US 11,808,502 B2
Raw material gas liquefying device and method of controlling this raw material gas liquefying device
Naotaka Yamazoe, Akashi (JP); Tomohiro Sakamoto, Akashi (JP); Hidetaka Miyazaki, Kobe (JP); Daisuke Kariya, Kobe (JP); Yasuo Miwa, Kobe (JP); Yuichi Saito, Akashi (JP); and Yosuke Kimura, Kakogawa (JP)
Assigned to KAWASAKI JUKOGYO KABUSHIKI KAISHA, Kobe (JP)
Appl. No. 16/465,430
Filed by KAWASAKI JUKOGYO KABUSHIKI KAISHA, Kobe (JP)
PCT Filed Dec. 4, 2017, PCT No. PCT/JP2017/043510
§ 371(c)(1), (2) Date May 30, 2019,
PCT Pub. No. WO2018/105565, PCT Pub. Date Jun. 14, 2018.
Claims priority of application No. 2016-238535 (JP), filed on Dec. 8, 2016.
Prior Publication US 2020/0003070 A1, Jan. 2, 2020
Int. Cl. F25B 9/06 (2006.01); F25J 1/00 (2006.01); F25J 1/02 (2006.01)
CPC F25B 9/06 (2013.01) [F25J 1/001 (2013.01); F25J 1/005 (2013.01); F25J 1/0007 (2013.01); F25J 1/0052 (2013.01); F25J 1/0065 (2013.01); F25J 1/0067 (2013.01); F25J 1/0204 (2013.01); F25J 1/0221 (2013.01); F25J 1/0244 (2013.01); F25J 2210/42 (2013.01); F25J 2215/32 (2013.01); F25J 2270/16 (2013.01)] 10 Claims
OG exemplary drawing
 
1. A raw material gas liquefying device comprising:
a feed line which feeds a raw material gas whose boiling temperature is lower than a boiling temperature of nitrogen;
a refrigerant circulation line which circulates a refrigerant for cooling the raw material gas, the refrigerant circulation line including an expansion unit of a turbine type which expands the refrigerant to generate cryogenic energy, and an expansion unit entrance valve provided at an entrance side of the expansion unit;
a heat exchanger which exchanges heat between the raw material gas and the refrigerant;
a cooler which performs initial cooling of the raw material gas and the refrigerant by heat exchange with liquid nitrogen;
an expansion unit rotation speed sensor which detects a rotation speed of the expansion unit; and
a controller configured to manipulate an opening rate of the expansion unit entrance valve, wherein:
before start-up of the expansion unit, the opening rate of the expansion unit entrance valve is manipulated so that the expansion unit entrance valve opened and a flow rate of the refrigerant flowing into the expansion unit is reaching a predetermined initial cooling flow rate, a flow of the refrigerant with the predetermined initial cooling flow rate through the expansion unit does not rotate the expansion unit, and
at the start-up and stop of the expansion unit, the opening rate of the expansion unit entrance valve is manipulated, by performing a feedback control, so that the rotation speed of the expansion unit reaches a predetermined target value.