Abstract:

In order to implement thermoeconomics analysis and evaluation for complex energy system and find new ways to improve the thermal economy of nuclear power unit, a general model of exergy cost analysis on thermal system of pressurized water reactor （PWR） nuclear power units was established based on exergoeconomics theory and matrix algorithm. Taking the thermal system of a 900 MW PWR nuclear power unit as an example, the unit exergy cost of 39 exergy flows were calculated and analyzed, and explicit optimization improvements were proposed for the specific equipment. The results show that the unit exergy cost of each exergy flow increases firstly and then decreases along the direction of thermodynamic cycle； the maximum unit exergy cost is that of condenser output exergy flow, which is 7,1754, and followed by that of condensate pump and 1 low pressure heater, 5,249 and 4,1911 respectively. Compared with the traditional exergy cost analysis, the matrix algorithm has advantages in simple structure, convenient filling for each element of matrix, explicit physical meanings and obvious regularity. According to the programmability of matrix algorithm, a corresponding calculation and analysis software can be conveniently developed, which can provide a theoretical basis for the thermal system optimization and fault diagnosis of nuclear power units.

Key words: nuclear power units, pressurized water reactor, thermal system, unit exergy cost, matrix equation