JPH11166793A - Crossflow cooling tower - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the height of a crossflow cooling tower having white smoke preventing function. SOLUTION: A gas-liquid contact heat exchanging sections 5, 5 are disposed in the opposite sides of a tower body 3 and a pair of heaters 12, 12 are disposed in the air passage 9, i.e., the space between the sections 5, 5. The space between the heaters 12, 12 serves as an outer air introduction passage 14. On the side wall 7 of the tower body 3 where the gas-liquid contact heat exchanging section 5 is not disposed, an outer air introduction port 15 with damper 16 communicating with the outer air introduction passage 14 is provided. When there is a possibility of providing white smoke, outer air is introduced by opening the damper 16 and discharged to time air passage 9 after being heated through the heater 12. Heated air passed through the heater 12 and the heated and humidified air passed through the gas-liquid contact heat exchanging section 5 are mixed and stirred in the air passage 9 before being discharged from an exhaust port 10 to the atmosphere.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cross-flow type cooling tower for cooling water to be cooled by flowing water to be cooled and air in the tower so as to be orthogonal to each other. It relates to a mold cooling tower.

[0002]

2. Description of the Related Art During operation of a cooling tower, especially in winter, when air that has been heated and increased in humidity after passing through the cooling tower is discharged as exhaust gas outside the tower, the exhaust gas is discharged. When it comes into contact with cold outside air, the water vapor in the exhaust gas liquefies and becomes mist, it looks like white smoke, and it looks like white smoke at the time of fire, or emits harmful exhaust gas The environment may be seen as if it is polluting the environment, and if a large amount of white smoke is generated, the visibility may be obstructed and traffic may be obstructed.

In order to prevent such generation of white smoke, a conventional cross-flow type cooling tower employs a system in which an indirect heating coil 21 is installed on a gas-liquid contact heat exchange section 22, as shown in FIG. It has been. This system uses the heat of the return water of the cooling water as a heat source so that no extra heat is required, and sensible heat is given to the air by passing a part of the air through the indirect heating coil 21. The rise was not to occur. With the air to which the sensible heat is applied,
When air passing through the gas-liquid contact heat exchange section 22 and mixing sensible heat and air whose latent heat has risen, that is, air whose temperature and humidity have risen, are mixed, the humidity of the whole mixed air is lower than the humidity of the latter air. Even if the discharged mixed air comes into contact with cold outside air, white smoke can be prevented from being generated. At this time, for example, an operation of adjusting the amount of air to be indirectly heated according to the temperature and humidity conditions of the outside air is performed.

However, in this method, the tower height is increased, the size of the apparatus is increased, and the installation position of the indirect heating coil 21 is generally restricted to the left and right due to the structure of the cooling tower. It is difficult to install in the direction, and twisting of the airflow by the exhaust fan is restricted to about 18 °, so that it is difficult to obtain good stirring and mixing of air, and it is not possible to obtain sufficient white smoke prevention effect. There is a disadvantage that.

[0005] In the cross-flow cooling tower disclosed in Japanese Patent Publication No. 4-1273, an indirect heating coil is provided upright at the center of the tower between a pair of gas-liquid contact heat exchangers arranged opposite to each other. A damper (first damper) for switching the flow path is provided at the top of the tower between the one gas-liquid contact heat exchange section and the indirect heating coil, and further, a damper for permitting or blocking the flow of air to the indirect heating coil. (A second damper). In this cross-flow type cooling tower, by switching the air flow path by opening and closing both dampers, when there is no danger of generating white smoke, air is passed through both gas-liquid contact heat exchange parts and the indirect heating coil During the operation when there is a risk of generating white smoke without passing air through the tower, the cooling function of one of the gas-liquid contact heat exchange units must be stopped before this gas-liquid contact heat exchange The air passing through the indirect heating coil is passed through the indirect heating coil, and the air passing through the other gas-liquid contact heat exchange unit having a cooling function is mixed with the air passing through the indirect heating coil and discharged outside the tower. .

