Download or read book Modelling and Flow Measurement of Shallow Geothermal Systems with Downhole Heat Exchangers written by Charles Ray Miles and published by . This book was released on 1978 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt: The low temperature geothermal deposits in the Klamath Falls area are commonly used for heating buildings. The system often used to accomplish this consists of a heat exchanger that extends the full length of the casing within the well. This casing has slots cut in it to allow geothermal water from the aquifer to circulate through the casing and past the heat exchanger. A mathematical model for the thermosyphoning in this system was developed. The model was extended to include: a partial-length heat exchanger, the effects of the mixing of the fluid from inside the casing with that from the aquifer, and the effects on heat transfer coefficients caused by the scaling of the casing and heat exchanger. A parametric study of the system showed that the energy extraction rate from the heat exchanger is largely dependent upon: the temperature of the reservoir, the surface area of the heat exchanger, the ratio of the flow area inside the casing to the area of the annulus between the casing and the well bore, and the degree of mixing between the water from the aquifer and the cooler water from inside the casing. Flow measurements were made to verify the mathematical model. A hot-film anemometer was used to measure the convective flows within the casing but its use is greatly limited because the coating that protects the hot-film does not hold up at the temperatures encountered in a geothermal well. Construction of an energy balance around the heat exchanger in the well made it possible to estimate the convective flows within the well. Alternative designs for heat exchangers were examined. A short multi-loop heat exchanger was designed, built, and tested. Initial results indicate that this type of heat exchanger could be used to replace the full-length heat exchangers.presently in use for residences.
Download or read book Flow Measurement and Characterization in Shallow Geothermal Systems Used for Downhole Heat Exchanger Applications written by and published by . This book was released on 1977 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In the largest non-electrical application of geothermal energy presently occurring in the United States, over 400 relatively shallow wells are being used for extraction of energy with downhole heat exchangers. Despite this large amount of application, the exact nature of the flows in the wells has not before been characterized. Knowledge to date on the nature of flows in the systems is summarized, and an ongoing experimental program for making appropriate downhole measurements to determine flows is described in detail. Flow characterization was a principal object of this study. Horizontal cross-flows of geothermal fluid may occur at upper and/or lower levels in the well where perforations in the well casing are situated. In addition, natural convection may induce vertical flows within the well casing which would be influenced by the presence or absence of a heat exchanger. Three main aspects of the experimental program are reported on: (i) a review of potentially applicable methods for measuring vertical and horizontal flows in wells, (ii) the limitations and preliminary results of using a vane anemometer for measuring vertical flows, and (iii) the description of the selected hot-film probe, its associated pressurized calibration facility, and means of making well measurements.
Download or read book Testing and Modeling of Downhole Heat Exchangers in Shallow Geothermal Systems written by and published by . This book was released on 1978 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Results are reported of work on: characterizing flow in wells with perforated casings with and without downhole heat exchangers (DHE) installed, determining energy extraction rates for conventional DHES in both cased and uncased wells, and modeling of DHE systems to predict effects of heat exchangers and well variable changes.
Download or read book Computational Modeling of Shallow Geothermal Systems written by Rafid Al-Khoury and published by CRC Press. This book was released on 2011-09-30 with total page 256 pages. Available in PDF, EPUB and Kindle. Book excerpt: A Step-by-step Guide to Developing Innovative Computational Tools for Shallow Geothermal Systems Geothermal heat is a viable source of energy and its environmental impact in terms of CO2 emissions is significantly lower than conventional fossil fuels. Shallow geothermal systems are increasingly utilized for heating and cooling of buildings and greenhouses. However, their utilization is inconsistent with the enormous amount of energy available underneath the surface of the earth. Projects of this nature are not getting the public support they deserve because of the uncertainties associated with them, and this can primarily be attributed to the lack of appropriate computational tools necessary to carry out effective designs and analyses. For this energy field to have a better competitive position in the renewable energy market, it is vital that engineers acquire computational tools, which are accurate, versatile and efficient. This book aims at attaining such tools. This book addresses computational modeling of shallow geothermal systems in considerable detail, and provides researchers and developers in computational mechanics, geosciences, geology and geothermal engineering with the means to develop computational tools capable of modeling the complicated nature of heat flow in shallow geothermal systems in rather straightforward methodologies. Coupled conduction-convection models for heat flow in borehole heat exchangers and the surrounding soil mass are formulated and solved using analytical, semi-analytical and numerical methods. Background theories, enhanced by numerical examples, necessary for formulating the models and conducting the solutions are thoroughly addressed. The book emphasizes two main aspects: mathematical modeling and computational procedures. In geothermics, both aspects are considerably challenging because of the involved geometry and physical processes. However, they are highly stimulating and inspiring. A good combination of mathematical modeling and computational procedures can greatly reduce the computational efforts. This book thoroughly treats this issue and introduces step-by-step methodologies for developing innovative computational models, which are both rigorous and computationally efficient.
