WOOD-BURNING STOVE COMBUSTION MONITORING SYSTEM

Description

Field of the invention

[0001] The present invention relates to monitoring and improving combustion in wood-burning stoves.

Background of the invention

[0002] Modern wood-burning stoves arranged in e.g. living rooms or other rooms of a building are used for providing heat, mainly to the respective room in which it is arranged, but also in some degree to other rooms of the building.

[0003] The wood-burning stoves, especially wood burning stoves of the convection type, provides a type of heat that is appreciated by users, and the wood-burning stoves may also provide a cost efficient alternative to other types of heat sources for heating the room of a building.

[0004] However, present wood-burning stoves also suffer from some problems. For example, the outdoor environment may be negatively affected by the combustion in the combustion chamber of a wood-burning stove. Another example may be that especially un-experienced users may unintentionally set up for a non-optimal combustion.

[0005] A number of documents disclose installing various sensors, e.g. temperature sensors, inside the exhaust pipe of stoves, to monitor characteristics of the flue gas, e.g. temperature, see for example US 2011/0300494 A1, EP 2 345 848 A1, US 2012/0116589 A1, DE 10 2008 057 697 A1 and US 4,712,095. The measured characteristics are used in automatic control of the combustion or for notifying users about certain conditions that need attention. Furthermore, document US 2007/0289589 A1 discloses a method according to the preamble of claim 1 and a wood-burning stove according to the preamble of claim 5.

[0006] It may thus be an object of the present invention to solve the above problems. It may moreover be an object of the invention to provide a solution that may motivate and/or facilitate owners of existing wood-burning stoves to solve the above problems.

Summary of the invention

[0007] The invention relates to a method of providing combustion-related information related to a combustion of solid fuel according to claim 1.

[0008] An advantageous way of, non-invasively with respect to the combustion chamber, establishing relevant and helpful information about a combustion taking place inside a combustion chamber of a wood-burning stove is hereby provided.

[0009] The advantages of the present invention makes it beneficial for retrofitting to existing wood-burning stoves, contrary to other combustion monitoring solutions that requires installation inside or penetration into the combustion chamber.

[0010] The advantageous invention is also incredible helpful for average stove users who like the cosy heating, but are not able to optimize the burning to improve their inside and outside environment and reduce the amount of effort and wood supplies. By the present invention such users can easily monitor the combustion and act when told or suggested to by the method. With the present massive presence of smartphones and tablet computers, most of them Bluetooth enabled, the present invention is relatively inexpensive compared to other more automated solutions, and available to practically everyone.

[0011] By not requiring a temperature sensor inside the combustion chamber, the present invention features several advantages over systems with an internal temperature sensor. For example a cheaper temperature sensor may be used with the invention as it only has to withstand and monitor considerably lower temperatures and is not exposed to soot and flue gas. These improved circumstances also mean that an outside temperature sensor according to the invention typically lasts longer and does not need maintenance, e.g. cleaning of soot.

[0012] The processing of the temperature representations in an advantageous embodiment comprises analysing the development of temperature with time, e.g. by means of a time-temperature curve. The advantageous invention enables for example an embodiment where the processing comprises predicting the development of the combustion so as to for example estimate and present an optimal time for refuelling, provide advice and tips with regards to for example opening or closing air regulators, etc., or processing different models related to different settings of air regulators or the like so as to estimate optimal refuelling times or heating efficiency for different settings.

[0013] The present invention enables the establishment of a continuously self-adjusting combustion prognosis for a specific scenario, possibly based on certain user-adjustable parameters such as desired heating power, desired time for next refuelling, desired amount of wood for next refuelling, etc. In other words, the present invention makes it possible to plan a wood stove combustion, besides only monitoring it, and thereby helps the user to obtain a clean, efficient, optimal combustion.

[0014] In an advantageous embodiment said temperature sensor is attached to said outside of the inner stove, preferably to an upper part or upper rear part of said outside, even more preferably adjacent to an exhaust opening (18) of said inner stove.

[0015] In an advantageous embodiment the combustion monitoring system of the present method further comprises a start switch (25) electrically coupled to a circuit of the processing and communicating arrangement, and wherein the processing and communicating arrangement starts a temperature measuring session based on an event related to the start switch, the start switch preferably being mechanically coupled to a primary air damper (14) and/or a primary air regulator (19) and/or a door (15), and wherein the event related to the start switch thereby also relates to the primary air damper, regulator or the door.

[0016] In an advantageous embodiment the temperature sensor is exposed to temperatures below 450 degree C, preferably below 400 degree C, even more preferably below 350 degree C.

[0017] In an advantageous embodiment said combustion monitoring system comprises a wireless transceiver, preferably a Bluetooh LE transceiver, for transmitting said temperature representation to said output device, preferably a Bluetooth-enabled mobile device such as a smartphone or tablet or laptop computer.

[0018] The present invention further relates to a wood-burning stove according to claim 5.

