JPH06323761A - Closed cooling tower - Google Patents

Abstract

PURPOSE:To provide a closed cooling tower wherein it is miniaturized, made light weight and inexpensive by improving heat transfer performance and wherein water saving is ensured by making simple scale removal cleaning. CONSTITUTION:There are provided latent heat heat cooling means 13 for cooling spread water emanating from a spreading apparatus 9 is cooled with latent heat via a filling member 13a, cooling water passage means 14 for feeding as cooling water the spread water from which heat is taken by the cooling means to a dry cooler 5 and further feeding the spread water back to the spreading apparatus, and heat exchange means 16 disposed on the cooler for ensuring heat transfer between circulaated water and the cooling water.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hermetically sealed cooling tower capable of transmitting heat generated from electric equipment such as a transformer, a reactor, a rotary condenser, a thyristor valve, etc. through water and finally dissipating it to the atmosphere. Regarding

[0002]

2. Description of the Related Art FIG. 2 shows heat generated from a power transformer.
The main configuration of the cooling system and the closed cooling tower when the air is diffused into the atmosphere using the closed cooling tower is shown.

In the figure, 1 is a transformer which is a heat source, and 1 is a transformer.
a is a refrigerant system of the transformer 1, 1b is a refrigerant pump for circulating the refrigerant of the transformer 1 in the refrigerant system 1a, 2 is heat exchange for transferring the heat of the transformer 1 to circulating water which is an intermediate refrigerant. Vessel 3 is a circulating water pump for circulating circulating water,
Reference numeral 4 denotes a closed cooling tower for finally dissipating the heat of the transformer 1 to the atmosphere.

The closed cooling tower 4 comprises a dry heat exchanger 5, a wet heat exchanger 6, a water tank 7, a sprinkler pump 8, a spraying device 9, an eliminator 9a and a blower 10.

Reference numeral 11 is a cylindrical body which surrounds the whole, and 12 is an outside air intake port.

Explaining the operation of the above device, the heat generated in the transformer 1 is transferred to the circulating water as an intermediate refrigerant via the heat exchanger 2. The circulating water is heated by the heat exchanger 2 and then sent to the closed cooling tower 4 by the circulating water pump 3.
After being cooled here, the heat of the transformer 1 is continuously dissipated to the atmosphere by repeating the cycle of returning to the heat exchanger 2 and receiving heat again.

In the cooling tower 4, however, the circulating water first enters the dry cooler 5, where heat is exchanged with the air after flowing in from the outside air intake 12 and passing through the air passage of the wet cooler 6. After being cooled, it is moved to the circulating water passage of the wet cooler 6. The outer surface of the circulating water passage of the wet cooler 6 is covered with a water film sprayed from the water tank 7 by the water spray pump 8 through the spraying device 9, and the surface of the water film is evaporated to evaporate the wet cooler 6. Remove the heat of circulating water in the circulating water passage. Therefore, the circulating water is sent to the outside of the cylindrical body 11 after its retained heat is further removed by the wet cooler 6.
On the other hand, a flow of air is generated in the cylinder 11 by the blower 10, and this air evaporatively cools on the outer surface of the circulating water passage of the wet cooler 6 and sensible heat on the outer surface of the circulating water passage of the dry cooler 5. Cooling is promoted, and heat transfer efficiency in the cylindrical body 11 is promoted.

[0008]

In the conventional closed cooling tower, the wet cooler 6 uses a bare pipe or a low fin pipe in its circulating water passage in consideration of scale removal and cleaning of the outer surface thereof. Moreover, these pipes cannot be densely arranged, so that the water film surface area per unit volume of the spray water in the wet cooler 6 does not become large, and the flow of the spray water in the cooler 6 is hardly generated. Since it relies on gravity flow, the cooling efficiency by the sprayed water in the same cooler 6 does not become large, and therefore the cooling tower becomes large and expensive.

Further, although the circulating water passage of the wet cooler 6 has a pipe arrangement in consideration of cleaning as described above,
It takes a lot of labor and time to remove the scale on the outer surface of the tube group, which usually has several hundred pipes. Furthermore, in order to suppress the generation of scale on the outer surface of the circulating water passage of the wet cooler 6, the water in the water tank 7 is prevented. It is necessary to blow some of them out of the system at appropriate intervals, but there are drawbacks such that a sufficient amount of blow is required due to the difficulty of cleaning, and a large amount of water is consumed.

The present invention has been made to eliminate the above-mentioned conventional drawbacks, and improves heat transfer performance, simplifies scale removal and cleaning, and prevents wasteful consumption of water. It is an object of the present invention to provide a closed cooling tower.

[0011]

In order to achieve the above object, the present invention provides a latent heat cooling means for performing latent heat cooling of spray water flowing out from a spraying device through a filling material, and the cooling means heats the sprayed water. Cooling water passage means for sending the sprayed water deprived of the water to the dry cooling device as cooling water and returning it to the spraying device are provided, and the cooling device is provided with the circulating water to be cooled and the cooling water. A heat exchange means is provided between which heat is transferred.