Download or read book Flow Measurement and Characterization in Shallow Geothermal Systems Used for Downhole Heat Exchanger Applications written by David J. Churchill and published by . This book was released on 1977 with total page 346 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis reports on an investigation of flow patterns in shallow geothermal wells in Klamath Falls, Oregon, Although wells have been extensively used in the area, the exact nature of the flows in the wells has not been characterized. Flow characterization is a principal object of this study. Horizontal crossflows of geothermal fluid may occur at upper and/or lower levels in the well where perforations in the well casing are situated. In addition, natural convection may induce vertical flows within the well casing which would be influenced by the presence or absence of a heat exchanger. Preliminary vertical flow measurements were made with a type of turbinemeter called a "spinner" which was calibrated in a vertical pipe. This type of instrument had limitations in regard to the overall objectives of the study in that (i) the spinner partially blocked flow in the well, possibly altering flow patterns and rates, and (ii) the spinner could not detect or measure horizontal flows. In order to obtain a more satisfactory flow-measuring method, a literature search on flow measurement in confined spaces was undertaken. As a result of the search, a hot-film anemometer was selected to make the detailed flow measurements. The hot-film anemometer was a two-sensor probe that was calibrated in a special calibration system. The high-temperature water in the system was pressurized so that local boiling would not occur at the heated hot-film surface. A number of difficulties occurred with the probe during calibration, possibly due to the severe environment. Measurements of vertical and horizontal flows were attempted on a single cased well with no downhole heat exchanger. A steel cage was built to provide protection for the probe when in the well. Vertical flow measurements showed agreement with past analytical work and also confirmed the effect of spinner flow blockages. Turbulence in the lower perforation region was detected with the vertical flow Measuring channel. Turbulence in the tower perforation region was again detected with the horizontal flow measuring channel. There was difficulty in separating horizontal and vertical flow components. No evidence of high horizontal velocities was found.
Download or read book Natural Convection Heat Transfer Models for Downhole Heat Exchanger Applications in Shallow Geothermal Systems written by and published by . This book was released on 1977 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Downhole heat exchangers are widely used at Klamath Falls, Oregon, for low temperature heating applications. The design of such systems leads to the consideration of several interesting problems of buoyancy driven heat transfer in enclosures. Two models are considered: (i) free convection in the uncased wellbore and (ii) thermosyphoning through and around the wellbore casing which is perforated at two or more depths. Preliminary temperature measurements in the uncased well indicate little bulk vertical flow in the upper part of the well and possible circulation in the lower part. An analytical model is formulated to investigate this problem, and the results are compared with the results of some previous investigations of natural convection in similar enclosures. An analytical model is developed for the thermosyphoning case to determine the limitations of energy extraction for downhole heat exchangers that rely on thermosyphoning as the major mechanism of circulation in the well. Theoretical results from the model are presented showing that observed energy extraction rates are possible as a result of thermosyphoning only.
Download or read book Geothermal Energy written by Ingrid Stober and published by Springer Nature. This book was released on 2021-05-24 with total page 392 pages. Available in PDF, EPUB and Kindle. Book excerpt: The internal heat of the planet Earth represents an inexhaustible reservoir of thermal energy known as Geothermal Energy. The 2nd edition of the book covers the geologic and technical aspects of developing all forms of currently available systems using this "renewable" green energy. The book presents the distribution and transport of thermal energy in the Earth. Geothermal Energy is a base load energy available at all times independent of climate and weather. The text treats the efficiency of diverse shallow near surface installations and deep geothermal systems including hydrothermal and petrothermal techniques and power plants in volcanic high-enthalpy fields. The book also discusses environmental aspects of utilizing different forms of geothermal energy, including induced seismicity, noise pollution and gas release to the atmosphere. Chapters on hydraulic well tests, chemistry of deep hot water, scale formation and corrosion, development of geothermal probes, well drilling techniques and geophysical exploration complete the text. This book, for the first time, covers the full range of utilization of Geothermal Energy.
Download or read book Geothermal Energy Update written by and published by . This book was released on 1976 with total page 668 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Energy Research Abstracts written by and published by . This book was released on 1990 with total page 480 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Geoenergy Modeling II written by Haibing Shao and published by Springer. This book was released on 2016-10-06 with total page 99 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is dedicated to the numerical modeling of shallow geothermal systems. The utilization of shallow geothermal energy involves the integration of multiple Borehole Heat Exchangers (BHE) with Ground Source Heat Pump (GSHP) systems to provide heating and cooling. The modeling practices explained in this book can improve the efficiency of these increasingly common systems. The book begins by explaining the basic theory of heat transport processes in man-made as well as natural media. . These techniques are then applied to the simulation of borehole heat exchangers and their interaction with the surrounding soil. The numerical and analytical models are verified against analytical solutions and measured data from a Thermal Response Test, and finally, a real test site is analyzed through the model and discussed with regard to BHE and GSHP system design and optimization.
