WO2005007273A1

WO2005007273A1 - Method and device for air-conditioning a room with an air mixture having a lowered oxygen partial pressure

Info

Publication number: WO2005007273A1
Application number: PCT/EP2004/007598
Authority: WO
Inventors: Axel Jahn
Original assignee: Axel Jahn
Priority date: 2003-07-11
Filing date: 2004-07-09
Publication date: 2005-01-27
Also published as: RU2006104981A; EP1654051A1; RU2325942C2

Abstract

The invention relates to a method and a device (10) for air-conditioning at least one room (38) with an air mixture having a lowered oxygen partial pressure in comparison with ambient air in an overall pressure substantially corresponding to an ambient air pressure. According to the inventive method, at least part of the oxygen (O2) contained in the ambient air is chemically reduced to a reaction product, preferably the reaction product is separated and the thus treated low-oxygen air mixture is fed as inlet air to the room to be air-conditioned. A core element of the inventive device is an O2 reductor (16) for reducing at least part of the oxygen contained in the ambient air into a reaction product. The O2 reductor (16) can preferably be a fuel cell, a combustion engine, a turbine or a combustion chamber.

Description

Method and device for air conditioning a room with an air mixture with reduced oxygen partial pressure

The invention relates to a method and a device for air conditioning a room with an air mixture which has an oxygen partial pressure which is lower than that of ambient air.

It has long been known to train athletes at great geographical heights, for example at 2,000 to 4,000 m above sea level (normal zero, NN), for the purpose of increasing their performance. At higher altitudes, the overall air pressure is lower than at sea level, which also lowers the partial pressure of oxygen, the so-called oxygen partial pressure. The percentage composition of air is essentially unchanged compared to sea level, ie the volume fraction of oxygen is about 21% as high as at sea level. Due to the low oxygen partial pressure at high altitude, there is a reduced oxygen uptake of the blood. After some time, and especially when under stress, the body reacts by adapting to the lack of oxygen through adaptation or acclimatization in order to compensate for the reduced oxygen uptake and oxygen transport. When returning to normal pressure and thus to normal oxygen conditions, the body has an improved oxygen supply, which leads to an increase in performance. This effect persists a few weeks after returning to NN.

Staying at an altitude also leads to an increased pulse rate, which strengthens the circulatory leads without physical exertion. Although the underlying effects are currently still being researched, they are already being used therapeutically in the area of rehabilitation by sick people.

According to sports science findings, the effect of altitude training or altitude therapy can also be achieved in an atmosphere at normal pressure, in which, however, the oxygen partial pressure is reduced so that it corresponds to the oxygen partial pressure of a certain height above sea level. In order to obtain an air mixture with a reduced oxygen partial pressure at normal total air pressure, the partial pressure of other air components, in particular nitrogen, must be increased accordingly. Air conditions with an oxygen partial pressure corresponding to a certain height and at the same time normal total air pressure are also referred to as normobaric hypoxia. For example, air with an oxygen volume fraction of 14.3% corresponds to a height of approximately 3,000 m above sea level or 16.2% to a height of 2,000 m above sea level. An overview of the basics of altitude training can be found in U. Fuchs and M. Reiss: Height training, Trainer Bibliothek 27, Philippka-Verlag, 1990, 12-27.

Known methods for producing air mixtures with low oxygen partial pressure or with a low oxygen content at normal atmospheric pressure use techniques of dilution / mixing, air separation on membranes, the adsorption of oxygen and the use of breathing masks with recirculation of the exhaled and processed air.

In the latter method, a breath exhaled and breathed through human breathing (breathing mask training) recycled with oxygen-reduced air in a processed form and fed back to the trainee via the breathing mask. The preparation here requires the removal of carbon dioxide from absorbers to lower the increased CO ₂ partial pressure (U. Fuchs, M. Reiss: Altitude Training, Trainer Bibliothek 27, Philippka-Verlag, 1990, 26-27).

During the dilution, the air is mixed with an inert gas, usually nitrogen (for example WO 96/37176 A), or with CO ₂ . The method is technically simple to implement and also has the advantage that undesired components of the air, such as CO ₂ , odorants or particles, are diluted to the same extent as oxygen, but the dilution medium may not contain any odorants or other undesirable components. However, the process is expensive because the diluent media nitrogen or other inert gases are expensive and are required in large quantities. In order to produce 1 m ^{3 of} an air mixture with 14% oxygen, starting from an oxygen content of 21%, about 330 1 dilution medium are already necessary. An additional cost-increasing factor is that when the room to be air-conditioned is started up to the desired oxygen content, air that has already been diluted is displaced from the room by supplying the dilution medium. As a result, the expensive dilution media are increasingly discharged unused until the desired oxygen content is reached. This eliminates the dilution process for the production of larger quantities of air for large rooms, which are also in constant unwanted air exchange with the environment. In addition, some of the dilution media are foreign gases for humans. Since C0 ₂ is harmful to humans in higher concentrations, it is out of the question as a dilution medium for rooms intended for personal use and is only used for fire protection purposes and in specially protected areas Rooms, such as data centers. Recent developments in fire protection therefore use nitrogen as a dilution medium.

