DE102016002114A1 - BIOMASS OVEN AND METHOD FOR CONTROLLING A BIOMASS OIL - Google Patents

Abstract

The invention relates to a biomass oven, in particular a pellet stove, comprising: a combustion chamber (2) configured to receive free-flowing fuel (6) and having a glowing section (8), and an afterburner (3) for post-combustion combustion gas (24), wherein the combustion gas (24) from the Glutstockabschnitt (8) in the post-combustion chamber (3) is passed.

Description

FIELD OF THE INVENTION

The present invention relates generally to biomass furnaces, and more particularly to a biomass furnace designed to incinerate bulk biomass and to a method of controlling such biomass furnace.

BACKGROUND OF THE INVENTION

Biomass furnaces, in particular pellet stoves, are generally known, which, for example, can also be installed as a wood-burning stove in living spaces and can serve as a heating device.

Moreover, it is known to form wood stoves as a wood gasification boiler, in which fuel, such as logs or the like is incompletely burned and the gases produced during combustion are further oxidized in a second step.

In such known ovens, the fuel supply typically takes place by hand or in pellet stoves, for example. Via a pellet conveyor screw or the like, which makes the fuel supply tedious or technically complex.

The object of the present invention is to provide an improved biomass furnace and a control method for such a biomass furnace.

SUMMARY OF THE INVENTION

According to a first aspect, the present invention provides a biomass furnace, in particular a pellet stove, comprising: a combustor space adapted to receive a friable combustible and having a glowing section, and an afterburner room for post combustion combustible gas, the combustion gas being discharged from the Glutstockabschnitt is passed into the post-combustion chamber.

According to a second aspect, the present invention provides a method for controlling a biomass furnace, in particular according to the first aspect, wherein the biomass furnace comprises a combustion chamber configured to receive a bulk fuel and having a glowing section and an afterburner compartment for post-combustion Combustion gas, wherein the combustion gas is passed from the Glutstockabschnitt in the post-combustion chamber, the method comprising: igniting a combustion of a fuel in the combustion chamber in the region of the Glutstockabschnitts; and controlling a primary air supply into the emberstock section such that a glowing stick forms in the emberstock section.

Further aspects and features of the present invention will become apparent from the dependent claims, the accompanying drawings and the following description of preferred embodiments.

BRIEF DESCRIPTION OF THE DRAWING

Embodiments of the invention will now be described by way of example and with reference to the accompanying drawings, in which:

1 an embodiment of a pellet stove illustrated; and

2 a method of controlling the pellet stove of 1 shows.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In 1 is an embodiment of a pellet stove 1 illustrated in accordance with the present invention. Before a detailed description follows first general explanations to the embodiments and their advantages.

As mentioned at the beginning, known biomass furnaces, such as, for example, wood-burning stoves, require a manual arrangement of the fuel, ie. H. in this case the billet in the combustion chamber of the wood-burning stove. In known pellet stoves, for example, pellets are filled in a pellet container and can be automatically guided from there via a chute or a screw conveyor into a combustion chamber, where they are burned.

The present embodiments relate to a biomass oven, in particular a pellet stove, which comprises a combustion chamber, which is designed to receive pourable fuel, and having a Glutstockabschnitt. In addition, the biomass furnace comprises an afterburner space for afterburning of combustion gas, wherein the combustion gas is passed from the Glutstockabschnitt in the post-combustion chamber.

The biomass can, for example, be designed as a (central) heating device for a building, as a stove or the like. The pourable biomass contains, for example, pellets, Holzbricks, wood chips or the like, so that it is suitably free-flowing and, for example, in bags or the like or directly into the fuel chamber can be filled.

In some embodiments, the biomass can be arranged with a surrounding container, such as. Sack directly into the fuel chamber, which can be configured according to receive a fuel bag (pelletsack or the like). Bags that burn residue-free or low in pollutants are known in principle. For this example, corresponding films or the like can be used, from which the bags, z. As pellet or wood chips bags, are made, and the corresponding pollutant-free or -arm are combustible.

In addition, the fuel chamber has a Glutstockabschnitt, which can be arranged, for example. In a lower portion of the fuel chamber. The Glutstockabschnitt receives fuel and it may be designed fireproof by being made of a refractory material and / or provided with a refractory material. As a refractory material metal, firebricks, refractory concrete or the like can be used.

