JPH0429243Y2 - - Google Patents

Description

[Detailed description of the invention] A. Purpose of the invention (industrial application field) This invention relates to a heat exchanger used in a cross-flow cooling tower.

(Prior art) The air discharged from this type of cooling tower is hot and humid, and when the outside temperature is low, such as in winter, the moisture in the exhausted air solidifies and becomes white smoke when it is exhausted. Excreted from the mouth.

As a conventional technology to prevent the generation of white smoke, a cooling tower that mixes high temperature dry air with exhaust air to reduce humidity and increase the exhaust temperature is disclosed in Japanese Patent Publication No. 59-16200 and Japanese Patent Publication No. 60-45798. Official gazette and Japanese Patent Application Publication 1986-
Each is described in Publication No. 82780.

Of the three known examples above, in the cooling tower described in the first publication, outside air flows through all the gaps between the packing materials, and cooling water is supplied to every other gap by a cooled water distributor to keep them wet. Since the dry preheated air flow and the humid air flow are discharged from the outlet between the fillers in a nearly one-to-one ratio, all the fillers are effective in cooling the water to be cooled in winter. The cooling tower cannot be used as a cooling tower, and requires a specially constructed water distribution device to be cooled in place of the upper water tank that is normally provided in a normal cross-flow cooling tower, which reduces the heat exchange performance of the cooling tower as a whole. The structure is complicated, and it is difficult to mix the two types of air flows uniformly.

In addition, in the cooling tower described in the second publication,
A high-temperature dry air distribution mechanism consisting of a main duct and branch ducts is installed in the cooling tower exhaust passage without any modification to the filler, and the main duct of this distribution mechanism is connected to a high-temperature dry air generator to reduce white smoke in winter. In addition to the normal cross-flow type cooling tower, a high-temperature dry air generator and the above-mentioned distribution mechanism must be separately provided, resulting in a larger overall size and an increased occupied area.

The gas-liquid indirect contact type heat exchanger described in the third publication had an unnecessarily complicated structure, and the cross-sectional area of the outside air passage was narrow, resulting in low heat exchange efficiency.

B. Structure of the invention (means for solving the problem) This invention is a gas-liquid indirect contact heat exchanger for a cross-flow cooling tower that can be freely loaded between an upper water tank and a filler located directly below it. A large number of air-only channels, which are approximately parallel to the air flow direction passing between the fillers, are formed in parallel to form a tunnel-like structure. The passages are partitioned with water-impermeable wall plates that allow for free heat exchange.Both ends of these hot water flow passages in the air flow direction are closed, and the upper ends of the hot water flow passages are separated from the upper water tank. It serves as an inlet for flowing hot water, and its lower end is
The cross flow is provided as a sprinkling port for hot water to the filling material, and the narrow width of the dedicated hot water flow path is 1/2 to 1/3 of the width of the air dedicated flow path. This is a heat exchanger for type cooling towers.

(Function) The function of the heat exchanger of the present invention having the above structure will be explained below along with its usage method.

This heat exchanger is installed between the upper water tank and the filler in an existing cross-flow type cooling tower, and the discharge port of the air-only flow path opens into the cooling tower exhaust passage, and the inlet port opens into the cooling tower outside air intake. Assemble it so that it is facing.

The hot water in the upper water tank flows out from a group of small holes provided at its bottom, flows into each hot water flow dedicated passage from the inlet of the hot water flow dedicated passage in the heat exchanger, and flows downward from the water sprinkling port at the lower end. Spray on the filler.

The hot water flowing down on the surface of these fillers and between the fillers comes into contact with the airflow sucked in perpendicularly to the direction of flow of the hot water, as in a normal cross-flow cooling tower, and a portion of it evaporates. It is cooled by its latent heat action. The heated air that has cooled this hot water rises toward the exhaust port in a hot and humid state.

On the other hand, the outside air that flows into the air-only flow path of this hot water flow-down type heat exchanger does not come into direct contact with the hot water flowing through the narrow hot water flow-only flow path, and while moving within this flow path, This airflow is heated through the non-water permeable wall plate by the flowing hot water without increasing the absolute humidity, and is discharged as high-temperature dry air from the outlet of this air-only flow path into the cooling tower exhaust passage. be done.

