JPH09303984A - Thermal element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To move an arbitrary quantity of heat to an arbitrary place at an arbitrary time by arbitrarily connecting and disconnecting a flow of heat from a high heat temperature to a low heat temperature. SOLUTION: A heat element comprises a hollow pipe 13 for a heat pipe having a heating part 11 and a cooling part 12; a gas chamber 14 communicated with the cooling part side of the hollow pipe; a heater cooler 16, for example, an electric heater; and an electric switch 18. A capillary tube structure 13a (a wick) is formed in the inner wall of the hollow pipe 13 and the interior is sealed with a heating medium boiled by a heating part and condensed by a cooling part. Further, the interior of the gas chamber 14 is sealed with non- condensing gas 8 not condensed in a working temperature range. By the electric switch 18, energization to the heater cooler is brought into ON/OFF by the electric switch 18 to heat/cool non-condensing gas in the gas chamber. The heating medium and non-condensing gas an interface 9 therebetween is located in an intermediate position A between a gas chamber and a cooling part during cooling and positioned closer to the heating part side B than the cooling part during heating of non-condensing gas.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat element capable of arbitrarily interrupting the flow of heat.

[0002]

2. Description of the Related Art FIG. 5 is a schematic diagram of a heat pipe. In the heat pipe 1, a working fluid (heat medium 2) is enclosed in a sealed tube, the working fluid evaporates in the evaporator 3 and absorbs heat from the outside, and this vapor flows to the condenser 4 due to a pressure difference, The condensation part 4 condenses and radiates heat, and the condensate returns to the evaporation part by being driven by the capillary force in the capillary structure 5 (wick, groove, wire mesh, etc.) provided on the inner wall. Therefore, the heat medium (liquid) sealed in the tube has a function of boiling in the heating section and condensing in the cooling section, and in the meanwhile, the condensate is repeatedly refluxed and the evaporated gas is repeatedly moved to transfer heat. In addition, in this figure, 6 is a heat insulation part.

Since the heat pipe is composed of a combination of boiling heat transfer and condensation heat transfer having a very large heat transfer coefficient, it has an extremely high heat transfer performance, for example, several hundred times that of pure copper having a high heat conductivity. ~ Equivalent to a thousand times.

As described above, the ordinary heat pipe has an extremely high heat transport performance, but the amount of heat transfer cannot be adjusted. For example, when the heat pipe is used as a heat radiation means, it is There is a problem that heat retention becomes difficult due to large heat radiation. Therefore, a heat pipe (hereinafter, referred to as a variable conductance heat pipe, VCHP: Variable Conduct) capable of solving this problem and adjusting the amount of heat transfer
ance Heat Pipe) has been proposed and used in some parts (for example, "Theory and Application of Heat Pipes", p166-).
p185, Jatec Publishing, published June 23, 1978).

VCHP is, as schematically shown in FIG.
A gas reservoir 7 communicating with the heat pipe 1 is filled with a non-condensable gas 8 such as nitrogen or argon, and the non-condensable gas 8 covers a part of the condensing heat transfer surface. FIG. 7 is an explanatory diagram of the operation of this VCHP. In this figure, in the initial and cold state of (A), the non-condensable gas 8 fills the inside of the pipe, and the non-condensable gas 8 covers almost all the heat transfer surfaces in the pipe including the condensing part. It is in a non-functional state as a pipe. (B) When the heat medium 2 in the heat pipe starts to evaporate and the pressure in the pipe rises as the temperature of the heating section rises, the noncondensable gas 8 is compressed and its volume decreases, and the condensing surface 4 Part of the function is restored. (C) Further, when the temperature of the heating portion rises, all of the condensation surface 4 recovers its function and operates as a normal heat pipe.

Therefore, by effectively operating the operations shown in FIGS. 7A, 7B and 7C, heat transfer is extremely small below a specific temperature, but when the temperature is exceeded, the heat transfer amount increases rapidly. As a result, the temperature can be maintained within a specific temperature range regardless of the amount of heat generated by the heating section.

