An Efficient Pulse Tube Cryocooler for BOG Recondensation in LNG Tanks

Abstract Small liquid natural gas (LNG) distribution stations require compact, highly efficient cryocoolers to condense boil-off gas in the LNG tank. This paper reports a pulse tube cryocooler measuring 420*690*780 mm and weighing 180 kg. Using low input electric power, the relative Carnot efficiency was greater than 20%. Increasing the power to 11 kW, the cryocooler produced approximately 1.2 kW of cooling at 120 K. Approximately 293 normal cubic meters of boil-off NG per day can be condensed. If heat transfer in the main heat exchanger was improved, cooling power and efficiency could be improved. It presents a new efficient, compact and reliable configuration for the energy saving in LNG distribution stations.