THE ROLE OF ENERGY SOURCES OF DIFFERENT TYPES IN ATMOSPHERIC POLLUTION AND HEAT SUPPLY OPTIONS IN IRKUTSK CITY

摘要

The structure of energy (heat) sources making up the heating system of Irkutsk city is typical of old Siberian cities, which became industrial centres in the XX century. The high fraction of small-capacity sources, including large number of household stoves is peculiar for such cities. The installed capacity of stoves is 30% of the overall, while their fuel consumption is 8.5% only. 76% of boiler houses have unit capacity less than 5 MW; they use mostly fixed-bed combustion. One more feature of Irkutsk heating system is the large fraction of coal in the fuel balance: in Irkutsk it comprises 80%, while in the European Russia natural gas constitutes the major fraction. According to the existing practice the emission factors of heat sources are determined mostly using computational technique and for the small sources they are often considerably underestimated. In order to reveal the actual emission factors of small heat sources we performed a series of measurements at operated boilers and stoves (Table 1). In order to disclose the most important factors causing the deviation of actual emission factors from the designed values we carried out a series of comparative combustion of a number of Siberian coals under a wide range of combustion conditions (Filippov S.P. et al, 1999). It was shown that the proper operation of boilers and stoves can result in an appreciable decrease in emissions of products of incomplete burning like CO, soot, and PAH. The study of sulphurous substances emission is complicated by high variability of their composition. The fraction of initial coal sulphur emitted in the form of SO_2 varies from 30 to 85% depending on the quality of burning operation.