WO2015023200A1

WO2015023200A1 - Ejector type turbine

Info

Publication number: WO2015023200A1
Application number: PCT/RO2014/000015
Authority: WO
Inventors: Mihail PUŞCAŞ-CERNAT
Original assignee: S.C. Topintel Consult S.R.L.
Priority date: 2013-05-09
Filing date: 2014-05-07
Publication date: 2015-02-19
Also published as: EP2994636A4; EP2994636A1; RO128851A0

Abstract

The invention relates to an ejector type turbine, designed to transform kinetic energy of a fluid into mechanical or electrical energy, by capturing and accelerating an engine jet of fluid. The turbine according consists from an fluid intake equipped, where the fluid flow is accelerated and sent as engine jet fluid via a supply pipe to an ejector type device, in which the engine jet fluid expands through a nozzle in a suction chamber and subsequently released with the ejected fluid into the atmosphere through an exhaust device, in the suction chamber is built in an annular turbine consisting from an annular rotor, and an annular stator to direct the flow of ejected fluid in the rotor, the jet of aspirated fluid, called ejected fluid, acts the annular rotor's blades which lead through a pulley mounted on the outer circumference of the rotor, a power generation system.

Description

EJECTOR TYPE TURBINE

The invention relates to an equipment of relatively small size capable to generate more power per unit of fluid intake area, which can be integrated on land vehicles, river and sea ships, designed to convert the kinetic energy of a fluid into mechanical energy and / or electricity, by capturing and accelerating a fluid jet engine which is transferring energy to another jet of fluid, called ejected fluid, which at its turn acts the blades of a ring turbine built in a suction chamber, which leads a power generation system.

Are known different types of equipments used to convert wind and hydraulic energy into mechanical energy or electricity. From the variety point of view the most diverse equipments are in the field of wind energy conversion, and generally are consisting from a tower which supports a nacelle that accommodates the mechanical power amplification systems and / or power generation systems, that are driven by a rotor whose blades captures the wind's energy.

Are two types of wind turbines, as follows:

1. Horizontal axis wind turbines (HAWT) see fig. 1 and 2

2. Vertical axis wind turbine (VAVVT), see fig. 3.

Also the wind turbines are classified function of the principles of energy transfer, as follows:

a. Wind turbine that works by drag on the base of action and reaction force principle - the wind pushes the blades and the blades are pushing the wind resulting their rotation.

b. Wind turbines that operate on the lifting forces principle.

So there is horizontal axis wind turbine that works by drag as are the traditional wind mills and horizontal axis wind turbines that operate on the principle of lifting forces such as modern horizontal axis turbines. The last ones are the most common due to the following advantages:

• Variable blade pitch, which gives the turbine blades the optimum incidence angle, so the turbine collects maximum wind energy all the time and in any season. - The tall tower base allows access to stronger winds in sites with wind shear. In upper wind shear sites, wind speed can increase by 20% resulting approx. 34% more power.

Horizontal axis wind turbines generally have the following disadvantages:

^• The tall towers and blades up to 90 meters long are difficult to transport. Transportation costs represent about 20% of equipment costs. Also due to the large sizes are difficult to install, needing very tall cranes and skilled operators.

^• Massive tower construction is required to support the heavy blades, gearbox and generator.

^• This type of wind turbines requires a control and positioning system to turn the blades toward the wind. Small turbines have a vertical tail surface disposed opposite the rotor (fig. 2) which plays the role of positioning system but at large turbines there is a complex system of sensors and actuators that control and position the rotor into the wind.

Vertical axis turbines have the advantage that the rotor does not need to be pointed into the wind to be effective, such turbines operating regardless wind's direction. VAWT can be either by drag or by lift forces. The most common subtypes are Darrieus, Giromill and Savonius.

General advantages of vertical axis turbines are:

• No massive tower structure is needed.

• No positioning system (yaw mechanism) is needed.

• Blades with square or rectangular cross-section have a larger swept area for a given diameter than the circular swept area of a horizontal axis turbine of the same diameter.

• The rotor starts to spin at a lower wind speed than horizontal axis turbines, so the majority of VAWT have an easy start without requiring additional energy.

The main disadvantages of vertical axis turbines are:

• Most VAWTs produce energy at only 50 % of the efficiency of HAWTs in large part because of the additional drag it have when their blades rotate against the wind, see Fig. 4. Versions that reduce drag produce more energy, especially those that funnel wind into the collector area. • The spinning speed of the blades cannot exceed the wind speed.

To minimize the disadvantages and / or to maximize the benefits of wind turbines, have been developed over the time multiple and various constructive solutions focused on the following aspects: optimizing the blade profile, funneling the air flow to turbine's collection area, beating a stator in front of a rotor such us to direct the wind on rotor's blades under optimum incidence angle by the means of the fixed stator's blades, for VAWT have been created control and positioning systems which allows to rotor's blades to be wind exposed on a side and to the other side to have a minimized wind exposure, see fig . 5 and control and positioning systems which allows wind exposure of the blades on one side and on the other side the wind exposure is blocked and additionally bends the air flow generated by the wind increasing blades wind exposure, see Fig. 6 and 7.

In recent decades, significant attention has been paid to study tornado type air flows and the possibility of their use for the production of energy, developing a new concept of wind turbines called Tornado -Type Wind Energy Systems (TWES).

The main advantage of TWES wind turbines is the difference of pressure which occurs between the periphery and the center of the swirl. Thus it was found that in a swirl, its center has an accentuated low pressure area that can "attract" and "accelerate" non- vortex air masses at higher speeds then the speed of the wind which creates whirlwind. The practical use of this concept lies in placing a turbine in the bottom center of a device or installation capable to generate a vortex flow, the turbine having an air intake located such as to "absorb" air masses outside the swirl. Besides the low pressure area was discovered to be favorable for spinning turbine also the rotation of the swirl behind the turbine's blades. For example we add figures 8 -14 which contains some TWES patented installations.

Among the latest inventions in the field of wind energy mention the wind turbine with mixers and ejectors as patent U.S. 7,976,268 B2 shows, see fig. 15, which thru the special profiled diffuser and its skirting succeeds to generate behind turbine's rotor a low-pressure area and an vortex flow; also mention the wind turbine according to U.S. 7,176,584 B1, see fig. 6, which is equipped with a conic inlet in order to accelerate the captured wind. Wind turbine's power is calculated according to Betz's theory using the following formula:

P = ½ p S v3 C_p, where:

P - Power in Watts

p - Density of air in kg/m³

S - Area swept by the rotor blades in m²

v - Wind speed in m/s

Cp - Power factor dimensionless

According to Betz's theory C_pmax = 0.59259259 and modern wind turbines achieves a power factor of about 0.5.

We see that the power of a wind turbine is proportional to the cube of the speed and to rotor's surface.

It is also known that the mechanical power of a rotary shaft is given by the product of the torque and the angular velocity, expressed by below formula:

P = ω M, where:

P - Power

M - Moment or Torque

ω - Angular velocity

Note that mechanical shaft power of the turbine is dependent on its size, more exactly on its radius, in the sense of the torque is direct proportional to the rotor's radius and the angular velocity is inversely proportional to the radius of the rotor. So an optimal dimensioning of a turbine's rotor ensures the minimal starting torque in order to start generate electric power from lower wind speeds and an angular velocity corresponding to optimal regimes for speed of rotations.

Using the conic inlet as is shown in the wind turbine according with patent U.S. 7,176,584 B1 , has in addition to advantage of accelerating the captured wind flow a disadvantage by increasing the aerodynamic opposition of the equipment, resistance which increases with the increase of the size of the inlet and implicit with its acceleration factor. The increased aerodynamic opposition involves increased difficulties to maintain the equipment toward the wind imposing a more robust positioning system, for example a vertical tail with a wider surface and as result with more weight. In conclusion, this type of turbine has the advantage to "process" captured air-flow, meaning to accelerate the wind captured, but with limited "level of processing" function of equipment's aerodynamic opposition.

We can remark that a wind turbine has to "process" effectively the captured wind, requiring to use a device that can accelerate as much possible the trapped air-flow, in conic inlet case to have the ratio between the surface of the upstream intake and the surface of downstream exhaust as high possible, while maintaining a surface of the upstream intake as small as possible in order to ensure a low aerodynamic opposition, and the turbine's rotor to have an optimum size in order to generate a sufficient torque and a rotational speed corresponding to the conditions offered by the "processed" airflow.

Wind turbines mentioned above presents the following disadvantages:

« The power generated per unit area is low due to the low level of "processing" of the captured air-flow or in the most of these turbines the airflow is not "processed "at all.

• The shape and the design of the existing wind turbines are strictly limited to capture atmospheric air currents ( wind ) from fixed positions, without the possibility to adapt to an efficient collection of " artificial " air-flows like those generated by the movement of transport vehicles.

