Hot atmospheric air (373 K) is forced through a 2 meter long pipe having a dismeder...
“A pipe is carrying hot water through a cold storage facility. The ambient air in the cold storage has temperature of ?5?C. To maintain uniform temperature in the cold storage, blowers installed in the facility induce a 3 m/s velocity to the cold air (which can be assumed to be flowing across the water pipe). Hot water inside the pipe has a mean velocity of 0.5 m/s. The internal and exter- nal diameter of the pipe are 8.4 cm and...
T,= 75 °C T= 25°C V = 10 m/s Air 3. (25 pts) Atmospheric air at 25 °C flows across a long pipe at a uniform velocity of 10 m/s. The pipe has an external diameter of 120 mm and its surface temperature is maintained at 75 °C. Determine the rate of heat transfer per unit length of the pipe and the drag force exerted per unit length of the pipe. Hint: You can use the information on the next...
2) (35 pt) Atmospheric air at 25 Centers a duct having a cross section of an equilateral triangle 2 cm on a side with a velocity of 1.5 m/s. The length of the duct is 10 m. A constant heat flux is imposed on the duct wall. The mean temperature of the air at the duct exit is 75 °C. a. Is the flow at the duct exit hydrodynamically and thermally fully developed? Show. T-75 °C b. Calculate the convection...
Problem 3 (20 points) A cross-flow heat exchanger consists of a bundle of 32 tubes in a long duct. Hot water at 150°C and a mean velocity of 0.5 m/s enters the tubes having inner and outer diameters of 10.2mm and 12.5mm and has to be cooled to 136°C. The tubes are made of steel of thermal conductivity k-40 W/m.K. Air at 10°c enters the exchanger (unfinned) with a volumetric flow rate of 1.0 m3/s. The convective heat transfer coefficient...
Heat Exchanger type Problem, need help thanks! 1. (20 points) Supplementary: Hot water at 98 °C flows through a 2-in schedule 40 horizontl steel pipe (k 54 WIm C) and is exposed to atmospheric air at 20 °C. The water velocity is 25 cm/s. Calculate the overall heat transfer coefficient based on the outer area of the pipe whose dimensions are ID = 2.067 in.-0.0525 m and OD = 2.375 in.-0.06033 m 1. (20 points) Supplementary: Hot water at 98...
Metal Shield = 0.8 4-02 4. (Total 8pts) Hot gases flows into a long pipe of 0.05-m diameter and at a certain location the flow has a temperature of T.-700K and heat transfer coefficient of h. For safety reasons, the pipe is to be covered with a thin concentric metal shield at Tai - 337K with a 0.1-m diameter. The emissivity of the pipe wall surface is Epi-. The inside and outside surface emissivities of the shield are a =...
Waste heat of exhaust hot air from a manufacturing process may be recovered by passing water through a thin-walled tube of 1.00 cm diameter as shown. Assume the temperature of the hot air is 177℃ in cross flow with a velocity of 20 m/s over the tube. The inlet and outlet temperature of water are 20C and 60 C, rospectively, and the ilow rate is 0.2 k/s. Deiemine (a) the total heat transfer rate from air to water, (b) The...
Hot CO2 gas at a temperature T-1 = 250°C is flowing through a steel pipe (kı = 70 W/(m.K)) whose inner and outer radiuses are 12 cm and 14 cm, respectively, in a cold environment at Tm2 = -10°C. As shown in the figure below, the steel pipe is insulated with 7.0 cm thick spray-foam insulation (k2 = 0.03 W/(m.K)) and 5.0 cm thick glassfiber insulation (k3 = 0.05 W/(m.K)). Consider the heat transfer coefficients of CO2 gas and the...
Problem 4: Consider the heat exchanger design illustrated. Hot air flows at speed of r0.6 m/s through the center pipe. The center pipe has an outer diameter of D=7 cm and length 4-2 m Cold water flows at 20-25 cm3/s through a smaller helical pipe having an outer diameter d = 1 cm and wall thickness of mm. The helical pipe is wrapped around the center pipe to form a heat exchanger. The center pipe has a thermal conductivity of...
Problem 2 (30%). Liquid nitrogen is used to cool hot air exhausting from a gas turbine. The exhausted air at 200 °c (T) flows into a circular pipe of diameter D 2.54 cm and length L 5 m at a velocity V= 10 m/s. The surface of the pipe is maintained at a constant temperature, T,-- 146°C. Determine the average convective coefficient and rate of heat transfer over the entire length of the pipe.