Integrated control strategy of district heating system based on load forecasting and indoor temperature measurement

Abstract

District heating system (DHS) plays an important role in attaining sustainable energy systems, which can conveniently provide energy-efficient space heating. At present, it is common that heat source and stations are operated and regulated separately by different owners. Their own technicians adjust the operation parameters empirically with fine-tune according to users’ complaint. This kind of isolated and extensive regulation often results in imbalance of supply and demand featuring in large indoor temperature fluctuation and waste of energy. In order to tackle this problem, this paper proposes an integrated control strategy based on load forecasting and correction according to indoor temperature measurement. Firstly, regulation period and regulation time nodes of heat source and stations are determined. Then, water supply temperature of heat source and heat stations are predicted respectively. The predicted water supply temperature of heat stations is corrected by the measured average indoor temperature under their own heating zone, while the overall average is used to correct the predicted water supply temperature of the heat source. Field study in a realistic DHS project shows that the proposed method effectively improved the users’ thermal comfort reducing indoor temperature non-uniformity coefficient from 0.0310 to 0.0196. Hydraulic instability index reduced from 0.63 to 0.19 which means pipe network pressure fluctuation is mitigated. An energy saving rate about 6.75% was yield which is quite considerable.

Keywords

• District heating
• Supply demand balance
• Regulation period
• Heating load prediction
• Regulation time node