Преимущества импульсного подвода тепла для покрытия переменных нагрузок в системах теплоснабжения

Abstract

Practical applications of previously obtained theoretical results on the use of pulsed (cyclic) heat supply from a heat source (boiler) operating on a heating network to cover substantially variable loads of a heat supply system are considered. The analysis of the efficiency of a heat supply system with various blocks of boiler plants and the parameters of heat supply systems at variable loads is carried out based on the analysis of the developed mathematical dynamic model of the heat production and distribution system. The obtained engineering theory also served as the basis for the development of system optimization algorithms for the stepwise regulation of heat supply by heat sources by switching them to idle speed, including a deep reduction in the load, or with their complete shutdown, at variable modes of the boiler room while covering uneven schedules of its loads. At the same time, the costs of consumed thermal energy were estimated in order to increase economic efficiency and select a certain composition of the boiler equipment in the proposed modes. Depending on the capacity of the heating network and / or heat storage devices, the values of heat consumption and regulation modes, rational layout of boiler equipment with minimization of energy consumption are determined. The effective values of the duration of the heat supply pulses by the boiler units and the pause between pulses, as well as the duty cycle of the pulses using various blocks of boiler equipment, are estimated. An important characteristic of the reliability of the heat supply system is the frequency of cycles that limit the number of regulated starts of boilers of the corresponding capacity due to the presence of fatigue stresses in them. The significant influence of the listed factors and the specified functional parameters on the characteristics of the pulsed connection of heat sources and the intensity of the energy supply at variable loads is shown. It is characteristic that when comparing different modes of pulsed supply (with and without idle), the more preferable mode is the mode with the heat sources completely disconnected from the heating network. At the same time, efficiency increases with the number of operating units and reaches 10% compared to the traditional method of supplying heat to cover the variable loads of heating networks. The results obtained can also be useful for solving optimization problems when operating an individual boiler house in variable modes when covering it with various ones, including annual, load schedules. This approach and the presented solutions can be extended to any other sources of heat, using both liquid and gas (steam) as a working medium, to cover the uneven corresponding thermal loads.