• The shape and the design of the existing wind turbines are not allowing integration in the structure of land, river and sea transport vehicles.

• The shape and current constructive solutions are not effective in collecting highspeed air-flows; basically the turbines are shut-down when winds achieve high speeds.

The technical problem solved by this invention is to provide an equipment capable to collect, accelerate and operate with high-speed fluid stream, which have a small coefficient of aerodynamic opposition and which can be easily integrated in the structure of land transport vehicles, river and sea ships.

The equipment according with the invention solves the technical problem by been composed by a fluid intake fitted with a device to control the flow of fluid and to shut-down the admission (ex. fiap-shutter system), which is directly connected with a conic nozzle, where the fluid flow is accelerated and sent through a supply pipe to an s ejector -type device as engine jet of fluid, which expands through a nozzle into a suction chamber and then released in the atmosphere through an exhaust nozzle or exhaust diffuser. In the suction chamber is built in an annular turbine consisting of an annular rotor and an annular stator meant to direct the flow of absorbed fluid with the optimum incidence angle to the rotor's blades. In this manner the engine jet of fluid drives the fluid from suction chamber resulting a low pressure area behind the annular rotor, so more fluid is absorbed in the suction chamber through an annular stator device which guides the absorbed fluid to rotor blades. The sucked jet of fluid, called the ejected fluid, acts the blades of the annular rotor which drives thru a crown gear or a pulley, mounted on the outer circumference of the rotor, an electric power generation system.

The equipment according to the invention has the following advantages:

• Generate more power per unit of intake area due to the transfer of energy from the engine fluid, which have a greater speed than the speed of captured fluid.

« The equipment can be used both as a wind turbine and the hydraulic turbine, steam turbine, air - steam turbine - turbine that uses as engine fluid and ejected fluid any combination of technical fluids.

• As hydraulic turbine can operate without fall of water, generating a fluid differential pressure by accelerating it in the conic nozzle, considering the water supply ensures a sufficient flow.

• The components and their arrangement within the equipment permits to integrate it in the structure of electric vehicles as wind power generator designed to recharge their electric batteries while driving, improving their autonomy.

• The equipment can be also integrated in the structure of trains as auxiliary wind generator to reduce fuel consumption or the consumption from electric grid, and on the decks structure of ships as auxiliary wind power generator to reduce fuel consumption.

• The rotor ring structure having shared resistance on both, inner circumference and outer circumference, act more efficiently as fly-wheel allowing a better take-over of jerking thai can occur due to sudden braking and accelerating, inherent in the operation and use of vehicles. • Transmission on the outer circumference of the rotor allows a greater versatility in positioning and engagement of the power generation system in the sense that a generator which provides efficient conversion up to a certain rotation speed may be located on one side and another effectively functioning in another rotation speed range can be placed on other side, those may be driven alternative by turbine's rotor function of its working conditions.

The equipment according to the invention is made up from an ejector type device equipped with an engine fluid supply pipe connected to a conic nozzle which accelerates the fluid flow captured by means of a intake fitted with a device meant to control the flow of fluid and to shut-down the admission. The engine fluid releases in a suction chamber where drives more fluid creating another jet of fluid called ejected fluid and then together are exhausted through an exhaust nozzle or exhaust diffuser. The ejected fluid is absorbed in the suction chamber through an annular turbine built in the suction chamber, consisting of an annular rotor and an annular stator device meant to direct the flow of ejected fluid in the optima! incidence angle on the rotor's blades. The annular rotor has a crown gear or a pulley located on the outer circumference which leads a power generation system.

Depending on the way of use or the placement, the ejector type turbine can have additional features, such as:

• In the case of been used as wind turbine the equipment will be located on a swivel equipped with a positioning system to keep the inlet towards the wind. Swivel will be placed on top of a support tower designed to place the equipment in a more favorable height.

• For use as a component in the structure of electric vehicles or trains, the ejected fluid intake will be equipped with tubing and / or designed fairing meant to ensure the efficient management of the air flow from the outside of vehicle body or train to the suction inlet. The equipment's components will be fitted with brackets or constructed to be functional assembled or functional embedded in the structure and construction of electric cars or trains. • When using as auxiliary wind generators on the deck of ships or boats the equipment will be fitted with a mounting bracket designed to provide fixation and its connection to the ship's systems.

