JP4500971B2 - Top heat type heat pipe - Google Patents

Description

  The present invention relates to a heat pipe. The present invention particularly relates to a so-called top heat type heat pipe that transports warm heat downward and cold heat upward, and a cooling system using the heat pipe.

  The heat pipe has a feature of moving heat to a distant place at a high speed, and is used, for example, for removing heat locally generated by a notebook personal computer or the like, or for preventing freezing of a road, melting snow, and the like. Among the heat pipes, a so-called top heat type heat pipe is known that transports warm heat downward and cold heat upward.

For example, in Patent Document 1 and Patent Document 2, a liquid storage tank 2a is installed at a higher position than the evaporator 1a as shown in FIG. 2, and a gas phase region of the evaporator 1a and a lower position than the evaporator 1a. The condenser 3a installed in the tank is communicated with a vapor pipe 4a, the condenser 3a and the liquid storage tank 2a are communicated with each other through a liquid pipe 5a, and the evaporator 1a and the liquid storage tank 2a are connected by gas. When the liquid level of the evaporator 1a falls below a predetermined level, or when the liquid level of the liquid storage tank 2a exceeds a predetermined level, the pipe 6a and the liquid supply pipe 7a communicate with each other. An on-off valve 8a that opens when the top of the liquid supply pipe 7a is installed, and a flow control valve 9a that controls the liquid to flow only from the liquid storage tank 2a to the evaporator 1a is installed in the liquid supply pipe 7a. Type heat pipe has been proposed .
JP-A-7-91870 JP-A-7-218164

  However, the conventionally proposed top heat type heat pipe is an excellent heat pipe in that it can be cooled or heated without using power, but many problems remain in actual operation. ing. For example, there is a problem that the influence of the heat transport distance (= the difference in height between the evaporator and the condenser) on the heat transfer characteristics (= temperature difference between the evaporator and the condenser) of the heat pipe is large. A heat pipe that transports heat with the temperature difference between the evaporator and the condenser as small as possible is desired. However, in the case of a conventional top heat type heat pipe, this temperature difference increases as the height of the heat pipe increases. Therefore, there was a problem that the height of the heat pipe could not be increased.

  Further, in Patent Document 1 and Patent Document 2, an auxiliary tank is provided in order to operate the heat pipe stably, but there is a problem that the structure is complicated and maintenance is troublesome.

  The present invention aims to solve the drawbacks of the conventional top heat type heat pipe, and a top heat type heat pipe capable of increasing the height of the heat pipe, and a cooling system using the top heat type heat pipe. It is to provide. Another object of the present invention is to provide a top heat type heat pipe that can operate stably, and a cooling system using the top heat type heat pipe.

That is, the present invention relates to a heat exchange tank installed at a high place, a heat exchange zone installed at a lower position than the heat exchange tank, and a hot liquid that communicates the liquid phase region of the heat exchange tank with the heat exchange zone. A pipe, installed above the highest liquid level of the heat exchange tank, the gas phase region of the heat exchange tank and the gas phase region communicate with each other through a gas connection pipe, and the gas phase or liquid phase region of the heat exchange tank A liquid storage tank in which the liquid phase region is connected by a liquid supply pipe, a cold / hot liquid pipe that connects the heat exchange zone and the liquid storage tank, and a gas connection pipe, and the liquid level of the heat exchange tank is An open / close valve that opens when the liquid level of the liquid storage tank is lower than a predetermined level or when the liquid level of the liquid storage tank is higher than a predetermined level, and is installed in the liquid supply pipe so that the liquid flows from the liquid storage tank to the heat exchange tank. Flow path control that controls to flow only in A valve, which is the top heat heat pipe, characterized in that the thermal fluid tube, the heat exchange zone, is cold liquid pipe is always filled with hydraulic fluid.

