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6ВЕТРОЭНЕРГЕТИКА
WIND ENERGY
Статья поступила в редакцию 09.10.14. Ред. рег. № 2107
The article has entered in publishing office 09.10.14. Ed. reg. No. 2107
УДК 621.548
ЭЛЕКТРОСТАНЦИЯ НА ВЫСОТНОМ СТРУЙНОМ ТЕЧЕНИИ
В.М. Лятхер
ООО «Новая Энергетика» 125363 Москва, ул. Штурвальная, д. 5, корп. 1, кв. 129 Тел./факс: 7(499)492-53-84 New Energetics Inc.
563 Bartow La., Richmond Hts., OH 44143 USA Тел.: 1(216)272-6765; e-mail: vlyatkher@sbcglobal.net; lyatkhervm@yandex.ru
Заключение совета рецензентов: 15.10.14 Заключение совета экспертов: 20.10.14 Принято к публикации: 25.10.14
Рассмотрена конструкция ветровой электростанции большой мощности, располагаемой в зоне струйных течений атмосферы. Станция состоит из ортогональных турбин, объединенных в пространственную конструкцию, соединенную с землей газонаполненным тросом с электропроводной оболочкой. Положение станции может контролироваться за счет управления вектором сил, действующих на турбины. Этот контроль осуществляется путем подачи струй в пограничный слой рабочих лопастей турбины. Рассмотрены варианты схем создания таких струй. Даются экономические оценки, подтверждающие высокую эффективность предложения.
Ключевые слова: ветровая электростанция, струйные течения в атмосфере, управление циркуляцией на лопастях турбин, управление вектором сил.
HIGH JET POWER PLANT V.M. Lyatkher
New Energetics 129 Shturvalnaya str., 5, corp.1, Moscow, 123363, Russia Tel./fax: 7(499)492-53-84 New Energetics Inc.
563 Bartow La., Richmond Hts., OH 44143 USA Tel.: 1(216)272-67-65; e-mail: vlyatkher@sbcglobal.net; lyatkhervm@yandex.ru
Referred: 15.10.14 Expertise: 20.10.14 Accepted: 25.10.14
The considered design of a wind power plant big capacity, located in the area of jet streams in the atmosphere. The station consists of orthogonal turbines, combined in a three-dimensional construction connected with the ground gas-filled cable with conductive shell. The position of the station can be controlled by controlling the vector forces acting on the turbine. This control is exercised by filing jets in a boundary layer of the working blades of the turbine. The variants of schemes for the creation of such jets. Given the economic evaluation, confirming the high efficiency of the proposal.
Keywords: wind power, jet stream, control circulation on blades of turbine, vector force control.
Виктор Михайлович Лятхер
Сведения об авторе: д-р техн. наук, профессор, генеральный директор компании New Energetics Ltd (Москва) и президент компании New Energetics Inc. (США).
Образование: Московский энергетический институт (МЭИ), мех.-мат. МГУ.
Область научных интересов: научные исследования и разработки в области гидравлического моделирования; гидравлики рек, озер и потоков океана; гидрологии, управления водными ресурсами, сейсмологии и сейсмостойкого строительства; гидроэнергетики, энергии приливов и отливов и строительства ветроэнергетического оборудования.
Our purpose is proposal to create operating demonstration wind power plant capacity 50-100 MW, having high economic efficiency at full ecological safety [1]. It is very important that this object can be
used to place the high-power laser system, scanning a significant portion of airspace in the area of the object, and is able to kill any body, unauthorized crossing this space, it is also Important that the proposed system is
№ 18 (158) Международный научный журнал
robust even in Autonomous conditions at the breakage of the mechanical linkage with the earth.
Proposal refers to wind-power engineering, namely to wind power plants that use the energy of altitude jet streams. Technical result consists in efficiency coefficient increase, material-output ratio decrease, plant safety improvement, provision of secure communication with the land. Altitude wind power plant includes aerodynamic components in a form of a framework, the units of which are located on the elliptical surface; the framework is connected with ground support by cables and on the framework along its span there located are orthogonal well-balanced bladed rotors arranged at an obtuse angle in relation to each other. The cables are performed in a form of sectional hoses, the sections of which are filled with helium and are connected by gates. Rotors are located between framework units, their blades are equipped with jet devices of circulation control. The jet management in the boundary layer of the blades may be formed from an air tank with high pressure or formed during the combustion of the fuel mixture fed into the internal cavity of the blades.
There is known an altitude aerostatic plant that holds aircraft performed in a form of cargo-carrying kite, the load-bearing surface of which has annular wing consisting of aerodynamic components with different in curvation and chord by span. Around the periphery of the ring there arranged are wind-engines behind the rear edge of the aerodynamic components and wind-engines in horizontal plan before aerodynamic elements, note that the engines have different rotation direction. Each wind-engine has a compressor of centrifugal type, speed-increasing gear and blade propeller mechanically connected with each other, flow parts are interconnected by connection of the outlet of the following part with the inlet of the previous one. Note that the outlet of the last compressor is connected with the input of power machine located on land by pressure hose [2]. The disadvantage of this decision is the need to use aerostatic structure as well as insufficient security of the system in case of land fixture rupture.
There known is a wind plant for high altitudes [3]. It consists of load-carrying surface along the span of which there located is a sectional wind-catching device with generators attached with the help of attaching elements on the support. Wind plant has a fixed balloon in a form of load-carrying surface with an empennage. Along the span of load-carrying surface there is a sectional wind-catching device formed by several multi-blade rotors with horizontal rotation axis located close to each other. Rotor annular rim is installed with the possibility of rotation at roller supports attached in cantilever fashion on load-carrying surface, where there installed is a two-shaft generator. The disadvantage of this decision is the need to use aerostatic structure, rotors with horizontal rotation axis, lack of secure connection with the land.
There known is "the best invention of 2008y" SWP technology (www.skywindpower.com) using 4 HAWT located vertically in the angles of the frame, connected with the ground by the cable-tross. The disadvantage of this decision is the low efficiency of the wind power system in cross wind flow.
