...Title: Forced Convection Objective: To demonstrate the use of extended surface such as fin and pin to improve the heat transfer in forced convection. Introduction: Convection is the study of conduction in a fluid as enhanced by its "convective transport", that is, its velocity with respect to a solid surface. It thus combines the energy equation, or first law of thermodynamics, with the continuity and momentum relations of fluid mechanics. The causes of convection are generally described as one of either natural or forced. However the distinction between natural and forced convection is particularly important for convective heat transfer. Forced convection or also known as heat advection studies the heat transfer between a moving fluid and a solid surface. There are various types of forced convection, such as flow in a tube or across a flat plate and so on. In forced convection, the fluid has a nonzero streaming motion in the field away from the body surface, caused perhaps by a pump or fan or other driving force independent of the presence of the body. Also in this class are bodies moving through a still fluid, since fluid velocities are forced and may be large, heat transfer via forced convection will usually be significantly larger. It should be considered as one of the main methods of useful heat transfer as significant amounts of heat energy can be transported very efficiently and this mechanism is found very commonly in everyday life, including central heating, air...
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...Method and theory of 3D micro heat pipe cooling introduction: The traditional heat dissipation method has included different parts, such as Air cooling and Water cooling. When IC chip generate heat in working on a high level, there has to be some methods to reduce heat make sure that the chips will not be damaged. With some theory [Surface area of evaporator, Heat input in Watt act.] there are several advanced method and theory of 3D micro heat pipe cooling. Key word: LPMHP, Tube transfer ,Moore's Law ,Heat-Pipe, Fluids, Cooling rate. Method and theory in experimental A experimental study has been performed to investigate the heat transfer characteristics of looped parallel micro heat pipes of circular geometry having inner diameter of 1.8mm and length of 150mm placed parallel, connected by two U tubes of same diameter at the top and bottom ends. The experimental parameters are condenser inclination angel, heat input and properties of the working fluids. Taking acetone and ethanol as working fluids, heat transfer characteristics are determined experimentally for different condenser inclination angels a different heat input. With the advancement of micro and nanotechnologies, the power densities in the electronic equipments are increasing rapidly. Overheating of integrated circuit(IC),microchip etc. It is very important to facilitate optimum cooling of electronic components in a smaller electronic device because integrated circuit lifetime depends...
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...Turbulence 10 References 13 Abstract The fires problem is one of the hazard pose a threat to life and property. Flames behave differently under various conditions which include: the oxygen available, combustible material, orientation of surfaces, etc. this a complex phenomena which is influenced by multiple factors that includes ignition, heat release rate, flame spread and the generation of different products of combustion like carbon IV oxide and carbon II oxide. The research was performed by studying various sources in the library and in the internet and also performing experiments to simulate a real life situation. Introduction The Fire Problem The flammability of a material is a complex event which is influenced by multiple factors that includes ignition, heat release rate, flame spread and the generation of different products of combustion like carbon IV oxide and carbon II oxide. In order to better protect the people and property from risk posed by the unwanted fires, it become necessary to understands all these factors under different conditions. Babrauskas and Vytenis 1992 suggested that heat release rate is the main variable in fire hazard; but Kashiwagi and Ito argued effectively that, the flame spread over the surface of combustible material such a wall and a floor is the main variable responsible for the growth of fire at the initial stages of fire. In addition, the angle of orientation of the combustible material has been found to contribute...
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...lean/rich MEA heat exchanger E-114. This heat exchanger is a counter flow shell and tube heat exchanger and is designed to heat up the rich MEA stream flowing from the CO2 absorber to the stripper. The principle that is applied is heat exchange between cold stream and hot stream which in this case the heat energy is transferred from the lean MEA stream to the rich MEA stream. Apart from this, the chemical engineering design for this heat exchanger includes the determination of its dimensions and heat exchange coefficient as well as pressure drop. The mechanical design covers the design of pressure vessel, head, supports and piping. In addition, the operating design which includes the commissioning, start-up, shutdown and maintenance procedures, process control, and HAZOP study is considered. 2.0 Process Description Figure 2.1 Schematic of rich/lean MEA heat exchange process flow sheet The lean/rich MEA heat exchange process is presented in Figure 2.1. The MEA-2 stream containing rich CO2 is flowing from CO2 absorber and enters the heat exchanger to be heated up from 61°C to 80°C by MEA-7 before entering the stripper. The MEA-7 is then cooled down from 105°C to 84°C when pass through the heat exchanger and recycle back to the CO2 absorber. The cold stream in this case is MEA-2 and MEA-3 while the hot stream is MEA-7 and MEA-8. 3.0 Chemical Engineering Design 3.1 Design Methodology The rich/lean MEA heat exchanger is a counter flow shell and tube heat exchanger. The...
