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Tytuł:
Modular heat storage in waste heat recovery installations
Autorzy:
Górszczak, Piotr
Rywotycki, Marcin
Hojny, Marcin
Filo, Grzegorz
Powiązania:
https://bibliotekanauki.pl/articles/27312237.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
heat storage
heat recovery
waste heat
CFD
Opis:
The paper presents the methodology of designing a system for accumulating waste heat from industrial processes. The research aimed to analyse the fluid’s movement in the heat accumulator to unify the temperature field in the volume of water constituting the heat buffer. Using the computer program Ansys Fluent, a series of computational fluid dynamics simulations of the process of charging the heat storage with water at 60◦C, 70◦C, and 80◦C was carried out. The selected temperatures correspond to the temperature range of unmanaged waste heat. In the presented solution, heat storage is loaded with water from the cooling systems of industrial equipment to store excess heat and use it at a later time. The results of numerical calculations were used to analyse the velocity and temperature fields in the selected structure of the modular heat storage. A novelty in the presented solution is the use of smaller modular heat storage units that allow any configuration of the heat storage system. This solution makes it possible to create heat storage with the required heat capacity.
Źródło:
Archives of Thermodynamics; 2023, 44, 3; 301--323
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of energy transfer between pipes of U-type borehole heat exchanger
Autorzy:
Złotkowski, A.
Druzgała, A.
Zeljaś, D.
Powiązania:
https://bibliotekanauki.pl/articles/298765.pdf
Data publikacji:
2017
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
heat pumps
borehole heat exchanger
heat flux
Opis:
Use of low-temperature energy accumulated in the ground for heating buildings requires the borehole heat exchangers. The amount of heat exchanged (by the heat exchanger with the urethane) depends on the construction material parameters used to make the exchanger. One of the problems with the efficiency of the heat exchanger is the amount of heat transferred between the borehole pipes. This phenomenon can be described using numerical simulations or by studying a laboratory model. This article shows the results of laboratory measurements of the heat flux permeating between the pipes of the heat exchanger.
Źródło:
AGH Drilling, Oil, Gas; 2017, 34, 4; 843-853
2299-4157
2300-7052
Pojawia się w:
AGH Drilling, Oil, Gas
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research on efficiency of heat recovery in the cross-plate heat exchanger made of plastic
Autorzy:
Sas, S.
Kasprzyk, P.
Powiązania:
https://bibliotekanauki.pl/articles/88926.pdf
Data publikacji:
2015
Wydawca:
Politechnika Wrocławska. Wydział Geoinżynierii, Górnictwa i Geologii. Instytut Górnictwa
Tematy:
heat exchanger
heat recovery
Opis:
The article content the results of study of heat exchanger. Exchanger was made of plastic material: polystyrene. The measurement results were used for efficiency analysis of this type of heat exchanger as an alternative to the commonly used heat exchangers made of aluminum.
Źródło:
Mining Science; 2015, 22, Special Issue 2; 151-159
2300-9586
2353-5423
Pojawia się w:
Mining Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An analysis of a temperature change in a cross‑section of borehole heat exchanger
Autorzy:
Zlotkowski, A.
Szczesiul, P.
Powiązania:
https://bibliotekanauki.pl/articles/299265.pdf
Data publikacji:
2013
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
borehole heat exchangers
heat pump
transport of heat
Opis:
Underground heat exchangers (BHE) are used witch elements to transport energy between the ground and other objects on the surface of the land. For simplification described in mathematical apparatus, they works are explain how linear heat source. The temperature is the same in all bodies of this model. This reduction to let easy describe theoretical changes temperature in BHE through transporting energy to / from rock in analytic mathematic method. The bad effect of this method is present by the same value of temperature in horizontal cross‑section and along BHE. The analysis of change of temperature field in the sealing cement BHE is a possibility for numerical simulation or laboratory model. Computer simulation needed according energy transport law. It to say about quantity of energy conducting between horizontal cross‑section of BHE cells, on which is divided. The second method obtains value of temperature points of the sealing cement. This is to be realized by sensors set up in to the horizontal cross‑section of BHE of laboratory model. This is possible thanks constructed the model of cross‑section of BHE.
Źródło:
AGH Drilling, Oil, Gas; 2013, 30, 4; 459-468
2299-4157
2300-7052
Pojawia się w:
AGH Drilling, Oil, Gas
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ventilation system with ground heat exchanger
Autorzy:
Pisarev, V.