From another aspect, the present invention is a heat exchange tank that is installed at a high place and absorbs the heat of the object to be cooled, and a heat exchange that releases heat to the outside of the system installed at a lower place than the heat exchange tank. A zone, a hot liquid pipe that communicates the liquid phase region of the heat exchange tank and the heat exchange zone, and is installed higher than the highest liquid level of the heat exchange tank, and the gas phase region and the gas phase of the heat exchange tank A storage tank in which the region is connected by a gas connection pipe and the gas phase or liquid phase area of the heat exchange tank and the liquid phase area are connected by a liquid supply pipe, and the heat exchange zone and the storage tank are in communication. A cold / hot liquid pipe that is installed in the gas connection pipe, and opens and closes when the liquid level of the heat exchange tank falls below a predetermined level or when the liquid level of the liquid storage tank rises above a predetermined level, And installed in the liquid supply pipe, the liquid is stored in the liquid storage tank. Use with a flow path control valve for controlling the flow only to the heat exchange tank direction, thermal fluid tube, the heat exchange zone, the top heat-type heat pipe, characterized in that the cold liquid pipe is always filled with hydraulic fluid It was a cooling system.

  In the top heat type heat pipe and the cooling system according to the present invention, the hot liquid pipe, the heat exchange zone, and the cold hot liquid pipe, which are lower than the heat exchange tank, are always filled with the working liquid. Operates regardless. That is, the top heat type heat pipe according to the present invention solves the disadvantages of the conventionally proposed top heat type heat pipe. Further, in the top heat type heat pipe according to the present invention, since the working fluid circulates without introducing external power as described later, it is possible to transport the heat at a lower cost. Furthermore, the top heat type heat pipe according to the present invention has a simple structure and can be easily maintained.

  Embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a first embodiment of the present invention. In FIG. 1, 11 is a heat exchange tank, 12 is a hot and cold liquid pipe, 13 is a heat exchange zone, 14 is a cold / hot liquid pipe, 15 is a liquid storage tank, 16 is a gas connection pipe, 17 is a liquid supply pipe, and 18 is an on-off valve. , 19 is a flow path control valve, 20 is a discharge port, and 21 is a working fluid.

  As the material of the heat pipe of the present invention, a material that has mechanical strength and is not corroded by the hydraulic fluid, such as stainless steel, may be selected.

  The heat exchange tank 11 has a tank structure in which hydraulic fluid can be stored. On the other hand, a fin or the like may be provided outside so that the hydraulic fluid can easily absorb heat. The heat exchange tank 11 receives heat from the object to be cooled and a part of the working fluid evaporates, and the pressure causes the working fluid in the tank to be heated from the discharge port 20 provided in the liquid phase region, preferably the tank bottom. It flows down to the heat exchange zone 13 through the liquid pipe 12. Next, when the amount of the hydraulic fluid in the heat exchange tank 11 becomes a certain amount or less, the hydraulic fluid is received from the liquid storage tank 15. The heat exchange tank 11 is located at the top of the entire heat pipe.

  As the hydraulic fluid 21 used in the heat pipe of the present invention, various low-viscosity liquid media such as water, aqueous ammonia, methanol, ethanol, and mixtures thereof can be used. Depending on the purpose of use of the heat pipe, the relationship between the temperature of the liquid and the pressure of the steam should be taken into consideration.

  The amount of hydraulic fluid depends on the size of the heat exchange tank 11, the hot and cold liquid tube 12, the heat exchange zone 13, and the cold and hot liquid tube 14, but from the heat exchange tank 11 in order for the heat pipe to operate smoothly. In the lower part, the hot liquid pipe 12, the heat exchange zone 13, and the cold liquid pipe 14 must always be filled with the working fluid.

  The object to be cooled that can be cooled by the heat pipe of the present invention is not particularly limited, but is installed at a high place such as a hot water cooling device or a solar battery panel installed in a building, and moves heat in the height direction. It can be preferably used for a subject in need.

  A hot liquid pipe 12 is provided between the liquid phase region of the heat exchange tank 11, preferably the bottom of the heat exchange tank 11, and the heat exchange zone 13 installed at a lower position than the heat exchange tank 11. . The hydraulic fluid heated in the heat exchange tank 11 flows down to the heat exchange zone 13 through the hot-heat liquid pipe 12.

