Refrigerating Systems. Evaporative condensers

Evaporative condensers, apparently, with water-cooled design and principle of operation of the cooling through evaporation of water in the moving air stream. The effectiveness of this evaporative cooling depends on the wet bulb temperature of the air entering the unit, airflow volume and efficiency of air/water interface.

Evaporative condensers use jets of water and air for the condensation of the refrigerant vapor inside the tubes. The condensed refrigerant flows into a reservoir called liquid receiver. Refrigerant sub-cooling can be achieved by passing the liquid from the receiver back through a sump where additional cooling reduces the temperature of the liquid even further.

In evaporative condenser (Fig. 3.19a), cooled fluid circulates inside the pipe heat exchanger coil. The flows of heat from the process liquids through the coil pipe out of the water, which cascades down the tube. Air is forced up through the coil, vaporizing a small percentage of water absorbing the latent heat of vaporization, and the discharge of heat to the atmosphere. The rest of the water falls into a settling tank for recirculation pump and the water is involved in the airflow will be recultivated and returned to the sump of the mist separators loading device. Only water is consumed, the number of evaporated plus a small fee that intentionally injected limit the concentration of impurities in the pan. With more advanced surface coil water recirculation pump can be switched off and the unit operated dry periods belowdesign ambient temperatures. Air continue to go up through the coil, but the heat now dissipated into the atmosphere reasonable cooling alone.

Below are some of the characteristics of these capacitors:

Reduction of water circulation capacity,
Water treatment
Limited space requirement
Smal the pipe sizes and short overall length,
Smal system pumps, and
The presence of large volume and indoor configurations.

The amount of water used evaporative condensers, is significant. Not only water will evaporate, just to reject heat, but water must be added to avoid the buildup of dissolved solids in the basins of the evaporative condensers. If these solids build up to such an extent that they foul condenser surfaces, the performance of the unit can be greatly reduced.

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