Two Papers on Engine Cooling First Paper: The Cooling of Diesel Engines by Water under Pressure
Water cooling in diesel engines is studied, with particular reference to the application of these engines in locomotives of high power. In this context, problems relating to weight, volume and radiator design become progressively more difficult to solve with the tendency towards increased unit powers. In the solution considered the water in the cooling system is put under a high static pressure, which makes it possible to raise the water temperatures above the usual levels. Resulting from this, the formation of steam bubbles is reduced or eliminated, ‘cavitation corrosion’ is reduced considerably, and cavitation in the water pump is prevented. Water consumption is markedly reduced. Standard equipment for locomotives is described. Cooling the supercharge air and the lubricating oil at relatively low temperatures is compatible with cooling the engine at a high temperature if two cooling circuits are used, with their radiators placed in series in the cooling air current. The case of cooling engines of high supercharge is examined; in these, the heat taken from the admission air and from the lubricating oil exceeds that taken from the engine. Future designs of heating and cooling systems for engines with very high supercharge are proposed.