RECOVERY of WIND ENERGY by a STATIC SENSOR to replace a conventional WIND TURBINE

Abstract

This provisional patent application complements the one filed in November 2021. We remind you that this is a system for capturing static wind energy associated with a very small shrouded turbine. The system is composed of a large number of venturi-type cells. Being static, it is no longer the site of significant vibrations and is no longer subject to the thresholds of 12 and 25 m / s, which set the operating range of conventional wind turbines. In the current application, we have supplemented the previous venturi module with an additional element, in this case a convergent module. This is formed and delimited by the walls of the venturi modules [Fig.7] and [Fig.8]. This convergent creates a depression at the outlet of the venturi module and drives the air flow to bring it to atmospheric pressure. The gain in power per m2 is significant compared to the basic module presented in November 2021.In the structure, these converging spaces, empty of any equipment, have a dimension much greater than that of the venturi modules. They therefore only require an enlargement of the structure, the recompression of the air taking place in the open air outside it. The various modules, as previously, are always arranged in parallel, in the form of honeycombs. The capture system can also be achieved by concentric crowns or rings §3.8. The main goal has therefore remained the same, namely, A static system, therefore not subject to vibrations and therefore to the thresholds of 12 and 25 m / s mentioned above A turbine with a section much smaller than that developed by a wind turbine The study finally concerns the erasure of the turbine, partial or total, in the presence of disturbances or for needs related to the driving. §3.10.The turbine, which has very low inertia compared to a wind turbine, is isolated and then stopped by closing the multiple shutters located at the entrance to the mixers.

Description

Title of the invention: RECOVERY of WIND ENERGY by a STATIC SENSOR to replace a conventional WIND TURBINE

[0001] Second patent application 1. Reminder#

[0002] This second patent application supplements the patent application filed on November 13, 2021, under national number and ref. FR 2112019. It is published under reference FR 3129183.

[0003] This first patent concerned and still concerns the replacement of a conventional wind turbine with a static wind energy capture system. This replacement is particularly relevant when the wind regime is the site of significant or sudden variations in the wind regime, both in speed and direction (gusts). This static system is therefore no longer subject to the constraints linked to the thresholds of 12 and 25 m / s, levels from which the power of the wind turbine is kept constant and then stopped.

[0004] The proposed capture system is composed of a large number of venturi-type modules, mounted in parallel in a honeycomb structure and in the form of a honeycomb.

[0005] This static structure is associated with a small, shrouded turbine driving a generator.

[0006] The 2021 patent application did not directly take into account pressure losses. This second patent application will therefore take them into consideration. The previous isentropic transformations then become adiabatic with friction.

[0007] In the 2021 application, the analysis of the operation was only carried out on a single module independently of any interaction with all the modules in parallel. This second patent application will more particularly concern the developments in a double venturi, the second venturi being made up of only one convergent.

[0008] In the following we will deal successively with: - pressure losses. In our first study of November 2021, we considered all the evolutions as isentropic, that is to say without friction, to then apply an overall efficiency to the entire system, a value that can be found in the literature. In the study, which we present now, we will consider the pressure losses of each of the elements making up the system in order to better highlight the role of the various parameters taken in isolation. - we will then discuss the double venturi, which is a complementary element to the main venturi module. More precisely, it is a convergent element surrounding the venturi module. It is intended to create a depression at the outlet of the venturi module and to draw all the air to atmospheric pressure. This element constitutes the essential point of our present patent application. - we will conclude with practical considerations and the examination of the prototype.

[0009] For a good understanding of the project it might seem easier to approach the subject by reading chapter 3, which is more descriptive, without neglecting the importance of pressure losses and the decisive role they will play in the validity of the project.

[0010] 2. Taking into account pressure losses

[0011] 2.1. Impact of pressure losses on the energy available at the mixer inlet

[0012] First, let us give a brief reminder of the representation of the expansion of air in the enthalpy diagram.

[0013] Figure [Fig.l] represents the expansion of air from atmospheric pressure until it enters the mixer.

