Challenging the Design Process: High Electrical Cabinet Cooling Requirements vs. Stringent Airborne Noise Requirements

2003 ◽  
Author(s):  
Erick B. Cushman ◽  
Bob Gwin ◽  
Reed Shipman
Keyword(s):  
Cost Effective ◽  
Operating Conditions ◽  
Production Unit ◽  
Worst Case ◽  
Speed Reduction ◽  
Ambient Temperatures ◽  
Normal Operating ◽  
Cost Effective Method ◽  
Airborne Noise ◽  
Fan Speed

An operationally critical, manned control station’s design was challenged to meet stringent airborne noise requirements. Through an innovative, interdisciplinary engineering approach, a solution was implemented, resulting in the first production unit meeting airborne noise requirements. The manned control station was initially designed with nine tubeaxial fans continuously operating at maximum rated speed to provide sufficient cooling to internal components at the station’s worst-case maximum ambient operating temperature of 122°F. Initial testing of a prototype unit showed airborne noise requirements were exceeded by as much as 22 dB (re 20 micro-Pascals). Fan speed reduction and installation of temporary internal acoustic absorption material were tested to measure effectiveness, but were not sufficient to meet airborne noise requirements. The normal operating condition of the control station was reviewed and detailed modeling and testing of the station’s actual cooling requirements under various operating scenarios was conducted. During this process, it was recognized that under normal operating conditions, the worst-case ambient operating temperatures were improbable and that a balancing of cooling requirements and acoustic requirements was possible. A new cost-effective method of fan control in conjuction with the installation of permanent internal absorption material and a redesign of ventilation ducting was implemented. In normal ambient temperature conditions, six of the nine internal fans operate at minimum rated speed. If ambient temperatures rise above normal (the control station’s airborne noise requirments only apply at normal “non-casualty” ambient temperatures), three additional exhaust fans automatically turn on at minimum rated speed to minimize additional airborne noise contributions. If ambient temperatures continue to rise, all nine fans are automatically switched on at maximum rated speed to protect the internal components of the operationally critical control station. Acoustic performance evaluations predicted these improvements would result in meeting the stringent airborne noise requirements. These predictions were validated during testing of the first production unit, which passed all airborne noise requirements.

CAD Of Anticorrosive Protection Of Steel Structures

2019 ◽  
pp. 18-23
Keyword(s):  
Protective Coating ◽  
Computer Aided Design ◽  
Steel Structures ◽  
Cost Effective ◽  
Operating Conditions ◽  
Computational Tool ◽  
Protection Method ◽  
Cost Effective Method ◽  
The Cost ◽  
Aided Design

The choice of cost-effective method of anticorrosive protection of steel structures is an urgent and time consuming task, considering the significant number of protection ways, differing from each other in the complex of technological, physical, chemical and economic characteristics. To reduce the complexity of solving this problem, the author proposes a computational tool that can be considered as a subsystem of computer-aided design and used at the stage of variant and detailed design of steel structures. As a criterion of the effectiveness of the anti-corrosion protection method, the cost of the protective coating during the service life is accepted. The analysis of existing methods of steel protection against corrosion is performed, the possibility of their use for the protection of the most common steel structures is established, as well as the estimated period of effective operation of the coating. The developed computational tool makes it possible to choose the best method of protection of steel structures against corrosion, taking into account the operating conditions of the protected structure and the possibility of using a protective coating.

scholarly journals Evaluation of Property Methods for Modeling Direct-Supercritical CO2 Power Cycles

2017 ◽  
Vol 140 (1) ◽  
Author(s):  
Charles W. White ◽  
Nathan T. Weiland
Keyword(s):  
Power Plants ◽  
Physical Property ◽  
Aspen Plus ◽  
Cost Effective ◽  
Operating Conditions ◽  
Working Fluid ◽  
Power Cycles ◽  
As Species ◽  
Cost Effective Method ◽  
Open Nature

