JP2762117B2 - Deep-depth hot spring water temperature drop prevention facility - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a hot-water pumping facility for hot spring wells, which is effective for increasing the hot-water temperature of hot spring wells at large depths. is there.

(Prior art and problems of the present invention)

The internal structure of a conventional deep-water hot spring well is schematically as shown in FIG. This conventional hot spring well draws high-temperature water from a high-temperature water layer under a bedrock 1000 m underground to the ground via a hot water pipe 3 by a submersible pump. In this well, a hot water pipe 3 having a diameter of 50 mm is inserted into a large-diameter casing pipe 1 having a diameter of 150 mm reaching the ground from the high-temperature water layer C, and a submersible pump 2 is attached to a lower end thereof. The entire length of the hot water pipe 3 is slightly above the strainer position where the maximum slit is provided.

The hot water in the high-temperature water layer C rises in the casing pipe 1 to above the submersible pump 2 due to the underground pressure. Therefore, by lowering the submersible pump to a depth slightly above the above-mentioned strainer position, the high-temperature water of the high-temperature water layer C having a depth of 1000 m or more can be lifted to the ground.

In the case of hot water at a large depth, the temperature of the hot water layer is generally not so high, and because of being pulled up to the ground through a long pipeline, the pumping temperature is often around 30 degrees,
Since it can hardly be used as it is, it is heated by a boiler and used for bath water, hot water for heating, etc.

If the temperature of the pumping water does not reach 40 degrees Celsius, the cost for setting up the facility for reheating, maintaining the facility, and operating and managing it is large.If the temperature of the pumping water can be raised several degrees, these costs will decrease significantly. However, it is strongly desired to raise the temperature of the pumped water even slightly.

Even if the temperature of the hot water in the high-temperature water layer reaches 40 degrees, the temperature of the hot water drawn from the pumping pipe drops to around 30 degrees. This is because the hot water is cooled while ascending in the casing pipe 1 which is cooled by the layer above the bedrock, that is, the cold water layer having a depth of several hundred meters. The pumping pipe 3 has a diameter of 50 mm while the casing pipe has a large diameter of 150 mm.
Therefore, the heat exchange area between the cold water in the cold water layer outside the casing pipe 1 and the hot water inside the casing pipe is large, the speed at which the hot water rises inside the casing pipe is low, and the rising distance is as long as several hundred meters. This is the main cause of the decrease in the temperature of the warm water rising inside the casing pipe.

SUMMARY OF THE INVENTION It is an object of the present invention to reduce or reduce the temperature of hot water in the middle of hot water as little as possible by reducing a rising distance of hot water in a casing pipe to zero or less.

[Measures taken to solve the problem]

Means taken to solve the above problems are as follows, assuming a deep hot spring well with a hot water pipe inserted into a casing pipe and a submersible pump attached to the lower end of the hot water pipe. (B).

(A) The above-mentioned hot water pipe is extended near the bedrock layer or to the bedrock layer. (B) The pipe is covered with a non-water-absorbing heat insulating material.

(Operation)

The hot water that rises in the casing pipe immediately rises in the hot water pipe as soon as it passes through the bedrock portion. The flow velocity in the hot water pipe is about 9 times the flow velocity in the casing pipe, the residence time in the pipe is extremely short, and since the hot water pipe is covered with a non-water-absorbing heat insulating material, the heat insulating property of the hot water pipe is high. The heat radiation during the rise in the hot water pipe is extremely low. The amount of heat dissipated in the warm water before being lifted to the ground,
That is, it is possible to reduce the temperature of the hot water to 1/10 or less of that of the prior art. Specifically, for example, when hot water of a high-temperature water layer of 40 degrees
If so, it can be kept at 39 degrees by applying the present invention.

In addition, since the inside of the casing pipe is filled with water, even if the submersible pump is lowered, this hardly increases the pumping load of the pump, so it is possible to adopt a pump with the same pump capacity as the conventional pump. it can.

