Consider a 20-cm-thick large concrete plane wall
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Heat and Mass Transfer: Fundamentals and Applications
- 3.16 A large, 2.54-cm.-thick copper plate is placed between two air streams. The heat transfer coefficient on one side is and on the other side is . If the temperature of both streams is suddenly changed from 38°C to 93°C, determine how long it takes for the copper plate to reach a temperature of 82°C.arrow_forward2.38 The addition of aluminum fins has been suggested to increase the rate of heat dissipation from one side of an electronic device 1 m wide and 1 m tall. The fins are to be rectangular in cross section, 2.5 cm long and 0.25 cm thick, as shown in the figure. There are to be 100 fins per meter. The convection heat transfer coefficient, both for the wall and the fins, is estimated to be K. With this information determine the percent increase in the rate of heat transfer of the finned wall compared to the bare wall.arrow_forwardConsider a large plane wall of thickness L = 0.4 m, thermal conductivity k=2.3 W/m °C,and surface area A= 20 m2. The left side of the wall at x= 0 is subjected of T1 = 80 C. while the right side losses heated by convection to the surrounding air at Too=15 C with a heat transfer coefficient of h=24 W/m2 .C. Assuming constant thermal conductivity and no heat generation in the wall, (a) express the differential equation and the boundary conditions for steady one-dimensional heat conduction through the wall, (b) obtain a relation for the variation of temperature in the wall by solving the differential equation, and (c) evaluate the rate of heat transfer through the wallarrow_forward
- A large plane wall has a thickness of 0.4 m, thermal conductivity k= 2.3 W/m. °C, and surface area 30 m?. The left side of the wall is maintained at a constant temperature of 90°C while the right side loses heat by convection to the surrounding air at 25°C with a heat transfer coefficient of 24 W/m². °C. Assuming constant thermal conductivity and no heat generation in the wall, (i) Express the differential equation and the boundary conditions for steady one-dimensional heat conduction through the wall (ii) Obtain a relation for the variation of temperature in the wall (iii) Evaluate the rate of heat transfer through the wallarrow_forwardHEAT TRANSFER (a) Determine the thermal conductivity of an insulating material given the following data: steel pipe with 0.1025 m inner diameter and 0.1150 m outer diameter, insulation thickness 3 cm, heat flow per meter is 150 W/m, steel thermal conductivity 55 W/m-°C, and overall temperature difference of 72.2°C. If the temperature of the steam inside the pipe is 128°C, (b) find the outside temperature of the insulating material.arrow_forwardi need the answer quicklyarrow_forward
- A carbon steel pipe (thermal conductivity of 38 W/m oC) with an external diameter of 5 cm and a wall thickness of 4 mm, transports saturated water vapor to an equipment in which water evaporates from the sucrose solution to produce sugar. There are few curves in the system, so you decide to neglect their effects. The ambient temperature in which the pipe is located is 28°C and the temperature of the steam for the pressure in which it is in the line is 120°C. By using an empirical correlation to estimate the convection coefficient of the cooling law of Newton for steam condensing inside tubes you find the value of 15000 W/m 2 oC. This value is so high that we can neglect the resistance to convective transport inside the pipe, if you want, calculate the resistance in question and check. Considering an external convective coefficient of 25 W(m2 oC), we estimate that the water will lose ____________ W/m of pipe. If we want to insulate the pipe with urethane foam (conductivity between 0.016…arrow_forwardA rectangular wall of length "L" m and height "H" m is made from a thick bricklayer. The rectangular wall has a surface area as 11 m2 & Thermal conductivity as 0.53 W/mK. The wall is subjected to heat transfer due to the outside temperature 43 °C and inside temperature 24 °C. If the energy loss is 11219 kJ in 484 minutes. (HINT: 1 minute = 60 %3D seconds) Determine the following -- i) Heat transfer rate, ii) Thickness of the wall.arrow_forwardQ₁: Consider a large plane wall of thickness L = 0.4 m, thermal conductivity k-2.3 W/m °C, and surface area A= 20 m². The left side of the wall at x= 0 is subjected of T1 = 80°C. while the right side losses heated by convection to the surrounding air at T-15 °C with a heat transfer coefficient of h=24 W/m² °C. Assuming constant thermal conductivity and no heat generation in the wall, (a) express the differential equation and the boundary conditions for steady one-dimensional heat conduction through the wall, (b) obtain a relation for the variation of temperature in the wall by solving the differential equation, and (c) evaluate the rate of heat transfer through the wall Ans: (c) 6030 Warrow_forward
- heat transferarrow_forwardQ1: Consider a large plane wall of thickness L = 0.4 m, thermal conductivity k=2.3 W/m °C, and surface area A= 20 m2. The left side of the wall at x= 0 is subjected of T1 = 80°C. while the right side losses heated by convection to the surrounding air at T-15 °C with a heat transfer coefficient of h=24 W/m2 C. Assuming constant thermal conductivity and no heat generation in the wall, (a) express the differential equation and the boundary conditions for steady one-dimensional heat conduction through the wall, (b) obtain a relation for the variation of temperature in the wall by solving the differential equation, and (c) evaluate the rate of heat transfer through the wall Ans : (c) 6030 Warrow_forwardThe temperature of a gas stream is measured by a thermocouple whose junction can be approximated as a 1-mm-diameter sphere. Take the junction’s properties as: k of 32 W/m K, density of 8.2 kg/m^3, c of 300 J/Kg K. On its surface, the overall heat transfer coefficient is 200 W/m^2 K. Neglect any conduction loss from the sphere to other parts of the thermocouple. Create a plot of measurement error as a function of time for the thermocouple.arrow_forward
- Principles of Heat Transfer (Activate Learning wi...Mechanical EngineeringISBN:9781305387102Author:Kreith, Frank; Manglik, Raj M.Publisher:Cengage Learning