scholarly journals A Method for Measurement of Terrestrial Heat Flow Density in Water Wells

2018 ◽  
Vol 4 (2) ◽  
pp. 45
Author(s):  
Janilo Santos ◽  
Valiya M. Hamza ◽  
Po-Yu Shen
Keyword(s):  
Thermal Conductivity ◽  
Heat Flow ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Flow Density ◽  
Heat Flow Density ◽  
Terrestrial Heat Flow ◽  
The Mean

ABSTRACT. A simple method for measurement of terrestrial heat flow density in wells drawing groundwater from confined aquifers is presented. It requires laboratory determination of thermal resistance but the field work is simple, being limited to measurement of temperature of water at the well mouth during pumping tests.The aquifer temperature (Ta) is calculated from the measured temperature at the well mouth (Tw), the mass flow rate (M) and the depth to the top of the aquifer (H) using the relation(Tw – To) / (Ta – To) = M'R [1 – exp(–1/M'R)]where To is the mean annual surface temperature, R a dimensionless diffusion parameter and M' = MC/KH is the dimensionless mass flow rate, C being the specific heat of water and K the thermal conductivity of the rock formation penetrated by the well. The heat flow density (q) is then calculated from the relationq = (Ta –To) / ∑ n (i=1) Pi Zjwhere Pi is the thermal resistivity of the jth layer of thickness Zi and n the number of layers. The procedure also allow corrections for the influence of thermal conductivity variations oi the wall rocks.This method was used for the determination of heat flow density values for thirteen sites in the northeastern part of the Paraná basin. The mean value obtained is 62±4 mW/m2 in good agreement with the mean of 59±9 mW/m2 obtained by the conventional method for thirteen sites in the Paraná basin. Though similar in principle to the bottom-hole temperature method used in oil wells, the present technique has some inherent advantages. lt is potentially capable of providing a wider geographic representation of heat flow density (being not limited to petroleum fields) and is relatively free of the sampling problems normally encountered in working with oil companies. 0n the other hand the present method may provide unreliable values in the case of wells drawing water from more than one aquifer. RESUMO. Apresenta-se neste trabalho, um método simples para a determinação do fluxo geotérmico em poços em atividade de bombeamento de água subterrânea. O método requer a determinação em laboratório da resistência térmica total das camadas atravessadas pelo poço mas, o trabalho de campo é simples, limitando-se à medida da temperatura da água na boca do poço durante ensaios de bombeamento.A temperatura do aquífero (Ta) é calculada a partir da temperatura da água (TW), medida na boca do poço da vazão (M) expressa em massa  de água produzida pelo poço por unidade de tempo e, da profundidade do topo do aquífero (H) usando-se a relação(Tw – To) / (Ta – To) = M'R [1 – exp(–1/M'R)]onde TO é a temperatura média anual da superfície, R é um parâmetro adimensional de difusão, M' = M C/K H é a vazão adimensional do poço, C é o calor específico da água e, K é a condutividade térmica da rocha atravessada pelo poço. O fluxo geotérmico (q) é calculado pela relaçãoq = (Ta –To) / ∑ n (i=1) Pi Zjonde Pi é a resistência térmica da i-ésima camada de espessura Zi e, n é o número de camadas.O método permite também a introdução de correções da influência das variações de condutividade térmica das paredes do poço.Este método foi utilizado na determinação do fluxo geotérmico em treze localidades no nordeste da Bacia do Paraná. O valor médio obtido foi de 62±4 mW /m2 concordando com o valor médio de 59±9 mW/m2 obtido pelo método convencional de determinação de fluxo geotérmico em treze localidades da Bacia do Paraná. Apesar de ser um método similar ao das temperaturas de fundo de poço usado em poços de petróleo, esta técnica apresenta algumas vantagens. O método é potencialmente capaz de fornecer uma representação geográfica mais ampla do fluxo geotérmico, não estando limitado a campos de produção de petróleo, e é relativamente livre de problemas de amostragem normalmente encontrados quando se trabalha com companhias de petróleo. Por outro lado, este método pode fornecer valores irreais de fluxo geotérmico no caso em que o poço extraia água de mais de um aquífero. 

