▎ 摘　　要

NOVELTY - The system (1) has a thermal circuit (3) with a working fluid that is configured to perform a thermodynamic cycle and/or an energy transfer process. The thermal circuit is arranged with a piping system (5) for conveying the working fluid, and energy transfer device is configured to transfer a portion of energy from one portion of thermal circuit to another portion of the thermal circuit. A portion of the thermal circuit is arranged with a coating layer on surfaces in contact with the working fluid. The coating layer is included with an inert material that is inert with respect to the working fluid during operation and that maintains structural integrity at a temperature above 550 K. The inert material in a pure state/form has a thermal conductivity above 50 W/mK at room temperature. The working fluid is non-corrosive and an organic liquid. The inert material is graphene or contains graphene. The surfaces coated with the coating layer are made of stainless steel. USE - Energy transfer system e.g. large scale solar power system for use in heat pump, thermal oil bath, concentrated solar collector, and organic rankine cycle electric generator. ADVANTAGE - The performance of energy transfer systems is improved. The reliability is improved and/or manufacturing and maintenance costs for energy transfer systems are reduced. The design of energy transfer system is improved. The thermal stability limit temperature of a working fluid in energy transfer system is improved. The efficiency in energy transfer systems is improved. The temperature of the working fluid in the thermal circuit is kept below thermal stability temperature in order to prevent detrimental effects such as fluid decomposition. The high thermal conductivity in combination with inert properties can result in a higher thermal stability limit temperature of the working fluid, thus enabling an enhancement of the performance and/or efficiency of the energy transfer system, without causing a decrease in the heat transfer properties of the heat transfer equipment. The working fluids for heat transfer processes have a high heat capacity and a high boiling point to enable efficient heat transfer by an amount of fluid as small as possible, and to minimize the risk to vaporization at high temperatures. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: a method of manufacturing energy transfer system; and a method of increasing thermal stability limit temperature of working fluid in energy transfer system. DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of the energy transfer system. 1Energy transfer system 3Thermal circuit 5Piping system 7Component