• When used as a hydraulic turbine, steam turbine, steam - air turbine, etc. the conic nozzle can be removed, the supply pipe for engine fluid may be connected to a feed pipe under pressure, and the start / stop system and regulating the flow consists of two valves manually and / or electrically operated, one located on the supply / feed pipe and one on the discharge pipe. Also the ejected fluid intake should be submerged and the around area should be specifically prepared in order to reduce the effects of sediment deposition, clogging, etc. We recommend blow-off the fluids into the atmosphere. The equipment will have a support system designed to provide fixation and anchoring it in the optimum position.

The following describes an embodiment of the present invention, as is shown in the Figures 17 ... 21 :

• Figure 17, a scheme for the ejector type turbine - side section and front view.

• Figure 18, a scheme of a wind ejector type turbine.

• Figure 19, a scheme of ejector type turbine included in a car body - side and top views.

• Figure 20, hydraulic ejector type turbine equipped with conic nozzle;

• Figure 21 hydraulic ejector type turbine connected to a pressurized feed pipe.

The equipment, according to the invention, is composed from an fluid intake equipped with a system to shut-down and to regulate the flow of captured fluid (1), which is in connection with a conic nozzle |2), where the fluid flow is accelerated and sent as engine jet fluid via a supply pipe (3) to an ejector - type device, in which the engine jet fluid expands through a nozzle (4) in a suction chamber (5) and subsequently released with the ejected fluid into the atmosphere through an exhaust nozzle or exhaust diffuser (6). In the suction chamber (5) is built in an annular turbine consisting from an annular rotor (7), and an annular stator (8) to direct the flow of ejected fluid in the rotor. The jet of aspirated fluid called ejected fluid, acts the annular rotor's blades (7) which lead through a crown gear (9) or a pulley (10) mounted on the outer circumference of the rotor, a power generation system (11). Depending on the use and fluids we have:

• a pivoting support (12) equipped with a positioning system (13) designed to keep the fluid intake towards the wind, mounted on a support tower (14) when the equipment is used as a wind turbine, see Fig . 18.

• A duct (15) and / or fairing (16) designed to ensure the efficient management of the air flow from the outside of vehicle's body or train, to the ejected fluid intake, see fig. 19.

• A mounting bracket and / or anchoring system (17) designed to fix / anchor the equipment on the deck of ships, when is used as auxiliary wind generator.

• Valves (18) and (19) meant to power on / off the equipment and to regulate the flow of fluid, and a bracket and / or anchoring system (17) intended to ensure fastening / anchoring by various other structures, when is used as a hydraulic turbine, steam turbine, steam - air turbine - turbine that uses any combination of technical fluids as engine fluid and ejected fluid, see fig. 20 and 21.

The ejector type turbine, according to the invention produces, more energy per unit area due to the "process" of captured fluid as is shown by the following calculation performed by a set of dimensions for illustration of Fig. 22 and assuming that the turbine is using a "perfect gas" under ideal conditions without loss of load and with constant temperature: Rj - inner radius of the annular turbine (downstream exit of conic nozzle) = 0.1880 m x - Multiplying factor for turbine's externa! radius = 1.4

R_t = x ^* Rj - turbine annular outer radius = 0.2633 m

S_t * RT² = π - π * R ² - turbine intake area = 0.1067 m² y - Multiplying factor for the air intake cross section = 3

Rc = y * i - the radius of the air intake = 0.5642 m z - Multiplying factor for conic nozzle length = 8

l_c = z ^* Rj - conic nozzle length = 1.50 m a - angle of the conic nozzle 0.24498 rad (14.03624 °)

So = π ^* c² - conic nozzle intake area = 1.00 m² v_v - wind speed = 10.00 m/s (36.00 km/h) A_t = 8 ^* R| - nozzle length = 1.50 m

S_a = TT ^* Rj² - nozzle's exit area = 0.11 m²

v_a = ( S_c / S_a) ^* v_v - speed at the exit from conic nozzle = 90.00 m/s w - Multiplying factor for exhaust nozzle radius = 1.2

R_e = w * Rj- radius of exhaust nozzle = 0.2257 m S_e = π ^* R_e ² - exhaust nozzle area = 0.16 m² v_e = (S_a / S_e) ^* v_a - exhaust speed from suction chamber = 62.50 m/s

v_t = (Se / S_t) ^* v_e - turbine's intake air velocity = 93.75 m/s p = Po / (1 - β Δρ) - air's density under isothermal conditions where:

