Fuel Consumption Test Results for a Self-Adaptive, Maintenance-Free Wood Chipper Drive Control System

Abstract

Both energy consumption and the ecology of mobile wood-chipping machines are important issues in forest management. One way of improving the efficiency of wood-chippers is to use innovative design solutions in drive unit control systems. This can result in a reduction in fuel consumption and quantitative exhaust gas emissions. This article presented the results of research conducted on the fuel consumption of a cylindrical wood chipper driven by a small engine. We carried out testing of the unmodified chipper (A), made two different chipper modifications (B) and (C), and tested the modified versions to achieve the indicated results. The process allowed analysis and comparison of recorded data. For this purpose, the engine was supplied with fuel in three different ways: carburetor (factory-made) (A), the injector (B), and injector with an adaptative drive control system (designed by the authors) (C). The construction of a maintenance-free and adaptive drive control system where its functioning depended on operating conditions was done following patent application P.423369. All three fuel supply systems: A, B, and C were tested experimentally in terms of fuel consumption. The research was conducted in both set exploitation conditions (idle work with high (1) and low (2) rotational speed, with a continuous chipping process (3)) and transient exploitation conditions (4) (resulting from the delivery time of wood waste). Thus, the first stage of research involved two constructions (A, B) for three different working conditions (1-3). The second stage consisted of three constructions (A-C) tested in the fourth working conditions (4). The tests showed that the injection system reduced fuel consumption by around 61% during the continuous chipping process in comparison with the carburetor system. The adaptive drive control system (C) reduced fuel consumption by 55–74% in comparison with the carburetor system (A), and by 24–60% in comparison with the injection system (B) without an adaptive drive control system. The level of energy consumption in these systems depended directly on the ratio of idle work time during the chipping process.