Weldon, “ Initial study of railplugs as an aid for cold starting of diesels,” SAE Paper No. Pfefferie, “ Diesel engine cold starting with catalytically ignited recirculated exhaust gas,” SAE Paper No. Intake air heaters, either electric, using a direct fuel flame burner, or catalytically ignited recirculated exhaust gas, can be used to provide the solution to the cold start problem. compiled a useful summary of starting aids and their utility in the modern diesel engine. Schmitz, “ Cold-start equipment for diesel direct-injection engines,” SAE Paper No. Ramírez-Hernández, “ Ignition and combustion development for high speed direct injection diesel engines under low temperature cold start conditions,” Fuel 90, 1556– 1566 (2011). There are some studies focused on the effect of glow plugs on cold start performance of diesel engines. Glow plugs affect the flow characteristics of air and fuel spray in the chamber. However, being heater in the combustion chamber causes some other problems after the engine starts. Glow plugs are electric heaters and they increase the temperature of air in the combustion chamber for about 2 or 3 s before the engine starts. To minimize the cold starting problems of this type of engines, glow plugs are commonly used in the combustion chamber. Durations of engine starting-cranking, cranking-idling, and idling-stabling were decreased due to the increase in the intake air temperature. Experimental results showed that the cold starting performance of the engine can be successfully improved by using vortex tubes.
Experiments were started when the ambient air and engine cooling fluid temperatures were at 0 ☌, which is a critical temperature for cold-starting diesel engines. Variation in the cold starting events was observed by both in cylinder pressure data and revolution of engine crank shaft. Pressured air was supplied to the vortex tube from the air tank of the compressed-air brake system of the truck. To increase the engine intake air temperature, hot exhaust of vortex tube was introduced to the engine intake manifold. In this study, a vortex tube was used to improve the cold start performance of a six cylinders, four stroke and direct injection diesel engine of a truck.
Cold and hot exhaust flows of vortex tubes can be used for different purposes. Vortex tubes use a compressed gas flow and separate it into low and high temperature regions without using any moving mechanical parts.