WO2003076779A1

WO2003076779A1 - Gas turbine engine system

Info

Publication number: WO2003076779A1
Application number: PCT/IL2003/000192
Authority: WO
Inventors: Haim Rom
Original assignee: NEWTON PROPULSION TECHNOLOGIES Ltd
Current assignee: NEWTON PROPULSION TECHNOLOGIES Ltd
Priority date: 2002-03-14
Filing date: 2003-03-10
Publication date: 2003-09-18
Anticipated expiration: 2004-09-14
Also published as: CA2479235C; EP1490587B1; AU2003214599A1; JP4541707B2; CA2479235A1; DE60324119D1; US8109074B2; JP2005520085A; AU2003214599B2; ATE411455T1; AU2003214599C1; EP1490587A1; US20060101800A1; IL164057A0

Abstract

An engine system comprises at least a first volumetric device, and a second volumetric device in which said second volumetric device is larger in volume than said first volumetric device, in which, during continuous flow of a compressible fluid from said first to said second volumetric device work is performed.

Description

GAS TURBINE ENGINE SYSTEM

Field of the Invention

The present invention relates to the field of thermal engine systems,

particularly gas turbines. More particularly the invention relates to a gas

turbine in which a controlled volume of fluid undergoes a continuous- flow

positive displacement cycle.

Background of the Invention

The vast majority of world-wide prime mover capacity is in the form of

internal combustion engines. These include engines in automobiles, trucks,

tractors, ships, airplanes, and stationary plants. Thermodynamically, engines are classified according to their basic cycle. With respect to reciprocating and

other types of volumetric internal combustion engines.

A volumetric internal combustion engine possesses an advantage over a

conventional gas turbine engine in that it operates by means of static pressure within a closed volume which enables effective and efficient

operation with low dependence on engine velocity and therefore relatively

high efficiency and output through a wide range of engine velocity. Also its

parts can generally work at temperatures much less than the maximum cyclic temperature. As a result, said maximum cyclic temperature may be high,

thereby allowing for a high cyclic efficiency. Other advantages associated with the volumetric internal combustion engine include its relatively low cost, high mechanical efficiency and wide variation in speed and load. These advantages

are of particular importance in the field of land transportation.

A typical single-shaft open-type gas turbine engine designated by numeral 10

is illustrated in Fig. 1. Gas turbine engine 10 comprises compressor 2,

combustor 5 and turbine 7, which is coupled to the compressor by shaft 8. Atmospheric air 3 enters compressor 2, in which its pressure and temperature

is increased. The compressed air is then forced into combustor 5, in which it

mixes and burns with a fuel. Hot pressurized combustion gases 9 expand within turbine 7 and achieve a higher velocity, causing shaft 8 to rotate,

thereby driving compressor 2 and any load connected to the shaft, due to the

kinetic energy of the combustion gas stream. Combustion gases 9 are then

discharged to the atmosphere. The net work of the cycle is the difference

between the work obtainable in the expansion process and the work of

compression.

Relative to a volumetric engine, a gas turbine engine has a greater power to

weight ratio, and therefore its size is smaller than its volumetric engine

counterpart at a given power output. A gas turbine engine is capable of rapid

start-up and loading, and is likely to have a long life. Also, an open-type gas

turbine engine offers the advantage of simple sealing systems. No effective

cooling is possible. A gas turbine engine has good efficiency at full load when the operation

temperature and kinetic energy of the combustion gases, compressor pressure

ratio, and rotational velocity of the shaft are high. However, the efficiency is

reduced when the load is lowered, such as by lowering the operation

temperature or the rotational velocity of the shaft. Consequently, prior art gas

turbine engines have been usually found to be suitable for those applications

requiring substantially constant rotational velocity and output, such as

transcontinental aircraft or power plants, but heretofore have been found not

to be suitable for uses such as land transportation or light aircraft, which

require wide variations in speed and load.

It is an object of the present invention to provide a combustion engine system,

particularly a gas turbine engine, that allows for a wide variation in speed and load.

It is an additional object of the present invention to provide a gas turbine

engine that is suitable for use in land transportation.

It is an additional advantage of the present invention to provide a combustion

engine system that can efficiently burn a broad range of fuels.

It is another object of the present invention to provide a combustion engine system that is cost effective. It is a further obje'ct of the present invention to provide a gas turbine engine

that overcomes the disadvantages of the prior art devices while retaining

their inherent advantages.

It is a still further object of the present invention to combine the advantages

of volumetric systems with those of flow systems.

Other objects and advantages of the invention will become apparent as the

description proceeds.

Summary of the Invention

The present invention provides an improved combustion engine system

comprising at least a first and a second volumetric device, through which

work is performed during continuous flow of a compressible fluid from said first to said second volumetric device.

According to a preferred embodiment, the engine comprises an additional

work producing device, particularly a turbine, driven by the fluid discharged from said second volumetric device.

As referred to herein, a "fluid displacement cycle" is defined as a process by

which a fluid is displaced in a succession of stages, which may be repeated as many times as desired, theoretically for an unlimited number of times. If the displacement of the fluid in each stage is determined by the displacement or

displacements of a' "mechanical element or a number of such elements from a

first to a second position, the cycle is called a "positive displacement cycle".

