Experimental Study of a Robust Foil Regenerator in the Oscillating Flow

2018 ◽  
Author(s):  
Koji Yanaga ◽  
Songgang Qiu ◽  
Pawan Kumar Yadav
Keyword(s):  
Friction Coefficient ◽  
Thermal Efficiency ◽  
High Efficiency ◽  
High Reliability ◽  
Stirling Engine ◽  
Oscillating Flow ◽  
Modeling Software ◽  
Regenerator Material ◽  
High Reynolds ◽  
Commercial Applications

The Stirling engine is a high efficiency and high reliability energy converter which is expected to be a solution for future space power generation and commercial applications. One of the key components in a Stirling engine, to keep high efficiency, is the regenerator. Currently, woven screens or random fibers are mostly used as the regenerator material. However, since both woven screen and random fiber regenerators are composed of wires, the flow across the wires is similar to cylinders in cross flows. As a result, flow separation occurs and the regenerator results in high friction losses and thermal dispersion. In the previous study, a robust foil type regenerator is designed and CFD analysis of the regenerator was conducted to predict the friction coefficient and the thermal efficiency under oscillating flow conditions. In this research, a regenerator test bench was designed and constructed to investigate the friction coefficient and thermal efficiency of the regenerator. The experiment conditions are decided based on the one-dimension thermodynamic modeling software SAGE. The experiment result shows that the friction coefficient of the experiment is close to CFD prediction at high Reynolds number.

Stirling Engine Robust Foil Regenerator Efficiency

2019 ◽  
Author(s):  
Koji Yanaga ◽  
Yuan Gao ◽  
Ruijie Li ◽  
Songgang Qiu
Keyword(s):  
Nusselt Number ◽  
Friction Coefficient ◽  
Test Bench ◽  
High Efficiency ◽  
Waste Heat ◽  
Combined Heat And Power ◽  
Stirling Engine ◽  
Engine Efficiency ◽  
Manufacturing Techniques ◽  
Save Energy

Abstract Combined Heat and Power (CHP) systems are one of the solutions to save energy by utilizing waste heat for addressing global warming and the global energy crisis. In many CHP technologies, the Stirling engine is outstanding since it has the advantage of various energy sources such as solar, geothermal, and industrial heat waste. The regenerator plays a key role in building a high efficiency Stirling Engine. Since it works as an energy storage component in the Stirling engine, its performance directly affects the Stirling engine efficiency. In the previous research, a new regenerator called the robust foil regenerator was designed to improve the performance of the regenerator. The regenerator was manufactured through the method of additive manufacturing techniques since the thickness of each flow channel is 0.3mm. In this research, a test bench was designed and manufactured to reveal the characteristics of the regenerator experimentally. By measuring the pressure drop and the temperature difference through the regenerator, the friction coefficient and the Nusselt number correlations were derived respectively. These correlations were compared to the published friction factor and Nusselt number correlations. In addition, to evaluate the geometrical configuration of the regenerator, the NPH/NTU ratio was calculated using the derived friction coefficient and Nusselt number.

Development of an 8MW-Class High-Efficiency Gas Turbine, M7A-03

2007 ◽  
Author(s):  
Kazuhiko Tanimura ◽  
Naoki Murakami ◽  
Akinori Matsuoka ◽  
Katsuhiko Ishida ◽  
Hiroshi Kato ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Thermal Efficiency ◽  
High Performance ◽  
High Efficiency ◽  
High Reliability ◽  
Pressure Ratio ◽  
Combined Cycle ◽  
Gas Temperature ◽  
Turbine Cooling ◽  
Distributed Power Generation

The M7A-03 gas turbine, an 8 MW class, single shaft gas turbine, is the latest model of the Kawasaki M7A series. Because of the high thermal efficiency and the high exhaust gas temperature, it is particularly suitable for distributed power generation, cogeneration and combined-cycle applications. About the development of M7A-03 gas turbine, Kawasaki has taken the experience of the existing M7A-01 and M7A-02 series into consideration, as a baseline. Furthermore, the latest technology of aerodynamics and cooling design, already applied to the 18 MW class Kawasaki L20A, released in 2000, has been applied to the M7A-03. Kawasaki has adopted the design concept for achieving reliability within the shortest possible development period by selecting the same fundamental engine specifications of the existing M7A-02 – mass air flow rate, pressure ratio, TIT, etc. However, the M7A-03 has been attaining a thermal efficiency of greater than 2.5 points higher and an output increment of over 660 kW than the M7A-02, by the improvement in aerodynamic performance of the compressor, turbine and exhaust diffuser, improved turbine cooling, and newer seal technology. In addition, the NOx emission of the combustor is low and the M7A-03 has a long service life. These functions make long-term continuous operation possible under various environmental restraints. Lower life cycle costs are achieved by the engine high performance, and the high-reliability resulting from simple structure. The prototype M7A-03 gas-turbine development test started in the spring of 2006 and it has been confirmed that performance, mechanical characteristics, and emissions have achieved the initial design goals.

