bluuebunny/crossref_metadata_2025_split huggingface dataset:
Scale Model Testing Towards Primary Air Optimization of a CFB Boiler
Authors: Hughes Tyler , Kang John , Porter Daniel , Munukutla Sastry , Idem Stephen 
Published: February 2014

Primary air flow is supplied to the wind box of a 300 MW CFB boiler by means of three primary air ducts connected to a common plenum. A flow rate measurement is performed in each duct using an Annubar flow meter. Due to the tight configuration of the piping and the associated turbulence, the measured flows in the three ducts were not consistent, resulting in improper air flow distribution in the boiler. A primary air duct flow study was performed in an effort to improve measurement accuracy, which will lead to improved combustion efficiency and low load cycling by allowing precision air flow control in the furnace.
The objective of this project was to employ a 1/10th scale model test to determine the best method to improve the flow upstream of each Annubar flow meter. Tests were conducted with room temperature air at several flow rates generated by a centrifugal fan. Reynolds number independence was achieved in the tests. Appropriate dimensionless Grashof and Prandtl number scaling was used to extrapolate the scale model tests to the high temperature conditions prevalent in the unit. Flow visualization and measurements using a five-hole directional velocity probe were performed. It was determined that mounting 50% open area screens in the primary air duct of the scale model had the effect of significantly reducing both yaw and pitch angles across the Annubar measurement plane. A complimentary benefit was that the velocity profiles in the flow direction were notably flattened by the addition of the screens. Furthermore the performance of the Annubar flow meters could be improved if the measurement plane was moved further upstream of the opposed blade flow control damper.
A New Robotic Process for In Situ Heat Treatment on Large Steel Components
Authors: Boudreault Eric , Hazel Bruce , Godin Stéphane , Côté Jean 
Published: February 2014

To avoid dismantling very large equipment while ensuring high-quality repair, a new robotic process is developed for local post weld heat treatment in situ.
The temperature around the area repaired is controlled using a coil-type portable induction heating source. By using a high-frequency parallel resonant converter, the system can be made portable enough to be installed on a compact manipulator. A method using finite element analysis is proposed to generate heating paths over complex shapes that keep temperature uniform in the volume treated.
A heat treatment performed on a 13Cr-4Ni stainless steel component demonstrates the precision of the robotic process.
Development of a Plate Heat Exchanger for High-Temperature and High-Pressure
Authors: Ishihama Kiyoshi , Matsumura Seiichi , Funabiki Takahisa , Kushima Yukiko , Nakamura Junichi , Kusunoki Kenji , Hiwatashi Isamu , Iwaki Mana 
Published: February 2014

A gasketed plate heat exchanger that has a seal pressure of 6.5 MPa or more has been developed. This heat exchanger can be applied to heat exchangers (design temperature: 182°C, design pressure: 3.43 MPa) for the residual heat removal (RHR) systems of boiling water reactors (BWR).
Practical use of gasketed plate heat exchangers under the condition of higher temperature and higher pressure has been achieved by developing a high-pressure-retaining plate and frame, as well as a heat- and radiation-resistant gasket. Various element tests related to strength and performance were conducted in the process of this development. A verification test using a prototype heat exchanger was also conducted, and pressure resistance, heat resistance, radiation resistance, endurance against thermal transients, and heat transfer performance have been confirmed.
As a result of this development, gasketed plate heat exchangers can be applied for use under the condition of higher temperature and higher pressure, and various effects such as lower system flow, smaller footprint, easier maintenance, and lower cost for weld inspection are expected, compared to conventional shell & tube heat exchangers.
Smart Asset Management: Using Real Time Transient Data to Determine Equipment Damage, Maintenance Costs, and Operational Strategy in Power Plants
Authors: Kumar Nikhil , Lefton Steven A. , Nissen Aaron , Christensen Garry , Hilleman Douglas , Agan Dwight 
Published: February 2014

Real time monitoring for asset management is fast gaining popularity in the power industry. Power plants are transitioning from the initial data gathering to projects creating measurable value for the owner and operator. The authors present an integrated approach, allowing real-time monitoring and advanced analytics for asset management. We specifically look at the changing landscape for plant operators in a renewable integrated grid. Moreover, in today’s volatile electricity markets, most power plants must be flexible; often load following to minimum loads, and frequently cycling on-off. This type of cycling operation can be very damaging to fossil power plants, and add large costs due to increased equipment wear and tear, and adverse heat rate effects. For some large generation units, these costs can amount to millions of dollars per year. These costs can be greatly reduced by proper operations tuning and operator training.
This paper will specifically discuss the value of real time monitoring and advanced analytics to plant operators. We will address the uncertainty, given that plant’s typically follow instructions from dispatch, and provide business case examples of what needs to be done and what value it will actually bring to the industry.
Specified Maintenance of Steam Turbines in Geothermal Power Plants
Authors: Gunnarsson Almar , Elisson Ari , Jonsson Magnus , Unnthorsson Runar 
Published: February 2014