Technical results of the our proposed unit are: efficiency coefficient increase, material-output ratio decrease, plant safety improvement, provision of secure communication with the land. Technical results are achieved by the fact that in altitude wind power plant consisting of load-carrying aerodynamic component connected with ground support by means of cables and orthogonal well-balanced bladed rotors arranged at an obtuse angle in relation to each other along its span the aerodynamic component is performed in a form of a framework, the units of which are located at elliptical surface, cables are in a form of sectional hoses, the sections of which are filled with helium and are connected by gates, rotors are located between framework units with their blades equipped with jet devices of circulation control. Furthermore, in wind power plant rotor blades are made with channels for air supply control through the holes on blades surface into jets that control the circulation around the blades. This provides the possibility to control the value and direction of total average lifting force that is applied to rotors and plant in general.
Orthogonal rotors rotate in opposite directions providing the balancing of torques and lateral forces. Jet devices in rotor blades designed for local circulation control increase plant power generation and, if necessary, in condition of no wind at plant lifting and lowering create lifting force, direction and value that can be changed allowing plant control as an aircraft. Rotor axes form obtuse angle that provides system turning down the wind and its stable balance. In case of cable rupture or one of rotor destruction the plant overturns and smoothly lands to the ground maintaining automatic control by radio beacon station. The sections of the cable, performed in a form of hoses, and some elements of the frame are filled with helium under excessive pressure and create lifting force of cable allowing optimization of wind plant position by height. The main constructive ideas of the balanced turbines are protected by patents of Russia [4], patents of the USA - Lyatkher V.M. [5] and Gorlov A.M. [6]. New innovative technologies and materials can improve the yield and power of wind turbines and can improve the ratio energy yield investing costs. Currently parallel developments are the R&D activities in the field of high altitude wind turbines. The power and maximal energy will increase for these turbines, because of the higher average wind speed at higher altitudes. This will increase the economic feasibility of wind energy. In Fig. 1 distribution of streams of wind power over Moscow at different times is shown years.
№ 18 (158) Международный научный журнал
Рис. 1. Изолинии потоков энергии ветра (кВт/м ) в струйном течении над Москвой Fig. 1. Isolines of mean streams of wind power (kW/m2) over Moscow
Рис. 2. Плотность потока энергии ветра (кВт/м ) с вероятностью превышения 5, 32, 50, 68, 95% по данным измерений NCEP/Департамент Энергии США в период 1979-2006 гг. на разной высоте от Земли для разных городов (b-f) и в среднем по поверхности Земли (а) -данные Кристины Арчер и Кена Кальдейра [7] Fig. 2. Wind power density (kW/m2) that was exceeded 5%, 32%, 50%, 68%, and 95% of the time during 1979-2006 as a function of altitude from the NCEP/DOE reanalyses by Cristina L. Archer, and Ken Caldeira [7]. The profiles at the five largest cities in the world are shown in (b-f). The global average profile (а) is the area weighted mean of values like those represented in panels (b) through (f) at all grid points
In Fig. 2 distribution on height of density of a stream of wind power over the different cities of the world is shown [7].
U.S. jet stream covered the entire Central part. Over Northern California, the energy flux density in the jet reaches a height of 6 km on average 7-10 kW/m2, over New York - up to 16 kW/m2. One of the most favorable places for projects on the use of jet streams is almost the entire East coast from Florida to New England. Total reserves of wind energy in the atmosphere is estimated at 4-1012 kW or 3.5-1016 kWh/year, of which less than 7% refers to the bottom layer thickness of 100 m, mostly above the water surface. Energy "wind river" - the jet stream is 100 times more hydropower potential of rivers around the world. Half percent of this energy is enough to provide 8 billion future inhabitants of the Earth by modern standards the most comfortable countries.
The wind power plant operation principle is the following. Each power plant consists of three structures, connecting in one space building. Each of structures consists of three or more assemblies of orthogonal rotors united by one building unit (Fig. 3 shows the structure model with three rotors, which is the minimal plant model), the components of which are located at an imaginary elliptical plane (Fig. 4). The orthogonal rotors create circulation which assures the necessary lifting capacity in the normal conditions.
Рис. 3. Блоки высотной ветроэлектростанции Fig. 3. The blocks of High-Altitude Wind Power Plant
№ 18 (158) Международный научный журнал
Рис. 4. Схема высотной ветроэнергетической установки (ВВЭУ). Слева: 1 - несущая конструкция блока, объединяющая 3 турбины; 2 - полый газонаполненный кабель-трос; 3, 4 - ротор и генератор, решетка лопастей ортогональной турбины
с большим затенением; 4 - анкер и устройства приема энергии от генераторов. Справа: ВВЭУ небольшой мощности с прямыми лопастями: 1 - анкер и устройства приема энергии от генераторов; 2 - полый газонаполненный кабель-трос; 3, 4, 5 - несущая конструкция блока, объединяющая турбины; 6 - сбалансированные турбины с прямыми лопастями Fig. 4. High-Altitude Wind Power Plant (HAWPP). Left: Plant with 3 blocks included Orthogonal Turbines for Conversion of Jet Streams in Atmosphere: 1 - building consists 3 (or more) rotors; 2 - the power block is tethered by a hollow divided cable filled by helium or hydrogen and transmitted power to the ground; 3, 4 - rotor and generator; blades in variant with high solidity. Right: Small plant with straight blades: 1- the anchor and the device receiving power from generators; 2 - cable filled by helium or hydrogen for transmitted power to the ground; 3, 4, 5 - substructure unit, uniting turbines; 6 - balanced turbine with straight blades
The power extracted P (W) of a orthogonal turbine or complex turbines may be defined by the follow relation:
P = CN pV3Qb/2, Q b = A а, а = ib/D.
