The present disclosure relates generally to vehicle heat exchangers, and to a method for selectively controlling elements thereof.
Two goals for heat exchanger manufacturing often include forming a product that exhibits efficient transfer of heat, while maintaining a relatively simple manufacturing process. In the automotive industry, in particular, it has also become desirable to combine multiple functions into a single heat exchanger assembly. Combo-coolers and tri-coolers are examples of such assemblies, and each includes multiple, preferably coplanar coolers (non-limiting examples of which include oil coolers, condensers, radiators, etc.). In a combo- or tri-cooler, the tubes of each cooler are connected to the same pair of manifolds or end tanks. The coolers are often formed having a tube and fin structure, in part because of cost efficiency and ease of assembly.
Features and advantages of embodiments of the present disclosure will become apparent by reference to the following detailed description and drawings, in which like reference numerals correspond to the same or similar, though perhaps not identical, components. For the sake of brevity, reference numerals having a previously described function may or may not be described in connection with subsequent drawings in which they appear.
Embodiments of the vehicle heat exchanger disclosed herein generally include two end tanks connected via a main core having various heat exchanger elements therein. Each end tank advantageously includes a control element; and as such, each vehicle heat exchanger includes multiple control elements. The multiple control elements are configured to separately control heat exchanger elements operatively connected thereto. By including a control element on each of the end tanks, it is believed that flexibility and variability in control over the cooling loop is increased. Furthermore, each of the control elements may advantageously be serviceable. Various embodiments of the vehicle heat exchanger are shown and discussed further hereinbelow in reference to the figures.
Referring now to
As shown in
The tubes 18, 20 may have different internal configurations for defining fluid passages therein. The tubes 18, 20 may also have different external configurations defining one or more outer peripheral surfaces. It is contemplated that the internal configurations, external configurations or combinations thereof may vary along the length of the tubes 18, 20. Furthermore, the internal configuration of the tubes 18, 20 may be the same or different from the external configuration. Non-limiting examples of internal and external configurations includes grooves, ridges, bosses, or other like structures integrated along some or all of the tube 18, 20 length for assisting in heat transfer and/or for adding strength to the structure.
The internal configurations may also generate turbulence within the fluid, or otherwise control the nature of the flow of fluid therethrough. In other embodiments, the internal configuration of the tubes 18, 20 may be smooth, planar, grooved, ridged, contoured (e.g., including several patterned ridges), ribbed (i.e., including several protrusions), dimpled (e.g., including several depressions) or the like.
In still other embodiments, the tubes 18, 20 may include one or more internal inserts, which are fabricated separately from the tubes 18, 20 and are assembled therein. It is contemplated that inserts may be formed in a variety of configurations and shapes for insertion into the fluid passages or portions of fluid passages. As a non-limiting example, the inserts may be members (e.g., straight or contoured members) with complex or simple configurations. Alternatively, inserts may be coils, springs or the like.
The fluid passages of the tubes 18, 20 may have any suitable configuration, including square, rectangular, circular, elliptical, irregular, or the like. The fluid passages of the tubes 18, 20 may also include one or more partitions, fins or the like.
Formation of tubes 18, 20 may be accomplished using several different techniques. As non-limiting examples, the tubes 18, 20 may be drawn, rolled, cast or otherwise formed. Additionally, the tubes 18, 20 may be formed of a variety of materials including plastics, metals, carbon, graphite, other formable materials or the like. More specific non-limiting examples of suitable tube 18, 20 materials include a metal selected from copper, copper alloys, low carbon steel, stainless steel, aluminum alloys, titanium alloys, magnesium alloys, or the like, or combinations thereof. In a non-limiting example, the tubes are formed of aluminum, or copper-based alloys. The tubes 18, 20 may also be coated or otherwise surface treated over some or all of its length for locally varying the desired property. Still further, it is to be understood that the tubes 18, 20 may be dimpled or otherwise configured with other features which generate increased heat transfer through turbulence.
The tubes 18, 20 may also have the same or different hydraulic diameters. In some instances, some of the tubes 18, 20 within the same heat exchanger element HE1, HE2 may have different hydraulic diameters. The hydraulic diameter is generally configured to obtain maximum effectiveness of the exchanger element HE1, HE2. As used herein, the hydraulic diameter (DH) is determined according to the following equation:
D
H=4AP/Pw
wherein
Ap=wetted cross-sectional area of the passageway of a tube; and
Pw=wetted perimeter of the tube.
Each of the variables (Pw and Ap) for the hydraulic diameter (DH) are determinable for a tube 18, 20 according to standard geometric and engineering principles and will depend, at least in part, upon the configuration of a particular tube 18, 20 and the aforementioned variables for that tube 18, 20 (i.e., the number of partitions, the number of portions, the size of the portions, the size of the fluid passages, or combination thereof).
Heat transfer and pressure drop for a fluid flowing through the tubes 18, 20 can be determined for a range of hydraulic diameters using sensors such as pressure gauges, temperature sensors or the like.
If desired, baffles 24 may be included to partition the end tanks 12, 14. In some instances, the baffles 24 separate the first and second heat exchangers HE1, HE2. It is to be understood that the baffles 24 divide the tubes 18, 20 into separate zones, and through control elements 26, 28 (discussed further hereinbelow), one may operate the zones as a single heat exchanger or as multiple heat exchangers HE1, HE2 (as shown in
While not shown in
As shown in
In still another embodiment (not shown in the Figures), each control element 26, 28 is operatively positioned in a respective housing 30, 32, and each housing 30, 32 is integrally formed with and/or is attached to one of the end tanks 12, 14.
