Application And Analysis Of High Back Pressure Transformation Of 2×300MW Units In Baotou Thermal Power Plant

In this paper,aiming at the project of high back pressure heat supply retrofitting of 2×300MW units in the Second Thermal Power Plant of Baotou,the background and the necessity of the reformation are analyzed,and the economic benefits of the design scheme and reformation are studied.Increasing circulating water backpressure for heating is the current trend of heating by increasing the pressure on steam turbines without steam.It requires minimizing the condenser vacuum,cooling water with temperature is not too low,or canceling the condenser,and setting to heat the heating network heaters.The cooling water used to cool the exhaust of the steam turbine directly enters the heat net for heating.The advantage of this method is that the latent heat of vaporization of the steam turbine exhaust can be utilized to increase the circulating water temperature as much as possible,reduce the cold source loss greatly,improve group cycle thermal efficiency greatly.The advantages of heating by this method are many: without increasing the capacity of the unit,reducing the amount of steam extracted for heating,greatly increasing the heating range,reducing the amount of construction,shortening the construction period,saving the reconstruction cost,improving the economic efficiency significantly.Many heating manufacturers have carried out the transformation.In our country to vigorously promote energy-saving emission reduction policies under the national conditions,the heating area of electricity-based condensing steam turbine unit into a combined heat and power unit,has become the inevitable trend of the development of Chinese power enterprises.For example,Huaneng Jinqiao Thermal Power Plant has completed a high-pressure unit transformation,heating economy greatly improved.In 2014,Inner Mongolia Baotou No.2 Thermal Power Plant further upgraded 2 × 300 MW air-cooled units on the basis of the original waste heat recovery heat supply project to improve the heat-supply capacity of the units.In this paper,it comprehensively tracks the high back pressure reconstruction project of Baotou No.2 Thermal Power Plant,introduces the analysis of heating load needed for the reformation and the problems to be solved urgently in the process of reformation,and carries out a comprehensive test on the operation of the rebuilt unit analysis.According to different power generation load,a comprehensive cost-coal consumption method is adopted to compare the operation heat consumption rate,power generation coal consumption rate and coal consumption rate of coal-fired power unit under high back-pressure after transformation,and to determine the most economical operation adjustment mode.Finally,Resulting in economic benefits,social and environmental benefits,calculation of investment recovery cycle and so on.For the future other high-pressure power plant heating retrofit provide examples of reference and experience.