Cooling System Heater
|Especially economic engines do not supply sufficient heat|
Modern diesel direct fuel injection engines are so efficient that they may be unable or too slow to transmit enough heat to the coolant to supply the interior with heat according to demand. In order to keep the interior
comfort steady, there are electrical (picture 1 - 3) or exhaust gas heating (picture 4) solutions to add the missing heat. It is also important that the engine does not fall short of its operating temperature due to too
intensive heating use. A closed thermostat valve does not guarantee sufficient protection for the engine against it.
|Warming up the coolant electrically or the air directly|
The pictures show three different possibilities how to generate additional heating for the interior, starting from the relatively simple warming of the coolant by three (or more) glow pins, auxiliary heaters, up to the
somewhat extraordinary exhaust gas heat exchanger. Initially, they make use of a high current, thus the systems must have suitable fuses and cable cross sections. However, due to the PTC-like characteristics it
does not last for long. The system displayed in picture 1 can be switched on only when the engine is running; the others can also be operated without engine.
|Exhaust gas warming almost for free|
In terms of energy saving, the system displayed in picture 4 is most interesting. The coolant is heated in the exhaust gas pipe according to the counter-flow process. If a certain temperature is exceeded, the exhaust
gas stream can be diverted by a pneumatically operated flap. This construction is not completely free of charge, though, it causes some additional weight, and exactly the engines with little fuel consumption often also
have especially low exhaust gas temperatures.