[0019] In an advantageous embodiment the method, or the wood-burning stove, comprises a timing unit to associate said temperature representations with timestamps. In order to not only being able to monitor but also to predict how the combustion will develop and in particular at which time certain combustion zones will be reached, most particularly estimate when it will be the optimal time to refuel the stove, it is very advantageous to have the temperature measurements associated with timestamps. In a preferred embodiment the timestamps are transmitted to the output device together with the temperature representations, in particular if the temperature representations are not transmitted at the time of acquisition but are delayed and/or grouped together for fewer transmissions or for catching up after a period of unavailability of the output device.

[0020] In an advantageous embodiment said temperature sensor is a sensor of a thermocouple or resistor temperature detector (RTD) type. In a preferred embodiment the temperature sensor is for example a type "K" thermocouple.

[0021] In an advantageous embodiment the temperature measured by said temperature sensor, during combustion of solid fuel, is lower that the internal temperature in the upper part of said combustion chamber.

[0022] In an advantageous embodiment said output device processes said received temperature representation together with further wood-burning stove depending parameters

[0023] According to the invention, said output device present combustion-related information to a user of said output device.

[0024] According to the invention, said combustion-related information comprises an estimated time for optimally refilling the combustion chamber with solid fuel such as wood.

[0025] In an advantageous embodiment said combustion-related information comprises suggestions to the user to adjust air flow to the combustion chamber.

[0026] In an advantageous embodiment said output and/or combustion-related information at least partly depends on the specific type of wood-burning stove in which said combustion is performed.

[0027] In an advantageous embodiment said combustion-related information is at least partly based on experiential information relating to a temperature development in a predefined type of wood-burning stove dependent of the amount of solid fuel used for combustion.

[0028] In an advantageous embodiment said combustion-related information comprises chimney draft related information.

[0029] In an advantageous embodiment said specific type of wood-burning stove is selected from a predefined list of different wood stoves.

[0030] In an advantageous embodiment said combustion monitoring system is battery powered.

[0031] In an advantageous embodiment the combustion monitoring system measures and transmits the temperature representation at a predefined interval to said output device, e.g. determined by a timer function, the interval preferably being less than 1 minute, even more preferably less than 30 seconds, and most preferably about 10 seconds.

The drawings

[0032] The invention will in the following be described with reference to the drawings where

figs. 1 - 2 illustrate embodiments of the invention with temperature sensor outside the combustion chamber,

fig. 3 illustrates an embodiment of the invention with a start switch,

fig. 4 illustrates an embodiment of the invention with a start switch and primary air regulator,

fig. 5 - 9 illustrate an embodiment of the invention, in particular the simplicity of retrofitting, and

fig. 10 illustrates a screen from a smartphone app according to an embodiment of the invention.

Detailed description

[0033] Fig. 1 illustrates an embodiment of the invention. It illustrates a wood-burning stove 1 with a combustion chamber 11. The wood-burning stove is preferably of the convection type where surrounding air is heated and thereby made to circulate between an inner stove 12 and an outer covering, of which for reasons of simplicity only an outer covering top 161 and an outer covering bottom 162 are illustrated.

[0034] The inner stove 12 preferably comprises a baffle 122 and a primary air intake 13. A primary air damper 14 is preferably provided to facilitate regulation of the primary air flow, for example by arranging the primary air damper 14 in a sliding manner with primary air damper vents 141 corresponding to vents of the primary air intake 13, so that sliding the primary air damper 14 as indicated by the arrows will dislocate or align the primary air damper vents 141 away from or with, respectively, the vents in the primary air intake 13. In a preferred embodiment additional air intakes, e.g. so-called secondary air intakes, are further provided at different locations of the stove for facilitating fine control of the air flow.

[0035] The wood-burning stove 1 further comprises a door or opening arrangement 15, providing access to the combustion chamber for firing and refilling firing wood, and a chimney 17 coupled to an exhaust opening 18 of the inner stove 12.

[0036] The illustrated wood-burning stove is merely sketched in principle with the features that facilitate the description of the present invention. A person skilled in the art of wood-burning stoves will appreciate that several alternative principles and variations on stoves are known and within the scope of the present invention as defined in the appended claims. In particular it should be noted that the present invention, within its scope, also applies to radiation stoves as well as convection stoves, stoves with alternative primary air intakes, e.g. at the front, sides or rear instead of or in addition to the illustrated bottom vents, alternative primary air dampers or regulators, e.g. a damper located in an air intake through the outer cover or in an air duct instead of in direct cooperation with vents in the inner stove, alternative or additional baffle configurations, additional air intakes

[0037] and air or flue gas regulators or dampers, any door or opening arrangement, with or without additional air flow features, etc.

[0038] The embodiment of Fig. 1 further comprises a combustion monitoring system 2 according to an embodiment of the invention. The combustion monitoring system 2 comprises a processing and communication arrangement 21, a temperature sensor 22 and a temperature sensor wire 221.

