  Modular high temperature gas cooled reactor (MHTGR) is a small modular reactor with inherent safety, which is suitable for load following to improve economic competitiveness. The heat regenerative system for MHTGR nuclear power plant, which contains five-stage feed-water heaters and one deaerator, is crucial for the improvement of thermal efficiency by its virtue of reducing cold source loss and irreversible loss of heat transfer. Traditionally, the enthalpy drop distribution method (EDM) is used to study the relationships between thermal efficiency and distribution of extraction steam revealing that the best regenerative distribution is “the specific enthalpy rise of feed water through #(i) heater is equal to specific enthalpy drop of steam between #(i-1) and #(i) extraction point of steam turbine”. However, this strategy is mainly used for off-line design of steam turbine to maximize thermal efficiency under rated conditions. For load following operation, it is hard to guarantee the extraction steam distribution of EDM due to the highly nonlinear “flowrate-pressure-temperature” coupling of the fluid network. Thus, in this paper, the thermal efficiency is derived analytically based on the steady state model of fluid network. Then the thermal efficiency optimization is cast into a nonlinear programming problem, in which physical constraints can be considered explicitly, such as flowrate, temperature and pressure limit for different nodes in the fluid network, load requirement and topological structure variation of fluid network. The proposed method for extraction steam distribution is of significance for improving the thermal efficiency of normal operation of nuclear power plant and lays a foundation for further research on flowrate-pressure control of the fluid network.


Thermal Efficiency Optimization of a Modular High Temperature Gas-Cooled Reactor Plant by Extraction Steam Distribution

Division / Sponsors: 
Power Division & Nuclear Engineering Division (NED)

Power Conference
Paper Proceedings: https://asmedigitalcollection.asme.org/POWER/POWER2020/volume/83747

International Conference on Nuclear Engineering
Paper Proceedings: https://asmedigitalcollection.asme.org/ICONE/ICONE2020/volume/83761

POWER-ICONE - Virtual Conference

Supporting the need among researchers worldwide for additional online and multimedia content, ASME now offers the ASME Conference Video Collection. This platform will collect and provide long-term access to conference presentation videos, encompassing all technology areas within ASME's technical conference and events program. About 30,000-40,000 engineers across all mechanical engineering and related disciplines participate in ASME conferences each year. This includes authors of approximately 6,000 to 8,000 technical papers published by ASME, the majority of whom also submit video presentations for our virtual conferences. The video collection will be available as an add-on to existing product packages or as a separate subscription.