JPH11173769A - Counterflow type cooling tower - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress a height of a counterflow type cooling tower having a white fuming preventing function to low. SOLUTION: An upper atmosphere inlet 14 is provided at an outside of an exhaust port 12 at a top plate 10 of the cooling tower 1, and a heater 18 is installed in an oblique attitude in an air passage 11 near an edge of the tower 1 crossing at the plate 10 and a sidewall 5. The atmosphere introduced from the inlet 14 into the tower is heated in the case of passing the heater 18, and discharged into the passage 11. The atmosphere introduced from louvers 6 into the tower is brought into contact with water to be cooled scattered from a sprinkling tube 8 in an air-liquid contact heat exchanger 7, heat exchanged, heated and humidified, and exhausted into the passage 11. The atmosphere passed through the heater 18 and the atmosphere passed through the exchanger 7 are agitated to be mixed in the passage 11, and exhausted from the port 12 into the atmosphere.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a counterflow type cooling tower for cooling water to be cooled by flowing water to be cooled downward and flowing air upward to bring the water to be cooled into contact with the air in counterflow.
In particular, the present invention relates to a counter-current cooling tower capable of preventing white smoke.

[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 the generation of such white smoke, a conventional counterflow type cooling tower employs a system in which an indirect heating coil 21 is installed in a space 30 above an eliminator 22, as shown in FIG. It has been. In this countercurrent cooling tower,
An upper outside air inlet 25 is provided along the side wall 24 immediately below the top plate 23 of the cooling tower, and the indirect heating coil 21 is installed in an upright position inside the upper outside air inlet 25. The heat source of the indirect heating coil 21 is the heat of the cooled water that is the return water of the cooling water.
After passing through, water is sprayed from the water spray device 26 to the gas-liquid contact heat exchange unit 27. The indirect heating coil 21 is connected to the upper outside air inlet 2
The sensible heat is given to the outside air introduced from 5, but the rise of the latent heat does not occur, so that the temperature rises but the humidity does not rise. On the other hand, the gas-liquid contact heat exchanging section 27 gives sensible heat and latent heat to the outside air introduced from the lower outside air inlet 28, and thus increases the humidity with the temperature. The air to which only the sensible heat is applied (that is, the air whose temperature is increased only) and the air whose latent heat is increased together with the sensible heat (that is, the air whose temperature and humidity are increased) are combined with the eliminator 22 and the top plate 23. When the mixed air is mixed in the space 30, the humidity of the whole mixed air is lower than the humidity of the latter air. Therefore, even if the mixed air discharged from the exhaust port 29 comes into contact with cold outside air, no white smoke is generated. You can do so. At this time, for example, an operation of adjusting the amount of air introduced from the upper outside air inlet 25 according to the temperature and humidity conditions of the outside air is performed.

The space 30 between the eliminator 22 and the top plate needs to have a minimum height in order to stabilize the air flow and make the flow velocity uniform. In the counter-flow cooling tower, the space 30 needs to be higher than the required minimum height in order to install the indirect heating coil 21 in the upright posture. As a result, the tower height increases,
There has been a problem that the size of the apparatus increases and the cost increases.

Further, since the upper outside air inlet 25 is provided on the side wall 24, when a plurality of cooling towers are connected in series, an appropriate space is provided between the cooling towers in order to utilize the upper outside air inlet 25. It was necessary to provide a large space, and a large installation space was required.

SUMMARY OF THE INVENTION The present invention has been made in view of such problems of the prior art, and has as its object to provide a countercurrent cooling tower capable of preventing the generation of white smoke without increasing the tower height. Aim.

[0007]

The present invention has the following features to attain the object mentioned above. The present invention provides an exhaust port having an exhaust fan at the top of the tower, provides a lower outside air inlet on at least a part of the tower side, and supplies cooling water inside the tower located above the lower outside air inlet. Providing a water sprinkling part, between the lower outside air inlet and the water sprinkling part,
Providing a gas-liquid contact heat exchange section for flowing the outside air introduced from the lower outside air inlet upward, flowing the cooled water sprinkled from the water spray section downward, contacting the outside air and the water to be cooled, and exchanging heat, The inside of the tower located between the section and the exhaust port is an air passage, an upper outside air inlet is provided at the top of the tower, and the outside air introduced from the upper outside air inlet and the heat medium are not contacted in the air passage. A heating element for performing heat exchange in a state is provided, and outside air introduced from the lower outside air introduction port and heated through the gas-liquid contact heat exchange section, and heated through the heating element introduced from the upper outside air introduction port and heated. In the counter-flow cooling tower in which the outside air can be mixed in the air passage, the upper outside air introduction port is provided at the top of the tower and outside the exhaust port, and the heating element is located between the top of the tower and the side of the tower. Inclined into the air passage near the tower edge where the sections meet Characterized by providing the energizing.

