High-efficiency hybrid PV-TEG system with intelligent control to harvest maximum energy under various non-static operating conditions

Background: The fly ash produced by coal-fired power plants is an industrial waste. The environmental pollution problems caused by fly ash have been widely of public environmental concern. As a waste of recoverable resources, it can be used in the field of building materials, agricultural fertilizers, environmental materials, new materials, etc. Unburned carbon content in fly ash has an influence on the performance of resource reuse products. Therefore, it is the key to remove unburned carbon from fly ash. As a physical method, triboelectrostatic separation technology has been widely used because of obvious advantages, such as high-efficiency, simple process, high reliability, without water resources consumption and secondary pollution. Objective: The related patents of fly ash triboelectrostatic separation had been reviewed. The structural characteristics and working principle of these patents are analyzed in detail. The results can provide some meaningful references for the improvement of separation efficiency and optimal design. Methods: Based on the comparative analysis for the latest patents related to fly ash triboelectrostatic separation, the future development is presented. Results: The patents focused on the charging efficiency and separation efficiency. Studies show that remarkable improvements have been achieved for the fly ash triboelectrostatic separation. Some patents have been used in industrial production. Conclusion: According to the current technology status, the researches related to process optimization and anti-interference ability will be beneficial to overcome the influence of operating conditions and complex environment, and meet system security requirements. The intelligent control can not only ensure the process continuity and stability, but also realize the efficient operation and management automatically. Meanwhile, the researchers should pay more attention to the resource utilization of fly ash processed by triboelectrostatic separation.

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Comprehensive Parameters Identification and Dynamic Model Validation of Interior-Mount Line-Start Permanent Magnet Synchronous Motors

Machines ◽

10.3390/machines7010004 ◽

2019 ◽

Vol 7 (1) ◽

pp. 4 ◽

Cited By ~ 3

Author(s):

Luqman S. Maraaba ◽

Zakariya M. Al-Hamouz ◽

Abdulaziz S. Milhem ◽

Ssennoga Twaha

Keyword(s):

Mathematical Model ◽

Permanent Magnet ◽

High Efficiency ◽

Experimental Tests ◽

Induction Machines ◽

Test Methods ◽

Operating Conditions ◽

Test Method ◽

Permanent Magnet Synchronous Motors ◽

Synchronous Motors

The application of line-start permanent magnet synchronous motors (LSPMSMs) is rapidly spreading due to their advantages of high efficiency, high operational power factor, being self-starting, rendering them as highly needed in many applications in recent years. Although there have been standard methods for the identification of parameters of synchronous and induction machines, most of them do not apply to LSPMSMs. This paper presents a study and analysis of different parameter identification methods for interior mount LSPMSM. Experimental tests have been performed in the laboratory on a 1-hp interior mount LSPMSM. The measurements have been validated by investigating the performance of the machine under different operating conditions using a developed qd0 mathematical model and an experimental setup. The dynamic and steady-state performance analyses have been performed using the determined parameters. It is found that the experimental results are close to the mathematical model results, confirming the accuracy of the studied test methods. Therefore, the output of this study will help in selecting the proper test method for LSPMSM.

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Octane Index Applicability over the Pressure-Temperature Domain

Energies ◽

10.3390/en14030607 ◽

2021 ◽

Vol 14 (3) ◽

pp. 607

Author(s):

Tommy R. Powell ◽

James P. Szybist ◽

Flavio Dal Forno Chuahy ◽

Scott J. Curran ◽

John Mengwasser ◽

...

Keyword(s):

High Efficiency ◽

National Laboratory ◽

Operating Conditions ◽

Dominant Factor ◽

Compression Ignition ◽

Oak Ridge ◽

Operating Modes ◽

Wide Range ◽

Thermodynamic Conditions ◽

Si Engines

Modern boosted spark-ignition (SI) engines and emerging advanced compression ignition (ACI) engines operate under conditions that deviate substantially from the conditions of conventional autoignition metrics, namely the research and motor octane numbers (RON and MON). The octane index (OI) is an emerging autoignition metric based on RON and MON which was developed to better describe fuel knock resistance over a broader range of engine conditions. Prior research at Oak Ridge National Laboratory (ORNL) identified that OI performs reasonably well under stoichiometric boosted conditions, but inconsistencies exist in the ability of OI to predict autoignition behavior under ACI strategies. Instead, the autoignition behavior under ACI operation was found to correlate more closely to fuel composition, suggesting fuel chemistry differences that are insensitive to the conditions of the RON and MON tests may become the dominant factor under these high efficiency operating conditions. This investigation builds on earlier work to study autoignition behavior over six pressure-temperature (PT) trajectories that correspond to a wide range of operating conditions, including boosted SI operation, partial fuel stratification (PFS), and spark-assisted compression ignition (SACI). A total of 12 different fuels were investigated, including the Co-Optima core fuels and five fuels that represent refinery-relevant blending streams. It was found that, for the ACI operating modes investigated here, the low temperature reactions dominate reactivity, similar to boosted SI operating conditions because their PT trajectories lay close to the RON trajectory. Additionally, the OI metric was found to adequately predict autoignition resistance over the PT domain, for the ACI conditions investigated here, and for fuels from different chemical families. This finding is in contrast with the prior study using a different type of ACI operation with different thermodynamic conditions, specifically a significantly higher temperature at the start of compression, illustrating that fuel response depends highly on the ACI strategy being used.

