Steam at 2 MPa and 250°C in a rigid cylinder is cooled until the quality is 30%. Find the heat rejected from the cylinder. @ 2 Mpa and 250°C: υ = 0.11144 m3/kg u = 2679.6 kJ/kg @ 2 Mpa, (saturated): υf = 0.0011767 m3/kg υg = 0.09963 m3/kg uf = 906.44kJ/kg ug = 1693.8 kJ/kg

An ideal gas turbine operates with a pressure ratio of 10 and the energy input in the high temperature heat exchanger is 300 kW. Calculate the air flow for temperature limits of 30°C and 1200°C.

Predict the pressure of nitrogen gas at T = 200 K and υ = 0.00385 L/g and b = 0.00141 L/g; a = 0.178 L2-kPa/g2. Use Van der Waals equation.

A pump delivers 20 cfm of water having a density of 62 lb/ft³. The suction and discharge gage reads 5 in. Hg vacuum and 30 psi respectively. The discharge gage is 5 ft above the suction gage. If pump efficiency is 70%, what is the motor power?

Specific volume is the number of cubic meters of mixture per kilogram of dry air. If dry air has these following properties: Ra = 287 J/kg-K, T = 303 K, Pa = 99.604 kPa. Solve for the specific volume

A cubical tank of 2 m sides is constructed of metal plate 12 mm and contains water at 75°C. The surrounding air temperature is 16°C. Calculate the overall heat transfer coefficient from water to air. Take the coefficient of thermal conductivity of the metal as 48 W/m-K, the coefficient of heat transfer of water is 2.5 kW/m²-K and the coefficient of heat transfer of the air is 16 W/m²-K

One insulated wall of a cold-storage compartment is 8 m long by 2.5 m high and consists of an outer steel plate 18 mm thick. An inner wood wall is 22.5 m thick. The steel and wood are 90 mm apart to form a cavity which is filled with cork. If the temperature drop across the extreme faces of the composite wall is 15°C. Calculate the heat transfer per hour through the wall and the temperature drop across the thickness of the cork. Take the coefficients of thermal conductivity for steel, cork and wood as 45, 0.045, and 0.18 W/m-K respectively.

A centrifugal pump with a 3 ft impeller diameter operates at 800 rpm. If the speed is to be increased to 1200 rpm, determine the impeller diameter that should be used so that the same shaft input power would be required.

A gas turbine power plant operating on the Brayton cycle delivers 15 MW to a standby electric generator. What are the mass flow rate and the volume flow rate of air if the minimum and maximum pressures are 100 kPa and 500 kPa respectively and temperature of 20°C and 1000°C?

An air compressor takes in 9 kg/min of air at 98 kPa; υ1 = 0.125 m³/kg and discharges it at 680 kPa; υ2 = 0.03 m³/kg. The increase of internal energy is 93 kJ/kg and the work done on air is 163 kJ/kg; the change in potential and kinetic energy are neglected. How much heat is transferred per kg of air?

The weight of ammonia circulated in a machine is found to be 21.8 lb/hr. if the vapor enters the compressor with a specific volume of 9.6 ft³/lb, calculate the piston displacement, assuming 80% percent volume efficiency.

A vapor compression refrigeration system is designed to have a capacity of 150 tons of refrigeration. It produces chilled water from 22°C to 2°C. Its actual coefficient of performance is 5.86 and 35% of the power supplied to the compressor is lost in the form of friction and cylinder cooling losses. Determine the condenser cooling water required for a temperature rise of 10°C.

Compute the amount of condensate formed during a 10 minute warm-up of 180 meter pipe conveys the saturated steam with enthalpy of vaporization, hfg = 1947.8 kJ/kg. The minimum external temperature of pipe is 2°C. The final temperature of pipe is 195°C. The specific heat of pipe material is 0.6 kJ/kg-°C. The specific weight is 28 kg/m.

