BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a simple schematic view illustrating a known arrangement consisting of an internal combustion engine and a turbocharger powered by exhaust gases from the exhaust system of the engine.
FIG. 2 is a simple schematic view illustrating a known arrangement consisting of an internal combustion engine and a centrifugal blower powered by crankshaft power from the engine.
FIG. 3 is a simple schematic view of a known arrangement where a centrifugal blower is driven by an electric motor.
FIG. 4 is a schematic view of an arrangement of the present invention that illustrates a fluid flow amplifier in combination with a turbocharger, and an internal combustion engine
FIG. 5 is a schematic view of an arrangement of the present invention similar to one shown in FIG. 4, but with sequenced valves for the air intake of an internal combustion engine.
FIG. 6 is a schematic view of an arrangement of the present invention similar to one shown in FIG. 5 but including a conventional turbocharger for twin turbocharging.
FIG. 7 is a schematic view of an arrangement of the present invention similar to one shown in FIG. 5 but for a nozzle type air amplifier.
FIG. 8 is a schematic view of an arrangement of the present invention similar to one shown in FIG. 6 but for a nozzle type air amplifier.
FIG. 9 is a schematic view of an arrangement of the present invention similar to one shown in FIG. 4 but for a system without intercooling.
FIG. 10 is a longitudinal sectional view of an air flow amplifier used in the systems of the present invention.
FIG. 11 is a sectional view along the line XI-XI of FIG. 10 illustrating a shim with a plurality of nozzle slits.
FIG. 12 is a longitudinal sectional view of an air flow amplifier of a nozzle type suitable for the systems of the present invention.
FIG. 13 is a cross-sectional view along line XIII-XIII of FIG. 12.
FIG. 14 is a sectional along line XIII-XIII of FIG. 10 illustrating the construction of the cooling unit for the air amplifier of the invention
DETAILED DESCRIPTION—PREFERRED EMBODIMENTS
The inventors herein found out that if an flow amplifier (that operates on the principle of entraining a large volume of air as a secondary flow under the effect of a primary high-speed flow supplied from an external source) is used instead of a turbocharger or additionally with the turbocharger, it becomes possible to significantly improve the construction of a turbocharger by dramatically reducing the rotational inertia and by using materials that are not concerned with heat issues of hot expanding exhaust gases, or high friction gearing or pulley systems. This benefit allows for freeing up of needed power to drive the turbocharger, which leads to lower power requirements to produce compressed air for pneumatic applications, such as force inducting an internal combustion engine.
The second aspect of the invention is based on increasing a temperature difference between the working medium at the entrance to the turbine and the working medium at the exit from the turbine. More specifically, it is known that a turbocharger constitutes a heat machine the efficiency of which in ideal case is proportional to 1−T0/T1, where T1 is a temperature of a working medium, and T0 is a temperature of a cooling medium.
At constant temperatures of hot (T1) and cold (T0) sources, the following formula can be written for the maximal thermal efficiency of a heat machine, based on the previous formula:
h
t=1−T0/T1
The smaller the ratio T0/T1 the closer the conditions to the ideal machine, i.e., the greater the difference of temperatures between the inlet to the turbine and the outlet from the turbine, the higher is the efficiency of the machine. The present invention is based on this conception and consists of providing a fluid flow amplifier with the option of using an intercooler for cooling pressurized air prior to feeding thereof to the fluid flow amplifier for use as a primary flow that entrains an ambient air as a secondary flow.
Considering the flow of the fluid flow amplifier is smooth unlike the exhausts of an internal combustion engine, which pulses, the turbine efficiency is greatly increased. The turbine efficiency is also increased by routing the exhaust of the turbine to the compressor, which lowers the backpressure of the turbine.
FIG. 4 is a detailed schematic view of an arrangement of a system of the present invention that contains a fluid flow amplifier in combination with a turbocharger, and an internal combustion engine. The system consists of the following components: a turbine 22c that is driven into rotation by a gas flow; a pressurized fluid source 34c, such as a container with a compressed gas, an auxiliary small compressor that takes power from the turbine shaft, or a direct supply from a compressed air line (not shown); a fluid flow amplifier 40c, e.g., of the type disclosed in U.S. Pat. No. 5,402,938 (issued in 1995 to R. Sweeney), that is located between the pressurized fluid source 34c and the turbine 22c with a flow control valve 36c and an intercooler 38c located between the pressurized fluid source 34c and the fluid flow amplifier 40c; a centrifugal compressor 24c driven into rotation by an output shaft 28c of the turbine 22c; and a fluid channel 16c between an exhaust 26c of turbine 22c and the input port of the centrifugal compressor 24c. The valve 36c may be a computer control valve, manual valve, or a solenoid valve. The intercooler 38c be, e.g., an air-to-water intercooler, air-to-dry-ice intercooler, etc. Lastly is an internal combustion engine 10b containing an air intake 12b.
The system operates as follows. A pressurized fluid source 34c supplies a fluid under pressure, e.g., compressed air, through the fluid control valve 36c, the intercooler 38c, and the air flow amplifier 40c to a turbine 22c. The compressed air is made cooler after passing through the intercooler 38c. As the cooled pressurized air flow passes through the air flow amplifier 40c, the latter, in a manner described in U.S. Pat. No. 5,402,938, entrains a secondary air from the ambient atmosphere under the effect of the primary compressed air supplied from the pressurized fluid source 34c. The cold high-volume and high-velocity fluid flow shown in FIG. 4 by arrow 42c is produced as a result of mixing of the primary compressed air with the secondary ambient atmospheric flow.
The cold high volume-high velocity mixed fluid flow 42c enters the turbine 22c and expands to form a flow shown by the exhaust 26c. The turbine 22c transmits the power provided by the cold high-volume high-velocity mixed fluid flow 42c to a shaft 28c, which transfers the power to the centrifugal compressor 24c being connected to the shaft 28c. The centrifugal compressor 24c receives a portion of low-pressure air through the channel 16c and readily spins at a high velocity. The centrifugal compressor 24c compresses the air to a high pressure level, so that the compressed air, which is exhausted from the compressor 24c in the form of a high-pressure flow 14c, which is supplied to the air intake 12c of the internal combustion engine 10c. If the pressurized fluid source 34c is off, the air intake 12c will receive air through the turbocharger (not shown).
Such components of the system shown in FIG. 4 as the turbine 22c and the centrifugal compressor 24c can be made of low-density materials, preferably with the density lower than that of aluminum. These components can be made, e.g., from a magnesium alloy such as Ia-141, which has a density about half of aluminum casting alloy but is comparable with aluminum in strength. Due to the use of a light material such as magnesium alloy Ia-141, it becomes possible to reduce the total weight of the compressor and turbine to about 0.05 kg, while a T3 50 trim turbocharger of a comparable size produced by Garrett, where aluminum is used for the compressor and Inconel is used for the turbine, weighs about 0.3 kg. Thus the system of the invention with the use of an intercooler and the new arrangement of the light-weight components results in weight reduction of up to about 83%. The components can also benefit from air bearings rather than conventional ball bearings, which have surface contact between the rolling elements an require the use of an oiling system. Air bearings can allow for the primary pressurized fluid flow to the air flow amplifier to be shut off and still maintain a high rotational velocity, which can provide energy recovery and saving capabilities.
FIG. 5 is a diagram similar to one shown in FIG. 4. In FIG. 5, the components of the system which are identical to those of the system of FIG. 4 are designated by the same reference numerals with an addition of letter “d”. The description of FIG. 5 and its operation of the system as a whole is partially omitted in view of similarity with the system of FIG. 4. The difference is that in the system of FIG. 5 the air intake 12d contains the solenoid valves 50d and 52d. Valve 50d allows the air intake 12d of the internal combustion engine 10d to draw in regular atmospheric air, while valve 52d allows the air intake 12d to be force inducted by receiving a high-pressure flow 14d coming from centrifugal compressor 24d. When force induction is not needed and therefore the pressurized fluid source 34d is not used, valve 52d stays closed, while valve 50d remains open. When force induction is needed the pressurized fluid source 34d is used, and valve 50d is closed, while valve 52d is open. The opening and closing sequence of valves 50d and 52d make it possible to prevent exit of the high-pressure flow 14d to the atmosphere through the valve 50d when tight seal is needed for forcing the air to the intake 12c. Therefore, during force induction of the air intake 12d the valve 50d should be closed.
FIG. 6 is a diagram similar to one shown in FIG. 5. In FIG. 6, the components of the system which are identical to those of the system of FIG. 5 are designated by the same reference numerals with an addition of letter “f”. The difference is that the system of FIG. 6 contains a conventional turbocharger 60f that produces a high-pressure flow 70f. The description of FIG. 6 and operation of the system as a whole is partially omitted in view of similarity with the system of FIG. 5. The air intake 12f of the system of FIG. 6 is equipped with solenoid valves 50f and 52f that are sequenced differently. Valve 50f receives the high-pressure flow 70f from the turbocharger 60f, which force inducts the air intake 12f of the internal combustion engine 10f, while valve 52f allows the air intake 12f to be force inducted by receiving the high-pressure flow 14f coming from a centrifugal compressor 24f. When extra force induction is not needed and therefore the pressurized fluid source 34f is not used, the valve 52f stays closed, while valve 50f remains open making the internal combustion engine 10f a regular turbocharged engine. When extra force induction is needed the pressurized fluid source 34f is used, and the valve 52f is opened allowing for the high-pressure flow 14f to be received by the air intake 12f. The opening and closing sequence of valves 50f and 52f makes it possible to selectively use the engine with or without a turbocharger.
FIG. 7 is a diagram similar to one shown in FIG. 5 but for a nozzle type air amplifier 44g. In FIG. 7, the components of the system which are identical to those of the system of FIG. 5 are designated by the same reference numerals with an addition of letter “g”, and description of their operation and operation of the system as a whole are omitted in view of similarity with the system of FIG. 5. Thus, in FIG. 7 the centrifugal compressor is designated by reference numeral 24g, the turbine is designated by 22g, the shaft by 28g, etc. The nozzle type air amplifier 44g can be viewed at (http://www.rexresearch.com/coanda/1coanda.htm) where various versions of air amplifiers with Coanda profiles are illustrated.
FIG. 8 is a diagram similar to one shown in FIG. 6 but for a nozzle type air amplifier 44i. In FIG. 8, the components of the system which are identical to those of the system of FIG. 6 are designated by the same reference numerals with an addition of letter “i” and description of their operation and operation of the system as a whole are omitted in view of similarity with the system of FIG. 6. Thus, in FIG. 8 the centrifugal compressor is designated by reference numeral 24i, the turbine is designated by 22i, the shaft by 28i, etc. The nozzle type air amplifier 44i can be viewed at (http://www.rexresearch.com/coanda/1coanda.htm) where various versions of air amplifiers with Coanda profiles are illustrated.
FIG. 9 is diagram similar to one shown in FIG. 4 but for a system without intercooling. In FIG. 9, the components of the system which are identical to those of the system of FIG. 4 are designated by the same reference numerals with an addition of letter “k”, and description of their operation and operation of the system as a whole are omitted in view of similarity with the system of FIG. 4. Thus, in FIG. 9 the centrifugal compressor is designated by reference numeral 24k, the turbine is designated by 22k, the shaft by 28k, etc. In FIG. 9 the system without intercooling also applies for FIGS. 5-8 considering they all refer back against each other, with FIG. 4 being the first system in which FIGS. 5-8 refer back to, thus FIGS. 5-8 can also be operated without an intercooling system.
Having described the arrangement of the components of the proposed system in a block-diagram form, let us consider now some components of the system in more specific form.
An example of an air flow amplifier 40c (FIG. 4) suitable for the purposes of the present invention is shown in FIG. 10, which is a longitudinal cross-sectional view of the amplifier. As in the arrangement of FIG. 4, the air flow amplifier 40c is connected to the turbine 22c. The amplifier 40c contains two main parts, i.e., a plug 112 to be connected to an engine and a fluid flow amplifier body 114. An O-ring 116 is typically used to seal the pressurized mating surfaces between the plug 112 and the body 114. For connection to the turbine 22c, the plug portion 112 may have an outer thread 118. The air flow amplifier 40c has on one end thereof an ambient air inlet 120 in the form of an annular mouth with a tapered inner surface 122 through which the ambient air drawn into the throat 124 and further through a guide channel 126 to an outlet port 128 of the air flow amplifier 40c.
