Patents by Inventor Zheji Liu
Zheji Liu has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 11946678Abstract: A system includes a dynamic compressor and a controller having a processor and a memory. The compressor includes a first compressor stage having a first variable inlet guide vane (VIGV) and a second compressor stage having a second VIGV. The memory stores instructions that program the processor to operate the compressor at a current speed, a first position of the first VIGV, and a second position of the second VIGV to compress the working fluid, and to determine if a condition is satisfied. If the condition is not satisfied, the processor is programmed to continue to operate the compressor at the current speed, the first position of the first VIGV, and the second position of the second VIGV. If the condition is satisfied, the processor is programmed to change the second position of the second VIGV to a third position and maintain the first position of the first VIGV.Type: GrantFiled: January 27, 2022Date of Patent: April 2, 2024Assignee: Copeland LPInventors: Michael M. Perevozchikov, Matthew J. Swallow, Zheji Liu
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Patent number: 11852153Abstract: A bearing system includes a bearing housing and a foil bearing assembly. The bearing housing includes a sleeve defining a cylindrical bore, and a mounting structure for connecting the bearing system to a compressor housing. The foil bearing assembly is positioned within the cylindrical bore and includes an outer foil assembly, an inner foil assembly, and a bump foil assembly positioned between the outer and inner foil assemblies. The bump foil assembly includes a plurality of bump foils disposed circumferentially about the inner foil assembly. Each bump foil is coupled to the outer foil assembly at a respective land and spaced circumferentially from an adjacent bump foil to define a gap therebetween. The inner foil assembly includes a cylindrical inner surface defining a plurality of openings extending radially therethrough. Each opening is radially aligned with one of the lands or one of the gaps between adjacent bump foils.Type: GrantFiled: January 31, 2023Date of Patent: December 26, 2023Assignee: Copeland LPInventors: Patrick Shawn O'Meara, Michael M. Perevozchikov, Zheji Liu
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Publication number: 20230235935Abstract: A system includes a dynamic compressor and a controller having a processor and a memory. The compressor includes a first compressor stage having a first variable inlet guide vane (VIGV) and a second compressor stage having a second VIGV. The memory stores instructions that program the processor to operate the compressor at a current speed, a first position of the first VIGV, and a second position of the second VIGV to compress the working fluid, and to determine if a condition is satisfied. If the condition is not satisfied, the processor is programmed to continue to operate the compressor at the current speed, the first position of the first VIGV, and the second position of the second VIGV. If the condition is satisfied, the processor is programmed to change the second position of the second VIGV to a third position and maintain the first position of the first VIGV.Type: ApplicationFiled: January 27, 2022Publication date: July 27, 2023Inventors: Michael M. Perevozchikov, Matthew J. Swallow, Zheji Liu
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Patent number: 11686341Abstract: A bearing system includes a bearing housing and a foil bearing assembly. The bearing housing includes a sleeve that defines a cylindrical bore and includes at least one bearing assembly locking feature, and a mounting structure. The foil bearing assembly includes an outer foil assembly, an inner foil assembly, and a bump foil assembly positioned between the outer foil assembly and the inner foil assembly. The outer foil assembly includes at least one outer foil pad that extends circumferentially from a first end including a bearing retention feature to a second end. The bearing retention feature is cooperatively engaged with the at least one bearing assembly locking feature. The inner foil assembly includes a plurality of circumferentially-spaced inner foil pads. Each inner foil pad extends circumferentially from a tab to a free end. At least one inner foil pad is welded to the outer foil assembly along the tab.Type: GrantFiled: February 4, 2021Date of Patent: June 27, 2023Assignee: Emerson Climate Technologies, Inc.Inventors: Zheji Liu, Michael M. Perevozchikov
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Patent number: 11644227Abstract: An HVAC system includes an unloading device, a centrifugal compressor, a gas foil bearing, a VFD and a controller. The controller is programmed to start the centrifugal compressor from a stopped condition by operating the unloading device to remove a load from the centrifugal compressor, accelerating the motor to a first speed above a liftoff speed of the gas foil bearing and below an operating speed of the centrifugal compressor, running the motor for a period of time, operating the unloading device to apply the load to the centrifugal compressor, and accelerating the motor to the operating speed.Type: GrantFiled: September 1, 2020Date of Patent: May 9, 2023Assignee: Emerson Climate Technologies, Inc.Inventors: Michael D. Oakley, Zheji Liu, Michael M. Perevozchikov, Matthew J. Swallow
