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 a rate of 30,000 kJ/h. If the power consumed by the heat pump is 3 kW, find the coefficient of performance of the heat pump.

3) A heat engine cycle is executed with steam in the saturation dome. The pressure of steam is 2 MPa during heat addition, and 0.1 MPa during heat rejection. Determine the highest possible efficiency of this heat engine.

4) A heat engine receives heat from a source at 800 °C and rejects the waste heat to a sink at 40 °C. If heat is rejected from this engine at a rate of 80 kJ/s, what is the maximum power this heat engine can produce?

Solutions

Expert Solution

samet mamat answered 1 year ago

Next > < Previous

Related Solutions

Air containing 50,000ppm acetone at 1 atm is cooled from 150°F to 0°F. What percent of...

Air containing 50,000ppm acetone at 1 atm is cooled from 150°F to 0°F. What percent of the acetone will condense when cooled?

An incompressible fluid is flowing through a vertical pipe with a constriction. The wide section is...

An incompressible fluid is flowing through a vertical pipe with a constriction. The wide section is 2.00 cm in diameter and is at the top of the pipe. The pressure of the fluid in the wide section at the top is 200 kPa. The velocity of the fluid in the wide section is 4.00 m/s. The narrow section is located 4.00 m below the wide section. What is the diameter of the narrow section for the pressure of the fluid...

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 flowing at 1000 ft3 /min, 66°F, and 1 atm enters a heat exchange unit and...

Air flowing at 1000 ft3 /min, 66°F, and 1 atm enters a heat exchange unit and exits at 76°F and 1 atm. Saturated steam at 12 psia is used to heat the air and leaves the unit operation as saturated water at 12 psia. The system is not adiabatic and heat is lost to the surroundings at -3 Btu/lbm steam condensed. Calculate the mass flow rate of the steam.

Consider a pipe (diameter of 50 mm) with air flowing through it. The inlet conditions are:...

Consider a pipe (diameter of 50 mm) with air flowing through it. The inlet conditions are: Mach 3; total pressure = 1000 kPa and 550 K. The friction coefficient (f) is 0.004. The exit Mach number decreases with the length of the pipe. Assume adiabatic, steady flow. Write a short Matlab code and plot the following, while the exit Mach number changes from 2.5 to 0.99 with increments of ?M=0.01. Find the length of the pipe that is going to...

Air enters a 30-cm-diameter cooling section at 1 atm, 35 C, and 60 percent relative humidity...

Air enters a 30-cm-diameter cooling section at 1 atm, 35 C, and 60 percent relative humidity at 120 m/min. The air is cooled by passing it over a cooling coil through which cold water flows. The water experiences a temperature rise of 8 C. The air leaves the cooling section saturated at 20 C. (a) Determine the rate of heat transfer. Round your answer to the nearest tenth. Qout = _____ kJ/min (b) Determine the mass flow rate of...

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...

The resistance of blood flowing through an artery is R = C L r4 where L...

The resistance of blood flowing through an artery is R = C L r4 where L and r are the length and radius of the artery and C is a positive constant. Both L and r increase during growth. Suppose r = 0.1 mm, L = 1 mm, and C = 1. (a) Suppose the length increases 10 mm for every mm increase in radius during growth. Use a directional derivative to determine the rate at which the resistance of...

Air at 1 atm flowing at a rate of 0.1 kg / s has to be...

Air at 1 atm flowing at a rate of 0.1 kg / s has to be cooled from 400 to 300K in a tube of 10 cm in diameter with a uniform wall temperature of 250 K. Determine the length of the tube.

1. An aluminum air-cooled engine cylinder head for a single cylinder, 2-stroke engine is to be...

1. An aluminum air-cooled engine cylinder head for a single cylinder, 2-stroke engine is to be die-cast. The overall diameter of the cylinder head is 101.6 mm. If the projected plan area of the runners and gating system is 100 mm2 and the casting pressure is 10 MPa (1500 psi), what minimum locking force is required for the die-casting machine in kN.

Subjects