DETERMINATION OF DIFFERENT METHODS OF TRACTORS DIESEL ENGINE PRE-START PREPARATION AT ITS STARTING CHARACTERISTICS
The article presents the results of an experimental study of a tractor diesel engine 4CHN15/20,5, equipped with various pre-start preparations tools, starting characteristics in a climate chamber at low ambient temperatures. The purpose of the study is the determination of different methods of tractors diesel engine pre-start preparation at its starting characteristics. Engine was sequentially equipped with electric starter system, together with the liquid starting preheater, and starter engine, which exhaust gases were used for oil heating in the crankcase of a diesel engine. On the engine was installed hydrotransformer that allowed to reproduce the actual conditions of engine operation more accurately. The study found out that engine with liquid starting preheater always starts at ambient temperature not lower than minus 30 ° C, but the pre-start preparation time is longer than one hour. Long warm-up time leads to discharge of even fully charged and warm batteries, which limits the start of diesel engine at lower temperatures. The use of a heater only for heating the coolant with heated oil in the diesel fuel tray with the exhaust gases of the heater slightly increases the rate of heating of the oil, compared with the use of water-oil heat exchangers, and has practically no effect on the speed of heating the coolant. Using the starter engine with forced coolant circulation and exhaust gases outlet for heating the crankcase and oil pump, allows to start diesel with cold batteries at minus 40 ° C during 30 minutes, that corresponds to the requirements of existing regulations. Results of the study were used for the modernization of production and development of new "Uraltrac" tractor diesel engines models and can be recommended for implementation in diesel engine companies.