When separating air on membranes, air is forced through a suitable oxygen-permeable membrane, in particular a hollow fiber membrane, by means of positive or negative pressure. Oxygen diffuses through the membrane while nitrogen is retained. The oxygen separated in this way is discharged separately and the oxygen-poor air generated is fed to the room to be air-conditioned. The method is used particularly in fire protection. Here, special, comparatively small storage rooms for high-quality goods, such as works of art, books or computer data, are brought and kept once to an oxygen content in the air below about 15%. Since these rooms, with their generally smaller room volumes and dense surrounding areas, are not intended for people to stay and are hardly subject to an air exchange with the surroundings, there are relatively small amounts of air and low air quality to be started up (and only if this is done in recirculation mode) and to hold required. From the documents WO 01/78843 A, EP 0 865 796 A or WO 96/37176 A, the use of membrane technology for generating air mixtures for normobaric hypoxia training or hypoxia therapy is also known, but here the breathing air is basically available via breathing masks provided, so that comparatively small amounts of air are necessary here. The supply of sleeping tents using this technique is described in WO 99/06115 A. In addition to the low air output in the range of one cubic meter per hour, membrane technology has the disadvantage of being expensive and energy-intensive in relation to the air output due to the high costs for the pumps and the membrane. Furthermore, the sound generated by the apparatus is' low frequency quenz (infrasound) disturbing the well-being. This means that membrane technology cannot currently be used to generate large amounts of air.

In adsorption technology, air is usually passed through a suitable porous material under high pressure, which adsorbs oxygen. Molecular sieves with a zeolitic structure are usually used here. Since the material used has to be regenerated from time to time when the storage capacity is exhausted (usually by air release), this is a discontinuous process. Its use for normobaric hypoxia for training or therapy purposes is known from WO 96/37176 A, WO 01/78843 A, WO 99/06115 A or WO 98/34683 A, where in some cases continuous operation by using two alternately operated adsorption units is described. However, only small amounts of air are made available through breathing masks. In addition, breathing mask training basically represents a severe impairment of the training conditions.

The air conditioning of rooms intended for personal stay under the conditions of normobaric hypoxia affects the area of room ventilation technology as a sub-area of room air conditioning technology. In contrast to process air technology, which relates to technical air mixtures for machine systems or as compressed air, room air technology has the task of creating the desired climatic conditions in rooms, room areas or also limited outdoor areas. A typical task of ventilation technology is the setting of a thermal comfort with the parameters air temperature, radiation temperature, perceived temperature, relative and absolute air humidity, air speed, degree of turbulence and others. These requirements are met by known measures such as heating, cooling, humidifying and dehumidifying, Air duct, type of air introduction (with or without induction) and the like coped. A further task of indoor air technology concerns the particle content of the air, with inorganic or organic particles such as dust, pollen, spores or bacteria being removed by measures such as air filtering, air washing or air renewal. In particular for rooms intended for personal use, room ventilation technology must also ensure adequate air quality and air hygiene. Components such as C0 _2f odorous substances, exhaust gases, spores, decomposition products of organic substances and the like are to be reduced or removed. Other known areas of ventilation technology relate to pollution control, fire and smoke protection, protection of components or room contents, in particular against moisture or temperature fluctuations, and other areas. Classic ventilation technology therefore has to regulate a large number of parameters at the same time. Many of these tasks are usually solved by supplying outside air (air renewal). The usual supply of outside air in rooms with low loads, such as offices, is at least one to two room volumes per hour to ensure the air quality in common rooms. A significantly higher supply of outside air is even necessary in sports rooms. However, the supply of outside air in untreated form leads to an oxygen entry in the room air and is therefore excluded for rooms conditioned by normobaric hypoxic conditions. The air conditioning of common rooms with an air mixture in accordance with the conditions for normobaric hypoxia thus represents a new area of responsibility for indoor air technology. Also new is the requirement for pollution control for rooms of normobaric hypoxia in order to counteract the penetration of (good) outside air. Separation of by-products of the chemical reaction may also be necessary or desired. The object of the present invention is to provide a method for the air conditioning of rooms, including necessary air renewal, in particular of common rooms for people, which enables the setting of normobaric hypoxia conditions in an economically efficient manner. A device for carrying out the method is also to be made available.

This object is achieved by a method having the features of claim 1 and a device according to claim 20. According to the invention, at least part of the oxygen 0 ₂ contained in the ambient air is chemically reduced to a reaction product and the (oxygen-reduced) treated in this way Supply air mixture as supply air to the at least one room to be air-conditioned. It goes without saying that the supply air largely has normal air pressure, that is to say essentially the air pressure prevailing in the outside air (ambient air). The use of a chemical reaction to convert the molecular oxygen allows sufficiently high production rates of the oxygen-reduced supply air to also air-condition larger rooms which are in a certain unavoidable or deliberate air exchange with the environment. In addition, with a suitable choice of the chemical reaction, the released reaction energy can be fed back into the air conditioning process - in the form of electrical energy and / or mechanical energy and / or thermal energy - and thus can apply part of the energy to be used for the process. Other uses of the energy are of course also possible. This energetic advantage makes the process particularly economical compared to all known processes discussed above. The chemical reduction of oxygen is preferably carried out by reaction with at least one fuel, in particular a combustible gas such as methane, ethane, propane, butane, natural gas, molecular hydrogen (H ₂ ) or mixtures thereof. Natural gas, which has proven to be particularly economical, is preferably used. Natural gas typically consists of approximately 90% by volume methane and also contains minor amounts of ethane, propane, butane, nitrogen and carbon dioxide. Depending on the choice of chemical implementation, liquid fossil fuels can also be used. When using fuel gases or fuel liquids, the aftertreatment of the treated air mixture is required before being fed into the room to be air-conditioned due to the combustion products of the fuel and / or oxygen that are produced. In particular, CO ₂ , CO, unburned hydrocarbons, and / or NO _x , but also vaporous water, must be at least partially separated off or converted catalytically.

