US 11,913,719 B2
Liquefaction apparatus
Takuya Kaneda, Hyogo (JP)
Assigned to L'Air Liquide Societe Anonyme Pour L'Etude Et L'Exploitation Des Procedes Georges Claude, Paris (FR)
Filed by L'Air Liquide, Societe Anonyme pour l'Etude et l'Exploitation des Procedes Georges Claude, Paris (FR)
Filed on Jan. 22, 2021, as Appl. No. 17/155,749.
Claims priority of application No. 2020-008148 (JP), filed on Jan. 22, 2020.
Prior Publication US 2021/0222948 A1, Jul. 22, 2021
Int. Cl. F25J 1/02 (2006.01); F25J 1/00 (2006.01); F25J 3/04 (2006.01)
CPC F25J 3/04412 (2013.01) [F25J 1/0037 (2013.01); F25J 1/004 (2013.01); F25J 1/0221 (2013.01); F25J 1/0224 (2013.01); F25J 1/0234 (2013.01); F25J 1/0252 (2013.01); F25J 1/0254 (2013.01); F25J 3/04393 (2013.01); F25J 1/0015 (2013.01); F25J 2230/24 (2013.01); F25J 2230/42 (2013.01)] 2 Claims
OG exemplary drawing
 
1. A liquefaction apparatus for liquefying a product gas, said liquefaction apparatus comprising:
a compressor configured to compress the product gas, said compressor having a variable discharge flow rate;
a heat exchanger configured to cool and liquefy the product gas exiting the compressor to form a liquid product;
a distributed control device comprising:
one or more processors; and
memory coupled to the one or more processors, the memory storing instructions that, when executed by the one or more processors, cause the one or more processors collectively to perform operations comprising:
obtaining a predicted amount of power used by the compressor after a predetermined time has elapsed, on the basis of an integrated power value obtained by integrating a usage power of the compressor;
comparing the predicted amount of power used by the compressor and a moving average of an amount of power used by the compressor, and controlling the discharge flow rate of the compressor in such a way as to reduce the difference of the moving average of the amount of power used by the compressor and a target value of power used by the compressor, without exceeding the target value, and while using the larger value of the predicted amount of power and the moving average of the amount of power used by the compressor as a value being controlled, and wherein the liquefaction apparatus comprises:
an expansion valve; and
wherein the one or more processors are further configured to collectively to perform an operation of controlling a temperature difference of an inlet and an outlet of the expansion valve.