Union Gas Ltd.

Toronto, Canada

Union Gas Ltd.

Toronto, Canada

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Kibsey M.,Carleton University | Huang X.,Carleton University | Koul A.,Life Prediction Inc. | Hildebrand M.,Union Gas Ltd
Proceedings of the ASME Turbo Expo | Year: 2012

In a previous study, high pressure turbine blades from an RB211-24C aero-derivative industrial gas turbine engine were sectioned and metallographically examined. The turbine blades were made of cast Mar-M002, a nickel-based superalloy. It was found that stress-assisted grain boundary oxidation (SAGBO) had occurred along the inner cooling channels near the leading edge at the turbine blade root, which accelerated crack formation and propagation through dynamic embrittlement. The cracks were characterized by the presence of large Hf, Al and O concentration. It appeared that the presence of oxygen in the inner cooling channels and the rapid oxidation of hafnium carbides aggravated the onset of failure through the action of SAGBO cracking. Following this examination, a creep life prediction analysis of the RB211-24C first stage blades was performed at Life Prediction Technologies Inc. (LPTi). According to the results from LPTi's creep life prediction, the leading edge region near the blade root is most vulnerable to combined creep and oxidation damage accumulation due to high strain accumulation, as a result of high temperatures, stress, and limited inspection ability of the inner channels. In the present study, the LPTi prediction results are compared with the metallographic analysis of RB211-24C blades. It is confirmed that SAGBO in combination with creep leads to cracking in the predicted region and the worst case creep analysis results match favorably with the field experience. Copyright © 2012 by ASME.


Selvig A.,Carleton University | Huang X.,Carleton University | Hildebrand M.,Union Gas Ltd | Stek D.,Union Gas Ltd
Journal of Engineering for Gas Turbines and Power | Year: 2011

Modern superalloys have enabled high pressure turbine (HPT) blades in gas turbine engines (GTE) to operate at higher temperatures. Unfortunately, the complexity of these materials can make it difficult to understand the failure mechanisms of these blades. HPT blades made of the nickel-based superalloy Mar-M002 have been found to suffer from stress assisted grain boundary oxidation (SAGBO) cracking. HPT blades removed from an RB211-24C aeroderivative industrial GTE were sectioned, and the cracks and microstructure were studied using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). No cracks were found on the external surface of the blade, which had been coated with an oxidation resistant material. Surface irregularities were found along the walls of the inner cooling channels throughout the entire blade. Larger SAGBO cracks were observed to be near the lower 25% span of the blade and had initiated from the surfaces of the cooling channels. SEM/EDS analyses showed that these cracks had large amounts of alumina and hafnium-rich particles within them. It is evident that these cracks occurred in locations where the combination of high stress and high temperature led to higher rates of oxygen diffusion and subsequent oxidation of grain boundary carbides. Hafnium carbide precipitates along the grain boundaries expanded as they converted into hafnium oxide, thus further increasing the stress. It is envisaged that this increase in stress along the grain boundary has caused the cracks to initiate and coalesce. Based on this observation, it is believed that the inner cooling channels of these HPT blades could benefit from the application of an oxidation resistant coating in order to prevent or delay the formation of these cracks. © 2011 American Society of Mechanical Engineers.


Selvig A.,Carleton University | Huang X.,Carleton University | Hildebrand M.,Union Gas Ltd | Stek D.,Union Gas Ltd
Proceedings of the ASME Turbo Expo | Year: 2010

Modern superalloys have enabled High Pressure Turbine (HPT) blades in Gas Turbine Engines (GTE) to operate at higher temperatures. Unfortunately the complexity of these materials can make it difficult to understand the failure mechanisms of these blades. HPT blades made of the nickel based superalloy Mar-M002 have been found to suffer from Stress Assisted Grain Boundary Oxidation (SAGBO) cracking. HPT blades removed from an RB211-24C aero-derivative industrial GTE were sectioned and the cracks and microstructure were studied using Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDS). No cracks were found on the external surface of the blade which had been coated with an oxidation resistant material. Surface irregularities were found along the walls of the inner cooling channels throughout the entire blade. Larger SAGBO cracks were observed to be near the lower 25% span of the blade and had initiated from the surfaces of the cooling channels. SEM/EDS analysis showed that these cracks had large amounts of alumina and Hafnium-rich particles within them. It is evident that these cracks occurred in locations where the combination of high stress and high temperature led to higher rates of oxygen diffusion and subsequent oxidation of grain boundary carbides. Hafnium Carbide precipitates along the grain boundaries expanded as they converted into Hafnium Oxide, thus further increasing the stress. It is envisaged that this increase in stress along the grain boundary has caused the cracks to initiate and coalesce. Based on this observation, it is believed that the inner cooling channels of these HPT blades could benefit from the application of an oxidation resistant coating in order to prevent or delay the formation of these cracks. Copyright © 2010 by ASME.


