This article may be of interest to researchers who are designing new machine systems for felling-area works with autonomous energy supply. A methodology based on the decomposition method for creating an simulation functional model of a system consisting of a mobile wood chipper for felling-area works and a mobile energy module is proposed. The machine system of interest is an original technical solution. It consists of an autonomous energy supply module with powered by wood fuel external combustion engine and a logging machine for the production of wood chips. The functioning equipment units of the system is simulated using the MATLAB Simulink dynamic simulation environment. For the convenience of experiments, the use of LabVIEW virtual instruments is proposed for setting input and control parameters, as well as displaying output parameters. The input, control, disturbing and output parameters of each functional block of the system are described: gas generator, external combustion engine, electric generator, uninterruptible power supply, electric motor, propulsion device, wood chipper unit, hydraulic manipulator. It is supposed to use this simulation model to justify the main parameters of the autonomous system for the production of wood chips, as well as the further development of an automated control system.

Keywords: fuel chips, wood fuel, unmerchantable tree, simulation model, LabVIEW, Simulink, mobile chipper, autonomous power supply, logging

It is proposed to use energy efficiency as a criterion for optimizing of wood fuel production when comparing different technologies with the help of simulation modeling. The results of the calculation of the specific consumption of energy resources per unit of produced fuel chips are considered under the processing technologies under consideration. The costs of energy resources are taken into account starting from the stage of harvesting of low quality fuel wood in the cutting area, ending with shipment of fuel chips to the consumer. The energy efficiency of the considered technological process for the production of fuel chips with the help of a system of machines consisting of an feller buncher, a mobile wood chipper and a chip transport machine accounted for 93.76% with a chip transport distance of 50 km, the energy intensity of the product was 7.949 tons of fuel equivalent for 1 thousand dense cubic meters of fuel chips. The offered technique allows to make the comparative estimation of power efficiency of various technologies of manufacture of fuel chips.

Keywords: fuel chips, production technique of wood fuel, optimization criterion, energy-output ratio, energy efficiency