bluuebunny/crossref_metadata_2025_split huggingface dataset:
High Rate Interactive Energy System Through the Use of PV and EV
Authors: Mitsumoto Yuta , Kose Norihiro , Nakagawa Tsuguhiko 
Published: February 2014

After the Great East Japan Earthquake disaster, it was necessary to build a new energy system that would enable us to be less dependent on nuclear power, as well as reduce carbon dioxide emissions. To accomplish this, it is necessary to consider a new method of energy supply and consumption combined with the promotion of energy conservation and the increased use of natural energy. One example, called “Smart Community”, has attracted attention. It optimizes a balance between energy supply and demand, and utilizing energy efficiently. The “Smart Community” is envisioned as different from the conventional one-way power system currently supplied by electric and fuel companies.
In this study, the authors investigate a way to efficiently use photovoltaic (PV) power in an interactive energy system. In the system, PV power is used in homes and factories as an energy source, and in electric vehicles (EV) for transportation and energy storage. The system is a two-way system, and it is important for users to determine which supply and demand method they want. For example, if you choose to include PV power in your electrical power system, there will be the problem of increased DC-AC conversion energy loss. This is due to the re-conversion of AC-DC after DC-AC conversion. In addition, the cost will increase.
In order to solve this problem, the authors propose an efficient installation location and space for PV, and an optimized battery capacity for EV with energy consumption. The authors also propose a way to cut down the DC-AC conversion loss. As a result, the system achieved a 30% reduction in carbon dioxide emissions in homes, and reduced costs. In addition, with the increased use of PV, the system also equalized electric-load. The authors also found that the new system improved PV power rate to 90%.
Numerical Simulation of Turbulent Combustion Flows for Coaxial Jet Cluster Burner
Authors: Yunoki Keita , Murota Tomoya , Miura Keisuke , Okazaki Teruyuki 
Published: February 2014

We have developed a burner for the gas turbine combustor, which was high efficiency and low environmental load. This burner is named the “coaxial jet cluster burner” and, as the name indicates, it has multiple fuel nozzles and holes in a coaxial arrangement. To form lean premixed combustion, this burner mixes fuel and air in the multiple holes rapidly. The burner can change the combustion form between premixed and non-premixed combustion by controlling the mixing. However, the combustion field coexisting with premixed and non-premixed combustion is complicated. The phenomena that occur in the combustion field should be understood in detail.
Therefore, we have developed the hybrid turbulent combustion (HTC) model to calculate the form in which non-premixed flame coexists with premixed flame. Turbulent flow has been simulated using a large eddy simulation (LES) with a dynamic sub grid scale (SGS) model coupled with the HTC model. These models were programmed to a simulation tool based on the OpenFOAM library. However, there were unclear points about their applicability to an actual machine evaluation and the predictive precision of CO concentration which affects burner performance. In this study, we validate the HTC model by comparing its results with measured gas temperature and gas concentration distributions obtained with a coaxial jet cluster burner test rig under atmospheric pressure. In addition, we analyze the CO generation mechanism for the lean premixed combustion in the burner.
Analysis of High-Speed Electrical Generators for Utility Applications
Authors: Petrov Miroslav P. 
Published: February 2014

High-speed alternators are believed to be well developed nowadays, following the improvement in performance and decrease of costs for electronic power converters and permanent magnet materials. Their compact design and their ability to vary the rotational speed in off-design conditions promise superior performance when compared to conventional generators. High-speed alternators are only available in limited sizes for small-scale applications, whereas improvements in efficiency and optimized part-load behavior are particularly important especially for small-scale electricity generation.
Enhanced energy utilization for electricity production by small utility plants or by distributed units located at private homes or commercial buildings, based on thermodynamic cycles powered by natural gas or various renewable energy sources, is possible to be achieved through a wider application of grid-integrated high-speed technology. This study presents a critical review of previous research and demonstration work on high-speed electrical machines and a summary of the technical challenges limiting their performance and their expansion into larger sizes. Conclusions are drawn for finding appropriate solutions for practical high-speed electricity generation units and their readiness for a much wider deployment.
Closer analysis is attempted on the thermal and mechanical integrity of high-speed alternators and the technical challenges that slow down their scale-up to MW-size units for utility applications. The necessary research and development work that needs to be done in the near future is outlined and discussed herein.
Lifecycle Water Consumption of Geothermal Power Systems
Authors: Clark Corrie , Harto Christopher 
Published: February 2014

