Patent Application
20120160209
This present disclosure relates to the field of energy conversion, and more specifically, to a turbine having cooperating and counter-rotating rotors.
Most combustion engines and most compressors use one or more pistons alternating within cylinders to produce torque or to compress a gas. The ubiquitous alternating piston engine generates volume variation, which is required both in motor or compressor applications, in an inefficient manner. Due to heavy losses inherent to its alternating mode, this engine generates tremendous heat, suffers from important levels of friction, vibrates, generates shocks at high pressure levels and high temperatures, and is noisy. The overall thermal efficiency of a typical alternating piston engine used in an automotive application is very low, typically in the range of 25%.
In a four-cycle engine, the fact that the four strokes (intake, compression, combustion, exhaust) take place within a same volume, delimited by the movement of the piston within its cylinder, is a major conceptual limitation to the efficiency of the motor: An ideal volume for one stroke, for example admission, is not necessarily the ideal volume for another stroke, for example expansion during combustion. At the top-dead center of its revolution, the engine creates high pressure levels and high temperatures while not producing any torque, leading to heavy heat transfer towards the engine block, thereby reducing the efficiency of the engine. Moving parts such as pistons and connecting rods need to be very rigid and heavy in order to withstand heat shocks, pressure shocks, and constant acceleration/deceleration cycles. Additionally, high pressure coupled with high-heat points within the cylinders form a condition that is prone to the formation of nitrous oxide (NOx), an important pollutant. The quasi-sinusoidal movement produced by pistons, crankshafts and like components lead to an uneven output torque produced by the engine. The addition of a heavy flywheel is required for smoothing the output torque of such conventional engine. The engine needs to evacuate a large fraction of the generated energy to the atmosphere, with limited evacuation restriction. The engine is thus very noisy because exhaust gases are pulsed and expelled from the engine at well above atmospheric pressures. Compressor applications wherein, for example, an electric motor drives one or more pistons, generally suffer from most of the same inconveniences.
Rotary engines such as the well-known Wankel motor only partially overcome the above-mentioned deficiencies of the alternating piston engines. Rotary engines rely on heavy, eccentrically rotating pistons that still generate considerable vibrations due to the constant shift of the mass of the rotating pistons. Moreover, in comparison to the traditional alternating piston engine, the Wankel engine suffers from important fuel and lubricating oil consumption. This engine requires the use of seals for preventing burning gases from reaching gases that are in their compression phase; failure of these seals have plagued many rotary engine applications. Friction is also an important problem of the Wankel engine.
Traditional turbines such as those used in aircrafts or in thermal power plants are very complex and too costly for most applications. These turbines need to operate at very high rotating speeds and are only efficient within a very limited range of operating speeds in order to ensure that gases enter at a precise velocity. Due to its architecture comprising fans operating in aerodynamic mode, it is not possible to create pressure within a traditional turbine at a low rotating speed. Additionally, traditional turbines become fragile when exposed to non-ideal conditions; for example a turbine used in nuclear or thermal power plant may be severely impacted when subject to “unclean” vapor containing small droplets of water. These droplets may severely erode the fans of the turbine.
Therefore, there is a need for an improved turbine capable of compressing or pumping a fluid and/or generating torque, at improved energy efficiency levels, the turbine having a low production cost.
Therefore, according to the present disclosure, there is provided a turbine for use in energy generation, energy recovery, motor, pump, and compressor applications.
According to an aspect of the present disclosure, there is also provided a turbine comprising a housing having a perimeter connected to a top and a bottom, an input port and at least one output port. The turbine also comprises two counter-rotating spiral-shaped rotors enclosed within the housing, each rotor having an axis of rotation. The rotors have a thickness allowing slightly spaced or barely contacting relation with the top and the bottom of the housing. The rotors also have four curved arms. The arms of a first rotor are curved in a direction of rotation of the first rotor while the arms of a second rotor are also curved in the direction of rotation of the first rotor. A diameter of each one of the rotors extends in length for slightly spaced or barely contacting relation of a tip of the arms to the perimeter of the housing over at least 90 degrees of rotation of the rotors. A distance between the two axes is such that the tip of an arm of the first rotor comes in slightly spaced or barely contacting relation between two arms of the second rotor at some angle of rotation. As the two rotors rotate, chambers are formed between some of the arms of the two rotors and between some of the arms and the perimeter of the housing, in continuously varying shapes. Volumes of the chambers delimited by theses shapes are further delimited by the top and the bottom of the housing. A first chamber defined between some arms of the two rotors and the perimeter of the housing is in an expansion phase when a second chamber is created and starts to expand between some arms of the two rotors. One of the first and second chambers is in connection with the input port. The first and second chambers are expanding while at least a third chamber is in connection with the at least one output port.
