A refrigerating plant for an air-conditioning system removes 10,000 Btu/min from the air. The plant circulates 170 lb. of refrigerant per min and the internal power delivered is 60 Hp. The refrigerant evaporation temperature is 40 F, and it's condensation temperature is 100F. Calculate the capacity of the plant in tons. (include diagram)

Explain the condenser coils of a refrigerator must be cleaned periodically, and the airflow passages must not be blocked to maintain high performance.

I think its Chemisty... If an evaporator outlet temperature on an R-410A system is 50f and the evaporator superheat is 10f, what is the evaporating pressure of the refrigerant in the system?

Superheated steam at 18 MPa, 560 °C enters the steam turbine. The pressure at the exit of the turbine is 0.06 MPa and saturated liquid water leaves the condenser at 0.06 MPa. Pressure is increased to 18 MPa again after the pump. Find: (a) Sketch the process on a T-s diagram. (b) The net work per unit of steam flow in kJ/kg. (c) Heat transfer to steam passing through the boiler, in kJ/kg.