WO2009036532A2

WO2009036532A2 - Sub-cooler for an air conditioning unit

Info

Publication number: WO2009036532A2
Application number: PCT/BR2007/000239
Authority: WO
Inventors: Carlos Afonso Tesche; Carlos Alberto Garcia; Rafael Schabbach; Regis Silva; Luciano Da Luz Moraes
Original assignee: Carrier Corporation
Priority date: 2007-09-18
Filing date: 2007-09-18
Publication date: 2009-03-26
Also published as: CN101802517A; BRPI0722034A2; WO2009036532A3

Abstract

An air conditioning unit includes a sub-cooler that is at least partially submergible within condensate water collected in a base pan. The sub-cooler receives refrigerant flow from a condenser heat exchanger and provides multi-directional refrigerant flow within the condensate water. A positioning feature is formed on a condenser shroud and is used to hold the sub-cooler in the condensate water.

Description

SUB-COOLER FOR AN AIR CONDITIONING UNIT

BACKGROUND OF THE INVENTION

This disclosure relates to a sub-cooler for an air conditioning unit that provides multi-directional flow.

Air conditioning units, such as room air conditioning units for example, include a compressor that circulates refrigerant from an evaporator to produce cooled air for a room. The refrigerant is circulated to a condenser, which is typically rearward mounted and exposed to an outside environment. The condenser receives air from a fan to reject heat from the refrigerant in the condenser to the outside environment.

A base pan collects condensate water from the evaporator. Some air conditioning units include a sub-cooler that is positioned within the condensate water, and which is used to cool heated refrigerant from a condenser heat exchanger. In one example, a sub-cooler includes a single tube that conducts heated refrigerant in only one direction through the condensate water. In another example, multi-directional refrigerant flow is provided by multiple tube portions; however, due to space constraints, these tube portions contact each other which reduces cooling effectiveness.

Further, in each of these examples, the sub-cooler is mounted to the air conditioning unit by fixing the tubes directly to the base pan. The sub-cooler should be mounted such that the tubes are properly positioned in the base pan. If the tubes are lifted away from the base pan, then contact with the condensate water is reduced, which in turn decreases the effectiveness of the sub-cooler. In one example, a separate plastic mounting sleeve is used to mount the tubes directly to the base pan such that the tubes are held in place in the condensate water. This is disadvantageous from assembly and cost perspectives.

Accordingly, there is a need for a sub-cooler that addresses the disadvantages with the prior art as discussed above.

SUMMARY OF THE INVENTION

An air conditioning unit has a base pan that is to collect condensate water. A sub-cooler is at least partially submergible within the condensate water and receives refrigerant from a condenser heat exchanger. The sub-cooler provides multi-directional refrigerant flow. A positioning feature on a condenser shroud is used to hold the sub-cooler in the condensate water.

In one example, the sub-cooler includes at least first and second tube portions that allow the refrigerant to flow in different directions. The positioning feature is formed as an extension on the condenser shroud and cooperates with the first and second tube portions to hold the sub-cooler in the condensate water.

In one example, the first and second tube portions are connected by a curved tube portion that allows refrigerant to change direction from a first flow direction, defined by the first tube portion, to a second flow direction, defined by the second tube portion. The first and second tube portions have a non-contact relationship such that heated refrigerant from the condenser heat exchanger can efficiently be cooled by the condensate water before the refrigerant is returned to the evaporator. In one example, the condenser shroud includes a shroud body having an opening to receive a fan. The positioning feature comprises a plate that extends outwardly from a bottom portion of the shroud body. The plate contacts upper surfaces of the first and second tube portions and exerts a downward force to press the first and second tube portions against the base pan.

BRIEF DESCRIPTION OF THE DRAWINGS

The various features and advantages of this invention will become apparent to those skilled in the art from the following detailed description of the currently preferred embodiment. The drawings that accompany the detailed description can be briefly described as follows.

Figure 1 is an exploded perspective view of an air conditioning unit.

Figure 2 is perspective assembled view of the air conditioning unit of Figure 1 including a sub-cooler.

Figure 3 is an enlarged view of a portion of Figure 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Figure 1 illustrates an air conditioning unit 10 that has a housing including a base pan 12 and wrapper 14. The base pan 12 supports a compressor 16 that pumps refrigerant to a condenser 18. An expansion device (not shown) is arranged in a known manner, for example, upstream from the condenser 18. The expanded refrigerant flows to an evaporator 20 before returning to the compressor 16. A motor 22 blows air through the evaporator 20 using a blower 24 to provide cooled air through a front grille 26, which is exposed to an interior room for example.

Refrigerant from the evaporator 20 is exposed to the outside environment in one example. A fan 30 is driven by the motor 22 to blow air across the condenser 18 to reject heat from the refrigerant to the outside environment. A condenser orifice or condenser shroud 32 provides a seal between the condenser 18 and the fan 30. In one example, the housing also includes a condenser cover 34 arranged over the shroud 32 and condenser 18 to provide an enclosure about the fan 30.

In one example, an evaporator orifice or evaporator shroud 36 is positioned between the evaporator 20 and the partition 28. A blower scroll top

38 is positioned over the evaporator shroud 36 and a blower scroll bottom 39 to provide an enclosure about the blower 24. A blower scroll top 38 cooperates with the evaporator shroud 36 to provide an enclosure for the evaporator 20.

