Patent Publication Number: US-2006016182-A1

Title: Power plant and process for the production of electric power from wind

Description:
This patent concerns, in general a plant for the production of electric power, in particular an innovating plant for the production of electric power by the use of wind generators.  
      During the last decades the study and development of alternative systems to oil for the production of power energy, has been subject for very accurate researches all over the world. This effort is justified by different factors, first of all the limited availability of the oil resource, the costs and risks connected with oil extraction and also the open research for alternative systems able to satisfy a steadily increasing energy demand in conjunction with a strong need to reduce the atmospheric pollution.  
      We cannot neglect the needs of the poor and developing countries and the possibility for them to be autonomous, at least for covering their essential needs, without technologically depending on complicated plants, which are difficult to maintain.  
      Among the different alternative resources, the production of clean energy using the wind flows already known for many centuries has seen a rapid and significant growth.  
      We have witnessed the development of advanced generators able to reach hourly productions that were unimagined in the past and systems capable to maintain a constant frequency regardless of the direction and speed variations of the wind. Last but not least the generators need a minimum and very simple maintenance and have a considerably long life.  
      These modern systems are based on advanced materials and technologies. They have very high towers; enormous wing span and they are usually positioned in selected geographic areas, where the wind flows are present. Unfortunately, despite the tangible progress obtained with the new generations of windmills, there are still limits to the use of the existing technology, the huge dimensions very often generate negative impact on the environmental impact and the use is mainly limited to preferential geographical areas where the wind speed can justify the installation.  
      Another limit is represented by the rather high capital costs of the plant and its operational cost. For this reason the kilowatt cost from wind energy is relatively far from being competitive on an industrial scale.  
      The main purpose of this patent is to attain (introduce) a power plant for the production of electric energy that can be installed in every geographical area, independently from the presence of natural wind flows.  
      Another purpose of this patent is to attain a power plant for the production of electric energy, where the production rate is constant, continuous and with stable frequency outcome.  
      And additional purpose of this invention is to attain a power plant, for the production of electric energy, simple to operate and particularly suitable for the developing countries.  
      This patent reaches the above and other purposes, introducing a power plant and its relative process that are efficient, innovating and particularly simple to build.  
      In particular, the electric power plant according to this invention includes at least one conventional wind generator that is located inside a high vertical structure (chimney) anchored to the ground, featuring a cylindrical shape, and suitable dimensions, said structure being provided with at least one radial air inlet positioned at ground level in correspondence with the structured bottom anchored to the ground and a discharge air outlet located at high altitude in correspondence to the structure tip, suitable to convey a warm air flow from the bottom toward the top, characterised in that: 
          each radial air inlet is provided with a horizontally positioned intake tunnel having suitable dimensions and length for collecting and conveying the airflow towards the corresponding air inlet;     auxiliary interacting heating means are provided, located inside the intake tunnel each of which can be individually operated and controlled, designed to release energy to the circulating air by means of heating which results in an air temperature increase inside the tunnel;     microprocessor based control means are provided, connected to each said heating means, designed to simultaneously manage the amount of heat released to the air from each individual heating means orchestrating to maintain a constant temperature of the incoming air independently from the outer atmospheric conditions; 
 
 the tangible size and height of the chimney already being able to create a substantial air density difference between the intake air inlet and the discharge air outlet and maintaining a natural positive air flow which starts from the bottom, enters the vertical conduit throughout the intake tunnel and proceeds in forced circulation with a certain speed towards the top, activating the generators means that absorb a substantial portion of the kinetic as well as potential energy, each of said heating means being able to boost the natural flow, said microprocessor operating a control strategy on each of the said heating means by modulating each individual heat contribution in order to achieve a constant temperature of the air flow inside the chimney regardless of the weather conditions and or from the variation of the heating power over time of each heating means
       

    
    
     This patent will be described by the attached figures:  
       FIG. 1  is schematically showing a section of the power plant according to the present invention.  
       FIG. 2  is schematically showing a section of the intake tunnel of the power plant in  FIG. 1 .  
       FIG. 3  is schematically showing a top view, partially sectioned in correspondence to the intake tunnel positioned at the bottom of the power plant in  FIG. 1 .  
       FIG. 4  is schematically showing a flow chart of the process of the power plant.  
       FIGS. 5    a ,  5   b  and  5   c  are schematically showing a section of power plant aspiration tunnel comprising several possible combinations of different heating means of the incoming air.  
       FIG. 6  is schematically showing a section of a different embodiment of the power plant represented in  FIG. 1 .  
       FIG. 7  is schematically showing a section of another embodiment of power plant represented in  FIG. 1 . 
    
