The Challenge 0
Combined heat and power (CHP) units generate electricity and simultaneously
use the generated heat for heating. This achieves a total
efficiency of 90% and more. Every manufacturer wants to surpass his
competitor; Every extra percentage point is important. Thus, it is obvious
that also the engine driving the CHP-machine should be optimized.
Generally, modified standard engines are used for this purpose. In
these turbo charged engines the compressed charge air is cooled with
ambient air to the necessary engine inlet temperature. However, the
heat transfer that is transmitted to the cooling air cannot be used or can
be used only with great difficulty. This is different when water is used as
cooling media. The energy balance (when water cooled charge air cooler
is used) is thus improved by about 5 % of the engine power.
The Compact 72 from Airec can be used to solve this challenge. It is a highly efficient stainless steel heat exchanger designed for asymmetric heat transfer, such as air-to-liquid heat transfer. In this case, this means that relatively little compressed air is cooled with cold water in countercurrent flow arrangement. It is a big advantage that all connections are integrated in the exchanger, I e the two gas connections, two water connections and a condensate connection. The Compact 72 can be installed
easily and quickly, with minimum space requirement.
Tippkötter from Warendorf (Germany) manufactures CHPs from 30 to 2100 kW of electrical power. The stationary diesel engines for this purpose are supplied by various manufacturers, but without the usual air / air cooler. Instead of this, the engine is equipped with the Compact 72, adapted to the motor power, which cools the charge air to at least the required inlet gas temperature of 75°C.
The following example shows the high efficiency of the heat exchanger: