Thermodynamic peculiarities of alpha-type Stirling engines for low-temperature difference power generation: Optimisation of operating parameters and heat exchangers using a third-order model

Hoegel, Benedikt; Pons, Dirk J.; Gschwendtner, Michael; Tucker, Anne M.; Sellier, Mathieu

doi:10.1177/0954406213512120

Cited by 8 publications

(9 citation statements)

References 17 publications

(16 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The indicated power generated at a phase angle of 90° is 714 W, which is 5% lower than that at 105°. This deviation could be more pronounced at higher engine frequencies [27].…”

Section: Compression Expansionmentioning

confidence: 91%

Influence of phase angle and dead volume on gamma-type Stirling engine power using CFD simulation

Alfarawi

Al-Dadah

Mahmoud

2016

Energy Conversion and Management

View full text Add to dashboard Cite

Link to publication on Research at Birmingham portal General rights Unless a licence is specified above, all rights (including copyright and moral rights) in this document are retained by the authors and/or the copyright holders. The express permission of the copyright holder must be obtained for any use of this material other than for purposes permitted by law. • Users may freely distribute the URL that is used to identify this publication. • Users may download and/or print one copy of the publication from the University of Birmingham research portal for the purpose of private study or non-commercial research. • User may use extracts from the document in line with the concept of 'fair dealing' under the Copyright, Designs and Patents Act 1988 (?) • Users may not further distribute the material nor use it for the purposes of commercial gain. Where a licence is displayed above, please note the terms and conditions of the licence govern your use of this document. When citing, please reference the published version. Take down policy While the University of Birmingham exercises care and attention in making items available there are rare occasions when an item has been uploaded in error or has been deemed to be commercially or otherwise sensitive.

show abstract

“…The indicated power generated at a phase angle of 90° is 714 W, which is 5% lower than that at 105°. This deviation could be more pronounced at higher engine frequencies [27].…”

Section: Compression Expansionmentioning

confidence: 91%

Influence of phase angle and dead volume on gamma-type Stirling engine power using CFD simulation

Alfarawi

Al-Dadah

Mahmoud

2016

Energy Conversion and Management

View full text Add to dashboard Cite

show abstract

“…Hoegel et al [4] performed a theoretical analysis of the operating and geometric parameters of low-temperature difference Stirling engines. The engine was an alpha type using helium at a mean pressure of 5 MPa.…”

Section: Introductionmentioning

confidence: 99%

A Stirling engine for use with lower quality fuels

Paul

Engeda

2015

Energy

View full text Add to dashboard Cite

a b s t r a c tA Stirling engine for use with lower quality fuels was designed. The design is a derivative of the GPU-3 (ground power unit-3), modified to be used with a lower combustion gas temperature (900 C). It is to be used in a generator set producing 5 kWe. The engine model used is based off of the ideal adiabatic model with decoupled loss mechanisms. Single-cylinder and two-cylinder engines were analyzed using a preheater and CGR (combustion gas recirculation). The analysis shows that the external surface area of the heater plays a very important role in determining the system performance. Maximum system efficiency was found by significantly increasing the surface area at the expense of increased dead volume. A single-cylinder configuration was found to offer the best combination of system efficiency (23.6%) and manufacturing cost.

show abstract

“…However, the pressure difference can be reduced by increasing the phase angle and dead volume. In addition, increasing the phase angle leads to an increase in the heat transfer, and thus the conventional choice of the 90 o phase angle is mainly due to mechanical design reasons …”

Section: Introductionmentioning

confidence: 99%

“…In fact, many researchers showed that it is important to tune the phase angle to achieve the optimal performance of a Stirling engine. Høeg et al showed that the Franchot engine in the SPP 4‐106 heat pump is chosen for the ability to use phase angles other than 90°, especially with low temperature sources.…”

Section: Introductionmentioning

confidence: 99%

Performance investigation of a novel Franchot engine design

Daoud

Friedrich

2017

Int J Energy Res

View full text Add to dashboard Cite

Summary The double‐acting Franchot engine is inferior to the double‐acting Siemens engine under configurations limited by the Siemens engine. In this contribution, the performance of a novel Franchot engine design without the Siemens engine limitations is investigated with a new mathematical definition of the regenerator end temperatures, and the initial statement is challenged. The main advantages of the Franchot engine compared with the Siemens engine are the free control of the phase angle and the thermal separation of the cylinders. Here, the performance of a cylinder‐heated/cooled air‐filled Franchot engine is investigated at medium temperature under variations of engine speed, phase angle, geometry, dead volume, and gas density. A second‐order thermodynamic model with nonconstant, polytropic heat transfer is developed and implemented in Matlab/Simulink for this investigation. The nonconstant heat transfer is crucial to accurately model the behaviour of the direct cylinder heating and cooling. The results show that the phase angle and air charge density have the largest effect on the engine performance. An increase of the phase angle from 90o to 150o at a speed of 1000 RPM led to an increased output power of 58 W compared with a maximum power less than 20 W for a phase angle of 90o. The efficiency at a phase angle of 150o is approximately 25% which is slightly lower than the ideal Curzon and Ahlborn efficiency of 29.3%. This discrepancy can be explained by the nonconstant, polytropic heat transfer. In addition to the increase in engine power, the operation at higher phase angles reduces the pressure difference across the power piston by a factor larger than 4 which leads to a significant reduction in gas leakage across the power pistons. This shows that at higher phase angles, the 2 main disadvantages compared with the Siemens engine are at least reduced and arguably completely removed. Thus, the Franchot engine has the potential to be superior to the Siemens engine if freed from the operational restrictions of the Siemens engine.

show abstract

Thermodynamic peculiarities of alpha-type Stirling engines for low-temperature difference power generation: Optimisation of operating parameters and heat exchangers using a third-order model

Cited by 8 publications

References 17 publications

Influence of phase angle and dead volume on gamma-type Stirling engine power using CFD simulation

Influence of phase angle and dead volume on gamma-type Stirling engine power using CFD simulation

A Stirling engine for use with lower quality fuels

Performance investigation of a novel Franchot engine design

Contact Info

Product

Resources

About