Dynamics of Melting Process in Phase Change Material Windows Determined Based on Direct Light Transmission
Detailed analyses of melting processes in phase change material (PCM) glazing units, changes of direct transmittance as well as investigation of refraction index were provided based on laboratory measurements. The main goal of the study was to determine the direct light transmittance versus time und...
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| Format: | Article |
| Language: | English |
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MDPI AG
2021-01-01
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| Series: | Energies |
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| Online Access: | https://www.mdpi.com/1996-1073/14/3/721 |
| _version_ | 1827596784345546752 |
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| author | Dariusz Heim Michał Krempski-Smejda Pablo Roberto Dellicompagni Dominika Knera Anna Wieprzkowicz Judith Franco |
| author_facet | Dariusz Heim Michał Krempski-Smejda Pablo Roberto Dellicompagni Dominika Knera Anna Wieprzkowicz Judith Franco |
| author_sort | Dariusz Heim |
| collection | DOAJ |
| description | Detailed analyses of melting processes in phase change material (PCM) glazing units, changes of direct transmittance as well as investigation of refraction index were provided based on laboratory measurements. The main goal of the study was to determine the direct light transmittance versus time under constant solar radiation intensity and stable temperature of the surrounding air. The experiment was conducted on a triple glazed unit with one cavity filled with a paraffin RT21HC as a PCM. The unit was installed in a special holder and exposed to the radiation from an artificial sun. The vertical illuminance was measured by luxmeters and compared with a reference case to determine the direct light transmittance. The transmittance was determined for the whole period of measurements when some specific artefacts were identified and theoretically explained based on values of refractive indexes for paraffins in the solid and liquid state, and for a glass. The melting process of a PCM in a glass unit was identified as a complex one, with interreflections and refraction of light on semi layers characterized by a different physical states (solid, liquid or mushy). These optical phenomena caused nonuniformity in light transmittance, especially when the PCM is in a mushy state. It was revealed that light transmittance versus temperature cannot be treated as a linear function. |
| first_indexed | 2024-03-09T03:15:23Z |
| format | Article |
| id | doaj.art-dad21ddc930b44de89ac9bf45ea8c550 |
| institution | Directory Open Access Journal |
| issn | 1996-1073 |
| language | English |
| last_indexed | 2024-03-09T03:15:23Z |
| publishDate | 2021-01-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Energies |
| spelling | doaj.art-dad21ddc930b44de89ac9bf45ea8c5502023-12-03T15:22:35ZengMDPI AGEnergies1996-10732021-01-0114372110.3390/en14030721Dynamics of Melting Process in Phase Change Material Windows Determined Based on Direct Light TransmissionDariusz Heim0Michał Krempski-Smejda1Pablo Roberto Dellicompagni2Dominika Knera3Anna Wieprzkowicz4Judith Franco5Department of Environmental Engineering, Lodz University of Technology, ul. Wolczanska 213, 91-164 Lodz, PolandDepartment of Environmental Engineering, Lodz University of Technology, ul. Wolczanska 213, 91-164 Lodz, PolandInstituto de Investigaciones en Energía No Convencional (INENCO), 5150 Bolivia Av., Salta 4400, ArgentinaDepartment of Environmental Engineering, Lodz University of Technology, ul. Wolczanska 213, 91-164 Lodz, PolandDepartment of Environmental Engineering, Lodz University of Technology, ul. Wolczanska 213, 91-164 Lodz, PolandInstituto de Investigaciones en Energía No Convencional (INENCO), 5150 Bolivia Av., Salta 4400, ArgentinaDetailed analyses of melting processes in phase change material (PCM) glazing units, changes of direct transmittance as well as investigation of refraction index were provided based on laboratory measurements. The main goal of the study was to determine the direct light transmittance versus time under constant solar radiation intensity and stable temperature of the surrounding air. The experiment was conducted on a triple glazed unit with one cavity filled with a paraffin RT21HC as a PCM. The unit was installed in a special holder and exposed to the radiation from an artificial sun. The vertical illuminance was measured by luxmeters and compared with a reference case to determine the direct light transmittance. The transmittance was determined for the whole period of measurements when some specific artefacts were identified and theoretically explained based on values of refractive indexes for paraffins in the solid and liquid state, and for a glass. The melting process of a PCM in a glass unit was identified as a complex one, with interreflections and refraction of light on semi layers characterized by a different physical states (solid, liquid or mushy). These optical phenomena caused nonuniformity in light transmittance, especially when the PCM is in a mushy state. It was revealed that light transmittance versus temperature cannot be treated as a linear function.https://www.mdpi.com/1996-1073/14/3/721triple glazingsolar radiationenergy storageoptical propertiesrefractive index |
| spellingShingle | Dariusz Heim Michał Krempski-Smejda Pablo Roberto Dellicompagni Dominika Knera Anna Wieprzkowicz Judith Franco Dynamics of Melting Process in Phase Change Material Windows Determined Based on Direct Light Transmission Energies triple glazing solar radiation energy storage optical properties refractive index |
| title | Dynamics of Melting Process in Phase Change Material Windows Determined Based on Direct Light Transmission |
| title_full | Dynamics of Melting Process in Phase Change Material Windows Determined Based on Direct Light Transmission |
| title_fullStr | Dynamics of Melting Process in Phase Change Material Windows Determined Based on Direct Light Transmission |
| title_full_unstemmed | Dynamics of Melting Process in Phase Change Material Windows Determined Based on Direct Light Transmission |
| title_short | Dynamics of Melting Process in Phase Change Material Windows Determined Based on Direct Light Transmission |
| title_sort | dynamics of melting process in phase change material windows determined based on direct light transmission |
| topic | triple glazing solar radiation energy storage optical properties refractive index |
| url | https://www.mdpi.com/1996-1073/14/3/721 |
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