Thermodynamic Properties Calculation Program For Moist Air And Aid Decision Making System For Combined Cycle Based On UML

To meet the demand of all range scientific research and engineering optimization design for the new thermodynamic cycles, the calculation method with wide range of temperature and pressure cover many thermodynamic parameters of moist air is presented. At low temperature and pressure, the method which considers moist air as ideal gas is simple and high precision. At high temperature and pressure, moist air is considered as actual mixture of dry air and water vapor. Semiempirical model with Virial state equation was used to set up mathematical model of the thermodynamic properties of moist air. Up-to-date research progress of Virial coefficients was used in the model. Up-to-date formulation of the thermodynamic properties of steam released by the international association for the properties of water and steam (IAPWS) was used in the model. The method has wider range and high precision.Aid decision making system contains maintenance interval calculation module and real time performance calculation module. Based on gas turbine maintenance data, maintenance interval is defined by factor-starts and fator-hours. According to the basic principles of combined cycle, thermal parameters of gas turbine, HRSG, steam turbine and the whole combined cycle unit, and revise them to ISO condition.The Unified Modeling Language (UML) is used to specify, visualize and construct object-oriented program for calculating thermodynamic properties of moist air and aid decision making system. Modularity method enforces reusability and extension of the code.