ABSTRACT: Geothermal systems are very complex. Apart from the Hydrogeologie systems, thesesystems include phase change and heat flow. Consequently, its very difficult to suggestvariation depend on the discharge and recharge relation in such a complex, system. Inthis stage, modeling approach is obtained very important role to put forward the futurestate of the system,. Many advances in simulating fluid flow and heat transport in porousmedia have recently been made parallel to geothermal energy research.. These modelsare used to verify and improve conceptual models of geothermal systems.. The main goalof the modeling of geothermal systems is to provide answers to* important problems aboutpotential of reservoir and injection effects. In this paper, a. summary of heat transportmodeling in geothermal systems presented and the governing equations for heat flowbriefly described
ABSTRACT: Extensive groundwater exploitation over the last two decades has resulted in piezometric level decline and- water quality degradation in the fresh water aquifer in the AfyonPlain., Under these conditions, the prediction of the consequences of the overexploitationrequires the identification of the current head distribution. For this purpose, the spatialand temporal extent of the hydraulic head over the plain is simulated by MODFLOW(Modular -three-dimensional-finite-difference ground-water flow model). The hydraulic` head distribution declines from NW to SE over the plain. The.model shows that there isan increase in the decline of the piezomètric levels after the year 1976 when an intensivegroundwater exploitation is started, and after 1990 when the exploitation is considerablyincreased.. It is .simulated that the-hydraulic head is decreased 5 to 10 m in some parts ofthe plain front the year 1965 to 1998. Under these conditions, groundwater usage In the Plain should he regulated to* establish the natural hydraulic balance and, the terminationof ike uncontrolled gromidwater exploitation
ABSTRACT: Afyon Ömer-Gecek is one of the important geothermal areas in Turkey, with lots of boreholes drilled by MTA and other organizations, These boreholes yield 4-100 l/s hot waterat 48-98 °C. AFJET` Corporation established by Afyon Private City Directory utilizes this hot water which has been obtaining from deep boreholes for the heating of the Afyon city.The short distance between the boreholes causes interference between the wells and thetempérature reduction. The hot water aquifer composed of Afyon metamorphics of Paleozoic age. The hoi water,is located in the cracks of this low permeable (kW12 rmt) formation.. Within the scope of this study, it is aimed to conceptualize the hot water circulationsystem, to indicate the effects of the current exploitation activities on the aquifer systemby modeling the temperature and pressure distribution with the HST3D numerical model.,According the results derived from the model, the temperature and pressure around theboreholes decrease gradually in time. Due to the low permeability, the turnover of thesystem requires a long time., Therefore, new wells should be located far away from, theexisting wells and exploited with low rates in order to prevent temperature interferences..