Performance Analysis of Brayton and Rankine Cycle Microsystems for Portable Power Generation

2002 ◽  
Author(s):  
Norbert Mu¨ller ◽  
Luc G. Fre´chette
Keyword(s):  
Material Properties ◽  
Large Scale ◽  
Design Space ◽  
Rankine Cycle ◽  
Pump Efficiency ◽  
Brayton Cycle ◽  
Performance Potential ◽  
Portable Power ◽  
And Performance ◽  
Design Challenges

The presented work analyses the design space and performance potential of microfabricated Brayton cycle and Rankine cycle devices, accounting for lower component efficiencies, temperatures limited by the material properties and system implementation—constraints imposed by silicon microfabrication and miniaturization. By exploring the design space of such microsystems, their potential thermal efficiency and power density are defined. Results for both types of devices are shown graphically and design challenges and guidelines are determined and found to be different from their large-scale counterparts. Similar analysis was performed for Brayton and Rankine cycle devices, with more complete assessment of the latter by including, windage, generator, conductive and heat sink losses. In contrast to the Brayton cycle, the compression work of the Rankine cycle is minimal and the pump efficiency is not critical. The investigation suggests a higher potential for Rankine cycle devices than for Brayton cycle devices.

Hybrid-Electric Powertrain Design Evaluation for Future Tactical Truck Vehicle Systems

2006 ◽  
Author(s):  
Pierluigi Pisu ◽  
Lorenzo Serrao ◽  
Codrin-Gruie Cantemir ◽  
Giorgio Rizzoni
Keyword(s):  
Large Scale ◽  
Design Space Exploration ◽  
Design Space ◽  
Combustion Engine ◽  
Space Exploration ◽  
Trade Offs ◽  
And Performance ◽  
Storage Batteries ◽  
Hybrid Electric Powertrain ◽  
Scale Design

The article presents the results of a large-scale design space exploration for two vehicles part of the Future Tactical Truck System (FTTS) family. A multi-objective optimization tool is presented, that allows designers to make appropriate trade-offs amongst different vehicle characteristics, on the basis of simulations run varying vehicle parameters over a broad range of values. Several powertrain architectures were taken into consideration for the Maneuver Sustainment Vehicle (MSV) and Utility Vehicle (UV). The architecture alternatives include the number of axles in the vehicle (2 or 3), the number of electric motors per axle (1 or 2), the type of internal combustion engine, the type and quantity of devices for energy storage (batteries, electrochemical capacitors or both together). A control strategy for energy management was developed to provide efficiency and performance. The control parameters are tunable and have been included into the design space exploration.

The Environmental Design Space: Modeling and Performance Updates

2021 ◽  
Author(s):  
Luis Salas Nunez ◽  
Jimmy C. Tai ◽  
Dimitri N. Mavris
Keyword(s):  
Design Space ◽  
Environmental Design ◽  
Space Modeling ◽  
And Performance

scholarly journals Component-Oriented Modeling of a Micro-Scale Organic Rankine Cycle System for Waste Heat Recovery Applications

2021 ◽  
Vol 11 (5) ◽  
pp. 1984
Author(s):  
Ramin Moradi ◽  
Emanuele Habib ◽  
Enrico Bocci ◽  
Luca Cioccolanti
Keyword(s):  
Electric Power ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Operating Conditions ◽  
Working Fluid ◽  
Pump Efficiency ◽  
Micro Scale

Organic Rankine cycle (ORC) systems are some of the most suitable technologies to produce electricity from low-temperature waste heat. In this study, a non-regenerative, micro-scale ORC system was tested in off-design conditions using R134a as the working fluid. The experimental data were then used to tune the semi-empirical models of the main components of the system. Eventually, the models were used in a component-oriented system solver to map the system electric performance at varying operating conditions. The analysis highlighted the non-negligible impact of the plunger pump on the system performance Indeed, the experimental results showed that the low pump efficiency in the investigated operating range can lead to negative net electric power in some working conditions. For most data points, the expander and the pump isentropic efficiencies are found in the approximate ranges of 35% to 55% and 17% to 34%, respectively. Furthermore, the maximum net electric power was about 200 W with a net electric efficiency of about 1.2%, thus also stressing the importance of a proper selection of the pump for waste heat recovery applications.

scholarly journals Review of Battery Management Systems (BMS) Development and Industrial Standards

Technologies ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 28
Author(s):  
Hossam A. Gabbar ◽  
Ahmed M. Othman ◽  
Muhammad R. Abdussami
Keyword(s):  
Energy Storage ◽  
Large Scale ◽  
Comprehensive Evaluation ◽  
Storage System ◽  
Energy Storage System ◽  
Battery Management System ◽  
Battery Management ◽  
Electrical Power System ◽  
Safety Aspects ◽  
And Performance

The evolving global landscape for electrical distribution and use created a need area for energy storage systems (ESS), making them among the fastest growing electrical power system products. A key element in any energy storage system is the capability to monitor, control, and optimize performance of an individual or multiple battery modules in an energy storage system and the ability to control the disconnection of the module(s) from the system in the event of abnormal conditions. This management scheme is known as “battery management system (BMS)”, which is one of the essential units in electrical equipment. BMS reacts with external events, as well with as an internal event. It is used to improve the battery performance with proper safety measures within a system. Therefore, a safe BMS is the prerequisite for operating an electrical system. This report analyzes the details of BMS for electric transportation and large-scale (stationary) energy storage. The analysis includes different aspects of BMS covering testing, component, functionalities, topology, operation, architecture, and BMS safety aspects. Additionally, current related standards and codes related to BMS are also reviewed. The report investigates BMS safety aspects, battery technology, regulation needs, and offer recommendations. It further studies current gaps in respect to the safety requirements and performance requirements of BMS by focusing mainly on the electric transportation and stationary application. The report further provides a framework for developing a new standard on BMS, especially on BMS safety and operational risk. In conclusion, four main areas of (1) BMS construction, (2) Operation Parameters, (3) BMS Integration, and (4) Installation for improvement of BMS safety and performance are identified, and detailed recommendations were provided for each area. It is recommended that a technical review of the BMS be performed for transportation electrification and large-scale (stationary) applications. A comprehensive evaluation of the components, architectures, and safety risks applicable to BMS operation is also presented.

