PEPPA P3

The rate of flow of water in a pump installation is 60.6 kg/sec. The intake static gage is located 1.22 m below the pump centerline and reads 68.95 kPa gage; the discharge static gage is 0.61 m below the pump centerline and reads 344.75 kPa gage. The gages are located close to the pump as much as possible. The area of in intake and discharge ppes are 0.093 m^2 and 0.069 m^2, respectively. The pump efficiency is 70% . Take density of water equals 1000 kg/m^3. What is the hydraulic power in kw?

Water in the rural areas is often extracted from underground water source whose free surface is 60 m below ground level. The water is to be raised 5 m above the ground by a pump. The diameter of the pipe is 10 cm at the inlet and 15 cm at the exit. Neglecting any heat interaction with the surroundings and frictional heating effects, what is the necessary power of the pump for a steady flow of water at the rate of 15liters in kw?

A pump delivers 500 gm of water against a total head of 200 ft and operating at 1770 rpm. Changes have increased the total head to 375 ft. At what rpm should the pump be operated to achieve the new head at the same efficiency?

A pump operating at 1750 pm delivers 500 gal/min against a total head of 150 ft. Changes in the piping system have increased the total head to 360 ft. At what rpm should the pump be operated to achieve this new head at the same efficiency?

It is desired to deliver 5 m^3/s at a head of 640 m in a single stage pump having specific speed not to exceed 40. If the speed is not to exceed 1352 rpm, how many stages are required?

An air compressor is to compress 8.5 m^3 per min from 98.56 KPa to 985.6 kPa. Assuming conditions ideal, and with n= 1.3, what will be the saving in work due to two staging?

A single stage air compressor handles 0.454 m^3/sec of atmospheric pressure, 27°C air, and delivers it to a receiver at 652.75 kPa. Its volumetric efficiency is 0.72, its compression efficiency on an isothermal basis is 0.85 and its mechanical efficiency is 0.90. If it rotates at 350 rpm, what power in kw is required to drive it?

N ideal single-stage air compressor without clearance takes in air at 100 kPa with a temperature of 16 degree C and delivered it at 413 KPa after isentropic compression. What is the discharge work done by the compressor in kJ/kg?

A two-stage compressor with an ideal intercooler receives 0.5 kg/s of helium at 120 kPa and 300°K and discharges it at 4500 kPa. Calculate the intercooler pressure in kPa.

What is Hp supplied to air moving at 20 fpm through a 2 x 3 duct under a pressure of 3 in water gage?

A fan whose static efficiency is 40% has a capacity of 60,000 ft/hr at 60°F and barometer of 30 in Hg and gives a static pressure of 2 in of water column on full delivery. What size electric motor should be used to drive this fan?

A fan delivers 4.7 m^3/s at a static pressure of 5.08 cm of water when operating at a speed of 400 rpm. The power input required is 2.963 kw. If 7.05 m^3/s are desired in the same fan and installation, find the pressure in cm of water.

Air enters a fan through a duct at a velocity of 6.3 m/s and an inlet static pressure of 2.5 cm of water less than atmospheric pressure. The air leaves the fan through a duct at a velocity of 11.25 m/s and a discharge static pressure of 7.62 cm of water above atmospheric pressure. If the specific weight of the air is 1.20 kg/m and the fan delivers 9.45 m. What is the fan efficiency when the power input to the fan is 13.75 kw at the coupling?

A fan described in a manufacturer's table is rated to deliver 500 m®min at a static pressure gage of 254 cm of water when running at 250 rpm and requiring. 3.6 kw. If the fan speed is changed to 305 rpm and the air handled were at 65°C instead of standard 21°C, find the power in kw.

A steam boiler on a test generates 885,000 lb of steam in a 4-hour period. The average steam pressure is 400 psia, the average steam temperature is 700°F, and the average temperature of the feedwater supplied to the boiler is 280°F. If the boiler efficiency for the period is 82.5%, and if the coal has a heating value of 13,850 Btu per lb as fired, find the average amount of coal burned in short tons per hour.

Steam is admitted to the cylinder of an engine in such a manner that the average pressure is 120 psi. The diameter of the piston is 10 in and the length of the stroke is 12 in. What is the hp of the engine when it is making 300 rpm?

In a cogeneration plant, steam enters the turbine at 4 MPa and 400°C. One fourth of the steam is extracted from the turbine at 600 kPa pressure for process heating. The remaining steam continues to expand to 10 kPa. The extracted steam is then condensed and mixed with feedwater at constant pressure and the mixture is pumped to the boiler pressure of 4 MPa. The mass flow rate of steam through the boiler is 30 kg/s. Disregarding any pressure drops and heat losses in the piping, and assuming the turbine and pump to be isentropic, how much process heat is required in kw? Steam Properties: At 4 MPa and 400°C: h = 3213.6 kJ/kg, s = 6.7690 kJ/kg-°K

23.5 kg of steam per second at 5 MPa and 400°C is produced by a steam generator. The feedwater enters the economizer at 145°C and leaves at 205°C. The steam leaves the boiler drum with a quality of 98%. The unit consumes 2.75 kg of coal per second as received having a heating value of 25,102 kJ/kg. What would be the overall efficiency of the unit in percent?

A steam plant operates with initial pressure of 1.7 MPa and 370°C temperature and exhaust to a heating system at 0.17 MPa. The condensate from the heating system is returned to the boiler at 65.5°C and the heating system utilizes from its intended purpose 90% of the energy transferred from the steam it receives. The n, is 70%. If the boiler efficiency is 80%, what is the cogeneration efficiency of the system in percent. Neglect pump work. Steam Properties: At 1.70 MPa and 370°C: h = 3187.1 kJ/kg S = 7.1081 kJ/kg-°K

A 2-stage air compressor operates between constant pressure limits of 98.6 kPa and 1.103 MPa. The swept volume of the low pressure piston is 0.142 cu. meter. Due to failure of the cooling water supply to the intercooler, air is passed to the high pressure cylinder without reduction in temperature.Using PV1.2=C, determine the percentage increase in power.