Solar Air-Conditioning Systems Focus on Components and Their Working Principles

Total Page:16

File Type:pdf, Size:1020Kb

Solar Air-Conditioning Systems Focus on Components and Their Working Principles 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
Recommended publications
  • Solar Energy: State of the Art
    Downloaded from orbit.dtu.dk on: Sep 27, 2021 Solar energy: state of the art Furbo, Simon; Shah, Louise Jivan; Jordan, Ulrike Publication date: 2003 Document Version Publisher's PDF, also known as Version of record Link back to DTU Orbit Citation (APA): Furbo, S., Shah, L. J., & Jordan, U. (2003). Solar energy: state of the art. BYG Sagsrapport No. SR 03-14 General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. Users may download and print one copy of any publication from the public portal for the purpose of private study or research. You may not further distribute the material or use it for any profit-making activity or commercial gain You may freely distribute the URL identifying the publication in the public portal If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim. Editors: Simon Furbo Louise Jivan Shah Ulrike Jordan Solar Energy State of the art DANMARKS TEKNISKE UNIVERSITET Internal Report BYG·DTU SR-03-14 2003 ISSN 1601 - 8605 Solar Energy State of the art Editors: Simon Furbo Louise Jivan Shah Ulrike Jordan Department of Civil Engineering DTU-bygning 118 2800 Kgs. Lyngby http://www.byg.dtu.dk 2003 PREFACE In June 2003 the Ph.D. course Solar Heating was carried out at Department of Civil Engineering, Technical University of Denmark.
    [Show full text]
  • Electriq AC60E EVAPORATIVE COOLER with HUMIDIFIER User
    USER MANUAL EVAPORATIVE COOLER WITH HUMIDIFIER AC60E Thank you for choosing electriQ Please read this user manual before using this innovative Air Cooler and keep it safe for future reference. Visit our page www.electriQ.co.uk for our entire range of Intelligent Electricals CONTENTS SAFETY INSTRUCTIONS 3 FEATURES AND OPERATION 4 PARTS LIST AND INSTALLATION 5 CONTROL PANEL AND SETTINGS 6 REMOTE CONTROL 7 CLEANING AND MAINTENANCE 7 TROUBLE SHOOTING 8 APPENDIX 8 Page 2 of 9 SAFETY INSTRUCTIONS IMPORTANT! Carefully read the instructions before operating the unit This appliance is for indoor use only. Rating: This unit must only be connected to a 220-240 V / 50 Hz earthed outlet. Installation must be in accordance with regulations of the country where the unit is used. If you are in any doubt about the suitability of your electrical supply have it checked and, if necessary, modified by a qualified electrician. This air cooler has been tested and is safe to use. However, as with any electrical appliance - use it with care. Disconnect the appliance from the power socket before changing filters, dismantling, assembling or cleaning. Avoid touching any moving parts within the appliance. Never insert fingers, pencils or any other objects though the guard. This appliance is not intended for use by persons (including children) with reduced physical, sensory or mental capabilities. It is also not intended for use by those with a lack of experience and knowledge, unless they have been given supervision or instruction concerning the use of the appliance by a person responsible for their safety.
    [Show full text]
  • Wind- Chimney
    WIND-CHIMNEY Integrating the Principles of a Wind-Catcher and a Solar-Chimney to Provide Natural Ventilation A Thesis presented to the Faculty of California Polytechnic State University, San Luis Obispo In Partial Fulfillment of the Requirements for the Degree Master of Science in Architecture by Fereshteh Tavakolinia December 2011 WIND-CHIMNEY Integrating the Principles of a Wind-Catcher and a Solar-Chimney to Provide Natural Ventilation © 2011 Fereshteh Tavakolinia ALL RIGHTS RESERVED ii COMMITTEE MEMBERSHIP TITLE: WIND-CHIMNEY Integrating the Principles of a Wind-Catcher and a Solar-Chimney to Provide Natural Ventilation AUTHOR: Fereshteh Tavakolinia DATE SUBMITTED: December 2011 COMMITTEE CHAIR: James A. Doerfler, Associate Department Head COMMITTEE MEMBER: Jacob Feldman, Professor iii WIND-CHIMNEY Integrating the principles of a wind-catcher and a solar chimney to provide natural ventilation Fereshteh Tavakolinia Abstract This paper suggests using a wind-catcher integrated with a solar-chimney in a single story building so that the resident might benefit from natural ventilation, a passive cooling system, and heating strategies; it would also help to decrease energy use, CO2 emissions, and pollution. This system is able to remove undesirable interior heat pollution from a building and provide thermal comfort for the occupant. The present study introduces the use of a solar-chimney with an underground air channel combined with a wind-catcher, all as part of one device. Both the wind-catcher and solar chimney concepts used for improving a room’s natural ventilation are individually and analytically studied. This paper shows that the solar-chimney can be completely used to control and improve the underground cooling system during the day without any electricity.
