Technical Field

The present invention relates to a configuration of a solar chimney which is used to produce electricity from solar energy by means of a thermal method.

Background of the I nvention ( Prior Art)

I n the present state of art, the system known as solar chimney is used for producing electrical energy from solar energy by means of a thermal method. The solar chimney system , also originally known as the Solar Updraft Tower (SUT) in the relevant literature, utilizes a technique which initially converts solar energy into thermal energy and then to kinetic energy, and finally converts said kinetic energy into electrical energy.

Compared to conventional energy generation systems, the SUT system has a very different working principle and it includes three fundamental physical principles: the greenhouse effect, updraft effect and kinetic energy conversion. As shown in Figures 23 and Figure 24, the air located under a circular glass collector is heated via solar radiation which hits the collector surface. Since there is a density difference between warm air and the cold ambient air, the air under the collector moves to the center of the collector horizontally, and it accelerates by the updraft force of the chimney, and is discharged to environment from the open top part of the chimney.

The accelerated air flow enters the chimney, produces electrical energy by rotating the generator which is connected to the turbine located at the entrance of the chimney. This cycle will happen faster when the solar radiation is stronger. Since the chimney pulls the air under the collector, a continuous operation is obtained by the suction of air from the edges of the collector that are open.

I n a classical solar chimney technique, energy is generated via a horizontal axis turbine (HAT) , inside the chimney that is located at the mid section of the collector. I n axial turbine systems also known as HAT, a single chimney is used and the overall system efficiency is directly related to the height of the chimney. As the height of the chimney increases, the efficiency increases; however the production costs and feasibility limits also increase.

On the other hand, the horizontal axis turbines (HAT) used in classic solar chimneys, allow the energy production to be carried out via the unidirectional air flow similar to wind turbines, and this situation is an aspect that decreases energy production efficiency or in technical terms, the power production coefficient.

The first large-scale application of SUT technique was a solar chimney installed at the south of Spain, in 1982. A team led by a German engineer Jorg Schlaich installed an experimental solar chimney which had 50 kW power capacity. This solar chimney that has a collector diameter area of 244m, was 194.6 m in height, 1 0 m in diameter and under non load conditions it reached up to 15m/s inner chimney air velocity and it operated until 1989.

As it can be seen from this example, the efficiency of solar chimney systems was very low considering their size. For this reason, up until today they have not able to have a widespread use in the known art.

I t is the aim of the subject of invention to resolve the productivity problem of the solar chimney systems and make them a feasible recyclable energy source.

Brief Description and Objects of the I nvention

I n the present invention, the developed chimney configuration consists of three separate chimney systems. I n the tripartite chimney system, the central chimney has an “updraft” function, while the other two adjacent chimneys have a“downdraft” function.

I n addition, in the embodiment of the invention, vertical turbines are used which are placed at the entrance of the chimney instead of the interior part of the chimney itself . Vertical turbines, also known in the art as VAT (Vertical Axis Turbines) , are the turbines whose rotor blade shaft is positioned perpendicular to the direction of the wind flow.

The following is aimed by the development of the solar chimney configuration subject to the invention ;

• Reducing the height of the chimney,

• I ncreasing the energy generation efficiency, namely the power coefficient

• I ncreasing the performance continuity,

• I ncreasing feasibility and functionality, • Avoiding the inefficiency of the turbines resulting from unidirectional air flow and improving overall turbine efficiency.

Description of the Figures I llustrating the I nvention

To better illustrate the solar chimney configuration developed by the present invention, the following figures and associated explanations are as follows.

Figure 1 : Top perspective view of the solar chimney configuration.

Figure 2: Close-up perspective view of the top of the solar chimney configuration.

Figure 3: Front view of the solar chimney configuration.

Figure 4: Side view of the solar chimney configuration.

Figure 5: Cross-sectional side view of the solar chimney configuration.

Figure 6: Cross-sectional top view of the solar chimney configuration.

Figure 7: Front view of illustrative air flow in the solar chimney configuration.

Figure 8: Side view of illustrative air flow in the solar chimney configuration.

Figure 9: Frontal close-up view of illustrative air flow in the solar chimney configuration.

Figure 10 : Frontal close-up view of illustrative air flow in a different embodiment of solar chimney configuration.

Figure 1 1 : Top view of the solar chimney configuration.

Figure 12: Top view in a different embodiment of solar chimney configuration.

Figure 13: Top view in another embodiment of solar chimney configuration.

Figure 14: Top view in another embodiment of solar chimney configuration.

Figure 15: Front view of illustrative air flow in a venturi cap embodiment of solar chimney configuration.

Figure 16: Cross-sectional top view of turbine section in the solar chimney configuration. Figure 17: Cross-sectional top view of the embodiment of the multiple-stage turbine group in the solar chimney configuration.

Figure 18: Cross-sectional top view of another embodiment of the multiple-stage turbine group in the solar chimney configuration. Figure 1 9 : Cross-sectional top view of another embodiment of the multiple-stage turbine group in the solar chimney configuration.

