Chilled water enters a thin-shelled 5-cm-diameter, 150-m-long pipe at 7°C at a rate of 0.98 kg/s...
Water at 340 K and a flow rate of 5 kg/s enters a black, thin‐walled tube, which passes through a large furnace whose walls and air are at a temperature of 700 K. The diameter and length of the tube are 0.25 m and 8 m, respectively. Convection coefficients associated with water flow through the tube and airflow over the tube are 300 W/m2·K and 50 W/m2·K, respectively. Write an expression for the linearized radiation coefficient corresponding to radiation exchange...
Problem 3 (30): Steam at Too,1 340 °C flows in a cast iron pipe [k- 80 W/m.°C] whose inner and outer diameter are Di 6 cm and D2 -8 cm, respectively. The pipe is covered with a 4-cm thick glass wool insulation [k-0.05 W/ m°C]. Heat is lost to the surroundings at Too,2 - 21°C by natural convection and radiation, with a combined heat transfer coefficient of h- 18 W/m2 °C. Taking the heat transfer coefficient inside the pipe to...
Water enters a 5-mm diameter and 13-m long tube at 15 °C with a velocity of 0.3 m/s and leaves at 45 °C. The tube is subject to a uniform heat flux of 2000 W/m2. Assume the following properties of water: p = 996 kg/m3, Cp = 4178 J/kg.K, K = 0.615 W/m.K. u = 0.798 x 10-kg/mus. Pe=5.42. (7) What is the average convective heat transfer coefficient considering the entire length of the pipe? (a) 791 W/m2K (b) 681...
S A 10-m-long section of an 8 cm (r=4 cm) of external diameter horizontal steam water pipe passes through a large room whose temperature is To =15°C. The pipe is insulated with an insulating material of conductivity k=0.01 W/m-°C and 1 cm thick. If the inner surface temperature of the pipe is 95 °C (at r2) and the pipe is exposed to a cross wind of 6.0 m/s, determine the rate of heat loss from the pipe (neglect radiation). Thermal...
Water at 320 K and a flow rate of 5 kg/s enters a black, thin-walled tube, which passes through a large furnace whose walls and air are at a temperature of 700 K. The diameter and length of the tube are 0.25 m and 8 m, respectively. Convection coefficients associated with water flow through the tube and airflow over the tube are 300 W/m2K and 50 W/m2.K, respectively. Tube, D-0.25 m L-8 me-1 Air 7-700 K Water -5 kas -Fumace,...
A stainless pipe having an inner wall thickness of 5 cm, an outer wall thickness of 5.5 cm and a thermal conductivity of 15 W/m˚C transfers steam at 320˚C from one location to another. The pipe is insulated with a 3 cm thick glass wool having a thermal conductivity of 0.038 W/m˚C. Heat is lost to the surroundings by natural convection and radiation at a rate of 15 W/m2˚C and the heat transfer coefficient inside the pipe is 80 W/m2˚C....
Cold water (Cp = 4180 J/kg · °C) leading to a shower enters a thin-walled double-pipe counter-flow heat exchanger at 15°C at a rate of 0.25 kg/s and is heated to 45°C by hot water (Cp = 4190 J/kg · °C) that enters at 100°C at a rate of 3 kg/s. If the overall heat transfer coefficient is 950 W/m2 · °C. determine the rate of heat transfer and the heat transfer surface area of the heat exchanger using the...
Consider a 2.5 cm diameter thin walled horizontal cylindrical pipe that carries chilled water at about 5°C. The pipe is very long and is indoors in a climate controlled area with essentially still air. Design an insulation system that will reduce heat gain per unit length of pipe by at least 75% as compared to the heat gain to the bare pipe. Completely specify the insulation system (materials, dimensions, etc.) you design. In your design report, include enough information about...
P11-104. Cold water (Cp = 4180 J/kg-K) leading to a shower enters a thin-walled double-pipe counterflow heat exchanger at 15°C at a rate of 0.25 kg/s and is heated to 45°C by hot water (cp=4190 J/kg K) that enters at 100°C at a rate of 3 kg/s. If the overall heat transfer coefficient is 950 W/m2.K, determine the rate of heat transfer and the heat surface area of the heat exchanger using the effectiveness-NTU method.
1. A steel tube [k 15 W/(m.°C)] of outside diameter 7.6 cm and thickness 1.3 cm is covered with an insulation material [k 0.2 W/(m. C)] of thickness 2 cm. A hot gas at 320°C with a heat transfer coefficient of 200 W/(m2.C) flows inside the tube. The outer surface of the insulation is exposed to cooler air at 20°C with a heat transfer coefficient of 50 W/(m2·°C). Calculate a) The heat loss from the tube to the air for...