Patents by Inventor Zongtao Lu
Zongtao Lu 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: 11293677Abstract: A cooler system includes a plurality of cooler units; a condensed water flow path, an aqueous medium in the condensed water flow path sequentially flowing through each of the cooler units; a cooling water flow path, an aqueous medium in the cooling water flow path sequentially flowing through each of the cooler units in a flow direction opposite to a flow direction of the aqueous medium in the condensed water flow path; a plurality of current sensors used for detecting working currents of the cooler units; water temperature sensors used for detecting an entering water temperature and a leaving water temperature of the cooling water flow path; at least one virtual temperature sensor arranged between the cooler units and used for acquiring a middle water temperature between the cooler units; and a controller.Type: GrantFiled: April 12, 2017Date of Patent: April 5, 2022Assignee: CARRIER CORPORATIONInventors: Xing Cai, Zhongjian Li, Yuanming Yuan, Zongtao Lu, Junqiang Fan, Shufu Ding, Hong Zhang
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Publication number: 20190137155Abstract: A cooler system includes a plurality of cooler units; a condensed water flow path, an aqueous medium in the condensed water flow path sequentially flowing through each of the cooler units; a cooling water flow path, an aqueous medium in the cooling water flow path sequentially flowing through each of the cooler units in a flow direction opposite to a flow direction of the aqueous medium in the condensed water flow path; a plurality of current sensors used for detecting working currents of the cooler units; water temperature sensors used for detecting an entering water temperature and a leaving water temperature of the cooling water flow path; at least one virtual temperature sensor arranged between the cooler units and used for acquiring a middle water temperature between the cooler units; and a controller.Type: ApplicationFiled: April 12, 2017Publication date: May 9, 2019Inventors: Xing Cai, Zhongjian Li, Yuanming Yuan, Zongtao Lu, Junqiang Fan, Shufu Ding, Hong Zhang
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Load estimator for control of vapor compression cooling system with pumped refrigerant economization
Patent number: 9845981Abstract: A cooling system has a direct expansion mode and a pumped refrigerant economizer mode and a controller. The controller includes a load estimator that estimates real-time indoor load on the cooling system and uses the estimated real-time indoor load to determine whether to operate the cooling system in the pumped refrigerant economizer mode or in the direct expansion mode.Type: GrantFiled: October 4, 2013Date of Patent: December 19, 2017Assignee: Liebert CorporationInventors: Zongtao Lu, Greg Haggy, Timothy J. Schrader, Stephen Sillato, John F. Judge -
Patent number: 9746224Abstract: A system includes an error module configured to integrate a difference between a superheat signal and a superheat setpoint to generate an error signal, wherein the superheat signal indicates suction superheat values of a compressor. A comparison module is configured to compare the error signal to a first predetermined threshold to generate a first comparison signal based on the comparison. A zero-crossing module is configured to compare a first count value to a second predetermined threshold to generate a second comparison signal. The first count value is generated based on at least one comparison between the superheat signal and the superheat setpoint. A setpoint module is configured to adjust the superheat setpoint based on the first comparison signal and the second comparison signal.Type: GrantFiled: November 13, 2013Date of Patent: August 29, 2017Assignee: Liebert CorporationInventors: Zongtao Lu, Zhiyong Lin, Craig Ward, Benedict J. Dolcich, John F. Judge
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Publication number: 20160061495Abstract: A cooling system has a cooling circuit that includes an evaporator disposed in a cabinet, a condenser, a compressor, a liquid/vapor separator tank and a liquid pump. The cooling circuit has a mode wherein the compressor and liquid pump are both on with the liquid pump pumping refrigerant through the evaporator with the refrigerant leaving the evaporator circulated to an inlet of the liquid/vapor separator tank and not to an inlet of the condenser. The cooling circuit also has a pumped refrigerant economizer mode wherein the liquid pump is on and the compressor is off and bypassed with the refrigerant leaving the evaporator circulated to the inlet of the condenser and not to the inlet of the liquid/vapor separator tank.Type: ApplicationFiled: October 9, 2015Publication date: March 3, 2016Applicant: LIEBERT CORPORATIONInventors: Stephen Sillato, Timothy J. Schrader, Greg Haggy, Thomas Harvey, Zongtao Lu, John F. Judge
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Patent number: 9038404Abstract: A cooling system has a cabinet and a plurality of separate cooling stages including an upstream cooling stage and a downstream cooling stage. At least the upstream cooling state is a variable capacity cooling stage. Each cooling stage has a cooling circuit. Evaporators of the cooling circuits are arranged in the cabinet so that air passes over them in serial fashion. A controller when a Call for Cooling first reaches a point where cooling is needed, operating the upstream cooling circuit to provide cooling and not the downstream cooling circuit. When the Call for Cooling has increased to a second point, the controller additionally operates the downstream cooling circuit to provide cooling. The cooling capacity at which the upstream cooling circuit is being operated is less than its full capacity when the Call for Cooling reaches the second point.Type: GrantFiled: April 13, 2012Date of Patent: May 26, 2015Assignee: Liebert CorporationInventors: John F. Judge, Timothy J. Schrader, Stephen Sillato, Roger Noll, Gary A. Helmink, Pierpaolo Barbato, Giuseppe Dalla Mana, Lou Monnier, Zhiyong Lin, Benedict J. Dolcich, Daniel J. Schutte, Greg Haggy, Thomas Harvey, Zongtao Lu