The present disclosure further relates to a turbine comprising a housing having an input port and at least one output port and two rotors enclosed within the housing. The rotors are counter-rotating in a same plane. A plurality of chambers are formed within the housing and delimited by arms of the rotors. The arms of the rotors cooperate in their rotation to create a first chamber and a second chamber, the first chamber and the second chamber concurrently expanding as the rotors rotate, the first chamber starting to expand earlier than the second chamber. One of the first and second chambers is in connection with the input port. A third chamber is in contact with the at least one output port.
The present disclosure also relates to a motor, comprising a combustion turbine. The combustion turbine comprises a housing having an input port and at least one output port, two rotors enclosed within the housing and counter-rotating in a same plane, a plurality of chambers formed within the housing and delimited by arms of the rotors, an ignition mechanism, and an output shaft is operably connected to at least one of the two rotors. The arms of the rotors cooperate in their rotation to create a first chamber, the first chamber and at least a second chamber concurrently expanding as the rotors rotate, the second chamber starting to expand earlier than the first chamber, one of the first and second chambers being in connection with the input port, a third chamber being in contact with the at least one output port. The motor also comprises a compression turbine operating in reverse mode from the combustion turbine for admitting and compressing an air and fuel mixture and for providing the compressed air and fuel mixture to the input port of the combustion turbine. A synchronization shaft is operably connected to each turbine. Torque from at least one of the two rotors is received at the output shaft.
Embodiments of the disclosure will be described by way of example only with reference to the accompanying drawings, in which:
a is a cutaway view of a housing bottom according to an embodiment;
b is a partial view of the housing bottom of
a is a partial cutaway view of the motor of
b is another partial cutaway view of the motor of
c is a detailed view of a bottom part of the motor of
a is yet another perspective view showing additional parts of the motor of
The present disclosure is directed to a turbine that may be used as a pump, a compressor, as an energy recuperation device for generating torque, an air engine, a steam turbine, or as a part of a motor. A basic turbine comprises a housing that encloses two counter-rotating and cooperating spiral-shaped rotors. Each rotor has a plurality of curved arms, or blades, for example four (4) arms. While the rotors are counter-rotating, the arms of both rotors are curved in a same direction. For example, the arms of a first rotor and the arms of a second rotor may both be curved in a direction of rotation of the first rotor. The rotors rotate within a same plane, within the housing. The rotors have a width, or depth that closely matches a distance between two substantially parallel internal surfaces of the housing. The internal surfaces of the housing may be flat or substantially flat in order to maximize areas of contact between these surfaces and the rotors. The rotors also have an overall diameter, defined by a circumference covered by a full rotation of a tip of the curved arms. An internal perimeter of the housing may be generally shaped as two partially overlapping circles having a circumference generally matching the circumference of the rotors.
Because the width of the rotors closely matches the distance between the two parallel internal surfaces of the housing, a relation between the rotors may be characterized as “edging”, in the sense that a balance is attained between a minimal friction between the surfaces and a minimal gaseous leakage. The tips of the arms of the rotors may thus come in slightly spaced or barely contacting relation—hereinafter edging contact—with the internal perimeter of the housing. Edging contact of a tip of a curved arm may be made with the internal surface of the housing over at least 90 degrees of rotation. The two rotors may also come in edging contact with each other. A distance between axes of rotation of the two rotors is such that the tip of an arm of one rotor comes in contact with the other rotor, in a void between its own two arms, at some rotation angles.
In an embodiment, minimal friction is attained between barely contacting parts of the turbine. In another embodiment, a slight spacing is maintained between the various parts of the turbine. Some spacing may allow minimal leak between, for example, the arms of the rotors and the parallel interface surfaces of the housing. Turbulence between fixed and mobile parts minimizes further such leaks. This effect, which is well-known to those skilled in the art of conventional high-speed turbines, is in fact applicable in the turbine of the present disclosure.
From the following description of various embodiments, the skilled reader will observe that no strict tolerance of various dimensions of the components of the turbine is required, as some internal leakage is not detrimental to the operation of the turbine. Additionally, some embodiments disclosed hereinbelow reveal how leakage may be controlled and how adverse aerodynamic effects may be circumvented.
The housing is generally sealed except for at least one input port and one or more output ports. Multiple chambers, or cavities, are defined within the housing by the cooperation of the rotors: the chambers have a volume delimited in one dimension by the two parallel internal surfaces of the housing and in the other two dimensions by varying combinations comprising the arms of the rotors and the perimeter of the housing. Because the rotors are rotating, the chambers continuously change in size and in shape. As the rotors rotate, new chambers are continuously created and expand while other chambers reduce in size and disappear.
The creation of a new chamber may cause, as it expands, a negative pressure. When the negative pressure is present at the input port, a gas—or more generally a fluid, including for example a gas comprising a part of liquid droplets—may be aspirated into the expanding chamber. Likewise, a chamber that is reducing in size acquires a higher pressure and may expel gas through an output port. A chamber that, at a given time, maintains a constant size may also expel gas through an output port if the chamber has been pressurized earlier. Hence, if an external mechanical force or torque is applied to the turbine and engages the rotors in a rotating motion, the turbine may act as a compressor or as a pump.
A pressurized fluid may alternatively be applied at the input port. The pressurized fluid forces the expansion of a chamber by rotation of the rotors. The pressure of the fluid is reduced as the chamber expands and may then be expelled at a lower pressure at an output port. Hence, the turbine may be used to convert the pressure of the fluid applied at the input port into an output torque. This property of the turbine may be used in an electrical power plant.
Referring to
The housing, comprising the top part, the bottom part 110 and the perimeter 120, may be generally sealed, apart from the various input and output ports. The rotors 130 and 140 are held in place at their axes 138 and 148 of rotation by rotating shafts (not shown), which prevent lateral movement of the rotors 130 and 140 but allow rotational movement. In an embodiment, each of the rotors 130 or 140 and its respective axe 138 or 148 may be machined as one single piece, providing higher resistance to mechanical forces, higher reliability, limiting mechanical movement between the rotors and their axes, and further allowing higher pressures within the turbine 100. The rotors 130 and 140 do not significantly move perpendicularly to the axes because their width W is more or less equal, within some mechanical tolerance to the distance between the top and bottom parts. External components such as bearings (not shown) connected to the rotating shafts may further be used to maintain the rotors 130, 140 in place. In their rotation, the rotors 130, 140 may come in edging contact with each other, with the top part and the bottom part 110, and with the internal surface 122 of the perimeter 120. In contrast with traditional engines, mechanical tolerances between the rotors 130, 140 and the internal surface 122 may be relatively relaxed: various “spaces”, called “chambers” formed between the rotors themselves or between the rotors and the housing may withstand a modest level of leakage without adverse effect on the operation and performance of the turbine 100. As illustrated on
Referring now concurrently to
It may thus be observed that a new chamber is created from the cooperation of the rotors 130, 140 at every 90 degrees of rotation, or four times per revolution of the rotors. Over a complete revolution of the rotors, chambers C, D, A and B have been created near the axis 138 of the rotor 130 and have gone through phases of expansion, splitting into distinct chambers temporarily having a constant volume as for example chambers C1 and C2 of
Returning to
On
Eventually, as the rotors continue turning, split chambers such as D1 and D2 join again. For example, chambers C1 and C2 that have constant volumes in
As expressed hereinabove, the housing of the turbine 100 is sealed except for an input port and one or more output ports. An input port may be located in the bottom of the housing, as shown on
The rotors 130 and 140 may be synchronized, for example using synchronizing gears (not shown) located outside of the housing, and connected to axes 138 and 148 via the rotating shafts. Synchronization helps in minimizing friction between the rotors 130, 140 and in maximizing mechanical torque upon the rotating shafts.