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Improvement Effect of Green Remodeling and Building Value Assessment Criteria for Aging Public Buildings

Energies ◽

10.3390/en14041200 ◽

2021 ◽

Vol 14 (4) ◽

pp. 1200

Author(s):

Yong-Joon Jun ◽

Seung-ho Ahn ◽

Kyung-Soon Park

Keyword(s):

High Efficiency ◽

Energy Performance ◽

Operating Conditions ◽

Energy Usage ◽

Public Buildings ◽

Value Judgment ◽

Relationship Analysis ◽

Improvement Effect ◽

The Relationship ◽

Usage Data

The Green Remodeling Project under South Korea’s Green New Deal policy is a government-led project intended to strengthen the performance sector directly correlated with energy performance among various elements of improvement applicable to building remodeling by replacing insulation materials, introducing new and renewable energy, introducing high-efficiency equipment, etc., with public buildings taking the lead in green remodeling in order to induce energy efficiency enhancement in private buildings. However, there is an ongoing policy that involves the application of a fragmentary value judgment criterion, i.e., whether to apply technical elements confined to the enhancement of the energy performance of target buildings and the prediction of improvement effects according thereto, thus resulting in the phenomenon of another important value criterion for green remodeling, i.e., the enhancement of the occupant (user) comfort performance of target buildings as one of its purposes, being neglected instead. In order to accurately grasp the current status of these problems and to promote ‘expansion of the value judgment criteria for green remodeling’ as an alternative, this study collected energy usage data of buildings actually used by public institutions and then conducted a total analysis. After that, the characteristics of energy usage were analyzed for each of the groups of buildings classified by year of completion, thereby carrying out an analysis of the correlation between the non-architectural elements affecting the actual energy usage and the actual energy usage data. The correlation between the improvement performance of each technical element and the actual improvement effect was also analyzed, thereby ascertaining the relationship between the direction of major policy strategies and the actual energy usage. As a result of the relationship analysis, it was confirmed that the actual energy usage is more affected by the operating conditions of the relevant building than the application of individual strategic elements such as the performance of the envelope insulation and the performance of the high-efficiency system. In addition, it was also confirmed that the usage of public buildings does not increase in proportion to their aging. The primary goal of reducing energy usage in target buildings can be achieved if public sector (government)-led green remodeling is pushed ahead with in accordance with biased value judgment criteria, just as in the case of a campaign to refrain from operating cooling facilities in aging public buildings. However, it was possible to grasp through the progress of this study that the remodeling may also result in the deterioration of environmental comfort and stability, such as the numerical value of the indoor thermal environment. The results of this study have the significance of providing basic data for pushing ahead with a green remodeling policy in which the value judgment criteria for aging existing public buildings are more expanded, and it is necessary to continue research in such a direction that the quantitative purpose of green remodeling, which is to reduce energy usage in aging public buildings, and its qualitative purpose, which is to enhance their environmental performance for occupants’ comfort, can be mutually balanced and secured at the same time.

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Evaluation of a High-Performance Solar Home in Loveland, Colorado

Journal of Solar Energy Engineering ◽

10.1115/1.2710248 ◽

2006 ◽

Vol 129 (2) ◽

pp. 226-234

Author(s):

Robert Hendron ◽

Mark Eastment ◽

Ed Hancock ◽

Greg Barker ◽

Paul Reeves

Keyword(s):

