Heating device with improved efficiency

Abstract

To provide a heating device, preferably for the combustion of biomass products, in particular pellets made from biomass, with increased efficiency, a method for increasing the efficiency of the heating device and a corresponding use.SOLUTION: A heating device comprises: a burner part comprising a combustion chamber, a double-walled internal hollow combustion chamber wall 10 having an upper opening leading from above a combustion zone to the inside of the combustion chamber, a flue gas duct 22 for conducting flue gas downward along the combustion chamber, a heat exchanger area following the flue gas duct 22, the heat exchanger area comprising a flat tube flue gas heat exchanger 3 and a tertiary air heat exchanger 2, and a radiant heat exchanger 5 disposed above the combustion chamber; and a heating part comprising an air suction blower 23, an exhaust heat exchanger 7 having the same heat transfer medium as the flat tube flue gas heat exchanger 3, and an outlet opening 24 for heated air. The flat tube flue gas heat exchanger 3 forms a heat exchange circuit with the exhaust heat exchanger 7.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] All documents cited in this application are hereby incorporated by reference in their entirety into this disclosure.

[0002] The present invention relates preferably to biomass products with improved efficiency, particularly heating devices for burning pellets made from biomass, (corresponding) methods for improving the efficiency of the heating devices, and corresponding uses.

Background Art

[0003] From the prior art, a wide variety of heating devices are known. It is also known to operate heating devices using pellets. For example, prior art heating devices also include a heat exchanger adjacent to the combustion chamber or the high-temperature exhaust pipe in addition to the combustion chamber where the combustible material is burned, and this heat exchanger is used to release heat to the air to be heated, and water or air is used as the heat transfer medium.

[0004] For example, the specification of German Utility Model Registration No. 202010016404 or the specification of German Utility Model Registration No. 202018001770 can be cited as the prior art.

[0005] In terms of design, in the case of prior art devices, a relatively large amount of unused heat is released into the environment via the exhaust gas. The efficiency of these devices is not optimal.

[0006] In this regard, there are still quite a few possibilities for improvement starting from the prior art.

Prior Art Documents

Non-Patent Documents

[0007]

Non-Patent Document 1

Non-Patent Document 2

[0008] Therefore, an object of the present invention is to provide a heating device that exhibits an improved level of efficiency compared to conventional devices.

[0009] At the same time, an object of the present invention is to provide a method that can achieve improved efficiency of a heating device.

[0010] Ultimately, the feasibility of using heating devices with improved efficiency should be found.

[0011] Further objectives can be understood from the following explanation. [Means for solving the problem]

[0012] These and other objectives are resolved in the context of the present invention by the subject matter of the independent claims.

[0013] Preferred embodiments can be seen from the dependent claims and the following description.

[0014] In the context of this invention, temperature specifications are in degrees Celsius (°C) unless otherwise specified.

[0015] Unless otherwise specified, combustion takes place at ambient pressure (=normal pressure / atmospheric pressure), i.e., 1,013 mbar.

[0016] In the context of this invention, the term “comprise” also includes “consisting of.” That is, the corresponding list may include other elements in addition to the explicitly mentioned elements (=comprise), or may contain exactly these elements (=consisting of) (non-essential elements such as screws and markings are not considered).

[0017] In the case of relative information such as up and down, left and right, in the context of the present invention as a reference system, an observer standing upright on the ground in front of the object under discussion is assumed.

[0018] In particular, the subject matter of the present invention is a heating device, A) a burner section, - a combustion chamber, - a double-walled internal hollow combustion chamber wall having an upper opening leading into the combustion chamber from above the combustion zone, - a flue gas duct for guiding flue gas downward along the combustion chamber, - a heat exchanger region following the flue gas duct, - firstly, a flat tube flue gas heat exchanger, - then, a tertiary air heat exchanger, and a heat exchanger region comprising the same, - a flue gas ventilation stack, - a radiant heat exchanger arranged above the combustion chamber, - a flue gas flap at the upper end of the flue gas duct that connects the flue gas duct to the stack when open and a burner section comprising the same, B) a heating section, - an air suction blower, - an exhaust heat exchanger having the same heat transfer medium as the flat tube flue gas heat exchanger, - an outlet opening for the heated air and a heating section comprising the same, and a heating device in which the flat tube flue gas heat exchanger forms a heat exchange circuit with the exhaust heat exchanger.

[0019] In a preferred embodiment of the present invention, the combustion chamber comprises an inlet duct or inlet opening for primary air and secondary air, a grate and a burner, a supply opening for combustible material and a combustible material waste collection chamber and / or a combustible material waste discharge device, preferably a duct via a screw conveyor for removing combustible material waste connected to the combustion chamber in particular. Furthermore, a variant can provide an inspection window through which the combustion in the combustion chamber can be visually confirmed. However, in a variant of the present invention, electronic monitoring, for example by thermal sensors and cameras, to monitor the combustion (automatically) is also possible and preferred.

[0020] In some preferred variants of the present invention, the primary intake to the combustion chamber is at the end of an air suction channel guided along the combustion chamber wall. This allows the primary air to enter a system that is already preheated (by the heat radiated through the combustion chamber wall) during operation, and furthermore, the heat radiated through the combustion chamber wall is sensibly used and not released unused. At the same time, the secondary air can also be preheated via a corresponding duct.

[0021] The ignition of the combustion can be carried out by any conventional method. For example, a gas flame can be used for ignition. This can be part of a device in the form of a small gas burner. Or a ceramic ignition element as part of the device can be used for ignition by an air flow.

[0022] In a preferred embodiment of the present invention, the heating device comprises a (pellet) storage container connected to the combustion chamber via a supply opening for combustible material, preferably via a screw conveyor.

[0023] In a preferred embodiment of the present invention, the upper opening of the double-walled internal hollow combustion chamber wall leads to the combustion chamber above the combustion zone and post-combustion zone. Furthermore, in a preferred variant of the present invention, the double-walled internal hollow combustion chamber wall may be provided with a lower opening or connection configured to introduce tertiary air. This achieves that air already preheated by the tertiary air heat exchanger is further heated through the walls (of the combustion chamber) within the double-walled internal hollow combustion chamber wall and introduced into the combustion chamber in a quasi-double preheated state above the combustion zone, where it is mixed with the flue gas. This yields several desirable effects: on the one hand, the flue gas is diluted so that the exhaust gas exiting the flue has a lower pollutant concentration; on the other hand, energy is "captured" by the tertiary air, otherwise the energy escapes unused from the system, on the one hand immediately after the heat exchanger region and on the other hand through the combustion chamber wall.

[0024] In a preferred embodiment of the present invention, the flue gas duct is positioned against the double-walled, hollow combustion chamber wall on the opposite side of the combustion chamber, and the flue gas is guided downward along the wall of the flue gas duct positioned within the combustion chamber. Thus, a kind of counterflow principle is applied, thereby the flue gas is further heated by the heated wall (of the combustion chamber). Along with the use of tertiary air, this also results in the use of thermal energy radiated through the combustion chamber wall, preventing the system from remaining unused.

[0025] In a more preferred embodiment of the present invention, the combustion chamber sidewalls can be completely surrounded by flue gas ducts and double-walled hollow combustion chamber walls, based on the ratio of the circumference of each covered combustion chamber wall, for example, about half, or 1:2, or 1:3, or 1:4, or any other ratio of flue gas ducts to double-walled hollow combustion chamber walls, away from the inlets for supplying primary and secondary air and combustible material and, where applicable, for discharging combustible material. This can optimize the "capture" of energy radiated through the combustion chamber sidewalls. Of course, in this case, it is also possible to provide, for example, additional openings for observation and / or inspection windows.

[0026] In a preferred embodiment of the present invention, the heat exchanger region is positioned in the direction of flue gas flow beyond the flue gas duct. The flat-tube flue gas heat exchanger operates using hot oil as a heat transfer medium. The hot oil is preferably selected from mineral oil, synthetic oil, or silicone oil, and particularly preferably silicone oil is used in the context of the present invention. The tertiary air heat exchanger comprises an inlet duct or inlet opening for tertiary air and an outlet connected to a double-walled, hollow combustion chamber wall for heated tertiary air. The tertiary air heat exchanger draws in air from the outside, which is then heated by the flue gas. The air thus heated is then guided to the double-walled, hollow combustion chamber wall, where it is further heated, and finally guided to the combustion chamber above the combustion zone.

[0027] The double-walled combustion chamber walls are preferably designed with internal baffles that each obstruct a portion of the flow path and thus redirect the airflow, resulting in an airflow that flows through the interior of the double-walled combustion chamber walls in a meandering or intertwined manner. This causes the tertiary airflow to flow almost entirely along the (hot) combustion chamber walls, thus ensuring the most effective heat transfer possible to the tertiary air.

[0028] In a preferred embodiment of the present invention, the region having the induced draft blower is adjacent to the heat exchanger region. However, in a modification, and where applicable, the induced draft blower may also be located within or therein in the flue gas ventilation stack. These blowers are intended to generate negative pressure in the burner section, so that air (primary, secondary, and tertiary air) is drawn through the device on the one hand, and flue gas is not allowed to escape due to any possible leaks on the other hand.

[0029] In a preferred embodiment of the present invention, the heating section preferably comprises an air intake section in the form of at least one air duct, the air intake section drawing in air from above or through the radiant heat exchanger.

[0030] In a preferred embodiment of the present invention, the air suction blower for the heating section is configured or converted to draw in air from the air suction section, at least partially, preferably partially, 40 to 60%, particularly 50%, of which air is drawn in from the environment, otherwise the percentage refers to the total volume of air drawn in.

[0031] In a preferred embodiment of the present invention, the two parts A) and B) (burner section and heating section) are connected to the exhaust heat exchanger by piping of a flat-tube flue gas heat exchanger, and, where applicable, by connecting the air intake section of the heating section to the radiant heat exchanger, otherwise they are physically separated units. However, in the context of the present invention, and therefore in a modified version, it is also possible and therefore preferable to firmly join the two parts (by screwing, welding, riveting, etc.).

[0032] A particularly preferred heating device according to the present invention is preferably for the combustion of biomass, especially pellets derived from biomass, and accordingly, A) The burner section, - A combustion chamber, - Inlet ducts or inlet openings for primary and secondary air, - Grate and burner, - A supply opening for flammable materials, - A combustion chamber comprising a combustible waste collection chamber and / or combustible waste discharge device, preferably a duct via a screw conveyor for removing combustible waste connected in particular to the combustion chamber, - A (pellet) storage container connected to the combustion chamber via a supply opening for flammable material, preferably via a screw conveyor, - A double-walled internal hollow combustion chamber wall having an upper opening that leads into the combustion chamber above the combustion zone, preferably above the combustion zone and post-combustion zone, and a lower opening or connection configured to introduce tertiary air, - A flue gas duct positioned on the other side of the combustion chamber relative to the double-walled internal hollow combustion chamber wall, which guides flue gas from top to bottom along the wall adjacent to the combustion chamber, - A heat exchanger region adjacent to the flue gas duct and positioned beyond the flue gas duct from the field of view of the combustion chamber, - First, a flat-tube flue gas heat exchanger, preferably having hot oil as a heat transfer medium, - Next, a heat exchanger region comprising a tertiary air heat exchanger having an inlet duct or inlet opening for tertiary air and an exhaust section for heated tertiary air connected to the double-walled internal hollow combustion chamber wall, - Optionally, a region adjacent to the heat exchanger region having an induced draft blower, - Flue gas ventilation stack, - A radiant heat exchanger positioned above the combustion chamber, - When open, the flue gas flap at the top of the flue gas duct connects to the stack. A burner section equipped with, B) Heating section, - An air intake unit that draws in air from above or through the radiant heat exchanger, - An air suction blower that draws air at least partially, preferably partially, from an air suction section, particularly preferably 40 to 60%, particularly 50%, otherwise draws air from the environment, where the percentage refers to the total amount of air drawn in. - An exhaust heat exchanger having the same heat transfer medium as a flat-tube flue gas heat exchanger, preferably hot oil, - Outlet opening for heated air and A heating section comprising, and comprising or consisting thereof, The flat-tube flue gas heat exchanger forms a heat exchange circuit with the exhaust heat exchanger, and the two parts A) and B) are connected to the exhaust heat exchanger by piping of the flat-tube flue gas heat exchanger, and, where applicable, by connecting the air intake of the heating section to the radiant heat exchanger, otherwise they are physically separated units.

