GB861924A - Improvements in or relating to binary fluid power plants - Google Patents

Abstract

861,924. Generating combustion products under pressure; gasefying solid and liquid fuels. BABCOCK & WILCOX Ltd. May 24, 1957 [May 24, 1956], No. 16500/57. Classes 51 (1), 55 (1) and 55 (2). [Also in Group XXVI] In a binary fluid turbine power plant, an ashforming fuel and a free-oxygen containing gas, such as air, under pressure are passed into a first combustion zone, the ratio of fuel to oxygen being insufficient for complete combustion, the fuel being partially burned in the first combustion zone thereby producing gaseous combustible products which contain entrained solids and vaporized ash products. The gaseous products and entrained solids are then passed through a first cooling zone where they are cooled by heat exchange with a vaporizable fluid so as to condense substantially all of the vaporized ash products, the entrained solids are then removed from the combustible gaseous products, and the cleaned combustible gaseous products are then burned, so as to produce clean, hot combustion gas under pressure which is expanded through a gas turbine, the vaporizable fluid being vaporized under pressure, the vapour being superheated and the superheated vapour expanded through a vapour turbine. In Fig. 1, ash-forming fuel and air under pressure are introduced into the combustion space 12 by means of the injector 10 and the fuel is partially burned so as to produce a combustible gas containing carbon monoxide and hydrogen. The combustible gas is then passed through a bank of steam generator tubes 26 and is thereby cooled and the vaporized ash products are condensed. The combustible gas then flows over a bank of superheater tubes 32 and interstage reheater tube banks 34, 36 and finally discharges through a Venturi nozzle 38 where washing liquid such as water is sprayed into the gas. The gas and water mixture then passes into a gaswater separator 40, the clean gas passing through outlet 42 and the water and ash products pass into a liquid-solid separator 44, the ash products being returned into the combustion space by means of the conveyer 46. The clean combustible gas enters the second combustion space 50 where it is burned with air under pressure supplied through the duct 52, and the resulting clean combustion gas is cooled by flowing across interstage reheater tube banks 56, 58 and superheater tubes 60, the cooled combustion gases finally discharging through duct 62 into the gas turbine 64 which drives the air compressor 14 also an electric generator 66. Steam from the second superheater 60 passes to the highpressure steam turbine 68, the exhaust of which passes through reheaters 34, 58 before entering the intermediate pressure turbine 70, the exhaust of which passes through reheaters 36, 56 before entering the low-pressure turbine 72 the exhaust of which is condensed and returned to the steam generator 26. The steam turbines drive an electric generator 76. In Fig. 2 the clean combustible gas discharged from the gas-water separator 40 is divided into two streams, one of which is fed to the second combustion space where it is partially burned with air under pressure supplied through the duct 82, the combustion gases being subsequently cooled by flowing across the interstage reheaters 86, 88 and the superheater 90, the cooled gases then passing through duct 91 to the gas turbine 92 from which they are led to a fourth combustion space 100. The remainder of the combustible gas from the separator 40 flows to a third combustion space 94 where it is completely burned with air under pressure supplied through the duct 95. The combustion gases are cooled in flowing across the interstage reheaters 97, 98 and the gases then enter turbine 99 from which they discharge into the fourth combustion space 100. The exhaust gases from the turbine 92 which contain combustible gases and the gases from the turbine 99 which contain excess oxygen are caused to burn in the fourth combustion space 100 by means of catalysts 101, the combustion gases finally passing to turbine 102. The turbines 92, 99 and 102 drive the air compressor 14 and an electric generator. The plant includes steam turbines 68, 70, 72 as in the first embodiment. In a third embodiment, the gases from the first combustion space 12 after cooling are fed to a gas cleaning device which operates both as a mechanical separator for separating out solid particles carried by the gas and as an electrostatic precipitator, the cleaned gases then passing to the second combustion space 50 as in the first embodiment. In Fig. 4, the gases from the first combustion space 12 after cooling in the gas pass flow through a gas cleaning device 380 where the gas is washed by water sprayed from ring 382 on to a liquid surface expanding device 384. The liquid collects in the lower portion of the cleaning device and is then passed through a solid-liquid separator 44 as in Fig. 1. The clean combustible gas is then passed through a heater 390 in the gas cooling pass 24 and then enters a second combustion space 50 where it is burned with air under pressure from the compressor 14, combustion catalysts 392 being disposed in the combustion space. The combustion gases finally enter the gas turbine 64 which drives the air compressor 14 and an electric generator. The plant includes steam turbines 68, 70, 72 as in the first embodiment.