JPS60213793A - Heat transfer device - Google Patents

Abstract

PURPOSE:To make the evaporating temperature of working medium variable and permit to operate the device in the optimum condition of the system at all times by a method wherein one end of a tubular vessel is connected to a liquid receiving vessel while the other end of the tubular vessel is provided with a pressure control valve and is connected to the liquid receiving vessel by a recirculating pipe through a condenser. CONSTITUTION:When liquid refrigerant, overflowed in the liquid receiving vessel 10, flows down through an inclined section 12A to a heating unit 14 and is heated by external room-cooling objectives in respective heat pipes 12, the liquid refrigerant evaporates under a pressure in the vessel 18 and a temperature determined by the kind of the refrigerant. The pressure in the vessel 18 is preset by the adjustment of the pressure control valve 24 at a value wherein the refrigerant can be evaporated and the heat transfer efficiency thereof becomes optimum. The evaporated refrigerant gas flows into the direction shown by an arrow sign A in the diagram and enters into a header 26 through the pressure control valve 24. Further, it is transferred into the condenser 30 through the recirculating pipe 28. The refrigerant gas, entered into the condenser 30, receives cooling effect and condensed into liquid condition. The refrigerant returns into the liquid receiving vessel 10 through the recirculating pipe 40 after being condensed and, thus, above-described operation is repeated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a heat transfer device, and particularly to a heat transfer device using a pipe-shaped container as a heat transfer element.

[Background technology] Heat pipes transfer heat by using the latent heat associated with vaporization and liquefaction of the working heat medium, and have extremely high thermal conductivity] It is a heat transfer element that has been widely used in recent years for recovery, air conditioning, and cooling of electronic components.

Conventional heat pipes have a structure in which the inside of a container is evacuated, a heat guide part called a wick is installed along the inner wall, and an operating heat medium is sealed in this container, and one end of the container is heated. Then, the working heat transfer medium evaporates and moves to the other cooled end where it condenses. The condensed working heat medium moves inside the wick by capillary action, returns to the heating section, and evaporates again, thereby transporting heat from the heating section to the condensing section.

However, conventional heat pipes have limited thermal efficiency, and because the container has a closed structure, the evaporation temperature of the working heat medium is uniquely determined by the pressure inside the container and the type of the working heat medium. For this reason, it is not possible to control the pressure inside the container in response to the temperature of the heating section and adjust it to the optimum evaporation temperature. Especially when there are multiple heating sections, it is not possible to adjust the pressure inside the container to the optimum evaporation temperature individually. Therefore, there was a risk that a situation would occur in which the heat transfer effect by effectively utilizing each heating section could not be achieved.

[Object of the invention] Taking the above facts into consideration, the present invention has been developed to reduce the evaporation temperature of the working heat medium to 5.
(The equipment can always be operated in the optimum state of the system,
The objective is to obtain a heat transfer device with a long lifespan without design constraints on long-distance heat transfer.

[Summary of the Invention] A heat transfer device according to the present invention connects one end of a pipe-shaped container to a liquid receiver storing a working heat medium, and is provided with an inclined portion that is gradually lower than the liquid receiver, so that the surface area of the heat medium is reduced. Equipped with a pressure control valve at the other end of the pipe-shaped container, which is connected to the liquid receiver via a condenser through a reflux pipe, so that the desired pressure can be obtained by operating the pressure control valve. It has become.

[Embodiment of the Invention] Fig. 1 shows an embodiment of the heat transfer device according to the present invention. A plurality of heat pipes (two in the unimplemented example) 1 are placed in the liquid receiver lO as a container.
2 are branched and connected in parallel. Each heat pipe 1
As shown in the figure, the pipe-shaped container 2 is extended from the liquid receiver 10 to a heating section 14 for, for example, an object to be cooled, and then bent and extended to near the condenser 30.