[0033] The fact that the heating element and burner element are separate units allows for flexible handling. Therefore, if a part is faulty, it can be quickly replaced without the need to replace the entire heating device. Furthermore, it is possible to replace individual parts to adapt to the situation, for example, to set up a larger or smaller unit. Nevertheless, the heating element and burner element are usually used / transported / set up as a single unit, especially when designed as a movable variant (which may be a frame or support frame that can be a car trailer frame).

[0034] In the context of the present invention, the outlet opening for heated air may, in a suitable further embodiment, be equipped with a hose so that the escaping heated air can be better directed / guided to its intended destination.

[0035] Furthermore, the subject matter of the present invention is - As described in the context of the present invention, combustion is carried out in the combustion chamber under the supply of primary air through the combustion zone and secondary air at the upper end of the combustion zone, - First, the flue gas is guided through a flat-tube flue gas heat exchanger, and then through a tertiary air heat exchanger. - The tertiary air thus heated is then guided to the wall of the double-walled hollow combustion chamber for further heating. - Heated tertiary air from the double-walled hollow combustion chamber wall above the combustion zone, preferably above the combustion zone and post-combustion zone, is introduced into the combustion chamber and mixed with the flue gas. - Heat is transferred to at least a portion of the air heated by a heat exchanger located above the combustion chamber, - A method for improving the efficiency of a heating device by transferring further heat to the air heated by the exhaust heat exchanger using a heat transfer medium heated in a flat-tube flue gas heat exchanger and / or a thin-plate heat exchanger, preferably hot oil, especially silicone oil.

[0036] Another subject of the present invention, as described separately in this application, is a burner section for a heating device. In this case, the piping of a heat exchanger for heat transfer to the heating section is merely optional and may be installed in advance, but is not required. The air and gas flow associated with the heat exchanger on which the burner section is installed is essential to this subject of the present invention.

[0037] Therefore, preferably the burner section for the heating device is preferably, - A combustion chamber comprising inlet ducts or inlet openings for primary and secondary air, a grate and burner, a supply opening for combustible materials, a combustible waste collection chamber and / or a combustible waste discharge device, - A (pellet) storage container connected to the combustion chamber via a supply opening for flammable material, preferably via a screw conveyor, - A double-walled internal hollow combustion chamber wall having an upper opening that leads into the combustion chamber above the combustion zone, preferably above the combustion zone and the post-combustion zone, and a lower opening configured to introduce tertiary air, - A flue gas duct positioned on the other side of the combustion chamber relative to the double-walled internal hollow combustion chamber wall, which guides flue gas from top to bottom along the wall adjacent to the combustion chamber, - A heat exchanger region comprising: a flat-tube flue gas heat exchanger adjacent to the flue gas duct and positioned beyond the flue gas duct in the direction of flue gas flow, first preferably having hot oil as a heat transfer medium; and second preferably a tertiary air heat exchanger having an inlet duct or inlet opening for tertiary air connected to the double-walled internal hollow combustion chamber wall, and an outlet for heated tertiary air; - Optionally, a region adjacent to the heat exchanger region having an induced draft blower, - Flue gas ventilation stack, - A radiant heat exchanger positioned above the combustion chamber, - It includes a flue gas flap located at the top of the flue gas duct, which connects the flue gas duct to the flue when open.

[0038] Another subject of the present invention is the use of the heating apparatus according to the present invention for heating areas to be heated, in particular (partially) isolated areas, in particular rooms. In the context of the present invention, rooms also include tents, stalls, etc., in addition to chambers.

[0039] Furthermore, the subject matter of the present invention is also the use of the method according to the present invention to improve the efficiency of heating devices.

[0040] Furthermore, the subject matter of the present invention is also the use of the burner unit according to the present invention for burning combustible materials, preferably biomass, in particular wood pellets, or optionally for heating an area to be heated, in conjunction with a heating unit, particularly a heating unit as otherwise described herein.

[0041] Further preferred embodiments can be found below.

[0042] The heating device of the present invention can be designed as both a fixed unit and a movable unit. In some preferred modifications, it is designed as a movable unit. In this case, rollers or wheels may be attached to the bottom of the heating device. In other modifications, the heating device can be mounted on or positioned on a commercially available automobile trailer. In yet another modification, it can be designed as a device on a wheel having a trailer hitch, i.e., it can constitute a trailer itself.

[0043] The heating device of the present invention is not fixed to a certain size. However, for the most flexible and economical use possible, a size that corresponds to or fits commercially available automobile trailers is preferred. In this regard, a preferred embodiment of the device of the present invention is about 1 to 3 m in length, 1.5 to 2.5 m in width, and 1.5 to 2.5 m in height.

