Solar Air-Conditioning Systems Focus on Components and Their Working Principles
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eBook-edition Solar Air-Conditioning Systems Focus on components and their working principles Nathan Rona Building Services Engineering, Department of Building Technology CHALMERS UNIVERSITY OF TECHNOLOGY Göteborg, Sweden 5765/2004 Solar Air-Conditioning Systems Focus on components and their working principles Nathan Rona eBook-edition Internserie: I2004:01 ISSN 1652-6007 Copyright © 5765/2004 by Nathan Rona, some rights reserved. Readers are encouraged to help in worldwide distribution of this work, pleas read the copyright appendix for more information and conditions that applies. Everyone is permitted to copy and distribute verbatim copies of this document or parts of it for educational and non commercial purposes under the terms stated in the “Copyright License” section Although great care has been taken in the compilation and publication of this report, no warrantees, expressed or implied are given in connection with the material. Neither the publisher nor the author takes any responsibility for any claims arising from the use of this information. However, the author welcomes and invites comments an suggestions from readers for additions and corrections to future editions, preferably by email to: eBook-edition note: In the eBook-edition hyperlinks has been added within the document to make reading on an electronic device easier. Also the quality some of the illustrations has been reduced to make the document smaller in order to make distribution easier. Published at: Building Services Engineering, Department of Building Technology CHALMERS UNIVERSITY OF TECHNOLOGY Göteborg, Sweden 5765/2004 Abstract Air-conditioning is one of the major consumers of electrical energy in many parts of the world today and already today air-conditioning causes energy shortage in for example China. The demand can be expected to increase because of changing working times, increased comfort expectations and global warming. Air-conditioning systems in use are most often built around a vapor compression systems driven by grid-electricity. However, most ways of generating the electricity today, as well as the refrigerants being used in traditional vapor compression systems, have negative impact on the environment. Solar air-conditioning might be a way to reduce the demand for electricity. In addition many solar air-conditioning systems are constructed in ways that eliminate the need for CFC, HCFC or HFC refrigerants. Alternatives to using solar energy are to use waste heat from different industrial proc- esses such as refineries, garbage treatment facilities etc. Even driving the air- conditioning systems directly with fossil fuels might in some cases be a more environ- mental friendly alternative than using electricity This report deals with a wide range of components, from room air-conditioners to solar collectors, which can be used as subcomponents in a solar air-conditioning system. However, most of the components and subsystems covered are not only suitable for solar air-conditioning. Some components are used for electrically, mechanically or heat driven air- conditioning. And of course other sources of mechanical energy or heat could be used for powering these components. Other components are used for solar energy collection and storage, which can be used in solar energy system with other purposes than just driving a solar air-conditioning system. An aim of the report is to describe and explain the working principles of the components and subsystem in such general terms that the report is usable not only to those specifically interested in solar air conditioning, but to anyone interested in air conditioning, heat driven air-conditioning and solar energy. The last section of the report briefly deals with how the components can be combined to form a complete solar air-conditioning system. Solar Air-Conditioning Systems Focus on components and their working principles Nathan Rona Building Services Engineering, Department of Building Technology CHALMERS UNIVERSITY OF TECHNOLOGY Göteborg, Sweden 5765/2004 Keywords: Air conditioning, Absorption chillers systems, Cogeneration, Heat driven air conditioning, Solar air conditioning, Solar energy, Solar equipment, Solar heat engines,Thermal Heat Pumps, Waste heat utilization. III בס״ד Preface This report is the result of of two individual adapted advanced courses in solar air- conditioning, given by the department of Building Technology at Chalmers University of Technology. These courses will be part of my master of science degree in engineering. The report could not have been written without all the assistance I have received from people, both at the department and outside the department. My thanks are therefore due to all those who have assisted, provided information or given feedback to the report, whether named or unintentionally forgotten. Particular thanks are due to Professor Per Fahlén, Doc. Jan-Olof Dalenbäck and especially Dr. Torbjörn Lindholm (my primary supervisor). Special thanks also due to Professor Gershon Grossman, head of Energy Engineering Research Center, Faculty of Mechanical Engineering, Technion - Israel Institute of Technology, Wimolsiri Pridasawas Ph.D. student at the Division of Applied Thermodynamics and Refrigeration, Department of Energy Technology, Royal Institute of Technology, Sweden, and Dr. Warick for their valuable assistance and feedback. Thanks also to Alain Dahan at SOLEL Solar Systems Ltd. and to Erwin Kose at microtherm Energietechnik GmbH for providing me with information, as well as to all those who those who have given me permission to use there illustrations in the report, especially to those who gave it free of charge (all except Taylor & Francis). If you come to appreciate this report, give a thought of thanks also to the ones mentioned above who have helped me writing it, but above all, to the One above who gave me the abilities, the understanding and the wisdom needed to write it. This work may be freely copied, distributed, and displayed, in whole or in part, in electronic form or in print, provided that the terms of the distribution license in appen- dix D are adhered to. The author will be most grateful for any help in distribution of this report and the knowledge it contains worldwide. You are however kindly re- quested to carefully read the license conditions before any copying or distribution. Any feedback on the report will be highly appreciated. Göteborg, Kislev 5765/Nov. 2004 Nathan Rona IV Table of contents 1. Introduction...............................................................................1 1.1 General Background............................................................................1 1.2 Report background, aims and coverage............................................2 1.3 Report structure...................................................................................2 1.4 Definitions and concepts.....................................................................3 2. Components..............................................................................4 2.1 Distribution...........................................................................................5 2.1.1 All-air-systems.................................................................................5 2.1.2 Hydronic systems............................................................................6 2.1.3 Decentralized systems....................................................................6 2.2 Processing (Refrigeration and dehumidification)............................8 2.2.1 Mechanical and Electric Heat Pumps............................................8 2.2.1.1 Vapor Compression System....................................................8 2.2.1.2 Stirling cooling........................................................................11 2.2.1.3 Brayton refrigeration cycle ....................................................13 2.2.1.4 Thermoelectric modules.........................................................14 2.2.2 Heat engines.................................................................................16 2.2.2.1 Rankine power cycle..............................................................16 2.2.2.2 Stirling engine........................................................................19 2.2.2.3 Brayton power cycle...............................................................21 2.2.2.4 Thermoelectric generator.......................................................22 2.2.3 Thermal Heat Pumps....................................................................23 2.2.3.1 Carré cycle absorption heat pump.........................................24 2.2.3.2 Diffusion (Platen Munters) absorption cycle...........................39 2.2.3.3 Open absorption cycle ..........................................................42 2.2.3.4 Solid sorption heat pumps.....................................................47 2.2.3.5 Ejector (steam jet) cycle.........................................................51 2.2.4 Evaporative cooling ......................................................................54 2.2.4.1 Direct evaporative cooling......................................................55 2.2.4.2 Indirect evaporative cooling ..................................................56 2.2.4.3 Indirect-direct evaporative cooling .......................................56 2.2.5 Desiccant dehumidification..........................................................57 2.2.5.1 Solid desiccant dehumidification ...........................................57 2.2.5.2 Liquid