Research On The Determination Of Optimal Vacuum Pressure Of The Condenser For Unit With 1000MW Capacity

It is of great importance to reduce the energy consumption by improving the energy efficiency and determining the optimal operating parameters of the critical system of coal-fired power units.According to the first law of thermodynamics,condenser loss accounts for the largest proportion of total system loss.The vacuum of the condenser has a great influence on the cycle heat efficiency of the unit.In addition,the double back pressure condenser has been widely used in large steam turbine units and obtained the corresponding benefits.Therefore,it is necessary to find the optimum vacuum of a double back pressure condenser for the unit with 1000 MW capacity.Firstly,the energy efficiency index system of the condenser system was established based on the analysis of the performance of the condenser.What is more,the structure and heat transfer characteristics of a double back pressure condenser were studied.Secondly,based on the fault tree analysis method and fault mode effect analysis,the reason,symptom,influence and treatment measure of condenser vacuum drop were analyzed and the fault tree was established in term of the typical failure of condenser vacuum drop.According to the equivalent enthalpy drop method,performance was studied under the influence of several factors with different work condition such as circulating water flow rate,inlet water temperature and so on.And it was calculated by C++program.Finally,the regression model of condenser vacuum and circulating water flow rate,circulating water inlet temperature and load was established by neural network,respectively.A1000 MW ultra-supercritical wet unit was taken as an example.Results show that the model has good generalization ability and can be used to predict the vacuum of condenser.