In a parallel flow heat exchanger, hot fluid enters the heat exchanger at a temperature of 150°C and a mass flow rate of 3 kg/s. The cooling medium enters the heat exchanger at a temperature of 30°C with a mass flow rate of 0.5 kg/s and leaves at a temperature of 70°C. The specific heat capacities of the hot and cold fluids are 1150 J/kg·K and 4180 J/kg·K, respectively. The convection heat transfer coefficient on the inner and outer side of the tube is 300 W/m2·K and 800 W/m2·K, respectively. For a fouling factor of 0.0003 m2·K/W on the tube side and 0.0001 m2·K/W on the shell side, determine (a) the overall heat transfer coefficient, (b) the exit temperature of the hot fluid and (c) surface area of the heat exchanger.

In a parallel flow heat exchanger, hot fluid enters the heat exchanger at a temperature of 150°C and a mass flow rate of 3 kg/s. The cooling medium enters the heat exchanger at a temperature of 30°C with a mass flow rate of 0.5 kg/s and leaves at a temperature of 70°C. The specific heat capacities of the hot and cold fluids are 1150 J/kg·K and 4180 J/kg·K, respectively. The convection heat transfer coefficient on the inner and outer side of the tube is 300 W/m2·K and 800 W/m2·K, respectively. For a fouling factor of 0.0003 m2·K/W on the tube side and 0.0001 m2·K/W on the shell side, determine (a) the overall heat transfer coefficient, (b) the exit temperature of the hot fluid and (c) surface area of the heat exchanger.

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

8th Edition

ISBN:9781305387102

Author:Kreith, Frank; Manglik, Raj M.

Publisher:Kreith, Frank; Manglik, Raj M.

