13–122 Consider a water-to-water counter-flow heat ex- changer with these specifications. Hot water enters at 95°C while cold water enters at 20°C. The exit temperature of hot water is 15°C greater than that of cold water, and the mass flow rate of hot water is 50 percent greater than that of cold water. The product of heat transfer surface area and the overall heat transfer coefficient is 1400 W/m² . °C. Taking the specific heat of both cold and hot water to be C, = 4180 J/kg - °C, determine (a) the outlet temperature of the cold water, (b) the effective- ness of the heat exchanger, (c) the mass flow rate of the cold water, and (d) the heat transfer rate. Cold water 20°C | Hot water 95°C FIGURE P13-122

13–122 Consider a water-to-water counter-flow heat ex- changer with these specifications. Hot water enters at 95°C while cold water enters at 20°C. The exit temperature of hot water is 15°C greater than that of cold water, and the mass flow rate of hot water is 50 percent greater than that of cold water. The product of heat transfer surface area and the overall heat transfer coefficient is 1400 W/m² . °C. Taking the specific heat of both cold and hot water to be C, = 4180 J/kg - °C, determine (a) the outlet temperature of the cold water, (b) the effective- ness of the heat exchanger, (c) the mass flow rate of the cold water, and (d) the heat transfer rate. Cold water 20°C | Hot water 95°C FIGURE P13-122

Principles of Heat Transfer (Activate Learning with these NEW titles from Engineering!)

8th Edition

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Author:Kreith, Frank; Manglik, Raj M.

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Chapter7: Forced Convection Inside Tubes And Ducts

Section: Chapter Questions

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