scholarly journals Hydropower, Geothermal, and Ocean Energy

MRS Bulletin ◽  
2008 ◽  
Vol 33 (4) ◽  
pp. 389-395 ◽  
Author(s):  
Ralph E.H. Sims
Keyword(s):  
Renewable Energy ◽  
Large Scale ◽  
New Technologies ◽  
Materials Science ◽  
Development Stage ◽  
Design Development ◽  
Ocean Energy ◽  
Improve Design ◽  
And Performance ◽  
Improve Reliability

AbstractSome forms of renewable energy have long contributed to electricity generation, whereas others are just emerging. For example, large-scale hydropower is a mature technology generating about 16% of global electricity, and many smaller scale systems are also being installed worldwide. Future opportunities to improve the technology are limited but include upgrading of existing plants to gain greater performance efficiencies and reduced maintenance. Geothermal energy, widely used for power generation and direct heat applications, is also mature, but new technologies could improve plant designs, extend their lifetimes, and improve reliability. By contrast, ocean energy is an emerging renewable energy technology. Design, development, and testing of a myriad of devices remain mainly in the research and development stage, with many opportunities for materials science to improve design and performance, reduce costly maintenance procedures, and extend plant operating lifetimes under the harsh marine environment.

A Streamflow and Water Level Forecasting Model for the Ganges, Brahmaputra, and Meghna Rivers with Requisite Simplicity

2018 ◽  
Vol 19 (1) ◽  
pp. 201-225 ◽  
Author(s):  
Wahid Palash ◽  
Yudan Jiang ◽  
Ali S. Akanda ◽  
David L. Small ◽  
Amin Nozari ◽  
...  
Keyword(s):  
Water Level ◽  
Lead Time ◽  
Large Scale ◽  
Predictive Ability ◽  
Large River ◽  
Modeling Framework ◽  
Forecasting Accuracy ◽  
Weather Model ◽  
And Performance ◽  
The Ganges

A forecasting lead time of 5–10 days is desired to increase the flood response and preparedness for large river basins. Large uncertainty in observed and forecasted rainfall appears to be a key bottleneck in providing reliable flood forecasting. Significant efforts continue to be devoted to developing mechanistic hydrological models and statistical and satellite-driven methods to increase the forecasting lead time without exploring the functional utility of these complicated methods. This paper examines the utility of a data-based modeling framework with requisite simplicity that identifies key variables and processes and develops ways to track their evolution and performance. Findings suggest that models with requisite simplicity—relying on flow persistence, aggregated upstream rainfall, and travel time—can provide reliable flood forecasts comparable to relatively more complicated methods for up to 10 days lead time for the Ganges, Brahmaputra, and upper Meghna (GBM) gauging locations inside Bangladesh. Forecasting accuracy improves further by including weather-model-generated forecasted rainfall into the forecasting scheme. The use of water level in the model provides equally good forecasting accuracy for these rivers. The findings of the study also suggest that large-scale rainfall patterns captured by the satellites or weather models and their “predictive ability” of future rainfall are useful in a data-driven model to obtain skillful flood forecasts up to 10 days for the GBM basins. Ease of operationalization and reliable forecasting accuracy of the proposed framework is of particular importance for large rivers, where access to upstream gauge-measured rainfall and flow data are limited, and detailed modeling approaches are operationally prohibitive and functionally ineffective.

scholarly journals Analysis and Enhancement of IEEE 802.15.4e DSME Beacon Scheduling Model

2014 ◽  
Vol 2014 ◽  
pp. 1-15 ◽  
Author(s):  
Kwang-il Hwang ◽  
Sung-wook Nam
Keyword(s):  
Internet Of Things ◽  
Large Scale ◽  
Ieee 802.15.4 ◽  
Design Model ◽  
Abstract Model ◽  
Modes Of Operation ◽  
Network Construction ◽  
Scheduling Model ◽  
And Performance ◽  
Ieee 802.15.4E

In order to construct a successful Internet of things (IoT), reliable network construction and maintenance in a sensor domain should be supported. However, IEEE 802.15.4, which is the most representative wireless standard for IoT, still has problems in constructing a large-scale sensor network, such as beacon collision. To overcome some problems in IEEE 802.15.4, the 15.4e task group proposed various different modes of operation. Particularly, the IEEE 802.15.4e deterministic and synchronous multichannel extension (DSME) mode presents a novel scheduling model to solve beacon collision problems. However, the DSME model specified in the 15.4e draft does not present a concrete design model but a conceptual abstract model. Therefore, in this paper we introduce a DSME beacon scheduling model and present a concrete design model. Furthermore, validity and performance of DSME are evaluated through experiments. Based on experiment results, we analyze the problems and limitations of DSME, present solutions step by step, and finally propose an enhanced DSME beacon scheduling model. Through additional experiments, we prove the performance superiority of enhanced DSME.

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