Direct supercritical carbon dioxide (sCO2) power cycles are an efficient and potentially cost-effective method of capturing CO2 from fossil-fueled power plants. These cycles combust natural gas or syngas with oxygen in a high pressure (200–300 bar), heavily diluted sCO2 environment. The cycle thermal efficiency is significantly impacted by the proximity of the operating conditions to the CO2 critical point (31 °C, 73.7 bar) as well as to the level of working fluid dilution by minor components, thus it is crucial to correctly model the appropriate thermophysical properties of these sCO2 mixtures. These properties are also important for determining how water is removed from the cycle and for accurate modeling of the heat exchange within the recuperator. This paper presents a quantitative evaluation of ten different property methods that can be used for modeling direct sCO2 cycles in Aspen Plus®. Reference fluid thermodynamic and transport properties (REFPROP) is used as the de facto standard for analyzing high-purity indirect sCO2 systems, however, the addition of impurities due to the open nature of the direct sCO2 cycle introduces uncertainty to the REFPROP predictions as well as species that REFPROP cannot model. Consequently, a series of comparative analyses were performed to identify the best physical property method for use in Aspen Plus® for direct-fired sCO2 cycles. These property methods are assessed against several mixture property measurements and offer a relative comparison to the accuracy obtained with REFPROP. The Lee–Kessler–Plocker equation of state (EOS) is recommended if REFPROP cannot be used.

Inhibitor Selection for Internal Corrosion Control of Pipelines

1998 ◽  
Author(s):  
S. Papavinasam ◽  
R. W. Revie
Keyword(s):  
Laboratory Experiments ◽  
Cost Effective ◽  
Operating Conditions ◽  
Future Application ◽  
Experimental Conditions ◽  
Performance Simulation ◽  
Internal Corrosion ◽  
Cost Effective Method ◽  
Selection For ◽  
User Friendly

Addition of inhibitors can provide a cost-effective method for controlling internal corrosion of pipelines. To select appropriate inhibitors and their concentrations, several laboratory experiments are usually performed. Test methodologies to evaluate inhibitors for a particular field should be carried out to simulate the conditions in the pipeline. Because several interacting parameters influence corrosion, and hence inhibitor performance, simulation of field operating conditions in the laboratory is often difficult. In this paper, user-friendly software to optimize the laboratory experimental conditions to simulate field operating conditions is discussed. The merits of the program in selecting commercial inhibitors and in designing cost-effective inhibitors for future application are described.

Ash Fouling Under Co-Firing in a Pulverized Fuel Combustion Rig

2006 ◽  
Author(s):  
Luis I. Di´ez ◽  
Cristo´bal Corte´s ◽  
Mariano Berdusa´n ◽  
Eduardo Ferrer
Keyword(s):  
Heat Transfer ◽  
Large Scale ◽  
Cost Effective ◽  
Fuel Combustion ◽  
Operating Conditions ◽  
Tube Bank ◽  
Power Stations ◽  
Cost Effective Method ◽  
Pulverized Fuel ◽  
Potassium Enrichment

Co-firing of coal and biomass in existing coal-fired power stations is a cost-effective method to reduce CO2 emissions in energy generation. Nevertheless, the introduction of biomass has to be carefully considered since it could significantly modify combustion and heat transfer phenomena and enhance fouling and corrosion inside the boiler. This paper investigates the effect of substituting a fraction of coal by biomass on the heat transfer and ash deposition rates, by performing pilot tests under different operating conditions in a pulverized fuel combustion rig. Fouling rates have been characterized by means of air-cooled deposition probes installed at one tube bank, reproducing the performance of a large-scale superheater. Heat transfer has been simulated coupling thermal radiation models with semi-empirical approaches for the tube bank behaviour. Ash samples compiled from the wind- and the lee-side of the probe has been collected and analysed by SEM (Scanning Electron Microscopy). Low-to-moderate fouling rates have been typically observed for the tested coal and coal + biomass blends, but with somewhat potassium enrichment at the lee-side deposits when biomass is introduced. As a matter of fact, sootblowing manoeuvres in utility boilers should not be affected when co-firing the tested fuels. Furthermore, chlorine-induced corrosion on heat transfer surfaces is not expected to be significant since the concentration of chlorine in the sampled deposits has been always found to be negligible.

Qualification Testing of Mechanical Pipe Joining Method

2014 ◽  
Author(s):  
Dave McColl ◽  
Adam Whiting
Keyword(s):  
Oil And Gas ◽  
Cost Effective ◽  
Operating Conditions ◽  
Performance Criteria ◽  
Innovative Technology ◽  
Pipeline System ◽  
Internal Corrosion ◽  
Regulatory Standards ◽  
Cost Effective Method ◽  
Pipeline Failures