Figure 20 : Cross-sectional top view of another embodiment of the multiple-stage turbine group in the solar chimney configuration.

Figure 21 : Cross-sectional top view of an embodiment of the multiple turbine group and multiple tower in the solar chimney configuration.

Figure 22 : Cross-sectional top view of another embodiment of the multiple turbine group and multiple tower in the solar chimney configuration.

Figure 23 : The solar chimney configuration perspective view of the prior art.

Figure 24 : The solar chimney configuration cross-sectional side view of the prior art.

Descriptions of Elements / Parts / Components of the I nvention

To explain better the developed solar chimney configuration within this invention, parts and elements in drawings are numbered and designated separately as follows,

1 . Solar chimney configuration

2. Updraft chimney

3. Downdraft chimney

4. I nterconnect part

5. Vertical turbine group

6. Collector

7. Venturi cap

8. Updraft air flow

9. Downdraft air flow

1 0. Diffuser wall

1 1 . Vertical turbine

1 2. Turbine case

1 3. Chimney separation wall

1 4. Solar chimney (prior art)

1 5. Collector (prior art)

1 6. Greenhouse area (prior art) Detailed Description of the I nvention

I n the solar chimney configuration (1 ) subject to the invention, different from solar chimneys in prior art (14) , three different chimney systems have been provided.

I n the tripartite chimney system, one chimney at the center is an updraft chimney (2) , which sucks up the hot air provided by collector (6) , and the air is discharged to the environment from the opening of the chimney (2) that opens upward. By means of this chimney (2) the hot air provided by the collector (6) moves towards the chimney (2) , where it is further accelerated due to the suction effect of the chimney (2) , then it passes through the vertical turbine group (5) in the Y axis direction, and it rotates the vertical turbines (1 1 ) , and provides electricity generation from the generators connected to vertical turbines (1 1 ) .

The two outer chimneys that have been placed adjacent to the chimney (2) , on both sides of said updraft chimney (2) are downdraft chimneys (3) , where said chimneys are at least two chimneys that have been placed on each side of said updraft chimney (2) .

The downdraft chimneys (3) , speed up the outside air and transfer it to the vertical turbine group (5) which is located at the bottom of the chimneys (3) . The downdraft chimneys (3) pull down the outside air by means of the following factors:

• As a result of the density difference between outside air and the warm air located in the vertical turbine group (5) , the outside air is sucked from the downdraft chimneys (3) , and it is pushed down.

• The outside air is sucked from the downdraft chimneys (3) and pushed downward by the effect of the negative pressure created by the downdraft chimneys (3) of the vertical turbine group (5) during the rotation of the vertical turbine group (5) rotated by the hot air.

• The environment air is sucked from the downdraft chimneys (3) and pushed down due to the effect of the pressure difference between high atmospheric air pressure formed at the entrance of the downdraft chimneys (3) and the low pressure caused by the hot air flow in the vertical turbine group (5) .

• The outside air is sucked from downdraft chimneys (3) and pushed down due to the wind pressure caused by the wind which affects the entrance of the downdraft chimneys (3) .

• Besides natural factors, it is possible to obtain forced air by means of mechanical humidification systems in downdraft chimneys (3) . I n this case, the outside air is sucked from the downdraft chimneys (3) and is pushed down due to the difference between the high density formed at the entrance the downdraft chimneys (3) , and low density at the vertical turbine group (5) .

As a result of the factors described above, the outside air which flows down from the downdraft chimneys (3) , after it accelerates, passes through the vertical turbine group (5) and enables the vertical turbines (1 1 ) to rotate and therefore enables the generators connected to the turbines (1 1 ) to produce electricity.

Since both air flow systems operate simultaneously, the vertical turbines (1 1 ) of the vertical turbine group (5) rotate by being driven with the combined air flow (8 and 9) transferred from both the updraft chimney (2) and downdraft chimneys (3) .

By means of this flow arrangement, which is the main novelty of the invention, the flow arrangements of the updraft and downdraft systems, which normally operate as separate mechanisms are combined.

The main factor that enables the combination of the updraft and downdraft mechanisms in one system, is the turbine arrangement in the solar chimney configuration

(I ) subject to the invention. I n the new turbine arrangement, the vertical turbine group (5) and the vertical turbines (1 1 ) located therein, are positioned at the entrance of chimney, not inside the chimney itself, like in the classical application. Here, above-mentioned chimney entrance defines the starting point of the interconnection part (4) where the bottom sections of the updraft chimney (2) and downdraft chimneys (3) join each other and which enables the connection of chimneys (2 and 3) to vertical turbine group (5) .

The turbine type in the vertical turbine group (5) is a vertical axis turbine (VAT) , not a horizontal axis turbine (HAT) known in the state of art. By using this, the vertical turbine

(I I ) blades benefit from the “double-sided” air flow (8 and 9) which is provided by the chimneys (2 and 3) .

