EP3176517B1 - Method and device for producing heat - Google Patents

Description

Technical field of the invention

The invention relates to a method for generating heat and a device with which the method can be carried out. The method and the device are preferably used to generate heat for hot water preparation and the heating of buildings.

State of the art

There are numerous methods and devices that use a wide variety of operating materials for generating heat in general, as well as for heating buildings and for preparing hot water. In the context of this disclosure, operating materials are understood to mean substances and forms of energy from which heat can be generated by physical or chemical processes. The following substances or mixtures of substances can therefore serve as operating materials, as well as electricity and the energy contained in the solar radiation spectrum: fossil fuels such as crude oil, natural gas, lignite, hard coal and peat, regenerative fuels such as wood and geothermal energy. In addition to the aforementioned operating materials, substances or substance mixtures can also be used as operating materials, with the help of which energy can be reversibly stored and released again in the form of thermal energy without a combustion process being involved. These include, for example, zeolites and hygroscopic salts or salt mixtures as well as generally heat transfer fluids. In addition, water, aqueous liquids and oils, so-called thermal oils, are used as operating materials in a wide variety of heat generating devices.

In the Offenlegungsschrift WO 2010/072 830 A1 describes a two-fuel burner for solid fuels and fluid fuels, consisting of a solid fuel burner which has a fire bowl and a swiveling fluid-fuel burner. The fluid-fuel burner is designed to be pivotable between a rest position located on the edge of the combustion chamber and the extended operating position, in which it extends over the brazier of the solid-fuel burner, and the entire flame area and the hot combustion gases during operation of the fluid-fuel -Burner are directed away from the fire bowl so that it is not damaged.

In the Offenlegungsschrift GB 2,446,954 A it is disclosed that the flame of a fluid burner is directed substantially away from the location of the solid combustion. Only a small part of the flame is directed onto the solid fuel by means of a "flame transfer device" in order to ignite it. Furthermore teaches GB 2,446,954 A explicitly that it is advantageous to direct the small part of the fluid burner flame only on a small part of the solid fuel, so that as little carbon monoxide (CO) as possible is produced in the ignition phase of the solid fuel.

In the patent specification CH 385 888 A discloses a steam generating device with water preheater and air preheater in the flue gas shaft, which is heated with residues, for example garbage or rubbish. Furthermore, an oil burner is provided in the wall of the combustion chamber opposite the filling shaft, which promotes the burnout in the case of hardly combustible residues. This oil burner is used exclusively to support combustion in the case of non-combustible fuels.

In the Offenlegungsschrift FR 2 733 303 A1 describes a boiler which is preferably operated with natural gas and which is also suitable for the incineration of household waste. The boiler according to FR 2 733 303 A1 contains at least two burners for a "staged", ie spatially separate, combustion of the fluid fuel. The waste materials to be incinerated are placed between these two incineration zones. This waste incineration zone is thus located between the two combustion zones of the two burners. Furthermore, the device in FR 2 733 303 A1 another shredder to shred the waste.

Until a few decades ago, almost exclusively fossil fuels and occasionally wood and electricity were used as operating resources. In the course of the realization that fossil fuels are finite and that the CO ₂ accumulation in the earth's atmosphere associated with their combustion is also harmful ("greenhouse effect"), renewable, sustainable operating materials are increasingly being used. In the course of the restructuring of our energy and heat supply, which is necessary for reasons of sustainability, it is an inevitable development that the variety of operating materials for the generation of heat, especially hot water and space heating, is increasing. The almost complete monopoly of fossil fuels, which existed until a few decades ago, is being broken up by current developments and it is foreseeable that there will be no further monopoly of any individual energy source in the future.

Renewable energy sources as operating resources for heat generation devices for heat generation in general, as well as hot water preparation and living space heating in particular, are often only available seasonally in the region, which makes year-round supply more difficult. A year-round supply with a favored regenerative energy source therefore inevitably leads to transport costs that worsen the ecological balance. In addition, the dependency on a single usable fuel represents a not insignificant factor of uncertainty with regard to the reliability of the heat generating device can be used in an optimal way throughout the year without restriction.

