US2274442A - Heat exchange device - Google Patents

Description

Feb. 24, 1942. R. J. WOODS HEAT .EXCHANGE DEVICE Filed April 28, 1939 2 Sheets-Sheet 2 fbazerj M003 Patented Feb. 24, 1942 UNITED STATES PATENT OFFICE to Bell Aircraft Corporation, corporation of New York Application April as, 1939, Serial No. 270,666

4 Claims. (01. '12a-174) positioned the nozzle of an exhaust pipe of an This invention relates generally to a means for increasing the flow of gases through a conduit, having a Venturi section by utilizing the energy of exhaust gases of an engine, and more especially to the utilization of this idea for purposes of heat exchange by positioning a heat exchange device in a conduit of this construction. While I cooling combustion engines by 'the useof radiators,- and this is especially true when the machine is at rest or moving slowly. This difliculty is present under all conditions" in vehicle constructions in which the radiator does not have a frontal area as is the case with rear end drive buses and cars. My invention will also increase the efficiency of the cooling systems of tanks,

'- armored cars and Diesel locomotives Many types of airplanes also employ radiators and other heat exchange devices, such as lubricatirig oil coolers, which are positioned so as not to have an opening normal to the direction of flight. In order to obtain adequate cooling in airplanes of this type, air scoops are employed to internal combustion engine.

Still another object of my invention is to increase the air flow through a conduit of the type just described by creating a suction efiect by discharging the exhaust gases from the engine into the Venturi section.

Yet another object of my invention is to provide a cooling unitfor an internal combustion engine which consists of a conduit in which is positioned a heat exchange device, suchas a ra diator,.for reducing the temperature of the cooling medium'or the lubricating oil of the engine, said conduit being provided with a Venturi section in which is positioned the nozzle of an exhaust pipe from the internal combustion engine. A further object of my invention is'to provide a cooling unit of the type described in which the conduit does not have a frontal opening normal to the direction of motion, thereby enabling the volume of the flow of air through the conduit to be principally controlled by the engine speed rather than the velocity at which the vehicle is moving.

With these and other objects in view, my invention embraces broadly the 'concept of providinduce increased air flow for purposes of cooling,

or the radiators and oil coolers are placed partly outside the contour of the airplane to obtain adequate air flow. Either of these structures materially increases the drag upon the airplane.

' to keep it warm.

. One of the objects of my invention is to overcome the above-mentioned disadvantages of the prior art.

Another object of my invention isto provide ing a conduit through which a gas may freely circulate, which is provided with a reduced portion in which the nozzle of the exhaust pipe of an internal combustion engine may be positioned insuch a manner that the exhaust gases may be discharged at high velocity into this restricted portion of the conduit, thereby creating a suction efiect which will increase the flow of gases lubricating system of an internal combustion engine. Such construction can be used in connection with either stationary engines or engmes used to propel vehicles, and is especially suitable foruse in buses and cars having rear end drives, and in airplane construction to lessen drag. The use of this invention will also overcome 'the difliculties which have been encountered in cooling the power units of certain special types of vehicles, such as armored cars, tanks,

. and Diesel locomotives.

Figure 1 of the drawings .discloses a fragmenta co u t having & uri Section which is in longitudinal section of an airplane in which is positioned at of the cooling units which form the basis of this invention.

Figure 2 of the drawings discloses a fragment in side elevation of the fuselage of an airplane. Figure 3 discloses a fragmental plan view partly in section of a modification of the invention.

For purposes of illustration I have shown in the drawings the manner in which my invention is applied to cooling an internal combustion engine which forms the power unit of an section and is mounted on the right side of the fuselage as shown at 8 at a point directly above the airfoil 2. The skin of the fuselage 3 at this point is provided with an aperture through which the duct 8 communicates with the atmosphere. A grill 9 is positioned in the aperture to filter the incoming air. a

The cylindrical portion of the air duct 8 extends transversely across the fuselage 3 until it is in close proximity with the left wall of the fuselage and then turns rearwardly and is narrowed to form a Venturi section III in the narrowest part of which is positioned a nozzle ll of an exhaust pipe H in a manner which will be subsequently described. The rearward extremity of the duct 8 is flared and is mounted on the left side of the fuselage 3 at a position rearward ofthe trailing edge of the airfoil 2 as shown at l2. An aperture I2 is provided through the skin of the fuselage at this point so that the air duct 8 forms a continuous conduit from one side of the fuselage 3 to the other.

