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Air conditioning for a university campus is provided by chilled water pumped through a main supply line ..The pipe-which makes a three-mile loop around the campus, is made of commercial steel and must be sized to handle 12,000 gpm. Chilled water enters the pipe at 38°F and leaves at 59°F.The pump/motor efficiency is 67 percent; […]

The Alaskan pipeline runs 798 miles from Prudhoe Bay to Valdez. Both cities are located at sea level. The design specifications for the pipeline require a capacity of 2.4 million barrels per day (1 barrel of oil = 42 gallons). The crude oil, which is maintained at 140°F,has a specific gravity of 0.86 and a

1. Why is the effectiveness ~of a heat exchanger a good measure of the amount of energy that could be exchanged from two streams at different temperatures? 2. Are fins constructed from a low-k or a high-k material more effective? Explain. 3. Are fins more effective when added to a high- he or a low-

Cooling water is to be pumped from a reservoir to rock drills at a quarry site using the system sketched in Fig. P1-40. The required flow rate is 600 gpm, and the water must leave the nozzle at 120 ft/s. The system is operated 80 hr per week. Electricity costs are $0.05/kWh energy charge and

1. Is a parallel or counter flow heat exchanger more effective for a given area? Why? 2. What is the difference in accuracy between the LMTD method and the NTU method? 3. CDlin/Cma

In a single-pass counter flow heat exchanger, 10,000lbmlhr of water (C = 1.0 Btu/ibm-F) enters at 60°F and cools 20,000 lbm/hr of oil (C = 0.5 Btu/Ibm-OF),which enters at 200°F. For the exchanger, UA = 5,500 Btu/hr- “E Determine the fluid outlet temperatures.

Water enters a counter flow, double-pipe heat exchanger at a rate of70 kg/min and is heated from 1ST to 60’C by an oil with a specific heat of 1.9 kJ/kg-K. The oil enters at 116’C and leaves at 27’C. The overall heat transfer coefficient is 300 W/m2 -K. (a) What heat transfer area is required? (b)

Compressed air is used in a heat-pump system to heat water that is subsequently used to warm a house. The house demand is 95,000 Btu/hr. Air enters the exchanger at 200’F and leaves at 120’F; water enters and leaves the exchanger at 90’F and 125’F,respectively. Choose, from the following alternatives, the unit that is most

Water at 300’F and 8 ftls enters a 50-ft-Iong schedule 40 I-in. cast-iron pipe. If air at 32’F flows perpendicularly to the pipe at 40 ft/s, determine (a) the outlet temperature of the water, (b) the outlet water temperature if the air velocity is increased to 160 ft/s, (c) the outlet water temperature if the

Water at 300’F and 8 ftls enters a 50-ft-Iong schedule 40 I-in. cast-iron pipe. If air at 32’F flows perpendicularly to the pipe at 40 ft/s, determine (a) the outlet temperature of the water, (b) the outlet water temperature if the air velocity is increased to 160 ft/s, (c) the outlet water temperature if the