US20160195345A1

US20160195345A1 - Condensate drain devices for heat exchanger coil and methods for making the same

Info

Publication number: US20160195345A1
Application number: US14/654,782
Authority: US
Inventors: Robert Fredrick Schult; Jun Wang; Roger J. Voorhis; Justin Slade Winters
Original assignee: Trane International Inc
Current assignee: Trane International Inc
Priority date: 2012-12-21
Filing date: 2013-12-20
Publication date: 2016-07-07
Also published as: WO2014100712A1; CN104870922A; CN104870922B

Abstract

A condensate drain device includes an elongate base having a first end, a second end and side edges extending between the first and second ends; a plurality of teeth extending away from a side edge of the base; and a lip formed on the side edge of the base opposite from the teeth. Each tooth includes a free end and two side edges. The condensate drain device is configured to be attached to a microchannel coil to collect condensate including a plurality of tubes and a plurality of fins coupled to the tubes, with each tooth being received in a space formed between two adjacent fins.

Description

FIELD

This disclosure relates generally to a heat exchange assembly, and more particularly, this disclosure relates to a condensate drain device for a heat exchanger coil for collecting and draining condensate formed on the heat exchanger coil.

BACKGROUND

Heat exchanger coils are typically used in HVAC (heat, ventilation and air conditioning) systems. For example, when air flows through a heat exchanger coil, moisture in the air can condense to liquid and collect on the coil. In some circumstances, a drain pan can be provided for collection of condensate. For example, a drain pan has been designed to be placed at a bottom of a heat exchanger coil to collect the condensate dripping down the coil. A condensate line can be used to connect an outlet of the drain pan to allow the condensate to be removed from the heat exchanger coil. Subsequently, the condensate drain line can be piped to either a floor drain or to the outside atmosphere.

SUMMARY

Some embodiments of the condensate drain device can be secured to a heat exchanger coil for collecting condensate dripping from the coil. The condensate drain device can be positioned between a first header and a second header of the coil and is spaced away from both the first and second headers. This allows the condensate drain device to collect the condensate formed on an upper section between the first header and the condensate drain device, which is located above the condensate drain device. In some embodiments, the first header is located at an upper side of the coil and the second header is located at a lower side of the coil.
In particular embodiments, the condensate drain device can have a comb shaped contour including a continuous base and a plurality of teeth extending away from a side edge of the base. Each tooth can be received between a space formed between fins of the coil to allow the condensate drain device to be secured to the coil. The condensate drain device is configured to be spaced away from the second header of the coil to collect the condensate formed on the upper section located above the condensate drain device.
In some embodiments, a condensate drain device includes an elongate base including a first end, a second end and side edges extending between the first and second ends, a plurality of teeth extending away from a side edge of the base, and a lip formed on the side edge of the base opposite from the teeth. Each tooth includes a free end and two side edges. The plurality of teeth are disposed generally parallel with each other, with a gap formed between each two adjacent teeth to allow a flat tube or tubes of a heat exchanger coil to be received. In one embodiment, the condensate drain device is configured to be attached to a microchannel coil to collect condensate including a plurality of tubes and a plurality of fins coupled to the tubes, with each tooth being received in a space formed between two adjacent fins.
Some embodiments may include a heat exchanger coil assembly including a heat exchanger coil and a condensate drain device. The heat exchanger coil includes a first header, a second header, a plurality of tubes extending between the first and second headers, and a plurality of fins coupled to the tubes. The condensate drain device includes an elongate base including a first end, a second end and side edges extending between the first and second ends; and a plurality of teeth extending away from a side edge of the base. The plurality of teeth are disposed generally parallel with each other. The condensate drain device is attached to the heat exchanger coil at a location between the first and second headers and spaced away from both the first and second headers.
Other embodiments may include a method for assembling a condensate drain device to a heat exchanger coil. The heat exchanger coil includes a plurality of tubes and a plurality of fins coupled to the tubes. The method includes inserting a plurality of teeth of the condensate drain device in corresponding spaces formed between adjacent fins to allow the condensate drain device to be attached to the heat exchanger coil; and securing the condensate drain device to the heat exchanger coil. In some embodiments, an upper surface of the condensate drain device is sloped at an angle with a horizontal direction along which the first and second headers extend.
These and other embodiments described herein may provide one or more of the following benefits. First, the condensate drain device can be located between the first and second headers of the heat exchanger coil. This helps drain condensate down to the device from an upper section of the coil located between the first header and the condensate drain device, thereby preventing the moisture from being carried over to the conditioned space. Second, the condensate drain device can be oriented at an angle with a horizontal direction, when assembled with the heat exchanger coil. This helps facilitate drainage of the condensate at one end of the condensate drain device. Third, the condensate drain device can be located at a leading air side of the heat exchanger coil, such that the condensate can be blown away from the heat exchanger coil, instead of being blown toward the coil. This helps prevent condensate from flowing back to the coil which may subsequently cause frost to form on the coil.
The details of one or more embodiments are set forth in the accompanying drawings and the description below. Other features, objects and advantages of the embodiments will be apparent from the description and drawings, and from the claims.

