WO2015122756A1

WO2015122756A1 - Combined air extractor, that uses solar and wind energy, for passively ventilating industrial warehouses, dwellings and/or buildings (solar-wind chimney)

Info

Publication number: WO2015122756A1
Application number: PCT/MX2014/000046
Authority: WO
Inventors: Jesús ARCE LANDA; María José JIMÉNEZ TABOADA; Leonel LIRA COTÉS; Juan de Dios GUZMÁN DOMINGUEZ; Jesús Perfecto XAMÁN VILLASEÑOR; Sergio CASTAÑO CASTAÑO; Ángel TLATELPA BECERRO; Ibán NAVEROS MESA; Gabriela del Socorro ÁLVAREZ GARCÍA; María del Rosario HERAS CELEMÍN
Original assignee: Dirección General De Educación Superior Tecnológica De La Sep; Dirección General De Educación Superior Tecnológica De La Secretaría De Educación Pública; Centro De Investigaciones Energéticas, Medioambientales Y Tecnológicas
Priority date: 2014-02-13
Filing date: 2014-02-13
Publication date: 2015-08-20
Also published as: MX2016009619A

Abstract

The invention relates to a method for the passive ventilation and/or heating of dwellings, industrial warehouses and/or buildings, using a solar air heater or collector. The invention also relates to a natural method of ventilating dwellings, industrial warehouses and/or buildings, using two passive systems, a solar heater and a dynamic-type atmospheric air extractor, coupled in series. In the new combined system, air is extracted by means of a maximised double effect: the solar-thermal effect and the dynamic-wind effect. The solar heater is coupled to the atmospheric extractor by means of a trapezoidal nozzle-type constriction having a characteristic shape and dimensions. The entire system should be installed in such a way that it facilitates the collection of solar energy incident on its absorption plate, to permit improved heating and exploitation thereof. At the same time, the system should also be installed at a sufficient height to make use of the effect of the wind, and to make the dynamic air extractor rotate in an adequate manner. By coupling both devices (the solar heater and the dynamic-type atmospheric extractor) via a nozzle-type constriction having characteristic dimensions, an improved effect is achieved, the extraction of air in enclosed spaces and/or buildings being maximised by up to four times more than both systems could achieve separately, as was conventionally done. This new combined air extraction system is called a solar-wind chimney.

Description

MIXED AIR EXTRACTOR, USING SOLAR AND WIND ENERGY, TO PASSIVENTLY VENTILATE INDUSTRIAL, HOUSING, AND / OR BUILDINGS (SOLAR-WIND CHIMNEY)

BACKGROUND Currently, natural ventilation is considered one of the main requirements in the design of homes and / or buildings, mainly in those buildings oriented to low energy consumption. Natural ventilation is a concept of air conditioning systems, which due to its characteristics has been called a passive system, and is considered essential for comfort inside rooms and for human well-being.

Passive air conditioning systems, unlike conventional air conditioning systems (air conditioning systems and electric heaters, etc.), are characterized by their easy manufacture and very little maintenance required, in addition to their zero dependence on conventional energy , such as those of fossil origin. The use of these systems contributes decisively to the reduction of greenhouse gas emissions, the saving and efficient use of non-renewable resources. The issue of proposing new alternatives and improving existing ones to achieve comfort within the premises, and simultaneously reducing the consumption of conventional energy, is one of the current challenges of our modern society. The use of renewable energies, such as solar energy, wind energy and others, for use in passive ventilation systems in enclosures such as residential and non-residential buildings, industrial buildings, warehouses, Classrooms, etc., are clear examples of this.

In the literature you can find different theoretical concepts of types of ventilation applied to a house or building, (Hazim B. Awbi, 2003, "Ventilation of Buildings" Renewable and Sustainable Energy "Second Edition, Spon Press), these can be:

Simple ventilation: When the air flow enters through one or more openings on one side of the room, for example, through a window.

Cross ventilation: It is a concept used in Bioclimatic Architecture, to define a mode of ventilation of buildings. When air enters one side of a room through one or more openings and exits on the opposite side through one or more openings. Induced draft ventilation: In this case the buoyant force, due to thermal gradients is the main driving force, where the height of the shot is considered fundamental. When using the concept of solar induced ventilation, some types of passive ventilation devices can be mentioned, which are governed by the same physical principles, among them ^ Wind Towers, the Wall or Trombe Wall, the Ventilated Facade, the Solar roof with ventilation and the Solar Fireplace, among others.

Wind Towers are appropriate in places where buildings are low-rise and where there is adequate wind speed, a wind tower collector is an architectural device of Persian tradition used for many centuries to provide natural ventilation and cooling inside of the buildings. The Trombe Walls, although they can be used to ventilate a room, their main function is to produce passive heating. The Trombe Wall or Trombe-Michel Wall sensor is a sun-oriented wall or wall, preferably to the North in the southern hemisphere and to the South in the northern hemisphere, it is commonly constructed with materials that can store heat under the effect of thermal mass ( such as stone, concrete, adobe or water), combined with an air space, a glass cover and vented holes forming a thermal solar collector. In this way, the air inside the channel is heated and rises due to the buoyant forces, which generates natural ventilation by induced draft. This same process can be used for passive heating inside the enclosure, or to generate a natural ventilation of it, if it is expelled outside the enclosure. The Ventilated Facades, in addition to generating ventilation in a building, can be used to control, in some way and in some proportion, the light intensity and the noise level from the outside to the inside in a building. The Solar Roofs with ventilation can be used in certain latitudes to passively ventilate an enclosure and at the same time they are part of the structure of the same enclosure or building.A solar collector of the type Solar Roof with ventilation allows that in certain latitudes it is possible to use the roof surface to capture a certain amount of solar energy and at the same time can be used to ventilate a building and / or housing.

