Heat exchanger system and method of operating the same

This patent application is a national stage filing under 35 U.S.C. 371 of International Application No. PCT/U.S.2008/054386, filed 20 Feb. 2008, and claims priority to U.S. provisional patent application, Ser. No. 60/902,314, filed Feb. 20, 2007, the entire contents of which are incorporated herein by reference.

The present invention relates to heat exchange systems, and more particularly, to heat exchange systems for cooling charge air in vehicle engines and methods of operating such systems.

In some embodiments, the invention provides a heat exchange system extending through a vehicle engine. The system can include a first charge air cooler and a second charge air cooler arranged in parallel to receive a first working fluid from a radiator. Each of the first and second charge air coolers can be operable to transfer heat between the first working fluid and a second working fluid. In some embodiments, the second working fluid travels through a first turbo charger before entering the first charge air cooler and travels through a second turbo charger before entering the second charge air cooler.

The invention also provides a heat exchange system extending through a vehicle engine, the system including a first charge air cooler, a second charge air cooler, and a pump for supplying a first working fluid non-sequentially to both the first and second charge air coolers. Each of the first and second charge air coolers can be operable to transfer heat between the first working fluid and a second working fluid.

In some embodiments, the present invention provides a heat exchange system including a radiator operable to remove heat from coolant and an air flow path extending through a first charge air cooler and a second charge air cooler. The first charge air cooler can be operable to transfer heat from air to the coolant. The second charge air cooler can be positioned downstream from the first charge air cooler along the air flow path to receive the air from the first charge air cooler and being operable to transfer heat from the air to the coolant. The heat exchange system can also include a coolant circuit extending between a coolant pump, the radiator, and the first and second charge air coolers.

The present invention also provides a heat exchange system including a radiator being operable to remove heat from coolant and a coolant circuit extending between a coolant pump, a radiator, and first and second charge air coolers. Pressure differences along the coolant flow path can distribute a first predetermined quantity of the coolant from the radiator to the first charge air cooler and a second predetermine quantity of coolant from the radiator to the second charge air cooler. The heat exchange system can also include an air flow path extending through the first and second charge air coolers. The first and second charge air coolers can be operable to transfer heat from air traveling along the air flow path to the coolant traveling along the coolant circuit through the first charge air cooler and to the coolant traveling through the second charge air cooler.

In addition, the present invention provides a method of operating a heat exchange system including the acts of directing a coolant along a coolant circuit through a pump and a radiator, dividing the coolant from the radiator between a first charge air cooler and a second charge air cooler, directing air along an air flow path through the first charge air cooler and the second charge air cooler transferring heat from the air to the coolant in the first charge air cooler, and transferring heat from the air to the coolant in the second charge air cooler.

The present invention also provides a method of operating a heat exchange system including the acts of directing air along an air flow path sequentially through a first turbo charger, a first charge air cooler, a second turbo charger, and a second charge air cooler, and controlling pressure differences along a coolant circuit to divide coolant traveling along the coolant circuit and exiting a radiator into each of a first charge air cooler and a second charge air cooler.

Other aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings.

FIG. 1 is a schematic representation of a heat exchange system according to some embodiments of the present invention.

Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items.

Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings. In addition, terms such as “first” and “second” are used herein for purposes of description and are not intended to indicate or imply relative importance or significance.

FIG. 1 illustrates a heat exchange system 10 for use in a vehicle, such as, for example, a truck, a tractor-trailer combination, a bus, a van, an automobile, farm equipment, off-road vehicles, etc. In some embodiments of the present invention, the heat exchange system 10 can include a pump 12 , a first radiator 16 , a second radiator 18 , a first charge air cooler 20 , and a second charge air cooler 22 positioned along and fluidly connected by a heat exchange circuit 24 . As shown in FIG. 1 , at least a portion of the heat exchange system 10 can extend through the vehicle engine 14 .

In some embodiments, the pump 12 is operable to direct a first quantity of a relatively low temperature working fluid (e.g., water, a water-glycol mix, and the like) (represented by arrows 26 in FIG. 1 ) along a branch 28 of the heat exchange circuit 24 toward the vehicle engine 14 . The working fluid 26 then travels through the vehicle engine 14 or a portion of the vehicle engine 14 . As the working fluid 26 travels through the vehicle engine 14 , heat can be transferred from the vehicle engine 14 to the working fluid 26 , thereby elevating the temperature of the working fluid 26 and cooling the vehicle engine 14 or a portion of the vehicle engine 14 .

Although not shown in FIG. 1 , the heat exchange system 10 can also or alternatively include a heating clement positioned along the heat exchange circuit 24 . In some embodiments, high temperature working fluid 26 exiting the vehicle engine 14 can be directed through the heating element to provide heat to the passenger space of the vehicle. In some such embodiments, the heating element supplements the heat provided to the passenger space by a primary passenger space heating element.

From the vehicle engine 14 , or alternatively from the heating element, the working fluid 26 travels along the heat exchange circuit 24 through the branch 28 toward the first radiator 16 . In some embodiments, the first radiator 16 can be positioned in or adjacent to the vehicle engine 14 . In other embodiments, the first radiator 16 can be positioned in other locations around the vehicle.

As the working fluid 26 travels through the first radiator 16 , heat can be transferred from the working fluid 26 to the atmosphere, or alternatively, to a coolant flowing through the first radiator 16 . In this manner, the first radiator 16 lowers the temperature of the working fluid 26 . From the first radiator 16 , the working fluid 26 travels along the heat exchange circuit 24 and back to the pump 12 to be re-circulated through the heat exchange circuit 24 .