The high-temperature and humid airflow rising through this filling material and the high-temperature dry air discharged from the outlet of the air-only flow path mix on the suction side of the exhaust fan, and although the humidity decreases, it remains white in winter. Exhaust without producing smoke.

(Example) Next, a typical example of the present invention will be described based on the drawings.

In FIG. 1 and FIG. 2, A is a heat exchanger, which has a box-shaped machine frame 10 as a whole, and this box-shaped machine frame 10.
Inside, a plurality of passages 11 exclusively for hot water flow and approximately horizontal tunnel-shaped air passages 12 formed between these passages 11 exclusively for hot water flow are arranged alternately in the width direction.

Each of the air-only channels 12 is formed to pass through the box-shaped machine frame 10 in the longitudinal direction, and one end thereof is connected to the inlet port 1.
3, and the other end serves as a discharge port 14. The adjacent hot water flow passage 11 and air exclusive flow passage 12 are separated from each other by a water-impermeable wall plate 15 made of, for example, synthetic resin and capable of free heat exchange.

Both ends 16 and 17 of the hot water flow dedicated passage 11 in the air flow direction are connected to end plates 18 and 1 of the machine frame 10.
9, and these hot water dedicated passages 11
The upper end is provided as a hot water inlet 20, and the lower end is provided as a water spout 21.

The width b of the hot water flow path 11 is approximately 1/2 to 1/3 of the width B ₀ of the air flow path 12, and the hot water flow path 11 and the air flow path 12 are as follows: It is formed in a wavy meandering manner in the vertical direction.

The ceiling walls of these air flow passages 12 are formed as upwardly convex round ceiling walls 22 that connect the hot water inlets 20 of the adjacent hot water flow passages 11.

An opening/closing damper 23 is provided on the discharge port 14 side of the air-only flow path 12 to open and close the discharge ports 14 of all the air-only flow paths 12 at the same time. It has a shape that projects into the exhaust passage 30 of the AC cooling tower A from its lower end 25 which is hinged to the machine frame 10.

Even if the opening/closing damper 23 is divided into two or three parts and the air flow rate from the discharge port 14 can be changed in stages, the invention remains the same.

Moreover, instead of the meandering shape, the hot water flow dedicated passage 11 and the air dedicated flow passage 12 may be formed straight, and even if the opening/closing damper 23 is not installed, the same technical scope can be achieved as this invention. belong to

This hot water flow-down type heat exchanger A is manufactured in advance as a single unit, and when used, it is attached to the top of the filler 32 filled in the main body 31 of the existing cross-flow type cooling tower A and the bottom surface of the water spraying tank 33. Loaded and assembled in between.

At the time of this assembly, the intake port 13 of the air-only flow path 12 opens to the outside air intake port 34 provided on the side wall of the main body 31, and the discharge port 14 thereof opens into the exhaust passage 30 of the cooling tower B. At the same time, the hot water inlet 20 of the hot water flow dedicated passage 11 is connected to the upper water tank 3.
The water sprinkling port 2 is located below the bottom of the water sprinkling hole 2 at the bottom of the
1 opens on the filling material 32 side.

In order to cool hot water by operating the exhaust fan 35 of the existing cross-flow cooling tower B incorporating the heat exchanger A, the opening/closing damper 23 is closed when the outside air temperature is high, such as in the summer. All the discharge ports 14 of the air-only flow path 12 are closed.

In this state, the high-temperature hot water in the upper water tank 33 is dropped onto the hot water flow dedicated passage 11 of the heat exchanger A, and is caused to flow down the hot water flow dedicated passage 11 in a meandering manner, and is caused to flow down through the water spout at the lower end thereof. 21 onto the filler material 32 below, and flow down the surface of the filler material 32.

On the other hand, due to the operation of the exhaust fan 35, the outside air intake port 34
Outside air is drawn into the main body 31 from the air.

At this time, since the discharge port 24 is closed, the outside air suction action of the exhaust port 35 does not reach the heat exchanger A, and no air flow is generated in the air-only flow path 12, and the air The air remains in the air-only flow path 22, and in this heat exchanger A, almost no indirect heat exchange is performed between the hot water and the air.

