US 2109237 A
Description (OCR text may contain errors)
L. LUSTIG POWER PLANT Feb. 22, 1938.-
Filed June 25, 1934 2 Sheets-Sheet 1 4 8 EXH/Yl/JTEI? P947 Mot El? DEM/51V Pun 7P INVENTOR [HOW/6 1057/3. 4o 4! BY 4 RNEY ATTO
L. LUSTIG POWER PLANT Feb. 22, 1938.
Filed June 25, 1934 2 Sheets-Sheet 2 94 f? CONTROL INVENTOR ZflfiW/G Aver/( v Ear/mum Ema/NE ATTORN EY Patented Feb. 22, 1938 UNITED STATES PATENT OFFICE,
POWER PLANT Ludwig Lustlg, Manhasset, N. Y. Application June 25, 1934, Serial No. 732,196
My invention relates to power plants and particularly to power plants including an internal combustion engine and a super-charger for supplying air or an explosive mixture to the engine.
In using a super-charger with an internal combustion engine the air or the explosive charge is admitted to the engine cylinder under pressure. Therefore, after explosion of the charge the quantity, the volume and the temperature of the exhaust gases leaving the cylinder are considerably greater than when the super-charger is not employed. This increase in volume of the exhaust gases gives rise to considerable back pressure which tends to offset the advantages gained by the use of the super-charger. For example the resistance to the passage of the large volume of exhaust gases from the cylinder presented by the valves, exhaust. manifold, etc., causes a substantial portion of the exhaust gases to remain in the cylinder when a new charge is admitted. In ordinary operation with a supercharger the back pressure of these gases may amount to as much as 20 or 30 lbs. per square inch above atmospheric pressure. For this reason considerable difficulty is experienced in properly scavenging the cylinder preparatory to the introduction of the succeeding explosive charge. The explosive charge which is subsequently introduced into the cylinder is, therefore, diluted' by the remaining exhaust gases and the amount of the air or explosive mixture actually admitted to the cylinder is reduced. The force required to operate the valves and to expel the exhaust gases from the cylinder is also increased when a super-charger is employed due to the increased pressure of the gases in the cylinder at the completion of the piston stroke. Furthermore, the temperature of the exhaust gases leaving the engine is higher when a super-charger is employed and thus the heat contained in the gases is wasted.
In accordance with my invention the back pressure of exhaust gases leaving the engine cylinder 7 is reduced and in fact a suction or sub atmospheric pressure may be produced so as to aid in the removal of the exhaust gases from the cylinder. scavenging of the cylinder is therefore improved, the amount of air or explosive mixture introduced into the cylinder is increased and the force required to operate the valves and to expel exhaust gases from the cylinder is reduced.
The means employed for reducing the back pressure on the cylinder in accordance with my invention utilizes the heat contained in the exhaust gases as a source of energy for operating the same. Furthermore, this energy may also be used for operating the super-charger thus increasing the efliciency of the power plant.
In that form of my invention hereinafter de- 5 scribed, heat contained in the exhaust gases is employed in the generation of steam for the operation of the exhauster for reducing back pressure of the exhaust gases and for operating the super-charger through the use of a turbine.
One of the objects of my invention is to provide a power plant including an internal com-' bustion engine and a super-charger together with an exhauster wherein back pressure of the ex-v haust gases is reduced. 18
Another object of my invention is to provide mechanical means for reducing back pressure on the engine.
A further object of my invention is to utilize waste heat from. the engine for reducing the back pressure of the exhaust gases.
Another object of my invention is to render the admission of air or an explosive mixture to the engine cylinders and the scavenging of the cylinders independent.
Another object of my invention is to provide a waste heat boiler utilizing heat in exhaust gases leaving the engine to generate steam for supplying power to actuate a super-charger for the engine and an exhauster functioning to reduce .back pressure of the exhaust gases.
A further object of my inventionis to provide means for simultaneously effecting thermal and mechanical evacuation of exhaust gases from a super-charged internal combustion engine.
These and other objects of my invention will appear from the following description thereof in which reference is made to the accompanying figures of the drawings illustrating typical embodiments thereof.