[0039] The processing and communication arrangement 21 is preferably battery-driven, but may in an embodiment comprise a different power supply, such as a mains-driven power supply, or it may be driven by alternatively generated electricity, e.g. generated by heat from the stove, e.g. by means of thermocouples or thermopiles.

[0040] The temperature sensor 22 is located at an outside 121 of the inner stove 12, preferably near the exhaust opening 18, e.g. immediately adjacent to the chimney 17 or within a few centimetres. The temperature sensor may be fastened to the outside 121 of the inner stove by magnetic force, bolts, temperature resistant glue, etc., or, in stoves with an outer covering 16, 161, e.g. convection stoves, the temperature sensor may be fastened by wedging, squeezing or clamping the sensor or a fitting or other mounting in or on which the sensor is fixed into the narrow space between the inner stove and the outer covering, e.g. by fixing the sensor to a suitably shaped spring metal or other material, e.g. a bended sheet metal which in the direction of spring force has a dimension greater than the distance between the inner stove and the outer covering, but which when inserted in the narrow space becomes compressed in the direction of spring force and thereby is wedged sufficiently firmly to hold the temperature sensor in place.

[0041] The temperature sensor is preferably of the thermocouple type, preferably a type "K" thermocouple, but any temperature sensitive component, e.g. a thermocouple, a resistor temperature detector (RTD) or a thermistor with appropriate temperature range of operation according to the location on the stove, may be used. A person skilled in the art of converting absolute or relative temperature to an electrical characteristic (voltage, current or resistance) will appreciate the wide range of temperature sensor technologies applicable within the scope of the invention, as well as their practical implementation to measure stove outside temperatures.

[0042] In a preferred embodiment the temperature sensor wire 221 transfers a raw analog sensor output signal, e.g. a voltage difference established by applying a fixed current through an RTD or a potential generated by a thermocouple, to the processing and communication arrangement 21, which preferably comprises circuitry arranged to convert and process the sensor output signal. The circuitry may e.g. comprise operational amplifiers, current and/or voltage sources, voltage dividers, etc. In a preferred embodiment the circuitry consists of a dedicated integrated circuit appropriate for the sensor type, e.g. a thermocouple amplifier with voltage or digital output or an RTD-to-voltage or RTD-to-digital integrated circuit. If the result is represented by a voltage range, the conversion circuitry may preferably also comprise an analog-to-digital converter (A/D-converter) to allow digital processing of the detected temperature.

[0043] Alternatively, circuitry as mentioned above for converting the sensor output signal to a suitable analog range, e.g. 0 - 5V, or to a digital signal, e.g. 16 bit pulse code modulated (PCM), may be integrated with the temperature sensor 22, and the temperature sensor wire 221 be used to transfer the converted value to the processing and communication arrangement 21 for direct processing.

[0044] The processing and communication arrangement 21 may be located anywhere, but may advantageously be located on a rear, outer covering, e.g. by magnets, for easy access for battery replacement or operation of any buttons. The processing and communication arrangement preferably comprises a processor of any suitable kind and a semiconductor memory, preferably a non-volatile but writable memory, e.g. an EEPROM or flash memory, for storing measured temperatures together with time of measurement.

[0045] The processing and communication arrangement 21 further comprises a communication interface for establishing a communicative coupling 23 to provide the measurement data and/or processed conclusions to an output device 24 or receive control information. The output device 24, which may in a preferred embodiment also be used as an input device, preferably comprises a smartphone, but alternatively it may be a tablet, laptop or desktop computer, a computer monitor or other display, a traditional text message enabled cell phone, an advanced universal remote control, etc., or it may be a dedicated output device manufactured or adapted specifically for use with the combustion monitoring system 2. The communication interface is preferably a Bluetooth interface, even more preferably a Bluetooth Low Energy (Bluetooth LE) interface, which is very well suited for power-efficient short range communication with smartphones. Any other suitable communication interface is within the scope of the invention, e.g. wireless interfaces such as e.g. WiFi (WLAN or WiFi Direct) or other short range radio communication technologies, GSM or other cell phone communication technologies, e.g. more specifically use of an SMS or data service, near-field communication NFC, infrared communication, e.g. using IrDa protocols, etc., or wired interfaces such as e.g. USB, HDMI, DisplayPort, etc.

[0046] The processing and communication arrangement 21 may in an embodiment comprise a user interface e.g. comprising one or more buttons or knobs, e.g. to reset or initialize the combustion monitoring system 2, set reference values, etc.

[0047] In a preferred embodiment all or most user interaction is performed by means of the output device 24, preferably by means of a smartphone application, a combustion monitoring app 241, specifically adapted for use with the combustion monitoring system of the present invention and communication with the processing and communication arrangement 21 via the communicative coupling 23.

