Thermal performance analysis of submerged combustion vaporizer at supercritical pressure

Abstract

In this paper, an energy balance-based model considering icing effects was established for estimating the heat transfer of submerged combustion vaporizer (SCV) under supercritical LNG pressure, where introduces some empirical correlations to evaluate the convection heat transfer of water bath-side and LNG-side. Based on this model, the thermal performance of a typical SCV was predicted numerically, and good agreement between the predictedand actual water bath temperatures indicates that the model is reliable. The results indicated that the operation parameters, such as LNG pressure, operating load, inlet LNG temperature, have significantly different influences on the thermal performance of SCV, including required minimum water bath temperature and flue gas flow rate, and the length and average thickness of ice layer outside the LNG tube bundle. The heat transfer enhancement techniques can improve the heat transfer efficiency markedly, although they also cause an increase in flow resistance. The wire coil insert with a helix angle of 75° is a better choice than the twisted tape insert with a helix angle of 45° and the wire coil insert with a helix angle of 45° considering its effects on both heat transfer and flow resistance.