(1)
Here V (m/s) = nDn/60 - blades speed; Qb (m) -area of blades; A = D H - swept area; a - solidity; i -numeral of blades; b - chord of blade; D - blade's way diameter; p (kg/m3) - density of air. Power factor CN is function of the turbine shape, advance speed ratio V/U, roufness of the blades surface, etc. U (m/s) - steady free-stream wind velocity.
Power factor CN is approximated by linear function
Cn = B(U0/V - B0) if 0 < V < U /B0.
(2)
Parameter 1/B0 is the maximum of blade speed without a breake torquet moment and constant wind speed.
nmax = 60U/kDB0 (rpm).
(3)
Maximum of turbine capacity Pm frequency of rotation nopt
will be with
= 2/3 nmax = 40 U /nDB0;
opt
Pmax = CPmaxpU3A/2, CPmax = 4Bа/27 Bçl
(5)
Turbine capacity as a function of frequency of rotation and wind speed is
P = Bpn2D3Han2(U0 - B0nDn/60)/2 602. (4)
For the 3-blades turbine (a = 0.45), optimized by prof. A.Gorlov was fined: B0 = 0.336, B = 0.60. Turbines with 3 and 6 curved blades (a = 0.45 and 0.90), proposed and tested by author in 1981y were shown: B0 = 0.28 and 0.34, B = 0.44 and 0.14 for a = 0.45 u 0.90. These results may be used to estimate the sizes of turbines, blocks and plant. Many other results are published in the books of V.M. Lyatkher [8, 9]. Real-optimized design of orthogonal wind turbines according to the experimental data are efficiency, reaching 43%. Optimization is achieved by selecting shading, frame rotor design, and reversal of the blades (Fig. 5).
Longitudinal Fx and lateral force Fy acting on the orthogonal machines are characterized by the coefficients C„, Cy (Fig. 6). Fx = CxpU2DL/2, Fy= = CypU2DL/2, L is the length of the turbine rotor, D is the rotor diameter.
№ 18 (158) Международный научный журнал
0.27
J Ь-0-
у
0.21 0.42 0.63 0.84 1
05 UIV
Рис. 6. Относительные нагрузки, действующие на один ярус двухлопастной турбины. Rev = 8,5105. Затенение 0.306. Схема турбины по рис. 5 Fig. 6. The relative loads acting on one tier of two-bladed turbine. Rev = 8.5105. Solidity 0.306. Turbine on Fig. 5
Рис. 5. Максимальная эффективность ротора рамного типа
с двумя лопастями профиля NACA 0015. Затенение 0,3. CP = 0,43 при V/U = 2,2. Оптимизации угла ф разворота лопастей ротора ReV = 4,0105. 1 - ф = -5° (носок лопасти - снаружи от касательной в центре лопасти); 2 - ф = 0; 3 - ф = -10°; 4 - ф = +3°. Опыты ЦАГИ [10] Fig. 5. Maximum efficiency of a frame two-bladed rotor with a solidity 0.3 reaches Cp =0.43 at V/U = 2.2. Rev = 4,0105: 1 - ф = -5°; 2 - ф = 0; 3 - ф = -10°; 4 - ф = +3°. Tests ZAGI [10]
The maximum efficiency of the orthogonal turbine increases with decreasing number of blades while maintaining the optimum shading. However, with the decrease in the number of blades increases the torque pulsations and all the forces acting on the rotor.
If design wind speed according to nominal capacity 50 MW will get 35 m/s, power efficiency blades speed has to be 50 m/s about. The total surface of the blades must be 6,410 m2, solidity a = 0.45 and sizes of the plant will be 120x120 m2, one block - 40x120 m2
Besides, the rotor blades are equipped with jet local circulation control devices. These devices are to boost the energy generation by the plant, and when it is necessary (there is no wind, or the plant is being lifted or lowered), they can create the lifting capacity the direction and value of which can be modified, which permits to guide the plant like an aircraft. The axes of the rotors form an obtuse angle, which makes the plant turn downwind automatically and keep its stable equilibrium. In case of emergency (cable breakdown or destruction of one of the rotors) the plant turns over and smoothly goes down to the ground or to the lake. It can still be automatically controlled through radio beacons.
The operation of the circulation control system is based on the idea that letting out an air stream to the blades at the right moment can change considerably the lifting capacity of the blade in the wind flow, change its direction and even create the lifting capacity on the rotor revolving in the still air.
№ 18 (158) Международный научный журнал
Jet devices in rotor blades designed for local circulation control increase plant power generation and, if necessary, in condition of no wind at plant lifting and lowering create lifting force, direction and value that can be changed allowing plant control as an aircraft. Rotor axes form obtuse angle that provides system turning down the wind and its stable balance. In case of cable rupture or one of rotor destruction the plant overturns and smoothly lands to the ground maintaining automatic control by radio beacon station. The sections of the cable, performed in a form of hoses, are filled with helium under excessive pressure and create lifting force of cable allowing optimization of wind plant position by height.
Rotor blades are equipped with jet devices of local circulation control. These devices should increase power generation and, if necessary, in condition of no wind at plant lifting and lowering create lifting force, direction and value that can be changed allowing plant control as an aircraft. Rotor axes (in plan) form an obtuse angle that provides system automatic turning down the wind and its stable balance. In case of accident (for example, cable rupture or one of rotors destruction) the plant overturns and smoothly lands to the ground maintaining automatic control by radio beacon station.
The idea of circulation control system on the blades consists in the fact that at the right moment of jet supply on the blade it is possible significantly to change blade lifting force in the wind stream, to change its direction and even to create lifting force at rotor that is rotated in
stationary air. In real altitude wind station jet control scheme should be more complicated. To simple elements there added are elements that in case of emergency cable rupture allow the system not only smooth descending, but movement in specified direction so that the landing is done in specified place, for example, on the surface of the specified water body. Such complicated movement is performed due to the use of independent circulation control systems at each rotor (Fig. 7). This allows provision of necessary lifting force vector and moment that deliver the station to specified landing point during falling (or lifting). Altitude wind power plant consists of carrying aerodynamic element 3 connected with ground support 1 with the help of hollow cable 2 with orthogonal blade rotors 4 arranged along the element at an obtuse angle in relation to each other, carrying inductors and rotor of line (curved) electric generators. Aerodynamic element 3 is performed in a form of framework, the units 5 of which are located at elliptical surface, the cable 2 is performed in a form of sectional hoses, the sections of which are filled with gas and connected between themselves by gates. Rotors 4 are located between framework 3 units 5, their blades 6 are equipped with jet devices 7 of circulation control. Rotor 4 blades are supported at the shaft 8 by cross bars 9, 10. Hole 11, 12 position adjustment for controlling the maximum lifting force point is performed by distributing shaft 13 or special system of automatically controlled valves.
