수치해석 및 실험을 통한 트롬월 시스템의 적용성 검토

Abstract

From the solar thermal systems used in building structures, the nature-type solar energy system that applied nature circulating method for the heat transfer is consisted of direct gain, indirect gain and isolated gain. Among them, a type of the representative indirect gain method, the passive system method, is largely classified in the trombe wall method with the upper and lower air circulation vent and the mass wall only with the energy storage mass. The trombe wall method has relatively high system efficiency and easier to apply for the southern walls from the nature-type solar energy system that it is the most widely applied system.

In general, there were many theoretical and empirical advance on the trombe wall system, but there is an insufficient analysis on heat efficiency following the air flow distribution, heat transfer characteristics and vertical gap in the opening by using the computational fluid dynamics. Therefore, in this study, as a result of principle on operation of air flow and heat in engineering verification by using the CFD analysis when the Trombe wall system is applied on building structure as well as anlyzing the indoor air flow and thermal movement on night condition, following conclusion has been acquired.

1. Interpretation of existing general trombe wall system, was applied for -10℃, the same temperature for both indoor and external wall boundary conditions without classification. However, under this research, it was considered that the interior part of the building structure could not be the sane as the external temperature of -10℃ in winter that the interior wall temperature was assumed for 10℃, and as a result of its interpretation, the temperature showed the characteristics of air flow pattern and thermal movement that had the warm indoor air to escape to the glass window with declining temperature and the cold air from the heat loss flowing into the indoor.

2. By using the CFD analysis, when the analysis was made by affixing the figures of the 'opening area'(D) and 'cavity interval'(W) and changing the figure of the 'step'(S) height, the optimal efficiency step (S) figure in the Trombe wall was analyzed. As a result, when the step (S) figure was 30cm, it was shown to have the best efficiency.

3. When the analysis was made by applying the figure with the optimal efficiency from the figure of step (S) that was analyzed earlier by using the CFD analysis and affixing the opening area (D) and changing the cavity interval (W) figure, the optimal efficient cavity interval (W) figure in the Trombe wall was analyzed. As a result, the efficiency was the best when the cavity interval (W) figure was 20cm.

4. In the efficiency review of the Trombe wall system through the experiment, if the Trombe wall was applied in the building structure, the Trombe wall had the indoor temperature increased at the time the temperature was declining that the Trombe wall had the stored heat into the interior. In addition, in the event that the Trombe wall was not applied, the initial indoor average measurement temperature was measured higher than the case applied for the Trombe wall. However, it was decreased with significant range of change with the lapse of time, and when the experiment was completed, the external wall and the temperature were similarly measured to have greater heat loss when applied the Trombe wall. In the event that the Trombe wall was applied on building structure, it was proven to have higher effect in the energy efficiency aspect.