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 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 Thermal Use of Shallow Groundwater written by Fritz Stauffer and published by CRC Press. This book was released on 2013-12-12 with total page 306 pages. Available in PDF, EPUB and Kindle. Book excerpt: The thermal use of the shallow subsurface is increasingly being promoted and implemented as one of many promising measures for saving energy. A series of questions arises concerning the design and management of underground and groundwater heat extraction systems, such as the sharing of the thermal resource and the assessment of its long-term potential. For the proper design of thermal systems it is necessary to assess their impact on underground and groundwater temperatures. Thermal Use of Shallow Groundwater introduces the theoretical fundamentals of heat transport in groundwater systems, and discusses the essential thermal properties. It presents a complete overview of analytical and numerical subsurface heat transport modeling, providing a series of mathematical tools and simulation models based on analytical and numerical solutions of the heat transport equation. It is illustrated with case studies from Austria, Germany, and Switzerland of urban thermal energy use, and heat storage and cooling. This book gives a complete set of analytical solutions together with MATLAB® computer codes ready for immediate application or design. It offers a comprehensive overview of the state of the art of analytical and numerical subsurface heat transport modeling for students in civil or environmental engineering, engineering geology, and hydrogeology, and also serves as a reference for industry professionals.
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 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 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 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 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 Energy Research Abstracts written by and published by . This book was released on 1979 with total page 440 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Numerical Modelling of Multiple Borehole Heat Exchanger Array for Sustainable Utilisation of Shallow Geothermal Energy written by Shuang Chen and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Proceedings written by and published by . This book was released on 1989 with total page 214 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Geothermal Well Downhole Heat Exchanger Design Analysis written by David Brian Kreitlow and published by . This book was released on 1977 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt: The low temperature geothermal resource at Klamath Falls, Oregon is widely used for heating buildings. A common technique for using this resource consists of a heat exchanger down in the well inside a casing which extends the full length of the well. Slots are cut in the casing to allow circulation of the geothermal water into the casing and past the downhole heat exchanger. This results in thermosyphoning between the inside and outside of the casing. Mathematical models of thermosyphoning through the well casing were developed for both with and without downhole heat exchanger present. Results of the model without heat exchanger present showed that thermosyphoning is sufficient to account for observed flow rates through the casing. Model results with heat exchanger included show the substantial influence of thermosyphoning on heat transfer rates and indicate several promising approaches to maximizing output. Because of the importance of scaling and corrosion on the success of a downhole heat exchanger installation, a study of available literature on scaling and corrosion relevant to downhole heat exchangers in low temperature geothermal systems was made and recommendations for corrosion control were developed. Scaling was not deemed severe enough to justify available control measures.
Download or read book Energy Research Abstracts written by and published by . This book was released on 1979 with total page 692 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Downhole Heat Exchangers Performance Analysis written by Michael Graham Dunstall and published by . This book was released on 1992 with total page 250 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Energy a Continuing Bibliography with Indexes written by and published by . This book was released on 1979 with total page 890 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Geothermal Downhole Heat Exchanger Experimental Study of a Model Well DHE System written by Steffen Hailer and published by . This book was released on 1992 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt:
