A 4-in. schedule 80 steel pipe (ID = 3.826 in., OD = 4.5 in.) carries a heat-transfer fluid at 600 F and is covered with a 1/2 -in. thick layer of pipe insulation. The pipe is surrounded by air at 80 F. The vendor’s literature states that a 1-in. thick layer of the pipe insulation has an R-value of 3. Neglecting convective resistances, the resistance of the pipe wall, and thermal radiation, estimate the rate of heat loss from the pipe per foot of length.

.240mm steam main pipe, 210m long is covered with 50mm of high temperature insulation (k-0.092 W/m °C) and 40mm of low temperature insulation (k-0.062 W/m °C). The inner and the outer surface temperature as measured are 390 °C and 40 °C respectively. Calculate: 1- The total heat loss per hour. 2- The temperature between two layers of insulation.

In a multi-layered square wall, the thermal resistance of the first layer is 0.005 ° C / W, the resistance of the second layer is 0.4 ° C / W, and the third layer is 0.1 ° C / W. The overall temperature gradient in the wall is multilayered from one side. to the other side is 60 ° C. a. Determine the heat flux through the walls. = Answerwatts / m2. b. If the thermal resistance of the second layer is changed to 0.2 ° C / W, what is the effect in% on heat flux, assuming the temperature gradient remains the same? = %. Answer

In a multi-layered square wall, the thermal resistance of the first layer is 0.005 ° C / W, the resistance of the second layer is 0.4 ° C / W, and the third layer is 0.1 ° C / W. The overall temperature gradient in the wall is multilayered from one side. to the other side is 60 ° C. a. Determine the heat flux through the walls. = Answerwatt / m2. b. If the thermal resistance of the second layer is changed to 0.2 ° C / W, what is the effect in% on heat flux, assuming the temperature gradient remains the same? = AnswerAnswer%.

A 15 cm (schedule 80, IPS) steam main has a 10 cm thick 'preformed' mineral fibre insulation on it. The thermal conductivity of the insulation is 0.035 W/m °C, and the heat transfer coefficient at the outer surface of the insulation is 10 W/m² °C. What is the critical insulation thickness?