A temperature control strategy to achieve low-temperature district heating in North China

Low-temperature district heating (LTDH) systems can improve energy efficiency and better combine with factory waste heat and renewable energies. In this paper, we develop a data-based temperature control method to reduce the supply and return temperature of the heat exchange station. The relationship between distribution temperature and outdoor temperature is used to achieve lower supply temperature. The reduction of supply temperature is used to evaluate the benefit of the control strategy. Moreover, a return temperature prediction model is established to verify the feasibility of different control strategies proposed in our article. The comparison results of different control strategies indicate that the hourly average supply temperature can be reduced by more than 4°C whereas the return temperature keeps above 29°C at all times. To sum up, the supply temperature control strategy proposed in this paper provides a guide for the transformation of existing heat exchanger stations to low-temperature district heating systems in North China. © 2020, Aalborg University press. All rights reserved.