Performance Of New System Research Articles

Experimental and simulation study on a new gradient waste heat recovery system with a wider application range

This paper proposes a cascade sustainable waste heat recovery technology with low power consumption and the ability to recover waste heat in a wider temperature range, namely, the Absorption-Compression Coupled Heat Pump System. Experiments and simulations were conducted to reveal the effects of different factors on system performance. The results demonstrate that the coefficient of performance and exergy efficiency of the new system increase with an increase in generator outlet water temperature. The coefficient of performance of the new system decreases with an increase in supply heating water inlet water temperature, while the exergy efficiency increases with an increase in supply heating water inlet water temperature. As intermediate temperature increases, the coefficient of performance of new system shows a trend of first increasing and then decreasing, the total heating shows a trend of first increasing and then stabilizing, and the exergy efficiency shows a decreasing trend. Compared to single-effect absorption heat pump system, the new system can recover heat at lower heat source temperatures, and compared to compression heat pump system, it can reduce electricity consumption. Finally, by comparing with experimental data, it was found that the proposed model has good reliability, with a comprehensive error within ±7 %.

Study on MCFC-integrated GSCC systems with SEGR in parallel or series and CO2 capture

In this paper, two new molten carbonate fuel cell (MCFC)-integrated gas–steam combined cycle (GSCC) systems with selective exhaust gas recirculation (SEGR) and CO2 capture are proposed and analyzed. The CO2 concentration in the gas turbine emission is increased because CO2 is selectively recycled with the help of SEGR. Molten carbonate fuel cells (MCFCs) are another way to increase CO2 concentration in the gas turbine flue gas by translating only CO2 from the cathode to the anode. In these two new gas–steam combined cycle systems, SEGR connected with MCFC, either in parallel or series, increases CO2 concentration beyond 11%. A gas–steam combined cycle system combined with MCFC and CO2 capture without SEGR is used as the reference system. Aspen Plus software is adopted to build the system models, and the performances of different systems are discussed and compared. The research results reveal that for the MCFC-integrated gas–steam combined cycle system with SEGR in series and CO2 capture, the CO2 concentration of gas turbine exhaust increases to 11.72% and the thermal efficiency is 56.29% when the overall CO2 capture rate is 88.16%, which is 1.13% higher than that of the reference system; for the MCFC-integrated gas–steam combined cycle system with SEGR in parallel and CO2 capture, the CO2 concentration of gas turbine exhaust increases to 14.15% and the thermal efficiency is 56.62%, which is 1.46% higher than that of the reference system. Furthermore, the economic analysis results show that the economic performances of new systems are mainly influenced by MCFC cost and will be gradually improved with the decrease in the MCFC cost.

Performance analysis of a new ORC-VCC system with mechanical overheating and correlation fitting of most important system parameter

Abstract This paper proposes a new ORC-VCC(Organic Rankine Cycle+Vapor compression cycle) system(with mechanical overheating refrigeration cycle), and this system can not only reduce the heat absorption of the ORC evaporator, but also increase the refrigeration capacity of the system. Simulations were conducted to analyze the thermal efficiency and performance of the new system, and compare it with the system of ORC-VCC(with regenerator). The results show that the ηth, ηsys and COPsys(coefficient of performance) of new system are higher than the system of ORC-VCC(with regenerator), ηth, ηsys and COPsys of new system increased by up to 31.6%, 6.48%, 10.63% respectively. And the influence of superheat on both systems is stronger than other factors, the influence of superheat on the new system is obviously stronger than those of the system of ORC-VCC(with regenerator), and the influence of superheat on R245fa and Butane is stronger than those of other working fluids. In addition, ηth, ηsys, COPsys and ηex of system increase with the increase of Te-mech and decrease with the increase of Tg-mech. Finally, the correlation of δTmax with the change of ηexp and Te-orc is fitted, the results will provide some reference for the development of the ORC-VCC system in the future.

