Optimal selection of two-phase tube-side heat transfer model for small-scale LNG spiral wound heat exchanger

Abstract

Small-scale devices of liquefied natural gas (LNG) have been widely applied in the natural gas industries, especially for stranded gas production. As the key equipment of LNG plants, the performance of the spiral wound heat exchanger (SWHE) influences operating costs, reliability and safety of the whole system. In order to obtain the accurate two-phase tube-side heat transfer model for small-scale LNG SWHE and analyze its thermal performance, an experimental device of dual mixed refrigeration (DMR) is constructed. A multi-phase multi- -stream calculation code for SWHE is developed to solve the energy balance equations among tube-side feed gas, tube-side refrigerant and shell-side refrigerant, based on experimental results and thermal property calculation. The results show that the homogeneous flow model can be applied to two-phase tube-side heat transfer calculation of feed gas and Bell and Ghaly’s model and Shah’s model can be both applied to the mixed refrigerant. The relative errors between the results of the experiment and program are all within the range of ±12%.

Keywords

• LNG
• DMR
• spiral wound heat exchanger
• experimental
• thermal model