Unglazed transpired solar collectors (UTSCs) preheat makeup ventilation air for buildings, thereby reducing energy used for heating. The performance of the UTSC is dependent on the heat loss from the absorber plate, which is strongly affected by the wind speed. To date, correlations to determine UTSC heat loss are limited to flat or sinusoidal plate corrugations. In reality, trapezoidal corrugations have been added to UTSCs to provide them with structural stiffness. These corrugations prevent the attachment of the flow to the absorber plate and cause flow separation which increases the heat loss. In this study, a numerical simulation of a UTSC with trapezoidal shape corrugation has been performed to investigate the heat loss in the developing region due to wind on the UTSCs. It has been found that heat loss from new configuration is up to three times greater than the heat loss from a perforated flat absorber plate. A correlation of heat loss due to the wind speed and suction velocity was developed. This study also includes an evaluation of the effectiveness in the asymptotic region. In this case, wind speed had no effect. A correlation was derived in terms of suction velocity.

Unglazed transpired solar collectors (UTSCs) preheat makeup ventilation air for buildings, thereby reducing energy used for heating. The performance of the UTSC is dependent on the heat loss from the absorber plate, which is strongly affected by the wind speed. To date, correlations to determine UTSC heat loss are limited to flat or sinusoidal plate corrugations. In reality, trapezoidal corrugations have been added to UTSCs to provide them with structural stiffness. These corrugations prevent the attachment of the flow to the absorber plate and cause flow separation which increases the heat loss. In this study, a numerical simulation of a UTSC with trapezoidal shape corrugation has been performed to investigate the heat loss in the developing region due to wind on the UTSCs. It has been found that heat loss from new configuration is up to three times greater than the heat loss from a perforated flat absorber plate. A correlation of heat loss due to the wind speed and suction velocity was developed. This study also includes an evaluation of the effectiveness in the asymptotic region. In this case, wind speed had no effect. A correlation was derived in terms of suction velocity.

Baigiamajame magistro darbe atliktas eksperimentinis neįstiklinto pratakaus saulės kolektoriaus efektyvumo tyrimas. Eksperimento metu parinkta ir sumontuota matavimo ir duomenų kaupimo įranga. Pagal gautus meteorologinius ir kolektoriaus parametrų duomenis išanalizuotas kolektoriaus veikimas. Nustatyta kolektoriaus paviršiaus ir tiekiamojo oro temperatūrų, temperatūrinio efektyvumo ir bendro efektyvumo priklausomybė nuo išorinių veiksnių. Atliktas rezultatų palyginamas esant pastoviam ir kintamam tiekiamojo oro debitui, ir nustatyta jo įtaka kolektoriaus veikimui. Remiantis šilumos srauto principu ir naudojantis parinkta matavimo įranga, nustatyta kolektoriaus veikimo įtaka išorinei pastato atitvarai. Nustatyti galimi šilumos pritekiai šildymo sezono ir vasaros metu, naudojant kolektorių kaip apsauginę priemonę nuo tiesioginių saulės spindulių. Atliktas kolektoriaus ekonominis ir energinis vertinimas naudojantis RETScreen programa ir, lyginant gautus rezultatus su kitais baziniais šildymo būdais, apskaičiuotas kolektoriaus atsipirkimo laikotarpis. / Master thesis carried out an experimental study of unglazed transpired solar collector. During the experimental required measuring equipment was selected and installed. Performance of the collector was analyzed according to measured meteorological collector’s parameters data. Collector surface and supply air temperature, thermal efficiency and overall efficiency dependency on external factors was investigated. The study results are compared with constant or variable supply air flow rate and its impact on the operation of the collector. Collector operation impact to building’s external wall is investigated based on the principle of heat flow and using the selected measurement equipment. Study investigated possible heat inflow during the heating season and summer time, using collector as a shield against direct sunlight. Collector economical and energetic assessment was done using RETScreen software.