Experimental results of the study of underburned hydrogen during burning in oxygen medium

Abstract

The area of research is the experimental study of the composition of steam as a result of the combustion of hydrogen in an oxygen atmosphere in order to assess the underburning of hydrogen. The existing experience of experimental research on the combustion of hydrogen in an oxygen atmosphere is analyzed. Among the known works, the underburning of hydrogen was determined after mixing the dissociated vapor with a cooling component, which contributes to its sharp decrease in temperature. As a result, this leads to a decrease in the number of recombinations of unreacted hydrogen towards the formation of steam, which leads to an increased content of hydrogen in the steam. A large number of works are devoted to the combustion of various types of fuel with hydrogen additives in internal combustion engines in a number of European and Asian countries.The purpose of the article is to supplement and summarize a series of experiments on the study of hydrogen underburning when burning in an oxygen atmosphere without using a cooling component for mixing with combustion products (water vapor). Only external cooling of the flame tube of the experimental setup was used. This experiment was performed for the first time. For the conditions of experiments carried out by the authors of the article, a diagram, components and measuring instruments of the experimental setup are presented. The initial data on the pressure and temperature of hydrogen, oxygen, cooling water are given. The main expressions of the procedure for determining the underburning of hydrogen are given. The main results of experimental measurements are presented. The graphical results of measuring the steam temperature along the length of the flame tube of the experimental setup, the flow rates of hydrogen and oxygen, the temperature and flow rate of cooling water, the pressure inside the flame tube and in the steam extraction pipeline for chemical analysis are shown. On the basis of generalization of a series of experiments, an exponential character of the decrease in the underburning of hydrogen along the length of the flame tube of the experimental setup was obtained, which indicates the intense processes of hydrogen recombination towards the formation of steam. It was found that during the time of 0.069 s with the movement of dissociated steam inside a flame tube 980 mm long, the underburning of hydrogen decreases from 5.85 to 0.016% of the mass during stoichiometric combustion and to 0.0138% of the mass with an excess of the oxidant equal to 1.4.