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Patent number: 11560900Abstract: A compressor system includes a compressor housing and a driveshaft rotatably supported within the compressor housing. The compressor system further includes an impeller that imparts kinetic energy to incoming refrigerant gas upon rotation of the driveshaft, a thrust disk coupled to the driveshaft, and a bearing assembly mounted to the compressor housing. The impeller includes an impeller bore having an inner surface, and the thrust disk includes an outer disk and a hub. The bearing assembly rotatably supports the outer disk of the thrust disk. The hub is disposed within the impeller bore, and includes a hub outer surface in contact with the inner surface of the impeller bore. A first contact force between the hub outer surface and the inner surface of the impeller bore increases with increased rotational speed of the driveshaft.Type: GrantFiled: June 9, 2020Date of Patent: January 24, 2023Assignee: Emerson Climate Technologies, Inc.Inventors: Jason Wilkes, Zheji Liu
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Publication number: 20220243762Abstract: A bearing system includes a bearing housing and a foil bearing assembly. The bearing housing includes a sleeve that defines a cylindrical bore and includes at least one bearing assembly locking feature, and a mounting structure. The foil bearing assembly includes an outer foil assembly, an inner foil assembly, and a bump foil assembly positioned between the outer foil assembly and the inner foil assembly. The outer foil assembly includes at least one outer foil pad that extends circumferentially from a first end including a bearing retention feature to a second end. The bearing retention feature is cooperatively engaged with the at least one bearing assembly locking feature. The inner foil assembly includes a plurality of circumferentially-spaced inner foil pads. Each inner foil pad extends circumferentially from a tab to a free end. At least one inner foil pad is welded to the outer foil assembly along the tab.Type: ApplicationFiled: February 4, 2021Publication date: August 4, 2022Inventors: Zheji Liu, Michael M. Perevozchikov
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Patent number: 11306726Abstract: A bearing system includes a bearing housing that includes a sleeve and a mounting structure for connecting the bearing system to a compressor housing. The sleeve has a radial inner surface that defines a cylindrical bore, and includes a locking feature located along the radial inner surface. The mounting structure is located radially outward from the sleeve. The bearing system also includes a foil bearing assembly positioned within the cylindrical bore. The foil bearing assembly includes an outer foil, an inner foil, and a bump foil positioned between the outer foil and the inner foil. At least one of the outer foil and the inner foil includes a bearing retention feature cooperatively engaged with the locking feature to maintain the foil bearing assembly within the bearing housing at a fixed rotational position.Type: GrantFiled: March 5, 2020Date of Patent: April 19, 2022Assignee: Emerson Climate Technologies, Inc.Inventors: Michael M. Perevozchikov, Chris N. Siefring, Craig F. Robillard, Zheji Liu
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Publication number: 20220065513Abstract: An HVAC system includes an unloading device, a centrifugal compressor, a gas foil bearing, a VFD and a controller. The controller is programmed to start the centrifugal compressor from a stopped condition by operating the unloading device to remove a load from the centrifugal compressor, accelerating the motor to a first speed above a liftoff speed of the gas foil bearing and below an operating speed of the centrifugal compressor, running the motor for a period of time, operating the unloading device to apply the load to the centrifugal compressor, and accelerating the motor to the operating speed.Type: ApplicationFiled: September 1, 2020Publication date: March 3, 2022Inventors: Michael D. Oakley, Zheji Liu, Michael M. Perevozchikov, Matthew J. Swallow
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Publication number: 20210381522Abstract: A compressor system includes a compressor housing and a driveshaft rotatably supported within the compressor housing. The compressor system further includes an impeller that imparts kinetic energy to incoming refrigerant gas upon rotation of the driveshaft, a thrust disk coupled to the driveshaft, and a bearing assembly mounted to the compressor housing. The impeller includes an impeller bore having an inner surface, and the thrust disk includes an outer disk and a hub. The bearing assembly rotatably supports the outer disk of the thrust disk. The hub is disposed within the impeller bore, and includes a hub outer surface in contact with the inner surface of the impeller bore. A first contact force between the hub outer surface and the inner surface of the impeller bore increases with increased rotational speed of the driveshaft.Type: ApplicationFiled: June 9, 2020Publication date: December 9, 2021Inventors: Jason Wilkes, Zheji Liu