In an embodiment, as a chamber expands due to the rotation of the cooperating rotors, a negative relative gas or fluid pressure is created in the expanding chamber. In another embodiment, a positive gas pressure applied in a chamber forces the chamber to expand, creating a force applied to the blades, or arms, of the rotors, creating a torque around the axes of the rotors. It will therefore be apparent to those of ordinary skill in the art that the turbine 100 may be used to convert energy present in a pressurized gas, such as for example water vapor from a boiler in a thermal or nuclear power plant, converting an energy from the pressurized gas into a mechanical torque at the axes of the rotors, usable for example for driving an electric generator.
An embodiment of a torque generator based on the turbine 100 will now be described. The torque generator operates according to the cycle described in relation to
In an embodiment, because the pressure within those chambers that are neither expanding nor compressing does not generate any torque, a part of the energy contained within this pressure may be recuperated. Gas from the output ports 150, 152 may be fed into a secondary turbine that also generates some torque. Alternatively, some of the gas from the output ports 150, 152 may be recirculated throughout cooling passages within the housing, thereby reducing the need for other cooling means. Furthermore, when the gas absorbs some additional heat by passing in the cooling passages, its volume expands, increasing an amount of residual enthalpy of the gas, whereby energy can be harnessed by the secondary turbine. This reduces any amount of energy required to cool the turbine 100 while also increasing a net torque output. Those of ordinary skills in the art will appreciate that heat management within the turbine 100 may depend on its intended use. For example, when the turbine 100 is used for generating torque from hot water vapor, heat losses from the turbine 100 may be minimized so that a maximum possible amount of energy is extracted from the vapor.
In an exemplary embodiment of a torque generator, the turbine 100 is not negatively impacted if a gas entering the input port 112 is contaminated with some liquid. As an example, “unclean” vapor containing a significant amount of water droplets may be processed by the turbine 100 without significant adverse effect on the rotors 130, 140. The eventual presence of small water droplets in vapor processed by the turbine 100 may at once provide a level of air tightness between the rotors and the housing while, as rotational speeds of the turbine are relatively low, remaining harmless to the rotors, Some treatment of fixed and mobile components of the turbine 100 may further counteract any erosion effects from such water droplets.
An embodiment of a compressor based on the turbine 100 will now be described. In this embodiment, the turbine 100 operates in a reverse mode compared to the cycle described in relation to
In various embodiments of a torque generator or compressor based on the turbine 100, valves such as alternating valves or rotating valves may be used to control opening of the input port and of the output ports.
Instead of a gas, an uncompressible liquid, for example water, may flow through the turbine 100. Though the liquid does not compress, its pressure on the rotors 130, 140 still generates torque. As such, the turbine 100 may be used to generate torque from a flow of water, for example, in a hydroelectric power plant. Likewise, the turbine 100 may be used for pumping a liquid, when operating in reverse mode compared to the cycle described in relation to
Referring now to
Curve 810 represents a torque provided by a piston of a conventional engine on its crankshaft. At a zero degree point, the piston is at the top of its course within a cylinder. Because of its position, there is no lever effect from the piston to the crankshaft. Even though a compression within the cylinder is at its maximum and even though ignition occurs shortly before that point, no torque is provided by the piston due to the lack of leverage. The torque provided by the piston is at its maximum when the crankshaft has rotated by 90 degrees. Of course, the piston of a conventional four-stroke motor produces power only once per every two revolutions. Hence the peak torque obtained at 90 degrees is followed by inefficient periods during the next three strokes following the combustion cycle. The piston actually absorbs some torque during the exhaust, admission and compression strokes. As a result, an overall torque curve from the piston is somewhat sinusoidal, including periods during which the net torque output is negative.
The turbine 100 creates chambers that generate torque over about 145 degrees of rotation, new chambers being generated four (4) times per revolution, which implies that periods of time in which two successive chambers generate torque may overlap, the torque from the two chambers being combined at the axes. Referring again to
Of course, while the torque is still very significant at 90 degrees of rotation, another cycle is already beginning within the turbine 100, as a new chamber is created with every quarter of a revolution. This compares favorably with a piston in a four-stroke engine, igniting once ever 720 degrees of rotation. As a result, an additional curve such as curve 820, 822 or 824 is initiated and added at every 90 degrees of rotation of the turbine 100, and the net output torque of the turbine 100 is relatively constant and flat.
As mentioned hereinabove, mechanical tolerances between the rotors 130, 140 themselves as well as between then rotors various surfaces of the housing 110 may be relatively relaxed. A modest amount of gaseous or fluidic leakage between the various chambers within the turbine 100 is not detrimental to its performance. In fact, any leakage occurs from high pressure chambers to lower pressure chambers, creating at least some modest level of torque in those constant volume chambers, minimizing net losses. If gases exiting the turbine 100 through the output ports 150, 152, 154 are fed to a secondary turbine, net losses are minimized even further. In addition, Bernoulli effects may occur within the turbine 100 at high rotating speeds. In order to circumvent these effects, optional embodiments of the rotors such as shown on
Indentations 900-908 and 1000-1006 also allow avoiding mechanical impacts between the rotors 130 and 140 or between the rotors themselves and other components of the turbine 100. As shapes of some turbine components may be plastically altered under high heat, high pressure and/or high speed conditions, these indentations may prevent collisions between moving parts and between moving and fixed parts. Some attenuation in the geometry of the rotors 130 and 140, creating small gaps between tips of their arms 131-134 and 141-144 and other fixed or mobile surfaces, may further reduce any risk of mechanical shocks between the rotors.
Owing to the capabilities of the turbine 100 to compress a gas when a torque is applied and to create a torque when gas pressure is applied, the turbine 100 may, in an embodiment, be used as a building block for producing a motor. The motor acts as a four-cycle motor in which admission and compression cycles are made in a first turbine while combustion and exhaust cycles are continuously and concurrently made in a second turbine, as in the case of a conventional gas turbine.
The compression turbine 1410 has a top part 1420 while the combustion turbine 1460 has a bottom part 1470. Perimeters of the two turbines 1410, 1460 are not shown in order to show rotors 1432, 1434 of the compression turbine 1410 and rotors 1482, 1484 of the combustion turbine. Though distinct, the two turbines 1410, 1460 may optionally share some components. For example, a plate 1458 is at once a bottom part of a housing for the compression turbine 1410 and a top part of a housing for the combustion turbine 1460. The plate 1458 may comprise output ports (not shown) for the compression turbine 1410, internally connected to one or more input ports (not shown) for the combustion turbine 1460. As such, the plate 1458 may be a transfer plate for transferring the output of the compression turbine 1410 directly into the input of the combustion turbine 1460.
In an embodiment an output port on the compression turbine 1410 is within the plate 1458 and the output port communicates directly therethrough with an input port of the combustion turbine 1460, allowing the compressed air or air and fuel mixture to enter the combustion turbine 1460. In this case, the combustion turbine 1460 comprises ignition means, such as a spark plug (not shown), and ignition of the air fuel mixture takes place within the combustion turbine 1460. In another embodiment, one or more output ports of the compression turbine 1410 are connected with one or more input ports of the combustion turbine 1460 through an intermediate conduit, in which case ignition may take place either within the intermediate conduit or within the combustion turbine 1460. Regardless, combustion generates high pressure within chambers of the combustion turbine 1460, this high pressure acting on rotors to generate a torque.