[0014] Point A represents the state of the air at the inlet of the venturi module and AC the expansion when there is no friction. In the case of friction, the pressure losses are translated by the evolution of the dotted curve. The pressure loss at the inlet of the mixer corresponds to the difference in enthalpy between points C and D expressed in Joules / kg. These are friction losses. These losses can be transferred to the inlet of the venturi determining point E. Thus the enthalpy difference AB represents the total energy, without friction, available to perform the engine work in the turbine. Taking into account the pressure losses, it is the difference EB which represents the available energy.

[0015] We can already measure the impact of these losses and, among other things, their increase when the pressure in the mixer decreases (or the depression increases) [Fig.2]. Too much depression at the mixer inlet drastically reduces the energy available to perform the engine work. But a reduction in this pressure has the beneficial effect of increasing the pressure difference between the inlet and outlet of the turbine and therefore reducing its size. A compromise must therefore be found!

[0016] 2.2. Impact of pressure at the mixer inlet

[0017] The overall yield of .6 retained in the 2021 patent application is the result from research on the internet and in literature. Furthermore, in the early 1980s we produced a fairly basic prototype which, to a certain extent, confirmed our choice. However, this prototype only included one module and had only been tested on site and not in a wind tunnel. A new prototype will be presented in chapter 3.11.

[0018] The diagram [Fig.3] will illustrate what has just been explained (§2.1). Thus, a lower pressure in the mixer increases the speed of the expanded air (curve 3), therefore the pressure losses and finally the power produced (curve 1). But this lower pressure has the beneficial effect of reducing the size of the turbine, which is reflected in curve 2, which expresses the ratio between the outlet surface of the venturi module and the rotating surface of the turbine.

[0019] These two effects, namely the power developed and the surface area of ​​the turbine, are therefore contrary, the increase in power being to the detriment of the size of the turbine and vice versa.

[0020] A compromise between power and turbine size will have to take into account local conditions and, above all, investment. This will be discussed in particular in Chapter 3 when examining the double venturi.

[0021] 2.3. Optimization of the power delivered by the turbine as a function of the speed of venturi module outlet

[0022] Diagram 2 [Fig.4] shows the corresponding curves, curve 1 without taking into account the pressure losses, curve 2 for pressure losses as retained in §2.1 and 2.2.

[0023] The wind inlet speed is 12 m / s.

[0024] The power reaches a maximum for a wind speed of 7 m / s without taking into account pressure losses and 5.5 m / s otherwise. This difference in speed is the consequence of the reduction in the effective air speed at the inlet of the venturi in the presence of pressure losses, as explained above in § 2.1 and § 2.2.

[0025] Finally, we remind you that the comments as they appear in the November 2021 patent application remain relevant and that repeating them here would only complicate the presentation.

[0026] 2.4. Optimization of the power delivered by an adequate choice of the output speed turbine air (or mixer inlet)

[0027] The effect of the air speed at its entry into the mixer (or turbine outlet) was developed in the November 2021 patent application on page 6.

[0028] As a reminder, the first effect of increasing the speed is to reduce the work per kg of air delivered by the turbine.

[0029] But in the mixer, the effect of the air speed is predominant, so that the power per m2 increases considerably with this speed.

[0030] Diagram 3 [Fig.5] reflects this increase in power. At around 17 m / s, this speed confirms the overall efficiency of .6 retained in §2.2.

[0031] The increase in speed is also accompanied by a reduction in the size of the turbine.

[0032] This beneficial effect of speed, however, has the consequence of increasing the pressure losses in the connections from the turbine to the very numerous venturi modules. Measures are taken accordingly but they will be set out in the double venturi section, because they will be integrated into all the provisions relating to the aforementioned connections leading to the chambers in the mixers. (Questions relating to erasure, AU, and load regulation will be dealt with on this occasion §3.10)

[0033] 2.5. Estimation of the module efficiency when the wind speed is different from the one that was used to define this module

[0034] Let the module be sized for a wind speed of 12 m / s. It will be tested for winds up to 32 m / s (115 km / h).

[0035] [Fig.6] gives the power in W / m2 as a function of the wind speed. This diagram has already been presented in the 2021 patent application. It is supplemented here by curve 6. This shows the evolution of the power per m2 when the module has been defined for a wind of 12 m / s. It can be seen that the efficiency decreases more as the wind speed increases, gradually going from .6 to .5. For speeds below 12 m / s, curves 5 and 6 practically merge.