[0007]

The above-mentioned conventional variable conductance heat pipe (VCHP) has an extremely high heat transfer performance and can adjust the amount of heat transfer during operation to some extent, but the heat flow is It cannot be interrupted arbitrarily. This is because the heat flow in any heat transfer including a heat pipe is negatively determined according to the temperature difference (potential) and the heat transfer coefficient (conductance), and can be turned on / off positively by a switch like an electric device. Because you can't.

If a "heat switch" capable of actively turning on / off the heat flow, such as a switch in an electric device or a valve in a fluid, can be realized, the heat flow from the high temperature part to the low temperature part can be arbitrarily set. It can be intermittent and can transfer any amount of heat, at any time. Furthermore, by providing multiple heat switches, multiple heat flows can be provided, and any amount of heat can be moved to any place at any time, creating a dream heat sequence for those involved in thermal control. Is possible.

The present invention was created to meet such a demand. That is, an object of the present invention is to provide a thermal element that can intermittently interrupt the flow of heat from a high temperature portion to a low temperature portion, thereby moving an arbitrary amount of heat to an arbitrary place at any time. It is in.

[0010]

According to the present invention, a heat having a heating portion and a cooling portion, a capillary structure is formed on the inner wall, and a heat medium that boils in the heating portion and condenses in the cooling portion is enclosed inside the heat. A hollow pipe for pipes, a gas chamber provided in communication with the cooling unit side of the hollow pipe and filled with a non-condensable gas that does not condense within the operating temperature range, and the non-condensable gas in the gas chamber is heated and cooled. The heating / cooling device and an electric switch for turning on / off the power supply to the heating / cooling device. The interface between the heating medium and the non-condensable gas is between the gas chamber and the cooling part when the non-condensing gas releases heat. There is provided a thermal element, which is located at a position and is set so as to be located closer to the heating unit than the cooling unit when the non-condensable gas is heated.

According to the above configuration of the present invention, the non-condensable gas is heated / heated by turning on / off the power supply to the heating / cooling device (for example, an electric heater or a Peltier element) with an electric switch.
It can be cooled and the volume can be increased / decreased by thermal expansion / contraction to cover the cooling section with non-condensing gas and / or expose the cooling section to the vapor of the heat carrier. When the non-condensable gas releases heat (during cooling), the interface between the heat medium and the non-condensable gas is at an intermediate position between the gas chamber and the cooling unit, and the cooling unit is exposed to the vapor of the heat medium. The heat medium condenses at
Heat is transferred from the heating section to the cooling section as a normal heat pipe. On the other hand, when heating the non-condensable gas, the interface between the heat medium and the non-condensable gas is located closer to the heating part than the cooling part, and the non-condensing gas covers the cooling part, so the condensation of the heat medium in the cooling part is stopped. Then, the operation of the heat pipe stops. Therefore, by turning on / off the electric switch, the heat pipe can be stopped / operated, and the flow of heat from the high-temperature part to the low-temperature part can be arbitrarily interrupted. Further, by using a plurality of the thermal elements, it is possible to transfer an arbitrary amount of heat to an arbitrary place at an arbitrary time.

The heating / cooling device may be an electric heater and / or a Peltier element. The electric heater can heat the heat medium, and the Peltier element can cool the heat medium. Therefore, the heating and / or the cooling of the noncondensable gas can be controlled by the electric switch by using both or either of them.

According to a preferred embodiment of the present invention, the hollow tube has a heating part and a plurality of cooling parts communicating with the heating part, and the gas chamber, the heating / cooling device, and the electric switch are A plurality of hollow tubes are provided so as to communicate with each cooling section side. With this configuration, by turning on / off a plurality of electric switches, it is possible to stop / operate the condensation of the heat medium in each cooling unit, and a single heat element can prevent the heat from the heating unit to the plurality of cooling units. The flows can be interrupted separately and any amount of heat can be transferred to any location at any time.

The heat medium is selected from water, dowsome, ammonia, freon, ethanol, methanol, mercury, or sodium, and the noncondensable gas is argon,
It is selected from nitrogen, air or helium. By using these heat medium and non-condensable gas, the non-condensable gas does not react with the heat medium and the hollow pipe for heat pipe, and there is no deterioration due to temperature, so the heat transfer performance of a normal heat pipe is improved. It can be held for a stable period.