The Solar Fireplace is very similar to the Trombe Wall collector, with the difference that the upper opening is used to expel hot air from the channel to the outside and in this way there is ventilation of the enclosure to which it is attached. Generally, the solar chimney is integrated into the building with an orientation in such a way that it takes full advantage of the incident solar energy, in order to heat the absorber plate and therefore the air inside the canal.

A Solar Fireplace can be defined as an elongated ventilated cavity, usually located in the sunniest part of a house and / or building. Its main function is to remove the volume of air in an enclosure, with the simple purpose of ventilating the home to improve air quality, or, with the additional purpose of generating thermal comfort conditions if the air entering the Room is pre-conditioned, either passively or actively. Under normal operating conditions, a Solar Chimney receives radiant energy from the Sun, which affects the absorption plate through a glass cover. A simple classification of these systems by their application is: Solar chimneys of daytime use (with metal absorber plate), and chimneys of night use (with absorber plate of great thermal storage capacity).

Natural ventilation using Solar Fireplaces is not a recent technique. There are references to the use of these devices in historical buildings of the 16th century (Spencer S., "An experimental investigation of a solar chimney natural ventilation system" A Thesis in the Department of Building, Civil and Environmental Engineering, Concordia University, Montreal, Quebec, Canada, 2001).

Other studies, particularly on induced draft and the capacity of conventional chimneys, are published by Mingle J., 1925 ("Draft and capacity of chimneys" Combustion Publishing Corporation, New York, Eleven Broadway, 1925).

Currently, building ventilation has become an important factor that must be taken into account when designing any building or home, and Solar Fireplaces are now an alternative for this. In the literature you can find several studies on these systems, these studies can be divided into three large groups: a) Theoretical studies.

b) Experimental studies.

c) Theoretical-experimental studies.

The references of each group are presented below: a) Theoretical studies

A theoretical description of the thermal operation of a solar chimney can be found in the following bibliographical references:

Barrra O. and Carratelli E., "Theoretical study of laminar free convection in 1-D solar induced flows", Solar Energy. Vol. 23. Pages. 211-215, 1979.

Awbi H.B., "Design considerations for naturally ventilated building". Renewable Energy Vol., 5. Pages. 1081-1090, 1994.

Aboulnaga M. "Aroof solar chimney assisted by cooling cavity for natural ventilation in buildings in hot arid climates: an energy conservation approach in al-ain city", Renewable Energy, Vol., 14-1-4. P. 357-363, 1998.

Hamdy I., Fikry M., "Passive solar ventilation", Renewable Energy, Vol. 14, p. 381-386, 1998.

Aboulnaga M. and Abdrabboh "Improving nigh ventilation into low-rise buildings in hot-arid climates exploring a combined wall-roof solar chimney", Renewable Energy, Vol., 19. Pg. 47-54, 2000. Dai Y., Sumathy K., Wang R, Li Y., "Enhancement of natural ventilation in a solar house with a solar chimeney and a solid adsorption cooling cavity", Solar Energy, Vol., 74. 65-75, 2003. Ong K., "A mathematical model of a solar chimney", Renewable Energy, Vol., 28, p. 1047-1060, 2003.

Martí H., J. and M.R., Heras C. "Dynamic physical model for a solar chimney", Solar Energy, Vol., 81. Pages. 614-622, 2006.

Nouanégué H.F., Alandji L.R., and Bilgen E. "Numerical study of solar-wind tower systems for ventilation of dwellings", Renewable Energy, Vol., 33. 434-443, 2007.

Harris D.J., Helwig N., "Solar chimney and Building ventilation", Applied Energy, Vol., 84, p. 135-146, 2007.

J. Arce, J. Xamán, G. Álvarez, M.J. Jiménez, M.R. Heras, J.D. Guzman "Theoretical study on a diurnal solar chimney with double air flow", "EUROSUN 2008. lst international Congress on Heating, Cooling and Buildings". Lisbon (Portugal) 2008.

M. J. Jiménez, J. Arce, J. D. Guzman, M. R. Heras; "Estimation of the main thermal parameters of a real size solar chimney from outdoor dynamic tests", presented in "Passive 2nd PALENC Conference and 28th AIVC Conference on Building Low Energy Cooling and Advanced Ventilation Technologies in the 2 lst century", Crete (Greece) , September 2007.

J. Arce, J. Xamán, G. Álvarez, M.J. Jiménez, R. Enriquez, M.R. Heras "A simulation of the thermal performance of a small solar chimney already installed in a building". Journal of Solar Energy Engineering, Transactions of the ASME. Vol., 135. Pages 11005-111005-10, 2013. b) Experimental studies

Among the experimental studies on these passive ventilation systems, those made by:

Akbarzadeh A., Charters W., Lesslie D., "Thermocirculation characteristics of a trombe wall passive test cell", Solar Energy. Vol. 28, p. 461-468, 1982.

Khedari J., Boonsri B., Hirunlabh J., "Ventilation impact of a solar chimney on indoor temperature fiuctuation and air change in a school building", Energy and Building, Vol. 32, p. 89-93, 2000. Ong K., and Chow C, "Performance of a solar chimeney", Solar Energy, Vol. 74, p. 1- 17, 2003.

Khedari J., Rachapradit N., Hirunlabh J., "Field study of performance of solar chimney with air-conditioned building", Energy, Vol., 28. Pages 1099-1114, 2003. Chen Z., Bandopadhayay P., Halldorsson J., Byrjalsen C, Heiselberb P., Li Y., "An experimental investigation of a solar chimney model with uniform wall heat flux", Building and Environment, Vol. 38, p. 893-906, 2003. Chakraborty J., Fonseca E., "Analysis and evaluation of a passive evaporative cool tower in conjuntion with a solar chimney". Plea'2005-The 22 ^nd Conference on Passive and Low Energy Architecture. Beirut, Lebanon, 13-16 November 2005. College of Architecture and Environmental Design, Arizona State University, Tempe Arizona, USA.