    [Show full text]
  • Solar Heating and Cooling & Solar Air-Conditioning Position Paper
    Task 53 New Generation Solar Cooling & Heating Systems (PV or solar thermally driven systems) Solar Heating and Cooling & Solar Air-Conditioning Position Paper November 2018 Contents Executive Summary ............................................................. 3 Introduction and Relevance ................................................ 4 Status of the Technology/Industry ...................................... 5 Technical maturity and basic successful rules for design .............. 7 Energy performance for PV and Solar thermally driven systems ... 8 Economic viability and environmental benefits .............................. 9 Market status .................................................................................... 9 Potential ............................................................................. 10 Technical potential ......................................................................... 10 Costs and economics ..................................................................... 11 Market opportunities ...................................................................... 12 Current Barriers ................................................................. 12 Actions Needed .................................................................. 13 This document was prepared by Daniel Neyer1,2 and Daniel Mugnier3 with support by Alexander Thür2, Roberto Fedrizzi4 and Pedro G. Vicente Quiles5. 1 daniel neyer brainworks, Oberradin 50, 6700 Bludenz, Austria 2 University of Innsbruck, Technikerstr. 13, 6020 Innsbruck, Austria
    [Show full text]
  • Ammonia As a Refrigerant
    1791 Tullie Circle, NE. Atlanta, Georgia 30329-2305, USA www.ashrae.org ASHRAE Position Document on Ammonia as a Refrigerant Approved by ASHRAE Board of Directors February 1, 2017 Expires February 1, 2020 ASHRAE S H A P I N G T O M O R R O W ’ S B U I L T E N V I R O N M E N T T O D A Y © 2017 ASHRAE (www.ashrae.org). For personal use only. Additional reproduction, distribution, or transmission in either print or digital form is not permitted without ASHRAE’s prior written permission. COMMITTEE ROSTER The ASHRAE Position Document on “Ammonia as a Refrigerant” was developed by the Society’s Refrigeration Committee. Position Document Committee formed on January 8, 2016 with Dave Rule as its chair. Dave Rule, Chair Georgi Kazachki IIAR Dayton Phoenix Group Alexandria, VA, USA Dayton, OH, USA Ray Cole Richard Royal Axiom Engineers, Inc. Walmart Monterey, CA, USA Bentonville, Arkansas, USA Dan Dettmers Greg Scrivener IRC, University of Wisconsin Cold Dynamics Madison, WI, USA Meadow Lake, SK, Canada Derek Hamilton Azane Inc. San Francisco, CA, USA Other contributors: M. Kent Anderson Caleb Nelson Consultant Azane, Inc. Bethesda, MD, USA Missoula, MT, USA Cognizant Committees The chairperson of Refrigerant Committee also served as ex-officio members: Karim Amrane REF Committee AHRI Bethesda, MD, USA i © 2017 ASHRAE (www.ashrae.org). For personal use only. Additional reproduction, distribution, or transmission in either print or digital form is not permitted without ASHRAE’s prior written permission. HISTORY of REVISION / REAFFIRMATION / WITHDRAWAL
    [Show full text]
  • Regional Climate Zone Modeling of a Commercial Absorption Heat Pump