Impact of Operating Parameters on Beta Type Regenerative Stirling Machine Performances

2015 ◽  
Author(s):  
Houda Hachem ◽  
Ramla Gheith ◽  
Sassi Ben Nasrallah ◽  
Fethi Aloui
Keyword(s):  
High Efficiency ◽  
High Reliability ◽  
Water Flow Rate ◽  
Cooling Water ◽  
Cooling Capacity ◽  
Operating Parameters ◽  
Fast Cool ◽  
Heating And Cooling ◽  
Cooling Water Flow Rate ◽  
Commercial Applications

Due to its high efficiency, fast cool-down, small size, light weight, low power consumption, high reliability, Stirling cycle machine has many successful commercial applications such as heating and cooling. In the present paper, performances of a Beta type Stirling machine having a regenerative displacer were investigated. Energy analysis is reproduced taking into account complex phenomena related to compressible fluid mechanics, thermodynamics and heat transfer. A special attention is paid to the effect of such operating parameters as pressure, temperature, frequency and cooling water flow rate on Beta type regenerative Stirling machine performances. A MATLAB program was developed. Net cooling capacity, imputed work and COP inside the machine were assumed and compared to the experimental values. Comparing the results obtained by this code with experimental data, an acceptable agreement can be deduced for the predicted performance of the Stirling machine. The optimum speed is investigated.

scholarly journals A Study of Mesh Sheets of 3-kW Stirling Engine

2021 ◽  
Vol 313 ◽  
pp. 05001
Author(s):  
Takeshi Enomoto ◽  
Atsushi Matsuguchi ◽  
Noboru Kagawa
Keyword(s):  
Low Temperatures ◽  
High Performance ◽  
High Efficiency ◽  
Heating Temperature ◽  
Engine Performance ◽  
Stirling Engine ◽  
Working Fluid ◽  
Heat Engines ◽  
Exhaust Heat ◽  
Regenerator Material

In recent years, the interest in low-pollution and high-efficiency heat engines has been increasing due to the growing awareness of environmental protection, and power generation at relatively low temperatures, such as use of exhaust heat and sunlight, has been attracting attention. Compared with other heat engines, Stirling engine is very important because it can be driven by any heat source at low temperatures, such as exhaust heat, and it does not emit exhaust gas. In order to realize a more efficient Stirling engine, it is essential to design a heat exchange system that is suitable for each component. Performance measurement and analysis on a new mesh regenerator material at low temperature difference using a 2-piston alpha-type 3-kW Stirling engine, NS03T are carried out. Mesh sheets developed for high performance Stirling engines can be designed with CAD and CAM technologies by etching process. For this study, M5 and M7 mesh sheets which are thin sheets of stainless steel with square holes in a grid arrangement, are used. With nitrogen and helium as the working fluid, the engine performance is measured by changing the charge pressure, heating temperature, and engine speed to clarify the flow resistance and heat transfer characteristics of the M5 and M7.

"Recent Patents on the Triboelectrostatic Separation of Fly Ash"

2019 ◽  
Vol 13 ◽  
Author(s):  
Haisheng Li ◽  
Wenping Wang ◽  
Yinghua Chen ◽  
Xinxi Zhang ◽  
Chaoyong Li
Keyword(s):  
Fly Ash ◽  
Power Plants ◽  
High Efficiency ◽  
Separation Efficiency ◽  
High Reliability ◽  
Operating Conditions ◽  
Security Requirements ◽  
Unburned Carbon ◽  
Efficient Operation ◽  
Triboelectrostatic Separation

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.

scholarly journals Theoretical Studies of the Interaction between Screw Surface and Material in the Mixer

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 962
Author(s):  
Andrzej Marczuk ◽  
Vasily Sysuev ◽  
Alexey Aleshkin ◽  
Petr Savinykh ◽  
Nikolay Turubanov ◽  
...  
Keyword(s):  
Friction Coefficient ◽  
High Efficiency ◽  
Animal Feed ◽  
Structural Features ◽  
Power Demand ◽  
Friction Coefficients ◽  
Length Unit ◽  
Mixing Chamber ◽  
Size Of Particles ◽  
The Impact

