Cooling - Thermal Management 1
Definitely not our best photo, but it has some character. Namely, it's a look under the transverse engine at folded down underbody panelling up front. Below in the picture you can see even the inside with small, air-filled
cubes for noise and heat insulation. The mat is, of course, completely smooth from the rear side.
But it's not about the front axle entirely rear but rather about the cooling front top. The oil sump is in-between, indeed from aluminum, but not because of cooling. On the contrary, it is also specially packaged before it is
finally covered completely with the mat..
Earlier was cooled, one keeps away the cooling today. The best example is the exhaust manifold in the cylinder head. The covering on top of the cylinder head has not only the task of noise insulation.
|Normal operation (90-105°C)|
The table is to emphasize once again how greatly the cylinder head is at the centre of the heating and no heat is dissipated before the has not reached at least 25°C. Unfortunately, one prioritises the occupants,
especially in luxury class models. Most an air conditioning with adjustable temperature is installed, which is also virtually unchanged then and asks heat early.
Amazingly enough, the transmission (usually automatic) follows then. So it's actually wrong, its heat exchanger to designate as a cooler only. Not until then the engine block and finally the engine oil is heated by its heat
exchanger. As a rule, it warms up still slower than the coolant already broadly used
All this is controlled by the engine management, either by disengageable mechanically driven and/or electric coolant pumps. In principle, no pump is working under 25°C at the cylinder head and subsequently only
partially supplying the interior or the transmission oil.
Nice to have another circuit for the low temperature, for example, for the cooling of the recirculated exhaust gases or charge air. The can be used then even more complicated, for faster heating. Recently may even be
restricted the inflow of eventual cooling air through the engine compartment.
So when we talk of heat exchangers, such can be used for heating or cooling. Incidentally, the on the transmission is possibly air-cooled additionally. To that belong temperature sensors which the controller makes
clear the respective need. Incidentally, particularly small sensors report temperature changes much faster than large ones.
The control of coolant flows is usual by valves which do not constrict the cross-section unnecessary. Such valves are still rather controlled by negative pressure as directly electrically. Thus, the engine control unit has
additional actuators. Of course, it is looking for contact to the transmission and comfort controller via the CAN bus.
Modern additives for coolant should not attack the many existing aluminum and contribute to favourable CO2 emissions. Because they require distilled water, we want to suggest its use in principle. In
addition to maintain a certain pressure (strictly observe manufacturer's instructions), one may suspect next to a leak also air in the system at its rapid drop. 09/15