[0036] It can be seen that this drop in efficiency is therefore only effective beyond the operating range of the wind turbines, where their power must be limited, before the wind turbine is stopped.

[0037] Up to now, the file has only concerned one venturi module independently of the others. In the following, the space between the modules will be taken into consideration. It will make it possible to optimize the efficiency of capturing wind energy by grouping these venturi modules and their spaces in the structure, in a honeycomb. This is the main subject of this second patent application.

[0038] 3. Description of the Double Venturi Module

[0039] 3.1. Presentation [Fig.7]

[0040] This is a venturi identical in every respect to the one we have examined so far, but with which a converging space is associated.

[0041] This convergent is formed by the walls of the venturi modules alone, as indicated [Fig.7]

[0042] The purpose of this space is to create a depression at the outlet of the venturi module. The increase in the pressure difference between the inlet and the outlet of the venturi module leads to a considerable increase in the flow rate in the turbine and therefore the power delivered. The depressurized air leaving the venturi module is entrained by the air coming from this converging space.

[0043] The size of this space, called the interventuri space, is achieved by transversely moving the venturi modules away from each other.

[0044] A material, energy and momentum balance is carried out at the level of the two air flows, one leaving the main venturi, the other from the convergent (or interventuri). This balance must achieve the conditions required so that the total air leaving the system, venturi and interventuri, is at atmospheric pressure. The interventuri space is sized accordingly.

[0045] The effective outlet section, that is to say that which corresponds to the space occupied in the structure, is located at the level of the mixing of the air flows. As for the zone of mixing and recompression of the air, it is located outside the structure like the recompression of the wind downstream of the blades of a wind turbine.

[0046] We now understand the interest of this divergent which allows the venturi module to exit under depression, thus increasing the power, without the need for additional equipment. Only the size of the structure increases.

[0047] Finally, the various sections of the venturi module are square and the outer casing therefore appears in the form of a rectangular parallelepiped, at least in this first approach. [Fig.8]

[0048] 3.2. Dimensioning in the case of a wind of 12 and 25 m / s.

[0049] In the following, we have retained pressure losses as defined in Chapter 2. Similarly, in the air recompression phase outside the structure, we have retained the same factor. These are losses by friction, ventilation, identical to those suffered downstream of the blades of a wind turbine in the air recompression zone.

[0050] We will successively consider wind speeds of 12 and 25 m / s, values ​​which represent the two thresholds from which the power delivered by the wind turbine is first kept constant, then beyond 25 m / s, the wind turbine is stopped.

[0051] We also wanted to show the impact of variations in various parameters to conclude on the need to rely on an experimental prototype, more complete than the one we used during the years 1979 / 1984.

[0052] The parameters that will define the operation of the venturi module are as follows:

[0053] Pressure at the mixer inlet after expansion in the venturi module convergent

[0054] A reduction in the pressure at the mixer inlet has a double effect. The first is to increase the pressure difference between the inlet and outlet of the turbine. Consequently, for the same required power, the air flow rate decreases and therefore the size of the turbine. This effect is therefore beneficial. On the other hand, a reduction in the pressure would increase the speed in the converging part of the venturi module, therefore the pressure losses and finally reduce the available power. §2.1 [Fig.2]

[0055] The effect is therefore the opposite of the previous one and will lead to a search for optimization.

[0056] Venturi module outlet pressure

[0057] For a given wind speed, the pressure in the mixer is constant, and therefore also the inlet flow rate in the venturi module. A decrease in the pressure at the outlet of the module has the effect of increasing the total flow rate. In this case, this is the only flow rate in the turbine. The power delivered increases considerably.

[0058] A limit appears, however. As the total air flow increases and the pressure at the outlet of the venturi module decreases, the work of the convergent (or interventuri space) to drive the air at atmospheric pressure will have to increase and therefore its sizing.

[0059] Air velocity from the turbine to the mixer inlet

[0060] We know the beneficial effect of the air speed at the mixer inlet (§2.4). We have chosen an air speed of 17m / s.

[0061] These three previous parameters completely define the venturi module.

