ГАЗОДИНАМИКА УСТОЙЧИВОГО ГОРЕНИЯ В КАМЕРЕ СГОРАНИЯ ГАЗОТУРБИННОЙ УСТАНОВКИ С ВНЕШНИМ ПОДОГРЕВОМ КОМПОНЕНТОВ

Abstract

The relevance of the study is due to the need to organize stable low-emission low-temperature combustion of a lean mixture in a single-zone uncooled combustion chamber, which is an integral part of a micro-gas turbine power plant. The stable position of the flame front in combustion chambers of this type mainly depends on the ratio between the average flow rate of the combustible-air mixture and the rate of turbulent combustion. This ratio depends on many factors, the main of which are the pressure and temperature of the components supply, the excess air ratio, the pulsating speed of the gas flow and autoturbulization of the flame, the consumption of the combustible-air mixture. In this work, we investigate the effect of external heating of the components on the expansion of the lower combustion limit and on the stable position of the flame front. The aim of the study is to obtain areas of breakthrough, stable position and flame blowout when organizing low-temperature lean combustion with large values of the excess air ratio; determination of the ranges of relative flow rate, at which a stable position of the flame front is observed, using experimental data and the results of numerical modeling; development of recommendations for determining the geometric appearance of a single-zone uncooled chamber of a micro-gas turbine power plant in the presence of air and fuel gas recuperators. As a result, the dependences of the normal combustion rate on the excess air ratio were obtained taking into account the lower combustion limit, the relationship between the average flow rate and the turbulent combustion rate in various combus-tion modes, and ranges for the relative flow rate in the region of low-temperature stable combustion. Based on the developed gas-dynamic model, the geometric and gas-dynamic parameters and characteristics of turbulent combustion in the flow in the combustion chambers of micro-gas turbine power plants with a capacity of 100 and 300 kW with external heating of air and fuel gas using a turbocompressor with a compression ratio of 3.0 are determined and analyzed.