scholarly journals Thermodynamics Performance Analysis of Solar Stirling Engines

2012 ◽  
Vol 2012 ◽  
pp. 1-14 ◽  
Author(s):  
A. Asnaghi ◽  
S. M. Ladjevardi ◽  
P. Saleh Izadkhast ◽  
A. H. Kashani
Keyword(s):  
Gas Phase ◽  
Working Conditions ◽  
Engine Performance ◽  
Stirling Engine ◽  
Effective Parameters ◽  
Isothermal Model ◽  
Calculate Heat Transfer ◽  
Simulation Process ◽  
Maximum Value ◽  
Stirling Engines

This paper provides numerical simulation and thermodynamic analysis of SOLO 161 Solar Stirling engine. Some imperfect working conditions, pistons' dead volumes, and work losses are considered in the simulation process. Considering an imperfect regeneration, an isothermal model is developed to calculate heat transfer. Hot and cold pistons dead volumes are accounted in the work diagram calculations. Regenerator effectiveness, heater and cooler temperatures, working gas, phase difference, average engine pressure, and dead volumes are considered as effective parameters. By variations in the effective parameters, Stirling engine performance is estimated. Results of this study indicate that the increase in the heater and cooler temperature difference and the decrease in the dead volumes will lead to an increase in thermal efficiency. Moreover, net work has its maximum value when the angle between two pistons shaft equal to 90 degrees while efficiency is maximum in 110 degrees.

Optimization of Stirling Engine Performance Based on Multipoint Approximation Technique

1994 ◽  
Author(s):  
Vassili V. Toropov ◽  
Henrik Carlsen
Keyword(s):  
Computing Time ◽  
Engine Performance ◽  
Stirling Engine ◽  
Optimization Techniques ◽  
Approximation Technique ◽  
Working Cycle ◽  
Design Variables ◽  
Stirling Engines ◽  
Multipoint Approximation ◽  
Conventional Optimization

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.

Thermodynamic Analysis and Performance Investigation of an Alpha-Type Stirling Engine

2012 ◽  
Author(s):  
E. D. Rogdakis ◽  
I. P. Koronaki ◽  
G. D. Antonakos
Keyword(s):  
Thermodynamic Analysis ◽  
Power Output ◽  
System Performance ◽  
Engine Performance ◽  
Energy Systems ◽  
Stirling Engine ◽  
Operating Conditions ◽  
System Capacity ◽  
Stirling Engines ◽  
Alpha Type

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.

scholarly journals Thermodynamic Model for Performance Analysis of a Stirling Engine Prototype

Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2655 ◽  
Author(s):  
Miguel Torres García ◽  
Elisa Carvajal Trujillo ◽  
José Vélez Godiño ◽  
David Sánchez Martínez
Keyword(s):  
Heat Transfer ◽  
Decision Making ◽  
Stirling Engine ◽  
Decision Making Process ◽  
Actual Behavior ◽  
Isothermal Model ◽  
Working Cycle ◽  
Stirling Engines ◽  
Expected Values ◽  
The Ideal

In this study, the results of simulations generated from different thermodynamic models of Stirling engines are compared, including characterizations of both instantaneous and indicated operative parameters. The aim was to develop a tool to guide the decision-making process regarding the optimization of both the performance and reliability of Stirling engines, such as the 2.9 kW GENOA 03 unit—the focus of this work. The behavior of the engine is characterized using two different approaches: an ideal isothermal model, the simplest of those available, and analysis using the ideal adiabatic model, which is more complex than the first. Some of the results obtained with the referred ideal models deviated considerably from the expected values, particularly in terms of thermal efficiency, so a set of modifications to the ideal adiabatic model are proposed. These modifications, mainly related to both heat transfer and fluid friction phenomena, are intended to overcome the limitations due to the idealization of the engine working cycle, and are expected to generate results closer to the actual behavior of the Stirling engine, despite the increase in the complexity derived from the modelling and simulation processes.