The exhaust pipe II. is mounted on the left block of the engine 4 and exhausts the burnt vapors from the six cylinders which form this block. This exhaust pipe extends rearwardly, through a close fitting aperture in theair duct 8 and discharges the exhaust gases into the Venturi section III, as has previously been described.

A liquid radiator I3 is rigidly mounted in the large section of the air duct 8 between the grill 9 and the Venturi section ID. This radiator 13 is connected to the cylinder jackets of the engine 4 by means of the pipes l4. v

In operation the air passes through the grill 9, through the radiator I3, and the remainder of the air duct to the left side of the fuselage 3 where it is discharged through the opening l2. The force required to induce this air flow through the air duct 8 and across the fuselage 3 is obtained by the suction effect created by the discharge of exhaust gases fromthe nozzle 4 ll of the exhaust pipe ll into the Venturi section 10.

The cooling unit 1 consists of, an air duct I which is similar in construction to that of the air duct 8. The intake end of the air duct 15 is mounted, however, on the left side of'the fuselage 3, as indicated at I6, above the airfoil 2 and is provided with a grill i! which is positioned in an aperture through the fuselage skin. The cylindrical portion of the air duct Venturi section I 8 in the narrowest part of .which is positioned the nozzle IQ of an exhaust pipe end which is mounted on the right side of the fuselage 3 as shown. at 20 and surrounds an aperture 28 which is provided in the skin of the fuselage at this point. An oil cooler 2| is positioned in the cylindrical portion of the air duct l5 and is connected to the lubricating system of the engine 4 by any suitable means.

The exhaust pipe I9 is connected to the exhaust ports of three of the cylinders which form the right block of the engine 4 and extends rear- I5 extends transversely across the fuselage to a 1 point adjacent the right side of the fuselage and then extends rearwardly and narrows to form a wardly into the air duct IS in a manner similar to that described in connection with the exhaust pipe H. The burnt gases from the remainder of the cylinders which compose the right block of the engine 4 are exhausted through the exhaust pipe indicated at 22.

In operation the air passes through the strainer grill H, the oil cooler 2| .and the remainder of the air duct Hi to the exhaust aperture 20'. The force required to induce this air flow is obtained by the suction efiect created by discharging the gases into "the narrowest part of the Venturi section i8 at high velocity.

By employing this suction effect, a large volume of air can be drawn through the air ducts 8 and IS without. employing air scoops or the use of grills having a frontal area normal to the line of flight. Moreover, the radiator or oil cooler need not be positioned in such a manner that they extend out into the air flow. By eliminating these constructions, the engine may be. eificiently cooled without obstructing the air flow surface of the airplane.

Another important feature resides in the fact that the amountof air flowing over the heat exchange devices is proportional to the engine speed and is not dependent upon the velocity of the airplane. For this reason, during power off dives when the engine speed is cut to a minimum, the suction created by the exhaust gases ,in the Venturi sections of the air ducts isin-.

stantly reduced'with a corresponding reduction of the volume of air which is drawn through the ducts. This'prevents the lubricating oil and cooling medium from being chilled during the dive, and removes the necessity of gunning the engine.

Moreover, when the engine is being driven with an open throttle with the airplane at rest upon the ground, the increased velocity and volume of the exhaust gases being discharged into the Venturi sections draws a large volume of air through the ducts, thereby increasing the heat exchange capacity of the radiator and cooler and increasing the general efliciency of the engine.

