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Thermal Modelling (thermal + modelling)
Selected AbstractsBURIAL HISTORY RECONSTRUCTION AND THERMAL MODELLING AT KUH-E MOND, SW IRANJOURNAL OF PETROLEUM GEOLOGY, Issue 4 2003M. R. Kamali At the Kuh-e Mond anticline (Fars Province, SW Iran) and in nearby offshore structures, large volumes of natural gas are reservoired in the Permian , Early Triassic Dehram Group while heavy oil has been discovered in the Cretaceous Sarvak and Eocene Jahrum Formations. In this paper, we use data from six exploration wells and from nearby surface exposures to reconstruct the burial history at Kuh-e Mond. Regional observations show that the thick sedimentary fill in this part of the Zagros Basin was subjected to intense tectonism during the Zagros Orogeny, with a paroxysmal phase during the late Miocene and Pliocene. Thermal modelling and geochemical data from Kuh-e Mond and adjacent fields allows possible hydrocarbon generation and migration mechanisms to be identified. Maturities predicted using Lopatin's TTI model are in accordance with maturities obtained from vitrinite reflectance measurements. We show that formations which have source potential in the nearby Dezful Embayment (including the Pabdeh, Gurpi, Gadvan and Kazhdumi Formations) have not reached the oil window in the Mond wells. Moreover, their organic carbon content is very low as they were deposited in oxic, shallow-water settings. Underlying units (including the Ordovician and Cambrian) could have reached the gas window but contain little organic matter. Silurian shales (Sarchahan Formation), which generate gas at Kuh-e Gahkum and Kuh-e Faraghan (north of Bandar Abbas) and in Saudi Arabia and elsewhere in the Middle East, are absent from the Mond structure. The absence of source rocks suggests that the gas and heavy oil accumulations at Kuh-e Mond and at nearby fields have most probably undergone long-distance lateral migration from distant source kitchens. [source] Thermal modelling and experimental validation of ground temperature distribution in greenhouseINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 1 2004M.K. Ghosal Senior Research Fellow Abstract A periodic analysis for daily and monthly variations of ground temperature with depths is presented both under greenhouse and bare surface conditions of Delhi and for bare surface condition in other climates of India in order to design an efficient earth to air heat exchanger for greenhouse system. Calculations were carried out for a typical winter and summer day of Delhi in year 2000. Predicted values of ground temperature at 1 m depth were in fair agreement with experimental values under both conditions. Ground temperatures at various depths inside greenhouse were found to be on an average 7,9°C and 3,6°C higher than bare surface for daily and monthly variations respectively. Copyright © 2004 John Wiley & Sons, Ltd. [source] Low- P,high- T metamorphism and the role of heat transport by melt migration in the Higo Metamorphic Complex, Kyushu, JapanJOURNAL OF METAMORPHIC GEOLOGY, Issue 9 2004K. MIYAZAKIArticle first published online: 7 JAN 200 Abstract This paper characterizes the metamorphic thermal structure of the Higo Metamorphic Complex (HMC) and presents the results of a numerical simulation of a geotherm with melt migration and solidification. Reconstruction of the geological and metamorphic structure shows that the HMC initially had a simple thermal structure where metamorphic temperatures and pressures increased towards apparent lower structural levels. Subsequently, this initial thermal structure has been collapsed by E,W and NNE,SSW trending high-angle faults. Pressure and temperature conditions using the analysis of mineral assemblages and thermobarometry define a metamorphic field P,T array that may be divided into two segments: the array at apparent higher structural levels has a low-dP/dT slope, whereas that at apparent lower structural levels has a high-dP/dT slope. This composite array cannot be explained by heat conduction in subsolidus rocks alone. Migmatite is exposed pervasively at apparent lower structural levels, but large syn-metamorphic plutons are absent at the levels exposed in the HMC. Transport and solidification of melt within migmatite is a potential mechanism to generate the composite array. Thermal modelling of a geotherm with melt migration and solidification shows that the composite thermal structure may be formed by a change of the dominant heat transfer from an advective regime to a conduction regime with decreasing depth. The model also predicts that strata beneath the crossing point will consist of high-grade solid metamorphic rocks and solidified melt products, such as migmatite. This prediction is consistent with the observation that migmatite was associated with the very high-dP/dT slope. The melt migration model is able to generate the very high-dP/dT segment due to the high rate of heat transfer by advection. [source] BURIAL HISTORY RECONSTRUCTION AND THERMAL MODELLING AT KUH-E MOND, SW IRANJOURNAL OF PETROLEUM GEOLOGY, Issue 4 2003M. R. Kamali At the Kuh-e Mond anticline (Fars Province, SW Iran) and in nearby offshore structures, large volumes of natural gas are reservoired in the Permian , Early Triassic Dehram Group while heavy oil has been discovered in the Cretaceous Sarvak and Eocene Jahrum Formations. In this paper, we use data from six exploration wells and from nearby surface exposures to reconstruct the burial history at Kuh-e Mond. Regional observations show that the thick sedimentary fill in this part of the Zagros Basin was subjected to intense tectonism during the Zagros Orogeny, with a paroxysmal phase during the late Miocene and Pliocene. Thermal