The arena refrigeration plant uses ammonia as a refrigerant to transfer heat from the brine to the evaporative condenser. When ammonia leaves the compressor, it is in a superheated state. At a typical pressure of 170 psig, the temperature of the superheated vapour would be around 240°F.
A hot gas desuperheater could be installed in the hot gas line to draw heat from the compressed ammonia to preheat domestic hot water or flood water.
From an energy savings standpoint, desuperheaters can deliver significant amounts of energy with relatively short paybacks. From a practical standpoint, however, costs associated with a poorly designed or poorly maintained desuperheater system can far outweigh the energy savings. One small ammonia leak can quickly erase years of utility savings.
Install bypass circuits on both the refrigerant and heated water lines so that normal operation can continue in the event of a leak within the unit.
Issues and Concerns
Care must be taken throughout the detailed design and commissioning stages to ensure that a high quality desuperheater is selected and properly installed. Annual inspections and maintenance must be undertaken to ensure that problems do not arise over the life of the equipment.
Analysis text here