Awall 2 cm thick is to be constructed from material that has an average thermal conductivity of 1,3 w/m.°c. the wall is to be insulated with material having an average thermal conductivity of 0.35 w/m.ºc, so that the heat loss per square meter will not exceed 1830 w. assuming that the inner and outer surface temperatures of the insulated wall are 130°c and 30°c, calculate the thickness of insulation required.

Refrigerant-134a enters the compressor of a refrigerator as superheated vapor at 0.14 mpa and -10°c at a rate of 0.05 ka/s and leaves at 0.8 mpa and 50°c. the refrigerant is cooied in the condenser to 0.72 mpa and 26'c. it is then throttled to 0.15 mpa. sketch the t-s diagram for the system and evaluate: 6) the rate of heat removai from the refrigerated space (kw), it) the power input to the compressor (kw), ii) the isentropic efficiency of the compressor (%), and iv) the cop of the refrigerator.