In the drawings:
Fig. 1 is a vertical sectional view of one form of power plant embodying my invention;
Fig. 2 is a vertical sectional view of a portion of the mechanism shown in Fig. 3 taken. on the 45 line 2-2 of Fig. 3; V
Fig. 3 illustrates an alternative construction of certain elements of the combination;
Fig. 4 is a sectional view of a detail of the device shown in Fig. 3 taken on the line 4- 4; and 50 Fig. 5 illustrates a further alternative construction adapted for use with the device as shown in Fig. 1. 4
In that form of my invention chosen for illustration in Fig. 1, the device comprises an internal combustion engine 2 having a cylinder and an intake manifold 6 through which air or an explosive charge is passed to the various cylinders of the engine from the conduit 8. An exhaust manifold ill connected to the cylinders 4 through which exhaust gases are passed communicates with the exhaust conduit l2.
In order to supply the engine with air or an explosive mixture under pressure a super-charger N is employed. As shown, the super-charger comprises an impeller l6 mounted on a shaft I8 which is rotatable at high speed to draw air in through the opening 20 and to discharge the same to the engine cylinders under the desired pressure through conduit 8. The construction and operation of super-chargers of this, type is well known and may be varied to meet the needs of any particular installation.
While the super-charger may be driven from the engine or any other suitable source of power, I prefer to relieve the engine of this burden in order to increase the poweravailable for useful work. For this reason I utilize heat in the exhaust gases as a source of energy for the operation of the super-charger. This is eflected 'by passing the hot exhaust gases from the engine cylinders to a waste heat boiler 22 through the exhaust conduit H. The boiler, which may be of any suitable construction, is shown to comprise a lower chamber II to which the exhaust gases are admitted and with heating tubes 26 through which the hot exhaust gases pass in heat exchanging relation with water in the casing 28. The upper ends of the tubes communicate withanupperchamberlllfromwhich thegases are withdrawn by an cxhauster as hereinafter described.
In order to pre-heat water supplied to the waste heat boiler for producing steam, I prefer to provide suitable circulating means for heated water from the en ine cooling system to the casing 2. as needed to maintain the. desired amount of waterintheboilen, For this purposethe cooling system includes es II extending about thecylinderwallstowhichcoolwaterisadmitted through an inlet 32 and from which heated water is withdrawn through an outlet 8|. Water circulatedinthiswayispreheatedsothat heatcon- .tainedinthe exhaustgasespassingtothe waste heat boiler is used primarily-in the generation of steam and only a relatively small amount of such heat is required for raising the temperature of the boiler water. Ordinarily the boiler is not capable of convertingall of the cooling water circulating s5 cooling system into steam and I therefore provide the outlet 34 with a by-pass 36 for returning a portion of the cooling wa'terto the cooling system. Theremaining water is used as feed-water for the boiler and is introoo duced into the same by means of a pump II or other means, driven by a suitable controllable prime mover. The additional cold water necessary to maintain the supply of cooling water passing to the engine is supplied through a conas duit 40 provided with suitable valves ll.
Steam produced by the absorption of heat from theexhaustgasesthroughthewasteheat boiler is utilized in the form of my invention illustrated for driving a turbine 42. Any suitable type ofturbinemaybeemployedforthis p such as the single stage turbine illustrated. Tim comprises a rotorv 44' having blades 46 against which steam is projected through the nozzles 48. Thesteamfromtbecasing 2| ottheboiler through the passage II to the annular chamber 52 which is provided with any desired number of nozzles 48 located at suitable positions adjacent the blades of the turbine.
The pressure of the steam generated in the waste heat boiler will depend largely upon the 5 type of boiler employed, the construction and operation of the turbine and engine and various other factors. However, in order to increase the efliciency of the turbine and to obtain the maximum pressure differential on the opposite sides 10 thereof, I prefer to provide communication between the annular'exhaust chamber 54 of the turbine and suitable pressure reducing means such as an exhauster-condenser 56. Suflicient cool water is introduced into the exhauster to 15 effectively condense the steam from the turbine so that the exhauster functions also as a condenser producing a maximum pressure diiferential on the opposite sides of the turbine and increasing the amount of power derived therefrom. go
In order to reduce back pressure of exhaust gases passing from the engine cylinder the exhauster-condenser associated with the turbine is provided with communication with the upper chamber 30 of the boiler through the passage 58. as
With this construction the exhaust gases after through the waste heat boiler wherein they are considerably reduced in temperature pass to the upper chamber 30 of the boiler and thence to the exhauster It through the e an I! to the annular chamber II and 62. As shown the exhauster comprises a rotatable impeller 64 on shaft l8 by memo! which the exhaust gases are forcibly withdrawn from the waste heat boiler and from the engine cylinders. 36 The gases enter the exhauster tangentially and in the direction of rotation thereof near the center and are cooled by water introduced through inlets '6 supplied through pipes 61 shown in Fig.