[0048] The processing and communication arrangement 21 preferably comprises a temperature sensor circuit receiving the temperature sensor wire 221 and converting the signal to a temperature representing voltage, and a Bluetooth LE integrated circuit system which besides the Bluetooth functionality further comprises a microcontroller for carrying out the processing, analog voltage inputs and A/D converters for converting the temperature representing voltage to a digital temperature value and monitoring battery voltage, and an EEPROM memory or flash memory for storing temperature measurements and settings, e.g. user-defined system identification name.

[0049] The combustion monitoring system 2 is arranged to maintain a relationship between temperature and time, so as to facilitate a time-dependent monitoring of the temperature, and to facilitate making analysis and provide advice based on the temperature development during a burning. The time stamping of temperature measurements or other mapping of measured temperatures to time is preferably provided by the processing and communication arrangement 21, whereas the use of the time-temperature relationship is preferably taking place in the output device 24, preferably by the combustion monitoring app 241.

[0050] The relationship between the actual combustion and the temperature measured by the temperature sensor at the outside of the combustion chamber for a specific stove model may preferably be established by analysing and correlating combustion chamber outside temperatures, e.g. measured by the combustion monitoring system 2 of the invention, with inside temperatures, e.g. measured with an additional temperature sensor, during a number of burnings, e.g. 5 - 200 burnings, preferably a considerable number of burnings such as e.g. 100 burnings. This calibration process is preferably performed by a stove manufacturer for each stove model for which a combustion monitoring system 2 should be mounted or made available for retrofitting.

[0051] Fig. 2 illustrates an embodiment similar to that described above with reference to Fig. 1, the description thereof applying, mutatis mutandis, to the embodiment of Fig. 2. The difference is that in the embodiment of Fig. 2 the exhaust opening 18 and chimney 17 are configured at the rear side of the wood-burning stove 1, and the temperature sensor 22 is located at the outside 121 of the inner stove 12, preferably near the exhaust opening 18, e.g. immediately adjacent to the chimney 17 or within a few centimetres. The temperature sensor may be fixed with generally any of the same methods as described above with reference to Fig. 1.

[0052] Fig. 3 illustrates an embodiment similar to that described above with reference to Fig. 1, the description thereof applying, mutatis mutandis, to the embodiment of Fig. 3. This embodiment further comprises a start switch 25 connected to the processing and communication arrangement 21. The start switch may be arranged for user operation, e.g. by means of a pushbutton on the front of the stove, a coupling with the stove door, or may preferably as illustrated in Fig. 3 be arranged in correspondence with e.g. a primary air damper 14 in such a way that the state of the start switch 25 is changed when the primary air damper 14 is pulled out to provide free access for air through the primary air intakes 13. As primary air should preferably be added for a few minutes upon firing up the stove or adding wood, a correspondence between the primary air damper 14 and the start switch 25 may be used to signal to the processing and communicating arrangement each time new wood is placed in the combustion chamber 11. In the embodiment of Fig. 3 the start switch 25 is a simple circuit breaker which, due to a suitable flange added to the primary air damper 14, breaks the circuit facilitated by a start switch wire 251 when the primary air damper is pulled out, and closes the circuit when the primary air damper is pushed in. In a preferred embodiment the combustion monitoring system uses this information to trigger the temperature monitoring, preferably by starting the monitoring when the start switch indicates that the primary air damper has been pulled out. In a preferred embodiment, the triggering of the start switch causes a new monitoring session and resets the temperature-monitor time to zero, so that a new time-temperature curve may be produced. A person skilled in the art of switches and detectors will appreciate that there are numerous ways, including numerous switch or input configurations, of establishing and providing a signal to the processing and communication arrangement at the time of firing up or adding wood in order to trigger the start or restart of temperature monitoring, which are within the scope of the invention.

[0053] Fig. 4 illustrates an embodiment similar to that described above with reference to Figs. 1 and 3, the descriptions thereof applying, mutatis mutandis, to the embodiment of Fig. 4. This embodiment further comprises a primary air regulator 19, which in the specific illustrated embodiment comprises a cylinder with a spring-biased plunger cooperating with the primary air damper 14 to automatically slide the primary air damper to a position with little or no primary air flow subsequent to a manual sliding out the primary air damper to increase primary air flow. An adjustable valve for only letting air into the cylinder very slowly facilitates extending the plunger travelling time for several minutes, e.g. 5 - 7 minutes. During this time, in a preferred embodiment, the primary air flow will decrease gradually from full flow to no or little flow. If more time is needed with increased air flow, e.g. during starting a fire in a cold stove, the primary air damper may be fixed in the fully open position, thereby preventing the primary air regulator 19 from closing it. Even though the present invention is herein described with reference to embodiments using a spring-and vacuum-biased plunger as primary air regulator, any suitable primary air regulator 19 for automated decrease of primary air flow after refilling of wood, is within the scope of the invention. The combination of an automatically closing primary air damper and configuring the start switch so that its state depends on the state of the primary air damper, makes the start switch automatically reset to a state where each refuelling is detected by the start switch and thereby usable in the processing and communication arrangement for e.g. restarting the monitoring.

