RU137356U1 - FLEXIBLE CONTOUR HEAT PIPE - Google Patents

Abstract

1. A heat pipe, characterized in that it includes an evaporator and a condenser connected by a spatially separated steam and condensate conduit into a closed circuit in which a two-phase coolant circulates, and inside the condensate pipe, evaporator and condenser there is a wire spiral enclosed in a grid capillary structure with a central spiral muffled from the ends liquid channel. 2. A heat pipe according to claim 1, characterized in that the inner surfaces of the evaporator and condenser are lined with capillary grid structures. The heat pipe according to claim 1, characterized in that the steam pipe and the condensate pipe have a serpentine shape.

Description

The utility model relates to two-phase heat transfer devices, in particular, to flexible contour heat pipes and is intended for transporting heat flux from moving oscillating objects to a heat-dissipating element. The preferred area of use of the utility model is strapdown inertial navigation systems (SINS).

Currently, in the field of designing SINS, the tendency to reduce their overall mass characteristics is ahead of the reduction in power consumption. An increase in the thermal load on inertial sensors impedes their reliable functioning and leads to an increase in SINS errors. The problem of improving SINS includes the task of increasing the efficiency of heat removal from inertial sensors, especially near the upper limit of the ambient temperature.

The SINS sensor unit is arranged in a molded case or on a frame and is shock-absorbed to protect it from vibration and shock. The mechanical vibrations of the block are characterized by six degrees of freedom and are caused both by external disturbances (vibration of the base, shock, movement of the base), and internal sources (functioning of vibro-suspensions of laser gyroscopes). For this reason, the block of sensitive elements is separated from the external SINS housing by an air gap, through which heat is removed, accompanied by significant temperature drops at the boundaries of the gap.

A more effective solution to the problem under consideration is the integration of a heat-removing device into the structure of the SINS, in the preferred case made in the form of a heat pipe. However, the specifics of the problem of heat removal from inertial sensors SINS leads to additional requirements:

- the placement of the heat-removing device should not change the characteristics of the oscillations of the block of sensitive elements relative to the outer casing and impose additional restrictions on the control of the frequency supports of laser gyroscopes;

- fluctuations in the block of sensitive elements relative to the outer casing should not affect the characteristics of the heat sink device.

Known heat pipe made with a bend of 90 degrees, [1] in which the working area of the heat transfer is separated from the areas of evaporation and condensation and is located outside the main elements of the cooled object. The disadvantages of this solution are the restrictions on the number of degrees of freedom for spatial vibrations of the cooled object and the low efficiency of heat transfer.

Known heat pipe with a flexible structure [2], which is formed on the corrugated portion of a cylindrical metal pipe, and the woven mesh located inside the pipe acts as a capillary structure and adheres to the body using a support element in the form of a spiral. The disadvantages of the proposed solution are the small area of evaporation and condensation, the risk of violating the integrity of the capillary structure when bending at angles exceeding 90 °, the complexity of manufacturing the device if it is placed inside small gaps.

Known heat pipe [3], containing a housing with zones of evaporation and condensation and located inside the housing artery, consisting of a capillary base, reinforced externally with a wire spiral, and the base is made in the form of a bundle of wire spirals, each of which has a central fluid channel muffled from the ends. The disadvantage of this heat pipe is the small surface area of the evaporator and condenser, which in the case of heat removal from large surfaces reduces the efficiency and uniformity of heat transfer. In addition, a large number of spiral arteries causes difficulties when placed inside small gaps, and their free location in the evaporator and condenser reduces the efficiency of heat transfer under vibration conditions.

Closest to the technical nature of the claimed device is a contour heat pipe with a flexible artery in the form of a grid [4], in which the evaporator and condenser are spaced in space using steam and condensate lines, while a flexible mesh artery is laid in the condensate line. The disadvantage of this technical solution is the inability to give the steam and condensate conduit a shape that provides low rigidity in the case of oscillations with several degrees of freedom, since when the radius of the bend of the channel with the mesh artery decreases, its transport function is violated, and vibration can cause locking of the capillary pores.

The aim of the proposed technical solution is to remove heat from oscillating moving elements without introducing distortions into their mechanical movements.

To achieve this goal, a heat pipe is proposed, characterized in that it includes an evaporator and a condenser connected by a spaced-apart steam pipe and a condensate pipe into a closed loop in which a two-phase coolant circulates. Inside the condensate line, evaporator and condenser there is a wire spiral enclosed in a grid capillary structure with a central liquid channel muffled from the ends.