2. These inlets are positioned and directed so as 49 to bring the cold water into intimate contact with the exhaust gases and with the steam entering the exhauster-condenser through the es II and a respectively. Furthermore the turbuperature and volume of the exhaust gases is decreased as much as possible. This reduction in volume in the exhaust gases increases the 5; density thereof so that the exhauster operates more effectively to reduce the back pressure on the engine. The condensate and cooled exhaust gases pass from the exhauster through the outlet II to a trap II, where liquids are separated from so the gases.
In the operation of the power plant shown in Pig. 1 and described above the super-charger supplies air or an explosive mixture to the engine under pressure to the cylinder of the engine as where it is'utilized on explosion for producing power. The resulting hot gases are withdrawn and forced from the engine cylinder upon completion of the expansion cycle by means of the exhauster I6 and the cooling and contraction of 70 tbegasesin'their w w e throughthewaste heat boiler. The action of the exhauster in withdrawing the exhaust gases from the engine cylinder renders it possible to delay the opening of the intake valve somewhat since it is unn to 75 rely upon the admission of the succeeding air,or explosive charge to assist in the scavenging of the cylinder. In other words the intake and exhaust cycles need not overlap as in present operation so that there need be no loss in the admission of unused air or explosive mixture to the cylinder.
with the arrangement described the exhauster and super-charger are carried by the same shaft and driven directly from the turbine. While this construction is not essential to my invention it insures'corresponding and uniform operation of the exhauster and. super-charger. Thus any change in the pressure or volume of the air supplied to the engine by the supercharger is met by a corresponding change in the action of the exhauster. Furthermore, the supply of heat to the boiler from the exhaust gases is dependent in part at least on the velocity of flow of the gases so that the supply of steam to the turbine is varied by the action of the other elements of the combination.
Ordinarily it will be found on starting the engine that the temperature of the boiler water is low and the water from the'engine cooling system is comparatively cool. The piston and cylinder walls may also be cool or cold. For this reason the temperature of the exhaust gases passing to the waste heat boiler is often much lower when the engine is started than will be the case after the engine has been operated for some time. On the other hand the demand for power from the engine is frequently at a maximum on starting so that it may be important at such times for the super-charger to be operated and for the back pressure of the exhaust gases to be reduced. However, although the demands for steam from the waste heat boiler are high steam is not available for proper operation of the turblue to drive the supercharger and exhauster. In order to overcome this difllculty I have shown in Fig. 3 a construction for driving the supercharger and exhauster independently of the turbine until such time as the pressure of steam in the boiler has become high enough to drive the turbine and operate the super-charger and ex-- hauster satisfactorily. In this construction the shaft 14 of the turbine 42' is provided with a clutch I6 of suitable construction normally urged into disengaged position by a spring 18 to permit the super-charger l4 and exhauster 56' to be freely rotated while the turbine remains stationary. The right hand member of the clutch in Fig. 3 is carried by a shaft 80 to which the rotor 64' of the exhauster is keyed. The rotor l6 of the super-charger may be secured in any suitable way to a hollow shaft 84 which preferably is formed integral with therotor for the exhauster. The means shown comprises a nut 86 cooperating with a shoulder 81 on shaft 84. The outer extremity of the tubular shaft 84 is provided with a separable coupling 88 which is connected with the shaft of an electric motor 90 for driving the supercharger and exhauster independently of the turbine when the engine is being started. The coupling means employed is preferably in the form of a friction clutch adapted to provide a driving connection with the motor.
