JPH08284106A - Heat pipe type snow-melting apparatus - Google Patents

Abstract

PURPOSE: To reduce equipment cost, and to melt snow surely and efficiently. CONSTITUTION: The evaporating section 4 of a heat pipe 1, in which a working fluid 7 is sealed into a container 2 consisting of a sealed metallic pipe under an evacuated state, is extended and disposed on the geothermal fluid 3 side at a high temperature. The condensing section 5 of the heat pipe 1 is buried in approximately parallel with a ground surface 6 just under the ground surface 6. A valve 8 selectively interrupting the fluidization of the working fluid 7 in the container 2 is fitted to the intermediate section of the evaporating section 4 and condensing section 5 of the heat pipe 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a snow melting device which employs a heat pipe as a heat transporting means and utilizes underground heat as a heat source.

[0002]

2. Description of the Related Art Snow removal on roads and sidewalks is particularly important for securing transportation in winter, but these road surfaces are directly exposed to the natural environment, and the target area is Due to its large size, it takes a lot of labor and time to remove snow manually. If artificial heat energy is used to remove the snow, running costs will increase. Therefore, various attempts have heretofore been made to utilize natural energy as effectively as possible in melting snow to remove snow, and one example thereof is Japanese Patent Laid-Open No. 63-40002.
It is shown in the publication.

To briefly explain the device described in this publication, an upper end portion of a heat pipe having a straight pipe shape is arranged immediately below the ground surface where snow is melted. Then, the lower end side of the heat pipe is extended to a deep place in the ground. In addition, a damper (leakage type butterfly valve) that controls the vapor flow of the working fluid is provided inside the container that constitutes this heat pipe, and the liquid phase working fluid is moved from the bottom side to the top side by the capillary action. A wick for pumping to the inside of the container is provided on the inside wall. Then, by the snowfall sensor, the ground surface temperature sensor, and the underground temperature sensor installed near the heat pipe, the damper is detected when the underground temperature is higher than the surface temperature and there is no snowfall. It is configured so that the heat pipe is closed and does not operate.

Therefore, in the above-mentioned snow melting apparatus, when the sensors detect that there is snowfall and the underground temperature is higher than the surface temperature, the damper is opened in the heat pipe, so that the container is opened. The working fluid heated and evaporated by the geothermal heat on the lower end side (ground side) of the container can reach the upper end side (ground surface side) without being blocked in the middle of the container. That is, the heat existing in the ground is transported to the ground surface side by the working fluid of the heat pipe. Then, by continuing the heat transport to some extent, the snow on the ground surface is melted.

On the other hand, the damper inside the heat pipe is kept open even when it is detected that the ground surface temperature is higher than the ground temperature, although there is no snowfall, such as in summer. Then, in this case, the working fluid accumulated in the lower end of the container is pumped up to the upper end by the wick and heated by the geothermal heat near the ground surface. Then, the working fluid that has become vapor flows to the lower end side of the container, and releases heat toward the low temperature underground. Thereby, the heat source energy required for snow melting in winter can be stored underground.

[0006]

As described above, in the above-mentioned snow melting device, the vapor flow of the working fluid is shut off by the damper (leakage type butterfly valve), and the liquid phase working fluid is wicked by the upper end side of the container. Since the wick is attached to the entire inner surface of the container in a continuous state, even if the damper is closed, a slight gap due to the wick is generated between the inner wall surface of the container and the edge of the damper. Will be formed. Therefore,
For example, when the surface temperature is lower than the underground temperature, a small amount of liquid-phase working fluid is pumped up, or when the underground temperature is higher, steam flows to the upper end side. The movement of the pipes could not be completely controlled, which could lead to unintended heat transfer.

Further, in the above-mentioned snow melting device, since the heat pipe is buried almost vertically, the heat radiation area of the heat pipe in the spreading direction on the ground surface is small, that is, the snow can be melted by one heat pipe. The area of the ground surface is extremely small. Therefore, in order to uniformly and efficiently melt the snow in a certain range of the ground surface by the above-mentioned snow melting device, a large number of heat pipes are required, and there is a problem that equipment cost increases.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a snow melting apparatus which can surely and efficiently perform snow melting and has a low equipment cost.

[0009]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention is directed to a case where an evaporation portion of a heat pipe in which a working fluid is sealed in a container made of a closed metal tube in a vacuum deaerated state is The heat pipe condensing section is arranged to extend in the middle high temperature region, and the condensing section of the heat pipe is laid directly under the ground surface and in a direction substantially parallel to the ground surface, and further, with the evaporating section of the heat pipe. In the middle part with the condensation part,
A valve for selectively blocking the flow of the working fluid inside the container is provided.