[0008] The outside air flowing into the tower from the upper outside air inlet is discharged to the air passage inside the tower through the heating element. This air is heated as it passes through the heating element. Outside air that has flowed into the tower from the lower outside air inlet contacts the cooled water sprinkled from the water sprinkling section when passing through the gas-liquid contact heat exchange section, performs heat exchange, is heated and humidified, and is released to the air passage Is done. In the air passage, the air heated through the heating element and the air heated and humidified through the gas-liquid contact heat exchange section are mixed and stirred, and are exhausted from the exhaust port to the atmosphere.

Since the heating element is provided in an inclined position in the air passage near the tower edge, the tower height of the cooling tower can be kept low. Since the upper outside air inlet is provided at the top of the tower, the outside air inlet for the heating element can be secured even if the cooling tower is arranged in close proximity and the installation space can be reduced.

[0010] 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 the introduced outside air and the sprinkled water to be cooled are brought into contact with each other so as to make heat exchange. Examples include a type in which the water to be cooled is sprayed from above and a type in which water is sprayed without providing a filler and brought into direct gas-liquid contact. 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.

Preferably, the upper 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. In order to prevent water from entering the cooling tower from the upper outside air introduction port in rainy weather or the like, an opening / closing lid is preferably provided.

[0013]

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

FIG. 1 is a longitudinal sectional view of a countercurrent cooling tower 1,
The cooling tower 1 has a rectangular shape when viewed from a plane. The cooling tower 1 has a water tank 2 at the bottom, and the cooled water to be cooled is stored in the water tank 2 and supplied to an air conditioner or the like by a pump 3. In the figure, reference numeral 4 denotes an overflow tube.

The four side walls 5 of the cooling tower 1 are provided with gulls 6 at positions above the water tank 2. The gallery 6 constitutes a lower outside air inlet. A gas-liquid contact heat exchanging section 7 is provided inside the cooling tower 1 located above the gallery 6, and a filler (not shown) for increasing the contact area between the air and the liquid is provided here. Is filled.

Above the gas-liquid contact heat exchange unit 7, there is provided a water sprinkling pipe 8 for uniformly spraying the water to be cooled to the gas-liquid contact heat exchange unit 7. An eliminator 9 for preventing the water to be cooled sprinkled from the sprinkler tube 8 from scattering upward is provided above the sprinkler tube 8.

An air passage 11 is provided between the top plate 10 of the cooling tower 1 and the gas-liquid contact heat exchange unit 7, and an inverted conical exhaust port connected to the air passage 11 is provided at the center of the top plate 10. 12 are erected. The exhaust port 12 has an exhaust fan 13.

When the exhaust fan 13 is rotated, the dust 6
Outside air is introduced into the cooling tower 1 from the gas-liquid contact heat exchange section 7.
Flowing upwards. On the other hand, since the water to be cooled sprinkled from the water pipe 8 flows downward through the gas-liquid contact heat exchange unit 7, the water to be cooled and the outside air come into contact with each other and exchange heat in the gas-liquid contact heat exchange unit 7. The water to be cooled is cooled, the outside air is warmed, and the humidity rises. The air having the increased temperature and humidity is exhausted to the outside through the air outlet 11 through the air passage 11.

A plurality of upper outside air inlets 14 are provided on the top panel 10 located outside the outlets 12 along the outer edges of the four sides. A damper 15 for adjusting the amount of inflow of outside air and a lid 16 for preventing inflow of rainwater or the like in rainy weather or the like are provided at the upper outside air inlet 14 so as to be remotely operable.

In the air passage 11, each side wall 5 and the top plate 10 are connected by a shielding plate 17 installed at an angle of about 45 degrees with respect to the side wall 5. This shielding plate 17
Is formed with an opening 17a, and a heating element 18 is installed so as to close the opening 17a.
7 (see FIG. 2).

The heating element 18 is of a coil type, in which water to be cooled as a heat medium flows in the coil, and when the air passes between the coils, the air is heated without increasing the humidity. It has become. That is, the heating element 18 is a non-contact heat exchanger that gives sensible heat to the air but does not increase latent heat.

A space surrounded by the side wall 5, the top plate 10, the shielding plate 17, and the heating element 18 forms a second air passage 19, and the outside air introduced from the upper outside air inlet 13 is supplied to the second air passage 13.
The air flows into the air passage 19, passes through the heating element 18, and
Runs into one.

The water to be cooled flows into the heating element 18 from a header pipe 20a provided above the eliminator 9,
The water to be cooled that has passed through the heating element 18 flows through the water sprinkling pipe 8 via the header pipe 20 b installed in the second air passage 19, and is sprinkled from the water sprinkling pipe 8 to the gas-liquid contact heat exchange unit 7. ing.

Next, the operation of the cooling tower 1 of this embodiment will be described. If there is no possibility of generating white smoke when the exhaust gas flows out from the exhaust port 12 of the cooling tower 1, the upper outside air inlet 1
The cooling tower 1 is operated with the damper 15 of 4 closed. When the exhaust fan 13 is rotated with the damper 15 closed, the inflow of outside air from the upper outside air inlet 14 is prevented, and the outside air flows into the cooling tower 1 only from the gallery 6. The outside air that flows in
When passing through the gas-liquid contact heat exchanging section 7, it contacts the cooling water sprinkled from the water sprinkling pipe 8 to perform heat exchange and cool the cooling water. 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 11 and is exhausted from the exhaust port 12 into the atmosphere.

On the other hand, when there is a possibility that white smoke may be generated when the exhaust gas flows out of the exhaust port 12 of the cooling tower 1 such as in winter, the damper 15 and the lid 16 of the upper outside air inlet 14 are opened to open the cooling tower 1. To drive. When the damper 15 and the lid 16 are opened and the exhaust fan 13 is rotated, the outside air flows into the cooling tower 1 not only from the gallery 6 but also from the upper outside air inlet 14. The outside air flowing from the gallery 6 is heated and humidified by the gas-liquid contact heat exchanging unit 7 as described above, and
Rises inside. The outside air flowing from the upper outside air inlet 14 passes through the heater 18 from the second air passage 19 and is discharged into the air passage 11, but is heated when passing through the heater 18. The heated air that has passed through the heating element 18 and the air that has been heated and humidified by passing through the gas-liquid contact heat exchange unit 7 are sufficiently stirred and mixed in the air passage 11 and exhausted from the exhaust port 12 to the atmosphere. No white smoke is generated during exhaust.

Further, regardless of whether or not air is introduced from the upper outside air inlet 14, the shielding plate 17 and the heater 18, which are installed at the corner of the tower in the air passage 11, are inclined. Flow and reduce ventilation resistance.

In order to prevent the generation of white smoke, the stirring and mixing of air in the air passage 11 is the most important point. To sufficiently perform the stirring and mixing, a duct is provided downstream of the heating element 18. Preferably, this duct extends to an appropriate position toward the center of the cooling tower 1.

Also, a small fan is provided for each heating element 18,
An embodiment in which air is pushed in is also possible. By the way, the distance between the eliminator 9 and the top plate 10 needs to have a predetermined minimum size in order to stabilize the air flow in the air passage 11 and to make the flow velocity uniform. When the required minimum dimension H is set, the installation position of the eliminator 9 is generally a virtual line S (see FIG. 2) drawn from the base 12a of the exhaust port 12 (see FIG. 2) at an angle of about 45 degrees with respect to the top panel 10. 2
(Indicated by a two-dot chain line in FIG. 2) is a point where the side wall 5 is abutted. In the cooling tower 1, the heating element 18 is
In the air passage 11 near the tower edge where the 0 and the side wall 5 intersect,
Since the heater 18 is installed at an angle of 45 degrees with respect to the top plate 10, the eliminator 9
There is no need to make the distance between the top plate 10 and the top plate 10 larger than the required minimum dimension H. Therefore, 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.

Further, when the heating element 18 is installed in the existing cooling tower 1 in which no measures are taken to prevent the generation of white smoke,
Remodeling is possible without changing the tower height of the cooling tower 1. FIG. 3 and FIG. 4 show a case where three cooling towers 1 are connected in close proximity to each other,
FIG. 5 shows a case where six cooling towers 1 are arranged in close proximity. Since the upper outside air inlet 14 is provided on the top panel 10, even when the cooling towers 1 are closely arranged in this way,
An outside air intake for the heating element 18 can be secured. As a result, when a plurality of cooling towers are connected in series, the installation space can be reduced.

