JPH0829074A - White smoke preventing device for closed cross flow cooling tower - Google Patents

Abstract

PURPOSE:To reliably prevent the production of white smoke even during a winter season, in a closed cross flow cooling tower. CONSTITUTION:In a closed type cross flow cooling tower 1 wherein a white smoke preventing device for a closed type cross flow cooling tower comprises a blower 16, an upper water tank 4, a filler 6, a heat-exchanger 7, a lower water tank 8, and a sprinkling water pump 9, a suction surface forms monosurface or double surface suction, water from a load, (hereinafter referred to as process water), is cooled at a heat-exchanger 7 part by sprinkling water and air, and sprinkling water is cooled in the filler 6 through direct contact with air, the upper water tank 4 is partitioned in an arbitrary position as seen from the air suction port 3 side. Further, a branch tank 5 is arranged at the partitioned upper water tank 4, the inlet side is connected to the outlet side of the sprinkling water pump 9 through pipings 10 and 11, a bypass piping is located in the middle of one piping, and a direct flow to the lower water tank 8 is practicable. Moreover, wax type three-way valves 12 and 13 are incorporated in the bypass piping and the branch part of a sprinkling water piping.

Description

Detailed Description of the Invention

[0001]

[Industrial application] Cooling towers are widely used for cooling cooling water for air-conditioning equipment, industrial equipment, etc.
When the outside air temperature decreases, the air discharged from the cooling tower becomes white smoke, which is a problem. The present invention relates to a white smoke prevention device for a closed cross-flow cooling tower designed to prevent the white smoke.

[0002]

2. Description of the Related Art A cooling tower is used for cooling cooling water in air conditioning equipment, industrial equipment and the like. The air discharged from this cooling tower is hot and humid, and when the outside air temperature is low such as in winter, the humidity in the discharged air is discharged as white smoke.
There is a risk that it will be a traffic obstacle and that it may be mistaken for a fire if it is exposed to light at night. In order to prevent the generation of this white smoke, the conventional technology is to install a packing and a heat exchanger together, and a resin heat exchanger in the cooling tower or the packing part where the dry heat exchanger (plate fin coil) is arranged. There is a cooling tower that incorporates.

[0003]

The conventional closed type cooling tower with the dry heat exchanger is large in size because it requires a space for incorporating the dry heat exchanger, and the air pressure loss is large, so that a blower is required. Power up. Furthermore, a connecting pipe for the dry heat exchanger, a temperature control valve, etc. are required, and a special structure is required and a special tower body is required. On the other hand, the one in which the resin heat exchanger is incorporated in the packing becomes complicated in structure, and the cooling capacity is remarkably lowered in the winter season, which requires a large tower body, and the water temperature is lowered in the winter season to cause overcooling. Therefore, the ratio of moist air is higher than the ratio of dry air, and white smoke is likely to be generated. Further, since the air that has passed through the packing and the heat exchanger is rectified and not sufficiently mixed in the tower, there is a problem that white smoke is generated in the moist air portion when discharged to the outside air by the blower.

An object of the present invention is to reliably prevent the generation of white smoke in a closed cross-flow type cooling tower even in winter.

[0005]

In order to solve the above problems, the cooling tower of the present invention comprises a blower, an upper water tank, a packing, a heat exchanger, a lower water tank, a spray water pump, a three-way valve and a mixing plate. The upper water tank is partitioned at arbitrary positions when viewed from the air suction port side, and is formed as upper water tanks A and B. The spray water is sent by a spray water pump, but it is piped from the lower water tank to the spray water pump to the upper water tank, and a three-way valve is installed in the middle of each, and the spray water is bypassed directly to the lower water tank through the bypass pipe. It has become so. The three-way valve is a wax-type temperature control valve that automatically opens and closes according to the water temperature, closes the bypass side when the water temperature rises, and opens it when the water temperature falls. Of these, the three-way valve for the upper water tank A is fully opened on the bypass side when the water temperature becomes low, and the entire amount is bypassed.
The three-way valve for upper water tank B is on the bypass side 1 when the water temperature becomes low.
Open from less than 00% to about 50%, and the amount of water equivalent to this is bypassed. Packings, heat exchangers are provided in one stage or two or more stages, the heat exchangers provided in each stage are divided at the position of the partition of the upper water tank, and adjacent heat exchangers are connected by piping. The process water is cooled in the heat exchanger A and then in the heat exchanger B. Further, a mixing plate is provided on the air blowing side of the packing or on the blowing side of the heat exchanger so that the packing and the air blown from the heat exchanger are mixed in the tower. The mixing plate may be of a fixed type or a rotary type, and has a fixed V-shape, which is guided in parallel to the air flow from the packing or the heat exchanger, and is composed of a single unit or a plurality of units. In the case of the rotary type, two or more blades attached to the rotary shaft are formed so as to rotate by receiving the wind by the blower.