In the prior art, attempts are made to counter this by combining two mutually matching operating means. For example solar thermal energy with natural gas or geothermal energy with heating oil. This alleviates the problem a little, but due to the very different types of equipment, there are still some combinations, which up to now could not be combined with one another or only with great difficulty. In the prior art, particularly among fuels, there has not yet been any possibility of combining them with one another or of using them in a single device without manual intervention having to be undertaken. For example, so-called alternating fire boilers allow solid or liquid fuels to be used, but only one or the other; When switching from one fuel to the other, structural changes must be made to the relevant heat generating device, such as replacing the furnace door with an oil burner with one with openings for firing with logs. Furthermore, so-called two-chamber boilers are known in the prior art, which have two separate combustion chambers, for example one for solid fuels and one for liquid fuels. Disadvantages of this are, on the one hand, the complicated structure (high material consumption, complicated flue gas routing), on the other hand, a separate ignition device is required for each fuel, which is also very expensive. The creation of the possibility of being able to select the currently used operating resources as freely and without restriction as possible depending on the seasonal occurrence or the current purchase price, or to switch from one fuel to another automatically and without manual intervention, is therefore a particular advantage for the Operation of a heat generating device, both from a cost perspective and with regard to the availability of operating resources due to failure safety and user-friendliness.

task

The object of the present invention is to provide a method and a device with which it is possible to provide heat, inter alia, for hot water preparation and room heating, without being restricted in the choice of operating media, in particular the fuels. This eliminates the prior art limitation of choosing the Having to restrict the heat generating device to an operating medium, in particular a fuel, has been overcome. The object of the invention furthermore comprises significantly improving the user-friendliness of devices for generating heat that can use several fuels / operating media.

This object is achieved by the method according to the invention with the characterizing features of independent claim 1 and the device according to the invention with the characterizing features of claim 8. The dependent claims show further advantageous embodiments of the method according to the invention.

The method according to the invention and the device according to the invention thus make it possible to use fuels in any physical state, depending on which fuel is currently available, both in combination with one another and independently of one another. In particular, the method according to the invention can be carried out independently of the device according to the invention. However, the method according to the invention is preferably carried out in the device according to the invention.

description

The device according to the invention is described below with reference to FIG Fig. 1 is described in more detail with reference to the exemplary embodiment shown schematically therein, without limiting the device according to the invention to this exemplary embodiment. For the sake of clarity, the fuels which can be used according to the invention are shown in FIG Fig. 1 not shown.

A device according to the invention for generating heat is a device in which the method according to the invention can be carried out in at least one embodiment or in a combination of at least two embodiments. It comprises a combustion chamber 100 and a feed device for at least one fuel. In Fig. 1 are exemplary three feeding devices 1a, 1b and shown schematically for fuels 1c, is to be assumed as an example for the further description that feeding means is adapted 1a for gaseous fuels, feeding means 1b (lumpy) for liquid fuels and supply device 1c for solid fuels, so that in the combustion chamber 100 at least one combustion process can take place.

For the combustion of the fuels and the generation of heat, the device according to the invention has at least one supply device 2 for combustion air, at least one discharge device 3a for the exhaust gases produced by the at least one combustion process, and optionally at least one discharge device 3b for the ashes and produced by the at least one combustion process at least one igniter to 5 wherein at least one of the fuel can be ignited with the at least one ignition device. 5 The at least one supply device 2 for combustion air can be structurally combined with one or more supply devices 1a , 1b or 1c for fuels, so that combustion air and fuel are supplied through at least one common, suitably designed, supply device. All feed devices are usually connected to suitable conveyor devices in each case, and these in turn with corresponding storage devices, which, however, for the sake of clarity in Fig. 1 is not shown.