A liquid with a specific gravity of 1.26 is being pumped in a pipeline from A to B. At A, the pipe diameter is 60 cm and the pressure is 300 kN/m². At B, the pipe diameter is 30 cm and the pressure is 330 kN/m². Point B is 1.0 m lower than A. Find the flow rate if the pump puts 16kW into the flow. Neglect head loss

A steam generator with economizer and air heater has an overall draft loss of 25.78 cm of water. If the stack gases are at 177°C and if the atmosphere is at 101.3 kPa and 26°C, what theoretical height of stack in meters is needed when no draft fan is used? Assume that the gas constant for the flue gases is the same as that for air.

Steam is expanded through a nozzle and the enthalpy drop per kg of steam from the initial pressure to the final pressure of 60 kJ. Neglecting friction, find the velocity of discharge and the exit area of the nozzle to pass 0.20 kg/s if the specific volume of the steam at exit is 1.5 m³/kg

If the load on water-cooled condenser is 150,000 Btu/hr and the temperature rise of the water in the condenser is 10°F, what is the quantity of water circulated in gpm?

A 150 Hp motor is used to drive the compressor. If the heat loss from the compressor is 25 kW and the mass flow rate of the refrigerant entering the compressor is 0.50 kg/s, determine the difference of the enthalpies between the inlet and outlet of the compressor

The tank of an air compressor has a volume of 3 ft³ and is filled with air at a temperature of 40°F. If a gage on the tank reads 150 psig, what is the mass of the air in the tank?

Calculate the drive horsepower for pumping 1703 L/min cold water to a tank suction at 127 mmHg vacuum, delivery at 5.3 kg/cm² ga., both measured close to pump, ep = 0.65.

A Pelton type turbine has 25 m head friction loss of 4.5 m. The coefficient of friction head loss (Morse) is 0.00093 and penstock length of 80 m. What is the penstock diameter?

An ideal Brayton cycle has a net work output of 150 kJ/kg and backwork ratio of 0.4. if both the turbine and the compressor had an isentropic efficiency of 80%, the net work output of the cycle would be?

The journals of a shaft are 380 mm diameter, it runs at 105 rpm and the coefficient of friction between journals and bearings is 0.02. If the average load on the bearings is 200 kN, find the heat generated per minute at the bearings.

A fan draws 1.42 m3 per second of air at a static pressure of 2.54 cm of water through a duct 300 mm diameter and discharges it through a duct of 275 mm diameter. Determine the static fan efficiency if total fan is 75% and air is measured at 25°C and 760 mm Hg.

A model pump delivering water at 180°F (γ = 60.6 lb/ ft^3; pvapor = 7.54 psia) at 900 gpm and 2500 rpm begins to cavitate when the inlet pressure and velocity are 13 psia and 22 fps. Find the required NPSH of a prototype which is 4 times larger and runs at 1100 rpm.

The tailwater and headwater of a hydro-electric plant are 150 m and 200 m respectively. What is the water power if the flow is 15 m³/s and a head loss of 10% of the gross head?

A single acting, twin cylinder, Ammonia compressor with bore equal to stroke is driven by an engine at 250 rpm. The machine is installed in a chilling plant to produce 700 kW of refrigeration at -18°C evaporating temperature. At this temperature the cooling effect per kg mass is 1160 kJ. The specific volume of vapor entering the compressor is 0.592 m^3 per kilogram. Assume 85% volumetric efficiency, determine the bore in mm.

A piston-cylinder device whose piston is resting on top of a set of stops initially contains 0.50 kg of helium gas at 100 kPa and 25°C. The mass of the piston is such that 500 kPa of pressure is required to raise it. How much heat must be transferred to the helium before the piston starts rising?

To what height will a barometer column rise if the atmospheric conditions are 13.9 psia and 68°F and barometer fluid is ethyl alcohol? Note: @ 68°F; Pv =138.5 lbf/ft^3 and specific gravity of 0.79 for ethyl alcohol: