Research On District Heating System Planning Based On Demand-side Uncertainty

With the proposal of carbon peak and carbon neutralization goals,as well as the increasingly stringent requirements of environmental protection,the development of heat supply in the consumption of renewable energy to achieve low-carbon transformation has become a focus of attention.At the same time,due to the continuous improvement of living standards,users have higher requirements for the independent regulation of central heating.Traditional central heating systems do not consider the synergy between source and load well enough and often ignore the changes brought about by demand-side uncertainties,resulting in lower overall operational efficiency,higher carbon emissions and higher operating costs,which are not conducive to the future development of central heating.To this end,this paper integrates renewable energy into district heating systems and focuses on a planning approach based on multi-scenario technology for demand-side uncertainty.By comparing and analysing a variety of planning methods for system uncertainty,a planning method based on multi-scenario technology is proposed in conjunction with the characteristics of district heating systems.The implementation process of the method is mainly divided into the establishment of physical and mathematical models,the generation of energy consumption scenarios and the secondary planning of the system,where the mathematical model takes the minimum annual present value of total costs as the objective function and takes into account thermal constraints,equipment capacity constraints,equipment efficiency constraints and carbon emission indicators.Based on the basic information of district heating system planning and relevant design standards,geometric and physical models of each type of building in the district heating system were successively built using Open Studio and Energy Plus,and the influence of six uncertainties on the demand side on the heating energy consumption of each type of building was investigated through scenario analysis,and the results showed that indoor temperature and ventilation per unit area had the greatest influence.The abstract demand-side uncertainties were then concretised using Monte Carlo simulations to generate a variety of deterministic energy consumption scenarios,which were compared with those of the deterministic model.The results of the analysis show that the annual energy consumption values obtained from the Monte Carlo simulation fluctuate between-15.79% and 7.37% using the annual energy consumption values of the deterministic model as a benchmark,and the average energy consumption values are lower than the deterministic model energy consumption values.Finally,a secondary planning of the system was carried out.The first planning was based on the renewable energy sources that could be utilised in the planning area to develop different heat source configuration scenarios,and the optimal heat source configuration scenario was obtained by comparing the planning results under different scenarios.Using this scenario as a benchmark for the second planning,the planning results of the district heating system were obtained for different scenarios and the relationship between its total cost and carbon emissions and the reliability of the system was analysed.The results show that when the reliability of the system increases linearly,the increase in total system cost and carbon emissions is non-linear and there is a sudden increase in the inflection point.The planning results can provide a theoretical reference for the planning of district heating systems with integrated consideration of cost and carbon emissions.