Рис. 7. Слева - разрез по оси турбины. Момент максимальной подъемной силы. Рабочие лопасти аэродинамического профиля с двумя изолированными внутренними полостями, каждая из которых через каналы в траверсах 8 имеет возможность сообщаться с внутренней полостью управляющего вала 11, размещенного внутри вращающегося турбинного вала 7. Момент возникновения подъемных сил на лопастях определяется положением отверстий в управляющем валу 11, напротив которых проходят входные отверстия каналов в траверсах 8. Справа - разрез по струйной системе. Нумерация элементов по рис. слева и патенту [11]. 14 - катушки индуктивности, зажигающие свечи внешнего или внутреннего контура
в варианте с подачей горючей смеси Fig. 7. Left - Longitudinal section of plant blades (one layer). The Max. lifting force. The working blade airfoil with two isolated internal cavities, each of which through the channels in traverse 8 has the ability to communicate with inside cavity of the main shaft 11, placed inside the rotating turbine shaft 7. When lifting forces on the blades is determined by the position of the holes in the control shaft 11, in front of the inlet channels in 8 traverse. Right - Sections of channels supplying air to blade surface for circulation control. The numbering of the items in Fig. left and patent [11]. 14 - inductance coil, ignition spark external or internal contour in the variant
with the feed gas mixture
№ 18 (158) Международный научный журнал
The plant is operated as follows.
Original lifting force is provided by coactions of lifting force of gas-filled hoses 2 and lifting force created by the work of generators of the rotors 4 in engine mode at adequate action of jet devices 7 of circulation control at rotor 4 blades 6. With the help of jet devices, for example, changing the position of holes 11, 12 of distribution shaft 13 in relation to the land, it is possible to change "support" direction and, thus, control the position of wind plant in relation to ground.
Torque moment developed by rotors 4 at wind stream approaching is transmitted to generators, and from generators the generated power is supplied to the ground through current-conducting elements located in rod 2.
The arrangement of each pair of rotors 4 axes at an obtuse angle in relation to each other provides automatic turning of the whole system down the wind and it stable balance. In case of an accident (cable 2 rupture) the plant turns and smoothly lands maintaining automatic control by radio beacon stations from the land. Rotor 4 rotation and plant smooth descending is performed due to power batteries arranged at the plant and generators operation in engine mode. Each blade (1) has two separate volume, connected with the shaft of turbine (2) by traverses (3) and (4). Tube located in the traverse (3) is connected with outside volume of the blades. Tube in the traverse (4) is connected with inside volume of the blades. The distribution shaft (8) gets inside the shaft of turbine (2). The distribution shaft has two opposite holes (6) and (7). The distribution shaft is connected with high pressure volume or pump by line (5). When the high pressure air is going through the hole 6 at the right traverse 3 and through hole 7 at the left traverse 4 the lift force acted at right. I opposite situation the lift force will act at left. Jet management of circulation on blades of the orthogonal turbine is an essential element of the offered project of the highly effective wind power station transforming energy of high-rise jet currents. In this project management of circulation on blades is used for formation of the carrying power providing maneuvering (lifting lowering) with the block of power plant irrespective of a mode of a wind. Stationary modes of a flow of profiles with jet control circulation are studied quite in detail (Fig. 8) [12].
Influence of a jet of management in non-stationary conditions, characteristic for modes of a flow of blades in orthogonal turbines, on the instructions of the author was studied on oscillatory installation in a flat hydrodynamic pipe at Institute of mechanics of the Moscow State University of Lomonosov in 1989-1991 (Research supervisors - V.P. Karlikov, A.N. Khomyakov, G.I. Sholomovich). Tests are carried out in the conditions of a flat task with a considerable excessive pressure of water (2.5 bar), excluding aeration and cavitation on the blade, with the careful accounting of possible mistakes. Non-stationary and stationary characteristics were received for the NACA-0010, 0015, 0017.5, 0020 profiles with a chord of b = 0.2 m at a stream speed to m U = 10.2 m/s.
Ж
- С -Ж
Рис. 8. Коэффициент подъемной силы крыла по испытаниям в воде в функции угла атаки при импульсах струи 1 - 0; 2 - 0,05; 3 - 0,10; 4 - 0,15 и 5 - 0,20 Fig. 8. Coefficient of a lifting force of a wing on tests in water as an angle of attack at impulses of a jet 0, 0.05, 0.10, 0.15 and 0.20
Change of an angle of attack was carried out or with sign preservation - under the law
а = 15°sin(2raf) + 15°
(7)
or according to the scheme closer to real operating conditions of turbines, - with sign change:
а = 14°sin(2nnf) - 1°.
(S)
Not stationarity is characterized by number of Strukhal
Sh = bflU.
(9)
In the same hydrodynamic pipe with considerable excessive pressure of water (2.5 atm.), on the same oscillatory system on which were tested a profile without jet giving, characteristics of two options of blades of the NACA 0021 profile with a chord of b = 200 mm with release of a flat jet by thickness of a = 0.83 mm in tail part of a profile (at distance 0.65b from a profile sock) - option 1 in Fig. 9 and in head part of a profile at distance 0.30b
1
№ 18 (158) Международный научный журнал
from a profile sock - option 2 were studied. Influence of a jet is characterized by the relative size of an impulse
Cs = (U\/U)(a/b),
(10)
where U1 - expiration speed of jet, U - speed of a running stream.
