scholarly journals Start up Failure Analysis and Treatment Measure of Circulating Air Compressor

2016 ◽  
Vol 06 (06) ◽  
pp. 129-133
Author(s):  
志宝 殷
Keyword(s):  
Failure Analysis ◽  
Air Compressor ◽  
Start Up ◽  
Treatment Measure

scholarly journals Experimental investigation on the extreme cold start-up of an air compressor for electric heavy vehicles

2019 ◽  
Vol 604 ◽  
pp. 012065
Author(s):  
Gianluca Valenti ◽  
Stefano Murgia ◽  
Ida Costanzo ◽  
Antonino Ravidà ◽  
Giovanni Pio Piscopiello
Keyword(s):  
Experimental Investigation ◽  
Cold Start ◽  
Heavy Vehicles ◽  
Air Compressor ◽  
Start Up ◽  
Extreme Cold

Metallurgical Failure Analysis of Cracking in Exhaust Stack Liner Fastening Bolts

2021 ◽  
Vol 58 (10) ◽  
pp. 662-671
Author(s):  
A. Neidel ◽  
M. Giller ◽  
S. Riesenbeck
Keyword(s):  
Failure Analysis ◽  
Gas Turbine ◽  
Shear Loading ◽  
Mean Stress ◽  
Test Rig ◽  
Exhaust Gases ◽  
Start Up

Abstract Exhaust stack liners of a test rig for gas turbine burners failed locally by ruptured fasteners and fallen-off liner plates. Misalignment of the plating relative to each other and relative to their fasteners caused restraint of the expanding and shrinking liner plates upon start-up and shutdown of the burner rig. The fastening holes of the failed liner plates were not concentric, but misaligned relative to each other and relative to their fastener bolts. This exerted a shear loading on the threads of the fastening bolts, which in turn caused a mean stress shift and damaged the threads of the fasteners by nicking. So pre-loaded, the fastening bolts were not able to withstand the vibratory loads from the flowing exhaust gases and failed due to fatigue.

scholarly journals Failure analysis of structural screw joint in a start-up neutron detector handling mechanism

2019 ◽  
Vol 14 ◽  
pp. 688-695 ◽  
Author(s):  
Sudheer Patri ◽  
Hemant Kumar ◽  
K. Krishna Prasad ◽  
C. Meikandamurthy ◽  
B.K. Sreedhar ◽  
...  
Keyword(s):  
Failure Analysis ◽  
Neutron Detector ◽  
Start Up ◽  
Screw Joint ◽  
Handling Mechanism

scholarly journals Experimental Determination of the Performances during the Cold Start-Up of an Air Compressor Unit for Electric and Electrified Heavy-Duty Vehicles

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3664
Author(s):  
Gianluca Valenti ◽  
Stefano Murgia ◽  
Ida Costanzo ◽  
Matteo Scarnera ◽  
Francesco Battistella
Keyword(s):  
Volume Flow Rate ◽  
Cold Start ◽  
Input Power ◽  
Compressed Air ◽  
Compressor Unit ◽  
Heavy Duty ◽  
Air Compressor ◽  
Start Up ◽  
Heavy Duty Vehicle ◽  
Heavy Duty Vehicles

Compressed air is crucial on an electric or electrified heavy-duty vehicle. The objective of this work was to experimentally determine the performance parameters of the first prototype of an electric-driven sliding-vane air compressor, specifically designed for electric and electrified heavy-duty vehicles, during the transient conditions of cold start-ups. The transient was analyzed for different thermostatic temperatures: 0 °C, −10 °C, −20 °C, and −30 °C. The air compressor unit was placed in a climatic chamber and connected to the electric grid, the water-cooling loop, and the compressed air measuring and controlling rig. The required start-up time was greater the lower the thermostatic temperature, ranging from 30 min at 0 °C to 221 min at −30 °C and depending largely on the volume of the lubricant oil filled initially. The volume flow rate of the compressed air was lower than nominal at the beginning, but it showed a step increase well beyond nominal when the oil reached 50 °C and then decreased gently towards nominal, while the input power kept steady at nominal after a short initial peak. These facts must be considered when estimating the time and the energy required by the air compressor unit to fill up the compressed air tanks of the vehicles.

Thermal Shock Failure Analysis and Remediation Design of an Internal Catalyst Structure

2002 ◽  
Author(s):  
John E. Camburn ◽  
Kenneth L. Saunders
Keyword(s):  
Thermal Stress ◽  
Failure Analysis ◽  
Thermal Loading ◽  
Seismic Analysis ◽  
Rapid Heating ◽  
Catalyst Structure ◽  
Design Changes ◽  
Start Up ◽  
Remediation Design ◽  
Leading Edges

The catalyst structures of interest are internals for four identical cogeneration units which together produce about one half million kilograms per hour of steam for an adjacent refinery and 385 megawatts of electricity. They are structural steel frames made of 304SS with approximate dimensions of 42 feet high by 38 feet wide by 8 feet deep. During start up of the heat recovery steam generator (HRSG) units, hot combustion gases from the gas turbine exhaust flow through the HRSG units producing rapid heating of the interior components. However, because the catalyst structure internals are not pressure containing like the HRSG units, they were designed using structural codes that do not consider thermal loading. Cracking was observed along leading edges of structural members and at the connections of cross bracings. A transient thermal analysis was completed to calculate temperature distributions as a function of time at the critical locations. Thermal stress calculations were then prepared and stress values compared to fatigue curves for the material at temperature. It was found that computed thermal stress values were sufficient to initiate and propagate cracks consistent with those observed. Several remediation options were considered before two were selected and design changes were detailed. The remediation options included removing some of the bracing after a detailed seismic analysis showed that they were not required and adding refractory materials to leading edges to minimize the thermal gradients generated during start up of the HRSG units. Thermocouple data collected at remediation locations and unchanged areas during start up supported the hypothesized failure analysis cause and the benefit of the remediation design changes.

Failure Analysis With the Scanning Electron Microscope

1972 ◽  
Vol 30 ◽  
pp. 482-483
Author(s):  
John R. Devaney
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Integrated Circuits ◽  
Failure Analysis ◽  
High Reliability ◽  
Military Applications ◽  
Small Structure ◽  
Useful Life ◽  
Insight Into ◽  
Scanning Electron

Occasionally in history, an event may occur which has a profound influence on a technology. Such an event occurred when the scanning electron microscope became commercially available to industry in the mid 60's. Semiconductors were being increasingly used in high-reliability space and military applications both because of their small volume but, also, because of their inherent reliability. However, they did fail, both early in life and sometimes in middle or old age. Why they failed and how to prevent failure or prolong “useful life” was a worry which resulted in a blossoming of sophisticated failure analysis laboratories across the country. By 1966, the ability to build small structure integrated circuits was forging well ahead of techniques available to dissect and analyze these same failures. The arrival of the scanning electron microscope gave these analysts a new insight into failure mechanisms.

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