scholarly journals INVESTIGATION ON VOLUME VARIATION FOR ALPHA STIRLING ENGINES ON ISOTHERMAL MODEL

2020 ◽  
Vol 19 (2) ◽  
pp. 10
Author(s):  
M. K. Gussoli ◽  
J. C. D. de Oliveira ◽  
M. Higa
Keyword(s):  
Power Output ◽  
Engine Performance ◽  
Isothermal Model ◽  
Volume Variation ◽  
Stirling Engines ◽  
The Matrix ◽  
Waste Energy ◽  
Feasible Alternative ◽  
The Difference ◽  
Engine Cycle

The usage of renewable energies is approximately 11% of the matrix energy worldwide. In countries known for its renewable sources, such as Brazil, the percentage is close to 38%. The importance to study Stirling engines and propose a prototype is that they are a feasible alternative for generation of power and electricity when considering low quality sources such as solar and waste energy. This paper will compare two different approaches of the volume variation, sinusoidal and kinematic, using an isothermal model that represents the Stirling engines. The comparison is made for an a type engine. Such approaches are capable of representing an estimative of work and power output for Stirling engines since the difference of results for these approaches are 8.07% for power output. As both approaches are a valid choice for analyzing the Stirling engine cycle, the availability of the data determines which approach is the most suitable for characterizing the engine performance.

scholarly journals INVALIDITY OF ISOTHERMAL ANALYSIS IN ESTIMATING THE THERMAL PERFORMANCE OF STIRLING ENGINE AND CRYOCOOLER

2021 ◽  
Vol 21 (4) ◽  
pp. 274-288
Author(s):  
Hailaa Jabbar Kareem ◽  
Ali A. F. Al-Hamadani ◽  
Ali Noaman Ibrahim
Keyword(s):  
Heat Exchangers ◽  
Heat Engine ◽  
Engine Performance ◽  
Thermodynamic Cycle ◽  
Low Noise ◽  
Stirling Engine ◽  
Isothermal Model ◽  
Working Space ◽  
Isothermal Analysis ◽  
Noise Vibration

The Stirling engine is an external heat engine, which is considered as the best option for extracting work from concentrated solar power applications. The most prominent characteristics of the engine are low noise, vibration, and emissions besides reflexivity of usage with any kind of heat source such as solar, biomass, industrial heat, etc. In the present paper, the STE-1008 gamma-type Stirling engine had been analyzed by using an isothermal model to demonstrate the failure of the model in analyzing the STE-1008 considering it firstly as an engine and secondly as a cryocooler. The energy equation had been used to demonstrate the disability of the isothermal model in achieving a successful thermal analysis for engine performance. In addition, a MATLAB code had been developed to check the credibility of the isothermal model in the estimation of the engine thermal parameters. The findings of the isothermal analysis revealed that the heat exchangers are unnecessary. But, in reality; all the necessary heat transfer occur within the heat exchangers rather than in the working space boundaries. Therefore, that is invalid conclusion. However, Schmidt's theory is capable of capturing the essential engine features superbly. In particular, it is capable of capturing the fundamental interplay between the mechanically restricted movement of the engine components as well as the thermodynamic cycle which is obtained from this theory.

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.

Effects of the regenerator on engine performance of a rhombic drive beta type stirling engine

2021 ◽  
pp. 1-9
Author(s):  
Fatih Aksoy ◽  
Hamit Solmaz ◽  
Muhammed Arslan ◽  
Emre Yılmaz ◽  
Duygu İpci ◽  
...  
Keyword(s):  
Engine Performance ◽  
Stirling Engine

Design of a Small Renewable Resource Model based on the Stirling Engine with Alpha and Beta Configurations

2017 ◽  
Vol 8 (2) ◽  
pp. 360
Author(s):  
Faisal Zahari ◽  
Muhammad Murtadha Othman ◽  
Ismail Musirin ◽  
Amirul Asyraf Mohd Kamaruzaman ◽  
Nur Ashida Salim ◽  
...  
Keyword(s):  
Temperature Variation ◽  
Waste Heat ◽  
Renewable Resource ◽  
Stirling Engine ◽  
Heat Energy ◽  
Maintenance Cost ◽  
Resource Model ◽  
Stirling Cycle ◽  
Cooling Agent ◽  
Stirling Engines

<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>

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