Fault handling processes in district heating customer installations : Current and future solutions

Sammanfattning: When trying to integrate more fossil-free heat sources such as renewable energy and heatrecycled from other processes into the current district heating systems, problems occur due tothe high temperature levels in the systems. There are many reasons to why the temperaturelevels are high, but one frequently occurring issue is that the return temperatures of thecustomer installations are undesirably high due to faults in the substations or internal heatingsystems of the installations. This cause the return temperature of the entire district heatingsystem to increase. Therefore, it is of great importance to be able to identify the customerinstallations with high return temperatures and eliminate the faults that are causing the hightemperature levels.The focus of this thesis has been to investigate what fault handling processes are currentlybeing employed by district heating utilities to detect customer installations containing faults,and what could be done in addition to improve these. The first aim was to gather experiencesfrom the existing district heating systems about how the utilities are working with their cus-tomers to decrease the system temperatures, and what faults are currently the most commonones. The second aim of the thesis was to investigate if the customer data that is availablefrom the customers could be used to detect when and where a fault occurs. This was of interestsince the large amount of customer installations in the district heating systems makes it hardto manually survey the performance of all installations. Therefore, automatic fault detectionmethods are needed.The overall results show that the most important aspects of the faults handling process isto clearly involve the customer in the process and for the utilities to gain physical access to,and mandate to fix faults in, the customer installations. The results also show that the faultdetection methods developed in the thesis are able to detect installations containing faults andthat they may be a good addition to the already existing fault handling processes to simplifythe work at the utilities