scholarly journals Stirling Engine and oil-free compressors

2021 ◽  
Vol 313 ◽  
pp. 04005
Author(s):  
Thierry Raballand
Keyword(s):  
Stirling Engine ◽  
French Patent ◽  
Stirling Engines ◽  
The Right ◽  
Crank Mechanism

Refering to figure 1 [Fig.1], an oscillating « flipper » piston (1) and its associated chamber (2) are maintained without reciprocal contact. No oil is required because there is no contact and so no friction. An oscillating shaft (22) maintains the oscillating « flipper »piston (1). Around shaft (22), a twisting seal (8) allows for absolute sealing. This characteristic is important for Stirling engines and oil-free compressors. Referring to figure 4 [Fig.4], the two oscillating « flipper » pistons on the left belong to a Stirling-Franchot engine, more particularly to a Stirling-Franchot engine with two oscillating « flipper » pistons and so with two quadric crank mechanisms. The oscillating « flipper » piston on the right belongs to an oil-free compressor. The Stirling engine shaft (11), which is in alternative rotation, directly powers the oil-free compressor shaft (22). This prevents the use of a third quadric crank mechanism from shaft (33) to shaft (22). A Stirling engine connected to an oilfree compressor is useful when the fluid is precious or dangerous. A French patent was taken out on Februar 1st, 2020.

scholarly journals Stirling Engine and absolute sealing

2021 ◽  
Vol 313 ◽  
pp. 04004
Author(s):  
Thierry Raballand
Keyword(s):  
Main Part ◽  
Stirling Engine ◽  
French Patent ◽  
The Right

Referring to the sketches, the alternative rotation of shaft (101) allows for absolute sealing between the left side and the right side of seal (1020). A device for total sealing around a shaft in alternating rotation is characterized in that a seal (1020), the main part of the device, called a torsion disc, constitutes the material insulator and is fixed on a shaft (101) by means of two spacers (610) and (620), where the spacer (610) is held in position by the bearing (710) and the spacer (620), which clamps the seal (1020), is held in position by the bearing (720). Along the shaft (101) on both sides of the seal (1020), O-rings (510) and (520) and possibly temperature insulating rings (410) and (420) can be arranged. On both sides of the seal (1020) there are possibly two pressure isolating stops (210) and (220), which slide in rotation on two other stops (110) and (120). The two bearing housings (228) and (8) are positioned relative to each other by means of shims (7) in order to clamp the seal (1020) at the bore and at the shaft. Connecting screws connect the bearing housings (228) and (8) and further connecting screws connect the housing (8) and the wall (22). Absolute sealing of a kinematic Stirling engine is now achievable. A French patent was taken out on August 27th, 2020.

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.

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.

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>

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 Stirling engines - the state of technology development and computational models

2021 ◽  
Author(s):  
Mariusz Furmanek ◽  
Jacek Kropiwnicki
Keyword(s):  
Power Systems ◽  
Computational Models ◽  
Waste Heat ◽  
Numerical Models ◽  
Renewable Energy Sources ◽  
Primary Energy ◽  
Stirling Engine ◽  
Correct Selection ◽  
Engine Operation ◽  
Stirling Engines

Stirling engines represent a technologically important solution in combined heat and power systems. Their use enables the achievement of over 90 percent efficiency in the management of the primary energy source with a very high durability of the device, mainly due to the lack of contact of the working gas with external factors and a very small number of mechanical components. The use of a Stirling engine may be equally important when applying renewable energy sources or waste heat from other processes. The first part of the work presents an overview of available commercial Stirling engine solutions. The second part of the work presents an overview of numerical models of Stirling engine operation, which enable the correct selection of the main geometrical features of the devices and the improvement of the structure in order to maximize efficiency or power.

scholarly journals A Comprehensive Perspective of Waste Heat Recovery Potential from Solar Stirling Engines

2021 ◽  
Vol 313 ◽  
pp. 06001
Author(s):  
Siddharth Ramachandran ◽  
Naveen Kumar ◽  
Venkata Timmaraju Mallina
Keyword(s):  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Payback Period ◽  
Stirling Engine ◽  
Economic Feasibility ◽  
Levelized Cost Of Electricity ◽  
Stirling Engines

Despite the higher efficiency advantage, the cost reduction of PV technology has been more successful compared to the dish Stirling engine (DSE) due to the large market volume and sturdy competition. Irrespective of the types of source, there exists a potential of waste heat recovery from Stirling engines operating at higher temperature regime. Accordingly, to make DSE commercially viable and efficient, innovative ways such as hybridization (combing a bottoming cycle), Co-generation, Tri-generation etc. need to be explored. In this paper, the techno-economic feasibility of hybridization of a typical solar DSE with a bottoming organic Rankine cycle (ORC) via. a heat recovery vapour generator (HRVG) is explored. The overall energetic and exergetic efficiency of the DSE has been improved by 5.79% and 5.64% while recovering the waste heat through a bottoming ORC. The design and effective incorporation of the HRVG with cooler side of the Stirling engine is identified to be crucial for the overall exergetic performance of solar Stirling-ORC. Further, the economic feasibility of a solar String-ORC combination is evaluated in terms of levelized cost of electricity (LCOE) and payback period. Both LCOE and payback period are found to be in comparable range with the PV technology.

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.

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