System for supplying urea solution

Abstract

The present disclosure provides a system for supplying a urea solution, comprising a storage tank, an injection module, and a urea pump, the urea pump comprising: a housing; the first liquid conveying pipeline and the second liquid conveying pipeline are arranged in the shell, the first liquid conveying pipeline is connected with the liquid inlet pipeline, and the second liquid conveying pipeline is connected with the liquid outlet pipeline; the pump core module is configured to be connected with the first liquid conveying pipeline and the second liquid conveying pipeline; the backflow structure is arranged in the shell and comprises a backflow pipeline and a one-way backflow valve arranged in the backflow pipeline, the inlet end of the backflow pipeline is connected to the second liquid conveying pipeline, and the outlet end of the backflow pipeline is connected to the first liquid conveying pipeline. Therefore, pipelines and pipeline heaters can be saved, and the liquid feeding efficiency of the urea pump can be improved.

Description

technical field [0001] The present disclosure relates to the technical field of diesel engine exhaust after-treatment, and in particular, to a system for supplying urea solution. Background technique [0002] In order to meet increasingly stringent exhaust emission standards, exhaust gas from diesel vehicles is often subjected to aftertreatment. At present, the mainstream post-treatment technology in the diesel vehicle market is the Selective Catalytic Reduction (SCR) technology for diesel engines. The SCR technology uses urea solution as a reducing agent to remove nitrogen oxides from diesel engine emissions. The related SCR system usually includes a urea solution storage tank, a urea solution pump, a urea solution nozzle, an electrical control unit, and the like. Under the high temperature environment, the urea solution nozzle sprays the urea solution into the catalytic reaction module. The urea solution produces water and ammonia gas at high temperature. The ammonia gas ...

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Problems solved by technology

[0004] However, for the above-mentioned urea solution supply system, during the pressure-building injection process, the overflow solution is transported to the storage tank through the return line and then drawn from the storage tank by the pressure-building pump again. Reduce, and then shorten the service life of the infusion mechanism including the pressure building pump, etc.

In addition, during the pressure build-up process, it is necessary to control the intermittent opening of the nozzle, and cooperate with the return line to exhaust the pump so that the pump pressure can quickly rise to the rated pressure. This exhaust process is more complicated in operation and not easy to control; and in During the injection process, there will be continuous bubbles in the urea solution, which can only be discharged through the nozzle and the one-way valve set in the return line, which will cause the pump pressure to be unstable

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