[0044] If the heating device (or burner unit) according to the present invention has wheels or rollers, or is loadable onto an automobile trailer, the device may be called a mobile heating device.

[0045] In a modified version, the heating device (or burner unit) according to the present invention is preferably electronically tuned and / or controlled. For this purpose, a corresponding sensor and at least one control unit are arranged on the device. Thus, the control unit comprises an operating unit that can be operated by a user.

[0046] If necessary, a control unit that can be operated remotely and therefore controlled remotely can be placed in the device (for example, if the temperature in the heated area becomes too high, the output of the device can be reduced). Such remote control can be performed, for example, using a (smartphone) app, or via W-LAN, Bluetooth (or other wireless communication).

[0047] The control device according to the present invention is preferably operated to ensure optimal air supply and flue gas removal by adjusting the intensity of the induced draft blower in the burner section, in particular, during the start-up and ongoing operation of the heating or combustion process, and by opening and closing throttle valves in the primary, secondary, and tertiary air ducts or inlets, where applicable. Furthermore, the air intake blower in the heating section is modified to achieve an optimal airflow / heat absorption ratio. It is preferable not to supply tertiary air during heating and startup. For example, this cools the flue gas flow initially and thus reduces the stacking effect (resulting in more power being required for the blower).

[0048] During the combustion process (i.e., after heating / starting), the suction effect of air rising within the walls of the double-walled hollow combustion chamber (due to the fact that it is heated) is sufficient to introduce the required amount of tertiary air into the system. However, in the context of the present invention, it is also possible to place a blower auxiliaryly within the tertiary air system. Similarly, the opening / inlet for air supply is usually sufficient for primary or secondary air. However, in this case, the blower may also be placed in each case to support the respective airflow (for example, to "blow air" to the combustion).

[0049] Furthermore, it is preferable that the position of the flue gas flap be adjusted according to the temperature inside the burner. While this can be implemented via a mechanical device such as a fuse, such a fuse is not preferable in that it must be replaced after use. In this regard, the flue gas flap is preferably adjusted electronically.

[0050] Due to its structure, a flat-tube gas heat exchanger allows the gas to pass through relatively slowly (or flow around the flat-tube thin plate), thereby giving it ample time to effectively transfer heat to the heat transfer medium, especially hot oil.

[0051] In a preferred modification of the present invention, the control of the supply of combustible material is performed via the rotational speed of a screw conveyor from the (pellet) storage container to the combustion chamber. This allows for effective adjustment of the supply of combustible material, on the one hand, so that too much is not supplied, which could lead to excessively high temperatures, and on the other hand, so that too little combustible material is supplied, resulting in combustion not stopping or generating too little heat.

[0052] Therefore, a preferred modification of the present invention involves electronically adjusting the entire apparatus, particularly preferably the air supply, flammable material supply, flammable material residue monitoring data, temperature (inside the combustion chamber), blower power, pump power of the heat exchanger circuit of the flat-tube flue gas heat exchanger / exhaust heat exchanger, and flue gas flaps, to detect possible emergency stop conditions via sensors and electrically (re)adjust accordingly.

[0053] In the context of the present invention, it has been surprisingly found that very high efficiency can be achieved by the heating device, burner section, or method according to the present invention.

[0054] This means that, according to the present invention, a very high utilization of the heat generated by combustion is achieved by all constructive means, far exceeding what has been achieved in the prior art. In the context of the present invention, heat is transferred directly to the heating section via two heat exchangers (a flat-tube flue gas heat exchanger and a radiant heat exchanger). Furthermore, a highly effective energy management system operates within the burner section due to the effect that the heat generated in the combustion chamber is not simply transferred through the flue gas, but passes along the flue gas duct on the combustion chamber wall, further heating the flue gas by mixing it with already heated tertiary air. Moreover, the "enclosure" of the combustion chamber, having a flue gas duct, a double-walled, hollow combustion chamber wall, and, where applicable, primary and secondary air supply ducts, achieves effective utilization of the heat radiated through the combustion chamber wall, and therefore is not released unused into the environment or necessitates additional complex and expensive insulation of the combustion chamber.

[0055] Therefore, overall, in this invention, the energy released by combustion is captured or converted as effectively as possible at as many locations as possible.

[0056] The function of the heating device according to the present invention can also be briefly described as follows.

[0057] In the combustion chamber, combustible material, preferably biomass-based, is ignited, particularly (wood) pellets that have been pushed into the combustion chamber by a conveying device, especially a screw conveyor. Combustion receives air from primary and secondary air ducts, which generates flue gas. Negative pressure is generated by an induced draft blower. Thus, the flue gas is mixed with tertiary air (which is drawn in from the outside by negative pressure through a tertiary air heat exchanger, connected to the double-walled internal hollow combustion chamber wall, and then through the combustion chamber wall). This mentioned tertiary air is heated in two stages. The first stage is a tertiary air heat exchanger where the residual flue gas temperature is used. In the second stage, the already preheated air is led to the double-walled internal hollow combustion chamber wall through a duct with a continuously variable throttle valve, and is therefore further heated by radiant heat. The flue gas mixed with tertiary air is drawn through side ducts into a flat-tube flue gas heat exchanger and a tertiary air heat exchanger. These are then released into the atmosphere through a stack.

[0058] The hot oil is heated by flue gas flowing through a flat-tube flue gas heat exchanger. This is then transported by a pump through an exhaust heat exchanger within the heating section. The exhaust heat available in the heating section is generated in two stages. Meanwhile, a portion of the intake air for the exhaust module is preheated by a radiant heat exchanger. The exhaust is heated via an exhaust heat exchanger.