• Alternatively, the chemical conversion of oxygen with molecular hydrogen H ₂ as a fuel is advantageous, since water is produced as a combustion product, which is environmentally friendly and at the same time easily separable from the air mixture. If hydrogen is used, it can be generated by electrolysis of water. The electrical energy to be applied for this can, for example, be applied photovoltaically by means of solar cells. When using a fuel cell (see below) to reduce oxygen, the electricity generated in this way can cover part of the energy required for electrolysis. Alternatively, the hydrogen can also be generated by reforming hydrocarbons, in particular fuel gases or gasoline. It is preferably provided that reaction products of the oxygen and / or of the at least one fuel, in particular when using natural gas or the like, are at least partially separated off or catalytically converted from the remaining air mixture before it is supplied to the at least one space to be air-conditioned. This can be done, for example, by reducing the oxygen to a liquid or condensable, solid or sublimable reaction product which is removed from the air mixture by a corresponding phase separation. It is also conceivable to remove the reaction or combustion product, for example by air washing, adsorption or catalytic conversion.

Several options for the chemical reduction of oxygen are conceivable. According to a particularly preferred embodiment, the oxygen is reduced by its electrochemical conversion with a suitable fuel in a fuel cell. In particular, molecular hydrogen H _{2 is} used as fuel, with which the oxygen is converted to water H ₂ 0, which can be easily separated from the remaining air mixture after condensation. In principle, however, methanol CH ₃ 0H is also known as a fuel of the so-called DMFC cell type (direct methanol fuel cell) and can be used in the context of the present invention. In addition to the environmentally friendly reaction product water, the use of the electrochemical fuel cell has the advantage of generating electrical energy that can be fed back into the process or used externally.

An alternative embodiment sees the reduction of

Oxygen through supply and open combustion one of the

Air supplied fuel in an internal combustion engine or a gas turbine, where natural gas or mole- Kular hydrogen are provided as preferred fuels. It is advantageous here to generate exergetically particularly valuable mechanical energy, which can be used in the process to reduce the energy requirement.

Alternatively, the oxygen can also be reduced by combustion with a substantially open flame in a combustion chamber, air and a suitable fuel (mixed or separate) being fed to the combustion chamber and the fuel being burned with the oxygen. Any combustible gas, in particular natural gas, methane, ethane, propane, butane, hydrogen, preferably natural gas, can be used as fuel. In principle, however, a liquid fuel such as gasoline or the like can also be burned in the combustion chamber. The water generated when using hydrogen can easily be separated from the remaining air mixture by condensation. In the case of the combustion of natural gas or lower alkanes, the main combustion product is carbon dioxide C0 ₂ , for example by adsorption or by introduction into suitable aqueous solutions or. Air wash can be separated. In any case, maintaining relatively low combustion temperatures is advantageous in order to suppress the generation of nitrogen oxides N0 _X as much as possible. There is a lot of experience here in boiler construction or with internal combustion engines. Basically, all burner types (boilers) known in heating system construction or specially developed burner types can be used as the combustion chamber.

According to a further alternative, the oxygen is reduced by reaction with a fuel on a suitable catalyst. It is also conceivable, especially when using air with a relatively low oxygen content (for example in recirculation mode), that the oxygen on electrically heated wires with a burner implement material. In addition, a chemical reaction of the oxygen with suitable reactants, for example salts, which convert the oxygen to a solid is known in principle.

Although the use of known devices as 0 ₂ reducers has been discussed above (fuel cells, boilers, turbines, piston engines, etc.), it goes without saying that special developments for exhaust gas generation according to the invention, i.e. for producing an air mixture with a reduced oxygen partial pressure by burning oxygen, can be used as 0 ₂ ~ reductors in the context of the invention.

In principle, the method is able to adjust the partial oxygen pressure in the entire range from very low volume fractions, for example 5%, to the natural fraction in the air of 21%. If rooms for training or therapy / rehabilitation measures are to be air-conditioned, the oxygen partial pressure is reduced in particular to volume fractions of 12 to 16%, in particular to about 14%. The method can advantageously also be operated in a controlled manner, an oxygen partial pressure measured in the room to be air-conditioned (for example with a lambda probe) being compared with a desired oxygen partial pressure and a conversion rate of the chemical reduction of oxygen and / or an air supply rate in the at least one room to be air-conditioned is set as a function of a deviation of the measured from the desired oxygen partial pressure.

Since the process is primarily for air conditioning from

People stay in certain rooms, but also smaller ones

Is intended for ventilation or mask ventilation, i.e. in any case a "breathable" air mixture is to be generated, te the supply air produced with reduced oxygen partial pressure has the usual "freshness effect" of good outside air. For this purpose, the usual climatic parameters of ventilation technology explained at the beginning can be set. It is therefore preferably provided to subject the oxygen-reduced supply air to at least one of the following treatment measures before it is supplied to the room to be air-conditioned:

- Filtration and / or air wash (in direct contact with water) to remove particles,

- catalytic aftertreatment and / or air washing to remove gaseous components,

- temperature control for setting a predetermined air temperature,

- humidifying or dehumidifying to set a predetermined air humidity, setting a predetermined C0 ₂ content,

- Ionization to set an air quality.

