EP1462723A2 - Exhaust system for solid fuel combustion apparatus - Google Patents

Abstract

The exhaust for a solid fuel stove or cooker has an exhaust flap movable by an actuator (12) between open and closed positions. There is an operating parameter sensor (18) for determining the time points for the operation of the burner, connected to an initiating control (32) for the opening of the flap. An operating control (28) is also provided for the flap actuator to retain the flap open for a set time.

Description

The present invention relates to an exhaust system for a solid fuel fireplace, in particular for burning wood, coal, paper, comprehensively an exhaust flap and an actuator for adjusting the exhaust flap between a closed position and at least one open position.

Fireplaces where solid fuels are burned, e.g. tiled stoves, Coal or wood burner systems and the like are usually used as well still manually fired today. For this, a certain amount of solid fuel, such as coal or logs, placed in a burner chamber and then burns over a more or less long time.

Among other things, because of the relatively tedious loading of fuel Solid fuel fireplaces are often only used sporadically, e.g. on Evening, during weekends etc. They are therefore the bulk of the Quiet for some time with the result that the associated exhaust gas extraction devices (Fireplaces) are not required. Because fireplaces Are open to the environment, they represent effective cold bridges for the In the event that the fireplaces associated with them do not last for a long time are used to noticeably cool the fume cupboard system to lead. This can be the deductibility for exhaust gas after restarting severely affect the fireplace. Beyond that such cold bridges also for the overall energy balance of a building unfavorable.

Exhaust flaps arranged in the exhaust system are intended to remedy this so this during times when the fireplace is not in Operation is closed to the environment. With common central heating systems, which is now mostly controlled automatically it is very easy to automatically detect when a burner is in Operation should be started or switched off, so that a timely automatic control of the opening or closing of an exhaust flap is easily possible. Such an exhaust system can therefore on the one hand, handled comfortably and, on the other hand, operated in a fail-safe manner become. In the case of solid fuel fireplaces, however, there is usually none automatic control of the fireplace provided. This leads to when there is an exhaust flap in the exhaust system, this must be operated manually, i.e. must be opened before commissioning and must be closed again after the flame has extinguished. Besides one for the operator's cumbersome handling becomes incorrect operation provoked, so it is feared that in the end such Exhaust flaps equipped solid fuel fireplaces hardly any acceptance find at the consumer.

In view of these circumstances, it is an object of the present invention an exhaust system for a solid fuel fireplace to provide, which has an exhaust flap, which, if necessary, on simple Can be transferred from a closed position into an open position and which ensures that the exhaust system is relative to the environment remains closed if the fireplace is out of operation for a long time is.

• eine Abgasklappe,
• einen Stellantrieb zur Verstellung der Abgasklappe zwischen einer Schließstellung und wenigstens einer Öffnungsstellung und
• eine Inbetriebnahme-Erfassungseinheit zur Erfassung des Zeitpunkts einer Inbetriebnahme der Feuerstätte,

wobei eine Einschalt-Stellantriebsansteuerung vorgesehen ist, um ab dem Zeitpunkt der Erfassung einer Inbetriebnahme für wenigstens eine vorbestimmte Zeitdauer den Stellantrieb zur Öffnung der Abgasklappe anzusteuern und eine Betriebs-Stellantriebsansteuerung vorgesehen ist, um den Stellantrieb über die vorbestimmte Zeitdauer hinaus zur Öffnung der Abgasklappe anzusteuern, sofern bis zum Ablauf der vorbestimmten Zeitdauer eine vorbestimmte Betriebsbedingung erfüllt ist.To achieve the stated object, the present invention provides an exhaust system for a solid fuel fireplace, in particular for burning wood, coal, paper, comprising:

• an exhaust flap,
• an actuator for adjusting the exhaust flap between a closed position and at least one open position and
• a commissioning registration unit for registering the time of commissioning of the fireplace,

wherein a switch-on actuator drive is provided in order to control the actuator for opening the exhaust gas flap for at least a predetermined period of time from the time of detection of a start-up, and an operating actuator drive control is provided in order to control the actuator for opening the exhaust gas flap beyond the predetermined time period, if a predetermined operating condition is met by the end of the predetermined period of time.

