Falling film evaporator

• US 20060080998A1
• Filed: 10/12/2005
• Published: 04/20/2006
• Est. Priority Date: 10/13/2004
• Status: Active Grant

• Current Assignee: Johnson Controls Tyco IP Holdings LLP (Johnson Controls International plc)
• Original Assignee: York International Corporation (Johnson Controls International plc)
• Inventors: Kulankara, Satheesh, De Larminat, Paul, Judge, John Francis, Le Cointe, Luc
• Granted Patent: US 7,849,710 B2
• Time in Patent Office: Days
• US Class Current: 62/515
• CPC Class Codes: F25B 2339/0242 having tubular elements
• CPC Class Codes: F25B 2341/0011 Ejectors with the cooled primary flow at reduced or low pressure
• CPC Class Codes: F25B 39/028 having distributing means
• CPC Class Codes: F28D 3/02 with tubular conduits
• CPC Class Codes: F28F 13/187 especially adapted for evaporator surfaces or condenser surfaces, e.g. with nucleation sites
• CPC Class Codes: F28F 9/0265 by using guiding means or impingement means inside the header box
• CPC Class Codes: F28F 9/22 Arrangements for directing heat-exchange media into successive compartments, e.g. arrangements of guide plates

Abstract

A falling film evaporator is provided for use in a two-phase refrigeration system or process system. The evaporator includes a shell having an upper portion, a lower portion, and a tube bundle having tubes extending substantially horizontally in the shell. A hood is disposed over the tube bundle, the hood having an upper end adjacent the upper portion above the tube bundle, the upper end having opposed substantially parallel walls extending toward the lower portion, the walls terminating at an open end opposite the upper end. Once liquid refrigerant or liquid refrigerant and vapor refrigerant is deposited onto the tube bundle, the substantially parallel walls of the hood substantially prevent cross flow of refrigerant vapor or liquid and vapor between the tubes of the tube bundle.

Claims

1. A refrigeration system comprising:

a compressor, a condenser, an expansion device and an evaporator connected in a closed refrigerant loop; and

the evaporator comprising;

a shell having an upper portion and a lower portion;

a tube bundle, the tube bundle having a plurality of tubes extending substantially horizontally in the shell;

a hood disposed over the tube bundle, the hood having a closed end and an open end opposite the closed end, the closed end being disposed above the tube bundle adjacent the upper portion of the shell, the hood further having opposed substantially parallel walls extending from the closed portion toward the open portion of the shell;

a refrigerant distributor disposed below the hood and above the tube bundle, the refrigerant distributor being configured to deposit liquid refrigerant or liquid and vapor refrigerant onto the tube bundle; and

wherein the substantially parallel walls of the hood substantially prevent cross flow of the refrigerant between the plurality of tubes of the tube bundle.

2. The refrigerant system of claim 1 wherein the substantially parallel walls extend substantially vertically.

3. The refrigerant system of claim 1 wherein the substantially parallel walls substantially laterally surround the plurality of tubes of the tube bundle.

4. The refrigerant system of claim 1 wherein at least one tube of the plurality of tubes of the tube bundle are finned, the at least one finned tube being disposed in an upper region of the tube bundle.

5. The refrigerant system of claim 1 wherein at least one tube of the plurality of tubes of the tube bundle has a porous coating applied to at least a portion of an outer surface of the at least one tube.

6. The refrigerant system of claim 4 wherein at least one tube of the plurality of tubes of the tube bundle has a porous coating applied to at least a portion of an outer surface of the at least one tube.

7. The refrigerant system of claim 1 wherein an ejector provides flow of refrigerant to the refrigerant distributor.

8. The refrigerant system of claim 1 wherein the refrigerant distributor is configured to at least partially expand the refrigerant.

9. The refrigerant system of claim 1 wherein the refrigerant distributor includes at least one spraying nozzle.

10. A falling film evaporator for use in a refrigeration system comprising:

a shell having an upper portion and a lower portion;

a tube bundle, the tube bundle having a plurality of tubes extending substantially horizontally in the shell;

a hood disposed over the tube bundle, the hood having a closed end and an open end opposite the closed end, the closed end being disposed above the tube bundle adjacent the upper portion of the shell, the hood further having opposed substantially parallel walls extending from the closed portion toward the open portion of the shell;

a refrigerant distributor disposed below the hood and above the tube bundle, the refrigerant distributor being configured to deposit liquid refrigerant or liquid and vapor refrigerant onto the tube bundle; and

wherein the substantially parallel walls of the hood substantially prevent cross flow of the refrigerant between the plurality of tubes of the tube bundle.

