Air is cooled from 300 K to 273 K as it flows steadily through a duct....

Air is cooled from 300 K to 273 K as it flows steadily through a duct. Frictional dissipation may be neglected. Cooling is achieved by removing heat via a heat pump. The work requirement is 1.15 times that of a reversible heat pump operating between 263 and 310 K. For each mole of air flowing through the duct, calculate: Air can be assumed an ideal gas with a constant heat capacity cP of 3.50R. The temperature of the surroundings is 300 K

a) Total irreversibility in J/mole

b) Irreversibility due to heat transfer between air and the heat pump

c) Irreversibility due to heat transfer between the heat pump and the surroundings

d) Internal irreversibility of the heat pump

Expert Solution

Amanda K answered 5 months ago

Heat flows from a reservoir at 373 K to a reservoir at 273 K through a...

Heat flows from a reservoir at 373 K to a reservoir at 273 K through a 0.39-m copper [thermal conductivity 390 J/(s

Air flows through a 0.25-m-diameter duct. At the inlet the velocity is 300 m/s, and the...

Air flows through a 0.25-m-diameter duct. At the inlet the velocity is 300 m/s, and the stagnation temperature is 90°C. If the Mach number at the exit is 0.3, determine the direction and the rate of heat transfer. For the same conditions at the inlet, determine the amount of heat that must be transferred to the system if the flow is to be sonic at the exit of the duct.

1) Air is flowing steadily through a cooling section where it is cooled from 86 °F...

1) Air is flowing steadily through a cooling section where it is cooled from 86 °F to 59 °F at a rate of 0.55 lbm/s. If the average COP of the air-conditioner is 2.8 and the unit cost of electricity is $0.07 per kWh, determine the cost of electricity consumed by this air-conditioner per day (24 hours). 2) A heat pump absorbs heat from the cold outdoors at 3 °C and supplies heat to a house at 20 °C at...

Air flows through a constant area duct. The pressure and temperature of the air at the...

Air flows through a constant area duct. The pressure and temperature of the air at the inlet to the duct are P1 = 100 kPa absolute, and T1 = 298 K, respectively. Inlet Mach number is M1 = 0.1. Heat is transferred to the air as it flows through the duct and as a result the Mach number at the exit increases. Write a Matlab code and plot the following: a) Find the pressure and temperature at the exit, while...

3) Air flows steadily at the rate of 0.4 kg/s through an air compressor, entering at...

3) Air flows steadily at the rate of 0.4 kg/s through an air compressor, entering at 6 m/s with a pressure of 1 bar and a specific volume of 0.85 m3/kg, and leaving at 4.5 m/s with a pressure of 6.9 bar and a specific volume of 0.16 m3/kg. The internal energy of air leaving is 88 kJ/kg greater than that of the air entering. Cooling water in a jacket surrounding the cylinder absorbs heat from the air at...

Air flows through a short duct with a smooth inside surface and gradually changing flow area....

Air flows through a short duct with a smooth inside surface and gradually changing flow area. The measured flow rate is equal to 288 lbm/min. At the duct inlet, the temperature is equal to 82 deg F, and the pressure is equal to 15 psia. The inlet velocity is equal to 924 ft/s. At the duct exit, the pressure is equal to 21.7 psia. (I.) Calculate the cross-sectional flow area of the duct inlet. (II.) Estimate the temperature and velocity...

Air flows through a heating duct with a square cross-section with 5-inch sides at a speed...

Air flows through a heating duct with a square cross-section with 5-inch sides at a speed of 5.3 ft/s. Just before reaching an outlet in the floor of a room, the duct widens to assume a square cross-section with sides equal to 13 inches. Compute the speed of the air flowing into the room (in ft/s), assuming that we can treat the air as an incompressible fluid. Answer should be in Ft/s

Air flows steadily through a converging-diverging nozzle with a throat area equal to 1.395 in2 ,...

Air flows steadily through a converging-diverging nozzle with a throat area equal to 1.395 in2 , and an exit area equal to 2.79 in2 . A normal shock wave stands at the exit plane of the nozzle. The exiting jet flows into a large room, where the pressure is equal to 14.7 psia. The temperature of the air in the exit jet stream, just after the nozzle exit, is measured at 87 deg F. Calculate the mass flow rate through...

Hot air flows with a mass flow rate of 0.05 kg/s through an insulated square duct...

Hot air flows with a mass flow rate of 0.05 kg/s through an insulated square duct with side of 0.15m, the hot air enters at 103 oC and after a distance of 5m, cools to 85 oC. The heat transfer coefficient between the duct outer surface and the ambient air (Tair = 0 oC) is 6 W/m2 K. Calculate the heat transfer coefficient between hot air and duct inner wall. Air Cp = 1.011 KJ/kg K; air k = 0.0306...

In an air-conditioning system, dry air flows over tubes carrying refrigerant R134a. The air is cooled...

In an air-conditioning system, dry air flows over tubes carrying refrigerant R134a. The air is cooled by transferring heat to the R134a; the air enters with a volume flow rate of 0.75 m3 s–1 at 305 K and 100 kPa, and it exits at 290 K and 95 kPa. The R134a enters at 4 bar in a vapor-liquid coexistence state with a quality of 20%; it exits at 4 bar and 30 °C. Ignoring heat transfer at the outer surface...

Question