RU2267727C2 - Vertical eddy-type evaporative condenser - Google Patents

Abstract

FIELD: refrigerating engineering.

SUBSTANCE: the vertical eddy-type evaporative condenser has an axial-flow fan with profiled blades, eddy heat exchanger in the form of a tube twisting the air flow with U-shaped ribs fastened on the outer surface and forming ducts for passage of the refrigerant agent, separator, water collecting tray, filter, circulation pump, comb and nozzles for irrigation of the tube inner surface. The tube is vertical and air flow is fed into it from the bottom upwards at an angle of 30-60 deg. to the tube generating line, and water is injected into the counter-flow through the nozzles. The condenser has a trap for collection of the water film drained over the tube inner and outer surfaces, at the bottom of the tube the fan body is positioned with a clearance in the mentioned trap, the separator is installed in the upper part of the tube and provided with a trap with a perforated bottom, positioned in the lower part of the separator, and with a truncated rim guiding the water flow in the form of a film over tube outer surface.

EFFECT: enhanced efficiency.

2 cl, 4 dwg

Description

The invention relates to refrigeration and can be used on distribution refrigerators, refrigerators, meat and fruit processing industry.

Known evaporative condensers used in industry, including fans, heat exchangers, a condenser, a casing and a circulation pump (see Refrigeration. Heat exchangers, automation devices and testing refrigeration machines. Reference book. M .: Legpischeprom, 1984).

The commercial operation of such evaporative condensers shows that a “water stone” (salt deposition) is formed on their heat exchange surface from the water side, which significantly impairs heat transfer and reduces the productivity of the apparatus.

To restore the initial characteristics of the apparatus, the "water stone" must be cleaned.

Cleaning "water stone" is a very time-consuming operation and is not always possible due to inaccessibility to the tube bundle pipes inside it.

The prototype is a vortex evaporative condenser (see AS No. 185941, USSR). The vortex evaporation condenser is a large diameter pipe enclosed in a common casing, on the outside of which there are wavy troughs, inside which the refrigerant vapor condenses. The air is sucked in by the fans in the upper part of the apparatus, washes the outer surface of the pipes, goes into the pan, then goes through the swirls and moves inside the pipes in the form of a vortex. Water is sprayed into the swirling flow of air inside the pipes through the nozzles. Then the air, passing the separator, is discharged into the environment. Drops of water are separated from the air stream in the separator.

To intensify heat and mass transfer through nozzles, the outer surface of the pipes is also irrigated.

The disadvantage of such a vortex evaporation condenser is the presence of a swirler, the absence of irrigation of the inner surface of the pipes with nozzles after the swirl.

Due to the horizontal arrangement of the heat exchanger tubes from the corrugated gutters, the condensed refrigerant is slowed down, and therefore the heat transfer is deteriorated, in addition, the apparatus occupies a relatively large usable area.

These shortcomings are accompanied by increased both mass and cost indicators.

The basis of the invention is the task of improving the "Vertical Vortex Evaporative Condenser" by reducing the occupied area, equipping devices to ensure its operability and, as a result, the intensification of heat transfer and the reduction of mass indicators.

The problem is solved in that in a "Vertical vortex evaporative condenser" containing an axial fan with profiled blades that swirl the air flow, a vortex heat exchanger in the form of a pipe with U-shaped ribs fixed on the outer surface, forming channels for the passage of refrigerant, a separator, a tray for water collection, filter, circulation pump, comb and nozzles for irrigation of the inner surface of the pipe, according to the invention in a vertical heat exchange pipe is swirling upward th air flow fan at an angle to the forming pipe of 30 ° ÷ 60 °, while in counterflow water is sprayed through the nozzles.

At the bottom of the heat exchanger there is a trap for collecting a film of water flowing down the inner and outer surfaces of the pipe, and at the bottom of the pipe the fan housing is placed with a gap in the specified trap, and the separator is installed in the upper part of the pipe and equipped with a trap with a perforated bottom located in the lower part of the separator, and a conical rim directing the flow of water in the form of a film along the outer surface of the pipe.

As follows from the above, the vertical installation of the heat exchanger contributes to higher runoff rates of the liquid condensate film of the refrigerant inside the channels formed by the U-shaped ribs, as well as the water film both on the inner and outer surfaces of the pipe, which significantly intensifies the heat transfer of the apparatus.

In addition, the vertical installation of the vortex heat exchanger significantly reduces the occupied usable area.

The flow into the heat exchanger of air flow swirled by axial fans from the bottom upward at an angle of 30 ° to 60 ° to the generatrix of the pipe contributes to the action of a field of centrifugal forces that cause water droplets sprayed by nozzles (in counterflow) to penetrate the air flow at a high relative speed, which contributes to intense heat and mass transfer in the volume of the pipe.