Emad H., "Passive options for solar cooling of buildings in arid areas", Energy, Vol. 31, p. 1332-1344, 2006.

Chungloo S., Limmeechokchai B., "Application of passive cooling systems in the hot and humid climate: The case study of solar chimney and wetted roof in Thailand", Building and Environment, Vol., 42. 3341-3351, 2007.

Burek, S.A.M., Habeb, A., "Air flow and thermal efficiency characteristics in solar chimneys and Trombe Wall", Energy and Building, Vol. 39, p. 128-135, 2007.

J. Arce, M.J. Jiménez, J.D. Guzmán, M.R. Heras, G. Álvarez, J. Xamán. "Experimental study for natural ventilation on a solar Chimney". Renewable Energy 2009. Vol., 34. P. 2928-2934, 2009. c) Theoretical-experimental studies

As theoretical-experimental studies on these same systems we can mention those carried out by: Bouchair Ammar, "Solar induced ventilation in the Algerian and similar climates", PhD thesis. Department of Civil Engineering, The University of Leeds, October 1989.

Afonso C. and Oliveira A., "Solar chimneys: simulation and experiment", Energy and Building, Vol., 32. 71-79, 2000.

Raman P., Mande S., Kishore V., "A passive solar system for thermal comfort conditioning of buildings in composite climates", Solar Energy, Vol., 70. 319-329, 2001.

Condori M., Mealla L. Saravia L., "Study and modeling of a new design of solar chimney", Advances in Renewable Energy and Environment, Vol., 5.Pages. 02.19-02.24, 2001. Adam, Z., Yamanaka, T., Kotani, H., "Mathematical model and experimental study of airfiow in solar chimneys", Proceedings of 8 ^th International Conference ^" on Air Distribution in Rooms (ROOMVENT 2002) pp. 621-624, 2002. Martí H., Jaime "Analysis of the solar chimney of LECE for its energy characterization as a natural ventilation system in the building", Solar Energy Project in the Building. Department of Renewable Energies. Ciemat Avd. Complutense 22, Madrid 28040. September 2003.

Bansal N., Mathur J., Mathur S., and Jain M., "Modeling of window-sized solar chimneys for ventilation", Building and Environment, Vol., 40. 1302-1308, 2005. Chantawong P., Hirunlabh J., Zeghmati B., Khedari J., Teekasap S., Win M., "Investigation on thermal performance of glazed solar chimney walls", Solar Energy. Vol., 80. Pages. 288-297, 2006.

Bacharoudis E., Vrachopoulos M., Koukou M., Margaris D., Filios A., and Mavrommatis S., "Study of the natural convection phenomena inside a wall solar chimney with one wall adiabatic and one wall under a heat flux", Applied Thermal Engineering. Vol., 27. Pages. 2266-2275, 2007.

Within the study of the technique some of these passive ventilation devices are also referenced, of which some inventions are registered and others are in the process of registering Industrial Property. Some of them are referred to in the following Table.

The vast majority of these inventions contemplate electric power generation systems where a solar chimney is attached. Some designs consider that the energy generated is used for the use of pumps in greenhouses, for irrigation of crops in arid and desert regions. In other inventions, wind towers, a chimney and the generation system are considered, where industrial waste heat and solar energy are used and other inventions take into account the generation of energy with night storage of thermal energy.

Table. Patent Documents Recovered from different databases.

Database and No. Application or Patent Title Inventor (s) Office Date application and / or grant

European Office of JO1800 (B) -1994-12- Solar Powered Brosow Jorgen 1994-12-25 Patents (EPO / 25 Installation

EPO) Database

spácenet

CN 102852744 (A) Method for combining Wang Zilong; Zhang

agricultural production Hua; Hu Liye

with solar chimney

power generation

system.

Cn202690324 (U) Air flue device for Zhou Xinping; Qian 2013-01-23 chimney ventilation Peng; Liu Chi; Qian

device Chaoqun

CN202628197 (U) Solar power-generated Zhang Xingcai, and 2012-12-26 turbine Zhang Jinzhu

WO2012127134 (A2) Hibrid Solar-Wind UngSeng-Hong 2012-09-27

Power station

According to the review of all these patent documents in process of registration or with publication dates, none contemplate a similar design as the one presented and claimed in the present application. On the other hand, and within another classification of the same passive ventilation systems, there are the so-called dynamic extractors of the commercial type, which are devices that are also used to ventilate a building or house. Among these devices, the best known are atmospheric or wind extractors, whose operation is explained below.

Operation of atmospheric or wind extractors. Atmospheric or wind extractors are natural ventilation systems of the mechanical type, which work mainly with wind energy, however, for their operation, they also take advantage of a small differential of air temperatures, between the exterior and interior of the building.

