Experimental investigation on the control performance of an active chilled beam system under dynamic cooling loads

Abstract

Abstract In this study, the control performance of an active chilled beam (ACB) system was investigated, in order to find the suitable control parameter for controlling room air temperature and preventing surface condensation when the cooling load suddenly increases. For this purpose, the impact of ACB control parameters on the cooling capacity was evaluated with mock-up experiments. Compared to the baseline condition in this study, the adjustment of the chilled water temperature and primary air flow rate raised the cooling capacity by 47% and 98%, respectively, while the adjustment of the chilled water flow rate and primary air temperature led to a relatively small increase in cooling capacity. In addition, the control performance of room air temperature was evaluated with the room air temperature drop for one hour after a step change in cooling load. It was observed that the room air temperature dropped 0.2 °C with chilled water temperature control and 0.7 °C with primary air flow rate control, whereas it dropped 1.0 °C with the simultaneous control of the chilled water temperature and primary air flow rate. The test results further showed that simultaneous control of the chilled water temperature and primary air flow rate is effective for preventing the surface condensation while providing the sufficient cooling capacity. The findings of this study can provide the information on the thermal behavior of ACB system, which is necessary for establishing control strategies for ACB systems.