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...ofACRC Project 01 Refrigerant-Side Evaporation and Condensation Studies 1. C. Chato, Principal Investigator The Air Conditioning and Refrigeration Center was founded in 1988 with a grant from the estate of Richard W. Kritzer, the founder of Peerless of America Inc. A State of Illinois Technology Challenge Grant helped build the laboratory facilities. The ACRC receives continuing support from the Richard W. Kritzer Endowment and the National Science Foundation. Thefollowing organizations have also become sponsors of the Center. Acustar Division of Chrysler Allied-Signal, Inc. Amana Refrigeration, Inc. Brazeway, Inc. Carrier Corporation Caterpillar, Inc. E. I. du Pont de Nemours & Co. Electric Power Research Institute Ford Motor Company Frigidaire Company General Electric Company Harrison Division of GM ICI Americas, Inc. Modine Manufacturing Co. Peerless of America, Inc. Environmental Protection Agency U. S. Army CERL Whirlpool Corporation For additional iriformation: Air Conditioning & Refrigeration Center Mechanical & Industrial Engineering Dept. University of Illinois 1206 West Green Street Urbana IL 61801 2173333115 INITIAL EVAPORATIVE COMPARISON OF R·22 WITH ALTERNATIVE REFRIGERANTS R·l34a AND R·32/R·125 J.P. Wattelet, J.C. ehato, A.L. Souza, and B.R. Christoffersen ABSTRACT Initial R-22 alternatives were examined for conditions found in stationary air conditioning system evaporators. Heat transfer coefficients for both R-134a and a 60%/40% azeotropic mixture...
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...LABORATORY 2 ME 11L SUBMITTED BY: Alega, Ulysses Jr. H. Bicaldo, Mark Zedrick L. Engaño, Moises A. Sabida, Ricalyn B. SUBMITTED TO: Engr. Manuel E. Europeo March 10, 2014 INTRODUCTION Heat conduction (or thermal conduction) is the transfer of internal energy by microscopic diffusion and collisions of particles or quasi-particles within a body due to a temperature gradient. The microscopically diffusing and colliding objects include molecules, electrons, atoms, and phonons. They transfer disorganized microscopic kinetic and potential energy, which are jointly known as internal energy. Conduction can only take place within an object or material, or between two objects that are in direct or indirect contact with each other. Conduction takes place in all forms of ponderable, such as solids, liquids, gases and plasmas. Whether by conduction or by thermal radiation, heat spontaneously flows from a hotter to a colder body. In the absence of external drivers, temperature differences decay over time, and the bodies approach thermal equilibrium. In conduction, the heat flow is within and through the body itself. In contrast, in heat transfer by thermal radiation, the transfer is often between bodies, which can be spatially separate. Also possible is transfer of heat by a combination of conduction and thermal radiation. In convection, internal energy is carried between bodies by a material carrier. In solids, conduction is mediated by the combination of vibrations and...
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...partan Heat Exchangers Inc. Group Case Study Spartan Heat Exchangers Inc. Current State Spartan Heat Exchangers Inc. has been a leading designer and manufacturer of specialized industrial heat transfer equipment for more than 10 years. The company’s primary products are transformer coolers, hydro generator coolers, air-cooled heat exchangers and transformer oil coolers. Their USP are Fin tube type heat exchangers and long lasting products. “… A heat exchanger is a device that is used to transfer thermal energy (enthalpy) between two or more fluids, between a solid surface and a fluid, or between solid particulates and a fluid, at different temperatures and in thermal contact. …” The company is into highly customized heat equipments. Presently, due to entry of new competition from European and Korean companies they have changed their corporate policy, which emphasize on reducing the variety and standardizing the product. The new business policy also aims at reducing the current lead time from 14 weeks to 6 weeks. Problem Statement The Materials Department headed by Rick Coyne has to take many initiatives internally to incorporate the various implications of the new strategy, and submit his report to his boss Max Brisco with the changes suggested by him within a week. The major challenges that Rick faces include: • Change from responsive to anticipatory model of production. • Increase inventory turns from present 4 times to 20 times. • Eliminate material shortages...