Mixing is one of the most commonly used processes in food, animal feed, chemical, cosmetic, etc., industries. It is supposed to provide high-quality homogenous, nutritious mixtures. To provide appropriate mixing of materials while maintaining the process high efficiency and low energy consumption it is crucial to explore and describe the material flow caused by the movement of mixing elements and the contact between particles. The process of mixing is also affected by structural features of the machine components and the mixing chamber, speed of mixing, and properties of the mixed materials, such as the size of particles, moisture, friction coefficients. Thus, modeling of the phenomena that accompany the process of mixing using the above-listed parameters is indispensable for appropriate implementation of the process. The paper provides theoretical power calculations that take into account the material speed change, the impact of the material friction coefficient on the screw steel surface and the impact of the friction coefficient on the material, taking into account the loading height of the mixing chamber and the chamber loading value. Dependencies between the mixer power and the product degree of fineness, rotational speed of screw friction coefficients, the number of windings per length unit, and width of the screw tape have been presented on the basis of a developed model. It has been found that power increases along with an increase in the value of these parameters. Verification of the theoretical model indicated consistence of the predicted power demand with the power demand determined in tests performed on a real object for values of the assumed, effective loading, which was 65–75%.

scholarly journals Fast Accurate and Automatic Brushstroke Extraction

2021 ◽  
Vol 17 (2) ◽  
pp. 1-24
Author(s):  
Yunfei Fu ◽  
Hongchuan Yu ◽  
Chih-Kuo Yeh ◽  
Tong-Yee Lee ◽  
Jian J. Zhang
Keyword(s):  
Neural Network ◽  
Efficient Algorithm ◽  
Deep Neural Network ◽  
High Efficiency ◽  
State Of The Art ◽  
High Reliability ◽  
The Other ◽  
Manual Annotation ◽  
Stroke Extraction ◽  
Art Research

Brushstrokes are viewed as the artist’s “handwriting” in a painting. In many applications such as style learning and transfer, mimicking painting, and painting authentication, it is highly desired to quantitatively and accurately identify brushstroke characteristics from old masters’ pieces using computer programs. However, due to the nature of hundreds or thousands of intermingling brushstrokes in the painting, it still remains challenging. This article proposes an efficient algorithm for brush Stroke extraction based on a Deep neural network, i.e., DStroke. Compared to the state-of-the-art research, the main merit of the proposed DStroke is to automatically and rapidly extract brushstrokes from a painting without manual annotation, while accurately approximating the real brushstrokes with high reliability. Herein, recovering the faithful soft transitions between brushstrokes is often ignored by the other methods. In fact, the details of brushstrokes in a master piece of painting (e.g., shapes, colors, texture, overlaps) are highly desired by artists since they hold promise to enhance and extend the artists’ powers, just like microscopes extend biologists’ powers. To demonstrate the high efficiency of the proposed DStroke, we perform it on a set of real scans of paintings and a set of synthetic paintings, respectively. Experiments show that the proposed DStroke is noticeably faster and more accurate at identifying and extracting brushstrokes, outperforming the other methods.

Stirling Engine Technology for Parabolic Dish-Stirling System Based on Concentrating Solar Power (CSP)

2015 ◽  
Vol 785 ◽  
pp. 576-580 ◽  
Author(s):  
Liaw Geok Pheng ◽  
Rosnani Affandi ◽  
Mohd Ruddin Ab Ghani ◽  
Chin Kim Gan ◽  
Jano Zanariah
Keyword(s):  
High Efficiency ◽  
Combustion Engine ◽  
Renewable Energy Sources ◽  
Stirling Engine ◽  
Energy Sources ◽  
Heat Engines ◽  
Stirling Engines ◽  
Parabolic Dish ◽  
Mechanical Devices ◽  
And Control

Solar energy is one of the more attractive renewable energy sources that can be used as an input energy source for heat engines. In fact, any heat energy sources can be used with the Stirling engine. Stirling engines are mechanical devices working theoretically on the Stirling cycle, or its modifications, in which compressible fluids, such as air, hydrogen, helium, nitrogen or even vapors, are used as working fluids. When comparing with the internal combustion engine, the Stirling engine offers possibility for having high efficiency engine with less exhaust emissions. However, this paper analyzes the basic background of Stirling engine and reviews its existing literature pertaining to dynamic model and control system for parabolic dish-stirling (PD) system.

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