Application Of Coal Characteristic Online Identification In The Thermal Power Units

Under the background of shortage of primary energy consumption and low rate of energy utilization efficiency, saving energy and improving energy efficiency are the responsibility of each company. Accuracy of the boiler efficiency is an important index to measure the boiler combustion economy, it calculated online is mainly affected by coal composition, exhaust gas temperature and oxygen, carbon content of fly ash and slag. For the complexity of coal, online calculation program of boiler efficiency under complex coal conditions was proposed. Through the depth analysis of the inherent relationships between elemental compositions of coal, a coal database applicable to the program was established with clustering algorithms and other mathematical methods, achieving online access to coal in the process of boiler efficiency calculation online. Practical results that the data of 22 days in December, 2012, from Datang Yunnan Red River Power Plant units show that: the trend of coal calorific selected from virtual coal database is highly consistent with that tested by power plants, with the average error being about 3.77%. So it can meet the needs of online calculation in engineering.Before the coal characteristic online identification, the article can make preliminary identification of coal characteristic in the coal quality database by analyzing the relationship between sulfur dioxide in flue gas and the content of the sulfur content in the as received basis in the coal, and analyzing the water content in the coal. The research has proved that the content of the sulfur content in the as received basis in the coal increases along with the sulfur dioxide in flue gas. The basic method of coal characteristic online identification is the mutual check between positive and negative balance, according to the image of ratio between the amount of coal and the load, it will identify the coal characteristic when the graph appears big step change, and it can get better result. Compared with the former method that made coal characteristic online identification every once in a while, the new method saves the identification times and it can also reflect the fact operation status. At the end of the article, a program was designed and developed that can be used for coal characteristic online identification. It is based on the train of thought of coal characteristic online identification, uses MYSQL database, and commercial software named Deiphi7 of Borland. Through the test that form historical data and real time data of Datang Yunnan Red River Power Plant units,the calculation precision can meet the needs of fact operation. The System is simple,easy to operate and stable, so it has important guiding role for coal characteristic online identification and energy saving optimization of thermal Power Units.