Rabczak, S.
Nowak, K.
Powiązania:
https://bibliotekanauki.pl/articles/123849.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
ground heat exchanger
ventilation
heat pump
heat source
Opis:
Ventilation systems consume more and more energy because of the often complex treatment of the air supplied to closed spaces. Looking for sources of energy allow for significant savings costs, which often translate into renewable energy sources. One of the more popular solutions is to use energy from the ground by various methods. Known and relatively common solutions are based on ground heat exchanger and ground collector cooperating with a heat pump. The paper presents the possibility of cooperation ventilation system with ground air heat exchanger and heat pump both in summer and winter period. A number solutions of this type of system, supported by calculation examples and moist air transformation in the Moliere chart have been presented. Support ventilation system with renewable energy sources allows significant savings in operating as shown in the article.
Źródło:
Journal of Ecological Engineering; 2016, 17, 5; 163-172
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Simulating heat-transfer processes in two-phase heat-utilizer at heat pipes
Autorzy:
Kulikova, N.
Redko, A.
Powiązania:
https://bibliotekanauki.pl/articles/402078.pdf
Data publikacji:
2014
Wydawca:
Politechnika Świętokrzyska w Kielcach. Wydawnictwo PŚw
Tematy:
boiler unit
heat carrier
heat pipes
heat utilizer
Opis:
The choice of rational heat-utilizer heating scheme is a very current problem of energy saving when using boiler units. This article proposes the heat computation technique of heat exchanger at heat pipes with deep combustion - product cooling in boilers and water steam condensation. In addition, the construction scheme of heat exchanger made with two units in which the heat pipes are filled with different working medium is described. The numerical study results of heat carrier temperature and pressure distribution, namely: combustion products and water being heated according to counterflow - heat exchanger length are presented. The efficiency of two-phase heat-utilizer is determined.
Źródło:
Structure and Environment; 2014, 6, 2; 35-43
2081-1500
Pojawia się w:
Structure and Environment
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Determination of heat transfer coefficient in the phase-change heat storage device
Autorzy:
Pavlenko, A. M.
Koshlak, H. V.
Piotrowski, J. Z.
Powiązania:
https://bibliotekanauki.pl/articles/402411.pdf
Data publikacji:
2016
Wydawca:
Politechnika Świętokrzyska w Kielcach. Wydawnictwo PŚw
Tematy:
heat transfer coefficient
heat accumulator
Opis:
This article describes information about the research of the heat transfer coefficient from air to water on the basis of comparison of theoretical calculations with the use of mathematical modeling and experimental studies of small copies of the heat accumulator to operate in the charging mode and discharging process without phase change.
Źródło:
Structure and Environment; 2016, 8, 4; 278-281
2081-1500
Pojawia się w:
Structure and Environment
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Examination of Different Heat Exchangers and the Thermal Activities of Different Designs
Autorzy:
Ipek, O.
Kan, M.
Gurel, B.
Powiązania:
https://bibliotekanauki.pl/articles/1031281.pdf
Data publikacji:
2017-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
heat exchangers
compact heat exchanger
micro channel heat exchanger
Opis:
In this study, instead of gasketed or brazed plate heat exchangers, which are used in various fields of application, a direct metal sintering method is used to design a heat exchanger with its original geometry and with different geometries. Studies of heat exchangers found in published literature were reviewed, and the thermal behaviors of the proposed unique designs were examined. Usually heat exchangers using this design do not use channel spacing angles of 30-45-60-75° for the plate ducts. The thermal behaviors of the fluid-circulating systems were analyzed using ANSYS FLUENT software, and they used the boundary conditions found in the literature for this design. Heat transfer between the heat exchanger channels and channel walls was calculated. The analyses results show that an increase in the amount of heat transfer surface area and also an increase in surface roughness increased the amount of positive heat transfer.
Źródło:
Acta Physica Polonica A; 2017, 132, 3; 580-584
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Emission and trends in reclaiming waste heat in industrial instalations
Autorzy:
Hys, L.
