PL EN Your account Create account

Registered articles list

Analysis of the use of engines in agricultural tractors used in transport

The progressive complication of the construction of modern agricultural tractors means that to integrate the operation of individual components, digital data buses are used, which on the one hand allow for vehicle control, and on the other hand are the basis of the on-board diagnostic system. This design allows for the ongoing evaluation of the tractor\'s technical condition, as well as the collection of operational data that can be analyzed on-line and off-line. The aim of the research was to analyze the operational data obtained from the diagnostic system of a farm tractor used in the transport system for harvesting biomass for silage or biogas. The tested object was a JD 7430 tractor with a power of 165 HP aggregated with a tandem trailer with a volume of 44 m3. The tests covered 7 years of vehicle operation, and the total time of tractor operation was 3579 hours of operation. During the tests, both the parameters of the engine and other vehicle components were recorded. When analyzing the work cycle of the tested tractor, empty runs, loading, transport of biomass and unloading at the storage site were distinguished. Moreover, the course of the engine rotational speed and the tractor driving speed as a function of time are presented. However, the driving speed did not fully reflect the variability of the engine loads, therefore the current engine load read from the on-board diagnostic system, which identifies the amount of fuel dose at a given rotational speed, was taken into account in the further analysis. In addition, the analysis took into account the internal resistances of the engine by subtracting the value of the current load for idling at each rotational speed, which made it possible to determine the percentage of engine load at a given rotational speed. When analyzing the obtained results, the entire range of engine rotational speed was divided into ranges, and the time of their occurrence was summed for individual loads. Moreover, the values of loads and rotational speed for each data group were averaged, and the obtained data made it possible to prepare a load profile of the engine used in biomass transport. The engine of the tested JD 7530 tractor worked over 30% of the time in the range of the lowest rotational speed at low loads. Within the nominal speed range, the engine was only running at 7%, at a load of 50 to 70%. Moreover, the engine operation in the area between the rotational speed of the maximum torque and the rotational speed of the maximum power was 50% with variable load. The tested vehicle was also characterized by a reduction of the engine load below 92%, regardless of the rotational speed. This limitation resulted mainly from the use of an automatic gearbox in the tractor, which allowed gear changes under load. On the other hand, the engine idling was associated with frequent stoppages while waiting for loading or unloading, which resulted from the technological process of harvesting and transporting biomass. Identification of the vehicle engine usage profile allows to minimize their negative impact on the natural environment. In addition, it allows you to select vehicle operating parameters, and thus reduce operating costs, and in some cases eliminate downtime. However, the information obtained from the user plays an important role in the comprehensive assessment of the vehicle\'s operational use, and the knowledge of the vehicle\'s use allows for drawing appropriate conclusions and making adjustments regarding the selection of optimal operating parameters.
Topic: Engine testing and modelling
Author: Paweł Krzaczek
Co-authors: Andrzej Bochniak