THERMODYNAMICS (LL)-W/ACCESS >CUSTOM<
9th Edition
ISBN: 9781266657610
Author: CENGEL
Publisher: MCG CUSTOM
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Chapter 2.8, Problem 68P
An 80-percent-efficient pump with a power input of 20 hp is pumping water from a lake to a nearby pool at a rate of 1.5 ft3/s through a constant-diameter pipe. The free surface of the pool is 80 ft above that of the lake. Determine the
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A pump takes water at 60°F from a large reservoir and delivers it to the bottom of an open elevated tank 25 ft above the reservoir surface through a 3 inch ID pipe. The inlet to the pump is located 10 ft below the water surface, and the water level in the tank is constant at 160 ft above the reservoir surface. The pump delivers 150 gal/min. If the total loss of energy due to friction in the piping system is 35 ft·lbf/lb, Calculate the horsepower required to do the pumping. The pump and its motor have an overall efficiency of 55 %.
i. What is Delta Z (Z2 - Z1) ? in ft.
ii. Determine the theoretical shaft work required in foot-pound force per pound mass..
iii.Determine the actual shaft work needed for this particular mass flow rate in (ft-lbf)/s.
A pump takes water at 60°F from a large reservoir and delivers it to the bottom of an open elevated tank 25 ft above the reservoir surface through a 3 inch ID pipe. The inlet to the pump is located 10 ft below the water surface, and the water level in the tank is constant at 160 ft above the reservoir surface. The pump delivers 150 gal/min. If the total loss of energy due to friction in the piping system is 35 ft·lbf/lb. The pump and its motor have an overall efficiency of 55 %.
i. Determine Delta Z (Z2 - Z1) in ft.
ii. What is the actual shaft work needed for this particular mass flow rate in (ft-lbf)/s.
iii. What is the mass flow rate of the water in lbm/s?
A pump takes water at 60°F from a large reservoir and delivers it to the bottom of an open elevated tank 25 ft above the reservoir surface through a 3 inch ID pipe. The inlet to the pump is located 10 ft below the water surface, and the water level in the tank is constant at 160 ft above the reservoir surface. The pump delivers 150 gal/min. If the total loss of energy due to friction in the piping system is 35 ft·lbf/lb. The pump and its motor have an overall efficiency of 55 %.
i.Let us set our first point at the surface of the large reservoir, and the second point at the surface of the open elevated tank. Determine the velocity of the water at point 1 in ft/s.
ii.What is the density of water at the conditions stated in lb/ft3?
iii.If 1 horsepower is equivalent to 500 (ft-lbf)/s, the pump should be able to supply how much hp?
Chapter 2 Solutions
THERMODYNAMICS (LL)-W/ACCESS >CUSTOM<
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