[0010]

Since the heat pipe in the snow melting apparatus of the present invention is arranged such that the lower end portion thereof is extended to the high temperature area in the ground, it is located between the condensation section on the ground surface side and the evaporation section in the deep ground during snowfall. Temperature difference occurs. Therefore, when the valve is opened in this state, the working fluid is supplied to the evaporation portion, and the working fluid is heated by the heat of the ground and evaporated.

The working fluid vapor ascends toward the condensing portion where both the internal pressure and the temperature are low, and at the same time, the soil near the ground surface deprives the heat and condenses. That is, heat is released to the ground surface and the soil in the vicinity thereof. Then, this heat melts snow on the ground surface. In this case, since the container on the condenser side is laid substantially parallel to the ground surface, the pumped geothermal heat is dissipated over a wide area on the ground surface. Therefore, the snow melting area per heat pipe becomes large, so that the required number of heat pipes is reduced and the equipment cost can be reduced.

Further, the liquefied working fluid flows down due to gravity toward the wall surface of the container toward the evaporation section side, and is heated again there. Such a working fluid cycle is continued as long as there is a temperature difference between the evaporation section and the condensation section with the valve opened.

Further, in the snow melting device of the present invention, since the wick is not attached to the inner wall surface of the heat pipe container, the airtightness of the valve is extremely high, and therefore the unintended operation of the heat pipe due to the leakage of the working fluid is caused. There is no danger of it being done.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An example in which the present invention is applied to a snow melting device for a road will be described below with reference to the drawings. As shown in FIG. 1, in a heat pipe 1 buried in the ground, a container 2 is generally L-shaped as a whole, and its lower end side is arranged in a substantially vertical state up to the depth of a high temperature region. Has been done. In addition, the high temperature region where the lower end of the container 2 is located is a place where a predetermined temperature is maintained throughout the year, such as a groundwater zone, and where the high temperature geothermal fluid 3 serving as a heat source exists. .
Therefore, the evaporating portion 4 of the heat pipe extends from the lower end of the container 2 to a predetermined length.

On the other hand, the upper end portion side of the heat pipe 1 which becomes the condensing portion 5 is buried just below the road surface 6 formed of asphalt or the like and substantially parallel to it. More specifically, the tip of the container 2 is located slightly higher than the bent portion, and is arranged close to the road surface 6. That is, heat is transferred to and from the road surface 6 side at the tip end side of the bent portion, the area is widened, and the condensed working fluid 7 is quickly returned to the evaporation section 4 side (lower end side). be able to.

The heat pipe 1 is vapor-condensed within a target temperature range in a vacuum degassed state inside a closed metal tube made of copper, aluminum or the like having excellent thermal conductivity like a general one. Water, ammonia, freon or the like is used as a working fluid.

The evaporation section 4 and the condensation section 5 of the heat pipe 1
An electromagnetic valve 8 for controlling the flow of the working fluid 7 is provided between the and. As the electromagnetic valve 8, various configurations can be adopted. For example, the valve body 8b is biased by an elastic body 8c such as a spring toward the valve seat 8a provided on the inner peripheral portion of the container 2, Further, a coil 8d for generating an electromagnetic force for urging the valve body 8b away from the valve seat 8a is arranged on the outer peripheral side of the container 2, and the coil 8d is energized and excited to open the valve, It is configured to be closed by demagnetizing. Depending on the arrangement of the springs, the valve may be excited to close the valve and demagnetized to open the valve. A control device 9 for controlling the opening / closing of the solenoid valve 8 is provided.

On the other hand, above the road surface 6 on the ground, as an example, a snowfall sensor 10 for detecting the presence or absence of snowfall is provided by a photoelectric tube. A road surface temperature sensor 11 for detecting the road surface temperature is provided in the ground immediately below the road surface 6 and near the upper end of the heat pipe 1. further,
An underground temperature sensor 12 is embedded near the lower end of the heat pipe 1, that is, at a position deeper in the ground than the road surface temperature sensor 11. These snowfall sensor 10, road surface temperature sensor 11 and underground temperature sensor 12 are
The control device 9 is connected to each of the signal lines 13, 14 and 15 respectively.
It is connected to the. Further, the solenoid valve 8 is connected to the control device 9. And each sensor 10, 11,
Whether the solenoid valve 8 is opened or closed is determined based on the temperature information obtained by 12, and the solenoid valve 8 is controlled to be opened only when snowfall is detected and the road surface temperature is higher than the underground temperature. ing.

Next, the operation of the embodiment configured as described above will be described. When the snowfall sensor 10 detects snow and the ground surface temperature sensor 12 and the road surface temperature sensor 11 detect that the road surface temperature is lower than the ground surface temperature, the solenoid valve 8 is output by the output signal from the control device 9.
Is opened.

In this case, since the temperature in the ground is higher than the temperature on the ground surface side, there is a difference in temperature between both ends of the heat pipe 1, and the solenoid valve 8 opens to open the evaporator 4 and the condenser. The working fluid 7 can flow between the two. Therefore, on the lower end side of the container 2, the working fluid 7 in the liquid phase is heated by the heat of the geothermal fluid 3 and evaporated, and the vapor is transferred to the condensation section 5 side which is in a low temperature state due to snow or cold air on the surface side. Flow.

The vapor of the working fluid 7 which has flowed into the condensing section 5 radiates heat here and condenses due to the low ambient temperature. In this way, the heat of the geothermal fluid 3 is transported to the road surface 6 by the working fluid 7 of the heat pipe 1, so that the snow on the road surface 6 is melted by the heat and removed. In that case, since the condensing part 5 which is the part of the upper end side of the container 2 having a predetermined length is laid substantially parallel to the road surface 6, the entire surface of the long condensing part 5 over the entire length forms a heat radiating surface. Therefore, a wide range of the road surface 6 can be heated by one heat pipe 1.

On the other hand, the working fluid 7 liquefied in the condensing part 5 of the heat pipe 1 flows down by the gravity toward the lower end of the wall surface of the container 2. Then, in the evaporator 4, the heat is again received from the geothermal fluid 3 to evaporate, and the vapor rises toward the condenser 5. Such a heat transport cycle by the working fluid 7 is continued until the solenoid valve 8 is closed, specifically, until snowfall is no longer detected or the height relationship between the geothermal temperature and the road surface temperature is reversed.

Since the solenoid valve 8 can be opened and closed as desired, the solenoid valve 8 may be controlled as follows except when the snowfall occurs and the ground temperature is higher than the road surface temperature. For example, when it is detected that the temperature of the road surface 6 is higher than the underground temperature in spite of the detection of snowfall, or no snowfall is detected and the road surface temperature is higher than the underground temperature. When such is detected, the solenoid valve 8 is maintained in the closed state.

Since the heat transfer area between the condensing portion 5 and the road surface 6 in each heat pipe 1 is large as described above, the number of heat pipes 1 to be provided as a whole can be reduced as compared with the conventional one, thereby reducing the equipment cost. The cost can be reduced. Further, the electromagnetic valve 8 is configured to shut off between the evaporator 4 and the condenser 5, and since the wick made of wire mesh or the like is not attached to the inner wall surface of the container 2, the flow of the working fluid 7 is ensured. Can be shut off.
That is, it is possible to prevent unintended operation of the heat pipe.

Next, a second embodiment of the present invention will be described with reference to FIG. The same members as those in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted. As shown in FIG. 2, the heat pipe 1 in this embodiment is a so-called loop heat pipe. That is, both ends of the evaporation pipe 17 are connected by the liquid return pipe 18 to form a circulation path as a whole,
Similar to the container 2 in the above-described embodiment, the evaporating pipe 17 is buried immediately below the intermediate curved portion, just below the road surface 6 so as to be substantially parallel to the road surface 6, and the portion below the curved portion is geothermal. It is extended to a high temperature region where the fluid 3 exists. The lower end portion of the evaporation pipe 17 is the evaporation portion 4
In addition, the portion immediately below the road surface 6 is the condensing portion 5.

On the other hand, the liquid return pipe 18 is, for example, a pipe bent in substantially the same manner as the evaporation pipe 17, and is connected to both ends of the evaporation pipe 17, respectively. An electromagnetic valve 8 similar to the electromagnetic valve 8 shown in the above-described embodiment is provided in the middle of the liquid return pipe 17. As described above, a condensable fluid such as water, alcohol, or Freon is sealed as the working fluid 7 in the vacuum degassed state inside the closed circulation path constituted by the evaporation pipe 17 and the liquid return pipe 18 and the heat pipe. Is configured.

According to the snow melting apparatus configured as shown in FIG. 2, snow melting is performed as follows. That is, the fact that the snowfall sensor 10 detects snow and the road surface temperature is lower than the ground temperature is that the ground temperature sensor 12 and the road surface temperature sensor 11 are
When it is detected by the control device 9 and the solenoid valve 8
Is opened. Then, the liquid-phase working fluid 7 flows down to the lower ends of the liquid return pipe 18 and the evaporation pipe 17, and is heated by the heat of the geothermal fluid 3.

The evaporated working fluid flows through the inside of the evaporation pipe 17 toward the upper condensation part 5 having a low temperature, and is condensed by being deprived of heat by the road surface 6 and the low-temperature soil immediately below it. That is, the heat of the geothermal fluid 3 is transported to the vicinity of the road surface 6 and released.
And, the snow on the road surface 6 is melted by this heat.

The liquefied working fluid 7 flows down inside the liquid return pipe 18 toward the evaporation section 4 due to gravity, is heated again into vapor, and rises toward the condensation section 5. This heat transport cycle of the working fluid 7 is continued until snowfall is no longer detected or the geothermal temperature becomes lower than the road surface temperature and the electromagnetic valve 8 is closed.

When the solenoid valve 8 is closed, the condensed working fluid 7 is gradually accumulated upstream of the solenoid valve 8. On the other hand, in the evaporating section 4, the working fluid 7 is constantly heated by the geothermal fluid 3 to evaporate, so the working fluid 7 remaining in the evaporating section 4 sequentially moves to the condensing section 5, and Since the working fluid is not newly supplied to the evaporator 4,
Eventually, the working fluid does not exist in the evaporation section 4, and the so-called dry-out state is set. As a result, the function of the heat pipe stops. In that case, even if the solenoid valve 8 is closed, the entire inside of the heat pipe 1 is in a communicating state, so that an extreme difference in internal pressure does not occur. In other words, both sides of the solenoid valve 8 are sandwiched. Therefore, the solenoid valve 8 will not be overpressured and leaked, and the evaporation pipe 17 and the liquid return pipe 18 will not be locally overpressured.

In each of the above embodiments, the solenoid valve 8 is used as a valve.
In addition to the above, the control device 9 controls the opening and closing, but the present invention is not limited to the above embodiment.

[0032]

As described above, according to the present invention,
The evaporating part of the heat pipe is extended to the high temperature area in the ground, and the condensing part is arranged to extend almost parallel to the ground surface directly below the ground surface. Since the valve is provided in the intermediate portion between the section and the condensation section, snow melting on the ground surface can be carried out reliably and efficiently. Further, since the heat radiation area per heat pipe is wide, the number of heat pipes required for the required snow melting area may be small, and as a result, the equipment cost can be reduced.

[Brief description of drawings]

FIG. 1 is a schematic view showing a first embodiment of the present invention.

FIG. 2 is a diagram showing a second embodiment employing a loop heat pipe.

[Explanation of symbols]

1 ... Heat pipe, 2 ... Container, 3 ... Geothermal fluid,
4 ... Evaporating part, 5 ... Condensing part, 6 ... Road surface, 7 ... Working fluid, 8 ... Solenoid valve.

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[Procedure amendment]

[Submission date] May 25, 1995

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0002

[Correction method] Change

[Correction content]

[0002]

BACKGROUND ART snow, such as roadways or sidewalks, on top is especially important in ensuring winter transportation, these road surface that is directly exposed to the natural environment, the area of interest Due to its large size, it takes a lot of labor and time to remove snow manually. If artificial heat energy is used to remove the snow, running costs will increase. Therefore, various attempts have heretofore been made to utilize natural energy as effectively as possible in melting snow to remove snow, and an example thereof is disclosed in Japanese Patent Laid-Open No. 63-40002.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Uemura 1-324-23 Nakashima-cho, Niigata City, Niigata (72) Inventor Norihiko Koizumi 1-2-8 Yamaguchi-cho, Suwon-cho, Kitakanbara-gun, Niigata (72) Inventor Michio Komatsuzaki 5295 Niban-cho, Niigata-shi, Niigata-shi, Nikko, Nikko, Kowauchi, a stock company (72) Inventor, Mikiyuki Ono, 1-5-1, Kiba, Koto-ku, Tokyo, Fujikura Co., Ltd. (72) Inventor, Masataka Mochizuki Fujikura Co., Ltd. 1-5-1 Kiba, Koto-ku, Tokyo (72) Inventor Koichi Masuko 1-5-1 Kiba, Koto-ku, Tokyo Fujikura Co., Ltd.

Claims (1)

[Claims] 1. An evaporating portion of a heat pipe, in which a working fluid is enclosed in a vacuum degassed state, inside a container made of a closed metal tube, is arranged so as to extend to a high temperature region in the ground, and the heat of the heat pipe is also provided. The condensing portion of the pipe is laid right below the ground surface and in a direction substantially parallel to the ground surface, and further, in the intermediate portion between the evaporating portion and the condensing portion of the heat pipe, the working fluid of the inside of the container is A heat pipe type snow melting device, which is provided with a valve for selectively blocking a flow.