Metering transportation method and apparatus for abstracting, metering and releasing liquid

Abstract

The invention relates to a measurement conveying method of extraction, measurement and release of a reducing agent of an after treatment system of exhaust purification of an internal combustion engine, comprising the following steps: 1) liquid which is more than the needed dosage is extracted excessively and the dosage is determined by a container with fixed volume; 2) the extracted liquid is adjusted to the needed dosage and simultaneously the residue liquid is returned to the liquid source; and 3) the liquid with the dosage is released. The invention provides an economical and effective reducing agent measurement conveying method and a device for the market; as the preposing and pressurization are canceled, the invention leads the whole after treatment system to have more simple and reliable structure, the manufacturing cost is further reduced and the installation space is reduced further; and simultaneously, the invention also has all the advantages of other metering pumps, such as stable dosage supply, strong anti-interference performance to outside, small installation volume, little energy consumption, low cost and the like. Besides, a new pipeline leads a reducing agent conveying system to have sensible response to the change of the working condition of the engine and further reduces the energy consumption of a metering pump.

Description

technical field [0001] The invention relates to emission control of an internal combustion engine, in particular to a metering delivery method and a device thereof for extracting, metering and releasing a reductant in a post-treatment system for exhaust gas purification of an internal combustion engine. Background technique [0002] Due to the urgent need to improve fuel economy, the application of diesel engines and lean burn gasoline engines has increased rapidly in recent years. However, because the combustion chamber and its exhaust gas contain too much oxygen, these engines emit a large amount of nitrogen oxides and the method of using a common three-way catalyst cannot work. In response to this problem, various post-treatment technologies for reducing nitrogen oxides have been proposed. Among them, injecting ammonia into the exhaust gas as a reducing agent and using it in conjunction with a selective reduction catalyst (SCR) is considered to be the most effective meth...

AI Technical Summary

Problems solved by technology

Although Ching H.Wu's invention has the advantages of small size, energy saving, accurate dosage and low manufacturing cost, it needs pre-pressurization

In practice, it has been found that if there is no pre-pressurization to effectively supply the liquid to the metering pump, the pumping capacity of the metering pump itself is insufficient to achieve accurate metering

The Bosch system has a complex structure, high energy consumption, high cost and large volume. Compared with a single metering pump system, it has no commercial prospects

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