[0006]

[Operation] In the cooling tower of the present invention, the cooling water (process water) from the load passes through the tubes of the heat exchangers 7A and 7B on the left and right of each stage in the tower, is cooled, and is then sent to the load again. Further, the water in the lower water tank is sent to the upper water tank by a spray water pump, and the water is sent to each of the tanks partitioned on the left and right, and is sprayed from the water spray holes. The sprinkled water intersects with the outside air sucked by the blower at a right angle in the filling, the water and the air exchange heat by direct contact, the water is cooled, and the air is heated and humidified. Next, in the heat exchanger part, the water cooled in the filling flows along the outer surface of the pipe to cool the process water in the pipe.
At this time, the outside air sucked by the blower comes into direct contact with the sprayed water, and the sprayed water and the process water in the pipe are cooled by the evaporation heat of water. The sprayed water that has passed through the heat exchanger section passes through the lower packing material and the heat exchanger and is collected in the lower water tank. When the air passes through the packing and the heat exchanger, it is heated and humidified, mixed by a mixing plate, and then discharged outside the tower by a blower.
When the outside air temperature decreases in winter etc., the spray water temperature also drops, and the three-way valve installed in the middle of the pipe from the spray water pump to the upper water tank operates. Bypassing from less than 100% to about 50%. Therefore, no water is sent to the one upper water tank 4A side, and 50% to the other upper water tank B side.
Water is sent between 100% and water is sprayed from the water spray holes. On the side of the upper water tank 4A where the sprayed water does not flow, water does not flow in the filling and only air passes, and the outside air passes through the outer surface of the pipe in the heat exchanger 7A, and heat exchange with the process water in the pipe (sensible heat). Heat exchange), the outside air is only heated and the humidity drops,
The process water is cooled. On the other side of the upper water tank 4B,
Although the amount of sprayed water is small, heat exchange is performed as in summer.
In this case, the proportion of humidity with a small amount of sprayed water decreases. After the air passing through one of the packings 6A, the high temperature and low humidity air passing through the heat exchanger 7A, and the other packing 6B and the hot and humid air passing through the heat exchanger 7B are mixed by the mixing plate, the air is blown by the blower. Even if it is exhausted and exposed to low temperature outside air, it does not turn into white smoke due to high temperature and low humidity.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A white smoke prevention device for a closed crossflow type cooling tower according to the present invention will be described below with reference to the embodiments shown in the drawings. Figure 1,
In FIG. 2, reference numeral 1 is a closed cross-flow type cooling tower, both opposing surfaces of the tower body 2 are air inlets 3, and the upper water tank 4 is divided into two left and right by a partition plate 19, It is divided into one upper water tank 4A and the other upper water tank 4B. In the inside of the tower body 2, the packing 6 is also divided into the right and left like the upper water tank 4, and the packing 6A is placed below the upper water tank 4A.
In the same manner, the filler 6B is provided below the upper water tank 4B, and the heat exchanger 7 is also divided in the same manner to provide the heat exchangers 7A and 7B in one or more stages. A lower water tank 8 for collecting water is provided in the lower part. A blower 16 and an electric motor 17 for driving the blower 16 are provided on the upper portion of the tower body 2.

The process pipes 14 and 15 are heat exchangers 7A,
7B, and the left and right heat exchangers 7A
2 and 7B are connected by a connecting pipe as shown in FIG.

Next, the spray water pipes 10 and 11 are connected to the lower water tank 8.
Further, it is connected to the upper water tank 4 through a spray water pump 9 and a spray water pipe 10 and a spray water pipe 11, and the spray water pipes 10 and 11 have a three-way valve 12 and a three-way valve 13 incorporated therein.

A fixed mixing plate 18 is provided in the tower body 2 as shown in FIGS. When this mixing plate is of the rotary type, it is formed as shown in FIGS.

Next, the operation of the cooling tower according to the present invention constructed as described above will be described. The water (spray water) stored in the lower water tank 8 is sprayed by the spray water pump 9 to the spray water pipe 1.
It flows through the inside of 0 and 11, and is supplied to upper water tanks 4A and 4B, respectively. The sprayed water is sprayed from the spray holes of the upper water tanks 4A and 4B, passes through the fillers 6A and 6B and the heat exchangers 7A and 7B, and is collected in the lower water tank 8. The outside air is sucked in by the blower 16, heat is exchanged by direct contact between water and air in the fillers 6A, 6B, the sprayed water is cooled, the air becomes heated and humid, and the heat exchangers 7A, 7B process The sprayed water flows on the outer surface of the pipe through which water flows, heat is exchanged by direct contact between the sprayed water and air, and the process water in the heat exchanger is cooled mainly by the evaporation heat of water. The hot and humid air is mixed by the mixing plate 18, and then discharged by the blower 16 to the outside of the tower.

When the outside temperature decreases in winter, the three-way valve 1
No. 2 is fully opened to the bypass side, and spray water is not sent to the upper water tank 4A. A part (50% to less than 100%) of the three-way valve 13 flows to the bypass side, and the remaining water is sent to the upper water tank 4B.

