CONTROLLING METHOD FOR RECOVERING POWER FROM MIXED MEDIUM RANKINE CYCLE UTILIZING CRYOGENIC HEAT OF LIQUEFIED NATURAL GAS AND CONTROLLING DEVICE THEREFOR

摘要

PURPOSE:To stably operate an electric power generating system at a maximum efficiency by a method wherein a turbine controlling valve, which sets the maximum opening degree in accordance with the consumption of the natural gas, is provided. CONSTITUTION:Liquefied natural gas and the mixed medium working in Rankine cycle are heat-exchanged with each other at a heat exchanger 7. The output signal S4 of a temperature regulator 27 serves as a cascade signal to a turbine exhaust pressure regulator 40. Pressure before turbine P1 and exhaust pressure P2 are inputted to a pressure ratio calculator 22. The output signal S9 of an opening degree regulator 52 serves as a cascade setting signal to a pressure ratio regulator 23. In such a manner as mentioned above, the maximum opening degree of the controlling valve 25 is calculated by means of a function generator 53 so as to control the controlling valve 25 at the maximum opening degree by means of the regulator 23.