The pipe-shaped container 18 of the heat vibrator 12 is attached to the inner wall of the container 18.
A large number of annular ribs 22, which are chevron-shaped protrusions, are protruded around the longitudinal axis of the tube to increase the liquid surface by capillary action. A substantially chevron-shaped protrusion can also be formed by carving a similarly shaped groove into a flat inner wall.

The connecting portion of the heat vibrator 12 to the liquid receiver 1O is formed as an inclined portion 12A that is gradually lowered from the liquid receiver 1O. Therefore, the liquid refrigerant that overflows in the liquid receiver 10 flows in the inclined part 12A by gravity, but since there are many annular ribs 22 protruding inside, the refrigerant stays in the grooves between these ribs 22 and , it climbs over the rib 22 and reaches the next groove. Furthermore, the refrigerant that remains in the grooves rises along the wall surface along the grooves due to capillary action, so it has a large surface area and is easily vaporized. While traveling in the direction, the refrigerant absorbs heat from the object to be cooled and evaporates in the heating section 14. This evaporation may also be performed at the inclined portion 12A. The flat portion of the container 18 other than the inclined portion 12A may be inclined, and any arrangement other than vertical may be sufficient.

Note that the ribs 22 are not limited to the annular shape shown in the drawings, but may be spiral or formed in the axial direction of the container 18, and the cross section is not limited to the chevron shape. It may also be in the form of a fiber to achieve a capillary action.

Each heat pipe 12 is equipped with a pressure control valve 24 at the return end of the heat pipe 12, and the outlet side of the pressure control valve 24 is commonly connected to a header 26 as a collector. There is. Pressure control valve 2 of heat vibrator 12
On the 4th side, a pressure detector 27 and an indoor temperature (or humidity) detector 28 are provided for each heat pipe 12. Pressure detector 27 and/or indoor temperature (or humidity) detector 2
The detection signal of 8 is input to the controller 29, and the pressure control j "2
By controlling the opening degrees of the heat pipes 4, it is possible to independently set the pressure inside the container 18 to a desired value for each heat pipe 12.

A condenser 30 is connected to the header 26 via a reflux pipe 28. This condenser 30 has a large number of radiation fins 3.
It consists of a main body 34 which has two sides 11, and a fan 36 that sends cold air to the main body 34, and this fan 36 is rotationally driven by a motor 38.

The outlet side of the condenser 30 is connected again to the bottom surface of the liquid receiver 10 via the reflux pipe 40, so that the liquid receiver IO, the heat pipe 12, and the class 1iiJ device 30 form a closed loop. The liquid receiver 1O is designed so that it can be easily replenished with cold tofu that has leaked from a closed type inlet (not shown).

Note that there is a pipe 42 and a vacuum header 44 in the middle of the circulation pipe 28.
A vacuum pump 46 is connected via the
The degree of vacuum within the reflux tube 28 can be maintained at a predetermined value. A solenoid valve 48 is interposed in the middle of the piping 42 to maintain airtightness within the device system. This vacuum pump 46 may be connected near the heating section 14-1.

Next, the operation of this embodiment will be explained.

1 First, turn on the computer 38.

: Blows cold air to the main body 34 of the condenser 30,
1 30 is in the cooling operation state. The inside of the condenser 30, the reflux pipe 28, and the header 26 become negative pressure, and at the same time, the condensed refrigerant returns to the liquid receiver IO. The pressure control valve 24 is then adjusted to maintain the pressure within each vessel 18 for each heat pipe 12 at any suitable constant pressure.

In each heat pipe 12, the liquid refrigerant that overflows in the liquid receiver 10 flows down the inclined portion 12A due to gravity and reaches the heating portion 14. When the liquid refrigerant that has arrived at the heating unit 14 is heated by an external object to be cooled, it evaporates at a temperature determined by the pressure inside the container 18 and the type of refrigerant. Here, the pressure inside the container 18 is set in advance by adjusting the pressure control valve 24 to a value that allows the refrigerant to evaporate and optimizes heat transfer efficiency, taking into consideration the temperature of the object to be cooled. When the refrigerant evaporates, it absorbs a large amount of heat of vaporization from the outside and cools the object to be cooled.
Ribs 22 are provided inside, and the surface area of the refrigerant is large, making it easy to vaporize, so the amount of heat absorbed is large.

