Research On Optimization Of Thermal Economy Of Thermodynamic System Of Large Nuclear Power Steam Turbine

With a large number of high parameter and large capacity nuclear power group in the coming into operation in china,the importance and strategic significance of safe and high efficient operation of unit beyond the conventional generator. In this paper, nuclear motor group of variable operating condition level group pressure calculation classic formula Friuli Greig formula is improved, and the optimization design of the system structure and parameters for a 1400 MW nuclear steam turbine is carried out. The main contents are as follows:First of all, in view of the large steam humidity of the steam turbine of nuclear power steam turbine,the actual gas equation has been improved, and the real gas state equation of ideal gas equation is used to replace the Flugel formula derivation,established a calculation model more reasonable than the Friuli Greig formula. Compared the calculation results with the data provided by the manufacturer indicated that the improved formula is proposed in this paper can effectively solve the steam humidity excessive level variable condition calculation accuracy.Secondly, the thermal system structure optimization design of 1400 MW nuclear power steam turbine is studied. Four kinds of system structure modification schemes are designed from two aspects: the hydrophobic mode of the regenerative system and the return series of the feed water heater, and the thermal economic index of the unit was calculated by thermal equilibrium method. The four schemes are compared with the original scheme by combining the complexity of the system equipment structure and the reliability of the operation safety.Combined with system device structure complexity and operation safety reliability of No. 1 and No. 2 low plus additional drain cooler reform proposals, not only improve the system of thermal economy, also the safe operation of the system is good.And then, the two reheating system of the nuclear motor group is designed to improve the steam humidity of the low pressure cylinder. Simulation studies show that due to the second hot pressure is low, leading to decline in the average temperature of the endothermic and using middle pressure cylinder first stage extraction steam as the secondary reheat steam when, low-pressure cylinder exhaust steam dryness increased 0.59%, but unit heat consumption ratio 0.21%; the use of high pressure cylinder exhaust steam as the secondary reheat steam, low pressure cylinder exhaust steam dryness increased 1.6%, but unit heat consumption ratio 0.30%. Therefore, in the current state of the parameter, it is not suitable to use the two unit of the nuclear power unit.Finally,for the target making the heat consumption rate minimum, the traditional heat quality method combined with intelligent genetic algorithm and particle swarm optimization algorithm.was considered to using to optimize the outlet pressure of High pressure cylinder and the intermediate point temperature of two stage reheating by program of MATLAB software,searching for the effect of cylinder pressure and intermediate point temperature on heat consumption rate of the unit. In this process, it established the objective function by using heat quality method and achived optimization by using genetic algorithm and particle swarm optimization algorithm. This paper has an important guiding significance for the energy saving transformation and economic operation of the thermodynamic system, and can provide quantitative data support for the energy saving transformation of the thermodynamic system.