Pipeline infrastructure is the backbone of the energy industry and remains the safest and most cost effective method for transporting oil and gas. For decades corrosion has presented a significant challenge to pipeline operators. According to Alberta Energy Regulator data, internal corrosion is considered to be the root cause for more than 54% of all documented pipeline failures in Alberta [1]. Spoolable composite pipeline technologies have become a mainstream corrosion solution over the last 10 years, however these products are limited to smaller pipelines, typically less than 6 inches in diameter. Traditional slip-lining (field installed plastic lined steel pipe) is used for internal corrosion protection of larger pipelines, however it is costly, requiring labour intensive field construction, often completed in inhospitable environmental conditions. As a result project delays and cost over-runs are commonplace. Recognizing the need for a cost effective pipeline corrosion solution for larger gathering pipelines, an innovative technology was developed that combines a unique mechanical pipe joining system with an integrated electro-fusion coupler. The new joining system enables insertion of an HDPE liner in a factory environment where costs and quality can be tightly controlled. The new joining system eliminates conventional welding of the pipeline in the field and instead uses a custom field press to quickly energize the mechanical pipe joint. Field scope is significantly reduced, construction completed in less time, and associated costs greatly reduced. This paper discusses the testing completed to qualify the new joining system for use in oilfield gathering pipelines. The qualification test plan includes all requirements identified in applicable regulatory standards (primarily CSA Z662-11), and prudent engineering requirements based on anticipated field handling and anticipated operating conditions. The test regime was ultimately designed to ensure the suitability of the pipeline system for intended service. Testing included hydrostatic burst, static gas pressure, bend, cyclic pressure and thermal, vacuum, tensile, and compressive tests on the joint. The test results show that in all cases the jointing system successfully met the established design performance criteria and in most cases exceeded the actual mechanical properties of the parent pipe, thus proving the joining system ready for field installations.

Infrared Emission Spectroscopy as a Reliability Tool

1999 ◽  
Author(s):  
Q. Kim ◽  
S. Kayali
Keyword(s):  
Spatial Resolution ◽  
Emission Spectroscopy ◽  
Hot Spot ◽  
Cost Effective ◽  
Infrared Emission ◽  
Test System ◽  
Operating Conditions ◽  
Yield Enhancement ◽  
Infrared Emission Spectroscopy ◽  
Channel Temperature

Abstract In this paper, we report on a non-destructive technique, based on IR emission spectroscopy, for measuring the temperature of a hot spot in the gate channel of a GaAs metal/semiconductor field effect transistor (MESFET). A submicron-size He-Ne laser provides the local excitation of the gate channel and the emitted photons are collected by a spectrophotometer. Given the state of our experimental test system, we estimate a spectral resolution of approximately 0.1 Angstroms and a spatial resolution of approximately 0.9 μm, which is up to 100 times finer spatial resolution than can be obtained using the best available passive IR systems. The temperature resolution (<0.02 K/μm in our case) is dependent upon the spectrometer used and can be further improved. This novel technique can be used to estimate device lifetimes for critical applications and measure the channel temperature of devices under actual operating conditions. Another potential use is cost-effective prescreening for determining the 'hot spot' channel temperature of devices under normal operating conditions, which can further improve device design, yield enhancement, and reliable operation. Results are shown for both a powered and unpowered MESFET, demonstrating the strength of our infrared emission spectroscopy technique as a reliability tool.

Monitoring effluent quality in hypertrophic wastewater reservoirs using remote sensing

1996 ◽  
Vol 33 (8) ◽  
pp. 23-29 ◽  
Author(s):  
I. Dor ◽  
N. Ben-Yosef
Keyword(s):  
Water Quality ◽  
Theoretical Model ◽  
Principal Component ◽  
Cost Effective ◽  
Operational Parameters ◽  
Effluent Quality ◽  
Optical Images ◽  
Routine Monitoring ◽  
Cost Effective Method ◽  
Wastewater Quality

About one hundred and fifty wastewater reservoirs store effluents for irrigation in Israel. Effluent qualities differ according to the inflowing wastewater quality, the degree of pretreatment and the operational parameters. Certain aspects of water quality like concentration of organic matter, suspended solids and chlorophyll are significantly correlated with the water column transparency and colour. Accordingly optical images of the reservoirs obtained from the SPOT satellite demonstrate pronounced differences correlated with the water quality. The analysis of satellite multispectral images is based on a theoretical model. The model calculates, using the radiation transfer equation, the volume reflectance of the water body. Satellite images of 99 reservoirs were analyzed in the chromacity space in order to classify them according to water quality. Principal Component Analysis backed by the theoretical model increases the method sensitivity. Further elaboration of this approach will lead to the establishment of a time and cost effective method for the routine monitoring of these hypertrophic wastewater reservoirs.

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