scholarly journals Efficiency Advantages of the Separated Electric Compound Propulsion System for CNG Hybrid Vehicles

Energies ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 8481
Author(s):  
Emiliano Pipitone ◽  
Salvatore Caltabellotta
Keyword(s):  
Internal Combustion Engines ◽  
Storage System ◽  
Electric Energy ◽  
Energy Storage System ◽  
Propulsion System ◽  
Spark Ignition Engine ◽  
Maximum Efficiency ◽  
Compound System ◽  
Turbine Generator ◽  
Hybrid Propulsion

As is widely known, internal combustion engines are not able to complete the expansion process of the gas inside the cylinder, causing theoretical energy losses in the order of 20%. Several systems and methods have been proposed and implemented to recover the unexpanded gas energy, such as turbocharging, which partially exploits this energy to compress the fresh intake charge, or turbo-mechanical and turbo-electrical compounding, where the amount of unexpanded gas energy not used by the compressor is dedicated to propulsion or is transformed into electric energy. In all of these cases, however, maximum efficiency improvements between 4% and 9% have been achieved. In this work, the authors deal with an alternative propulsion system composed of a CNG-fueled spark ignition engine equipped with a turbine-generator specifically dedicated to unexpanded exhaust gas energy recovery and with a separated electrically driven turbocompressor. The system was conceived specifically for hybrid propulsion architectures, with the electric energy produced by the turbine generator being easily storable in the on-board energy storage system and re-usable for vehicle traction. The proposed separated electric turbo-compound system has not been studied in the scientific literature, nor have its benefits ever been analyzed. In this paper, the performances of the analyzed turbo-compound system are evaluated and compared with a traditional reference turbocharged engine from a hybrid application perspective. It is demonstrated that separated electric compounding has great potential, with promising overall efficiency advantages: fuel consumption reductions of up to 15% are estimated for the same power output level.

scholarly journals Parametric Optimisation of a Trigenerative Small Scale Compressed Air Energy Storage System

Proceedings ◽  
2019 ◽  
Vol 23 (1) ◽  
pp. 5
Author(s):  
Mohamad Cheayb ◽  
Sébastien Poncet ◽  
Mylène Marin-Gallego ◽  
Mohand Tazerout
Keyword(s):  
Energy Storage ◽  
Storage System ◽  
Electric Energy ◽  
Optimal Solution ◽  
Energy Storage System ◽  
Compressed Air ◽  
Design Parameters ◽  
Small Scale ◽  
Compressed Air Energy Storage ◽  
Study Results

Recently, major improvement on compressed air energy storage technology has been made by using the heat of compression for heating energy or using it to preheat the compressed air in the expansion phase and by demonstrating its ability to produce cooling energy. Thus, the trigenerative compressed air energy storage has been introduced. In this paper, we introduce a configuration of trigenerative compressed air energy storage system giving the preference to the electric energy production. The study then focuses on undertaking an optimization study via a parametric analysis considering the mutual effects of parameters. This analysis is applied to a micro-scale application including the existing technological aspects. The parametric study results applied on the hot temperature of the thermal energy storage indicate the possibility to find an optimal solution as a trade-off between system performances and other parameters reflecting its cost. On the contrary, the selection of the maximal storage pressure cannot be achieved by finding a compromise between energy density and system efficiency. A complete study of other design parameters will be addressed in a future publication.

Frequency control of a wind turbine generator–flywheel system

2017 ◽  
Vol 41 (6) ◽  
pp. 397-408 ◽  
Author(s):  
Djalloul Achour ◽  
Mohamed Kesraoui ◽  
Ahmed Chaib ◽  
Abdeldjalil Achour
Keyword(s):  
Wind Turbine ◽  
Power Flow ◽  
Frequency Control ◽  
Storage System ◽  
Energy System ◽  
Energy Storage System ◽  
Turbine Generator ◽  
Integral Control ◽  
Wind Turbine Generator ◽  
Hybrid Renewable Energy System

The aim of this article is to propose an enhanced frequency regulator of a wind turbine generator associated with a flywheel applying an adaptive fuzzy proportional integral control, to supply a stand-alone load at 50 Hz. The flywheel energy storage system is used to balance the produced and consumed powers; it means the flywheel stores energy in case of power excess and delivers it in the opposite case. This power flow control stabilizes more the frequency around the set point. This hybrid renewable energy system is simulated by SIMPOWER in MATLAB Simulink software. Furthermore, performance improvement of the proposed new control is validated by the obtained satisfying results.

