Quantitative Analysis And Optimization Of Energy Conservation For WGGH System Of 1030MW Ultra Supercritical Unit

This paper mainly introduces the main situation of boiler,turbine and generator of a power plant unit for the WGGH system of 1030 MW ultra-supercritical coal-fired unit,and introduces in detail the development history,environmental protection background,system composition and technical characteristics of the WGGH system after transformation.This paper quantitatively analyzes the influence of WGGH system on steam turbine squeezing out exhaust after recovering part of boiler low temperature flue gas and entering the turbine regenerative system,puts forward the concept of energy-saving optimization in this system,and analyzes the thermal system characteristics of 1030 MW ultra-supercritical units.Thermodynamic analysis model was established by using the equivalent heat drop method.The heat transfer capacity of the condensate water heater was calculated by the efficiency-heat transfer unit number method.The expression of equivalent heat drop of total extraction steam is established,and the equivalent heat drop of total extraction steam from condensate water system of steam turbine under different working conditions is given.The energy-saving effect of WGGH system is calculated quantitatively by means of chart analysis.The results show that the condensate flow rate(condensate flow coefficient)which is extracted after exchange heat with medium water has a great influence on the energy-saving effect.There is an optimum point under different unit operating conditions,and the maximum energy-saving effect can be obtained under this optimum point.Although the condensate flow coefficient has an optimum point,the condensate flow rate is limited by the anticorrosion requirements of the chimney.In this paper,the maximum extraction flow of condensate is calculated by iteration,mathematical fitting and so on.Combining with the optimal condensate curve,the recommended condensate flow curves under different unit loads are given.According to this curve,the maximum energy saving of WGGH system can be realized under the premise of guaranteeing the anticorrosion of chimney.Using the recommended curve proposed in this paper,the energy-saving effect can be improved by 8.5% under the Wie 100% THA condition,and 110% under 75% condition.The results show that the research results have great adaptability and theoretical validity.