JP4204187B2 - Loop heat pipe - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a loop heat pipe that transports heat from a heat source to an endothermic source, and in particular to one that effectively controls the temperature of the heat source.
[0002]
[Prior art]
Conventionally, a loop heat pipe has been known as a heat transport device for space, industrial, and home use. For example, it is shown in US Pat. No. 4,765,396 and Japanese Patent Laid-Open No. 10-246583. Yes.
[0003]
In this loop heat pipe, heat is absorbed from a heat generation source by an evaporator to evaporate the working fluid into a gas phase, and the obtained vapor is supplied to a condenser, where it dissipates heat to the heat absorption source to become a liquid phase. For this reason, for example, in a spacecraft, heat generated by various internal devices is absorbed by an evaporator, and this heat is dissipated to the space by a condenser to control the temperatures of the various devices. In particular, since such a loop heat pipe has no mechanical drive part, it can be used stably for a long time in an unmanned spacecraft or the like.
[0004]
[Problems to be solved by the invention]
However, in the above conventional example, when the temperature of the heat absorption source changes, the temperature of the working fluid from the condenser changes, thereby changing the temperature of the working fluid flowing into the evaporator. Therefore, there has been a problem that the heat absorption in the evaporator changes and the temperature of the heat source changes, and the temperature adjustment of the heat source cannot be made as desired.
[0005]
Further, US Pat. No. 4,515,209 is a heat exchange system similar to a loop heat pipe, and has a reservoir for holding a working fluid by connecting to a liquid pipe connecting a condenser and an evaporator. A capillary pump loop is shown. In this capillary pump loop, when the temperature of the heat absorption source decreases, the pressure in the reservoir is increased by gas pressurization or heating by the heater, and the working fluid is pushed out of the reservoir, thereby the liquid phase working fluid region in the condenser. To increase the temperature of the vapor phase working fluid.
[0006]
However, in the loop heat pipe, unlike the capillary pump loop, a reservoir independent of the evaporator is not provided, and the working fluid is circulated by heat exchange in the evaporator and the condenser. Therefore, even if the reservoir is provided, it is provided adjacent to the evaporator or integrated in the evaporator.
[0007]
Therefore, the reservoir is thermally strongly coupled to the evaporator and the pressure in this reservoir cannot be directly controlled. Therefore, it is required to efficiently control the temperature of the heat source in the loop heat pipe.
[0008]
The present invention has been made in view of the above problems, and an object of the present invention is to provide a loop heat pipe that can perform efficient heat source temperature control in the heat source loop heat pipe.
[0009]
[Means for Solving the Problems]
The present invention is a loop heat pipe that transports heat from a heat generation source to a heat absorption source, an evaporator that absorbs heat from the heat generation source and evaporates the working fluid, a condenser that radiates heat to the heat absorption source and condenses the working fluid, A vapor pipe for transporting the vapor-phase working fluid from the evaporator to the condenser; a liquid pipe for transporting the condensed liquid-phase working fluid from the condenser to the evaporator; and a heating means and a cooling means. Temperature adjusting means for adjusting the temperature by heating or cooling the working fluid in the pipe, and temperature detecting means for detecting the temperature in the liquid pipe, and the temperature adjusting means according to the temperature detection result of the temperature detecting means Thus, the temperature of the working fluid flowing into the evaporator is adjusted to a predetermined temperature .
[0010]
Thus, according to the present invention, the temperature of the working fluid to the evaporator can be adjusted by the temperature adjusting means. Therefore, it is possible to control the heat absorption from the heat source by eliminating the influence of the temperature change of the heat absorption source. Moreover, the temperature of the working fluid can be reliably controlled to a predetermined temperature by controlling the temperature adjustment by the temperature adjusting unit according to the temperature detection result of the temperature detecting unit.
[0011]
The temperature adjusting means is preferably a heating / cooling means having a heater and a Peltier element. By using either the heater or the Peltier element, the temperature of the working fluid flowing into the evaporator can be arbitrarily controlled.
