Dielectric behaviour of liquid natural gas compared to vacuum insulation

Abstract

This paper prestents investigations into the electrical properties of liquid natural gas(LNG). The electric strength measurements, under alternating- and direct-voltages, showed reasonable values when compared to vacuum and other liquid gases. Partial discharge activity was measured, using a pulse height analyzer, and the behaviour was very satisfactory. The improvements were significant under d-c conditions. The dielectric constant and the loss-factor were measured and showed promising use of LNG as an electrical insulator in cryoequipment. On account of being used as insulator in cryoequipment it can be used as coolant for solid dielectrics. This would be an economical turn over to LNG when compared with liquid helium(LHe).