Performance analysis of a new mechanical superheat coupled-orc refrigeration system with thermoelectric conversion

This paper proposes a new refrigeration and energy conversion system, namely Expander Mechanical Overheating-Organic Rankine Cycle (EMO-ORC) system. Compared with the existing carbon dioxide (R744) refrigeration system, the new system can not only improve the coefficient of performance (COP) of the system and reduce the discharge pressure, but also effectively recover the waste heat of the system, and convert it into electrical energy. Simulation were conducted to compare its system performance with R744 refrigeration system (with heat exchanger), at the same time, the effect of different factors on the performance of new system is analyzed. The results demonstrate that, at the same evaporation temperature and gas cooler outlet temperature, compared with the system (with heat exchanger), the COP of the new system increased by 8.2% and 8.9% on average, respectively. And the discharge pressure decreased by 0.88% and 0.79%, respectively. In the given superheat degree range, compared with the system(with heat exchanger), the COP of the new system is increased by 4.5% on average, and increased by 10.2% at the highest level. Under the most given working conditions, the cooling capacity of new system is higher than that of the system (with heat exchanger), and the power consumption is lower than that of the system (with heat exchanger). In the new system, the narrow point temperature difference and the outlet temperature of the first stage gas cooler have a greater impact on the COP, with the increase of both, the COP of the new system increases by 5.6% and decreases by13.7%, respectively.

Exergoeconomic evaluation of novel solid oxide fuel cell-integrated solar combined cycle with different solar integration modes

The active use of fuel cells and solar energy in power generation systems can help reduce fossil energy consumption and improve the work capacity of the system, which is an important means to achieve the goal of “carbon neutrality”. In this study, novel solid oxide fuel cell-integrated solar combined cycle systems with different solar integration modes are proposed and investigated. The thermodynamic, environmental and economic performances of new systems with different solar collector integration modes are evaluated using the exergoeconomic theory and environmental performance analysis. The results show that when the new system uses trough solar collectors to replace part of the heating load of the second-stage high-pressure economizer and high-pressure boiler drum, the system has the highest exergy efficiency (52.91%), the lowest unit exergoeconomic cost (0.102109 $/kWh) and the lowest specific CO2 emission rate (475.27 g/kWh). When the operating conditions of the system remain unchanged, this solar energy integration mode has the highest solar-to-electricity efficiency (26.69%) as well as thermal-to-electricity efficiency (44.22%), and can obtain the best profit in the same operating life. The new system can attain maximum energy efficiency and optimal economic benefits by using this solar energy integration mode.

Outdoor test facilities for the experimental performance evaluation of construction materials and systems: The BeTOP case

Proposing new materials and systems to improve the performance and energy efficiency of buildings is often followed by performance evaluation to monitor how they perform and contribute. Experimental performance characterization of new and existing building materials and systems is crucial to understanding their behaviour in relation to indoor environmental and conditional changes, in addition to outdoor environmental changes. Full-scale experimental test cell facilities have been at the forefront of experimental performance evaluation in building-related research, as they can provide a realistic representation of buildings, which includes environmental conditions, building structure, and operational characteristics. In this paper, the new test cell facility of BeTOP, located in the city of Toronto, Ontario, is introduced as a full-scale experimental facility with the capability of multiple practical tests simultaneously. This paper describes the characteristics of this test cell, including structure details, testing capabilities, system details, previous testing campaigns, and future testing potential. The design of such a full-scale testing facility is shown to be crucial in a continental climate, such as Toronto, to observe the long-term performance of new systems under variable boundary conditions with cold winters and hot and humid summer seasons.

Investigating Internet of Things Impact on e-Learning System: An Overview

e-Learning systems have reached their peak with the revolution of smart technologies. In the past few years, the Internet of Things (IoT) has become one of the most advanced and popular technologies, affecting many different areas. Using IoT in an e-learning system is a fantastic technology that improves the e-learning system and makes it more inventive and cutting-edge. The key challenge addressed in this study is the acceptance of IoT usage in e-learning systems as well as how to improve it so that it can be utilized properly. This research concentrates on how IoT can benefit e-learning systems and how it might benefit users of e-learning systems. A comprehensive literature review was conducted to get acquainted with the important research related to IoT technology and e-learning systems through online research databases and reliable scientific journals. The first research finding is that e-learning systems need such modern techniques as IoT to enable interconnection, increase reliability, and enhance the enjoyment of the educational process. The second result is that research related to the development of new technologies like the IoT has a significant impact on enhancing the performance of new systems and bringing about positive change. This study highlights the value of IoT, particularly in e-learning systems. It aids in the development of new strategies that will improve the efficacy of e-learning systems and stimulate researchers to develop advanced technology.

