Avapour compression cycle using r134a refrigerant operated with an evaporator absolute pressure of 2 bar and a condenser saturation absolute pressure of 8 bar. the vapour entering the compressor is saturated at 2 bar and the liquid leaving the condenser is saturated at 8 bar. assuming the compression process is isentropic i. sketch the process on a p-h diagram. ii. identify the pressure and enthalpy at each of the four points on the refrigeration cycle. iii. calculate the coefficient of performance of the cycle.

Amass of m 1.5 kg of steam is contained in a closed rigid container. initially the pressure and temperature of the steam are: p 1.5 mpa and t 240°c (superheated state), respectively. then the temperature drops to t2= 100°c as the result of heat transfer to the surroundings. determine: a) quality of the steam at the end of the process, b) heat transfer with the surroundings. for: p1.5 mpa and t 240°c: enthalpy of superheated vapour is 2900 kj/kg, specific volume of superheated vapour is 0. 1483 m/kg, while for t 100°c: enthalpy of saturated liquid water is 419kj/kg, specific volume of saturated liquid water is 0.001043m/kg, enthalpy of saturated vapour is 2676 kj/kg, specific volume of saturated vapour is 1.672 m/kg and pressure is 0.1 mpa.

The y form of iron is known as: a) ferrite b) cementite c) perlite d) austenite

Different types of steels contain different elements that alter the characteristics of the steel. for each of the following elements, explain what the element does when alloyed with steel.