In the embodiment shown in FIG. 10, the body portion 114 of the air flow amplifier 40c has an annular chamber 130 one side of which is connected via a control valve 132 and an intercooler 134 to a source of a pressurized gas, e.g., a container 136 with compressed air. The container 136 with compressed air is shown only as an example, and the compressed air may be supplied to the air flow amplifier by a small compressor (not shown in FIG. 10). The control valve 132 can be, e.g., a computer controlled valve, a manual valve or a solenoid valve.
The container 136 with compressed air is connected to the annular chamber 130 of the air flow amplifier 40c by cooling pipe segments 138a and 138b that passe via a cooling unit 134 that comprises a pair of semi-circular chilling elements 140a and 140b which surround the cooling pipe segments 138a and 138b. The construction of the cooling unit 134 is shown in more detail in FIG. 14. More specifically, both element 140a and 140b can be easily removed from casing parts 143a and 143b that are pivotally connected at 145 and secured to each other at their flanged parts 149a and 149b. The pipe segments 138a and 138b are made in the form of a battery of interconnected semicircular members. In FIG. 10, reference numeral 153a designates an input pipe union for the supply of compressed air to the pipe segments, and reference numeral 153b designates an output pipe unit for exit of the chilled primary flow from the pipe segments 138a and 138b.
An example of the aforementioned low-temperature substances 140a and 140b that keep low temperature over a long time and cools the air flow passing through the cooling pipe may be a re-usable and freezable packaged chiller medium of the type marketed by Rubbermaid, Inc. of Wooster, Ohio under the trade name Blue Ice.
As seen in FIG. 10, the annular chamber 30 is formed between the body 14 and the plug portion 12. The aforementioned throat 124 is located in the area where the tapered air inlet 122 merges the guide channel 126. In the area where the narrow passage 142 that connects the annular chamber 130 with the throat 124 and with the guide channel 126 the throat 124 has a Coanda profile 144.
Installed in the throat 124 is also a shim 146 shown in a simplified plan view in FIG. 11 with a plurality of slits 146a that act as nozzles for air of the primary flow when this air leaves the narrow passage 142 and enters the throat 124. More about the shim 146 can be read in U.S. Pat. No. 5,402,938 issued in 1994 to Sweeney. In general, the shim has projections 146b and slits 46a between the projections which function as small nozzles that inject the entrained ambient air to the guide channel 126.
The air flow amplifier 40c of FIG. 10 that is intended for use as a component of a forced induction system of FIG. 4 operates as follows.
When the pressurized air leaves the passageway 142, it is discharged through the slits 146a (FIG. 11) of the shim 146 to the guide channel 126 and through the Coanda effect entrains a secondary flow of ambient air, in the direction shown by the arrows in FIG. 10, to the air inlet 120 in a larger quantity as compared to the amount of pressurized air of the primary flow. The shim 146 allows the pressurized air to follow the Coanda profile 144 over a wider range, resulting in more ambient airflow and increased resistance to backpressure. Both flows are mixed, and the resulting mixed flow of a high volume and high velocity travels to the air outlet port 128 of the air flow amplifier 40c, and then further to the destination, which in the case of the present invention is a turbine 22c. In FIG. 1A, reference numeral 148 designates an air intake pipe of the turbine 22c (FIGS. 4 and 7).
FIG. 12 illustrates an air flow amplifier 150 of a nozzle type that, according to the invention, also can be used instead of a turbocharger or in combination with a turbocharger for an internal combustion engine. In the embodiment of FIG. 12, one end of the air flow amplifier 150 is connected to an air intake pipe of the engine, and the other end of the air amplifier 150 is connected to a source of a compressed air, e.g., of the same type as the container 136 with compressed air (FIG. 10). The source of compressed air is connected to the air flow amplifier via a helical pipe 154 wound around the cylindrical body 151 of the air amplifier 150. The pipe 154 passes through a cooling unit 156, of the same type as the cooling unit 134 (FIG. 10), and a control valve 158.