As referred to herein, a "volumetric device" is a device that delivers the same

volume of fluid that it receives. Generally, such a device uses a positive

displacement cycle to transfer the same amount of fluid at each cycle. It

should be understood that this need not be and generally is not the sole

function of a volumetric device, but rather one of its functions. Typically, the

same volume of fluid is received and delivered by the device in each stage.

Said volume of fluid will be called hereinafter "controlled volume".

The transfer of a fluid from a first volumetric device to a second volumetric

device, wherein fluid is transferred during each stage of the positive

displacement cycle of the volumetric devices, is considered herein to be and is

called "continuous flow" .

A "turbine" is defined herein as a device for outputting work or for

turbocharging fluid by transferring kinetic energy of a driving fluid into

mechanical energy upon passage thereof across turbine blades. In

embodiments of this invention comprising turbines, the driving fluid is the exhaust of the second of two volumetric devices. In one preferred embodiment, the present invention provides an engine

system which comprises:

a) a first volumetric device;

b) means for feeding a compressible fluid to said first volumetric transfer unit;

c) a heat source or sources;

d) means for driving said first volumetric transfer unit for sequentially

transferring controlled volumes of said fluid to said heat source by positive displacement cycles;

e) a second volumetric device, larger then the first one, for receiving heated

controlled volumes of said fluid from said heat source;

f) means for driving said second volumetric device for sequentially

discharging said heated controlled volumes of said fluid by positive displacement cycles; and

g) means for synchronizing said means for driving said first and second volumetric device.

In preferred embodiments:

I) the means for synchronizing said means for driving said first and

second volumetric device comprise a common shaft supporting said first and second volumetric devices for rotation. II) the means for feeding a compressible fluid to a first volumetric

transfer "unit include means for increasing the pressure of said

fluid, preferably a compressor;

III) the engine system further comprises a turbine and the discharge of

said second volumetric device is the inlet of said turbine;

IN) the heat sources are combustors fed with a fuel, which receive

controlled volumes of fluid and cause said fuel to burn, thereby

heating said fluid, wherein said fuel may but need not be any fossil-

based engine fuel;

V) the , compressor, if any, the first and second volumetric device, and

the turbine, if any, are keyed to the same main shaft;

VI) the compressible fluid is usually air;

VII) the engine system further comprises an additional work producing

device, which is preferably but not necessarily a turbine, which

device is driven by the fluid discharged from said second volumetric

device and produces work from the kinetic energy of said discharged

fluid.

Since said first volumetric device transfers fluid to said second volumetric

device, it may be called "transfer volumetric device". Since said second

volumetric device receives heated controlled volumes of fluid from the heat

source or sources, it may be called "expansion volumetric device". A torque is

exerted on said common shaft means or said main shaft of said engine system, due to a static pressure between said transfer and said expansion

volumetric device ' chambers, independent on the torque exerted by the gas

turbine or other additional work producing device, if any.

"Energy" denotes herein the net work done by the compressible fluid within the engine system while flowing to the discharge of said second volumetric

device.

The positive displacement cycle is effected by means of apparatus selected from the group of rotors provided with lobes, Wankel mechanism,

reciprocating piston systems, or any other common or specially designed

volumetric system.

In a particular embodiment of the invention, the engine system further comprises at least one stage of intercoolers.

In another embodiment, the engine system comprises two independent shafts

to one of which is coupled a load, and preferably a one-way clutch for

engaging and disengaging the two independent shafts, depending on a magnitude of the load.

The engine system of the present invention is suitable for operation at a

variable load and speed. Therefore the engine system may be incorporated into a motor vehicle propulsion system. In one embodiment, the motor vehicle

propulsion system' 'comprises a secondary heater for heating exhaust from the

second volumetric device and further comprises a third volumetric device

rotating about an independent shaft, wherein the discharge from the

secondary heater is the working fluid of said third volumetric device, said

third volumetric device being adapted to be a speed and torque converter in

response to a variable load coupled to said independent shaft, the engine system further comprising a rotational direction controller of said

independent shaft by a valve means which directs said discharge from the

secondary heater alternatively between the inlet and outlet ports of said

third volumetric device. If necessary, a bypass valve that serves as engage and disengage device between the motor assembly and torque converter

assembly is installed so that torque converter can be repressed while the

motor is operating.

The motor vehicle propulsion system may further comprise a first stage intercooler for cooling the discharge flowing from a first compressor to a

second compressor and .a second stage intercooler for cooling the discharge

flowing from the second compressor to the turbocompressors of the

turbochargers. It may further comprise a third stage intercooler for cooling

the discharge flowing from the turbocompressor of the turbocharger to the first volumetric device, and a heat exchanger for heating the fluid flowing from the first volumetric device to the heat source by means of the discharge

from the turbine of the turbocharger.