In a geothermal power plant the working fluid used to produce electricity is often wet steam composed of corrosives chemicals. In this situation, more frequent maintenance of the equipment is required. By constructing an overview for maintenance in geothermal power plants and how it can be done with minimum power outages and cost, the geothermal energy can be made more competitive in comparison to other energy resources.
This work is constructed as a part of a project, which has the aim of mapping the maintenance management system at the Hellisheiði geothermal power plant in Iceland. The object of the project is to establish Reliability Centered Maintenance (RCM) program for Hellisheiði power plant that can be utilized to establish efficient maintenance management procedures. The focus of this paper is to examine the steam turbines, which have been defined as one of the main subsystems of the power plant at Hellisheiði. A close look will be taken at the maintenance needed for the steam turbines by studying for example which parts break down and how frequently they fail.
The local ability of the staff to repair or construct turbine parts on-site is explored. The paper explores how the maintenance and condition monitoring is carried out today and what can be improved in order to reduce cost.
The data collected is analyzed using Failure Mode and Effect Analysis (FMEA) in order to get an overview of the system and to help organizing maintenance and condition monitoring of the power plant in the future. Furthermore, the paper presents an overview of currently employed maintenance methods at Hellisheiði power plant, the domestic ability for maintaining and repairing steam turbines and the power plant’s need for repairs.
The results show that the need for maintenance of the geothermal steam turbines at Hellisheiði power plant is high and that on-site maintenance and repairs can decrease the cost.
Wastewater Treatment in Support of Ash Pond Closures
Authors: Nanni Bernardino P. , Bolender Justin L. , Whittier Spencer D. 
Published: February 2014

The Environmental Protection Agency (EPA) is evaluating rules that will not permit the storage of coal combustion residuals (CCRs) in surface impoundments, and require CCRs to be stored in Subtitle C or Subtitle D landfills. In addition, the EPA is evaluating more stringent effluent guidelines for water discharges which may impact NPDES permits in the future. To support these changes, the Tennessee Valley Authority (TVA) is evaluating the elimination of wet CCR handling and surface impoundments at their coal fired facilities. If CCR conveyance is converted to dry methods and the surface impoundments are closed, the other wastewater streams that utilize these impoundments as a point of discharge will also be affected. Therefore, TVA is investigating options to handle the miscellaneous wastewater streams that currently discharge to the impoundments, and meet more stringent effluent limits that may be implemented in the future.
This investigation includes characterization of the existing wastewater streams, determining the effects on wastewater streams associated with future plant modifications and anticipated regulatory changes, developing methods to reduce and reuse wastewater streams to avoid discharge, and developing methods to treat the remaining wastewater streams that may be discharged in accordance with potential future effluent limits.
TVA is in the forefront of addressing the pending EPA rules that may affect CCR handling and storage, and water discharges. This paper discusses and presents the process being used by TVA to address these changes, the results obtained to date, and how this may be applicable to others potentially impacted by these changes.
Improving Dust Control to Upgrade PRB Coal Handling
Authors: Marshall Daniel 
Published: February 2014

Plant management had a mission: to make the Midwestern 646-megawatt power plant a leader in the clean and safe handling of PRB coal.
To accomplish that goal, the organization embarked on an ambitious five-year plan to upgrade the plant’s coal handling system. The plant improved its conveyor transfer points, and installed new dust management systems, controlling dust and spillage, and improving plant safety and efficiency.
This presentation will discuss the initial surveys that led to the development of the 5-year plan, and the resulting project priorities, the problem areas, application points identified, and the various technologies applied. Included in the goals for the upgraded systems installed were the elimination of spillage through the improvement of transfer points on coal-handling conveyors using improved belt support and sealing systems.
In addition, new air cleaners were installed at seven loading zones, and a foam dust-suppression system added at one location to provide dust management throughout the plant’s coal handling system. These new dust control systems allowed the plant to eliminate its older central dust collection system that had greater risks of explosions.
A continued series of monthly inspection and service visits by conveyor maintenance technicians helps continue the coal handling system’s high levels of performance.
This five-year plan helped the power plant take “great leap forward” in controlling dust and spillage from handling PRB coal.
Evaluation of Irradiation Effects on Concrete Structure: Gamma-Ray Irradiation Tests on Cement Paste
Authors: Kontani Osamu , Sawada Shohei , Maruyama Ippei , Takizawa Masayuki , Sato Osamu 
Published: February 2014

