An Extended Heating Regulation Schedule: Definition and Assessment of Its Efficiency in Heat-Supply Systems

Autor: A. A. Pyatin, D. M. Suvorov
Rok vydání: 2021
Předmět:
Zdroj: Thermal Engineering. 68:310-323
ISSN: 1555-6301
0040-6015
DOI: 10.1134/s0040601521040066
Popis: An extended heating regulation schedule with which the heat-transfer agent thermal potential is utilized to the maximum possible extent, the required indoor temperature in the heated rooms is maintained, and the energy expenditures for heat-transfer agent transportation are kept to a minimum is studied. A new equation of relative heating load at which the required indoor air temperature is maintained taking into account heat release and heat expenditures for infiltration is considered. A new heating regime regulation equation is used and verified, which takes into account the heating load, water flowrate supplied to the heating system, the system’s nominal capacity margin, the power exponents of the heat-transfer coefficient dependences on the temperature difference and water flowrate through the system, and other factors. With using the extended schedule, the return water temperature is decreased in the heating season’s main part down to 30–40°С provided that a sufficient heating system capacity margin is available. As a result, the heat-transfer agent is cooled to a fuller extent, its flowrate is decreased, smaller energy expenditures are required for driving the heat-supply source network pumps, a smaller amount of heat is lost in the network, and more efficient operation of the combined heat and power plant is achieved. For estimating the heat-supply system’s performance, it is proposed to use the heat-transfer agent’s thermal potential utilization factor. An assessment of the effects resulting from transition of the heating systems to the extended schedule, which was carried out on a model heat-supply system for a heating season, has shown that the heat-transfer agent’s thermal potential utilization factor determined taking into account the recurrence of one-degree outdoor air temperature interval increases from 58 to 83% with such a transition, the supply water flowrate decreases from 88 to 38% of its design value, the energy expenditures for driving the network pumps are decreased by a factor of three, and the amount of heat supplied from the heat-supply source is decreased by 12.5%, or by 10.0% with taking hot-water supply into account.
Databáze: OpenAIRE
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