[0062] Let us now size the convergent (or interventuri space) so that it can entrain the air leaving the venturi module and bring all the air flows to atmospheric pressure.

[0063] 3.3. Case of a wind of 12 m / s.

[0064] [Fig.9] represents the fluid circulation diagram.

[0065] In accordance with what has been retained: - Mixer inlet pressure: .97 bar abs, corresponding to speed at neck: 75 m / s - Venturi module outlet pressure: .997 bar abs - Turbine outlet and mixer inlet speed: 17 m / s - Venturi module inlet air flow: 10 kg / s

[0066] Consequently: - Power delivered: 1380 W - Turbine outlet section: 0.0265 m2 - Venturi module outlet section: 1.25 m2 - Convergent outlet section (interventuri): 5.25 m2 - Complete module output section (1.25+5.25) or footprint: 6.5 m2 (output structure)

[0067] In conclusion, concerning the size, the ratio of the convergent module outlet surfaces / venturi module outlet is 4.2, meaning that the surface occupied by the "empty" space is 4.2 times larger than the space at the outlet of the venturi module. We will designate by active surface, the outlet of the venturi module, i.e. 1.25 m2 and by surface additional, the empty space only requiring an extension of the structure, i.e. 5.25 m2.

[0068] The power reported to the occupancy in the structure is 1380 / (1.25+5.25) or 212 W / m2

[0069] The power reported to the active surface is 1380 / 1.25 or 1104 W / m2

[0070] The power of 212 W / m2 is located on curve 4 of [Fig.6]. We note that This curve does not take into account pressure losses, so the value of 212 W / m2 includes them.

[0071] The interest of this interventuri space was shown thanks to three preliminary provisions, namely: - the creation of a depression at the outlet of the venturi module, considerably increasing the power - the pressure at the mixer inlet (depression) in order to minimize the size of the turbine - the creation of the working area of ​​the interventuri at the level of the air flows, the recompression taking place in the external environment, as in the case of wind turbines

[0072] Let us also note that the space occupied by the convergent is empty. It is a space formed by the walls of the venturi modules, having an area only in the structure.

[0073] It is now understood that the choice of values ​​for these parameters will depend on local conditions, wind conditions and the cost of the investment.

[0074] 3.4. Case of a wind of 25 m / s with pressure at the mixer neck of .97 bar abs.

[0075] The wind speed will increase from 12 to 25m / sec. The wind inlet flow rate is still the same, namely 10 kg / sec, as an initial data.

[0076] [Fig. 10] represents the fluid circulation diagram.

[0077] In accordance with what has been retained: - Mixer inlet pressure: .97 bar abs, corresponding to speed at neck: 75 m / s - Venturi module outlet pressure: .987 bar abs - Turbine outlet and mixer inlet speed: 17 m / s - Venturi module inlet air flow: 10 kg / s

[0078] Consequently: - Power delivered: 8687 W - Turbine outlet section: .153 m2 - Venturi module outlet section: 0.73 m2 - Convergent outlet section (interventuri): 3.4 m2 - Complete module output section (.73+3.4) or footprint: 4.13 m2 (structure output)

[0079] In conclusion, concerning the size, the ratio of the convergent module outlet surfaces / venturi module outlet is 4.66. We will designate by active surface, the outlet of the venturi module, i.e. 0.73 m2 and by additional surface, the empty space requiring only an extension of the structure, i.e. 3.4 m2.

[0080] The power reported to the occupancy in the structure is 8687 / (.73+3.4) or 2104 W / m2

[0081] The power reported to the active surface is 8687 / .73 or 11900 W / m2

[0082] The power of 2104 W / m2 is located on curve 4 of [Fig.6]. We note that This curve does not take into account pressure losses, so the value of 2104 W / m2 includes them.

[0083] All these values ​​are quite acceptable with the major exception of the ratio between the rotating surface of the turbine and the size which is only 4.13 / .153 or 27, a value which is too low and unacceptable. Consequently, it is imperative to reduce the pressure at the neck of the venturi module, despite the drop in power / m2 which will be the consequence. This will be the subject of the following section.

[0084] 3.5. Case of a wind of 25 m / s with pressure at the mixer neck < .97 bar abs.