The BeTOP facility for performance testing of building systems

Proposing new materials and systems to improve buildings' performance and energy efficiency often requires testing their performance in the field. Experimental performance characterization of new and existing building systems is crucial to understanding their behaviour. Full-scale experimental test cell facilities have been at the forefront of experimental performance evaluation in building-related research, as they provide a realistic representation of buildings, including environmental conditions, assembling challenges, and operational characteristics. In this paper, trends in the design and construction of outdoor testing facilities are first discussed. Then, based on the current literature and the knowledge gained through visits to multiple facilities, the new test cell facility “BeTOP”, located in Toronto (Ontario), is described. BeTOP is a full-scale experimental facility with the capacity to perform multiple experimental tests simultaneously. This paper describes its characteristics, including structure details, testing capabilities, system details, current monitoring campaigns, and future testing potential. The paper concludes by showing that the design of a full-scale testing facility is crucial to observe the long-term performance of new systems under variable boundary conditions in a continental climate with cold winters and hot and humid summers.

A Survey Paper on Sketch to Face Recognition by using Machine Learning

Our goal is to create a tool that assists forensic investigators in accurately identifying victims. However, police sketching tactics are a common component of law enforcement investigations and are frequently used to identify suspects from the recollection of an eyewitness. This time-honored method of identification is typically laborious and slow, and it could not result in the appropriate criminal being apprehended. In order to accurately identify the criminal from a collection of face photos, an automatic face sketch identification system is needed. Because faces and sketches are produced from many sources and have varied gaps to be filled at low and high levels, such technology design presents an open research problem. Although other approaches have been suggested, we are not aware of any surveys on this specific subject. Measuring the performance of new systems and of current systems becomes extremely critical as we propose new algorithms and construct more systems. Below is an overview of systematic data collecting and evaluation of facial recognition systems. It can be difficult to identify a 3D item from its 2D representation. For appearance- or image-based techniques, the posture and illumination concerns are two significant problems. To address these difficulties, numerous strategies have been put forth, the bulk of which focus on domain knowledge.

Design and Performance Analysis of New Ultra-Supercritical Double Reheat Coal-Fired Power Generation Systems

In order to solve the existing problems of large mean heat transfer temperature differences of regenerative air heaters and high superheat degrees of regenerative extraction steam in double reheat coal-fired power generation systems, two new design schemes of ultra-supercritical double reheat cycles are proposed, which can realize the deep boiler-turbine coupling among the heat transfer processes of air, feeding water and regeneration extraction steam on the base of the principle of energy level matching. A typical 1000 MW ultra-supercritical double reheat cycle system is selected as the reference system and the overall system model is built by using the Ebsilon simulation software. The performances of two new systems are analyzed by using both the exergy method and energy equilibrium method. The results show that net output powers of both new systems 1 and 2 increase by 6.38 MW and 6.93 MW, respectively, and the standard coal consumptions of power generation decrease by 1.65 g/kWh and 1.79 g/kWh, respectively. The off-design performances of new systems and the reference system are analyzed, and the results show that performances of two new systems are better than that of the reference system. The system flow of the new system 2 is more complex compared with that of the new system 1. Generally speaking, the performance of new system 1 is better than that of new system 2. On the basis of new system 1, new system 3 is further optimized and its full operating condition performance characteristics are analyzed. The standard coal consumption rate of new system 3 is reduced about 1 g/kWh at higher load, and around 0.2 g/kWh at low load.

Assessment of a new combined thermal and compressed energy storage coupled with an absorption power cycle: Thermodynamic study

Energy storage technologies highly flourish in past years along with the quick progress of renewable energies. Compressed air energy storage has captured the world attention due mainly to its eco-friendliness, long lifetime, safety and good economic benefits. In the paper a new hybrid energy storage system is put forward. It comprises a combined thermal-compressed air energy storage and an ejector-based superheated Kalina cycle. Mathematical model of the hybrid energy storage system is developed for thermodynamic analysis and parametric study is conducted to examine the effects of some key parameters on the performance of new system. The results demonstrate that the separation pressure enjoys an optimum valve firstly and then at a higher separation temperature the increase of it gives a monotonical increase in the round trip efficiency. As the ammonia mass fraction increases, the round trip efficiency increases first and decreases with existing an optimum value. In general, the new hybrid system enjoys 6.13–9.32% higher round trip efficiency than the baseline standalone system. Therefore, the proposed system has a positive potential for storing renewable power in large scale in favour of increasing penetration level of renewable energies.

