Wyniki wyszukiwania - BazTech

1

Modelling of the solar heating of a multi-layered spherical cone

Siedlecka Urszula

Journal of Applied Mathematics and Computational Mechanics

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2023

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Vol. 22, nr 4

53-63

EN

In this paper, the solar heating of a multi-layered spherical body with azimuthal symmetry is considered. The mathematical model is related to the determination of the steady state of the temperature distribution in the spherical cone consisting of concentric spherical layers. The solar heating is composed of two parts of the heat flux: direct and diffusion. Also, the simultaneous cooling of the cone by its outer surface (as convective heat flow to the environment) is taken into account. The proposed system of the partial differential equations supplemented by the adequate boundary conditions is solved in the analytical way by using, among others, the Legendre functions of the first kind. The sample results of temperature distribution in the cross-section of the cone with different polar angles are also presented.

2

Conceptual adsorption system of cooling and heating supplied by solar energy

Turski M.

Chemical and Process Engineering

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2016

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Vol. 37, nr 2

293--304

EN

This paper presents the possibility of reducing the demand for nonrenewable primary energy for buildings using a new conceptual adsorption system of cooling and heating supplied by solar energy. Moreover, the aim of this study is to shorten the payback time of investment in the standard adsorption cooling system through its integration with the heating system. Research has been carried out for an energy-efficient medium-sized single-family building with a floor area of 140 m 2 and a heat load of 4.2 kW and cold load of 4.41 kW. It has been shown that the use of an adsorption system of cooling and heating supplied by solar energy decreased the demand for nonrenewable primary energy by about 66% compared to the standard building that meets the current requirements.

3

Temperature in the adhesive layer of externally bonded composite reinforcement heated by the sun

Krzywoń R.

Architecture Civil Engineering Environment

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2016

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Vol. 9, no. 1

79--84

EN

The paper describes the measurements of temperature growth in different types of the epoxy adhesive bonding external strengthening. A total of six types of models were tested: CFRP sheet and strip, two SRP tapes adhered to the concrete sample, CFRP strip and SRP tape on a timber sample. Changes in temperature were investigated during the summer in the southern Poland. The maximum measured temperatures for all models exceeded regarded as safe temperature limit of 45°C. The highest recorded adhesive temperature refers to a sample of CFRP strengthened timber and exceeded 70°C. For the structure such a high temperature may result in almost complete loss of adhesion and thus the efficiency of strengthening. Test results may be a warning against the use of FRP external strengthening exposed to direct sunlight without any protection.

PL

W artykule opisano pomiary wzrostu temperatury w różnych rodzajach klejów epoksydowych połączeń wzmocnień zewnętrznych. Przebadano łącznie sześć rodzajów modeli: matę i taśmę CFRP, dwie taśmy SRP przyklejone do próbki betonu, taśmę CFRP i taśmę SRP na próbce drewna. Zmiany temperatury były badane w okresie letnim w południowej Polsce. Maksymalne zmierzone temperatury dla wszystkich modeli przekroczyły uznawaną za bezpieczną granicę temperatury 45°C. Najwyższa zanotowana temperatura kleju dotyczy próbki drewnianej wzmocnionej CFRP i przekroczyła 70°C. Tak wysoka temperatura w konstrukcji może spowodować prawie całkowitą utratę przyczepności, a tym samym efektywności wzmocnienia. Wyniki badań mogą być ostrzeżeniem przed stosowaniem zewnętrznego wzmocnienia FRP poddanego bezpośredniemu działaniu nasłonecznienia bez żadnej ochrony.

4

Bivalent heating installation with a heat pump and solar collectors for a residential building

Magiera J, Pater S.

Environment Protection Engineering

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2012

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Vol. 38, nr 2

127--140

EN

Solar energy systems and heat pumps are two promising means of reducing the consumption of fossil energy resources and the cost of delivered energy for residential heating. The integration of these two installations presents a novel combined heating system, so-called bivalent system, operating more economically. The major objective of this paper was to analyze the possibility of construction and benefits of a bivalent system composed of a heat pump and solar collectors for heating and cooling residential buildings.

5

Take off for Solar District Heating in Europe

Dalenbäck J. O.

