Chapter 5, Problem 5.38P

An air conditioner is a device used to cool the inside of a home. It is, in essence, a refrigerator in which mechanical work is done and heat removed from the (cooler) inside and rejected to the (warmer) outside. A home air conditioner operating on a reversible Carnot cycle between the inside, absolute temperature T2, and the outside, absolute tempera- ture T1 > T2, consumes P joules/sec from the power lines when operating continuously. (a) In one second, the air conditioner absorbs Q2 joules from the house and rejects Q1 joules outdoors. Develop a formula for the efficiency ratio Q2/P in terms of T1 and T2. (b) Heat leakage into the house follows Newton's law Q = A(T, – T2). Develop a formula for T, in terms of T1, P, and A for continuous operation of the air conditioner under constant outside temperature T and uniform (in space) inside temperature T2. (c) The air conditioner is controlled by the usual on-off thermostat and it is observed that when the thermostat set at 20°C and an…

Find the mean effective pressure of the thermodynamic cycle shown in the figure below.

Air within a piston-cylinder assembly executes a Carnot heat pump cycle, as shown in the figure below. For the cycle, TH = 600 K and TC = 300 K. The energy rejected by heat transfer at 600 K has a magnitude of 1000 kJ per kg of air. The pressure at the start of the isothermal expansion is 325 kPa.   Assuming the ideal gas model for the air, determine: (a) the magnitude of the net work input, in kJ per kg of air, and (b) the pressure at the end of the isothermal expansion, in kPa.