In the case of this cross-flow cooling tower, the tower height can be made lower than that of the conventional cross-flow cooling tower. Since the structure must pass through the first damper, pressure loss is large and power consumption is disadvantageous.

Further, in the operation when there is a risk of generating white smoke in the cross-flow type cooling tower, the cooling function of the one gas-liquid contact heat exchange section is stopped, so that the amount of treated water decreases. There is a disadvantage that. In addition, since the indirect heating coil and the gas-liquid contact heat exchange part are provided at substantially the same height position, and the structure is such that the air outlet is located immediately above, the air passing through the indirect heating coil and the air Mixing and agitation with air that passed through the other gas-liquid contact heat exchange section became insufficient,
In some cases, the effect of preventing white smoke is not sufficiently obtained.

[0008] The present invention has been made in view of such problems of the conventional technology, and an object of the present invention is to provide a cross-flow cooling tower that can reduce the tower height and is excellent in preventing white smoke.

[0009]

The present invention has the following features to attain the object mentioned above. According to the present invention, an exhaust port having an exhaust fan is provided at the top of a tower, and outside air is introduced into at least a part of the tower side from the side of the tower, and the outside air is contacted with water to be cooled sprayed from above to generate heat. In a cross-flow type cooling tower provided with a gas-liquid contact heat exchange section to be exchanged and having a hollow portion inside the tower located between the exhaust port and the gas-liquid contact heat exchange section as an air passage, a tower side or a tower In the upper part, an outside air introduction port is provided separately from the gas-liquid contact heat exchange section, and a heating element for exchanging heat between the air and the heat medium in a non-contact state, and outside air introduced from the outside air introduction port are provided in the hollow section. Providing an outside air introduction passage leading to the heating body, the outside air heated through the gas-liquid contact heat exchanging section, and the outside air introduced from the outside air introduction port and heated through the heating body, in the hollow portion. It is characterized in that it can be mixed.

The outside air flowing from the outside air introduction port passes through the outside air introduction passage, passes through the heating element, and is discharged into the hollow portion inside the tower. This air is heated as it passes through the heating element. The outside air that has passed through the gas-liquid contact heat exchange unit is heated and humidified and released into the hollow portion inside the tower, where the air is mixed and stirred with the heated air that has passed through the heating element, and exhausted to the atmosphere from the exhaust port. . Since the heating element is installed in the hollow portion inside the tower, the tower height of the cooling tower can be kept low.

[0011] The structure of the heating element is not limited as long as it causes heat exchange between the air and the heating medium in a non-contact state and gives sensible heat to the air but does not increase latent heat. Examples include a shape, a spiral, a spiral, and a meandering tube. The heat medium in the heating element can be exemplified by liquid, gas, vapor and the like.

The gas-liquid contact heat exchanging section is not particularly limited in its structure and the like, as long as it is capable of exchanging heat by bringing the inflowing outside air into contact with the water to be cooled. And a type in which water to be cooled is sprayed downward from above, and a type in which water is sprayed without providing a filler and brought into direct gas-liquid contact can be exemplified. Further, there is no particular limitation on the state of spraying the water to be cooled.
It may be in the form of a droplet, a spray, or a coexistence thereof.

It is preferable that the outside air inlet is provided with opening / closing means such as a damper. In this way, the outside air inlet can be opened only when there is a risk of generating white smoke.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a cross-flow cooling tower according to the present invention will be described below with reference to FIGS.

First Embodiment As shown in FIGS. 1 and 2, a cross-flow type cooling tower 1 according to a first embodiment has a substantially rectangular shape in plan view, and a tower body 3 is provided above a water tank 2. Is installed.

A support 4 is provided at the bottom of the tower body 3, and a pair of gas-liquid contact heat exchangers 5 are installed on the support 4 on opposite sides of the tower body 3. A watering tank 6 is provided above the heat exchange unit 5.