[0015]

Preferred embodiments of the present invention will be described below with reference to the drawings. In each of the drawings, common portions are denoted by the same reference numerals, and redundant description will be omitted. The "thermal element" proposed here is a heat pipe (H
P: Heat Pipe) is filled with non-condensable gas such as argon and nitrogen, and the gas volume is operated with a weak electric energy to turn on / off the function as a heat pipe. As described above, heat pipes are known to have extremely high heat transport performance. Converting the heat transport property into a thermal conductivity, it is generally equivalent to several hundred times to several thousand times more than that of a copper material. Therefore, the heat pipe function is turned on /
If turned off, this is expected to be a "heat transport switch".

FIG. 1 is a block diagram of a thermal element according to the present invention. In this figure, the heating element 10 of the present invention is the heating unit 1
Hollow pipe 13 for heat pipe having 1 and cooling unit 12
A gas chamber 14 provided in communication with the hollow tube 13 on the side of the cooling unit 12, a heating / cooling device 16 for heating / cooling the gas chamber, and electricity for turning on / off the power supply to the heating / cooling device 16. And a switch 18.

The heating / cooling unit 16 may be an electric heater and / or a Peltier element. The electric heater can heat the heat medium, and the Peltier element can cool the heat medium. Therefore, the heating and / or the cooling of the non-condensable gas can be controlled by the electric switch 18 by using both or either of them. In the following example, a case where only the electric heater is used as the heating / cooling device 16 will be described.

The heat pipe hollow tube 13 has a capillary structure 13a (for example, a wick) formed on the inner wall thereof, and the heat medium 2 which is boiled in the heating section and condensed in the cooling section is enclosed therein. This heat medium 2 is, for example, water, dowsome, ammonia, freon, ethanol, methanol, mercury,
Or sodium, which can be appropriately selected depending on the temperature range used. The heat medium 2 of the present invention is not limited to these, and a known heat medium used for a heat pipe can be used.

The heating section 11 is heated to a temperature above the boiling point of the enclosed heat medium 2, and the cooling section 12 is cooled to a temperature below the condensation point. Further, a heat insulating part 6 is provided between the heating part 11 and the cooling part 12 so as to insulate the space between them. With the configuration described above, the hollow tube 13 can be operated as an ordinary heat pipe.

The gas chamber 14 is filled with a non-condensable gas 8 which does not condense within the operating temperature range. The non-condensing gas 8 is selected from argon, nitrogen, air or helium. Since these non-condensed gases 8 do not react with the heat medium 2 or the hollow pipe 13 for the heat pipe and are not deteriorated by the temperature, the hollow pipe 13 is operated as a normal heat pipe and its heat transport performance is improved. Can be stably maintained for a long period of time.

The electric heater 16 is connected to an external power source 19 via an electric switch 18, and the electric switch 18 turns on / off the power supply to the electric heater 16.
The non-condensable gas 8 in the gas chamber 14 is heated / radiated. When the switch is turned off and the non-condensable gas 8 is radiated, the temperature of the non-condensed gas 8 is low due to the heat radiated from the gas chamber 14 and / or the heat radiated from the cooling unit 12. (Hereinafter referred to as T1). On the contrary, when the switch is turned on to heat the non-condensable gas 8, the temperature of the non-condensable gas 8 is higher than T1 (hereinafter,
T2). The temperatures T1 and T2 can be set independently of the temperatures of the heating section 11 and the cooling section 12. Further, it is preferable that these temperatures are maintained at a predetermined constant temperature by controlling the input of the heater or the interruption or the like.

As described above, the heat medium 2 and the non-condensable gas 8 are enclosed in the hollow tube 13 and the gas chamber 14, which are in communication with each other, and their interfaces 9 are formed without mixing. The interface 9 between the heat medium 2 and the non-condensable gas 8 is at an intermediate position A between the gas chamber 14 and the cooling section 12 when the heat of the non-condensable gas 8 is released (that is, at the temperature T1).
It is set so as to be located on the heating section side B from the cooling section 12 at the time of heating (that is, at the temperature T2).