The motor vehicle propulsion system preferably further comprises a

transmission comprising:

a) a plurality of coaxial volumetric devices rotatable about the independent

shaft;

b) a plurality of conduits through which the discharge from the secondary

heater flows in parallel to each of said plurality of volumetric devices,

respectively;

c) a plurality of selector valves provided with each of said plurality of

volumetric devices, respectively, for changing the directional direction of

the independent shaft by directing the flow through a corresponding conduit alternatively between the inlet port and outlet port of the

corresponding volumetric device upon actuation of each of said selector

valves in unison; and

d) a plurality of bypass valves in communication with each of said conduits,

respectively, for selecting through which combination of said plurality of

volumetric devices discharge from the secondary heater will flow, wherein said motor vehicle propulsion system produces a maximum amount

of torque when the discharge from the secondary burners is directed to all of said plurality of volumetric devices in parallel, a lowered level of torque upon deactivation of at least one of said bypass valves, and an increased level of

torque upon activation of at least one more of said deactivated bypass valves.

Preferably the plurality of selector valves are automatically actuated upon

input of an operator or speed and torque controller.

In another preferred embodiment, the engine system is a turbofan engine system which further comprises a turbocompressor for compressing

atmospheric air and delivering said compressed air to a transfer volumetric

device and a turbine driven by discharge from an expansion volumetric device for driving said turbocompressor, wherein the main shaft drives a fan which

generates a crossfan streamline and a main thrust for an aircraft, exhaust from said turbine being discharged to the atmosphere and providing auxiliary

thrust which is in addition to said main thrust. Alike embodiment can be

realized without a turbocompressor by using the fan thrust also for the feeding of the volumetric device.

In another preferred embodiment of the present invention, the engine system

is a turbojet engine system, wherein the expansion volumetric device provides auxiliary thrust which is in addition to the main thrust for an

aircraft provided by a jet stream generated by a main burner, an air stream from said at least one compressor feeding the inlet volumetric chamber and the main burner. Alike embodiment can use turbo compressor(s) in order to

improve efficiency' and output.

Brief Description of the Drawings

In the drawings:

Fig. 1 is a schematic drawing of a prior art gas turbine system;

Fig. 2 is a schematic drawing of a volumetric system comprised of two

unequally sized chambers;

Fig. 3 is a flow diagram of an engine system which does not drive a

compressor or a turbine;

Fig. 4 is a flow diagram of an engine system which does not drive a

turbine;

Fig. 5 is a flow diagram of an engine system according to the present invention; Fig. 5A is a schematic drawing of the system of Fig. 5; Fig. 5B is a

schematic drawing of a similar engine system with the addition of secondary

burners and a secondary shaft; Fig. 5C illustrates the addition of a one-way

clutch; and Fig. 5D demonstrates the capacity of constructing a volumetric

system like that of Fig. 5 and other embodiments of the invented system, with multiple buffered sectors (four in Fig. 5D) in accordance with any

specific design;

Figs. 6A and 6B are schematic and flow diagrams, respectively, of an engine system which incorporates a turbocharger, showing the operation of a rotary lobe positive displacement cycle; Fig. 7 is a flow diagram of an engine system which incorporates a

turbocharger, showing the operation of a Wankel-based positive displacement

system;

Fig. 8 is a flow diagram of an engine system which incorporates a

turbocharger, showing the operation of a reciprocating piston positive

displacement system;

Fig. 9 is a flow diagram of an engine system which incorporates

intercoolers and heat exchangers;

Figs. 10A and 10B are flow and schematic diagrams, respectively, of an

engine system suitable for motor vehicles, while Fig. IOC illustrates the

operation of a selector valve and declutching (bypass) valve;

Fig. 10D is a schematic drawing of a motor vehicle transmission

system (torque converter) comprising a plurality of coaxial volumetric devices

rotatable about an independent shaft and their control system;

Fig. 11 is a schematic drawing of an engine system suitable for a turbofan, and

Fig. 12 is a schematic drawing of an engine system suitable for a turbojet.

Detailed Description of Preferred Embodiments

In one embodiment thereof, the present invention provides a novel gas turbine engine system in which the working fluid imparts a torque upstream to the turbine blades, so that a wide variation in load and shaft speed may be

realized without a significant reduction in cyclical efficiency. Prior art gas turbine engines achieve a relatively high cyclical efficiency at full load when

the kinetic energy 'of combustion gases flowing from a combustor to a turbine

is at a maximum; however, their efficiency is significantly lowered following a

reduction in kinetic energy of the combustion gases and a concomitant

reduction in shaft speed. Use of prior art gas turbine engines is therefore

precluded for those applications which require a wide variation in speed and

load, such as land transportation or light aircraft. In contrast, the engine

system of the present invention incorporates a positive displacement cycle by

which a transfer volumetric device and an expansion volumetric device in

fluid communication with one another by means of conduits and a combustor.

A torque, exerted on the main engine shaft, is generated due to difference in

size (and volume) between the two volumes and rotors under the same

pressure. The energy of the working fluid is therefore utilized for various

applications, as will be described hereinafter, which increases the cyclical efficiency of the engine system as well as its flexibility in terms of performing

work during changes of speed and load.