Previous assessments of the sustainability of geothermal energy have focused on resource management and associated environmental impacts during plant operations. Within these constraints, studies have shown that overall emissions, water consumption, and land use for geothermal electricity production have a smaller impact than traditional base-load electricity generation technologies. According to the Energy Information Administration (EIA) of the U.S. Department of Energy (DOE), geothermal energy generation in the United States is projected to increase nearly threefold, from 2.37 GW to 6.30 GW, by 2035 (EIA 2012). With this potential for significant growth in geothermal electricity production, there is a need to improve understanding of the environmental impacts across the life cycle of geothermal energy production systems.
This paper assesses the use of freshwater in construction, drilling, and production activities of various geothermal power plants. Four geothermal technologies were evaluated: air-cooled enhanced geothermal systems (EGSs), air-cooled hydrothermal binary systems, evaporative-cooled hydrothermal flash systems, and air-cooled geopressured systems that coproduce natural gas. The impacts associated with these power plant scenarios are compared to those from other electricity generating technologies as part of a larger effort to compare the lifecycle impacts of geothermal electricity generation to other power generation technologies.
A Phenomenological Analysis of Exergy Destruction During Hydrogen Combustion With Electronically Excited Oxygen
Authors: Washington DeVon A. , Shapiro Howard N. 
Published: February 2014

This study investigates the effects of introducing electronically excited oxygen on trends in exergy destruction during hydrogen combustion. Electronically excited oxygen enhances many properties of combustion. By understanding how it alters the chemical kinetics, and hence the destruction of exergy, it may be possible to improve the overall exergetic efficiency of combustion thereby reducing fuel use to achieve desired energy conversion.
A numerical model was developed of an adiabatic plug flow reactor using CHEMKIN-PRO; in conjunction with a hydrogen oxidation mechanism that includes explicit reaction pathways for various electronically excited species. Exergy destruction was calculated for cases where singlet oxygen composed 0%–100% of the oxidizer while maintaining a stoichiometric oxidizer-fuel ratio; all other inlet conditions were held fixed.
Results show that an optimal range of exergetic combustion efficiency exists between 0%–20%, with the maximum occurring at approximately 10%. A detailed assessment of the total exergy destruction reveals that, for the optimal range of exergetic combustion efficiencies, as much as 60% of the total exergy destruction occurs prior to ignition. For inlet percentages of singlet oxygen greater than 20%, the majority of the total exergy destruction occurs after ignition. This paper examines the phenomenological events taking place in the reaction mechanism that give rise to the destruction of exergy during combustion. Understanding these mechanisms and the effects of introducing excited oxygen into the combustion process, sheds light on how we might use excited oxygen to increase the exergetic efficiency of combustion.
Get More Out of Less, Best Practices for Main Steam Measurement
Authors: Verhaagen Don , Hausman Katie , Saopraseuth Emily 
Published: February 2014

The way DP flow is applied and choice of primary element often follows tried and tested methods, this can lead to higher capital expenditures (CAPEX) and operating expenditures (OPEX) costs than is necessary. The latest technology allows an alternative, better practice approach to DP flow that can result to better measurement accuracy and CAPEX and OPEX reductions.
In this study, best practices for steam flow measurement in main steam lines to allow for optimization are identified. The inherent advantages with measuring each critical point around the main steam line are discussed. There are major benefits associated with direct measurement over inferred measurement in high pressure and temperature applications. By measuring main steam line flows directly, plant and process visibility is gained. These measurements are quite accurate because changing process conditions can be captured in the flow measurement.
A technology comparison between a flow nozzle and averaging pitot tube shows the advantages of utilizing the averaging pitot tube technology for critical steam measurements. Installation and maintenance best practices are highlighted.
Another case study depicts the advantages to making direct measurements around the turbine, especially with trending demand. A case study focusing on cost savings depicts how using modern flow technology can provide significant cost and energy savings.
Measurement of Thickness and Reflectivity of Fouling Deposits on Wall Tubes in a Pulverized-Coal Firing Furnace
Authors: Menn Naftaly , Chudnovsky Boris 
Published: February 2014

It is well known that fouling deposits on the wall of power generation units where solid fuels, like pulverized coal, is burnt cause significant reduction of the overall efficiency of the furnace and the boiler. In order to take fouling into account in the overall balance of the boiler it is necessary to measure two main parameters — thickness of the deposits and their reflectivity (emissivity) in the wavelength of visible and IR region.
In the present paper an electro-optical system is described which enables to perform direct on-line measurement of these two parameters of heat transfer in the course of normal operation of the power unit. The system is capable to carry out measuring procedure inside the furnace chamber at temperatures up to 1800 C. Dynamic measurement of thickness of the fouling deposits created on the wall tubes is measured with accuracy of 0.1mm. Spectral reflectivity of the wall is also continuously measured and compared with the reflectivity of the stainless steel specimen located inside the system. Experimental results are reported obtained during three months operation of the system on the power unit of Israel Electric Company (power station in Hadera).
Design Factors for Avoiding FAC Erosion in HRSG Low Pressure Evaporators
Authors: Moelling David , Malloy James , Graham Marc , Taylor Mark , Fabricius Andreas 
Published: February 2014