Since the lower end of the hot water pipe reaches the bedrock layer B, the total length of the hot water pipe reaches several hundred meters to 1000 meters.
It is impossible to support the own weight of such a long tube material by the top plate, and the hot water pipe itself may not be able to withstand its own weight. In the present invention, since the hot water pipe is a clad pipe covered with a non-water-absorbing heat insulating material, a large buoyancy acts on the hot water pipe, and this buoyancy offsets most of the weight of the hot water pipe. Therefore,
The problem of supporting the hot water pipe with the increase of its own weight due to the long overall length of the hot water pipe does not occur at all. Therefore, the lower end of the hot water pipe can be lowered to a required depth.

〔Example〕

 Next, an embodiment will be described with reference to FIG. 2 and FIG.

The structure of the well of this embodiment is exactly the same as the structure of the conventional well.

The hot water pipe is a hollow double pipe 3 ', and the hollow double pipe 3'
Has an inner cylinder 10 having a diameter of 50 mm and an outer cylinder 11 having a diameter of 80 mm. The end face of the double pipe is sealed by a joint flange 12. A double pipe of a fixed length is successively joined, and a joint portion is sealed between the joint flanges 12 and 12 via a packing 13. Further, in order to improve the heat insulating property of the hollow double tube, a heat insulating material 14 made of foamed resin is packed in the hollow chamber to cover the inner cylinder 10.

The gist of the present invention is, as is apparent from the above description, that the length of the hot water pipe is lengthened and the underwater pump at the lower end is lowered to or near the bedrock layer.
And it is to give buoyancy to the hot water pipe. Therefore, the problem can also be sufficiently solved by extending the hot water pipe in the prior art (FIG. 1) and forming the water pipe with a covering pipe whose outside is covered with a non-water-absorbing (for example, foamed plastic) heat insulating layer. . It is necessary that this coating layer be sufficiently thick to generate sufficient heat insulation and buoyancy. Reference numeral 4 denotes a slit.

(Effect)

According to the present invention, the deep-water hot spring temperature can be set at 10
This has the following advantages, since it can be increased by as much as:

First, the reheating temperature can be significantly reduced, and in most cases the heating facility can be significantly reduced in size. Therefore, installation and operation management costs can be significantly reduced. Depending on the water temperature of the high-temperature water layer, what has conventionally required heating may not require reheating at all.

In addition, the present invention can be applied to a newly-installed facility, but can be easily and easily applied to an existing facility by a simple construction simply by replacing a hot water pipe.

In addition, in order to reduce the drop in hot water temperature while raising the hot water pipe, the deep hot spring well is partially double-pipe, and the air is evacuated from the hollow chamber to raise the degree of vacuum. Are described in Japanese Utility Model Laid-Open No. 63-76093. This also can sufficiently suppress the decrease in the temperature of the hot water while the degree of vacuum in the hollow chamber is maintained, but when the seal of the hollow chamber is broken due to deterioration over time after installation, water enters the hollow chamber. The heat insulation is impaired. In the present invention, since the heat insulating means is made of a non-water-absorbing heat insulating material instead of a vacuum, the heat insulating property does not deteriorate over time, and therefore, the initial heat insulating effect is exhibited over a long period of time. Furthermore, in the above-mentioned known materials, since vacuum breaking of the hollow double tube is fatal for heat insulation, the welding process requires precision in order to improve the durability as much as possible, thus increasing the cost. In the present invention, since the heat insulating means is a non-water-absorbing heat insulating material, the processing cost for heat insulation is much lower than that of the above-mentioned known materials.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a conventional deep hot spring well, FIG. 2 is a cross-sectional view of an embodiment of the present invention, and FIG. 3 is an enlarged view of a portion M in FIG. In the drawing, 1 ... casing pipe, 2 ... submersible pump, 3 ... hot water pipe, 3 '... closed hollow double pipe, 10 ... inner cylinder, 11 ... outer cylinder, 12 ... joint flange, 13 ... packing, 14 ... heat insulating material, A ... cold water layer, B ... rock bed, C ... high temperature water layer.

Claims (1)

(57) [Claims] 1. A hot water pipe is inserted into a casing pipe,
For a deep-water hot spring well with a submersible pump attached to the lower end of the hot water pipe, the above hot water pipe is extended near the rock layer or to the rock layer, and the water pipe is covered with a non-water-absorbing heat insulating material. A pumping facility that prevents the temperature of the pumping water from dropping.