This invention relates to the geometric shape and/or configuration of the fluid flow chambers of the individual disks and/or brackets in bladeless (disk) turbine(s), bladeless (disk) compressor(s) and/or bladeless (disk) pump(s). This invention offers improvements in the fluid flow chamber design to increase the efficiency of energy extraction or infusion between the working mechanical components and the working fluid or vice versa whether the working fluid be compressible, incompressible, Newtonian or non-Newtonian in nature.
Microturbines are gas turbines generally implemented for electrical power generation applications. Relatively small in comparison to standard power plants, they can be located on sites with space limitations for power production. Microturbines are composed of a compressor, combustor, turbine, alternator, recuperator, and generator assembled in any number or order on one, two or three spools. Waste heat recovery can be used in combined heat and power systems to achieve energy efficiency levels greater than 80 percent. Such combinations include but are not limited to combined power and water heating cycles or combined power, heating-ventilation-air-conditioning and water heating systems. In addition to stationary and portable electrical power generation, microturbines offer an efficient and clean solution to direct mechanical drive markets such as compression, machine tools and air conditioning.
In the commercial, residential and government electrical power markets, independence from the power grid is being sought to lessen the production burden on central power companies and traditional power sources. This move will begin to decentralize the power sources and assure service to all areas under United States sovereignty. Such decentralization protects the power supply from general failure to provide for individual consumers such as homes and businesses. Furthermore, power service is commonly affected by storms, hurricanes, tornadoes, earthquakes and other natural disasters through the interruption of power service to thousands of individuals in the surrounding areas. Terrorist activities, nuclear meltdowns, acts of God or the public enemy; fires; floods; riots; strikes; shortage of labor, inability to secure fuel and/or material supplies, affect power supply and account for shortages thereof. Existing and future laws or acts of the Federal or of any State or Territorial Government (including specifically but not exclusively any orders, rules or regulations issued by any official agency or such government) or other unpredictable occurrences also provide service barriers creating situations prone to a lack of power and inappropriate service for consumers. Beyond the discomfort of the power loss, some residents find themselves in desperate circumstances fighting extreme cold or heat.
The benefits of microturbines are to provide power to individual consumers through individual micro power plants at a reasonable cost with a reasonable payback period of the consumer's investment over the life of the product. Eight benefits of microturbines as reported by the World Watch Institute (“Micropower: The next electrical era”, Worldwatch Paper 151, July 2000) are given as:
Technology trends as witnessed by U.S. Pat. No. 6,324,828 (Willis et al.); U.S. Pat. No. 6,363,712 (Sniegowski et al.); U.S. Pat. No. 6,392,313 (Epstein et al.); U.S. Pat. No. 6,526,757 (MacKay) and U.S. Pat. No. 6,814,537 (Olsen) demonstrate the implementation of conventional radial compressors and turbines in creating microturbines to power the electrical generation system currently on the market and in development. In particular, Olsen demonstrates a method for a rotor assembly with conventional turbine allowing interchangeability.
A bladeless turbine design was first patented by Nikola Tesla (U.S. Pat. No. 1,061,206) in 1913 for use as a steam turbine to extract energy from a working fluid. This original patent included the grouping of a series of disks and blades with identical passage holes symmetrically grouped around the rotor. The working fluid was introduced at pressure and temperature through a form of nozzle at an angle on the outer perimeter of the disks. With only the passage holes in the disks as an outlet for the working fluid, it was forced across the disks radially and angularly inward to exit through an axially located outlet which path resulted in reduction of pressure and temperature of the working fluid and the consequent rotation of the rotor assembly. This configuration is known as a Tesla turbine, bladeless turbine, disk turbine, Tesla pump, bladeless pump or disk pump. The general concept has been widely implemented as a pump, witnessed in U.S. Pat. No. 3,644,051 (Shapiro); U.S. Pat. No. 3,668,393 (Von Rauch); and U.S. Pat. No. 4,025,225 (Durant) and a turbine, witnessed in U.S. Pat. No. 1,061,206 (Tesla); U.S. Pat. No. 2,087,834 (Brown et al.); U.S. Pat. No. 4,025,225 (Durant); U.S. Pat. No. 6,290,464 (Negulescu et al.); U.S. Pat. No. 6,692,232 (Letourneau); and U.S. Pat. No. 6,726,443 (Collins et al.). In form without brackets between the disks, the bladeless turbine is referred to as a Prandtl Layer turbine as witnessed in U.S. Pat. No. 6,174,127 (Conrad et al.); U.S. Pat. No. 6,183,641 (Conrad et al.); U.S. Pat. No. 6,238,177 (Conrad et al.); U.S. Pat. No. 6,261,052 (Conrad et al.); and U.S. Pat. No. 6,328,527 (Conrad et al.)
Standard practice among individual researchers and hobbyists is to combine multiple disks each of identical outer radius and chamber size in the same turbine, compressor or pump assembly. This method may be termed as a constant-geometry disk assembly and is witnessed in U.S. Pat. No. 1,061,206 (Tesla); U.S. Pat. No. 3,644,051 (Shapiro); U.S. Pat. No. 3,668,393 (Von Rauch); U.S. Pat. No. 4,025,225 (Durant); U.S. Pat. No. 4,201,512 (Marynowski et al.); U.S. Pat. No. 6,227,795 (Schmoll, III); U.S. Pat. No. 6,726,442 (Latourneau); U.S. Pat. No. 6,726,443 (Collins et al.); and U.S. Pat. No. 6,779,964 (Dial).
