Heat exchange system for vehicles and heat exchanger therefor
BACKGROUND OF THE INVENTION 
     The field of the present invention is heat exchanger construction and systems for vehicles. 
     Heat exchangers have long been employed in vehicles for both cooling of the engine, commonly referred to as radiators, and for heating the passenger compartment, commonly referred to as heater cores. In both systems, tubes are provided for the engine coolant liquid. The tubes are positioned in an open matrix such that air can be forced or naturally flow past the tubes for heat exchange. Fins associated with the tubes, air flow baffles and the like are used to enhance the heat transfer efficiency between the liquid coolant and the air. 
     Vehicle efficiency has become of significant interest in the light of competition and regulation. The vehicle coolant heat exchange systems impact significantly on that efficiency. The efficiency of both the radiator and the heater core contribute inversely to weight, size, vehicle frontal area and engine temperature stability. Consequently, improving the efficiency of these devices can significantly impact on the overall vehicle efficiency. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to heat exchange technology wherein the coolant flows through the shell and the air stream passes through tubes open at both ends outwardly of the shell. 
     In a first aspect of the present invention, a heat exchange system for a vehicle includes a heat exchanger having a shell which receives the coolant from the system. Tubes extend across the shell and open outwardly for airflow and efficient heat transfer. The tubes may include fins for increased heat transfer. 
     In a second aspect of the present invention, a heat exchanger structure includes two tube sheets with tubes extending from one of the sheets and extending through holes in the second sheet. The exchanger may additionally include baffles of various configurations. In one configuration, baffles extend inwardly between the tubes from either side to create a circuitous path for coolant through the shell side of the exchanger. 
     Accordingly, it is an object of the present invention to provide an improved heat exchange system and improved components therefor. Other and further objects and advantages will appear hereinafter. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a schematic view of a heat exchange system for an engine. 
     FIG. 2 is a side view of a heat exchanger with portions broken away for clarity. 
     FIG. 3 is a side view of the heat exchanger of FIG. 2 with portions broken away for clarity. 
     FIG. 4 is a cross section of a first tube configuration. 
     FIG. 5 is a cross section of a second tube configuration. 
     FIG. 6 is a side view of a heat exchanger showing an alternate baffle arrangement with portions broken away for clarity. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Turning in detail to the drawings, FIG. 1 illustrates a heat exchange system for an engine 10. Cooling passages 12 and are coupled with the cooling system of the engine 10 and are in communication with a heat exchanger, generally designated 16. A fan 18 Schematically illustrates airflow enhancement mechanisms to insure adequate flow through the heat exchanger 16. 
     FIG. 2 details a first embodiment of the heat exchanger 16. The heat exchanger 16 includes a shell 20 and a plurality of tubes 22. There are four sidewalls 24, 26, 28 and 30 arranged in a rectangular structure. The upper and lower sidewall is 24 and 26 include an inlet 32 and an outlet 34, respectively. Couplings 36 and 38 may be associated with and become part of the cooling passages 12 and 14. A baffle 40 having holes 42 extends fully across the interior of the shell 20. Thus, flow through the inlet 32 must pass through the holes 42 of the baffle 40 before encountering the tubes 22. Thus, an appropriate distribution of coolant to all tubes 22 may be achieved. 
     The heat exchanger 16 is constructed of a series of formed elements which may be brazed or otherwise joined together. A first tube sheet 44 is shown to be integrally formed with the tubes 22. Holes 48 extend through the tube sheet to align with the centers of the tubes 22 for communication with the air. A second tube sheet 50 has holes 52 which extend therethrough. The holes are sized to accommodate the tubes 22 such that they may extend at least part of the way through the sheet 50. The tubes 22 may be appropriately brazed or otherwise sealed with the sheet 50. The sheet 50 is formed with the four sidewalls 24, 26, 28 and 30. The first tube sheet 44 abuts against the sidewalls where it may be appropriately sealed through brazing or other means. 
     The tubes may be of various configurations. FIGS. 4 and 5 represent two such configurations. The tubes 22 include longitudinally oriented radially directed fins 54 in the embodiment of FIG. 4. The embodiment of FIG. 5 illustrates additional longitudinally oriented fins 56 which extend radially inwardly. 
     A further embodiment is illustrated in FIG. 6. The shell 20 includes baffles 58 and 60 extending inwardly from either of the sidewalls 28 and 30, respectively. The baffles 58 and 60 do not extend fully across the shell and are shown alternate with rows of tubes 22 therebetween. With the baffles 58 and 60 extending fully between the tube sheets 44 and 50, the coolant flow must traverse back and forth through the shell 20. Thus, residence time within the shell is better controlled for the entire flow. It may be further advantageous to locate the inlet 32 and outlet 34 at appropriate corners of the shell 20 so as to obtain maximum advantage of both the uppermost and lowermost rows of tubes 22. 
     The schematic of FIG. 1 also further illustrates additional cooling mechanisms which may be applied for efficient cooling. Fins 62 may be located on the outer side of the shell 20 for further heat transfer from the exchanger. 
     Accordingly, an improved heat exchange system with an improved a heat exchanger have been disclosed. While embodiments and applications of this invention have been shown and described, it would be apparent to those skilled in the art that many more modifications are possible without departing from the inventive concepts herein. The invention, therefore is not to be restricted except in the spirit of the appended claims.