Combustion Parameters

In power stations or other combustion units above a capacity of, say, 1 MW, UV sensors for flame monitoring are not unusual. Here, even combustion parameters like the air or fuel supply are controlled by sensing the UV emission spectrum of the flames. 

In order to implement the control methodologies indicated, one needs proper measurements (sensors and diagnostics), controllers, and actuators. Extensive research and development are carried out to realize the most appropriate sensors and actuators for various applications. Diagnostics developed serve dual purpose to physically measure the various combustion parameters and interpret the results as quickly as possible, preferably in situ, so that the mechanisms involved can be understood and to validate the numerical computer codes so that... 

Several papers give excellent introductions to the problems of spray combustion (5A, 9A, ISA, JHAy 19A). Lloyd (14A) includes a diagrammatic sketch of the physical and chemical factors influencing combustion. The fuel used, method, and degree of atomization, and the many combustion parameters all affect the final combustion efficiency. 

Nitrogen pressure had the same qualitative effect on the combustion characteristics for all the metals studied. As low pressures, combustion parameters increased almost linearly with increasing pressure, but at higher values of pressure they reached a plateau value, becoming independent of pressure. The results from this dependence on pressure, combined with results on the particle size, can provide fruitful ideas for the design of SHS reactors. 

The observation that, at high pressures, the combustion parameters become nearly independent of gas pressure (a phenomena typical for solid-solid systems) is very important and can lead to significant simplications in the modeling of these gas-solid reactions. 

The quantity of NO formed in a petrol engine or diesel engine depends on the combustion parameters and, to a certain extent, can be controlled by adjustment of the engine operation. For example, NO formation may be limited by retarding the spark timing in petrol engines and the fuel injection in diesel engines [8]. 

Tab. 4.11 Calculated combustion parameters for hydrazinium aminotetrazolate- Hy-At/ADN formulations with p = 45 bar.

In order to elucidate the different properties of single, double and triple base gun propellants and to compare these values with the ones obtained for a new high-nitrogen propellant (e.g. NILE, see above), we calculated the relevant combustion parameters using the EXPL05 code under the assumption of isochoric combustion. The results are summarized in Table 4.15. 

We have tried to correct some omissions and errors which can not be avoided in a first edition and have also updated the references where appropriate. In addition, five new chapters on Combustion (Ch. 1.4), NIR formulations (Ch. 2.5.5), the Gurney Model (Ch. 7.3), dinitroguanidine chemistry (Ch. 9.4) and nanothermites (Ch. 13.3) have been included in the English edition. The chapter on calculated combustion parameters (Ch. 4.2.3) has been extended. 

Detailed information about material flammability derived from macroscopic combustion parameters is given by Petrella who considered the effect of an external heat source on the mass rate of polymer combustion. From the energy conservation law it follows ... 

Equations (62) and (66) provide as a function of cur, with n. A, and B appearing as the relevant steady-state combustion parameters. 

The effects of the determining combustion parameters on the positive ion yield are compared in Table I. It is important that the total yield... 

Optimization of internal engine combustion in respect of fuel efficiency and pollutant minimization requires detailed insight in the microscopic processes in which complex chemical kinetics is coupled with transport phenomena. Due to the development of various pulsed high power laser sources, experimental possibilities have expanded quite dramatically in recent years. Laser spectroscopic techniques allow nonintrusive measurements with high temporal, spectral and spatial resolution. New in situ detection techniques with high sensitivity allow the measurement of multidimensional temperature and species distributions required for the validation of reactive flow modeling calculations. The validated models are then used to And optimal conditions for the various combustion parameters in order to reduce pollutant formation and fuel consumption. 

The influence of the primary air input on the NO, emission of chipboard chip combustion can be seen in Fig. 5, which shows a number of measurement results with the primary air input as the variable parameter. All the other combustion parameters (especially heat output respecting fuel input and 02-concentration of the flue gas) were held approximately invariant. The heat power was 250 kW. 

A paper by Isaksson and Rittfcldt [23] described the examination of black powder of different origins. Tliey came to the conclusion that samples of different origins can be identified on the basis of their combustion parameters. 

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