Change of an angle of attack was set by blade turn concerning an axis located in the middle of the blade (0.50b from a sock):
а = 14.5°sin(2n/).
(11)
The general conclusion of the carried-out tests consists that at both options of an arrangement of a jet its action on shady side very effectively increases lifting and pulling forces in stationary and in non-stationary modes (Fig. 10-14).
а =-14.5
:
:
: ^
1 -J
/ \ А
—X ПТГТТТТТ-00 010 1 11 1 Г ! ! 1 > ЛВС! V """ 1111 ' i M 1.S0 1.60 1 _ 1.2.0
Рис. S. Варианты расположения щели для подачи струи:
a = 0^З мм; b = 200 мм Fig. S. Options of an arrangement of a crack for giving of a jet: a = 0^З mm; b = 200 mm
o.o
Ct i
a =-14.5° Стационарный режим
Cs-0.0 Cs = 0.038
Cs = 0.159
Cs=O.OB2
I Г 1 1 ("TTTT" Cs=C.O 1 1 1 1 ■ 1 i TTT-ГТТТТ"
Рис. 10. Вариант 1. Струя на теневой стороне в конце профиля Fig. 10. Option 1. Jet on shady side at the end of a wing
Рис. 11. При отрицательных углах струя на затененной стороне. Влияние струи при малых числах Струхаля Fig. 11. At negative corners a jet on the shaded party. Jet influence at small numbers Strukhal
№ 18 (158) Международный научный журнал
Рис. 12. Влияние струи при больших числах Струхаля Fig. 12. Jet influence at large numbers Strukhal
O.JO
Ct
0.20
0.10 -0.00
Sh=0,009 v=5.00m/с b=0.2m vl = 0.0 m/с v1/v=0-C
f^O^Scr1
-ojo ■
í\ 1 \ \ \
\ ч \ \ \ \ \Cs=0.08 \ ч \ ч 3 / //
\ á У ' ' А /
Cs=Q.O
-16.00
-a.oo
o.oo
э.оо
16.00
Рис. 13. Вариант 2 - струя в начале крыла. Малые числа Струхаля. При стационарном режиме и угле атаки -14,5° коэффициент нормального давления равен -0,5, -0,86 и -1,08 при импульсе 0, 0,082 и 0,15, коэффициент тянущей силы равен 0,09 и 0,29 при импульсе 0 и 0,086 соответственно Fig. 13. Option 2 - a jet at the beginning of a wing. Small numbers Strukhal. At a stationary mode and an angle of attack -14.5° coefficient of normal pressure is equal -0.5, -0.86 and -1.08
at an impulse 0, 0.082 and 0.15, the coefficient of pulling force is equal 0.09 and 0.29 at an impulse 0 and 0.086 respectively
№ 18 (158) Международный научный журнал
Рис. 14. Вариант 2. Большие числа Струхаля. Струя на теневой стороне профиля заметно увеличивает подъемную и тянущую силу крыла Fig. 14. Option 2. Large numbers Strukhal. The jet on shady side of a profile considerably increases the lifting and pulling force of a wing
In the studied range of change of number Strukhal 0 < Sh <0.113 and a relative impulse of a jet 0 < Cs < 0.155 influence of a jet is considerably shown only when it is on shady side of a profile. In this case in both constructive options - at a stream arrangement at the beginning or at the end of a profile giving of a stream increases lifting and pulling forces of a profile, especially on big (subcritical) angles of attack in direct ratio to a jet impulse. At the maximum tested angle of attack 14.5° at a relative impulse of a jet 0.085-0.088 increase in carrying power made 60%, and increase in the pulling force - about 200% from values of these sizes without jet. Criterion influence Strukhal on this result was insignificant. Thus, nearly, a capacity of the turbine at the expense of a jet can be increased almost by 3 times and the carrying power of the blade more, than by 1.5 times.
Inkjet devices in the blades of the rotor to control the local circulation increases energy production installation. Published reports that jet circulation control on the blades of the orthogonal model of wind turbine with shading 0.1 can increase the maximum efficiency of the unit CP from 0.32 to 0.42 with a decrease in the optimal rotor speed from V/U = 5 to 4 [12]. In our design control jets on the blades in the absence of wind, when the raising and lowering of the installation, create a lifting force, the direction and magnitude of which can vary, allowing you to control the installation as aircraft.
The main ideas of the turbine with operated circulation on the blades, providing any choice of the direction of the resultant force operating on the turbine as a whole, were checked on large model of a fragment of the two-bladed unit (Fig. 15).
Рис. 15. Общий вид модели и схема подачи струи управления. На противоположную сторону струя подается из другого канала , расположенного в лопасти Fig. 15. General view of model and Scheme of giving of a stream. On the opposite side of the blade the stream moves from other channel in the blade
№ 18 (158) Международный научный журнал
The turbine model with hollow blades in which air through cuts in distributive to a shaft is brought, placed in a bearing shaft of the turbine, was made in the dimensions shown in Fig. 16.
Рис. 16. Модель турбины с полыми лопастями и валом Fig. 16. The turbine model with hollow blades and shaft
Рис. 17. 1 - носок лопасти; 2 - положение максимальной толщины профиля лопасти; 3 - щель для выпуска струи управления
Fig. 17. 1 - sock of the blade; 2 - an alignment of the greatest thickness of the blade; 3 - cracks for release of an operating current of air
The system of a suspension bracket of model was made in two options - with the external electric drive in the form of a high-speed electric motor and without it. In the latter case dispersal of the turbine is carried out at the expense of reaction of the operating stream which is let out on the external or internal parties of blades through cracks about 1 mm of high (Fig. 17).
