| Title |
Performance Enhancement of Solar Thermal Storage Tank with Heat Exchange Coils(Part 2 : Simulation) |
| Authors |
Jong-Hyun Kim ; LongJie Li ; Uk-Jae Lee ; Hiki Hong |
| DOI |
http://dx.doi.org/10.6110/KJACR.2016.28.9.361 |
| Keywords |
삼방향밸브 ; 집열효율 ; 태양열 의존율 ; 온도역전 ; 트란시스 ; 변유량 제어 3-way valve ; Collector efficiency ; Solar fraction ; Temperature reversal ; TRNSYS ; Variable flowrate control |
| Abstract |
As an alternative of well-mixed storage tank with lower coil only, we have proposed a tank with lower and upper coils and verified a superior thermal stratification in a tank, which results in increased collector efficiency and solar fraction. But the phenomenon of temperature reversal was often experimentally observed in the tank, so a revised control was successfully applied which is to heat only lower coil using three way valve if temperature reversal occurs and to operate the collector with low flow rate when the condition of solar radiation is not good. In the present study, using TRNSYS we compared the existing lower heating and the proposed lower and upper heating with a control preventing temperature reversal. The results showed that the proposed method has an increase of collector efficiency by 5.1% and solar fraction by 3.2%. |