Figure 1 shows a vertical vortex evaporation condenser.

Figure 2 shows a cross section of a separator with zigzag plates and a perforated bottom of the water trap.

Figure 3 shows a cross-section of a heat exchanger with U-shaped ribs forming channels for condensation of a vaporous refrigerant inside them.

Figure 4 shows a cross section at the level of the fan and trap for collecting water flowing from the inner and outer surfaces of the vortex heat exchanger.

The vertical vortex evaporation condenser includes a separator 1 with zigzag plates 17, a water trap 2 with a perforated bottom, a vapor supply pipe 3 for refrigerant vapor, U-shaped ribs 4, a heat exchanger pipe 5, an atomizer comb 6, nozzles 7, drain pipes 8, a circulation pump 9 , a filter 10, a pan 11 for collecting water, a fan 12, a trap 13 for trapping a film of water from the inner surface of the pipe 5, a pipe 14 for draining the liquid refrigerant, a cone-shaped rim 15 for draining the water and feeding it to the outside surface heat exchanger, a displacement cone 16, a bottom 18, a trap for collecting water from the outer surface of the film tube.

Vertical swirl evaporative condenser operates as follows.

Air from the environment is taken in by an axial fan 12, the blades of which swirl the flow and feed it into the heat exchanger pipe 5 at an angle to the pipe generatrix 30 ° ÷ 60 ° (depending on the process intensification required by the heat and mass transfer conditions). The swirling air flow in the pipe creates a field of centrifugal forces, which rejects at high relative speed (relative to the air flow) water droplets sprayed into the counter-flow to the flow by nozzles 7. As a result of the contact of numerous water droplets rapidly moving relative to the air flow, intense heat and mass transfer occurs , as a result, water droplets are cooled and fall on the inner surface of the pipe 5, where they flow down in the form of a film. In the lower part of the pipe, a trap 13 is installed, in which flowing water is collected. From the trap 13, the drain pipes 8 drain water into the pan 11. From the pan 11 through the filter 10 with the pump 9, water is drawn and fed to the comb 6, where it is distributed through the nozzles 7 over the entire volume of the pipe 5. The air flow swirled at the inlet of the pipe 5 by the fan 12 moves from bottom to top and carries with it part of the drops of water.

To separate water droplets from the air stream, a separator 1 with zigzag vertical plates 17 is installed in the upper part of the heat exchanger. For uniform displacement of air with small drops of water along the height of the separator, a cone 16 is installed inside it.

Once in the separator 1, a rotating air stream with water droplets is evenly distributed along the lateral inner surface of the separator and, through the gaps between the zigzag plates 17, enters the environment.

The presence of zigzags between the plates contributes to a change in the direction of movement of the air flow with water droplets and the latter to drop onto the surface of the plates and in the form of a film to flow down. A trap 2 with a perforated bottom is arranged in the lower part of the separator, which makes it possible to evenly distribute a stream of water along the perimeter of the pipe. After passing through the perforated bottom, water enters the cone-shaped rim 15, which facilitates its entry onto the outer surface of the pipe 5, where it flows into the trap in the form of a film 18. The trap 18 has a perforated bottom, from where the water flows into the trap 13 and then into the tray 11.

The refrigerant vapors pass through pipeline 3 into vertical channels formed by U-shaped ribs, which are interconnected at the top and bottom (not shown), condense on their walls and flow down in the form of a film and into the refrigeration system through pipeline 14. Condensation is carried out by removing heat from the refrigerant vapor with a film of water moving from top to bottom along the inner and outer surfaces of the heat exchanger.

The built-in fan with a clearance in the lower trap contributes to the compactness of the fan-trap assembly.

The vertical arrangement of the heat exchanger creates the conditions for rapid removal from the heat exchange surface of both the liquid refrigerant inside the channels and the film of water from the inner and outer surfaces, which contributes to an increase in heat transfer.

Claims (2)

1. A vertical vortex evaporative condenser containing an axial fan with profiled blades twisting the air flow, a vortex heat exchanger in the form of a pipe with U-shaped ribs fixed on the outer surface, forming channels for the passage of refrigerant, a separator, a water collection tray, a filter, a circulation pump , comb and nozzles for irrigation of the inner surface of the pipe, characterized in that the pipe is made vertical and it is supplied from the bottom up air flow at an angle to the generatrix of the pipe are 30-60 °, and in counterflow water is injected through nozzles. 2. The condenser according to claim 1, characterized in that it contains a trap for collecting a film of water flowing down the inner and outer surfaces of the pipe, the fan housing being placed with a gap in the indicated trap at the bottom of the pipe, the separator is installed in the upper part of the pipe and equipped with a perforated trap the bottom, located at the bottom of the separator, and a cone-shaped rim directing the flow of water in the form of a film on the outer surface of the pipe.

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