Fundamentals of Heat and Mass Transfer
7th Edition
ISBN: 9780470501979
Author: Frank P. Incropera, David P. DeWitt, Theodore L. Bergman, Adrienne S. Lavine
Publisher: Wiley, John & Sons, Incorporated
expand_more
expand_more
format_list_bulleted
Textbook Question
Chapter 4, Problem 4.14P
Two parallel pipelines spaced 0.5 m apart are buried in soil having a thermal conductivity of
Expert Solution & Answer
Learn your wayIncludes step-by-step video
schedule03:41
Students have asked these similar questions
A steel duct whose internal diameter is 5.0 cm, and external diameter is 7.6 cm and thermal conductivity is: k = 15.0 (W/(m ºC)) is covered with an insulating material whose thickness is 2.0 cm and of thermal conductivity k = 0.2 (W/(m ºC)). A hot gas flows through the interior of the duct at a temperature of 330.0 ºC that generates a heat transfer coefficient by forced convection h=400.0 (W/(m^2 · ºC)). The outer surface of the insulating layer is exposed to air whose temperature is 30.0 ºC with forced convection heat transfer surface h = 60.0 (W/(m^2 · °C)).
As a process engineer and in charge of company operations, you have been asked to:
i. Determine the heat loss experienced by the pipe along 10.0 m.ii. The temperature drops that are generated in the different thermal resistances of the system. That is, on the air side, the duct wall and on the hot gas side.
Steel pipe (outer diameter 100 mm) is covered with two layers of insulation. The inner layer, 40 mm thick, has a thermal conductivity of 0.07 W / (m K). The outer layer, 20 mm thick, has a thermal conductivity of 0.15 W / (m K). Pipes are used to deliver steam with a pressure of 700 kPa. The temperature on the outer insulation surface is 24 ° C. If the pipe is 12 m long, determine the following: (assuming that the conduction heat transfer resistance of the steel pipe and the vapor convection resistance are negligible).
a. Heat loss per hour. = Answer
kJ / hour.
b. Temperature between insulation layers. = Answer
° C.
Steel pipe (outer diameter 100 mm) is covered with two layers of insulation. The inner layer, 40 mm thick, has a thermal conductivity of 0.07 W / (m K). The outer layer, 20 mm thick, has a thermal conductivity of 0.15 W / (m K). Pipes are used to deliver steam with a pressure of 600 kPa. The temperature on the outer insulation surface is 24 ° C. If the pipe is 8 m long, determine the following: (assuming that the conduction heat transfer resistance of the steel pipe and the vapor convection resistance are negligible).
a. Heat loss per hour. = kJ / hour.
b. Temperature between insulation layers. = ° C
Chapter 4 Solutions
Fundamentals of Heat and Mass Transfer
Ch. 4 - In the method of separation of variables (Section...Ch. 4 - A two-dimensional rectangular plate is subjected...Ch. 4 - Consider the two-dimensional rectangular plate of...Ch. 4 - A two-dimensional rectangular plate is subjected...Ch. 4 - A two-dimensional rectangular plate is subjected...Ch. 4 - Using the thermal resistance relations developed...Ch. 4 - Free convection heat transfer is sometimes...Ch. 4 - Consider Problem 4.5 for the case where the plate...Ch. 4 - Prob. 4.9PCh. 4 - Based on the dimensionless conduction heat rates...
Ch. 4 - Determine the heat transfer rate between two...Ch. 4 - A two-dimensional object is subjected to...Ch. 4 - An electrical heater 100 mm long and 5 mm in...Ch. 4 - Two parallel pipelines spaced 0.5 m apart are...Ch. 4 - A small water droplet of diameter D=100m and...Ch. 4 - A tube of diameter 50 mm having a surface...Ch. 4 - Pressurized steam at 450K flows through a long,...Ch. 4 - The temperature distribution in laser-irradiated...Ch. 4 - Hot water at 85°C flows through a thin-walled...Ch. 4 - A furnace of cubical shape, with external...Ch. 4 - Laser beams are used to thermally process...Ch. 4 - A double-glazed window consists of two sheets of...Ch. 4 - A pipeline, used for the transport of crude oil,...Ch. 4 - A long power transmission cable is buried at a...Ch. 4 - A small device is used to measure the surface...Ch. 4 - A cubical glass melting furnace has exterior...Ch. 4 - An aluminum heat sink (k=240W/mK), used to cool an...Ch. 4 - Hot water is transported from a cogeneration power...Ch. 4 - A long constantan wire of 1-mm diameter is butt...Ch. 4 - A hole of diameter D=0.25m is drilled through the...Ch. 4 - In Chapter 3 we that, whenever fins are attached...Ch. 4 - An igloo is built in the shape of a hemisphere,...Ch. 4 - Prob. 4.34PCh. 4 - An electronic device, in the form of a disk 20 mm...Ch. 4 - The elemental unit of an air heater consists of a...Ch. 4 - Prob. 4.37PCh. 4 - Prob. 4.38PCh. 4 - Prob. 4.39PCh. 4 - Prob. 4.40PCh. 4 - One of the strengths of numerical methods is their...Ch. 4 - Determine expressionsfor...Ch. 4 - Consider