By placing a certain number of wind extractors on the roof of a building, a continuous process of air extraction is generated. Under certain conditions, the hottest air, which normally accumulates in the highest part of the interior of the building, is sucked by the blades of the extractor, and in turn is driven and displaced towards the outside by the forces of wind, mainly. Then, the vacuum that leaves is naturally compensated by the entry of outside air into the bottom of the building that infiltrates through windows, doors, gates, vents, etc. This permanent process of air extraction, allows to improve the habitability conditions of the building, eliminates to a certain extent not only excessive heat, but also humidity, odors, vapors, fumes and other harmful elements that may be contained in the interior environment of the building. The speed of this extraction process is given by the flow of stale air that is displaced from the building and replaced by fresh air in a certain period of time, under certain temperature conditions, mainly. This gives rise to the term "number of hourly renovations", which is nothing more than the number of times that the volume of air contained inside the building can be replaced per unit of time (usually units per hour). Then, the amount of hourly renovations necessary for a certain size of building, mark an index of hydrodynamic comfort in the habitability of the same and in turn depend on the intended use. Of course, this desired number of hourly renovations will depend on the quantity, capacity and size of the wind extractors, as well as the wind speed and direction. All of the above under the supposed case that the building has sufficient air infiltrations, since the amount of exhaust air must be compensated in the same way for air entering the same building, in turn will also depend on the amount of extractors that are strategically placed in the highest possible part of the building. In summary of all the above, it can be said that different types of solar collectors or heaters are referenced in the literature, examples of which are: Wind Towers, Trombe Walls, Solar Roofs with ventilation, Ventilated Facades and Solar Chimneys, among others. On the other hand, commercially there is an infinity of models of dynamic atmospheric extractors, which serve to ventilate enclosed spaces such as: residential buildings, industrial buildings, warehouses, party halls, etc. However, no system has been found that integrates the coupling of a solar collector or heater with a dynamic extractor for the ventilation of residential buildings, industrial buildings, warehouses, party halls, etc.

With the use of solar collectors or heaters it has been possible to exchange the air volume of an enclosure or building a number of times per unit of time. In parallel, with the use of dynamic extractors, it is also possible to exchange the air volume another number of times per unit of time. However, sometimes the size of the building is such that it is necessary to increase the number of equipment, either solar collectors or heaters, or atmospheric extractors, in order to renew the total air volume of said building . Therefore, and under these conditions, it is necessary to propose new strategies that make use of a minimum of atmospheric collectors or extractors, and in this way the total investment cost is reduced. This new strategy is explained below, which is the justification for this document.

It is proposed to use a strategy of mixed extraction of natural ventilation, which consists of using in a coupled way a dual-channel solar air heater and an atmospheric type air extractor. This new system is called Solar-Wind Chimney, and may be able to induce air through the enclosure using two energy sources, whose purpose is to generate environmental comfort inside homes, industrial buildings and / or buildings , thanks to taking advantage of two types of effects (solar and wind), this being the invention that is claimed. TECHNICAL FIELD OF THE INVENTION

The use of passive systems to ventilate homes, industrial buildings and / or buildings, for energy saving purposes and to improve the thermal and hydrodynamic conditions inside them is a new challenge. It is a strategy to be used in natural ventilation processes for poorly ventilated spaces through the coupled use of three main elements, in series connection arrangement; a solar collector or heater, an atmospheric exhaust fan and a nozzle reduction. It can be used to generate environmental comfort inside homes, industrial buildings and / or buildings, with the use of both solar energy and wind energy.

With the proper use of these passive ventilation systems, greater thermal and hydrodynamic comfort can be achieved, as well as an improvement in the quality of the air inside enclosures, homes, storage rooms. At the same time, it is also possible to obtain more comfortable working conditions.

The only atmospheric air extractor is of the commercial type, and can be obtained commercially in the market, in Figures 1-6 six different ones are shown configurations However, the acquisition of solar air heaters or heaters is not fully commercialized, and therefore, they are not entirely accessible. So far these solar air heaters are of the artisan type, in Figures 7-9 three different configurations are shown that have been called, by the function they play, Solar Fireplaces. The technical information that exists on these artisanal solar collectors or heaters is not completely standardized, and therefore their commercial acquisition is not so accessible, it is expected that, at some point they will begin to gradually enter the market. In general any type of solar collector or heater that has the appropriate form to be able to attach an atmospheric extractor of the commercial type, through a nozzle reduction, or, by manufacturing an adapter that meets the minimum coupling specifications of the commercial atmospheric extractor, will serve to generate the new mixed ventilation extractor or solar-wind chimney.

The new Solar-Wind Chimney for air extraction to passively ventilate industrial buildings, homes, and / or buildings, consists of the coupling of a solar collector or heater and a conventional atmospheric extractor of dynamic type, through a nozzle type reduction with characteristic dimensions, resulting in a mixed extraction system that presents considerable improvements and advantages over those of the traditional ventilation systems that they can provide separately. BRIEF DESCRIPTION OF THE INVENTION

The present invention relates to the coupling of a passive natural ventilation system of the Solar Chimney type with an Atmospheric Air Extractor of the dynamic type. Said coupling is made through a nozzle reduction with trapezoidal geometry and characteristic dimensions. It is a coupling in a series type arrangement between two natural ventilation systems and a nozzle type reduction as a coupling element. With this, it is possible to take advantage of the thermal effect of the natural draft of the solar collector or heater added to the induced draft effect generated by the wind with the dynamic type atmospheric extractor. The result is a flow rate of up to four times higher compared to the air flow rate that each separate system could provide, under similar operating conditions, as has traditionally been done. Additionally and once both systems are coupled, it is recommended that the system as a whole be given an installation orientation such that the incident solar radiation on its absorber surface is maximized, as well as the wind speed and direction.

BRIEF DESCRIPTION OF FIGURES. In Figures 1-6, six different configurations of commonly known atmospheric extractors are shown, any of them can be used to couple it to a passive solar chimney ventilation system, the capacities and dimensions will depend on the size of the enclosure to be ventilated.

Figures 7-9 show three different configurations of solar chimneys, referenced in the literature, where L, and d are the height and thickness of the channel respectively, and At the entrance height.

Figure 10 shows the simplified configuration of the dual channel solar chimney, which is the object of the present invention. The different heat transfer processes involved in the system are also shown.

In a small part of the glass cover (4 '), to the left of Figure 10, of the present application, an amplified segment of one of the glass covers is indicated where the reflected energy, the absorbed energy and The transmitted energy.