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...poikioltherm, homeotherm, ectotherm and endotherm. Provide an example of an animal for each of the following combinations and explain why it fits these terms: - Poikioltherm: An animals whose body temp varies with the surrounding temperature -Homeotherm: An organism such as a bird or mammal, having a body temp that is constant and largely independent of the temperature surrounding. -Ectotherm- heat acquired from external environment -Endotherm- heat generated by metabolism Poikilotherm & ectotherm: Fish, amphibians, reptiles. Poikilotherm & endotherm: Mammals and birds, insects Homeotherm & ectotherm: tropical reptiles Homeotherm & endotherm: Mostly birds and mammals 3. Describe the 4 mechanisms through which animals exchange heat with their environments. -Radiation: Release of electromagnetic waves by all objects warmer than absolute zero. -Convection: Transfer of heat by movement. Warm blood from core moves to extremities. -Conduction: Direct transfer to thermal motion between molecules of objects in contact with each other. -Evaporation: Removal of heat from the surface of a liquid that is losing some of its molecules as gas. 4. For each of the...
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...needed to be optimized in building envelop. Extended Research Task Temperature Control in Homes ---- Windows Extended Research Task Temperature Control in Homes ---- Windows Temperature Control in Homes --- Windows 1. Abstract: The window insulation always plays an important role in building design and thermal comfort, it is one of the main parts needed to be optimized in building envelop. Window insulation is a basic element which can decide the insulation capacity. The large heat loss from the window is the main part of wasting energy, and simultaneously, there is also difficult to explore the new energy source and to improve the current heat generation device efficiency. Therefore, building a proper insulated window system is a good approach to keep an acceptable indoor climate as well as to reduce energy use and negative climate effects. The aim of this extended research task is to introduce readers to different ways of windows insulation that can efficiently reduce heat loss in an average household during Tasmanian winter. 2. Introduction Tasmania has cold temperature climate with four distinct seasons, with the most distinctive season during the winter month between June and July. During the winter season Tasmania become the wettest and coolest state in Australia with most high lying areas receiving considerable snowfall. Winter maximums are 12 °C (54 °F) on average along coastal areas and 3 °C (37 °F) on the Central Plateau, thanks to a series of...
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...This page intentionally left blank SEVENTH EDITION Fundamentals of Heat and Mass Transfer THEODORE L. BERGMAN Department of Mechanical Engineering University of Connecticut ADRIENNE S. LAVINE Mechanical and Aerospace Engineering Department University of California, Los Angeles FRANK P. INCROPERA College of Engineering University of Notre Dame DAVID P. DEWITT School of Mechanical Engineering Purdue University JOHN WILEY & SONS VICE PRESIDENT & PUBLISHER EXECUTIVE EDITOR EDITORIAL ASSISTANT MARKETING MANAGER PRODUCTION MANAGER PRODUCTION EDITOR DESIGNER EXECUTIVE MEDIA EDITOR PRODUCTION MANAGEMENT SERVICES Don Fowley Linda Ratts Renata Marchione Christopher Ruel Dorothy Sinclair Sandra Dumas Wendy Lai Thomas Kulesa MPS Ltd. This book was typeset in 10.5/12 Times Roman by MPS Limited, a Macmillan Company and printed and bound by R. R. Donnelley (Jefferson City). The cover was printed by R. R. Donnelley (Jefferson City). Founded in 1807, John Wiley & Sons, Inc. has been a valued source of knowledge and understanding for more than 200 years, helping people around the world meet their needs and fulfill their aspirations. Our company is built on a foundation of principles that include responsibility to the communities we serve and where we live and work. In 2008, we launched a Corporate Citizenship Initiative, a global effort to address the environmental, social, economic, and ethical challenges we face in our business. Among the issues we are addressing...
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...UNIVERSITÀ DEGLI STUDI DI PADOVA Facoltà di Ingegneria Dipartimento di Fisica Tecnica Tesi di laurea FEED-FORWARD CONTROL APPLIED TO THERMALLY ACTIVATED CONCRETE SLABS – A CASE STUDY Relatore: Correlatori: Prof. Ing. Roberto ZECCHIN Dott. Ing. Michele DE CARLI Dott. Ing. Dietrich SCHMIDT Laureando: Alessio PULLIERO Anno accademico 2003-2004 To my parents …. ABSTRACT The main purpose of this thesis is to investigate different control strategies for the heating and cooling system of the ZUB (Centre for Sustainable Building), situated in Kassel, Germany. It is an experimental office building, with a very detailed monitoring system for studying low-energy and low-exergy building technologies. The conditioning system is a TABS (Thermally Activated Building System), with water pipes embedded in the centre of a structural concrete slab, thus resulting in a ceiling radiant system. The high thermal capacity of the slab offers great opportunities to store heat, to dampen temperature fluctuations or to shift the peak-load; but, on the other hand, it implies a slow response of the system, which requires an accurate regulation strategy to front the variability of several factors, and to achieve the desired indoor temperature. A TRNSYS model of an office room has been developed, thus allowing to implement several regulations in the software and to test their performance. The main conclusion, carried out from the simulations, is that the implementation of a Feed-forward...
