Melting characteristics of TBAB CHS in fan coil units and room air flow field distribution

The Tetrabutylammonium bromide clathrate hydrate slurry (TBAB CHS), employed as a cooling medium in air conditioning systems, presents notable advantages including a high energy storage density and an optimal phase equilibrium temperature. The melting prediction model of TBAB CHS in fan coil units was established, alongside simulations elucidating the airflow distribution in the room. To maximize the use of cold capacity, the model was designed to ensure TBAB CHS melts exactly following heat exchange through the fan coil unit. The melting heat transfer characteristics and parameter design rules of TBAB CHS in fan coil units under different cooling load and supply air temperature were analyzed. Additionally, the distribution characteristics of flow field in air-conditioned rooms at different supply air temperatures were studied. The results showed that the design flow velocity increases and the initial mass fraction decreases when the supply air temperature decreases. With the increase of cooling load, the design flow velocity of TBAB CHS increases, and the initial mass fraction decreases first and then increases. Notably, when implementing low-temperature air supply, the air distribution is characterized by horizontal uniformity and vertical stratification. In actual engineering, air distribution should be adjusted to prevent cold air from sinking and accumulating.