Study On Steam Concentration Test And Application Of Large Turbo - Generator Unit

At present, with the performance of electric market reform and the complicated and diversified supply and demand in electric power market, it has increacing difference between maximum and minimum load in power grid. The peak-load model of generator unit is commonly on the 30%～50% load scope, and the in depth peak load cycling can reach 80%. There have poor safety and low economy when units take part in peak load operation.Most active genenrators are designed and operated with base load, rarely considered the peak load operation.When the load peak needed and valley supplied has enormous difference,which the conventional method of load regulating mode cannot meet its demand, thermal power units of large capacity the in depth regulating mode are needed. In a deeper amplitude of load modulation, it even requires an oil supporting combustion. The unit running state is far from the design condition in the depth of peak load running state, and the safety and economy of unit decline obviously. To further improve the peak-load ability of thermal power units, it should be carry on a study in depth peak-load units’ reliability and economy. It is necessary to carry out theoretical analysis and experimental study to make a comprehensive evaluation and reliably guide the operation of the unit in the future.This paper is mainly about a 600MW subcritical steam turbine of a power plant in Guizhou Province, when the turbine in peak-load interval operation it have poor safety and low economy, while the lack of coordination. The steam distribution optimization tests have been done in some load mode. To improve the safety and economy of unit operation, some work should be consided in the following two aspects.(1) With increasing a sequence valve mode, the experimental study has been carryed on the optimization of valve unit order. The valve form a symmetric diagonal admission, compared with the original design of the unit mixed steam distribution mode, to find the best valve mode in some steam load interval and improve the safety operation of the unit.(2) In the peaking interval operation and with the sequence valve of steam distribution mode of the unit, seek to change the process of some load in the lowest unit heat consumption rate when the corresponding operating pressure is optimum operating pressure, so as to determine the peaking interval optimum sliding pressure curve, making the unit in sliding pressure operation according to the sliding pressure curve and the unit economy has greatly improved.After the steam distribution optimization test, the comparative analysis shows that the unit safety and economy are greatly improved in the peaking interval with an increasing optimized sequence valve of steam distribution mode during its operation, making power supply coal consumption decreased, and great economic benefit has been obtained. At the same time the unit load dynamic response capacity enhance, and coordinated control level has greatly improved. Therefore, steam distribution optimization test can effectively improve the utilization efficiency of large thermal power units, enhance the ability of grid scheduling, contribute to energy-saving emission reduction targets and accelerate its realization. It is of great significance and valuable to get a promotion.