[0059] The (pellet) storage container is preferably connected to the combustion chamber so that (adjustable) flammable material or flammable material (these two terms are used synonymously in the present invention) is supplied to the combustion chamber. Preferably, this is done via a screw conveyor, which offers various advantages, among other things, good controllability (of quantity) and a low risk of backfire. The (pellet) storage container is typically a large container filled with flammable material, which reaches its lower end by gravity, and in this respect, the container is preferably inclined at least partially downward. At this lower end, in a preferred embodiment, is a screw conveyor that transports the (adjusted) flammable material to the combustion chamber.

[0060] Furthermore, the level monitoring device may be placed inside or on the (pellet) storage container. In principle, this can be any suitable device, but preferably an ultrasonic or radar probe, particularly a radar probe, is used.

[0061] The heat exchanger used in the heating device of the present invention is a conventional heat exchanger in which a heat transfer medium flowing through pipes is heated or cooled by a fluid flowing around these pipes, thereby the fluid transferring heat to the heat transfer medium or absorbing heat from the heat transfer medium. In the context of the present invention, the fluid is, on the one hand, flue gas (or flue gas / tertiary air mixture), and on the other hand, the air that is heated.

[0062] In the context of the present invention, preferably, hot oil (which may also be referred to as hot oil in the context of the present invention) is used as a heat transfer medium for transferring heat between the burner section and the air heating section via a flat-tube gas heat exchanger / exhaust heat exchanger circuit.

[0063] Such hot oils for oil cooling and heating industrial plants and processes in closed circuits are basically known, and these hot oils can have different properties depending on their chemical composition. In the context of the present invention, mineral oil (e.g., diesel oil), synthetic oil (e.g., silicone oil), and aromatic hydrocarbons (e.g., DP / DPO) can preferably be used as hot oils. Particularly preferably, therminol SP is used as the heat transfer fluid.

[0064] Flue gas (combustion exhaust gas) is extracted from the heating device, more precisely from the combustion chamber, via an induced draft blower. This ensures that components such as the (pellet) storage container, combustion chamber, heat exchanger area, and tertiary air ducts (especially the ducts within the double-walled hollow combustion chamber walls) have an internal pressure lower than the ambient pressure. This is particularly preferable when starting the heating device, but also provides a supportive effect during ongoing operation. Furthermore, it is ensured that the flue gas flows only through stacks (i.e., induced channels) and not through any possible leaks. The induced draft blower can consist, for example, of a speed-controlled blower motor that drives a fan propeller.

[0065] The blower located in the heating section may have a speed control motor that drives the fan propeller. However, the blower in the heating section can be a composite device of several fan propellers.

[0066] In a preferred embodiment, the flammable material supply section of the heating device via a screw conveyor has a relatively small cross-section with relatively large longitudinal expansion, resulting in most of the heat being radiated across the (steel) walls of the supply device, and the temperature from the combustion chamber toward the (pellet) storage container decreasing very rapidly. Furthermore, a relatively small amount of flammable material is contained in the screw conveyor, which typically does not generate enough heat for a return fire, as heat loss is dominant and any possible residue cannot continue. Therefore, the screw conveying of flammable material into the combustion chamber according to the preferred invention is classified as having a low risk of return fire from the combustion chamber toward the (pellet) storage container. However, in a modification of the invention, for safety reasons, a fuse, such as a molten fuse, may still be placed therein, which can trigger water, CO2, N2, or another extinguishing agent to extinguish such a return fire.

[0067] The better the insulation of the connection between the flat-tube flue gas heat exchanger and the exhaust heat exchanger, and the shorter the connection, the more effective the thermal efficiency of heat transfer becomes. In this respect, in the context of the present invention, it is preferable that this connection be as short as possible and insulated.

[0068] Therefore, some aspects of the present invention that are worth mentioning are, in particular, the following:

[0069] The heating device of the present invention preferably uses a biomass-derived combustible material, particularly wood pellets, and preferably uses hot oil as a heat transfer medium from the burner section to the heating section.

[0070] The heating device of the present invention preferably also uses tertiary air adjusted to improve efficiency (the amount of tertiary air drawn in is adjusted by a fan flap that can be continuously adjusted according to the temperature in the combustion chamber, and initially no tertiary air is drawn in when the heating device is started), and the energy is obtained in two stages, the first stage being a tertiary air heat exchanger in which newly drawn tertiary air is heated by flue gas (or flue gas / air mixture), and the second stage being the radiant heat of the combustion chamber as the tertiary air preheated in the tertiary air heat exchanger flows through the double-walled hollow combustion chamber wall.

[0071] The heating device of the present invention is equipped with a flue gas flap that reliably and regularly causes overheating protection (automatically).

[0072] The heating device of the present invention enables direct heat recovery by using a radiant heat exchanger in combination.

[0073] In one modification, the heating device of the present invention preferably includes automatic monitoring of the supply of a flammable material (pellets) by a radar probe for continuous measurement and monitoring of the supply of the biomass-based flammable material.

[0074] The grates within the combustion chamber consist of preferred variations of high-temperature steel layers on a central shaft, where they are mounted in an anti-torsion manner.

[0075] In this case, the grate plates are held at a predetermined distance by spacer elements, thus allowing on the one hand the supply of primary air (under flow) to the combustible material, and on the other hand facilitating washing or discharge of ash into the ash container below (supportively).

[0076] In some preferred modifications, the cleaning is automatically initialized according to the exhaust gas value determined by a lambda probe. The cleaning process can be carried out, for example, by performing a rotational movement of the grate at a predetermined angle, which is pulled through a fixed comb at the end of the movement. The comb itself preferably consists of a fixed thin plate.

[0077] Heat exchangers for heating hot oil are particularly useful as flat-tube flue gas heat exchangers (for energy conversion in the primary circuit of a heating chamber), and such heat exchangers are commercially available, for example, from Fercher GmbH.