[0012]
In addition, it is preferable that temperature detection means for detecting the temperature in the liquid pipe is further provided, and temperature adjustment is controlled by the temperature adjustment means in accordance with a temperature detection result of the temperature detection means. Thus, by detecting and controlling the temperature, the temperature of the working fluid can be reliably controlled to a predetermined temperature.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0014]
Drawing 1 is a figure showing an example of 1 composition of a loop heat pipe concerning an embodiment. In the figure, an evaporator 1 absorbs heat from a heat source and heats and evaporates an internal working fluid 5. Here, the heat source may be in direct contact with the evaporator 1, but is usually physically separated from the evaporator 1, and heat is transferred through a heat medium or the like. The condenser 2 radiates heat to the heat supply source, and cools and condenses the internal working fluid 5. The heat absorption source is usually in direct contact with the condenser 2, but heat may be transferred by a heat medium or the like as in the case of the evaporator 1.
[0015]
A vapor pipe 3 is connected to the outlet of the evaporator 1 and the inlet of the condenser 2, and the outlet of the condenser 2 and the inlet of the evaporator 1 are connected by a liquid pipe 4. The working fluid 5 is a fluid that undergoes a phase change between a liquid phase and a gas phase by transferring heat. In the figure, 5a indicates a liquid phase and 5b indicates a vapor phase (gas phase). In the figure, the liquid phase 5a and the gas phase 5b are indicated by different hatchings.
[0016]
Further, inside the evaporator 1, there is provided a wick 1a made of a cylindrical porous body as shown in Japanese Patent Laid-Open No. 10-246583, whereby the liquid-phase working fluid 5a on the inner side is provided. It is divided into a chamber and a chamber of a gas-phase working fluid 5b on the outer peripheral side. Between the wick 1a and the casing (container) of the evaporator 1, a spacer or the like for favorably transferring heat from the outside to the wick 1a is disposed.
[0017]
In particular, in the present embodiment, the space on the left side of the evaporator 1 in the figure is a reservoir 6 communicating with the inside of the wick 1a, and a predetermined amount of the liquid-phase working fluid 5a is stored therein.
[0018]
In order to use latent heat of vaporization for heat transport, a fluid having good vaporization characteristics is generally selected as the working fluid, and for example, ammonia, alcohol or the like is used.
[0019]
In such an apparatus, the evaporator 1 absorbs heat from an external heat source to heat the wick 1a, and the liquid-phase working fluid 5a evaporates from the surface of the wick 1a. The working fluid 5 b that has become a vapor flows through the vapor pipe 3 to the condenser 2. In the condenser 2, the working fluid 5b dissipates heat to an external heat absorption source and condenses into a liquid. The working fluid 5 a that has become liquid returns to the evaporator 1 through the liquid pipe 4.
[0020]
In this way, the heat of the heat generation source can be radiated to the heat absorption source by the loop heat pipe.
[0021]
Here, in the present embodiment, the liquid pipe 4 is provided with a temperature regulator 7 including a heater and a Peltier element. Note that the temperature controller 7 may have only one of the heater and the Peltier element and perform only heating or cooling. Further, the heating means may be one that is heated via a heating medium instead of the directly heated heater, or the cooling means may be one that is cooled via a refrigerant instead of the Peltier element. In this embodiment, the temperature controller 7 is attached to the outside of the liquid pipe 4 and the working fluid 5a is heated via the liquid pipe 4. However, the present invention is not limited to this, and the working fluid inside the liquid pipe 4 is used. You may make it heat 5a directly.
[0022]
Further, a temperature sensor 8 that detects the temperature of the working fluid is provided near the inlet of the evaporator 1, and the detection result is supplied to the controller 9. The controller 9 controls heating or cooling by the temperature regulator 7 according to the detection result of the temperature sensor 8.