As shown in
In some instances, the control elements 26, 28 may be integrated with the cap 34, such that when the cap 34 is removed, so is the control element 26, 28.
Referring now to
Operatively disposed in the housing 30, 32 is the control element 26, 28. Non-limiting examples of suitable control elements 26, 28 include pressure actuated devices, temperature activated devices (e.g., a thermostat), and combinations thereof. Another non-limiting example of a suitable control element 26, 28 is an electromechanical device actuated via external signals. Some non-limiting examples of suitable electromechanical devices include solenoid activated valves, electric motor driven valves, memory metal actuated valves, or the like, or combinations thereof. As such, some embodiments of the control element 26, 28 may include an additional component (e.g., an external signaling device) that is located remotely from the first or second end tank 12, 14. It is to be understood that whether the control elements 26, 28 are self-actuated or externally actuated, they are used to regulate the flow of fluid through different areas of the main core 16 to correspond to a predetermined fluid loop.
Generally, the control element 26, 28 sits on a mating flange in the housing 32, 34, and is clamped into place by a cover or cap held in by fasteners (examples of which are mentioned above). In addition to the cap 34, other seals 42 may be used to secure the control element 26, 28 in the housing 32, 34. Non-limiting examples of such seals 42 include those formed of elastomeric materials.
Also shown in
Referring now to
Referring now to
In any of the embodiments disclosed herein, it is to be understood that more than one control element 26, 28 may be operatively connected to an end tank 12, 14. The end tank 12, 14 may include additional housings 30, 32 formed integrally therewith or attached thereto. Such additional control elements 26, 28 may be used to control additional heat exchanger elements HE1, HE2 operatively positioned in the main core 16.
Furthermore, in any of the embodiments disclosed herein, the first and second ends tanks 12, 14 may be part of a low temperature loop. In vehicle cooling loops, the engine cooling loop is often considered a high temperature loop, and the main engine is part of the loop. Generally, a single control element in an integrally formed housing 30, 31, 32 is not suitable when the heat exchanger is part of a high temperature loop, or is part of an engine cooling loop. However, when multiple control elements 26, 28 are used as taught in the present disclosure, the heat exchanger may advantageously be used in any cooling loop and may be housed in integrally formed or separately attached housings 30, 31, 32.
Low temperature loops have been implemented to cool additional areas of vehicle. In some instances, low temperature loops provide fluids to different areas of the vehicle (e.g., charge air cooler, transmission oil cooler, engine oil cooler, fuel cooler, exhaust gas cooler, etc.) at a lower temperature when compared to the main engine loop or high temperature loop. It is to be understood that the heat exchanger 10, 10′, 10″ disclosed herein and cooling loops may be configured such that a high temperature loop and a low temperature loop may be achieved in one heat exchanger 10, 10′, 10″, or such that a high temperature loop and a low temperature loop may be achieved through multiple heat exchangers 10, 10′, 10″. When an independent low temperature loop is used, the engine is not part of the loop, and cooling fluid is managed within a completely separate loop that is not part of the engine cooling loop. In this instance, the heat exchanger 10, 10′, 10″ (or low temperature radiator) does not support cooling of the engine.
In one non-limiting example, the vehicle heat exchanger 10, 10′ disclosed herein may be integrated into a low temperature cooling loop. In cold conditions, the control elements 26, 28 may be closed, allowing fluid to by-pass the heat exchanger elements HE1, HE2, and flow directly to an exhaust gas cooler, a transmission oil cooler, a fuel cooler, and a charge air cooler. In warm conditions, one of the control elements 26, 28 may be opened to allow approximately ⅓ of the fluid to flow through one of the heat exchanger elements HE1, HE2 and then into the fuel cooler and the charge air cooler. The other control element 28, 26 remains closed such that the other ⅔ of the fluid by-passes the other heat exchanger element HE2, HE1 and is directed to the exhaust air cooler and the transmission oil cooler. In hot conditions, both of the control elements 26, 28 may be opened to allow all of the fluid to flow through the heat exchanger elements HE1, HE2. Generally, about ⅓ of the fluid flows through one of the heat exchanger elements HE1, HE2 and into the fuel cooler and the charge air cooler, while about ⅔ of the fluid flows through the other of the heat exchanger elements HE2, HE1 and into the exhaust air cooler and the transmission oil cooler. It is to be understood that the vehicle engine may or may not be a part of this cooling loop.
Embodiments of the vehicle heat exchanger 10, 10′, 10″ disclosed herein include, but are not limited to the following advantages. It is believed that the cost of manufacturing such a device is reduced, in part because the housing 30, 31, 32 may be integrally formed with the end tank(s) 12, 14. It is further believed that the lifetime of the control elements 26, 28 may be advantageously increased, in part because the housing 30, 31, 32 creates an efficient seal for the control elements 26, 28, thereby reducing the exposure of the elements 26, 28 to fluids. Furthermore, the configuration of the housing 30, 31, 32 for the serviceability of the control elements 26, 28 enables relatively easy replacement of such elements 26, 28.
While several embodiments have been described in detail, it will be apparent to those skilled in the art that the disclosed embodiments may be modified. Therefore, the foregoing description is to be considered exemplary rather than limiting.