[0054] Figs. 5 - 9 illustrate an embodiment of the present invention similar to the embodiments described above with reference to Figs. 1 - 4, the description there applying to the embodiments of Fig. 5 - 9, mutatis mutandis. In Figs. 5 - 8 the outer covering 16 and the outer covering top 161 have been removed in order to retrofit a combustion monitoring system 2 according to the present invention, comprising a processing and communication arrangement 21, a temperature sensor 22, a temperature sensor wire 221, a start switch 25 and a start switch wire 251 to the wood-burning stove 1. The easy retrofitting property of the present invention is partly produced from the non-invasive nature: according to the present invention no temperature sensor or other sensors need to be integrated in the combustion chamber 11, but can simply be mounted on the outside of the combustion chamber, or even on the outer covering 16. In a preferred embodiment using a smartphone as output device 24, the retrofitting procedure may further comprise installing the combustion monitoring app 241 on the smartphone and establish the communicative coupling 23.

[0055] Fig. 10 illustrates an example of a main screen of a combustion monitoring smartphone app. The specific instance of a view shown in Fig. 10 informs the user that the communicative coupling with the processing and monitoring arrangement is established, that the battery is still in good condition, that the best time to supplement with new wood to the stove is in 45 minutes, and if that is not achieved, then the latest time to add the wood will be in 60 minutes. The screen further shows the measured temperature development for the current logging session, i.e. since last reset by the start switch, mapped upon a diagram illustrating the different combustion quality zones with respect to temperature and time. The diagram is based on estimated combustion behaviour for the particular setup of stove, chimney and amount of wood used.

[0056] In a preferred embodiment, if the connection to the processing and communication arrangement 21 is lost, e.g. because the user takes the smartphone with him away from the house, the combustion monitoring smartphone app may convert the duration until the optimal refuelling, e.g. 45 minutes, to an estimated time for the next refuelling, e.g. 10.37 a.m., and possibly set this time as an alarm in the smartphone.

[0057] Upon return of the smartphone into transmission distance, the smartphone app may get all or a summary of meantime measurements transmitted from the storage memory of the processing and communications arrangement in order to update the illustrated combustion development and recalculate estimated combustion zones, in particular the estimated time for optimal refuelling.

[0058] In a preferred embodiment of the invention the activities performed by the processing and communication arrangement 21 comprise the following:

A1. Staying in sleep mode, i.e. low power consumption mode, until start switch is activated by user opening the primary air damper.

A2. Logging temperatures from the outside of the combustion chamber frequently, e.g. every 10 seconds, and store in non-volatile memory.

A3. Keep logging temperatures for a considerable time, e.g. 4 hours, since the last activation of the start switch.

A4. Start a new logging session each time the start switch is activated. Depending on available memory and logging frequency, a number of previous sessions are preferably stored, preferably e.g. 2 previous sessions together with an active session.

A5. Monitor battery voltage regularly, e.g. every 30 minutes.

A6. Accept Bluetooth connection from at least one output device, i.e. preferably a Bluetooth LE enabled smartphone.

A7. Continually transmit active session data and battery status to smartphone app.

[0059] In a preferred embodiment the processing and communication arrangement 21 may be adapted to also perform special tasks besides the above-described normal operation, e.g.:

B1. Change Bluetooth identification name of the communication interface upon request, preferably by allowing a smartphone app user to define a new identification name. This is particularly relevant if the same user monitors and controls two or more stoves by the same smartphone.

B2. Manage saved temperature log files, e.g. export to a smartphone app user or delete.

[0060] In a preferred embodiment the combustion monitoring smartphone app may be arranged to initialize itself at first use by performing the following steps:

C1. Request the user to select a predetermined combustion scheme, preferably by presenting the user with a list of supported wood-burning stoves and letting the user select the relevant stove, and have each stove associated with a predetermined combustion scheme.

C2. Optionally show installation instructions for how to mount the combustion monitoring system to the selected particular wood-burning stove.

C3. Connect the smartphone to the processing and communication arrangement by Bluetooth LE.

C4. Guide the user through a chimney test in order to determine how the particular stove installation affects the predetermined combustion scheme, probably measured at the manufacturers place. The chimney test preferably involves requesting the user to burn a particular weight of wood within a certain humidity range in his stove with particular damper settings, etc., and having the combustion monitoring app monitoring the temperature development. The effect of the particular chimney may preferably be decided based on the maximum temperature achieved during the chimney test, e.g. for a particular stove determining the chimney to be a low effect chimney if largest measured temperature was in the range of 190 - 239 degree C, a normal effect chimney if max temperature in the range of 240 - 269 degree C, and a high effect chimney if max temperature from 270 degree C and up.

