Diskussion von verschiedenen Einflussfaktoren auf die Verfügbarkeit von Fernwärmesystemen

The purpose of this report is to deal with the various factors influencing the availability of district heat, and thus draw conclusions for the further operation and extension as well as the maintenance of existing district heating systems. Because the availability of a district heating system as abosolute value hardly allows a comparison with other systems, new references figures were specifically set up. In the specific availability per length unit, the simplication is made of considering the entire district heating system as a pure series circuit. Using this reference figure the nominal width with the worst availability is defined, under the consideration that detailed surveys including diagnosis must follow, to provide information on potential causes of damage. Furthermore additional surveys must be made on certain dependencies of the availability reference figure and such figures as pipeline or network length, number of incidences occurring in district heating systems, period of survey or total downtime. Also the dependence of the number of fittings per length unit and nominal width is analyzed with the goal of obtaining a characteristic network reference figure which allows a comparison in view of the state of fittings of the district heating system. The practicability is explained using examples