Evaporative condenser for refrigeration systems are now becoming popular in refrigeration system due to various benefit, Shell and tube condensers are used to be most widely used condensers for the condensation of high pressure refrigerant of refrigeration system with cooling water.
In countries where cooling water is available at above 30 Deg C, there is possibility of energy saving with the use of Evaporative Condenser. In general cooling tower is designed for 3-4 Deg C approach and cooling water is pumped to the condenser with a typical difference of 5 Deg C of inlet and outlet cooling water temperature. For understanding cooling tower approach, click here
Approach in condenser (Condensation temp of liquid – Cooling water return temperature) typically lies from 3-5 Deg C. if we see complete cycle of condensation the temperature difference between condensation temperature and wet bulb temperature is 12-14 Deg C. A Cooling tower, Pump and piplines are required for perform task of cooling in refrigeration system.
This complete process of cooling tower,pumping and condensation can be integrated to evaporative condenser,
The evaporative condenser is essentially a combination of a water-cooled condenser and an air-cooled condenser, utilizing the principle of heat rejection by the evaporation of water into an air stream traveling across the condensing coil.
Evaporative condensers can be designed to operate refrigerants condensation point to 7-10 Deg C above wet bulb temperature. Thus reducing condensation temperature by 3-4 Deg C along with lower pumping cost. Reduction of 1 Deg C in condensation power will save approx 2.5% of Specific power consumption (SPC) in case of NH3 refrigerant and 3% of SPC in case of R134 refrigerant. for impact study of condensing temperature on power consumption, please click here
Benefit with evaporative condenser
With evaporative condenser of refrigeration system power saving can be expected in the range of 12-20% in comparison with conventional condensers. Saving will depend on the the design of both condensers, installation location & water quality. Typical payback for the investment can be expected as 15-24 Months depending upon power and equipment cost.
For guideline on efficient chiller operation please click here