scholarly journals Multiphase Stirling Engines

2009 ◽  
Vol 131 (2) ◽  
Author(s):  
Artin Der Minassians ◽  
Seth R. Sanders

Analysis, design, fabrication, and experimental assessment of a symmetric three-phase free-piston Stirling engine system is discussed in this paper. The system is designed to operate with moderate-temperature heat input that is consistent with solar-thermal collectors. Diaphragm pistons and nylon flexures are considered for this prototype to eliminate surface friction and to provide appropriate seals. In addition, low loss diaphragm pistons, etched and woven-wire screen heat exchangers, and plastic flexures, as the main components of the system, are outlined. The experimental results are presented and compared with design analysis. Experiments successfully confirm the design models for heat exchanger flow friction losses and gas spring hysteresis dissipation. Furthermore, it is revealed that gas spring hysteresis loss is an important dissipation phenomenon for low-power Stirling engines and should be carefully addressed in design. Analysis shows that the gas hysteresis dissipation is reduced drastically by increasing the number of phases in a multiphase Stirling engine system. It is further shown that for an even number of phases, half of the engine chambers could be eliminated by utilizing a reversing mechanism within the multiphase system. The mathematical formulation and modal analysis of multiphase Stirling engine system are then extended to a system that incorporates a reverser. By introducing a reverser to the fabricated prototype, the system successfully operates in engine mode. The system proves its self-starting capability and validates the computed start-up temperature.

2007 ◽  
Vol 130 (1) ◽  
Author(s):  
Francisco J. García Granados ◽  
Manuel A. Silva Pérez ◽  
V. Ruiz-Hernández

One parabolic dish—Stirling engine system—has been in operation at the Engineering School of Seville since March 2004. The unit, based on the Eurodish system, is one of the several Country Reference Units of the EnviroDish project. The system has achieved a maximum thermal efficiency (solar to electricity) close to 20% during operation. The analysis of the different parameters suggests a high potential for improvement. A thermal model of the main components of the engine package (cavity, receiver, and Stirling engine) can help to evaluate possible modifications of the system and identify the most promising ones. The development of such a thermal model and its comparison with experimental data gathered during this period are reported in this work. Model results exhibit a good qualitative agreement with the available measurements. However, the validation of the model will require measuring more parameters at the cavity, receiver, and engine.


Author(s):  
H Nilsson

The Stirling power module V4-275R, integrated with a liquid oxygen system, is currently built for submarines for the Royal Swedish Navy and for the offshore company Comex in France. Since mid 1985 the Stirling engine system for the Swedish Navy has been successfully tested in a full-scale submarine test section. The next step in this programme will be an integration of the Stirling system into an operational Swedish submarine. A contract has been signed having Kockums as the main contractor. The French programme means a 500 ton manned diver lock-out submarine, the SAGA I, which is under final construction at Comex in Marseille. The energy system for the SAGA submarine consists of two V4–275R Stirling engines of maximum 100 kW power each. The oxygen storage, manufactured by AGA Cryo in Gothenburg, consists of two liquid oxygen tanks providing a total capacity of 10000 kWh, allowing the submarine to perform missions of up to 14 days submerged.


2015 ◽  
Vol 785 ◽  
pp. 576-580 ◽  
Author(s):  
Liaw Geok Pheng ◽  
Rosnani Affandi ◽  
Mohd Ruddin Ab Ghani ◽  
Chin Kim Gan ◽  
Jano Zanariah

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.


Author(s):  
Vassili V. Toropov ◽  
Henrik Carlsen

Abstract The ideal Stirling working cycle has the maximum obtainable efficiency defined by Carnot efficiency, and highly efficient Stirling engines can therefore be built, if designed properly. To analyse the power output and the efficiency of a Stirling engine, numerical simulation programs (NSP) have been developed, which solve the thermodynamic equations. In order to find optimum values of design variables, numerical optimization techniques can be used (Bartczak and Carlsen, 1991). To describe the engine realistically, it is necessary to consider several tens of design variables. As even a single call for NSP requires considerable computing time, it would be too time consuming to use conventional optimization techniques, which require a very large number of calls for NSP. Furthermore, objective and constraint functions of the optimization problem present some level of noise, i.e. can only be estimated with a finite accuracy. To cope with these problems, the multipoint explicit approximation technique is used.


Author(s):  
Faisal Zahari ◽  
Muhammad Murtadha Othman ◽  
Ismail Musirin ◽  
Amirul Asyraf Mohd Kamaruzaman ◽  
Nur Ashida Salim ◽  
...  

<p>This paper presents the conceptual design of Stirling engine based Alpha and Beta configurations. The performances of Stirling engine based Beta configuration will be expounded elaborately in the discussion. The Stirling engines are durable in its operation that requires less maintenance cost.  The methodology for both configurations consists of thermodynamic formulation of Stirling Cycle, Schmidt theory and few composition of flywheel and Ross-Yoke dimension. Customarily, the Stirling engine based Beta configuration will operate during the occurrence of low and high temperature differences emanating from any type of waste heat energy. A straightforward analysis on the performance of Stirling engine based Beta configuration has been performed corresponding to the temperature variation of cooling agent. The results have shown that the temperature variation of cooling agent has a direct effect on the performances of Stirling engine in terms of its speed, voltage and output power. </p>


2017 ◽  
Vol 40 (3) ◽  
pp. 274-284 ◽  
Author(s):  
D. J. Shendage ◽  
S. B. Kedare ◽  
S. L. Bapat

2015 ◽  
Vol 159 ◽  
pp. 633-650 ◽  
Author(s):  
Joseph A. Araoz ◽  
Marianne Salomon ◽  
Lucio Alejo ◽  
Torsten H. Fransson

Author(s):  
E. D. Rogdakis ◽  
I. P. Koronaki ◽  
G. D. Antonakos

The Stirling engine, as an external combustion engine, can be powered using a variety of heat sources including the continuous combustion process thus achieving significantly reduced emissions. Energy systems powered by a Stirling engines meet the needs of various applications not only in the domestic and industrial sections but in military and space gadgets as well. Stirling engines can also be used as cryocoolers in medical applications where they are called to achieve very low temperatures. Each energy system using Stirling Engine optimizes its performance in specific operating conditions. The system capacity depends on the geometric and structural characteristics, the design of the unit, the environment in which the engine is allowed to it works as well as the size of the load. In order to study the function and the efficiency of Stirling energy systems a CHP SOLO 161V -ALPHA TYPE STIRLING ENGINE was installed in the Laboratory of Applied Thermodynamics of NTUA. A thermodynamic analysis has been conducted using appropriate computing codes. The effect of each independent variable on the system performance was investigated. The study was divided into distinct levels of detail, bringing out each variable. Initially, the performance of the heat engine was examined assuming an ideal regenerator. Then, the effectiveness of the regenerator was evaluated as well as its effect on the engine performance, while the effect of the pressure drop and the energy dissipation on the engine efficiency was also investigated. Measurements were conducted using different operational conditions concerning the heating load of the engine. The effect of the geometrical characteristics of the regenerator on power output and engine performance was examined based on the results of a simulation analysis. Moreover, the power output and the efficiency of the machine in relation to the thermal load of the unit and the average pressure of the working medium were investigated. Major performance input characters affecting geometrical and operational parameters of the unit were identified leading to unit optimization with specific combinations leading to increased system performance. Simulation results were validated by comparison to corresponding values obtained by relative experiments conducted with the SOLO unit. Finally, a sensitivity analysis was performed in order to investigate the effect of the operating conditions on the performance of an alpha type Stirling Engine.


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