Optimal operation of an Ammonia refrigeration cycle

Cyclic processes for heating and cooling are widely used in many applications and their power ranges from less than 1 kW to above 100 MW. Most of these applications use the vapor compression cycle to “pump” energy from a low to a high temperature level. The first application, in 1834, was cooling to produce ice for storage of food, which led to the refrigerator found in every home (Nagengast, 1976). Another well-known system is the air-conditioner (A/C). In colder regions a cycle operating in the opposite direction, the “heat pump”, has recently become popular. These two applications have also merged together to give a system able to operate in both heating and cooling mode.