Other treatment measures known in roughened air technology can of course also be used here.

The invention further relates to a device for air conditioning at least one room with an air mixture which has an oxygen partial pressure which is lower than that of the ambient air, comprising a 0 ₂ reducer for reducing at least part of the oxygen contained in the ambient air to a reaction product and a feed device for Feeding the treated air mixture into the at least one room to be air-conditioned.

The device according to the invention is inexpensive to create and operate, and is also suitable for larger rooms Air conditioning conditions of normobaric hypoxia. Further advantageous embodiments of the invention are the subject of the remaining subclaims.

The invention is explained in more detail below in exemplary embodiments with reference to the associated drawings. Show it:

FIG. 1 schematically shows an overview of an entire air conditioning system and the associated process stages;

FIG. 2 shows six different advantageous design variants of the 0 ₂ reducer;

Figure 3 air and water treatment for the separation of the reaction products and for heat dissipation and

Figure 4 Climate and air quality after-treatment.

Figure 1 shows a schematic representation of an advantageous structure of an inventive device for air conditioning a room under normobaric hypoxia. At the same time, FIG. 1 illustrates the course of the method according to the invention. If alternative measures are shown, these are identified by italics.

Beginning on the left-hand side, in the middle of FIG. 1, the device designated overall by 10 has a suction device 11, not shown, with which air is sucked in from the environment and fed into the system 10. The ambient air drawn in passes through a mixing chamber 12, in which recirculated air recirculated from the process can be admixed in any proportion. Then the air can be cleaned in an optional step in a cleaning device 14, for example a particle filter or air washer. Air pretreatment can be particularly important for removing air components that can burn to undesired products in the subsequent reduction process. The circulating air can also be cleaned in a corresponding manner in a second cleaning device 42 (see below).

Subsequently, in a 0 ₂ reducer 16 there is a chemical conversion of part of the molecular oxygen 0 ₂ contained in the ambient air and / or the recirculated air, which is converted into a reaction product with a suitable reaction partner (fuel). The 0 ₂ reducer 16 can be designed in various design variants, which will be explained in more detail later with reference to FIGS. 2A to 2F.

The fuel required for the reduction of the oxygen is supplied from a fuel tank 18. Depending on the choice of the 0 ₂ reducer 16, the fuel used is, for example, molecular hydrogen H ₂ . In this case, the fuel tank 18 is an H ₂ storage. Alternatively, particularly in the case of natural gas, the fuel can also be supplied directly via gas lines, which are also indicated, without being stored.

Two alternatives for the production of molecular hydrogen H ₂ are indicated in the upper part of FIG. 1, with 20 denoting electrolytic H ₂ production and 22 the ^ production by reforming. Both methods are known and should therefore only be explained in principle. In the electrolytic production of H ₂ 20, water, which is usually present as an alkaline, aqueous electrolyte solution, is decomposed on electrodes (cathode and anode) in an electrolytic cell 24. Molecular hydrogen H ₂ is released at the cathode and molecular oxygen 0 ₂ at the anode. The electrical current required for water decomposition can be obtained, for example, in a photovoltaic system 26 using solar energy or from other energy sources. If electricity is generated by the 0 ₂ reducer 16, this current can also be fed in here in order to cover part of the electricity requirement.

When H _{2 is} obtained by reforming 22, fossil fuels, usually fuel gases, such as natural gas, methane gas, town gas, are converted in a reformer 28, for example with the addition of water vapor. In addition to molecular hydrogen H _2, further reaction products such as CO ₂ and low molecular weight hydrocarbons are formed. The heat energy generated by some reforming processes in the form of superheated steam can be used.

The necessary hydrogen production can take place externally or - especially in the case of electrolytic production - also on site. The storage of the hydrogen in the storage 18 decouples the need from the available solar radiation or from the delivery by tanker.

After leaving the 0 ₂ reducer 16, the air mixture has, for example, a volume fraction of oxygen of 14%, corresponding to an oxygen partial pressure of approximately 140 mbar. This gas mixture is at least largely freed from the reaction products of the oxygen and the fuel and any by-products that may be produced in an air maker 30. Is the reaction product in the If hydrogen is used as gaseous or vaporous water, the separation is preferably carried out by condensation. The water separated in this way can be treated by means of a water treatment device 32, for example in order to prevent contamination. Details of the air heater 30 and the water treatment device 32 are explained in more detail below with reference to FIG. 3.

After the reaction products have been separated off, the oxygen-reduced air mixture passes through a temperature control device 34 in which a desired air temperature is set by means of heating and / or cooling. As an alternative, the temperature control can also take place before the reaction products are separated off.

The desired air quality is then set in a post-treatment device 36, in particular inorganic or organic particles, CO ₂ , odorants and the like being removed from the air. Details of the temperature control and aftertreatment device 34 and 36 are shown below in connection with FIG. 4.