Leakage Prediction in Mechanical Seals Under Hydrostatic Operating Condition

2007 ◽  
Author(s):  
S. Elhanafi ◽  
K. Farhang
Keyword(s):  
Closed Form ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Rough Surfaces ◽  
Mechanical Seals ◽  
Operating Condition ◽  
Form Equation ◽  
Macro Scale ◽  
The Mean

This paper considers leakage in mechanical seals under hydrostatic operating condition. A contact model based on the Greenwood and Williamson contact of rough surfaces is developed for treating problems involving mechanical seals in which both the micron scale roughness of the seal face and its macro scale profile are used to obtain either a closed-form equation or a nonlinear equation relating mean plane separation to the mass flow rate. The equations involve the micron scale geometry of the rough surfaces and physical parameter of the seal and carriage. Under hydrostatic condition, it is shown that there is an approximate closed-form solution in which mass flow rate in terms of the mean plane separation, or alternatively, the mean plane separation in terms of the leakage mass flow rate is found. Equations pertaining to leakage in nominally flat seal macro profile is considered and closed form equation relating to leakage flow rate to pressure difference is obtained that contain macro and micron geometries of the seal.

Application of Thermal Sensors for Determination of Mass Flow Rate and Velocity of Flow in Pipes of Hermetic Systems

2019 ◽  
Vol 826 ◽  
pp. 117-124
Author(s):  
Yurii Baidak ◽  
Iryna Vereitina
Keyword(s):  
Temperature Distribution ◽  
Mass Flow Rate ◽  
Cross Section ◽  
Correction Factor ◽  
Mass Flow ◽  
Flow Rate ◽  
Thermal Sensors ◽  
Pipe Surface ◽  
Pipe Cross Section

The paper relates to the field of measuring technologies and deals with the enhancement of thermoconvective method when it is applied for the experimental determination of such hydrodynamics indicators as mass flow rate and velocity of flow by their indirect parameters - capacity of the heater and the temperatures obtained from two thermal sensors, provided that they are located on the hermetic piping system surface. The issue of determination of correction factor on heterogeneity of liquid temperature distribution in the pipe cross section depending on pipe diameter and fluid movement velocity was clarified. According to the results of numerical calculations, the dependencies of temperature gradient on the pipe surface and the correction factor on the heterogeneity of the temperature distribution along the pipe cross-section under the heater in the function of the velocity of flow in pipes of different diameters are plotted. These dependencies specify the thermal method of studying the fluid flow in the pipes, simplify the experiment conduction, are useful in processing of the obtained results and can be applied in measuring engineering.

Air Blowing Into Boundary Layer Of A Flat Plate With Length-Dependent Permeability

2016 ◽  
Vol 11 (3) ◽  
pp. 16-26
Author(s):  
Vladimir Kornilov ◽  
Andrey Boiko ◽  
Ivan Kavun ◽  
Anatoliy Popkov
Keyword(s):  
Boundary Layer ◽  
Friction Coefficient ◽  
Flat Plate ◽  
Skin Friction ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Skin Friction Coefficient ◽  
Air Blowing ◽  
The Mean

A generalized analysis of the results of numerical and experimental studies of air blowing into a turbulent boundary layer through finely perforated surface consisting of alternating permeable and impermeable sections of varying length providing a sudden change in the flow conditions at the boundaries of these sections is presented. The air blowing coefficient Cb determined by the mass flow rate per unit area of the active perforated sample varied in the range from 0 to 0.008. It is shown that as Cb grows, the maximum reduction in the mean surface skin-friction coefficient CF, which is the value through the permeable area of perforated sample, reaches about 65 %. When keeping the equal mass flow rate Q for all tested combinations, the mean skin-friction coefficient remains constant, independent of geometrical parameters of permeable and impermeable sections. Increasing the length of the last permeable section leads to the growth of relaxation region which is characterized by the reduced skin friction values on the impermeable part of the flat plate.

scholarly journals Analysis of Selected Properties of Biocomposites Based on Polyethylene with a Natural Origin Filler

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4182
Author(s):  
Emil Sasimowski ◽  
Łukasz Majewski ◽  
Marta Grochowicz
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Wheat Bran ◽  
Natural Aging ◽  
Polyethylene Matrix ◽  
Grain Sizes ◽  
Aging Period ◽  
Processing Properties

The study investigates the effect of the content and size of wheat bran grains on selected properties of a lignocellulosic biocomposite on a polyethylene matrix. The biocomposite samples were made by injection method of low-density polyethylene with 5%, 10% and 15% by weight of wheat bran. Three bran fractions with grain sizes <0.4 mm, 0.4–0.6 mm and 0.6–0.8 mm were used. The properties of the mouldings (after primary shrinkage) were examined after their 2.5-year natural aging period. Processing properties, such as MFR (mass flow rate) and processing shrinkage, were determined. Selected physical, mechanical and structural properties of the produced biocomposite samples were tested. The results allowed the determination of the influence of both the content of bran and the size of its grains on such properties of the biocomposite as: color, gloss, processing shrinkage, tensile strength, MFR mass flow rate, chemical structure (FTIR), thermal properties (DSC, TG), p-v-T relationship. The tests did not show any deterioration of the mechanical characteristics of the tested composites after natural aging.