    Purdue University Purdue e-Pubs International Refrigeration and Air Conditioning School of Mechanical Engineering Conference 2016 Regional Climate Zone Modeling of a Commercial Absorption Heat Pump Hot Water Heater - Part 1: Southern and South Central Climate Zones Patrick Geoghegan Oak Ridge National Laboratory, [email protected] Bo Shen Oak Ridge National Laboratory, [email protected] Christopher Keinath Stone Mountain Technologies, Inc., [email protected] Michael Garrabrant Stone Mountain Technologies, Inc., [email protected] Follow this and additional works at: http://docs.lib.purdue.edu/iracc Geoghegan, Patrick; Shen, Bo; Keinath, Christopher; and Garrabrant, Michael, "Regional Climate Zone Modeling of a Commercial Absorption Heat Pump Hot Water Heater - Part 1: Southern and South Central Climate Zones" (2016). International Refrigeration and Air Conditioning Conference. Paper 1791. http://docs.lib.purdue.edu/iracc/1791 This document has been made available through Purdue e-Pubs, a service of the Purdue University Libraries. Please contact [email protected] for additional information. Complete proceedings may be acquired in print and on CD-ROM directly from the Ray W. Herrick Laboratories at https://engineering.purdue.edu/ Herrick/Events/orderlit.html 2552, Page 1 Regional Climate Zone Modeling of a Commercial Absorption Heat Pump Hot Water Heater – Part 1: Southern and South Central Climate Zones Patrick Geoghegan1*, Bo Shen1, Chris Keinath2, Michael Garrabrant2 1Oak Ridge National Laboratory 1 Bethel Valley Road Oak Ridge, TN 37831 [email protected] 2Stone Mountain Technologies, Inc. 609 Wesinpar Road Johnson City, TN 37604 *Corresponding Author ABSTRACT Commercial hot water heating accounts for approximately 0.78 Quads of primary energy use with 0.44 Quads of this amount from natural gas fired heaters.
    [Show full text]
  • Evaporative Cooler Parts Accessories
    COOLER PUMPS DIAL CTN CTN MODEL CFM /GPH* VOLTS COLOR APPROVAL** P/N QTY WT RESIDENTIAL CONCENTRIC UL Classified Flame Retardant Motor Housing Heavy Duty Motor Auto Reset Thermal Overload Grounded 3 Prong Plug Low Level Pump 1150 UL5500 Premium Pump 5,500 / 240 115V Black UL/UЯ 12 24.5 1175 UL7500 Premium Pump 7,500 / 360 115V Blue UL/UЯ 12 27.9 1195 UL11000 Premium Pump 11,000 / 420 115V Green UL/UЯ 12 32.5 1279 UL7500-2 Premium Pump 7,500 / 360 230V Orange/Black UL/UЯ 6 14.1 1286 UL11000-2 Premium Pump 11,000 / 420 230V Orange/Black UL/UЯ 6 15.4 COMMERCIAL CONCENTRIC UL Classified & City of L.A. Approved Molded 3 Prong Plug Low Level Operation Auto Reset Thermal Overload Grounded Round SJT Power Cord Low Level Splash Protection Flame Retardant Motor Housing Extra Heavy Duty Motor 1414 UL7500LA Pump 7,500 / 375 115V Black UL/UЯ/ COLA 12 31.5 1424 UL11000LA Pump 11,000 / 440 115V Black UL/UЯ/ COLA 12 35.6 1428 UL7500-2LA Pump 7,500 / 375 230V Orange/Black UL/UЯ/ COLA 6 15.2 1429 UL11000-2LA Pump 11,000 / 440 230V Orange/Black UL/UЯ/ COLA 6 16.5 INDUSTRIAL CONCENTRIC Same features as Commercial Pumps 6 Ft Grounded Round SJT Power Cord Requires 5/8 Or 3/4 Inch I.D.Pump Hose 1387 UL15000LA Pump 12 to 21,000 / 505 115V Black UL/UЯ/ COLA 6 17.4 1400 UL25000LA Pump 15 to 25,000 / 580 115V Black UL/UЯ/ COLA 6 17.3 1396 UL15000-2LA Pump 12 to 21,000 / 505 230V Orange/Black UL/UЯ/ COLA 6 17.6 1402 UL25000-2LA Pump 15 to 25,000 / 580 230V Orange/Black UL/UЯ/ COLA 6 16.3 REPLACEMENT FOR MASTERCOOL®/ARCTIC CIRCLE® Replacement Pumps for Mastercool® (using 8” and 12” Media) and Arctic Circle® Coolers UL Classified Exceeds OEM Pump Performance and Longevity Includes Mesh Basket and Mounting Bracket 1442 MC8500UL Pump 4 to 8,500 / 360 115V Tan UL/UЯ 6 14.0 1443 MC8500-2UL Pump 4 to 8,500 / 360 230V Orange/Black UL/UЯ 6 14.5 *Gallons per hour flow rate at 1 foot head height.
