Patent Application
20200300212
The disclosure generally relates to waste energy harvesting. More particularly the disclosure generally relates to waste energy harvesting using a wind turbine.
Conventional wind turbine systems utilize the kinetic energy from the wind, which is in turn used to rotate the blades of the turbine by making use of Bernoulli's principle (an increase in in the speed of the fluid occurs simultaneously with a decrease in pressure).
Unnatural wind sources may include systems that have high volumes of exhaust produced by various machines, including ventilation, heat exchange, air conditioning, or other exhaust systems. Such systems draw electricity from the power grid to spin a fan or start a blower. This process produces exhaust air in various manufacturing plants, power plants, homes, and businesses. This energy is effectively returned to the atmosphere and is not utilized by hardware or machinery sold on the market today.
Many manufacturing plants around the world line their walls with high volume ventilation systems—many of which run full-time. For example, in cold climates, fans often run twenty-four hours per day to prevent freezing. These produce significant energy through the generation of wind. This energy is never utilized.
Manufacturing plants also vent all kinds of air for removing chemicals, heat, dust, etc. Along with high volume ventilation fans, cooling towers produce wind while cooling power plants and other structures.
Air conditioning units use fans to cool their condensers. These are located on many homes, businesses, and various other buildings.
Therefore, waste wind energy sources exist, and such waste wind energy sources can be harvested as a source of energy.
An embodiment of the present disclosure includes a system for generating electric power from an exhaust wind expelled by an exhaust system having an exhaust outlet. The system may comprise a conical framework, a Newtonian turbine, and an electric generator. The conical framework may be disposed substantially downstream of the exhaust outlet. The Newtonian turbine may be disposed substantially downstream of the exhaust outlet. The Newtonian turbine may be positioned at a first distance from the exhaust outlet, and may be substantially concentric with the conical framework. The Newtonian turbine may be disposed partially or completely within the conical framework.
Another embodiment of the present disclosure is a method for generating electric power from an exhaust wind expelled by an exhaust system having an exhaust outlet. Such a method may comprise passing the exhaust wind through a conical framework; impinging the exhaust wind on a Newtonian turbine operatively connected to a low-speed driveshaft after passing the exhaust wind through a portion of the conical framework; and generating electric power using an electric generator.
There may be support legs connected to the conical framework. The conical framework may be connected to the exhaust outlet. The conical framework may be connected to the exhaust system using a ring brace. The Newtonian turbine, the low-speed driveshaft, and the electric generator may be disposed within the conical framework. The conical framework may include a duct disposed such that a portion of the exhaust wind passes through the duct before impinging on the Newtonian turbine. The duct may be converging, diverging, or straight. A conical framework inlet diameter of a conical framework inlet of the conical framework may be smaller than an exhaust outlet diameter of the exhaust outlet. The conical framework may be tapered such that it is substantially frustoconical in shape, so that the conical framework may have an inlet diameter of an inlet smaller than an outlet diameter of an outlet.
There may be a regulation system configured to regulate a taper of the conical framework. The regulation system may be a hydraulic system. The regulation system may be controlled by a controller based on a wind speed input and a maximum operating torque of the electric generator. The wind speed input may include a wind speed measured by an anemometer.
The first distance may be determined to maximize a wind velocity through the turbine, to minimize an accumulation of heat or air between the exhaust outlet and the Newtonian turbine, or based on an exhaust outlet diameter of the exhaust outlet.
The Newtonian turbine may include a rotor, a hub, and a turbine blade. The Newtonian turbine may be connected to the conical framework via a bearing.
The rotor may have an outer rotor surface and a rotor diameter. The rotor may be operatively connected to a low-speed driveshaft.
The hub may be substantially concentric with the rotor. The hub may have an inner hub surface and a hub diameter. The hub diameter may be smaller than or substantially equal to an exhaust outlet diameter of the exhaust outlet. The hub may be tapered such that it is substantially frustoconical in shape, so that the hub may have an inlet diameter of an inlet smaller than an outlet diameter of an outlet.