[0061] In a preferred embodiment use of a wood-burning stove with a combustion monitoring system according to the present invention guided by the combustion monitoring smartphone app may preferably involve the following normal operation steps:

D1. Connect to the processing and monitoring arrangement of the stove. D2. Optionally, but preferably, the user inputs the approximate amount of wood used at a time. This may be set as a standard user preference value, or input for each refill.

D3. Optionally, but preferably, the user inputs the effect class of the particular setup of wood-burning stove and chimney, preferably simply by choosing among low, medium or high effect stove setups. The relevant effect class depends on the chimney effect as determined by the chimney test described above, and the effect setting of the stove if applicable to the particular stove. The combined effect class may be set as a standard user preference value, or input for each refill.

D4. Continually receive temperature and battery data

D5a. If the measured temperature on the outside of the combustion chamber is below a certain minimum, e.g. 100 degree C, assume that the stove is starting up from a cold state and postpone further calculations and guidance until temperature reaches e.g. 200 degree C; then request user to unlock the primary air damper so that it will return to closed state within a few minutes if the stove is provided with a primary air regulator as described above with reference to Fig. 4.

D5b. If the measured temperature is above, e.g., 100 degree C from the beginning, assume that new wood has been added to burning stove, and commence calculation and guiding.

D6. Display an assumed time to next refill, based on the predetermined combustion scheme and/or past experience for a certain amount of time until the measured temperature variation attains a negative coefficient or until a predetermined time has passed, e.g. between 30 minutes and 60 minutes, depending on the particular stove.

D7. Calculation of estimated refill time t based on actual temperature measurement may be determined by the following equation:

where

T₀ = measured temperature,

T_t = target temperature, e.g. 150 degree C for ideal refill time, and e.g. 110 degree C for latest refill time, i.e. just above the minimum temperature for considering it a cold start, the target temperature depends on the particular wood-burning stove and the location of the temperature sensor,

T_a = a constant, e.g. in the amount of around 100

k = a constant, e.g. in the amount of around 0.0004

Both constants are selected by a lookup-table or a formula in dependency of the particular stove and preferably information about the amount of solid fuel put into the combustion chamber at the last refill. The constants may be set based on past experience or measurements performed by the manufacturer.
The above calculations of refill times are preferably updated for each new temperature measurement, e.g. each 10 seconds.

D8. Determine if the currently measured temperature falls within a bad combustion zone, see illustration in Fig. 10, and display suggestions to the user for countermeasures, e.g. set stove to higher effect, increase flow of primary air, etc.

D9. Display suggestions for optimal restart if the measured temperature has dropped below minimum limit, e.g. 110 degree C.

D10. Restart procedure when new temperature logging session starts, i.e. triggered by start switch on the stove, e.g. in the embodiments of fig. 3 and 4 when user refills stove and pulls out primary air damper.

[0062] An example of assumed refill times to use for the temperature rising phase described in step D6 above, for a particular wood-burning stove is provided by the following table 1:

Table 1

Wood amount: 1.5 kg
Effect class	Wait time before going to step D7 [minutes]	Assumed duration to optimal refill [minutes]	Minimum temperature Tmin	Assumed duration for latest refill [minutes]
		(T = 150 degree C)	[Celcius]	(T = Tmin)
High	33	78	110	133
Med	40	78	110	133
Low	50	80	120	112

Wood amount: 2.0 kg
Effect class	Wait time before going to step D7 [minutes]	Assumed duration to optimal refill [minutes]	Minimum temperature Tmin	Assumed duration for latest refill [minutes]
		(T = 150 degree C)	[Celcius]	(T = Tmin)
High	37	92	110	143
Med	43	93	110	145
Low	53	95	120	145

Wood amount: 2.5 kg
Effect class	Wait time before going to step D7 [minutes]	Assumed duration to optimal refill [minutes]	Minimum temperature Tmin	Assumed duration for latest refill [minutes]
		(T = 150 degree C)	[Celcius]	(T = Tmin)
High	37	100	110	167
Med	43	103	110	170
Low	53	107	120	142

Wood amount: 3.0 kg
Effect class	Wait time before going to step D7 [minutes]	Assumed duration to optimal refill [minutes]	Minimum temperature Tmin	Assumed duration for latest refill [minutes]
		(T = 150 degree C)	[Celcius]	(T = Tmin)
High	40	117	110	183
Med	47	122	110	188
Low	57	125	120	163

[0063] It is noted, that alternatives and variations of the above-described procedures and values are within the scope of the present invention.