In a preferred utility model, the interior surfaces of the evaporator and condenser are lined with grid capillary structures.

In another preferred case, the steam line and the condensate line are serpentine.

The technical result of the utility model is to increase the efficiency of heat removal to the heat-dissipating element without introducing distortions into the mechanical vibrations of the cooled object.

The implementation of the device is shown in an example that fully illustrates the essence of the proposed solution, but does not limit the scope of its use.

The proposed device is illustrated by drawings, which depict:

FIG. 1 is a general view of the device.

FIG. 2 - design features of a flexible contour heat pipe.

FIG. 3 - section and types of capillary structure of the heat pipe

FIG. 4 - flexible spiral artery.

FIG. 5 - options for coverage of the spiral structure of the mesh structure

FIG. 6 - placement of a heat pipe on a refrigerated facility with six degrees of freedom.

The described device includes a condenser 1 and an evaporator 2, interconnected by a flexible steam pipe 3 and condensate pipe 4. The shells of the evaporator 2 and condenser 1 are flat in shape. Their inner surface is lined with a capillary structure 5 in the form of a mesh web. The working surfaces of the evaporator and condenser in the transverse plane (ZOY) of the heat pipe are spaced apart in space by a distance exceeding the maximum possible oscillation amplitude of the cooled element. The distance between the evaporator and the condenser in the longitudinal plane (XOZ) of the heat transfer device is determined by the requirements for structural rigidity and the vibration that occurs in the device. Structural rigidity is regulated by choosing the geometry and shape of the flexible structure of pipelines. In order to ensure high axial permeability along the channel 4, as well as inside the evaporator and condenser, a flexible artery 6 is made in the form of a wire spiral. Such an artery provides a very low stiffness to the condensate line, which means that it does not affect the vibration characteristics of the block of sensitive elements. It should also be noted that an artery in the form of a wire spiral during vibrational movements does not change the cross-sectional area of the central fluid channel, thereby preventing the condensate from moving.

To fully realize the capillary properties of the artery, its central fluid channel is fenced off from the vapor space using end caps 7. The artery in the evaporator and condenser is covered by a grid structure for better mass transfer between them by the heat carrier. The coolant is selected in accordance with the temperature range of the heat pipe. As a condenser and evaporator, flexible thermal panels with a multilayer capillary structure from the group of grooves, sintered powder, fiber and mesh can be used.

The proposed heat pipe works as follows: when heat is supplied to 2, the coolant evaporates from the capillary structure 5. The resulting vapors move along the transport section of pipeline 3 to 1, where they condense on a capillary structure similar to 5. Condensate formed by means of an artery 6 and channel 4 returns to the evaporator and the cycle repeats.

Due to the organization of the separate movement of steam and liquid using pipelines, the steam flow leaving the evaporator does not interfere with the oncoming liquid flow. The connection with the spiral artery makes it possible to provide a snakelike form of pipelines without violating the capillary properties of the structure. The driving capillary pressure developed by the spiral artery is determined by the width of the inter-turn gaps, and the axial permeability is determined by the diameter of the central fluid channel. To fully realize capillary properties, that is, to completely fill the artery with coolant, the central liquid channel is fenced off from the vapor space using plugs 7. The coverage of the spiral artery with the mesh structure ensures an efficient exchange of coolant between them and a uniform temperature field along the surface of the evaporator and condenser. Pipeline channels allow heat to be removed from moving oscillating objects to a heat dissipating element.

Literature

1. US patent No. 8284004 B2 from 10.10.2012, Heat pipe supplemented transformer cooling.

2. US patent No. 2011/0088874 A1 dated 04/21/2011, Heat pipe with a flexible structure.

3. Patent SU No. 1108323 A dated 08/15/1984, Heat pipe.

4. US patent No. 2008/0078530 A1 dated 04/03/2008, Loop heat pipe with flexible artery mesh.

Claims (3)

1. A heat pipe, characterized in that it includes an evaporator and a condenser connected by a spatially separated steam pipe and a condensate pipe into a closed loop in which a two-phase coolant circulates, inside the condensate line, evaporator and condenser there is a wire spiral enclosed in a grid capillary structure with a central liquid channel muffled from the ends. 2. The heat pipe according to claim 1, characterized in that the inner surfaces of the evaporator and condenser are lined with capillary grid structures. 3. The heat pipe according to claim 1, characterized in that the steam pipe and the condensate pipe have a serpentine shape.

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