<Examples> 1. Regarding the upper outside air inlet 14 The air volume introduced from the upper outside air inlet 14 is set to 20 to 30% of the total air volume of the cooling tower 1, and the wind speed of the air passing through the upper outside air inlet 14 is changed by gas-liquid contact heat exchange. If it is set to twice the wind speed of the air passing through the section 7, for example, in the case of the cooling tower 1 having an air passage cross section of 10 m square, the opening area of the upper outside air inlet 14 is 10 to 15 m ² (ie, 10 m ² ). ~
15%). When the upper outside air inlet 14 is provided along the four edges of the top plate 10 as in the above-described embodiment, the opening per upper outside air inlet 14 provided along one edge. The area is 1/4, about 2.5-4m ²
Becomes Further, if the upper outside air introduction port 14 provided along one edge is divided into four, the opening area per one becomes 0.4 to 1 m ² . Upper outside air inlet 14
If the opening area per one of these is sufficient, damper 1
5 and lid 16 can also be easily installed.

2. Heating Body 18 When the surface wind speed of the heating body 18 is 2.5 to 3 m / s, the heating body 18 needs an apparent area of 15 to 30% of the cross-sectional area of the cooling tower 1. Heating element 1 as in the above-described embodiment
If four 8 are provided along each side wall 5, an apparent area required for the heating body 18 can be secured without difficulty.

[0032]

As described above, according to the present invention,
An exhaust port having an exhaust fan at the top of the tower, a lower outside air inlet provided at least at a portion of the side of the tower, and a water sprinkling section for spraying water to be cooled into the tower located above the lower outside air inlet. Provided, between the lower outside air inlet and the water sprinkling section, the outside air introduced from the lower outside air introduction port flows upward, and the water to be cooled sprinkled from the water sprinkling section flows downward to cool the outside air and the water to be cooled. Providing a gas-liquid contact heat exchanging unit that makes contact and heat exchange, the inside of the tower located between the water sprinkling unit and the exhaust port is an air passage, and an upper outside air inlet is provided at the top of the tower,
In the air passage, provided a heating element for exchanging heat in a non-contact state between the outside air and the heat medium introduced from the upper outside air introduction port,
The outside air introduced from the lower outside air introduction port and heated through the gas-liquid contact heat exchange unit and the outside air introduced from the upper outside air introduction port and heated through the heating body are mixed in the air passage. In the enabled countercurrent cooling tower, the upper outside air inlet is provided at the top of the tower and outside the exhaust port, and the heating element is provided near the tower edge where the tower top and the tower side cross each other. By providing the passage in an inclined position, it is possible to reliably prevent the generation of white smoke during exhaust, and to keep the tower height low, making the cooling tower compact and reducing costs. There is an effect that can be. Further, there is an effect that the installation space can be reduced when a plurality of cooling towers are connected in series.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of one embodiment of a countercurrent cooling tower of the present invention.

FIG. 2 is an enlarged cross-sectional view of a main part of the countercurrent cooling tower according to the embodiment.

FIG. 3 is a plan view when three countercurrent cooling towers of the present invention are provided in series.

FIG. 4 is a longitudinal sectional view when three countercurrent cooling towers of the present invention are provided in series.

FIG. 5 is a plan view showing a case where six countercurrent cooling towers of the present invention are provided in series.

FIG. 6 is a longitudinal sectional view of a conventional countercurrent cooling tower.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Counter-current type cooling tower 5 Side wall (tower side part) 6 Gutter (lower outside air inlet) 7 Gas-liquid contact heat exchange part 8 Water sprinkling part (water sprinkling pipe) 10 Top plate part (tower top part) 11 Air passage 12 Exhaust port 13 Exhaust fan 14 Upper outside air inlet 18 Heating body

Claims (1)

[Claims] An exhaust port having an exhaust fan is provided at the top of the tower, a lower outside air inlet is provided at least at a part of the side of the tower, and cooling water is provided inside the tower located above the lower outside air inlet. A water sprinkling section for spraying water is provided, and between the lower outside air inlet and the water sprinkling section, the outside air introduced from the lower outside air introducing port flows upward, and the cooled water sprinkled from the water sprinkling section flows downward to allow the outside air to flow. A gas-liquid contact heat exchange unit for exchanging heat by contacting the water to be cooled is provided, an inside of a tower located between the water sprinkling unit and the exhaust port is used as an air passage, and an upper outside air inlet is provided at the top of the tower. In the air passage, a heating element for exchanging heat in a non-contact state between the outside air and the heat medium introduced from the upper outside air inlet is provided, and the heater is introduced from the lower outside air inlet and passes through the gas-liquid contact heat exchange unit. Introduced from the heated outside air and the upper outside air inlet Wherein the outside air heated through the heating element is allowed to be mixed in the air passage, wherein the upper outside air introduction port is provided at a tower top and outside the exhaust port, A counter-current cooling tower, wherein the heating element is provided in an inclined position in the air passage near a tower edge where a tower top part and a tower side part intersect.