A residential micro-cogeneration system based on a Stirling engine unit was modified to operate with wood derived fast pyrolysis liquid (bio-oil)-ethanol blend. A pilot stabilized swirl combustion chamber was designed to replace the original evaporative burner due to bio-oil’s nondistillable nature. This also required modifications of the engine’s control systems. Efficiencies for the bio-oil/ethanol blend were found be higher than those of diesel due to the higher heat loss incurred with diesel. Based on a modified efficiency, which disregarded the heat loss through the combustion chamber, power efficiencies were found to be comparable. The maximum time of operation with the bio-oil/ethanol blend was approximately 97 minutes due to the clogging of the narrow passages. Carbon monoxide emissions were higher for the bio-oil/ethanol blend due to the operation conditions of the combustion chamber. Oxides of nitrogen emissions were also higher for the bio-oil/ethanol blend due to its inherent nitrogen content.

A residential micro-cogeneration system based on a Stirling engine unit was modified to operate with wood derived fast pyrolysis liquid (bio-oil)-ethanol blend. A pilot stabilized swirl combustion chamber was designed to replace the original evaporative burner due to bio-oil’s nondistillable nature. This also required modifications of the engine’s control systems. Efficiencies for the bio-oil/ethanol blend were found be higher than those of diesel due to the higher heat loss incurred with diesel. Based on a modified efficiency, which disregarded the heat loss through the combustion chamber, power efficiencies were found to be comparable. The maximum time of operation with the bio-oil/ethanol blend was approximately 97 minutes due to the clogging of the narrow passages. Carbon monoxide emissions were higher for the bio-oil/ethanol blend due to the operation conditions of the combustion chamber. Oxides of nitrogen emissions were also higher for the bio-oil/ethanol blend due to its inherent nitrogen content.

abstract: While much effort in Stirling engine development is placed on making the high-temperature region of the Stirling engine warmer, this research explores methods to lower the temperature of the cold region by improving heat transfer in the cooler. This paper presents heat transfer coefficients obtained for a Stirling engine heat exchanger with oscillatory flow. The effects of oscillating frequency and input heat rate on the heat transfer coefficients are evaluated and details on the design and development of the heat exchanger test apparatus are also explained. Featured results include the relationship between overall heat transfer coefficients and oscillation frequency which increase from 21.5 to 46.1 Wm-2K-1 as the oscillation frequency increases from 6.0 to 19.3 Hz. A correlation for the Nusselt number on the inside of the heat exchange tubes in oscillatory flow is presented in a concise, dimensionless form in terms of the kinetic Reynolds number as a result of a statistical analysis. The test apparatus design is proven to be successful throughout its implementation due to the usefulness of data and clear trends observed. The author is not aware of any other publicly-available research on a Stirling engine cooler to the extent presented in this paper. Therefore, the present results are analyzed on a part-by-part basis and compared to segments of other research; however, strong correlations with data from other studies are not expected. The data presented in this paper are part of a continuing effort to better understand heat transfer properties in Stirling engines as well as other oscillating flow applications. / Dissertation/Thesis / M.S. Mechanical Engineering 2011

Stirling engines are an external combustion heat engine that converts thermal energy into mechanical work that a closed cycle is run by cyclic compression and expansion of a work fluid (commonly air or Helium) in which, the working fluid interacts with a heat source and a heat sink and produces network. The engine is based on the Stirling cycle which is a subset of the Carnot cycle. The Stirling cycle has recently been receiving renewed interest due to some of its key inherent advantages. In particular, the ability to operate with any form of heat source (including external combustion, flue gases, alternative (biomass, solar, geothermal) energy) provides Stirling engines a great flexibility and potential benefits since it is convinced as engines running with external heat sources. However, several aspects of traditional Stirling engine configurations (namely, the Alpha, Beta, and Gamma), specifically complexity of design, high cost, and relatively low power to size and power to volume ratios, limited their widespread applications to date. This study focuses on an innovative Stirling engine configuration that features a rotary displacer (as opposed to common reciprocating displacers), and aims to utilize analytical and numerical analysis to gain insights on its operation parameters. The results are expected to provide useful design guidelines towards optimization. The present study starts with an overview of the Stirling cycle and Stirling engines including both traditional and innovative rotary displacer configurations, and their major advantages and disadvantages. The first approach considers an ideal analytical model and implements the well-known Schmidt analysis assumptions for the rotary displacer Stirling engine to define the effects of major design and operation parameters on the performance. The analytical model resulted in identifying major variables that could affect the engine performance (such as the dead volume spaces, temperature ratios and the leading phase angle). It was shown that the dead volume could have a drastic effect over the engine performance and the optimum phase angle of the engine is 90o. The second approach considers a non-ideal analytical model and aims to identify and account the main sources of energy losses in the cycle to better represent the engine performance. The study showed that the ideal efficiency and the non-ideal efficiency could have 15% difference that could have as an enormous effect on the engine performance.

This article contains description of basic principles of stirling engine, construction types and its parts, which supplies motor run and description of using in real life too. The main topic is analyses of driving mechanism supplying both pistons movement of stirling engine on Robert Stirling‘s drawing from 1816.

No description available.

No description available.

No description available.

This work deals with the structural design of the Stirling engine beta modifications for increasing the thermal efficiency of the regenerator. This work is an attempt to propose a regenerator, or propose ways of working fluid through the heater and the heat exchanger to cool the chamber. All using different design elements. Furthermore, this work deals with stress analysis using computer software.

This dissertation about the Stirling engine deals with the history and formation of the heat engine. At the beginning of this work, fundamental parts and their functions are described, elucidating the principle of operation explained by the thermodynamic cycle and subsequently comparing the ideal and the real Stirling cycle and last but not least provides various modifications whilst describing their differences. The mathematical model of the Stirling engine is processed by Schmidth’s theoretical analysis and thereafter is created in PScad v46. The process of creating a model is shown in one of the chapters of this dissertation. The results were taken into account in the design of 3D models in Inventor Professional by Autodesk. The work concludes with the evaluation of the computational model and its functionality as well as the documentation of the 3D model.