4- A furnace wall consists of three layers of blocks. The inner layer is of 10 cm thickness made of fire block (k = 1.04 W/m K). The intermediate layer of 25 cm thickness is made of normal block (k = 0.69 W/m K) followed by a 5 cm thick concrete wall (k = 1.31 W/m K). When the furnace is in continuous operation, the inner surface of the furnace is at 800°C while the outer concrete surface is at 50°C. Calculate (a) the rate of heat loss per unit area of the wall (b) the temperature at the interface of the fire block and normal block and (c) the temperature at the interface of the normal block and concrete wall. Take A=1m2. Anw(1515W, 654°C, 105°C)

4- A furnace wall consists of three layers of blocks. The inner layer is of 10 cm thickness made of fire block (k = 1.04 W/m K). The intermediate layer of 25 cm thickness is made of normal block (k = 0.69 W/m K) followed by a 5 cm thick concrete wall (k = 1.31 W/m K). When the furnace is in continuous operation, the inner surface of the furnace is at 800°C while the outer concrete surface is at 50°C. Calculate (a) the rate of heat loss per unit area of the wall (b) the temperature at the interface of the fire block and normal block and (c) the temperature at the interface of the normal block and concrete wall. Take A=1m2. Anw(1515W, 654°C, 105°C)

Elements Of Electromagnetics

7th Edition

ISBN:9780190698614

Author:Sadiku, Matthew N. O.

Publisher:Sadiku, Matthew N. O.

ChapterMA: Math Assessment

Section: Chapter Questions

Problem 1.1MA

See similar textbooks

Similar questions

A refrigerator door of area 0.6 sq.m consists of 25 mm of insulation on top of a thin metal sheet. The film heat transfer coefficients inside and outside the refrigerator are 10.0 and 15.0 W m-2K -1 , respectively, and the thermal conductivity of the insulation is 0.25 W m-1K -1 . If the working temperature of the refrigerator is 0oC and ambient temperature is 20oC, determine the heat flow through the refrigerator door and the temperature of the inside surface of the door.
One side of a copper (401 W/m-oC) block 5 cm thick is maintained at 175 oC, the other side is covered with fiberglass (k = 0.026 W/m-0C) 2.5 cm thick. The outside of the block is maintained at 38 oC, and the total heat flow is 44 kW. Find the overall heat transfer coefficient. (four decimal places for final answer)
In the walls of a warehouse, the inner plaster thickness is 2 cm and the heat conduction coefficient is 0.60 W / moC, the curtain concrete thickness is 10 cm, the heat conduction coefficient is 1.3 W / moC, the outer plaster is 2.5 cm and the heat conduction coefficient is 1.2 W. It is known to be / moC. Inner surface heat transfer coefficient is 8 W / m2oC and outer surface heat transfer coefficient is 21 W / m2oC. Indoor temperature, outdoor temperature and relative humidity of indoor environment are given in the table. How much of the insulation material with thermal conductivity coefficient should be used between the gas concrete and the outer plaster in order to prevent condensation on the inner wall of this warehouse. The indoor and outdoor ambient temperatures of the warehouse and the relative humidity of the storage environment are given in the table.K insulation: 0.032T inner: 14T outside: -15Relative humidity: 60
Calculate the overall heat transfer coefficient of the steel pipe based on the inner surface. The inner diameter of the pipe is 12.7 cm, and the thickness of the pipe is 2.4 cm. The convection heat transfer coefficient in the pipe is 350 W / (m² ° C), the convective heat transfer coefficient outside the pipe is 25 W / (m² ° C), the thermal conductivity of the steel pipe is 15 W / (m ° C). If the pipe is used to deliver steam at 110 ° C and the ambient temperature is 20 ° C, determine the heat transfer rate of the pipe per meter. q = Watt / m
Steam at 200ºC flows in a cast iron pipe (k = 80 W/m⋅ºC) whose inner and outer diameters are D1 = 0.20 m and D2 = 0.22 m, respectively. The pipe is covered with 2-cm-thick glass wool insulation (k = 0.05 W/m⋅ºC). The heat transfer coefficient at the inner surface is 75 W/m2⋅ºC. If the temperature at the interface of the iron pipe and the insulation is 194ºC, the temperature at the outer surface of the insulation is
The efficiency of a single cylindrical cross-section fin is 85%. The diameter of the fin is 13 mm and it extends 32 mm from the base. The base is 65 K hotter than the surrounding fluid, and the heat transfer coefficient is 32 W/m2K. How many fins would be required to increase heat transfer from the base by 50 W? Give your answer as an integer.
A 12-m-long and 5-m-high wall is constructed of two layers of 1-cm-thick sheetrock (k = 0.17 W/m·K) spaced 16 cm by wood studs (k = 0.11 W/m·K) whose cross section is 16 cm * 5 cm. The studs are placed vertically 60 cm apart, and the space between them is filled with fiberglass insulation (k = 0.034 W/m·K). The house is maintained at 20°C and the ambient temperature outside is 29°C. Taking the heat transfer coefficients at the inner and outer surfaces of the house to be 8.3 and 34 W/m2·K, respectively, determine (a) the thermal resistance of the wall considering a representative section of it and (b) the rate of heat transfer through the wall.
The walls of the refrigerated storage room are 10 m long and 3 m high and constructed with 90 mm concrete blocks (k = 0.935 W / [m ° C]) and 8 cm fiber insulation board (k = 0.048 W). / [m ° C]). The cold room temperature is -10 ° C and the convective heat transfer coefficient is 40 W / (m² K); the outside air temperature is 30 ° C with the outer wall surface convection heat transfer coefficient of 10 W / (m² K). Calculate the overall heat transfer coefficient. Overall heat transfer coefficient = Answer W / (m² K).
Convective heat transfer coefficient is 15 W/(m*K), surface area of the fin is 2 m^2, the temperature at the base is 70 C and the ambient temperature is 20 C. Determine the fin efficiency if the actual heat transfer rate from the fin is 500 W? A) 66 % B) not sufficient information C) none of the above D) 33 % E) 15 %
The walls of the refrigerated storage room are 10 m long and 3 m high and constructed with 90 mm concrete blocks (k = 0.935 W / [m ° C]) and 12 cm fiber insulation board (k = 0.048 W). / [m ° C]). The temperature of the cold room is -10 ° C and the convective hot coupling is 40 W / (m² K); The outside air temperature is 30 ° C with a convection heat transfer coefficient of 10 W / (m² K). Calculate the total heat wave. Total heat transfer coefficient = Answer W / (m² K).
the composite wall of a refrigerator has a thermal conductivity of 0.05 W/m-K and a wall thickness of 50 mm. In a room of 25 °C, the refrigerated cold space inside the refrigerator is maintained at 4 °C. Assume the inner and outer convection heat transfer coefficients are 5 W/m² K and 10 W/m².K, respectively. Neglect radiation heat transfer. Determine the rate of heat leaking into the refrigerator per unit surface area.
A 10-cm diameter pipe is covered by 2 layers of lagging. The insidelayer is 4 cm thick and has a coefficient of thermal conductivity of 0.08W/m-K. The outside layer is 3cm thick and has a coefficient of thermalconductivity of 0.15 W/m-K. The steam main conveys steam apressure of 1.7 MPa with 25 C superheat. The outside temperature ofthe lagging is 27 C. If the steam main is 30 m long, determine theinterface temperature of the lagging and overall coefficient of heattransfer based on outside area.