A cold storage wall, whose components and dimensions are given below, is formed by connecting layers A, B, C, D, E and F in series and in parallel. The temperature of the outside air is 30 oC and the temperature of the inside of the warehouse is -4 oC. If the film heat transfer coefficient between the air in the warehouse and the E layer is 24 W/m2 oC and the film heat transfer coefficient between the outer surface of the flat wall (A and F layers surface) and the atmospheric air is 16 W/m2 oC; Calculate the heat transferred in a day. (KA= 0.17 W/m.K, KBK= 0.024 W/m.K, kc= 0.98 W/m.K) (kD= 0.21 W/m.K, KF= 0.58 W/m.K) KE=0.01 W/m.K,

A cold storage wall, whose components and dimensions are given below, is formed by connecting layers A, B, C, D, E and F in series and in parallel. The temperature of the outside air is 30 oC and the temperature of the inside of the warehouse is -4 oC. If the film heat transfer coefficient between the air in the warehouse and the E layer is 24 W/m2 oC and the film heat transfer coefficient between the outer surface of the flat wall (A and F layers surface) and the atmospheric air is 16 W/m2 oC; Calculate the heat transferred in a day. (KA= 0.17 W/m.K, KBK= 0.024 W/m.K, kc= 0.98 W/m.K) (kD= 0.21 W/m.K, KF= 0.58 W/m.K) KE=0.01 W/m.K,

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 room is well insulated apart from a single-glazed window measuring 1 m2 and 4 mm thick. The internal air temperature is 22oC and outside it is -12oC. If the external convective heat transfer coefficient, hout, is double that of the inside coefficient, and the conductivity in the glass is negligible. Determine hout if Q = 100 W.
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
What is the product of overall heat transfer coefficient and area (UA) for a heat transfer equipment with the geometry as shown in the diagram? The inner tube (the shaded area in the figure) is made of a material with thermal conductivity of 1.2 W/m.K. The convection coefficient of the hot fluid (in the inner tube) is 25 W/m².K and that of the cold fluid is 12 W/m².K. The dimensions shown in the figure are r₁ 0.1 m, r₂ = 0.15 m, and r3 = 0.3 m. The length is 1 m. 4.86 W/ Cold Fluid Hot Fluid TI =
Consider a 5.5-m-high, 8-m-long, and 0.22-m-thick wall whose representative cross section is as given in the figure. The thermal conductivities of various materials used, in W/m · °C, are kA= kF= 5.58, kB = 13.18, kC= 29.58, kD= 19.38, and kE = 39.88. The left and right surfaces of the wall are maintained at uniform temperatures of 300°C and 100°C, respectively. Assuming heat transfer through the wall to be one-dimensional, determine the rate of heat transfer through the wall
A cylindrical nuclear fuel rod generates heat at a rate of 71 MW3. It is cooled by fluid at 417 K such that the temperature profile in the rod does not change over time. The heat transfer coefficient between the rod and the fluid is 67 kW/m2K. The rod is 7.5 cm in diameter and has a thermal conductivity of 25 W/mK. Starting from the general conduction equation in cylindrical coordinates, what is the maximum temperature in the rod? Give your answer in Kelvin to the nearest integer.
Water flows through a cast steel pipe with k = 53 W/m-K with an outer diameter of 110 mm and 3.5 mm wall thickness. Calculate the thickness of insulation to be lagged on the pipe if the heat transfer per unit length is 6.5 W/m. The thermal conductivity of the insulation is 0.045 W/m-K. The water temperature is 15°C with convective heat transfer coefficient of 30 W/m2 -K while the outside air is -8°C and 18 W/m2 -K.
A house has a three meter deep basement (foundation) wall that is in a 10 meter by eight meter rectangular shape based on interior dimensions. On average, 2.5 meters of the wall is below grade. Assume the outside air temperature is 38°C and the inside temperature is 20°C; there is an average ground temperature of 27°C. Determine the rate of heat loss through the wall if it is insulated with an R-value of about 30°C.m^2/W.
3- Pipes with inner and outer diameter of 50mm and 60mm, respectively, are used for transporting superheated vapor in a manufacturing plant. The pipes with thermal conductivity of 16 W/m.K are connected together by flanges with combined thickness of 20mm and outer diameter of 90mm. Air condition surrounding the pipes has a temperature of 25C and a convection heat transfer coefficient of 10 W/m².K. If the inner surface temperature of the pipe is maintained at a constant temperature of 150C, determine the temperature at the base of the flange and the rate if heat loss through the flange. Air, 25 °C h= 10 W/m².ºC D;= 90 mm D;, = 50 mm T; = 150 °C Pipe, k = 16 W/m•°C D,= 60 mm t= 20 mm
A 0.5-ampere current is flowing through a long electrically conducting cylindrical rod. The diameter of the rod is 6 mm, the electrical resistance of the rod is R = 2000 /m, and k =0.9 W/m K for the rod. The rod is encased in a 2-mm thick Pyrex tube and a 20°C liquid is flowing over the outer surface of the Pyrex tube. The convection heat transfer coefficient for the liquid h= 800 W/m2 . K. The interfacial conductance (contact resistance) at the interface between the rod and the Pyrex tube is h = 1200 W/m² - K. a) Compute the rate of heat generation in the rod and use it compute the volumetric rate of heat generation. b) Find the temperature drop across the interface between the outer surface of the rod and the inner surface of the Pyrex tube. c) Find the temperature at the center of the rod.
Q4/A 2-mm-diameter and 10-m-long electric wire is tightly wrapped with a 1-mm-thick plastic cover whose thermal conductivity is k-0.15 W/m "C. Electrical measurements indicate that a current of 10 A passes through the wire and there is a voltage drop of 8 V along the wire. If the insulated wire is exposed to a medium at Ts= 30°C with a heat transfer coefficient of h-24 W/m² C, determine the temperature at the interface of the wire and the plastic cover in steady operation. Also find the critical radius of plastic insulation. [334 T=30°C Electrical wire Insulation bale 10 m
Heat Transfer A wall of an oven with a wire in it. Across the wire a voltage of 50 Volts and a current of 2 Amps is applied, and 80% of the electrical power is converted to thermal energy. The oven is a convection oven and has air flowing through it at 240 C and h = 10 W/m^2 K. The wall of the oven is 0.1 m thick and 1.5 m tall and 1.5 m wide and is made of steel (k = 15 W/m K). Find the surface energy balance on the inner wall of the oven and determine the temperature of the ineer wall at steady state. Then do an energy balance on the outer wall, assume that the oven is free standing and has an emissivity, e = 0.6, and the surrounding temperature is 25 C. The air in the surrounding has a convective heat transfer coefficient of 25 W/m^2 K. Just set up the balance equation that would enable to solve, no need to actually solve.
A steel pipe with heat transfer coefficient of 42 W/mK contains flowing water. The outer diameter of the pipe is 90 mm and the wall thickness is 3mm. Calculate: i. The heat loss by convection and conduction per meter length of un-insulated pipe when the water temperature is 14°C, the outside air temperature is -10°C, the water side heat transfer coefficient is 30 KW/m^2K and the outside heat transfer coefficient is 20 KW/m^2K. ii. Calculate the corresponding heat loss when the pipe is lagged with insulation having an outer diameter of 200 mm, and thermal conductivity of K = 0.05 W/mK