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Wyszukujesz frazę "heat emission" wg kryterium: Temat


Wyświetlanie 1-7 z 7
Tytuł:
Heat exchange in the system mould - riser - ambient. Part II: Surface heat emission from open riser to ambient
Wymiana ciepła w układzie forma - nadlew - otoczenie. Część II: Współczynnik emisji ciepła z otwartego nadlewu do otoczenia
Autorzy:
Krajewski, P. K.
Gradowski, A.
Krajewski, W. K.
Powiązania:
https://bibliotekanauki.pl/articles/352192.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
castings
risers
surface heat emission
heat balance
solidification modelling
odlewy
nadlew
emisja ciepła
bilans cieplny
modelowanie krzepnięcia
Opis:
The subject of the paper is heat exchange in the system casting - riser - ambient. The examinations were focused on evaluating temperature dependence of the coefficient of heat exchange from open (not shielded) top surface of riser to ambient. The examinations were carried out on the open surface of cast steel riser, of temperatures 1000-1500°C. On the basis of the performed examinations it was stated that heat emission coefficient changes its mean values by about 50% during feeding process of the mild steel casting, i.e. from about 0.28 in liquid state to about 0.42 at temperatures close to solidus. This wide range of surface heat emissivity changes should be taken into account when boundary conditions are formulated in elaborated models of solidification and in designing risering systems.
Przedmiotem artykułu jest wymiana ciepła w systemie odlew - nadlew - otoczenie. Celem badań było wyznaczenie temperaturowej zależności współczynnika wymiany ciepła z odkrytej, nieizolowanej powierzchni nadlewu do otoczenia. Badania wykonano dla odlewu staliwnego z odkrytym nadlewem, dla zakresu temperatury powierzchni nadlewu 1000-1500°C. Na podstawie wykonanych badań stwierdzono, iż współczynnik emisji ciepła z nieizolowanej powierzchni nadlewu do otoczenia zmienia swą wartość w badanym zakresie temperatury o około 50%, tj. od około 0.26 - 0.30 dla metalu w stanie ciekłym do około 0.42 - 0.46 dla metalu w stanie stałym, w pobliżu temperatury solidus. Powyższy szeroki zakres zmian emisyjności powinien być uwzględniany w budowanym modelach symulacji procesu krzepnięcia i projektowania systemów zasilania krzepnących odlewów.
Źródło:
Archives of Metallurgy and Materials; 2013, 58, 4; 1149-1153
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Pollutant concentrations from deciduous wood fuelled heat station
Autorzy:
Juszczak, M.
Powiązania:
https://bibliotekanauki.pl/articles/185275.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
stacja ciepła
spalanie
emisja
drewno
heat station
wood
combustion
emission
Opis:
CO, NO, NO2 and dust concentrations from combustion of deciduous wood (birch, beech, lime-tree) logs and pellets in two heating boilers (15 and 25 KW), situated in a heat station were investigated. Time dependences of pollutant concentrations as well as the impact of temperature in the combustion chamber and oxygen concentration on pollutant concentrations were presented. Pollutant emission indices have been estimated.
Źródło:
Chemical and Process Engineering; 2011, 32, 1; 41-55
0208-6425
2300-1925
Pojawia się w:
Chemical and Process Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Concentrations of carbon monoxide and nitrogen oxides from a 25 kW boiler supplied periodically and continuously with wood pellets
Autorzy:
Juszczak, M.
Powiązania:
https://bibliotekanauki.pl/articles/185416.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
pelety
spalanie
emisja
stacja ciepła
coniferous
wood pellets
combustion
emission
heat station
Opis:
The impact of the fuel feeding mode (continuous or periodic with different stand-by/operation time ratios) on carbon monoxide (CO) and nitrogen oxides (NO, NOx) concentration values in the flue gas was analysed for coniferous wood pellet firing. Experiments were performed in a 25 kW water boiler equipped with an over-fed wood pellet furnace located in a full scale heat station simulating real-life conditions. Influence of oxygen concentration and temperature in the combustion chamber on carbon monoxide and nitrogen oxide concentrations was presented in diagrams. Dust and hydrocarbon concentrations were also monitored. It was concluded that the commonly used periodic fuel supply does not necessarily cause a significant increase of carbon monoxide concentration, as compared to the continuous fuel feeding mode. Continuous fuel supply can even induce higher carbon monoxide concentrations when fuel mass stream is not chosen properly. Each time new fuel type is used in a specific furnace, one should perform experiments to determine the adequate settings (stand-by/operation time ratio, fuel mass streams, air stream) to obtain the optimal, lowest possible emission for a certain boiler heat output.
