CN110987440A

CN110987440A - SCR catalyst NH3 storage test method

Info

Publication number: CN110987440A
Application number: CN201911305016.2A
Authority: CN
Inventors: 臧志成; 邹海平; 许晓巍
Original assignee: Kailong High Technology Co Ltd
Current assignee: Kailong High Technology Co Ltd
Priority date: 2019-12-17
Filing date: 2019-12-17
Publication date: 2020-04-10

Abstract

The invention discloses a storage test method of an SCR catalyst NH3, which comprises the following steps: s101, a working condition selection test; s102.NH3 storage test; s103, NH3 storage amount calculation; and S104, calculating the NOx conversion efficiency. The SCR catalyst NH3 storage test method provided by the invention can accurately and rapidly calculate the NH3 storage amount and the NOx conversion efficiency of the SCR catalyst at different temperatures and airspeeds.

Description

SCR catalyst NH3 storage test method

Technical Field

The invention relates to the technical field of engine tail gas treatment, in particular to a storage test method of an SCR catalyst NH 3.

Background

An SCR (Selective Catalytic Reduction) system is a NOx treatment system installed in the exhaust system of a diesel engine that can treat NOx emissions into N2 and water before they enter the atmosphere. The SCR catalyst requires the amount of NH3 stored to be controlled within a reasonable target range for NOx conversion at different temperatures to ensure higher NOx conversion efficiency. The storage characteristics of the SCR catalyst NH3 used in the sixth emissions phase of China are more sensitive to NOx conversion efficiency, the control system puts higher demands on the control of the storage amount of the SCR catalyst NH3, and a method is needed for calculating the storage amount of NH3 and the NOx conversion efficiency of the SCR catalyst at different temperatures and space velocities.

Disclosure of Invention

The object of the present invention is to solve the problems mentioned in the background section above by means of a SCR catalyst NH3 storage test method.

In order to achieve the purpose, the invention adopts the following technical scheme:

an SCR catalyst NH3 storage test method, the method comprising:

s101, a working condition selection test;

s102.NH3 storage test;

s103, NH3 storage amount calculation;

and S104, calculating the NOx conversion efficiency.

Specifically, the step S101 includes: and selecting the single-point test working condition of the engine.

In particular, said step S102 comprises: engine single point operating mode NH3 storage test.

Specifically, the step S103 includes: the amount of NH3 stored is calculated for different temperatures and space velocities of the SCR catalyst.

In particular, said step S104 comprises: conversion efficiencies corresponding to different temperatures of the SCR catalyst and the amount of stored NH3 are calculated.

Specifically, the selecting the single-point test operating condition of the engine specifically includes: universal characteristic tests and single-point working condition selection of the engine; the universal characteristic test is used for determining the corresponding relation among the rotating speed, the torque, the exhaust temperature and the airspeed; and the single-point working condition selection is to select a rotating speed and torque working condition point corresponding to the temperature and the airspeed according to universal characteristic data.

Specifically, the storage test of the engine single-point working condition NH3 specifically comprises the following steps: and gradually and incrementally controlling the urea injection quantity according to different equivalence ratios under the selected working condition points according to the original NOx concentration emitted by the engine until the test is stopped when NH3 leakage is detected at the rear end of the SCR catalyst.

The SCR catalyst NH3 storage test method provided by the invention can accurately and rapidly calculate the NH3 storage amount and the NOx conversion efficiency of the SCR catalyst at different temperatures and airspeeds.

Drawings

Fig. 1 is a schematic flow chart of a SCR catalyst NH3 storage test method according to an embodiment of the present invention.

Detailed Description

The invention is further illustrated by the following figures and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It is also to be noted that, for the convenience of description, only a part of the contents, not all of the contents, which are related to the present invention, are shown in the drawings, and unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

Referring to fig. 1, fig. 1 is a schematic flow chart of a SCR catalyst NH3 storage test method according to an embodiment of the present invention.

The storage test method of the SCR catalyst NH3 in the embodiment specifically comprises the following steps: s101, a working condition selection test; s102.NH3 storage test; s103, NH3 storage amount calculation; and S104, calculating the NOx conversion efficiency.

Specifically, in this embodiment, the step S101 includes: and selecting the single-point test working condition of the engine.

Specifically, in this embodiment, the step S102 includes: engine single point operating mode NH3 storage test.

Specifically, in this embodiment, the step S103 includes: the amount of NH3 stored is calculated for different temperatures and space velocities of the SCR catalyst.

Specifically, in this embodiment, the step S104 includes: conversion efficiencies corresponding to different temperatures of the SCR catalyst and the amount of stored NH3 are calculated.

Specifically, in this embodiment, the selecting an engine single-point test operating condition specifically includes: universal characteristic tests and single-point working condition selection of the engine; the universal characteristic test is used for determining the corresponding relation among the rotating speed, the torque, the exhaust temperature and the airspeed; and the single-point working condition selection is to select a rotating speed and torque working condition point corresponding to the temperature and the airspeed according to universal characteristic data.

Specifically, in this embodiment, the storage test of engine single-point operating mode NH3 specifically includes: and gradually and incrementally controlling the urea injection quantity according to different equivalence ratios under the selected working condition points according to the original NOx concentration emitted by the engine until the test is stopped when NH3 leakage is detected at the rear end of the SCR catalyst.

The technical scheme provided by the invention can accurately and rapidly calculate the NH3 storage amount and the NOx conversion efficiency of the SCR catalyst at different temperatures and airspeeds.

It will be understood by those skilled in the art that all or part of the above embodiments may be implemented by the computer program to instruct the relevant hardware, and the program may be stored in a computer readable storage medium, and when executed, may include the procedures of the embodiments of the methods as described above. The storage medium may be a magnetic disk, an optical disk, a read-only memory or a random access memory.

It is to be noted that the foregoing is only illustrative of the preferred embodiments of the present invention and the technical principles employed. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described herein, but is capable of various obvious changes, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, although the present invention has been described in greater detail by the above embodiments, the present invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the spirit of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. An SCR catalyst NH3 storage test method, the method comprising: s101, a working condition selection test; s102.NH3 storage test; s103, NH3 storage amount calculation; and S104, calculating the NOx conversion efficiency.

2. The SCR catalyst NH3 storage test method of claim 1, wherein the step S101 comprises: and selecting the single-point test working condition of the engine.

3. The SCR catalyst NH3 storage test method of claim 1, wherein the step S102 comprises: engine single point operating mode NH3 storage test.

4. The SCR catalyst NH3 storage test method of claim 1, wherein the step S103 comprises: the amount of NH3 stored is calculated for different temperatures and space velocities of the SCR catalyst.

5. The SCR catalyst NH3 storage test method of claim 1, wherein the step S104 comprises: conversion efficiencies corresponding to different temperatures of the SCR catalyst and the amount of stored NH3 are calculated.

6. The SCR catalyst NH3 storage test method of claim 2, wherein selecting an engine single point test operating condition specifically comprises: universal characteristic tests and single-point working condition selection of the engine; the universal characteristic test is used for determining the corresponding relation among the rotating speed, the torque, the exhaust temperature and the airspeed; and the single-point working condition selection is to select a rotating speed and torque working condition point corresponding to the temperature and the airspeed according to universal characteristic data.

7. The SCR catalyst NH3 storage test method of claim 3, wherein the engine single point operating condition NH3 storage test specifically comprises: and gradually and incrementally controlling the urea injection quantity according to different equivalence ratios under the selected working condition points according to the original NOx concentration emitted by the engine until the test is stopped when NH3 leakage is detected at the rear end of the SCR catalyst.