The turbine blade may have a first blade end and a second blade end. The first blade end may be connected to the outer rotor surface and the second blade end may be connected to the inner hub surface. There may be multiple rotor blades, each having a respective first blade end and second blade end, with each respective first blade end connected to the outer rotor surface and each respective second blade end connected to the inner hub surface.
The electric generator may include a high-speed driveshaft. The high-speed driveshaft may be operatively connected to the low-speed driveshaft. The electric generator may be configured to generate electric power when the high-speed driveshaft is turned. The electric generator may be an asynchronous generator, a doubly-fed induction generator, a permanent magnet system generator, or a squirrel cage induction generator.
The low-speed driveshaft may be supported by a bearing and a mount, and the high-speed driveshaft may be operatively connected to the low-speed driveshaft via a gearbox.
In some embodiments, there may be an extrusion on the fan blade. Such an extrusion may have a cross-section of a right triangle having a straight or curved hypotenuse.
For a fuller understanding of the nature and objects of the disclosure, reference should be made to the following detailed description taken in conjunction with the accompanying drawings, in which:
Although claimed subject matter will be described in terms of certain embodiments, other embodiments, including embodiments that do not provide all of the benefits and features set forth herein, are also within the scope of this disclosure. Various structural, logical, process step, and electronic changes may be made without departing from the scope of the disclosure. Accordingly, the scope of the disclosure is defined only by reference to the appended claims.
Ranges of values are disclosed herein. The ranges set out a lower limit value and an upper limit value. Unless otherwise stated, the ranges include all values to the magnitude of the smallest value (either lower limit value or upper limit value) and ranges between the values of the stated range.
All ranges provided herein include all values that fall within the ranges to the tenth decimal place, unless indicated otherwise.
Embodiments disclosed herein include energy harvesting systems and methods of using the same. A harvesting system may comprise a Newtonian turbine operating in concert with a conical framework to harness energy produced by unnatural wind sources such as, inter alia, cooling towers, high-volume ventilation fans, and air conditioning unit condenser fans. Other wind sources are possible and these are merely listed as examples. In this way, the harvesting turbine may convert incoming kinetic energy from exhaust or other waste wind into rotating mechanical energy.
The wind produced by unnatural wind sources may be harvested in energy recovery according to embodiments of the present disclosure. Thus, a portion of the unused energy from unnatural wind sources can be captured, such as those described herein, and returned to the power grid to enable higher efficiency of machinery operation.
The present disclosure includes a Newtonian turbine. A Newtonian turbine uses Newton's second law of motion to exploit wind energy, as compared to typical wind turbines in the art that rely on Bernoulli's principle (e.g., a Bernoulli turbine). A Newtonian turbine is configured to operate based on the impact of an air mass on its blades. A Bernoulli turbine operates based on low-pressure zones to increase wind velocity. A Newtonian turbine in accordance with the present disclosure is predicted to produce nearly one hundred times more electricity converted from wind energy as compared to a Bernoulli turbine of comparable size.
A conical framework according to the present disclosure can be placed downstream of exhaust systems and supported. The conical framework may also house the Newtonian turbine and may house bearings, mounts, braces, a gearbox, and a generator. The Newtonian turbine can be placed at the beginning of the conical framework and may be connected to a low-speed driveshaft. The low-speed driveshaft may be connected to a high-speed driveshaft via a gearbox. The high-speed driveshaft may be connected to the generator.
The entire structure, which may include the conical framework, may be mounted using support structures or braces, which are attached to the walls where the exhaust fan is located. System stands and welding may be used to connect the fans themselves and support the structure of the turbine.
As wind exits an exhaust system, vortices may be created around the edges of the exhaust outlet. These vortices may form circular shapes and eventually converge back together in a triangular shape, and may have a maximum wind velocity at a certain distance from the exhaust outlet.
The wind may be funneled and concealed in a conical duct system, or conical framework. The conical framework may be decreasing in size (converging), similar to a Venturi, or increasing in size (diverging). The conical framework may have a system of flow straighteners to control turbulence in the wind passing through it.
