DEVELOPMENT OF SUBMERGED COMBUSTION-BASED SYSTEM FOR HEAT SUPPLY OF PRODUCTION PREMISES

摘要

Local decentralized heat supply of industrial premises has a numerous advantages in comparison with district central one. An effective installation of this purpose is developed, tested both by computations and by experiments for case of submerged combustor (SCA) as a basic unit of heat supply plant (SCA-HSP). Some type-sizes of the SCA of various heat capacities are developed and designed. Heat and mass transfer processes could be highly intensified in contact liquid-gas system, particularly at SCA, that prove an assumption of saturation state of combustion products/ water vapor mixture as an available principle to obtain additional process advantages, on the one hand, and to compute main and recovery contact units, on the other hand.. Thermodynamical calculations are carried out to compute power efficiency, water preheat temperature and thermal capacity of the SCA-HSP plant in dependence on the system design and operational parameters. The methods to achieve of SCA-HSP plant power efficiency higher than 100% in respect to low heat value of fuel due to use of latent heat of vapor condensation are discussed. The system based upon SCA with no supplementary units provides 100% efficiency only by water preheating temperature lower than dew point t_d. The higher is the projected temperature in the water heat-supply network the deeper should be heat recovery to ensure 100% and more power efficiency. The methods and the plants intended to combine submerged combustion unit with waste heat recovery facilities first of all being of contact type make an appropriate choice. Some methods of approach to power efficiency increase basing upon combustion air preliminary preparation by heating and humidification along with heat treatment of water flow are considered and compared. The "vapor pump" facility is used to preheat and to humidify the combustion air and it seems to be the most efficient recovery system. The heating plant of SCA being equipped with heat recovery mass exchanger is implemented at the industrial enterprise of stringent ambient temperature requirements for heating the production premises.