able -longitudinally thereof by means of a pivoted lever 94 having a yoke 95 engaging the collar 92. Movement of the lever 94 to the left serves to disconnect clutch 88 from the motor 99 and to move clutch member 19 into engagement to connect the turbine to shaft 88 for driving the impellers of the super-charger and exhauster. The selection of the source of power employed is preferably effected automatically in response to a condition of an elementof the power plant. As shown lever 94 is actuated by means of a pressure operated device, such as the sylphon bellows 98 communicating with the upper portion of the waste heat boiler. In order to .prevent free escape of steam from the boiler during the starting period and to build up suflicient steam pressure in the boiler to supply the necessa power to the turbine, the bellows 96 may also serve to actuate valve 91 to admit steam to the turbine when lever. 94 is moved to disengage the clutch for the motor 90 and connect Throttle 99 may operation of the completing and breaking the electric circuit for energizing the motor 99 so as to maintain the motor in operation until the pressure within the waste heat boiler has reached a predetermined point, say lbs. per square inch. Thereafter upon the operation of the sylphon bellows, or pressure responsive means, the lever 94 is actuated'and the motor energizing circuit is broken so that the turbine is substituted for the motor as a source of power for driving the supercharger and exhauster and the motor is allowed to remain idle.
In the operation of the mechanism shown in Fig.- 3 the lever 94 on starting'the engine is in position to complete the motor circuit by engagement of the segment 98 with the contacts I90. In this position the clutch operating shaft 80 is withdrawn to the right holding clutch 88 in connected position for driving the super-charger and exhauster from the motor. The clutch member I9 is then held out of engagement with the coopcrating element carried by shaft 14 of the turbine so that the turbine may remain idle. The engine is thus operated supplying air or an explosive mixture to the engine under pressure and relieving back pressure of the exhaust gases by the action of the exhauster. Heat contained in the exhaust gases is taken up by water in the waste heat boiler 22' raising the temperature thereof and converting it into steam. When the pressure of the steam has reached a suitable point the pressure responsive means or sylphon bellows is actuated to open valve 91 to admit steam to the turbine and to force the lower end of the lever 94 o twardly to move the collar 92 and clutch operating shaft 89'to the left disengaging the motor clutch 88 and bringing the clutch element 16 into engagement connecting the turbine to the rotors of the super-charger and exhauster for driving the same. At the same time the circuit for energizing the motor is broken by movement of the segment 98 on the lever 94 out of engagement with the contacts I88 which form a part of the motor circuit. Thus the motor remains idle when the turbine drives the super-charger and exhauster whereas the turbine is disconnected when the motor is used for driving the supercharger and exhauster. The transfer from one source of power to the other for driving these elements is effected by the pressure actuated means to insure proper operation 01' the supercharger and exhauster at all times.
In Fig. 5 oi. the drawings I have illustrated alternative means for insuring proper operation of the super-charger andexhauster during the initial operation of the power plant. In this construction the waste heat boiler is provided with a supplemental source 01' heat such as the oil or gas burner I02 projecting into the chamber 24 in the base oi the waste heat boiler. The burner is designed to be operated to maintain the temperature of the boiler water sufllciently high to permit the immediate production of steam when the engine is started or to provide a surplus of steam during the initial period of operation if this should be desirable. The supplemental heating device may be operated by a motor I under the control of a thermostatic device I 06 responsive to changes in temperature of the exhaust gases in the exhaust conduit II. For this purpose the thermo-couple I0. is provided which as shown is located in the exhaust conduit, the mechanism used being oi any suitable type such as that disclosed in the patent to Mertelmeyer and Koester 1,203,230. I
With this construction the supplemental heating device is operated preparatory to starting the engine so as to raise the temperature of the boiler water and generate sui'ilcient steam to operate the turbine. When the engine is started the exhaust gases are drawn through the waste heat boiler by the exhauster adding their heat to that oi. the supplemental heating device and acting upon the thermo-couple to reduce the supply oi heat from the burner I02 proportionately. As the temperature of the exhaust gases rises upon the continued operation 0! the power plant the requirement for heat from the burner III! is decreased and the amount of heat provided is correspondingly reduced by the action 01' the thermostatic device I until the additional heat supply is reduced to a minimum or eliminated altogether.
This construction insures a continuous supply of steam for the turbine at all times when required and renders it possible to regulate the steam production to accommodate varying loads upon the power plant.
