In induced hypothermia, the temperature of a particular organ, such as the heart, is lowered to reduce the metabolic rate during surgery. Cooling is achieved by circulating blood through a heat exchanger  outside  the  body. When the cooled blood is reintroduced through blood vessels in the organ, it cools the organ to the desired temperature. Develop the preliminary design of a vapor-compression refrigeration system to cool blood during heart surgery. Determine the necessary temperature requirements and specify a refrigerant, operating pressures and temperatures for the working fluid, and the refrigeration capacity.