The solar vortex engine prototype at Universiti Teknologi PETRONAS
The concept of a vortex engine or atmospheric vortex engine (AVE), independently proposed by Norman Louat [1] and Louis M. Michaud,[2] aims to replace large physical chimneys with a vortex of air created by a shorter, less-expensive structure. The AVE induces ground-level vorticity, resulting in a vortex similar to a naturally occurring landspout or waterspout.
Michaud's patent claims that the main application is that the air flow through the louvers at the base will drive low-speed air turbines, generating twenty percent additional electric power from the heat normally wasted by conventional power plants. That is, the vortex engine's proposed main application is as a "bottoming cycle" for large power plants that need cooling towers.
The application proposed by Louat in his patent claims is to provide a less-expensive alternative to a physical solar updraft tower. In this application, the heat is provided by a large area of ground heated by the sun and covered by a transparent surface that traps hot air, in the manner of a greenhouse. A vortex is created by deflecting vanes set at an angle relative to the tangent of the outer radius of the solar collector. Louat estimated that the minimum diameter of the solar collector would need to be 44+ metres in order to collect "useful energy". A similar proposal is to eliminate the transparent cover.[3] This scheme would drive the chimney-vortex with warm seawater or warm air from the ambient surface layer of the earth. In this application, the application strongly resembles a dust devil with an air-turbine in the center.
Since 2000, Croatian researchers Ninic and Nizetic (from the Faculty of Electrical Engineering, Mechanical Engineering and Naval ArchitectureUniversity of Split) have also developed this technology[4] and patents.[5][6]
The solar research team at Universiti Teknologi PETRONAS (UTP), Malaysia, headed by Prof. Hussain H. Al-Kayiem, developed the first experimental prototype of a solar vortex power generation (SVPG) technology that uses solar energy as a heat source.[7] The basic prototype was then subjected to a series of developments and performance enhancements by integration with sensible thermal energy storage (TES) and modification in the design of the vortex generator. The team carried out and published an experimental evaluation, theoretical analysis, and computational simulations of the SVPG and compiled the findings in a book which summarizes the fundamentals of this technology.[8]
Theory of operation
Conceptual illustration of a vortex engine by Louis Michaud. Diameter 200 m (660 ft.) or greater
(applicable primarily to the Michaud patent)
Elevation (side) view of an 80 m-wide (260 ft) vortex engine. It's constructed mostly of reinforced concrete. (48) is grade level (the surface of the ground).
In operation, the vortex centripetally expels heavier, colder external air (37), and therefore forms a large, low-pressure chimney of hot air (35). It uses about twenty percent of a power-plant's waste heat to drive its air motion. Depending on weather, a large station may create a virtual chimney from 200 m to 15km high, efficiently venting waste power plant heat into colder upper atmosphere with minimal structure.
The vortex is begun by briefly turning on a diffuse heater (83) and electrically driving the turbines (21) as fans. This moves mildly heated air into the vortex arena (2). The air must have only a mild temperature difference because large temperature differences increase mixing with cold ambient air and reduce efficiency. The heat might be from flue gases, turbine exhaust or small natural gas heaters.
The air in the arena rises (35). This draws more air (33, 34) through directing louvers (3, 5), which cause a vortex to form (35). In the early stages, external airflow (31) is restricted as little as possible by opening external louvers (25). Most of the heat energy is at first used to start the vortex.
In the next stage of start-up, the heater (83) may be turned off and the turbines (21) by-passed by louvers (25). At this time, low-temperature heat from an external powerplant drives the updraft and vortex via a conventional crossway cooling tower (61).
As the air leaves the louvers (3, 5) more rapidly, the vortex increases in speed. The air's momentum causes centrifugal forces on the air in the vortex, which reduce pressure in the vortex, narrowing it further. Narrowing further increases the vortex speed as conservation of momentum causes it to spin faster. The speed of spin is set by the speed of the air leaving louvers (33, 34) and the width of the arena (2). A wider arena and faster louver speed cause a faster, tighter vortex.