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Patent number: 10844791Abstract: A gas turbine may include a rotatable shaft, a compressor disposed about the rotatable shaft and configured to output compressed air, and a combustor disposed about the rotatable shaft. The combustor may be configured to receive the compressed air and output high temperature compressed gas. The gas turbine may further include a power turbine disposed about the rotatable shaft and configured to receive the high temperature compressed gas, and a first liner defining a plurality of holes and disposed around the combustor. The power turbine may be configured to expand the high temperature compressed gas and rotate the rotatable shaft. The first liner may have a first end and a longitudinally opposite second end. The first end may be coupled to an inner surface of the casing at or adjacent an upstream end of the combustor and the second end may be substantially free from any connection with the casing.Type: GrantFiled: March 6, 2017Date of Patent: November 24, 2020Assignee: DRESSER-RAND COMPANYInventors: Andrew J. Olsen, Ivar Austrem, Serkan Yildirim, Zheji Liu
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Publication number: 20200291953Abstract: A bearing system includes a bearing housing that includes a sleeve and a mounting structure for connecting the bearing system to a compressor housing. The sleeve has a radial inner surface that defines a cylindrical bore, and includes a locking feature located along the radial inner surface. The mounting structure is located radially outward from the sleeve. The bearing system also includes a foil bearing assembly positioned within the cylindrical bore. The foil bearing assembly includes an outer foil, an inner foil, and a bump foil positioned between the outer foil and the inner foil. At least one of the outer foil and the inner foil includes a bearing retention feature cooperatively engaged with the locking feature to maintain the foil bearing assembly within the bearing housing at a fixed rotational position.Type: ApplicationFiled: March 5, 2020Publication date: September 17, 2020Inventors: Michael M. Perevozchikov, Chris N. Siefring, Craig F. Robillard, Zheji Liu
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Patent number: 10386065Abstract: A system for attenuating acoustic energy in machines is provided. The system may include an inner tube disposed about a central axis, an outer tube disposed about the inner tube and the central axis, and a middle tube disposed about the central axis and between the inner tube and the outer tube. The system may also include a first annular ring extending radially from the outer tube and configured to couple the outer tube to the middle tube. The system may further include a second annular ring extending radially from the inner tube and configured to couple the inner tube to the outer tube, such that an acoustic resonator may be formed by the first annular ring, the second annular ring, a portion of the inner tube, a portion of the outer tube, and a portion of the middle tube.Type: GrantFiled: September 18, 2015Date of Patent: August 20, 2019Assignee: DRESSER-RAND COMPANYInventor: Zheji Liu
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Patent number: 10119554Abstract: A compressor and a method for reducing acoustic energy generated in the compressor are provided. The compressor may include a housing defining a fluid pathway and a shunt hole fluidly coupling the fluid pathway with another component of the compressor. The compressor may also include an impeller at least partially disposed in the fluid pathway and coupled with a rotary shaft. The impeller may be configured to rotate with the rotary shaft to direct a process fluid through the fluid pathway of the compressor. A disk may be disposed between the fluid pathway and the shunt hole. The disk may define a plurality of openings fluidly coupling the fluid pathway with the shunt hole and configured to reduce acoustic energy generated in the compressor.Type: GrantFiled: August 12, 2014Date of Patent: November 6, 2018Assignee: DRESSER-RAND COMPANYInventors: Zheji Liu, Scott D. Wisler
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Patent number: 10062369Abstract: An acoustic resonator assembly may include a first acoustic liner and a second acoustic liner. The first acoustic liner may define a first plurality of openings extending between first and second surfaces thereof. The second acoustic liner may be rotatably coupled to the first acoustic liner and at least one of the first acoustic liner and the second acoustic liner may be configured to rotate relative to each other to attenuate one or more frequencies of acoustic energy generated by working fluid flowing past the acoustic resonator assembly. The second acoustic liner may define a second plurality of openings extending between first and second surfaces thereof. A number of degrees of freedom of the acoustic resonator assembly may be varied by rotating the first acoustic liner and/or the second acoustic liner.Type: GrantFiled: July 7, 2017Date of Patent: August 28, 2018Assignees: DRESSER-RAND COMPANY, KING FAHD UNIVERSITY OF PETROLEUM AND MINERALSInventors: Samir N. Mekid, Muhammad A. Hawwa, Zheji Liu