The feed devices 1a , 1b and 1c each have at least one suitably designed and dimensioned outlet opening through which the respective fuel enters the combustion chamber. The relevant details of the feed devices 1a , 1b and 1c as well as the conveying devices required for transporting the fuels are shown in Fig. 1 not shown for the sake of clarity. The person skilled in the art knows numerous possibilities for conveying the fuels as well as design possibilities for the outlet openings which can be used according to the invention. As a combustion chamber is understood to mean that space region within the combustion chamber 100 which cannot be clearly delimited in which the at least one combustion process takes place. This combustion chamber approximately encompasses that space area within the combustion chamber 100 which is covered by the supply devices 1a , 1b , 1c , and 2 , possibly the ignition device 5 , the discharge devices 3a and possibly 3b as well as the at least one support surface 6 on which the at least one solid fuel during of the combustion process rests on, is incompletely delimited. It should be noted that the at least one support surface 6 is only required if at least one solid fuel is used. What has been said above with regard to the support surface 6 also applies analogously to the at least one discharge device 3b . It should also be noted that the ignition device 5 does not necessarily have to be arranged on the edge or in the vicinity of the edge of the combustion chamber. It can also be located at least partially inside or outside the combustion chamber. The person skilled in the art knows numerous design options for the support surface 6 from the prior art, which can be used according to the invention. The following may be mentioned by way of example: grids, gratings, perforated plates and the like. According to the invention, the bottom of the combustion chamber 100 can also form the support surface 6 in sections or completely.

In the embodiment of Fig. 1 the ignition device 5 is arranged on at least one outlet nozzle of the feed device 1b for liquid fuels, so that the liquid fuel used in each case is ignited with the ignition device 5. After the liquid fuel has been ignited, gaseous fuels supplied with the supply device 1a ignite automatically at the flame in the combustion chamber that is fed by the liquid fuel. The same also applies to solid fuels that are fed in: these too are ignited by the respective burning liquid fuel. In this way it is possible to use any fuels with an ignition device optimized for a fuel to ignite automatically. It is obvious to the person skilled in the art that the inventive concept is not restricted to the current exemplary embodiment, but also applies to any other analogous arrangement. For example, it is equally preferred to arrange an ignition device 5 that can be used for gaseous fuels in the vicinity of the at least one outlet nozzle of the feed device 1a for gaseous fuels and thus to ignite the liquid fuels and the solid fuels by the respective burning gaseous fuel. What has been said also applies to the use of ignition devices 5 for solid fuels, these usually not being arranged in the vicinity of the outlet opening of the feed device 1c . Numerous ignition devices which can be used according to the invention are known to the person skilled in the art from the prior art. Examples include: electrical and piezoelectric ignition devices for gaseous and liquid fuels, matches, fire lighters, hot air ignition devices and the like for igniting solid fuels. The ignition device 5 can be operated both manually and automatically. The ignition device 5 used in each case can either be permanently fixed on or in the combustion chamber 100 , or be detachable and refastenable on or in the combustion chamber 100 , or can be temporarily inserted into the combustion chamber 100 independently of the combustion chamber 100 to achieve the desired Carry out ignition process.

Furthermore, the device according to the invention comprises at least one device 4 for dissipating the useful heat generated. Here, too, the person skilled in the art is familiar with numerous devices for dissipating useful heat, so-called heat exchangers, which can be used according to the invention. In Fig. 1 is an example of the execution as a heating coil, so a spiral bent pipe in which a heat transfer medium circulates, symbolized. The device 4 for dissipating the useful heat can of course also be at least partially integrated into the wall and / or the ceiling and / or the floor of the combustion chamber 100 , as is the case with the so-called articulated boilers made of cast iron segments.

1. a) Die erfindungsgemäße Vorrichtung enthält nicht nur eine Zuführungseinrichtung für Brennstoffe, wie es im Stand der Technik üblich ist, sondern drei Zuführungseinrichtungen 1a, 1b, 1c für drei Brennstoffe (fest, flüssig, gasförmig).
2. b) Die Zuführungseinrichtungen 1a, 1b, 1c, 2, sowie die Auflagefläche 6 für Festbrennstoffe sind so geformt dimensioniert und zueinander angeordnet, daß der Verbrennungsprozeß jedes Brennstoffs in dem im wesentlichen gleichen räumlichen Bereich der Brennkammer, dem Brennraum, erfolgt, wodurch sichergestellt wird, daß jeder aktuell gerade brennende Brennstoff jeden anderen zudosierten Brennstoff entzündet.
3. c) Es müssen keine baulichen Veränderungen an der Vorrichtung vorgenommen werden, um von einem Brennstoff auf einen anderen Brennstoff zu wechseln oder das Mischungsverhältnis der Brennstoffkombination zu verändern.