Po = 1.2300 kg/m³ - the air's density under standard conditions

β = 1/101325 m² / N - coefficient of isothermal compressibility of a perfect gas Δρ = p - po - pressure difference - calculated according to Bernoulli and in this case we have:

Po - p = p t² / 2. - po v_v ² / 2

- Δρ = 4394.53 p - 50 p₀ = 50 (4394.53 p₀ / (1 - β Δρ)) - 50 p₀ = (4344.53 p₀ + 50 po β Δρ) / (1 - β Δρ)

β Δρ² - Δρ = 4344.53 ρ₀ + 50 ρ₀ β Δρ = 5343.77 + 61.50 β Δρ

β Δρ² - Δρ - 6 ,50 β Δρ - 5343.77 = 0

Δρ² / 101 ,325 - 0.00061 Δρ - Δρ - 5343.77 = 0

0.0000098 Δρ² - 1.00061 Δρ - 5343.77 = 0

From the solution of this equation, taking into account the fact that the difference in pressure must be negative, since the back pressure of turbine is smaller than that from its front (p < po ) results the following :

Δρ = - 5087.06 N/m² that:

p = 101325 - 5087.06 = 96237.94 N/m² and

p = Po / (1 - β Δρ) = 1.23 / (1 + 5087.06 /101325) = 1.17 kg/m3 C_p - power coefficient (max. 0.593) = 0.50

P = ½ p S_t t³ Cp / 1000 - turbine's power in kW = 25.7160 kW

In the case of a classic wind turbines with a swept area of 1 m², equal to conic nozzle intake, swept by a wind speed of 10 m/s equal to the speed of the wind captured by ejector type turbine, and which has a power coefficient of 0.50 we get according to Betz's theory the power P = ½ p₀ S_c v_v ³ C_p / 1000 expressed in kW, that:

P = 0.5 * 1.23 * 1 ^* 10^{3 *} 0.5 / 1000 = 0.3075 kW

Comparing between these two turbines, results that power per unit area is about 83 times higher in the case of ejector type turbine than a conventional turbine.

If we consider a wind turbine according to U.S. 7,176,584 B1, with the same dimensions and the same "level of processing" will have the same power as the ejector type turbine but aerodynamic opposition coefficient is much different. In our case we compare only the surface "exposed to the wind" even the aerodynamic opposition coefficient is dependent on both, surface and form, and in terms of form the ejector type turbine is more advantageous due to the opening of the central feed pipe. Even so, considering that area "exposed to the wind " is given by the difference between air's exit surface and air's intake surface of conic inlet, according to fig. 22 , we have:

• For ejector type turbine:

5₁ = Sc - Sa = TT * R_c ² - TT * Ri² = 1.00 - 0.11 = 0.89 m²

• For other turbine:

5₂ = Sp - S_t = π ^* (3 ^* Rt)² - rr ^* t² = 1.9601 - 0.2177 = 1.7424 m²

Claims

1. Ejector type turbine characterized by a fluid intake equipped with a system to shutdown and to regulate the flow of captured fluid (1) , directly connected to a conic nozzle (2) mounted on the supply pipe (3) discharging through a nozzle (4) in a suction chamber (S) which absorbs the ejected fluid thru an built in annular turbine which consists from a annular rotor (7) and an annular stator (8) to directing the fluid drawn into the annular turbine and discharged together with the engine fluid through an exhaust nozzle or exhaust diffuser (6). The annular rotor (7) drives through a crown gear (9) or a pulley (10) mounted on the outer circumference of the rotor, a power generation system (11).

2. The ejector type turbine according to claim 1 , characterized by that the equipment have a pivoting support (12) equipped with a positioning system (13) mounted on a support tower (14).

3. The ejector type turbine according to claim 1 , characterized by that the equipment have a duct (15) and / or a fairing ( 6) to ensure the efficient management of the air flow from the outside of the electric vehicle's body or train, to the ejected fluid intake.

4. The ejector type turbine according to claim 1 , characterized by that the equipment have the valves (18) and (19) to power on / off the equipment and to regulate the flow of fluid, and a mounting bracket and / or anchoring system (17) designed to fix / anchor the equipment on various other structures when is used as a hydraulic turbine, steam turbine, gas turbine, steam - air turbine, and turbine that uses any combination of technical fluids as engine fluid and ejected fluid.

5. The ejector type turbine according to claim 1 , characterized by that it is equipped with a mounting bracket and / or anchoring system (17) designed to ensure the fixing / anchoring the equipment on the deck of river or sea ships, when is used as auxiliary wind generator.