METHOD FOR CONTROLLING NATURAL GAS LIQUEFACTION UNIT Russian patent published in 2021 - IPC F25J1/02 F25B49/02 

FIELD: liquefied natural gas production.

SUBSTANCE: method to control the start-up of a liquefied natural gas (LNG) production unit. The heat exchanger is cooled down from the first temperature profile at the first time point to the second temperature profile at the second time point in step (a), wherein the first temperature profile has a first average temperature that is greater than the second average temperature of the second temperature profile. The following steps (b) are performed in parallel with the execution of step (a). (i) The first temperature is measured at the first location within the heat exchange system. (ii) The first value is calculated, including the rate of change of the first temperature. (iii) The first setpoint is provided – the preferred rate of change of the first temperature. (iv) The flow rate of the raw material flow through the heat exchanger (108) is controlled based on the first value and the first setpoint.(v) Regardless of step (b) (iv), the flow rate of the first refrigerant flow (142, 144) is controlled so that the flow rate of the first refrigerant flow is greater at the second time point than at the first time point.

EFFECT: increased efficiency and level of automation of the unit.

15 cl, 10 dwg, 1 tbl