Sterilization of liquid food in cans was studied and analyzed using computational fluid dynamics ... more Sterilization of liquid food in cans was studied and analyzed using computational fluid dynamics (CFD). In all the simulations studied, saturated steam at 121oC was used as the heating medium. The different liquid foods studied in this work were assumed to have constant specific heat, thermal conductivity and volume expansion coefficient, while the viscosity was taken as a function of temperature. Density variations were governed by the Boussinesq approximation. The software package code PHOENICS was used, which is based on finite volume method of analysis (FVM). The results of the simulations were presented in the form of transient temperature and velocity profiles. The shapes and movement of the slowest heating zone were followed throughout the sterilization time. The simulations show clearly the action of natural convection, which forces the slowest heating zone (SHZ) to migrate towards the bottom of the can as expected.
ABSTRACT Pressure, Temperature and Spinner (PTS) probes/tools are commonly used in the characteri... more ABSTRACT Pressure, Temperature and Spinner (PTS) probes/tools are commonly used in the characterization of geothermal wells during drilling, completion testing, and monitoring throughout the life of the well. These well tests include static formation temperature testing, water loss surveys, injection fall-off tests, drawdown build-up tests, warm-up surveys, flowing surveys, and other tests. The challenge when using these tools is to ensure that the electronic components of the different sensors, signal processing, and memory are not affected by the heat generated from the tool's internal energy use, internal supply (battery), and from the high temperatures inside the well. This buildup of heat limits the working time available for the tool down the geothermal well and can affect/limit the acquisition and quality of the data. A survey was conducted on the current state of electronics and electronic packaging for the use in geothermal, and oil and gas probes/tools. Techniques for high temperature performance were reviewed including the use of Dewar flasks for the thermal insulation of electronic components of the PTS tool and the use of electronics for operation at higher temperatures. An in-depth analysis of the performance of the widely used commercial PTS tool developed by MB Century Ltd. was completed using SolidWorks™ thermal simulation software. The model was optimized and compared to PTS probe test data taken from five different test cases. The calibrated model was used to evaluate several different heat sink materials, with results showing that the current tool design cannot be easily optimized further. However, predictions based on the calibrated model showed an alternative operating procedure that can provide an increase in the operating down-hole time of the tool.
Resource estimates in geothermal "green" fields involve significant inherent uncertaint... more Resource estimates in geothermal "green" fields involve significant inherent uncertainty due to poorly constrained subsurface parameters and multiple potential development scenarios. There is also limited published information on probabilistic resource assessments of geothermal prospects. This paper explores the applications of a systematic experimental design (ED) approach to a geothermal reservoir simulation model to generate probabilistic resource assessment results. A Plackett-Burmann design was used to build 12 simulation experiments for a geothermal system, investigating six model parameters at two levels. A probabilistic 30-yr power capacity was successfully generated from the resulting response surface. Analysis of the response also showed that the power capacity was significantly affected by only three of the tested parameters: reservoir temperature, permeability, and well depth. Volumetric methods, both "heat in place" and mass in place, were applied to...
Lake Waikare, situated within the Huntly coalfield in North Waikato, is host to a small island (P... more Lake Waikare, situated within the Huntly coalfield in North Waikato, is host to a small island (Punikanae Island) where a silica sinter-depositing spring is located. This is the only sinter depositing spring known outside the Taupo Volcanic Zone. The chemical analysis from the two spring samples complimented by geological information gathered during a short field visit and other technical data available in the literature are the sets of information used in this study. Based on the Cl-SO 4 -HCO 3 ternary plot that was used to classify the geothermal waters with respect to major anion composition and the Na-K-Mg ternary plot to classify fluids according to the state of equilibrium at given temperatures, the origin of the geothermal system that feeds the spring is thought to be mature neutral chloride waters that probably originate from an up-flow zone beneath Punikanae Island with the Maungaroa Fault as its main conduit. Up-flow zones are generally characterized by silica sinter depos...