[0085] [Fig. 11] represents the fluid circulation diagram.

[0086] We will verify that the choice of a lower neck pressure has the effect of reducing the diameter of the rotating part of the turbine, to the detriment however of the power per m2.

[0087] Let the pressure at the neck of the venturi module be 0.87 bar abs. Its outlet pressure is 0.983 bar abs. The speed at the neck rises to 152 m / s.

[0088] We remember: - Mixer inlet pressure: 0.87 bar abs, corresponding to speed at neck: 152 m / sec. - Venturi module outlet pressure: .983 bar abs - Turbine outlet and mixer inlet speed: 17 m / s - Venturi module inlet air flow: 10 kg / s

[0089] Consequently: - Power delivered: 5089 W - Turbine outlet section: 0.024 m2 - Venturi module outlet section: .59 m2 - Convergent outlet section (interventuri): 3.2 m2 - Complete module output section (.59+3.2) or footprint: 3.79 m2 (structure output)

[0090] The ratio between the total surface area presented to the wind (bulk) and the rotating surface area of ​​the turbine becomes 3.79 / .024 or 158, an acceptable value this time, although no optimization has been sought.

[0091] On the other hand, the power has decreased. It now represents only 1350 W / m2. On the diagram in [Fig.6], we move this time from curve 4 to curve 5. But we must not forget that the power per m2 obtained compared to the wind turbine is 1350 / 420, i.e. 3.2 higher, in the absence of any optimization. (420 W / m2 corresponding to the wind turbine)

[0092] All of the above shows that the prototype we tested in 1980 is not sufficient in the case of a venturi module with convergent and that wind tunnel tests are necessary.

[0093] 3.6. Results of the calculation of a structure in order to achieve a power of 1 MW 10kW cell and 12 m / s wind

[0094] This cell is part of a wind capture surface composed of 100 cells (venturi and divergent module) arranged in parallel in a honeycomb. The power is then 1 MW.

[0095] In the following, the developments are considered with friction in accordance with the provisions already retained in chap 2.

[0096] The approach is identical to that described in § 3.3, [Fig.9] for a power of 1380 W.

[0097] The values ​​are as follows for a 10 kW cell, circular in shape, a shape which will be recommended in §3.8. Turbine air flow: 3.8 kg / s, (.53*10000 / 1380) Venturi module air flow: 72 kg / s Convergent air flow: 609 kg / s Dimensions: Venturi module inlet surface: 5 m2

[0098] Venturi module outlet surface: 9 m2

[0099] surface area of ​​the total venturi module + convergent space: 47 m2, of which 20% for the venturi module and 80% for the interventuri space

[0100] . venturi module length (= interventuri): 7.4 m

[0101] . ratio between surf presented to the wind and rotating turbine surf: 245

[0102] Finally, let us recall that the interventuri space is empty and therefore limited by the faces of the venturi modules and therefore only requires an enlargement of the structure.

[0103] It is understood that the space delimited by the broken lines [Fig. 12] is occupied by the venturi modules themselves and the interventuri space which surrounds them. This space is materialized by a cell structure, in which the venturi modules are housed. 20kW cell and 25 m / s wind

[0104] This cell is part of a wind capture surface composed of 50 cells (venturi and divergent module) arranged in parallel in a honeycomb. The power is then 1 MW.

[0105] In the following, the developments are considered with friction in accordance with the provisions already retained in chap 2

[0106] The approach is identical to that described in § 3.5, [Fig. 11] for a power of 5089 W.

[0107] The values ​​are as follows for a 20 kW cell, circular in shape, a shape which will be recommended in §3.8. Turbine air flow: 1.76 kg / s Venturi module air flow: 39.3 kg / s Convergent air flow: 409 kg / s Dimensions: Venturi module inlet surface: 1.3 m2

[0108] Venturi module outlet surface: 2.32 m2

[0109] surface area of ​​the total venturi module + convergent space: 15 m2, of which 16% for the venturi module and 84% for the interventuri space

[0110] Venturi module length (= interventuri): 3.52 m

[0111] ratio between surf presented to the wind and turbine rotating surf: 158

[0112] Finally, let us recall that the interventuri space is empty and therefore limited by the faces of the venturi modules and therefore only requires an enlargement of the structure.