The air treated in this way is fed via a supply device 37 as supply air (room air) to a room 38 (or rooms) to be air-conditioned. These are rooms that are operated under conditions of normobaric hypoxia, in particular training rooms for athletes or therapy rooms for the rehabilitation of convalescents or the elderly. In order to protect room 38 against the ingress of untreated ambient air, from outside or from neighboring rooms, an excess of supply air is preferably used. The size of the surplus depends on leaks in the containment areas and the frequency with which access gates are used by people. It is also conceivable that To drive room 38 in special cases under control of an excess pressure of, for example, 2 to 3 Pa.

The air leaving space 38 can either be discharged into the environment as exhaust air or can be returned to the treatment process completely or partially in recirculation mode via mixing chamber 12. Recirculation mode can be particularly useful in the case of using a 0 ₂ reducer in the form of a combustion chamber in which oxygen is burned with an open flame with a fuel in order to lower the combustion temperature and thus suppress the NO. Formation. Corresponding measures are known, for example, in internal combustion engines in the form of internal or external exhaust gas recirculation.

To treat the circulating air, a thermal circulating air treatment device 40 can optionally be provided, which comprises the functions heating, cooling, humidifying and / or dehumidifying. This is particularly useful in rooms 38 of normobaric hypoxia with a high moisture load, for example caused by swimming pools, where dehumidification of the circulating air is necessary. This can be done in a known manner via surface coolers or by means of a dehumidification heat pump.

Furthermore, a further cleaning device 42 can be provided in the circulating air line in order to avoid unwanted combustion products of organic or inorganic compounds. Particulate filters, activated carbon filters or, in special cases, air washers can be used for this. It is also conceivable to combine the cleaning devices 14 and 42 into a single cleaning device downstream of the mixing chamber 12. Of course, the device 10 also includes necessary air delivery devices (fans), not shown, for transporting the air through the air lines and into the various devices.

FIGS. 2A to 2F show six different embodiments of the 0 ₂ reducer 16. The direction of flow of the entering or exiting gas mixture is identified by the horizontal double arrows.

According to FIG. 2A, the 0 reductor 16 is designed as a fuel cell. A large number of individual cells are provided in the form of a cell stack 44. The function of the fuel cell is generally known. In principle, molecular hydrogen H _{2 is} electrochemically converted to water H ₂ 0 with the oxygen 0 _{2 present} in the air. The spatial separation of the two partial reactions, oxidation of hydrogen H ₂ to H ⁺ and reduction of oxygen 0 ₂ to 0 ' ^~ , make it possible to use the electrons emitted by the hydrogen in the form of an electrical current. Since this is an exothermic reaction, the heat energy generated can also be used. There are various types of fuel cell is known, for example, the alkaline fuel cell, the polymer electrolyte membrane fuel cell, the phosphoric acid ^'fuel cell and others. The direct methanol fuel cell is also known which uses methanol as the fuel instead of hydrogen. In principle, all known or still to be developed types can be used within the scope of the present invention. The air mixture leaves the fuel cell with a reduced oxygen content and thus reduced oxygen partial pressure and contains gaseous or vaporous water as the reaction product of the oxygen. FIG. 2B shows a 0 ₂ reducer 16 designed as a combustion chamber. Here, the inflowing air mixture first meets a rectifier 46, which essentially has the task of distributing the air mixture homogeneously in the chamber. The air mixture then enters a combustion chamber 48 in which a gas burner 50 is arranged. The gas burner 50 has a large number of nozzles from which a supplied fuel, here hydrogen H ₂ , emerges and burns with an open flame using oxygen. Alternatively, other fuel gases, such as natural gas, can also be used. The combustion reaction is preferably carried out at low combustion temperatures in order to largely suppress the formation of nitrogen oxides. The resulting heat of combustion is removed via a downstream, preferably dry, heat exchanger 52 before the oxygen-reduced air leaves the 0 ₂ reactor. Alternatively or additionally, the heat dissipation can also be dissipated via the walls of the combustion chamber 48 by radiation and / or convection. In a departure from the embodiment shown, other types of burners known in particular from boiler construction can also be used here, for example premix burners in which mixture preparation takes place outside the combustion chamber; Matrix radiant burners in which the air / gas mixture is burned practically flameless on the surface of a stainless steel mesh; atmospheric or overpressure burners; Burners that have a catalytic coating that supports combustion or combinations of the principles mentioned.

FIG. 2C shows a 0 ₂ reducer 16 in the form of a catalytic combustion device. The air mixture first enters a prechamber 54, in which it is mixed with hydrogen, natural gas or another fuel which is supplied via a gas distributor lance 56. following the gas mixture flows through a porous catalyst block 58 which comprises a plurality of flow channels which have a catalytically active material on their surface. The catalytic reduction of the atmospheric oxygen with the supplied fuel takes place at the catalyst block 58. At the same time, the catalyst block 58 functions as a rectifier. The resulting heat energy is removed via the downstream dry heat exchanger 52 before the gas mixture leaves the reductor 16.

FIG. 2D shows a 0 ₂ reducer 16 in the form of a combustion chamber operated with heating wires. After flowing through the rectifier 46, the air mixture enters the combustion chamber 48, where it is mixed with a fuel, in particular hydrogen or natural gas, which is supplied via the gas distributor lance 56. Also arranged in the combustion chamber 48 are electrically heated heating wires 60, for example in the form of a wire network. The heating wires 60 cause the fuel to burn continuously. Dry heat is also removed here via the heat exchanger 52 before the oxygen-reduced air mixture leaves the 0 ₂ reducer 16. The principle shown in FIG. 2D for oxygen reduction on electrically heated wires is particularly suitable for air mixtures with a relatively low oxygen content. This means that recirculated air or mixed air from recirculated air and ambient air with an already reduced oxygen content can also be used.