Thomas M.,CANMET Energy | Hayden A.C.S.,CANMET Energy | Ghiricociu O.,Union Gas Ltd. | Cane R.L.D.,Caneta Research | Gagnon R.,Caneta Research
ASHRAE Transactions | Year: 2011

In 2007/2008 the Renewables and Integrated Energy Systems Group at Natural Resources Canada (NRCan), a department of the Canadian Federal Government, initiated a new study of residential hot-water use with the aim of determining whether or not there had been any significant change since the last study conducted. The NRCan study utilized low-cost data loggers together with accurate flowmeters to monitor the volume of hot water drawn every two to four seconds, for a period of approximately two to three weeks, at each test site. This study monitored 38 households in the greater Ottawa area and, as such, is believed to be the largest such study of its kind conducted since the earlier work completed by Perlman and Mills (1985) or Werden and Spielvogel (1969a, 1969b). NRCan has now extended the hot-water use monitoring to other regions in Ontario, in collaboration with Union Gas, Ltd., and with the assistance of Caneta Research, Inc., adding another 36 households to the study. The new regions covered included Hamilton, London, and Sudbury. As a result of our new study, we have found that people's habits have changed and that hot-water use today is quite different to the assumptions used in the current performance test standards; for example, the total household average daily hot-water volume appears to have decreased, the average draw volume flow rates are lower, and the average number of draws per day are much greater. The authors present the results of monitoring 74 households' hot-water use and discuss the implications of these results with respect to the water heater performance test standards and the derived energy factor. © 2011 ASHRAE.


Segall S.M.,Corrosion Service Company Ltd | Gummow R.A.,Corrosion Service Company Ltd | Fingas D.,Corrosion Service Company Ltd | Shore J.,Union Gas Ltd
NACE - International Corrosion Conference Series | Year: 2012

An effective In-line Inspection (ILI) program must provide a prioritized excavation response plan to address anomalies identified as being of particular concern. Locations that show potential for imminent or short term failure are prioritized under Phase 1 and Phase 2 responses respectively. Anomalies that could grow to become a severe risk for pipeline integrity prior to the next ILI are prioritized as Phase 3 excavations. This paper describes the use of External Corrosion Direct Assessment (ECDA) principles in prioritizing Phase 3 anomalies on a gas pipeline in northern Ontario, resulting in a more effective excavation program. A type of ECDA prioritization criterion, based on the results of an integrated Close Interval Potential Survey/Direct Current Voltage Gradient (CIPS/DCVG) survey in conjunction with the results of Phase 1 and Phase 2 digs, is proposed. ©2012 by NACE International.


Majeski A.,CANMET Energy | Runstedtler A.,CANMET Energy | D'Alessio J.,U. S. Steel Canada Inc. | Macfadyen N.,Union Gas Ltd.
ISIJ International | Year: 2015

Injecting pulverized coal and natural gas into blast furnaces for ironmaking decreases metallurgical coke requirements, providing a net decrease in the CO2 emissions and in many cases, operating costs associated with iron production. Ideally, the fuel would enter the raceway partially reacted and the injection would not have negative impacts on the equipment or process. Success in achieving this outcome is sensitive to the details of how the injection is implemented. Given this sensitivity and that it is difficult to make accurate, detailed observations in blast furnaces or devise representative pilot-scale experiments, computational fluid dynamics (CFD) has become a useful and complementary tool for the analysis and design of fuel injection methodologies. This study uses CFD to examine the interaction of the blast air and fuel flows in the blowpipe and tuyere nozzle for different fuel injection strategies. Important operating issues such as initiation of partial combustion and heat loads on the tuyere nozzle are examined. It was found that two key fuel injection strategies developed separately for coal and natural gas can be combined effectively in a single combined fuel lance that leverages a bluff body effect to help coal dispersion and has radial nozzles to improve natural gas combustion. The bluff body effect is a simple process whereby the interaction between the blast air flow and a thick-walled lance creates a wake that can impart coal dispersion without the complexity or costs of adding an auxiliary dispersive fluid, such as an annular swirling flow of air. The performance of this combined fuel lance is compared against two configurations for separate fuel lances. Copyright © 2015. ISIJ.


Segall S.M.,Corrosion Service Co. | Gummow R.A.,Corrosion Service Co. | Shore J.,Union Gas Ltd.
Materials Performance | Year: 2012

The interpretation of indirect inspection data is a critical factor in conducting a successful external corrosion direct assessment process. The data must be validated, discrepancies resolved, and indications identified, classified, and prioritized to select the sites for direct examinations. This article analyzes the various types of data provided by indirect inspection tools and their interrelation.

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