CN212701291U

CN212701291U - Accurate control system that sprays of aqueous ammonia

Info

Publication number: CN212701291U
Application number: CN202020618244.7U
Authority: CN
Inventors: 章平衡; 陆宏; 冯一帆; 卓晓龙; 严锦浒; 郭晨星; 黄先蛟; 胡启森
Original assignee: Zhejiang Products Huanneng Pujiang Thermal Power Co ltd
Current assignee: Zhejiang Products Huanneng Pujiang Thermal Power Co ltd
Priority date: 2020-04-23
Filing date: 2020-04-23
Publication date: 2021-03-16
Anticipated expiration: 2030-04-23

Abstract

The utility model discloses an accurate control system that sprays of aqueous ammonia relates to aqueous ammonia emission technical field, to single, the adjustment process ubiquitous hysteresis of traditional DCS system control mode, the aqueous ammonia sprays valve feedback lag, sprays the time point, the aqueous ammonia sprays unable accurate control scheduling problem, now proposes following scheme, including data platform, database, server, electric appearance auxiliary assembly, AI control system, AI management system. The AI control system and the AI management system are the main contents, and the other contents serve the two contents. The utility model discloses establish big data database, calculate, the analysis reachs best mode of production through the database. The production prediction control system is established through relevant measuring points in the production process, parameters can be adjusted in time, the material consumption can be changed, certain foresight is achieved, stable transition of production can be achieved when the boiler load and the pollutant concentration change, accurate control of NOX emission concentration is achieved, and the ammonia water consumption is saved.

Description

Accurate control system that sprays of aqueous ammonia

Technical Field

The utility model relates to an aqueous ammonia discharges technical field, especially relates to an accurate control system that sprays of aqueous ammonia.

Background

At present, 3 130t/h high-temperature and high-pressure circulating fluidized bed boilers are adopted to operate in the market, each boiler is provided with an SNCR + SCR coupling denitration system, an electric bag dust remover, a limestone-gypsum wet desulphurization system and a wet-electric deep dust removal system, one boiler is matched with one tower, and the operation is controlled by a DCS (distributed control System).

The traditional DCS is single in control mode, a hysteresis phenomenon generally exists in the adjusting process, the feedback of an ammonia water spraying control valve is delayed, the spraying time point and the ammonia water spraying usage amount cannot be accurately controlled, the system is high in energy consumption and material consumption, outlet NOX fluctuates, when the boiler load is unstable, the data of a discharge port exceeds the standard in a short time, and manual intervention is needed. And the service life of the equipment is influenced by frequent start and stop of part of equipment. Because the production data all come from the DCS system, remote monitoring or working can not be carried out, and the reference of operation decision can not be directly provided.

SUMMERY OF THE UTILITY MODEL

The utility model provides an accurate control system that sprays of aqueous ammonia has solved above-mentioned problem.

In order to achieve the above purpose, the utility model adopts the following technical scheme:

the utility model provides an accurate control system that sprays of aqueous ammonia, includes data platform, database, server, electricity appearance auxiliary assembly, AI control system, AI management system. The AI control system and the AI management system are the main contents, and the other contents serve the two contents.

Preferably, a CEMS analyzer for measuring and analyzing NOx and oxygen concentration is installed at the inlet of the boiler cyclone separator, and a signal of the CEMS analyzer is connected to an ultralow-emission DCS standby point.

Preferably, the original power frequency ammonia pump of the ammonia water system is upgraded into a variable frequency metering pump capable of accurately controlling ammonia spraying amount, the variable frequency metering pump is powered by an original power supply loop, and a control point is connected to the ultra-low emission DCS.

Compared with the prior art, the beneficial effects of the utility model are that: the system of the scheme establishes a big data database, and the best production mode is obtained through calculation and analysis of the database. A production prediction control system is established through measuring points related to the production process, parameters can be adjusted in time, the material consumption can be changed, and the method has certain prospect. This system can ensure when boiler load and pollutant concentration change, realizes producing steady transition, realizes practicing thrift the aqueous ammonia use amount to NOX emission concentration accurate control. In addition, the problem of blockage of the air preheater of the boiler can be solved by accurately controlling the ammonia water, the resistance of the section of the air preheater is reduced, and the energy consumption of a draught fan is reduced.