The support 4, the side walls 7, 7 of the tower body 3 where the gas-liquid contact heat exchange sections 5, 5 are not provided, the gas-liquid contact heat exchange sections 5, 5 and the top plate section 8 of the tower body 3. The inside of the enclosed tower body 3 is hollow, and forms an air passage 9. From the top plate 8, a cylindrical exhaust port 10 connected to the air passage 9 is provided upright. The exhaust port 10 includes an exhaust fan 11.

The gas-liquid contact heat exchange section 5 has a side surface serving as an outside air inlet 5a, and the inside thereof is filled with a filler (not shown) for increasing the contact area between air and liquid. I have. Then, when the exhaust fan 11 is rotated, the outside air introduced from the outside air introduction port 5 a passes through the gas-liquid contact heat exchange unit 5 and flows into the air passage 9. Further, a large number of water spray holes are provided at the bottom of the water spray tank 6, and water to be cooled is sprayed from the water spray holes to the gas-liquid contact heat exchange unit 5. In the gas-liquid contact heat exchange unit 5, the water to be cooled that flows downward and the outside air that flows substantially horizontally contact each other to exchange heat, and the water to be cooled is cooled, the outside air is warmed, and the humidity rises.
The air having the increased temperature and humidity passes through the air passage 9 and is exhausted from the exhaust port 10 to the outside.

A pair of heaters 12, 12 are installed at substantially the center of the air passage 9. Both heating elements 12
The lower part is grounded to the supporting floor 4, and the lower part is oppositely installed from the one side wall 7 to the other side wall 7 in such a manner that the lower part is inclined in the shape of "C". The upper ends of both heating elements 12
The obstruction plate 1 is located at approximately the middle of the height of the air passage 9.
3 are connected. And both heating bodies 12, 1
A space surrounded by the support 2, the floor 4, and the closing plate 13 is an outside air introduction passage 14.

Further, an outside air introduction port 15 connected to the outside air introduction passage 14 is provided at the lower center of each side wall 7 of the tower body 3. The outside air inlet 15 is provided with a damper 16 for closing the outside air inlet 15 as needed.

The heating element 12 is of a coil type, in which hot water as a heat medium flows in the coil so that when the air passes between the coils, the air is heated without increasing the humidity. Has become. That is, the heating element 12 is a non-contact type heat exchanger that gives sensible heat to the air but does not increase latent heat.

The outside air flowing from the outside air introduction port 15 passes through the outside air introduction passage 14, passes through the heater 12, and flows out to the air passage 9. A large number of drain holes are provided in the support floor 4 except for the outside air introduction passage 14.
The water to be cooled which has been sprinkled from the water and has flowed down the gas-liquid contact heat exchange section 5 flows into the water tank 2 through the drain hole. In addition, instead of providing the drainage hole in the support floor 4, the support floor 4 may be installed to be inclined downward toward the side edge.

Next, the operation of the cooling tower 1 of this embodiment will be described. When there is no possibility that white smoke will be generated when the exhaust gas flows out from the exhaust port 10 of the cooling tower 1, the cooling tower 1 is operated with the damper 16 of the outside air inlet 15 closed. Damper 16
Is closed and the exhaust fan 11 is rotated, the inflow of outside air from the outside air introduction port 15 provided in the side wall 7 is prevented, and the outside air enters the cooling tower 1 only from the outside air introduction port 5a of the gas-liquid contact heat exchange unit 5. Inflow. The inflowing outside air is supplied to the gas-liquid contact heat exchange section 5.
When passing through, water is cooled by contacting the water to be cooled sprinkled from the water spray tank 6 to cool the water to be cooled. This heat exchange warms the outside air and raises the humidity by evaporating some of the water to be cooled. The heated and humidified air rises in the air passage 9 and is exhausted to the atmosphere from an exhaust port 10. Since the heating element 12 is located at the lower center of the air passage 9 away from the gas-liquid contact heat exchange section 5, the heating element 12 does not obstruct the flow of air in the air passage 9.

