The Impact of Thermal Energy Storage on the Emission of Particulate Pollutants into the Atmosphere

To improve the energy, operational, and ecological efficiency of a district heating system (DHS) powered by a combined heat and power (CHP) plant or a heating plant, thermal energy storage (TES) should be used. The presented paper examines the impact of the use and operation of TES built in a CHP plant supplying a large DHS, based on the amount of particulates emitted into the atmosphere. Detailed research was carried out for the Siekierki–Warsaw and Białystok CHP plants in Poland. The analysis helped to determine the factors affecting the reduction in pollutant emissions and the volume of the energy effect of using TES in the CHP plant. In order to objectify the results of the comparative analysis of the impact of TES in the CHP plant on the emission of particulates, the so-called comparative index (CI) was introduced. The CI takes into account the volume of electricity and heat production and climatic conditions in the analyzed time periods. The CI for the analyzed years should have a similar value so that the results of the comparative analysis are fully representative. This condition is met for the CHP plant and DHS of Białystok, so the detailed results of the analysis are presented for this facility. As a result of the application of TES in the Białystok CHP plant, significant environmental effects related to the reduction in particulate emissions have been achieved; for example, the total amount of annual particulate matter (PM) emission (PM 10 and PM 2.5 ) has been reduced by 27% and the maximum emission by 29%. On the other hand, the average decrease in particulate emissions in the heating season varied in the range of 10–50%, while in the summer season, the values of particulate emissions were at a comparable level. A significant decrease in annual and one-hour average concentrations for PM 10 and PM 2.5 and particulate fallout for these two analyzed years was also found. The use of TES to reduce the occurrence and nuisance of the smog phenomenon, the main components of which are PM, is proposed, and selected models of forecasting concentrations of pollutants in the air, including particulate emissions, are presented in order to implement this type of activity.