The refrigerant gas that has become vapor in the heating section 14 flows in the direction shown by arrow A from the return section of the heat pipe 12 to the pressure control valve 24.
The header 26 is then entered. After the refrigerant gas sent from each heat pipe 12 is collected by this header 26, it is further passed through a reflux pipe 28. The released heat is transferred to the radiation fin 3
From 2 onwards, it is exhausted into a large locust.

The refrigerant after condensation returns to the liquid receiver 10 through the reflux pipe 40,
The above operations are repeated.

In this way, in this embodiment, a plurality of heat pipes are provided,
Each heat pipe was equipped with an individual pressure control valve. Therefore, in response to the environmental conditions of a plurality of objects to be cooled, it is possible to efficiently apply a desired cooling effect to each object to be cooled independently and without affecting each other for each heat pipe by appropriate and simple operations. I can do it.

Note that the number of heat pipes in the above embodiment is not limited to two, but may be three, four or more, and the pressure control valve is adjusted by detecting the environmental conditions of the object to be cooled and by detecting the pressure. This may be done automatically by feedback control with a pressure detector or a temperature sensor, or may be done manually by an operator while observing the indicated value of a pressure detector or room temperature (or humidity) detector.

Further, a plurality of condensers 30 may be arranged in parallel or in series. In this case, the number of units to be used can be selected depending on the heat load, so operation can be controlled more accurately and energy can be saved.

Fig. 3 shows an example of a structure in which a pump for refrigerant circulation is used, Fig. 4 shows an example in which a fan is used for refrigerant circulation, and Fig. 5 shows an example in which four heat pipes are used. FIG. 6 is a schematic diagram of an air vent jr showing another embodiment of the present invention. Components common to those in FIG. 1 are given the same reference numerals, and redundant explanations will be omitted.

In FIG. 3, the pump 50 for refrigerant circulation is connected to the reflux pipe 40.
It is located in the middle of the. In this case, the refrigerant that has passed through the condenser 30 and has become liquid is sent to the pump 5.

0 into the receiver lO. Therefore, the liquid is forcibly transported by the pump 50, and the layout can be such that the liquid receiver 1O1 is placed at a high place and the heating section 14 is placed at a low place. Therefore, the equipment can be made three-dimensional, and the installation space can be reduced. Moreover, since the liquid refrigerant that has exited the liquid receiver IO is fed into the heating section 14 from a high place under the action of gravity, the refrigerant can be stably supplied to the heating section 14.

In addition, since the refrigerant is forced to circulate with the pump 50, it is possible to transfer a large amount of heat over a longer distance than in the case of FIG.
The heating section 14 and the condenser 30 can be arranged freely depending on the structure of the facility, such as by separating them. Further, a liquid reservoir 52 may be provided in the middle of the container 18, and the liquid may be returned to the reflux pipe 40 by gravity through a pipe 54.

In FIG. 4, a fan 56 for refrigerant circulation is provided in the middle of the reflux pipe 28. In this case, the refrigerant that has passed through the header 26 and has become gaseous is fed into the condenser 30 by the fan 56 . Therefore, since gas is forcibly transported by the fan 56, heat can be transported over a longer distance than in the case of liquid transport shown in FIG. If a situation occurs in which the refrigerant sealed in IO leaks to the outside, it can be quickly dealt with.

゛In Fig. 5, two liquid receivers IO are provided,
Two heat pipes 12 are branched in parallel and connected to each liquid receiver lO, and they merge at the return side end to the pressure control valve 2.
4 to the header 26.