DESCRIPTION OF THE DRAWINGS

FIG. 1A is a perspective view of a condensate drain device for a heat exchanger coil with the condensate drain device being attached to the heat exchanger coil.

FIG. 1B is a close-up view of the condensate drain device of FIG. 1A.

FIG. 2 is a schematic top view of the condensate drain device of FIG. 1A with the condensate drain device not being assembled with the heat exchanger coil.

FIG. 3 is a schematic front view of the drain system of FIG. 1A, with the condensate drain device being assembled.

Like reference symbols in the various drawings indicate like elements.

DETAILED DESCRIPTION

References are made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration of the embodiments in which the methods and systems described herein may be practiced. The term “upper section” refers to a section of the heat exchanger coil defined between a first header and a condensate drain device, which is located above the condensate drain device. When the condensate drain device is located approximately half way between the first header and a second header, the distance between the condensate drain device and the first header is generally equal to a corresponding distance between the drain device and the second header. In some embodiments, the condensate drain device is located closer to the first header than to the second header. In these embodiments, the distance between the condensate drain device and the first header is smaller than a distance between the condensate drain device and the second header. In some embodiments, the first header is located at an upper side of the coil and the second header is located at a lower side of the coil. Solely for the convenience of description, the first and second headers will be described as upper and lower headers, respectively, in this disclosure.
Referring to FIGS. 1A-B, a condensate drain device 10 is secured to a heat exchanger coil 12 for collecting condensate dripping from the coil 12. The condensate drain device 10 can be positioned between an upper header 14 and a lower header 16 of the coil 12 and is spaced away from both the upper and lower headers 14, 16. This allows the condensate drain device 10 to collect the condensate formed on an upper section 18 defined between the upper header 14 and the condensate drain device 10. For example, in some embodiments, the condensate drain device 10 can have a comb shaped contour including a continuous base 20 and a plurality of teeth 22 extending away from a side edge 24 of the base 20. Each tooth 22 can be received between a space 25 (referring to FIG. 3) formed between pleats 40 of each fin 28 to allow the condensate drain device 10 to be secured to the coil 12, which will be described in more detail below. The condensate drain device 10 is configured to be spaced away from the lower header 16 of the coil 12 to collect the condensate formed on the upper section 18 located above the condensate drain device 10.
The condensate drain device 10 is particularly useful when used with tall evaporator coils. In some cases, the height H of the tall evaporator coils can range generally greater than about 30 inches. For these relatively tall evaporator coils, condensate water may not be able to drip from the top of the coil down to a drain pan located at the bottom of the coil before being blown off the coil and into a conditioned space. As a result, the moisture can be carried over to the conditioned space. The condensate drain device 10 helps catch condensate from an upper section 18 of the coil located between the upper header 14 and the condensate drain device 10 above the condensate drain device 10 and then drain the condensate, thereby preventing the moisture from being carried over to the conditioned space.
As shown in FIGS. 1A-B, in some embodiments, the heat exchanger coil 12, such as an evaporator coil, a condenser coil, or the like, can be a microchannel coil 30. The microchannel evaporator coil 30 includes a first end 31, a second end 32, a front side 33 and a rear side 34 defined between the first and second ends 31 and 32. The microchannel evaporator coil 30 also includes the upper header 14, which can be an inlet header, and includes the lower header 16, which can be an outlet header, where the inlet and outlet headers 14, 16 are fluidly connected by a plurality of flat tubes 36. The inlet header 14 includes an inlet port (not shown) for receiving refrigerant, and the outlet header 16 includes an outlet port (not shown) for discharging the refrigerant. Each flat tube 36 has two opposing edges 35, 37 extending between the inlet and outlet headers 14, 16, and sides walls 38 defined between the edges 35, 37. The flat tubes 36 may be formed to include multiple internal passageways, or microchannels (not shown) to allow efficient heat transfer between the airflow passing over the flat tubes 36 and the refrigerant carried within the microchannels. The coil 30 also includes a plurality of pleats 40 of a fin 28 coupled to and positioned along the flat tubes 36. In some cases, the pleats 40 can be generally arranged in a zig-zag (e.g., as shown in FIG. 1B) pattern between adjacent flat tubes 36, aiding in the heat transfer between the airflow passing through the coil 30 and the refrigerant carried by the microchannels. In the embodiment as shown in FIG. 1A, airflow is blown through the coil 30 in a direction from the rear side 34 to the front side 33 of the coil 30, as indicated by the arrows in FIG. 1A. It is to be understood that in other embodiments, the heat exchanger coil 12 can be other types of heat exchanger coils, such as tube-and-fin coils.
