Study on optimal distribution of heating load based on the first law of thermodynamics

Abstract

The principle of external heat supply for cogeneration units is to meet the maximum heat load demand of the heating network, and the heat load of the heating network will vary significantly with the climate and solar light intensity. The heat supply system of extraction steam unit with high back pressure heating unit is taken as the research object to study the influence of heat load peak and valley change on the economy of cogeneration units. The energy consumption and operation economy of the cogeneration unit are analyzed by the heat consumption theory and the standard coal consumption of generating and heating income standard. The results show that the heat consumption of cogeneration units is reduced by 411.62 kJ(kW·h)−1 during the peak heat load in the extreme cold period than the low heat load in the end of the heat supply. The standard coal consumption per yuan income of the generation and heating is increased by 15 g.RMB−1. The daily gross income of generating and heating is reduced by about 47196 RMB per day for 12 hours of heat load. The cogeneration unit should use the return network temperature of the heat network as the basis for the change of the peak and valley of the heat network load when adjusting the external heating parameters and the operation mode of the unit.