The Regenerative System Characteristic Research Of The 1000MW Double Row High Pressure Heaters Based On The Second Law Of Thermodynamics

Using the large capacity and the supercritical technology in thermal power unit is the effective means to improve the economy of steam turbine generating unit. Compared with the same capacity subcritical thermal power unit, the efficiency of supercritical unit is increased about 2%-2.5% and the efficiency of ultra-supercritical unit is increased about 5%. In many advanced countries around the world and our country. The ultra-supercritical unit has been applied greatly.At present,about thermal system analysis of the ultra-supercritical unit, it is based on the first law of thermodynamics without considering the "quality" differences of the different energy,but exergy analysis method takes into account the"quantity"and"quality"two properties of energy, analyzing more scientifically.This paper based on quality unit analysis method, with using the first law of thermodynamics and the second law of thermodynamics, derives the general exergy loss distribution equation of quality units. On this basis, for a double row high pressure heaters regenerative system of a 1000MW unit, the paper establishes exergy analysis physical model of a double row high pressure heaters regenerative system, steam water distribution equation, exergy loss distribution equation of the regenerative system and its exergy economic index calculation equation of units were derived. The caculating program of heaters and the unit's exergy economic indexs are given by using C# language, and caculated under different condition. Based on established exergy analysis model, general calculation equation of the influence on exergy economic index is derived with small perturbation theoretical analysis method when the auxiliary steam flow and upper terminal temperature difference and extraction steam pressure loss and heat loss of the heater is changed in regenerative system. Double row high pressure heaters regenerative system of a 1000MW unit is analyzed by derived influence general equation. Influence laws of the above parameters on heater and the whole units are got and a simple fast and a practical method is provided for exergy analysis of ultra-supercritical unit.