Chapter7: Forced Convection Inside Tubes And Ducts

Section: Chapter Questions

Problem 7.54P

See similar textbooks

Similar questions

Water (cp = 4180 J/kg·K) is to be heated by solarheated hot air (cp = 1010 J/kg·K) in a double-pipe counter- flow heat exchanger. Air enters the heat exchanger at 90°C at a rate of 0.3 kg/s, while water enters at 22°C at a rate of 0.1 kg/s. The overall heat transfer coefficient based on the inner side of the tube is given to be 80 W/m2·K. The length of the tube is 12 m and the internal diameter of the tube is 1.2 cm. Determine the outlet temperatures of the water and the air.
A cross-flow heat exchanger with both fluids unmixed has an overall heat transfer coefficient of 200 W/m2·K, and a heat transfer surface area of 400 m2. The hot fluid has a heat capacity of 40,000 W/K, while the cold fluid has a heat capacity of 80,000 W/K. If the inlet temperatures of both hot and cold fluids are 80°C and 20°C, respectively, determine the exit temperature of the cold fluid.
Water (cp = 4180 J/kg·K) is to be heated by solar-heated hot air (cp = 1010 J/kg·K) in a double-pipe counter-flow heat exchanger. Air enters the heat exchanger at 102°C at a rate of 0.3 kg/s, while water enters at 25°C at a rate of 0.1 kg/s. The overall heat transfer coefficient based on the inner side of the tube is given as 80 W/m2·K. The length of the tube is 12 m and the internal diameter of the tube is 1.2 cm. Determine the outlet temperature of water. (Round the answer to a single decimal place.) The outlet temperature of water is ______ °C.
Water (cp = 4180 J/kg·K) is to be heated by solar-heated hot air (cp = 1010 J/kg·K) in a double-pipe counter-flow heat exchanger. Air enters the heat exchanger at 102°C at a rate of 0.3 kg/s, while water enters at 25°C at a rate of 0.1 kg/s. The overall heat transfer coefficient based on the inner side of the tube is given as 80 W/m2·K. The length of the tube is 12 m and the internal diameter of the tube is 1.2 cm.determine the outlet temperature of water and air.The outlet temperature of water is ____ CThe outlet temperature of air is ____C
In a double-pipe, counter-flow heat exchanger, water entering at 1.5 kg/s is heated from 25°C to 70°C as it flows thru the inner pipe. Hot oil enters the heat exchanger at 2.5 kg/s and 115°C. The convection heat transfer coefficients in the cold- and hot-sides are 100 and 50 kW/m2∙°C, respectively. Calculate the required heat transfer area in m2. Take cp = 4.18 kJ/kg∙°C for water and cp = 1.67 kJ/kg∙°C for oil.
Consider a shell-and-tube water-to-water heat exchanger with identical mass flow rates for both the hot- and cold-water streams. Now the mass flow rate of the cold water is reduced by half. Will the effectiveness of this heat exchanger increase, decrease, or remain the same as a result of this modification? Explain. Assume the overall heat transfer coefficient and the inlet temperatures remain the same.
In a textile manufacturing plant, the waste dyeing water (cp = 4295 J/kg·K) at 75°C is to be used to preheat fresh water (cp = 4180 J/kg·K) at 15°C at the same flow rate in a double-pipe counter-flow heat exchanger. The heat transfer surface area of the heat exchanger is 1.65 m2 and the overall heat transfer coefficient is 625 W/m2·K. If the rate of heat transfer in the heat exchanger is 35 kW, determine the outlet temperature and the mass flow rate of each fluid stream.
Air (Cp = 1005 J/kg °C) enters a cross-flow heat exchanger at 10 C at a rate of 3 kg/s, where it is heated by a hot water stream (Cp = 4190 J/kg °C) that enters the heat exchanger at 95 °C at a rate of 1 kg/s. Determine the maximum heat transfer rate and the outlet temperatures of the cold and the hot water streams for that case.
Consider a water-to-water double-pipe heat exchanger whose flow arrangement is not known. The temperature measurements indicate that the cold water enters at 20°C and leaves at 50°C, while the hot water enters at 80°C and leaves at 45°C. Do you think this is a parallel-flow or counter-flow heat exchanger? Explain.
Answer the following questions about heat transfer in a double tube heat exchanger.(1) In a double tube heat exchanger in which hot and cold fluids flow into a countercurrent flow, the temperature of the hot fluid dropped from 60°C to 30°C, and the temperature of the cold fluid rose from 20°C to 55°C. Calculate the heat flux [kcal/m2h] when the overall heat transfer coefficient of this heat exchanger is constant at 69 kcal/m2h℃.(2) In a double tube heat exchanger in which hot and cold fluids flow in parallel flow, the temperature of the hot fluid dropped from 60°C to 45°C, and the temperature of the cold fluid rose from 20°C to 40°C. When the heat flux of this heat exchanger is 600 kcal/m2h, calculate the overall heat transfer coefficient of this heat exchanger [kcal/m2h℃].
Glycerin (cp = 2400 J/kg·K) at 20°C and 0.5 kg/s is to be heated by ethylene glycol (cp = 2500 J/kg·K) at 60°C in a thin-walled double-pipe parallel-flow heat exchanger. The temperature difference between the two fluids is 15°C at the outlet of the heat exchanger. If the overall heat transfer coefficient is 240 W/m2·K and the heat transfer surface area is 3.2 m2, determine (a) the rate of heat transfer, (b) the outlet temperature of the glycerin, and (c) the mass flow rate of the ethylene glycol.
Cold water (cp = 4180 J/kg·K) enters the tubes of a heat exchanger with 2-shell passes and 12-tube passes at 14°C at a rate of 3 kg/s, while hot oil (cp = 2200 J/kg·K) enters the shell at 200°C at the same mass flow rate. The overall heat transfer coefficient based on the outer surface of the tube is 300 W/m2·K and the heat transfer surface area on that side is 20 m2. Determine the rate of heat transfer using (a) the LMTD method and (b) the ε–NTU method