IMPROVING THE EFFICIENCY OF COMPLEX HEAT RECOVERY SYSTEMS OF BOILER PLANTS
Abstract
The results of studies for heating boiler plants of the main thermal characteristics of complex heat recovery systems with deep cooling of flue gases of higher thermal efficiency are presented. Systems for heating various heat-transfer agents, which, in accordance with the needs of heating boiler houses, can be return heat-network water, cold water entering the chemical water-purification system (CWP), and combustion air are considered. Two effective variants of such complex systems have been developed. These options differ in the sequence of installation of heat recovery exchangers for heating combustion air and cold water for the chemical water-purification. In the first variant, the heat-recovery exchanger for heating air is placed after the heat-recovery exchanger for heating the heat-network water in front of the heat exchanger for heating water for the CWP, and in the second, on the contrary, after the latter. In order to protect the gas exhaust ducts from condensate formation, these systems provide for the joint application of two thermal methods: air and drying in the gas-heater. The thermal efficiency of the developed system options was investigated according to such indicators as efficiency and coefficient the use heat of fuel of boiler CUHF, heating capacity and condensate formed volume of the system in different modes of boiler operation during the heating period. Studies have shown that these systems provide a 6.8-8.3% increase in coefficient the use heat of fuel of boiler CUHF. At the same time, the total indicators of the considered heat recovery systems are approximately the same for the two options. The redistribution of the values of these indicators is carried out in separate heat-recovery exchangers. On the basis of the conducted studies, the choice of the most rational option of the complex heat recovery system with the placement of heat recovery exchangers according to the second of the considered options is substantiated. This technical solution allows the aggregation of two water-heating exchangers in one housing. This aggregation provides increased compactness of the heat-recovery equipment and reduction of heat losses from the surface of the connecting gas ducts and pipelines.
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14. Котельна установка: пат. 124125 Україна: МПК F22В 33/00, F22D 1/36, F24H 8/00, F23L 15/00. № 201910480; заявл. 21.10.19; опубл. 21.07.21, Бюл. № 29.
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