JPH0120358B2 - - Google Patents

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 that accompanies the vaporization and liquefaction of the working heat medium, and because they have extremely high thermal conductivity, they are used for waste heat recovery in factories, etc. It is a heat transfer element that has been widely used in recent years for applications such as heating, air conditioning, and cooling of electronic components.

Conventional heat pipes have a structure in which the inside of the container is evacuated, a heating medium guide part called a heat medium is installed along the inner wall of the container, and an operating heating medium is sealed in the container, and one end of the container is heated. Then, the working heat medium is evaporated and transferred to the other end, where it is condensed. 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 condenser.

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 determined primarily by the pressure inside the container and the type of 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 necessary to adjust the pressure individually to the optimum evaporation temperature. 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.

[Objective of the Invention] Taking the above facts into consideration, the present invention makes it possible to always operate the installation in the optimum state of the system by varying the evaporation temperature of the working heat medium, and there is no design restriction on long-distance transport of heat, and the service life is shortened. The aim is to obtain a long heat transfer device.

[Summary of the Invention] A heat transfer device according to the present invention connects one end of a plurality of pipe-shaped containers to a liquid receiver storing a working heat medium and is provided with an inclined portion that is gradually lower than the liquid receiver. Equipped with a pressure control valve at the other end of each pipe-shaped container, which is connected to the receiver through the condenser by a reflux pipe, and the pressure control valve can be operated to increase the efficiency. It's starting to come under pressure. (In particular, since the pressure control valve is installed downstream of the heating section, that is, in the gas area where the heat medium has evaporated,
This enables faster cooling temperature control than when controlling the liquid portion of the heat medium. ) [Embodiment of the Invention] FIG. 1 shows an embodiment of the heat transfer device according to the present invention. In FIG. 1, a refrigerant as a working heat medium is stored in a liquid state up to a predetermined level. A plurality of (two in this embodiment) heat pipes 12 are branched and connected in parallel to a liquid receiver 10 serving as a reservoir. As shown in the figure, the pipe-shaped container constituting each heat pipe 12 is extended from the liquid receiver 10 to a heating section 14 such as an object to be cooled, and then bent and extended to near the condenser 30.

The pipe-shaped container 18 of the heat pipe 12 has a plurality of annular ribs 22, which are chevron-shaped protrusions, protruding from the inner wall around the longitudinal axis of the container 18 to increase the liquid surface by capillary action. A substantially chevron-shaped protrusion can also be formed by cutting similarly shaped grooves into the flat inner wall.

The vicinity of the connecting portion of the heat pipe 12 to the liquid receiver 10 is an inclined portion 12A that is gradually lowered from the liquid receiver 10. 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. At the same time, it climbs over the rib 22 and reaches the next groove. Furthermore, the refrigerant that remains in the groove portion rises along the wall surface along the groove due to capillary action, and therefore has a large surface area and is easily vaporized. Similarly, the surface area of the refrigerant is large in the flat portion, and it is easy to vaporize. While traveling in the direction of arrow A, the refrigerant absorbs heat from the object to be cooled and evaporates in the heating section 14. This evaporation occurs in the inclined part 12A.
Sometimes it is done. Inclined portion 12 of container 18
The flat portions other than A can also be inclined, as long as they are not vertically arranged.

Note that the rib 22 is not limited to the annular shape shown in the figure, but may be spirally formed or formed in the axial direction of the container 18, and the cross section is not limited to the chevron shape. moreover,
Instead of these ribs 22, the ribs 22 may be fibrous or the like to perform a general capillary action.

A pressure control valve 24 is provided for each heat pipe 12 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. On the pressure control valve 24 side of the heat pipe 12, a pressure detector 27 and an indoor temperature (or humidity) detector 28A are provided for each heat pipe 12. Pressure detector 27 and/or room temperature (or humidity) detector 28
By inputting the detection signal A to the controller 29 and controlling the opening degree of the pressure control valve 24, 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. The condenser 30 consists of a main body 34 having a large number of radiation fins 32, and a fan 36 that sends cold air to the main body 34, and the 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 10, the heat pipe 12, and the condenser 30 form a closed loop. The liquid receiver 10
The refrigerant can be easily replenished with leaked refrigerant from a closed injection port (not shown).

A vacuum pump 46 is connected to the middle of the reflux tube 28 via a pipe 42 and a vacuum header 44, and by this operation, the degree of vacuum in 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.

Next, the operation of this embodiment will be explained.

First, the motor 38 is rotated and the fan 36 blows cold air to the main body 34 of the condenser 30, thereby putting the condenser 30 into a 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 10. 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 has overflowed in the liquid receiver 10 is moved by gravity to the inclined portion 12A.
flows down and reaches the heating section 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 the container 18,
Since the refrigerant has a large surface area and is easily vaporized, it absorbs a large amount of heat. (In the present invention, since the pressure of the refrigerant in a vaporized state is controlled by the pressure control valve 24, evaporation of the refrigerant in the heating section 14 can be quickly stopped. When controlling the flow rate of the liquid refrigerant, even if the flow of the liquid refrigerant is stopped, the remaining refrigerant will evaporate in the heating section 14, so the cooling operation cannot be stopped quickly.