[0113] It is understood that the space delimited by the broken lines [Fig. 12] is occupied by the venturi modules themselves and by the interventuri space which surrounds it. This space is materialized by a cell structure, in which the venturi modules are housed.

[0114] The length of the venturi modules will take into account questions of stability of the structure.

[0115] Finally, the construction, transport and assembly of these “small” elements should not require new technology, unlike the gigantism of current wind turbines.

[0116] 3.7. Wind speed different from the wind speed that defined the system

[0117] Wind speed: 18 m / s from the definition for a wind of 12 m / s.

[0118] The system, venturi and interventuri space, being defined for a wind of 12 m / s, what happens when the wind speed increases to 18 m / s?

[0119] All the dimensions defined for a wind of 12 m / s are maintained in the presence of a wind of 18 m / s and the same is true for the various ratios, such as the size of the turbine in relation to the total surface area presented to the wind.

[0120] We remember: - Mixer inlet pressure goes from .976 bar abs to .924 bar abs - Venturi module outlet pressure goes from .997 bar abs to .993 - Venturi module output speed increases from 75 m / s to 115 m / s

[0121] - Turbine output and mixer input speed goes from 7 m / s to 25 m / s - Venturi module inlet air flow rate increases from 10 kg / s to 15 kg / s - Power delivered increases from 1380 W to 4995 W

[0122] The sections remain the same as at 12m / s.

[0123] The power in relation to the occupation in the structure is 4995 / 6.5 or 768 w / m2, a value found on curve 4 of [Fig.6]. We note that this curve does not take into account the pressure losses, whereas the value of 768 W / m2 has included them.

[0124] The conclusions of § 3.3 apply in full here.

[0125] One remark is necessary, however. It concerns a certain uncertainty regarding the recompression of the air outside the structure. It is, however, similar to the recompression of the air at the outlet of a conventional wind turbine. In any case, a firm answer could only be provided by tests on a prototype §3.11.

[0126] However, whatever the results on the prototype, an adaptation would be the following. It consists of interrupting the air supply from the turbine to a certain number of mixers, according to the needs. The modules concerned would have an operating mode identical to that of the interventuri spaces and would increase the overall driving power of this "interventuri" space.

[0127] The means of obtaining these results are presented in § 3.10, relating to Erasure and Emergency Stop.

[0128] 3.8. Shapes and arrangement of cells.

[0129] In the above we have adopted square sections.

[0130] For other forms, the relationships remain strictly the same, only the pressure loss factors will be different.

[0131] The arrangement of the cells in the structure is examined. Thus [Fig. 12], the staggered arrangement will be preferred to the symmetrical shape, the air circulation being more homogeneous in the first case. In addition to this staggered arrangement, a circular shape will be preferred, combining several advantages including:

[0132] - less pressure loss resulting from the absence of blind spots or other discontinuities, - better resistance to pressure differences between the various parts of the sensor with respect to the outer casing.

[0133] Finally, we retain an arrangement of the zones in concentric rings already described in our first patent application and recalled here [Fig. 13]. The modules are of annular shape, the “venturi module” and “interventuri” zones being arranged in successive concentric rings. As before, the air leaving the venturi module is entrained by the air from the interventuri space, sized to entrain all the flows at atmospheric pressure.

[0134] This arrangement would allow the entire structure to be mounted on a pylon. There would only be one anchor, in the event of installation, particularly on dry land. It would not require any rolling path imposed by the structure when it rotates according to the direction of the wind.

[0135] The turbine would be located in the center of the structure and connected to the rings by star connections forming a homogeneous assembly.

[0136] Let us recall that the problem of orientation no longer arises, or arises less, in the case of installation on a barge at sea (first patent application).

[0137] 3.9. From turbine to mixer

[0138] Consider the connection of the turbine to the mixer.

[0139] It is already known that a higher speed of the air coming from the turbine and entering the mixer improves the efficiency of the system expressed in W / m2. A higher speed would however increase the pressure losses in this connection. In order to avoid this, this connection could then be equipped with a divergent at the turbine discharge and a convergent at the mixer inlet or, as will be seen in §3.10, at the numerous inlets in the mixer. This would considerably reduce the losses in the connections.