It has been found by others that variations in the disk shape through disk bending, gap differentiation, variation in outer diameters of disks within a single assembly and variation in diameter of flow chambers from one disk to the next alter the performances of the disk assembly. Those are listed as follows:
The variations in the assemblies just described pertain to the disks in the assembly only. Only in U.S. Pat. No. 2,626,135 (Serner) is an alteration to the fluid chamber on the disk taken into account. Serner takes the bridge of the disk and bends it to induce higher efficiency in energy translation from the fluid to the rotor or vice versa. For all other designs, the bridge crossing from the hub or shaft to the working surface of the disk and thereby creating the fluid flow chamber is straight in the axial and angular planes.
Variations in fluid flow chamber design and consequentially the bridge portion of the disk extending from the shaft to the surface area of the disk are not considered in the public domain beyond that discussed above. Improvements in the design of the bridge and fluid flow chamber will better optimize the functionality of the overall turbine, compressor or pump assembly.
These issues have brought about the present invention.
A bladeless turbine, compressor or pump working with a compressible or incompressible fluid relies on the viscosity of the fluid to propel the disk assembly through the extraction of energy. Likewise, when energy is added into the working fluid from the disk assembly energy is transferred. Thus, as a working fluid with lower kinematic viscosity is implemented, the ability of the disks to extract or infuse energy through their working surfaces into or from the fluid system is proportionally decreased whether this variational relationship be constant, linear or non-linear in nature.
Individual researchers and hobbyists will reduce the distance between disks in a given assembly to increase the likelihood of energy exchange between the mechanical and fluid systems as the viscosity decreases. When the working fluid is no longer incompressible, but compressible the viscosity changes by several factors. For example, the kinematic viscosity of an incompressible fluid could be on the order of 1e-1 while the kinematic viscosity of a compressible fluid could be on the order of 1 e-6. The inability to reduce the distance between disks by such a great factor—assuming a linear relationship between the effects—as the kinematic viscosity is reduced leads to the conclusion that the mechanical system must work harder to increase the pressure and temperature gradients to obtain similar mass flow rates for compressible fluids as with incompressible fluids.
The most common implementation of bladeless turbines, compressors and pumps is with incompressible fluids for this very reason. One can gain satisfactory performance with an incompressible fluid running the bladeless device in a range from 0-25,000 RPM. When implementing a compressible fluid, this range of rotational speed accomplishes very little compression and mass flow in comparison. To obtain the design point of bladeless devices with compressible flow, they must be run at speeds up to 100,000 RPM and beyond.
Running a rotational device at high RPM as just described brings the outer diameter of the rotor near to stalling speed by approaching, reaching or surpassing the speed of sound under its operating conditions. For this reason, only smaller bladeless turbines, compressors and pumps ranging in size from 1 nanometer to around 150 centimeters are suited for working at high rotational speeds.
A disk working at such high rotational speeds with a compressible fluid inherently causes the bridge, holding the hub of the disk to the working surface of the disk and creating the flow chamber, to become an object with which the fluid will collide. Said collision is another method, perhaps the primary method at such high speeds, through which energy is exchanged from the working fluid to the mechanical system or vice versa. The low kinematic viscosity of the compressible working fluid at high RPM having a lesser effect on energy transfer. The importance of these phenomena is reversed in incompressible working fluids running with a bladeless rotor at low RPM.
An object of this invention is to define the reference system and the variables necessary to produce variation in fluid flow chamber design beyond those standardly used in prior art.
An object of the invention is to improve disk performance at high rotational speeds through implementing the variation in outer and/or inner diameter of the flow chambers from one chamber to another in any given configuration on a disk.
A further object of the invention is to provide improved flow chamber geometry to maximize efficiency and improve performance at high RPM with a compressible fluid through the tear-drop shaped chamber that maximizes the energy extraction or infusion to and/or from the working fluid.
Another object of the invention is to define the variables and geometry of flow chamber implemented with incompressible fluids and improve upon them, especially for applications with compressible fluids, through showing the limitations of the conventional practices and providing descriptive means for developing geometries beyond those found in prior art.
Further, an object of the invention is to provide a variation in geometries of the tear-drop shaped flow chamber which, based on the implementation of the bladeless turbine, compressor or disk, will maximize the efficiency of energy transfer within various performance parameters.
Finally, an object of the invention is to provide several alternate geometries capable of improving the disk performances at high RPM.
a, 7b & 7c: Variations of tear-drop chamber geometry in
a, 8b, 8c & 8d: Alternative geometries for flow chambers;
According to the present invention, the best coordinates used to describe the geometry related to a disk are cylindrical coordinates as shown in
To understand prior art designs of the bridge connecting the hub and working surface of the disk,
Said bridge(s) may be a single unit or more than one unit. In general practice, the number of bridges, m, may vary between two and six or more and are angularly spaced a distance, δ, apart according to the equation in
Variation from the tear-drop shaped fluid flow chamber in
Whereas prior art has demonstrated three and four-sided fluid flow chambers and
The above figures depict, but do not limit in concept the intention of the invention, possible flow optimizations through the combination of design and variation of individual fluid flow chamber geometries in a given disk of a bladeless compressor, pump or turbine. The geometry of the individual fluid flow chambers themselves is recommended in this invention, but does not limit as to the possible design or configuration of the fluid flow chambers, to be maximized for compression and energy extraction purposes. These designs may be oriented on the disk in any fashion to maximize the efficiency of energy addition or extraction to the compressible or incompressible working fluid.
Number | Date | Country | |
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60621929 | Oct 2004 | US |