Abstract
Hydraulic oil degrades expediently during operating at elevated temperatures, and due to oil degradation, malfunction of all hydraulic components starts that hampers the hydraulic functioning of the machine. An inefficient component of the hydraulic system converts useful energy into heat. Overheating starts when the rate of heat energy escaping from the system overcomes the rate of heat dissipation. Viscosity, total acidic number (TAN), rheology, and FTIR analyses were carried out on the oil samples collected chronically, and the reasons for degradation and sludge formation were evaluated; the results showed that thermal cracking resistance capacity of the oil was low due to the imbalance percentage of additives in the base oil. Sludge impaired the system efficiency and prejudicially creates repercussions on power consumption. Sludge can be recycled for biofuel and to avoid imbalance in the ecosystem. The test result is plotted in a 3D view graph using the MATLAB R 2019 software for a better explanation. Variation in the behaviour of the hydraulic fluid with respect to time, temperature, shear stress, and shear rate was studied, and the result is validated with correlation and regression analyses.
Highlights
LHD 811MK V is a DGMS-approved electrohydraulically operated machine used in underground mines for loading coal from coal faces, hauling, and discharging coal at the discharge point. e volume of the push plate bucket is 1.5 m3, and it can haul 1.5 tons of coal
Fourier Transform Infrared (FTIR) analysis showed that oxidation takes place at elevated temperatures, and the by-products of oxidation are gummy and sticky compounds. e oil mainly consists of hydrocarbons, which react with oxygen during the oxidation process
Conclusions and Recommendations e cynosure of this experimental study elucidates the rate of degradation of hydraulic oil accrued expeditiously when a machine is running continuously at elevated temperature range, i.e., 70°C to 80°C, and formed varnish or sludge
Summary
LHD 811MK V is a DGMS-approved electrohydraulically operated machine used in underground mines for loading coal from coal faces, hauling, and discharging coal at the discharge point. e volume of the push plate bucket is 1.5 m3, and it can haul 1.5 tons of coal. Critical analyses were performed on chemical changes that occurred at elevated temperatures in a particular batch of hydraulic fluids, which affected the physical performance of the hydraulic components of the LHD. Tribology of hydraulic fluids are drastically affected by thermal degradation, and overall performance of the machine is affected considerably. If the viscosity of the oil goes beyond the limits of the recommended range (i.e., TOW), the performance of hydraulic components is drastically affected. E polymerization of hydraulic oil is caused by thermal degradation due to continuous running at elevated temperatures [4]. Fire-resistant hydraulic fluid HFDU-68, Viscosity Grade VG-68, 240 litres, is used in the LHD working underground coal mines where fire risk is more. Heredia-Cancino et al [15] studied the effects of elevated temperature degradation of engine oil on tribological performance.
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call