FUEL GAS FILLING CONTROL METHOD AND FUEL GAS FILLING CONTROL DEVICE

PROBLEM TO BE SOLVED: To provide a fuel gas filling method for stably and efficiently filling an on-vehicle tank mounted to a vehicle traveling by using fuel gas such as hydrogen with the fuel gas, and further to provide a fuel gas filling device.SOLUTION: A fuel gas filling device includes a gas conduit refrigeration section 3 provided therein. In a fuel gas filling control method, the gas conduit refrigeration section 3 controls filling of an on-vehicle tank mounted to a vehicle with fuel gas while refrigerating the fuel gas passing through a gas conduit 33 by CO2 supplied from a CO2 refrigeration section 4. The CO2 refrigeration section 4 is constituted of a refrigeration cycle including a compressor 41, a condenser 42, an expansion valve 43 and an evaporator 44 of primary refrigerant. A pressure sensor 46 for measuring a pressure of the CO2 inside the evaporator 44 of the refrigeration cycle is provided. The fuel gas filling control method includes the steps of: performing capacity control of the compressor 41 while comparing a CO2 actual measurement temperature calculated from a detection value of the pressure sensor 46 and individual preset temperatures at the time of fuel gas filling and at the time of fuel gas non-filling different from each other, the preset temperatures being T1, T2 (T1>T2) at the time of gas filling and T3, T4 (T1-T2