On the other hand, when there is a possibility that white smoke may be generated when exhaust gas flows out of the exhaust port 10 of the cooling tower 1 such as in winter, the cooling tower 1 is operated by opening the damper 16 of the outside air inlet 15. When the exhaust fan 11 is rotated by opening the damper 16, the outside air flows into the cooling tower 1 not only from the outside air inlet 5 a of the gas-liquid contact heat exchange unit 5 but also from the outside air inlet 15 provided on the side wall 7. I will be. The outside air flowing from the outside air inlet 5a of the gas-liquid contact heat exchange unit 5 is heated and humidified by the gas-liquid contact heat exchange unit 5 as described above, and flows into the air passage 9.
It rises in the air passage 9. The outside air flowing from the outside air introduction port 15 passes through the heating body 12 from the outside air introduction passage 14, flows into the air passage 9, and is heated when passing through the heating body 12. And the heating air which passed through the heating body 12,
The air heated and humidified after passing through the gas-liquid contact heat exchange section 5 is
Since the mixture is sufficiently stirred and mixed in the air passage 9 and exhausted to the atmosphere from the exhaust port 10, white smoke is not generated at the time of exhaust.

Here, the height of the air passage 9 is higher than the height of the heating element 12, and there is a considerable distance from the upper end of the heating element 12 to the entrance of the exhaust port 10. The contact heat exchanger 5 has the same area (that is, the side walls 7, 7).
In this case, the heated air passing through the heating element 12 and the air heated and humidified through the gas-liquid contact heat exchange section 5 come into contact and mix with each other. Will be sufficiently mixed and stirred.

The heating element 12 is connected to the gas-liquid contact heat exchanging section 5,
Since the cooling tower 1 is installed in the air passage 9 between the cooling towers 5, the tower height of the cooling tower 1 does not need to be high, and the cooling tower 1 can be made compact and the cost can be reduced.

[Second Embodiment] Next, a cooling tower 1 according to a second embodiment will be described with reference to FIGS. In the following description of the second embodiment, the same components as those of the cooling tower 1 of the first embodiment will be denoted by the same reference numerals, and description thereof will be omitted, and differences from the first embodiment will be omitted. Only points will be explained.

In the cooling tower 1 according to the second embodiment,
4 below the four corners of the side where the gas-liquid contact heat exchange part is provided
Two outside air inlets 15 are provided. The opposed outside air introduction ports 15 are connected to each other by an outside air passage 17 provided along the side wall 7, and each outside air passage 17 communicates with an outside air introduction passage 14 between the heating elements 12. The outside air passage 17 can be formed of a zinc iron plate, a vinyl chloride lining steel plate, a vinyl chloride plate, a stainless steel plate, or the like.

The gas-liquid contact heat exchanging section is connected to the outside air passages 17, 17.
The gas-liquid contact heat exchange section 5A provided between the
The gas-liquid contact heat exchanging section 5A is provided above the base plate 4 and the top plate section 8 of the tower main body 3 from the supporting floor 4 in the same manner as in the first embodiment. Up to the height.

In the case of this embodiment, the outside air inlet 1
When the damper 16 is opened, the outside air flowing from the outside air inlet 15 flows into the outside air introduction passage 14 from the outside air passage 17 and passes through the heating element 12.

In the cooling tower 1 of the second embodiment, the same operation and effect as those of the cooling tower 1 of the first embodiment can be obtained.

Third Embodiment Next, a cooling tower 1 according to a third embodiment will be described with reference to FIGS. In the following description of the third embodiment, the same components as those of the cooling tower 1 of the first embodiment will be denoted by the same reference numerals, and description thereof will be omitted, and differences from the first embodiment will be omitted. Only points will be explained.

In the cooling tower 1 according to the third embodiment,
An outside air inlet 15 is provided in the top plate 8 between the gas-liquid contact heat exchangers 5 and 5 and on both sides of the outlet 10. The outside air inlet 15 is connected to the outside air introduction passage 14 by an outside air passage 18 provided vertically in the air passage 9. The outside air passage 18 can be formed of a zinc iron plate, a vinyl chloride lining steel plate, a vinyl chloride plate, a stainless steel plate, or the like.