With the above-described structure, by turning on / off the power supply to the electric heater 16 by the electric switch 18,
The non-condensable gas 8 can be heated / heat-dissipated, the volume is increased / decreased by thermal expansion / contraction, and the non-condensed gas 8 covers the cooling part 12 and / or exposes the cooling part to the vapor of the heat medium. You can When the non-condensed gas 8 is dissipated, the interface 9 between the heat medium 2 and the non-condensed gas 8 is separated from the gas chamber 14 and the cooling unit 12.
Since the cooling unit 12 is exposed to the steam of the heat medium 2 at the intermediate position A of the above, the heat medium 2 is condensed in the cooling unit 12 and heat from the heating unit 11 to the cooling unit 12 as a normal heat pipe. Transport will take place. On the other hand, when heating the non-condensed gas 8,
Since the interface 9 between the heat medium 2 and the non-condensable gas 8 is located on the heating section side B from the cooling section 12 and the non-condensable gas 8 covers the cooling section 12, the condensation of the heat medium 2 in the cooling section 12 is stopped. Then, the operation of the heat pipe stops. Therefore, the electric switch 18
By turning on / off, the heat pipe is stopped / operated,
The heat flow from the high temperature part to the low temperature part can be intermittently interrupted.

That is, the above-mentioned thermal element 10 has the following features. By sending an electric signal, it is possible to turn on / off a large amount of heat transport arbitrarily. The electric power added by the electric heater is determined by the heating amount required to increase the volume of the gas in the gas chamber to the extent that it expands to the condensing part, and the electric power amount = gas weight x specific heat x (T2-T1) + heat loss. . Here, the gas weight is several grams, and the first term on the right-hand side is a negligible electric power. The second term is the hollow tube 13
If the structure is such that the volume ratio of the gas chamber 14 is reduced, the heat radiation will be concentrated in the gas chamber 14, and the heat loss of the gas chamber 14 should be prevented. Both of them depend on the design, but the input power amount can be suppressed to several W to 10 w of the signal level. The conventional VCHP is a self-temperature control type, and the VCHP
The specific temperature is determined in the design stage (in other words, the VCHP is designed according to the specific temperature (operating temperature)). On the other hand, the “heat element” of the present invention turns on / off the function (heat transportation) of the heat pipe by turning on / off the electric contact in response to an external signal. If so, you are not subject to that restriction.

FIG. 2 is another structural diagram of the thermal element according to the present invention. In this figure, a hollow tube 13 has a heating part 11 and a plurality of cooling parts 12 that communicate with and branch from the heating part 11, and the gas chamber 14, the electric heater 16, and the electric switch 18 are
A plurality of hollow tubes are provided so as to communicate with respective cooling sections. Although the number of heating units 11 is one in this figure, a plurality of heating units 11 may be provided. Other configurations are similar to those of the embodiment of FIG.

With this structure, a plurality of electric switches 18 are provided.
By turning on / off the heat medium, it is possible to stop / activate the condensation of the heat medium in each cooling unit 12, and the single heat element 10 heats the heat from the single or plural heating units 11 to the plural cooling units 12. Can be interrupted separately and any amount of heat can be transferred to any place at any time.

FIG. 3 is a diagram showing a usage pattern of the thermal element of the present invention. In this figure, (A) and (B) are examples using the thermal element of FIG. 1, and (C) is an example using the thermal element of FIG. As shown in FIG. 3, by using a plurality of thermal elements of the present invention, it is possible to transfer an arbitrary amount of heat to an arbitrary place at an arbitrary time, and it can be used as a “thermal element”. For example, as in (A), the heat element 10 of FIG. 1 can be used to selectively transfer heat from the high temperature fluid 1 to the two low temperature fluids 2, 3. Further, as shown in (B), a large number of thermal elements 10 of FIG. 1 may be provided to selectively transfer heat by an arbitrary route. In this case, a different heating medium is used if necessary. Further, as in (C), using the thermal element 10 of FIG.
It is also possible to selectively transfer heat to No. 5.