The conical framework may include a hydraulic system configured to control the expansion or contraction of the conical framework, thus regulating wind velocity. This could be used in a variable-wind-speed design. The hydraulic system can be controlled by a microcontroller, or processor. The microcontroller can be configured to receive readings from a small anemometer installed in the wind stream path to adjust, and it can adjust the pitch of the conical framework accordingly to attain maximum power generation efficiency. The maximum power generation efficiency may be ascertained from a power generation curve for induction motors.
Another embodiment of the present disclosure includes a triangular rib design for fan blades. The design would incorporate small triangles, which could be right triangles, or other curved structures along the front side of a fan blade. These triangles may have an arcuate hypotenuse. The small triangles can contribute to the formation of eddies on the blade's pressure side, thus increasing the wind velocity and increasing efficiency of the energy conversion.
One embodiment of the present disclosure is a fixed system. The fixed system uses an asynchronous generator in combination with a gearbox to generate power with similar voltage and frequency characteristics to the supply line. In the fixed system, the fans operate at a relatively constant speed (e.g., revolutions per minute). The fixed system may also include a three-phase soft starter for protection and stability.
Another embodiment of the present disclosure is a system using a permanent magnet system and a converter to produce varying levels of power at varying fan speeds.
Embodiments disclosed herein include a system for generating electric power from an exhaust wind expelled by an exhaust system having an exhaust outlet.
As depicted in
Exhaust system 4 may include at least one ventilation fan or combustion source. Fluid dynamics testing can be performed to determine the most effective first distance the turbine should be placed from the exhaust system outlet to maximize captured wind velocity. For example, in a test, for a 60-inch fan, it was found that an optimal configuration included placing the turbine 16.5505 inches from the fan blades.
Exhaust outlet 2 may be positioned relative to an outer portion 4 of an exhaust system. For example, outer portion 4 may be a wall.
Bearing 16 may be used to connect Newtonian turbine 3 to conical framework 1.
Conical framework 1 may be connected to exhaust outlet 2, exhaust system 4, via, for example, structural supports 23. Conical framework 1 may have legs connected to it to provide support.
Conical framework 1 may serve to house some or all of the components of the system. Certain mechanical components, including Newtonian turbine 3, low-speed driveshaft 13, high-speed driveshaft 14, bearing 16, mount 17, brace 18, gearbox 19, and/or electric generator 7 may be disposed within conical framework 1. Conical framework 1 may be connected to exhaust outlet 2 using, for example, connection means 22. Alternatively, conical framework 1 may be connected to exhaust system 4 using, for example, supports 23. Further, conical framework 1 may be connected to exhaust system 4 using supports 23 and connection means 22. Connection means 22 may be a ring brace, multiple ring braces, or other appropriate connection means.
Hub 6 may have a hub diameter chosen such that the swept diameter of blade 7 is substantially equal to an exhaust outlet diameter of exhaust outlet 2, as depicted in
Hub 6 may be tapered, and thus may have a frustoconical shape. In this way, hub 6 may have an inlet side 24 and an outlet side 25. In this way, the outlet side 25 may have a diameter that is greater than the diameter of an inlet side 24. Hub 6 may improve the efficiency of the capture of wind energy through the Newtonian turbine 3 by tuning its velocity. Hub 6 may have an approximately frustoconical shape and encompass blade 7 and rotor 5. The thickness of hub 6 may be selected based on the thickness of blade 7. With hub 6, the increase in volume and extra currents passing over a tapered edge of hub 6 results in generation of eddy currents in the downstream direction of the wind. This can result in formation of low-pressure zones, which improve the flow of the wind from the exhaust to the ambient space.
Tapered hub 6 may have the function of increasing the volume of wind passing through the Newtonian turbine 3 within the same diameter, but with reduced inlet area swept by the blade 7. The tapered hub 6 may also create eddies around the outer edges of hub 6. The increase of volume, along with the smaller swept area compared to the outlet area and the creation of eddies allows wind to pass through Newtonian turbine 3 with little-to-no resistance. This can reduce the stress to the fan(s) of exhaust system 4 Newtonian turbine 3 is placed downstream of to a near-negligible amount.
As depicted in
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Conical framework 1 may be variably tapered using a regulation system 26 as depicted in
Conical framework 1 may have an inlet diameter smaller than the diameter of exhaust outlet 2, and an outlet diameter larger than the diameter of hub 6.