Download or read book Masters Theses in the Pure and Applied Sciences written by W. H. Shafer and published by Springer Science & Business Media. This book was released on 2013-03-14 with total page 307 pages. Available in PDF, EPUB and Kindle. Book excerpt: Masters Theses in the Pure and Applied Sciences was first conceived, published, and dis seminated by the Center for Information and Numerical Data Analysis and Synthesis (CINDAS) * at Purdue University in 1957, starting its coverage of theses with the academic year 1955. Beginning with Volume 13, the printing and dissemination phases of the ac tivity were transferred to University Microfilms/Xerox of Ann Arbor, Michigan, with the thought that such an arrangement would be more beneficial to the academic and general scientific and technical community. After five years of this joint undertaking we had concluded that it was in the interest of all concerned if the printing and distribution of the volume were handled by an international publishing house to assure improved service and broader dissemination. Hence, starting with Volume 18, Masters Theses in the Pure and Applied Sciences has been disseminated on a worldwide basis by Plenum Publishing Corporation of New York, and in the same year the coverage was broadened to include Canadian universities. All back issues can also be ordered from Plenum. We have reported in Volume 24 (thesis year 1979) a total of 10,033 theses titles from 26 Canadian and 215 United States universities. We are sure that this broader base for theses titles reported will greatly enhance the value of this important annual reference work. While Volume 24 reports these submitted in 1979, on occasion, certain universities do report theses submitted in previous years but not reported at the time.
Download or read book Natural Convection Heat Transfer Models for Downhole Heat Exchanger Applications in Shallow Geothermal Systems written by M. Fukuda and published by . This book was released on 1977 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Crustal Heat Flow written by G. R. Beardsmore and published by Cambridge University Press. This book was released on 2001-08-06 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt: A handbook for geologists and geophysicists who manipulate thermal data; professionals researchers, and advanced students.
Download or read book Advances in Ground Source Heat Pump Systems written by Simon Rees and published by Woodhead Publishing. This book was released on 2016-05-13 with total page 484 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advances in Ground-Source Heat Pump Systems relates the latest information on source heat pumps (GSHPs), the types of heating and/or cooling systems that transfer heat from, or to, the ground, or, less commonly, a body of water. As one of the fastest growing renewable energy technologies, they are amongst the most energy efficient systems for space heating, cooling, and hot water production, with significant potential for a reduction in building carbon emissions. The book provides an authoritative overview of developments in closed loop GSHP systems, surface water, open loop systems, and related thermal energy storage systems, addressing the different technologies and component methods of analysis and optimization, among other subjects. Chapters on building integration and hybrid systems complete the volume. Provides the geological aspects and building integration covered together in one convenient volume Includes chapters on hybrid systems Presents carefully selected chapters that cover areas in which there is significant ongoing research Addresses geothermal heat pumps in both heating and cooling modes
Download or read book Flow and Heat Transfer in Geothermal Systems written by Aniko Toth and published by Elsevier. This book was released on 2016-10-11 with total page 396 pages. Available in PDF, EPUB and Kindle. Book excerpt: Flow and Heat Transfer in Geothermal Systems: Basic Equations for Description and Modeling Geothermal Phenomena and Technologies is the ideal reference for research in geothermal systems and alternative energy sources. Written for a wide variety of users, including geologists, geophysicists, hydro-geologists, and engineers, it offers a practical framework for the application of heat and flow transport theory. Authored by two of the world’s foremost geothermal systems experts, whose combined careers span more than 50 years, this text is a one-stop resource for geothermal system theory and application. It will help geoscientists and engineers navigate the wealth of new research that has emerged on the topic in recent years. Presents a practical and immediately implementable framework for understanding and applying heat and flow transport theory Features equations for modelling geothermal phenomena and technologies in full detail Provides an ideal text for applications in both geophysics and engineering
Download or read book Geothermal Energy An Important Resource written by Carolyn B. Dowling and published by Geological Society of America. This book was released on 2016-03-17 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nothing provided
Download or read book Geothermal Reservoir Engineering written by Malcomm Grant and published by Elsevier. This book was released on 2013-02-07 with total page 384 pages. Available in PDF, EPUB and Kindle. Book excerpt: Geothermal Reservoir Engineering offers a comprehensive account of geothermal reservoir engineering and a guide to the state-of-the-art technology, with emphasis on practicality. Topics covered include well completion and warm-up, flow testing, and field monitoring and management. A case study of a geothermal well in New Zealand is also presented. Comprised of 10 chapters, this book opens with an overview of geothermal reservoirs and the development of geothermal reservoir engineering as a discipline. The following chapters focus on conceptual models of geothermal fields; simple models that illustrate some of the processes taking place in geothermal reservoirs under exploitation; measurements in a well from spudding-in up to first discharge; and flow measurement. The next chapter provides a case history of one well in the Broadlands Geothermal Field in New Zealand, with particular reference to its drilling, measurement, discharge, and data analysis/interpretation. The changes that have occurred in exploited geothermal fields are also reviewed. The final chapter considers three major problems of geothermal reservoir engineering: rapid entry of external cooler water, or return of reinjected water, in fractured reservoirs; the effects of exploitation on natural discharges; and subsidence. This monograph serves as both a text for students and a manual for working professionals in the field of geothermal reservoir engineering. It will also be of interest to engineers and scientists of other disciplines.