A solar chimney configuration (1 ) that has been developed to produce electrical energy by means of the transfer of the accelerated airflow in the chimneys and the rotation of the turbines and the generators that are connected to the these turbines, wherein said chimney configuration comprises the following in order to produce electrical energy via simultaneous usage of two different airflows (8 and 9) that move both up and down;

• At least one updraft chimney (2) which is connected to an interconnection part (4) from the bottom that is used to accelerate the hot air provided by collector (6) and to discharge it to the surroundings, • At least two downdraft chimneys (3) that are connected to the interconnection part

(4) from the bottom , that is positioned adjacent to the updraft chimney (2) from the sides, which allows the transfer of the ambient air that has been received from the top section of the chimney, to the interconnection part (4) by accelerating the air downward,

• At least an interconnection part (4) which enables the transfer of airflows (8 and 9) between the chimneys (2 and 3) and the vertical turbine group (5) , where the updraft chimney (2) and the downdraft chimneys (3) are coupled adjacently to each other.

• A vertical turbine group (5) , where the air flows (8 and 9) are directed by the downdraft chimneys (3) and the collector (6) and which houses diffuser walls (10) , vertical turbines (1 1 ) , turbine cases (12) , chimney separation walls (13) , and generators connected to the vertical turbines (1 1 ) ,

• A collector (6) which is connected to vertical turbine group (5) , and which provides hot air flow to said group,

• Two diffuser walls (10) that are used to accelerate and transfer the hot air from collector (6) to vertical turbines (1 1 ) , and which are positioned at the edges of the collector (6) , on the side of vertical turbine group (5) ,

• At least one vertical turbine (1 1 ) that is used to convert mechanical energy to kinetic energy, which is driven by the force of the air flows (9) provided by the collector (6) and downdraft chimneys (3) ,

• At least one turbine case (12) for the turbine (1 1 ) which limits the positioning area of the vertical turbines (1 1 ) and,

• At least two chimney separation walls (13) which prevent the mixing of downdraft air flow (9) provided by downdraft chimney (3) to vertical turbine group (5) via the interconnection part (4) , and the air flow (8) provided by the vertical turbine group

(5) to the updraft chimney (2) via the interconnection part (4) .

I n another embodiment of the invention, to provide functions described below, at least one venturi cap (7) for each chimney (2 and 3) is used which is mounted at the top points of the chimneys (2 and 3) (Figure 15) ;

• Acceleration of the updraft air flow (8) at the chimney outlet point, that is discharged via the updraft chimney (2) after it is received from the vertical turbine group (5) and

• Acceleration of the downdraft air flow at the chimney (3) entrance point that is initially sucked in from the outside environment by the downdraft chimneys (3) . The collector (6) element of the solar chimney configuration (1 ) subject to the invention is basically a structural connection part, that enables the hot air that is provided by solar energy, glass greenhouses, photovoltaic/thermal methods, geothermal sources, waste heat sources or hot air provided from any other heat sources and collects said air and transfers it to the vertical turbine group (5) and that provides airflow between the hot air source and the vertical turbine group (5) (Figure 1 and Figure 4) .

The updraft chimney (2) and downdraft chimneys (3) can have a prismatic or circular fixed sectional geometry (e.g. Figures 1 1 -14) , or in another embodiment of the invention, they can have a diffuser shape where the bottom cross sections are narrower compared to the top cross sections (e.g. Figures 8-10) .

Although the downdraft chimneys (3) are positioned adjacently to the updraft chimney (2) sides (e.g. Figures 7,9, 1 1 ) , in different embodiment of the invention, it is also possible for chimneys (2 and 3) to be placed telescopically (e.g. Figures 10, 13, 14) .

The vertical turbines (1 1 ) used inside the vertical turbine group (5) may be turbines (1 1 ) with lift type airfoil blades or drag type blades. Or it is possible for the vertical turbines (1 1 ) to be vertical turbines (1 1 ) which have both lift type airfoil and drag type blades. I n the case of a single type vertical turbine (1 1 ) use, there could be one vertical turbine (1 1 ) in the vertical turbine group (5) , or it is possible to use at least two vertical turbines (1 1 ) together in the vertical turbine group (5) .

At the same time, in one embodiment of the invention, in addition to diffuser walls (10) or in the case when diffuser walls (10) are not used, it is possible to use guide vanes to speed up the air flow velocity at the entrances of the vertical turbines (1 1 ) on the collector side (6) , or the interconnection parts (4) .

I n the basic embodiment of the invention, as shown in Figure 16, a one stage vertical turbine (1 1 ) configuration may be used, or like in different embodiments of the invention, as shown in Figure 17 and Figure 19, it is possible to use a multi-staged vertical turbine (1 1 ) configuration.

I n the basic embodiment of the invention, the connection of vertical turbine group (5) with updraft chimney (2) and downdraft chimneys (3) could be a single-sided connection as shown in Figure 18; or in different embodiments of the invention, as shown in Figures 20-22, it is possible to have a connection on more than one side or at more than one point.