TAKES in AMBIENT air and raises its pressure.The temperature of the air is increased when it flows through the combustion chamber where fossil fuel is burned or a HEAT exchanger (nuclear fuel being used as a source of energy) is present.The high-pressure, high-temperature WORKING fluid, mostly a gas, enters a turbine where it expands to low pressure (equal to or a little above the atmospheric pressure) fluid.In an open cycle, the gas is released from the turbine to the surroundings.A significant part of the power developed by the turbine is utilised to drive the compressor and any other auxiliaries and the remainder is available as the useful work. Condenser:It is a heat transfer device in which exhaust steam of turbine or an engine is condensed by means of cooling water at a pressure below to the atmospheric.The condensed steam is known as condensate.In a steam power plant, the condensate from the condenser is used as feed water to the boiler.Vapour compression refrigeration cycleThe above-mentioned figure is a schematic diagram of vapour compression refrigeration cycle.Process 1-2 : isentropic compressionProcess 2-3 : constant pressure heat rejectionProcess 3-4 : iso-enthalpic expansionProcess 4-1 : constant pressure heat absorptionFrom the schematic diagram, we can see that the components of the vapour compression cycle areEvaporator; Compressor; Expansion valve; Condensor.vapour absorption system:In the vapor absorption system, the energy input is given in the form of the heat.While in the vapour compression system the energy input is given in the form of the mechanical work from the electric motor run by the electricity.Waste Heat or free energy is effectively used in the vapour absorption refrigeration cycleThus, the Vapour absorption system works on low-grade thermal energy such as waste heat or solar energy.The compressor of the vapour compression cycle requires large quantities of power for its operation, in case of the vapour absorption system refrigeration system, the pump requires a very small amount of power.