Wiak, T
Powiązania:
https://bibliotekanauki.pl/articles/952453.pdf
Data publikacji:
2013
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
heat emission
waste heat
heat waste reclaim
distributed generation
Opis:
The article presents the analysis of waste heat emission in a typical industrial installation. On the basis of the process monitoring system, periodic analyses of fumes composition, installation process manual and the conducted measurements of the heat fluxes from individual sources emitting heat on the way of natural convection from the devices’ coats and forced convection in the fumes flux were calculated. According to the authors the heat of temperature 140–155 °C and surface power density 860–970 W/m2 emitted by devices’ covers can be reclaimed in ORC techniques, Peltier’s modules and the systems realising Stirling cycle. Part of the waste heat included in fumes, which makes c.a. 76% of the total emission from the installation, should be returned to the process of fuel oxidation, what will reduce the emission by c.a. 18% and the volume of consumed fuel by c.a. 25 m3 CH4/h, according to the presented calculations.
Źródło:
Journal of Ecological Engineering; 2013, 14, 2; 26-30
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Impact of the manufacturing conditions and operating position on heat transport ability of the heat pipe filled with Fluorinert FC-72
Autorzy:
Čaja, A.
Nemec, P.
Mančikova, V.
Malcho, M.
Powiązania:
https://bibliotekanauki.pl/articles/402136.pdf
Data publikacji:
2014
Wydawca:
Politechnika Świętokrzyska w Kielcach. Wydawnictwo PŚw
Tematy:
heat pipe
heat transport
cooling
Opis:
Heat pipes are devices, which transfer heat at a minimum temperature difference between evaporating and condensing phase. Operating temperature of heat pipe is determined by the working fluid and vacuum achieved during its production. This paper is focused on the determining the effect of the initial temperature of the ambient air to the performance characteristics of produced heat pipes. In general, the decrease in pressure decreases the boiling liquid. Based on this it can be presumed that achieving a lower temperature during production of heat pipe, the lower vacuum, the boiling point of working fluid while increasing ability of heat transport in various positions.
Źródło:
Structure and Environment; 2014, 6, 2; 44-47
2081-1500
Pojawia się w:
Structure and Environment
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of the modified method of finite elements to identification of temperature of a body heated with a moving heat source
Zastosowanie zmodyfikowanej metody elementów skończonych do identyfikacji temperatury ciała nagrzewanego ruchomym źródłem ciepła
Autorzy:
Maciejewska, B.
Powiązania:
https://bibliotekanauki.pl/articles/281862.pdf
Data publikacji:
2004
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
moving heat source
2D heat conduction
FEM
heat polynomials
Opis:
A transient 2-dimensional problem of heat flow with a moving heat source is considerent. It is assumed that the heat source is moving along one of the sides of a rectangle with a constant velocity. The unknown is the temperature distribution in a flat rectangular area. The paper presents an approximate solution which is based on the finite element method with a modified basis function. The space-time basis functions are combinations of heat polynomials which strictly satisfy the heat equation. Cartesian coordinates were used to solve the problem.
W pracy rozważane jest dwuwymiarowe niestacjonarne zagadnienie przepływu ciepła z ruchomym źródłem ciepła na brzegu obszaru. Zaklada się, że źródło ciepła porusza się wzdłuż brzegu prostokąta ze stałą prędkością. Poszukiwany jest rozkład temperatury w obszarze o kształcie prostokąta. Przybliżone rozwiązanie problemu zaprezentowane w pracy opiera się na metodzie elementów skończonych ze zmodyfikowanymi funkcjami bazowymi. Skonstruowane czasoprzestrzenne funkcje bazowe są kombinacją wielomianów cieplnych, tzn. wielomianów ściśle spełniających równanie przewodnictwa ciepła. Zagadnienie rozwiązane zostało we współrzędnych kartezjańskich.
Źródło:
Journal of Theoretical and Applied Mechanics; 2004, 42, 4; 771-787
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigation of thermal-flow characteristics of the minichannel heat exchanger of variable louvers height
Autorzy:
Romaniak, Artur
Kowalczyk, Michał Jan
Łęcki, Marcin
Gutkowski, Artur
Górecki, Grzegorz
Powiązania:
https://bibliotekanauki.pl/articles/27312209.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
CFD
heat transfer
heat pump
louvered fin
minichannel heat exchanger
Opis:
The numerical simulation of the heat transfer in the flow channels of the minichannel heat exchanger was carried out. The applied model was validated on the experimental stand of an air heat pump. The influence of louver heights was investigated in the range from 0 mm (plain fin) to 7 mm (maximum height). The set of simulations was prepared in Ansys CFX. The research was carried out in a range of air inlet velocities from 1 to 5 m/s. The values of the Reynolds number achieved in the experimental tests ranged from 93 to 486. The dimensionless factors, the Colburn factor and friction factor, were calculated to evaluate heat transfer and pressure loss, respectively. The effectiveness of each louver height was evaluated using the parameter that relates to the heat transfer and the pressure drop in the airflow. The highest value of effectiveness (1.53) was achieved by the louver height of 7 mm for the Reynolds number of around 290.