Figs. 2A to 2C are a schematic illustration of a principle that is applied in the

invention. Fig. 2A shows a volumetric system generally indicated as 18,

which comprises two interconnected chambers 20 and 25 of unequal volume

and of unequal diameters Dl and D2. Pistons 30 and 35 are displaceable

within chambers 20 and 25, respectively, and are connected by rod 40 parallel to the longitudinal axis of system 18. The volume between the two pistons comprises two portions, each belonging to one of the two chambers. As the

pistons move alon'g the longitudinal axis of the system both portions vary. If

a fluid is admitted to the system via inlet 45, a pressure is produced in each

of said two chamber portions. Since piston 35 has a larger surface than piston

30, said pressure generates a resultant force (directed to the right as seen in

the figures) on the assembly of the two pistons and rod 40, said assembly is

displaced in said direction, and work can be obtained from said displacement.

As more fluid is admitted through inlet 45, said assembly is additionally

displaced, and more work may be obtained from volumetric system 18. Figs.

2B and 2C show successive stages of said process.

All of the following embodiments are described as comprising two

independent flow paths of working fluid. It will be understood that any

number of flow paths may be employed with similar results, and two flow

paths have been chosen to simplify the description.

FIG. 3 demonstrates the very basic concept of the present invention: a

volumetric device consist of at least two volumetric units; transfer unit 60

and expansion unit 70 rotating about a common shaft 58.

Said transfer unit 60 is charged through intake conduits 94 and 94A and then connected to said expansion unit via conduits 80 and 80A and combustors 75 and 75A. At the end of each expansion sector, the burnt

mixture is discharged from expansion unit 70 through exhaust conduits 95 and 95A. Most of the forthcoming embodiments of the present invention are

based on the above described device (FIG 3) or alike with different,

corresponding peripheral systems.

As shown in Fig. 4, an engine system 90 may be without a turbine, and the

pressure of the fluid between transfer unit 60 and expansion unit 70 can be

utilized for driving a load connected to shaft 58. Compressor 55 forces

compressed working fluid into the system, whereby it is transferred to

combustors 85 and 85A, heated in accordance with the present invention, and

then discharged through exhaust ports 95 and 95A.

Figs. 5 and 5A schematically illustrate a gas turbine engine system based on

a volumetric (rotary lobe herein) positive displacement cycle in accordance with the present invention. The system is indicated generally as 50. It

comprises a compressor 55, a (first) transfer volumetric device 60, a (second)

volumetric device 70, which is an expansion volumetric device, and a turbine

80, all of which devices rotate about a common shaft 58. In Fig. 5A the system is shown in schematic side view, while in Fig. 5 the said devices are

shown in schematic cross-section as laterally displaced from one another

while in fact they are aligned along a common longitudinal axis. Working

fluid 59, after being compressed by compressor 55, flows through conduits 62 and 62A and is admitted to transfer volumetric device 60 via ports 64 and 64A, respectively. In this embodiment transfer volumetric device 60 is provided with three lobes

66. It will be appreciated that any number of lobes may be employed. In the

position of said device shown in Fig. 5, an inlet chamber is defined between

casing 63, lobe 66B and buffer 68A . During rotation lobe 66C is passing

buffer 68A and then maximum volume of the chamber is defined between casing 63 and lobes 66B and 66C. On continuation of clockwise rotation lobe

66B is passing buffer 68 and said chamber become an outlet chamber while

it's volume is diminishing between lobe 66C and buffer 68 urging the fluid

into combustor 85 through conduit 87. The same process is taking place at

the other half of the same device. The different in lobe area (and as a result, in volume) between the expansion volumetric device and the transfer volumetric device, when under pressure generates moment about shaft 58

causing it to rotate (clockwise). As said shaft rotates, said inlet chambers are

increased and said outlet chambers are reduced. The content of said outlet chambers is fed to combustors 85_. and 85A. Said content has the volume that

is referred herein as the "controlled volume". Concurrently and gradually

through a rotation of shaft 58 by 180° (generally, a number of degrees equal

to 360 divided by the number of buffers), in accordance with the description hereinabove, it is understood that every lobe that is passing through a buffer is forming a new inlet chamber behind it and defining an outlet chamber

ahead of it. Whenever an inlet chamber is connected by a feed conduit to the compressor

and an outlet chamber is concurrently connected by a discharge conduit to a

combustor, communication between the feed conduit and the discharge

conduit must be prevented. This is obtained by providing rotary buffers 68

and 68A which have seats so shaped as to be engaged by any one of the lobes

66 to form a seal between conduits 62 and 87 and between conduits 62A and

87A, respectively. The combination of a buffer and a lobe, therefore, acts as a

valve. Each rotary valve, together with the lobe that follows it in the direction of rotation of the volumetric transfer unit 60, demarcates a

controlled volume of fluid through which work is obtainable in the engine

system, and additionally urges said controlled volume to combustors 85 and

85A. In the condition shown in Fig. 5, rotary buffer 68A is engaged by lobe

66C. As device 60 continues to rotate in a clockwise direction, lobe 66A engages rotary buffer 68A. During this stage, compressed working fluid is

discharged in bursts to combustors 85 and 85A via conduits 87 and 87A

respectively, and another charge of working fluid is concurrently admitted to

the transfer unit 60.

