Method for observing ammonia coverage rate and storage capacity of diesel engine series SCR system

Abstract

The invention discloses a method for observing the ammonia coverage rate and storage capacity of a diesel engine series SCR system, and belongs to the technical field of tail gas treatment. The methodcomprises the steps that a state space model is established firstly according to a main chemical reaction in the series SCR system and is simplified into a single state space model; on the basis, theammonia coverage rate and the total ammonia storage capacity of the surface of an average catalyst of two SCR reaction tanks are estimated by using an EKF algorithm; and finally, the ammonia coveragerates and storage capacity of the two reaction tanks are estimated correspondingly by using a two-time-scale method, and thus the purpose of reducing the calculating load is achieved. According to the method for observing the ammonia coverage rate and storage capacity of the diesel engine series SCR system, the ammonia coverage rate and storage capacity on the surface of the catalyst can be estimated effectively and simultaneously, and a basis is provided for subsequent controller design; and the two-time-scale method is adopted, the calculation time of the algorithm is effectively decreased,and the method is applied to the practice more advantageously.

Description

technical field [0001] The invention belongs to the technical field of tail gas treatment, and relates to a control estimation method, which is especially suitable for the estimation and observation of the ammonia coverage and storage capacity in the catalyst of the SCR system for after-treatment of the tail gas of medium and heavy diesel engines. Specifically, it refers to a diesel engine serial SCR Observation method of system ammonia coverage and storage capacity. Background technique [0002] In the past ten years, as my country's emission regulations have become more and more stringent, the issue of diesel engine exhaust emissions has attracted the attention of the general public. The Selective Catalytic Reduction (SCR) system of diesel engine has become the most promising diesel exhaust aftertreatment system due to its high conversion efficiency of nitrogen oxides and fuel economy, and it has also attracted the attention of many researchers. [0003] The SCR system is...

AI Technical Summary

Problems solved by technology

This method is very complicated and will greatly increase the calculation load of the vehicle ECU, so it is difficult to apply it in practice

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