As mentioned above, the pump 12 is operable to direct a first quantity of a relatively low temperature working fluid 26 along the branch 28 of the heat exchange circuit 24 toward the vehicle engine 14 . In some embodiments, the pump 12 is also or alternatively operable to direct a second quantity of the working fluid 26 along a branch 34 toward the second radiator 18 .

As the working fluid 26 travels through the second radiator 18 , heat can be transferred from the working fluid 26 to the atmosphere, or alternatively, to a coolant flowing through the second radiator 18 . In this manner, the second radiator 18 lowers the temperature of the working fluid 26 .

From the second radiator 18 , the working fluid 26 travels along the heat exchange circuit 24 , through the branch 34 toward the first charge air cooler 20 or alternatively, through the branch 34 toward the second charge air cooler 22 . In some embodiments, approximately 40% by volume of the working fluid 26 is directed to the first charge air cooler 20 and approximately 60% by volume of the working fluid 26 is directed to the second charge air cooler 22 . In other embodiments, an approximately equal volume of the working fluid 26 is directed to each of the first and second charge air coolers 20 , 22 . In still other embodiments, approximately 60% by volume of the working fluid 26 is directed to the first charge air cooler 20 and approximately 40% by volume of the working fluid 26 is directed to the second charge air cooler 22 . In yet other embodiments, the heat exchange circuit 24 can direct different volumes of the working fluid 26 to each of the first and second charge air coolers 20 , 22 .

In embodiments, such as the illustrated embodiment of FIG. 1 , in which the working fluid 26 is directed to either of the first and second charge air coolers 20 , 22 , the flow of the working fluid 26 through the heat exchange circuit 24 and the distribution of the working fluid 26 to each of the first and second charge air coolers 20 , 22 can be at least partially controlled by maintaining the pressure of the working fluid 26 traveling through one or more of the elements of the heat exchange system 10 within a desired range. In some such embodiments, the heat exchange system 10 can distribute a desired volume of the working fluid 26 to each of the first and second charge air coolers 20 , 22 without the use of valves or other flow-control or flow-regulating apparatus. In other embodiments, the heat exchange system 10 can also or alternatively include a valve or other flow-control or flow-regulating apparatus positioned along the heat exchange circuit 24 .

As shown in FIG. 1 , the vehicle engine 14 can include an air intake 42 , a first turbo charger 44 , and a second turbo charger 46 arranged along an air flow path 48 . As also shown in FIG. 1 , the air flow path 48 can extend through or past the first and second charge air coolers 20 , 22 .

In some embodiments, atmospheric air (represented by an arrow 52 in FIG. 1 ) enters the air flow path 48 through the air intake 42 at approximately atmospheric pressure and travels toward the first turbo charger 44 . As the air 52 travels through the first turbo charger 44 , the air 52 is compressed, thereby elevating the temperature of the air 52 .

The compressed air 52 then travels along the air flow path 48 toward the first charge air cooler 20 , where heat is transferred from the air 52 to the working fluid 26 , thereby elevating the temperature of the working fluid 26 and lowering the temperature of the air 52 . The air 52 then continues along the air flow path 48 toward the second turbo charger 46 , and the working fluid 26 then continues along the heat exchange circuit 24 and is returned to the pump 12 to be re-circulated through the heat exchange circuit 24 .

As the air 52 travels through the second turbo charger 46 , the air 52 is further compressed and the temperature of the air 52 is increased. The compressed air 52 then travels along the air flow path 48 toward the second charge air cooler 22 , where heat is transferred from the air 52 to the working fluid 26 , thereby elevating the temperature of the working fluid 26 and lowering the temperature of the air 52 . The air 52 then continues along the air flow path 48 toward the vehicle engine 14 , and the working fluid 26 then continues along the heat exchange circuit 24 and is returned to the pump 12 to be re-circulated through the heat exchange circuit 24 .

In some embodiments, the first and second turbo chargers 44 , 46 , the first and second charge air coolers 20 , 22 , and/or the other elements of the heat exchange system 10 are designed together as an integral system such that the heat exchange system 10 is operable to supply low temperature working fluid 26 to the first and second charge air coolers 20 , 22 on high temperature days (i.e., when the ambient temperature is greater than or equal to approximately 25° C.). Alternatively or in addition, the first and second turbo chargers 44 , 46 , the first and second charge air coolers 20 , 22 , and/or the other elements of the heat exchange system 10 are designed to minimize the pressure drop experienced by the working fluid 26 and to prevent the working fluid 26 from boiling while traveling through the heat exchange circuit 24 .

In some embodiments, the heat exchange system 10 of the present invention is operable to maintain a relatively constant intake manifold temperature. More particularly, the first and second charge air coolers 20 , 22 are operable to maintain the temperature of air entering the intake manifold at or within a relatively narrow range surrounding a desired operating temperature. In some embodiments, the temperature of the air entering the intake manifold can be further regulated using a system controller and/or a valve arrangement for regulating the flow of working fluid 26 through the first and second radiators 16 , 18 . Moreover, because the intake manifold temperature is maintained at a relatively constant temperature, the vehicle engine 14 can be operated relatively efficiently, thereby reducing emissions and minimizing fuel consumption.

In some embodiments, the heat exchange system 10 is also or alternatively operable to warm the vehicle engine 14 or a portion of the vehicle engine 14 on cold days. In some such embodiments, as the working fluid 26 travels through the heat exchange circuit 24 , the working fluid 26 distributes heat from the first and/or second turbo chargers 44 , 46 to the vehicle engine 14 or portions of the vehicle engine 14 , thereby effectively preheating the vehicle engine 14 .

The embodiments described above and illustrated in the figures are presented by way of example only and are not intended as a limitation upon the concepts and principles of the present invention. As such, it will be appreciated by one having ordinary skill in the art that various changes are possible.