Sterilization of liquid food in cans was studied and analyzed using computational fluid dynamics ... more Sterilization of liquid food in cans was studied and analyzed using computational fluid dynamics (CFD). In all the simulations studied, saturated steam at 121oC was used as the heating medium. The different liquid foods studied in this work were assumed to have constant specific heat, thermal conductivity and volume expansion coefficient, while the viscosity was taken as a function of temperature. Density variations were governed by the Boussinesq approximation. The software package code PHOENICS was used, which is based on finite volume method of analysis (FVM). The results of the simulations were presented in the form of transient temperature and velocity profiles. The shapes and movement of the slowest heating zone were followed throughout the sterilization time. The simulations show clearly the action of natural convection, which forces the slowest heating zone (SHZ) to migrate towards the bottom of the can as expected.
ABSTRACT Pressure, Temperature and Spinner (PTS) probes/tools are commonly used in the characteri... more ABSTRACT Pressure, Temperature and Spinner (PTS) probes/tools are commonly used in the characterization of geothermal wells during drilling, completion testing, and monitoring throughout the life of the well. These well tests include static formation temperature testing, water loss surveys, injection fall-off tests, drawdown build-up tests, warm-up surveys, flowing surveys, and other tests. The challenge when using these tools is to ensure that the electronic components of the different sensors, signal processing, and memory are not affected by the heat generated from the tool's internal energy use, internal supply (battery), and from the high temperatures inside the well. This buildup of heat limits the working time available for the tool down the geothermal well and can affect/limit the acquisition and quality of the data. A survey was conducted on the current state of electronics and electronic packaging for the use in geothermal, and oil and gas probes/tools. Techniques for high temperature performance were reviewed including the use of Dewar flasks for the thermal insulation of electronic components of the PTS tool and the use of electronics for operation at higher temperatures. An in-depth analysis of the performance of the widely used commercial PTS tool developed by MB Century Ltd. was completed using SolidWorks™ thermal simulation software. The model was optimized and compared to PTS probe test data taken from five different test cases. The calibrated model was used to evaluate several different heat sink materials, with results showing that the current tool design cannot be easily optimized further. However, predictions based on the calibrated model showed an alternative operating procedure that can provide an increase in the operating down-hole time of the tool.
Resource estimates in geothermal "green" fields involve significant inherent uncertaint... more Resource estimates in geothermal "green" fields involve significant inherent uncertainty due to poorly constrained subsurface parameters and multiple potential development scenarios. There is also limited published information on probabilistic resource assessments of geothermal prospects. This paper explores the applications of a systematic experimental design (ED) approach to a geothermal reservoir simulation model to generate probabilistic resource assessment results. A Plackett-Burmann design was used to build 12 simulation experiments for a geothermal system, investigating six model parameters at two levels. A probabilistic 30-yr power capacity was successfully generated from the resulting response surface. Analysis of the response also showed that the power capacity was significantly affected by only three of the tested parameters: reservoir temperature, permeability, and well depth. Volumetric methods, both "heat in place" and mass in place, were applied to...
Lake Waikare, situated within the Huntly coalfield in North Waikato, is host to a small island (P... more Lake Waikare, situated within the Huntly coalfield in North Waikato, is host to a small island (Punikanae Island) where a silica sinter-depositing spring is located. This is the only sinter depositing spring known outside the Taupo Volcanic Zone. The chemical analysis from the two spring samples complimented by geological information gathered during a short field visit and other technical data available in the literature are the sets of information used in this study. Based on the Cl-SO 4 -HCO 3 ternary plot that was used to classify the geothermal waters with respect to major anion composition and the Na-K-Mg ternary plot to classify fluids according to the state of equilibrium at given temperatures, the origin of the geothermal system that feeds the spring is thought to be mature neutral chloride waters that probably originate from an up-flow zone beneath Punikanae Island with the Maungaroa Fault as its main conduit. Up-flow zones are generally characterized by silica sinter depos...
Uploads