A controller 40 communicates with the compressor 16 and motor 22 in a known manner to provide a desired conditioned air to the room.

A sub-cooler 50 is installed within the air conditioning unit 10 as shown in Figures 2-3. The sub-cooler 50 receives heated refrigerant from the condenser heat exchanger and cools the refrigerant in the condensate water before going through the expansion device and before returning the refrigerant to the evaporator 20. The sub-cooler 50 provides multi-directional refrigerant flow within the condensate water and is held in place by a positioning feature 52 formed on the condenser shroud 32. The sub-cooler 50 includes a first tube portion 54 that allows refrigerant to flow in a first direction and a second tube portion 56 that allows refrigerant to flow in a second direction different than the first direction. A curved tube portion 58 is used to connect the first 54 and second 56 tube portions, and is used to change direction from the first direction to the second direction. The tube portions 54, 56, 58 can be formed from a single tube, or can be formed as separate tube portions that are connected to each other.

In one example, the first 54 and second 56 tube portions are generally straight tube portions that extend in a generally lateral direction, i.e. in a direction across a width of the air conditioning unit 10. In the example shown, the first 54 and second 56 tube portions are generally parallel to each other.

The curved tube portion 58 connects the straight tube portions together, and thus forms a U-shaped structure with the curved tube portion 58 forming the base of the U, and the straight tube portions 54 and 56 forming the legs of the U. The legs are in a non-contact relationship with each other. The non-contact relationship between the straight tube portions, i.e. the legs, increases heat transfer area and increases the effectiveness of the sub-cooler 50.

As discussed above, the positioning feature 52 is formed on the condenser shroud 32. The shroud 32 includes a shroud body 60 that includes an opening 62 for receiving the fan 30. The positioning feature 52, which is shown in greater detail in Figure 3, comprises an extension that extends outwardly from the shroud body 60 near a bottom edge portion 64 of the shroud body 60. The extension comprises a generally flat plate 66 that extends over and contacts the first 54 and second 56 tube portions. Arm portions 68 are used to attach opposing edge portions 70 of the plate 66 to the shroud body 60. The plate 66 is positioned laterally outwardly of the opening 62 and extends in a direction that is transverse to the first and second flow directions defined by the first 54 and second 56 tube portions, respectively.

The plate 66 exerts a downward force against the first 54 and second 56 tube portions. This downward force presses the first 54 and second 56 tube portions against the base pan 12. As such, the tube portions 54, 56, 58 are held within the condensate water to maximize contact area with the condensate water. This increases the effectiveness of the sub-cooler 50.

Further, by using a positioning feature 52 on the condenser shroud 32, there is no longer a need for separate mounting hardware for the sub-cooler 50. This provides assembly time and material cost savings.

Although a combination of features is shown in the illustrated examples, not all of them need to be combined to realize the benefits of various embodiments of this disclosure. In other words, a system designed according to an embodiment of this disclosure will not necessarily include all of the features shown in any one of the Figures or all of the portions schematically shown in the Figures. Moreover, selected features of one example embodiment may be combined with selected features of other example embodiments.

The preceding description is exemplary rather than limiting in nature. Variations and modifications to the disclosed examples may become apparent to those skilled in the art that do not necessarily depart from the essence of this disclosure. The scope of legal protection given to this disclosure can only be determined by studying the following claims.

Claims

1. An air conditioning unit comprising: a condenser having a heat exchanger; a base pan to collect condensate water, said base pan supporting said condenser; a condenser shroud associated with said condenser, said condenser shroud including a positioning feature; and a sub-cooler at least partially submergible within the condensate water, said sub-cooler receiving refrigerant flow from said condenser heat exchanger and providing multi-directional refrigerant flow within the condensate water, and wherein said positioning feature holds said sub-cooler in the condensate water.

2. The air conditioning unit according to claim 1 where said sub-cooler includes at least a first tube portion that allows refrigerant flow in a first direction and a second tube portion that allows refrigerant flow in a second direction different from said first direction, and wherein said positioning feature of said condenser shroud cooperates with said first and said second tube portions to hold said sub-cooler in the condensate water.

3. The air conditioning unit according to claim 2 wherein said positioning feature comprises an extension that exerts a downward holding force against said first and said second tube portions to press said first and said second tube portions against said base pan.

4. The air conditioning unit according to claim 2 wherein said condenser shroud includes a shroud body having an opening to receive a fan, and wherein said extension comprises a plate that extends outwardly from said shroud body to contact said first and said second tube portions.

5. The air conditioning unit according to claim 4 wherein said plate is positioned at a bottom portion of said shroud body and is spaced laterally outwardly away from said opening near a lateral edge of said shroud body.

6. The air conditioning unit according to claim 4 wherein said plate comprises a generally flat body that extends in a direction that is generally transverse to said first and said second directions.

7. The air conditioning unit according to claim 6 including first and second connecting arms that extend from said shroud body to connect opposing edges of said flat body to said shroud body.

8. The air conditioning unit according to claim 2 including a curved tube portion that connects said first tube portion to said second tube portion to allow refrigerant flow to change from said first direction to said second direction.

9. The air conditioning unit according to claim 8 wherein said first and said second tube portions have a non-contact relationship with each other.

10. The air conditioning unit according to claim 1 wherein heated refrigerant in said sub-cooler is cooled by the condensate water, with said sub-cooler transferring cooled refrigerant to an evaporator.