[0140] 3.10. Partial Load, Deletion and Emergency Stop

[0141] Let us return to the aforementioned orifices at the mixer inlet. (§3.9 above).

[0142] The air discharged by the turbine arrives in the space between the body of the venturi module and its truncated outer casing. It is introduced into the mixer through a series of converging orifices, in order to increase the speed and therefore the efficiency of the mixing. Valves upstream of these allow them to be isolated and thus allow the air coming from the turbine to enter or not enter the mixer.

[0143] We thus achieve:

[0144] - partial closing of the orifices in order to reduce the load or even to answer

[0145] to specific needs (maintenance, disruptions, etc.)

[0146] - the complete closure of all the orifices allowing the Erasure to be carried out or Emergency Stop, if the wind regime, speed or disturbance required the turbine to be stopped.

[0147] Closing the isolation valves would prevent any air flow to the mixer and would quickly stop the turbine. The turbine would rotate in a "vacuum" and would stop quickly, especially since it has low inertia, at least compared to a wind turbine.

[0148] The orifices would, depending on the circumstances, be isolated by the valves located in the aforementioned chamber, acting individually or more generally in groups.

[0149] The action required in an emergency would be rapid, of short duration, out of all proportion to the time constant of wind turbines.

[0150] Finally, let us recall the possible need to reduce the turbine load in the event that the wind speed is different from that used for the definition. §3.7.

[0151] Last remark. It is possible that in the presence of too strong a wind, it is absolutely necessary to reduce its speed. However, it is understood that the reduction of this speed only concerns the turbine whose flow rate is extremely low compared to the wind inlet flow rate in the venturi module and even more so compared to the flow rate in the converging space. These two circuits therefore retain all their efficiency. The turbine thus remains the only one involved. It would therefore be sufficient to intervene only at this level by reducing the wind speed. Production would only be slightly affected.

[0152] Indeed, for a 50% reduction in wind speed, the engine work would only be reduced by 5% and therefore also the production. The measurement of this incidence appears clearly on the enthalpy diagram [Fig.2], where only the total energy decreases under the effect of the reduction in wind speed at the turbine inlet.

[0153] Let us add that this reduction in wind speed at the turbine inlet could be achieved by a divergent which would combine the following advantages:

[0154] - the reduction in wind speed would be, at least partially, compensated by a increase in pressure at the turbine inlet and therefore in engine work

[0155] - this divergent at the turbine inlet, sufficiently long and well adapted to the wind irregularities, could still be effective in all cases of operation of a site, even if only as a forecast, without losing significantly in power, especially since the work is carried out outside the area concerned by the stress thresholds affecting wind turbines.

[0156] 3.11. Reflections on a Prototype

[0157] In 1980, we built a simple prototype in order to verify the validity of the pressure loss factor that we had chosen.

[0158] For this purpose, the flow coming from the turbine was replaced by a flow obtained by expanding the air in a valve.

[0159] Several outdoor tests (in nature), at various speeds, confirmed our choice.

[0160] It is imperative, however, to verify these results by wind tunnel tests, given the importance of knowing the pressure losses for the validity of the study.

[0161] The interventuri spaces also significantly improve the power produced. The prototype will therefore have to include several modules, in order to verify the overall efficiency of these spaces.

[0162] A prototype comprising only one module would lead to having to surround it with a cylindrical envelope in order to reproduce the interventuri space. This would have the consequence of introducing pressure losses created by the flow of air along a wall, which in reality does not exist.

[0163] This creates the need to produce a prototype which would be subjected to an air flow produced in a wind tunnel.

[0164] The expansion valve replacing the turbine will allow all components of the static system to be tested.

[0165] The expansion "close" to the adiabatic evolution in the turbine would be replaced by an expansion close to the isenthalpic in the valve. Such an assembly would make it possible to approach all the parameters of the static system, in particular the pressure losses.

[0166] 4. Conclusion

[0167] Compared to the patent application of November 2021, we were able to measure the great interest in modeling the space between the venturi modules in the form of convergents, despite the drop in power which appeared following the taking into account of the pressure losses.

