Heat Transfer in Geothermal Systems
TL;DR: In this paper, the authors discuss the mathematical formulation of convective heat transfer in geothermal systems and the prediction of reservoir behavior under production can be obtained by idealizing it as a saturated porous medium.
Abstract: Publisher Summary This chapter discusses the mathematical formulation of the problems of convective heat transfer in geothermal systems. Geothermal reservoirs may have numerous near-vertical faults and relatively impermeable intrusive interspersed in the aquifers. Both theoretical and experimental investigations of heat transfer in geothermal systems are reviewed. A qualitative understanding of the large-scale convection processes in a geothermal reservoir and the prediction of reservoir behavior under production can be obtained by idealizing it as a saturated porous medium. The identification of a viable geothermal reservoir and the estimation of its capacity remain major problems in the utilization of geothermal resources. Thermal anomalies in geothermal areas can be detected by surface manifestations, aerial infrared surveys, geochemical analyses, or exploratory drillings. Many of the analyses are applicable to a wide range of engineering problems whenever they can be idealized as convection in a porous medium. These include the problems of the secondary recovery of oil by thermal methods, the use of fibrous materials for thermal insulations, the design of aquifers as an energy storage system, and the deposition of mineral ore in the subsurface formation. Results from short-duration well testing are used to determine reservoir characteristics.
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TL;DR: In this article, a generalised non-Darcian porous medium model for natural convective flow has been developed taking into account linear and non-linear matrix drag components as well as the inertial and viscous forces within the fluid.
498 citations
TL;DR: Weaknesses and inconsistencies of current model-verification methods are discussed as well as benchmark solutions for solving the coupled spatio-temporal convection process, consistent velocity approximation, and error-based mesh adaptation techniques.
450 citations
TL;DR: Proposition d'une nouvelle methode de visualisation du transfert de chaleur dans un ecoulement de fluide. Application a la convection naturelle dans une enceinte carree chauffee lateralement
Abstract: Proposition d'une nouvelle methode de visualisation du transfert de chaleur dans un ecoulement de fluide. Application a la convection naturelle dans une enceinte carree chauffee lateralement
387 citations
TL;DR: In this paper, the authors reported a fundamental study of the phenomenon of natural convection heat and mass transfer near a vertical surface embedded in a fluid-saturated porous medium, which is due to the variation of temperature and concentration across the boundary layer.
357 citations
TL;DR: In this article, the authors analyzed the flow and heat transfer at the interface region for three general and fundamental classes of problems in porous media and derived detailed analytical solutions for both the velocity and temperature distributions for all of these interface conditions.
309 citations
References
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01 Jan 1972
TL;DR: In this paper, the Milieux poreux Reference Record was created on 2004-09-07, modified on 2016-08-08 and the reference record was updated in 2016.
Abstract: Keywords: Ecoulement souterrain ; Milieux poreux Reference Record created on 2004-09-07, modified on 2016-08-08
12,446 citations
TL;DR: In this paper, the viscous force exerted by a flowing fluid on a dense swarm of particles is described by a modification of Darcy's equation, which was necessary in order to obtain consistent boundary conditions.
Abstract: A calculation is given of the viscous force, exerted by a flowing fluid on a dense swarm of particles. The model underlying these calculations is that of a spherical particle embedded in a porous mass. The flow through this porous mass is decribed by a modification of Darcy's equation. Such a modification was necessary in order to obtain consistent boundary conditions. A relation between permeability and particle size and density is obtained. Our results are compared with an experimental relation due to Carman.
2,519 citations
01 Oct 1948
TL;DR: In this article, it was shown that under certain conditions convective flow may occur in fluid which permeates a porous stratum and is subject to a vertical temperature gradient, on the assumption that the flow obeys Darcy's law.
Abstract: It is shown that under certain conditions convective flow may occur in fluid which permeates a porous stratum and is subject to a vertical temperature gradient, on the assumption that the flow obeys Darcy's law. The criterion for marginal stability is obtained for three sets of boundary conditions, and the motion described. If such convection occurs in a stratum through which a bore-hole passes, the usual method of calculation of the heat flow must be modified, but in general the correction will not be large.
1,234 citations
TL;DR: In this article, the authors present a general theory that provides a starting point for the construction of special theories so that various drying processes can be studied analytically without recourse to an enormous computational effort.
Abstract: Publisher Summary The well-known transport equations for continuous media are used to construct a rational theory of simultaneous heat, mass, and momentum transfer in porous media. Several important assumptions regarding the structure of the gas–liquid system in a drying process are made that require theoretical or experimental confirmation. This chapter presents a general theory that provides a starting point for the construction of special theories so that various drying processes can be studied analytically without recourse to an enormous computational effort. It analyzes the motion of a liquid and its vapor through a rigid porous media. The development of the relevant volume averaged transport equations, which describe the drying process, is also focused. The transport of momentum in the gas phase and the laws of mechanics are applied to the drying process. The thermal energy equations are considered by forming the total thermal energy equation, and the problem of determining the mass average velocities in the gas and liquid phases are also discussed.
1,062 citations