RU2295099C2 - Cooling tower - Google Patents

Abstract

FIELD: heat exchange apparatus and direct-action sprinkling cooling plants.

SUBSTANCE: proposed cooling tower has housing with air supply nozzles, openings in casing and additional openings and water-to-air ejector. Each water supply nozzle is located inside tubular envelope introduced in housing; water-to-air ejectors are formed by air supply nozzles and tubular envelopes; clearances between air supply nozzles and tubular envelopes are filled with air and additional openings are formed by above-mentioned clearances; water supply nozzles and tubular envelopes are arranged inside cooling tower housing in such position that their inlet end faces are located near openings in casing.

EFFECT: enhanced heat exchange due to increased velocity of air flow and additional suction of "cold" air by energy of flow; saving of energy.

2 dwg, 1 tbl

Description

The invention relates to heat exchange units, and more particularly to irrigation refrigeration facilities (direct contact) of the type of cooling towers and can be used in the petrochemical industry.

Known analogues are fan cooling towers (Gladkov V.A., Arefyev Yu.I., Ponomarenko BC “Fan cooling towers.” M.: Stroyizdat, 1976, p. 127, Fig. 33), including a housing (frame, fastened with panels forming a continuous casing) and water supply nozzles located inside the casing. Moreover, the tower body has a special shape - cylindrical from the bottom - with free openings near the soil surface and a more complex shape (for installing a fan) at the top. An axial fan driven by an electric motor is installed in the upper part of the tower. The essence of the work of cooling towers is that the "hot" circulating water supplied from the production process to the cooling tower enters the casing inside the water supply nozzles, which form water flows - jets of a given length and diameter. At this time, the included electric motor rotates the axial fan blades, which draws air into the free openings (made at the bottom of the cylinder of the tower tower) and pumps it through jets of water. Water jets transfer heat to the air stream and are emitted by the fan into the atmosphere. Chilled water is collected in the lower part - on the bottom of the tower, with a pump returns to the production process for reuse.

The disadvantage of analog designs - fan cooling towers are:

- the need for power consumption of the fan motor and

- the costs associated with the laying and maintenance of power and control electric lines of the fan.

Known fan tower containing an exhaust tower with air ducts around the perimeter in the lower part, an air trap, a water distribution system with tapering nozzles and a tower located symmetrically relative to the longitudinal axis, an irrigator and a pool, which is divided into sections by partitions made of bimetal zigzag with the formation of alternating sections staggered confusers and diffusers (RF Patent No. 2200924, 7 F 28 С 1/00, BIPM No. 8, 2003). The disadvantage of this tower is also an overestimated power consumption.

Closest to the proposed technical solution is the design of a natural draft tower cooling tower used for cooling water in industry (Handbook of heat exchangers. In 2 volumes. Volume 2. Translated from English. Edited by OG Martynenko and others. - M .: "Energoizdat", 1987, p.128-129. Section 3.12.3, Fig. 1). The design of the cooling tower includes a tower-type casing (high frame with a “window”) and open (for air flow) openings in the casing. The openings are made in the lower ground zone of the tower casing. Inside the body of the tower cooling tower placed water supply nozzle.

The essence of the specified cooling tower is as follows. The circulating water to be cooled from the production cycle is pumped to the cooling tower and enters the housing into the water supply nozzles. Nozzles form a stream of water in the form of jets (the required sizes - length and diameter), films, mixed drip-air flows, increasing the open-contact heat exchange surface. At the same time, through open lower openings (in the cooling tower housing), under the influence of a tower traction, air flows enter the housing, which, in contact with the surface of the jets (films, drops), take part of the thermal energy. The contacted air with water vapor rises to the upper part of the tower building and "leaves" into the atmosphere. The temperature of the water flows decreases. Water jets then fall freely into the lower part of the tower, falling on the collecting bottom. Then, the pump returns water to the production cycle. The disadvantage of the design of the tower are: - low permissible specific thermal load on the tower and the increased temperature of the returned (into production) chilled water (in the summer). These disadvantages are due to the low speeds of the natural self-exhausting movement of the cooling air flow, which reduce the intensity of the heat exchange process.

The objective of the invention is to increase the intensity of heat transfer by increasing the speed of air flows and additional suction of "cold" air with the energy of water flows, as well as reducing the energy consumption.

