Prediction of CO emission from partially-premixed gas cooker

Abstract

Prediction of CO emission from gas cookers is the basis of decision on gas sources introduction, especially when introducing different gases into gas distribution networks has become a common practice to ensure supply reliability and flexibility nowadays. Given a cooker of specific structure, CO emission is affected by gas constituents and operation point, and the latter is influenced by gas constituents and initial adjustment, which makes it hard to investigate the influence of specific gas constituent upon CO emission quantitatively. In this paper, natural gas was simplified as a mixture of CH4–C3H8–N2 based on the conservation of carbon atoms, the ratio of carbon to hydrogen atoms and Wobbe index. Through comparing the CO emission of original gas and simplified gas by experiments, it was validated that the CH4–C3H8–N2 simplified gas was qualified to represent natural gas for CO emission studying. Gas with complicated constituents was simplified as two parameters by this gas constituents simplification method, and then experiments focused on CO emission were dramatically simplified and reduced. By experiments on cookers with injection mode, it was concluded that CO emission was linearly positive with methane percentage and exponentially positive with Wobbe index. By experiments on cookers with forced-mixed mode, it was found that CO emission was exponentially positive with both heat input and primary air coefficient. Then the shift of CO emission corresponding to initial operation points was theoretically derived, the influence of operation point on CO emission was achieved. Finally, a CO emission prediction method based on gas constituents and initial operation point was proposed, in which only several experiments were required. This prediction method dramatically decreases the complexity of experiments and provides an approach for quantitatively prediction of CO emission from gas cookers, which is the critical basis for gas sources introduction.