According to the actuator for opening the exhaust valve is through two actuator controls can be controlled, namely after commissioning first for the temporary opening of the trigger flap for a predetermined one Duration regardless of whether a combustion is already in progress, and only if there is sufficient within the predetermined period Combustion can be ascertained without a predetermined time from the beginning Restriction in operating actuator control. With one to be expected Commissioning the fireplace will open the flue at the latest with, possibly even before the generation of exhaust gases. It turns out thereafter, however, no stable combustion within the predetermined period on, the flap is closed automatically so that cooling of the exhaust system is excluded.

If there is also a flap for fresh air supply at the fireplace, or the room in which the fireplace is located, so it also makes sense to use an actuator to open this fresh air supply flap to be controlled accordingly. This way, before The fresh air supply flap and the exhaust flap is temporarily open. When fulfilling the predetermined Operating condition within the predetermined period, i.e. when a stable fire burns, it also remains permanently open, otherwise it will however, they closed again after the predetermined time.

Since it can be assumed that the exhaust flap is closed most of the time remains, it is advisable to design the actuator so that for Transfer of the exhaust flap from a closed position to an open position the actuator must exert a corresponding driving force. If this driving force is missing, the exhaust flap will be in its closed position back. As an actuator, e.g. an electric motor is provided be working against the action of a closing spring.

In the simplest case, the predetermined operating condition can be that a switch is actuated after the user ignites a flame will, if after a certain time the flame in his opinion has gotten going sufficiently. This can still be done by appropriate Precautions are supported, such as the lighting up of an information display and the same. However, since this type of manual confirmation is cumbersome and very likely to cause relatively frequent incorrect operation leads, it is advantageous if the exhaust system additionally at least comprises an operating state sensor for detecting at least one for the operation of the fireplace characteristic physical size.

For example, temperature, pressure, CO concentration are available for this or soot concentration in the exhaust gas, all using conventionally known ones Sensors are easily measurable. In order to detect changes in this Infer parameters without starting up the fireplace To be able to, it may be beneficial if several of these sizes at the same time can be detected, sometimes even using the same sensor is possible. This is especially true when it is relatively difficult to distinguish Signals, e.g. Exhaust gas pressure, but also acoustic signals or vibrations in the Exhaust gas.

The physical quantities characteristic of the operation of the fireplace do not necessarily have to be measured in the exhaust gas, even if this is particularly easy. As an alternative, for example, through in the burner chamber or in connection with the burner chamber standing sensors to record flame-specific signals, for example acoustic signals generated by burning wood and the like signals, or signals that can be detected optically, for example from the flame outgoing infrared radiation and the like. In addition, of course, too the temperature in the burner chamber or pressure and vibrations in the burner chamber characteristic of a blazing flame.

Arranged in the exhaust gas path and / or otherwise for the analysis of exhaust gases trained sensors are conventionally well known. In many plants Such sensors should also be available for other purposes anyway be so that the provision of an operating state sensor according to the present invention requires little additional effort.

Regardless of whether it is in the exhaust gas path or in the burner chamber or on is located at another location, the operating state sensor then particularly easy to implement if it is designed as a temperature sensor is. It is particularly beneficial if the sensor is a thermostat is trained. Thermostats can e.g. through bimetal switch, very simple, cheap and reliable execution. Such a thermostat can serve directly to switch a drive current for the servomotor, if a certain threshold temperature, for example 40 ° C, after commissioning the fireplace is reached / exceeded. With such a Execution can also be achieved immediately if it falls below this Threshold temperature is caused to close the exhaust flap.

It is usually provided that the operating actuator control includes the operating state sensor. In this case, in any Operating state of the fireplace the degree of opening of the exhaust flap a signal supplied by the operating state sensor can be controlled. On this ensures that there is always a sufficiently strong deduction set for the currently prevailing lighting level of the fireplace is. In addition, such an arrangement can reliably ensure that after the flame goes out the exhaust flap - under Circumstances after a certain delay time - automatically again is brought into the closed state and thus an unnecessarily long opening of the exhaust system is avoided.

The switch-on actuator control can be independent of the operating state sensor work. In this case the actuator is independent Controllable ways to open the exhaust flap. On the one hand provides the switch-on actuator control temporarily and independently of Exhaust valve control signal to the actuator for the burning state of the fireplace. The operating actuator control delivers regardless of this signal if the operating condition is fulfilled (i.e. sufficiently stable Burning state of the flame) a basically not limited in time Control signal to open the exhaust flap on the actuator. Both Actuator controls can use completely separate control paths feature. However, it is also conceivable that both actuator controls act on one and the same switching element to this actuate when commissioning of the fireplace has been recorded or / and if the operating condition is fulfilled.