Regarding the heat pipe 12, ribs 22 provided on the inner wall of the pipe-shaped container 18 are provided only in the vicinity of the heating section 14. This is because the liquid refrigerant leaving the liquid receiver IO passes through the heat pipe 12 which is inclined downward, so especially the rib 2
The refrigerant can reach the heating section 14 without being subjected to capillary action by the refrigerant guide portion such as the second refrigerant guide portion. Therefore, as shown in FIG. 1, it is possible to omit the rib 22 between the liquid receiver 10 and the heating section 14, thereby reducing costs.

The condenser 30 is a shell end tube heat exchanger that uses cooling water instead of a fan that sends cold air. A reservoir 1958 is provided at the outlet of the condenser 30, and the liquid refrigerant is sent to the liquid receiver 10 by the pump 50 or by a natural circulation method without using the pump 50.

A control valve 60 is interposed in the reflux pipe 40 between the pump 50 and the liquid receiver lO, and is controlled by a control device 162 operated by a signal from a heat load sensor, a timer, etc. . This control device 62 includes the pump 50,
The bypass control valve 64 of the pump 50 may also be controlled, and the amount of refrigerant supplied to the grass lacquerware IO can be controlled by these.

In the heat transfer device of the above embodiment, as a countermeasure in case air gets mixed into the device system and there is a possibility of deterioration of performance, the air vent valve 66 is connected to the condenser 3 as shown in FIG.
Alternatively, it may be provided in the condenser 30, i.e., air has a specific gravity lower than that of the refrigerant gas (for example, about 176 fluorocarbons) and flows into the condenser 310 according to the flow of the refrigerant gas. Since it collects, the condenser 30
An air vent valve 66 is installed inside or at the highest position near the entrance.
It is desirable to have a In addition, the air vent valve '66
It is even more effective to provide an air pocket 68 at the bottom of 1:. In addition to the above-mentioned purpose, the air vent 66 can also be used as a vacuum port and a refrigerant injection port, which is performed before refrigerant injection.

[Effect of 1jJ] As explained above, in the heat transfer device according to the present invention.

By using a liquid receiver that stores refrigerant and by providing a sloped part in the pipe-shaped container to communicate with the liquid receiver, it is possible to transfer large amounts of °C heat over long distances with high efficiency, and the heating and condensing parts can be easily It is possible to perform a flexible layout such as separating the pipes far apart according to the structure of the pipe, and since the pressure inside the pipe-shaped container can be varied using a pressure control valve, it is possible to always obtain the optimum heat transfer efficiency that matches the target conditions. Furthermore, since leaked refrigerant can be uniformly replenished without disassembling the device, a longer service life can be achieved.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing an embodiment of the heat transfer device according to the present invention, FIG. 2 is a cross-sectional view of a heat pipe, and 3rd
Fig. 4 is a block diagram showing an example in which a circulation fan is used, and Fig. 5 is an example in which a heat pipe is used in four pieces. , FIG. 6 is a schematic structural diagram of an air vent valve showing another embodiment of the present invention. 10... Refrigerant receiver, 12... Heat pipe, 14... Heating section, 2 2... Rib, 24...◆Pressure control valve, 26 Fist header, 28.40. ...reflux pipe, 30 points...condenser, 50...pump, 56...fan. Agent: Patent Attorney Atsushi Nakajima Figure 5 2p Figure 6

Claims (1)

[Claims] (1) A liquid receiver (lO) storing a working heat medium is connected to one end of the pipe-shaped container (18), and a receiver/lacquerware (lO) is connected to one end.
) to the heating part (14) via a gradually lowered slope part (12A), and the pipe-shaped container (18)
A pressure control valve (24) is provided on the opposite side of the liquid receiver (lO), and a condenser (30) is provided between the pressure control valve (24) and the liquid receiver (lO). With the reflux tube (28)
, (40) to form a closed loop circuit.