INTERNATIONAL ENERGY AGENCY IEA DISTRICT HEATING AND COOLING Programme of Research, Development and Demonstration on District Heating and Cooling District Heating and Cooling Connection Handbook Bard Skagestad1, Peter Mildenstein2 1Kattner/FVB District Energy Inc. Canada 2Sheffield Heat and Power Group, UK 1 Preface Introduction The International Energy Agency (IEA) was established in 1974 in order to strengthen the co- operation between member countries. As an element of the International Energy Programme, the participating countries undertake co-operative actions in energy research, development and demonstration. District Heating offers excellent opportunities for achieving the twin goals of saving energy and reducing environmental pollution. It is an extremely flexible technology which can make use of any fuel including the utilisation of waste energy, renewables and, most significantly, the application of combined heat and power (CHP). It is by means of these integrated solutions that very substantial progress towards environmental targets, such as those emerging from the Kyoto commitment, can be made. For more information about this Implementing Agreement please check our Internet site www.iea- dhc.org/ Annex VI In May 1999 Annex VI started. The countries that participated were: Canada, Denmark, Finland, Germany, Korea, The Netherlands, Norway, Sweden, United Kingdom, United States of America. The following projects were carried out in Annex VI: Title project ISBN Registration number Simple Models for Operational 90 5748 021 2 S1 Optimisation Optimisation of a DH System by 90 5748 022 0 S2 Maximising Building System Temperatures Differences District Heating Network Operation 90 5748 023 9 S3 Pipe Laying in Combination with 90 5748 024 7 S4 Horizontal Drilling Methods Optimisation of Cool Thermal Storage 90 5748 025 5 S5 and Distribution District Heating and Cooling Building 90 5748 026 3 S6 Handbook Optimised District Heating Systems 90 5748 027 1 S7 Using Remote Heat Meter Communication and Control Absorption Refrigeration with Thermal 90 5748 028 X S8 (ice) Storage Promotion and Recognition of 90-5748-029-8 S9 DHC/CHP benefits in Greenhouse Gas Policy and Trading Programs Introduction ii Benefits of Membership Membership of this implementing agreement fosters sharing of knowledge and current best practice from many countries including those where: • DHC is already a mature industry • DHC is well established but refurbishment is a key issue • DHC is not well established. Membership proves invaluable in enhancing the quality of support given under national programmes. The final materials from the research are tangible examples, but other benefits include the cross-fertilisation of ideas which has resulted not only in shared knowledge but also opportunities for further collaboration. Participant countries benefit through the active participation in the programme of their own consultants and research organizations. Each of the projects is supported by a team of Experts, one from each participant country. The sharing of knowledge is a two-way process, and there are known examples of the expert him/herself learning about new techniques and applying them in their own organization. Information General information about the IEA Programme District Heating and Cooling, including the integration of CHP can be obtained from: IEA Secretariat Mr. Hans Nilsson 9 Rue de la Federation F-75139 Paris, Cedex 15 FRANCE Telephone: +33-1-405 767 21 Fax: +33-1-405 767 49 E-mail: [email protected] or The Operating Agent NOVEM Ms. Marijke Wobben P.O. Box 17 NL-6130 AA SITTARD The Netherlands Telephone: +31-46-4202322 Fax: +31-46-4528260 E-mail: [email protected] Acknowledgements The work carried out for this project has been monitored by an Experts Group and the authors would like to thank the members for their valuable guidance and advice. The members of the Experts Group were: N. Andersen (Denmark) A. Jones (UK) K. D. Koo (South Korea) G. Nilsson (Sweden) P.G. Ramsek (The Netherlands) F. Schmidt (Germany) J. Stang (Norway) M. Tiitinen (Finland) R. Volla (Norway) Introduction iii 2 Summary This report is intended to assist engineers and consultants in designing and implementing conversions of building HVAC systems to accept chilled and hot water from district energy systems. Building types that are addressed include residential, commercial, institutional and industrial. The practical guidelines provided are based on extensive conversion and operating experience. As well as highlighting the most cost effective approach to conversions, the guidelines ensure that technically sound systems are built. The report looks at the fundamentals and principles of both district heating and cooling including energy sources, distribution and customer interface. Design considerations of these three main components of district energy are described, as well as the benefits that district energy can bring to the building owners, the municipality and the public. Critical points in designing the interface between the building energy system and the district energy system (energy transfer station) are outlined and are intended for use in the design of new building systems as well as for conversions of existing buildings. Detailed schematics of energy transfer stations are shown illustrating all components, including control equipment, heat exchangers and energy meter. Energy transfer station performance is detailed with graphs showing the impact of various parameters within a district energy system. The report also highlights the considerations of design and operation of the secondary system or the system that uses the energy from the district energy system. The report also breaks down, step by step, the procedure to convert a building to accept district energy. These include building survey and schematic design, energy consumption, compatibility, costs, system optimization, construction schedule, testing and commissioning. The suitability of a given system to be converted is also discussed. The importance of a correct determination of the heating and cooling demand of a building is stressed, because a proper sizing of the heat exchanger in the energy transfer station affects the operation of the system in a major way. Several methods to determine this load demand value are described. The optimization of the heat exchanger is also very important because it forms a large part of the capital cost of the energy transfer station. Some case histories of buildings connected to a district cooling system are described. Introduction iv Table of Contents 1 PREFACE ......................................................................................................................................................II 2 SUMMARY ................................................................................................................................................... IV PART I: COOLING SECTION .............................................................................................................. 10 3 INTRODUCTION ........................................................................................................................................... 12 4 FUNDAMENTALS OF DISTRICT COOLING ...................................................................................................... 13 Principles of District Cooling.................................................................................................................................................... 13 4.1.1 Cooling Source ............................................................................................................................................................... 13 4.1.2 Distribution..................................................................................................................................................................... 14 4.1.3 Customer Interface or Energy Transfer Station.............................................................................................................. 15 Design Considerations ............................................................................................................................................................... 16 4.1.4 General Considerations.................................................................................................................................................. 16 4.1.5 Cooling Sources.............................................................................................................................................................. 17 4.1.6 Distribution..................................................................................................................................................................... 20 4.1.7 Energy Transfer Stations ................................................................................................................................................ 21 Benefits of District Cooling Systems......................................................................................................................................... 22 4.1.8 Property / Building Owners............................................................................................................................................ 22 4.1.9 Municipalities ................................................................................................................................................................. 22 4.1.10 Society..........................................................................................................................................................................