Źródło:
Chemical and Process Engineering; 2014, 35, 2; 163-172
0208-6425
2300-1925
Pojawia się w:
Chemical and Process Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The use of geothermal energy in co-generated heat and power production in Poland : a case study
Autorzy:
Mróz, Tomasz Maciej
Grabowska, Weronika
Powiązania:
https://bibliotekanauki.pl/articles/2073770.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
cogenerated heat and power
CHP
organic rankine cycle
ORC
energy performance
CO2 emission
Opis:
The paper presents the results of energy and environmental evaluation of geothermal CHP plant. The variant of CHP plant based on Organic Rankine Cycle (ORC) has been taken into consideration as the most favorable for the geothermal conditions prevailing in Poland. The existing geothermal well located in the city of Konin in Greater Poland (Wielkopolska) voivodship has been chosen as the case study. The conceptual design of CHP plant has been proposed and evaluated from energy and environmental point of view. The non-renewable primary energy consumption has been chosen as energy performance criterion. In the case of environmental performance carbon dioxide emission has been taken as evaluation criterion. The analysis has been performed for different operating conditions and three working fluids. The best energy performance can be spotted for working fluid R123, for which the reduction varies between 15200 and 11900 MWh/a. The working fluid R134a has a worse energy performance, which allows for the reduction of fossil fuels energy consumption in the range of 15000 and 11700 MWh/a. The total reduction of CO2 emission is the highest for working fluid R123: 5300 to 4150 MgCO2/a, the medium one for working fluid R134a: 5200 to 4100 MgCO2/a and the lowest for working fluid R227: 5000 to 4050 MgCO2/a. It has been shown that the construction of geothermal CHP plants based on Organic Rankine Cycle can be reasonable solution in Polish conditions. It is important concerning the need of reduction of fossil fuels primary energy consumption and carbon dioxide emission.
Źródło:
Archives of Environmental Protection; 2021, 47, 3; 82--91
2083-4772
2083-4810
Pojawia się w:
Archives of Environmental Protection
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Pollutant emission from a heat station supplied with agriculture biomass and wood pellet mixture
Autorzy:
Juszczak, M.
Lossy, K.
Powiązania:
https://bibliotekanauki.pl/articles/185505.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
pozostałości rolnicze
drewno
spalanie
emisja
stacja ciepła
agricultural residue
wood
combustion
emission
heat station
Opis:
Tests for combustion of hay and sunflower husk pellets mixed with wood pellets were performed in a horizontal-feed as well as under-feed (retort) wood pellet furnace installed in boilers with a nominal heat output of 15 and 20 kW, located in a heat station. During the combustion a slagging phenomenon was observed in the furnaces. In order to lower the temperature in the furnace, fuel feeding rate was reduced with unaltered air stream rate. The higher the proportion of wood pellets in the mixture the lower carbon monoxide concentration. The following results of carbon monoxide concentration (in mg/m3 presented for 10% 02 content in flue gas) for different furnaces and fuel mixtures (proportion in wt%) were obtained: horizontal-feed furnace supplied with hay/wood: 0/100 - 326; 30/70 - 157; 50/50 - 301; 100/0 - 3300; horizontal-feed furnace supplied with sunflower husk/wood: 50/50 - 1062; 67/33 - 1721; 100/0 - 3775; under-feed (retort) furnace supplied with hay/wood: 0/100 - 90; 15/85 - 157; 30/70 - 135; 50/50 - 5179; under-feed furnace supplied with sunflower husk/wood: 67/33 - 2498; 100/0 - 3128. Boiler heat output and heat efficiency was low: 7 to 13 kW and about 55%, respectively, for the boiler with horizontal-feed furnace and 9 to 14 kW and 64%, respectively, for the boiler with under-feed furnace.