The following features are particularly essential to the invention:

1. a) The device according to the invention contains not only one feed device for fuels, as is customary in the prior art, but three feed devices 1a , 1b , 1c for three fuels (solid, liquid, gaseous).
2. b) The feed devices 1a , 1b , 1c, 2 , as well as the support surface 6 for solid fuels are shaped so dimensioned and arranged with respect to one another that the combustion process of each fuel takes place in essentially the same spatial area of the combustion chamber, the combustion chamber, which ensures that every fuel currently burning ignites every other fuel added.
3. c) There is no need to make any structural changes to the device in order to switch from one fuel to another fuel or to change the mixing ratio of the fuel combination.

The invention further comprises a method for generating heat, the heat being generated by at least one combustion process, which is characterized in that fuels of any aggregate state are burned to generate the heat without structural changes having to be made to the device, in which the at least one combustion process takes place in order to switch from one fuel to another fuel or to change the mixing ratio of the fuel combination.

"Fuels" in the context of the present disclosure are understood to mean all solid, liquid or gaseous substances or substance mixtures, which can be burned in air or in other oxygen-containing gas mixtures with the development of heat, the combustion proceeding automatically after ignition until the fuel is largely completely burned. Substances or substance mixtures whose combustion can only take place with sufficient additional combustion, ie joint combustion with an independently combustible fuel, are therefore not considered fuel in the sense of this disclosure. In the context of this disclosure, a “combustion process” is understood to mean both the combustion of a pure substance and the combustion of a substance mixture or a mixture of fuels.

The use according to the invention of at least three fuels of different physical state, or of the same or different composition, to generate heat in a device without having to physically change the device to change the fuel or the mixing ratio of at least three fuels, can be carried out in two variants . Variant 1 is characterized in that at least three fuels of different physical state are burned individually one after the other and in any order. Variant 1 thus represents the sequential use of different fuels. Variant 2 is characterized in that at least three fuels of different physical states are burned together. Variant 2 thus represents the simultaneous, ie simultaneous, use of different fuels. As a result of these two basic variants of the process control, the inventive method offers the special possibility of providing heat very flexibly using the currently best available energy sources, in particular fuels. The decision The choice of fuel can be made as desired - both depending on local direct availability and depending on the current purchase prices of the fuels. This decision-making and thus the setting of the desired process parameters, i.e. the current operating mode, can take place both manually and automatically, for example controlled by a microcontroller or a microprocessor-based computer system, for example a personal computer (PC). That is, the method is carried out according to the invention both in its entirety and in parts, both manually and automatically. The combined implementation, that is to say in parts manual and in parts automated, is also according to the invention.

The method according to the invention can be used universally. It is very particularly preferably used for the preparation of hot water and / or the heating of rooms, that is to say buildings and building complexes. However, it can of course also be used to provide process heat, for example in the chemical industry or other manufacturing industries. This means that the heat generated can not only be dissipated using water as a heat storage medium and / or heat transport medium, as is usual in the area of hot water generation and the provision of space heating. Rather, the method according to the invention also includes the transfer of the heat generated to an aqueous or non-aqueous, liquid, solid or gaseous heat storage medium or heat transport medium, the heat storage medium and / or the heat transport medium being selected from the list comprising thermal oils, salt solutions, molten salts, ionic liquids, molten metals and solids, the term “solids” including all solids which are stable at the temperatures and other ambient conditions prevailing in the context of the at least one combustion process. Other environmental conditions include the ambient pressure and the chemical composition of the surrounding atmosphere. The combustion gases themselves also represent a heat transport and / or heat storage medium.

