A steel plate having a thickness of 100 mm is suddenly exposed to a hot gas at 1000 oC in a furnace. One surface of the plate is heated while the other surface of the plate can be approximated to be adiabatic. The initial temperature of the steel plate is 20 oC. The thermal conductivity and thermal diffusivity of the steel plate are 34.8 W/m K and 0.555 x 10-5 m2 /s respectively. The convective heat-transfer coefficient is 174 W/m2 K. a) Determine the time necessary to raise the surface temperature of the steel plate to 500 oC. b) Determine the maximum temperature difference in the cross-section of the steel plate at the time evaluated in part a) above. c) Determine the heat energy transferred to the steel plate per unit wall surface area by the time evaluated in part a) above. Use the conduction charts

A steel plate having a thickness of 100 mm is suddenly exposed to a hot gas at 1000 oC in a furnace. One surface of the plate is heated while the other surface of the plate can be approximated to be adiabatic. The initial temperature of the steel plate is 20 oC. The thermal conductivity and thermal diffusivity of the steel plate are 34.8 W/m K and 0.555 x 10-5 m2 /s respectively. The convective heat-transfer coefficient is 174 W/m2 K. a) Determine the time necessary to raise the surface temperature of the steel plate to 500 oC. b) Determine the maximum temperature difference in the cross-section of the steel plate at the time evaluated in part a) above. c) Determine the heat energy transferred to the steel plate per unit wall surface area by the time evaluated in part a) above. Use the conduction charts

Principles of Heat Transfer (Activate Learning with these NEW titles from Engineering!)

8th Edition

ISBN:9781305387102

Author:Kreith, Frank; Manglik, Raj M.

Publisher:Kreith, Frank; Manglik, Raj M.

Chapter1: Basic Modes Of Heat Transfer

Section: Chapter Questions

Problem 1.60P: 1.60 Two electric resistance heaters with a 20 cm length and a 2 cm diameter are inserted into a...

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A steel plate having a thickness of 100 mm is suddenly exposed to a hot gas at 1000 oC ina furnace. One surface of the plate is heated while the other surface of the plate can beapproximated to be adiabatic. The initial temperature of the steel plate is 20 oC. The thermalconductivity and thermal diffusivity of the steel plate are 34.8 W/m K and 0.555 x 10-5 m2/srespectively. The convective heat-transfer coefficient is 174 W/m2 K.a) Determine the time necessary to raise the surface temperature of the steel plate to500 oC. Use the conduction charts
A steel plate having a thickness of 100 mm is suddenly exposed to a hot gas at 1000 °C in a furnace. One surface of the plate is heated while the other surface of the plate can be approximated to be adiabatic. The initial temperature of the steel plate is 20 °C. The thermal conductivity and thermal diffusivity of the steel plate are 34.8 W/m K and 0.555 x 10-5 m²/s respectively. The convective heat-transfer coefficient is 174 W/m²K. a) Determine the time necessary to raise the surface temperature of the steel plate to 500 °C. b) Determine the maximum temperature difference in the cross-section of the steel plate at the time evaluated in part a) above. c) Determine the heat energy transferred to the steel plate per unit wall surface area by the time evaluated in part a) above.
I need help on solving this question: A steel plate having a thickness of 100 mm is suddenly exposed to a hot gas at 1000 oC ina furnace. One surface of the plate is heated while the other surface of the plate can beapproximated to be adiabatic. The initial temperature of the steel plate is 20 oC. The thermalconductivity and thermal diffusivity of the steel plate are 34.8 W/m K and 0.555 x 10-5 m2/srespectively. The convective heat-transfer coefficient is 174 W/m2 K. (The pictures are the conduction charts given) a) Find the time necessary to raise the surface temperature of the steel plate to 500 oC. b) Find the maximum temperature difference in the cross-section of the steel plate at the time evaluated in part a). c) Determine the heat energy transferred to the steel plate per unit wall surface area by the time evaluated in part a).
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A 2-m-long, 4-cm-diameter electrical wire extends across a room at 20°C, as Shown in Fig. below. Heat is generated in the wire due to resistance heating, and the surface temperature of the wire is measured to be 252°C in steady operation. Also, the voltage drop and electric current through the wire are measured to be 80 V and 2 A, respectively. Heat loss transfer by radiation was 40 W from the surface of the wire. Heat transfer coefficient for heat 20 C transfer between the outer surface of the wire and the air in the room. 2 80 V T 252 If the heat generation by electrical wire increased up to 200 W, what is the surface temperature of the wire, assuming no change heat transfer coefficient?
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Ice water of 0°C is stored in a spherical container made of steel with an inner diameter of 3 m and a thickness of 1 cm. This container is located in a place where the external temperature is 25℃. The temperature of the entire container is assumed to be 0°C. If thermal resistance in the container is ignored, obtain (a) the heat transfer rate to ice water, and (b) the amount of ice that melts for 24 hours. The melting heat of ice at atmospheric pressure is 333.7 kJ/kg. The emissivity of the outer wall of the container is 0.75, and the convective thermoelectric transfer coefficient is 30 W/m2·K. The average temperature of the surrounding surface for radiation is 15℃. ***I would appreciate it if sir could write it in a way that I could read it well.**
A long cylindrical rod has a 20-cm-diameter at a uniform temperature of 600°C. The rod is then allowed to cool slowly in a room at 200°C with a heat transfer coefficient of 80 W/m² °C. Calculate the temperature at the center of the rod 45 min after the start of the cooling process. Also, determine the heat transfer per unit length of the rod during this time period.
During a picnic on a hot summer day, the only available drinks were those at the ambient temperature of 90°F. In an effort to cool a 12-fluid-oz drink in a can, which is 5 in high and has a diameter of 2.5 in, a person grabs the can and starts shaking it in the iced water of the chest at 32°F. The temperature of the drink can be assumed to be uniform at all times, and the heat transfer coefficient between the iced water and the aluminum can is 30 Btu/h·ft2·°F. Using the properties of water for the drink, estimate how long it will take for the canned drink to cool to 40°F.
A 3.0m-long, 0.45-cm-diameter electrical wire extends across a room at 61°F, as shown. Heat is generated in the wire as a result of resistance heating, and the surface temperature of the wire is measured to be 306°F in steady operation. Also, the voltage drop and electric current through the wire are measured to be 70 V and 1.73 A, respectively. Disregarding any heat transfer by radiation, determine the convection heat transfer coefficient (W/m2-K) for heat transfer between the outer surface of the wire and the air in the room.
A cylindrical rod with a diameter of 20 mm and a length of 300 mm is heated to a temperature of 200°C. The rod is then placed in a tank of water maintained at a constant temperature of 25°C. The convection heat transfer coefficient for the water is 2000 W/m²K. Determine the time taken for the temperature of the rod to reach 50°C.
Consider a curing kiln whose walls are made of 30-cm-thick concrete with a thermal diffusivity of a = 0.23 * 10-5 m2/s. Initially, the kiln and its walls are in equilibrium with the surroundings at 6°C. Then all the doors are closed and the kiln is heated by steam so that the temperature of the inner surface of the walls is raised to 42°C and the temperature is maintained at that level for 2.5 h. The curing kiln is then opened and exposed to the atmospheric air after the steam flow is turned off. If the outer surfaces of the walls of the kiln were insulated, would it save any energy that day during the period the kiln was used for curing for 2.5 h only, or would it make no difference? Base your answer on calculations.