The air amplifier 150 has a channel 159 that is started at the outlet of the valve 158 and is ended at an axial channel 160 of a nozzle 162 that has an outlet opening 164 at the end that faces the guide channel 163 for guiding a mixed flow towards the turbine 22c (FIG. 4). The outer surface of the nozzle 162 is made with a Coanda profile 168 which, as shown by the arrows in FIG. 11, entrains ambient air from the atmosphere to the guide channel 163 through the openings 170 formed between the nozzle holding spikes 172 shown in FIG. 13 which is a cross-sectional view along line XIII-XIII of FIG. 12.
The pressurized air ejected from the outlet opening 164 of the nozzle 162 helps centralize the pressurized air from the air amplifier and entrained a high volume of the ambient air in the form of a secondary high-velocity flow that is mixed in the guide channel 163 with the primary flow of the pressurized air emitted from the outlet opening 164. The enhanced mixed flow of air is sent to device that require a flow of gas, e.g., to the turbine 22c (FIG. 4). The description of the turbine is omitted.
In both embodiments, the cooling units 134 and 156 can be made in the form of two semi-circular halves which contain chilling elements 140a and 140b with connecting flanges as shown in FIG. 9. Prior to use the contents of these elements is frozen in a freezer of a refrigerator and may stay chilled for several hours.
Although the invention has been shown and described with reference to specific embodiments, it is understood that these embodiments should not be construed as limiting the areas of application of the invention and that any changes and modifications are possible, provided these changes and modifications do not depart from the scope of the attached patent claims. For example, any zone within the fluid flow amplifier and air compressor where this is an airflow an intercooler can be used, any compressor style can be used as the compressor instead of a centrifugal air impeller e.g., an axial air compressor fan, any fluid can be compressed by the compressor. Any zone within the fluid flow amplifier and air compressor where heat is developed, a radiator system such as a heat pipe can be used to transfer the heat elsewhere. The internal combustion engine if equipped with the fluid flow amplifier and air compressor can spin the device with just its intake airflow, which will provide self boosting abilities without depleting a pressurized fluid from a container or over using an engine powered air compressor. A separate fluid flow amplifier can be put anywhere where there is an air flow within the fluid flow amplifier and air compressor, such as the exhaust portion. The compressed air developed by the combination of the fluid flow amplifier and air compressor machine can be used for any application desired. Any device that can produce a pressurized fluid such as compressed air, or any pressurized fluid can supply the primary airflow to the fluid flow amplifier e.g., an eight cylinder combustion engine with two cylinders serving as two-stroke air compressors, while the remaining six cylinders operate as a four stroke, or a vessel of pressurized oxygen. The fluid flow amplifier and air compressor can serve as a powerful unit capable of turning a large generator at low cost. An example would be a self contained pressurized vessel of air of sufficient size such that the fluid flow amplifier can drive the air compressor e.g., an all composite two stage 4:1 pressure ratio turbocharger for a long duration. The turbocharger will produce compressed air to which fuel will be added and ignited to produce hot expanding gases to which drives a turbine-generator to produce energy. Power can be drawn from the generator or hot expanding gases to drive another air compressor e.g., a turbocharger to replenish the pressurized vessel when needed such as to have a continuos operation. The total starting energy and needed replenishing energy would be the fluid flow amplifier air consumption rate, while the rest of the energy is used for the producing electricity. The fluid flow amplifier and air compressor can flow its compressed air to a compressor of a conventional turbocharger of an internal combustion engine for high staging pressure discharge, or vise-versa. The fluid flow amplifier and air compressor can have more than one turbine and compressor. the fluid flow amplifier and air compressor can have multiple fluid flow amplifiers instead of one unit.
Although the fluid flow amplifiers presented above typically incorporate the Coanda profile, being a tangible surface and is defined by the word Coanda effect, which is the tendency of a fluid to cling to a surface that is near an orifice from which the fluid emerges, the Coanda profile is only one example of a fluid entrainment system for a fluid flow amplifier and a non-Coanda effect fluid entrainment system also can be utilized in the system of the invention (see, e.g., U.S. Pat. No. 4,046,492 issued in 1977 to Inglis). Many design variations are possible for the fluid flow amplifiers only a few herein presented in which the inventors are aware of.
Patent Application
20080047266