The following devices and processes are excluded from the scope of the invention:
The invention does not relate to combustion devices and combustion methods as e.g. B. be used in the field of residual or waste incineration (for example fluidized bed and fixed bed reactors), since there the various combustible substances, especially the residual or waste, cannot continue to burn independently of each other after ignition. It is therefore not a matter of fuels according to the present disclosure, but only of combustible substances. In addition, the actual task of such devices and methods is not to generate heat, but to dispose of residual or waste materials. Furthermore, the invention also does not relate to devices and methods in which at least one of the fuels is at least partially part of a product manufactured in the context of the method. An example of this is the use of scrap tires in cement production. Here, the combustible parts of the old tires are used to generate heat for the production of the cement clinker, and the ash part of the old tires becomes part of the cement clinker. Another difference of the invention disclosed here is that the heat generated in cement production is used in the device itself and is not dissipated from the device in order to use it for other purposes. The invention also does not relate to crematorial incineration devices.

In the drawings and the written description, the individual features of the invention are denoted by reference numerals, without this being associated with a restriction of the invention, and like reference numerals in the drawings and the written description as well as the claims refer to the same features throughout.

Further objectives, features, advantages and possible applications of the invention emerge from the following description of exemplary embodiments and the drawings.

List of reference symbols

• 1a : Feed device for gaseous fuels
• 1b : Feed device for liquid fuels
• 1c : Feed device for solid fuels
• 2 : Supply device for combustion air
• 3a : discharge device for combustion gases
• 3b : discharge device for ashes
• 4 : Device for dissipating useful heat
• 5 : Ignition device
• 6 : Support surface for solid fuels
• 10 : Process status or process step "Introduction of a first fuel"
• 20 : Process status or process step "fuel monitoring"
• 30 : Process status or process step "fuel ignition"
• 40 : Process status or process step "combustion operation"
• 50 : Process status or process step "combustion operation monitoring" resp. "Combustion Monitoring"
• 60 : Process status or process step "introduction of a second fuel"
• 70 : Process status or process step "Introduction of at least one further fuel"
• 100 : device according to the invention

Brief description of the drawings

Fig. 1 shows schematically an embodiment of the device according to the invention by way of example. The drawing is not to scale.

Fig. 2 shows an example of a flow chart by means of which the method according to the invention can be carried out. The individual process steps or process / operating states are symbolically represented by geometric figures (ellipses, rectangles, diamonds) and provided with reference symbols. The time sequences and / or effects of the individual process steps or process / operating states are indicated by arrows and explained in more detail in the description.

Embodiments

An embodiment of the device according to the invention has already been described above with reference to Fig. 1 described. The method according to the invention is carried out below by way of example and with the aid of Fig. 2 described on the basis of the implementation of the method according to the invention with three fuels of different physical states.

The method according to the invention begins with the introduction of a first fuel (1st fuel inlet, 10 ), which is monitored by means of appropriate sensors (fuel monitoring, 20 ) in order to avoid overdosing. When there is sufficient fuel in the combustion chamber 100 , the fuel is ignited (fuel ignition, 30 ), which according to the invention can be carried out both manually and automatically by means of the ignition device 5. Once the ignition has taken place, the central operating state (combustion mode, 40 ) of the method is reached. The combustion operation is monitored by means of suitable sensors that include at least one sensor (combustion operation monitoring "or" combustion monitoring ", 50 ). Suitable sensors for this are known to the person skilled in the art As soon as the first fuel burns stably, further fuels can be introduced directly into the combustion chamber (2nd fuel inlet, 60 ; further fuel inlet (s), 70 ), which is usually controlled or respectively controlled by the combustion monitor 50 is regulated. According to the invention, external information such as the fill levels of the fuel storage container, current market prices of fuels, etc. can also be used to make decisions, indicated by the broken arrow " ext .". In the exemplary embodiment disclosed here, it is not specified which fuel is used as "ignition fuel", ie which fuel is primarily ignited by ignition device 5 and then ignites the other fuels that can be metered in. The inventive concept provides that any fuel can be used for this, regardless of whether it is solid, liquid or gaseous. The implementation of the invention with a plurality of ignition devices 5 also falls within the scope of the invention; however, for reasons of cost it is usually preferred to opt for a "pilot fuel" and design the device accordingly. Preferred ignition fuels are liquid and gaseous fuels. The process is usually terminated by interrupting the supply of combustion air and / or the one or more fuels currently being used. The method can be carried out manually / manually as well as automated / program-controlled using mechanical and / or electronic computing devices such as microcontrollers (including the peripherals required for operation), complete data processing systems such as personal computers or industrial control systems. The integration of the dissipation of useful heat and combustion products is in Fig. 2 not explicitly shown, since the person skilled in the art is familiar with corresponding devices / methods which can be used according to the invention.

