Methods of improving of the thermal efficiency and performance reliability of heating turbines

Abstract

The methods of improving of thermal efficiency and reliability of the small (50–100 MW) and secondary (100–160 MW) power heat and steam turbine (HST), operating in nominal conditions under Heat Power Plant (HPP), based on the heating systems 150/70 theoretical temperature schedule, are considered. The main ways of increasing the technical-economic indicators (TEI) of operating mode of HST of this group are selected: 1) minimizing the consumption of steam in the low-pressure cylinder (LPC) and other steam flows into the condenser; 2) Useful use of thermal energy (enthalpy) of the hydrodynamic flow in the main beams and embedded condenser. The main directions of the reconstruction of mean power (100–160 MW) HST principal heat circuit (PHC) are selected: 1) Refurbishment of flow part of high-pressure cylinder (HPC) and medium pressure cylinder (MPC) based on: a) submitting of rotor blades of last stages of MPC (step with heating steam extraction) on the blade saber shape. In general, when designing suggest selections couple with the last stages of MPC, for heating the heating water in heat exchangers network horizontal and a vertical type; b) Removing (removal) steps of shaft mounted turbine HPC and MPC stages; 2) Transferring of the turbine to partial counter mode (PCM). This mode is established by the half-turn of the separation diaphragm between the MPC and LPC. As a result, еру steam consumption for LPC condenser is reduced (in comparison with the one set). From the thermal design and calculating of the T-110-120-130 LMZ turbine, with the help of the proposed of MEI procedure is established: 1) The removing of rotor blades of the 8, 9th stages (MPC) gives, at 110 MW, increasing of efficiency by 0.12 and reducing of thermal power deficit by 14.02 Gcal/h; 2) Improved 27th stage — low-pressure cylinder is provided by increasing the reactivity in the lower half of the step and reduce its height the gradient changes; 3) In partial counter mode (PCM) the relative internal turbine efficiency increases by 10 %.