heat transfer in a one-dimensional...Ch. 4 - In a two-dimensional cylindrical configuration,...Ch. 4 - Upper and lower surfaces of a bus bar are...Ch. 4 - Derive the nodal finite-difference equations for...Ch. 4 - Consider the nodal point 0 located on the boundary...Ch. 4 - Prob. 4.48PCh. 4 - Prob. 4.49PCh. 4 - Consider the network for a two-dimensional system...Ch. 4 - An ancient myth describes how a wooden ship was...Ch. 4 - Consider the square channel shown in the sketch...Ch. 4 - A long conducting rod of rectangular cross section...Ch. 4 - A flue passing hot exhaust gases has a square...Ch. 4 - Steady-state temperatures (K) at three nodal...Ch. 4 - Functionally graded materials are intentionally...Ch. 4 - Steady-state temperatures at selected nodal points...Ch. 4 - Consider an aluminum heat sink (k=240W/mK), such...Ch. 4 - Conduction within relatively complex geometries...Ch. 4 - Prob. 4.60PCh. 4 - The steady-state temperatures (°C) associated with...Ch. 4 - A steady-state, finite-difference analysis has...Ch. 4 - Prob. 4.63PCh. 4 - Prob. 4.64PCh. 4 - Consider a two-dimensional. straight triangular...Ch. 4 - A common arrangement for heating a large surface...Ch. 4 - A long, solid cylinder of diameter D=25mm is...Ch. 4 - Consider Problem 4.69. An engineer desires to...Ch. 4 - Prob. 4.71PCh. 4 - Prob. 4.72PCh. 4 - Prob. 4.73PCh. 4 - Refer to the two-dimensional rectangular plate of...Ch. 4 - The shape factor for conduction through the edge...Ch. 4 - Prob. 4.77PCh. 4 - A simplified representation for cooling in very...Ch. 4 - Prob. 4.84PCh. 4 - A long trapezoidal bar is subjected to uniform...Ch. 4 - Consider the system of Problem 4.54. The interior...Ch. 4 - A long furnace. constructed from refractory brick...Ch. 4 - A hot pipe is embedded eccentrically as shown in a...Ch. 4 - A hot liquid flows along a V-groove in a solid...Ch. 4 - Prob. 4S.5PCh. 4 - Hollow prismatic bars fabricated from plain carbon...
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, mechanical-engineering and related others by exploring similar questions and additional content below.Similar questions
- Determine the rate of heat transfer per meter length to a light oil flowing through a 2.5-cm-ID, 60-cm-long copper tube at a velocity of 0.03 m/s. The oil enters the tube at 16C, and the tube is heated by steam condensing on its outer surface at atmospheric pressure with a heat transfer coefficient of 11.3 kW/m K. The properties of the oil at various temperatures are listed in the following table: Temperature, T(C) 15 30 40 65 100 (kg/m3) 912 912 896 880 864 c(kJ/kgK) 1.80 1.84 1.925 2.0 2.135 k(W/mK) 0.133 0.133 0.131 0.129 0.128 (kg/ms) 0.089 0.0414 0.023 0.00786 0.0033 Pr 1204 573 338 122 55arrow_forwardPin fins are provided to increase the heat transfer from a hot surface. The perimeter of each fin is 4cm and its cross section area is 2 cm². The thermal conductivity of fin material is 200 W / mK. The fin base temperature is 230 ° C, the ambient air temperature is 30 ° C and the heat transfer coefficient is 20 W / (m²K). The fins are assumed of negligible end loss Which of the following arrangements will give higher heat transfer rate? (1) 6 fins of 10 cm length. (2) 12 fins of 5 cm lengtharrow_forwardSteel pipe (outer diameter 100 mm) is covered with two layers of insulation. The inner layer, 40 mm thick, has a thermal conductivity of 0.07 W / (m K). The outer layer, 20 mm thick, has a thermal conductivity of 0.15 W / (m K). Pipes are used to deliver steam with a pressure of 800 kPa. The temperature on the outer insulation surface is 24 ° C. If the pipe is 10 m long, determine the following: (assuming that the conduction heat transfer resistance of the steel pipe and the vapor convection resistance are negligible). a. Heat loss per hour. = AnswerkJ / hr. b. Temperature between insulation layers. = Answer ° C.arrow_forward
- Stainless steel pipes with a thermal conductivity of 17 W/ (m° C) are used to transport hot oil. The temperature inside the tube is 130 ° C. The inner diameter of the pipe is 8 cm and the thickness of the pipe wall is 2 cm. The pipe is then insulated with 4 cm thick insulation with a thermal conductivity of 0.035 W / (m° C). The ambient temperature of the pipe is 25 ° C. Calculate the temperature between the steel and the insulation if we assume a steady state. A picture of the pipe can be seen below.arrow_forwardA steel tube 150mm inside diameter and 10mm thick, conveys wet steam at 17 bar and is surrounded by air at 27°C. The coefficient of heat transfer from the steam to the tube is 10kW/m2 K and the thermal conductivity for steel is 46.6 W/mK. Under these circumstances the energy loss due to heat transfer is 2000W per metre length of pipe. Show that, because the resistance to heat transfer is