JPH0229438Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a heat exchanger, and particularly to a heat exchanger configured to avoid mixing of high temperature fluid and low temperature fluid.

For example, the temperature of insulating oil for power cables and transformers rises as the power cables and transformers generate heat. Oil was cooled with water, etc.

Conventionally, as the heat exchanger, a double pipe 2 as shown in FIGS. 1A and 1B is inserted into a container containing insulating oil 1, and an inner pipe 2a of the double pipe 2
A structure is known in which a cooling liquid such as water 3 is allowed to flow through the tube, and a leakage path is formed between the inner tube 2a and the outer tube 2b. According to this type of so-called double-tube heat exchanger, even if the insulating oil 1, water 3, or both leak, the leaked fluid will flow between the inner tube 2a and the outer tube 2b. Since the insulating oil 1 and the water 3 can be prevented from mixing together, the insulating oil 1 and the water 3 can be prevented from mixing, and the empty space between the inner pipe 2a and the outer pipe 2b can be communicated with an appropriate leak detector. By doing so, leakage of insulating oil 1, water 3, or both can be detected.

However, in the double pipe heat exchanger, since there is an air layer between the insulating oil 1 and the water 3,
The heat transfer coefficient between insulating oil 1 and water 3 is extremely low.
In other words, the heat exchange efficiency is poor, and as a result, double pipe 2
As a result of having to install a large number of heat exchangers, the overall size of the heat exchanger becomes large and the cost also increases. In addition, the double pipe 2
is fixed to the container by expanding the outer tube 2b, but since the inner tube 2a is inserted inside the outer tube 2b, it is difficult to expand the tube. The container is double tube 2
Coupled with the large number of pieces, it was difficult to manufacture.

Furthermore, in the conventional heat exchanger described above, the double tube 2 receives heat from the insulating oil 1 and thermally expands, but the double tube 2 cannot be made into a U-shaped tube. Both ends are water chambers containing water 3 (not shown)
Since the double tube 2 must be opened and fixed, the allowable amount of thermal expansion of the double tube 2 is extremely small, and the wall thickness of the inner tube 2a and outer tube 2b must be made thinner to reduce heat transfer resistance. The allowable thermal stress is low, so the conventional heat exchanger described above cannot be used when the temperature of the insulating oil 1 is high, as there is a risk that the double pipe 2 will be damaged by the thermal stress. .

This idea was made to solve the above problems, and it reliably prevents mixing of high-temperature fluid and low-temperature fluid, has good heat exchange efficiency, and can be used even when the temperature of high-temperature fluid is high. The purpose is to provide a heat exchanger.

Examples of this invention will be described below with reference to FIGS. 2 to 4.

FIG. 2 is a cross-sectional view showing one embodiment of this invention, and FIG. 3 is a cross-sectional view taken along the - line,
A high temperature chamber 10 through which a high temperature fluid such as insulating oil flows and a low temperature chamber 11 through which a cooling liquid such as water flows are both formed in a cylindrical shape with both ends sealed. One end plate of each end plate is arranged to face each other so as to be lined up in a line, and an appropriate spacer 12 is interposed between the peripheral edges of the end plate to connect and integrate the end plates. are partition walls 13 and 14 for partitioning the high temperature room 10 and the low temperature room 11, and the partition walls 13,
14 and the spacer 12 form an intermediate chamber 15. A plurality of heat pipes 16 as heat transfer bodies are attached to the partition walls 13 and 14 so that each end extends into the high temperature chamber 10 and the low temperature chamber 11, and a plurality of heat pipes 16 as heat transfer bodies are attached to the partition walls 13 and 14. A sealing member 17 is provided to maintain watertightness.

FIG. 4 is a detailed view showing an example of the sealing member 17, and the sealing member 17 has two main parts, namely, a first sleeve 18 and a second sleeve 19.
It consists of A first sleeve 18 is closely fixed to the outer peripheral surface of the heat pipe 16, and second sleeves 19 are fitted at one end to the outer periphery of the sleeve 18, and the sleeves 19 are connected to each of the partition walls 13, A packing 21 is interposed between the side surface of the flange 20 of the sleeve 18 on the high temperature room 10 side and the front end surface of the sleeve 19.
A packing 22 and a gland packing 23 for sealing the joint surfaces of the sleeves 18 and 19 are fixed to the side ends by packing holders 24. Furthermore, a cavity 25 is formed between the outer peripheral surface of the sleeve 18 and the inner peripheral surface of the sleeve 19,
The sleeve 18 is formed with a small hole 26 that communicates with the cavity 25 from the inner peripheral surface in contact with the heat pipe 16, and the sleeve 19 has a small hole 26 that opens from the cavity 25 with the outer peripheral surface of the sleeve 19 and communicates with the 15. Therefore, the sealing member 17 as a whole has a small hole 27 formed therein.
6 and 27 so that the surface in contact with the heat pipe 16 communicates with the intermediate chamber 15.

Note that inside the high-temperature chamber 10, a buttful 30 is provided in order to lengthen the flow path of the high-temperature fluid that enters from the inlet 28 and exits the outlet 29. Also, a baffle 33 is provided to lengthen the flow path of the low temperature fluid that flows from the inlet 31 and exits to the outlet 32. Further, a leak detector 34 is connected to the intermediate chamber 15 and is operated by the fluid leaked into the intermediate chamber 15.
The leak detector 34 is configured to detect leakage of fluid from the 1 .