Figure 1 1 shows a front view and a side view of the system as a whole that includes the solar chimney collector or heater and the reduction of the coupling nozzle type (3). At the top of the same Figure 11 the Atmospheric Extractor (2) is shown and it is indicated where it is coupled with the nozzle type reduction of the solar chimney type or dual-channel solar chimney heater.

Figure 12 shows the air velocity profiles in a section of the sensor and in the nozzle reduction, as a result of a numerical simulation using a commercial computing package (Algor). The velocity vectors are not as uniform due to the dimensions of the nozzle reduction.

Figure 13 shows the air velocity profiles in a section of the collector or heater and in the nozzle reduction, as a result of a second numerical simulation using a commercial computing package (Algor). The velocity vectors are also not seen as uniform because the dimensions of the nozzle reduction are also not appropriate.

Figure 14 shows the air velocity profiles in a section of the sensor and in the nozzle reduction, as a result of a numerical simulation using a commercial computing package (Algor). The velocity vectors, in this case, look very uniform because the dimensions of the nozzle reduction, in this case, are appropriate.

Figure 15 shows the regions of the air velocity limit layers that could be generated at some point between the vertical surfaces of the absorber plate and the internal vertical surfaces of the glass covers, or glazed surfaces. For simplicity, and for symmetry they are only shown for one of the two channels. DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to the coupling of an atmospheric exhaust fan of the dynamic type, with a solar chimney collector or solar heater. The atmospheric extractor can be of the commercial type like those shown in Figures 1-6, while the solar collector or heater is the one shown in Figure 13-14. However, they may also be used of the type referenced in the literature such as those shown in Figures 7-9. Both systems are connected through a nozzle type reduction (3) with characteristic dimensions.

The purpose of this invention is to generate a mixed passive air extraction system, with better characteristics and better performance than each separate system could have. The main intention of producing natural ventilation required in homes, industrial buildings and / or buildings (according to ASHRAE STANDAR-62-1999, "Ventilation for Acceptable Air Quality", American Society of Heating, Refrigeration and Air - Conditioning Engineers, Atlanta, GA) espara improve the quality of the air inside the enclosures and achieve passive cooling.

In Figural 1 the new MIXED AIR EXTRACTOR, USING SOLAR AND WIND ENERGY, TO PASSIVENTLY VENTILATE INDUSTRIAL, HOUSING, AND / OR BUILDINGS (SOLAR-WIND FIREPLACE), which will be described in detail, and which is the object of the present invention. The main parts of the system, the operation that each system can have separately, and the operation as a whole of it are described below.

Main parts and dynamic operation of atmospheric or wind extractors. The main parts of the atmospheric or wind extractors are their blades joined in a body that rotates freely on an axis and its coupling ring with the enclosure to be ventilated, in this case the atmospheric extractor has been coupled to the dual-channel solar chimney of air as shown in Figure 11. Atmospheric extractors are natural ventilation systems of the mechanical type, which work mainly with the impulse of the wind. Due to its aerodynamic design, the wind produces shear forces on its blades, which generates a torsional torque that rotates the body of the extractor, always in the same direction by the design of its blades, whose intensity depends on the magnitude of the forces of the wind and of course the geometry and dimensions of the blades of the extractor itself. As a consequence of the angular movement, a suction force is generated inside the extractor, which allows the extraction of air under the roof or roof of a building to which it is installed, giving rise to the replacement of air in the enclosure. This process is known as passive ventilation in buildings.

Although the main driving force in an atmospheric extractor comes from wind energy, there is also a natural thermal exploitation due to a small differential of air temperatures between the exterior and interior of the building to which it is coupled. Main parts and thermal operation of solar air heaters or heaters. Solar air collectors or heaters are natural ventilation systems of the thermal type, and they can also be used to passively heat a building, they work with the use of solar energy, mainly, and are characterized by zero dependence on energy use Conventional as those from fossil origin. The low need for maintenance makes its installation very attractive.

A simplified side view of the dual-channel solar chimney, which is the subject of the present invention, is shown in Figure 10. Its main parts shown are:

(l) - Absorber plate. It constitutes the main part of the solar chimney, since it is this one in charge of absorbing the incident solar radiation, and of transferring said energy to the working fluid, which in this case is air. For those solar chimneys for daytime use, that is, those that work preferably during the day, metallic material is usually used in the manufacture or selection of the absorber plates, additionally they are painted dark color, in order to increase their coefficient absorption. However, in those cases where night ventilation is sought, for the purpose of passively cooling a building, or for other reasons, such as improving the air quality inside said building, it is convenient to use building materials. high heat capacity in the construction of said absorber plates for solar chimneys, such as concrete. In the latter case, opening and closing flaps (19) are added to the entrance and exit of the air channels, in order to store the heat absorbed by the plate during the day, and to release it during the night when opening the air flaps, and allow the air flow to exit the system. The building is passively cooled by the air changes that are generated by extracting air with higher temperature from the top where the solar chimney is installed, and allowing air at a lower temperature from outside to occupy the empty space that is generated. If longer cooling times are required, there are two options, either solar chimneys are manufactured with larger absorber plates, or absorbent plates that can store heat are manufactured, as does a high heat capacity material that include phase changes at medium temperature, such as the use of paraffin. In this case, it is also necessary to use the hatches to retain heat during the day and release it during the night.

(4) - Glass roofs or transparent glazed surfaces. They serve to form the air channels, they are separated from the absorber plate (1) a distance (d). Its main function is to let the short-wave solar radiation pass through, and trap the long-wave radiation, thus causing the so-called greenhouse effect inside the system. (9) -Air inputs. Generally the air inlets are located in the lower part of the solar collector or heater and are connected to the enclosure by ventilating. (10 ') - Air outlets. Generally the outlets are located in the upper part of the collector or heater, and it is where the air is expelled to the outside.