    
       FIG. 1  is schematically showing a power plant section according to this invention, substantially composed by a self-bearing vertical conduit  1  featuring a cylindrical shape and a number of horizontal intake inlets  2  functioning as intake collectors. The inlets are anchored to the ground by means of a base  5  and bear inside a cavity that, as better explained hereby, is suitable to the transport of the air that is taken through the intake conduit and it is driven to the top as a result of the tangible difference in the air density between the intake level and the outlet level, due to the huge dimensions of the conduit  1 . Just as reference, the power plant could be provided with a conduit of two hundred meter diameter and more than a thousand meters high. The result is a powerful mechanical updraft generating a forced circulation of airflow with a tangible air speed depending on the conduit height and on air temperature T.  
      Different heating modules are positioned inside cavity  3  defined by each intake tunnel  2 . Module  6  represents a battery of wind generators suitable to convert a portion of the kinetic energy and potential energy of the circulating air into electric energy. Module  7  represents a battery of burners, for example gas burners suitable to increase the temperature and consequently the air kinetic and potential energy, being the burners strategically positioned on the circumference of duct  3  in order not to stop the main flow of circulating air while efficiently transferring energy to the flow of circulating air.  
      Module  8  represents a battery of radiators suitable to release energy to the circulating air in the form of heat collected by a number of solar panels  9  positioned and clung to the external surface of duct  1 .  
      Ducts  1  and/or  2  are provided with surfaces that are covered inside and/or outside by insulating materials, not represented in the figure, suitable to minimize the losses of heat that would otherwise reduce the energy of the circulating airflow.  
       FIG. 2  better shows the main components of the power plant in particular module I, represented above with 6 in  FIG. 1 , including the battery of electrical generators  10  each of them powered by connected propeller  11  as better shown in the enlargement.  
       FIG. 2   b . Module II, previously indicated with 7 in  FIG. 1 , including a number of burners  13  positioned parallel to the generators of a tapered surface  13 , each connected to a ring fuel distributor  14  feeding these burners; the burners are individually controlled by a process controller (as it will be better explained further on) controlling and regulating the amount of heat released by module II to the circulating air A.  
      Module III, previously indicated with 8 in  FIG. 1 , including a number of radiators  16  positioned inside a frame  15 , each hydraulically connected through suitable pipes and pumps, not shown in the figure, to the solar panels  9  transmitting the heat collected from the solar radiations through a thermal-vector fluid circulating and feeding the radiators in connection with suitable connections  17  and  18 . The pumps are individually controlled by a process controller, as it will be better explained further on, controlling and regulating the amount of heat released by module III to the circulating air A.  
      Module IV, better represented in the next figures, including a large sun collector which by the solar radiations, thanks to a large surface further increments the temperature of the air flowing from the external of the intake collectors toward the centre according to the path indications given by arrows A, B and C, respectively with a basic energy content of the air secured by the natural updraft and increased by the contribution of each single heating module described above.  
       FIG. 3  schematically represents an upper view, partially sectioned in the area of the intake tunnels positioned at the bottom of the power plant where the side walls  20  of the air inlets are shown. It must be noticed that the air inlets are more than two and they are radial converging towards the vertical central air inlet  4  of  FIG. 1 . The figure also shows in greater detail module IV of  FIG. 2  wherein the surface at the air inlet bottom  1  is closed inside a ring-shaped envelope having a height equivalent to the air inlet and a diameter even exceeding 1000 meters, divided into separate sections, each presenting a large surface exposed to the sun rays penetrating almost completely through the upper covering, purposely built with transparent materials, and almost totally absorbed by the base surface on the ground, purposely realized with materials having a high absorption index so that this absorbed heat is transferred to the air circulating through the space defined by the upper and lower surfaces of the solar collector. Practically the collector is a huge solar panel where the cooling fluid is the same circulating air; purposely build in order not to offer minimum pressure losses to the huge airflow crossing through.  
       FIG. 4  schematically represents the basic operating process of the power plant. P lease note as modules I, II, I and IV previously described and the direction of arrows A, B and C showing how the air flow is taken through the intake horizontal collectors  2 , then it flows at the basis of the duct  1  and finally travels vertically towards the top.  