Therefore, in the heat exchanger configured as described above, if high-temperature fluid is circulated inside the high-temperature chamber 10 and low-temperature fluid is circulated inside the low-temperature chamber 11, the high temperature is Heat possessed by the fluid is carried to the low temperature chamber 11 side, and heat exchange is performed with the low temperature fluid. In that case, in the above-mentioned heat exchanger, since heat is transferred by the heat pipe 16, the amount of heat transferred from the high-temperature fluid to the low-temperature fluid increases, and heat exchange can be performed efficiently.As a result, the heat transfer area Since the space can be narrow, the whole can be made compact.

Here, the results of experiments conducted by the present inventors show that using insulating oil (LV-25E) as the high-temperature liquid,
When the flow rate was set to 0.3 m/sec, and water was used as the low-temperature fluid, and the flow rate was set to 1.5 m/sec, the thermal conductivity was 250 to 300 kca/ ^m2..h .°C. On the other hand, in a heat exchanger using double copper pipes, the thermal conductivity was 100 to 150 kca/m2 ^· h·°C when the flow rate of each fluid was the same as in the above case.

As is clear from this result, according to the above heat exchanger, the heat exchange efficiency can be improved more than ever before.

Further, in the above heat exchanger, the high temperature fluid or the low temperature fluid is connected to the partition walls 13 and 1 of the heat pipe 16.
Even if the leakage occurs at the penetration part for 4, the leaked fluid will flow as shown by the dotted line in Figure 4.
Since all flow into the intermediate chamber 15, it is possible to reliably prevent the low temperature fluid from flowing into the high temperature chamber 10, or vice versa, to prevent the high temperature fluid from flowing into the low temperature chamber 11, and to prevent the two from mixing. Can be done.

Furthermore, since the heat pipe 16 has only a short length fixed in the middle and both ends are free ends, the heat pipe 16
6 is able to thermally expand freely and without any thermal stress, so the above heat exchanger can be used even when the temperature of the hot fluid is considerably high.
It can be used without any problems.

As is clear from the above description, according to the heat exchanger of this invention, a high temperature chamber through which a high temperature fluid flows and a low temperature chamber through which a low temperature fluid flows are arranged in two panels facing each other with a predetermined interval. The chamber is partitioned by a partition wall, and an intermediate chamber is formed between the partition walls into which fluid leaked from the high temperature chamber or the low temperature chamber flows, and the intermediate chamber is arranged to penetrate between the high temperature chamber and the low temperature chamber. A heat transfer body is fitted and held in the sealing member, and the sealing member is provided with a communication hole that communicates with the intermediate chamber from the empty chamber composed of two parts consisting of the first sleeve 18 and the second sleeve 19. Each fluid leaking from the high or low temperature chamber leaks into the intermediate chamber through the communication holes, allowing heat exchange between the high temperature and low temperature fluids without mixing them. Moreover, unlike conventional heat exchangers, there is no air layer between the high-temperature fluid and the low-temperature fluid, so high heat exchange efficiency can be obtained, and the overall configuration can be made compact. can do. That is, the communication hole allows the fluid leaked from the first sleeve 18 and the second sleeve 19 to flow from the empty chamber into the intermediate chamber, thereby allowing the leaked fluid to flow reliably.
Further, the heat pipe is fixed to the first sleeve 18, and one end of the first sleeve 18 is connected to the second sleeve 19.
The amount of thermal expansion is particularly limited because it is fixed at one point and is slidably engaged at the other end, with the end exposed to the hot fluid being a free end. Therefore, even if the high temperature fluid is considerably high temperature, it can be used without any problem.

[Brief explanation of the drawing]

FIG. 1A is a schematic diagram showing the main parts of a conventional heat exchanger, FIG. , FIG. 3 is a sectional view taken along the - line in FIG. 2, and FIG. 4 is a detailed view showing one of the seal members. 10... High temperature room, 11... Low temperature room, 13, 14
... Partition wall, 15 ... Intermediate chamber, 16 ... Heat pipe, 17 ... Seal member, 18 ... First sleeve, 19 ... Second sleeve, 25 ... Vacant room, 2
6,27...Small hole.

Claims (1)

[Scope of utility model registration request] A high-temperature chamber through which a high-temperature fluid flows and a low-temperature chamber through which a low-temperature fluid flows are formed by two partition walls facing each other at a predetermined distance to form an intermediate chamber into which fluid leaked from the high-temperature chamber or the low-temperature chamber flows. In a heat exchanger, a heat pipe for transferring heat between a high-temperature fluid and a low-temperature fluid is arranged to penetrate the partition wall and the intermediate chamber, and the heat pipe is held therethrough. A sealing member consisting of a first sleeve fixed to the heat pipe and a second sleeve fixed to the two partition walls, the ends of which are fitted into each other, penetrates the intermediate chamber to separate the high temperature chamber and the low temperature chamber. It is established between
A heat exchanger characterized in that the sealing member is formed with a communication hole that communicates with the intermediate chamber from the cavity formed by the first sleeve and the second sleeve.