Two types of flow-driven wear phenomena are a frequent source of failures in Heat Recovery Steam Generators (HRSGs): Flow-Accelerated Corrosion (FAC) and Liquid-Droplet Impingement (LDI). The two mechanisms combined are also known by an older term, erosion-corrosion. This better describes what can be viewed as a continuum of mechanisms, driven by chemistry and/or fluid velocity, which lead to wear and consequent thinning of pipe walls. One common failure location in the HRSG is in Low Pressure (LP) Evaporator circuits, both in regions with two-phase and with single-phase flow conditions.
Replacement and/or redesign of the LP Evaporator system is often required. Water chemistry is known to be a key factor in determining the risk of FAC; it can be modified if required during operation to potentially affect wear rates. Another key factor, determined at the design stage, is the chrome content of the steel. The emphasis here is on evaluating other design factors, particularly local process conditions throughout the LP Evaporator circuit, that affect susceptibility to FAC and LDI. LP systems today often are designed to operate at very low pressures (< 3 barg, 45 psi) with the goal of extracting the last practical amount of thermal energy from gas turbine exhaust gas. Furthermore, many combined cycle power plants (such as those in combined power and desalinization service) have variable loads that lead to wide variations in LP operating pressures.
The overall bulk fluid circulation in natural circulation LP Evaporators of several different HRSG designs is evaluated over a range of operating conditions. These circulation calculations are sensitive to small changes in heat transfer and load conditions at low pressures, due to the high void fraction in the two-phase region. An accurate estimation of void fraction is therefore required to determine local process conditions (flow velocities and flow regimes) in this region. The limitations of some of the common methods for estimating void fractions, such as asymptotic values for high void fractions at low pressures, are considered. The evaporator process conditions determined by modeling are used as inputs to assess the potential for wear by FAC and/or LDI using several established methods (Kastner, Sanchez-Caldera). The results are compared with case studies from field investigations to assess if wall thinning encountered in actual HRSG service can be correlated with certain design factors.
Maximizing Power Generating Asset Value Through Performance Management
Authors: Sunder Raj Komandur S. 
Published: February 2014

Power plant owners have been monitoring the performance of their power plant processes, equipment and instrumentation for several years. In recent years, however, they have been increasingly confronted with several challenges in maximizing the value of their generating plant assets.
The challenges include: deregulation, increased competition, aging of power plant equipment, inadequate instrumentation, aging workforce, lack of experienced/qualified personnel and tools to effectively monitor the operation, performance and condition of plant processes and equipment. These constraints have adversely impacted the capacity, availability and reliability and efficiency of the generating plant asset as well as the total cost of ownership and return on investment. On a positive note, however, technological innovations and tools such as the advent of the Internet, web-based and wireless technologies, advanced software applications and tools, automation, smart sensors and instruments with diagnostic capabilities, are all now making it possible for power plant owners to do more with less.
Using case studies, this paper discusses various initiatives and technological advances that are being utilized to maximize power generating asset value through performance management.
Using CFD for Metrology Prediction in Flowmetering: RCS Flow Measurement in PWRs With Elbow Taps
Authors: Deneux Olivier , Favennec Jean-Mélaine , Veau José , Antunes Johan , Piedfer Olivier 
Published: February 2014

The RCS flow measurement in PWRs is currently performed with a heat balance between primary and secondary systems: thus temperature heterogeneity impacts this measurement.
In case of RCS flow shutdown (incident situation), a relative measurement of the RCS flow is monitored using an existing elbow tap. The goal of the present study is to assess the feasibility of using the existing plant elbow taps to accurately measure an absolute value of the RCS flow continuously and independently of the RCS temperature measurements. RCS flow is basically proportional to the square root of the differential pressure in the pipe elbow taps. Experiments on a scale model and sensitivity analyses with CFD simulations have been carried out and show that only few parameters have an influence on the proportionality coefficient. CFD is seen as able to predict this coefficient with an adequate accuracy.
Potential applications of this method are RCS flow monitoring from start to full load after the change of primary coolant pumps or of steam generators.
Analysis of Turbine Cycle Performance, Operation and Reliability Issues Using Heat Balance Techniques
Authors: Sunder Raj Komandur S. 
Published: February 2014

