Over-all Heat Transfer Coefficients in Steam And Hot Water Injection Wells

1967 ◽  
Vol 19 (05) ◽  
pp. 607-615 ◽  
Author(s):  
G.P. Willhite
Keyword(s):  
Heat Transfer ◽  
Water Injection ◽  
Hot Water ◽  
Transfer Coefficients ◽  
Injection Wells ◽  
Heat Transfer Coefficients

Simulation of Heat Transfer to Turbulent Nanofluid Flow in an Annular Passage

2014 ◽  
Vol 925 ◽  
pp. 625-629 ◽  
Author(s):  
C.S. Oon ◽  
A. Badarudin ◽  
S.N. Kazi ◽  
M. Fadhli
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Heat Exchanger ◽  
Transfer Coefficient ◽  
Titanium Oxide ◽  
Convective Heat Transfer Coefficient ◽  
Hot Water ◽  
Transfer Coefficients ◽  
Ansys Fluent ◽  
Heat Transfer Coefficients

The heat transfer in annular heat exchanger with titanium oxide of 1.0 volume % concentration as the medium of heat exchanger is considered in this study. The heat transfer simulation of the flow is performed by using Computational Fluid Dynamics package, Ansys Fluent. The heat transfer coefficients of water to titanium oxide nanofluid flowing in a horizontal counter-flow heat exchanger under turbulent flow conditions are investigated. The results show that the convective heat transfer coefficient of the nanofluid is slightly higher than that of the base fluid by several percents. The heat transfer coefficient increases with the increase of the mass flow rate of hot water and also the nanofluid.

An Improved Simulation for Interpreting Temperature Logs in Water Injection Wells

1982 ◽  
Vol 22 (05) ◽  
pp. 709-718 ◽  
Author(s):  
John Fagley ◽  
H. Scott Fogler
Keyword(s):  
Heat Transfer ◽  
Digital Computer ◽  
Water Injection ◽  
Steam Injection ◽  
Hot Water ◽  
Injection Wells ◽  
Short Period ◽  
Injection Zone ◽  
Wellbore Temperature ◽  
Laplace Transformations

Abstract An improved simulation for temperature logs (TL's) in water injection wells is described. Improvements based on the reduction of assumptions used by previous investigators are demonstrated by comparison of field data and simulator results showing excellent agreement of TL profiles over the entire well depth. Initial work with the simulator has demonstrated the need for different operational procedures for definite TL surveys in mature wells (those having received significant long-term injection) as compared with young wells. The utility of short-period hot water (SPHW) injection just preceding shut-in as an injection profile amplifying scheme has been investigated in depth through the TL simulator. Finally, sensitivity studies have been run to identify the most important TL parameters and to develop guidelines for improved profiling. Introduction Injection of water into wells is done for three basic reasons: to maintain field pressure, for waterflooding, or to dispose of unwanted brine. For at least two of these it is desirable to know an injection profile. The TL is one way of defining injection profiles and is particularly useful in wells with outside-of-casing vertical flow.As fluid flows down the wellbore, the rock surrounding the wellbore (which is initially at the prevailing geothermal temperature) is heated or cooled by the injection water, depending on its temperature and the rate of heat transfer in the well. This effect is most pronounced in an injection zone where the fluid enters the rock formation, flowing radially outward, and where heat transfer occurs by both convection arid conduction. Except for hot-water and steam injection, the near-wellbore portion of the flooded zone normally will be cooled. Once the well is shut in and fluid flow is halted, the temperature of the well and the surrounding formation starts to return to the original geothermal temperature. The regions above and below the injection zone trend toward the geothermal temperature more rapidly than in the injection zone because of the greater heat transfer in the latter. Thus, by measurement of the wellbore temperature as a function of depth the location of the injection zone can be determined as the region where temperature anomalies occur.The interpretation of TL's to determine injection flow profiles has been attempted previously, both qualitatively and quantitatively. In early studies, quantitative analysis was made by use of Laplace transformations and Bessel function solutions. With the advent of the digital computer, more rigorous analysis can be made with numerical methods to treat heat transfer terms, which had to be removed by simplifying assumptions in the earlier studies.In this paper, we present an improved injection-well temperature simulator of the digital computer variety. This simulator offers an advantage over previous simulators in that wellbore-water heat transfer is modeled both before and after shut-in of the well. This capability allowed us to investigate possible solutions to the problem of lost profile definition in mature injection wells. We have found hot-water injection, for a short period before shut-in, to be a potentially important tool for defining injection fluid profiles in mature wells. SPEJ P. 709^

scholarly journals CONSIDERING THE ISSUE OF RENOVATING PUBLIC BUILDINGS WITH REFERENCE TO IN-KIND INVESTIGATIONS INTO WALL HEAT TRANSFER COEFFICIENTS / VISUOMENINIŲ PASTATŲ ATNAUJINIMO PROBLEMOS NAGRINĖJIMAS REMIANTIS NATŪRINIAIS SIENŲ ŠILUMOS PERDAVIMO KOEFICIENTŲ TYRIMAIS