Referring to FIGS. 1A-B and 2-3, the condensate drain device 10 includes the continuous elongate base 20. In the depicted embodiments as shown in FIGS. 1A-B and 2-3, the base 20 is rectangular, including a first end 52, a second end 54 and side edges 24, 26 extending between the first and second ends 52 and 54. A plurality of comb-like teeth 22 extend from the side edge 24 away therefrom. Each tooth 22 includes a free end 42 and side edges 44. In the depicted embodiment, each comb tooth 22 has a length L (as shown in FIG. 2) smaller than a depth of the fin 40 so that when the tooth 22 is received in a corresponding space 28 between tubes 36, the edge 24 of the condensate drain device 10 engages with a corresponding side edge 37 of the flat tube 36. Each tooth 22 also has a width W that is slightly smaller than a distance between the side walls 38 of each two adjacent flat tubes 36 of the coil 30, thereby can allow side edges 44 of each tooth 22 to have an interference fit with the corresponding side walls 38 of the flat tubes 36, when the condensate drain device 10 is assembled with the coil 30.
In the embodiments as shown in FIGS. 1A-B and 2-3, each tooth 22 can have a uniform width from the base 20 to the free end 42. In alternative embodiments, each tooth 22 can have a reduced width, e.g., each tooth is tapered, when extending from the base 20 to the free end 42 of the teeth 22. In the embodiment shown, the teeth 22 are spaced apart by about the same distance and are generally parallel to each other. The gap 46 between each two adjacent teeth 22 has a width W_Gthat is slightly greater than a thickness T_FTof the flat tube 36, thereby allowing the thickness of the flat tube 36 to be received in a corresponding gap 46. On the side edge 26 of the base 20 that is opposite to the side edge 24 where the teeth 22 extend from, a lip 48 is formed for preventing the condensate from draining over the side edge 26.
The condensate drain device 10 also includes an upper surface 60. When assembled to the coil 30, the upper surface 60 is sloped from the first end 52 of the condensate drain device downwardly to the second end 54 to direct the condensate to the second end 54. The second end 54 of the condensate drain device 10 can be properly sealed with the second end 32 of the coil 30 by an end wall 71. A drainage conduit 70 including an inlet 72 is located proximal the second end 54 to receive condensate collected by the upper surface 60.
The condensate drain device 10 may be made from a flexible compliant material, for example, a plastic or polycarbonate material such as Lexan, a metal material, or fiber glass. If using plastic material, the condensate drain device 10 can be made in one piece by injection molding.
To assemble the condensate drain device 10 to the coil 30, the condensate drain device 10 can be obtained by cutting an injection molded member to a suitable length for fitting with a width W_Cof the coil 30. The condensate drain device 10 is oriented to slope from a relatively high point 80 located at the first end 31 of the coil 30 to a relatively low point 82 located at the second end 32 of the coil 30 to direct condensate to the low point 82, with each tooth 22 of the condensate drain device 10 being received in a corresponding space 28 formed between adjacent tubes 36 of the coil 30 (referring to FIG. 1B). In some embodiments, an angle α is formed between the sloped condensate drain device 10 and a horizontal direction along with the upper and lower headers 14, 16 extend. The angle α is configured to be sufficient to drain condensate water by gravity at at least an operating conditions. In some embodiments, the angle α is configured to be sufficient to drain condensate water by gravity at all operating conditions. In some embodiments, the angle α can range from about 4 to about 5 degrees, and sometimes less depending on the coil, application. Accordingly, the edges 37 of the flat tubes 36 are received in the respective gaps 46 formed between each two adjacent comb teeth 22. In some embodiments, each side edge 44 of the teeth 22 is in an interference fit and sealed with the corresponding side walls 38 of the flat tubes 36 by contact or slight compression fit depending on the material used to prevent the condensate from bypassing around the teeth 22.
It is to be understood that the upper surface 60 of the condensate drain device 10 can be oriented at any angle relative to the flat tubes 36, as long as the upper surface 60 is oriented at a non-right angle relative to the gravity direction. For example, in case the condensate drain device 10 is oriented perpendicular relative to the flat tubes 36, the upper surface 60 of the condensate drain device 10 can still be oriented at an angle with a horizontal direction. This can be done by tilting the coil 30 such that the tubes 36 are oriented at an angle relative to the gravity direction.

