Solution Overview

Nitrogen oxides (NOx) are one of the main sources of air pollution, which not only have a significant impact on global climate change, but also participate in the destruction of the ozone layer. In the 12th Five Year Plan of the State Council, it is explicitly required that the nitrogen oxide emissions from the thermal power industry be 7.5 million tons by 2015, a decrease of 29% compared to 2010; During the 12th Five Year Plan period, "denitrification" will become a key focus of emission reduction work for power companies.

The technical measures for controlling NOX emissions can be divided into two categories: one is the so-called source control, which is characterized by controlling the generation of NOX during combustion through various technical means (i.e. low nitrogen oxide combustion technology); Another type is the so-called tail control, which is characterized by reducing the already generated NOx to N2 through some means, commonly known as flue gas denitrification. In the field of large-scale combustion of mineral fuels, NOx control technology denitrification devices have been installed, which inject ammonia into the reactor to react with nitrogen oxides, producing water and N2. The injected ammonia can be directly in the form of NH3, or it can be released through urea decomposition to obtain NH3 before injection. Regardless of the form, controlling the total amount of ammonia injection and the spatial distribution of ammonia in the reaction zone can significantly reduce NOx emissions. Insufficient ammonia injection will reduce the reduction conversion efficiency. Excessive ammonia injection not only fails to reduce NOX emissions, but also causes NH3 to escape from the reaction zone due to excessive ammonia. The escaped NH3 will react with the sulfate produced in the process flow to form ammonium sulfate, mainly ammonium sulfate. Ammonium salts can precipitate on the surface of solid components downstream of the boiler tail flue, such as on the fan surface of the air preheater, causing serious equipment corrosion and resulting in expensive maintenance costs. When the distribution of ammonia injected into the reaction zone does not match the distribution of NO and NO2, ammonia escape can also occur. The situation of high ammonia escape accompanied by a decrease in NOX conversion efficiency is a very bad phenomenon and a serious problem.

Based on years of research and development in gas analysis products, our company has designed high-performance online monitoring systems for the denitrification industry, including GA-5000DN, GA-5000nao, and CEMS-2001 series.

Scheme composition

ERUN-QZ9340 uses tunable laser analysis technology to measure gases such as NH3; The ERUN-QZ9340 series uses ultraviolet differential technology to measure NO, NO2, and SO2; GA-5000nao is an in-situ denitrification integrated machine that integrates tunable laser analysis technology and ultraviolet differential technology, and can simultaneously analyze NH3 gas NO, NO2, and SO2 gas. Customers can choose multiple combination solutions according to their needs.

Features of the Solution

The use of tunable laser analysis technology for sampling and measuring NH3 has advantages over in-situ methods, such as being unaffected by dust, temperature, and pressure fluctuations in the flue, and being able to achieve online calibration;

Using ultraviolet differential absorption technology to measure NOX, it has the advantages of measurement accuracy * not affected by moisture and dust (gas-phase water does not absorb in the ultraviolet band, while liquid-phase water and dust have no selectivity in absorbing ultraviolet light, belonging to slow spectral changes), low detection limit, and small temperature drift; There are no moving parts in the system, with high reliability and short response time.