In assessing reduction of concrete strength under irradiated conditions, reference levels are introduced: 1×1020 n/cm2 for fast neutrons and 2×1010 rad (2×105 kGy) for gamma-rays. Concrete structures are regarded as sound as long as irradiance levels accumulated during long-term operation are less than the reference levels.
Most experimental investigations of irradiation effects on concrete were performed in the 1960’s and 1970’s. However, there is no good explanation of how concrete deteriorates under neutron and gamma-ray irradiation.
Hilsdorf put the primal irradiation test data together to investigate effects of irradiance levels on residual strength ratio of concrete [1]. The reference levels were obtained from his paper. However, the test conditions in which the data quoted by Hilsdorf were obtained are very different from the irradiation and heat conditions usually found in a Light Water Reactor (LWR).
This paper summarizes the interactions between radiation and concrete components and presents the results of gamma-ray irradiation tests on cement paste in order to provide a better understanding of the deterioration mechanisms of concrete under irradiation and heat conditions in LWRs.
Concept and Application of Distributed Compressed Air Energy Storage Systems Integrated in Utility Networks
Authors: Petrov Miroslav P. , Arghandeh Reza , Broadwater Robert 
Published: February 2014

Distributed energy storage has been recognized as a valuable and often indispensable complement to small-scale power generation based on renewable energy sources. Small-scale energy storage positioned at the demand side would open the possibility for enhanced predictability of power output and easier integration of small-scale intermittent generators into functioning electricity markets, as well as offering inherent peak shaving abilities for mitigating contingencies and blackouts, for reducing transmission losses in local networks, profit optimization and generally allowing tighter utility control on renewable energy generation. Distributed energy storage at affordable costs and of low environmental footprint is a necessary prerequisite for the wider deployment of renewable energy and its deeper penetration into local networks.
Thermodynamic energy storage in the form of compressed air is an alternative to electrochemical energy storage in batteries and has been evaluated in various studies and tested commercially on a large scale.
Distributed compressed air energy storage (DCAES) systems in combination with renewable energy generators installed at residential homes, public or commercial buildings are a viable alternative to large-scale energy storage, moreover promising lower specific investment than batteries if a mass-market is established. Flexible control methods can be applied to DCAES units, resulting in a complex system running either independently for home power supply, or as a unified and centrally controlled utility-scale energy storage entity.
This study aims at conceptualizing the plausible distributed compressed-air energy storage units, examining the feasibility for their practical implementation and analyzing their behavior, as well as devising the possible control strategies for optimal utilization of grid-integrated renewable energy sources at small scales. Results show that overall energy storage efficiency of around 70% can be achieved with comparatively simple solutions, offering less technical challenges and lower specific costs than comparable electrical battery systems. Furthermore, smart load management for improving the dispatchability can bring additional benefits by profit optimization and decrease the payback time substantially.
Thermoeconomic Evaluation of Integration Concepts for Solar and Biomass Hybrid Power Plants
Authors: Salomon Popa Marianne , Petrov Miroslav P. , Krothapalli Anjaneyulu 
Published: February 2014

Solar thermal energy and biomass fuels are often available at locations where they can benefit from combined hybrid energy utilization methods for the generation of electricity, representing suitable and advantageous integration alternatives. The feasibility of concentrating solar power (CSP) systems depends on cost limitations, desired installed power capacity and direct solar insolation, where smaller scales and low-cost solutions can often be preferred to large-scale investment-intensive installations. Biomass residues of various types, on the other hand, can be considered as proven fuels for small-to-midscale utility or industry based power or cogen arrangements and utilized through various technologies. The thermodynamic integration between a biomass fired power plant and a CSP unit can help to significantly increase the availability of the plant, improve its partial load characteristics, compensate for the intermittency of the solar energy resource while preserving the purely renewable profile of the generated electricity, and at the same time showing better overall performance when compared to two separate plants while avoiding the need for costly energy storage solutions.
Biomass fuels can help reach better steam conditions in a steam plant based on CSP-generated steam, and thus improve the efficiency of energy conversion for the integrated hybrid system if compared with two individual single-fuel power units. In this study, an overview of feasible solar-biomass integration concepts is presented. A deeper thermoeconomic analysis of a selected integrated utility-scale biomass and CSP electricity generation plant is attempted, with certain simplifications. Furthermore, a multiobjective optimization strategy is regarded as very necessary and thus included in the analysis, where several major environmental aspects plus the cost of electricity are involved and defined in terms of desired parameters and conditions representative to Central Europe and Southeastern United States. The results are compared with conventional power generation alternatives. On that basis, a low-parameter CSP solution integrated with conventional biomass-fired combustion unit, where solar-generated steam is being superheated by the biomass fuel, has been chosen as the focus of the analysis in this study.
Nuclear Air-Brayton Combined Cycle (NACC) With Natural Gas Peak Power
Authors: Forsberg Charles , Curtis Daniel 
Published: February 2014

