Patents by Inventor Shitong Zha

Shitong Zha 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).

  • Publication number: 20210180851
    Abstract: A cooling system is provided that partially floods one of its freezers (e.g., the ice cream freezer) such that the refrigerant discharged by the freezer includes a liquid component. In this manner, the freezers in the system can operate at the same saturated suction temperature. A heat exchanger can be used to transfer heat to the liquid component of the discharge to evaporate the liquid component.
    Type: Application
    Filed: December 17, 2019
    Publication date: June 17, 2021
    Inventor: Shitong Zha
  • Publication number: 20210180846
    Abstract: A cooling system is designed to generally allow for one or more compressors to be bypassed when ambient temperatures are low. The system includes a bypass line and valve that opens when ambient temperatures are low and/or when the pressure of the refrigerant in the system is low. In this manner, the refrigerant can flow through the bypass line instead of through one or more compressors. These compressors may then be shut off. To supply any needed pressure to cycle the refrigerant, the system may include a pump that turns on when the bypass line is open. When ambient temperatures are extremely low, thermosiphon may be used to cycle the refrigerant.
    Type: Application
    Filed: December 17, 2019
    Publication date: June 17, 2021
    Inventor: Shitong Zha
  • Patent number: 11035599
    Abstract: An apparatus includes a flash tank that stores a refrigerant, a first load that uses the refrigerant to cool a first space, second and third loads, first and second compressors, and a valve. During a first mode of operation: the second load uses the refrigerant to cool a second space, the third load uses the refrigerant to cool a third space, the second compressor compresses the refrigerant from the second and third loads, and the first compressor compresses the refrigerant from the first load and the second compressor. During a second mode of operation: the second compressor compresses the refrigerant from the second load and directs the compressed refrigerant to the third load to defrost the third load and the valve prevents the refrigerant at the third load from flowing to the flash tank until a pressure of the refrigerant at the third load exceeds a threshold.
    Type: Grant
    Filed: July 2, 2019
    Date of Patent: June 15, 2021
    Assignee: Heatcraft Refrigeration Products LLC
    Inventors: Michael Hollister, Shitong Zha
  • Patent number: 11009266
    Abstract: A system includes a high side heat exchanger, a flash tank, an air conditioner load, an air conditioner ejector, a refrigeration load, a first compressor, a second compressor, and a vapor ejector. The high side heat exchanger removes heat from a refrigerant. The flash tank stores the refrigerant from the high side heat exchanger. The air conditioner load uses the refrigerant from the flash tank to remove heat from a first space proximate the air conditioner load. The air conditioner ejector pumps the refrigerant from the air conditioner load to the flash tank. The refrigeration load uses the refrigerant from the flash tank to remove heat from a second space proximate the refrigeration load. The first compressor compresses the refrigerant from the refrigeration load. The second compressor compresses a flash gas from the flash tank. The vapor ejector pumps the refrigerant from the refrigeration load to the flash tank.
    Type: Grant
    Filed: March 2, 2017
    Date of Patent: May 18, 2021
    Assignee: Heatcraft Refrigeration Products LLC
    Inventors: Shitong Zha, Masood Ali
  • Patent number: 10962266
    Abstract: An apparatus includes a high side heat exchanger, a subcooler heat exchanger, a flash tank, a load, and a compressor. The high side heat exchanger removes heat from a refrigerant. The subcooler heat exchanger receives the refrigerant. The flash tank stores the refrigerant. During a first mode of operation, the load uses the refrigerant to cool a space proximate the load and the compressor compresses the refrigerant. During a second mode of operation, the subcooler heat exchanger receives the refrigerant from the flash tank, transfers heat from the refrigerant from the high side heat exchanger to the refrigerant from the flash tank and directs the refrigerant from the flash tank to the compressor. During the second mode of operation, the compressor compresses the refrigerant from the subcooler heat exchanger and directs the compressed refrigerant to the load to defrost the load.
