A refrigerator operates on the ideal vapor-compressionrefrigeration cycle and uses refrigerant-134a as the workingfluid. The condenser operates at 300 psia and the evaporatorat 20F. If an adiabatic, reversible expansion device were availableand used to expand the liquid leaving the condenser, howmuch would the COP improve by using this device instead ofthe throttle device?

A thermodynamic cycde operates between a hot reservoir at temperature T ana a cold reservoir at 280 °K. A stcady State, the cycie generates 40 kw of power while rejècting 1000 kJ/min of energy by heat transfer to the Cold reservoir. Determine the minimum theoretical value for T in °K using 5 signifigant Figures.

Part (a)  The second step in the Otto cycle is isochoric (constant-volume) heating. Calculate the heat absorbed by the gas during this process, in joules, if the temperature is increased so that T3 = 1.53T2.  Part (b)  Calculate the pressure at the end of the isochoric heating step, in pascals, to three significant figures.  Part (c)  The third step in the Otto cycle is adiabatic expansion, which brings the volume back to its initial value. Calculate the work preformed on the gas, in joules, during the third step.  Part (d)  The fourth and last step in the Otto cycle is isochoric cooling to the initial conditions. Find the amount of heat, in joules, that is discharged by the gas during the fourth step.  Part (e)  Calculate the efficiency of this Otto cycle, expressed as a percent.

Suppose that heat removal from your kitchens electric refrigerator (including freezer) is at an average rate of 450 W. Assuming ideal operations at hot summer, estimate how much power must the refrigerator extract from the main wall power point?