초록 ▼

A method and system for the temperature control of superheated steam in a power plant having a boiler coupled to a turbine, and a turbine bypass valve, wherein temperature control is achieved by regulating opening of the turbine bypass valve. To this end, process quantities indicative of the superhe

A method and system for the temperature control of superheated steam in a power plant having a boiler coupled to a turbine, and a turbine bypass valve, wherein temperature control is achieved by regulating opening of the turbine bypass valve. To this end, process quantities indicative of the superheated steam temperature at the boiler outlet, the superheated steam pressure, the turbine inlet temperature, the turbine inner wall metal temperature, and the degree of opening of the turbine bypass valve are fed into a control system in which a mismatch temperature capable of leading steam into the turbine is calculated on the basis of such received process quantities. Then the control system outputs opening or closing operation command signals to the turbine bypass valve. The method is suitable to be carried out by means of a microprocesser.

대표청구항 ▼

A method for controlling boiler superheated steam temperature in a power plant having a boiler for generating superheated steam at an outlet thereof, a turbine having an inlet coupled to the boiler to be rotated by the superheated steam generated within the boiler, an electric generator coupled to t

A method for controlling boiler superheated steam temperature in a power plant having a boiler for generating superheated steam at an outlet thereof, a turbine having an inlet coupled to the boiler to be rotated by the superheated steam generated within the boiler, an electric generator coupled to the turbine for generating electric power, a condenser for condensing the superheated steam spent within said turbine, a water-feed pump for feeding water from the condenser into said boiler, a main steam stop valve disposed between said boiler and said turbine for stopping the superheated steam flowing into said turbine, a turbine bypass valve connected in parallel with the main steam stop valve and said turbine for leading the superheated steam generated within said boiler into said condenser, a first sensor for detecting a first process quantity indicative of the superheated steam temperature at said boiler outlet, a second sensor for detecting a second process quantity indicative of the superheated steam pressure, a third sensor for detecting a third process quantity indicative of the temperature at the turbine inlet, a fourth sensor for detecting a fourth process quantity indicative of a start-up mode of said turbine, and a fifth sensor for detecting a fifth process quantity indicative of opening of said turbine bypass valve, comprising the steps of: calculating a first mismatch temperature value of said turbine on the basis of said second process quantity, said third process quantity and said fourth process quantity; calculating a second mismatch temperature value capable of leading the superheated steam into said turbine on the basis of said fourth process quantity; comparing the first mismatch temperature value with the second mismatch temperature value; calculating an open-direction drive quantity of said turbine bypass valve on the basis of said fourth process quantity when it is judged that the first mismatch temperature value is less than the second mismatch temperature value; calculating a closed direction drive quantity of said turbine bypass valve on the basis of the first mismatch temperature value when it is judged that the first mismatch temperature value exceeds the second mismatch temperature value; calculating a change rate of said first process quantity, comparing the calculated change rate with a predetermined change rate, and producing a first lock signal when said calculated change rate is smaller than the predetermined change rate; calculating a difference between said first process quantity and said third process quantity, comparing the calculated difference with a predetermined value, and producing a second lock signal when said calculated difference is smaller than said predetermined value; outputting an open-direction operation command signal of said turbine bypass valve on the basis of said open-direction drive quantity, said first lock signal said second lock signal; and outputting a close-direction operation command signal of said turbine bypass valve on the basis of said close-direction drive quantity and said fifth process quantity.