In any option the model was carefully balanced and hung out on electronic and mechanical scales. The consider results of the experiments made without the external electric drive - the rotor rotated under the influence of reaction of the currents of air coming to a surfaces of blades during the periods when openings in walls of an air bringing pipe in an axis of a rotor coincided with entrance openings in channels inside a traverse, giving air in internal cavities of blades. The compressed air moved from a high-capacity receiver through system of air ducts. The moment (phase) of air supply in a cavity of blades and further - in a stream of management was established by means of the rotary lever, rigidly connected with by the hollow managing director of shaft (airgiving pipe) in a turbine axis. The results of the experiments conducted without external actuator - rotor is rotated under the action of reaction jets air-facing surface of the blades during periods when the holes in the walls air pipe inside the rotor axis coincident with the inlet holes in the channels inside the traverse, feed air in the inner cavity of the blades, is described in detail in the book of author. The main conclusion from the experiments and calculations -the proposed scheme is operational and can be effective.
The pressure source to create a jet in this case was external (compressor and pressure tank). However, in real high-pressure chambers of the blade can be generated due to the combustion of the fuel mixture or hydrogen supplied to the blade and ignited there at the right time due to an electric pulse (Fig. 18).
Рис. 18. Пример профиля лопасти: 1, 2 - отверстия, формирующие струи в пограничном слое лопасти; 3, 4 - свечи для поджига топливной смеси, подаваемой в полости лопастей Fig. 18. Example of the blade's profile (top): 1, 2 - nozzles, forming a wall jets on the blade surfaces; 3, 4 - spark ignition fuel mixture in the cavities of the blades
Complex movement when lifting or emergency lowering station is carried out through the use of two control system circulation on each rotor. One use of the system v modes fall (or rise) provides the necessary lift force, and the other forms a horizontal component of force, delivering station v set the wheel landing. Accordingly, within one of the hollow shaft shown in Fig. 7 add one or two more internal hollow shaft, and v the blades have additional partitions (Fig. 19).
№ 18 (158) Международный научный журнал
F = Ш^Р^ + U)2 + (V - Uf}Q.b,
(12)
in which V is the blade speed, U is the wind speed inside the rotor and Qb is total surface of the rotor blades. For the designed wind speed U0 = 35 m/s wind speed inside the rotor will be U = 0.8 U0 = 28 m/s.
And averaged lifting force may be
F = 1/6CLmax0.75{(50 + 28)2 + (50 - 28)2}6,410^ =
= 5,262,610Cimax = 0^x526 (ton).
(13)
Рис. 19. Сечение по каналам подачи воздуха в полости лопастей. Нумерация по рис. 7 и патенту [11] Fig. 19. Sections of channels supplying air to blade surface for circulation control. The numbering of the items in Fig. 7 and patent [11]
Each blade (1) has two separate cavities (2 and 3) separated (4) and (5) are connected with the cavity in the Central turbine shaft (6) through channels (pipes) in the traverse, for example, (7). Pipe in one traverse is capable of feeding air to the outer side of the blade, and a trumpet in the other traverse - on the inner side of the blade. Distribution system located inside the shaft of the turbine, has two oppositely located openings (10) and (11). Inside the shaft is constantly maintained high pressure air (for air duct). When this pressure is fed through a hole 10 in the upper yoke and through the hole (11) in the lower yoke, the lifting force is initiated jets on the blades will act up. Changing the position of the holes of the camshaft (8) relative to the earth or relative to the wind), you can change the direction of "lock". Additional flexibility of the system is achieved by the presence of cavities in the blade, the selected partition (5), and the second inner shaft (9). The pressure in these cavities is passed through the holes (12) and (13) in the inner shaft, the position of which does not depend on the position of the main control shaft (8).
A scheme of this type - with a turning wing and a flap controlled by the traction from the center offset from the rotor axis - has been successfully applied in practice. The jet control system of the circulation on the wing in this case may be easier and more long-lived than the ordinary high-lift device system. The averaged value of the lifting force F acting upon the rotor per one revolution is a little greater
At the ground when a wind is absent the averaged lifting force may be
F0 = 1/6CLmax1.23{502 + 502}6,4W = Cimax657 (ton).
(14)
The orthogonal turbine is connected with induction generator. It may be two variants - 3 or 6 turbines in the block (9 or 18 units in the plant). In variant 1 (3 turbines in block - Fig. 3) the turbine diameter will be D = 40 m and frequency of rotation n = 23.9 rpm. The weight of generators with so slow rotation will be too much. In the second variant (6 turbines in block) frequency of rotation will be 47.8 rpm and weight of generators will be 18 kg/KW about. Total weight is 900 ton. To choose the kind and numeral of rotors and generators will be compared the efficiency each variants. In the first variant with 3 turbines in block the overload on the blades by the inertia force (2 V2/gD) reaches 12.75, in other variant (6 turbines) it may be twice more -25.5. In modern sea fighters (as Sea Hawk or Sea Fury) the real overload reached 10.3 and more. For the all aircrafts safety factor has to be 2 or more. It means that in turbines blade construction the overload even 25.5 may be admitted. In the modern large aircrafts with cantilever wing length up to 24 m the mass of the wing reaches 29 to 35 kg per sq.m of the wing surface. The design load on the wing is 350 to 580 kg per sq.m. The real experience of the constructing and testing the plastic blades for the orthogonal turbines with cantilever blade length 2.3 m is shown that the mass of the blades may be up to 12 kg per sq.m of blade with overload 26.5 and static loads up to 656 kg per sq.m. In the proposed system the blades surface is 6410 sq.m in total. The mass of blades will be less of 225 metric ton, but realy up to 77 ton. If the mass of the connected elements will be 20% of the rotor mass the total mass of the browing power system will be 1.2(125 + 225) + 900 = 1320/.
Using the plastic in the power construction we will be able to decrease the mass to 155 + 900 = 1055/.
In variant with smaller turbines the total mass will decrease at least on 300/ reaches to 1020 (755)/.
To lift the system from the ground in accordance to (14) needs
Cr.
= 1.б - 2.0.
(15)
It reaches by any way with control of the blade circulation that provides CLmax = 2.4 and more.
№ 18 (158) Международный научный журнал
In the nominal operation position the averaged lift force will be 1262t. It is more than the weight of system made by high strength plastick on the surplus vertical force
Fv = 207 - 507t.
