Online measurement method for NOx emission of coal-fired boiler

A technology of a coal-fired boiler and a measurement method, applied in the electric power field, can solve the problems of large deviation between the calculated value and the actual value, difficult to obtain data, time-consuming and labor-intensive acquisition, etc., and achieves complete model fitness, high operational reliability, and low input cost. Effect

CN110032747AInactive Publication Date: 2019-07-19TAIYUAN UNIV OF TECH
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Publication Date
2019-07-19
Estimated Expiration
Not applicable · inactive patent

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Abstract

A NOx online measurement calculation model is established based on a deep belief network and a partial least squares support vector machine. The DBN network is formed by stacking two layers of restricted Boltzmann machines, each RBM comprises a visual layer v and a hidden layer h, the units of each layer are not connected, and the layers are fully connected; the method comprises steps of extracting deep feature pairs of the sample data set by using a DBN network model for training, completing establishment of a prediction model by minimizing an error between the output of a regression device and a real value of NOx; packaging and publishing DBN-LSSVM model as a dynamic link library, compling an interface program to obtain boiler side input parameters in real time, calling the dynamic linklibrary from a database, outputting a calculation result to a monitoring system, and measuring the NOx emission value online in real time. According to the NOX online soft measurement method providedby the invention, no extra measurement device needs to be added, the input cost is low, the operation reliability is high, the single measurement time is 0.05 s, and the real-time performance is good.
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Description

technical field

[0001] The invention belongs to the field of electric power and provides an X Real-time online measurement technology. Background technique

[0002] Coal burning in power plant boilers is an air pollutant NO X One of the main sources of NO emitted into the atmosphere X It will cause acid rain and photochemical smog pollution, destroy the ozone layer, threaten the ecological environment, and damage human health. The air pollutant emission standard for thermal power plants (GB13223-2011) requires that NOx emissions from coal-fired power plants be controlled at 100mg / m 3 Below, the ultra-low emission requirement is controlled at 50mg / m 3 the following. With the reduction of pollutant emission limits of coal-fired power plants, the on-line monitoring technology of flue gas pollutants needs to be continuously improved to monitor pollutant emissions in real time and accurately.

[0003] Power plant NO X There are two main types of measuring devices: one is a...

Examples

Embodiment Construction

[0047] The present invention is illustrated below by way of examples.

[0048] 1. Get sample data

[0049] Establish a multi-working-condition model data set based on test data, composed of test data, simulation optimization data and DCS data. The input parameters of the data set include: the coal feed rate of each coal mill, the particle size of coal powder, the primary air volume of each coal mill, the temperature of the air-powder mixture at the outlet of each coal mill, the secondary air volume of the furnace, and the primary and secondary air volume. temperature, pulverized coal particle size, and overfire air rate. The input parameters of the sample data set are denoted as x i , the corresponding NO X The emission value is the sample data label, denoted as y i , get the sample data set The sample data set is divided into a test set and a training set, where the training set accounts for 80% of the total data set and the test set accounts for 20%.

[0050] 2. Offli...