modelling and geochemical data from Kuh-e Mond and adjacent fields allows possible hydrocarbon generation and migration mechanisms to be identified. Maturities predicted using Lopatin's TTI model are in accordance with maturities obtained from vitrinite reflectance measurements. We show that formations which have source potential in the nearby Dezful Embayment (including the Pabdeh, Gurpi, Gadvan and Kazhdumi Formations) have not reached the oil window in the Mond wells. Moreover, their organic carbon content is very low as they were deposited in oxic, shallow-water settings. Underlying units (including the Ordovician and Cambrian) could have reached the gas window but contain little organic matter. Silurian shales (Sarchahan Formation), which generate gas at Kuh-e Gahkum and Kuh-e Faraghan (north of Bandar Abbas) and in Saudi Arabia and elsewhere in the Middle East, are absent from the Mond structure. The absence of source rocks suggests that the gas and heavy oil accumulations at Kuh-e Mond and at nearby fields have most probably undergone long-distance lateral migration from distant source kitchens. [source] Annual performance analysis and thermal modelling of passive solar still for different inclinations of condensing coverINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 14 2007Anil Kr. Abstract This paper reports the annual as well as seasonal performance analysis of single-slope passive solar stills having three different inclinations of condensing cover, namely 15, 30 and 45°. The analysis is based on the experiments conducted throughout the year from June 2004 to May 2005 on one clear day every month. Each experiment has been carried over for 24 h for the New Delhi (Latitude: 28°37, North and Longitude: 77°13, East) climatic conditions. It was observed that the 15° inclination of condensing cover gives maximum annual yield and distillation efficiency. The concept of solar fraction has been used for the validation of thermal modelling. The fair agreement has been noted between the values observed experimentally and calculated theoretically for temperatures and yield in all seasons. Copyright © 2007 John Wiley & Sons, Ltd. [source] Transient thermal modelling of heat recovery steam generators in combined cycle power plantsINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 11 2007Sepehr Sanaye Abstract Heat recovery steam generator (HRSG) is a major component of a combined cycle power plant (CCPP). This equipment is particularly subject to severe thermal stress especially during cold start-up period. Hence, it is important to predict the operational parameters of HRSGs such as temperature of steam, water, hot gas and tube metal of heating elements as well as pressure change in drums during transient and steady-state operation. These parameters may be used for estimating thermal and mechanical stresses which are important in HRSG design and operation. In this paper, the results of a developed thermal model for predicting the working conditions of HRSG elements during transient and steady-state operations are reported. The model is capable of analysing arbitrary number of pressure levels and any number of elements such as superheater, evaporator, economizer, deaerator, desuperheater, reheater, as well as duct burners. To assess the correct performance of the developed model two kinds of data verification were performed. In the first kind of data verification, the program output was compared with the measured data collected from a cold start-up of an HRSG at Tehran CCPP. The variations of gas, water/steam and metal temperatures at various sections of HRSG, and pressure in drums were among the studied parameters. Mean differences of about 3.8% for temperature and about 9.2% for pressure were observed in this data comparison. In the second kind of data verification, the steady-state numerical output of the model was checked with the output of the well-known commercial software. An average difference of about 1.5% was found between the two latter groups of data. Copyright © 2007 John Wiley & Sons, Ltd. [source] Estimating thermal stress in BIPV modulesINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 15 2006Petri Konttinen Abstract The thermal stress on building-integrated photovoltaic modules (BIPV) in Espoo, Finland, was studied with field-testing of amorphous silicon modules. Based on these results, the thermal stress at two other European locations (Paris and Lisbon) was estimated. The estimation procedure entailed thermal modelling of heat transfer in the façade with meteorological data as input. The results indicate that the thermal stress on BIPV modules in Lisbon is, in this case, approximately 50% higher that in Espoo and between 80 and 200% higher than in Paris, depending on the activation energy of the degradation process. The difference in stress between a BIPV module and a free-standing module in Espoo was 50,200%. Copyright © 2006 John Wiley & Sons, Ltd. [source] Evaluation of solar fraction (Fn) for the north wall of a controlled environment greenhouse: an experimental validationINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 3 2002G. N. Tiwari Abstract In this communication, an attempt has been made to define and evaluate the solar fraction (Fn) for a north wall on the basis of annual experimental studies. An even-span greenhouse has been considered for experimental studies for the climatic conditions of Delhi. Experiments were conducted from September 1999 to August 2000. A model based on Auto-CAD 2000 has also been developed for validation. It has been observed that the solar fraction mainly depends on angle of incidence, solar altitude angle and shape and size of the greenhouse. It is inferred that solar fraction (Fn) plays