(16)
The longitudinal force acted on the system in the nominal position is
Fx = Cx pUoA/2,
(17)
here A - swept area of system, blowing by wind; Cx - drag factor of system. For the design wind velocity U0 = 35 m/s, blades speed V = 50 m/s and solidity c = 0.45:
Cx < 0.5 and Fx = 331t.
(1S)
The power blocks are tethered by a hollow divided cable filled by hydrogen (or helium). This cable made by the kevlar. Kevlar is an Aramid fiber produced by the E.l. Dupont Company to offer a light-weight replacement for steel wire in products such as tires, conveyor belts and cables. KEVLAR's high strength and modulus, combined with ease of manufacturing. Results in high efficiency at competitive costs. Ropes and cables using KEVLAR have excellent fatigue resistance and are non-corrosive, non-magnetic and non-conductive, with low elongation, and have the highest combined specific strength and modulus. Specifically KEVLAR are: stronger than steel (3X stronger than Nylon and Polyester) - allowable cyclic stress 5250 kg/sm2 at least, at 1/5th the weight (density 1.6 g/sm3).
The cable consists from connected separate parts filled by hydrogen with small surplus pressure. Diameter of cable is 6 m or more. The lift force acted on the one meter of the length of the filled cable is 18.7 kg on the elevation of 6 km and much more near the ground. Chart 1 shows the total force acted on the cable from the power units with different surplus vertical forces. In accordance with this total force was calculated the cross section of the kevlar cable, the mass of cable per one meter of length and total length of cable. The power blocks are located on elevation 6 km in all variants.
Chart 1. Surplus lift force Fv, t Total force acted on cable, t
200 300 400 500
387 447 519 600
Square section of Kevlar, sm2 74 85 99 114
Mass of Kevlar per 1 m. of cable, kg 11.8 13.6 15.8 18.2
Cable length, km 11.6 8.94 7.79 7.2
On the surface of the cable will be fixed the aluminium wires to transmit the power from generators with generators voltage 10 kV. If the density of current will be 4 A/mm2 the weight of this wires has to be 3.4 kg per one meter of the cable length.
Thus, if the cable diameter is 6 m, surplus lift force has not be more 300 t and cable length has to be 8940 m. or more. When the wind speed will increase more design (35 mps) the power system will go down to the area with
slower winds itself. Opposite, when the wind speed will decrease the power system will go up itself. Additional control would be made by changing the lift force acting on the power system. The needed length of the cable may be decreased by the choosing the fixed point on the high elevation of ground (in the mountain area of California).
The surplus pressure of hydrogen in the parts of cable makes by the pumping to these parts through the individual pipes. If the losses of hydrogen will be about 0.8% per day, to keep the normal pressure it will be needed to use one unit of IMET-30 discharged 30 cub.m. of hydrogen per hour with installed capacity 200 kW.
On the outside of the cable surface may be moved the cabins to serve the power units and to go up the tourist groups.
The lifting capacity would be sufficient to operate the plant in emergency situations and while lifting it from the ground. In practice, circulation control is to be fulfilled automatically with the plant oriented by land-based radio beacons and the HAWPP gyroscope systems. In case of the cable breakdown, the revolution of rotors and smooth lowering of the plant to an assigned area is fulfilled with the aid of the HAWPP electric accumulators and operation of the HAWPP generators as engines. A similar routine is used while lifting the plant; the difference is that in this case line supply is employed.
The plant component being discussed is quite a complex structure and is the least developed one. Although its elaboration presents many difficulties, there is a practical solution of the problem. The comparison of a possible mass of the HAWPP and that of the cable shows that the HAWPP optimal unit power is to be about 70-100 or more MW, as the increase in the power plant capacity does not exert any significant influence on the cable mass, which makes the cost per unit of capacity drop. Preliminary calculations have shown that being production-run the plants of the given capacity would require specific capital investment of not more that 600 US dollars/kW.
It is advisable to accept the first experimental plant capacity of not less than 50 MW, as a considerable share of the plant development and manufacture self-cost would fall on the gas-filled cable. Further on, as the plant capacity doubles, the cable self-cost increases by not more than 20-30%, as most of the cable operation systems do not depend on the plant capacity. The first experimental model of 50 MW capacity would cost approximately 1.2 thousand US dollars/kW, including all the design and research expenses and costs of the equipment manufacture and plant construction, installation and commissioning. Taking into account the economic and ecological prospects of the proposed energy source, the above-named cost of the first model should not be considered excessive.
The whole complex of work including the plant turnkey and simultaneous preparation of further line production of the plant can be fulfilled within 2.5 years. The first step, including the check all ideas and
№ 18 (158) Международный научный журнал
numerals, in accordance with this applicant can be fulfilled within one year.
Further on, high-altitude wind power plants can be developed, which would have the capacity of 100-500 MW and annual production of 700-3,500 GW-hr and cost 60-250 mln. dollars or less.
The combination of lower investment costs and extra yield bring the payback time back with a factor 4, compared to traditional wind technologies. Due to this positive influence on investment costs, offshore wind energy can compete with traditional energy production, such as gas or coal fired power plant. Therefore wind can play an important role in the renewable energy mix. It can even provide a solution for substitution of more conventional power plants.
The created demonstration windmill (model) has the same external form, as well as future is skilled electric power plant (Fig. 4, right).
We accept following preliminary parameters of model:
Chord - 0.160 m
Diameter of a line of blades - 1.2 m Number of blades in one circle - 2 Number of circles - 7 Length of the blade - 0.6 m Length of the turbine - 4.2 m Weight of the complete set of blades of one turbine -14 kg
Nominal frequency of rotation - 750 rpm Settlement speed of blades (sliding 1.08) - 50 m/s The speed of a wind answering to the maximum capacity of 40 m/s
The speed of a wind answering to the beginning of delivery of capacity of 10 m/s Power factor CN = 0.25
Efficiency of the turbine at an optimum mode (a wind of 23 m/s) Cp = 0.43 (see Fig. 5).