In order to ignite the fuel in the area of the emberstock section, an ignition device may, for example, be provided in the area of the emberstock section. For example, the ignition device may include one or more heating elements or the like which are inserted into the fuel in the region of the glow section or arranged to abut the fuel and heat and ignite the fuel accordingly.

The post-combustion space is, as mentioned, configured for post-combustion of combustion gas, wherein the combustion gas is passed from the Glutstockabschnitt in the Nachverbrennungsraum. For this purpose, in some embodiments, a combustion gas transfer between the fuel chamber and the post-combustion chamber is provided.

During operation of the biomass furnace, an ember is formed after ignition of the fuel in the region of the ember, causing combustion gases to form. The combustion gases are, for example, wood gases, which arise because the fuel in the Glutstockabschnitt burns like a wood gasifier. The air supply of prevailing in Glutstockabschnitt combustion is such, z. B. stoichiometrically that the combustion gases do not burn or not completely in Glutstockabschnitt, but oxidize only in the afterburner.

The operation of the biomass furnace may be similar to that of a wood gasifier and the gasification of combustibles, such as. Wood pellets, in the stoichiometric range, d. H. at lambda values between 0 and less than 1, done. The gasification then takes place between the pyrolysis, in which the lambda value is zero and the combustion, in which the lambda value is greater than 1. As wood gasification agent is here typically used air, whereby the wood gasification corresponds to a controlled combustion of wood under air deficiency. The high temperature required for the reaction is produced by the reaction of the fuel with the chemically bound oxygen and the supplied air. On the one hand, to ensure that the process does not stop, it may be necessary to provide the right amount of air and, on the other, it may be necessary not to fall below a certain minimum temperature. Therefore, in some embodiments, as mentioned below, the Glutstockabschnitt be designed according to heat-insulating, so that enough heat to support the chemical reaction for wood gasification in Glutstockabschnitt ready. Furthermore, a part of the fuel is burned to provide appropriate heat. Accordingly, in the embodiments, the fuel is not necessarily completely converted into combustion gas, but a part of the fuel may be burned and another part may be converted into combustion gas (wood gas). In addition to the partial combustion of the fuel, in some embodiments, additional heat from the outside can be supplied to the ember section.

The combustion gases produced during the combustion of the fuel in the combustion chamber typically include all the gases that are produced due to combustion, wood gasification or other processes.

In some embodiments, the Glutstockabschnitt, as mentioned, designed heat-insulating. The thermal insulation promotes the formation of the Glutstocks in the area of the Glutstockabschnitts. Suitable materials are all heat-insulating materials that withstand the prevailing temperatures here.

In some embodiments, the combustion medium space and the post-combustion space are separated from each other in a heat-insulating manner. This can prevent excessive heating of the fuel in Brennmittelraum.

In some embodiments, the glow stick section has a primary air supply through which primary air is supplied. As mentioned above, in some embodiments, primary air is supplied substoichiometrically, so that resulting combustion gases do not burn (completely) in the ember but in the afterburner space. This makes a controlled formation of the glow stick in Brennmittelraum possible and it prevents the fuel burning off uncontrollably.

In and / or on the way to Nachverbrennungsraum then secondary air can be supplied to burn the combustion gases.

In some embodiments, a secondary air supply is provided in a combustion gas transfer line between the Glutstockabschnitt and the post-combustion space.

In addition, so-called disk scavenging air may be passed along a glass sheet of the post-combustion space to prevent soot from the glass sheet and to additionally supply air to the combustion of the combustion gases in the post-combustion space.

In some embodiments, the combustor space has an opening for supplying fuel. The opening may be configured so that, as stated above, a complete fuel sack (pellet sack or the like) may be passed through it into the combustion medium space. Typically, the combustion medium space is open at the top.

Further, a lid may be provided for airtight closing of the opening, wherein in addition a monitoring device may be provided which monitors whether the opening is closed. The monitoring device may, for example, a sensor or other monitoring means which outputs a signal when the lid is opened or closed. The monitoring device can also be implemented in the form of software and / or hardware in a control of the biomass furnace. For example, if the monitoring device detects that the lid is open, for example, a primary air supply may be stopped to prevent unwanted spread of the glow stick in the fuel. The primary air supply can be actively stopped by, for example, an air supply flap is closed or indirectly but by, for example, a flue gas fan, which generates a negative pressure, is stopped.

