Combustion Graphology Used To Improve Emulsions of Water-In-Heavy Fuel Oil,

Abstract Combustion graphology uses the infrared and luminous radiation of the flame and cenosphere of a burning droplet of heavy fuel oil in order to carry out scientific research with technical industrial applications. The rational combustion of the optimal water-heavy fuel oil emulsions in industrial power fumaces determines several advantages of which the most important is the de-pollution of the environment. Graphological testing for water-heavy fuel oil emulsion droplets is performed on a simulator and the result of the experiments is presented for two situations: when the effect of secondary atomisation is partially present and when the secondary atomisation is total, the whole droplet exploding. Experimental results are presented for samples processed in laboratory and in an industrial emulsifying installation. Generalities The combustion of mixtures of water (20%-30%) and heavy fuel oil, especially for attaining the reduction in smoke and soot emissions is a well-known method. Recently, this method was considerably improved in order to avoid the increase both of sulphur corrosive action and of the specific fuel consumption. First of all, it has been replaced the use of mixture of water and heavy fuel oil with emulsions, the water content in the emulsion being drastically reduced. Several beneficial advantages may be obtained by burning homogeneous emulsions of waterheavy fuel oil, with the water content limited to 3-6% [11, Due to the existence of a large number of various types of heavy fuel oil and emulsifying installations and in order to optimise the useful effects it is necessary to improve experimentally the quality of the water-heavy fuel oil emulsions. The emulsifying installations have adequate specific functioning rates; out of the range of these rates, the installation produces low quality emulsions, which are inappropriate to use. This work firstly gives explanations on what is the mechanism of the combustion of water-heavy fuel oil emulsions, the conclusions being based on experiments. The specific aspects of the droplet combustion graphology are herein set and a rapid and precise method for establishing the quality of waterheavy fuel oil emulsions is proposed. The validity of this method was verified in industrial and laboratory experiments. Some of these characteristic results are presented together with the applications of the combustion graphology method, which offers the possibility of fast and accurate processing of very economical activities in different fields. Secondary atomisation The meaning of the appearance of advantageous effects when using water-heavy fuel oil emulsions is related to the so-called secondary atomisation. If the water is finely dispersed into the fuel oil, the water droplets diameter is of the order of about 2-5 f.U' T1. During the primary atomisation process, these small water droplets will be incorporated into the oil droplets, the latter ones having a magnitude order of 20-150 11m. When the droplets enter the incandescent combustion chamber, they are heated up and a sudden vaporisation of the water droplets occurs, leading to a further atomisation of the oil droplets into smaller ones. The result is the secondary atomisation, produced by micro-explosions, which appear as a consequence of the important increase of the vapour pressure caused by the release of fine water droplets from the emulsion. As a conclusion, many constituents are released from the combustible mass of the fuel droplet. These components need a lower time to bum. The important decrease of the QIRT 96 -Eurotherm Series 50 -Edizioni ETS, Pisa 1997 http://d

Impact of CO₂-enriched combustion air on micro-gas turbine performance for carbon capture

Power generation is one of the largest anthropogenic greenhouse gas emission sources; although it is now reducing in carbon intensity due to switching from coal to gas, this is only part of a bridging solution that will require the utilization of carbon capture technologies. Gas turbines, such as those at the UK Carbon Capture Storage Research Centre's Pilot-scale Advanced CO2 Capture Technology (UKCCSRC PACT) National Core Facility, have high exhaust gas mass flow rates with relatively low CO2 concentrations; therefore solvent-based post-combustion capture is energy intensive. Exhaust gas recirculation (EGR) can increase CO2 levels, reducing the capture energy penalty. The aim of this paper is to simulate EGR through enrichment of the combustion air with CO2 to assess changes to turbine performance and potential impacts on complete generation and capture systems. The oxidising air was enhanced with CO2, up to 6.29%vol dry, impacting mechanical performance, reducing both engine speed by over 400 revolutions per minute and compression temperatures. Furthermore, it affected complete combustion, seen in changes to CO and unburned hydrocarbon emissions. This impacted on turbine efficiency, which increased specific fuel consumption (by 2.9%). CO2 enhancement could therefore result in significant efficiency gains for the capture plant

Design and Evaluation of the AIMS Combustor

ABSTRACT This paper describes a reduced NO x and CO, partially premixed flame combustor that has been developed for the 175 kW Advanced Integrated Microturbine System (AIMS) recuperated cycle gas micro-turbine. The AIMS turbine is equipped with a recuperated silo combustor. The new, reduced emissions combustor retains key features of the conventional Dry Low NO x (DLN) combustors; the differences are the arrangement of the premixers, the novel head-end assembly design, and the liner cooling and dilution features. The combustion system was designed and tested at the GE Global Research facilities in Niskayuna, NY and leverages technology developed by GE Power Systems (GEPS) and GE Aircraft Engines (GEAE). Laboratory tests show that when firing with natural gas, without water or steam injection, NO x and CO emissions from the new combustor are in single digits at full-speed, full-load conditions. CO emissions show a strong pressure effect, increasing at base load (when compared to similar conditions in commercial combustors running at higher pressures). The standard combustor on the AIMS gas turbine is a reversed flow cylindrical can. An array of 4 fuel nozzles is located at the head end of the can and produces a swirl stabilized premixed flame. The liner contains an array of cooling and dilution holes that provide the air needed to dilute the burned gas to the desired turbine inlet temperature