11. The falling film evaporator of claim 10 wherein the substantially parallel walls extend substantially vertically.

12. The falling film evaporator of claim 10 wherein the substantially parallel walls substantially laterally surround the plurality of tubes of the tube bundle.

13. The falling film evaporator of claim 10 wherein at least one tube of the plurality of tubes of the tube bundle are finned, the at least one finned tube being disposed in an upper region of the tube bundle.

14. The falling film evaporator of claim 10 wherein at least one tube of the plurality of tubes of the tube bundle has a porous coating applied to at least a portion of an outer surface of the at least one tube.

15. The falling film evaporator of claim 13 wherein at least one tube of the plurality of tubes of the tube bundle has a porous coating applied to at least a portion of an outer surface of the at least one tube.

16. The falling film evaporator of claim 10 wherein an ejector provides flow of refrigerant to the refrigerant distributor.

17. The falling film evaporator of claim 10 wherein the refrigerant distributor is configured to at least partially expand the refrigerant.

18. The falling film evaporator of claim 10 wherein the refrigerant distributor includes at least one spraying nozzle.

19. A hybrid falling film evaporator for use in a refrigeration system comprising:

a shell having an upper portion and a lower portion;

a lower tube bundle in fluid communication with an upper tube bundle, the lower and upper tube bundles each having a plurality of tubes extending substantially horizontally in the shell, the lower tube bundle being at least partially submerged by refrigerant in the lower portion of the shell;

a hood disposed over the upper tube bundle, the hood having a closed end and an open end opposite the closed end, the closed end being adjacent the upper portion of the shell above the upper tube bundle, the hood further having opposed substantially parallel walls extending from the closed end toward the open end adjacent the lower portion of the shell;

a refrigerant distributor, the refrigerant distributor being disposed above the upper tube bundle, the refrigerant distributor depositing refrigerant onto the upper tube bundle; and

wherein the substantially parallel walls of the hood substantially prevent cross flow of refrigerant between the plurality of tubes of the upper tube bundle.

20. The falling film evaporator of claim 19 wherein the substantially parallel walls extend substantially vertically.

21. The falling film evaporator of claim 19 wherein the substantially parallel walls substantially laterally surround the plurality of tubes of the upper tube bundle.

22. The falling film evaporator of claim 19 wherein at least one tube of the plurality of tubes of the upper tube bundle are finned, the at least one finned tube being disposed in an upper region of the tube bundle.

23. The falling film evaporator of claim 19 wherein at least one tube of the plurality of tubes of the upper tube bundle has a porous coating applied to at least a portion of an outer surface of the at least one tube.

24. The falling film evaporator of claim 22 wherein at least one tube of the plurality of tubes of the upper tube bundle has a porous coating applied to at least a portion of an outer surface of the at least one tube.

25. The falling film evaporator of claim 19 wherein an ejector provides flow of refrigerant to the refrigerant distributor.

26. The falling film evaporator of claim 19 wherein the refrigerant distributor is configured to at least partially expand the refrigerant.

27. The falling film evaporator of claim 19 wherein a fluid flowing in a tube bundle is subjected to a two pass system in which the fluid first flows inside the plurality of tubes of the lower tube bundle during a first pass, then the fluid flows inside the plurality of tubes of the upper tube bundle during a second pass.

28. The falling film evaporator of claim 19 wherein a fluid flowing in a tube bundle is subjected to at least a one pass system in which the fluid flows inside at least a portion of each of the plurality of tubes of the lower tube bundle and the upper tube bundle.

29. A falling film evaporator for use in a control process comprising:

a shell having an upper portion and a lower portion;

a tube bundle, the tube bundle having a plurality of tubes extending substantially horizontally in the shell;

a hood disposed over the tube bundle, the hood having a closed end and an open end opposite the closed end, the closed end being disposed above the tube bundle adjacent the upper portion of the shell, the hood further having opposed substantially parallel walls extending toward the lower portion of the shell;

a fluid distributor disposed below the hood and above the tube bundle, the fluid distributor being configured to deposit liquid fluid or liquid and vapor fluid onto the tube bundle; and

wherein the substantially parallel walls of the hood substantially prevent cross flow of the fluid between the plurality of tubes of the tube bundle.