Spraying nozzle blocking diagnostic system and method for urea water solution spraying system

Abstract

The invention provides a spraying nozzle blocking diagnostic system and method for a urea water solution spraying system. The urea water solution spraying system comprises a liquid storing tank, a spraying nozzle, and a pump connected between the liquid storing tank and the spraying nozzle through a fluid pipeline. The spraying nozzle blocking diagnostic system comprises a sensor module used for detecting fluid pressure in the fluid pipeline, and a control module used for receiving and analyzing a pressure detecting value of the sensor module and controlling the pump. The control module can control the pump to be started n times so that the spraying nozzle can pump back, wherein n is an integer and is larger than or equal to 1. For each time of pumping back process of the spraying nozzle,within a certain preset time interval, the sensor module detects the pressure value in the fluid pipeline, the detected pressure value is integrated through the control module, thus an integration value is obtained, and the control module judges whether the spraying nozzle is blocked or not and/or judges the blocking degree of the spraying nozzle according to n integration values obtained on the such basis.

Description

technical field [0001] The present application relates to a system and method for diagnosing clogged nozzles in aqueous urea injection systems used in diesel vehicles. Background technique [0002] For environmental reasons, selective catalytic reduction (SCR) systems are widely used in diesel vehicles to treat engine exhaust gas. The SCR system mainly includes a urea aqueous solution injection system, which injects urea aqueous solution into the engine exhaust pipe as required, so as to harmlessly treat the nitrogen oxides in the engine exhaust gas and discharge them to the outside. [0003] The urea aqueous solution injection system has been used for a long time, and the urea aqueous solution remaining in the nozzle will crystallize after spraying the urea aqueous solution each time, and this crystallization will block the nozzle; or if the urea aqueous solution itself contains impurities, such impurities will also cause the nozzle to be damaged after a long period of time...

AI Technical Summary

Problems solved by technology

[0003] The urea aqueous solution injection system has been used for a long time, and the urea aqueous solution remaining in the nozzle will crystallize after spraying the urea aqueous solution each time, and this crystallization will block the nozzle; or if the urea aqueous solution itself contains impurities, such impurities will also cause the nozzle to be damaged after a long period of time. block

Blocked nozzles will not be able to spray the required amount of urea solution, resulting in excessive engine exhaust emissions

[0004] Most of the existing technologies can only detect the nozzle situation after it has been completely blocked

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