Zero-emission two-stage urea injection system control system and method for hydrogen combustion engine

The invention provides a control system and method for a zero-emission two-stage urea injection system of a hydrogen-fired engine, and the system comprises a DOC system, a first SCR system, a second SCR system and an ASC system which are sequentially arranged and connected in the tail gas emission direction of the hydrogen-fired engine and are used for treating tail gas in sequence. The urea injection system is provided with a first urea nozzle used for injecting urea liquid to a carrier of the first SCR system and a second urea nozzle used for injecting urea liquid to a carrier of the second SCR system. The urea injection controller controls the injection action of the first urea nozzle and/or the second urea nozzle; the urea injection controller is arranged to control the urea injection system to work in a single-stage urea injection mode or a two-stage urea injection mode based on the air-fuel ratio of the hydrogen engine in the lean combustion mode. The urea injection control system is high in reliability