HEAT EXCHANGER
A heat exchanger including a heat exchange fluid inlet, tubing coupled to the heat exchange fluid inlet, the tubing being configured to direct a flow of heat exchange fluid through the heat exchanger, the flow of fluid having a main fluid flow direction, and an air inlet configured to direct a flow of air in a generally collinear relationship with the main fluid flow direction.
The present disclosure relates generally to heat exchangers. More specifically, the present disclosure relates to heat exchangers having a relatively low refrigerant charge.
In a refrigerant-based heat exchange system, there are numerous reasons why the amount of refrigerant may need to be limited. These can include, for example, cost considerations, regulatory/environmental requirements and safety requirements. This presents a challenge to refrigerant system designers because to maintain satisfactory performance of the system, the system needs to be designed to flood the heat exchanger as much as possible with the restricted refrigerant charge level.
In a typical refrigerant-based heat exchange system, the general refrigerant flow and air flow through the heat-exchanger (for example, an evaporator) are not collinear or in the same direction. For example, referring to
The size (e.g. internal volume) of the heat exchanger can be reduced to maintain satisfactory performance in a system that needs to use a limited amount of refrigerant. However, decreasing the size of the heat exchanger also decreases the heat exchange ability of the system as the surface area available to heat or cool the refrigerant within the heat exchanger is reduced.
It would be advantageous to have a refrigerant-based heat exchange system that is capable of satisfactorily exchanging heat with a limited amount of refrigerant running through the heat exchange system.
BRIEF DESCRIPTION OF THE INVENTIONAs described herein, the exemplary embodiments overcome one or more of the above, or other disadvantages known in the art.
One aspect of the exemplary embodiments relates to a heat exchanger. The heat exchanger includes a heat exchange fluid inlet, tubing coupled to the heat exchange fluid inlet, the tubing being configured to direct a flow of heat exchange fluid through the heat exchanger, the flow of fluid having a main fluid flow direction, and an air inlet configured to direct a flow of air in a generally collinear relationship with the main fluid flow direction.
Another aspect of the disclosed embodiments relates to a heat exchange system for a refrigerator/freezer. The heat exchange system includes a heat exchanger comprising tubing having a serpentine configuration, the tubing being configured to direct a flow of heat exchange fluid in a main fluid flow direction; and a fan configured to effect an airflow through the heat exchanger in a substantially collinear relationship with the main fluid flow direction. A substantially even distribution of liquid heat exchange fluid flows throughout the heat exchanger.
A further aspect of the disclosed embodiments relates to an appliance. The appliance includes a housing, a heat exchanger having heat exchange fluid flowing within the heat exchanger, and an airflow duct configured to allow an airflow to circulate within the housing and through the heat exchanger. The heat exchanger is configured to direct a flow of the heat exchange fluid in a main fluid flow direction, the airflow through the heat exchanger moving in a substantially co-directional relationship with the main fluid flow direction, effecting a substantially even distribution of liquid heat exchange fluid throughout the heat exchanger.
These as other aspects and advantages of the exemplary embodiments will become more apparent from the following detailed description considered in conjunction with the accompanying drawings. It is to be understood, however, that the drawings are designed solely for the purposes of illustration and not as a definition of the limits of the invention, for which reference should be made to the appended claims. Moreover, the drawings are not necessarily to scale and that, unless otherwise indicated, they are merely intended to conceptually illustrate the structures and procedures described herein. In addition, any suitable size, shape or type of elements or materials could be used.