As a result, in the summer, the filling material 3
Heat exchange occurs due to the contact between the hot water flowing down the 2 surfaces and forming a wet wall, and the air that cools the hot water and raises its own temperature is exhausted from the exhaust port 36 to which the exhaust fan 35 is attached. Because the temperature is high, the exhausted air does not turn into white smoke like before.

Next, when the outside air temperature is low, such as in spring, summer, and winter, the opening/closing damper 23 is rotated around the hinge axis of the lower end 25, and the upper end 24 is extended into the exhaust passage 30 of the cooling tower B. , all the discharge ports 14 of the air-only flow path 12 in this heat exchanger A are fully opened.

As a result, due to the suction action of the exhaust fan 35, a part of the outside air taken in from the outside air intake port 34 flows into this air-only flow path 12 from its intake port 13, and while moving within this flow path 12, some of the outside air is Due to the heat conduction of the hottest water in the cooling tower A flowing down through the hot water flow dedicated passage 11, this air flow is indirectly heated from the outside via the wall plate 15, in other words, the hot water is cooled. The high temperature dry air is blown out from the discharge port 14 into the exhaust passage 30 of the cooling tower B with the absolute humidity unchanged.

The hot water that indirectly heats this air flow and cools down slightly is uniformly spread onto the filling material 32 through the hot water flow dedicated passage 11 of this heat exchanger A, as in the summer, and is taken in from the outside air intake port 34. The remaining part is brought into contact with the outside air flow and cooled in the conventional manner. The airflow, which cools the hot water and raises its own temperature, becomes a high-temperature and humid airflow and is sucked upward toward the exhaust port 36. This rising airflow is caused by the narrowed portion of the exhaust passage 16 formed by the opened damper 23.
The flow rate reaching the exhaust port 36 is controlled, and the air is mixed with the side air flow blown out from the discharge port 14,
The air is exhausted to the outside from the exhaust port 36. Due to this mixing, the humidity is lower than that of the air exhausted from the exhaust port 36, and even if it comes into contact with low-temperature outside air after being exhausted, the moisture in the exhausted air will not immediately solidify and will not turn into white smoke.

The mixing ratio of the hot dry air from the discharge port 14 to the hot and humid air is adjusted by the opening/closing degree of the damper 23 depending on the outside air condition.

In an embodiment that does not include the damper 23, a part of the outside air taken in from the outside air intake port 34 passes through the air-only flow path 12 from the suction port 13 throughout the four seasons, and is constantly supplied to the cooling tower from the discharge port 14. It blows out into the exhaust passage 30 of B.

C. Effects of the invention In the present invention, which is structured and operates as described above, the heat exchanger can be simply loaded and incorporated between the upper water tank and the filler without significantly modifying the existing cross-flow cooling tower. , it is possible to effectively prevent the generation of white smoke during periods when the humidity of the outside air is low, such as in winter, and to maintain the same hot water cooling capacity as in the past.

In particular, the width of the hot water flow passage is narrow, 1/2 to 1/3 of the air passage through which outside air flows, so the high-temperature flowing water fills it and comes into contact with all wall panels without intervening air. The air flows down and exchanges heat with the air flow through the wall plate.

(Effects Unique to the Embodiment) By setting the width b of the hot water flow dedicated passage 11 to a dimension of approximately 1/2 to 1/3 of the width of each air dedicated flow passage 12, the hot water flow dedicated passage 11
Fill the inside with high temperature water without mixing air flow,
The hot water that has passed through this can be sprayed onto the filler 32, and an amount of air that is independent of the amount of water to be cooled can be flowed per unit time in the hot water downflow heat exchanger A. As a result, sufficient outside air can be supplied in winter. It can be heated and effectively prevent the generation of white smoke.

The hot water flow dedicated passage 11 and the air dedicated flow passage 1
In the embodiment in which 2 is formed in a wave-like meandering manner in the vertical direction, the indirect contact area between the hot water and the outside air is wider, the intake air can be efficiently heated by the hot water, and the generation of white smoke can be prevented. At the same time, there is no fear that outside air will be mixed into the cooled downstream passage 21 from the lower end to the upper end, and the hot water will not bubble, allowing heat exchange with the outside air without any trouble.