List of reference numbers

[0064] 

1

wood-burning stove

11

combustion chamber

12

inner stove

121

outside of inner stove

122

baffle

13

primary air intake

14

primary air damper

141

primary air damper vents

15

door or opening arrangement

16

outer covering

161

outer covering top

162

outer covering bottom

17

chimney

18

exhaust opening

19

primary air regulator

2

combustion monitoring system

21

processing and communication arrangement

22

temperature sensor

221

temperature sensor wire

23

communicative coupling

24

output device

241

combustion monitoring app

25

start switch

251

start switch wire

Claims

1. A method of providing combustion-related information related to a combustion of solid fuel, such as wood, in a wood-burning stove (1), the wood-burning stove comprising a combustion chamber (11) defined by an inner stove (12), the inner stove having an outside (121),
the wood-burning stove further comprising a combustion monitoring system (2),
the combustion monitoring system comprising

a temperature sensor (22) arranged substantially at said outside (121) of the inner stove (12), and

a processing and communication arrangement (21) being coupled to said temperature sensor (22) and further providing a communicative coupling (23) for enabling connection to an output device (24),

wherein the temperature sensor, during combustion of said solid fuel, provides a temperature sensor output,
wherein the processing and communication arrangement accepts a connection from the output device and transmits temperature representations relating to the combustion of solid fuel inside said combustion chamber, the temperature representations being derived from the temperature sensor output,
wherein the output device processes said temperature representations to provide an output based on said temperature representations, and
wherein said output device presents combustion-related information to a user of said output device, characterized in that said combustion-related information comprises an estimated time for optimally refilling the combustion chamber with solid fuel such as wood.

2. The method of providing combustion-related information according to claim 1, wherein said temperature sensor is attached to said outside of the inner stove, preferably to an upper part or upper rear part of said outside, even more preferably adjacent to an exhaust opening (18) of said inner stove.

3. The method of providing combustion-related information according to claim 1 or 2, wherein the combustion monitoring system further comprises a start switch (25) electrically coupled to a circuit of the processing and communicating arrangement, and wherein the processing and communicating arrangement starts a temperature measuring session based on an event related to the start switch, the start switch preferably being mechanically coupled to a primary air damper (14) and/or a primary air regulator (19) and/or a door (15), and wherein the event related to the start switch thereby also relates to the primary air damper, regulator or the door.

4. The method of providing combustion-related information according to any of the preceding claims, wherein the temperature sensor is exposed to temperatures below 450 degree C, preferably below 400 degree C, even more preferably below 350 degree C.

5. A wood-burning stove (1) comprising a combustion chamber (11) defined by an inner stove (12), the inner stove having an outside (121),
the wood-burning stove further comprising a combustion monitoring system (2),
the combustion monitoring system comprising

a temperature sensor (22) arranged substantially at said outside (121) of the inner stove (12), and

a processing and communication arrangement (21) being coupled to said temperature sensor (22) and further providing a communicative coupling (23) for enabling connection to an output device (24),

wherein the temperature sensor is arranged to provide a temperature sensor output during combustion of said solid fuel,
wherein the processing and communication arrangement is arranged to transmit temperature representations relating to the combustion of solid fuel inside said combustion chamber to the output device, the temperature representations being derived from the temperature sensor output,
wherein the output device is arranged with a software application to process said temperature representations to provide an output based on said temperature representations, and
wherein said output device is arranged to present combustion-related information to a user of said output device, characterized in that said combustion-related information comprises an estimated time for optimally refilling the combustion chamber with solid fuel such as wood.

6. The wood-burning stove (1) according to claim 5, wherein the combustion monitoring system further comprises a start switch (25), preferably mechanically coupled to a primary air damper (14) and/or a primary air regulator (19) and/or a door (15) of the wood-burning stove (1).

7. The method of providing combustion-related information or the wood-burning stove according to any of the preceding claims, wherein the temperature sensor is arranged so that it is not exposed to soot and flue gas.

8. The method of providing combustion-related information or the wood-burning stove according to any of the preceding claims, wherein said combustion monitoring system comprises a timing unit to associate said temperature representations with timestamps.

9. The method of providing combustion-related information or the wood-burning stove according to any of the preceding claims, wherein the temperature measured by said temperature sensor, during combustion of solid fuel, is lower than the internal temperature in the upper part of said combustion chamber.

10. The method of providing combustion-related information or the wood-burning stove according to any of the preceding claims, comprising predicting the development of the combustion so as to estimate an optimal time for refuelling.

11. The method of providing combustion-related information or the wood-burning stove according to any of the preceding claims, wherein said combustion-related information comprises suggestions to the user to adjust air flow to the combustion chamber.

12. The method of providing combustion-related information or the wood-burning stove according to any of the preceding claims, wherein said output and/or combustion-related information at least partly depends on the specific type of wood-burning stove in which said combustion is performed.

13. The method of providing combustion-related information or the wood-burning stove according to any of the preceding claims, wherein said combustion-related information is at least partly based on experiential information relating to a temperature development in a predefined type of wood-burning stove dependent of the amount of solid fuel used for combustion.

14. The method of providing combustion-related information or the wood-burning stove according to any of the preceding claims, wherein said combustion-related information comprises chimney draft related information.

15. The method of providing combustion-related information or the wood-burning stove according to claim 12 or 13, wherein said specific type of wood-burning stove is selected from a predefined list of different wood stoves.