    [Show full text]
  • A Review of Building Integrated Solar Thermal (Bist)
    enewa f R bl o e ls E a n t e n r e g Journal of y m a a n d d Zhang et al., n u A J Fundam Renewable Energy Appl 2015, 5:5 F p f p Fundamentals of Renewable Energy o l i l ISSN: 2090-4541c a a DOI: 10.4172/2090-4541.1000182 n t r i o u n o s J and Applications Review Article Open Access Building Integrated Solar Thermal (BIST) Technologies and Their Applications: A Review of Structural Design and Architectural Integration Xingxing Zhang*1, Jingchun Shen1, Llewellyn Tang*1, Tong Yang1, Liang Xia1, Zehui Hong1, Luying Wang1, Yupeng Wu2, Yong Shi1, Peng Xu3 and Shengchun Liu4 1Department of Architecture and Built Environment, University of Nottingham, Ningbo, China 2Department of Architecture and Built Environment, University of Nottingham, UK 3Beijing Key Lab of Heating, Gas Supply, Ventilating and Air Conditioning Engineering, Beijing University of Civil Engineering and Architecture, China 4Key Laboratory of Refrigeration Technology, Tianjin University of Commerce, China Abstract Solar energy has enormous potential to meet the majority of present world energy demand by effective integration with local building components. One of the most promising technologies is building integrated solar thermal (BIST) technology. This paper presents a review of the available literature covering various types of BIST technologies and their applications in terms of structural design and architectural integration. The review covers detailed description of BIST systems using air, hydraulic (water/heat pipe/refrigerant) and phase changing materials (PCM) as the working medium. The fundamental structure of BIST and the various specific structures of available BIST in the literature are described.
    [Show full text]
  • Overview of Chiller Compressors
    Overview of Chiller Compressors Course No: M04-027 Credit: 4 PDH A. Bhatia Continuing Education and Development, Inc. 22 Stonewall Court Woodcliff Lake, NJ 07677 P: (877) 322-5800 [email protected] OVERVIEW OF CHILLER COMPRESSORS Overview In HVAC industry, the refrigeration machine that produces chilled water is referred to as a “Chiller”. A chiller package operates either on the principles of vapor compression or vapor absorption. The vapor compression system uses mechanical energy in the form of electric motor to drive the cooling cycle whereas absorption chillers use heat to drive the process. The vapor compression chiller system, which is far more prominent in commercial buildings, consists of four major components: the compressor, evaporator, condenser and expansion device all packaged as a single unit. The classification of vapor compression chiller packages is generally by the type of compressor: centrifugal, reciprocating, and screw being the major ones. Chillers are the largest consumer of energy in a commercial building and it is therefore important to understand the relative benefits and limitations of various types in order to make the right economic decisions in chiller installation and operation. This course will talk about the type of compressor used in the water cooled chiller. The course is divided into 3 parts: Part - I: Types of Chiller Compressors Part – II: Comparison of Chiller Compressors Part –III: Economic Evaluation of Chiller Systems PART I - TYPES OF CHILLER COMPRESSORS Most cooling systems, from residential air conditioners to large commercial and industrial chillers, employ the refrigeration process known as the vapor compression cycle. At the heart of the vapor compression cycle is the mechanical compressor.
