Obiettivo To provide data on contaminants levels present in the turbine expansion gas after the fuel gas has passed through a LCV fuel gas, gas turbine combustor. This fuel gas was produced by the British Coal spouted fluidised bed gasifier and cleaned by filtration at 600 deg. C or below.The data was related to an existing materials test programme associated with the Grimethorpe Topping Cycle Project, which had the objective of predicting gas turbine blade lifetimes in utility machines.All aspects of the project described are innovative. The thermochemistry of the contaminants is such that confidence in the ability to provide a sufficiently clean coal gas to the gas turbine can only be adequate if the production, cleaning and combustion of the gas are carried out under pressure and on the scale proposed.A purpose built gas cleaning and combustion facility was designed, provisioned and operated within the schedule and budget provided. Modifications to an existing pressurized spouted bed gasifier were carried out successfully to provide coal derived fuel gas of the required quality for the experimental test programme.Alkali concentrations of 15 (+/- 8) ppb weight of sodium and 4 (+/- 4) ppb weight of potassium were measured in the fuel gas down-stream of the hot gas filter operating at 400 deg. C and 550 deg. C. These correspond to concentrations of 5 ppb weight sodium and 2.5 ppb weight potassium in the expansion gas passing to the gas turbine. At these levels of alkali, life limiting corrosion of the utility gas turbine blades would not be expected.Particulate concentrations of around 300 (+/- 30) ppb weight were measured in the fuel gas down-stream of the hot gas filter, corresponding to a concentration of around 35 ppb weight in the expansion gas passing to the gas turbine. Most of the material was less than 3 um. At this concentration and size, excessive fouling of the utility gas turbine would not be expected.Tests carried out on the gasifier during the experimental test programme indicated that operation of the gasifier for extended periods of time (> 130 hours) would not affect the gasifier performance.The project formed part of the Air Blown Gasification Cycle (ABGC - previously referred to as the British Coal Topping Cycle) development programme being carried out by British Coal in collaboration with PowerGen, GEC ALSTHOM and the UK Department of Trade and Industry. The British Coal spouted bed gasifier produces a raw fuel gas at 18 bar and 850 deg. C which is initially cleaned in high temperature cyclones.The experimental fuel gas combustion train received the partially cleaned fuel gas and passed it through five main processes. RAW GAS COOLERThe raw gas cooler was designed to operate at up to 18 bar, cooling the fuel gas from around 850 deg. C to 600 deg. C or below. Thermal oil was used to extract the heat, producing a cooled fuel gas typical of that expected in a utility ABGC plant.PARTICLE FILTERCeramic candle filters were utilised to remove dust and a large proportion of the alkali metal salts to levels representative of a utility ABGC plant. The filter elements werehoused in an insulated pressure shell. In operation, the dirty fuel gas will passed through the filter elements, depositing contaminants as a cake on the filter media.GAS COMBUSTORThe gas combustion system comprised a fuel control sub-system, a turbo-annular gas turbine combustor and an exhaust gas cooling and disposal train.The combustor was operated in a staged mode producing an extensive fuel-rich primary combustion zone. To achieve this, high pressure combustion air from a compressor was fed to the combustor which had aerodynamic design features to control the production of NOx. Air film cooling techniques were used.The combustor was operated at conditions typically up to 16 bar burning the total output from the gasifier at up to 1360 deg. C. RESEARCH INSTRUMENTATIONResearch Instrumentation was central to the project aims. Advanced dust and alkali measuring instrumentation was used to characterise key contaminants at points throughout the system.FLUE GAS COOLING AND DISPOSALA simple direct water injection cooling system was used to reduce the combustor flue gas to a temperature of 400-500 deg. C where conventional materials and control equipments were applicable.The programme was carried out in the 3 phases shown.1. Provision of Gas Combustor Oct 1991 April 1993 192. Gas Combustion Tests May 1993 April 1994 123. Evaluation & Reporting April 1992 Sept 1994 30 Programma(i) ENG-THERMIE 1 - Programme (EEC) for the promotion of energy technology in Europe (THERMIE), 1990-1994 Argomento(i) 7.2 - GASIFICATION Invito a presentare proposte Data not available Meccanismo di finanziamento DEM - Demonstration contracts Coordinatore BRITISH COAL CORPORATION (RESEARCH ESTABLISHMENT Contributo UE Nessun dato Indirizzo COAL RESEARCH ESTABLISHMENT STOKE ORCHARD, CHELTENHAM GL52 4RZ Gloucester Regno Unito Mostra sulla mappa Costo totale Nessun dato