[0078] The flue gas flap is an overheat protection mechanism where the temperature of the heat transfer medium and / or system is monitored, and when it reaches a critical limit temperature, the flue gas flap automatically opens. The limit for flue gas is 550°C, and the limit for hot oil under normal operation is 280°C. In the event of an emergency shutdown or power outage, this is triggered at a flue gas temperature of 150°C.

[0079] While this invention primarily relates to the use of biomass products as combustible materials, it should be understood that the heating device according to this invention is also suitable for the combustion of other materials. For example, coal can also be burned (and in a broader sense still qualify as biomass), or plastics, preferably in granular form. However, for the combustion of plastics, it may be necessary to install an exhaust gas filter or exhaust gas filter system (however, for example, pure polyethylene is also combustible without a filter with proper control of the heating device according to this invention). In this respect, the use of the heating device according to this invention for the combustion of plastics is also included in this invention.

[0080] Optionally, the heating device according to the present invention includes a device for generating electrical energy. Here, an element operating according to the Seebeck effect in a possible modification, preferably a commercially available Peltier element, is in good thermal conduction contact between a hot combustion gas on one side and a heat exchanger on the other side that is still or again cooled (or more cooled). This creates a temperature gradient within the element, generates a voltage, and allows electrical energy to be extracted. In the best case, the generated electrical energy is sufficient to supply a (transmission) motor for supplying flammable material, an induced draft blower, and a control device or control electronic equipment (if any), or to supply external small consumers such as LED lamps, or to charge a power storage device of a mobile device via a standardized connector. As a result, the heating device according to the present invention is also suitable for use in remote locations where neither a public power grid nor a connection to a vehicle or caravan battery is available.

[0081] Those skilled in the art can easily perform precise design of combustion chambers, for example, by designing them to accommodate specific flammable materials or specific energy conversion / heat generation, including size, wall thickness, and materials, within the scope of general technical knowledge.

[0082] In the description of the apparatus according to the present invention, where a part or the whole of the apparatus is marked as "consisting of," this should be understood to refer to the essential components. Obvious or inherent parts such as piping, valves, screws, and measuring devices are not excluded thereby. However, other essential components that change the function (mode), such as additional combustion chambers, are preferably excluded.

[0083] Various embodiments of the present invention, for example, the various embodiments of the dependent claims, which are not exclusive, can be combined with each other in any way, as long as such combinations do not contradict each other. [Brief explanation of the drawing]

[0084] The present invention will be described in more detail below with reference to the drawings. The drawings should not be interpreted restrictively and are not to scale. The drawings are schematic and do not include all features of a typical device, but they are reduced to features essential to the present invention and its understanding, for example, screws, connectors, etc., are not shown in detail.

[0085] The same reference numerals indicate the same features in the drawings, specification, and claims.

[0086] [Figure 1]This diagram schematically shows a modified embodiment of the heating device according to the present invention from the front. The burner section is shown on the left, and the heating section is shown on the right. In the burner section, an opening or inlet for primary air 9 is shown in the lower right (shown here as a single opening, but it may be multiple ducts, or it may be designed in a grid or other way, and the grid shape is itself proven to prevent any flammable material from escaping). Air flows from there into the combustion chamber 8. The combustion chamber shows a grate 19, a supply opening 20 for flammable material, and a screw conveyor 21 at the bottom for removing flammable material waste (the flammable material collection chamber itself is not shown here as it is behind the screw conveyor 21). Above the grate 19 is a secondary air intake section 6 (shown here as a filled-in rounded rectangle, but in reality it may be, for example, a grid shape, or it may be designed in other way, and the grid shape is itself proven to prevent any flammable material from escaping). In the combustion chamber 8, combustible material burns, causing flue gas to rise. These gases come into contact with the upper part of the boundary of the combustion chamber 8, where they transfer heat to the radiant heat exchanger 5 located in the combustion chamber 8, or otherwise follow a path to the left into the flue gas duct 22 (see filled arrow). The path through the flue gas duct 22 then leads downward in counterflow along the (hot) wall to the combustion chamber 8. Upon entering the bottom, the path proceeds to the left (see filled arrow) and upward toward the heat exchanger area. There, the flue gases first flow through the flat-tube flue gas heat exchanger 3 and then through the tertiary air heat exchanger 2. Above this, an induced draft blower 1 is located to generate negative pressure in the burner section. Finally, the flue gases flow out through the stack 11. Furthermore, to prevent overheating of the equipment or heat transfer medium within the flat-tube flue gas heat exchanger (shown here in the open position), a flue gas flap 4 is shown that establishes a direct connection from the beginning of the flue gas duct 22 to the beginning of the stack 11 if the temperature becomes too high. The tertiary air heat exchanger 2 is shown here as a series of circles representing tubes.These are circulated by the hot flue gas, and this tertiary air is drawn in from the outside. This tertiary air then flows through piping (not shown) into the double-walled internal hollow combustion chamber wall 10, shown here in a rectangular shape to indicate a baffle that causes a meandering flow induction. In the double-walled internal hollow combustion chamber wall 10, the tertiary air flows upward in a meandering manner, thereby being heated by the hot combustion chamber wall, and exits from the top end through the opening of the double-walled internal hollow combustion chamber wall 10, preferably flowing into the combustion chamber above the combustion zone and post-combustion zone. It then flows through the burner section together with the flue gas as described above. The heating section shown on the right side of the figure includes an air suction blower 23 that draws in heated air from the outside. The heating section also includes a connection to the radiant heat exchanger 5 at the upper end of the air suction section 25 (thereby the air heated therein is drawn in from above or through the radiant heat exchanger 5 - see filled arrow). Therefore, some of the drawn-in air is already heated (by the radiant heat exchanger 5) and drawn in, while some is drawn in directly from the environment. The partially heated air to be heated then flows downward over the exhaust heat exchanger 7 (see filled arrow), thereby heating the air. High-temperature hot oil flows through the exhaust heat exchanger 7, which is heated by high-temperature flue gas in the burner section of the flat-tube flue gas heat exchanger 3. The heated air then exits the device through an outlet opening for heated air 24 (see filled arrow) and can be used for heating. [Figure 2]Figure 2 shows the embodiment according to Figure 1 from the rear, and therefore the burner section is on the right and the heating section is on the left. Near the center of the figure is a (pellet) storage container 14 from which combustible material is transported to the combustion chamber. A radar probe 13 is shown at the top of the (pellet) storage container 14, which monitors the filling level of the (pellet) storage container 14. Furthermore, the induced draft blower 1 is shown as a circle on the right, as the corresponding drive motor of the blower is usually installed on the rear wall of the burner section (as shown here). Below the induced draft blower 1 is a heat exchanger, which is not shown further here. Meanwhile, the supply flow to the flat-tube flue gas heat exchanger 15 and the return flow from the flat-tube flue gas heat exchanger 16 are shown together with a pump 12. The pump 12 is shown below the housing here, but this is simply for the sake of illustration, and it is usually located directly above or in a small area behind the rear wall of the housing. Therefore, the supply flow to the exhaust heat exchanger 17 and the return flow from the exhaust heat exchanger 18 are also connected to the pump, because the two heat exchangers form a circuit through which a heat transfer medium, preferably hot oil, flows. These two lines terminate on the left side of the heating section at the location where the exhaust heat exchanger 7 is located. [Modes for carrying out the invention] [Examples]