a significant role in thermal modelling of an even-span type greenhouse. Further, it was noted that there is a fair agreement between experimental and theoretical results. Copyright © 2002 John Wiley & Sons, Ltd. [source] Controls on low-pressure anatexisJOURNAL OF METAMORPHIC GEOLOGY, Issue 2 2006C. C. GERBI Abstract Low-pressure anatexis, whereby rocks melt in place after passing through the andalusite stability field, develops under more restricted conditions than does low-pressure metamorphism. Our thermal modelling and review of published work indicate that the following mechanisms, operating alone, may induce anatexis in typical pelitic rocks without inducing wholesale melting in the lower crust: (i) magmatic advection by pervasive flow; (ii) crustal-scale detachment faulting; and (iii) the presence of a high heat-producing layer. Of these, only magmatic advection by pervasive flow and crustal-scale detachment faulting have been shown quantitatively to provide sufficient heat to cause widespread melting. Combinations of the above mechanisms with pluton-scale magmatic advection, shear heating, removal of the lithospheric mantle, or with each other provide additional means of developing suitable high temperatures at shallow crustal levels to generate low-pressure anatexis. [source] One-dimensional thermal modelling of Acadian metamorphism in southern Vermont, USAJOURNAL OF METAMORPHIC GEOLOGY, Issue 6 2000T. R. Armstrong One-dimensional thermal (1DT) modelling of an Acadian (Devonian) tectonothermal regime in southern Vermont, USA, used measured metamorphic pressures and temperatures and estimated metamorphic cooling ages based on published thermobarometric and geochronological studies to constrain thermal and tectonic input parameters. The area modelled lies within the Vermont Sequence of the Acadian orogen and includes: (i) a western domain containing garnet-grade pre-Silurian metasedimentary and metavolcanic rocks from the eastern flank of an Acadian composite dome structure (Rayponda,Sadawga Dome); and (ii) an eastern domain containing similar, but staurolite- or kyanite-grade, rocks from the western flank of a second dome structure (Athens Dome), approximately 10 km farther east. Using reasonable input parameters based on regional geological, petrological and geochronological constraints, the thermal modelling produced plausible P,T paths, and temperature,time (T ,t) and pressure,time (P,t) curves. Information extracted from P,T ,t modelling includes values of maximum temperature and pressure on the P,T paths, pressure at maximum temperature, predicted Ar closure ages for hornblende, muscovite and K-feldspar, and integrated exhumation and cooling rates for segments of the cooling history. The results from thermal modelling are consistent with independently obtained pressure, temperature and Ar cooling age data on regional metamorphism in southern Vermont. Modelling results provide some important bounding limits on the physical conditions during regional metamorphism, and indicate that the pressure contemporaneous with the attainment of peak temperature was probably as much as 2.5 kbar lower than the actual maximum pressure experienced by rocks along various particle paths. In addition, differences in peak metamorphic grade (garnet-grade versus staurolite-grade or kyanite-grade) and peak temperature for rocks initially loaded to similar crustal depths, differences in calculated exhumation rates, and differences in 40Ar/39Ar closure ages are likely to have been consequences of variations in the duration of isobaric heating (or ,crustal residence periods') and tectonic unroofing rates. Modelling results are consistent with a regional structural model that suggests west to east younging of specific Acadian deformational events, and therefore diachroneity of attainment of peak metamorphic conditions and subsequent 40Ar/39Ar closure during cooling. Modelling is consistent with the proposition that regional variations in timing and peak conditions of metamorphism are the result of the variable depths to which rocks were loaded by an eastward-thickening thrust-nappe pile rooted to the east (New Hampshire Sequence), as well as by diachronous structural processes within the lower plate rocks of the Vermont Sequence. [source] Tectonic evolution of the Himalaya constrained by detrital 40Ar,39Ar, Sm,Nd and petrographic data from the Siwalik foreland basin succession, SW NepalBASIN RESEARCH, Issue 4 2006A. G. Szulc ABSTRACT 40Ar,39Ar dating of detrital white micas, petrography and heavy mineral analysis and whole-rock geochemistry has been applied to three time-equivalent sections through the Siwalik Group molasse in SW Nepal [Tinau Khola section (12,6 Ma), Surai Khola section (12,1 Ma) and Karnali section (16,5 Ma)]. 40Ar,39Ar ages from 1415 single detrital white micas show a peak of ages between 20 and 15 Ma for all the three sections, corresponding to the period of most extensive exhumation of the Greater Himalaya. Lag times of less than 5 Myr persist until 10 Ma, indicating Greater Himalayan exhumation rates of up to 2.6 mm year,1, using one-dimensional thermal modelling. There are few micas younger than 12 Ma, no lag times of less than 6 Myr after 10 Ma and whole-rock geochemistry and petrography show a significant provenance change at 12 Ma indicating erosion from the Lesser Himalaya at this time. These changes suggest a switch in the dynamics of the orogen that took place during the 12,10 Ma period whereby most strain began to be accommodated by structures within the Lesser Himalaya as opposed to the Greater Himalaya. Consistent data from all three Siwalik sections suggest a lateral continuity in tectonic evolution for the central Himalayas. [source] | ||||||||||