Exergy Analysis Of 1000mw Ultra-supercritical Unit With Double Reheat Thermal System

As international energy tensions and environmental degradation become increasingly prominent,coal-fired power generation technologies are facing new challenges.An important direction for the future development of the thermal power industry is the development of efficient and clean power generation technology.Over the years,countries have been actively committed to the research and energy-saving transformation of large-capacity high-parameter thermal power generating units.Ultra-supercritical secondary reheat technology has the The major contribution is the effective and development-oriented energy-saving and emission-reducing power generation technology.Therefore,the simulation of the secondary reheating unit and the exploration of its energy consumption distribution are of great significance to its long-term development.This article takes 1000MW ultra-supercritical secondary reheating unit as the object,comprehensively adopts a variety of simulation calculation methods,and studies the system efficiency and loss distribution according to the analysis method,in order to guide the optimization and transformation of the secondary reheating unit and future changes.High-parameter unit technology development provides theoretical reference.First of all,the most advanced 1000MW ultra-supercritical double reheat unit currently developed in China is selected as the research object.Based on the system structure and design parameters,the EBSILON Professional power station analysis platform is used to build a system simulation model to establish the heat balance relationship.According to the exergy analysis of each equipment unit,it is found that the boiler has the largest exergy loss,accounting for about 84%.Although the boiler thermal efficiency reaches 94%,the exergy efficiency is only 55%,which has great potential for energy saving.Then make a more detailed exergy analysis and calculation of the boiler with the largest system exergy loss,and use ANSYS Fluent to conduct a numerical simulation of the combustion process in the furnace to explore the distribution of irreversible losses in the boiler and the operating load,working fluid parameters,etc.As a result,it was found that the exergy loss caused by the irreversible combustion process in the furnace was the largest,followed by the heat transfer exergy loss.By increasing the steam parameters,the temperature of the inlet air and the feed water temperature,the two parts of the exergy losses can be effectively reduced.Finally,the exergy efficiency of the system was changed when the steam parameter was increased to 3 5MPa and 700℃.It was found that when the steam parameter was increased,the amount of useful energy in the system increased,which made the overall energy efficiency level increase.Although the exergy loss of the boiler still accounts for the majority Partly,but obviously reduced,it provides a preliminary theoretical reference for guiding the transformation of high-parameter units.