(18) -Air channels. They are formed with the separation of the glass covers and the absorber plate. It is the path that travels the air flow in the extraction process.

(19) -Open and close hatches. They serve to allow or to obstruct the flow of air that enters and passes through the air channels of the solar chimney. In this way, if they are kept closed during the day, a large part of thermal energy can be stored on the absorber plate and if they are opened during the night, that heat absorbed during the day can be released. The hatches are used in nighttime fireplaces when the absorber plate is of high heat capacity and passive cooling is required, mainly. Its manufacture can be of metallic material or of some material transparent to solar radiation, preferably.

The different heat transfer processes involved in the system are described below.

In a very general way possible, the same Figure 10 shows the different processes of energy gain and transfer that participate in a section of the solar chimney, and which are described below:

Solar Radiation "G" (14). It is energy from the sun and arrives on the entire vertical glazed surface. In Figure 4 ', a fraction of the clear glass roofs or transparent glazed surfaces is shown, has a thickness of 4 mm, it is estimated that 8% of this energy is reflected "pG" (15), 14% is absorbed "a G" (16), and 78% is transmitted "TG" (17).

The aforementioned percentages have to do on the one hand, with the composition and geometry of the material, and on the other with the very nature of solar radiation. The glass (4) behaves as a transparent material in a certain short wavelength range, and as an opaque material for another long wavelength range. It is considered that, due to its finish characteristics of the absorber plate (matte black paint), little more than 90% of the solar radiation transmitted through the glass cover is absorbed. The amount of solar energy absorbed in the absorber surface (1) is converted into thermal energy, whereby its internal energy is increased in said plate, and consequently its temperature. Much of this energy is transmitted by conduction to the other side of the same plate, giving rise to a similar range of temperatures throughout its surface. Towards the air channels, from both surfaces of the plate, heat is transferred by conduction, to the adjacent air molecules, and then heat is transferred by convection (12), within the speed limit layer that develops on both surfaces of the absorber plate (see Figure 15). As a result of these velocity profiles, an upward flow of air occurs in both channels of the system. The length of the plate and the thickness of a channel, respectively, are expressed as (L ', d), while the regions of the type of flow regime that can take place in the system at any given time are: (20) It is the laminar flow region.

(21) It is the transition region of laminar-turbulent flow regimes.

(22) It is the turbulent flow region.

(23) It is the laminar sub-layer.

(24) It is the transition layer.

(25) It is a turbulent region.

Similarly, something similar happens, but with less intensity on both vertical surfaces of the glass cover (inner side and outer side), since the amount of energy absorbed by the glazed material is less. At the same time, and according to the theory of thermal radiation, it is well known that all materials emit and absorb electromagnetic radiation in all directions diffusely. The reason for this energy emitted and absorbed will depend on the internal surface temperatures in the chimney channel, as well as its same optical properties. This will be manifested in a radiative exchange between surfaces, giving rise to the third mechanism of heat transfer by Radiation (13).

Due to the nature of the processes mentioned above, it is estimated that the absorber surface will reach a higher temperature, and therefore emit more energy. According to the Planck Distribution Law, and according to the maximum temperature values reached on similar surfaces this surface will emit in the infrared (long wavelength), due to the nature of the glass, it will behave like an opaque material to this radiation, and therefore the known greenhouse effect within the system will be presented.

From both external glazed surfaces, it is also estimated that there is a heat transfer by radiation (13), and like the other two heat transfer mechanisms, conduction (11) and convection (12), it is also indicated in the same Figure 10

All the processes described above give rise to the movement of air by natural convection within the channels whose effect is known as Thermal Operation of the system. On the other hand, and under certain conditions, the effect due to wind forces may be present, however, it may or may not act in the direction of air flow. In the latter case, it manifests itself as an inverse flow through the system, which is undesirable in many cases. To avoid these air refluxes in these types of systems, there are some commercial accessories such as rotating caps. These accessories can be oriented in one direction or another according to the direction of the wind, in such a way that reflux is avoided, or that there is a reverse flow in the system.

Based on the previous study, in the present invention, it has been decided to install an atmospheric extractor of the dynamic type at the outlet of the solar collector or heater. For its coupling it was necessary to design a reduction of nozzle type coupling. The system as a whole is the one shown in Figure 11, where a front view (left side) and a side view (right side) are shown. On top of the Figure 11 shows the atmospheric extractor (2) and shows where it is coupled with the nozzle type reduction of a double chimney solar chimney. The main parts of the system as a whole are described below: (1) An absorber plate of length L 'and width W'. In this particular case, the plate is made of galvanized sheet and painted in matt black, for the purpose of absorb the greatest amount of incident solar energy on it. Details of other types of building materials for solar chimney absorber plates have been described above. (2) An atmospheric extractor of the dynamic type. It is usually made of galvanized sheet or aluminum, it is available in the market for commercial sale, in different sizes (... 10, 12, 14, 16 ... inches). The atmospheric extractor must be completely fixed and level, so that it has no imbalances in any direction and premature failures can be generated due to system fatigue.

(3) A nozzle type reduction of characteristic dimensions, which is used to couple the solar collector or heater and the atmospheric extractor. It is made with a metal structure and with glass covers or transparent glazed surfaces, however, some other type of rigid material can be used, as long as it is a transparent material so that the solar radiation that falls on the absorber plate is not obstructed. What characterizes the nozzle reduction is its geometric aspect ratio (A). The product of two quotients will be understood as aspect ratio

"A = - * -» <o.3 ", where Wy L is the width and length of the solar collector or heater of the

The

solar chimney type, respectively, and can be varied independently, 2d and a are the hydraulic discharge width or diameter and length of the nozzle type reduction respectively, and can be varied only dependently. This geometric aspect ratio guarantees the uniformity of the air flow within the nozzle reduction, which in turn reduces the pressure drop between the outlet of the solar collector or heater and the entrance to the atmospheric extractor, favoring in turn the extraction of air flow through the system. It will be ensured that the solar heater outlet fits perfectly with the nozzle reduction, and is with the entrance of the atmospheric extractor, in such a way that there are no air leaks between both connections. For the above, it is recommended to use some type of commercial silicone to seal possible air leaks around the joints and at the same time avoid water inflows in the rainy season.