Heated air (33, 34) from the crossway cooling tower (61) enters the concrete vortex arena (2) via two rings of directing louvers (3, 5, height exaggerated for clarity) and rises (35). The upper ring of louvers (5) seals the low-pressure end of the vortex with a thick, relatively high-speed air-curtain (34). This substantially increases the pressure difference between the base of the vortex (33) and the outside air (31). In turn, this increases the efficiency of the power turbines (21).
The lower ring of louvers (3) convey large masses of air (33) almost directly into the low-pressure end of the vortex. The lower ring of louvers (3) are crucial to get high mass flows, because air from them (33) spins more slowly, and thus has lower centripetal forces and a higher pressure at the vortex.
Air-driven turbines (21) in constrictions at the inlet of the cooling tower (61) drive electric motor-generators. The generators begin to function only in the last stages of start-up, as a strong pressure differential forms between the base of the vortex arena (33) and the outside air (31) At this time, the bypass louvers (25) are closed.
The wall (1) and bump (85) retain the base of the vortex (35) in ambient winds by shielding the low-velocity air-motion (33) in the base of the arena, and smoothing turbulent airflow. The height of the wall (1) must be five to thirty times the height of the louvers (3, 5) to retain the vortex in normal wind conditions.
To manage safety and wear of the arena (2), the planned maximum speed of the vortex base (33) is near 3m/s (10ft/s). The resulting vortex should resemble a large, slow dust-devil of water-mist more than a violent tornado. In uninhabited areas, faster speeds might be permitted so the vortex can survive in faster ambient winds.
Most of the unnamed numbered items are a system of internal louvers and water pumps to manage air velocities and heating as the engine starts.
Criticism and history
In early studies it was not absolutely clear that this could be made workable due to cross-wind disruption of the vortex.[9][10] This motivated later studies with wind tunnel empirical validation of the CFD model, which conclude, "The full scale simulations subjected to cross wind show that the power generation capacity is not affected by the cross winds."[11]
Michaud has built a prototype in Utah with colleague Tom Fletcher.[12]
Also, according to Michaud's patent application, the design was initially prototyped with a gasoline-powered 50cm "fire-swirl".
The University of Western Ontario's wind-tunnel laboratory, through a seed investment from OCE's Centre for Energy, is studying the dynamics of a one-metre version of Michaud's vortex engine.[13]
PayPal founder Peter Thiel's Breakout Labs sponsored an AVE test with a (2012) $300,000 grant.[14] The preliminary results (2015) for which were reported in The Atlantic.[15]
Disambiguation
The term « Vortex Engine » also refers to a new kind of internal combustion engine.[16]
An engine or motor is a machine designed to convert one or more forms of energy into mechanical energy.
A steam engine is a heat engine that performs mechanical work using steam as its working fluid. The steam engine uses the force produced by steam pressure to push a piston back and forth inside a cylinder. This pushing force can be transformed, by a connecting rod and crank, into rotational force for work. The term "steam engine" is most commonly applied to reciprocating engines as just described, although some authorities have also referred to the steam turbine and devices such as Hero's aeolipile as "steam engines". The essential feature of steam engines is that they are external combustion engines, where the working fluid is separated from the combustion products. The ideal thermodynamic cycle used to analyze this process is called the Rankine cycle. In general usage, the term steam engine can refer to either complete steam plants, such as railway steam locomotives and portable engines, or may refer to the piston or turbine machinery alone, as in the beam engine and stationary steam engine.
A power station, also referred to as a power plant and sometimes generating station or generating plant, is an industrial facility for the generation of electric power. Power stations are generally connected to an electrical grid.
The solar updraft tower (SUT) is a design concept for a renewable-energy power plant for generating electricity from low temperature solar heat. Sunshine heats the air beneath a very wide greenhouse-like roofed collector structure surrounding the central base of a very tall chimney tower. The resulting convection causes a hot air updraft in the tower by the chimney effect. This airflow drives wind turbines, placed in the chimney updraft or around the chimney base, to produce electricity.