scholarly journals An assessment on the efficient use of hybrid propulsion system in marine vessels

2020 ◽  
Vol 10 (2) ◽  
pp. 61-74
Author(s):  
Murat Bayraktar ◽  
Güldem A. Cerit
Keyword(s):  
Energy Efficiency ◽  
Fuel Consumption ◽  
Internal Combustion Engines ◽  
Focal Point ◽  
Renewable Energy Sources ◽  
Propulsion System ◽  
Environmental Benefits ◽  
Maritime Industry ◽  
Hybrid Propulsion ◽  
Marine Vessels

Many improvements are performed in the maritime industry to ensure sustainability and energy efficiency. The use of hybrid propulsion systems (HPS) in marine vessels constitutes one of the developments in this field. In this study,both economic and environmental benefits are targeted. The study aims to reduce the high fuel consumption of the engine per unit power at low loads and minimization of emissions by sourcing them from main engine by HPS. Overcoming the limitations of Annex VI (Prevention of Air Pollution from Ships) of International Convention for the Prevention of Pollution from Ships (MARPOL) are desired and the research hopes for a beneficial result on Energy Efficiency Measures such as Energy Efficiency Operational Indicator (EEOI). A comprehensive study is accomplished on the hybrid propulsion system components and the keywords used in the literature review are revealed. Furthermore, the articles that have “efficiency”, “vessel”, “propulsion” and “marine” topics published in Web of Science (WOS) between 1975-2020 are examined and 44 studies are obtained. The studies that have been reached are analyzed and interests of them are collect under the 18 heading and the focal point of each study is highlighted in article. According to the results, the hybrid system provides low fuel consumption, minimizes emissions and  costs, complies with the regulations of the International Maritime Organization, uses renewable energy sources, encourages the use of electric motors in addition to internal combustion engines, increases the efficiency of energy storage systems among other things. This article will be a significant resource for academicians, experts and companies on the Hybrid propulsion system in setting their focus.   Keywords: Hybrid propulsion, Energy saving, Global warming.

scholarly journals A Comparative Review on Energy Storage System for E-Transportation

2021 ◽  
Vol 9 (10) ◽  
pp. 1760-1763
Author(s):  
R. Sugashini
Keyword(s):  
Energy Storage ◽  
Electric Vehicle ◽  
Internal Combustion Engines ◽  
Storage System ◽  
Energy Storage System ◽  
Efficiency Index ◽  
Combustion Engines ◽  
Technological Improvement ◽  
Comparative Review ◽  
Index Terms

Abstract: Electric Vehicle is widely used with its technological improvement. It is superior to internal combustion engines in efficiency and simplicity. Energy Storage System (ESS) is a heart of electric vehicle though it faces challenges in storage capability. This paper is about the evaluation of different energy storage options for electric vehicle including the batteries, super-capacitors, and flywheel. This paper conveys a review of the energy storage systems with challenges, opportunities and future guidelines of EVs with energy storage. Suggest some of the options under study to increase storage capacity. The comparison of energy storage system carried out with the help of its parameters such as energy density, specific energy, lifecycle, efficiency. Index terms- Energy Storage System, batteries, supercapacitors, Electric Vehicle, flywheel

scholarly journals Operating conditions of electric energy storage system in DC traction power supply for single-track sections of railways

2021 ◽  
Vol 80 (4) ◽  
pp. 216-224
Author(s):  
V. L. Nezevak
Keyword(s):  
Energy Storage ◽  
Power Supply ◽  
Storage System ◽  
Electric Energy ◽  
Energy Storage System ◽  
Operating Conditions ◽  
Electric Energy Storage ◽  
Electric Energy Storage System ◽  
Traction Power Supply ◽  
Traction Power