(4) Glass covers or glazed surfaces. They mainly serve to form the two rectangular channels of the collector or heater, reduce convective and radiative losses, and also serve to create the greenhouse effect within the system. The glazed surfaces are also used in the trapezoidal nozzle type reduction.

(5) Metal fasteners. They are used to fix the absorber plate to the metal support structure of the collector or heater. (6) Coupling ring. It can be metallic or of some other material that guarantees the coupling between the nozzle type reduction (3) and the atmospheric extractor, and that at the same time serves as a fastener. (7) Support structure. It can be made of structural steel or some other material that serves to hold the absorber plate (1), the nozzle reduction (3), the glass covers (4) and the base of the solar collector (8) mainly.

(8) Base of the solar collector. It can be made of structural steel or, some other material that serves to engage with the building by ventilating, can be held in the upper part (Roof) of the building.

(9) Air flow to the inlet and into the two channels of the solar collector. They are convective air currents that are generated naturally due to buoyancy forces as a result of temperature differences between the absorber plate (1) and the adjacent air (9) in both channels of the system, or due to differences of pressure between the inlet and the outlet caused by the atmospheric extractor (2). (10) Air flow at the outlet of the atmospheric extractor. They are drafts of exhaust air expelled by the system, as a result of natural extraction due to pressure and / or temperature gradients between the inlet and outlet of the system.

Other dimensions of the system that are also shown in Figures 13-14 are; The length (L) and width (W) respectively of the solar chimney type solar collector, the length (L ') and width (W') respectively of the absorber plate. The diameter of the coupling ring (2) to connect the atmospheric extractor (2) with the nozzle reduction (3), is where the discharge of outgoing air from both channels is concentrated, the so-called hydraulic diameter (2d) also corresponds to the thickness of both air channels, and in the same way is the separation distance between the front and rear glass covers (4), (a) is the length of the nozzle type reduction, (¿) is the width of the coupling ring, and (c) is the height of the atmospheric extractor.

From the above it can be concluded that the air flow through a solar chimney originates when there are pressure differences between the inlet and the outlet of the system. Of course, we always seek to obtain differences in positive pressures, in order to avoid reflux when the solar chimney collector or heater is connected to a house or building. This effect is achieved as a result of the manifestation of two driving forces (buoyant forces due to thermal gradients, caused by heat gains on the sunny surface of the absorber plate, and dynamic forces caused by wind forces). However, experimentally it has been observed that, despite the different designs of solar air collectors referenced in the literature, and the different accessories that are commercially available in the market, many times the air flow required by a building is insufficient to that provided by the only collector or heater, or, by the only accessory, therefore, as a corrective measure to this demand has been opted to install a greater number of these equipment, which gives rise to a high consto of the system.

For all the above, the use of two previously selected devices, a solar chimney collector or heater and an atmospheric extractor of the dynamic type, is proposed as an invention, as shown in Figures 13 and 14. The coupling is made to through a nozzle reduction (3) with a characteristic geometry previously described. The new mixed air extractor is called Solar-Wind Chimney. It can be summarized that the invention consists of the coupling of two systems or devices, (an atmospheric air extractor of the commercial type, such as some of those shown in Figure 1-6 and a solar collector or heater of the type Chimney Solar, etc., as one of those shown in Figures 7-9 The purpose is to generate a mixed passive air extraction system, with better characteristics and better performance than each separate system could have. The intention is to produce a natural ventilation required in homes, industrial buildings and / or buildings (according to ASHRAE STANDAR-62-1999) to improve the quality of air inside the enclosures.The system as a whole must be installed with an orientation that favors the collection of solar energy incident on the absorption plate for greater heating, and at the same time at a height such that the effect of the wind is used to rotate the air extractor.

Figure 14 shows the air velocity profiles within the nozzle reduction that includes part of the body of the same sensor, as a result of a numerical simulation using a commercial computation package (Algor). Where W is the width of the absorber plate of the solar collector or heater, (2d) is the hydraulic diameter of the discharge and (a) the height of the discharge nozzle type reduction. The dimensions of these measurements depend on the length of the sensor, for the present simulation a length of L = 2 m was used. In the numerical simulation it was considered that there are circular ducts throughout the width of the solar collector, in order to compare the numerical results with the theoretical results, which are well defined profiles for this type of geometry. As can be seen, the uniformity of the parabolic profiles guarantees a uniform flow distribution across the entire width of the solar collector, thanks to the characteristic dimensions of the values of W, a and b. It is from these dimensions that a geometric aspect ratio is obtained, which is characteristic of the system and which has been described in detail in the present invention. The reduction material may be galvanized, but some other type of material may be used. It will be ensured that there are no air leaks, so that the solar heater outlet fits perfectly with the base of the atmospheric extractor. It is recommended to use some type of commercial silicone to seal possible air leaks in existing joints, and / or water ingress in the rainy season. The atmospheric extractor must be completely fixed and level, so that it has no imbalances in any direction and premature failures can be generated due to system fatigue.

