Numerical optimization and experimental study of a novel multi-mode chilled beam

Abstract

• The novel chilled beam can operate as three modes to meet various thermal needs. • Simulation of airflow and heat transfer in the novel beam validated by experiment. • New beam’s high thermal capacities demonstrated in simulation and lab tests. • Novel chilled beam is able to merge the advantages of two beams in one unit. • Simulation-based optimization proved effective and efficient in design process. Chilled beams have been widely used in many regions of the world due to the high energy efficiency and satisfactory thermal comfort they provide. This paper employed a CFD based optimization strategy to develop a novel multi-mode chilled beam (MCB) that could merge the advantages of both passive chilled beam and active chilled beam units. Depending on the specific thermal requirement of indoor space, the novel chilled beam could operate as three different modes which were fast cooling mode, fast heating mode and gentle cooling mode. With the optimal design parameters achieved through numerical optimization, a prototype was built for model validation and a comprehensive performance evaluation. Results showed that the cooling and heating capacities of the optimized MCB unit could reach 3600 W and 4000 W, respectively. Compared with conventional HVAC systems, MCB system improved the energy efficiency could by 9.2% under gentle cooling mode and by 19.0% under fast cooling mode. The noise level for the new chilled beam could be as low as 19.8 dB, providing a good acoustic performance. The CFD based optimization strategy, followed by experimental validation, proved to be an effective and efficient approach for developing a novel chilled beam unit.