Features of the operation of boiler equipment at minimum loads

Abstract

At industrial enterprises built in the former USSR, the capacity of the installed boiler equipment was determined based on the projected growth of heat loads. Due to the decline in production capacity of enterprises, the consumption of thermal energy is also reduced, and there is a problem of prolonged operation of steam and hot water boilers at minimum loads. The operational personnel of different enterprises solve this problem in practice in their own way, without being aware of the possible consequences of these regimes, which are not provided for by the manufacturers. The article analyses the risks of boiler transfer to one burner associated with the occurrence of condensate, which leads to the destruction of the exhaust duct and chimney. At operation on high-sulphur fuel oil at minimum loads conditions are created for formation of sulphuric acid in flue gases and flow of sulphuric acid corrosion of tail surfaces of boiler heating. The examples of boilers ПТВМ-50 and ДЕ-25-14 show that as heat load decreases heat loss increases and boiler efficiency decreases. It is noted that the nature of the change in heat loss depends on the design of the boiler. Recommendations on modernization of boilers operating at minimum loads are given. It is stated that the final decision on the possibility of operation of boilers with loads below those permitted by manufacturers can be made only after special tests with control of circulation of steam-water mixture in heating surface circuits. The article draws conclusions based on the results of research of real equipment of the Kirov region.