The heat exchanging means has a double pipe structure composed of an outer pipe and an inner pipe, the inside of the inner pipe serves as a cooling water passage, and the inner pipe and the outer pipe serve as circulating water passages. To do.

Further, the cooling water passage means may be provided with a bypass means for short-circuiting the inlet and outlet of the dry cooler.

[0014]

The heat exchange means transfers heat between the circulating water and the sprayed water as cooling water under the state where the sprayed water cooled by latent heat is positively flowed through the cooling passage means. Therefore, the forced heat transfer is carried out here. Therefore, compared to the conventional passive cooling method, in which heat is transferred between the sprayed water gravity-flowed to the outer surface of the circulating water passage and the circulating water in the circulating water passage, the circulating water and the sprayed water are The heat transfer is efficiently performed.

The sprayed water as cooling water for cooling the circulating water is circulated on the inner surface of the passage closed in the dry heat exchanger. Therefore, the sprayed water does not directly wet the outer surface of the circulating water passage exposed to air, and the scale due to the concentration of the sprayed water is prevented from occurring on the outer surface of the circulating water passage.

On the other hand, the filler is sprinkled with sprayed water to generate scale, but when it is contaminated beyond a certain limit, it is replaced with a new one.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described with reference to FIG.
FIG. 1 is a vertical sectional view of the device of the present invention. In FIG. 1, the same parts as those in the conventional example are designated by the same reference numerals.

In the figure, 13 indicates a latent heat cooling means,
It consists of the spraying device 9 and the filler 13a. This time filler 1
3a is for effectively expanding the surface area of the water sprayed from the spraying device 9, and may be fibrous or particulate.

Reference numeral 14 is a spraying device 9 for sending the sprayed water deprived of heat by the latent heat cooling means 13 to the dry cooler 5 as cooling water.
Which is a cooling water passage means for returning the water to the dry cooling device 5. Specifically, the water tank 7 is provided directly below the latent heat cooling means 13 and the cooling water pump 14a for sending the water in the water tank 7 to the dry cooler 5. And cooling water passages 14b and 14c, and a cooling water passage 1 for returning water from the dry cooler 5 to the spraying device 9.
It consists of 4d.

In the dry cooler 5, however, a large number of finned pipes 15 for forming the circulating water passage 5a are provided side by side and heat exchange means for forcibly conducting heat transfer with the cooling water. 16 is provided.

The heat exchange means 16 is a finned tube 1
An inner pipe 17 is provided at the central position of 5 to form a double pipe structure,
The inside of the inner pipe 17 serves as a passage for cooling water, while the inner pipe 17 and the finned pipe 15 serving as an outer pipe serve as a circulating water passage 5a.

A circulating water inlet section 18a is provided at one end of the dry cooler 5 for allowing the circulating water supplied from the circulating water path a to flow between the inner pipe 17 and the finned pipe 15. The other end is provided with a circulating water outlet section 18b for sending the circulating water flowing out from between the inner pipe 17 and the finned pipe 15 to the circulating water route (b).

Further, a cooling water inlet section 19a for allowing the cooling water supplied from the cooling water passage 14b to flow into the inner pipe 17 is provided outside one of these sections 18a and 18b, and the other outside thereof. Cooling water outlet section 19 for sending the cooling water flowing out from the inner pipe 17 to the cooling water passage 14d
b is provided.

Reference numeral 20 is a bypass means for short-circuiting the inlet / outlet of the cooling water of the dry cooler 5. Specifically, a branch passage 20a is provided in the middle of the cooling water passage 14b, and a remote operation is possible at this branch point. The three-way valve 20b is provided, and the branch passage 20a is connected in the middle of the cooling water passage 14d, and in the middle of the cooling water passage 14d on the upstream side of this connection point and in the middle of the branch passage 20a. Stop valve 20 operated in association with the three-way valve 20b
c and 20d are provided.

Next, an example of use of the above embodiment and its operation will be described. The circulating water receives heat generated by a transformer or the like to raise its temperature, and then is introduced into the circulating water inlet section 18a of the dry cooler 5 via the circulating water path a. After this circulating water is cooled by applying heat to the finned pipe 15 and the inner pipe 17, it reaches the circulating water outlet section 18b and flows out from there to the circulating water route (b).

On the other hand, the water sprayed from the spraying device 9 onto the filling material 13a is collected in the water tank 7 as cooling water, and then the cooling water pump 14a discharges the entire amount of the discharged water.
It is sent to the dry cooler 5 via c, where it absorbs heat from the inner pipe 17, and is then returned to the spraying device 9 again.

