Exhaust control method of gas-driven urea pump system

Abstract

The invention relates to the technical field of automobiles, and particularly discloses an exhaust control method for a gas-driven urea pump system. The exhaust control method comprises the followingsteps of: S1, judging whether a key door is powered off or not, if so, entering step S2, and if not, entering step S3; S2, judging whether the gas pressure in a urea box is in a preset range and the environment temperature is higher than a preset temperature at the same time or not, if yes, not exhausting the urea box, and if not, exhausting the urea box; and S3, judging whether the rotating speedof an engine is zero, the current fuel injection quantity is zero, the vehicle speed is zero and the accelerator pedal opening degree is not smaller than a preset value within preset time at the sametime or not, if yes, exhausting the urea box, and if not, not exhausting the urea box. By means of the exhaust control method, the problems that the urea box is frequently exhausted, air consumptionof an air compressor is wasted, personnel safety cannot be guaranteed during manual exhaust, and threads of a urea box cover are abraded can be solved.

Description

technical field [0001] The invention relates to the technical field of automobiles, in particular to an exhaust control method for an air-driven urea pump system. Background technique [0002] In order to reduce the emission of pollutants from automobile exhaust, a diesel oxidation catalyst (DOC) or a selective catalytic reduction (SCR) is usually arranged in the post-treatment of automobile exhaust. Among them, DOC uses noble metal catalysts to further oxidize harmful substances such as particulates, HC, CO, and NO in the engine exhaust, thereby reducing HC, CO, and PM in the exhaust. SCR utilizes the selective reduction reaction between urea and nitrogen oxides in the exhaust gas to reduce the nitrogen oxide content in the exhaust gas. The above reduction reaction needs to be carried out with the urea solution stored in the urea tank. The urea solution in the urea tank needs to be driven by pressure to reach the urea nozzle through the heating tube. The electronic control...

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Problems solved by technology

[0006] The purpose of the present invention is to provide an exhaust control method for an air-driven urea pump system, so as to solve the frequent exhaust of the urea tank and the waste of air consumption of the air compressor, as well as the manual exhaust, which cannot guarantee the safety of personnel and causes damage to the urea tank. Problems with cap thread wear

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