Polska Energetyka Słoneczna

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2009

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nr 1-4

9-13

EN

In total, there are about >25 million m2 of glazed solar collectors in Europe, corresponding to about 18 GWn, (thermal power), where the majority of the collectors are installed in small systems with up to a few kW,h. European large-scale solar heating plants having more than 500 m" (~350 kWlh) of solar collectors have only about 170 MWlh altogether, so only a minor part of the European collector market comprises large-scale applications, i.e. about 1% of the installations. However, the relevant heat loads vary from a few kWlh up to several GWlh and about 9% of the heating loads in Europe are covered by block and district heating systems. There is thus a need to develop large-scale applications in order to utilize the full potential of solar heat to cover existing heat loads. The further development of district heating systems is likely to play a major role on the future European energy market, e.g. in Germany and Poland. To acknowledge the importance of large-scale solar heating (and cooling) systems, the European Solar Thermal Technology Platform - ESTTP - has assigned one working group for Solar District Heating (and Cooling). The vision for large-scale systems is further developed in co-operation with representatives for Euroheat & Power with the intention to broaden the number of potential actors to develop, demonstrate and promote solar heat in district heating (and cooling) applications. A number of technologies are already applied in demonstration projects mainly in the northern parts of Europe, e.g. Sweden, Denmark, Germany and Austria. At present, there are about 40 plants with > 1 400 m2 (1 MWth) solar collectors and the largest plant so far in Europe is designed with 18 000 m2 (13 MWlh) solar collectors. The paper describes technology status, presents strengths, weaknesses, opportunities and threats, as well as a vision that claims that it could be feasible with close to 20 PJ solar heat in district heating systems in 2020 with a more progressive policy.

6

Określenie zależności pomiędzy parametrami klimatu zewnętrznego a przepływem strumienia ciepła w pasywnych systemach ogrzewania słonecznego

Lichołai L.

Zeszyty Naukowe Politechniki Rzeszowskiej. Budownictwo i Inżynieria Środowiska

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2008

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z. 47 [252]

239-242

PL

Przedstawiono zależności pomiędzy parametrami klimatu zewnętrznego a natężeniem przepływu ciepła przez przegrody budowlane wyposażone w pasywne systemy ogrzewania słonecznego. Analizie poddano następujące parametry klimatu zewnętrznego: temperatura powietrza zewnętrznego, natężenie promieniowania słonecznego, prędkość wiatru oraz ciśnienie i wilgotność powietrza. Wyniki przedstawiono na podstawie badań doświadczalnych w postaci graficznej oraz jako współczynniki korelacji.

EN

The paper describes correlations between parameters of the external climate and the intensity of the heat flow, appointed experimentally for walls with passive solar systems. The analysis is made for the following parameters of the external climate: temperature of the external air, the intensity of the solar radiation, the speed of the wind and the pressure and the atmospheric humidity. The results were showed in the graphic froms and as the coefficients of correlation.

7

Solar heating using roof module collectors examples from new and existng building areas

Dalenbäck J. O.

Polska Energetyka Słoneczna

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2006

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nr 1-2

15-21

EN

Solar heating plant or a district heating network. The paper will describe a development of roof integrated collectors from site built colectors to prefabricated roof module collectors based on two major applications: new residential buildings built by EKSTA Bostads AB and existing multifamily buildings renovated by Gärdstensbostäder AB, both municipal housing companies are in the Gőteborg area. Since early 1980`s EKSTA has built about 10 new residential developments with about 6000 m2 of solar collectors on a number of new buildings. The majority of buildings, typically better insulated than required by the Swedish building code, are connected to local heating plants combining wood pellet or briquette boilers and solar heating using roof-integrated solar collectors. Gärdstensbostäder has carried out a renovation project with the aim to demonstrate a comprehensive intyegrated concept, comprising energy concervation and utilisation of solar energy, as well as improved architectural and social conditions, making the buildings in a typical existing residential building area from the 1970`s more attractive. The project comprises 500 apartments in3-5 floor concrete element in six blocks. The renovation was carried out in two phases: one finished late 2000 and one finished in early 2004. One innovative feature is 1 410 m2 prefabricated roof modules with integrated solar collectors for pre-heating DHW.

8

Izolacje transparentne w systemie pasywnego ogrzewania słonecznego

Dudko K.

Izolacje

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2004

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R. 9, nr 1

28-33

PL

Zmiany na światowym rynku paliw (i in. źródeł energii), związane głównie z wyczerpywaniem się zasobów naturalnych, spowodowały wzrost międzynarodowego zainteresowania racjonalizacją gospodarki energetycznej we wszystkich dziedzinach życia. Przewiduje się [5], że przy obecnym poziomie produkcji ropy naftowej wystarczy na około 50 lat, gazu ziemnego na 70 lat, a węgla na 190 lat.

9

Możliwości wykorzystania energii promieniowania słonecznego do celów grzewczych w Polsce centralnej

Pomierny W.

Polska Energetyka Słoneczna

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2003

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nr 1

14-16

PL

W artykule przeanalizowano warunki dopływu energii promieniowania słonecznego oraz przedstawiono Regionalizacja helioenergetyczna Polski. Na podstawie przeprowadzonej długoterminowej symulacji numerycznej przedstawione wyniki charakteryzują możliwości wykorzystania promieniowania słonecznego do celów grzewczych dla Polski Centralnej.