[0168] These convergents are formed only by the free space left between the venturi modules. They therefore do not require any additional equipment, but only an extension of the structure.

[0169] The need for testing on a more complete prototype than the one we have experimented with proves very desirable not only to estimate the pressure losses but also to measure the effectiveness of the interventuri spaces in entraining the total air at atmospheric pressure.

[0170] Finally, erasure was taken into account either to limit the power or to completely isolate the turbine in a very short time.

[0171] This patent application follows a previous application dated November 13, 2021 under reference FR2112019 and publication number FR3129183.

[0172] This first application concerns a static system for recovering wind energy produced by a set of modules grouped in parallel in a honeycomb.

[0173] Let us recall the text of November 2021 concluding the claims chapter:

[0174] “In summary, the combination of the first and second claims constitutes the essential element of the patent application. It claims a turbine with a very small footprint compared to the surface swept by a wind turbine. It claims a means of capturing static wind energy, i.e. not sensitive to all the mechanical constraints unacceptable by a conventional wind turbine,

[0175]

[0176] when the winds exceed the threshold speed or are accompanied by gusts or gusts. » [Fig.l]: Air expansion from press, atm to mixer inlet [Fig. 10]: Arrangement of the modules in concentric rings

Claims

Claims

1. We claim the addition of convergent spaces surrounding the venturi modules. These convergent spaces are formed by the free space between the venturi modules. These modules in large numbers constitute the structure of the capture system. The convergent spaces between the modules create a depression at their outlets. The depression thus created drives the air leaving the venturi modules and brings it to atmospheric pressure. The entrainment effect achieved by the convergent space very significantly increases the power per m2 of the system. Since these convergents are formed only by the arrangement of the venturi modules in the structure, this only requires a simple enlargement of the empty space in it. Furthermore, the reduction of the pressure in the mixer has the effect of reducing the size of the turbine, as developed in §3.

2.

2. We claim the installation of convergent orifices on the air circuit coming from the turbine and located at the inlet of the mixers. We know that the increase in the speed of the air coming from the turbine and entering the mixers has the effect of increasing the power per m2. However, this speed of the air in the numerous connections to the mixers causes significant pressure losses. To minimize these, divergents will reduce the speed of the discharge from the turbine to the mixers. The air arriving at the mixers will be expanded in the aforementioned convergent orifices and therefore accelerated to the required speed. §3.

2. Upstream of the injectors, the low-pressure air is introduced into the chamber of the venturi modules, more precisely between the venturi itself and the frustoconical enclosure which surrounds it.

3. This claim also relates to the aforementioned orifices. In the present case, these are mainly intended to achieve the isolation of one or more venturi modules and in case of necessity. The rapid and complete isolation of the turbine from the mixers thus achieves the Erasure or even the Emergency Stop of the turbine. The latter has a very low inertia by compared to a wind turbine, due to its size. Finally, the orifices are preceded by isolation valves with very low pressure losses. The injectors will still be useful when the wind speed is different from the speed for which the venturi module was designed.

4. We claim the installation of a divergent advance at the turbine intake. Some sites with violent, strong or irregular winds (gusts) could require the installation of a advance at the turbine intake, in order to regulate the air flow. The resulting reduction in air speed would not have a significant effect on energy production. §3.

10. This divergent advance would also remain relevant in all cases of operation of a site, if only as a preventive measure in the presence of strong or irregular winds (gusts). The presence of this divergent advance also leads to an increase in the pressure at the turbine inlet and therefore in the engine work. Depending on the site characteristics, the advance could be convergent, in order to align the turbine inlet speed with the higher discharge speed, and thus minimize the size of the turbine.

5. This claim concerns the mounting of the modules in concentric Rings or Crowns developed around an axis. This is also the axis of the turbine §3.

8. These crowns have connections between them and to the turbine developing in stars. These connections are short and well distributed around the turbine. They allow attachment to a pylon. The entire system, structure and turbine, are oriented around the pylon, like a conventional wind turbine. Compared to this, the difference lies in the very small size of the turbine, which is also shrouded. Note also that installation on a pylon allows orientation around it according to the direction of the winds. The structure therefore does not require any rolling path.

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