Chapter 6, Problem 6.107P

Referring to the reversible heat pump cycle shown in the figure, p₁ = 14.7 lb/in², p = 41.5 lb/in², v₁ = 12.6 ft³/lb, v4 = 6.0 ft³/lb, and the gas is air obeying the ideal gas model. Step 1 Determine TH, in °R, and the coefficient of performance. Determine TH, in °R. TH= i P4 ºR P1 V4 VI 3 Tμ V

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.

H6. An air conditioner in an upper-floor apartment unit is turned on during a hot summer afternoon. If heat can be removed from the interior at a rate of 1.5 kW, estimate the time required to cool the air inside the apartment to its final temperature. Your estimate should create any needed input data and should incorporate factors like the size of the apartment and the behavior of air.

A thermodynamic cycle receives 150 J of heat from a cold reservoir and rejects 165 J of heat to a hot reservoir. What is its coefficient of performance as a refrigeration cycle, (B) ?

As shown in the figure, an air conditioner operating at steady state maintains a dwelling at 70°F on a day when the outside temperature is 103.5°F. The rate of heat transfer into the dwelling through the walls and roof is 30,000 Btu/h and the net power input to the air conditioner compressor is 3.45 hp. Step 1 B Inside, 70° F Determine the coefficient of performance for the air conditioner. = Evaporator i 30,000 Btu/h Determine the coefficient of performance of the air conditioner. Determine the power input required, in hp, and the coefficient of performance for a reversible air conditioner providing the same cooling effect while operating between the same cold and hot temperatures. Refrigerant loop Compressor Outside Q + Condenser

Air within a piston-cylinder assembly executes a Carnot heat pump cycle, as shown in the figure below. For the cycle, TH = 400 K and Tc = 300 K. The energy rejected by heat transfer at 400 K has a magnitude of 625 kJ per kg of air. The pressure at the start of the isothermal expansion is 325 kPa. TH Te p-v diagram for a Carnot gas refrigeration or heat pump cycle. 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.

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 625 kJ per kg of air. The pressure at the start of the isothermal expansion is 325 kPa. Part A 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. |Wcycle/m| = i TH Save for Later 4 Assuming the ideal gas model for the air, determine the magnitude of the net work input, in kJ per kg of air. kJ/kg p-v diagram for a Carnot gas refrigeration or heat pump cycle. Attempts: 0 of 5 used Part B The parts of this question must be completed in order. This part will be available when you complete the part above. Submit Answer

4. Two and one-half pounds of air actuate a cycle composed of the following processes: polytropic compression 1-2, with n = volume 3-1. The known data are: D1 = 20 psia, ti = 100°F, Qr = -1682 Btu. Determine (a) T2 nd Ts, (b) the work of the cycle using the pV plane, in Btu; (c) Qu (d) the thermal 1.5; constant pressure 2-3; constant efficiency, and (e) pn. Ans. (a) 1120°R, 4485°R; (b) 384.4 Btu; (c) 2067 Btu; (d) 18.60%: (e) 106.8 psia

Data are provided for two reversible refrigeration cycles. One cycle operates between hot and cold reservoirs at 27°C and 3°C, respectively. The other cycle operates between the same hot reservoir at 27°C and a cold reservoir at -35°C. The refrigerator removes the same amount of energy by heat transfer from its cold reservoir. Determine the ratio of the net work input values of the two cycles, WCycle,2 Wcycle,1