Is thermodynamic power cycle based on steam turbine. Widely used in fossil-fuel thermal power plants (consists of steam generator installed inside combustion chamber or flue-gases duct (source of heat), steam turbine connected to electrical generator, condenser, circulation pump, feedwater heaters; working fluid: subcritical- or supercritical-pressure water/steam). Widely used in all current nuclear power plants (subcritical-pressure cycle). Might be used in Generation-IV nuclear power plants (consists of reactor (source of heat), (heat exchanger for indirect cycle), steam turbine connected to electrical generator, condenser, circulation pump, feedwater heaters; working fluid: subcritical- or supercritical-pressure water/steam (direct and indirect cycles) or supercritical-pressure carbon dioxide (indirect cycle).
Published in Chapter:
Application of Supercritical Fluids in Thermal- and Nuclear-Power Engineering
Igor L. Pioro (University of Ontario Institute of Technology, Canada)
Copyright: © 2021
|Pages: 58
DOI: 10.4018/978-1-7998-5796-9.ch017
Abstract
Supercritical Fluids (SCFs) have unique thermophyscial properties and heat-transfer characteristics, which make them very attractive for use in power industry. In this chapter, specifics of thermophysical properties and heat transfer of SCFs such as water, carbon dioxide, and helium are considered and discussed. Also, particularities of heat transfer at Supercritical Pressures (SCPs) are presented, and the most accurate heat-transfer correlations are listed. Supercritical Water (SCW) is widely used as the working fluid in the SCP Rankine “steam”-turbine cycle in fossil-fuel thermal power plants. This increase in thermal efficiency is possible by application of high-temperature reactors and power cycles. Currently, six concepts of Generation-IV reactors are being developed, with coolant outlet temperatures of 500°C~1000°C. SCFs will be used as coolants (helium in GFRs and VHTRs, and SCW in SCWRs) and/or working fluids in power cycles (helium, mixture of nitrogen (80%) and helium (20%), nitrogen and carbon dioxide in Brayton gas-turbine cycles, and SCW/“steam” in Rankine cycle).