[0028]

EXAMPLE FIG. 4 is a diagram showing an example of the thermal element of the present invention. In this figure, (A) shows a heat element for medium temperature (200 ° C. or less), and (B) shows a heat element for high temperature (300 ° C. or more). In the example of FIG. 4A, argon is used as the gas and water is used as the working heat medium. If the internal pressure during operation of the heat pipe is 17 ata and the gas filling amount is 1.6 g (argon), the temperature rise necessary for the argon in the gas reservoir to cover the condensing part at the time of heat cutoff is approximately calculated. It becomes 250 ° C. However, actually 2
While the temperature is raised to 50 ° C, the internal pressure in the heat pipe increases, the boiling point temperature rises, the evaporation conditions are impaired, and the heat pipe does not operate at 250 ° C or lower.

Further, the heating amount is 0.1 Wh or less due to the small amount of gas filled, and the heater takes about 10 w in consideration of heat loss, and the response time is about 10 seconds.
The amount of heat transfer by the heat pipe varies depending on the structure of the wick (dryout is the limit due to the resistance of the liquid reflux), but in this example, about 1 kW or more is possible.

In the example of FIG. 4 (B), argon is used as the gas, and Dow Thermo A (filling pressure 2.
4ata, boiling point about 300 ° C) is used. The internal pressure during operation of the heat pipe is 2.4 ata, and the amount of gas filled is about 0.5 g. The required temperature rise at the time of heat cutoff is about 120 ° C., and the heater capacity is 0.01 Wh or less. Although the argon gas is cooled in the condenser, if the gas in the gas reservoir is thermally insulated, the amount of heat radiation can be considerably reduced, so that the heater can be set to about 10 w. The amount of heat transfer is estimated to be about 300 W from the measured value.

The present invention is not limited to the embodiments and examples described above, and it goes without saying that various modifications can be made without departing from the gist of the present invention.

[0032]

As described above, in the thermal element of the present invention, the flow of heat from the high temperature portion to the low temperature portion can be intermittently interrupted, whereby an arbitrary amount of heat and an arbitrary amount of heat can be generated. It has an excellent effect that it can be moved to a place.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a thermal element according to the present invention.

FIG. 2 is another configuration diagram of the thermal element according to the present invention.

FIG. 3 is a diagram showing a usage pattern of the thermal element of the present invention.

FIG. 4 is a diagram showing a usage example of the thermal element of the present invention.

FIG. 5 is a schematic structural diagram of a heat pipe.

FIG. 6 Variable Conductance Heat Pipe (VCHP)
It is a schematic block diagram of.

FIG. 7 is an operation explanatory diagram of VCHP.

[Explanation of symbols]

 1 Heat Pipe 2 Heat Medium (Working Fluid) 3 Evaporating Part 4 Condensing Part 5 Capillary Structure 6 Heat Insulating Part 7 Gas Reservoir 8 Noncondensing Gas 9 Interface 10 Thermal Element 11 Heating Part 12 Cooling Part 13 Heat Pipe Hollow Tube 13a Capillary Structure 14 gas chamber (gas reservoir) 16 heating cooler (electric heater) 18 electric switch 19 power supply

Claims (4)

[Claims] 1. A hollow pipe for a heat pipe, which has a heating portion and a cooling portion, and has a capillary structure formed on an inner wall thereof, and a heat medium that boils in the heating portion and condenses in the cooling portion is enclosed therein, and the hollow pipe. A gas chamber that is provided in communication with the cooling unit side of the pipe and is filled with a non-condensable gas that does not condense within the operating temperature range, a heating and cooling device that heats and cools the non-condensing gas in the gas chamber, and to the heating and cooling device. And an electric switch for turning on / off the energization of the heat medium and the non-condensable gas, the interface between the heat medium and the non-condensable gas is located at an intermediate position between the gas chamber and the cooling section when the non-condensable gas releases heat, A thermal element characterized by being set so as to be located closer to the heating section than the cooling section. 2. The thermal element according to claim 1, wherein the heating / cooling device is an electric heater and / or a Peltier element. 3. The hollow tube has a heating part and a plurality of cooling parts communicating with the heating part and branched, and the gas chamber, the heating / cooling device, and the electric switch respectively cool the hollow pipe. The thermal element according to claim 1, wherein a plurality of thermal elements are provided so as to communicate with each other. 4. The heating medium is selected from water, dowsome, ammonia, freon, ethanol, methanol, mercury, or sodium, and the noncondensable gas is argon,
Thermal element according to claims 1 to 3, characterized in that it is selected from nitrogen, air or helium.