Various embodiments of electric generator 15 are depicted in
As depicted in
The DFIG system may include a converter and a low-pass filter in the feedback generator rotor path. The DFIG system can permit up to 30% increase or decrease in the synchronous speed of the induction motor. This contributes to maximizing power generation and its return to the three-phase power supply.
As depicted in
As depicted in
Such embodiments are advantageous where wind velocity from the exhaust outlet is substantially constant. The SCIG configuration may include a turbine, gearbox, and asynchronous induction generator. The combination of the constant air flow coming out of exhaust outlet 2 and design of the gearbox 19 helps keep the SCIG operating at a relatively constant speed (e.g., revolutions per minute), which is roughly 3%-5% (slip) above the synchronous speed. This speed may result in the generation of maximum power and may be the same as the rated speed of the generator. The generator rotation speed may be monitored, and output of the generator may be connected only when the speed is within the optimal range for generating power.
Embodiments disclosed herein also include a method for generating electric power from an exhaust wind expelled by an exhaust system having an exhaust outlet. As seen in
The conical framework may be positioned at, or at a specified distance from, the exhaust outlet. The low-speed driveshaft may be operatively connected to the Newtonian turbine. The Newtonian turbine may be positioned a first distance from the exhaust outlet. The Newtonian turbine may include a rotor, a hub, and a turbine blade.
The rotor may have an outer rotor surface and a rotor diameter. The rotor may be operatively connected to a low-speed driveshaft.
The hub may be substantially concentric with the rotor, and may have an inner hub surface and a hub diameter. The turbine blade may have a first blade end and a second blade end. The first blade end may be connected to the outer rotor surface and the second blade end may be connected to the inner hub surface. The high-speed driveshaft may be operatively connected to the low-speed driveshaft, and the electric generator may be configured to generate electric power when the high-speed driveshaft is turned.
Embodiments of the present disclosure can benefit the environment significantly along with providing significant savings to operators. The present disclosure is unique, since it is able to harness the potential energy from the exhaust ventilation systems using a Newtonian turbine.
A typical Bernoulli turbine is expected to convert 0.5%-1.0% of the energy wind passing through its swept are into electricity. This is because much of the wind passing through a Bernoulli turbine's swept area is uncaptured, and thus captures only 4% of the potential wind energy passing through the diameter of the blades. In comparison, embodiments of the present disclosure capture nearly 100% of the wind energy passing through them as nearly all of the wind entering the swept area impinges on blade surfaces. Thus, embodiments of the present disclosure are expected to convert 40%-50% of the energy from wind passing through the swept area into electricity.
A test setup included a conical framework that decreased and then increased in size rapidly, with fins formed of equal length from the inlet of the conical framework to the point of minimum radius, as shown in
Projections include, for an embodiment having a 15 hp motor and using a 60 inch diameter turbine, the ability to generate more power than the motor powering the exhaust fan. Such an embodiment may produce 6.45 kWh from the generator, and the exhaust fan motor would be consuming 11.19 kWh, yielding a 57.6% efficiency in electricity generation compared to consumption. This is possible due to the high energy conversion rate of the Newtonian Turbine and the benefits to wind velocity from the conical framework disclosed herein. Testing of embodiments of the present disclosure has shown the benefits of the conical framework, including realizing significantly more velocity, which is cubic in the power generation formula, Power=(Density*Swept Area*Velocity{circumflex over ( )}3)/2. Since power scales to conversion directly, it can be shown that a 40%-50% conversion may result from a 144% power increase beyond only using a Newtonian turbine. This 144% increase is attributed to the inclusion of the conical framework.
The steps of the method described in the various embodiments and examples disclosed herein are sufficient to carry out the methods of the present invention. Thus, in an embodiment, the method consists essentially of a combination of the steps of the methods disclosed herein. In another embodiment, the method consists of such steps.
Although the present disclosure has been described with respect to one or more particular embodiments, it will be understood that other embodiments of the present disclosure may be made without departing from the scope of the present disclosure. Hence, the present disclosure is deemed limited only by the appended claims and the reasonable interpretation thereof.