In the case of this embodiment, the outside air inlet 1
When the damper 16 is opened, the outside air flowing from the outside air inlet 15 descends through the outside air passage 18, flows into the outside air introduction passage 14, and passes through the heating element 12.

In the cooling tower 1 of the third embodiment, the same operation and effect as those of the cooling tower 1 of the first embodiment can be obtained.

[0036]

As described above, according to the present invention,
An exhaust port having an exhaust fan is provided at the top of the tower, and outside air flows into the tower side from at least a part of the tower side, and the outside air comes into contact with the water to be cooled sprayed from above to perform heat exchange. In a cross-flow cooling tower provided with a contact heat exchange section and having a hollow portion inside the tower located between the exhaust port and the gas-liquid contact heat exchange section as an air passage, outside air is introduced into the tower side or the top of the tower. A heating element for exchanging heat between the air and the heat medium in a non-contact state, and an outside air introduction passage for guiding outside air introduced from the outside air introduction port to the heating element, wherein the gas-liquid Since the outside air heated through the contact heat exchange section and the outside air introduced from the outside air introduction port and heated through the heating body can be mixed in the hollow portion, generation of white smoke at the time of exhaustion is reduced. Can be reliably prevented, and the tower height can be kept low. That it can achieve compactness and cost reduction of the cooling tower.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a first embodiment of a cross-flow cooling tower according to the present invention.

FIG. 2 is a cross-sectional view of the cross-flow cooling tower according to the first embodiment.

FIG. 3 is a longitudinal sectional view of a second embodiment of a cross-flow cooling tower according to the present invention, and is a view along the line II in FIG.

FIG. 4 is a cross-sectional view of the cross-flow cooling tower according to the second embodiment.

FIG. 5 is a longitudinal sectional view of a third embodiment of a cross-flow cooling tower according to the present invention.

FIG. 6 is a cross-sectional view of the cross-flow cooling tower according to the third embodiment.

FIG. 7 is a longitudinal sectional view of a conventional cross-flow cooling tower.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cross-flow cooling tower 5 Gas-liquid contact heat exchange part 7 Side wall 8 Top plate part 9 Air passage (hollow part) 10 Exhaust port 11 Exhaust fan 12 Heating body 14 Outside air introduction path 15 Outside air introduction port

Claims (2)

[Claims] An exhaust port having an exhaust fan is provided at an upper part of a tower, and outside air is introduced into at least a part of the tower side from a side of the tower, and the outside air is brought into contact with water to be cooled sprayed from above. In a cross-flow type cooling tower provided with a gas-liquid contact heat exchanging section for heat exchange and having a hollow portion inside the tower located between the exhaust port and the gas-liquid contact heat exchanging section as an air passage, An outside air introduction port is provided separately from the gas-liquid contact heat exchange section, and a heating element for exchanging heat between air and a heat medium in a non-contact state in the hollow portion; and heating the outside air introduced from the outside air introduction port to the heating section. Providing an outside air introduction passage leading to the body, and mixing the outside air heated through the gas-liquid contact heat exchange section with the outside air introduced from the outside air introduction port and heated through the heating body in the hollow portion; A cross-flow type cooling tower characterized in that: 2. An exhaust port having an exhaust fan is provided at the top of the tower, and outside air is introduced into at least a part of the tower side from the side of the tower, and the outside air is contacted with water to be cooled sprayed from above. In a cross-flow type cooling tower provided with a gas-liquid contact heat exchanging section for heat exchange and having a hollow portion inside the tower located between the exhaust port and the gas-liquid contact heat exchanging section as an air passage, An inlet is provided, a heating element for exchanging heat between the air and the heat medium in a non-contact state, and an external air introduction passage for guiding external air introduced from the external air inlet to the heating element are provided in the hollow portion. A cross-flow cooling tower characterized in that the outside air heated through the liquid contact heat exchange section and the outside air introduced from the outside air introduction port and heated through the heating body can be mixed in the hollow portion. .