Evaluation of the combine thresher efficiency by grain losses under operating conditions
Authors: Chaplygin Mikhail , Zhalnin Eduard Viktorovich , Aldoshin Nikolay Vasilyevich 
Published: December 2024

BACKGROUND: The throughput capacity of the thresher of the combine is determined with permissible grain losses of 1.5% of its total amount collected in the combine bunker. The range of feeding of bread mass, for example, from a minimum of 0.5-1.0 kg/s to – is called the working characteristic of the threshing machine (WCT) of the combine harvester. The actual grain loss in the considered feed range is less than 1.5%, but their overall digital estimate is unknown. Nevertheless, this is the most important indicator of the miner's efficiency, since these losses are summed up (for example, at the level of 1-1.2%) and can reach a significant value, therefore, the assessment of the miner only in terms of throughput is insufficient to assess its efficiency, since the miner rarely works at the throughput level, and in WCT mode, grain losses are summed up every second/
AIMS operation consists in development of criterion for evaluation of combine thresher operation efficiency by grain losses at operating modes.
METHODS: The article proposes a new methodology for assessing the efficiency of the combine. Statistical dependences of grain losses change depending on change of bread mass supply into combine are used. The throughput capacity of the combine thresher in kg/s is determined with grain losses behind the thresher at the level of 1.5%.
RESULTS: Numerous laboratory-field tests have revealed a close correlation between the four threshing parameters (engine power and separation area of ​ ​ the hump, straw and cleaning, and the dynamics of grain loss growth depending on the feed of bread mass with great reliability in the range of WCT feeds is approximated by a logistic dependence. For practical calculations, computer software has been developed. This makes it possible to more quickly compare harvesters of different designs with each other.
CONCLUSION: For the first time, to assess the efficiency of the combine thresher, a new criterion is introduced with the name "average integral operational losses of grain behind the thresher in the working range of bread mass supply"; An increase in grain losses behind the thresher was detected with an increase in the throughput of the combine; The optimal harvesting area is determined, during harvesting of which the growth of grain losses is compensated during the operating mode of combines of high productivity per unit of bread mass supply. The optimum harvesting area depends to a greater extent on the throughput of the harvester and harvesting conditions according to the state of the agrofon and the zoning coefficient, that is, the degree of adaptation of the harvesters to the zonal features of the agrofon and the applied machine use methods; When calculating the economic efficiency of combines, it is advisable to take into account the average integral operational losses of grain for alternative versions of combines and, on this basis, give them a more comprehensive assessment. The use of the logistic function of grain losses from the supply of bread mass to the combine and, on its basis, the introduction of the criterion of average integral operational losses of grain behind the thresher of the combine represents scientific and practical novelty.