Reduction of nitrogen oxides emissions from the B4 boiler at Chvaletice power plant

This project was implemented by our company “turnkey” for the customer, who was engineering Chvaletice Power Plant. The goal was to reduce NOxZ emissions by 260 mg/Nm^{! 3} to 190 mg/Nm^{! 3} when observing ammonia slip below 5mg/Nm^{! 3}. Due to the form of realization, we also had to make adjustments to the pressure unit of the boiler, namely the bulges for the location of the injection spears, which are located in the membrane wall of the boiler. The main challenge in this project was the high temperature in the combustion chamber, which was not within the ideal range of 970 - 1050°C, which is needed for proper operation of SNCR technology. Therefore, it was necessary to equip the injection spear with the so-called SCL (selective cooling level) cooling floor system. In principle, it is a local reduction of the temperature in the combustion chamber by an injection of water placed just below the urea injection to achieve the ideal temperature for NOx reduction. If the BySCL technology was not installed, the NOx reduction alone would not reach the required values, since at a higher temperature the urea itself would not react with NOx emissions and thus the desired reduction would not occur.