This object is achieved in that the tower contains a housing with air-supplying nozzles, openings in the casing and additional openings, a water-air ejector. According to the invention, each water supply nozzle is placed inside the pipe shell introduced into the housing, the water-air ejectors are formed by said air supply nozzles and pipe shells, while gaps between the air supply nozzles and pipe shells are filled with air, and additional openings are formed by said gaps, while the water supply nozzles and pipe shells are placed inside the casing of the tower so that their inlet ends are located near the openings in the casing. The ratio of the inner diameter of the tube shell and the outer diameter of the water supply nozzle is 1.05-1.03: 1.

Figure 1, 2 shows a longitudinal section of the proposed cooling tower. In both sections, for simplicity, two nozzles with tube shells are shown. The frame of the cooling tower is conventionally not shown. In the embodiment of FIG. 1, pipe shells are inserted into a cooling tower casing. In the embodiment of FIG. 2, they are placed inside the casing with input ends located near existing openings in the casing. The proposed cooling tower is a frame-shield housing 1 with open openings below 2. The introduced pipe shells 3 according to the embodiment of FIG. 1 are inserted into the housing 1 with the formation of additional annular openings 4. According to the embodiment of FIG. 2, the pipe shells 3 are placed inside the housing 1 so that their inlet ends 5 are located near the existing openings 2. Inside each tube shell 3 there is a water supply nozzle 6, fed from a collector 7 located outside - Figure 1 or inside - Figure 2 of the tower body 1. The dimensions of each tube shell 3 and the water supply nozzle 6 are taken from the condition for the formation of a water-air ejector (occurrence in the annular opening - the gap 4 between the nozzle 6 and the shell 3 of a vacuum injecting air).

The work of the proposed cooling tower is as follows. The circulating circulating water used in the production with a supply of thermal and kinetic energy enters the collector 7 and then to the water supply nozzle 6. With high-speed outflow of water from the nozzles 6 placed inside the tube shells 3, a vacuum is formed (in accordance with the theory of the jet apparatus), which the additional (to the coming from the openings 2) air flow is sucked into the casing 1 of the tower. The intake air stream, accelerated by chamber vacuum, acquires an additional increase in speed to the speed created by self-pulling. Moreover, in the embodiment of FIG. 1, the air flow drawn into the annular gaps 4 is an additional volume to the flow entering the cooling tower body 1 through the openings 2.

In the event that the device of additional openings in the housing 1 of the tower complicates the design of the housing 1, it is permissible to place the input ends 5 of the pipe shells 3 near the already existing openings 2, as shown in Fig.2.

Thanks to the proposed solution - the implementation of air-powered ejectors on the basis of the water-supplying nozzles, the speed and volume of air masses passing through the cooling tower are increased, which ensures an increase in the heat transfer rate, an increase in the volume of hot air discharged and a decrease in the temperature of the circulating water cooled in the cooling tower (and again supplied to the production). The realized additional and accelerated air flow carried away by the ejection liquid — water and directed to the upper part of the tower — increases the mass fraction of the sprayed water in the tower in suspension, i.e. longer contact with “cold” air, which also increases the heat transfer rate. Moreover, it is possible not only air intake by the introduced designs of the inkjet apparatuses from the existing openings of the tower, but separate ring gaps-openings in the casing of the tower can be arranged.

The proposed solution is useful to use the previously unclaimed part of the energy of the water jet - kinetic, given to it by existing pumps that pump water. Moreover, the previously unclaimed kinetic energy of water jets was realized in increased erosion wear of the internal surfaces and elements of the cooling tower.

With the introduction of the proposed technical solution, the proportion of kinetic energy of the jets leading to equipment wear is reduced. The table below shows an example and technical and economic indicators of the proposed cooling tower in an industrial environment.

Cooling Tower Performance Prototype cooling tower Proposed cooling tower 1. Water consumption, m3 / h 4500 4500 2. Water consumption for recharge (loss), m3 / h 400 230 3. The temperature of the supplied water, ° C 28 28 4. Chilled water temperature, ° C 22 19 4. The presence of electric motors, pcs. 3 - 5. Air flow for cooling, m3 / h 3300 3500 6. Cooling surface, rel. units one 1,2

The table shows the advantage of the proposed cooling tower. Implementation is scheduled for 1 square. 2005 at Kuibyshevazot CJSC. The expected economic effect will be 1.8 million rubles per year.

Claims (1)

A cooling tower comprising a housing with air supply nozzles, openings in the casing and additional openings, a water-air ejector, characterized in that each water supply nozzle is placed inside the pipe shell introduced into the housing, water-air ejectors are formed by said air-supply nozzles and pipe shells, with gaps between the air-supply nozzles and pipe shells are filled with air, and additional openings are formed by the indicated gaps, while water-supplying nozzles and pipe shells are placed inside the gradient casing so that their inlet ends are located near the openings in the casing.

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