FIG. 2E shows a 0 ₂ reducer 16 in the form of an internal combustion engine, in particular in the form of a gas turbine 62 (combustion turbine). In the gas turbine is known in

A fuel, preferably natural gas or H ₂ , is burned with air in a combustion chamber, as a result of which a large part of the energy released is used to drive a turbine (not shown). The mechanical energy generated in this way is a form of energy that can be used particularly well in the process. If the turbine is designed as a generator, the mechanical energy can be converted into usable electrical energy. The heat energy released at the same time is removed from the high-pressure steam generated in the process via the heat exchanger 52.

FIG. 2F shows a 0 ₂ reducer 16 in the form of an internal combustion engine, in particular in the form of a piston engine 64. In a combustion chamber of engine 64, a suitable fuel, again preferably natural gas or H ₂ , is burned with air in a known manner, using the reaction energy to drive a movable piston, not shown. This means that usable mechanical energy is also generated in this process. The required cooling of the motor 64 usually takes place via the motor walls. In addition, cooling of the exhaust gas and thus heat dissipation can take place via the heat exchanger 52.

In particular when using internal combustion engines according to FIGS. 2E and 2F, it is advantageous to keep the combustion temperatures as low as possible in order to counteract the formation of nitrogen oxides NO _x . This is done on the one hand by cooling the motor housing and on the other hand by admixing low-oxygen recirculated air to the outside air. This procedure is known in engine technology as exhaust gas recirculation.

Basically, it applies to all 0 ₂ reducers 16 that heat energy released can already be dissipated in the reductor, the location of the highest temperature level, or even must be dissipated. It is economically interesting to decouple the heat of reaction in the 0 ₂ reducer, especially at temperatures> 110 ° C. This heat can be used on site and / or centrally in the field, for example Absorption chillers generate refrigeration, which can be used to cool and dehumidify the oxygen-reduced air to the required supply air condition, that is, in the air heater 30, in the temperature post-treatment 34 and / or the air quality post-treatment 34. By using the "by-product" thermal energy in this way, the energy costs of the process or the system can be significantly reduced.

Another design option (not shown) of the 0 ₂ reducer 16 uses a different method. A solution of a suitable reducing agent is sprayed or trickled while the air mixture is supplied, the dissolved reducing agent reacting with the atmospheric oxygen to form a solid which can be filtered out. For example, it is known from drinking water treatment to oxidize iron dissolved in water in this way with atmospheric oxygen to iron oxide.

In all of the illustrated embodiments of the 0 ₂ reducer 16, the reaction energy is released when oxygen is reduced or a fuel, in particular natural gas or H _{2, is} burned. Depending on the choice of the reducer 16, this energy is generated in the form of thermal energy, preferably also as electrical or mechanical energy. All forms of energy are preferably returned to the air conditioning process in order to partially cover the energy requirements. For example, the energy can be used to generate the fuel H ₂ or to generate cold, which is required for cooling, dehumidifying or cleaning the reaction air mixture. Other forms of use inside and / or outside the process are also conceivable. Details of the air heater 30 and the water treatment device 32 from FIG. 1 are shown in FIG. 3. The air maker 30 has the task of removing the combustion products of the 0 ₂ reducer 16 and any by-products that may arise from the air mixture. In the present case, the use of hydrogen as a reducing agent and thus gaseous or vaporous water as the reaction product to be separated is assumed. The gas mixture loaded with the gaseous or vaporous water enters the air maker 30 and meets there a surface cooler 66 which, under wet cooling, causes a partial condensation of the water and thus cooling and dehumidification of the remaining air mixture. Due to the dissipated heat, the cooling medium used is heated to approximately 40 to 50 ° C, so that the thermal energy can be used inside or outside the system. The water condensed on the cooler 66 flows into a washer trough 68, which is arranged at the bottom of a dehumidification chamber 70. In the dehumidifying chamber 70, the air mixture is treated with water, which is sprayed or sprinkled via a nozzle block 72 in the form of a spray or trickle humidifier, as a result of which the water contained in the air is further condensed. In order to achieve the desired dehumidification effect here, the sprayed or trickled water has a temperature corresponding to the target value of the dew point of the air mixture. (On the contrary, if the air is to be humidified at this point, the water temperature must exceed the dew point.) In addition to drying the air mixture to the desired moisture content, residues are removed

(Air wash) and binding of C0 ₂ - the latter is absolutely necessary in cases in which 0 ₂ reducer 16 instead of H ₂ uses hydrocarbon-containing fuels such as natural gas. The circulating or continuous water used for C0 ₂ binding can also be used in a known manner for this purpose Way to be conditioned. After passing through a drip separator 74, the air mixture leaves the air maker 30 and is thus freed from the reaction product of the oxygen and / or the fuel in question, has the desired atmospheric humidity and is already largely free of particles. In addition to the air washing explained here, other methods for removing the reaction products can also be used.

