Planning and Installing Solar Thermal Systems: A Guide for Installers, Architects and Engineers, Second Edition

369 Pages·2010·17.9 MB·English

by  German Solar Energy Society (DGS)

222x297mm spine 18mm
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solar thermal system, crucial to the successful uptake of this technology. All major topics for successful

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Planning & Installing
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applications. Details on how to market solar thermal technologies, a review of relevant simulation tools
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This is the definitive source of guidance for professionals who wish to install solar thermal technology
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About the Authors: l

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Energy/Engineering A guide for installers, architects and engineers
www.earthscan.co.uk
ISBN 978-1-84407-760-1
DGS
9 781844 077601
Deutsche Gesellschaft für Sonnenenergie e.V.
International Solar Energy Society, German Section
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Planning and Installing
Solar Thermal Systems
A guide for installers, architects and engineers
Second edition
A01_PAI_Solar Thermal Systems_Prelims:therimpr.qxd 31/03/2010 16:46 Page ii
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Planning and Installing
Solar Thermal Systems
A guide for installers, architects and engineers
Second edition
London (cid:129) Washington, DC
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First published in 2010 by Earthscan
Copyright © Deutsche Gesellshaft für Sonnenenergie, 2010
First edition published by James & James (Science Publishers) Ltd in the UK and USA in
2005
All rights reserved. No part of this publication may be reproduced, stored in a retrieval
system, or transmitted, in any form or by any means, electronic, mechanical, photocopying,
recording or otherwise, except as expressly permitted by law, without the prior, written
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While the author and publishers believe that the information and guidance given in this work
are correct, all parties must rely upon their own skill and judgement when making use of
them – it is not meant to be a replacement for manufacturer’s instructions and legal technical
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caused by any error or omission in the work. Any and all such liability is disclaimed.
This book was written using principally metric units. However, for ease of reference by
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brackets after their metric equivalents. Please note that some conversions may have been
rounded up or down for the purposes of clarity.
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Contents
Foreword xi
CHAPTER 1: Solar radiation and arguments for its use 1
1.1 Solar radiation 1
1.1.1 Solar energy 1
1.1.2 Astronomical and meteorological bases 1
1.1.3 Influence of orientation and tilt angle 8
1.1.4 Collection of dust and need for cleaning 10
1.2 The finiteness of energy resources 11
1.3 Climate change and its consequences 13
1.4 Good arguments for solar systems 16
CHAPTER 2: Components of solar thermal systems 17
2.1 How does a solar thermal system work? 17
2.2 Collectors 18
2.2.1 Unglazed collectors 21
2.2.2 Glazed flat-plate collectors 21
2.2.3 Vacuum collectors 30
2.2.4 Collector accessories 34
2.2.5 Collector characteristic curves and applications 35
2.2.6 Stagnation temperature 35
2.3 Heat stores 36
2.3.1 Storage materials 36
2.3.2 Domestic hot water stores 37
2.3.3 Buffer store 40
2.3.4 Combination stores 40
2.3.5 The thermostatic mixing valve 46
2.3.6 Connection of washing machines and dishwashers 46
2.3.7 Legionella contamination 46
2.4 Solar circuit 47
2.4.1 Pipelines 47
2.4.2 Solar liquid 48
2.4.3 Solar pumps 50
2.4.4 Solar heat exchanger (heat transfer unit) 51
2.4.5 Return-flow prevention 52
2.4.6 Rapid air bleeders 52
2.4.7 Flowmeters 54
2.4.8 Safety devices in the solar circuit 54
2.4.9 Solar station 55
2.5 Controller 55
2.5.1 Control principles for temperature difference control 59
2.5.2 Digital controller with special functions 59