In each of the forms of my invention illmtrated in Figs. 1 and 3, the turbine, exhauster and super-charger are constructed as separate.
castings mounted upon the top 01' the waste heat boiler so'as to present a compactinexpensive construction adapted to be readily applied to existing power plants without material alteration.
While I'have illustrated and described certain forms 01' my invention it will be apparent that my invention is not limited to the constructions shown. 'lhe power plant may include two cycle or tour cycle internal combustion engines oi either the Diesel or Otto type. The particular form or waste heat boiler employed as well as the former turbine, exhauster, and super-charger may be varied considerably with each installation depending upon the size, cost and other factors as desired. It should, therefore, be understood that the form of power plant herein illustrated and described is intended to represent a typical embodiment of my invention and is not intended to limit the scope thereof.
What is claimed is:
i. A power plant having in combination, an internal combustion engine, a super-charger for said engine, a waste heat boiler utilizing heat in exhaust gases from said engine to produce steam, a turbine for driving said super-charger and driven by steam from said waste heat boiler,
in said boiler for actuating said alternative device.
2. A power plant having in combination, an internal combustion engine, a super-charger for said engine, a waste heat boiler utilizing heat in exhaust gases from said engine to generate steam, a turbine utilizing steam from said waste heat boiler, a rotary exhauster-condenser serving to reduce back pressure of exhaust gases from said engine and to condense steam from said turbine, means for supplying cooling liquid to said exhauster-condenser, a shaft rotated by said turbine and impellers for said super-charger and said exhauster driven by said shaft.
3. A power plant having in combination, an internal combustion engine, a super-charger for said engine, a waste heat boiler utilizing heat in exhaust gases from said engine to generate steam, a turbine for driving said super-charger and driven by steam from said waste heat boiler, an exhauster condenser driven by said turbine serving to reduce back pressure of exhaust gases of said engine and to condense steam from said turbine to increase the difierence in pressure on the opposite sides of said turbine, and alternative means for supplying power to drive said super-charger and said exhauster-condenser, and means responsive to the pressure of the steam in said boiler for actuating said alternative means.
,4. A power plant comprising an internal combustion engine, a super-charger for said engine, a waste heat boiler utilizing heat in exhaust gases from said engine, an exhauster for drawing ex- .haust gases through said waste heat boiler, a
internal combustion engine, a super-charger for said engine, a waste heat boiler utilizing heat in the exhaust gases to generate steam, a turbine driven by steam from said boiler, an exhauster communicating with said turbine and said waste heat boiler, means for introducing a cooling medium into said exhauster to condense steam from the turbine and to cool said exhaust gases, a motor for driving said super-charger and exhauster, and means responsive to variations in the pressure 01' steam in said boiler to connect either said turbine or said motor selectively to the super-charger and exhauster to operate the same.
I 6. A power plant having in combination an internal combustion engine, a super-charger for said engine, a waste heat boiler utilizing heat in the exhaust gases'to generate steam, a turbine driven by steam from said boiler, common means for reducing back pressure on said engine and on said turbine, a motor for actuating said means and super-charger and means responsive to variations in the pressure of steam in said boiler to connect either said turbine or said motor selectively to the supercharger and said means to operate the same. 1
7. A power plant having in combination an internal combustion engine, a super-charger for said engine, a waste heat boiler utilizing heat in the exhaust gases to generate steam, a turbine driven by steam from said boiler, an exhauster communicating with said turbine and said waste heat boiler, a motor for driving said super-charger and exhauster and means responsive to variations in the pressureot steam in said boiler to connect either said turbine or said motor selectively to the super-charger and exhauster to operate the same.
8. A power plant comprising an internal combustion engine within which a piston reciprocates, a super-charger for supplying air underpressure to said engine, a waste heat boiler utilizing the heat from the exhaust gases from'sald engine to produce steam, a turbine for driving said super-charger and driven 'by steam from said waste heat boiler, common means for reducing pressure on the exhaust side of said turbine and for reducing the back pressure of said exhaust' gases irom said internal combustion engine, an alternative device driven independently of said engine for actuating said supercharger and said common means, and means responsive to the pressure of the steam in said boiler for actuating said alternative device.
" LUDWIG LUS'I'IG.