[0087] The present invention will be further described with reference to the following non-limiting examples.

[0088] As shown in the figure, commercially available wood pellets were supplied to the heating device as the combustible material, and combustion was started. After reaching a static state, a stable temperature between 220°C and 250°C was obtained on the flat-tube flue gas heat exchanger.

[0089] During combustion, the air suction fan operates at approximately 6000 m 3 It travels through the heating section with this output, for 10,000m 3 We achieved the required airflow and were able to heat the device to 82°C at an ambient temperature of 0°C.

[0090] A constant output of 200kW was achieved (excluding startup and shutdown).

[0091] The data shows that the heating device according to the present invention is very effective and achieves high efficiency. [Explanation of symbols]

[0092] 1. Induced draft blower 2. Tertiary air heat exchanger 3. Flat-tube flue gas heat exchanger 4. Flue gas flap 5 Radiant heat exchanger 6. Secondary air duct or inlet 7. Exhaust heat exchanger 8 Combustion Chamber 9. Primary air duct or inlet 10. Double-walled internal hollow combustion chamber wall (with internal baffles for meandering flow guidance) 11 stacks 12 pumps 13 (Radar) Probe 14 (pellet) storage containers 15. Supply flow to the flat-tube flue gas heat exchanger 16. Return flow from the flat-tube flue gas heat exchanger 17. Supply flow to the exhaust heat exchanger 18 Return flow from exhaust heat exchanger 19 Fire grates 20. Supply opening for flammable materials. 21. Screw conveyor for the removal of combustible waste 22 Flue gas duct 23 Air suction blower 24 Outlet opening for heated air 25 Air intake section that draws air from above or through the radiant heat exchanger.

Claims

1. A heating device, comprising: A) a burner section, a combustion chamber (8), a double-walled inner hollow combustion chamber wall (10) with an upper opening leading into said combustion chamber (8) from above the combustion zone; a flue gas duct (22) directing flue gases downwards along said combustion chamber (8); a heat exchanger area following the flue gas duct (22), firstly, a flat-tube flue gas heat exchanger (3), a heat exchanger area then comprising a tertiary air heat exchanger (2), - a flue gas ventilation stack (11), a radiant heat exchanger (5) placed above said combustion chamber (8); a flue gas flap (4) at the upper end of said flue gas duct (22) which, when open, connects said flue gas duct (22) to said stack (11); a burner unit including: B) a heating section, - an air suction blower (23), an exhaust gas heat exchanger (7) with the same heat transfer medium as the flat-tube flue gas heat exchanger (3); - an outlet opening (24) for heated air; a heating unit comprising: A heating device, wherein the flat tube flue gas heat exchanger (3) forms a heat exchange circuit with the exhaust gas heat exchanger (7).

2. The combustion chamber (8) - inlet ducts or inlet openings (6, 9) for the primary and secondary air; - a grate (19) and a burner, a feed opening (20) for combustible material; 10. Heating device according to claim 1, characterized in that it comprises a combustible waste collection chamber and / or a combustible waste discharge device.

3. 2. Heating device according to claim 1, characterized in that it comprises a (pellet) storage container (14) connected to the combustion chamber (8) via a feed opening (20) for the combustible material.

4. 2. The heating device according to claim 1, characterized in that the upper opening of the double-walled inner hollow combustion chamber wall (10) leads to the combustion chamber (8) above the combustion zone and the post-combustion zone, and the double-walled inner hollow combustion chamber wall (10) comprises a lower opening or connection configured to introduce tertiary air.

5. 2. The heating device according to claim 1, characterized in that the flue gas duct (22) is arranged against the double-walled inner hollow combustion chamber wall (10) on the other side of the combustion chamber (8) and directs the flue gases downwards along that wall into the combustion chamber.

6. 2. The heating device according to claim 1, characterized in that the heat exchanger area is arranged beyond the flue gas duct (22) from the line of sight of the combustion chamber (8), the flat-tube flue gas heat exchanger (3) is operated with thermal oil as the heat transfer medium, and the tertiary air heat exchanger (2) comprises an inlet duct or inlet opening for tertiary air and an outlet for the heated tertiary air connected to the double-walled inner hollow combustion chamber wall (10).

7. 2. A heating device according to claim 1, characterized in that the heat exchanger area is followed by an area with an induced draft fan (1) adjacent thereto or the induced draft fan (1) is arranged in or at the flue gas ventilation stack (11).