In the drawings:
Referring to
The aspects of the disclosed embodiments provide a heat exchange system 210 capable of providing sufficient cooling for the refrigerator 200 where the amount of heat exchange fluid such as, for example, refrigerant, that can be used in the heat exchange system 210 is limited. In one embodiment, the heat exchange system 210 is configured so that the heat exchanger 220 is flooded with as much of the limited amount of heat exchange fluid, in liquid form, as possible. The heat exchanger 220 is configured such that the air flow over and/or through the heat exchanger 220 is substantially co-directional, that is, generally in the same direction as the main flow of heat exchange fluid through the heat exchanger 220 so that the amount of stagnant heat exchange fluid within the heat exchanger 220 is minimized. The main flow refers to the direction in which the refrigerant flows from one row or column of tube to the next row of column of tube. To promote a heat exchange fluid flow with minimized stagnation, the relationship of vapor pockets 410 (
The aspects of the disclosed embodiments will generally be described herein with respect to the freezer side of the refrigerator 200. However, the aspects of the disclosed embodiments may also apply to any suitable portion or portions of the refrigerator, a standalone refrigerator or freezer, an air conditioning unit or any other suitable appliance with a heat exchanger. In this example, the refrigerator 200 includes a housing 200H, the heat exchanger 220, a fan 230, an icemaker 240, an ice bucket 245, freezer shelves 250 and freezer baskets 260. In other examples the refrigerator 200 may include any suitable components arranged in any suitable configuration. The heat exchanger 220 and the fan 230 are connected to the housing 200H and form part of the heat exchange system 210 (other components of the heat exchange system are not shown for clarity purposes). In this example, the heat exchanger 220 and the fan 230 are located towards the top 200T of the refrigerator 200, but in other examples the heat exchanger 220 and the fan 230 may be positioned in any suitable location of the refrigerator 200. The fan 230 may be any suitable fan configured to circulate a flow of air (e.g. airflow 280 indicated by the arrows in
Referring to
In this example the heat exchange fluid 400 may be any suitable refrigerant such as, for exemplary purposes, R-600a refrigerant, and compared to other systems using other refrigerants, the amount of the heat exchange fluid 400 can be limited. For example, the amount of heat exchange fluid 400 used in the heat exchange system 210 may be limited to approximately 50 grams of heat exchange fluid. In alternate embodiments, the amount of heat exchange fluid 400 used can be greater or less than approximately 50 grams.
As shown in
The heat exchange fluid 400 travels through the tubing 350 in the directions indicated by the arrows shown in
In one embodiment, the fan 230 shown in
In operation of the heat exchanger 220, the heat exchange fluid 400 is primarily liquid as it enters the inlet 310 of the heat exchanger 220. As the airflow 280 passes over/through the heat exchanger 220, the heat transfer from the air to the fluid 400 promotes boiling of the heat exchange fluid 400 inside the tubing 350. The boiling of the heat exchange fluid 400 causes vapor pockets 410 to form within the tubing 350 with liquid slugs 400S formed between the vapor pockets 410. As shown in
For testing purposes only, a comparison was made between the conventional heat exchanger as in
The same General Electric Monogram 42 inch side by side refrigerator was modified with a heat exchanger 220 of the invention so that the flow of refrigerant within the heat exchanger 220 and the airflow over the heat exchanger 220 were substantially collinear or co-directional. The refrigerant charge in this example was maintained at 55 grams of R600a refrigerant. Tests on the modified refrigerator with the heat exchanger 220 indicated that optimum heat exchanger flooding occurred and that heat exchanger temperatures were saturated up to a point about seven-eighths of the way through the heat exchanger. Refrigerant temperatures at the exit of the heat exchanger 220 exhibited only 1° F. of superheat.
Thus, while there have been shown and described and pointed out fundamental novel features of the invention as applied to the exemplary embodiments thereof, it will be understood that various omission and substitutions and changes, in the form and details of devices illustrated, and in their operation, may be made by those skilled in the art without departing from the spirit of the invention. For example, it is expressly intended that all combinations of those elements and/or method steps which perform substantially the same way to achieve the same results are with the scope of the invention. Moreover, it should be recognized that structures and/or elements and/or method steps shown and/or described in connection with any disclosed form or embodiment of the invention may be incorporated in any other disclosed or described or suggested form or embodiment as a general matter of design choice. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto.
Claims
1. A heat exchanger comprising:
- a heat exchange fluid inlet;
- tubing coupled to the heat exchange fluid inlet, the tubing being configured to direct a flow of heat exchange fluid through the heat exchanger, the flow of fluid having a main fluid flow direction; and
- an air inlet configured to direct a flow of air in a generally collinear relationship with the main fluid flow direction.
2. The heat exchanger of claim 1, wherein the tubing has an internal diameter and the airflow promotes boiling of the heat exchange fluid inside the tubing such that vapor pockets form within the tubing, the vapor pockets being configured to bridge the internal diameter so that liquid slugs are formed between the vapor pockets.
3. The heat exchanger of claim 2, further comprising a first side and a second side, the heat exchange fluid inlet being disposed proximate the first side, and the main fluid flow direction is in a direction moving from the first side to the second side to cause a greater amount of vapor pockets to form at the first side where the heat exchange fluid is primarily in a liquid form.
