Ammonia enters the compressor of a refrigeration plant and is compressed from 190.2kPa, 98% dry to 972.2kPa with 50K of superheat. The refrigerant leaves the condenser as a liquid at 24°C and circulates with a mass flowrate of 5kg/min. Calculate: (a). compressor power (b). heat rejected in the condenser per minute (c). coefficient of performance (d). condition at entry to evaporator (e). plant capacity if enthalpy of fusion is 333kJ/kg

Example: 100 TR refrigeration capacity of air condition plant using R134a has evaporating and condensing temperature of 0°C and 35°C respectively, the refrigerant enters with degree of super heat of 7°C. Find 1- Dryness fraction of the vapour entering the evaporato. 2- The mass flow rate of refrigerant, and 3- COP of the system

A vapour-compression refrigeration system operates with Refrigerant 134 with two evaporators with varying cooling capacity. The low temperature evaporator (#1) operates at -20°C with saturated vapour at its exit and has a refrigeration capacity of 3 tons. The higher temperature evaporator (#2) produces saturated vapour at 3.6 bar at its exit and has a refrigerating capacity of 2 tons. Compression is isentropic to the condenser pressure of 12 bar. There are no pressure drops in the flow through the condenser and the two evaporators and the refrigerant leaves the condenser as saturated liquid at 12 bar. Determine: The mass flow rate of the refrigerant in kg/s through each evaporators;The power input for the compressor, in kW;The coefficient of performance of this refrigeration system;The heat transfer through the condenser in kW;The rates of exergy destruction in each expansion valves in kW for T0 = 300K;Draw the T-s diagram of this system.

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