Fault Analysis for Low-Speed Heavy-Duty Crane Slewing Bearing Based on Wavelet Energy Spectrum Coefficient

2017 ◽  
pp. 63-74
Author(s):  
Yang Jiao ◽  
Guanghai Li ◽  
Zhanwen Wu ◽  
Huipo Geng ◽  
Jian Zhang ◽  
...  
Keyword(s):  
Energy Spectrum ◽  
Fault Analysis ◽  
Heavy Duty ◽  
Low Speed ◽  
Slewing Bearing ◽  
Wavelet Energy

scholarly journals Effects of multiple injections on combustion and emissions in a heavy-duty diesel engine at high load and low speed

2020 ◽  
Vol 12 (12) ◽  
pp. 168781402098462
Author(s):  
Yingying Lu ◽  
Yize Liu
Keyword(s):  
Diesel Engine ◽  
Single Injection ◽  
High Load ◽  
Post Injection ◽  
Heavy Duty ◽  
Low Speed ◽  
Multiple Injections ◽  
Heavy Duty Diesel Engine ◽  
Main Injection ◽  
Heavy Duty Diesel

Advanced multiple injection strategies have been suggested for compression ignition engines in order to meet the increasingly stringent emission regulations. Experiments and simulations were used to study effects of the main-injection mode (times), the post-injection proportion, and timing on combustion and emissions in a heavy-duty diesel engine at high load and constant low speed. The results reveal the following. The NOx emissions of 1main+1post, 2main+1post, and 3main+1post injections are all lower than those of single injection; the higher the number of main-injection pluses, the lower the NOx emissions. Enough main-post injection interval is needed to ensure post and main injections are relatively independent to entrain more fresh air to decrease the soot. Over-retarded post-injection timing tends to increase the soot due to the lower in-cylinder temperature. The combined effects of formation and oxidation determine the final soot. To gain the best trade-off of NOx and soot, compared with single injection, for the three multiple injections, the lowest soot emissions are gained at post-injection proportions of 15% and post-injection timings of 25°, 30°, and 35° CA ATDC, with soot reductions of 26.7%, −34.5%, and −112.8%, and NOx reductions of 5.88%, 21.2%, and 40.3%, respectively, for 1main+1post, 2main+1post, and 3main+1post injections.

Identification of Lightning Strike and Short-Circuit Fault Based on Wavelet Energy Spectrum and Transient Waveform Characteristics

2014 ◽  
Vol 596 ◽  
pp. 713-718
Author(s):  
Yan Feng Gao ◽  
Yong Li Zhu ◽  
Hong Yan Yan ◽  
Hong Wei Yan
Keyword(s):  
Energy Spectrum ◽  
Energy Distribution ◽  
Traveling Waves ◽  
Traveling Wave ◽  
Short Circuit ◽  
Lightning Strike ◽  
Transient Signals ◽  
Wavelet Energy ◽  
Simulation Results ◽  
Short Circuit Fault

The transient traveling waves generated by linghting can be used to linghting location, in order to improve fault identifiaction ability of current traveling wave location device, an identification method of lightning strike and short circuit fault based wavelet energy spctrum and transient waveform characteristics was presented in this paper. Through researched the current signals generated by non-fault lightning strike, fault lightning strike and short-circuit fault on 220kV transmission line, compared of the energy distribution of different transient signals in each prequence band, realized the identification of lightning strike and short-circuit fault; for lightning identification, by waveform characteristics calculated obtaining eigenvalue to identify the non-fault and fault linghtning. PSCAD/EMTDC simulation results identicate that the proposed method is correct and effective.

Predictive Indoor Wheel Testing of Heavy Duty Truck Tires

1987 ◽  
Vol 15 (1) ◽  
pp. 58-67
Author(s):  
R. L. Keefe
Keyword(s):  
Load Transfer ◽  
High Stress ◽  
High Load ◽  
Heavy Duty ◽  
Low Speed ◽  
Service Failures ◽  
Heavy Duty Truck ◽  
Truck Tire ◽  
Truck Tires ◽  
Load Tests

Abstract An indoor wheel test for heavy duty truck tires has been developed to predict in-service failures of commercial and developmental tires. The test, run at slow speed and high load to emphasize stress and fatigue rather than heat, is based on the premise that repeated high stress is the principal cause of in-service tire failure. These stresses occur when dynamic or transient overloads are caused by road bumps, load transfer during braking and cornering, or dual tire configuration on non-uniform surfaces. Although these overloads may occur infrequently, they can become very significant in the long distances run by truck tires. Other current heavy duty truck tire tests are generally run at higher speeds, emphasizing heat resistance of rubber compounds, or else are low-speed, much-overloaded bead tests which are unrealistically severe. Since its development in 1974 the present test has been broadly predictive for many belt, carcass, or fatigue related in-service failures of both bias and radial commercial and developmental truck tires. The test is called “The DuPont High Load Wheel Test” to distinguish it from other low-speed-high-load tests.

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