2013 ◽  
Vol 5 (2) ◽  
pp. 82-91 ◽  
Author(s):  
Robertas Volvačiovas ◽  
Zenonas Turskis ◽  
Česlovas Ignatavičius ◽  
Leonas Ustinovičius ◽  
Audrius Ruzgys
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Hot Water ◽  
Wall Heat Transfer ◽  
Transfer Coefficients ◽  
Public Buildings ◽  
Heat Transfer Coefficients ◽  
Before And After ◽  
The Heat Transfer Coefficient

This article raises the problem of high energy consumption stimulated by heating buildings and preparing hot water. The paper shortly revises the state of renovating public buildings in Lithuania. A number of scientists devote close attention to examining various aspects of building renovation (technical regulations on constructions, subsidies provided by the state, cost-effectiveness, factors influencing building renovation, etc.). The article presents a few studies by foreign scientists, lists factors that determine public building renovation (unsatisfactory indoor air hygiene and floor temperature, indoor relative humidity, indoor air velocity, indoor carbon dioxide concentration, physical deterioration of a large building, poor aesthetic appearance of the building, etc.) and demonstrates a few practical examples. In accordance with Lithuanian design codes, a methodology for determining heat transfer coefficients in public buildings is provided. Besides, investigations into heat transfer coefficients before and after the renovation of public buildings have been conducted. A few nursery school buildings in Lithuania have been examined applying laboratory equipment before and after renovation. It was found that the wall heat transfer coefficient of properly designed and insulated buildings falls by more than 4–5 times to reach the normal value of the heat transfer coefficient (value of the heat transfer coefficient falls from 1.12 to 0.22 W/(m2·K)). A comparison of an external thermal insulation plastering composite system with an external aeration heat-insulated system has been done. The estimation has revealed that due to lower costs, better results of thermal resistance obtained using the external thermal insulation plastering composite system can produce better wall heat transfer coefficient values. The obtained results have been determined referring to better wall insulation tightness. The paper also summarizes data on heating buildings and consumption of prepared hot water before and after renovation. On the basis of the findings acquired employing the degree-day–method, public building energy consumption for heating and hot water preparation decreased from 41.30 to 43.73%. Santrauka Straipsnyje trumpai apžvelgta pastatų energinio efektyvumo problematika, visuomeninių pastatų atnaujinimo situacija Lietuvoje, pateikiami keli užsienio valstybių mokslininkų darbų, kuriuose nagrinėjama pastatų atnaujinimo tematika, pavyzdžiai. Be praktinių pavyzdžių, nurodomi veiksniai, lemiantys visuomeninės paskirties pastatų atnaujinimą. Taip pat pateikiami visuomeninės paskirties pastatų sienų šilumos perdavimo koeficientų tyrimų, atliktų naudojant laboratorinę įrangą, rezultatai, ištyrus kelis visuomeninės paskirties pastatus Lietuvoje prieš ir po pastatų atnaujinimo. Palyginta išorinė tinkuojama sudėtinė termoizoliacinė sistema su išorine vėdinamąja termoizoliacine sistema, apibendrinta nagrinėjamų pastatų sąnaudų šildyti ir karštam vandeniui ruošti ekonominė nauda prieš ir po pastatų atnaujinimo taikant dienolaipsnių metodiką.

Analysis of a Load-Side Heat Exchanger for a Solar Domestic Hot Water Heating System

1998 ◽  
Vol 120 (4) ◽  
pp. 270-274 ◽  
Author(s):  
T. R. Smith ◽  
P. J. Burns ◽  
D. C. Hittle
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Heat Exchanger ◽  
Heating System ◽  
Hot Water ◽  
Transfer Coefficients ◽  
Adequate Model ◽  
Domestic Hot Water ◽  
Heat Transfer Coefficients ◽  
Convective Heat Transfer Coefficients

Testing is done of an unpressurized drainback system with a load-side heat exchanger. Analytical calculations for the heat exchanger effectiveness and three models for convective heat transfer coefficients from correlations are compared against the experimental data. TRNSYS simulations were performed using the average effectiveness of 0.78 (the calculated effectiveness varies from 0.68 to 0.95); the results compare favorably with experimental results, indicating that a constant effectiveness is an adequate model for the system.