The refrigerant gas evaporated in the heating section 14 is shown by arrow A.
Flows in the direction shown by from the return portion of the heat pipe 12 through the pressure control valve 24 and into the header 26. After the refrigerant gas sent from each heat pipe 12 is collected in this header 26, it is further transferred to the condenser 30 via the reflux pipe 28. The refrigerant gas that has come to the condenser 30 is condensed and becomes liquid under the cooling effect of the condenser 30, and at this time, the heat of condensation is released to the outside. The released heat is exhausted from the heat radiation fins 32 into the atmosphere.

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

As described above, in this embodiment, a plurality of heat pipes were provided, and each heat pipe was individually equipped with a 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 appropriately simple operations. Can be done.

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

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.

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

In FIG. 3, a pump 50 for refrigerant circulation is provided in the middle of the reflux pipe 40. In this case, the refrigerant that has passed through the condenser 30 and has become liquid is pumped 5
0 into the liquid receiver 10. Therefore, the liquid is forcibly transported by the pump 50, and the layout can be such that the liquid receiver 10 is installed in a high place and the heating section 14 is installed in a low place. Therefore, the equipment can be made three-dimensional, and the installation space can be reduced. In addition, since the liquid refrigerant that has exited the liquid receiver 10 is fed into the heating section 14 from a high place under the action of gravity, the heating section 14
refrigerant can be stably supplied to

In addition, since the refrigerant is forced to circulate with the pump 50, it becomes possible to transfer a large amount of heat over a longer distance than in the case shown in FIG. You can create a layout. In addition, a liquid reservoir 52 is provided in the middle of the container 18, and the reflux pipe 4
It may be returned to 0.

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 transferred to the fan 56.
It is sent to the condenser 30 by. 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. In the event that the sealed refrigerant leaks to the outside, it can be dealt with promptly.

In FIG. 5, two liquid receivers 10 are provided, and each liquid receiver 10 has two heat pipes 12.
are branched and connected in parallel, merge at the return side end, and are connected to the header 26 via the pressure control valve 24.

Regarding the heat pipe 12, the pipe-shaped container 1
The ribs 22 provided on the inner wall of the heating section 8 are provided only in the vicinity of the heating section 14. This is because the liquid refrigerant leaving the receiver 10 passes through the downwardly inclined heat pipe 12, so it can reach the heating section 14 without being subjected to capillary action by refrigerant guiding parts such as the ribs 22. 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 storage tank 58 is provided at the outlet of the condenser 30,
With or without the pump 50,
The liquid refrigerant is sent to the receiver 10 using a natural circulation method.

Reflux pipe 4 between this pump 50 and liquid receiver 10
A control valve 60 is interposed in the control device 6, which is operated by signals from a heat load sensor, a timer, etc.
2. This control device 62 may also be able to control the pump 50, the bypass controller 64 of the pump 50, etc.
With these, the amount of refrigerant supplied to the liquid receiver 10 can be controlled.

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 performance deterioration, the air vent valve 66 is connected to the inlet of the condenser 30 as shown in FIG. It is best to set it up nearby. Alternatively, it may be provided within the condenser 30. In other words, the specific gravity of air is lower than that of refrigerant gas (for example, about 1/6 of that of flon), and air flows into the condenser 3 according to the flow of refrigerant gas.
Therefore, it is desirable to provide the air bleed valve 66 at the highest position within the condenser 30 or near its inlet. Note that it is even more effective to provide an air reservoir 68 below the air vent valve 66. In addition to the above-mentioned purpose, the air vent valve 66 can also be used as a vacuum evacuation port and a refrigerant injection port before injection of refrigerant.

[Effect of the invention] 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 section in the pipe-shaped container to communicate with the liquid receiver, it is possible to transfer a large amount of heat over long distances with high efficiency, and the heating and condensing parts can be connected to the facility. The layout can be freely arranged depending on the structure, such as separating them far apart, and since the pressure inside the pipe-shaped container can be varied using a pressure control valve, it is possible to always obtain the optimal heat transfer efficiency that matches the target conditions. In addition, the cooling operation can be stopped quickly. Furthermore, since leaked refrigerant can be easily replenished without dismantling the device, a longer life can be achieved.

[Brief explanation of drawings]

FIG. 1 is a block 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 FIG. 3 is a block diagram showing an embodiment using a circulation pump. Fig. 4 is a configuration diagram showing an embodiment using a circulation fan, Fig. 5 is an embodiment using four heat pipes, and Fig. 6 is an air vent valve showing another embodiment of the present invention. FIG. 10... Refrigerant receiver, 12... Heat pipe,
14... Heating part, 22... Rib, 24... Pressure control valve, 26... Header, 28, 40... Reflux pipe,
30... Condenser, 50... Pump, 56... Fan.

Claims (1)

[Claims] 1 A liquid receiver 10 storing a working heat medium is connected to one end of the plurality of pipe-shaped containers 18, and the liquid receiver 10 is arranged to reach the heating part 14 via a gradually lowered slope part 12A, and the pipe A pressure control valve 24 is provided on the opposite side of the liquid receiver 10 of the shaped container 18, and the pressure control valve 24 and the liquid receiver 1 are connected to each other.
A reflux pipe 2 is connected to the reflux pipe 2 via a condenser 30 between the
1. A heat transfer device characterized in that a closed loop circuit is formed by connecting 8 and 40.