© Rabbit Tool USA, Inc. Patent Pending.
PROUDLY DESIGNED AND ENGINEERED IN THE USA!
Heat & Power 24/7 from Wind Power
A PRACTICAL REALITY
takes the opposite design approach to the current state of the art.
REAPER MODELS IN TESTING
(AVAILABLE SOON)
Wind and Water US Patent # 7,989,973 + 9,816,383 + 9,816,384 + pending
I am aware that many of you out there are certain that since the best utility scale machines are approaching GOD's, aka Betz's Limit, that there is no point in wasting your time looking further. It reminds me of the comfy smug physicists at the turn of the 19th century who thought that all there was to physics was just a little more precision in their experiments & all would be explained.
Now as then, there are a few niggling nagging details & questions I have for you:
Based on these simple observations, as a long term machine designer, I long thought that there must exist a better solution making more effective use of materials and the wind resource to be exploited. It's solution was not obvious, as dozens, if not hundreds of companies, have shown us plenty of bad ones. To me, this unusual proliferation of bad ideas is a symptom that the underlying theory is not clear, not correct.
Believing that most refinements to the existing 3-bladed approach had likely been already discovered, I took the opposite design approach looking for solutions where most of the forces developed would be driving the generator vs tipping over the tower. After a decade or so of work, what follows is my result.
Reaper uses only Reaction and Lift Forces
My resultant wind machine system most resembles the 19th century American farm wind mill, but I fixed its previous limitations for generating power. Now it has 12 thick, 25% chord, large nose radiused, OJB designed high lift, light weight, high tech aero blades which constructively and instantly interact to uniquely guide the flow through its array, combined with a unique, simple and critically necessary speed control system that allows it to linearly track the wind, keeping a constant wind angle of attack on the blades, aka TSR, over the full range of wind speeds. While it is quite capable of merely pumping water, we/I have equipped it to do far more, so that it can provide both heat and power, CHP, 24/7 for all your possible uses. Let's leave our petro resources in the ground for future generations.
Conventional high speed 3-bladed machines running at TSR's of 6 or more, require tall towers and non turbulent air flows as any turbulence confronting their naked narrow chorded blades instantly puts the blade into stall conditions; e.g. the flow to separate from the low pressure side of the blades; constant speed high inertia rotors only add to the problem by not allowing the rotor to adjust to different wind speeds. But, my variable speed reaction turbine operating at TSR's of 3 or less with its overlapping constructively interacting blades interact to uniquely enhance the Lift Forces keeping the flow attached under nearly all conditions. Make no mistake, we are strictly talking about Lift & Reaction forces here; no Drag Forces are involved. Short towers and turbulent conditions work for us; who needs zoning hassles and upset neighbors when they can all be avoided by a little creative design?
Additionally my machines have four more unique features that conventional machines do not share that mimic extra tower height and/or add to the energy capture:
Wind, as we all know, is the most fickle of energy sources, its speed bouncing up and down like some erratic, neurotic yo-yo. Yet we like our electrical supply to be steady-eddy 24/7. What is a designer to do? My solution was to have the electrical part of the system max out at say 11-12 mph, near the local average wind velocity, maintaining a very desirable higher electrical "capacity factor" and have all the rest be turned into heat which can be easily stored short-term. Smaller household size systems have a small hydraulic driven DC Genset, ~ 2 KW, with chargeable batteries connected to an inverter to supply grid quality electric power 24/7 to all your non heating loads. Larger systems additionally are equipped with an AC Genset synchronous generator.
As we all know, the wind does not always blow, so the end point of my heating system is a special "indirect" water heater with dual-coil input. One coil is attached to my wind machine, the other attached to either a wood stove, solar panel or a concentrated utility gas or electric heat source. End result: seamless electrical power and hot water 24/7 for all your "on demand" or radiant heating as well as electrical power needs.
My system has gears, but no "gearbox," meaning no mechanical gear drive, nor its problems.
The 12 wind-driven blades directly drive a large slow-turning hydraulic gear pump, which is connected through a swivel joint/yawl bearing via hoses, internal to the tower, in a closed loop with the Ground-Level "Power Kart" with the DC and AC Gensets driven via a high speed motors, the "indirect" water heater, filter and all controls. Ordinarily hydraulic gear pumps are thought to be too inefficient for this application, but that is not the case with how I use them, as heat is the major product of my system, so all of it is saved and transported to storage and eventually used.
An hydraulic drive was chosen as it is approximately 1/10th the size, weight and complexity of the electrical drive it replaces, more so since it needs no gearbox, reducing the size and weight of the towers and foundation, plus its working fluid, unlike electrons, carries the normally lost heat down to the Power Kart where it may be harvested and stored. Since the tower top pumps are physically not much different in size and weight from 10 to 100 KW, this allows me to use the same tower for all three sizes, all of which can be readily exchanged as conditions warrant to suit the customers' needs. Additionally as I stated, this hydraulic system permits an exceptionally simple control system to track the wind, orders of magnitude simpler, more rugged, reliable and cost-effective than any competing electrical system, known to the author. A simple precision orifice in the form of a simple needle valve or replaceable set screw with a hole in it does the trick! Once it is sized for a particular model machine, it works automatically over the whole wind speed range, plus it has a dual purpose: it also turns the fluid under pressure into heat!
The pump in the Nucelle assembly at the very top of the tower has a pressure relief valve with an integral heat exchanger, which recirculates excess fluid flow whenever the unit is operating above rated wind speed while allowing continuous power production at the Power Kart, even during storms. We strive to never having to shut down the system; who wants to be without power in a storm? The Power Kart also includes a shut-off valve to stop the turbine at any time to facilitate repairs, filter changing and/or decommissioning.
The Betz Limit is generally met and exceeded by the Reaction Forces alone; the Lift Force Energies mostly drive the generator vs tip over the tower and are totally extra freebie bennies not accredited in the Bernoulli Energy Equation.
Basically this array is constructed like a giant bicycle wheel with a cinched heavy duty plastic shipping strap acting as the rim, crimped into a pocket in the end of the spar of each blade keeping it from moving and fatiguing; it is a reaction turbine operating above its critical Reynolds number with interacting overlapping blades employing enhanced lift force capabilities. The old farm wind mill it replaces was also a reaction turbine, but it did not have the Hi Lift Aero Blades nor a sophisticated speed control system; it operated below its critical Reynolds number in Laminar flow regimes and apparently used this feature of nature to repeatedly and reliable pivot its blade array out of the wind stream to protect itself. However, this meant that it could never operate successfully at the higher power levels, nor was it designed structurally to do so. My machine is.
The number of blades in the array is truly unique: more blades would cause it to operate below the critical Reynolds numbers, while fewer blades would be too far apart to constructively interact.
My machine thoroughly dispatches A. Betz's silly theory of limits, which is coincidental not casual, and routinely exceeds COE (conservation of energy) equation predictions, as written, by several times, which is rendered KAPUT by the mere existance of this machine.
I guarantee that all of my machines exceed the Betz Limit, mainly because the Lift Forces are not properly accredited in the Bernoulli Energy Equation, but also because Newton's Momentum exchange forces are wrongfully excluded.
© Rabbit Tool USA, Inc. Patent Pending.