      In particular, following the air path from A to C, conduit  1  generates a natural updraft forcing air in motion and giving to the air the first-quid of kinetic and potential energy Q, then module IV releases a second energy amount Q 3  collecting solar energy in the ring-shaped collector, module III releases a third energy amount Q 2  from the solar energy collected by the solar panels hung on conduit  1 , module II releases the fourth energy amount Q 1  from the gas or other fuel combustion, and then module I instead of releasing takes from the air a portion of energy G through the interposed fans.  
      The heating means can be of different type, connected in series or in parallel. In FIGS.  5  different possible configurations are shown, in particular the most suitable for the developing countries where it is fundamental to maintain very simple plants with a minimum maintenance. In particular  FIG. 5   a  shows module I where the produced energy only depends on the natural whirlpool generated by vertical duct  1 ,  FIG. 5    b  only shows modules I and II where fuels burners generating heat are the only external energy source that is added to energy Q generated from the natural whirlpool.  
       FIG. 5    c  shows modules I, II and III where in addition to energy Q there are other contributions available that are coming from the burners and solar panels hung to duct  1 .  
       FIG. 6  shows different embodiment of the power plant of  FIG. 1 , wherein modules I, II and II are located vertically inside vertical duct  4 .  
       FIG. 7  shows a simple power plant featuring rather reduced capacities having a unique horizontal tunnel, a typical configuration for the developing countries. It is important to notice that conduit  1  presents a number of wire ropes  22  providing an efficient wind bracing thus allowing building conduit  1  more economically. This figure also shows that the plant can intake (through duct  28  inserting duct  3  of the horizontal collector  2 ) toxic fumes and discharge them at a high altitude, in order to reduce atmospheric pollution, or alternatively fumes able to provide an additional energy contribution Qr. Additional energy contributions Qs can also be brought by cooling fluid pumped to the radiator through additional piping  27 ,  
     Functioning  
      The process is similar to a hydroelectric power station where the fluid is the air, the turbine is a wind generator and the starting energy given to the air is of potential kind. Several modules are foreseen: each module is individually suitable to release energy to the air coming from different external sources. Each module is connected to a microprocessor  30 , suitable to control the individual contribution of each module so that the temperature of the incoming air is constant and consequently also the air speed and the produced electric energy will be constant. In case the contribution of external sources Qn or the contribution of the solar energy decrease during the night, microprocessor MP compensates by ordering to module II to produce more energy operating different burners simultaneously. The microprocessor is of programmable type and suitable to operate different running strategies including the partialisation of the energy released by the modules in case the energy demand decreases. From the above details it is clear that this patent achieves all original goals, in particular it achieves the following advantages:  
      This power plant or a plurality of these plants can be installed even in geographic areas with no winds, offering to countries the possibility to become independent as regards to their energy need,  
      The electric energy output is constant, continuous, with constant frequency and it does not depend on the intensity and/or direction of the winds.  
      The process requires the use of simple, economic and reliable generators, since the generated airflow has a rather constant speed that does not require sophisticated transmissions or controls usually present in order to secure the frequency control of the generated electric energy.  
      The power plant is particularly suitable to the developing countries since it is technologically simple and easy to run,  
      The electric generator, unique element requiring maintenance, is conveniently positioned at ground level, or in the immediate underground, so that the maintenance operations are extremely simple, economic and fast.  
      The plant is suitable to operate energy savings since it is able to convert into electric energy external heat sources, which could be otherwise hardly usable, especially in case they are available at a temperature not much different from the environmental air.  
      The vertical duct structure can be conveniently used for other purposes such as transmission aerials or toxic fumes evacuation for the control of the environmental pollution.  
      The considerable airflow taken at low altitude and then discharged at high altitude can be strategically used for producing real washings in areas with high pollution levels due to heavy and toxic gases, which would be otherwise imprisoned in highly populated areas.  
      Naturally the proposed solutions are for illustration purpose only, and they are not limited to the described embodiment of the invention as many modifications would be possible without departing from the protective shield of the invention illustrated above and claimed here below.