In some embodiments, a guide means is also provided which is adapted to guide a sack of fuel disposed in the combustion chamber. As a result, the bag is prevented from falling over and / or deforming, so that the free-flowing fuel drops down by itself due to gravity and slips down during combustion and does not catch, for example, in a fold formed in the bag.

Some embodiments relate to a method for controlling a biomass furnace, in particular a biomass furnace as described above, wherein the biomass furnace comprises a combustor space configured to receive bulk fuel and having a glow stock portion and an afterburner space for post combusting combustion gas, wherein the combustion gas is passed from the Glutstockabschnitt in the Nachverbrennungsraum, as stated above.

The method comprises igniting a combustion of a fuel in the combustion chamber in the region of the ember section and controlling a primary air supply in the Glutstockabschnitt such that forms a Glutstock in the Glutstockabschnitt. In addition, the method may include further measures, as has already been discussed above, such as. B. monitoring whether the combustion chamber is closed and the like.

Coming back to 1 illustrates this one embodiment of a pellet stove 1 ,

The pellet stove 1 has a fuel room 2 and an afterburning room 3 , Between the fuel room 2 and the afterburning room 3 is a curtain wall 4 arranged, which is designed heat-insulating and so heat radiation from the afterburner 3 from the fuel room 2 shields.

The fuel room 2 is designed to be a pellet bag 5 to pick up the pellets 6 contains. The pellet bag 5 is made of a film that burns low in pollutants. To guide the pelletsack 5 are guide plates 12 provided the pellet bag 5 hold. The guide plates 12 are designed removably in this embodiment and can be in corresponding brackets on the inner wall of the fuel chamber 2 be hung. In the 1 are two guide plates 12 illustrates, without that the present invention should be limited in this regard. The guide plates 12 extend in a vertical direction, starting from an area just below a lid 13 , the fuel chamber open to the top 2 hermetically seals, up to a Glutstockabschnitt 8th located in a lower area of the fuel room 2 is arranged.

The emberstock section 8th is made of refractory concrete and has a recess in the lower part of the pelletsack 8th is placed so that the pellet bag 8th through the Glutstock section 8th and the guide plates 12 altogether upright in the fuel room 2 is held.

An ignition device 9 is in the area of the Glutstockabschnitts 8th arranged, the two here Has heating elements, so that from two opposite sides each have a heating element, the pellets 6 in the area of the Glutstockabschnitts 8th can ignite by appropriate heating.

In the area of the Glutstockabschnitts 8th is a primary air supply 10 provided by the Glutstockabschnitt 8th Primary air is fed in laterally, igniting the pellets 6 and supplying the primary air an ember 7 in the embers section 8th formed. The primary air supply 10 is formed by air channels in the Glutstockabschnitt 8th are provided and extend substantially horizontally.

Below the glutinous section 8th is a thermal insulation 11 arranged horizontally over the entire area of the Glutstockabschnitts 8th into the area of the afterburning room 2 and extends over its entire bottom area and is formed of a suitable thermal insulation material and the formation and maintenance of the Glutstocks 7 supported.

In the afterburning room 3 is at the bottom of an ash box 16 provided in the solid combustion residues, resulting in combustion of the combustion gas 24 can form, fall. Besides, the afterburning room is 3 with a glass door 19 Mistake. A flue gas duct with openings 17a and 17b extends from an upper portion of the post combustion chamber 3 in a lower area below desselbigen, where a flue gas fan 18 is arranged and the flue gas via an exhaust duct 22 leads to the outside. The flue gas duct does not run here within the afterburner room 3 but is arranged laterally to this.

In the emberstock section 8th is a transfer channel 23 trained, the combustion gases 24 from the embers 7 through the transfer channel 23 in the afterburning room 3 passes.

There is also a secondary air supply 20 in the ember section 8th provided, the secondary air into the transfer channel 23 directs, so that from there secondary air together with combustion gases 24 mixed in the afterburning room 3 is directed.