Źródło:
Archives of Thermodynamics; 2023, 44, 3; 119--141
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Examination of thermal work of electric chamber furnace to thermal processing
Autorzy:
Kowalik-Wolska, M
Boryca, J.
Powiązania:
https://bibliotekanauki.pl/articles/102130.pdf
Data publikacji:
2015
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
heat treatment
heating costs
heat consumption
Opis:
The improvement of effectiveness of work furnaces depends on increasing the efficiency as well as the decrease the elementary consumption of energy. The character of the analyzed electric chamber furnace to thermal processing in work was introduced. over the discussed results concern the efficiencies, consumption of electric energy as well as the coefficient of elementary consumption of energy. The improvement of coefficients of furnace solutions were proposed.
Źródło:
Advances in Science and Technology. Research Journal; 2015, 9, 27; 11-16
2299-8624
Pojawia się w:
Advances in Science and Technology. Research Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An efficient analysis of steady-state heat conduction involving curved line/surface heat sources in two/three-dimensional isotropic media
Autorzy:
Mohammadi, M.
Hematiyan, M. R.
Shiah, Y. C.
Powiązania:
https://bibliotekanauki.pl/articles/279914.pdf
Data publikacji:
2018
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
heat conduction
concentrated heat source
curved heat source
mesh-free method
Opis:
In this paper, a new formulation based on the method of fundamental solutions for two/three- -dimensional steady-state heat conduction problems involving internal curved line/surface heat sources is presented. Arbitrary shapes and non-uniform intensities of the curved heat sources can be modeled by an assemblage of several parts with quadratic variations. The presented mesh-free modeling does not require any internal points as in domain methods. Four numerical examples are studied to verify the validity and efficiency of the proposed method. Our analyses have shown that the presented mesh-free formulation is very efficient in comparison with conventional boundary or domain solution techniques.
Źródło:
Journal of Theoretical and Applied Mechanics; 2018, 56, 4; 1123-1137
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Heat transfer in combustion chamber of piston engines
Autorzy:
Jankowski, A.
Powiązania:
https://bibliotekanauki.pl/articles/950137.pdf
Data publikacji:
2010
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
internal combustion engines
heat transfer
heat flux
combustion chamber
heat losses
Opis:
Measurements were made during downward propagation of a flat flame in a lean limit methane/air mixture. It was observed that the limit flames are very thick and that heat losses to the walls caused extensive cooling of the product gases within 0.05 m behind the propagating flame. Analysis of all data from well synchronized measurements as well as the results of following to them numerical calculations made possible to understand in detail physical picture of heat transfer from the hot gases to the cold walls. It is a unique way for explanation of heat transfer phenomenon. Measurements and calculations were used to prepare heat balance in a flammability tube. In the next step measurements were carried out in a rotating cylindrical combustion chamber. This chamber was treated as a model of piston engine combustion chamber with swirl. Temperature changes on a surface of the rotating combustion chamber were transmitted towards motionless data acquisition system. The temperature measurements were carried out with the use of special thermocouples located at the front wall of the chamber. Influence of rotation velocity on heat transfer was investigated in the range from 1000rpm to 5000 rpm. For a constant mixture concentration maximum temperature rise depended on the rotation velocity. Increased rotation velocity initially intensified heat transfer to the wall, with following to it increase of peak temperature, but further rise of rotation velocity resulted in local flame extinction near the s idę walls, decreased volume of combustion gases, and as a result of these, decreased value of peak temperature at the wall surface. Presented techniques make possible estimate heat losses to the walls in a combustion chamber of piston engines.
Źródło:
Journal of KONES; 2010, 17, 1; 187-197
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental investigation and characteristics of multiwalled carbon nanotube aqua nanofluids from a flat plate heater surface in a pool
Autorzy:
Vasudevan, D.
Senthil Kumar, D.
Murugesan, A.
Vijayakumar, C.