As shown, the compression turbine 1410 comprises a shaft 1416 connected to the rotor 1434, a second shaft connected to the rotor 1432 being omitted from the figure. Alternatively, shafts 1456 and 1454 may extend through the axes of rotors within the two turbines 1410 and 1460, substituting for the shaft 1416 and acting as a shaft for the rotor 1432. The combustion turbine 1460 is connected by use of the shafts 1456 and 1454 to two counter-rotating synchronizing wheels 1462 and 1464. The synchronizing wheels 1462 and 1464 as shown are frictionally connected. The synchronizing wheel 1464 transmits output torque from the shaft 1454 to the synchronizing wheel 1462, which in turn transmits a sum of this torque and of a torque from the shaft 1456 to a pick-up wheel 1466. The pick-up wheel is mounted on an output shaft 1468, from which a complete output torque from the motor 1400 may be used. A fraction of the output torque from the motor 1400 may be used to drive the compression turbine 1410, a remainder of the output torque forming a net output of the motor 1400. The output shaft 1468 may extend towards a transfer wheel 1412. The transfer wheel 1412 is operably connected to an input wheel 1414, further connected to the shaft 1416 and, therethrough, to the rotor 1434. Of course, the rotor 1432 is also connected to a shaft (not shown), itself connected to another input wheel (not shown) driven by the input wheel 1414. While synchronizing wheels 1462 and 1464 act to synchronize the rotors 1482 and 1484 within the combustion turbine 1460, the combustion turbine 1460 is further synchronized with the compression turbine 1410 via shafts 1468 and 1416 or, alternatively via shafts 1454 or 1456, which may all act as synchronizing shafts. Phase adjustment of the compression turbine 1410 and the combustion turbine 1460 may be obtained by adjusting the input wheel 1414 and the input wheel connected to the rotor 1432.
In the exemplary embodiment of
a is a partial cutaway view of the motor of
b is another partial cutaway view of the motor of
c is a detailed view of a bottom part of the motor of
It may be observed that ignition may occur within the combustion turbine 1460 four times per rotation, as a new chamber is created upon every 90 degrees of rotation of the rotors. Alternatively, ignition may occur at similar rates, or continuously, within an intermediate conduit between the compression turbine 1410 and the combustion turbine 1460. In either case, combustion pressure within the combustion turbine 1460 is consistently present. This compares to one ignition with every two revolutions within a traditional four-stroke cylinder. It may also be observed that, within the combustion chamber 1460, pressure within a chamber consistently generates torque, owing to the geometry of the rotors. As a result, a serious problem of traditional combustion engines, in which maximum pressure at top-dead center coincides with no torque output, does not occur. The motor 1400 thus operates more efficiently, generates a smoother torque output, generates less heat, and produces significantly less nitrous oxide (NOx).
Of course, variations from the basic structure of the motor of
The motor 1400 may operate with ordinary gas, methanol, ethanol, diesel fuel, and the like, some adaptations being made to adapt to a chosen fuel type. As is well-known to those of ordinary skill in the art, in the case where diesel fuel is used, fuel pressure, compression levels, ignition means, electronic control means, and the like differ from the case where ordinary gas is used.
Those of ordinary skill in the art will realize that the description of the turbine and of the motor are illustrative only and are not intended to be in any way limiting. Other embodiments will readily suggest themselves to such skilled persons having the benefit of this disclosure. Furthermore, the disclosed turbines and motors can be customized to offer valuable solutions to existing needs and problems related to the manufacturing costs and lack of efficiency of current compressors, turbines, pumps for incompressible fluids, and motors.
In accordance with this disclosure, the turbine components described herein may be implemented using various materials such as diverse metals and alloys, plastic, polymers, ceramics, and combinations thereof. Notably, a rotor and a rotating valve attached thereto may be made using distinct materials or distinct surface treatment. Selection of materials used for manufacturing the various components of the turbine would be based on considerations such as operating pressure, operating speed, operating temperature, nature of the fluids within the turbine, expected durability of the turbine, cost considerations and similar considerations.
In the interest of clarity, not all of the routine features of the implementations of turbines and motors are shown and described. It will, of course, be appreciated that in the development of any such actual implementation of the turbine, numerous implementation-specific decisions must be made in order to achieve the developer's specific goals, such as compliance with application-, system- and business-related constraints, and that these specific goals will vary from one implementation to another and from one developer to another. Moreover, it will be appreciated that a development effort might be complex and time-consuming, but would nevertheless be a routine undertaking of engineering for those of ordinary skill in the field of energy conversion having the benefit of this disclosure.
Although the present disclosure has been described hereinabove by way of non-restrictive illustrative embodiments thereof, these embodiments can be modified at will within the scope of the appended claims without departing from the spirit and nature of the present disclosure.