Forces, the moments, the capacity, turbines operating on one store by calculation (length 0.6 m)
Parameters Moment, Nm Power, kW Forces, N along across Forces on the blade, N Radial Tang
Averaged 4.8 0.4 142 -45 -1.б 2.4
Maximum 28.5 2.4 558 187 188 28.2
Minimum -9 -0.8 -91 -27б -339 -б
The force of inertia operating on one blade of 375 kg
The maximum averaged capacity of the turbine according to experiences 7-0.67-0.25-503-2-0.16-0.6/2 = 14 kW
Parameters* of a wind (height over the earth 6 km) Season of year
Winter Spring Summer Autumn
Average speeds of a wind, m/s 19.4 17.9 11.3 20.3
Energy stream, kW/m2 3.8 2.7 1.8 4.3
* These numerals for Moscow region. The datum for different regions are in Cristina K.Archer and other articles (Energies, 2009, 2, pp. 307-319).
Average temperature of air a minus 24 °C, average density of air of 0.67 kg/m3
Capacity of power station (maximum) 126 kW Capacity at an optimum mode (a wind of 23 m/s) 79 kW
Considering high reloading ability of asynchronous generators, we accept for model the engine-generator the AIR 132M2 in weight 54 kg with an admissible overload 3.5.
Management control jet.
Thickness of a jet 2mm
Air density in jet 1.25 kg/m3
Speed of air in jet 200 m/s
Relative impulse of a stream / forces CL
On 6 km 0.75/2.0
At the earth 0.40/1.6
Average carrying power on one turbine at the earth at speed of a stream of 200 m/s of 84 kg
The expense of air 16.8 litre/s
At speed of a stream about 120 kg
The expense of air 25 litre/s
The capacity is necessary for braking of station at the earth during 20 min. 2-3 m3 with pressure of air of 10 bar. Such capacity is located in dividing constructive elements in width 3m and height 0.15-0.25m
The wind station is fixed on the earth through the hollow cable filled with helium. At superfluous pressure of helium 0.5 bar superfluous carrying power makes 1 kg/m3 at the earth and 0.4 kg/m3 at height of 6 km.
The current strength from generators at voltage 660 V is 114 A. The section of copper wires nearby 28 mm2 with weight 249 g/m of length. For maintenance of deduction of such weight it is necessary to increase diameter of a cable with helium to 0.57 m at the earth and to 1 m at height of 6 km.
№ 18 (158) Международный научный журнал
The length of a cable will be defined by superfluous carrying power which is formed both at the expense of turbines and at the expense of gliders between turbines. The minimum length of a cable is 6.5-7 km. Superfluous "buoyancy" of station is reached at the expense of an aerodynamic flow of turbines and dividing profiles, and also (if necessary) at the expense of filling by helium of vertical elements of a design.
Each turbine has the open one-stage animator with transfer number 4 and the individual asynchronous generator with shortly closed rotor and nominal frequency of rotation of 3000 rpm.
All generators are united also by a uniform cable connected to a powerful electric network on the earth. In case of breakage of a cable generators are instantly switched to the battery of condensers through which power supply of elements of the management located directly on wind power model proceeds, and opening of valves for giving of operating streams, electric deduction of turbines from excessive dispersal, orientation model in space and its direction on an airfield is carried out.
Optimization of a design of the orthogonal unit is reached in a series of experiences with the orthogonal units having the form of a framework.
The turbine with operated jet circulation is as a project basis of "the flying car" [11].
References
1. Lyatkher V.M. High-rise wind power installation // News of the Russian Academy of Sciences. Power. 2006. No. 4. P. 47-57. Lyatkher V.M. High-rise wind power installation. Patent RF 2240444, May 05.2003. Lyatkher V.M. and Smirnov V.L. High-rise wind power station. C.C. USSR 1765495, October 03.1989.
2. Patent of the Russian Federation No. 2064085.
3. Patent of the USA No. 4659940.
4. Patents of the Russian Federation NN 1150395, 2240444.
5. Patent of the USA No.7741729.
6. Patent of the USA No.5451137.
7. Archer C.L., and Caldeira K. Global Assessment of High-Altitude Wind Power // Energies 2009, 2, 307319.
8. Lyatkher V.M. Renewable Power. Effective design. M.-Izevsk, Russia, 2011.
9. Lyatkher V.M. Wind Power. Turbine Design, Selection and Optimization. Wiley, 2013.
10. Vashkevich K.P., Samsonov V.V. The calculation of aerodynamic characteristics of windwheels vertical-axis type using the method of discrete vortices // Industrial aerodynamics, 1988, N 3(35). Baklushin P.G., Vashkevich K.P.and Samsonov V.V. // J. of Wind Engineering and Industrial Aerodynamics. Vol.39, N°1-3, May 1992.
11. Patent RF 2327059. Power installation for the vehicle drive / Lyatkher V.M. // Dec. 14.2006.
12. Amfilokhiyev V.B., Artyushkov H.P., Barbanel B.A., Korotkin A.I., Mazayev K.M., Maltsev L.I., Semenov B.N. Current state of the theory of management of an interface. St. Petersburg: Prod. SPMBM "Malachite", 2000. Bogdanov P.A., Kozhukharov P.G., Maltsev L.I., Mikuta V.I., Khadzhimikhalev V.Kh. Underwater wing with jet management of its hydrodynamic characteristics. Sb. Liquid currents with free surfaces and polymeric additives. Novosibirsk, 1986. P. 36-73.
13. Angle II G.M., Pertl F.A., Mary Ann Clarke, Smith J.E. Lift Augmentation for Vertical Axis Wind Turbines // International Journal of Engineering. Vol. 4, Issue 5. P. 430-442. McGrain D., Angle II G.M., Wilhelm J.P. Circulation Control Applied to Wind Turbines // ASME 2009 3rd International Conference on Energy Sustainability, Vol. 2, Paper no. ES2009-90076, P. 905-910.
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