The use of Evaporators and Condensers with high Thermal T ransfer Efficiency

In Indian industry, the specific power consumption for chilled water 6 8C, moderately well-kept vapour compression systems is likely to be around 0.8 kW/TR (only for compressors, pumps and fans are not included). The best systems available in India today can give specific power consumption-less than 0,6 kW/TR (capacity of the compressor). In the United States, in normal specific power consumption figures refrigeration plants will be approximately 0.56 kW/TR. High efficiency of the cooler Trane, USA, has the specific power consumption of 0.48 per kW/TR.

This low specific energy consumption has been achieved mainly through the use of larger and more efficient heat transfer area in the cooler and condenser. A large area involves a more efficient heat transfer. This, in turn, implies that the temperature of the refrigerant, for the same heat load will be higher in the evaporator and below in the condenser. Table 3.2 shows clearly that above the evaporator temperature and low temperature condenser lead to a significant reduction in specific energy consumption at the compressor inlet. Therefore, replacement of refrigeration/ capacitors or extension of areas of adding additional coolers/condensers at the same time can lead to significant energy savings.

1C above the temperature at the evaporator or 1C below the temperature of the condenser can reduce specific energy consumption by 2%to 3%. The use of plate heat Exchangers for Process and Condenser Cooling Refrigeration Machine using plate heat Exchangers for cooling the condenser may lead to lower temperature of the approach, therefore, reducing the power consumption of the compressor. Plate heat exchangers have a temperature of approach 1C 5C instead of about 5C 10C for shell and tube heat exchangers.

Avoid the Use of Air Cooled Condensers

To take advantage of the wet bulb temperature, avoid the use of air-cooled condensers for cooling large loads. Air cooled condensers can be admitted only for cooling of small loads or in conditions of the extreme shortage of water, or the lack of space for the cooling tower. Use the lowest temperature of the condenser water that hmm handle.

Evaporative Pre-chillers with Air-cooled Condensers

The performance of air-cooled condensers limited to the dry bulb temperature. The performance of these capacitors can be improved, in the dry weather conditions, providing humidified air near wet bulb temperature. It's a pre-cooler consists of a filler with the trickling of water, through which air enters. Depending on the design, fan power can be increased or auxiliary fan may be required to overcome an additional resistance to air flow. Energy saving potential in the dry summer months, may be about 30% to 40%...