[0023]
Here, the temperature difference between the liquid-phase working fluid 5 a at the outlet of the condenser 2 and the gas-phase working fluid 5 b at the outlet of the evaporator 1 is the amount of heat load on the evaporator 1 and the phase change in the evaporator 1. Determined by the ratio of quantities. That is, a temperature difference corresponding to the difference between the heat load and the phase change amount occurs between the outlet of the condenser 2 and the outlet of the evaporator 1.
[0024]
And in the apparatus of this embodiment, by supplying or removing heat to the working fluid in the liquid pipe 4, the ratio of the apparent heat load to the evaporator 1 and the phase change amount is changed, Temperature control of the evaporator 1 is performed.
[0025]
That is, when the temperature sensor 8 detects a temperature drop of the heat absorption source as a temperature drop of the working fluid in the liquid pipe 4, the controller 9 heats the liquid pipe 4 by the temperature controller 7 (for example, a heater). As a result, the temperature of the working fluid from the outlet of the condenser 2 is increased, the apparent phase change amount and the heat load amount are reduced, and the temperature difference for the sensible heat is increased. On the contrary, when the temperature sensor 8 detects the rise in the temperature of the heat absorption source as the working fluid temperature rises in the liquid pipe 4, the liquid pipe 4 is cooled by the temperature regulator 7 (for example, a Peltier element), and the apparent phase change amount Increase the ratio of heat load to reduce the temperature difference of sensible heat.
[0026]
Thus, in the present embodiment, the temperature of the working fluid 5a at the inlet of the evaporator 1 can be adjusted by the temperature adjuster 7. Therefore, the heat absorption from the heat source in the evaporator 1 can be arbitrarily controlled. For example, the temperature of the working fluid 5a at the inlet of the evaporator 1 can always be kept constant by controlling the heating or cooling by the temperature regulator 7 so that the temperature detected by the temperature sensor 8 becomes a constant temperature. Therefore, it is possible to control the heat absorption from the heat source by eliminating the influence of the temperature change of the heat absorption source.
[0027]
【The invention's effect】
As described above, according to the present invention, the temperature of the working fluid flowing into the evaporator can be adjusted by the temperature adjusting means. Therefore, it is possible to control the heat absorption from the heat source by eliminating the influence of the temperature change of the heat absorption source.
[0028]
Further, since the temperature adjusting means includes the heater and the Peltier element, the temperature of the working fluid flowing into the evaporator can be arbitrarily controlled by using either the heater or the Peltier element.
[0029]
Further, the temperature of the working fluid can be reliably controlled to a predetermined temperature by detecting the temperature and controlling the temperature adjustment by the temperature adjusting means.
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration of a loop heat pipe according to an embodiment.
[Explanation of symbols]
1 evaporator, 1a wick, 2 condenser, 3 vapor pipe, 4 liquid pipe, 5 working fluid, 6 reservoir, 7 temperature controller, 8 temperature sensor, 9 controller.

Claims (2)

A loop heat pipe that transports heat from a heat source to an endothermic source,
An evaporator that absorbs heat from the heat source and evaporates the working fluid;
A condenser that radiates heat to the heat absorption source and condenses the working fluid;
A vapor pipe for transporting the vaporized working fluid from the evaporator to the condenser;
A liquid pipe for transporting the condensed liquid phase working fluid from the condenser to the evaporator;
Temperature adjusting means having heating means and cooling means for adjusting the temperature by heating or cooling the working fluid in the liquid pipe;
Temperature detecting means for detecting the temperature in the liquid pipe;
Have
A loop heat pipe that adjusts the temperature of the working fluid flowing into the evaporator to a predetermined temperature by the temperature adjusting means according to the temperature detection result of the temperature detecting means . In the loop heat pipe according to claim 1,
The temperature adjusting means is a loop heat pipe which is a heating and cooling means having a heater and a Peltier element.

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