In an embodiment in which the opening/closing damper 23 is attached to the discharge port 14 of the air-only passage 12 and the upper end 33 of the damper 23 is extended into the exhaust passage 30 of the cooling tower B when the damper 23 is opened, it is possible to By opening this damper 23 when the temperature is low,
An appropriate amount of high-temperature dry air blown out from the discharge port 14 can be mixed with the high-temperature and humid air rising from the filling material 32 side in the exhaust passage 30 of the cooling tower B, and the humidity is removed from the exhaust port 36. The mixed air with reduced humidity can be exhausted from the exhaust port 36, and white smoke can be prevented.
A part of the exhaust passage 30 of the exhaust passage 30 can be constricted, and the amount of hot and humid air sucked upward from the filler 32 side while passing through this constricted part is controlled.
It joins with the high temperature air from air 4, and can be further mixed and exhausted by the exhaust fan 15. Also, this damper 2
By adjusting the opening/closing degree of No. 3, the mixing ratio of the hot dry air from the discharge port 14 to the hot and humid air can be adjusted steplessly with a single operation while keeping the overall air volume almost constant.

By closing this damper 23 when the outside air temperature is high, such as in the summer, and closing the discharge port 14, the function of the hot water flow-down type heat exchanger A can be stopped. The warm water is sprayed onto all the filling materials 32 below from the hot water flow dedicated passage 11, and the hot water can be sufficiently cooled with outside air sucked through the outside air intake port 34.

In this embodiment of the cross-flow type cooling tower equipped with the hot water flow type heat exchanger A having the discharge port 14 without the damper 23, the structure is simplified and white smoke is generated without requiring the opening/closing operation of the damper 23. can be prevented from occurring.

In the embodiment in which the hot water flow passages 21 and the air flow passages 12 are straight, the cooled water air can pass through without swirling, and the structure can be simplified.

In an embodiment in which hot water inlets 20 of adjacent hot water flow passages 11 are connected to each other by an upwardly convex vaulted ceiling wall 22 forming a ceiling wall of the air flow passage 12, It is possible to smoothly flow the airflow without disturbing the airflow, and the hot water in the upper water tank 33 can be distributed and supplied without stagnation in the passage 11 exclusively for hot water flow.

[Brief explanation of the drawing]

The drawings are related to this invention: Fig. 1 is a side view of a typical embodiment, Fig. 2 is a general sectional view taken along line 2-2 in Fig. 1, and Fig. 3 is a 3-- A longitudinal sectional view taken along line 3 and FIG. 4 are schematic diagrams of a cross-flow cooling tower loaded with the heat exchanger shown in FIG. 1. Explanation of main symbols in the figure: A...Heat exchanger, 11
... Passage exclusively for hot water flow, 12... Channel exclusively for air.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. In a gas-liquid indirect contact type heat exchanger for a cross-flow cooling tower that can be freely loaded between an upper water tank and a packing material located directly below, air flow passing between the packing materials. A large number of air-only channels that are approximately parallel to the direction are formed in a tunnel-like manner, and between adjacent air-only channels, there are narrow hot water flow channels that are impermeable and heat-resistant. They are partitioned by replaceable wall plates, and both ends of these hot water flow passages in the air flow direction are closed, and the upper end of the hot water flow passage serves as an inlet for hot water flowing down from the upper water tank. The lower end serves as a hot water sprinkling port for the filling material, and the narrow width of the dedicated hot water flow path is 1/2 to 1/3 of the width of the air dedicated flow path. A heat exchanger for cross-flow cooling towers featuring: 2. The heat exchanger for a cross-flow cooling tower according to claim 1, wherein the hot water flow dedicated passage and the air dedicated flow passage are formed to meander in a wave-like manner in the vertical direction. 3. The ceiling wall of the air-only flow path is an upwardly convex round ceiling wall that connects the hot water inlets formed at the upper ends of the adjacent hot water flow-only paths. Heat exchanger for type cooling tower. 4. The outlet of the air-only flow path has an opening/closing damper whose lower end is hinged, and when the opening/closing damper is opened, the opening/closing damper is shaped so that its upper end extends from the lower end into the cooling tower exhaust passage. is a heat exchanger for a cross-flow cooling tower according to claim 1 or 2 of the registered utility model.