  The heat exchange zone 13 is a zone (place) where the hydraulic fluid is cooled by exchanging heat with a cooling medium outside the system. The heat exchange zone 13 may have, for example, a structure in which several pipes are bundled so that the hydraulic fluid is easily cooled. The internal volume of the heat exchange zone 13 should be sufficiently large. Specifically, it is preferable to make the internal volume of the heat exchange zone 13 larger than the total amount of the internal volume of the heat exchange tank 11 and the internal volume of the hot liquid pipe 12. As will be described later, the heat pipe of the present invention repeats periodic operation. However, if the hydraulic fluid does not stay in the heat exchange zone 13 for more than one cycle, heat exchange between the hydraulic fluid and the cooling medium is sufficiently performed. Otherwise, the temperature of the system may gradually increase. In order to increase the internal volume in the heat exchange zone 13 as described above, for example, a heat exchanger in which a pipe is bent into a coil shape as shown in FIG. 3 may be used.

  As a cooling medium for cooling the working fluid in the heat exchange zone 13, a natural cooling source such as seawater, river water, groundwater or the like is used, or a working fluid is preferably obtained by flowing a coolant, for example, cooling water, preferably in a countercurrent. Cool down. The cooling water used for cooling in the heat exchange zone 13 may be used as hot water for bathing, washing, dish washing, snow melting or the like.

  The heat exchange zone 13 communicates with the liquid storage tank 15 through a cold / hot liquid pipe 14. The hydraulic fluid cooled in the heat exchange zone 13 rises in the cold hot liquid pipe 14 due to the pressure in the heat exchange tank 11, reaches the liquid storage tank 15, and is stored therein.

In order to prevent the working fluid in the liquid storage tank 15 from flowing back toward the heat exchange zone 13, a check valve is installed in the middle of the cold heat liquid pipe 14 that communicates the heat exchange zone 13 and the liquid storage tank 15. Also good.

  The liquid storage tank 15 stores the cooled hydraulic fluid, and when the amount of hydraulic fluid in the heat exchange tank 11 falls below a predetermined level, or the amount of hydraulic fluid in the liquid storage tank 15 is predetermined. When the level exceeds the level, the hydraulic fluid is supplied to the heat exchange tank 11 by the head difference. Therefore, the liquid storage tank 15 is installed at a higher position than the heat exchange tank 11. The internal volume of the liquid storage tank 15 is preferably equal to or greater than the internal volume of the heat exchange tank 11.

  The liquid storage tank 15 also has the same internal volume so that the vapor of the hydraulic fluid is easily absorbed into the hydraulic fluid after the on-off valve 18 installed in the middle of the gas connection pipe 16 described later is opened. It is preferable that the length and width are long, the depth is shallow, and the surface area of the gas-liquid interface is increased.

  The liquid storage tank 15 and the heat exchange tank 11 are connected by two pipes, a gas connection pipe 16 and a liquid supply pipe 17. The gas connection pipe 16 connects the gas phase region of the liquid storage tank 15 and the gas phase region of the heat exchange tank 11. On the other hand, the liquid supply pipe 17 is configured to connect the liquid phase region of the liquid storage tank 15 and the gas phase or liquid phase region of the heat exchange tank 11.

  The gas connection pipe 16 is provided with an on-off valve 18 that connects or shuts off the gas phase portions of the liquid storage tank 15 and the heat exchange tank 11 by the action of the valve. As the on-off valve, for example, an electromagnetic valve is preferable.

  The liquid supply pipe 17 is provided with a flow path control valve 19 formed so that the flow path resistance varies depending on the direction in which the liquid flows. The liquid flows only from the liquid storage tank 15 toward the heat exchange tank 11, It does not flow in the opposite direction. For example, a check valve is known as a valve that performs the above-described operation.

  In the top heat type heat pipe and the cooling system according to the present invention, the on-off valve 18 is configured so that the liquid level of the heat exchange tank 11 becomes a predetermined level or lower, or the liquid level of the liquid storage tank 15 exceeds a predetermined level. The most common means for such control is a float or the like that detects a change in the liquid level of the heat exchange tank 11 or the storage tank 15. A level sensor is installed, and the on-off valve 18 is configured to open and close according to the detection value of the level sensor.

  The top heat type heat pipe of the present invention can be manufactured by installing it in a place requiring cooling and enclosing an appropriate amount of working fluid in the heat pipe. At this time, the working fluid may be sealed after the inside of the heat pipe is vacuum degassed, or the working fluid may be sealed with the liquid storage tank 15 opened to the atmosphere.

