Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1981. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING. / Includes bibliographical references. / by Rahmatallah Shoureshi. / Ph.D.

Small combined heat and power generators have the potential to reduce energy consumption and greenhouse gas emissions of residential buildings. Recently, much attention has been given to these units. To date, the majority of studies in this field have concentrated on the steady operational performance of a specific generator type, and the available computer models have largely been theoretical in nature. <br /><br /> The main goal of this study was to evaluate the performance of the latest combined heat and power generators, when integrated into Canadian residential homes. A fair comparison of four 1 kW (electrical) units was made. The combined heat and power units studied were based on PEM fuel cell, solid oxide fuel cell, Stirling Engine, and internal combustion engine energy converters. <br /><br /> This study utilized recent test data in an attempt to evaluate the most efficient method of integrating the combined heat and power units into residential houses. Start-up, shut down, and load change transients were incorporated into the simulations. The impact of load variations due to building thermal envelope differences and varying building heating system equipment was evaluated. The simulations were evaluated using TRNSYS software. The building heat demands were determined with eQuest hourly building simulation software. <br /><br /> All of the combined heat and power units under study were capable of providing a net annual benefit with respect to global energy and greenhouse gas emissions. The fuel cells offer the highest integrated performance, followed closely by the internal combustion engine and lastly the Stirling engine. Annual global energy savings up to 20%, and greenhouse gas savings up to 5. 5 tonnes per year can be achieved compared to the best conventional high efficiency appliances. <br /><br /> Heat demand influences performance greatly. As the thermal output of the generator unit approaches half of the average building thermal demand, the system design becomes critical. The system design is also critical when integrating with a forced air furnace. Only the PEM fuel cell unit produces clear global energy and emissions benefits when operating in the summertime.

Texte remanié de: Diss.--München, 1995. / Bibliogr. p. 384-406. Table des ill.

Thesis (M.E.)--University of Canterbury, 2009. / Typescript (photocopy). Includes bibliographical references (leaves 106-109). Also available via the World Wide Web.

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.

Thesis (M.S.)--Ohio University, November, 1998. / Title from PDF t.p.

Techn. Universiẗat, Diss., 2004--Chemnitz.

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

El objetivo general de esta memoria es diseñar un motor Stirling de baja entalpía para estudiar la posibilidad de generar electricidad mediante fuentes geotérmicas con esta tecnología, principalmente para red domiciliaria. Para esto, se analizó el desempeño de un prototipo de motor Stirling en las dependencias del Departamento de Ingeniería Eléctrica. Así, los resultados obtenidos en el análisis de esta última fueron la base para el diseño del motor Stirling de baja entalpía. Se procedió a la recopilación de antecedentes en cuanto a la tecnología a utilizar, los costos asociados, y la potencialidad de los recursos disponibles. Posteriormente, se elaboraron modelos termodinámicos con el fin de estudiar el comportamiento de un motor Stirling ante las condiciones térmicas de las fuentes geotermales. Estos modelos permitieron seleccionar las dimensiones y la configuración de los elementos constituyentes de la máquina. Los modelos entregaron información valiosa sobre la potencia útil generada por la máquina y sus pérdidas asociadas, identificando sus partes críticas y las soluciones posibles. Se estudió en detalle los tipos de tecnología que se utilizan para motores Stirling de baja entalpía con el fin de elaborar un diseño óptimo. En este sentido, el diseño se basó en experiencias anteriores en este tema, buscando las mejores alternativas y optimizando aquellos diseños. Finalmente, se diseñó un motor Stirling para las condiciones específicas de las fuentes geotermales en Chile, utilizando tanto la información recopilada como las conclusiones obtenidas tras el trabajo en la minicentral.