At this time, the heat transfer mechanism of the finned tube 15 is heat transfer by sensible heat change between the circulating water and the air in the cylindrical body 11 and is similar to the conventional one, but the heat transfer mechanism of the inner tube 17 is circulated. Since it is the heat transfer between the water and the cooling water in the forced flow state, the heat transfer characteristics can be greatly improved as compared with that in the conventional gravity flow state of the spray water.

The cooling water is supplied from the spraying device 9 to the filler 13.
A water film of the sprayed water is formed by the water flowing down on the surface a, and the water is evaporated to be cooled by latent heat to become cold water. In this case, the filler 13a covers the surface of the water film per unit volume. Since the amount of heat is dramatically increased, the amount of heat transferred is large in the latent heat cooling of the spray water as compared with the conventional one.

During the operation of the apparatus, the cooling water passage means 14, particularly the inside of the inner pipe 17 which is a heat exchange point, is contaminated due to the concentration of the cooling water and scale is generated. For this reason, scale removal and cleaning of the inner surface of the inner tube 17 and the like are carried out, but the labor is easier than that of the outer surface of the tube. Also, the filler 13a is often soiled and therefore needs to be cleaned, but this is generally versatile and inexpensive, so it is regularly (3 to 5 years).
Will be exchanged. Thus, scale removal and cleaning is easier than conventional methods.

In the use of the product of the present invention, the load may be too small in the above-mentioned ordinary use mode. Even in this case, if the above-mentioned use mode is continued, the circulating water is excessively cooled and the cooling water pump 14a is used. Energy consumption due to wasteful operation of water and wasteful water consumption due to evaporation of water whose temperature has been raised by heat. In order to deal with this, in the present embodiment, the usage mode is switched to two stages as follows.

That is, in the first usage mode, the three-way valve 20b and the stop valves 20c and 20d are operated to operate the cooling water pump 14a.
The entire amount of the cooling water discharged from the above is sent to the spraying device 9 through the branch passage 20a, and the cooling water is not sent to the dry cooler 5. As a result, the cooling water is distributed to the spraying device 9 and the filler 13.
a, the water tank 7, the cooling water pump 14a, the branch passage 20a, and the spraying device 9 are circulated in this order. Also in this case, since the cooling water is effectively evaporated by the filler 13a as described above, the temperature of the outside air flowing through the cylinder 11 by the blower 10 is cooled from the dry-bulb temperature to the wet-bulb temperature. The air thus cooled serves to appropriately sensible heat cool the circulating water through the dry cooler 5. The amount of water evaporated in this usage mode is small because the amount of heat received by the water is small.

Even in the first mode of use, when the circulating water is still excessively cooled, the second mode of use is adopted. That is, the cooling water pump 14a is stopped to stop the flow of the cooling water. To As a result, the outside air is not cooled by latent heat, and the circulating water is appropriately cooled via the dry cooler 5 at the same temperature. It should be noted that there is no consumption of water in this usage mode.

[0032]

According to the present invention constructed as described above, since the heat transfer performance is improved, the apparatus is small and lightweight, which is inexpensive, and the scales due to the cooling water are adhered to the inner surface of the sealed passage. This makes it easier to remove and clean the scale, and in connection with the easier removal and cleaning of the scale, it is possible to reduce the amount of water blown and save water.

Further, according to the second aspect, the heat exchange means is made compact, which contributes to further downsizing of the apparatus.

According to the third aspect of the invention, the cooling water is not sent to the dry cooler, and efficient operation can be performed according to the magnitude of the load.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of a cooling tower according to the present invention.

FIG. 2 is an explanatory diagram showing a conventional cooling tower and the like.

[Explanation of symbols]

 5 Dry Cooler 5a Circulating Water Passage 9 Spraying Device 13 Latent Heat Cooling Means 15 Outer Pipe 14 Cooling Water Passage Means 16 Heat Exchange Means 17 Inner Pipe 20 Bypass Means

Claims (3)

[Claims] 1. A latent heat cooling means (13) is provided for cooling the sprayed water flowing out of the spraying device (9) through a filler (13a), and the cooling means (1) is provided.
The cooling water passage means (14) is provided for sending the sprayed water deprived of heat in 3) as cooling water to the dry cooler (5) and returning it to the spraying device (9). The closed cooling tower is characterized in that a heat exchange means (16) for performing heat transfer between the circulating water to be cooled here and the cooling water is provided. 2. The inner pipe (17), wherein the heat exchange means (16) has a double pipe structure composed of an outer pipe (15) and an inner pipe (17).
The inside does not serve as a passage for cooling water, and the inner pipe (17) and the outer pipe (15)
The closed cooling tower according to claim 1, wherein a circulating water passage (5a) is provided between the two. 3. By-pass means (2) for short-circuiting the inlet / outlet of the dry cooler (5) to the cooling water passage means (14).
0) is provided, The closed type cooling tower according to claim 1 or 2.