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Publication number: 20170309264Abstract: An acoustic resonator assembly may include a first acoustic liner and a second acoustic liner. The first acoustic liner may define a first plurality of openings extending between first and second surfaces thereof. The second acoustic liner may be rotatably coupled to the first acoustic liner and at least one of the first acoustic liner and the second acoustic liner may be configured to rotate relative to each other to attenuate one or more frequencies of acoustic energy generated by working fluid flowing past the acoustic resonator assembly. The second acoustic liner may define a second plurality of openings extending between first and second surfaces thereof. A number of degrees of freedom of the acoustic resonator assembly may be varied by rotating the first acoustic liner and/or the second acoustic liner.Type: ApplicationFiled: July 7, 2017Publication date: October 26, 2017Inventors: Samir N. Mekid, Muhammad A. Hawwa, Zheji Liu
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Patent number: 9728177Abstract: An acoustic resonator assembly may include a first acoustic liner and a second acoustic liner. The first acoustic liner may define a first plurality of openings extending between first and second surfaces thereof. The second acoustic liner may be rotatably coupled to the first acoustic liner and at least one of the first acoustic liner and the second acoustic liner may be configured to rotate relative to each other to attenuate one or more frequencies of acoustic energy generated by working fluid flowing past the acoustic resonator assembly. The second acoustic liner may define a second plurality of openings extending between first and second surfaces thereof. A number of degrees of freedom of the acoustic resonator assembly may be varied by rotating the first acoustic liner and/or the second acoustic liner.Type: GrantFiled: February 5, 2015Date of Patent: August 8, 2017Assignees: Dresser-Rand Company, KING FAHD UNIVERSITY OF PETROLEUM AND MINERALSInventors: Samir N. Mekid, Muhammad A. Hawwa, Zheji Liu
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Publication number: 20170219207Abstract: A system for attenuating acoustic energy in machines is provided. The system may include an inner tube disposed about a central axis, an outer tube disposed about the inner tube and the central axis, and a middle tube disposed about the central axis and between the inner tube and the outer tube. The system may also include a first annular ring extending radially from the outer tube and configured to couple the outer tube to the middle tube. The system may further include a second annular ring extending radially from the inner tube and configured to couple the inner tube to the outer tube, such that an acoustic resonator may be formed by the first annular ring, the second annular ring, a portion of the inner tube, a portion of the outer tube, and a portion of the middle tube.Type: ApplicationFiled: September 18, 2015Publication date: August 3, 2017Inventor: Zheji LIU
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Publication number: 20170175641Abstract: A gas turbine may include a rotatable shaft, a compressor disposed about the rotatable shaft and configured to output compressed air, and a combustor disposed about the rotatable shaft. The combustor may be configured to receive the compressed air and output high temperature compressed gas. The gas turbine may further include a power turbine disposed about the rotatable shaft and configured to receive the high temperature compressed gas, and a first liner defining a plurality of holes and disposed around the combustor. The power turbine may be configured to expand the high temperature compressed gas and rotate the rotatable shaft. The first liner may have a first end and a longitudinally opposite second end. The first end may be coupled to an inner surface of the casing at or adjacent an upstream end of the combustor and the second end may be substantially free from any connection with the casing.Type: ApplicationFiled: March 6, 2017Publication date: June 22, 2017Inventors: Andrew J. Olsen, Ivar Austrem, Serkan Yildirim, Zheji Liu
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Patent number: 9625158Abstract: A gas turbine may include a rotatable shaft, a compressor disposed about the rotatable shaft and configured to output compressed air, and a combustor disposed about the rotatable shaft. The combustor may be configured to receive the compressed air and output high temperature compressed gas. The gas turbine may further include a power turbine disposed about the rotatable shaft and configured to receive the high temperature compressed gas, and a first liner defining a plurality of holes and disposed around the combustor. The power turbine may be configured to expand the high temperature compressed gas and rotate the rotatable shaft. The first liner may have a first end and a longitudinally opposite second end. The first end may be coupled to an inner surface of the casing at or adjacent an upstream end of the combustor and the second end may be substantially free from any connection with the casing.Type: GrantFiled: December 11, 2014Date of Patent: April 18, 2017Assignee: Dresser-Rand CompanyInventors: Andrew J. Olsen, Ivar Austrem, M. Serkan Yildirim, Zheji Liu