Study of an Integrated Tower Solar Energy Combined Cycle System with the Simultaneous Integration Solar Energy with Top and Bottom Cycle

In this paper, based on a conventional integrated solar combined cycle system (ISCC), a novel integrated tower solar energy combined cycle system (ITSCC) with the simultaneous integration the solar energy with top and bottom cycle of combined cycle system is proposed. The system models are developed and different system performance evaluation indices are proposed. Then in the condition of the same solar radiation the thermal performance of new system is analyzed and compared with the reference ISCC system and gas-steam combined cycle (GTCC) system. Furthermore, the operating characteristics of the new system in the summer solstice are deeply investigated in consideration of the heat variation from direct solar radiation and the effect of the ambient temperature change on the solar collector system. The efficiency of solar energy utilization and the thermodynamic properties of different systems are analyzed. The result shows that, in the summer solstice the natural gas input of new system is less 3.28% than that of GTCC system and the net output power is increased by 1.5%, the solar-to-electric efficiency and the exergy efficiency can achieve 27.3% and 28.4%, respectively. In addition, the annual performance of new system is also better than that of the reference system.

COMPUTER AIDED DESIG:6 COMPUTER AIDED TESTING MODELLING TECHNIQUE

The dynamic behaviour of many physical systems such as mechanical manipulators are highly nonlinear and complex. Further-more, the inertia, stiffness and dissipation characteristics of most systems may depend on the environment which is often unknown. Because of these reasons, there is an increasing interest in combining computer aided design with computer aided testing into a unified CADCAT technique to obtain satisfactory modelling for physical systems.In this paper an integrated CADCAT technique is proposed and investigated. This approach utilizes computer aided finite element modelling CAD and computer aided modal testing CAT into a system analysis routine to predict the dynamic performance of new systems as well as to select the design modifications for existing systems. Some applications of this techni-que on some design problems are described.

The moderating role of just‐in‐time on sociotechnical practices' effect over quality and workers' health

AbstractSociotechnical (ST) theory emphasizes the notion that the design and performance of new systems can be improved, and can only work satisfactorily within an organization if the social and the technical aspects are brought together and treated as interdependent aspects of a work system. The implementation of lean manufacturing (LM) principles and practices has become popular, despite increasing demand on the current and emerging workforce to achieve higher levels of quality and flexibility with lower costs. Exploratory studies that investigate how LM practices influence the effect of ST practices on performance are still scarce, and a holistic view of such a relationship is needed. In this context, this study aims at verifying the moderating effect of just‐in‐time (JIT) practices on the relationship between ST practices and the performance of quality and workers' health. We carried out a survey with 144 different companies from Southern Brazil that are undergoing a lean implementation. Results indicate that ST practices have a positive significant relationship with such performance, and the concurrent adoption of JIT does not undermine quality and workers' health.

RF Circuit Implementation of a Real-Time Frequency Spread Emulator

Despite their reliability, on-site measurements are time-consuming and costly actions for the evaluation of new devices. Channel emulators are widely utilized measurement instruments to generate desired environmental channel effects in laboratory environments. Within these instruments, baseband emulators are expensive, and reverberation chambers provide limited control of the channel. However, radio-frequency (RF) circuit implementation of channel emulators provides an affordable and easy tool to test performances of new systems and methods under different channel effects. In this paper, a new RF domain Doppler emulator, which is compact and easy to control, is presented for measuring signal characteristics under frequency dispersive channel conditions. The circuit has been implemented using variable attenuators, switches, and power splitters to emulate the Doppler spread of air-ground channels, and the performance is evaluated through measurements. It is observed that the emulator indeed generates the desired Doppler model close enough to replicate environmental channels for mobile applications in laboratory environments.

