Modeling gas consumption in a local boiler room producing heat for a residential building

Abstract

The article presents an original mathematical model for forecasting gas consumption in multi-family buildings equipped with local gas boiler rooms. The developed model integrates the analysis of heat demand for central heating and domestic hot water preparation, taking into account actual outdoor temperature variability, daily water consumption profiles, boiler operating characteristics, and heating system parameters. The paper describes equations defining the supply temperature based on heating curves, cyclic operation of the burner and circulation pumps, and the process of mixing water in storage heaters. The model was validated based on operational data obtained from a residential building in Wrocław, achieving high consistency between the simulation results and hourly and monthly measurements. Simulations showed that the maximum hourly consumption of hot water was 420 dm³, which corresponded to the use of over 30% of the capacity of the heaters used. When the design outdoor air temperature was below zero, it was necessary to use almost the full available power of the boilers, and the share of power allocated to hot water preparation accounted for approximately 25% of the instantaneous heating power required for central heating purposes. The analyzed facility also justified the use of unit heat demand indicators: 57 W/m² for central heating and 45 dm³/(person·day) for hot water. These results confirm the high usefulness of the model for forecasting gas consumption in residential buildings.