Research On Energy Efficiency Assessment Method Of Iron And Steel Steam System

Though the steam system is the auxiliary production system, its distribution is complex and it’s difficult to manage scheduling. So the energy waste is very serious and it has a great potential for energy savings. The steam system energy efficiency assessment of the iron and steel enterprises is the basis of energy conservation and the development of energy-saving technologies. Comprehensive, correct and feasible evaluation results can scientifically demonstrate the energy use and explain the reason of energy consumption, providing ideas and theoretical basis for further potential for energy savings. However, the steam system will change as the user changes, then the boilers will be differently managed, causing a great deal of difficulties for the energy efficiency assessment of the steam system. Therefore, this passage deeply analyses the structure and production process of steam system, dividing steam system into several parts-production, pressure reducer, steam pipe network and condensate recovery. Also it studies the composition, the working theory and the energy consumption of the steam system.This paper chooses exergy analysis to assess the energy efficiency of the steam system, firstly giving the related concepts of exergy analysis and exergy loss, the basic formula for calculating the amount of exergy, explaining the energy from the perspective of exergy. After that, it talks about the structure of the steam system, from the perspective of exergy, discussing the working principle, the energy consumption and so on.And then it calculates the energy consumption to identify the energy consumption points of all aspects, qualitatively analyzing the proportion of energy consumption for each point and giving the corresponding equation of energy balance, the energy flow and energy loss figure. Finally, the paper describes the calculation methods of input exergy, effective exergy and exergy loss, and provides the energy efficiency assessment model of the typical steam system. On the basis of this model, the paper takes the actual operating datas of the steam system into the energy efficiency assessment model, combining the control variable method, to calculate the exergy efficiency and exergy loss of all aspects and the whole steam system. Due to the calculation results, this paper draws the corresponding histograms and pie charts to easily show the energy consumption and energy efficiency, And these graphs show the maximum energy consumption point and the largest steam system energy sectors, which can offer some help for the enterprises and government.At last, from the perspective of exergy, it gives the energy and economic benefits from the energy conservation aspects, such as the condensate recovery system makes the exergy efficiency from the original38.88%increase to39.67%. In this paper, it changes the energy consumption aspect and calculates the energy efficiency of the system before and after the transformation. When the pressure reducer is replaced by turbine, the exergy efficiency of the steam system increases from38.88%to43.34%. At last, it gives the corresponding energy efficiency comparison chart, which visually demonstrates the energy-saving benefits for the enterprise and specifies the direction for further energy saving and production costs reducing etc.