Modelling space heating systems connected to district heating in case of electric power failure

Since district heating (DH) is the dominating heating system in Scandinavia, and fairly common in large parts  of Europe, it is of vital interest to study the possibility  for buildings connected to DH to receive heat during an electric power failure. Our studies have proved it possible to achieve natural circulation in space  heating systems indirectly connected to DH if the DH network operation can be maintained. Natural circulation in modern heating systems has been simulated. The model shows good resemblance with field studies. By using a model the influence of different parameters can be studied, e.g., a changed DH supply temperature and different outdoor conditions.