Experimental investigation on combustion of hydrogen–oxygen and methane–oxygen mixtures in the medium of low-superheated steam

Abstract

Experimental data are represented on the investigation of combustion of hydrogen–oxygen and methane–oxygen mixtures in the medium of low-superheated (initial temperature of approximately 150°C) steam at atmospheric pressure. The influence of the ratio of mass flows of the combustible mixture and steam on the qualitative composition of combustion products and the temperature of produced steam is revealed. Main laws for combustion of the hydrogen–oxygen mixture within the steam flow, which affect the completeness of mixture combustion, are determined. Experimental data on the influence of concentrations of the hydrogen–oxygen mixture within the flow of the steam and the combustible mixture upon the completeness of combustion are given. It is found that, when burning the hydrogen–oxygen mixture within the steam flow with a temperature of 1000–1200°C, it is possible using a variation of the combustible mixture flow. At the same time, the volume fraction of noncondensable gases in the produced steam is no more than 2%. It is revealed that there are several combustion modes of the hydrogen–oxygen mixture within the steam flow, in which, in one case, the steam always suppresses combustion and, in another one, detonation of the combustible mixture combustible mixture occurs. It is found that with the excess air factor close to unit, the combustion of the methane–oxygen mixture within steam and the vapor conversion of methane, which result in the appearance of free hydrogen in the produced high-temperature steam, are possible. The description and the principle of the operation of the experimental bench for investigation of combustion of methane–oxygen and hydrogen–oxygen mixtures in the medium of steam are given. Results of experimental investigations of burning fuel and oxygen in the medium of steam are used in the development of a steam superheater for a hightemperature steam turbine.