Research On The Technology Of DEH Applied To Steam Turbine Of Thermoelectricity Plant

Nowadays,with the continuing growth of the forces of social production, the requirement to electric energy in all trades and in daily life is larger and larger, which urges the electric power enterprises to develop rapidly and continuously. More and more thermoelectric generating sets which have high parameter and big capability run into operation gradually,which demands the higher characteristic of corresponding control systems. Under this big environment,the digital electro-hydraulic control system (DEH), which has fast response adjust characteristic and is composed of nuclear computer technology, is being paid great attention, and is promoted gradually from big sets to medium and small sets.Take the case of the control system of the second turbine in one thermal power station, the thesis analyses the advantages and disadvantages of the hardware composing, basic principle and control performance in the conventional mechanical-hydraulic governor(MHG)and the digital electro-hydraulic control system(DEH)in particular. At the same time, the thesis analyses the DEH system contrasted with the MHG system from the Instrument and Control angle of the thermal power plant, with two aspects including the and the security control characteristic. Through the analysis, we know that the control logic of the DEH system is agility and abundance, the control function is more powerful, the adjustment and security control capability is improved extremely contrast with the MHG system.The thesis study the disadvantages of losing control of the intercept steam valve, LVDT faults, the OPC protection's misplay, rotate speed signal jamming in the DEH system. At the same time, the author devises the improving project resolving the disadvantages to power plants with the same DEH system for reference.