Powiązania:
https://bibliotekanauki.pl/articles/201185.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
nanofluids
critical heat flux
heat transfer coefficient
boiling
heat transfer enhancement
Opis:
In this experimental investigation, the critical heat flux (CHF) of aqua-based multiwalled carbon nanotube (MWCNT) nanofluids at three different volumetric concentrations 0.2%, 0.6%, and 0.8% were prepared, and the test results were compared with deionized water. Different characterization techniques, including X-ray diffraction, scanning electron microscopy and Fourier transform infrared, were used to estimate the size, surface morphology, agglomeration size and chemical nature of MWCNT. The thermal conductivity and viscosity of the MWCNT at three different volumetric concentrations was measured at a different temperature, and results were compared with deionized water. Although, MWCNT-deionized water nanofluid showed superior performance in heat transfer coefficient as compared to the base fluid. However, the results proved that the critical heat flux is increased with an increase in concentrations of nanofluids.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2020, 68, 3; 547-554
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sensitivity and specificity of using exercise heart rate in a thermoneutral environment to predict heat tolerance status
Autorzy:
Northway, Sarah
Jones, Douglas
Buono, Michael
Powiązania:
https://bibliotekanauki.pl/articles/2203015.pdf
Data publikacji:
2023-05-23
Wydawca:
Instytut Medycyny Pracy im. prof. dra Jerzego Nofera w Łodzi
Tematy:
exercise
heat
heart rate
heat intolerance
heat tolerance testing
return to activity
Opis:
Objectives Following heat illness, a return to activity may require passing a heat tolerance test (HTT). However, there are several logistical limitations to the widespread use of the HTT. Thus, it would be advantageous to develop a test that could be conducted in a thermoneutral (~22°C) environment to predict heat tolerance status. The purpose of the current study was to determine the sensitivity and specificity of using the criteria of a heart rate (HR) ≥130 bpm following 30 min of thermoneutral exercise in detecting heat-intolerant and heat-tolerant individuals. Material and Methods Sixty-five subjects visited the lab on 3 separate days. The first visit consisted of completing a maximal oxygen uptake (VO2 max) test to assess cardiovascular fitness. For lab visits 2 and 3, subjects randomly completed a 2-hour walking treadmill test in either a hot (40°C, 40% relative humidity [RH]) or thermoneutral (22°C, 40% RH) environment. Results Forty-eight subjects were classified as heat-intolerant and seventeen subjects as heat-tolerant. Using the criterion of a HR ≥130 bpm at 30 min of exercise in the thermoneutral environment, specificity (54%) and sensitivity (100%) of passing the HTT was calculated. Secondary analysis using multiple regression revealed 3 significant variables for predicting ending HR during the HTT. They were: 1) absolute VO2 max (l/min), 2) age, and 3) HR at 30 min of exercise during thermoneutral exercise. Conclusions Exercise in a thermoneutral environment had a positive predictive value of 100%, thus, if a subject has a HR ≥130 bpm at 30 min of exercise in a thermoneutral environment, they are very likely to fail a subsequent 2-hour HTT in the heat and be classified as heat-intolerant. Therefore, prior screening has the potential to save time and money, along with providing safety to a heat-intolerant subject.
Źródło:
International Journal of Occupational Medicine and Environmental Health; 2023, 36, 2; 192-200
1232-1087
1896-494X
Pojawia się w:
International Journal of Occupational Medicine and Environmental Health
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of Heat Loss of a Biogas Anaerobic Digester in Weather Conditions in Poland
Autorzy:
Teleszewski, T. J.
Żukowski, M.
Powiązania:
https://bibliotekanauki.pl/articles/125369.pdf
Data publikacji:
2018
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
biogas anaerobic digester
heat demand
heat losses
Opis:
Currently in Poland, the construction of biogas plants as alternative energy sources is increasing. Often, the technical solutions for design and building of biogas plants are transferred to Poland from the countries in which these technologies are developed without taking into account the specific climatic conditions prevailing in Poland. It does occur that newly built biogas plants have a problem maintaining a sufficiently high temperature in the winter, which is caused by the insufficient insulation of the biogas anaerobic digester envelope. This paper presents an analysis of heat loss, depending on the climatic conditions prevailing in Poland and the working conditions of a biogas plant, based on an existing facility located in Ryboly (Poland). The work is supplemented with the results of tests using a thermal imaging camera. It should be noted that currently there are no requirements in the literature regarding the design of a thermal insulating layer in biogas installations in Poland.