The extraction of air in the new mixed system or Solar-Wind Chimney is carried out by the double maximized effect, the Thermal effect and the Dynamic effect. The effect Thermal is produced when solar radiation strikes the absorber plate of the solar collector and this in turn heats the air adjacent to the inside of the channel. As a consequence the density of the air decreases and by natural effect it rises towards the exit, thus generating a natural induced draft effect through the system that produces the ventilation effect. The dynamic effect takes place when the wind speed is such that it breaks the resting state of the atmospheric extractor to produce a rotating effect that helps the extraction of air in the system.

By coupling both devices (the solar collector or heater and the dynamic type atmospheric extractor) through a nozzle reduction, a much greater resulting effect is obtained. The above tnaximizes the extraction of air in enclosures and / or buildings up to four times more than both systems could have separately.

Claims

CLAIMS Having sufficiently described our invention, we consider as a novelty and therefore claim as our exclusive property, what is contained in the following clauses:

1. A SOLAR CHIMNEY SOLAR RECEIVER OR HEATER, characterized by a double air channel, formed by the following main elements; a solar radiation absorber plate, glass covers or transparent glazed surfaces, as envelopes in a rectangular arrangement that form the two air channels, supported by a rigid structure in the form of an angle, and that, in addition, said solar collector or heater is characterized by carrying two pairs of opening and closing flaps to control the passage of air, as required to ventilate or passively heat during the day, or at night.

2. A SOLAR FIREPLACE OR SOLAR HEATER OF THE SOLAR FIREPLACE TYPE, THAT USES THE SOLAR ENERGY, TO PASSIVENTLY FAN INDUSTRIAL VESSELS, HOUSING, AND / OR BUILDINGS in accordance with clause 1 characterized in that also the absorber plate of the solar collector or heater of Air is metallic if ventilation is required, a building during the day.

3. A SUNSET OR SOLAR HEATER OF THE SOLAR FIREPLACE TYPE, USING THE SOLAR ENERGY, TO VENTILATE

PASSIVELY INDUSTRIAL, HOUSING, AND / OR BUILDINGS, in accordance with clause 1, which is characterized in that the absorber plate of the solar air collector or heater is made of a material with high heat capacity such as concrete if it is required to ventilate or heat a building at night.

4. A SOLAR FIREPLACE OR SOLAR HEATER OF THE SOLAR FIREPLACE TYPE, THAT USES THE SOLAR ENERGY, TO PASSIVENTLY FAN INDUSTRIAL VESSELS, HOUSING, AND / OR BUILDINGS in accordance with clause 1 characterized in that also the absorber plate of the solar collector or heater of Air is metallic and contains a high heat capacity material with phase change at working temperatures such as paraffin if it is required to ventilate or passively heat a building during the day, or during the night.

5. A TOPEAR TYPE REDUCTION OF TRAPEZOIDAL FORM, characterized in that it is formed mostly by transparent glazed surfaces, supported by a rigid structure in the form of an angle, and which is also characterized in that its dimensions are of such magnitudes that of a combination of them you get a characteristic geometric aspect ratio, "= - * -» ≤o.3 "that serves to drive inside

The

volumes of air and that with it the air flow through it moves uniformly and its pressure drop is minimal.

6. MIXED AIR EXTRACTOR, USING SOLAR ENERGY

AND THE WIND, TO PASSIVENTLY VENTILATE INDUSTRIAL, HOUSING, AND / OR BUILDINGS (SOLAR-WIND FIREPLACE), which is composed of three main elements or devices connected in a series type arrangement; a collector or solar air heater of the dual-channel Solar Chimney type, a Nozzle Trape Nozzle Reduction and an Atmospheric Extractor. Where the Solar Chimney is characterized by being double air channel, and has the following main elements; a solar radiation absorber plate, glass covers or transparent glazed surfaces as an envelope in a rectangular arrangement that form the air channels. The output of the Solar Chimney is coupled to the entrance of a Trapezoidal Nozzle Reduction, which is formed mostly by transparent glazed surfaces, supported by a rigid structure in the form of an angle, which is also characterized because its dimensions are of such magnitudes that a characteristic geometric aspect ratio is obtained from a combination of them, "= - * -» ≤o.3 "and that with

The

This means that the air flow inside the system moves uniformly and its pressure drop is minimal. The output of the trapezoidal nozzle type reduction is connected to the input of the Atmospheric Extractor by means of a coupling ring. The atmospheric extractor is a mechanical device of the dynamic type that rotates on a pivot or vertical axis, formed by blades.

7. MIXED AIR EXTRACTOR, USING SOLAR ENERGY

AND THE WIND, TO PASSIVENTLY VENTILATE INDUSTRIAL VESSELS, HOUSING, AND / OR BUILDINGS (FIREPLACE

SOLAR-WIND), in accordance with clause 6, characterized in that the absorber plate of the solar air collector or heater is also metallic if it is required to ventilate, a building during the day.

8. MIXED AIR EXTRACTOR, USING SOLAR ENERGY

AND THAT OF THE WIND, TO PASSIVENTLY VENTILATE INDUSTRIAL, HOUSING, AND / OR BUILDINGS (SOLAR-WIND CHIMNEY), in accordance with clause 6, which is characterized in that the absorber plate is also made of a material of high heat capacity such as concrete and which is also characterized by carrying opening and closing flaps, to control the passage of air, as required to ventilate during the day, or to ventilate and / or passively cool a building at night.

9. MIXED AIR EXTRACTOR, USING SOLAR AND WIND ENERGY, TO VENTILATE PASSIVELY VESSELS

INDUSTRIAL, HOUSING, AND / OR BUILDINGS (SOLAR-WIND CHIMNEY), in accordance with clause 6, which is characterized in that in addition the absorber plate is of a high heat capacity material with phase change like paraffin and which is also characterized by bring open and close hatches to control the passage of air, as required to ventilate during the day, or ventilate and / or passively cool a building at night.