- Steam at 250°C flows in a stainless steel pipe (k = 15 W/m.K) whose inner and outer diameters are 4 cm and 4.6 cm, res
Posted: Mon May 16, 2022 6:42 am
- Steam at 250°C flows in a stainless steel pipe (k = 15 W/m.K) whose inner and outer diameters are 4 cm and 4.6 cm, respectively. The pipe is covered with 3.5-cm thick glass wool insulation (k= 0.038 W/m.K) whose outer surface has an emissivity of 0.3. Heat is lost to the surrounding air and surfaces at 3°C by convection and radiation. Taking the heat transfer coefficient inside the pipe to be 80 W/m2.K, determine the surface temperature, when the length of the pipe is 0.6 m and when air is flowing across the pipe at 2 m/s. Evaluate the air properties at a film temperature of 10°C and 1 atm. Assuming a film temperature of 10°C and the properties of air based on this temperature are k = 0.02439 W/m.°C, v= 1.426 * 10–5 m2/s, Pr = 0.7336. = The surface temperature is °C.