Optimization of the gas-air path system parameters for trapping automotive fuel vapors

Introduction (statement of the problem and parameters relevance). The composition of the mixture of air and gasoline vapors differs in air and vapors ratio when purging the absorber at different time of the car operation. Therefore, the air-fuel mixture entering the engine for afterburning can create uncertainties in lambda control.

The purpose of the research was to determine the main features of lambda regulation in an unstable fuel-air mixture.

Methodology and research methods. An analysis of the mixed air and fuel vapor flows entering the engine during absorber purge was made. The composition and quantity effect of this mixture on the excess air coefficient was determined. The main parameters of air and gasoline vapor mixture in the fuel tank vapor space were established.

Scientific novelty and results. An equation obtained testifies that the excess air coefficients in the flows of the fuel-air mixture relate to the mixture flow rate during absorber purge. The requirements for the composition of the fuel-air mixture leaving the absorber have been formulated. In order not to exceed these values the threshold values of short-term fuel supply were corrected and the relative mass flow value rate of gasoline vapors from the tank in relation to the air flow rate purge was determined.

Practical significance. The factors limiting the flow sections of the absorber gas-air paths and the optimal ratios of the flow sections were determined on the example of a two-chamber absorber to exclude excessive enrichment of the fuel-air mixture entering the engine during purge.

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