In the arrangement 30, the wet surface cooler 66 can be omitted, but is useful for the use of the thermal energy. It is also conceivable not to supply the water condensed on the cooler 66 to the water treatment device 32, but to discharge it separately. Furthermore, the surface cooler 62 and the air washer consisting of the dehumidification chamber 70 and the nozzle assembly 72 can also be accommodated in separate device units. ,

The water collected in the scrubber pan 68 is at least partially fed to the water treatment device 32, where it is first heated to a degassing temperature via a heating device 76, for example a heat exchanger. The heated water then passes into a degassing chamber 78 equipped with a vacuum fan, from where the components gasifying under the vacuum, for example CO ₂ , are removed. Since there is no C0 ₂ when using hydrogen as fuel gas, thermal degassing (76, 78) can be omitted in this case. In a downstream water filter 80, solids are removed and drained from the water. The water is then cooled in a water cooler 82 to or below the dew point of the supply air to the air heater 30. The pH of the water is then adjusted in block 84. Optionally, the water treatment device 32 can also use a disinfection device (not shown). have a device in which bacteria, in particular Legionella, are killed, for example, by UN radiation. The treated water is fed to the dehumidifying / washing chamber 70 of the air heater 30 via a pump 86. Excess water is discharged via an outlet valve 88.

Optionally, the dry cooler 52 of the 0 ₂ reducer 16 from FIGS. 2A to 2F and the surface cooler 66 from FIG. 3 can be combined in one unit.

FIG. 4 shows details of the temperature control and post-treatment devices 34 and 36. In the temperature control device 34, an air cooler 90 and an air heater 92 are used to set the desired air temperature. As a rule, the air cooler 90 can be omitted. A desired air quality is set in the aftertreatment device 36, with solids, such as dust or bacteria, being removed from the air in a particle filter 94. Additionally or alternatively, an activated carbon filter 96 can be provided, which in particular binds odorous substances from the air. Likewise additionally or alternatively, an ionization chamber 98 can be provided, with which, for example, spores or decay products of organic substances can be removed by means of generated oxygen radicals and which in particular brings about the desired “freshness effect” of the air. Although the sequence shown is preferred, the reverse order of the devices 34 and 36 can also be provided in certain cases.

The air conditioning device 10 according to the invention can basically be operated in two operating states. At the beginning of the air conditioning of the room 38 with an air atmosphere of normobaric hypoxia, a pure or partial circulating air operation takes place, the one leaving the room 38 Exhaust air is completely or partially returned via the recirculation air line and the mixing chamber 12. This start-up continues until the space 38 to be air-conditioned has the desired oxygen content.

As soon as the desired oxygen content is reached, the system is switched to a regulated or controlled holding mode, in which the ambient air portion supplied via the mixing chamber 14 is limited to a necessary level. Several factors have to be taken into account when measuring the ambient air content. On the one hand, sufficient removal of loads from room 38, for example odorous substances, C0 ₂ , dust, fibers, etc., must be ensured. On the other hand, room 38 must be protected against the ingress of oxygen-rich outside air (pollution control) and the unavoidable air exchange with the surroundings must be compensated. Finally, as already mentioned, a certain circulating air / ambient air ratio or a reduced oxygen content to lower the combustion temperature and thus the N0 _X formation in the 0 ₂ reducer 16 can be required. Basically, the proportion of ambient air is measured based on the strongest of the factors to be taken into account, which automatically fulfills the other requirements. This excess air is then released into the environment, for example, as so-called protective air (the strongest factor in the case of immission protection), for example with a proportion of 0 to 20% of the air mass discharged from the room 38. The intake of ambient air is adjusted in accordance with the removed protective air and is therefore coupled to it. Depending on the type of 0 ₂ reductor 16 used, a higher proportion of ambient air than that resulting from the protective function or the other factors may also be necessary in order to achieve an oxygen concentration in the combustion gas necessary for the oxidation of the fuel gas. ensure combustion air. Alternatively, an excess of exhaust air can be used for emission protection purposes if neighboring rooms or areas are to be protected from the low-oxygen room air.

Both in the start-up and in the holding mode, regulation of the circulating air portion can be provided such that the oxygen content of the combustion air of the 0 ₂ reducer 16 is kept high enough to maintain the combustion process.

In a departure from the embodiment shown in FIG. 1, direct recirculation mode can also be provided, in which the exhaust air from room 38 - if necessary after separate recirculation air treatment for setting the temperature, air. quality etc. - is fed directly to the room 38 again without passing through the 0 ₂ reducer 16.

LIST OF REFERENCE NUMBERS

Device suction device mixing chamber cleaning device 0 ₂ reducer fuel tank / H ₂ storage electrolytic H ₂ recovery H ₂ recovery by reforming electrolytic cell photovoltaic system reformer air heater water treatment device temperature control device aftertreatment device supply device to be conditioned room thermal circulating air treatment device cleaning device cell stack rectifier combustion chamber gas burner catalyst gas preheater block heat exchanger exchanger Gas turbine piston engine surface cooler washer basin

Dehumidification / Waseherkammer

nozzle

demister

heater

degassing chamber

water filters

Water cooler pH grading

pump

outlet valve

air cooler

air heater

Partikeifilter

Activated carbon filter

ionization chamber

Claims

claims

1. A method for air-conditioning at least one room (38) with an air mixture which has an oxygen partial pressure that is lower than that of an ambient air, at least some of the oxygen (0 ₂ ) contained in the ambient air being chemically reduced to a reaction product and the air mixture treated in this way as Supply air is supplied to the at least one room (38) to be air-conditioned.