A feasibility study for CO2 recycle assistance with coke oven gas to synthetic natural gas

Based on the industrial technology from coke oven gas to synthetic natural gas, a process of CO2 recycle assistance with coke oven gas to synthetic natural gas is proposed, simulated, and optimized. The effects of key parameters on the performance of new system are investigated and the optimum parameters are determined. The coke oven gas reacts with the recycled CO2 separated from the CO2-rich exhaust gas to produce syngas for synthetic natural gas production. This CO2 recycle can significantly improve the hydrogen utilization efficiency in coke oven gas, which does not only increases the synthetic natural gas production and thus enhancing energy efficiency, but also reduces the CO2 emission simultaneously. The results show that the energy and exergy efficiency (79.0% and 81.1%) of the new process is increased by 6.3 and 6.6 percent points, synthetic natural gas production cost and direct CO2 emission reduced by 0.05US$/m3 and 99.9%, whereas the synthetic natural gas output increased by 20%, in comparison with the conventional coke oven gas to synthetic natural gas process. The proposed system provides a promising way for future improvements of coke oven gas to synthetic natural gas process, and can also be a guide for CO2 utilization or CO2 emission reduction in coking industry.

Protective layer of AL<sub>2</sub>O<sub>3</sub> nanocomposites and surface composition after electrical stress

The performance of nanocomposites for improved resistance to electrical discharges has resulted in increased interest in nano-loaded thermosetting resins. First assessments of the performance of new systems can be obtained by a plate-electrode construction according to IEC(b). Epoxy resins loaded with different amounts of spherical alumina particles were tested following this procedure and parameters such as erosion depth and standardized volume analyzed. Transmission electron microscopy (TEM) and a three-dimensional (3D) reconstruction using electron tomography were used to determine the particle size distribution. TEM analysis after preparation of the eroded samples indicates the advantages and disadvantages of using alumina nanoparticles to improve the erosion resistance and showed a novel effect of the surface-grafted polysiloxanes. A comparison with conventional nano-silica-loaded resins reveals that the lower sintering tendency of Al2O3 is important.

Research on Overlapped Time Division Multiplexing in the Amplify-and-Forward Cooperative Mode

In order to improve spectrum efficiency of cooperative communication system, Overlapped Time Division Multiplexing (OVTDM) is applied to Amplify-and-Forward (AF) cooperative communication system. The simulation results under Additive White Gaussian Noise (AWGN) channel show that the performance of new system is superior to that of corresponding AF cooperative communication system.

An Integration of Genetic Algorithm and Projected Clustering for Optimization of Content Based Image Retrieval System

In recent years especially in the last decade, the rapid development in computers, storage media and digital image capturing devices enable to collect a large number of digital information and store the minicomputer readable formats. The main objective of this paper is to build more generalized CBIR system which increase the searching ability and provide more accurate results. To improve the retrieval accuracy the system has taken the feedback from the user automatically. To evaluate the performance of new system, we use WANG database. The metrics used for evaluation are precision, recall and retrieval time. The performance can be evaluated by comparing some existing systems in CBIR. The performance of new system in terms of the metrics proves to good.

Study on zero CO2emission atmospheric pressure SOFC hybrid power system integrated with OTM

SUMMARY In order to further reduce the energy consumption of CO2 capture from the traditional SOFC hybrid power system, based on the principle of energy cascade utilization and system integration, a zero CO2 emission atmospheric pressure solid oxide fuel cell (SOFC) hybrid power system integrated with oxygen ion transport membrane (OTM) is proposed. The oxygen is produced by the OTM for the oxy-fuel combustion afterburner of SOFC. With the Aspen-plus software, the models of the overall SOFC hybrid power systems with or without CO2 capture are developed. The thermal performance of new system is investigated and compared with other systems. The effects of the fuel utilization factor of SOFC and the pressure ratio between two sides of OTM membrane on the overall system performance are analyzed and optimized. The research results show that the efficiency of the zero CO2 emission atmospheric pressure SOFC hybrid power system integrated with OTM is around 58.36%, only 2.48% lower than that of the system without CO2 capture (60.84%) but 0.96% higher than that of the zero CO2 emission atmospheric pressure SOFC hybrid system integrated with the cryogenic air separation unit. Copyright © 2014 John Wiley & Sons, Ltd.