The effect according to the invention can also be achieved if the switch-on actuator control depending on the operating state sensor is working. In this case e.g. be provided that the Actuation of the actuator after commissioning the fireplace first via the switch-on actuator control. This control is temporary until the end of the predetermined period and hangs does not depend on the burning state of the flame. If in the course of the predetermined Period of time then an evolving flame can be captured accordingly a corresponding to the reached (and recorded) burning state of the flame Change (i.e. extension) compared to the activation time the predetermined period of time until after reaching a predetermined Burning state is then switched to continuous operation. In At this moment the operating actuator control is an extension corresponds to the activation time to infinity.

To determine the predetermined duration and, if necessary, to change it the activation time can be provided that the switch-on actuator activation comprises a time control which is based on a detection of a Commissioning of the fireplace at least beyond the predetermined one Time period for activating the actuator is activated. To The time control then causes the expiry of the predetermined period of time to the control of the actuator is ended with the result that the Exhaust flap is transferred to its closed position. If necessary this time control can be designed such that an extension of the predetermined period of time is enabled when a certain burning condition the flame is reached, as described above.

The predetermined period of time over which the power-on actuator control regardless of the burning state of the flame, an opening of the exhaust flap suitably selected. If the opening times of the Exhaust system without the fireplace in operation threatens the danger cooling of the exhaust system or the room in which the fireplace is located located. It is also inconvenient for the user if for example, the presence after the end of the predetermined period of time a sufficiently large flame must be confirmed manually in order to prevent the exhaust flap from closing again and thereby a kindled one Flame goes out. On the other hand, if the exhaust flap closes too early, then a fire may not yet be fully lit and will unnecessarily choked if the exhaust valve is accidentally closed becomes. Therefore, the predetermined period of time should be between about 2 and 30 Minutes, preferably between about 5 and 15 minutes and especially preferably be about 7 minutes.

There are various ways to activate the commissioning registration unit Possibilities conceivable. The easiest to implement is manually activating commissioning detection unit, which comprises a switch, in direct connection with the commissioning of the fireplace is to be operated. "In direct context" can be used here during, shortly before (e.g. when opening a lighting flap) or shortly afterwards (e.g. when closing a lighting flap). Important is, however, that there is not yet too much smoke, until the exhaust flap after actuation of the commissioning detection switch is opened. The problem with this variant is, of course, that one such activity can easily be forgotten. That could do that encountered that clear instructions are attached to the fireplace or warning lights light up that correspond to the user recall.

A more elegant option is that the time of commissioning the fireplace is "automatically" detected. With central heating systems, where the burner is started automatically is controlled or always a corresponding measurement of decisive input variables (e.g. the amount of fuel supplied) is available, this variant should be the usual one. In case of Solid fuel fireplaces, however, have such input parameters not available, so automatic start-up detection must be done indirectly. For example, can be provided be that the commissioning registration unit is trained for this is, at least one to prepare for or when starting up the fireplace an event taking place or one caused by the event Capture change.

Such events are usually carried out manually by the user. Examples could be opening the fire hatch, to bring fuel into the combustion chamber and ignite a flame, or picking up or operating one provided on the stove Lighter, poker or other tool. These acts or events lead to changes that are usually easy to grasp the position of the lighting flap. The introduction of Fuel in the combustion chamber can e.g. about weight gain Matter in the combustion chamber are detected.

Another elegant, but possibly relatively expensive alternative forms the recording immediately when the fireplace is put into operation measurable sizes. Such sizes can e.g. be: the crackle of burning brushwood using acoustic sensors in the combustion chamber is measured, or one using optical image processing methods detected bright flare of a flame that has just been lit or a detectable strong temperature rise in the combustion chamber by means of infrared sensors. It is important with these variants that the commissioning detection signal can be provided as soon as possible before the flame is lit, but at the same time sufficiently insensitive to unwanted Interference.

Because the desired operational reliability when only one is detected Measured variable is relatively difficult to reach, it is beneficial if the commissioning registration unit is trained for commissioning then to be recorded when in association with each other at least two events or changes are recorded that are in preparation or during commissioning the fireplace, or / and if any of these events occur or changes over a predetermined period of time ongoing. In both alternatives, interference is achieved fluctuations, which may be relatively strong, due to a single size does not lead to faulty controls of the exhaust flap lead, as these are usually not in a fixed time assignment stand with each other or do not stop for a long time. As an an example for such a combination, for example, opening a firing flap, a subsequent weight gain in the burner chamber from the fuel brought in, a subsequent crackling by lighting a flame and then closing the lighting flap in question, all within predetermined periods of follow each other for a few seconds or minutes. On the other hand, it is also conceivable that only the opening time of the lighting flap as The basis is taken and commissioning is then accepted if it is open for a longer period, for example 5 minutes.