It should also be noted that the combustion operation monitoring 50 does not necessarily only - as in FIG Fig. 2 - monitors the metering of the at least two further fuels, but can also monitor the metering of the first fuel 20 , which represents a further simplified embodiment of the invention.

Advantages of the invention

The present invention allows a previously unknown flexibility and user-friendliness to use a wide variety of fuels in a single device for generating heat without having to make structural changes to change the fuel. In addition, it enables several fuels to be used at the same time.

Claims (8)

1. Method for generating heat, the generation of the heat being effected by at least one combustion process within a combustion space within a combustion chamber (100), characterised in that at least three fuels of different aggregate state, gaseous, liquid and solid, are burnt to generate the heat, whereat no structural changes have to be made to the apparatus, within which the at least one combustion process takes place and which contains an ignition device (5), in order to change from one fuel to another fuel or in order to change the mixing ratio of the fuel combination, and whereat one of the fuels is ignited by the ignition device (5) and then in turn ignites the other two fuels.
2. Method according to claim 1, characterised in that at least three fuels of different aggregate state are burnt one after the other and in any one order.
3. Method according to claim 1, characterised in that at least three fuels of different aggregate state are burnt together.
4. Method according to any one of the preceding claims 1 to 3, characterised in that the method is used for the preparation of hot water and/or the heating of rooms.
5. Method according to any one of the preceding claims 1 to 4, characterised in that the generated heat is transferred to an aqueous or non-aqueous, liquid, solid or gaseous heat storage medium or heat transport medium, whereat the heat storage medium and/or the heat transport medium are selected from the list comprising thermal oils, salt solutions, molten salts, ionic liquids, molten metals and solids, whereat the term "solids" includes all solids that are stable at the temperatures, pressures and chemical compositions of the surrounding atmosphere during the at least one combustion process.
6. Method according to any one of the preceding claims 1 to 5, characterised in that the method is carried out manually.
7. Method according to any one of the preceding claims 1 to 5, characterised in that the method is carried out automatically.
8. Apparatus for generating heat, arranged for carrying out a process according to at least one of the preceding claims or any combination of processes according to the preceding claims, comprising

   - a combustion chamber (100),

   - a supply device (1a) for at least one of the fuels, so that at least one combustion process can take place in the combustion chamber (100),

   - at least one supply device (2) for combustion air,

   - at least one discharge device (3a) for the exhaust gases produced by the at least one combustion process,

   - at least one device (4) for discharging the useful heat produced,

   - at least one ignition device (5), whereat at least one of the fuels is being ignitable by means of the at least one ignition device (5),

   - as well as - whereat at least one solid fuel is being combustible in the combustion chamber (100) -

   i) at least one supporting surface (6), on which the at least one solid fuel rests during the combustion process, and

   ii) at least one discharge device (3b) for the ashes produced by the at least one combustion process,
   characterized in that

   a) the apparatus has at least two further supply devices (1b and 1c), each one for at least one of the further fuels, and

   b) the supply devices (1a, 1b, 1c, 2) and the supporting surface (6) for solid fuels are shaped, dimensioned and arranged in such a way relative to each other that the combustion process of each fuel takes place in the substantially same spatial area of the combustion chamber (100), whereby it is ensured that each fuel currently burning ignites every other fuel added, and

   c) no structural modifications are made to the device in order to change from one fuel to another fuel or to change the mixing ratio of the fuel combination.

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