A novel demand-responsive control strategy for district heating systems, featuring return temperature reduction

Abstract

The paper presents a novel demand-responsive control strategy to be equipped centrally at the district level for district heating systems. The demand-responsive feature was maintained as to both the direct and the indirect substation configurations (by basing on their rating measures) in order to achieve lowest possible return temperature degrees from the end-user substations. Different than the traditional weather-compensation based supply temperature resetting, the new control strategy was formulated to adjust the supply temperature at the district level as to the cooling performance at the end-user substations. Two different simulations were carried out in order to quantify the benefits of the novel control strategy as compared to the traditional weather-compensation, equipped both at the substation level and the district level. The results obtained showed that the new control strategy, when considering the electricity loss at the heat production plant, shows superiority when compared to other control strategies.

Keywords

• District heating system
• Demand-responsive control
• Return temperature
• Improved cooling
• Low ∆T syndrome
• Weather-compensation