Źródło:
Journal of Ecological Engineering; 2018, 19, 4; 242-250
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Specifying the number of borehole heat exchangers based on thermal response test and geoenergetic analysis
Autorzy:
Śliwa, T.
Sapińska-Śliwa, A.
Gonet, A.
Jezuit, Z.
Bieda, A.
Kowalski, T.
Ozimek, J.
Złotkowski, A.
Powiązania:
https://bibliotekanauki.pl/articles/298689.pdf
Data publikacji:
2017
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
geoenergetics
borehole heat exchangers
geothermal heat pumps
Opis:
For the correct design, the number and the location of borehole heat exchangers, it is necessary to know thermal properties of rocks and the exchanger. This applies particularly to larger installations, more than 100 kW. One of the methods of determining these values is Thermal Response Test. This method is based on measurements in the first drilled borehole heat exchanger. Based on results of the TRT geothermal analysis is made. The analysis defines: the number of wells, the arrangement of wells, and the parameters of temperature of heat carrier after long-term use. This analysis based on calculations using specialist software. This paper presents the determination of the number of borehole heat exchangers and working conditions (temperature of the heat carrier) of an underground heat reservoir accessed using borehole heat exchangers for the building of the Primary School in Myszków.
Źródło:
AGH Drilling, Oil, Gas; 2017, 34, 1; 273-290
2299-4157
2300-7052
Pojawia się w:
AGH Drilling, Oil, Gas
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Honeycomb compact heat exchanger for compressor interstage cooling
Autorzy:
Michalak, B.
Domański, R.
Powiązania:
https://bibliotekanauki.pl/articles/242261.pdf
Data publikacji:
2009
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
compact heat exchanger
intercooler
interstage cooling
heat
Opis:
The paper presents results of numerical fmite volume analysis of an efficiency of honeycomb compact gas to gas heat exchanger usedfor compressor interstage cooling for aircraft jet engine. The main analysis starts with building geometry followed by the problem description and model discretization leading to the flnal results and summary. Eight cases were created for the basic model and also several more for afinned geometry. The parallel and counter-current flow modes were considered Special emphasis was laid on finding the heat transfer rate, LMTD parameter and temperature distribution. It was found out that a honeycomb structure is almost insensitive for flow arrangement change and that afinned structure assures much higher heat transfer rate. The honeycomb structure is almost insensitive for flow arrangement change while the finned structure turned out to provide a much better heat transfer. The structure is also almost insensitive for a more efficient (i. e. parabolic) fin shape could also increase the heat transfer in the required area. A more accurate mesh should be created to analyse the finned structure and get more reliable results. The honeycomb structure provides apossibility to create the heat transfer process between more then two fluids i. e. three or four.
Źródło:
Journal of KONES; 2009, 16, 2; 315-321
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Possibilities of heat transfer augmentation in heat exchangers with minichannels for marine applications
Autorzy:
Mikielewicz, D.
Wajs, J.
Powiązania:
https://bibliotekanauki.pl/articles/258932.pdf
Data publikacji:
2017
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
heat transfer intensification
heat exchangers
pumping power
Opis:
In the paper, new trends in the development of microchannel heat exchangers are presented. The exchangers developed in this way can be applied in marine industry. Main attention is focused on heat exchanger design with reduced size of passages, namely based on microchannels. In authors’ opinion, future development of high power heat exchangers will be based on networks of micro heat exchangers.
Źródło:
Polish Maritime Research; 2017, S 1; 133-140
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Heat transfer analysis for the hydraulic circuit of an expresso-coffee machine
Autorzy:
Fioretti, L.
Conti, M.
Powiązania:
https://bibliotekanauki.pl/articles/1964076.pdf
Data publikacji:
2001
Wydawca:
Politechnika Gdańska
Tematy:
heat transfer
Opis:
An Espresso-Coffee Machine supplies water which temperature must be confined within a narrow range in different operating conditions; this requires an accurate design at the component as well as the system level. In the present paper we develop a mathematical model to analyse the performances of the heating circuit of such a machine; our aim is to capture the main operating characteristics of the system with the maximum of simplicity. The governing equations of the model have been solved with the finite difference technique, and the first results have been compared with some experimental data.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2001, 5, 1; 99-107
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Operational measurement of ground/water hest pump in cold weather
Autorzy:
Vantúch, M.
Kapjor, A.
Malcho, M.
Hužvár, J.
Papučik, Š.
