Experimental study of flow distribution behavior on the shell side of spiral tube bundles in LNG spiral-wound heat exchangers

Abstract

Flow maldistribution could reduce the heat transfer capability of LNG spiral-wound heat exchangers (SWHEs). However, there remains a lack of clarity on the flow distribution behavior on the shell side of spiral tube bundles in SWHEs. To address the flow distribution behavior and improve distribution performance, we built a spiral-wound heat exchanger test section with thirteen-layer spiral tube bundles and an experimental system. The experimental conditions were as follows, the gas mass flow rate ranged from 180.00 kg·h−1 to 256.50 kg·h−1, the liquid mass flow rate ranged from 173.88 kg·h−1 to 420.00 kg·h−1, and the vapor quality ranged from 0.30 to 0.54. The results suggest the distribution of two-phase flow becomes better when mass flow rate or vapor quality increases in the absence of the distributor and is superior to those of the gas flow and liquid flow. When the mass flow rate rises from 378.00 kg·h−1 to 475.00 kg·h−1, the distribution of two-phase flow improves by 48.78%. When vapor quality increases from 0.40 to 0.48, the distribution of the two-phase flow improves by 35.00%. The distributor can improve the distribution of two-phase flow on the shell side of spiral tube bundles. After setting the distributor, the gap in flow rate between inner channels and outer channels is reduced from 29.09% to 26.30% when vapor quality is 0.54, it is decreased from 42.68% to 30.08% when the mass flow rate is 500 kg·h−1. These results can be used for the design of LNG SWHEs.