    Type: Grant
    Filed: October 24, 2018
    Date of Patent: March 30, 2021
    Assignee: Heatcraft Refrigeration Products, LLC
    Inventors: Shitong Zha, Michael Hollister
  • Patent number: 10895411
    Abstract: An apparatus includes a high side heat exchanger, a flash tank, a subcooler, an expansion valve, a load, and a compressor. The high side heat exchanger removes heat from a refrigerant. The flash tank stores the refrigerant. The subcooler heat exchanger receives the refrigerant. During a first mode of operation, the load uses the refrigerant to cool a space proximate the load and the compressor compresses the refrigerant. During a second mode of operation, the subcooler heat exchanger directs the refrigerant to the expansion valve, transfers heat from the refrigerant from the flash tank to the refrigerant from the expansion valve and directs the refrigerant from the expansion valve to the compressor. During the second mode of operation, the compressor compresses the refrigerant from the subcooler heat exchanger and directs the compressed refrigerant from the subcooler heat exchanger to the load to defrost the first load.
    Type: Grant
    Filed: October 24, 2018
    Date of Patent: January 19, 2021
    Assignee: Heatcraft Refrigeration Products LLC
    Inventors: Shitong Zha, Michael Hollister
  • Publication number: 20210003331
    Abstract: An apparatus includes a flash tank that stores a refrigerant, a first load that uses the refrigerant to cool a first space, second and third loads, first and second compressors, and a valve. During a first mode of operation: the second load uses the refrigerant to cool a second space, the third load uses the refrigerant to cool a third space, the second compressor compresses the refrigerant from the second and third loads, and the first compressor compresses the refrigerant from the first load and the second compressor. During a second mode of operation: the second compressor compresses the refrigerant from the second load and directs the compressed refrigerant to the third load to defrost the third load and the valve prevents the refrigerant at the third load from flowing to the flash tank until a pressure of the refrigerant at the third load exceeds a threshold.
    Type: Application
    Filed: July 2, 2019
    Publication date: January 7, 2021
    Inventors: Michael Hollister, Shitong Zha
  • Publication number: 20200400349
    Abstract: A system includes a high side heat exchanger, a flash tank, a first load, a second load, and a thermal storage tank. The high side heat exchanger is configured to remove heat from a refrigerant. The flash tank is configured to store the refrigerant from the high side heat exchanger and discharge a flash gas. The first load is configured to use the refrigerant from the flash tank to remove heat from a first space proximate to the first load. The second load is configured to use the refrigerant from the flash tank to remove heat from a second space proximate to the second load. The thermal storage tank is configured, when a power outage is determined to be occurring, to receive the flash gas from the flash tank, and remove heat from the flash gas.
    Type: Application
    Filed: September 2, 2020
    Publication date: December 24, 2020
    Inventors: Shitong Zha, Fardis Najafifard, Xi Sun
  • Publication number: 20200363102
    Abstract: An integrated system floods an air conditioning low side heat exchanger such that the air conditioning low side heat exchanger does not evaporate all the liquid refrigerant entering the air conditioning low side heat exchanger. As a result, both liquid and vapor refrigerant leave the air conditioning low side heat exchanger. The system includes an additional receiver that stores the refrigerant leaving the air conditioning low side heat exchanger. To prevent the liquid refrigerant in the receiver from overflowing, the liquid refrigerant in the receiver is used in a refrigeration system when the level of liquid refrigerant in the receiver exceeds a threshold (e.g., as detected by a sensor in the receiver).
    Type: Application
    Filed: December 19, 2019
    Publication date: November 19, 2020
    Inventor: Shitong Zha
  • Patent number: 10808966
    Abstract: A system includes a high side heat exchanger, a first load, a second load, a third load, a first compressor, a second compressor, a third compressor, and a fourth compressor. The high side heat exchanger removes heat from a refrigerant. The first load uses the refrigerant to remove heat from a first space proximate the first load. The second load uses the refrigerant to remove heat from a second space proximate the second load. The third load uses the refrigerant to remove heat from a third space proximate the third load. The first compressor compresses the refrigerant from the first load. The second compressor compresses the refrigerant from the second load. The third compressor compresses the refrigerant from the third load and the refrigerant from the second compressor. The fourth compressor compresses the refrigerant from the first compressor.
