Demand response with PCM-based pipe-embedded wall in commercial buildings: Joint influence mechanism of dual pre-cooling parameters

The PCM-based pipe-embedded wall (PCM-based PE-wall) is a novel composite wall structure combining active and passive heat transfer mechanisms to enhance energy storage rates in the pre-cooling period and release energy during demand response (DR) event in Heating Ventilation and Air Conditioning (HVAC) systems. However, how to improve the pre-cooling capacity of PCM-based PE-walls in operation require further research on the mechanism of parameter influence during the pre-cooling process. This paper presents a systematic study on the joint influence mechanism of the dual pre-cooling parameters (indoor pre-cooling temperature and pre-cooling duration) in terms of thermal performance, demand response performance, and economic benefits in a commercial building. The results show that lower indoor pre-cooling temperature or the longer pre-cooling duration can enhance thermal and DR performance, whereas it simultaneously reduces their marginal benefits. From an economic perspective considering the joint influence of the dual parameters, the optimal combination of dual pre-cooling parameters that can bring the minimized net cost of the HVAC system can be observed in the studied case, which is not entirely positively correlated with the pre-cooling temperature and duration. The optimal combination pre-cooling parameters (18 °C, 5h) could result in the lowest net cost, which is 8.91% lower than the combination (18 °C, 8h) with the longest pre-cooling duration in the studied cases. The study of joint influence mechanism of dual pre-cooling parameters will be beneficial for the more effective application of PCM-based pipe-embedded walls in practical engineering.