Źródło:
Chemical and Process Engineering; 2012, 33, 2; 231-242
0208-6425
2300-1925
Pojawia się w:
Chemical and Process Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Operational determinants of gaseous air pollutants emissions from coal-fired district heating sources
Eksploatacyjne uwarunkowania emisji zanieczyszczeń gazowych z węglowych źródeł ciepłowniczych
Autorzy:
Zwierzchowski, Ryszard
Różycka-Wrońska, Ewelina
Powiązania:
https://bibliotekanauki.pl/articles/2073776.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
district heating
gaseous air pollutant emission
emission indicators
unstable conditions
heat only boilers
ciepłownictwo
emisja gazowych zanieczyszczeń powietrza
wskaźniki emisji
niestabilne warunki
kotły grzewcze
Opis:
This study describes the correlation between emission of gaseous pollutants to the atmosphere and the combustion parameters of a coal-fired 25 MW heating capacity water boiler with mechanical grate (boiler type WR-25) in unstable working conditions: start-up, shutdown and loads below the technical minimum. Whereas measurements were made for a specific type and size of coal-fired water boiler with mechanical grate, the measurements and calculations are applicable to WR boilers with a different heating power as well as OR type steam boilers, which have a practically identical design. In sum, there are more than 1,000 coal-fired water and steam boilers of these types in Poland. In addition, the analysis reported in this paper highlights the important role played by boilers operating in unstable conditions in terms of emission of gaseous pollutants to the atmosphere. The conclusions are relevant for other boilers fi red with gas, oil or biomass operating under conditions such as start-up, shutdown and loads below the technical minimum. This article fi lls a gap in air protection engineering practice and the literature with regard to indicators and emission standards, drawing on measurements of pollutant concentrations in the exhaust gases from unstable WR boiler working conditions. The measurements can be used to assess the emission of pollutants to the atmosphere in such boiler working conditions and their impact on air quality. The analyses presented were based on the authors’ own measurements in WR-25 boiler technical installations using portable gas analyser GASMET DX-4000, which uses the FT-IR measurement method for compounds such as SO2, NOx, HCl, HF, NH3, CH4, and CO. Concentrations of CO, NOx and SO2 in exhaust gases were determined with multiple regression with the STATISTICA statistical software and with linear regression complemented by the “smart” package in the MATLAB environment. The study provides computational models to identify pollutant concentrations in the exhaust gases in any working conditions of WR-25 boilers.
Prezentowana praca badawcza opisuje korelację między emisją gazowych zanieczyszczeń powietrza do atmosfery, a parametrami spalania dla wodnego kotła rusztowego opalanego węglem typu WR-25, o mocy cieplnej 25 MW w niestabilnych warunkach pracy, takich jak: rozruch, odstawianie z ruchu i praca przy obciążenia poniżej minimum technicznego. Przedstawione analizy opierały się na własnych pomiarach autorów wykonanych dla kotłów rusztowych typu WR zasilających w ciepło miejskie systemy ciepłownicze oraz na wynikach z symulacji komputerowych wykorzystujących uzyskane dane pomiarowe. Autorzy prezentują, wskaźniki emisji zanieczyszczeń gazowych do atmosfery, w oparciu o pomiary tych emisji w niestabilnych warunkach pracy kotła typu WR, a których to wskaźników aktualnie brakuje zarówno w literaturze jak i praktyce inżynierii ochrony atmosfery. Wskaźniki te pozwolą na rzeczywiste oszacowanie wielkości emisji gazowych zanieczyszczeń do atmosfery w takich niestabilnych warunkach pracy kotła, jak również ich wpływ na jakość powietrza w otoczeniu. Prezentowana praca dostarcza modele obliczeniowe do identyfikacji obciążenia emisyjnego zanieczyszczeniami gazowymi do atmosfery w jakichkolwiek, a przede wszystkim w niestabilnych warunkach pracy kotłów typu WR-25.
Źródło:
Archives of Environmental Protection; 2021, 47, 3; 108--119
2083-4772
2083-4810
Pojawia się w:
Archives of Environmental Protection
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Correlation between air flow rate and pollutant concentrations during two-stage oak log combustion in a 25 KW residential boiler
Autorzy:
Juszczak, M.
Powiązania:
https://bibliotekanauki.pl/articles/184902.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
wood combustion
pollutant emission
heating boiler
heat station
spalanie drewna
emisja zanieczyszczeń
kocioł grzewczy
stacja ciepła
Opis:
It can be expected that there is a considerable correlation between combustion air flow rate and the concentrations of carbon monoxide, hydrocarbons and nitrogen oxide in the flue gas. The influence of temperature and oxygen concentration in the combustion zone on the concentrations of carbon monoxide, hydrocarbons and nitrogen oxide in the flue gas, for high and low combustion air flow, was analysed. Oxygen concentration for which the concentration of carbon monoxide is the lowest was determined, as well as the mutual relation between carbon monoxide and nitrogen oxide concentration.
Źródło:
Chemical and Process Engineering; 2016, 37, 3; 419-428
0208-6425
2300-1925
Pojawia się w:
Chemical and Process Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-7 z 7

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