Aspects:

It is noted that any of aspects 1-7 below can be combined with any of aspects 8-12 and aspects 13-16. Also, any of aspects 8-12 below can be combined with any of aspects 13-16.
1. A heat exchanger coil assembly, comprising:
a heat exchanger coil including:

- a first header;
- a second header;
- a plurality of tubes extending between the first and second headers; and
- a plurality of fins coupled to the tubes, and

a condensate drain device including:

- an elongate base including a first end, a second end and side edges extending between the first and second ends; and
- a plurality of teeth extending away from a side edge of the base, the plurality of teeth being disposed parallel with each other,

wherein the condensate drain device is attached to the heat exchanger coil at a location between the first and second headers and spaced away from both the first and second headers, and
wherein the elongate base is oriented such that an upper surface of the elongate base slopes from the first end toward the second end at an angle relative to a horizontal direction.
2. The heat exchanger coil assembly of aspect 1, wherein a height of the heat exchanger coil is greater than 30 inches.
3. The heat exchanger coil assembly of any of aspects 1-2, wherein each of the teeth is received in a space formed between two adjacent fins of the heat exchanger coil.
4. The heat exchanger coil assembly of aspect 3, wherein the teeth have a length smaller than a depth of the fin, so that when each of the teeth is received in the corresponding space, one of the side edges of the elongate base engages with a side edge of the corresponding flat tube.
5. The heat exchanger coil assembly of any of aspects 3-4, wherein each of the plurality of teeth has a width slightly smaller than a distance between the two respective adjacent tubes of the heat exchanger coil, thereby allowing side edges of each of the teeth to have an interference fit with corresponding side walls of the two respective adjacent tubes.
6. The heat exchanger coil assembly of any of aspects 1-5, wherein each of the plurality of teeth has a uniform width from the base to a respective free end of the respective tooth.
7. The heat exchanger coil assembly of any of aspects 1-6, wherein a height of the heat exchanger coil is greater than 30 inches.
8. A condensate drain device, comprising:
an elongate base including a first end, a second end and side edges extending between the first and second ends;
a plurality of teeth extending away from a side edge of the base, each tooth includes a free end and two side edges; and
a lip formed on the side edge of the base opposite from the teeth,
wherein the condensate drain device is configured to be attached to a heat exchanger coil to collect condensate including a plurality of tubes and a plurality of fins coupled to the tubes, with each tooth being received in a space formed between two adjacent fins.
9. The condensate drain device of aspect 8, wherein each of the plurality of teeth has a uniform width from the base to the respective free end of the respective tooth.
10. The condensate drain device of any of aspects 8-9, wherein the plurality of teeth are spaced apart by about the same distance and are generally parallel to each other.
11. The condensate drain device of any of aspects 8-10, further comprising an end wall attached to the second end of the base.
12. The condensate drain device of any of aspects 8-11, wherein the heat exchanger coil is a microchannel coil.
13. A method for assembling a condensate drain device to a heat exchanger coil, the heat exchanger coil including a plurality of tubes and a plurality of fins coupled to the tubes, comprising:
inserting a plurality of teeth of the condensate drain device in corresponding spaces formed between adjacent fins to allow the condensation drain device to be attached to the heat exchanger coil; and
securing the condensate drain device to the heat exchanger coil,
wherein the condensate drain device further includes an elongate base which has a first end and a second end, the elongate base being oriented such that an upper surface of the elongate base slopes from the first end toward the second end at an angle relative to a horizontal direction.
14. The method of aspect 13, wherein the condensate drain device comprises:
an elongate base including a first end, a second end and side edges extending between the first and second ends;
a plurality of teeth extending away from a side edge of the base, each tooth includes a free end and two side edges; and
a lip formed on the side edge of the base opposite from the teeth.
15. The method of aspect 14, wherein each of the plurality of teeth has a uniform width from the base to the respective free end of the respective tooth.
16. The method of any of aspects 14-15, wherein the plurality of teeth are spaced apart by about the same distance and are generally parallel to each other.
A number of embodiments of the invention have been described. Nevertheless, it is to be understood that various modifications may be made without departing from the spirit and scope of the invention. For example, in other embodiments, the lip can be any suitable configuration that can prevent the condensate from flowing over on the side edge. In another example, some embodiments of the condensate drain device 10 can be retained to the heat exchanger coil 12 by other fastening methods, such as glue or epoxy, or the like. In still another example, other types of drainage outlet can be used with the condensate drain device 10, for example, bottom drain outlet or the like. Accordingly, other embodiments are within the scope of the following claims.

