Heat losses from buried district heating pipes

Deals with heat losses from buried district heating pipes with specific interest in the transient behaviour. Theory of heat loss from district heating pipes is reviewed, and special equations intended for in-situ determination of heat losses from district heating systems in operation are derived. It has been emphasized to make methods and instrumentation so simple that the methods can easily be applied in practice. Some of the methods are based on steady state theory, others on line source theory - or both - and these assumptions have been tested by numerical methods and measurement data.