INCREASE LNG PLANT PRODUCTION BY USING DUAL ENHANCED HEAT TRANSFER SOLUTIONS

Dual enhanced tubes for LNG train pre-cooling circuit heat exchangers are now well known following their systematic use in all six AP-X trains in Qatar. Operational feedback since first startup in 2009 has been that the expected performance is met and even exceeded. For a given plant capacity, dual enhanced tubes provide a reduction in equipment size and associated cost savings. This technology has now been adopted for several grass root LNG plants as well as being considered for debottlenecking. The process design must be optimised to get maximum benefit from dual enhanced tubes. A balance is struck between reduction of the exchanger surface area and the reduction of the refrigerant compressor shaft power that results from using the reduced cold end temperature approach that is possible with this technology. This paper will describe the results of a study to assess the potential LNG production increase. Keeping the same liquefaction process (C3/MR) but using dual enhanced tubes, an increase in LNG capacity for constant refrigerant power and without any impact on the liquefaction unit CAPEX will be demonstrated. The paper will show that the use of dual enhanced tubes at an early stage of a project allows a significant increase in LNG plant capacity while minimizing the impact on :