    Type: Grant
    Filed: March 2, 2017
    Date of Patent: October 20, 2020
    Assignee: Heatcraft Refrigeration Products LLC
    Inventor: Shitong Zha
  • Patent number: 10808975
    Abstract: An apparatus includes a flash tank, a medium temperature low side heat exchanger, a low temperature low side heat exchanger, a first compressor, a second compressor, and an ejector. The flash tank stores a refrigerant. The medium temperature low side heat exchanger uses the refrigerant from the flash tank to cool a space proximate the medium temperature low side heat exchanger to a first temperature. The low temperature low side heat exchanger uses the refrigerant from the flash tank to cool a space proximate the low temperature low side heat exchanger to a second temperature that is lower than the first temperature. The first compressor compresses the refrigerant from the low temperature low side heat exchanger. The second compressor compresses the refrigerant from the medium temperature low side heat exchanger. The ejector directs a mixture of the refrigerant from the first compressor and the refrigerant from the second compressor to the low temperature low side heat exchanger during a defrost cycle.
    Type: Grant
    Filed: June 6, 2018
    Date of Patent: October 20, 2020
    Assignee: Heatcraft Refrigeration Products LLC
    Inventor: Shitong Zha
  • Patent number: 10782055
    Abstract: An apparatus includes an ejector, a first load, a second load, a third load, a first compressor, a second compressor, and an accumulator. The ejector directs a refrigerant to a flash tank that stores the refrigerant. The loads use the refrigerant from the flash tank to cool spaces. The first compressor compresses the refrigerant from the first load. During a defrost cycle, the first compressor directs the refrigerant to the third load to defrost the third load, the accumulator separates the refrigerant that defrosted the third load into a second liquid portion and a second vapor portion, the ejector directs the second liquid portion to the flash tank, and the second compressor compresses the second vapor portion.
    Type: Grant
    Filed: December 18, 2018
    Date of Patent: September 22, 2020
    Assignee: Heatcraft Refrigeration Products LLC
    Inventors: Shitong Zha, Xi Sun
  • Patent number: 10767911
    Abstract: An apparatus includes a flash tank, a load, a first compressor, a heat exchanger, and a second compressor. The flash tank stores a refrigerant and releases the refrigerant as a flash gas. The load uses the refrigerant to remove heat from a space proximate the load. The first compressor compresses the refrigerant from the load and directs the refrigerant to the flash tank. The heat exchanger transfers heat from the refrigerant from a high side heat exchanger to the refrigerant released from the flash tank as the flash gas. The second compressor compresses the refrigerant released from the flash tank as the flash gas.
    Type: Grant
    Filed: November 21, 2017
    Date of Patent: September 8, 2020
    Assignee: Heatcraft Refrigeration Products LLC
    Inventor: Shitong Zha
  • Patent number: 10767909
    Abstract: A system includes a high side heat exchanger, a flash tank, a first load, a second load, and a thermal storage tank. The high side heat exchanger is configured to remove heat from a refrigerant. The flash tank is configured to store the refrigerant from the high side heat exchanger and discharge a flash gas. The first load is configured to use the refrigerant from the flash tank to remove heat from a first space proximate to the first load. The second load is configured to use the refrigerant from the flash tank to remove heat from a second space proximate to the second load. The thermal storage tank is configured, when a power outage is determined to be occurring, to receive the flash gas from the flash tank, and remove heat from the flash gas.
    Type: Grant
    Filed: August 2, 2017
    Date of Patent: September 8, 2020
    Assignee: Heatcraft Refrigeration Products LLC
    Inventors: Shitong Zha, Fardis Najafifard, Xi Sun
  • Patent number: 10767906
    Abstract: A system includes a high side heat exchanger, a first load, a second load, a first compressor, a second compressor, and a third compressor. The high side heat exchanger removes heat from a refrigerant. The first load uses the refrigerant to remove heat from a first space proximate the first load. The second load uses the refrigerant to remove heat from a second space proximate the second load. The first compressor compresses the refrigerant from the first load and sends the refrigerant to the first load. The refrigerant defrosts the first load. The second compressor compresses the refrigerant from the second load and the refrigerant from the first load that defrosted the first load. The third compressor compresses the refrigerant from the first compressor.