A mesocyclone is a meso-gamma mesoscale region of rotation (vortex), typically around 2 to 6 mi in diameter, most often noticed on radar within thunderstorms. In the northern hemisphere it is usually located in the right rear flank of a supercell, or often on the eastern, or leading, flank of a high-precipitation variety of supercell. The area overlaid by a mesocyclone’s circulation may be several miles (km) wide, but substantially larger than any tornado that may develop within it, and it is within mesocyclones that intense tornadoes form.
The Brayton cycle, also known as the Joule cycle, is a thermodynamic cycle that describes the operation of certain heat engines that have air or some other gas as their working fluid. It is characterized by isentropic compression and expansion, and isobaric heat addition and rejection, though practical engines have adiabatic rather than isentropic steps.
Solar thermal energy (STE) is a form of energy and a technology for harnessing solar energy to generate thermal energy for use in industry, and in the residential and commercial sectors. Solar thermal collectors are classified by the United States Energy Information Administration as low-, medium-, or high-temperature collectors. Low-temperature collectors are generally unglazed and used to heat swimming pools or to heat ventilation air. Medium-temperature collectors are also usually flat plates but are used for heating water or air for residential and commercial use.
A combined cycle power plant is an assembly of heat engines that work in tandem from the same source of heat, converting it into mechanical energy. On land, when used to make electricity the most common type is called a combined cycle gas turbine (CCGT) plant, which is a kind of gas-fired power plant. The same principle is also used for marine propulsion, where it is called a combined gas and steam (COGAS) plant. Combining two or more thermodynamic cycles improves overall efficiency, which reduces fuel costs.
A cooling tower is a device that rejects waste heat to the atmosphere through the cooling of a coolant stream, usually a water stream, to a lower temperature. Cooling towers may either use the evaporation of water to remove heat and cool the working fluid to near the wet-bulb air temperature or, in the case of dry cooling towers, rely solely on air to cool the working fluid to near the dry-bulb air temperature using radiators.
The energy tower is a device for producing electrical power. The brainchild of Dr. Phillip Carlson, expanded by Professor Dan Zaslavsky from the Technion. Energy towers spray water on hot air at the top of the tower, making the cooled air fall through the tower and drive a turbine at the tower's bottom.
This is a list of meteorology topics. The terms relate to meteorology, the interdisciplinary scientific study of the atmosphere that focuses on weather processes and forecasting.
Landspout is a term created by atmospheric scientist Howard B. Bluestein in 1985 for a tornado not associated with a mesocyclone. The Glossary of Meteorology defines a landspout:
This timeline of heat engine technology describes how heat engines have been known since antiquity but have been made into increasingly useful devices since the 17th century as a better understanding of the processes involved was gained. A heat engine is any system that converts heat to mechanical energy, which can then be used to do mechanical work.They continue to be developed today.
Airborne wind energy (AWE) is the direct use or generation of wind energy by the use of aerodynamic or aerostatic lift devices. AWE technology is able to harvest high altitude winds, in contrast to wind turbines, which use a rotor mounted on a tower.
Tornadogenesis is the process by which a tornado forms. There are many types of tornadoes and these vary in methods of formation. Despite ongoing scientific study and high-profile research projects such as VORTEX, tornadogenesis is a volatile process and the intricacies of many of the mechanisms of tornado formation are still poorly understood.
Unconventional wind turbines are those that differ significantly from the most common types in use.
Energy tower may refer to:
A fan is a powered machine used to create a flow of air. A fan consists of a rotating arrangement of vanes or blades, generally made of wood, plastic, or metal, which act on the air. The rotating assembly of blades and hub is known as an impeller, rotor, or runner. Usually, it is contained within some form of housing, or case. This may direct the airflow, or increase safety by preventing objects from contacting the fan blades. Most fans are powered by electric motors, but other sources of power may be used, including hydraulic motors, handcranks, and internal combustion engines.
This glossary of meteorology is a list of terms and concepts relevant to meteorology and atmospheric science, their sub-disciplines, and related fields.
References
↑ Louat's International Patent Application is PCT/AU99/00037. International publication number WO0042320
↑ Michaud's U.S. Patent is US 2004/0112055 A1, "Atmospheric Vortex Engine"
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