Thermosiphon cooling
The thermosiphon is a cooling system primarily in connection with internal combustion engines is used. It is a closed water cooling system without a water pump. The circulation of the cooling medium (cooling water) is based on natural convection , i.e. the density differences caused by thermal expansion . Because of its lower relative density , the warmer medium rises and the colder sinks.
The term is derived from the thermosiphon effect.
function
The cooling water is heated in the engine block and thus rises upwards in the engine block and then further through the upper connection of the motor, the flow line and the upper connection of the cooler ( heat exchanger ) into the cooler. There it is cooled down and therefore heavier, sinks through the lower connection of the cooler, the return line and the lower connection of the motor back into the engine block and the entire process is repeated.
Advantages and disadvantages
The advantage of the thermosiphon cooling is the simple construction without a water pump, which is why it was often used in tractors and military vehicles in the past. The disadvantages are, on the one hand, that the cooling water circulates slowly without a pump and therefore comparatively large cross-sections are required for the cooling channels in the engine, the lines and the radiator for a sufficient cooling effect. The amount of cooling water is correspondingly large. On the other hand, the function of the gravity drive places special conditions on the individual components: the cooler must be arranged higher than the motor, there must be a connection at the top and bottom of the cooler and motor and the line must not be laid with vertical bends. The engine output that can be cooled is - at least because of the installation size in motor vehicles - smaller than with today's cooling systems. This cooling is not always operationally reliable, since the automatic water circulation is not sufficient, especially at low speeds.
use
Thermosiphon cooling is no longer found in current motor vehicles . It was quite common in automotive engineering until the 1950s. Cars with thermosiphon cooling included the Goliath GP 700, the IFA F8 and the AWZ P70 . These vehicles even managed without a fan. With a fan, this cooling was used in the IFA F9 and early models of the Wartburg 311 as well as various DKW models. In the case of small vans , the Framo V 901/2 and the Goliath Goli should be mentioned (both with fan wheel). Two- wheelers with thermosiphon cooling were also built, such as the Zündapp KS 50 watercooled or the Silk 700 .
Application example
- Small car IFA F8 Cabrio of the automotive industry association .
literature
- Peter A. Wellers, Hermann Strobel, Erich Auch-Schwelk: Vehicle technology expertise. 5th edition. Holland + Josenhans, Stuttgart 1997, ISBN 3-7782-3520-6
- Max Bohner, Richard Fischer, Rolf Gscheidle: Expertise in automotive technology. 27th edition. Verlag Europa-Lehrmittel, Haan-Gruiten 2001, ISBN 3-8085-2067-1
Web links
Individual evidence
- ↑ ommma.net ( Memento of the original from September 16, 2008 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
