SIMULATION OF OPERATION OF THE AUTOMATED SYSTEM OF LOCAL MULTI-CIRCUIT COOLING OF PARTS OF AUTOTRACTOR DIESEL ENGINE

Abstract

The results present the intermediate stage of the study of the thermal state of individual heat-stressed parts and units of a forced tractor diesel engine in the conditions of their local air cooling (LAC), which is regulated in automatic mode. Possibilities of practical implementation on the basis of microprocessor control systems of multi-circuit local cooling of parts of valve exhaust unit, bearing unit of turbocharger, if necessary, additional air cooling of the upper part of cylinder blocks in the area of cylinder liners are considered and evaluated. The listed parts, as evidenced by the results of many engine tests, differing in the values of the maximum critical temperatures, which in turn depend on the course of heat exchange processes in the corresponding interfaces, nodes. At the same time, in the conditions of operation with the use of the LAC system on the diesel engine there are additional problems associated with the complication of the cooling control algorithm, the need to move to multi-circuit options with their critical temperature values and required cooling air costs. At this stage of the study, a test was performed in the test mode of the algorithm for supply control and shutdown of the coolant supply, the corresponding circuit solutions for its implementation. In the engineless experiment, previously specially designed and thermocoupled units were used, which were heated separately with the set test temperatures, as well as a series-produced unit, which is part of the 4th generation gas cylinder equipment (GCE) of modern engines. The unit consists of four sections with solenoid valves, which dose the gas supply to the injectors according to a given algorithm (Valtek type 30). At the input of the engineless experiment, this unit was used to turn on and off the supply of compressed cooling air in separate circuits (from 2 to 4). The moments of operation of the valves (opening-closing) corresponded to the set test temperatures. In addition to the dynamics of temperature changes at the control points of the research units during the cooling process, the pressure, temperature, and coolant flow rates on individual circuits were also monitored. The conducted engineless experiment confirmed the correctness of the adopted circuit solutions, and also proves the possibility of further application of serial GCE units in LAC systems.