Heating and district heating systems

Abstract

Listen

Translate article

Systems for heating and district heating are described. This material is of great importance to the book for at least two reasons: heating systems are the foundation of most district heating systems and heating systems constitute one of the main technologies against which cogeneration must compete. Heating plants typically convert energy in the form of a fossil fuel or electricity to direct thermal heat or a heated medium such as hot gases, steam or hot water. A general model for heating and district heating systems is provided and illustrated, along with analyses of it using energy and exergy analyses. The resultant energy and exergy balances and efficiencies are also given. The various types of heating technologies are listed along with their characteristics. The types of heating technologies include fuel-based heating (e.g., heating using furnaces), electricity-based heating, heating via waste heat recovery, groundbased heating, solar-based heating and heating using heat pumps. The coverage for these systems includes basics, applications, types, classifications and operation factors. Extending this material, the many types of technologies for district heating are listed and described. Characteristics of district heating systems are provided, including advantages, operation, applications and energy sources. The types of district heating systems covered include fossil fuel, geothermal, solar, biomass and waste-toenergy-based district heating. Typical energy conversion efficiencies are given for heating and district heating, and it is demonstrated how the thermal product can be used in the residential, commercial and institutional sectors for processes such as space and water heating, and in the industrial sector for a wide range of activities. Attention is paid to the use of a central heat supply to meet residential-commercial heat demands via district heating given its prevalence (sometimes in tandem with the use of cogeneration-derived heat to drive absorption chillers for applications such as district cooling). Many of the uses for heat from heating systems are seen to be the same as the uses for heat from cogeneration systems.