Heat Traps

As a thermosiphon heat trap or heat siphon refers to a pipe arrangement in the form of a descending and then ascending tube ( eg in the form of a U ) that restricts the convection within the hot water connection pipe of a hot water storage, thus reducing energy losses.

Operation

The solar thermal convection within the connected pipe or in the event even through - When heat registers, such as those used for heat storage for the provision of hot water or solar thermal systems, for example in central heating systems, occurs in less favorable pipe routing - for example, directly from the storage vertically upwards the collector connected to. With a pipe laying in the form of a siphon - ie a short downhill and then back upstream pipe can reduce these convection losses, therefore, such a tube assembly also thermosyphon heat siphon or heat trap is called.

For a connection without thermosyphon the warm water rises due to its lower density and cools down over the course of the entire connected tube, after which it flows back into the reservoir along the lower pipe wall. The zurückstömende in the tank colder water can also destroy stratification within the tank. In a thermosiphon design this circulation takes place only until the siphon, as the warm water does not follow the downward pipe. Convection losses are thus not switched off, but are limited to the ( short ) distance to the siphon. An even better design therefore represent tanks, in which the connections are directly made ​​a short distance downstream.

Swell

• Handouts Waermeverluste by tube internal countercurrent circulation of the Institute for Solar Technology SPF, Hochschule für Technik Rapperswil online ( Accessed on 19 April 2010, PDF, 1.5 MB)