A long counter-flow heat exchanger cools water from 40°C to 10°C by passing the water via the inner cube through an enclosure of cold fluid. The water is flowing through a 3-cm diameter tube at a rate of 0.27 kg/s. The cold fluid enters the enclosure at -10°C and has a convection coefficient of 1200 W/m².K. The mass flow rate of the cold fluid and its specific heat are 1.2 kg/s and 1340 J/kg-K, respectively. (a) Assuming the flow is fully developed, find out the convection coefficient of the water flow. (b) What is the length of the heat exchanger? 1554 W/m²K 21.9m Water Cold Fluid

A long counter-flow heat exchanger cools water from 40°C to 10°C by passing the water via the inner cube through an enclosure of cold fluid. The water is flowing through a 3-cm diameter tube at a rate of 0.27 kg/s. The cold fluid enters the enclosure at -10°C and has a convection coefficient of 1200 W/m².K. The mass flow rate of the cold fluid and its specific heat are 1.2 kg/s and 1340 J/kg-K, respectively. (a) Assuming the flow is fully developed, find out the convection coefficient of the water flow. (b) What is the length of the heat exchanger? 1554 W/m²K 21.9m Water Cold Fluid

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 7.4P

See similar textbooks

Similar questions

A shell-and-tube process heater is to be selected to heat water (cp = 4190 J/kg.K) from 20°C to 90°C by steam flowing on the shell side. The heat transfer load of the heater is 600 kW. If the inner diameter of the tubes is 1 cm and the velocity of water is not to exceed 3 m/s, determine how many tubes need to be used in the heat exchanger.
A long counter-flow heat exchanger cools water from 40°C to 10°C by passing the water via the inner tube through an enclosure of cold fluid. The water is flowing through a 3-cm diameter tube at a rate of 0.27 kg/s. The cold fluid enters the enclosure at −10°C and has a convection coefficient of 1200 W/m².K. The mass flow rate of the cold fluid and its specific heat are 1.2 kg/s and 1340 J/kg-K, respectively. (a) Assuming the flow is fully developed, find out the convection coefficient of the water flow. (b) What is the length of the heat exchanger? 1554 W/m²K 2 21.9m Water Cold Fluid
A long counter-flow heat exchanger heats water from 15°C to 35°C by passing the water via the inner tube through an enclosure of hot air. The water is flowing through a 3.5-cm diameter tube at a rate of 0.3 kg/s. The air enters the enclosure at 80°C and exits at 30°C. 1536.7 W/m2K (a) Assuming the flow is fully developed, find out the convection coefficient of the water flow. (b) If the convection coefficient of air is 680 W/m².K, what is the length of the heat exchanger? 17.72 m Water Air
Consider the flow of saturated steam at 270.1 kPa that flows through the shell side of a shell-and-tube heat exchanger while the water flows through 4 tubes of diameter 1.25 cm at a rate of 0.25 kg/s through each tube. The water enters the tubes of heat exchanger at 20°C and exits at 60°C. Due to the heat exchange with the cold fluid, steam is condensed on the tubes external surface. The convection heat transfer coefficient on the steam side is 1500 W/m2·K, while the fouling resistance for the steam and water may be taken as 0.00015 and 0.0001 m2·K/W, respectively. Using the NTU method, determine (a) effectiveness of the heat exchanger, (b) length of the tube, and (c) rate of steam condensation.
Water (Cp = 4180 J/kg-°C) enters the 2.5- cm internal-diameter tube of a double-pipe counter-flow heat exchanger at 17°C at a rate of 3 kg/s. It is heated by steam condensing at 120°C (hfg = 2203 kJ/kg) in the shell. If the overall heat transfer coefficient of the heat exchanger is 1500 W/m2-°C, determine the length of the tube required in order to heat the water to 80°C. m
Hot oil is to be cooled in a double-tube counter-flow heat exchanger. The copper inner tubes have a diameter of 2 cm and negligible thickness. The inner diameter of the outer tube (the shell) is 3 cm. Water flows through the tube at a rate of 0.5 kg/s. The Nusselt number for the forced convection between the oil and the external surface of the tube is Nuo = 5.45. If the length of the tube is 1m and ΔTlm = 45°C. Determine the rate of heat transfer. Water properties: ρ = 990 kg/m3, Pr = 3.91, k = 0.637 W/m °C, ν = 0.000000602 m2/s. Oil properties: k = 0.138 W/m °C Select one: a. 261 W b. 745 W c. 567 W d. 421 W
Saturated liquid water is completely vaporized at 200 oC inside the tubes of a shell-and-tube heat exchanger that uses hot exhaust gases to vaporize the water. The hot gases enters the shell at 9000C at a flow rate of 22 kg/s. Assuming an overall heat transfer coefficient of 1000 W/m2K and heat exchanger surface area of 40 m2, determine the rate at which the water is vaporized. The latent heat of vaporization of water is hfg=1940 kJ/kg. The specific heat of the exhaust gas is cp,h=D1200 J/kg.K. Select one: a. 2.5 kg/s b. 7.4 kg/s c. 11.3 kg/s d. 0.75 kg/s
Hot oil is to be cooled in a double-tube counter-flow heat exchanger. The copper inner tubes have a diameter of 2 cm and negligible thickness. The inner diameter of the outer tube (the shell) is 3 cm. Water flows through the tube at a rate of 0.5 kg/s, and the oil through the shell at a rate of 0.8 kg/s. Taking the average temperatures of the water and the oil to be 45°C and 80°C, respectively, determine the overall heat transfer coefficient of this heat exchanger.
A steam condenser operates at 61 cm of Hg vacuum. The steam enters the condenser with a moisture content of 87%. Cooling water is supplied to the condenser at a temperature of 20 C with a terminal difference of 5 C. The water velocity of water inside the tube is to be limited to 2.5 m/s when using 2.5 cm outside diameter tubes whose thickness is 1.75 mm. The overall heat transfer coefficient of the tubes could be approximated by the equation U = 1213.4(v1/2), W/(m2-C) where v is the water velocity in m/sec. Determine: 1. The required mass flow of cooling water, kg/s 2. The required capacity of the circulating pump, liter per second 3. The Logarithmic Mean Temperature Difference, C 4. The required Number of tubes 5. The required length of tubes, (m), and number of passes
Milk is flowing through a heat exchanger at a rate of 2000 kg/h. The heat exchanger supplies 111,600 kJ/h. The outlet temperature of the product is 95°C. Determine the inlet temperature of the milk. The product specific heat 3.9 kJ/kg°C. Answer must be 80.69°C
Steam in the condenser of a power plant is to be condensed at a temperature of 30°C with cooling water from a nearby lake, which enters the tubes of the condenser at 14°C and leaves at 22°C. The surface area of the tubes is 45 m2, and the overall heat transfer coefficient is 2100 W/m2?K. Determine the mass flow rate of the cooling water needed and the rate of condensation of the steam in the condenser.
Consider a flow of water in a cylinder maintained at a constant temperature of 1000 C, the diameter of the cylinder is 50 mm and the length of the tube is 6m. The inlet and the outlet temperature of the water are Ti = 150 C and T0 = 570 C . Find the average heat transfer coefficient associated with the flow of water. Mass flow rate is 0.25 Kg/ s and Cp = 4.178 KJ/Kg.K