Thermodynamic Details
The energy produced by raising air at a pressure of 101 kPa to the 10 kPa level is zero when initial temperature and humidity are 24.5C and 90% respectively, increasing to 3,000 J/kg when initial temperature and humidity are 24.5C and 97% respectively. A mechanical energy of 3,000 J/kg corresponds to a velocity of 77 m/s, to a base pressure of 97.7 kPa, and to a base pressure reduction of 3.3 kPa. Work production increases with temperature and humidity. Saturating the air with 30C water before it starts to rise would yield specific work of 18,000 J/kg.
Based on specific work of 10 kJ/kg of air, a 200-MW vortex engine will have a heat input of 1,000 MW (remember, this is waste heat) and airflow of 20,000 kg/s. In a vortex engine with 20 peripheral wet heat exchangers, the work and heat duty per sector will be 10 MW and 50 MW respectively. Each sector will have a single 10-MW turbine with a diameter of 5 m. The cost of power could be as low as $0.03 per kWh; there is no fuel cost. The AVE concentrates the work produced from heat received over a long period of time and over a large area in a small location, producing a high-intensity energy source.
Many Other Advantages
An AVE will have advantages over the cooling towers it replaces beyond power production. An AVE will be shorter than a natural draft cooling tower and therefore easier to maintain. Air dampers in the tangential entry duct will permit maintenance of individual cooling cells and turbo-generators without shutting down the whole plant. The temperature of the cooled water will be lower than with conventional cooling towers, which will improve fossil plant operating efficiency. Maximum power production will occur during periods of high solar radiation, when the power is most needed. Placing an AVE on a thermal power plant is very attractive because the heat is already concentrated at a temperature 10C to 30C higher than ambient temperature.
The water production benefits would be invaluable in dry climates. Based on a precipitation rate of 12 grams of water per kilogram of air, the resulting precipitation would be 240 kg/s. The precipitation produced by a 200-MW vortex power station would cause rainfall of 2 mm/d when spread over an area of 10 km 2. The horizontal extent of the cloud cover in the downwind direction could be 20 km. The precipitation produced by an AVE is small compared to natural storms. Airplanes could easily avoid the small, highly visible vortex in a known location. An AVE may reduce the likelihood of natural storms by reducing the heat content of surface air in its vicinity.
Looking Ahead
The AVE has the potential to produce large quantities of carbon-free energy because the atmosphere is heated from the bottom by solar radiation and cooled from the top by infrared radiation. There is a potential of converting and capturing 12% of the heat carried upward by convection and converting it to electrical energy. This is equivalent to 3,000 times current world electrical energy production. The heat released in cooling the 100-m-deep layer of tropical water by 3C is 20 times the heat in the world’s remaining oil resources. The AVE provides a system for converting 10% to 30% of this heat to useful work.
The AVE also has potential for greatly reducing CO2 emissions. The output of a power plant could be increased by up to 40% without increasing CO2 emissions; alternatively, the existing output could be maintained, but with 20% less emissions. There is a potential for further CO2 reduction when the heat content of the lower layers of the atmosphere or of naturally warmed water are used as the heat source. The AVE can be turned off at will and therefore is far safer than other global warming mitigation proposals.
—Louis Michaud (lmichaud@vortexengine.ca) is president of AVEtec Energy Corp. Eric Michaud is engineering associate at AVEtec Energy Corp. Additional information, including thermodynamics analysis, drawings, videos, and reference material, is available on Vortex Engine’s web site (http://vortexengine.ca)
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