  The operation principle of the heat pipe of the present invention will be described. Warm heat is supplied from the object to be cooled to the heat exchange tank 11, and the working liquid evaporates in the heat exchange tank 11 by the heat. When the pressure in the heat exchange tank 11 rises due to the generation of steam, the working fluid flows from the outlet 20 of the heat exchange tank 11 to the liquid storage tank 15 via the hot-heat liquid pipe 12, the heat exchange zone 13, and the cold-heat liquid pipe 14. Inflow. Meanwhile, heat is exchanged with the cooling medium in the heat exchange zone 13 and the heat of the working fluid is released to the outside of the system, so that the warm heat is transported downward and the cool heat is transported upward.

  The flow of the working fluid from the heat exchange tank 11 to the hot-heat liquid pipe 12 proceeds, and the level of the working fluid in the heat exchange tank 11 falls below a predetermined level, or the level of the liquid storage tank 15 reaches a predetermined level. When the above is reached, the on-off valve 18 of the gas connection pipe 16 opens, the steam in the heat exchange tank 11 moves to the liquid storage tank 15, and the pressure in the heat exchange tank 11 and the liquid storage tank 15 becomes the same. The hydraulic fluid in the liquid tank 15 flows to the heat exchange tank 11 through the liquid supply pipe 17 due to the head difference. When the liquid level in the heat exchange tank 11 becomes a predetermined level or higher, or the liquid level in the liquid storage tank 15 becomes a predetermined level or lower, the on-off valve 18 is closed.

  When the on-off valve 18 is closed, the pressure in the heat exchange tank 11 is higher than the pressure in the liquid storage tank 15, so that the flow control valve 19 installed in the liquid supply pipe 17 works. The hydraulic fluid does not flow down from the storage tank 15 to the heat exchange tank 11. The on-off valve 18 is opened, and the hydraulic fluid flows from the storage tank 15 to the heat exchange tank 11 only after the pressure in the heat exchange tank 11 and the pressure in the liquid storage tank 15 become equal.

Further, the hydraulic fluid is pushed up from the heat exchange tank 11 through the heat exchange zone 13 to the liquid storage tank 15 due to the difference between the pressure in the heat exchange tank 11 and the pressure in the liquid storage tank 15. The mold heat pipe operates smoothly and continuously without external power for circulating the working fluid.

  When the heat exchange tank 11 is installed in the space or object to be cooled and the heat exchange zone 13 is installed in the cold source, the cold heat is transported from the cold source, so that the space or object to be cooled can be cooled. Thus, a cooling system can be comprised by using the heat pipe of this invention.

  EXAMPLES Next, although an Example is given and this invention is demonstrated in more detail, this invention is not restrict | limited at all to these Examples, unless the summary is exceeded.

Example 1
Experiments were performed using the experimental apparatus shown in FIG. In this embodiment, the internal volume of the heat exchange tank 11 is 12000 cm ³ , the internal volume of the liquid storage tank 15 is 12000 cm ³ (length: 30 cm, width: 40 cm, depth: 10 cm), and the hot liquid tube 12 is The acrylic pipe having an inner diameter of 1.4 cm and a length of 380 cm and the cold / hot liquid pipe 14 are made of an acrylic pipe having an inner diameter of 1.4 cm and a length of 430 cm, and the internal volume of the heat exchange zone 13 is set to 3600 cm ³ .

10500 cm ³ of hydraulic fluid (ammonia water) is sealed in the system of the top heat type heat pipe of this embodiment, and the operation in the heat exchange tank 11 is performed by the heater 31 having a heating value of 400 W inserted in the inner bottom portion of the heat exchange tank 11. The liquid was heated.

  On the other hand, as shown in FIG. 4, the heat exchange zone 13 was produced by winding a tube, and this was put in water kept at 20 ° C. in a thermostatic bath 32 and used for the experiment.

  The experimental results are shown in FIG. In the figure, T1 is the temperature in the liquid phase region of the liquid storage tank 15, T2 is the temperature in the liquid phase region of the heat exchange tank 11, T3 is the temperature at the outlet of the heat exchange zone 13, and T4 is the water temperature in the thermostat 32.

