amount of heat transported throughout the loop heat pipe can be controlled.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the loop-type heat pipe of the present invention will be described below with reference to FIGS. 1 and 2.

[0015] The loop type heat pipe 11 is an evaporation tube 12.
and a condensation section (not shown) are connected to form a circulation path as a whole, and within the evaporation tube 12 are four liquid return tubes 14 each having a heat insulating coating 13 on its outer periphery.
are equally spaced in contact with the inner circumferential surface of the evaporation tube 12, and are pressed outward and fixed by a coil spring type spacer 15 inserted into the center.

Furthermore, as shown in FIG. 2, four liquid return pipes 1
The lower end of each liquid return pipe 14 is closed, and the lower end side of each liquid return pipe 14 is connected to an evaporation section 12a formed at the lower end of the evaporation pipe 12.
A large number of nozzle holes 16 are formed at positions corresponding to the inner circumferential surface of the evaporation tube 12 and are directed toward the portion between the adjacent liquid return tube 14 and pass through the outer circumferential heat-insulating coating 13. has been done.

Although not shown, there are four liquid return pipes 14.
The upper end is disposed at the lower part of the condensing part formed at the upper end of the evaporation tube 12 so that the working fluid F condensed on the inner peripheral surface of the condensing part gathers and flows into the condensing part.

Next, the operation of this embodiment constructed as described above will be explained.

In the loop heat pipe of this embodiment, when the working fluid F is supplied to the evaporating section 12a, this working fluid F is heated by the heat input from the outside and evaporates into a vapor flow v. It passes between the coil spring type spacers 15 and rises through the space at the center of the evaporator tube 12 toward the condensing section.

As a result, the vapor of the working fluid F loses heat and condenses in the condensing section, and as it flows down the inner peripheral surface of the condensing section, it is collected and flows into the liquid return pipe 14, near the lower end. When the hydraulic fluid F flows down to the point where it flows down, a liquid pool is formed in each liquid return pipe 14, and due to the head pressure of this liquid pool, the working liquid F is ejected from the nozzle hole 16 as a jet flow f, and returns to the evaporator section 12.
It is supplied toward the inner circumferential surface of a, and the above cycle is repeated.

Therefore, the jet flow f of the working fluid F from the nozzle hole 16 at the lower end of each liquid return pipe 14 is jetted toward the nearest inner circumferential surface which is a short distance from the nozzle hole 16, so that it is not condensed. Since the vapor flow v of the working fluid F evaporated in the evaporation section 12a mainly ascends through the space in the center of the evaporation tube 12, it is still a jet flow of the working fluid F. Since the influence on f is small, the working fluid F can be constantly supplied to the evaporation section 12a, and in particular,
Even when the flow rate of steam is high, the jet flow f to the evaporation section 12a
Since the scattering of heat can be suppressed to a minimum, high heat transport efficiency can be maintained.

Furthermore, even if the diameter of the evaporator tube 12 is increased, the distance from the nozzle hole 16 of the liquid return tube 14 to the inner surface of the evaporator section 12a does not increase much. is also suitable.

[0023]

As explained above, the loop type heat pipe of the present invention is a loop type heat pipe equipped with a liquid return pipe in which a number of nozzle holes are formed for ejecting working liquid onto the inner surface of the evaporator tube. , the plurality of liquid return pipes are arranged close to the inner surface of the evaporator tube so that a vapor flow path along the axial direction is created in the center of the evaporator tube, so that the working liquid ejected from the nozzle hole is blown away by the vapor flow. Therefore, even when the flow rate of steam is high, the working fluid can be reliably supplied to the evaporator.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an evaporation section of a loop-type heat pipe according to the present invention.

FIG. 2 is a sectional view taken along line II-II in FIG. 1;

FIG. 3 is a cross-sectional view of an evaporation section of a conventional loop-type heat pipe.

FIG. 4 is a sectional view taken along the line IV-IV in FIG. 3;

[Explanation of symbols]

11 Loop type heat pipe 12 Evaporation tube 12a Evaporation section 13　Heat insulation coating 14 Liquid return pipe 15 Coil spring type spacer 16 Nozzle hole F　Hydraulic fluid f　Hydraulic fluid jet flow v Vapor flow of working fluid

Claims (1)

[Claims] 1. A loop heat pipe equipped with a liquid return pipe in which a large number of nozzle holes are formed for ejecting a working liquid to the inner surface of the evaporation pipe, wherein the plurality of liquid return pipes are arranged in the center of the evaporation pipe. A loop-type heat pipe characterized by being placed close to the inner surface of an evaporation tube so as to create a vapor flow path along the axial direction.