The combustors 85 and 85A comprise injectors 89 and 89A respectively. Fuel

is injected into the compressed working fluid by means of injectors 89 and

89A, so that the resulting combustible mixture is ignited and burned in a steady state, thereby raising the pressure and temperature of the working fluid. The combustion gases constitute a heated working fluid. They are

discharged to expansion volumetric device 70 via conduits 91 and 91A.

Expansion volumetric device 70 is structured like transfer volumetric device

6o except for its scale. It comprises a rotor with three lobes; 75A, 75B and

75C and rotary buffers; 77 and 77A. In the condition shown in Fig 5, an

expansion chamber is defined between buffer 77A and lobe 75A and an outlet

chamber is defined between lobe 75A and buffer 77 in one sector of 180° of the

expansion unit. A second expansion chamber is defined between buffer 77

and lobe 75C and an outlet chamber is defined between lobe 75C and buffer

77A in the other sector of 180° of the expansion unit. The third lobe 75B is crossing the rotary buffer 77 through a matching dent in order to perform the

same operation as lobe 75A and lobe 75C in a sequence. In the structure

shown in Figs. 3, 4, 6B and 5 the volumetric device (transfer and expansion)

is performing six complete cycles during each revolution of 360°. In the structure shown in Fig. 5D the volumetric device is performing twelve

complete cycles during each revolution of 360°. In Fig. 7, a Wankel system

volumetric device is performing six complete cycles of the rotors during each

revolution of 360°, but the main shaft (which is directly connected to the compressor fan) is rotating three times faster.

Since the pressure during the expansion cycle build up continually, the

remaining pressure at the end of each expansion sector is relatively high. This pressure is conducted to turbine 80 via conduits 93 and 93A in order to

use its kinetic energy in the turbine.

In Fig. 5B an engine configuration comprising two independent shafts is

illustrated. Compressor 55 and volumetric devices 60 and 70 rotate about

shaft 46, while turbine 80 rotates about shaft 47. As a result turbine 80

rotates at a speed independent of the speed of expansion volumetric device

70, according to an external load connected to coupling 49. Shaft 47 may drive for example a transmission system (not shown). Optionally, the exhaust

from expansion unit 70 may be reheated by secondary combustors 96 and 96A

before introduction to turbine 80 in order to increase the engine output. After expansion within expansion volumetric device 70, the burned combustion

gases still contain a sufficient amount of oxygen to warrant the use of

secondary combustors.

If so desired, one-way clutch 48 as illustrated in Fig. 5C may be used to further increase the flexibility of the engine configuration. When turbine 80

is under a heavy load at coupling 49 and the speed of shaft 47 is lowered to

substantially that of shaft 46, one-way clutch 48 is engaged and the power

performed by shaft 47 is added the power take of shaft 46. Upon reduction of

the load connected to coupling 49, the speed of shaft 47 can increase to a value much higher than shaft 46 and one-way clutch 48 is disengaged from shaft 46, to allow the two shafts to rotate at different speeds. Fig. 5D schematically illustrates an engine system which differs from that

illustrated in Fig. 5 only in that it comprises four, instead of two, buffered

sectors in each volumetric device. Fig. 5D is therefore self-explanatory. It will

be understood that different numbers of buffered sectors could be provided in

such engine systems, and four sectors are known in Fig. 5D only by way of example.

Another preferred embodiment of the present invention comprising a

turbocharged engine system generally indicated by 150 is illustrated in Figs.

6A and 6B. Intake air 159 is compressed in two stages, by compressor 155 coaxial with volumetric transfer unit 160 and expansion volumetric unit 170

and by turbocompressors 110 and 110A fed with compressed air from

compressor 155 through conduits 162 and 162A, respectively. Turbocharged

air flows through conduits 132 and 132A and is admitted to transfer unit 160

at entry ports 164 and 164A, respectively, with such an increased pressure

that more fuel may be burned in combustors 185 and 185A, respectively, and

that engine system 150 may generate more power at shaft 158. The exhaust

from expansion unit 170 flows through conduits 193 and 193A and provides

the motive force, by means of the kinetic energy of the combustion gases discharged from expansion unit 170 to rotate turbines 120 and 120A. Turbines 120 and 120A in turn drive turbocompressors 110 and 110A, respectively, and provide more power at the corresponding output shaft 125

and 125A, respectively.

The present invention may be performed by means of other positive

displacement devices. A system generally designated by 230 is illustrated in

Fig. 7, in which the positive displacement cycle is based on a Wankel

mechanism, in which a triangular rotor rotates on an eccentric shaft inside

an epitrochoidal housing. Intake air is compressed in two stages, namely by

compressor 155, which is coaxial with volumetric transfer unit 210 and with

expansion volumetric unit 240, which has a larger inner volume than that of

the first volumetric transfer unit 210, and by turbocompressors 110 and 110A

whose inlet is compressed air flowing from compressor 155 through conduits 162 and 162A, respectively. As the triangular rotor of a volumetric unit

rotates, each controlled volume of fluid which is sequentially admitted into

the corresponding volumetric unit is captured by two adjacent apexes of the

triangular rotors. Therefore transfer unit 210 can deliver turbocharged air to

the combustors and expansion unit 240 allows for the expansion of combustion gases so that a desired amount of work is obtainable at common

shaft 158, in accordance with the present invention.

