Thermal Analysis On Thermal System Of Extraction Steam Thermoelectric Unit

With the continuous development of social economy,energy consumption has gradually increased and energy shortage has become increasingly prominent.Energy saving has become the primary task in today’s society development.The energy consumption of the power industry is relatively large and the energy efficiency is low,so it is an important work to research energy conservation.As a new method of thermodynamic analysis,exergy analysis method can analyze the energy utilization process from two aspects of energy quality and quantity,and accurately reveal the energy utilization and loss.Therefore,the exergy analysis on the thermal system of power plant can fully satisfy the energy saving potential of the unit,which is of great significance to the development of the energy conservation work.In this paper,the EES software was used for exergy analysis on the thermal system of actual running generator set,based on this,local optimization studies are conducted to fully address the energy saving potential of the unit to achieve the goal of improving the unit’s exergy efficiency and operational level.Based on this,it provides scientific and reasonable theoretical guidance for energy saving transformation and operation optimization for the same type of power plant.Firstly,the analysis and calculation was performed on the thermal system of the extraction steam termoelectric unit,and all analysis evaluation indicators of the unit and the main equipment were obtained.After detailed analysis,the weak links of energy use in the system were found out.Boiler equipment has the highest exergy loss rate and exergy loss coefficient,and has the lowest exergy efficiency.It has a great deal of energy saving space and should be used as the focus of the unit’s energy saving work to conduct more detailed analysis.Secondly,the variation law of unit exergy efficiency was calculated and analyzed when the main steam parameters changed.The calculation results show that the unit exergy efficiency increases with the increase of main steam parameters.The effects of heater end differentials and extraction pressure loss changes at each level on the unit exergy efficiency were calculated and analyzed.It was concluded that unit exergy efficiency increased with the decrease of heater end differential and pressure loss,and the end differentials and pressure loss changes of the 1# and 3# heater have the greatest impact on unit exergy efficiency.Finally,a detailed analysis of the energy process of the boiler equipment was analyzed,the existence of irreversible losses in the boiler was the main reason for thedifferences between exergy efficiency and thermal efficiency.It was concluded that the exergy analysis was more comprehensive and accurate than the thermal analysis.The loss of exergy can be reduced and the exergy efficiency can be improved by increasing the initial steam and feedwater parameters,reducing the temperature of the flue gas,and strengthening the thermal insulation of the equipment.