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Publication number: 20140137585Abstract: A system includes an error module configured to integrate a difference between a superheat signal and a superheat setpoint to generate an error signal, wherein the superheat signal indicates suction superheat values of a compressor. A comparison module is configured to compare the error signal to a first predetermined threshold to generate a first comparison signal based on the comparison. A zero-crossing module is configured to compare a first count value to a second predetermined threshold to generate a second comparison signal. The first count value is generated based on at least one comparison between the superheat signal and the superheat setpoint. A setpoint module is configured to adjust the superheat setpoint based on the first comparison signal and the second comparison signal.Type: ApplicationFiled: November 13, 2013Publication date: May 22, 2014Inventors: Zongtao LU, Zhiyong LIN, Craig WARD, Benedict J. DOLCICH, John F. JUDGE
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Load Estimator For Control Of Vapor Compression Cooling System With Pumped Refrigerant Economization
Publication number: 20140033753Abstract: A cooling system has a direct expansion mode and a pumped refrigerant economizer mode and a controller. The controller includes a load estimator that estimates real-time indoor load on the cooling system and uses the estimated real-time indoor load to determine whether to operate the cooling system in the pumped refrigerant economizer mode or in the direct expansion mode.Type: ApplicationFiled: October 4, 2013Publication date: February 6, 2014Inventors: Zongtao LU, Greg HAGGY, Timothy J. SCHRADER, Stephen SILLATO, John F. JUDGE -
Publication number: 20130139529Abstract: An air conditioner system including a condenser fan, an ambient temperature sensor, a refrigerant pressure sensor, and a controller. The ambient temperature sensor is to sense ambient temperature at the system. The refrigerant pressure sensor is to sense pressure of a refrigerant of the system. The target refrigerant pressure module is to identify an optimum pressure of the refrigerant in the system. The controller is to generate an output representing a speed of the condenser fan operable to maintain the pressure of the refrigerant at about the optimum pressure as the ambient temperature of the system changes.Type: ApplicationFiled: June 7, 2012Publication date: June 6, 2013Applicant: LIEBERT CORPORATIONInventors: Zongtao Lu, Jianping Li, Hongyu Zhang, Wanlai Lin, Stephen Sillato, Roger Noll, John F. Judge, Yizhou Fan, Craig Ward
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Publication number: 20130098085Abstract: A cooling system has a cabinet and a plurality of separate cooling stages including an upstream cooling stage and a downstream cooling stage. At least the upstream cooling state is a variable capacity cooling stage. Each cooling stage has a cooling circuit. Evaporators of the cooling circuits are arranged in the cabinet so that air passes over them in serial fashion. A controller when a Call for Cooling first reaches a point where cooling is needed, operating the upstream cooling circuit to provide cooling and not the downstream cooling circuit. When the Call for Cooling has increased to a second point, the controller additionally operates the downstream cooling circuit to provide cooling. The cooling capacity at which the upstream cooling circuit is being operated is less than its full capacity when the Call for Cooling reaches the second point.Type: ApplicationFiled: April 13, 2012Publication date: April 25, 2013Applicant: Liebert CorporationInventors: John F. Judge, Timothy J. Schrader, Stephen Sillato, Roger Noll, Gary A. Helmink, Pierpaolo Barbato, Giuseppe Dalla Mana, Lou Monnier, Zhiyong Lin, Benedict J. Dolcich, Daniel J. Schutte, Greg Haggy, Thomas Harvey, Zongtao Lu
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Publication number: 20130098086Abstract: A cooling system has a cooling circuit that includes an evaporator disposed in a cabinet, a condenser, a compressor, an electronic expansion valve and a liquid pump. a direct expansion mode and a pumped refrigerant economizer mode. When the cooling system is in the pumped refrigerant economizer mode, the controller controls a temperature of the refrigerant to a refrigerant temperature set point by regulating a speed of a fan of the condenser, controls a temperature of air in a room in which the cabinet is disposed to a room air temperature setpoint by regulating a speed of the liquid pump, and maintains a pressure differential across the liquid pump within a given range by regulating an open position of an electronic expansion valve.Type: ApplicationFiled: April 13, 2012Publication date: April 25, 2013Applicant: Liebert CorporationInventors: Stephen Sillato, Timothy J. Schrader, Greg Haggy, Thomas Harvey, Zongtao Lu, John F. Judge
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Publication number: 20120291984Abstract: An air conditioner system including an indoor unit and an outdoor unit. The outdoor unit includes a condenser, a temperature sensor, a pressure sensor, and a controller. The controller detects a fault with at least one of the temperature sensor or the pressure sensor and adjusts a speed of the condensing fan according to the pressure identified by the pressure sensor when the pressure sensor is operating normally. The controller adjusts the speed of the condensing fan according to the sensed temperature sensor when the pressure experiences a fault and the temperature sensor is operating normally. The controller controls the speed of the condensing fan according to default values when both the pressure sensor and the temperature sensor experience a fault.Type: ApplicationFiled: November 14, 2011Publication date: November 22, 2012Applicant: Liebert CorporationInventors: Jianping Li, Lin Wang, Zheng Wang, Xianyao Yu, Hongyu Zhang, Zongtao Lu, Wanlai Lin, Stephen Sillato, John Judge