High Performance ◽

Energy Savings ◽

High Efficiency ◽

Building Envelope ◽

Operating Conditions ◽

Hot Water ◽

Space Heating ◽

Solar Water Heater ◽

Water Heater ◽

Solar Water

Building America (BA) partner McStain Neighborhoods built the Discovery House in Loveland, CO, with an extensive package of energy-efficient features, including a high-performance envelope, efficient mechanical systems, a solar water heater integrated with the space-heating system, a heat-recovery ventilator (HRV), and ENERGY STAR appliances. The National Renewable Energy Laboratory (NREL) and Building Science Consortium conducted short-term field-testing and building energy simulations to evaluate the performance of the house. These evaluations are utilized by BA to improve future prototype designs and to identify critical research needs. The Discovery House building envelope and ducts were very tight under normal operating conditions. The HRV provided fresh air at a rate of about 35L∕s(75cfm), consistent with the recommendations of ASHRAE Standard 62.2. The solar hot water system is expected to meet the bulk of the domestic hot water (DHW) load (>83%), but only about 12% of the space-heating load. DOE-2.2 simulations predict whole-house source energy savings of 54% compared to the BA Benchmark (Hendron, R., 2005 NREL Report No. 37529, NREL, Golden, CO). The largest contributors to energy savings beyond McStain’s standard practice are the solar water heater, HRV, improved air distribution, high-efficiency boiler, and compact fluorescent lighting package.

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Powder Spheroidization Using Induction Plasma Technology

Thermal Spray 2000: Proceedings from the International Thermal Spray Conference ◽

10.31399/asm.cp.itsc2000p0887 ◽

2000 ◽

Author(s):

N.M. Dignard ◽

M.I. Boulos

Keyword(s):

Energy Efficiency ◽

Maximum Energy ◽

Operating Conditions ◽

Side Reactions ◽

Induction Plasma ◽

Silica Alumina ◽

Change In The Mean ◽

The Individual ◽

Semi Empirical ◽

Objective Being

Abstract An experimental study of the spheroidization efficiency of induction plasma processes was completed. The main objective being to obtain models which could be subsequently used for the prediction of the spheroidization efficiency for various powders and plasma operating conditions. Silica, alumina, chromium oxide and zirconia powders were treated during the experimentation. For the plasma treatment of the powders the installation used had a maximum available power of 50 kW with an operating frequency of 3 MHz. Operating conditions were varied such to minimize side reactions and the evaporation of powders. The resulting powders did show the presence of cavities and a slight change in the mean diameters. The maximum energy efficiency based semi-empirical model did predict the spheroidization efficiency of the particles beyond a defined critical point known as the maximum energy efficiency point. For the model, the maximum energy efficiency is distinct for the individual powders but remain within a defined range which is reflected in the small variations in the Z constant.

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Development of the PGT 25 High Efficiency Gas Turbine: Part 2 — Aerodynamic Design and Performance

Volume 3: Coal, Biomass and Alternative Fuels; Combustion and Fuels; Oil and Gas Applications; Cycle Innovations ◽

10.1115/84-gt-62 ◽

1984 ◽

Author(s):

E. Benvenuti ◽

B. Innocenti ◽

R. Modi

Keyword(s):

Gas Turbine ◽

High Efficiency ◽

Performance Testing ◽

Operating Conditions ◽

Aerodynamic Design ◽

Direct Drive ◽

Gas Generator ◽

Full Load ◽

Wide Range ◽

Overall Performance

This paper outlines parameter selection criteria and major procedures used in the PGT 25 gas turbine power spool aerodynamic design; significant results of the shop full-load tests are also illustrated with reference to both overall performance and internal flow-field measurements. A major aero-design objective was established as that of achieving the highest overall performance levels possible with the matching to latest generation aero-derivative gas generators; therefore, high efficiencies were set as a target both for the design point and for a wide range of operating conditions, to optimize the turbine’s uses in mechanical drive applications. Furthermore, the design was developed to reach the performance targets in conjunction with the availability of a nominal shaft speed optimized for the direct drive of pipeline booster centrifugal compressors. The results of the full-load performance testing of the first unit, equipped with a General Electric LM 2500/30 gas generator, showed full attainment of the design objectives; a maximum overall thermal efficiency exceeding 37% at nominal rating and a wide operating flexibility with regard to both efficiency and power were demonstrated.

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Preparation of Flower-like Nickel-Based Bimetallic Organic Framework Electrodes for High-Efficiency Hybrid Supercapacitors

Crystals ◽

10.3390/cryst11111425 ◽

2021 ◽

Vol 11 (11) ◽

pp. 1425

Author(s):

Di Jiang ◽

Chuanying Wei ◽

Ziyang Zhu ◽

Xiaohui Xu ◽

Min Lu ◽

...