2.5.3 Temperature sensors 62
2.5.4 Overheating protection 65
CHAPTER 3: Systems for single-family houses 67
3.1 Introduction 67
3.2 Systems for charging/discharging the store 68
3.2.1 Charging by means of solar energy 68
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3.2.2 Charging by means of auxiliary heating 69
3.2.3 Store discharge 70
3.3 Systems for heating domestic water 70
3.3.1 Standard system 70
3.3.2 Water heating using the flow-through principle 71
3.3.3 Water heating by means of tank-in-tank store 71
3.3.4 Water heating over external heat exchanger 71
3.3.5 Drain back system 72
3.4 Systems for heating domestic water and space heating 72
3.4.1 Combined store system (store-in-store system) 73
3.4.2 System with buffer store, internal heat exchanger for heat removal
and downpipe 73
3.4.3 Stratified store with hot water heating in once-through flow and
heating support 73
3.4.4 Twin store system 73
3.5 Planning and dimensioning 74
3.5.1 Important features for preparing the quotation 74
3.5.2 The dimensioning of systems for domestic water heating 77
3.5.3 Dimensioning of systems for heating domestic water and heating
support (central European conditions) 89
3.6 Costs and yields 90
3.6.1 Prices and performance 90
3.6.2 Normalised solar heat costs 94
CHAPTER 4: Installation, commissioning, maintenance
and servicing 97
4.1 A brief study of roofing and materials 97
4.1.1 The purpose of the roof 97
4.1.2 Types of roof 97
4.1.3 The components of the roof 98
4.1.4 Pitched roofs 103
4.1.5 Roof installations and mountings 103
4.1.6 Flat roofs 103
4.1.7 Materials 103
4.2 Installation methods and safety 107
4.2.1 UK safety regulations 107
4.2.2 UK personal access and working at heights 108
4.2.3 Working equipment 109
4.2.4 Transport techniques 110
4.2.5 Installation techniques 110
4.3 Installation 111
4.3.1 Delivery of material 111
4.3.2 Setting up the site, preparatory work 111
4.3.3 Collector installation 111
4.3.4 Installation of the solar circuit 126
4.3.5 Store installation 128
4.3.6 Installation of fittings 133
4.3.7 Installation of sensors and controllers 136
4.4 Starting up, maintenance and servicing 136
4.4.1 Flushing out the solar circuit 136
4.4.2 Leak testing 137
4.4.3 Filling with solar liquid 137
4.4.4 Setting the pump and controller 138
4.4.5 Maintenance 138
4.4.6 Detecting and rectifying faults 139
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CONTENTS vii
4.5 Information sources for specific countries 146
4.5.1 USA 146
4.5.2 Australia 146
4.5.3 Canada 147
CHAPTER 5: Large-scale systems 149
5.1 The fundamentals of designing the system size 149
5.1.1 Possible application areas 149
5.1.2 Initial data required for planning the solar system 149
5.1.3 System planning and design 150
5.2 Systems 153
5.2.1 Systems with domestic water store(s) 153
5.2.2 Systems with thermal buffer stores 154
5.2.3 Integration of circulation systems 156
5.3 Control of the systems 156
5.3.1 Collector circuit/storage charging circuit 156
5.3.2 Buffer tank circuit discharging 161
5.4 Heat exchangers 162
5.4.1 Design types 162
5.4.2 Collector circuit heat exchangers 164
5.4.3 Buffer tank discharge circuit heat exchangers 165
5.5 Safety technology 168
5.5.1 Collector field 168
5.5.2 Collector circuit 169
5.5.3 Buffer store circuit 170
5.5.4 Expansion vessels 171
5.5.5 Fittings on the domestic water line 171
5.6 Economic considerations 172
5.6.1 Annuity method 172
5.6.2 Types of costs for solar energy systems 173
5.7 Solar contracting 174
5.8 Solar district heating 177
5.8.1 Solar energy systems with short-term heat storage 178
5.8.2 Solar systems with long-term heat storage 178
5.8.3 Guide values for the design of solar district heating systems 179
5.8.4 Components of solar district heating systems 179
5.8.5 Practical experience 181
CHAPTER 6: Solar concentrating systems 183
6.1 Concentration of solar radiation 183
6.2 Concentrating systems providing process heat 184
6.3 Concentrating solar thermal systems for electricity generation 189
6.3.1 Parabolic trough plants 189
6.3.2 Solar tower plants 193
6.3.3 Dish/Stirling systems 195
6.3.4 Economics and outlook 196
CHAPTER 7: Solar heating of open-air swimming pools 197
7.1 Introduction 197
7.2 Components 197
7.2.1 Absorbers 197
7.2.2 Piping and header pipes 201
7.2.3 Materials 202
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7.2.4 Pumps, heat exchangers and other components 202
7.2.5 Controllers 204
7.2.6 Covering of the swimming pool 206
7.3 Systems 206
7.3.1 Solar private open-air pool heating 206
7.3.2 Solar heating of public open-air swimming pools 208
7.3.3 Combined solar domestic water heating, open-air pool heating
and room heating support 210
7.4 Planning and dimensioning 211
7.4.1 Fundamental considerations 211
7.4.2 Approximation formulae for establishing absorber surface area,
volumetric flow and pressure loss 211
7.4.3 Computer-aided system dimensioning 214
7.5 Installation 214
7.5.1 Absorbers 214
7.5.2 Pipeline installation 217
7.6 Operation and maintenance 219
7.7 Costs and yields 219
7.8 Examples 220
7.8.1 Solar heating of a private swimming pool 220
7.8.2 Solar heating of a municipal open-air pool complex 220
CHAPTER 8: Solar air systems 223
8.1 Introduction 223
8.2 Components 224
8.2.1 Collector types 224
8.2.2 Fans, blowers 229
8.2.3 Piping 230
8.2.4 Heat exchangers and heat recovery units (air/water), recovery-
solar-box 230
8.2.5 Control 232
8.3 Systems 234
8.3.1 Central systems, decentralized systems and hybrid systems 234
8.3.2 Further terms of ventilation technology 234
8.3.3 Air collector systems in housing construction 235
8.3.4 Solar drying 239
8.3.5 Factories, halls and office buildings 240
8.4 Planning and dimensioning 242
8.4.1 Fundamental considerations 242
8.4.2 Calculation of required flow rate, required collector surface
area and connections of collectors 243
8.4.3 Calculation of fan power 244
8.4.4 Dimensioning of an air-to-water heat exchanger 244
8.4.5 Computer-assisted system sizing 245
8.5 Installation 246
8.5.1 Collector installation 246
8.5.2 Installation of pipelines 248
8.5.3 Positioning of the fan 248
8.6 Costs and yields 248
8.7 Examples 249
8.7.1 Domestic building, Potsdam, Germany 249
8.7.2 Solarwall on General Motors building in Ontario 250
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CONTENTS ix
CHAPTER 9: Solar cooling 253
9.1 Introduction 253
9.2 Theoretical bases 255
9.2.1 Overview of thermally driven cooling processes 255
9.2.2 Absorption cooling 255
9.2.3 Adsorption cooling 256
9.2.4 Desiccant cooling system 257
9.3 Integrated planning of solar cooling/air-conditioning systems 259
9.4 System technology 262
9.4.1 Autonomous solar-powered systems versus solar-assisted systems 262
9.4.2 Which collector technology for which cooling technology? 263
9.4.3 Circuit variants 264
9.5 System design 268
9.5.1 General procedure when designing systems 269
9.5.2 System design using empirical values 270
9.5.3 System design according to the peak load 270
9.5.4 Design of autonomous solar-powered systems 271
9.5.5 System design according to primary energy saving 271
9.6 More information 273
CHAPTER 10: Electronic media and software within the area
of solar thermal energy 275
10.1 Simulation programs for solar thermal systems 275
10.1.1 Utilization and possibilities of simulation programs 275
10.1.2 Market overview, organization and selection of simulation programs 276
10.1.3 Brief description of simulation programs 277
10.1.4 Evaluation of simulation results 289
10.1.5 Supplementary programs and data sources 289
10.1.6 Tools and utility programs 292
10.2 Materials from manufacturers 294
10.2.1 CD-ROMs, documentation, product catalogues 294
10.2.2 Simulation programs from manufacturers 294
10.3 Internet 294
10.3.1 Internet portals on the topic of solar energy 294
10.3.2 Manufacturer websites 294
10.3.3 Internet-based simulation 294
CHAPTER 11: Marketing and promotion 295
11.1 The fundamentals of solar marketing 295
11.1.1 Customer orientation: the central theme 295
11.1.2 The iceberg principle 295
11.1.3 The ‘pull’ concept 296
11.2 More success through systematic marketing 296
11.2.1 In the beginning is the benefit 296
11.2.2 The four pillars of the marketing concept 297
11.2.3 The range of marketing options 301
11.2.4 To the goal in six steps 311
11.3 The Soltherm Europe Initiative: European network of solar
thermal marketing campaigns 315
11.3.1 Publications 315
11.3.2 Partnership 316
11.3.3 Campaigns and market activities 316
11.3.4 Co-operation 317