Consider the refrigeration cycle in hw – 36 and do the following.

(a) determine the rate of entropy generation for each of the components, in kw/k.
(b) determine the total rate of entropy generation using a single closed-system entropy balance for the entire cycle and compare to entropy generation rate from part (a).
(c) replace the throttling valve with a turbine having a 100% isentropic efficiency and compare the cycle cop and entropy generation rate to those of the original cycle. assume that the mass flow and all states except for state 4 are the same. is it worth considering this option?

Determine the time of the day and month of the year at which the peak sensible cooling load occurs for a top floor, north-eastern corner room of an office building in durban for the following conditions: floor area: 8 x 8 x 3 m east and north walls: 115 mm face brick (outside), 20 mm air space, 115 mm ordinary brick (inside) with 15 mm plaster roof construction: suspended plasterboard ceiling, 450 mm air space, 150 mm concrete, 75mm screed, waterproofing no heat transfer across other surfaces window area 3x 1,5 m high in north wall only. ordinary glass with venetian blinds. lights and occupants : from 07: 00 to 18: 00 average light density: 25 w/m2 number of occupants : 5 seated, light office work room temperature 24°c