Another volumetriq system generally designated by 280 in accordance with the present invention is illustrated in FIG 8, in which the positive displacement cycle is based on a reciprocating piston system. In Fig 8, like with any other sort of adoptable volumetric mechanism of the present

invention, a wide 'variety of embodiments with different peripheral systems

in accordance. The following description of Fig 8 is just one of numbered

feasibilities.

Intake air is compressed in two stages, namely by compressor 155 coaxial with volumetric transfer unit 260 and expansion volumetric unit 290 and by

turbocompressors 110 and 110A whose inlet is compressed air flowing from

compressor 155 through conduits 162 and 162A, respectively. Each controlled

volume of turbocharged working fluid is sequentially fed to the first transfer

volumetric unit and is sequentially urged from the transfer unit 260 to the

expansion volumetric unit 290 by a predetermined timing of valve sets.

Fig 9 is an explanatory system which describes the adaptation feasibility of

common systems of prior art by the present invented system in order to

achieve higher performance and efficiency. An engine is generally indicated by 350, according to another preferred embodiment of the present invention

illustrated in Fig 9, showing the high adaptability of the present invention

for common peripheral systems in order to improve efficiency and output that

can be further increased by the employment of intercoolers, in order to cool the temperature of compressed working fluid and thereby to provide fluid at

higher density to the volumetric devices. Axial compressor 310 forces ambient

air 315 to first stage intercoolers 320 and 320A, after which the compressed and cooled air is additionally compressed at radial compressor 330 and second stage intercoolers 340 and 340A, respectively. A higher fluid density

therefore results "between expansion volumetric unit 370 and transfer

volumetric unit 360. Heat exchangers 390 and 390A, are using exhaust gases

temperature to preheat the working fluid at entrance to the combustors in

order to achieve higher efficiency and output.

With implementation of the various applications described hereinabove, an

engine of the present invention may be adapted for use with land motor

vehicle of all sorts, which requires a wide variation output in load and

rotational speed, with an immediate response to a change in one of the

operational parameters of the system. Due to the unique configuration, an

engine in accordance with the present invention is advantageously suitable for the burning of any existing engine fuel.

In one preferred embodiment of the invention, engine 400 which is suitable

for operation with motor vehicles is illustrated in Figs. 10A and 10B. Engine 400 comprises three stages of intercoolers: first stage intercoolers 420 and

420A for cooling compressed ambient air from axial compressor 410, second

stage intercoolers 440 and 440A for cooling compressed air from radial

compressor 430 which compresses the discharge from the first stage

intercoolers, and third stage intercoolers 455 and 455 A for cooling compressed air from turbocompressors 450 and 450A, respectively, which receive air from a corresponding second stage intercooler. The discharge from the third stage intercoolers is introduced to transfer unit 460. The discharge

from transfer unit' 460 is heated by heat exchangers 462 and 462A, which

utilize the exhaust from turbocompressors 450 and 450A, respectively, as

indicated by conduits 452 and 452A, respectively, before introduction into

primary combustors 485 and 485A, respectively, so as to increase the

available energy level of the working fluid. The fluid heated by the primary

combustors flows to expansion unit 470 and performs work at main shaft 480.

The flexibility and efficiency of engine 400 is further increased by providing a

third volumetric device 490, which rotates about an independent shaft 491 and transmits an additional amount of power. The exhaust from expansion

unit 470 is heated by secondary combustors 475 and 475A, so as to function

as a pressure generator for volumetric device 490 by utilizing the oxygen

content of the unburned exhaust. The heated exhaust from expansion unit

470 is introduced to selector valves 495 and 495A. As seen more clearly in Fig. 10C, selector valve 495, for example, is actuatable to direct the flow of

the expansion unit outlet into inlet port 496 resulting in clockwise rotation of

shaft 491 or into outlet port 497 resulting in counterclockwise rotation of

shaft 491. The exhaust from volumetric device 490 is then discharged by lines 498 and 498A, respectively, to the turbines of turbochargers 458 and

458A, respectively, which drive a corresponding turbocompressor. If so

desired, the exhaust from volumetric device 490 may be directed to a heat exchanger, or to any other suitable application. Any of the hereinabove peripheral units as secondary combustors, intercoolers and heat exchanger

can be in use or avoided according to any specific design.

Volumetric device 490 develops power by means of any of the positive

displacement cycles described hereinabove. Since independent shaft 491 is

coupled to a load, volumetric device serves as a torque converter, wherein the

torque applied by shaft 491 is variable, depending on the load and on the

pressure between expansion unit 470 and volumetric device 490. The volume of device 490 is advantageously relatively small if shaft 491 is desired to be

rotated at a relatively high velocity and low torque. Alternatively, the volume

of device 490 is chosen to be larger if shaft 491 is desired to be rotated at a

relatively low velocity and high torque. A locking mechanism is situated between main shaft 480 and secondary shaft 191 in order to enable

unification of the two shafts into one for certain utilizations. Bypass valves

465 and 465A are functioning as engagement/ disengagement device,

enabling to keep the engine running and idling while third volumetric unit

(torque converter) is disengaged.