4. The heat exchanger of claim 2, further comprising a heat exchange fluid outlet, the substantially collinear relationship between the direction of air flow and the main fluid flow direction causing the vapor pockets to push the liquid slugs through the tubing so as to increase the amount of liquid heat exchange fluid that is provided towards the heat exchange fluid outlet.
5. The heat exchanger of claim 1, wherein an amount of the heat exchange fluid comprises approximately 50 to approximately 55 grams of refrigerant.
6. The heat exchanger of claim 5, wherein the heat exchange fluid comprises R-600a refrigerant.
7. A heat exchange system for a refrigerator/freezer, the heat exchange system comprising:
- a heat exchanger comprising tubing having a serpentine configuration, the tubing being configured to direct a flow of heat exchange fluid in a main fluid flow direction; and
- a fan configured to effect an airflow through the heat exchanger in a substantially collinear relationship with the main fluid flow direction,
- wherein a substantially even distribution of liquid heat exchange fluid flows throughout the heat exchanger.
8. The heat exchange system of claim 7, wherein the tubing has an internal diameter, vapor pockets forming within the tubing from the boiling of the heat exchange fluid inside the tubing, the vapor pockets being configured to bridge the internal diameter of the tubing so that liquid slugs are formed between the vapor pockets.
9. The heat exchange system of claim 8, wherein the vapor pockets are configured to push the liquid slugs through the heat exchanger.
10. The heat exchange system of claim 8, wherein the heat exchanger further comprises a first side and a second side, the heat exchange fluid being primarily in a liquid form at the first side of the heat exchanger, the main fluid flow direction being in a direction moving from the first side to the second side to cause a greater amount of vapor pockets to form at the first side where the heat exchange fluid is primarily in a liquid form.
11. The heat exchange system of claim 8, wherein the heat exchanger further comprises a heat exchange fluid outlet, wherein the substantially collinear relationship between the airflow direction and the main fluid flow direction causes the vapor pockets to push the liquid slugs through the tubing such that a greater amount of liquid heat exchange fluid is provided towards the heat exchange fluid outlet.
12. The heat exchange system of claim 7, wherein an amount of the heat exchange fluid is in the range of 50 to 55 grams of refrigerant.
13. The heat exchange system of claim 12, wherein the heat exchange fluid comprises R-600a refrigerant.
14. An appliance comprising:
- a housing;
- a heat exchanger having heat exchange fluid flowing within the heat exchanger; and
- an airflow duct configured to allow an airflow to circulate within the housing and through the heat exchanger,
- wherein the heat exchanger is configured to direct a flow of the heat exchange fluid in a main fluid flow direction, the airflow through the heat exchanger moving in a substantially co-directional relationship with the main fluid flow direction, effecting a substantially even distribution of liquid heat exchange fluid throughout the heat exchanger.
15. The appliance of claim 14, wherein the heat exchanger comprises tubing having an internal diameter where the airflow through the heat exchanger promotes boiling of the heat exchange fluid inside the tubing such that vapor pockets form within the tubing, the vapor pockets being configured to bridge the internal diameter so that liquid slugs are formed between the vapor pockets.
16. The appliance of claim 15, wherein the vapor pockets are configured to push the liquid slugs through the heat exchanger.
17. The appliance of claim 15, wherein the heat exchanger comprises a first side and a second side such that the main fluid flow direction is in a direction moving from the first side to the second side to cause a greater amount of vapor pockets to form towards the first side where the heat exchange fluid is primarily in a liquid form.
18. The appliance of claim 15, wherein the heat exchanger further comprises a heat exchange fluid outlet, the substantially co-directional relationship of the airflow direction to the main fluid flow direction causing the vapor pockets to push the liquid slugs through the tubing such that a greater amount of liquid heat exchange fluid is provided towards the heat exchange fluid outlet.
19. The appliance of claim 14, wherein an amount of the heat exchange fluid is in the range of 50 to 55 grams of refrigerant.
20. The appliance of claim 19, wherein the heat exchange fluid comprises R-600a refrigerant.
Type: Application
Filed: Jul 31, 2009
Publication Date: Feb 3, 2011
Inventor: John C. STEIMEL (Louisville, KY)
Application Number: 12/533,285
International Classification: F28D 15/00 (20060101); F28D 1/00 (20060101);