Burner optimisation

Rice [15] made a comprehensive study of the reheated gas turbine eombined plant. He first analysed the higher (gas turbine) plant with reheat, obtaining (t o)h> turbine exit temperature, and power turbine expansion ratio, all as funetions of plant overall pressure ratio and firing temperatures in the main and reheat burners. (The optimum power turbine expansion ratio is little different from the square root of the overall pressure ratio.) He then pre-seleeted the steam eyele eonditions rather than undertaking a full optimisation. 

Aspirate organic solutions into a nitrous oxide—acetylene flame previously optimised on boron standards in an identical organic solvent matrix and measure boron absorbance at 249.68/249.77 nm. Prepare boron standards by chelating and extracting aqueous boron solutions in the same manner as sample digests. Flush the burner with extracting solution after aspiration of each standard and sample solution. 

A strongly reducing fuel-rich nitrous oxide—acetylene flame is superior to other flames for sensitivity and freedom from interferences. Optimisation of burner height is important as absorption signal is fairly dependent on observation height. In aqueous systems interference from calcium has been controlled by the addition of aluminium or Na2S04. Reduced sensitivity has been reported in the presence of acetone vapour from depleted acetylene cylinders. 

Optimisation of the boiler unit and combustion conditions in 4 - 5 MW size class. With small modifications, the research results will be applicable up to the burner output of 45 MW. 

Eskilsson, D. et al., Optimisation efficiency and emissions in pellet burners. Biomass... 

The Problem. The problem is to automatically and continually optimise combustion in a multiple burner furnace or boiler plant by altering the air inlet valve to each of the burners depending upon the carbon monoxide and oxygen readings taken from their common flue. The optimum air/fuel mixture will be different for each burner, because of their varying type, age and condition, and it can be achieved for a given supply of fuel by individually adjusting the air inlet valve to that burner. 

Rule-Based Optimisation of a Twelve Burner Zone of a Furnace... 

Flame atomisation In flame atomisation, the sample solution is introduced into the flame with a particularly designed nebuHser (Fig. 12.6). The function of the nebuHser is to disrupt the continuous sample stream into a mist of fine droplets of typically 5—20 pm diameter which are swept into the mixing chamber. The aerosol is then mixed with the fuel gas and the oxidant gas before reaching the burner head. As a number of physical and chemical reactions, e. g., vaporisation, dissociation, reduction, or oxidation, may occur, it becomes evident that precise control of the operating conditions of flame atomisation is required to obtain stable and sensitive signals. Optimisation of flame atomic absorption measurements has thus the double role of maximising the elemenf s response while minimising the undesired side-reactions. 

The principles of the optimisation are generally valid for iron melting in rotary furnaces using oxygen burners. The operational data have been established for a 3 tonnes/h furnace. For furnaces of other sizes, a site-specific optimisation is necessary. 

However, the special design of burner cores can be used advantageously to reduce the recriticality risk by exploiting inherent features. So, the available diluent system can be optimised to enhance the fuel discharge from the core under core-melt conditions. By an early fuel relocation, the escalation into a neutronically active whole-core-melt with its associated energetics might thus be prevented. 

The model is properly initialised and simulations are performed to obtain the static characteristics and dynamic responses of the SOFC. For obtaining the static characteristic curves of the SOFC, the FU and the OU have been interpreted in terms of the partial pressures of the gas species in the channels, for a given set of known and input parameters. The application of the tme bond graph model presented in this chapter for the optimisation of the operational efficiency of a SOFC system consisting of the cell, the after-burner and two pre-heaters under varying loads can be consulted in [12,14,16]. Readers may also refer to [12,15] for a control scheme to improve the dynamic performance of the SOFC using the true bond graph model presented in this chapter. 

A proper optimisation of a steam reformer must always be based on a furnace model, since the delivered heat flux profile is bounded by the furnace configuration and the flexibility of the burners. Seen from an exeigy point of view outer tube-wall temperature and heat flux profiles may decrease the exergy losses [335], but it should be checked if they can be provided by a furnace. 

Nebuliser and burner system. It should be ensured that the burner system is aligned and the burner height is eorreet. Also, the fuel-oxidation gas composition should be optimised. Moreover, attention should be paid to the acetylene tank pressure. Acetylene tanks contain acetone (as an acetylene dissolving agent) for safety purposes as the acetylene pressure drops a decrease in absorbance and increase in background due to acetone is observed. 

Simplex optimisation of the overall response of a simultaneous multi-element flame atomic absorption spectrometer (air to fuel ratio, slit width, height above the burner head, and four hollow cathode lamp currents). Cu, Fe, Mn and Zn were measured. 

The activities undertaken so far have served to indicate the great flexibility of fast reactors, which can be used either to consume plutonium or to generate it, and can utilise plutonium with a wide range of isotopic composition, from weapons-grade material which is high in Pu-239 to plutonium which has been recycled several times in thermal or fast reactors and contains more than 50% of the non-fissile isotopes Pu-240 and Pu-242. During the next decade further work to optimise the performance of burner reactors can be expected. Some of the outstanding questions are as follows. 

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