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...Design of heat exchangers required for a 50-100kW superheated Rankine cycle MECH 421 Huzeyfe SHAHIN Gokce SAGIR Usman Arshad SHAH 28th December 2015 Table of Contents 1. ABSTRACT .............................................................................................................................................. 3 2. INTRODUCTION ..................................................................................................................................... 3 3. LITERATURE REVIEW ............................................................................................................................. 3 4. SIMPLE DESIGN ..................................................................................................................................... 3 4.1 Evaporator at 800 kPa (Counter Flow) ................................................................................................ 4 4.1.1 Preheater ..................................................................................................................................... 4 4.1.2 Boiler ............................................................................................................................................ 4 4.1.3 Superheater ................................................................................................................................. 5 4.2 Evaporator at 800 kPa (Shell & Tube) ............................................
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...CHAPTER 4 SI UNIT PROBLEMS SOLUTION MANUAL SONNTAG • BORGNAKKE • VAN WYLEN FUNDAMENTALS of Thermodynamics Sixth Edition Sonntag, Borgnakke and van Wylen CONTENT SUBSECTION Correspondence table Concept problems Force displacement work Boundary work: simple one-step process Polytropic process Boundary work: multistep process Other types of work and general concepts Rates of work Heat transfer rates Review problems English unit concept problems English unit problems PROB NO. 1-19 20-30 31-46 47-58 59-70 71-81 82-94 95-105 106-116 117-122 123-143 Sonntag, Borgnakke and van Wylen CHAPTER 4 6 ed. CORRESPONDANCE TABLE The new problem set relative to the problems in the fifth edition. New 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 5th 1 2mod new New New 3 4 new New new New New 18 27 new new 5 new New 13 new new New New New 22 45 mod 8 12 14 New New New New 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 5th new 19 20 33 mod 37 36 15 30 6 New 32 7 9 34 10 New New 26 39 New 40 New New New New 58 59 60 61 New New New New New 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 5th new new new 43 new New new new New 47 HT 48 HT 49 HT 50 HT mod 51 HT mod 52 HT 53 HT 54 HT 55 HT 56 HT 57 HT 31 mod 11 16 17 23 21 mod 28 29 24 44 35 th Sonntag, Borgnakke and van Wylen The English unit problem set...
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...Transient, One-Dimensional Heat Conduction in a Convectively Cooled Sphere Gerald Recktenwald∗ March 16, 2006† 1 Overview This article documents the numerical evaluation of a well-known analytical model for transient, one-dimensional heat conduction. The physical situation is depicted in Figure 1. A sphere of uniform material is initially at a uniform temperature Ti . At time t = 0 the sphere is immersed in a stream of moving fluid at some different temperature T∞ . The external surface of the sphere exchanges heat by convection. The local heat flux from the sphere to the fluid is q = h(Ts − T∞ ) (1) where h is the heat transfer coefficient, and Ts is the local surface temperature. The problem is greatly simplified by assuming that the heat flux on the surface is uniform. Under this condition, Ts = T (r0 ) is also uniform and the temperature inside the sphere depends only on the radius, r, and time t, i.e., ∗ Mechanical and Materials Engineering Department, Portland State University, Portland, OR, 97201, gerry@me.pdx.edu † Corrections made 10 September 2011 h T ro Figure 1: A sphere immersed in and exchanging heat with stream of fluid. 1 2 T = T (r, t). The temperature field is governed by the heat equation in spherical coordinates ∂T α∂ 1 ∂T =2 (2) ∂t r ∂r r2 ∂r where α = k/(ρc) is the thermal diffusivity of the sphere material, k is the thermal conductivity, ρ is the density, and c is the specific heat. The boundary condition on the surface is k ∂T ∂r = h(T∞ − Ts ). (3) r =r0...
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...Introduction Background of the Study………………………………………………………………......3 Statement of the Problem ................................................................................5 Significance of the Study ................................................................................6 Scope and Limitations of the Study .................................................................6 Definition of Terms .........................................................................................6 Chapter 2: Review of Related Literature...........................................................7 Chapter 3: Methodology ..................................................................................8 Chapter 4: Results and Discussions ..............................................................10 Chapter 5: Summary, Conclusions, and Recommendations ...........................14 Bibliography..................................................................................................15 Southridge Private High School Antipolo City In Partial Fulfillment of the Requirements in Science and Technology IV A Study on the Feasibility of Identifying an Alternative Insulator for Ice Submitted to: Mrs. Marites N. Caslib (Physics Instructor) Submitted by: Jhann Reinner M. Pagayon February 6, 2012 Abstract Thermal insulation is the reduction of heat transfer between objects in thermal...
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