The first law of thermodynamics is universally used in steady-state modeling and performance analysis of power plant cycles. Mass and energy balances may be effectively utilized in analyzing and evaluating turbine cycle performance issues and associated heat rate and capacity losses.
Utilizing a case study for a fleet of coal-fired power plants and different examples, this paper examines applications of heat balance techniques in evaluating and quantifying performance losses. The focus of the paper will be in analyzing, diagnosing and quantifying performance, operation and reliability issues for the turbine cycle and major equipment.
Closed Cooling Water Heat Exchanger Design for Higher Tube Inlet Water Temperature
Authors: Muldoon Thomas J. , Bruno Joseph A. 
Published: February 2014

When the maximum temperature of cooling water slowly increases with temperature changes and shifting climate patterns, smaller LMTD’s (log mean temperature differences) for the CCW’s to meet the same performance heat rejection. Making the issue more critical is that the peak cooling water temperatures will usually occur at the same time as peak summer load demand.
A smaller LMTD means a larger heat exchanger and more effective tubing surface area. More surface, means more tubing or smaller diameter tubing. If the original LMTD was 12 °F, a 1 degree change may mean an increase of 9%. To maintain the same nozzle locations on a replacement exchanger means a smaller tube outside diameter and/or a larger shell. Such increases are necessary for the high summer load conditions with the highest inlet water temperatures. At lower water temperatures, the amount of excess thermal capability can become a performance and corrosion issue as the water flows are modulated to meet temperatures. To help reduce these problems, a design which allows operation with reduced surface at low temperatures is appropriate.
The temperature approach (Cooling Water Out – Service Water In) based on the higher inlet cooling water temperature can be significantly smaller than when the CCW was originally designed. This paper will address a design configuration that will work with both higher summer temperature cooling water with the flexibility of using less water for cooler winter operation. The overall affect is less pumping power during colder months, more consistent tube velocities which will help with heat transfer, and minimization of sediment settling in the tubes due to lower velocities.
Experimental Investigations on Temperature Distribution and Heat Removal Capability of Residual Heat Exchanger
Authors: Wu Jiangbo , Bi Qincheng , Zhou Chengsi 
Published: February 2014

The residual heat exchanger in nuclear power plant is the key component of secondary side passive residual heat removal system, where the performance of removing decay heat by condensation and pool boiling to the secondary water storage tanks in the residual heat exchanger is crucial to the safety of the nuclear power plant. In the present paper, an experimental facility is built to evaluate the heat removal capability of the residual heat exchanger in both steady state natural circulation and forced circulation at different pressures. The high pressure steam is forced to flow and enter into heat exchanger with a slight inclined tube, which is installed in a large water pool. Experiments are carried out to study the characteristics of the steam condensation in the residual heat exchanger at different parameters. A calculation code for modeling this process and predicting the outlet temperature is also developed.
The results show that the temperature difference between inlet and outlet increases with the increase of the inlet steam pressure due to the variation of latent heat. Meanwhile, the outlet temperature also increases with increasing flow rate. The calculation results accord with the experimental data at low mass flow rate. It is also found that the two calculation models proposed by J.R. Thome predict the flow pattern well, and the Shah’s equation is more suitable to estimate the heat transfer characteristic.
Cyclic Operation of Supercritical High Pressure Feedwater Heater Study
Authors: Muldoon Kellen 
Published: February 2014

As more renewable energy sources come on line with the inherent inconsistency of load dispatch feedwater heaters become subject to more frequent and rapid cyclic operation. In a recent project, American Exchanger Services (AM-EX) was asked to gather and analyze operating information on a high pressure feedwater heater during daily rapid load changes. This particular supercritical coal plant was designed to operate in flexible load environments, thus acquiring data during the summer months was optimal.
The heater was run from rest to full power while temperature data was acquired. All data from the study and supporting plant information was used to generate models for preparing maintenance projections, informing future designs, and repair recommendations. The primary component of focus is the desuperheating zone exhaust where tube failure tends to be greatest caused by wet wall conditions.
The result of the analysis was less conclusive than was anticipated. Actual performance of the heaters is a key issue and there were specific indications that the heaters were not performing to specifications. A more detailed thermal performance analysis using the ASME PTC12.1 should be considered to accurately determine the extent to which the heaters are meeting design performance.
Strategic Plan and Roadmap for Energy and Water Utilization: Water Energy Nexus
Authors: Khalil Essam E. 
Published: February 2014

All countries have realized the strategic importance of regional Energy-Water Roadmap and strategy as dictated by the world logistics and climatic changes. The purpose of the roadmap is to assess the effectiveness of existing water and energy development programs within the individual countries and among them in addressing energy and water related issues, and to assist in defining the direction of research, development, demonstration, and commercialization national and regional efforts to insure that:
1. Energy-related issues associated with providing adequate water supplies, optimal management and efficient use of water, and
2. Water-related issues associated with providing adequate supplies, optimal management and efficient use of energy are being adequately and efficiently addressed in the future.