Engine 400 is adapted to provide a flexible and gradual transmission by

employing a plurality of volumetric devices, as illustrated in Fig. 10C,

disposed at the outlet of secondary combustors 475 and 475A, with a number of selector valves in use to select through which combination of devices working fluid heated by secondary combustors will flow. Working fluid heated by secondary combustors flows in parallel conduits into a

corresponding volumetric device, and a separate selector valve in

communication with each conduit controls the flow through the

corresponding conduit. Each of these volumetric devices are coaxial and the

net power output from independent shaft 491 is the sum of the power output from each individual volumetric device. Accordingly, the engine produces a

maximum amount of torque when the discharge from the secondary

combustors is directed to all the volumetric devices in parallel. If an operator

desires to smoothly lower the torque and increase the speed of shaft 491, one selector valve is actuated to prevent the flow to the corresponding individual volumetric device, the same amount of fluid is then flowing through one less

device, causing augmentation of velocity on the account of torque diminution.

Similarly any number of volumetric devices may be by passed in order to

achieve a desired speed or torque. The direction of independent shaft 491 is

changed by actuating the selector valve of each volumetric device in unison.

Preferably the selector valves are automatically actuated upon input of an

operator.

Fig. 10D schematically illustrates an engine, comprising, in addition to

volumetric devices 701 and 702, such as have been illustrated in preceding

embodiments, three additional volumetric devices 708, ,709 and 710 that serve as torque converters. Numeral 700 indicates the shaft to which volumetric devices 701 and 702 are keyed. 703 is a compressor, 704 is a

combustor and 705' is a turbocharger. Said additional volumetric devices 708,

709 and 710 can be activated or disactivated by opening or closing valves

711, 712 and 713 respectively. While volumetric devices 708, 709 and 710 are

mounted on shaft 715, they may be mounted through one-way bearings 716,

717 and 718 respectively, so that if they are deactivated, they do not rotate

with shaft 715. The said additional volumetric devices vary the torque and

the speed of rotation of the engine in two ways: one, by activating

appropriate combination of volumetric transmission devices in general

accordance with load and speed and secondly b the variation of the pressure

buildup in the said volumetric activated units based on the compressible

nature of the fluid (usually air) in order to cope with load and speed

variations within a chosen combination of transmission volumetric units.

Another preferred embodiment of the present invention is illustrated in Fig.

11, for use as a turbofan engine generally designated as 550. Atmospheric air 510 is admitted to turbocompressors 520 and 520A under normal pressure

produced^' by the fan 530, and is compressed furthermore before delivery to

transfer unit 560. Transfer unit 560 discharges the compressed air to

combustors 585 and 585A, from which combustion gases flow to expansion volumetric device 570. As the combustion gases expand, a motive force is produced due to the pressure between expansion volumetric device 570 and transfer volumetric device 560, causing shaft 558 to rotate and to drive fan 530. Fan 530 generates a crossfan streamline 515 which flows through duct

590 and results in thrust. The exhaust from device 570 is delivered to

turbines 522 and 522A of the turbochargers, in order to drive a corresponding

turbocompressor. The exhaust from turbines 522 and 522A is discharged to

the atmosphere and provides additional thrust.

Fig. 12 illustrates another preferred embodiment in which a turbojet engine

system indicated generally by 650 comprises axial compressor 610, radial

compressor 620, transfer volumetric device 660, engine combustors 685 and

685A, expansion volumetric device 670 and main combustor 690. The

majority of the aircraft thrust is provided by main combustor 690.

Compressed air from compressors 610 and 620 introduced to main combustor

690 via apertures 675 is mixed with fuel injected by injector 640, and the

combustible mixture is burned to produce a powerful jet stream. Compressors

610 and 620 are driven by shaft 658, as a result of the torque imparted thereto by device 670. The remainder of the compressed air not admitted to

main combustor690 is cooling the main combustor and its envelope and

together with the exhaust from expansion unit 670 provide auxiliary thrust which streams to the rearward side of the engine, through outlet nozzle 695.

It will be appreciated that an aircraft engine corresponding to the embodiment of Fig. 11 or Fig. 12 drives the compressors by means of energy,

due to the pressure between the volumetric device, and therefore can operate at high efficiency despite a wide variation in speed and load. Consequently

such aircraft engines are suitable for applications that heretofore have been

unfeasible.

To -mass produce engines according to the present invention in a cost effective

manner, one may produce the engines of the present invention in a modular

fashion.

While some embodiments of the invention have been described by way of

illustration, it will be apparent that the invention can be carried into practice

with many modifications, variations and adaptations, and with the use of numerous equivalents or alternative solutions that are within the scope of persons skilled in the art, without departing from the spirit of the invention

or exceeding the scope of the claims.

Claims

1. Engine system, comprising at least a first volumetric device, and a second

volumetric device in which said second volumetric device is larger in volume

than said first volumetric device, in which, during continuous flow of a

compressible fluid from said first to said second volumetric device work is

performed.

2. Engine system according to claim 1, further comprising a turbine driven by

the fluid discharged from the second volumetric device.

