Multi-channel cyclic sampling gas analysis system with channel self-check function and control method

The invention discloses a multi-channel cyclic sampling gas analysis system with a channel self-check function and a control method. The system at least comprises sample gas channels, a sampling channel, an analysis channel, a discharge channel, a purging channel and a controller. The sampling channel and the discharge channel share the sample gas channels, and are switched between sampling and discharge by controlling a two-station three-way electromagnetic valve through the controller, so as to realize cyclic sampling and analysis of multiple paths of sample gas; each of the analysis channel and the discharge channel is provided with a flow switch; a channel self-check module of the controller learns whether each channel is blocked or leaked and the liked by judging the combined control of electromagnetic valves and pumps and the height state of the flow switches, so as to realize automatic check of the sample gas channels. The system and the method have the following advantages: the analyzed sample gas is cyclically switched between the sampling channel and the discharge channel, so that the investment cost of equipment is reduced, and the response speed and accuracy of gas analysis data are improved; the controller realizes automatic check of blockage or leakage of each channel, so that the manpower cost is reduced, and the analysis accuracy is improved.