Drawings

FIG. 1 is a working diagram of an ammonia water accurate spraying control system

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments.

In the embodiment, an ammonia water use data platform and a database are established, DCS data are collected through OPC interface software, the use amount of ammonia water under different loads of a boiler is recorded, and implementation information is issued to an enterprise intranet through a server.

In this embodiment, a CEMS analyzer is installed at the inlet of the cyclone separator of the boiler for measuring and analyzing NOX and oxygen concentrations. The analysis can analyze the concentration of nitrogen oxides in the flue gas in real time, adjust the flow of ammonia water in time and control the emission index. And the signal is accessed to an ultralow emission DCS standby point.

In this embodiment, the original power frequency ammonia pump of the ammonia water system is upgraded to a variable frequency metering pump. The AI control system can accurately control the ammonia spraying amount by optimizing the ammonia spraying model, thereby greatly reducing the consumption of ammonia water and reducing the operation cost of a company. The variable frequency metering pump is powered by an original power supply loop, and a control point is connected to the ultra-low emission DCS.

The working principle is as follows: a CEMS analyzer is additionally arranged at the outlet of a boiler furnace, an ammonia escape measuring point is arranged at the inlet of a low-temperature economizer, and the concentration of NOX, oxygen and ammonia in boiler flue gas is monitored in real time. And the data are transmitted to the DCS through a signal line, and the OPC server acquires relevant data from the DCS and quickly feeds the relevant data back to the AI control system and the large database. After a large amount of historical data are accumulated in the database, optimizing learning is conducted in a segmented mode, and a DMC dynamic matrix prediction model and a hybrid control model are built in the AI control system. The DMC dynamic matrix prediction model can be used for adjusting the concentration of NOX in the flue gas at the outlet of the hearth and the initial adjustment range of the ammonia water spraying amount under the concentration. And on the basis of the initial adjustment range, the mixing control model obtains the current optimal ammonia water spraying amount through mixing and calculating a plurality of additional parameters (such as boiler evaporation capacity and air volume) in the database. After the ammonia water accurate spraying control system is installed, the average ammonia water consumption of 3 boilers per week is 31.05m³Decrease by 15.6m³And the energy-saving effect is obvious. The accurate spraying control system of aqueous ammonia can guarantee that the condition that emission outlet nitrogen oxide concentration does not exceed standard, reduces ammonia escape volume, can improve boiler air preheater and block up the problem, reduces boiler flue gas and in air preheater section resistance, has reduced the draught fan energy consumption to accomplish energy saving and emission reduction's purpose. The AI management system can record the ammonia water usage and the ammonia water inventory, and when the ammonia water inventory is insufficient, a prompt is sent to request the staff to supplement in time. The intranet server collects all data of the system and then releases the data to the intranet of the company, and company managers can directly check the operation condition of the system through a computer or mobile equipment, so that relevant decisions can be conveniently made.

The above, only be the concrete implementation of the preferred embodiment of the present invention, but the protection scope of the present invention is not limited thereto, and any person skilled in the art is in the technical scope of the present invention, according to the technical solution of the present invention and the utility model, the concept of which is equivalent to replace or change, should be covered within the protection scope of the present invention.

Claims

1. The utility model provides an accurate control system that sprays of aqueous ammonia, its characterized in that includes data platform, database, server, electric appearance auxiliary assembly, AI control system, AI management system, and wherein AI control system and AI management system are main content, and other contents then all serve these two parts of contents.

2. The system for controlling the accurate spraying of ammonia water as claimed in claim 1, wherein a CEMS analyzer for measuring and analyzing NOx and oxygen concentration is installed at the inlet of the boiler cyclone separator, and the signal of the CEMS analyzer is connected to an ultralow emission DCS standby point.

3. The system of claim 1, wherein an original industrial frequency ammonia water pump of the ammonia water system is upgraded to a variable frequency metering pump capable of accurately controlling the ammonia spraying amount, the variable frequency metering pump is powered by an original power supply loop, and a control point is connected to the ultra-low emission DCS.