Device for regulating and controlling actual supply amount of urea entering exhaust system and regulating and controlling method

Abstract

The invention discloses a device for regulating and controlling the actual supply amount of urea entering an exhaust system. The device comprises an electronic control unit, a compressed air source device, a urea storing device, a compressed air controlling device, a metering pump / valve, a spray nozzle device, a main pipeline and a urea pipeline and further comprises a urea regulating and controlling device. The urea regulating and controlling device is in communication with the electronic control unit; and the actual supply amount of urea actually sprayed into the exhaust system from the spray nozzle device is controlled according to starting time and ending time. The device effectively avoids the situation that urea sprayed into the exhaust system is excessive, and by means of low-cost improvement, an original exhaust system accords with a higher emission standard. The invention further discloses a regulating and controlling method for regulating and controlling the actual supply amount of the urea entering the exhaust system.

Description

technical field [0001] The invention belongs to the technical field of internal combustion engine control systems, and in particular relates to a device and a control method for regulating the actual supply of urea entering an exhaust system. Background technique [0002] There are two types of internal combustion engines, gasoline engines and diesel engines. Their working mechanisms are different, and each has its own advantages: the gasoline engine is lightweight, with small vibration and good smoothness; the diesel engine has high efficiency, and its fuel consumption is more than 30% lower than that of the gasoline engine, with large torque and high power at low speed. Generally speaking, diesel engines have many advantages and disadvantages, and the development prospects are promising. The emission pollution of internal combustion engines is mainly divided into four categories: carbon monoxide CO, hydrocarbons HC, nitrogen oxides NOx, and particulate matter PM. Gasolin...

AI Technical Summary

Problems solved by technology

However, since there are many factors that affect the actual supply of urea, it is difficult to maintain a perfect balance between the amount of urea output from the urea tank and the amount of urea injected into the exhaust system, so even the best injection strategy is difficult to solve the maximum ammonia leakage problem, but only solves the problem of average ammonia leakage

In order to meet the standard’s requirements for NOx emissions and ammonia leakage at the same time, in the prior art, the SCR catalyst is increased, or EGR is used to reduce NOx first and then SCR is used, that is, EGR and SCR are cascaded, and other alternative methods, but the cost is too high. It is quite difficult to realize and popularize the high emission standards of the Euro VI standard

[0006] The invention overcomes the defects in the prior art that urea injection is difficult to control, excessive urea injection cannot meet the emission standards, and the process cost is too high, and proposes a device and a method for regulating the actual supply of urea entering the exhaust system

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