3. Engine system according to claim 1, which comprises:

a) a first volumetric device; b) means for feeding a compressible fluid to said first volumetric transfer

unit;

c) a heat source or sources; d) means for driving said first volumetric transfer unit for sequentially

transferring controlled volumes of said fluid to said heat source by positive

displacement cycles; e) a second volumetric device for receiving heated controlled volumes of said

fluid from said heat source; f) means for driving said second volumetric device for sequentially

discharging said heated controlled volumes of said fluid by positive displacement cycles; and g) means for synchronizing said means for driving said first and second

volumetric deviδ^'e.

4. Engine system according to claim 3, wherein the means for synchronizing

the means for driving the first and second volumetric device comprise a

common shaft supporting said first and second volumetric devices for

rotation.

5. Engine system according to claim 3, wherein the means for feeding a

compressible fluid to a first volumetric transfer unit include a compressor.

6. Engine system according to claim 2, wherein the discharge of the second volumetric device is the inlet of the turbine.

7. Engine system according to claim 3, wherein the heat sources are

combustors fed with a fuel, which receive controlled volumes of fluid and cause said fuel to burn, thereby heating and expanding said fluid.

8. Engine system according to claim 3, wherein the first and second

volumetric device are keyed to the same main shaft.

9. Engine system according to claim 8, comprising a compressor keyed to the main shaft.

10. Engine system according to claim 8, comprising a turbine keyed to the

main shaft.

11.. Engine system according to claim 1 or 3, wherein the compressible fluid

is air.

12. Engine system according to claim 3, wherein the heat source is a

combustion chamber into which fuel is injected and the compressible fluid is

air.

13. Engine system according to claim 3, wherein the positive displacement

cycle is effected by means of apparatus selected from the group consisting of

rotors provided with lobes, Wankel mechanism, reciprocating piston systems,

or any common or specially designed volumetric mechanism.

14. Engine system according to claim 3, further comprising at least one

compressor for increasing the pressure of each controlled volume of fluid.

15. Engine system according to claim 14, further comprising at least one

turbocharger.

16. Engine system according to claim 3, further comprising at least one stage

of intercoolers.

17. Engine system according to claim 3, comprising two independent shafts to

one of which are keyed the volumetric devices, a load being coupled to the

other shaft.

18. Engine system according to claim 17, further comprising a clutch for

engaging and disengaging the two independent shafts, depending on a

magnitude of the load.

19. Engine - system according to claim 15, further comprising a secondary

heater.

20. Engine system according to claim 14, further comprising a second

compressor and a first stage intercooler for cooling the discharge flowing

from the first compressor to said second compressor.

21. Engine system according to claim 20, further comprising a turbocharger

and a second stage intercooler for cooling the discharge flowing from the second compressor to the turbocompressor of the turbocharger.

22. Motor vehicle propulsion system comprising an engine system according

to claim 3 and further comprising a secondary heater for heating exhaust

from said system and a third volumetric device rotating about an

independent shaft, wherein the discharge from said secondary heater is the

working fluid of said third volumetric device, said third volumetric device

being adapted to be a torque converter in response to a variable load coupled

to said independent shaft, said engine system further comprising a rotational

direction controller of said independent shaft by a valve means which directs

said discharge from said secondary heater alternatively to an inlet port and

an outlet port of said third volumetric device.

23. Motor vehicle propulsion system according to claim 22, further

comprising a transmission comprising:

a) a plurality of coaxial volumetric devices rotatable about the independent shaft;

b) a plurality of conduits through which the discharge from the secondary

heater flows in parallel to each of said plurality of volumetric devices, respectively;

c) a plurality of selector valves provided with each of said plurality of

volumetric devices, respectively, for changing the rotational direction of

the independent shaft by directing the flow through a corresponding

conduit alternatively between the inlet port and outlet port of the corresponding volumetric device upon actuation of each of said selector

valves in unison; and

d) a plurality of selector valves in communication with each of said conduits,

respectively, for selecting through which combination of said plurality of

volumetric devices discharge from the secondary combustor will flow,

wherein said motor vehicle propulsion system produces a maximum amount

of torque when the discharge from the secondary combustors is directed to all

of said plurality of volumetric devices in parallel, a lowered level of torque

upon deactivation of at least one of said volumetric devices, and an increased

level of torque upon activation of at least an additional one of said volumetric devices.

24. Motor vehicle propulsion system according to claim 22, further comprising

a bypass valve to serve as engage and disengage device between the motor

assembly and torque converter assembly so that torque converter can be repressed while the motor is operating.

25. Motor vehicle propulsion system according to claim 22, further comprising

a heat source.

26. Turbofan engine system comprising an engine system according to claim

9, wherein the compressor is a turbocompressor driven by discharge from the

expansion volumetric device and a fan driven by said engine system, said fan generating a crossfan streamline and a main thrust for an aircraft, exhaust

from said turbocompressor being discharged to the atmosphere and providing

auxiliary thrust in addition to said main thrust.

27. Turbojet engine system, comprising an engine system according to claim 9

and further comprising a main combustor generating a gas stream providing

a main thrust for an aircraft.

28. Engine system, substantially as described and illustrated.

29. Motor vehicle propulsion system, substantially as described and

illustrated.