It appears particularly promising if the commissioning registration unit is trained to record commissioning, when the fireplace flap is above a predetermined one Opening period is open and / or after opening and before the firing flap is closed again, burning noises in the Burner chamber are detectable.

There are also several for activating the operating actuator control Variants conceivable. For example, it is conceivable that the operating actuator control is activated as soon as and as long as the operating condition is satisfied within the predetermined period. This variant is very easy to implement (e.g. using the already mentioned bimetal switch trained thermostat) and usually shows a quick response. Alternatively, it is also conceivable that the operating actuator control is activated as soon as the operating condition for a certain time is fulfilled. With periodic sampling or query of the operating condition this is true when the operating condition is a predetermined one Number of times in a row is fulfilled. This can Reaching a predetermined threshold is determined relatively reliably are and are hardly influenced by statistical fluctuations. Moreover can then be provided that after activation has taken place once the operating actuator control a return to the switch-on actuator control no longer occurred.

A relatively reliable detection of the operating condition and thus continuous switching of the operating actuator control can be guaranteed if the operating actuator control after Expiration of the predetermined time is activated when on average over the predetermined operating time is satisfied.

The invention further relates to a lighting device, in particular a furnace for solid fuels, especially coal, wood, paper, the includes an exhaust device as described above.

Fig. 1

ein schematisches Blockdiagramm eines Abgassystems gemäß der vorliegenden Erfindung.

The invention is described in detail below using an exemplary embodiment. It shows:

Fig. 1

is a schematic block diagram of an exhaust system according to the present invention.

1 shows in schematic form a simplified block diagram of a Exhaust system 10 for a solid fuel fireplace, for example can be fired as a tiled stove with wood or coal. That in Fig. 1 Exhaust system shown includes as an actuator for a not shown Exhaust flap an electric motor 12, one provided with a time control Relay 14, a switch 18 for actuating relay 14 and one Thermostat 26, which is a function of that in the exhaust gas of the fireplace measured temperature works.

The electric motor 12 is supplied with current via the lines 36 and 34 (indicated in Fig. 1 by the lines labeled L and N). He is configured so that the exhaust flap is in its closed position as long as the electric motor 12 is only on the lines 36, 34th is connected to the mains, but not additionally via the control line 20 a control signal (here designated L) Network phase). On the other hand, is located on the control line 20 Mains phase L, the electric motor 12 moves the exhaust flap into it Open position. This open position is held for as long as the control line 20 is connected to the mains phase L. Otherwise the Exhaust flap via appropriate reset devices (e.g. also one return spring, not shown) transferred back to its closed position.

In normal operation it is provided that the network signal L for control of the electric motor 12 via the thermostat 16, the line 28 and the control line 20 is led to the electric motor 12. requirement for this is that a bimetal contact 26 integrated in the thermostat 16 is closed is. The bimetallic contact 26 is designed such that at one Exhaust gas temperature, which is higher than 40 ° C, the closing of the bimetal contact he follows. It is assumed that an exhaust gas temperature of 40 ° C can only be reached if in the combustion chamber of the fireplace a sufficiently stable flame burns, which means putting the fireplace into operation displays. If the exhaust gas temperature falls below 40 ° C again, then the bimetallic contact 26 opens again, which subsequently leads to the fact that the exhaust flap is closed. Accordingly, it is assumed that such a drop in exhaust gas temperature when burning Flame cannot take place.

In the operating actuator control described above the exhaust valve only in its open position when a predetermined Operating condition is fulfilled, i.e. when the exhaust gas temperature is on the position of the thermostat 16 is greater than or equal to 40 ° C. This operating condition is true when the fireplace is in operation, not however at the time of commissioning or shortly thereafter. To also in To ensure that the exhaust flap opens during this period is next to the operating actuator control is a so-called switch-on actuator control provided in which the electric motor 12 to open the Exhaust flap via line 32, relay switch 24 and the control line 20 is temporarily controlled.