    Type: Grant
    Filed: March 2, 2017
    Date of Patent: September 8, 2020
    Assignee: Heatcraft Refrigeration Products LLC
    Inventors: Shitong Zha, Xi Sun
  • Publication number: 20200256602
    Abstract: An apparatus includes a high side heat exchanger, a heat exchanger, a flash tank, a first expansion valve, a second expansion valve, a load, a first compressor, and a second compressor. During a first mode of operation, the second expansion valve directs refrigerant from the flash tank to the load. The refrigerant from the load bypasses the first compressor. The heat exchanger transfers heat from the refrigerant from the high side heat exchanger to the refrigerant from the load. The second compressor compresses the refrigerant from the heat exchanger. During a second mode of operation, the first expansion valve directs refrigerant from the flash tank to the load. The first compressor compresses the refrigerant from the load and the second compressor compresses the refrigerant from the first compressor before the refrigerant from the first compressor reaches the high side heat exchanger.
    Type: Application
    Filed: February 7, 2019
    Publication date: August 13, 2020
    Inventor: Shitong Zha
  • Publication number: 20200256599
    Abstract: An apparatus includes a high side heat exchanger, a flash tank, a load, a compressor, and a heat exchanger. The high side heat exchanger removes heat from a refrigerant. The flash tank stores the refrigerant from the high side heat exchanger and to discharge a flash gas. The load uses the refrigerant from the cool a space proximate the load. The compressor compresses the refrigerant from the load. The heat exchanger transfers heat from the refrigerant from the compressor to the flash gas before the refrigerant from the compressor reaches the high side heat exchanger. The heat exchanger directs the flash gas to the compressor after heat from the refrigerant from the compressor is transferred to the flash gas and directs the refrigerant from the compressor to the high side heat exchanger after heat from the refrigerant from the compressor is transferred to the flash gas.
    Type: Application
    Filed: February 7, 2019
    Publication date: August 13, 2020
    Inventors: Shitong Zha, Xi Sun
  • Publication number: 20200217562
    Abstract: An apparatus includes a first expander, a flash tank, a first load, a first work recovery compressor, a valve, and a first compressor. The first expander expands a refrigerant. The flash tank stores a refrigerant from the expander. The first load uses the refrigerant from the flash tank to cool a space proximate the first load. The work recovery compressor compresses the refrigerant from the first load and is driven by the first expander. The valve reduces the pressure of the refrigerant from the work recovery compressor below a threshold. The first compressor compresses the refrigerant from the valve.
    Type: Application
    Filed: January 9, 2019
    Publication date: July 9, 2020
    Inventors: Xi Sun, Shitong Zha
  • Publication number: 20200191457
    Abstract: An apparatus includes an ejector, a first load, a second load, a third load, a first compressor, a second compressor, and an accumulator. The ejector directs a refrigerant to a flash tank that stores the refrigerant. The loads use the refrigerant from the flash tank to cool spaces. The first compressor compresses the refrigerant from the first load. During a defrost cycle, the first compressor directs the refrigerant to the third load to defrost the third load, the accumulator separates the refrigerant that defrosted the third load into a second liquid portion and a second vapor portion, the ejector directs the second liquid portion to the flash tank, and the second compressor compresses the second vapor portion.
    Type: Application
    Filed: December 18, 2018
    Publication date: June 18, 2020
    Inventors: Shitong Zha, Xi Sun
  • Patent number: 10663196
    Abstract: An apparatus includes a flash tank, a load, a first compressor, a coil, a first pipe, and a second compressor. The flash tank stores a refrigerant. The load uses the refrigerant from the flash tank to cool a space proximate the load. The first compressor compresses the refrigerant from the load. The coil within the flash tank receives the refrigerant from the first compressor such that the received refrigerant is within the coil. The refrigerant stored within the flash tank cools the refrigerant within the coil. The first pipe is within the flash tank. The first pipe directs the refrigerant from within the coil out of the flash tank. The second compressor compresses the refrigerant directed out of the flash tank.
    Type: Grant
    Filed: June 5, 2018
    Date of Patent: May 26, 2020
    Assignee: Heatcraft Refrigeration Products LLC
    Inventor: Shitong Zha