In the afterburning room 3 then the mixture of secondary air and combustion gas 24 continue to burn (oxidize). In addition, so-called disc cleaning air 21 above and below the glass pane 19 fed to a soot of glass 19 counteract. The disc cleaning air 21 also serves to burn the combustion gases.

It is also used to monitor the lid 13 a sensor 14 provided, the sensor signals to a controller 15 sends.

The control 15 has a microprocessor and a memory in which a control program for controlling the pellet stove 1 is stored.

The following is with reference to 2 a procedure 30 for controlling the pellet stove 1 described.

At first there is 31 a requirement, combustion in the pellet stove 1 to start. This can be done, for example, via a power button connected to the controller 15 is coupled.

The control 15 then check in 32 whether the lid 13 closed is. This is the status of the sensor signal 14 checked. The sensor can, for example, a current signal to the controller 15 submit when a contact with the lid 13 is present and accordingly the lid 13 closed is.

Represents the controller 15 notice that the lid 13 closed, it ignites 33 the pellets 6 by means of the ignition device 9 , In addition, the controller controls 15 the flue gas fan 18 such that correspondingly primary air via the primary air supply 10 into the embers section 8th arrives. This produces the flue gas blower 18 a negative pressure, which over the flue gas duct with its openings 17b and 17a through the afterburning room 3 and the transfer channel 23 Primary air via the primary air supply 10 sucks. Accordingly, for example, via a speed of the flue gas blower 18 the amount of primary air passing through the primary air supply 10 inside the glutinous section 8th in the area of the glow stick 7 is sucked, controlled.

The combustion gas path is thus as follows. By the of the flue gas fan 18 generated negative pressure is due to the primary air supply 10 Primary air into the embers 7 inside the Glutstockabschnitts 8th directed. In the embers 7 Combustion gases are created via the transfer channel 23 , in addition to secondary air via the secondary air supply 20 gets into the afterburning room 3 be directed. There, the combustion gases oxidize 24 together with the secondary air and the disc purging air 21 and the resulting flue gas passes through the inlet opening 17a into the flue and then flows down from the outlet 17b out, from where it passes through the flue gas fan 18 in the exhaust duct 22 arrives.

Claims (10)

Biomass furnace, in particular a pellet stove, comprising: - a combustion chamber ( 2 ), which is suitable for receiving free-flowing fuel ( 6 ) is configured, and the one Glutstockabschnitt ( 8th ), and - an afterburning space ( 3 ) for the afterburning of combustion gas ( 24 ), the combustion gas ( 24 ) from the Glutstock section ( 8th ) in the afterburning room ( 3 ). Biomass furnace according to claim 1, wherein the Glutstockabschnitt ( 8th ) is configured heat-insulating. Biomass furnace according to one of the preceding claims, wherein the combustion medium space ( 2 ) and the afterburning room ( 3 ) are isolated from each other in a heat-insulating manner. Biomass furnace according to one of the preceding claims, wherein the Glutstockabschnitt ( 8th ) a primary air supply ( 10 ) having. Biomass furnace according to one of the preceding claims, wherein a secondary air supply ( 20 ) in a combustion gas transfer ( 23 ) between the Glutstockabschnitt ( 8th ) and the afterburning room ( 3 ) is provided. Biomass furnace according to one of the preceding claims, wherein the combustion medium space ( 2 ) an opening for supplying fuel ( 6 ) having. Biomass furnace according to claim 6, wherein a lid ( 13 ) is provided for airtight closing of the opening. Biomass furnace according to claim 7, wherein a monitoring device ( 14 ) is provided, which monitors whether the opening is closed. Biomass furnace according to one of the preceding claims, wherein a guide means ( 12 ) designed to load a bag ( 5 ) with fuel ( 6 ), which enters the fuel room ( 2 ) is to lead. A method for controlling a biomass furnace, in particular according to one of the preceding claims, wherein the biomass furnace comprises a fuel chamber, which is designed to receive pourable fuel and having a Glutstockabschnitt, and an afterburner space for post combustion of combustion gas, wherein the combustion gas from the Glutstockabschnitt into the post-combustion space, the process comprising: igniting ( 33 ) combustion of a fuel in the combustion chamber in the region of the Glutstockabschnitts; and taxes ( 34 ) a primary air supply into the Glutstockabschnitt such that forms a Glutstock in the Glutstockabschnitt.

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