    [Show full text]
  • Air Conditioning and Refrigeration Systems
    AAS (60 SCH*) ® Air Conditioning *Semester Credit Hour 8/2020 First Semester - 15 SCH Second Semester - 15 SCH COSC 1301 - Introduction to Computing HART 1341 - Residential Air Conditioning HART 1301 - Basic Electricity for HVAC HART 1345 - Gas and Electric Heating HART 1307 - Refrigeration Principles HART 2341 - Commercial Air Conditioning HART 1310 - HVAC Shop Practices and Tools HART 2349 - Heat Pumps PSYC 1300 - Learning Framework SPCH 1321 - Business & Professional Communication Third Semester - 15 SCH Fourth Semester - 15 SCH HART 2331 - Advanced Electricity for HVAC HART 2334 - Advanced Air Conditioning Controls HART 2336 - Air Conditioning Troubleshooting HART 2343 - Industrial Air Conditioning HART 2338 - Air Conditioning Installation & Startup HART 1356 - EPA Recovery Certification Preparation HART 2345 - Residential Air Conditioning Systems Design MATH 1332 - Contemporary Mathematics ENGL 1301 - Composition I DRAM 1310 - Introduction to Theater Marketable Skills Program Outcomes Math Skills; manage time and materials; acquire and evaluate • Install, troubleshoot and repair refrigerators, freezers, and information; interpret and communicate information; oral and window air conditioners. written communications skills; computer skills; teamwork; cultural • Install, troubleshoot and repair split or package residential diversity; apply technology to work; creative thinking; decision air conditioning systems, including electric furnaces, gas making; problem solving; self-management; construction and furnaces and heat pumps. industrial
    [Show full text]
  • Investigating Absorption Refrigerator Fires (Part I)
    Orion P. Keifer Peter D. Layson Charles A. Wensley Investigating Absorption Refrigerator Fires (Part I) ATLANTIC BEACH, FLORIDA—In today’s recreational vehicles (RV), the then expels it when perco- most common refrigerator uses absorption refrigeration technology, lated in the boiler. It is this primarily because this type of system can operate on multiple sources action of the water which of power, including propane when electrical power is unavailable. makes the ammonia flow. These refrigerators have been under intense scrutiny in recent years The hydrogen in the re- due to numerous reported fires, apparently starting in the area of the frigeration coil maintains absorption refrigerator. Both the Dometic Corporation and Norcold a positive pressure of ap- Incorporated, two manufacturers of RV refrigerators, have been re- proximately 300-375 PSI quired by the National Highway and Traffic Safety Administration (2.07-2.59 MPa) when (NHTSA) to recall certain models of refrigerators which have been not in operation and, due identified as capable of failing in a fire mode. In summary, the three to its low partial pressure, NHTSA recalls indicate a fatigue crack may develop in the boiler tube promotes the evaporation of the cooling unit which may release sufficient pressurized flammable of the liquid ammonia. It coolant solution into an area where an ignition source is present. The should be noted that unlike NHTSA Recall Campaign ID Numbers are 06E076000 for Dometic conventional refrigeration (926,877 affected units), and 02E019000 (28,144 affected units) and systems which extensively 02E045000 (8,419 affected units) for Norcold. use copper due to its high thermal conductivity, the Applications Engineering Group, Inc.
    [Show full text]
  • Solar Air-Conditioning and Refrigeration - Achievements and Challenges
    Solar air-conditioning and refrigeration - achievements and challenges Hans-Martin Henning Fraunhofer-Institut für Solare Energiesysteme ISE, Freiburg/Germany EuroSun 2010 September 28 – October 2, 2010 Graz - AUSTRIA © Fraunhofer ISE Outline Components and systems Achievements Solar thermal versus PV? Challenges and conclusion © Fraunhofer ISE Components and systems Achievements Solar thermal versus PV? Challenges and conclusion © Fraunhofer ISE Overall approach to energy efficient buildings Assure indoor comfort with a minimum energy demand 1. Reduction of energy demand Building envelope; ventilation 2. Use of heat sinks (sources) in Ground; outside air (T, x) the environment directly or indirectly; storage mass 3. Efficient conversion chains HVAC; combined heat, (minimize exergy losses) (cooling) & power (CH(C)P); networks; auxiliary energy 4. (Fractional) covering of the Solar thermal; PV; (biomass) remaining demand using renewable energies © Fraunhofer ISE Solar thermal cooling - basic principle Basic systems categories Closed cycles (chillers): chilled water Open sorption cycles: direct treatment of fresh air (temperature, humidity) © Fraunhofer ISE Open cycles – desiccant air handling units Solid sorption Liquid sorption Desiccant wheels Packed bed Coated heat exchangers Plate heat exchanger Silica gel or LiCl-matrix, future zeolite LiCl-solution: Thermochemical storage possible ECOS (Fraunhofer ISE) in TASK 38 © Fraunhofer ISE Closed cycles – water chillers or ice production Liquid sorption: Ammonia-water or Water-LiBr (single-effect or double-effect) Solid sorption: silica gel – water, zeolite-water Ejector systems Thermo-mechanical systems Turbo Expander/Compressor AC-Sun, Denmark in TASK 38 © Fraunhofer ISE System overview Driving Collector type System type temperature Low Open cycle: direct air treatment (60-90°C) Closed cycle: high temperature cooling system (e.g.
    [Show full text]