A 30-m-long section of an 8-cm-diameter horizontal hot water pipe passes through a large room whose temperature is 20°C. If the outer surface temperature of the pipe is 70°C, determine the rate of heat loss from the pipe by natural convection. k 0.02699 W/m °C Pr = 0.7241, v = 1.749 x10-5.

A 30-m-long section of an 8-cm-diameter horizontal hot water pipe passes through a large room whose temperature is 20°C. If the outer surface temperature of the pipe is 70°C, determine the rate of heat loss from the pipe by natural convection. k 0.02699 W/m °C Pr = 0.7241, v = 1.749 x10-5.

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

Convection 2. For a boiling process such as shown in Figure below, the ambient temperature Tin Newton's law of cooling is replaced by the saturation temperature of the fluid Tsat. Consider a situation where the heat flux from the hot plate is q=20 x 105 W/m². If the fluid is water at atmospheric pressure and the convection heat transfer coefficient is hw=20 x 103 W/m2 K, determine the upper surface temperature of the plate, Ts, w. In an effort to minimize the surface temperature, a technician proposes replacing the water with a dielectric fluid whose saturation temperature is Teat, d=52 °C. If the heat transfer coefficient associated with the dielectric fluid is h = 3 x 103 W/m2 K, will the technician's plan work?
A steam is flowing through a 5.7 m long of steel tube that has inner and outer radii of r, = 0.015 and r, 0,024 m, and a thermal conductivity of 0.14 W/m.K. The steam and the outer surface of the tube is maintained at constant temperature of 150 °C and the air = 25 °C, h = 0.35 W/m2.k) is surrounding the tube. To prevent the outer surface of the steel from the environmental conditions, a material that has a thermal conductivity of 0.014 W/m.k is wrapped over the outer surface of the steel. What is the maximum heat transfer from the steam to the air (W)? NOTE: Enter your answer. Answer Air Th Steam Steel Tr 111 To
Need answer ASAP! Thank you Water at 5°C is being used to cool apples from an initial temperature of 25° to 10°C. Thewater flow over the surface of the apple creates a convective heat-transfer coefficientof 10 W/(m2-K). Assume the apple can be described as a sphere with an 8 cm diameterand the geometric center is to be reduced to 10°C. The apple properties include thermalconductivity of 0.4 W/(m-K), specific heat of 3.950 kJ/(kg-K), and density of 940 kg/m3 a. Determine the time that the apples must be exposed to the water.b. If the apple is submerged only for 2 hours, what will be its center temperature?
A:Find the amount of heat transferred through an iron fin of thickness 5 mm, length 10 cm and width 100 cm. Also determine the temperature difference e at the tip of the fin at: 1- adiabatic tip, 2-heat convection at the tip. Assuming the atmospheric temperature of 28°C K=50 w/mK, h=10 w/m’K, O,=80°C. B-Why is the dimensional heat flow assumption important in the analysis of fins problems? C- Why are the annular fins more efficiency than others?.
Heat transfer Calculate the heat transfer rate in Btu/hr through the pipe ona stainless steel pipe with a length of 12m has an inner diameterof 10in and an outer diameter of 13in. The temperature of theinner surface of the pipe is 50°C and the temperature of theouter surface is 48°C. The thermal conductivity of the stainlesssteel is 187 W/m-°C. Show complete solution in a clear paper.
Q2/ An aluminum sphere weighting 7kg and initially at a temperature of 533K is suddenly immersed in a fluid at 283K. if heat transfer coefficient between the sphere and fluid is 50W/m?.°C. Take density=2707kg/m3, specific heat=0.9KJ/kg.°C and thermal conductivity= 204W/m °C. إجابت * Determine the Bi number 0.00696 0.000696 0.0052 0.00052 0 أخری *.Determine the time required to cool sphere to 263K 26.28min 262.8min 52.56 min 525.6 min O أخری
How much heat is lost due to heat convection in a 25 minute period from 50*10ft wall. If the difference between the wall temperature and the air temperature is 54 F and the surface of the wall has a heat transfer ratio of 0.17 BTU/hr? Show detailed solution
Heat Transfer (Third year) 2020- 2021 Homework 01-03-2021 By Dr. Basil Noori Merzah one-dimensional heat transfer and disregarding radiation, determine the rate of heat transfer through the wall. Q4/ Steam at T01-320°C flows in a cast iron pipe (k=80W/m. C) whose inner and outer diameters are D,=5cm, and D,-5.5cm, respectively. The pipe is covered with 3 cm thick glass wool insulation with k=0.05W/m. C. Heat is lost to the surroundings at T2-5°C by natural convection and radiation, with a combined heat transfer coefficient to be h,=18W/m."C. Taking the heat transfer coefficient inside the pipe to be 2 0 h,-60W/m. C, determine the rate of heat loss from the steam per unit length of the pipe. Also determine the temperature drops across the pipe shell and the insulation. Q5/ Determine the overall heat transfer coefficient U based on the outer surface of a D=2.5cm, and D =3.34 cm steel pipe (k=54.0W/m. C) for the following conditions: inside and outside heat transfer coefficients are…
Water is entering a heated tube at mass ow rate of 1.2 kg/s. The temperature at the inlet is 20 C and at the outlet is 80 C. Assume the surface temperature of the tube is 100 C. The convection coe cient of the water ow is 28 W=m2 C. The speci c heat and density of water can be assumed to be 4180 J=kg C and 990 kg=m3. What is the rate of heat transfer to water during this proces
There are 2 different types of fins: circular section and square section. Both fins are 30 cm length and they are made of copper with 380W/mK_conductivity. The circular section fin diameter is D = 3mm and the lateral width of the square section fin is W = 50 mm. The fin base temperature is -10°C. The fins are immersed in an oil bath at 50°C and perpendicular velocity to the axis of the fins. Obtain the maximum heat rate absorbed in each types of fin for an oil velocity of 60 m/s. Justify every calculation and assumption. Answer: 27.42W (circular section); 987.53W (square section parallel oriented); 1018.6W (square section oblique oriented)
You are designing a small heatsink to cool a high-powered IC on a control unit PCB. The IC puts out 40,000 W/m2 and has a size of 40mm x 20mm. A fan blows 40 degrees C air across the IC at a speed of 4 m/s. The IC is well insulated on its back face. If the convection coefficient is 62 W/m2K, what is the surface temperature of the IC?
A composite plane wall consisting of materials, 1.5-in steel (k = 312 BTU-in/HR.ft2.0F) and 2-in aluminum (k = 1400 BTU-in/HR.ft2.0F), separates a hot gas at Ti = 2000F, hi = 2 BTU/HR.ft2.0F, from cold gas at To = 80 deg F, ho = 5. If the hot fluid is on the aluminum side, find: a) Transmittance, U; b) The heat through 100 sq. ft of the surface under steady state condition and c) The interface temperature at the junction of the metals.