Refrigeration system with tandem high-side compressors

Patent metadata

Field	Value
Publication number	US-2023213255-A1
Application number	US-202318149944-A
Country	US
Kind code	A1
Filing date	Jan 4, 2023
Priority date	Jan 4, 2022
Publication date	Jul 6, 2023
Grant date	—

Abstract

A refrigeration system is provided and includes a common suction line, a common discharge line, first and second high-side compressors disposed in parallel to receive low-pressure refrigerant from the common suction line and to direct high-pressure refrigerant to the common discharge line, a first pipe connected to the first and second high-side compressors at vertical heights at which an oil supply is required to remain higher and a second pipe connected to the first and second high-side compressors at vertical heights sufficient to maintain gas pressure balance between the first and second high-side compressors.

First claim

What is claimed is:

1 . A refrigeration system, comprising:
a common suction line; a common discharge line; first and second high-side compressors disposed in parallel to receive low-pressure refrigerant from the common suction line and to direct high-pressure refrigerant to the common discharge line; a first pipe connected to the first and second high-side compressors at vertical heights at which an oil supply is required to remain higher; and a second pipe connected to the first and second high-side compressors at vertical heights sufficient to maintain gas pressure balance between the first and second high-side compressors.

2 . The refrigeration system according to claim 1 , further comprising:
an evaporator from which the common suction line carries the low-pressure refrigerant; a condenser to which the common discharge line carries the high-pressure refrigerant; and an expansion valve fluidly interposed between the condenser and the evaporator.

3 . The refrigeration system according to claim 1 , wherein the first pipe includes a valve and the second pipe includes a valve.

4 . The refrigeration system according to claim 1 , wherein each of the first and second high-side compressors comprises:
a shell to define an interior; a compressor section disposed within the interior to compress the low-pressure refrigerant; and a motor disposed within the interior at a location, which is closer to the common discharge line than the common suction line, to drive operations of the compressor section.

5 . The refrigeration system according to claim 4 , wherein the first pipe allows oil to pass between the shell of each of the first and second high-side compressors.

6 . The refrigeration system according to claim 4 , wherein the motor comprises a stator and the shell defines a flow path by which gas flows about the stator for each of the first and second high-side compressors.

7 . The refrigeration system according to claim 6 , wherein the second pipe is connected to the shell of each of the first and second high-side compressors above the motor and opposite the flow path.

8 . The refrigeration system according to claim 4 , wherein the second pipe is positioned to minimize a shell pressure difference between the first and second high-side compressors.

9 . A refrigeration system, comprising:
a common suction line; a common discharge line; and first and second high-side compressors disposed in parallel to receive low-pressure refrigerant from the common suction line and to direct high-pressure refrigerant to the common discharge line, the first high-side compressor comprising a fixed speed compressor, and the second high-side compressor comprising a variable speed compressor.

10 . The refrigeration system according to claim 9 , further comprising:
an evaporator from which the common suction line carries the low-pressure refrigerant; a condenser to which the common discharge line carries the high-pressure refrigerant; and an expansion valve fluidly interposed between the condenser and the evaporator.

11 . The refrigeration system according to claim 9 , wherein:
the variable speed compressor has a capacity of a percentage of a total refrigeration system capacity requirement, and the fixed speed compressor has a capacity of a remainder of the total refrigeration system capacity requirement.

12 . The refrigeration system according to claim 9 , wherein each of the first and second high-side compressors comprises:
a shell to define an interior; a compressor section disposed within the interior to compress the low-pressure refrigerant; and a motor disposed within the interior at a location, which is closer to the common discharge line than the common suction line, to drive operations of the compressor section.

13 . The refrigeration system according to claim 9 , further comprising:
a first pipe connected to the first and second high-side compressors at vertical heights at which an oil supply is required to remain higher; and a second pipe connected to the first and second high-side compressors at vertical heights sufficient to maintain gas pressure balance between the first and second high-side compressors.

14 . The refrigeration system according to claim 13 , wherein the first pipe includes a valve and the second pipe includes a valve.

15 . The refrigeration system according to claim 13 , wherein the first pipe allows oil to pass between a shell of each of the first and second high-side compressors.

16 . The refrigeration system according to claim 13 , wherein a motor drives a compressor section and comprises a stator and a shell defines a flow path by which gas flows about the stator for each of the first and second high-side compressors.

17 . The refrigeration system according to claim 16 , wherein the second pipe is connected to the shell of each of the first and second high-side compressors above the motor and opposite the flow path.

18 . The refrigeration system according to claim 13 , wherein the second pipe is positioned to minimize a shell pressure difference between the first and second high-side compressors.

19 . A method of operating a refrigeration system, the method comprising:
operating first and second high-side compressors in parallel to receive low-pressure refrigerant from the common suction line and to direct high-pressure refrigerant to the common discharge line; maintaining an oil level within a shell of each of the first and second high-side compressors above respective oil equalization line connection heights; and maintaining a gas balance between the first and second high-side compressors via a gas equalization line connected to the respective shells above respective motors thereof and opposite respective flow paths by which gas flows about respective stators of the respective motors.

20 . The method according to claim 19 , wherein:
the first high-side compressor comprises a fixed speed compressor and the second high-side compressor comprises a variable speed compressor, the variable speed compressor has a capacity of a percentage of a total refrigeration system capacity requirement, and the fixed speed compressor has a capacity of a rest of the total refrigeration system capacity requirement.

Assignees

• Carrier Corp

Inventors

• Clark Matthew
• Mahmoud Ahmad M
• Healey Alexander
• Lee Jun Pyo

Classifications

• F25B49/022 Primary

  Compressor control arrangements · CPC title

• F25B31/002

  Lubrication · CPC title

• F25B31/02

  of motor-compressor units · CPC title

• F25B2600/0253

  with variable speed · CPC title

• F25B2500/05

  Cost reduction · CPC title