While for purposes of illustration I have shown the exhaust pipe [I connected to six cylinders of the engine 4 and the exhaust pipe IQ connected to three cylinders of the engine 4, it is to be understood that my invention is not to be limited by thisdisclosure, nor to the use of a twelve cylinder engine. Any type of gasoline or Diesel enginemay be used, and actual tests on airplanes of different designs may disclose that all thecy-linders are necessary to induce the proper 'air flow through one or more cooling units, and, on the other hand, it is possible that one or two cylinders may be sufficient. Obviously, the amount of suction produced by a specified engine and engine speed will depend upon the size and length of the air duct, and also The air duct I5 is provided with a flared the size'of the Venturi section. It is contem plated that these factors will be varied to apply in each of the said opposed walls, said openings my invention to different types and designs of machines in order to secure the desired results. Moreover, it is possible to construct a single air duct 25 in which to accommodate both'the 1 radiator I3 and the oil cooler 2| as shown in Figure 3 of the drawings; and my disclosure is therefore not limited to the use of two ducts.-

cars, armored cars, tanks, Diesel locomotives, or

in connection with stationary engines. It is especially effective for use in vehicles which present a difficult cooling problem, such as rear end drive buses, armored cars, and Diesel loco-' motives, and stationary engines, or where air drag must be reduced to the minimum as in the case of airplanes. In adapting the invention, the air duct is mounted in any suitablemanner at a point adjacent the engine to ;,be cooled.

v I therefore wish it understood that, although I have described only one form of my invention for purposes of illustration, I ,do not intend that the invention be limited to any particular type of airplane construction or to any particular type of vehicle. On the contrary; I desire the invention to be only limited by the prior art and the scope of. theappended claims.

I claim:

opposed walls and provided with an engine havsaid openings being positioned perpendicular to 1. A conditioning system for a vehicle-having 'ing an exhaust port and an oiling system, comprising an opening in each of said opposed walls,

the said air flow, a duct mounted within the vehicle, the extremities of said duct operatively communicatingwithsaid openings, one of said openings serving as an outlet and the other as an inlet to the duct, 9'. Venturi section in theduct adjacent the outlet opening, a heat'exchange device mounted in the duct. at a point interme diate the inlet opening and the Venturi section,

and an exhaust pipe extending through the wall of the duct and terminating inthe Yenturi section, said exhaust pipe and heat exchange device being operatively connected to the exhaust side of the engine and the oiling system, respectively.

2. A conditioning system for a vehicle having opposed walls and provided with an engine havbeingpositioned perpendicular to the said air flow, a pair of ducts mounted within the vehicle,

said ducts extending transversely across the vehicle and operatively communicating with the openings in the opposed walls, a Venturi section I in each of the ducts adjacent the outlet openings, a heat exchange device mounted in each of the ducts at points intermediate of the inlet opening and the Venturi section, and an exhaust pipe extending through the wall of each of the ducts and terminating in the Venturi section, said exhaust pipes and heat exchange device being operatively connected to the exhaust side of the motor and the cooling and oiling systems,

respectively. 3. A conditioning system for a vehicle having opposed walls and-providedwith an engine having exhaust ports, a liquid cooling system and an oiling system, comprising a pair of openings in each of the said opposed walls, said openings being positioned perpendicular to the said air flow, a pair of ducts mounted within the vehicle, said ducts extending transversely across the vehicle and operatively communicating 'withthe openings in the opposed walls, a Venturi section I-in each of the ducts adjacent the outlet openings, a heat exchange device mounted in each of the ducts at points intermediate of the inlet opening andthe Venturi section, and an exhaust pipe-extending through. the wall of eachof the ducts, each of said exhaust pipes terminating in the narrowest part of said Venturi section and each of said exhaust pipes being parallel to the longitudinal axis of the Venturi section in which it is positioned, said exhaust pipe and heat exchange device being operatively connected to the exhaust side oi the engine and the cooling and oiling systems, respectively.

4. A conditioning system for a vehicle having opposed walls and provided with an engine havingan exhaust pipe and liquid cooling and oilingsystems comprising an opening in each of the said opposed walls, said openings being posi-' tioned perpendicular to the said air flow, a duct mounted within the vehicle, the extremities of said duct operatively communicating with the said openings, one of the said openingsserving as an outlet and the other as an inlet for the duct, a Venturi section in the duct'adjacent the said outlet opening, a pair of heat exchange devices mounted in the duct at a point intermein; exhaust ports, a liquid cooling system and an'oiling system, comprising a pair of openings diate the inlet opening and the Venturi section,

and an exhaust pipe extending through thewall.

of the duct and terminating inthe Venturi section, said exhaust pipe being connected to the exhaust side .of the engine. and one of the heat exchange devices being connected to the liquid cooling system and the remaining heat exchange device being connected to the oiling system.

ROBERT J. wo'ons.

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