Considered are the issues of using electric energy storage system in the traction power supply of direct current of a single-track section. An overview of the main directions of domestic and foreign research in the field of using these systems to increase the capacity and energy efficiency of power supply systems is given. Modeling the operation of energy storage system in traction power supply is based on the calculation of load graphs within the boundaries of inter-substation zones, formed depending on the conditions for the passage of trains and traction load on the railway section. The main provisions of the method for choosing locations and determining the parameters of energy storage system in traction power supply are considered. On the example of one of the inter-substation zones of the Sverdlovsk railway, the influence of the power of the active sectioning station on the increase in the minimum voltage level at the pantograph of the electric rolling stock is shown. The graphs of the degree of charge and the corresponding frequency distributions are given, which make it possible to evaluate the operating conditions of the electric energy storage system depending on the conditions for the formation of the traction load, as well as the graphs of the load of the electric energy storage system and the corresponding charging characteristics for the operating conditions at the sectioning post. On the example of the section under consideration, the dependence of the discharge depth of the electric energy storage system on the nominal energy intensity is shown. Based on the results of calculations, an evaluation was made of the options for passing train batches in the even and odd direction in comparison with the schedule of the performed train operation. The range of variation of the nominal values of power and energy intensity of the electric energy storage system is obtained. Comparison of the accumulation system parameters for single- and double-track sections of railways, including those with a predominance of passenger traffic, is carried out.

Modeling and Simulation of Building Cooling System With Supercooling-Based Ice Energy Storage

2020 ◽  
Vol 1 (2) ◽  
Author(s):  
Yili Zhang ◽  
Sean Kissick ◽  
Hailei Wang
Keyword(s):  
Energy Consumption ◽  
Energy Storage ◽  
Cooling System ◽  
Low Cost ◽  
Storage System ◽  
Electric Energy ◽  
Energy Storage System ◽  
Heavy Load ◽  
Electricity Cost ◽  
Hourly Temperature

Abstract City’s electricity power grid is under heavy load during on-peak hours throughout summer cooling season. As the result, many utility companies implemented the time-of-use rate of electricity leading to high electricity cost for customers with significant cooling needs. On the other hand, the need for electricity and/or cooling decreases greatly at night, creating excess electricity capacity for further utilization. An innovative ice energy storage system is being developed leveraging a unique supercooling-based ice production process. During off-peak hours, the proposed system stores the low-cost electric energy in the form of ice; during on-peak hours, the system releases the stored energy to meet extensive home cooling needs. Thus, it can not only reduce energy and cost of cooling, but also increase the penetration of renewable energies (especially wind energy). In this paper, the working principles of the system is presented along with the modeling details of the overall system and several key components. The simulink model takes in hourly temperature and peak/off peak electricity cost data to dynamically simulate the amount of energy required and associated cost for cooling an average home. Both energy consumption and cost for homes using the cooling system with ice energy storage in two US cities have been compared with those using conventional HVAC cooling system. According to the model, huge reduction in energy cost (up to 3X) can be achieved over 6 months of cooling season in regions with high peak electricity rates. While only moderate reduction on energy consumption is predicted for the ice energy storage system, further energy reduction potentials have been identified for future study.

Second Law Analysis of an Energy Storage System Consisting of an Electrolysis Plant and the Graz Cycle With Internal H2/O2 Combustion

2019 ◽  
Author(s):  
Simeon Dybe ◽  
Tom Tanneberger ◽  
Panagiotis Stathopoulos
Keyword(s):  
Energy Storage ◽  
Power Plants ◽  
Storage System ◽  
Electric Energy ◽  
Energy Storage System ◽  
Working Fluid ◽  
Energetic Efficiency ◽  
Second Law ◽  
Electric Energy Storage ◽  
Second Law Analysis

Abstract The expansion of renewable energy generation must go hand in hand with measures for reliable energy supply and energy storage. A combination of hydrogen and oxygen as storing media provided from electrolysis at high pressure and zero emission power plants is a very promising option. The Graz cycle is an oxy-fuel combined power cycle that can operate with internal H2/O2 combustion and steam as working fluid. It offers thermal efficiencies up to 68.5% (LHV). This work applies a second law analysis to the Graz cycle and determines its exergetic efficiency. Exergy destruction is broken down to the cycle’s components thus providing insights on the location and magnitude of the cycle’s inefficiencies. A sensitivity analysis identifies the cycle’s exergetic and energetic efficiency as a function of representative parameters, offering an approach for future improvements. The combination of the cycle with an electrolysis plant is subsequently analyzed as an electric energy storage system. The round trip efficiency of the storage and back conversion system is computed by taking into account the additional compression of the reactants. As part of this analysis, the effect of the electrolyzer’s operational pressure is studied by comparing several commercial electrolyzers.

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