Powiązania:
https://bibliotekanauki.pl/articles/402452.pdf
Data publikacji:
2013
Wydawca:
Politechnika Świętokrzyska w Kielcach. Wydawnictwo PŚw
Tematy:
heat pump
Opis:
Article discusses the changes in heat flows in the secondary and primary circulation ground/water heat pump to low ambient temperature environments in winter. These results are compared with various HP power parameters. At the same time it describes the changes in the thermal potential at the initial start-up HP.
Źródło:
Structure and Environment; 2013, 5, 2; 40-42
2081-1500
Pojawia się w:
Structure and Environment
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Waste Heat Recovery from Servers Using an Air to Water Heat Pump
Autorzy:
Lipiński, Seweryn
Duda, Michał
Górski, D.
Powiązania:
https://bibliotekanauki.pl/articles/2069738.pdf
Data publikacji:
2021
Wydawca:
Uniwersytet Warmińsko-Mazurski w Olsztynie
Tematy:
air-water heat pump
server cooling
waste heat
heat recovery
domestic hot water
Opis:
The analysis of advisability and profitability of using an air to water heat pump for the purpose of waste heat recovery from servers being used as cryptocurrency mining rigs, was performed. To carry out such an analysis, the cooling unit of the computing server was connected to the heat pump, and the entire system was adequately equipped with devices measuring parameters of the process. Performed experiments proves that the heat pump coefficient of performance (COP) reaches satisfactory values (i.e., an average of 4.21), what is the result of stable and high-temperature source of heat at the pump inlet (i.e., in the range of 29.9-34.1). Economic analysis shows a significant reduction in the cost of heating domestic hot water (by nearly 59-61%). The main conclusion which can be drawn from the paper, is that in a case of having a waste heat source in a form of a server or similar, it is advisable to consider the purchase of air-to-water heat pump for the purpose of domestic hot water heating.
Źródło:
Technical Sciences / University of Warmia and Mazury in Olsztyn; 2021, 24(1); 105--113
1505-4675
2083-4527
Pojawia się w:
Technical Sciences / University of Warmia and Mazury in Olsztyn
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An influence of fouling gathered on the heat transfer surfaces on the heat performance characteristics of the ship steam systems heat exchangers
Autorzy:
Hajduk, T.
Powiązania:
https://bibliotekanauki.pl/articles/1841551.pdf
Data publikacji:
2021
Wydawca:
Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
Tematy:
marine power plant
gathering of fouling
heat transfer surface
heat performance characteristics
thermal resistance
heat trransfer
heat exchangers
Opis:
More than half of the incidents reported to EMSA relate to nautical events such as collision, groundings and contacts. Knowledge of accurate and high-integrity positioning is therefore not only a need for future automated shipping but a base for today’s safe navigation. Examples on accidents include Ever Given in the Suez Canal and HNoMS Helge Ingstad in Norway. A Network-RTK (NRTK) service can be used as an augmentation technique to improve performance of shipborne GNSS receivers for future positioning of manned and unmanned vessels in restricted areas, such as port areas, fairways, and inland water ways. NRTK service providers generate RTK corrections based on the observations of networks of GNSS reference stations which enables the users to determine their position with centimeter accuracy in real-time using a shipborne GNSS receiver. Selection of appropriate communication channels for dissemination of NRTK corrections data is the key to a secure positioning (localization) service. In PrePare-Ships project, the modern maritime communication system VDES (VHF Data Exchange System) is proposed to distribute SWEPOS (NRTK in Sweden) correction data to shipborne positioning modules. VDES is a very reliable technique and it is compatible with most onboard functionalities. In order to minimize the impact on the overall VDES data capacity in a local area, NRTK correction data shall only occupy a single VDES slot with a net capacity of 650 bytes. Update rates may vary but are preferably at 1Hz. However, NRTK correction data size changes instantly, depending on the number of visible GNSS satellites, and the data rate can therefore sometimes reach in excess of 1000 byte/s. In this study, a smart technique is proposed to reduce size of NRTK correction data to instantly adapt with the VDES requirements by choosing a combination of specific signals, satellites or even constellations such that the data rate is not more than 650 byte/s, and at the same time it achieves optimal positioning performance with the accuracy required by the PrePare-Ships project application.
Źródło:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation; 2021, 15, 1; 183-189
2083-6473
2083-6481
Pojawia się w:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-25 z 2980

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