comparatively small between the steam and the pipe and within the pipe, the corresponding temperature drops are small compared with the temperature drop between the outside surface of the pipe and the air. If the pipe is covered with a 50mm thick layer of insulating material which has a thermal conductivity of 0.346 W/mK, determine the heat loss in watts per metre length of pipe, and the rate of condensation per 100m of pipeline under these conditions. Assume that the heat transfer coefficient from the surface of the insulating material to the air is 0.714 times that for the bare pipe. Answer: 609…arrow_forwardSteel pipe (outer diameter 100 mm) is covered with two layers of insulation. The inner layer, 40 mm thick, has a thermal conductivity of 0.07 W / (m K). The outer layer, 20 mm thick, has a thermal conductivity of 0.15 W / (m K). Pipes are used to delivering steam with a pressure of 600 kPa. The temperature on the outer insulation surface is 24 ° C. If the pipe is 10 m long, determine the following: (assuming that the conduction heat transfer resistance of the steel pipe and the vapor convection resistance are negligible). a. Hourly heat loss ... (kj / hr)b. temperature between insulation layers ... (° C.)arrow_forward
- 3. Hot water flows inside a 2.5 cm inner diameter tube, the tube has a wall thickness of 0.8 mm (tube length=1m) with a conduction resistance of 0.000183 °C /W, the inner and outer convection resistance are (0.00662, 1.196 °C /W) respectively. The overall heat transfer coefficients depending on the outer diameter of the pipe is equal to: A. 9.94 W/m2 °C B. 200 W/m² °C C. 0.5 W/m² °C D. None of themarrow_forwardYou want to increase the heat flux dissipated by a tube, OD = 2.5 cm, by placing cooling fins circular. The thickness, height and thermal conductivity of the fins are: 1mm, 1.25 cm and 160 W/mC, respectively. The fins are equally spaced such that there are 100 fins for every meter of tube length. If the The outer surface temperature of the tube is 170 C, the ambient temperature is 30 C, and the transfer coefficient of heat is h = 200 W/m2K, determine the increase (percentage) in the heat flux dissipated by the tube by placing the cooling fins. Take the efficiency of each fin to be 85%.arrow_forwardWater vapor at a temperature of 120 ° C flows through a stainless steel pipe (k = 57 W / mK). The inner diameter of the pipe is 47 mm, the outer diameter is 50 mm, and the length is 100 m. The heat transfer coefficient between the water vapor and the pipe wall is 200 W / m²K, and the heat transfer coefficient between the outer surface of the pipe and the ambient air is 25 W / m_K. The outdoor air temperature is 10 ° C. Find the thermal conductivity coefficient of the insulation material, since it is desired to insulate with an insulation material with a layer thickness of 50 mm in order to reduce the loss of heat from the pipe by 60%.arrow_forward
- a 50cm diameter pipeline in the arctic carries hot oil where outer surface is maintained at 30C and is exposed to a surrounding temperature of -1x10^0 C. a special powder insulation 5cm thick surrounds the pipe and has a thermal conductivity of 7mW/mC. the convection heat transfer coefficient on the outside of the pipe is 9W/m^2C. estimate the energy loss from the pipe per meter of lenght.arrow_forwardWater vapor at a temperature of 120 ° C flows through a stainless steel pipe (k = 57 W / mK). The inner diameter of the pipe is 47 mm, the outer diameter is 50 mm, and the length is 100 m. The heat transfer coefficient between the water vapor and the pipe wall is 200 W / m²K, and the heat transfer coefficient between the outer surface of the pipe and the ambient air is 25 W / m_K. The outdoor air temperature is 10 ° C. Find the thermal conductivity coefficient of the insulation material, since it is desired to insulate with an insulation material with a layer thickness of 50 mm in order to reduce the loss of heat from the pipe by 60%.arrow_forwardIf the average connective heat transfer coefficient on the outer surfaçe of a tube (inner diameter = 9 mm, Length = 93 cm, thickness = 1.0 mm) is 82.4 W/m .K, What is the thermal conductivity (W/m.K) for an insulation material when the maximum possible insulation thickness is 7 mm?arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
- Principles of Heat Transfer (Activate Learning wi...Mechanical EngineeringISBN:9781305387102Author:Kreith, Frank; Manglik, Raj M.Publisher:Cengage Learning
Principles of Heat Transfer (Activate Learning wi...
Mechanical Engineering
ISBN:9781305387102
Author:Kreith, Frank; Manglik, Raj M.
Publisher:Cengage Learning
Heat Transfer – Conduction, Convection and Radiation; Author: NG Science;https://www.youtube.com/watch?v=Me60Ti0E_rY;License: Standard youtube license