For this purpose, the switch-on actuator drive control comprises a switching relay 14, which has a time control device, as well as one manually actuating switch 18. It is provided that a user when starting up the fireplace 18 closes the switch (briefly), which in addition leads that the relay switch 24 is also closed and at the same time the time control integrated in the relay starts to run. The relay switch 24 remains for the predetermined period of time, e.g. approx. 7 to approx. 15 minutes, kept closed. During this time the Transfer and holding the exhaust flap in their (r) open position required Drive current via line 32 and drive line 20 flow. After the end of the predetermined period of time, the time control causes that the relay switch 24 is opened, whereby the control of the Electric motor 12 breaks off and the exhaust valve in its closed position is reduced. However, at this point in time, have developed a sufficiently strong flame, so the the operating actuator control operating the switch-on actuator control a control signal is still available, which ensures that the exhaust flap remains open.

Claims (17)

Exhaust system (10) for a solid fuel fireplace, in particular for burning wood, coal, paper, comprising an exhaust flap, an actuator (12) for adjusting the exhaust flap between a closed position and at least one open position, a start-up detection unit (18) for detecting the point in time when the fireplace is started up, wherein a switch-on actuator drive (32, 14, 20) is provided in order to actuate the actuator (12) for opening the exhaust gas flap for at least a predetermined period of time from the time when a start-up is detected, and
an operating actuator drive (16, 28, 20) is provided in order to actuate the actuator (12) beyond the predetermined time period to open the exhaust gas flap, provided that a predetermined operating condition has been met by the end of the predetermined time period. Exhaust system (10) according to claim 1, characterized by at least one operating state sensor (16, 26) for detecting at least one physical variable characteristic of the operation of the fireplace. Exhaust system (10) according to claim 2, characterized in that the operating state sensor (16, 26) is designed to analyze the exhaust gas and / or is arranged in the exhaust gas path. Exhaust system (10) according to one of claims 2 and 3, characterized in that the operating state sensor (16, 26) is designed as a temperature sensor, preferably as a thermostat. Exhaust system (10) according to one of Claims 1 to 4, characterized in that the operating actuator control (16, 28, 20) comprises the operating state sensor (16, 26). Exhaust system according to one of claims 1 to 5, characterized in that the switch-on actuator drive (32, 14, 20) operates independently of the operating state sensor (16, 26). Exhaust system (10) according to one of claims 1 to 5, characterized in that the switch-on actuator drive (32, 14, 20) operates in dependence on the operating state sensor. Exhaust system (10) according to one of claims 1 to 7, characterized in that the switch-on actuator control (32, 14, 20) comprises a time control which, upon detection of commissioning of the fireplace, at least over the predetermined period of time for controlling the actuator (12) is activated. Exhaust system (10) according to Claim 8, characterized in that the predetermined time period is between approximately 2 and 30 minutes, preferably between approximately 5 and 15 minutes and particularly preferably approximately 7 minutes. Exhaust system (10) according to one of claims 1 to 9, characterized in that the commissioning detection unit (18) comprises a switch which is to be actuated in direct connection with the commissioning of the fireplace. Exhaust system (10) according to one of Claims 1 to 9, characterized in that the start-up detection unit (18) is designed to detect at least one event taking place in preparation for or when the fireplace is started up, or a change caused by the event. Exhaust system (10) according to claim 11, characterized in that the commissioning detection unit (18) is designed to detect commissioning when at least two events or changes are detected in association with one another, which are in preparation or during the commissioning of the Fireplace take place, and / or if one of these events or changes persists over a predetermined period. Exhaust system (10) according to claim 12, characterized in that the commissioning detection unit (18) is designed to detect commissioning when a firing flap of the fireplace is open for a predetermined opening period and / or after opening and before the firing flap in the burner chamber can be detected again. Exhaust system (10) according to one of claims 1 to 13, characterized in that the operating actuator control (16, 28, 20) is activated as soon as and as long as the operating condition is fulfilled. Exhaust system (10) according to any one of claims 1 to 13, characterized in that the operating actuator control (16, 28, 20) is activated as soon as the operating condition is fulfilled over a certain time. Exhaust system (10) according to one of Claims 1 to 13, characterized in that the operating actuator control (16, 28, 20) is activated after the predetermined time has elapsed if the operating condition is fulfilled on average over the predetermined time period. Firing device, in particular furnace, for solid fuels, in particular coal, wood, paper, comprising an exhaust system (10) according to one of claims 1 to 16.

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