Since the water is not sprinkled on the side of the upper water tank 4A, the air passing through the filling 6A is in the same state as the outside air, and the air passing through the heat exchanger 7A indirectly exchanges heat with the high temperature side of the process water flowing in the pipe ( Heat is exchanged by sensible heat), and the air is heated at a constant absolute humidity to become high-temperature low-humidity air. Next, in the upper water tank 4B side, the amount of sprayed water is sprinkled in a reduced state, the air passing through the filler 6B directly exchanges heat with the water to become hot and humid, and the air passing through the heat exchanger 7B comes into direct contact with the water. The heat is exchanged with the process water, and the process water is cooled by the evaporation heat at that time, and the spray water is also cooled, and the air becomes hot and humid.

Each packing 6A, 6B, heat exchanger 7A, 7B
The air that has passed through is mixed by the mixing plate 18 to become low-humidity air and is discharged to the low temperature outside air by the blower 16,
Does not produce super-saturated air and does not generate white smoke.

[0015]

According to the present invention, in the winter, one side of the upper water tank A side bypasses the entire amount of water due to the operation of the three-way valve and is not sprayed. It becomes dry air. On the other hand, on the side of the upper water tank B, the water is 50% to 100% due to the function of the three-way valve.
Bypassing less than%, the amount of water sprinkled is smaller than in the summer, so
The air that has passed through the filling material on the upper water tank side and the heat exchanger becomes medium-temperature and high-humidity air. Therefore, even if these blown-out air is mixed in the tower by the mixing plate and then discharged to the outside air whose temperature is lowered by the blower, it does not become supersaturated air, so that white smoke is not generated. Further, since the dry heat exchanger (plate fin coil) is not incorporated, the installation area is small, the piping of the dry heat exchanger is unnecessary, and no special tower body is required. Also, by incorporating a three-way valve in the middle of the spray water pipe and partitioning the upper water tank at any position, and by incorporating a mixing plate, an inexpensive tower can be used, and the partition of the upper water tank and selection of the three-way valve according to the capacity As a result, the cooling performance can be secured and the white smoke prevention function can be satisfied.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing an embodiment of a white smoke prevention device for a closed crossflow type cooling tower of the present invention.

FIG. 2 is a side view of the same.

FIG. 3 is a vertical sectional view of a different embodiment.

FIG. 4 is a transverse plan view of the same.

FIG. 5 is a detailed view of a header section.

FIG. 6 is a front view of a mixing plate.

[Explanation of symbols]

 1 Closed cross flow type cooling tower 2 Tower body 3 Air suction port 4 Upper water tank 5 Dividing tank 6 Filling material 7 Heat exchanger 8 Lower water tank 9 Spraying water pump 10 Spraying water piping 11 Spraying water piping 12 Three-way valve 13 Three-way valve 16 Blower 17 Electric motor 18 Mixing plate 19 Partition plate 20 Water amount control valve 21 Connection pipe 30 Header 32 Fixing plate 33 Bearing base 34 Rotating shaft 35 Bearing 36 Bearing 37 37 Sliding part

Claims (4)

[Claims] 1. A blower, an upper water tank, a packing, a heat exchanger,
It consists of a lower water tank, spray water pump, etc. The suction surface is one side or two sides suction, the water from the load (hereinafter referred to as process water) is cooled by the spray water and air in the heat exchanger section, and the spray water is filled. In a closed cross-flow type cooling tower that is cooled by direct contact with air inside an object, the upper water tank is partitioned at an arbitrary position as seen from the air suction port side, and a dividing tank is provided for each partitioned upper water tank. , The inlet side is connected to the outlet side of the spray water pump by piping, and one pipe is provided with a bypass pipe on the way to directly flow out to the lower water tank, and at the branch part of the bypass pipe and the spray water pipe. Is a white smoke prevention device for a closed cross flow type cooling tower, which is equipped with a wax type three-way valve. 2. The packing constituting the cooling tower and the heat exchanger are constituted by a single stage or two or more stages, and each stage of the heat exchanger is divided at the position of the partition plate of the upper water tank, and each stage is divided. The white smoke prevention device for a closed cross-flow cooling tower according to claim 1, wherein each heat exchanger is connected to each other. 3. A mixing plate is provided immediately below the blower at the packing outlet or the heat exchanger outlet, and is placed in a V-shape parallel to the flow of air from the packing or the heat exchanger. 2. The white smoke prevention device for a closed cross-flow cooling tower according to claim 1, wherein the mixture and the outlet air from the heat exchanger are mixed with each other. 4. A mixing plate is provided immediately below the blower at the filling material outlet portion or the heat exchanger outlet portion, and two or more blades attached to the rotary shaft rotate by receiving the wind by the blower, The white smoke prevention device for a closed cross-flow cooling tower according to claim 1, wherein the outlet air from the heat exchanger is mixed.