Flash tank economizer for two stage centrifugal water chillers

Patent metadata

Field	Value
Publication number	US-9890977-B2
Application number	US-201414504950-A
Country	US
Kind code	B2
Filing date	Oct 2, 2014
Priority date	Oct 3, 2013
Publication date	Feb 13, 2018
Grant date	Feb 13, 2018

Abstract

A system comprises the integrated combination of: a condenser having a condenser water path leg extending from a water inlet to a water outlet; a first expansion device; a flash tank economizer; a second expansion device; an evaporator having an evaporator water path leg extending from a water inlet to a water outlet; and a refrigerant flowpath passing sequentially through the condenser, the first expansion device, the economizer, the second expansion device and the evaporator. The flash tank economizer comprises a horizontally elongate body having a first end and a second end. The economizer has an inlet conduit having an outlet. The economizer has a liquid outlet, a vapor outlet, and a medium between the outlet of the inlet conduit and the liquid outlet. A length of the refrigerant flowpath between the first expansion device and the outlet of the inlet conduit is at least 0.5 m.

First claim

What is claimed is:

1. A system ( 20 ) comprising an integrated combination of:
a condenser ( 34 ) having a condenser water path leg extending from a water inlet ( 40 ) to a water outlet ( 42 );
a first expansion device ( 50 );
a flash tank economizer ( 60 ; 360 ; 420 );
a second expansion device ( 70 ; 190 );
an evaporator ( 72 ) having an evaporator water path leg extending from a water inlet ( 80 ) to a water outlet ( 82 ); and
a refrigerant flowpath ( 520 , 522 , 524 ) passing sequentially through the condenser, the first expansion device, the economizer, the second expansion device and the evaporator,

wherein:
the flash tank economizer comprises:
a horizontally elongate body having a first end ( 108 ) and a second end ( 110 );
an inlet conduit ( 120 ) having an outlet ( 122 );
a liquid outlet ( 66 );
a vapor outlet ( 64 ); and
a medium ( 158 ) between the outlet of the inlet conduit and the liquid outlet; and

a length of the refrigerant flowpath between the first expansion device and the outlet of the inlet conduit is at least 0.5 m.

2. The system of claim 1 wherein:
the outlet of the inlet conduit faces the first end; and
the liquid outlet is proximate the second end.

3. The system of claim 1 wherein:
the medium comprises a pair of perforated plates ( 160 , 162 ).

4. The system of claim 3 wherein:
the plates are parallel and spaced-apart from each other.

5. The system of claim 3 wherein:
the plates spaced-apart from each other by a gap of 10 mm to 25 mm.

6. The system of claim 4 wherein:
the plates comprise a first plate ( 160 ) and a second plate ( 162 ) and holes ( 170 ) of the first plate are offset from holes ( 170 ) of the second plate.

7. The system of claim 6 wherein:
the medium comprises a third plate ( 161 ) having holes offset from holes of the first plate.

8. The system of claim 7 wherein:
the holes of the third plate are aligned with the holes of the second plate.

9. The system of claim 6 wherein:
the holes of the first plate and the holes of the second plate are circular in a square array.

10. The system of claim 9 wherein:
the holes of the first plate and holes of the second plate are circular in planform and of the same diameter; and
the square array has an on-center spacing (S 10 ) 141% to 300% of the hole diameter (D 10 ).

11. The system of claim 1 wherein:
the economizer comprises a vessel having:
a main cylinder ( 370 ) extending from the first end toward the second end; and
a second cylinder ( 380 ) at the second end and forming a sump ( 400 ), the liquid outlet extending from the sump.

12. The system of claim 1 wherein:
the economizer lacks a spray bar and a wire mesh-type demister.

13. The system of claim 1 further comprising:
a compressor ( 22 ) having:
an outlet ( 26 ) upstream of the condenser along the refrigerant flowpath ( 520 );
a suction port ( 24 ) downstream of the second expansion device along a first branch ( 524 ) of the refrigerant flowpath; and
an economizer port ( 28 ) downstream of the economizer vapor outlet along a second branch ( 522 ) of the refrigerant flowpath.

14. The system of claim 13 being a chiller.

15. A method for using the system of claim 13 , the method comprising:
running the compressor to draw refrigerant from the suction port and the economizer port, compress said refrigerant, and drive the refrigerant downstream from the outlet along the refrigerant flowpath;
rejecting heat from the refrigerant in the condenser to water flowing along the condenser water path leg;
after the rejecting, expanding the refrigerant in the first expansion device;
passing the expanded refrigerant from the first expansion device to the flash tank economizer;
passing a first branch flow of the refrigerant from the flash tank economizer back to the economizer port;
passing a second branch flow of the refrigerant to the second expansion device;
passing the expanded refrigerant from the second expansion device to the evaporator;
absorbing heat by refrigerant passing through the evaporator from water passing along the evaporator water path leg; and
returning refrigerant from the evaporator to the suction port.

16. The method of claim 15 wherein:
the medium is effective to remove droplets of liquid refrigerant from a vapor flow passing to the vapor outlet and deliver said droplets to a liquid accumulation for forming a liquid flow from the liquid outlet.

17. The method of claim 16 wherein:
refrigerant discharged from the inlet conduit outlet is deflected off an interior surface of the body at the first end.

18. An economizer comprising:
an elongate body having a first end ( 108 ) and a second end ( 110 );
an inlet conduit ( 120 ) having an outlet ( 122 );
a liquid outlet ( 66 );
a vapor outlet ( 64 ); and
first ( 160 ) and second ( 162 ) flat spaced-apart foraminate plates between the outlet of the inlet conduit and the liquid outlet.

19. The economizer of claim 18 wherein:
the plates parallel and spaced-apart from each other by a gap of 10 mm to 25 mm.

20. The economizer of claim 18 wherein:
holes ( 170 ) of the first plate are offset from holes ( 170 ) of the second plate.

Assignees

• Carrier Corp

Inventors

• Li Hsihua
• Ding Haiping

Classifications

• F25B2341/0662

  Mechanical Engineering · mapped topic

• F25B1/005

  of the single unit type (F25B1/10 takes precedence) · CPC title

• F25B2500/01

  Geometry problems, e.g. for reducing size · CPC title

• F25B2400/13

  Economisers · CPC title

• F25B43/00 Primary

  Arrangements for separating or purifying gases or liquids (in analysers or rectifiers F25B33/00); Arrangements for vaporising the residuum of liquid refrigerant, e.g. by heat (F25B40/00 takes precedence) · CPC title