Modeling and Simulation of a Novel Combined Solar Photovoltaic-Thermal Panel and Heat Pump Hybrid System

2018 ◽  
Vol 1 (1) ◽  
pp. 89-113 ◽  
Author(s):  
Samuel Sami
Keyword(s):  
Heat Transfer ◽  
Heat Pump ◽  
Hybrid System ◽  
Energy Conversion Efficiency ◽  
Hot Water ◽  
Solar Panels ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Novel Concept ◽  
Energy Equations

A numerical simulation model for a novel concept of a hybrid composed of photovoltaic-thermal solar panels and a heat pump is presented. This concept was developed to assess the performance and energy conversion efficiency of the hybrid system used to produce domestic hot water and electricity. A two-dimensional heat transfer and fluid flow dynamic model was developed to describe the behavior of the hybrid system under different solar irradiance, heat pump boundary conditions and different refrigerants. The model is based on dynamic mass and energy equations coupled with the heat transfer coefficients, and the thermodynamic properties of refrigerants as well as material properties. The model compared fairly to experimental data.

Performance of Heat Exchanger with Nanofluids

2021 ◽  
Vol 1021 ◽  
pp. 160-170
Author(s):  
Amer Hameed Majeed ◽  
Yasmin Hamed Abd
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Flow Rate ◽  
Hot Water ◽  
Transfer Coefficients ◽  
Maximum Enhancement ◽  
Transfer Rates ◽  
Tube Heat Exchanger ◽  
Heat Transfer Coefficients ◽  
Cold Fluid

The effect of adding nanomaterial of aluminum oxide (Al2O3), titanium oxide (TiO2) and zirconium oxide (ZrO2) in different concentrations of 0.25, 0.5, 0.75, 1.0, and 1.25 g/L to the cold fluid (water) turbulently flowing with different flow rates of 75, 100, 125, 150, and 175 L/min in tube side countercurrently to hot water flowing with a constant flow rate of 60 L/min in the shell side of shell and tube heat exchanger on the heat transfer rates and overall heat transfer coefficients are experimentally studied. It is found that the addition of nanomaterials gives rise to outlet cold (nano) fluids temperatures causing to enhancement averagely 7.74, 11.25, and 17.38 percent for ZrO2, TiO2, and Al2O3 respectively in heat transfer rate and averagely 12.72, 19.47, and 28.71 percent for ZrO2, TiO2, and Al2O3 respectively in overall heat transfer coefficients. The maximum enhancement values in heat transfer rates and in overall heat transfer coefficients are attained at a flow rate of 150 L/min of cold fluid.

Average Boiling and Condensation Heat Transfer Coefficients of the Zeotropic Refrigerant Mixture R22/R142b in a Coaxial Tube-in-Tube Heat Exchanger

1999 ◽  
Vol 122 (1) ◽  
pp. 186-188 ◽  
Author(s):  
J. P. Meyer ◽  
J. M. Bukasa ◽  
S. A. Kebonte
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Heat Pumps ◽  
Hot Water ◽  
Outer Tube ◽  
Condensation Heat Transfer ◽  
Transfer Coefficients ◽  
Tube Heat Exchanger ◽  
Heat Transfer Coefficients ◽  
Coaxial Tube

Average boiling and condensation heat transfer coefficients were determined experimentally for a coaxial tube-in-tube heat exchanger used in hot water heat pumps. During manufacturing, the heat exchanger geometry used for the experiments changed from round tubes to elliptical tubes as no spacers were used to keep the inner tube from touching the outer tube. The refrigerant used was two different mixtures of R22 with R142b in mass ratios of 80 percent/20 percent and 60 percent/40 percent. The results were compared to theoretical results for straight tubes. It was concluded that the theoretical modes do not predict the heat transfer coefficients very well in coaxial tube-in-tube heat exchangers where the annulus touches the inside of the outer tube. [S0022-1481(00)01001-X]

ORC-Based Low-Temperature Geothermal Power Generation System

2014 ◽  
Vol 953-954 ◽  
pp. 663-666 ◽  
Author(s):  
Bing Hu ◽  
Yuan Shu Cao ◽  
Wei Bin Ma
Keyword(s):  
Heat Transfer ◽  
Power Generation ◽  
Low Temperature ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Hot Water ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Geothermal Power ◽  
Transfer Study

Based on the Organic Rankine Cycle，a low-temperature geothermal power generation were studied with R245fa as the working fluids ．Effects of hot water temperature,heat flux and heat-transfer temperature difference on overall heat-transfer coefficients 、net power and input heat were analyzed in detail．These results would provide a basis for the design of geothermal power generation．In addition，it would provide comparative data for the numerical simulation of heat ＆mass transfer study．

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