2. The method according to claim 1 or 2, characterized in that the chemical reduction of the oxygen (0 ₂ ) is carried out by reaction with at least one fuel.

3. The method according to claim 2, characterized in that a combustible liquid or a combustible gas, in particular methane, ethane, propane, butane, natural gas, molecular hydrogen (H ₂ ), or a mixture of these is used as fuel.

4. The method according to claim 3, characterized in that natural gas or molecular hydrogen (H ₂ ) is used as fuel.

5. The method according to claim 3 or 4, characterized in that the molecular hydrogen (H ₂ ) is generated by electrolysis of water or by reforming hydrocarbons, in particular fuel gases or gasoline.

6. The method according to any one of the preceding claims, characterized in that reaction products of the oxygen and / or the at least one fuel are at least partially separated from the treated air mixture before the supply air is fed into the at least one space (38).

7. The method according to any one of claims 1 to 6, characterized in that the reduction of oxygen is carried out by electrochemical reaction with a fuel in a fuel cell.

8. The method according to any one of claims 1 to 6, characterized in that the reduction of oxygen is carried out by supplying and burning a fuel supplied to the air in an internal combustion engine or a combustion turbine.

9. The method according to any one of claims 1 to 6, characterized in that the reduction of oxygen is carried out by supplying and burning a fuel supplied to the air in a combustion chamber.

10. The method according to any one of claims 1 to 6, characterized in that the reduction of oxygen is carried out by reaction with a fuel on a catalyst.

11. The method according to any one of claims 1 to 6, characterized in that the reduction of oxygen is carried out by reaction with a fuel on electrically heated wires.

12. The method according to any one of the preceding claims, characterized in that a chemical chemical Production of the oxygen generated, in particular electrical energy and / or mechanical energy and / or thermal energy, is used for the method and / or externally.

13. The method according to claim 12, characterized in that the thermal energy generated during the chemical reduction of the oxygen is used to generate cold.

14. The method according to any one of the preceding claims, characterized in that the oxygen partial pressure is reduced to a value corresponding to a volume fraction of 5 to 21%, in particular to 12 to 16%.

15. The method according to any one of the preceding claims, characterized in that the method is carried out in a controlled manner, wherein an oxygen partial pressure measured in the at least one room to be air-conditioned is compared with a desired oxygen partial pressure and a conversion rate of the chemical reduction of oxygen and / or an air supply rate in the at least one room to be air-conditioned is set as a function of a deviation of the measured from the desired oxygen partial pressure.

16. The method according to any one of the preceding claims, characterized in that the supply air generated is supplied to at least one room intended for the stay of a person.

17. The method according to claim 16, characterized in that the at least one room intended for the stay of persons _. (38) a training room for sports training under normobaric hypoxia conditions or a therapy room under normobaric hypoxia conditions for rehabilitation purposes.

Method according to one of the preceding claims, characterized in that the supply air is subjected to at least one of the following treatment measures before it is fed into the at least one space to be air-conditioned:

- Filtration and / or air washing to remove particles, catalytic aftertreatment and / or air washing to remove gaseous components, - temperature control to set a specified air temperature, humidification or dehumidification to set a specified air humidity, - setting a specified C0 ₂ content, - ionization for setting an air quality.

19. The method according to any one of the preceding claims, characterized in that before the chemical reduction of the oxygen of the ambient air, recirculated air from the at least one room is mixed in any proportion.

20. The method according to any one of the preceding claims, characterized in that the ambient air and / or the circulating air is filtered and / or cleaned before being fed to the chemical reaction.

21. Device (10) for air conditioning at least one room (38) with an air mixture with an oxygen partial pressure that is lower than that of ambient air, Comprising a 0 ₂ reducer (16) for reducing at least part of the oxygen (0 ₂ ) contained in the ambient air with at least one fuel to a reaction product and a feed device (37) for feeding the air mixture treated in this way into the at least one room to be air-conditioned (38).

22. The apparatus according to claim 21, characterized in that the 0 ₂ reducer (16) comprises a ^' fuel cell for the electrochemical conversion of oxygen with a fuel.

23. The device according to claim 21, characterized in that the 0 ₂ reducer (16) comprises an internal combustion engine or a combustion turbine for converting the oxygen with a fuel.

24. The device according to claim 21, characterized in that the 0 ₂ reducer (16) comprises a combustion chamber for converting the oxygen with a fuel.

25. The device according to claim 21, characterized in that the 0 ₂ reducer (16) comprises a catalyst for converting the oxygen with a fuel.

26. The apparatus according to claim 21, characterized in that the 0 ₂ reducer (16) comprises a chamber with electrically heated wires, on which the oxygen is reacted with a fuel.

27. Device according to one of claims 21 to 26, characterized in that the at least one fuel is a combustible liquid or a combustible gas, in particular methane, ethane, propane, butane, natural gas, molecular hydrogen (H ₂ ) or mixtures of these is, preferably natural gas or molecular hydrogen (H ₂ ) •

28. Device according to one of claims 21 to 27, characterized in that between the 0 ₂ -Reduktor (16) and the feed device (37), an air maker (30) for separating reaction products of the oxygen and / or the at least one fuel from the treated air mixture is provided.