Analysis and Design for Fixed Type Refrigerant Chiller in LNG and Ethylene Plant

Abstract

In LNG Plant using APCI Precooled MR process [1] (Propane precooling and Mixed Refrigerant as main cooling medium, Figure 1), Natural gas and Mixed Refrigerant chillers which installed upstream of the main cryogenic heat exchanger are one of the key process equipment of the plant. Similar application is often used in other petrochemical area such as Ethylene plant using light hydrocarbon refrigerant for evaporation chiller. It is always challenging to optimize the design to reduce necessary plot area while it satisfies various process and mechanical requirements. This paper will cover an analysis of typical chiller design of 4MTPA LNG project in respect of thermal design, process scenarios and mechanical integrity. Firstly starts thermal design review for better understanding on the back ground of equipment features and its function. Then discuss about process scenarios which are used for analysis cases. For mechanical integrity analysis, FEA method, result and review will be introduced. In the last section, design cases by using different tube thickness and optimization study will be presented as suggestion for future LNG projects.