8. 2. The heating device according to claim 1, characterized in that the heating section comprises an air suction section (25) for sucking air above or through the radiant heat exchanger (5).

9. 2. The heating device according to claim 1, characterized in that the air suction blower (23) of the heating section at least partly draws air from the air suction section (25) or otherwise draws air from the environment, and the proportion refers to the total amount of air drawn in.

10. 2. The heating device according to claim 1, characterized in that the two parts A) and B) are connected to the exhaust heat exchanger (7) by the piping of the flat tube flue gas heat exchanger (3) and, if applicable, by connecting the air suction part of the heating part to the radiant heat exchanger (5), but are otherwise physically separated units.

11. A) a burner section, a combustion chamber (8), - inlet ducts or inlet openings (6, 9) for the primary and secondary air; - grate (19) and burner a feed opening (20) for combustible material; a combustion chamber equipped with a combustible waste collection chamber and / or a combustible waste discharge device; a (pellet) storage container (14) connected to the combustion chamber (8) via a feed opening (20) for the combustible material; a double-walled internal hollow combustion chamber wall (10) having an upper opening leading into said combustion chamber (8) above the combustion zone and provided with a lower opening or connection adapted to introduce tertiary air; a flue gas duct (22) arranged on the other side of the combustion chamber (8) relative to the double-walled inner hollow combustion chamber wall (10) and directing flue gases from above downwards along the wall adjacent to the combustion chamber; a heat exchanger area adjacent to said flue gas duct (22) and arranged beyond said flue gas duct (22) in the flow direction of the flue gas, - firstly, a flat tube flue gas heat exchanger (3) with thermal oil as heat transfer medium; - then a heat exchanger area comprising a tertiary air heat exchanger (2) comprising an inlet duct or inlet opening for the tertiary air and an outlet for the heated tertiary air connected to said double-walled inner hollow combustion chamber wall (10); - a region adjacent to said heat exchanger region, comprising an induced draft fan (1); - a flue gas ventilation stack (11), a radiant heat exchanger (5) placed above said combustion chamber (8); a flue gas flap (4) at the upper end of said flue gas duct (22) which, when open, connects said flue gas duct (22) to said stack (11); a burner unit including: B) a heating section, an air intake (25) for drawing air from above or through said radiant heat exchanger (5); an air suction blower (23) that draws air at least partly from said air suction section (25) and otherwise from the environment, the percentage referring to the total amount of air drawn in; an exhaust gas heat exchanger (7) with the same heat transfer medium as the flat-tube flue gas heat exchanger (3); - an outlet opening for heated air; and a heating section comprising: the flat-tube flue gas heat exchanger (3) forms a heat exchange circuit with the exhaust heat exchanger (7), and the two parts A) and B) are connected to the exhaust heat exchanger (7) by the piping of the flat-tube flue gas heat exchanger (3) and, if applicable, by connecting the air suction part (25) of the heating part to the radiant heat exchanger (5), otherwise being physically separated units; 10. The heating device according to claim 1 for burning biomass.

12. A burner portion for a heating device, comprising: a combustion chamber (8), - inlet ducts or inlet openings (6, 9) for the primary and secondary air; - a grate (19) and a burner, a feed opening (20) for combustible material; a combustion chamber equipped with a combustible waste collection chamber and / or a combustible waste discharge device, a (pellet) storage container (14) connected to the combustion chamber (8) via a feed opening (20) for the combustible material; a double-walled inner hollow combustion chamber wall (10) having an upper opening leading into said combustion chamber (8) above the combustion zone and a lower opening adapted to introduce tertiary air; a flue gas duct (22) arranged on the other side of the combustion chamber (8) relative to the double-walled inner hollow combustion chamber wall (10) and directing flue gases from above downwards along the wall adjacent to the combustion chamber; a heat exchanger area adjacent to said flue gas duct (22) and arranged in the flow direction of said flue gas beyond said flue gas duct (22), - first a flat-tube flue gas heat exchanger (3) with thermal oil as heat transfer medium, a heat exchanger area comprising a tertiary air heat exchanger (2) then comprising an inlet duct or inlet opening for the tertiary air connected to said double-walled inner hollow combustion chamber wall (10) and a discharge for the heated tertiary air; - a region adjacent to said heat exchanger region, comprising an induced draft fan (1); - a flue gas ventilation stack (11), a radiant heat exchanger (5) placed above said combustion chamber (8); a flue gas flap (4) at the upper end of said flue gas duct (22) which, when open, connects said flue gas duct (22) to said stack (11); A burner section comprising:

13. - burning the combustion in a combustion chamber (8) according to any one of claims 1 to 12 under a supply of primary air through the combustion zone and a supply of secondary air at the top of said combustion zone, - conducting the flue gases first through a flat-tube flue gas heat exchanger (3) and then through a tertiary air heat exchanger (2), - directing the thus heated tertiary air into the double-walled inner hollow combustion chamber wall (10) for further heating; - directing heated tertiary air from said double-walled inner hollow combustion chamber wall (10) above the combustion zone into said combustion chamber (8) and mixing it with said flue gases; - transferring heat to at least a portion of the air heated by a heat exchanger (5) located above said combustion chamber (8); - transferring additional heat to the air heated by the exhaust heat exchanger (7) by means of the heat transfer medium heated in said flat tube flue gas heat exchanger (3); 20. A method for improving the efficiency of a heating device by

14. Use of a heating device according to any one of claims 1 to 11 for heating an area to be heated.

15. Use of the method according to claim 13 to improve the efficiency of a heating device.

16. 13. Use of a burner element according to claim 12 for the combustion of combustible materials or for a heating zone heated together with a heating element according to any one of claims 1 to 11.

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