The Fluoride-Salt-Cooled High-Temperature Reactor (FHR) is a new reactor concept that uses the graphite-matrix coated-particle fuel from gas-cooled reactors and a high-temperature liquid salt coolant. The reactor exit temperatures exceed 700°C with reactor inlet temperatures of ∼600°C. Because of these high temperatures the FHR can be coupled to a nuclear air-Brayton combined-cycle (NACC) plant with one or more air-Brayton turbines with hot exhaust directed to a steam recovery boiler.
Under normal base-load operating conditions, air is compressed, heated using salt-air heat exchangers, passed through a turbine, and exhausted to a heat recovery boiler, and added electricity is made from the steam that is generated. The NACC can have one or more salt-to-air reheat stages. After air compression and nuclear heating, the hot compressed air is above the auto-ignition temperature of natural gas (NG). Natural gas can be injected to increase gas temperatures and produce peak power. Because the plant operates continuously as a base-load system connected to the grid and there is no need to control the fuel-to-air ratio, the peak power can be varied and increased rapidly. At times of low electricity prices, steam from the heat recovery boiler can be sold to industrial users at lower prices than they can generate it from NG but above its value for electricity generation. The incremental capital cost for peaking capabilities is less than the cost of stand-alone NG plants. There is the potential for the NG-to-electricity efficiencies exceeding those of stand-alone NG plants. These capabilities imply plant revenue 20 to 50% greater than from an equivalent base-load nuclear plant.
The market requirements are being assessed to determine the requirements for the FHR and NACC power cycle. As a new-type of plant, much additional work is required to understand the design options and limitations.
Integrated Solar Combined Cycle Plants Using Solar Towers With Thermal Storage to Increase Plant Performance
Authors: Peterseim Juergen H. , Tadros Amir , Hellwig Udo , White Stuart 
Published: February 2014

In Australia both natural gas and an excellent solar irradiance are abundant energy sources and its combination is one option to implement concentrating solar power (CSP) systems in Australia’s traditionally low cost electricity market. The recently introduced carbon pricing mechanism in Australia is likely to steer investment towards combined cycle gas turbine (CCGT) plants. This will also lead to further plants being built in high solar irradiance areas where CSP could provide valuable peak capacity. Hybridisation would enable more competitive power generation than standalone CSP systems as hybrid plants share equipment, such as steam turbine and condenser, therewith lowering the specific investment.
This paper investigates the novel hybridization of CCGT and solar tower systems to increase the efficiency of integrated solar combined cycle (ISCC). Currently, all ISCC plants use parabolic trough systems with thermal oil as this technology is most mature. However, increases in plant efficiency, simpler solar tower integration as well as further synergies of solar tower ISCC systems, such as joint use of tower as CCGT stack, are likely to enhance the economic viability of new ISCC plants. In addition to a technical concept description this paper outlines the ideal sites for ISCC plants in Australia and presents a 200MWe ISCC case study with 3h molten salt thermal storage for the conversion of the Port Hedland open cycle gas turbine (OCGT) facility in Western Australia into a solar tower ISCC plant.
One Dimensional Model for Rotating Channels in the Turbine System: Part 1 — Formulation and Validation for Single Phase Flow
Authors: Prabhudharwadkar Deoras , Dweik Zain , Krishnan R. Murali 
Published: February 2014

The secondary air flow system of a gas turbine performs the cooling and sealing applications in those parts of the turbine which would otherwise be exposed to the high temperatures resulting in their life reduction or even failures. Accurate analysis of the secondary system is therefore necessary to ensure the safe design of the engine and accurate life predictions. The secondary system is analyzed through the flow network analysis which comprises of chambers or cavities connected through flow passages or restrictions (e.g. seals). The narrow flow channels form a majority of these passages especially in the turbine blades cooling system.
This paper provides a detailed formulation of a one-dimensional model for steady, compressible flow inside a channel which is based on the solution of two equations for a coupled system of mass, momentum and energy equations. The model is applicable over a wide range of subsonic to supersonic flow conditions. It has been validated for the choked flow situation and also has the capability to capture normal shocks. Hence, this model provides a fast, accurate and robust channel simulation technique that is compatible with a complex network analysis.