Claims

1. A heat exchanger coil assembly, comprising:

a heat exchanger coil including:

a first header;

a second header;

a plurality of tubes extending between the first and second headers; and

a plurality of fins coupled to the tubes, and

a condensate drain device including:

an elongate base including a first end, a second end and side edges extending between the first and second ends; and

a plurality of teeth extending away from a side edge of the base, the plurality of teeth being disposed parallel with each other,

wherein the condensate drain device is attached to the heat exchanger coil at a location between the first and second headers and spaced away from both the first and second headers, and

wherein the elongate base is oriented such that an upper surface of the elongate base slopes from the first end toward the second end at an angle relative to a horizontal direction.

2. The heat exchanger coil assembly of claim 1, wherein a height of the heat exchanger coil is greater than 30 inches.

3. The heat exchanger coil assembly of claim 1, wherein each of the teeth is received in a space formed between two adjacent fins of the heat exchanger coil.

4. The heat exchanger coil assembly of claim 3, wherein the teeth have a length smaller than a depth of the fin, so that when each of the teeth is received in the corresponding space, one of the side edges of the elongate base engages with a side edge of the corresponding flat tube.

5. The heat exchanger coil assembly of claim 3, wherein each of the plurality of teeth has a width slightly smaller than a distance between the two respective adjacent tubes of the heat exchanger coil, thereby allowing side edges of each of the teeth to have an interference fit with corresponding side walls of the two respective adjacent tubes.

6. The heat exchanger coil assembly of claim 1, wherein each of the plurality of teeth has a uniform width from the base to a respective free end of the respective tooth.

7. The heat exchanger coil assembly of claim 1, wherein a height of the heat exchanger coil is greater than 30 inches.

8. A condensate drain device, comprising:

an elongate base including a first end, a second end and side edges extending between the first and second ends;

a plurality of teeth extending away from a side edge of the base, each tooth includes a free end and two side edges; and

a lip formed on the side edge of the base opposite from the teeth,

wherein the condensate drain device is configured to be attached to a heat exchanger coil to collect condensate including a plurality of tubes and a plurality of fins coupled to the tubes, with each tooth being received in a space formed between two adjacent fins.

9. The condensate drain device of claim 8, wherein each of the plurality of teeth has a uniform width from the base to the respective free end of the respective tooth.

10. The condensate drain device of claim 8, wherein the plurality of teeth are spaced apart by about the same distance and are generally parallel to each other.

11. The condensate drain device of claim 8, further comprising an end wall attached to the second end of the base.

12. The condensate drain device of claim 8, wherein the heat exchanger coil is a microchannel coil.

13. A method for assembling a condensate drain device to a heat exchanger coil, the heat exchanger coil including a plurality of tubes and a plurality of fins coupled to the tubes, comprising:

inserting a plurality of teeth of the condensate drain device in corresponding spaces formed between adjacent fins to allow the condensation drain device to be attached to the heat exchanger coil; and

securing the condensate drain device to the heat exchanger coil,

wherein the condensate drain device further includes an elongate base which has a first end and a second end, the elongate base being oriented such that an upper surface of the elongate base slopes from the first end toward the second end at an angle relative to a horizontal direction.

14. The method of claim 13, wherein the condensate drain device comprises:

a lip formed on the side edge of the base opposite from the teeth.

15. The method of claim 14, wherein each of the plurality of teeth has a uniform width from the base to the respective free end of the respective tooth.

16. The method of claim 14, wherein the plurality of teeth are spaced apart by about the same distance and are generally parallel to each other.