Compressor system including a plurality of compressors

Patent metadata

Field	Value
Publication number	US-10330093-B2
Application number	US-201615209165-A
Country	US
Kind code	B2
Filing date	Jul 13, 2016
Priority date	Jul 14, 2015
Publication date	Jun 25, 2019
Grant date	Jun 25, 2019

Abstract

A compressor system includes: at least one variable-speed compressor, at least one fixed-speed compressor, a main suction pipe and a main discharge pipe; respective suction pipes of the variable-speed compressor and the fixed-speed compressor are connected to the main suction pipe in parallel, and respective discharge pipes of the variable-speed compressor and the fixed-speed compressor are connected to the main discharge pipe in parallel. The main suction pipe is configured with an oil-gas separation fitting structure, and the oil-gas separation fitting structure is designed to enable most oil of oil-gas mixture from the main suction pipe to move into the variable-speed compressor, and to make the variable-speed compressor stay in an oil-rich state.

First claim

What is claimed is:

1. A compressor system, comprising at least one variable-speed compressor, at least one fixed-speed compressor, a main suction pipe and a main discharge pipe;
wherein respective suction pipes of the variable-speed compressor and the fixed-speed compressor are connected to the main suction pipe in parallel, and respective discharge pipes of the variable-speed compressor and the fixed-speed compressor are connected to the main discharge pipe in parallel;
wherein the main suction pipe is configured with an oil-gas separation fitting structure, and the oil-gas separation fitting structure comprises:
a first opening connected with the main suction pipe, configured to introduce oil-gas mixture from the main suction pipe into the oil-gas separation fitting structure;
a second opening which is in communication with the fixed-speed compressor, configured to introduce gas of the oil-gas mixture from the main suction pipe into the fixed-speed compressor;
a third opening which is only in communication with the variable-speed compressor, configured to introduce most of the oil of the oil-gas mixture from the main suction pipe only into the variable-speed compressor, and to make the variable-speed compressor stay in an oil-rich state; and
the first opening, the second opening and the third opening are configured in such a way that the oil-gas mixture enters the first opening, passes the third opening and then flows to the second opening.

2. The compressor system of claim 1 , wherein the second opening is configured to be connected with a first pipeline extending to the fixed-speed compressor;
the third opening is configured to be connected with a second pipeline extending to the variable-speed compressor.

3. The compressor system of claim 2 , wherein the first pipeline and the oil-gas separation fitting structure are made as a one-piece part, and/or the second pipeline and the oil-gas separation fitting structure are made as a one-piece part.

4. The compressor system of claim 2 , wherein the first pipeline is configured to be welded to the oil-gas separation fitting structure, and/or the second pipeline is configured to be welded to the oil-gas separation fitting structure.

5. The compressor system of claim 2 , wherein the oil-gas separation fitting structure comprises a main body, and an axis of the main body is in a horizontal direction;
wherein the first pipeline is configured to extend along a direction of the axis of the main body; the second pipeline is configured to extend along a downward direction perpendicular to the axis of the main body, and to introduce most of the oil in the oil-gas mixture from the main suction pipe into the variable-speed compressor along sidewall of the second pipeline due to gravity.

6. The compressor system of claim 2 , wherein the oil-gas separation fitting structure comprises a main body, and an axis of the main body is in a horizontal direction;
wherein the first pipeline is configured to extend along an upward direction perpendicular to the axis of the main body; the second pipeline is configured to extend along a direction of the axis of the main body, and to introduce most of the oil in the oil-gas mixture from the main suction pipe into the variable-speed compressor along with a gas flow direction.

7. The compressor system of claim 2 , wherein the oil-gas separation fitting structure comprises a main body, and an axis of the main body is in a horizontal direction;
wherein the first pipeline is configured to extend along a downward direction perpendicular to the axis of the main body; the second pipeline is configured to extend along a direction of the axis of the main body;
wherein the first pipeline is configured with a wedge or nozzle structure at an end of the first pipeline close to the second opening, and the wedge or nozzle structure has a shape for preventing oil entrance to the second opening so that most of the oil in the oil-gas mixture from the main suction pipe moves to the variable-speed compressor along with a gas flow direction.

8. The compressor system of claim 7 , wherein the wedge structure comprises a first part and a second part;
wherein the first part is at an end where the first pipeline inserts into the oil-gas separation fitting structure and which is at upstream of a gas flow direction;
wherein the second part at the end where the first pipeline inserts into the oil-gas separation fitting structure and which is at downstream of the gas flow direction;
wherein a length of the first part inside the oil-gas separation fitting structure is larger than a length of the second part inside the oil-gas separation fitting structure.

9. The compressor system of claim 2 , wherein the oil-gas separation fitting structure comprises a main body, and an axis of the main body is in a vertical direction;
wherein the first pipeline is configured to extend along a direction perpendicular to the axis of the main body; the second pipeline is configured to extend along a direction of the axis of the main body;
wherein the first pipeline is configured with a wedge or nozzle structure at an end of the first pipeline closed to the second opening, and the wedge or nozzle structure has a shape for preventing oil entrance to the second opening so that most of the oil in the oil-gas mixture from the main suction pipe is introduced to the variable-speed compressor due to gas flow and gravity.

10. The compressor system of claim 9 , wherein the wedge structure comprises a first part and a second part;
wherein the first part is at an end where the first pipeline inserts into the oil-gas separation fitting structure and which is upstream in a gas flow direction;
wherein the second part at the end where the first pipeline inserts into the oil-gas separation fitting structure and which is downstream in the gas flow direction;
wherein a length of the first part inside the oil-gas separation fitting structure is larger than a length of the second part inside the oil-gas separation fitting structure.

11. The compressor system of claim 2 , wherein an axis of the second opening is perpendicular to an axis of the third opening.

12. The compressor system of claim 1 , wherein an axis of the second opening is perpendicular to an axis of the third opening.

13. The compressor system of claim 12 , further comprising an oil-gas balancing pipe;
wherein an end of the oil-gas balancing pipe is configured to connect to an oil sump of the variable-speed compressor, and an other end of the oil-gas balancing pipe is configured to connect to an oil sump of the fixed-speed compressor;
wherein the oil-gas balancing pipe is configured to reduce a pressure difference between the variable-speed compressor and the fixed-speed compressor when the variable-speed compressor is working at a low frequency, to avoid too much oil from being transferred from the variable-speed compressor to the fixed-speed compressor via the oil-gas balancing pipe, and to implement oil and gas balance between the variable-speed compressor and the fixed-speed compressor.

14. The compressor system of claim 12 , further comprising an oil balancing pipe and a gas balancing pipe;
wherein an end of the oil balancing pipe is connected to an oil sump of the variable-speed compressor, and an other end of the oil balancing pipe is connected to an oil sump of the fixed-speed compressor; the oil balancing pipe is configured to balance respective oil levels of respective oil sumps in the variable-speed compressor and the fixed-speed compressor;
wherein an end of the gas balancing pipe is connected to an upper part of the oil sump in the vari

Assignees

• Danfoss Tianjin Ltd

Inventors

• Fan Liang
• Genevois David
• Zhang Shuguang
• Liu Peng
• Dong Ying
• Lovan Kongkham

Classifications

• B01D19/0042

  modifying the liquid flow (B01D19/0021 takes precedence) · CPC title

• F04B39/023

  Hermetic compressors · CPC title

• F25B31/004

  oil recirculating arrangements · CPC title

• F04B49/20

  by changing the driving speed · CPC title

• F04B23/04

  Combinations of two or more pumps · CPC title