In the operation of a turbine system composed of apparatus (6,12,14,16) for generating steam and a turbine first stage (4) having inlet nozzles connected to be supplied with steam from the steam generating apparatus (6,12,14,16), the steam generating apparatus (6,12,14,16) being composed of a cascade arrangement of a boiler (6) producing steam at a selected pressure which has an assigned lower limit value, a primary superheater section (12), one or more division valves (14) presenting a steam flow passage having a controllable cross-sectional area, and a secondary superheater section (16) connected between the division valves (14) and the inlet nozzles, a method for reducing the output of the system at low load levels comprising: reducing the cross-sectional area of the steam flow passage presented by the division valves (14); and increasing the rate at which heat is supplied to the steam in the secondary superheater section (16) by an amount coordinated with the reduction imparted to the cross-sectional area of the steam flow passage by the reducing step.
In order to obtain a particularly compact steam power plant (1) with a plurality of pressure stages (4a, 4b) mounted on a common turbine shaft (6), a condenser (10) is mounted at the outflow side in the axial direction of the turbine shaft (6) and a feed-water preheater (14) has a modular design. The feed-water preheater (14) has a plurality of heat exchanger modules (20, 22) which are arranged in a common housing (24) and may be heated by steam (A.sub.N, A.sub.H) tapped from one or all pressure stages (4a, 4b). The heat exchanger modules (20, 22) are mounted in series at the feed-water side and in parallel at the tapped steam side.
A method of reducing turbine inlet temperature excursions during sudden load demand reductions on a steam turbine, the turbine being coupled to a controllable source of high pressure, high temperature steam, incorporates throttling of steam within the steam source in conjunction with steam throttling at the turbine so as to apportion temperature drops between the source and turbine. In one form, the method includes the steps of sensing a sudden drop in load demand on the steam turbine, operating the steam source to reduce exit pressure of the steam at the steam source and bypassing sufficient steam around the steam turbine to reduce steam flow through the turbine by an amount commensurate with the drop in load demand. The steam source may be controlled by adjusting division valves between primary and secondary superheaters in the steam source to throttle steam pressure at the secondary superheater and then heating the steam in the secondary superheater to a temperature which compensates for the temperature drop across the division valves caused by throttling.
A gas turbine combustion system and method used for generating electrical power includes a compressor that receives and compresses air. A first stage turbine nozzle is flowise connected to the compressor and receives a portion of the compressed air from the compressor within a first air flow. A torus configured combustion chamber is positioned around the first stage turbine nozzle and receives a portion of the compressed air from the compressor within a second air flow that is passed through the combustion chamber where air and fuel are mixed and combusted. The air is discharged at the first stage turbine nozzle to mix with the first air while achieving a dry low NOx combustion.