  As is clear from FIG. 5, the temperature T2 of the working fluid in the heat exchange tank 11 rises to 37 ° C. due to heating by the heater 31, but when the working fluid at 21 ° C. flows from the liquid storage tank 15, Immediately cool to 28 ° C. It can be seen that the repetition is performed at intervals of about 450 seconds. The temperature T3 at the outlet of the heat exchange zone 13 indicates a temperature around 21 ° C., and it can be seen that the system is cooled without any problem.

  The heat pipe of the present invention can be used for effective utilization of solar heat by a solar water heater, cooling system for buildings, or cooling of a heat source at a high place such as a solar battery panel. In particular, the use of the heat pipe of the present invention for cooling the solar cell panel can be expected to greatly improve the power generation efficiency of the solar cell panel.

FIG. 1 is a schematic view showing an example of a top heat type heat pipe of the present invention. FIG. 2 is a schematic view showing an example of a conventional top heat type heat pipe. FIG. 3 is a schematic view showing an example of a heat exchange zone in the top heat type heat pipe of the present invention. FIG. 4 is a schematic diagram of an experimental apparatus used in Example 1 of the top heat type heat pipe of the present invention. FIG. 5 is a diagram showing experimental results obtained in Example 1 of the top heat type heat pipe of the present invention.

Explanation of symbols

11: Heat exchange tank 12: Hot liquid pipe 13: Heat exchange zone 14: Cold hot liquid pipe 15, 2a: Liquid storage tank 16, 6a: Gas connection pipe 17, 7a: Liquid supply pipe 18, 8a: Open / close valves 19, 9a : Flow control valve 20: Discharge port 21: Hydraulic fluid 31: Heater 32: Thermostatic chamber 1 a: Evaporator 3 a: Condenser 4 a: Steam pipe 5 a: Liquid pipe T 1: Temperature of liquid storage tank liquid phase region T 2: Heat exchange Tank liquid phase temperature T3: Heat exchange zone outlet temperature T4: Water temperature in the thermostat

Claims (2)

A heat exchange tank installed in a high place, a heat exchange zone installed in a lower place than the heat exchange tank, a hot liquid pipe communicating the liquid phase region of the heat exchange tank and the heat exchange zone, the heat exchange It is installed higher than the highest liquid level of the tank, the gas phase region and the gas phase region of the heat exchange tank are communicated by a gas connection pipe, and the gas phase or liquid phase region and the liquid phase region of the heat exchange tank Is installed in a liquid storage tank connected by a liquid supply pipe, a cold / hot liquid pipe communicating the heat exchange zone and the liquid storage tank, and the gas connection pipe, and the liquid level of the heat exchange tank is below a predetermined level. An on-off valve that opens when the liquid level of the liquid storage tank reaches a predetermined level or more, and is installed in the liquid supply pipe so that the liquid flows only from the liquid storage tank to the heat exchange tank. comprising a flow path control valve for controlling, thermal fluid , Top heat heat pipe, wherein the heat exchange zone, is cold liquid pipe is always filled with hydraulic fluid. A heat exchange tank that is installed at a high place and absorbs the heat of the object to be cooled, a heat exchange zone that releases heat outside the system installed at a lower place than the heat exchange tank, and a liquid phase region of the heat exchange tank; A hot liquid pipe communicating with the heat exchange zone, installed at a location higher than the highest liquid level of the heat exchange tank, and a gas phase region and a gas phase region of the heat exchange tank are communicated by a gas connection pipe; and Installed in a liquid storage tank in which the gas phase or liquid phase region of the heat exchange tank and the liquid phase region are connected by a liquid supply pipe, a cold heat liquid pipe that connects the heat exchange zone and the liquid storage tank, and the gas connection pipe An open / close valve that opens when the liquid level of the heat exchange tank falls below a predetermined level or when the liquid level of the liquid storage tank rises above a predetermined level, and is installed in the liquid supply pipe. Flows only from the storage tank toward the heat exchange tank Comprising a flow path control valve for controlling such a cooling system using top heat heat pipe, characterized in that the thermal fluid tube, the heat exchange zone, is cold liquid pipe is always filled with hydraulic fluid.

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