scholarly journals Heat flow density estimates in the Upper Rhine Graben using laboratory measurements of thermal conductivity on sedimentary rocks

2019 ◽  
Vol 7 (1) ◽  
Author(s):  
Pauline Harlé ◽  
Alexandra R. L. Kushnir ◽  
Coralie Aichholzer ◽  
Michael J. Heap ◽  
Régis Hehn ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Heat Flow ◽  
Ambient Temperature ◽  
Sedimentary Rocks ◽  
Flow Density ◽  
Upper Rhine Graben ◽  
Heat Flow Density ◽  
Density Estimates ◽  
Wet Rocks ◽  
Upper Rhine

AbstractThe Upper Rhine Graben (URG) has been extensively studied for geothermal exploitation over the past decades. Yet, the thermal conductivity of the sedimentary cover is still poorly constrained, limiting our ability to provide robust heat flow density estimates. To improve our understanding of heat flow density in the URG, we present a new large thermal conductivity database for sedimentary rocks collected at outcrops in the area including measurements on (1) dry rocks at ambient temperature (dry); (2) dry rocks at high temperature (hot) and (3) water-saturated rocks at ambient temperature (wet). These measurements, covering the various lithologies composing the sedimentary sequence, are associated with equilibrium-temperature profiles measured in the Soultz-sous-Forêts wells and in the GRT-1 borehole (Rittershoffen) (all in France). Heat flow density values considering the various experimental thermal conductivity conditions were obtained for different depth intervals in the wells along with average values for the whole boreholes. The results agree with the previous heat flow density estimates based on dry rocks but more importantly highlight that accounting for the effect of temperature and water saturation of the formations is crucial to providing accurate heat flow density estimates in a sedimentary basin. For Soultz-sous-Forêts, we calculate average conductive heat flow density to be 127 mW/m2 when considering hot rocks and 184 mW/m2 for wet rocks. Heat flow density in the GRT-1 well is estimated at 109 and 164 mW/m2 for hot and wet rocks, respectively. Results from the Rittershoffen well suggest that heat flow density is nearly constant with depth, contrary to the observations for the Soultz-sous-Forêts site. Our results show a positive heat flow density anomaly in the Jurassic formations, which could be explained by a combined effect of a higher radiogenic heat production in the Jurassic sediments and thermal disturbance caused by the presence of the major faults close to the Soultz-sous-Forêts geothermal site. Although additional data are required to improve these estimates and our understanding of the thermal processes, we consider the heat flow densities estimated herein as the most reliable currently available for the URG.

Determination of vibration frequency depending on abrasive mass flow rate during abrasive water jet cutting

2014 ◽  
Vol 77 (1-4) ◽  
pp. 763-774 ◽  
Author(s):  
Pavol Hreha ◽  
Agáta Radvanská ◽  
Sergej Hloch ◽  
Vincent Peržel ◽  
Grzegorz Królczyk ◽  
...  
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Vibration Frequency ◽  
Water Jet ◽  
Abrasive Water Jet ◽  
Water Jet Cutting ◽  
Abrasive Water Jet Cutting

An analytical and experimental investigation of the velocities of particles entrained by the gas flow in nozzles

1968 ◽  
Vol 33 (1) ◽  
pp. 131-149 ◽  
Author(s):  
John H. Neilson ◽  
Alastair Gilchrist
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Particle Velocity ◽  
Flow Rate ◽  
Relative Velocity ◽  
Gas Flow ◽  
Wall Surface ◽  
Erosion Damage ◽  
Limiting Value

Among the parameters which determine the erosion damage sustained by the walls of a nozzle, in which a mixture of gas and particles is flowing is the speed attained by the particle before collision with the wall surface. This work is concerned with the determination of the particle velocity, and a number of relationships are given from which the variation in particle velocity can be obtained for a variety of gas conditions. The changes of state and velocity of the gas, occasioned by the interchange of heat and work between the gas and the particles are dependent on the ratio of the mass flow rate of particles to the mass flow rate of gas. It is shown that if this ratio is small the particle velocity may be obtained without serious error by assuming that the gas conditions are not affected by the presence of particles. Figures for the limiting value of this ratio for certain flows are given. The effects of particle size, density and initial relative velocity are investigated analytically and experimentally.

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