Chapter 5, Problem 5.66P

The heat loss from a chicken coop (chicken house) is K(Tnside - Totside) during the winter, where K is 1.5 kW/K. The chicken coop temperature can vary between 15 °C and 25 °C without harming egg production. A heat pump with a coefficient of performance of 40% of that of a reversible heat pump is used to heat the chicken coop. What are the minimum power requirements if the outside temperature is -5 °C? .

A bio-reactor is kept at 42°C by a heat pump driven by a motor of 2 kW. The reactor loses energy at a rate of 0.5 kW per degree difference to the colder ambient. The heat pump has a COP that is 50% that of a Carnot heat pump. What is the minimum ambient temperature for which the heat pump is sufficient?

3.0 A cold storage is to be maintained at -5°C while the surroundings are at 35°C. The heat leakage from the surroundings into the cold storage is estimated to be 30 kw. The actual C.O.P. of the refrigeration plant used is one third that of an ideal plant working between the same temperatures. Find the power required to drive the plant.

A solar collector absorbed 40W/m2 heat from the atmosphere. This is equal to the convection brought by air for drying purpose. If the temperature of the air is 40C while the solar collector area's temperature is 80C and neglecting effect of radiation, find the convective heat transfer coefficient.

Find out the COP of a Carnot heat pump operating between temperatures 6o C and 37o C.

A refrigeration system has a heat added of 440 kw. If COP is 7,find the mass of cooling water in the condenser for a temperature increase of 14°C.

A building is being heated through the help of a Carnot heat pump and is required to be maintained at 20 degrees C always. When the temp outside drops to -10 degrees C, the rate at which heat is lost from the building is 25kW. What is the minimum electrical power required (kW) in order to drive the heat pump?

A heat engine with a thermal efficency of 45% rejects 500kJ/kg of heat. How much heat does it recieve?

A system is proposed to generate power from wastewater of 54C. If the ambient temperature is 23C, what is the highest thermal efficiency of this system in %?