Keyword(s):

Specific Capacitance ◽

Electrode Materials ◽

High Efficiency ◽

Specific Capacity ◽

Maximum Energy ◽

Cycle Life ◽

High Porosity ◽

Hybrid Supercapacitors ◽

Metal Organic ◽

General Method

Metal organic frameworks (MOFs) have been rapidly developed in the application of electrode materials due to their controllable morphology and ultra-high porosity. In this research, flower-like layered nickel-based bimetallic MOFs microspheres with different metal central ions were synthesized by solvothermal method. Compared with Ni-MOFs, the optimization of the specific capacitance of NiCo-MOFs and NiMn-MOFs was been confirmed. For example, the specific capacitance of NiCo-MOFs can reach 882 F·g−1 at 0.5 A·g−1 while maintaining satisfactory cycle life (the specific capacity remains 90.1% of the initial value after 3000 charge-discharge cycles at 5 A·g−1). In addition, the NiCo-MOFs//AC HSCs, which are composed of NiCo-MOFs and activated carbon (AC), achieved a maximum energy density of 18.33 Wh·kg−1 at a power density of 400 W·kg−1, and showed satisfactory cycle life (82.4% after 3000 cycles). These outstanding electrochemical properties can be ascribed to the synergistic effect between metal ions, the optimized conductivity, and the unique layered stacked flower structure, which provides a smooth transmission channel for electrons/ions. In addition, this research gives a general method for the application of MOFs in the field of supercapacitors.

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Evaluation of a High-Performance Solar Home in Loveland, Colorado

Solar Energy ◽

10.1115/isec2005-76231 ◽

2005 ◽

Cited By ~ 1

Author(s):

Robert Hendron ◽

Mark Eastment ◽

Ed Hancock ◽

Greg Barker ◽

Paul Reeves

Keyword(s):

High Performance ◽

Energy Savings ◽

High Efficiency ◽

Building Envelope ◽

Operating Conditions ◽

Hot Water ◽

Space Heating ◽

Solar Water Heater ◽

Water Heater ◽

Solar Water

Building America (BA) partner McStain Neighborhoods built the Discovery House in Loveland, Colorado, with an extensive package of energy-efficient features, including a high-performance envelope, efficient mechanical systems, a solar water heater integrated with the space-heating system, a heat-recovery ventilator (HRV), and ENERGY STAR™ appliances. The National Renewable Energy Laboratory (NREL) and Building Science Consortium (BSC) conducted short-term field-testing and building energy simulations to evaluate the performance of the house. These evaluations are utilized by BA to improve future prototype designs and to identify critical research needs. The Discovery House building envelope and ducts were very tight under normal operating conditions. The HRV provided fresh air at a rate of about 75 cfm (35 l/s), consistent with the recommendations of ASHRAE Standard 62.2. The solar hot water system is expected to meet the bulk of the domestic hot water (DHW) load (>83%), but only about 12% of the space-heating load. DOE-2.2 simulations predict whole-house source energy savings of 54% compared to the BA Benchmark [1]. The largest contributors to energy savings beyond McStain’s standard practice are the solar water heater, HRV, improved air distribution, high-efficiency boiler, and compact fluorescent lighting package.

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Hydrogenotrophic denitrification in an attached growth reactor under various operating conditions

Water Science & Technology Water Supply ◽

10.2166/ws.2011.120 ◽

2012 ◽

Vol 12 (1) ◽

pp. 72-81 ◽

Cited By ~ 10

Author(s):

Wilawan Khanitchaidecha ◽

Futaba Kazama

Keyword(s):

Groundwater Remediation ◽

Inorganic Carbon ◽

High Efficiency ◽

Nitrate Nitrogen ◽

Sharp Decrease ◽

Operating Conditions ◽

Attached Growth ◽

N Removal ◽

Dissolved Hydrogen

To study the performance of an attached growth reactor on nitrate-nitrogen (NO3-N) removal by a hydrogenotrophic denitrification process, the reactor was operated under various H2 flow rates (30, 50 and 70 mL/min), hydraulic retention times (HRTs) (2.6, 3.1, 4.7 and 6.7 h) and inorganic carbon (IC) concentrations (excess and no IC addition). Synthetic NO3-N water was prepared in accordance with the groundwater quality of the study area: Chyasal in Kathmandu Valley, Nepal. The results show an increase in denitrification efficiency with H2 flow rate and HRT. Further, for effective denitrification, the dissolved hydrogen (DH) during operation should be maintained at greater than 0.1 mg/L. A sharp decrease in the denitrification efficiency from ∼96% (under excess IC) to 10–35% (under no IC) suggested occurrence of denitrification inside the attached growth reactor by a hydrogenotrophic process (using H2) as well as heterotrophic process (using internal organic carbon). The good performance of the attached growth reactor in terms of high efficiency, low H2 supply and short HRT requirement indicates the reactor's appropriateness for groundwater remediation through NO3-N removal.

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