Ansprüche

1. Verfahren zum Bereitstellen von verbrennungsbezogener Information, die eine Verbrennung eines festen Brennstoffs, wie etwa Holz, in einem holzverbrennenden Ofen (1) betrifft, wobei der holzverbrennende Ofen eine Verbrennungskammer (11) umfasst, die durch einen inneren Ofen (12) definiert wird, wobei der innere Ofen eine Außenseite (121) hat,
wobei der holzverbrennende Ofen außerdem ein Verbrennungs-Überwachungssystem (2) umfasst und wobei das Verbrennungs-Überwachungssystem Folgendes umfasst:

einen Temperatursensor (22), der im Wesentlichen an der Außenseite (121) des inneren Ofens (12) angeordnet ist, und

eine Verarbeitungs- und Kommunikationseinrichtung (21), die mit dem Temperatursensor (22) verbunden ist und die außerdem eine kommunikationsfähige Kopplung (23) bereitstellt, um eine Verbindung mit einer Ausgabevorrichtung (24) zu gestatten,

wobei der Temperatursensor, während der Verbrennung des festen Brennstoffs, eine Temperatursensorausgabe bereitstellt,
wobei die Verarbeitungs- und Kommunikationseinrichtung eine Verbindung von der Ausgabevorrichtung zulässt und Temperaturdarstellungen überträgt, die die Verbrennung des festen Brennstoffs innerhalb der Verbrennungskammer betreffen, wobei die Temperaturdarstellungen aus der Temperatursensorausgabe abgeleitet sind, wobei die Ausgabevorrichtung die Temperaturdarstellungen verarbeitet, um basierend auf den Temperaturdarstellungen eine Ausgabe bereitzustellen, und
wobei die Ausgabevorrichtung einem Benutzer der Ausgabevorrichtung verbrennungsbezogene Information präsentiert,

dadurch gekennzeichnet, dass

die verbrennungsbezogene Information eine geschätzte Zeitspanne für eine optimale Nachbefüllung der Verbrennungskammer mit einem festen Brennstoff, wie etwa Holz, umfasst.

2. Verfahren zum Bereitstellen von verbrennungsbezogener Information nach Anspruch 1, wobei der Temperatursensor an der Außenseite des inneren Ofens angebracht ist, vorzugsweise an einem oberen Teil oder einem oberen hinteren Teil der Außenseite und noch bevorzugter benachbart zu einer Abzugsöffnung (18) des inneren Ofens.

3. Verfahren zum Bereitstellen von verbrennungsbezogener Information nach Anspruch 1 oder 2, wobei das Verbrennungs-Überwachungssystem einen Startschalter (25) umfasst, der mit einer Schaltung der Verarbeitungs- und Kommunikationseinrichtung elektrisch verbunden ist, und wobei die Verarbeitungs-und Kommunikationseinrichtung eine Temperaturmessungsperiode basierend auf einem Ereignis startet, das dem Startschalter zugeordnet ist, wobei der Startschalter vorzugsweise mit einer primären Luftklappe (14) und/oder einer primären Luftregelung (19) und/oder einer Türe (15) mechanisch gekoppelt ist und wobei das dem Startschalter zugeordnete Ereignis damit auch der primären Luftklappe, dem Regler oder der Türe zugeordnet ist.

4. Verfahren zum Bereitstellen von verbrennungsbezogener Information nach einem der vorhergehenden Ansprüche, wobei der Temperatursensor Temperaturen von unter 450 Grad C ausgesetzt ist, vorzugsweise unter 400 Grad C und noch bevorzugter unter 350 Grad C.

5. Holzverbrennender Ofen (1), der eine Verbrennungskammer (11) umfasst, die durch einen inneren Ofen (12) definiert wird, wobei der innere Ofen eine Außenseite (121) hat,
wobei der holzverbrennende Ofen außerdem ein Verbrennungs-Überwachungssystem (2) umfasst und wobei das Verbrennungs-Überwachungssystem Folgendes umfasst:

einen Temperatursensor (22), der im Wesentlichen an der Außenseite (121) des inneren Ofens (12) angeordnet ist, und

eine Verarbeitungs- und Kommunikationseinrichtung (21), die mit dem Temperatursensor (22) verbunden ist und die außerdem eine kommunikationsfähige Kopplung (23) bereitstellt, um eine Verbindung mit einer Ausgabevorrichtung (24) zu gestatten,

wobei der Temperatursensor dafür eingerichtet ist, während der Verbrennung des festen Brennstoffs eine Temperatursensorausgabe bereitzustellen,
wobei die Verarbeitungs- und Kommunikationseinrichtung dafür eingerichtet ist, Temperaturdarstellungen an die Ausgabevorrichtung zu übertragen, die die Verbrennung des festen Brennstoffs innerhalb der Verbrennungskammer betreffen, wobei die Temperaturdarstellungen aus der Temperatursensorausgabe abgeleitet sind, wobei die Ausgabevorrichtung mit einer Softwareanwendung ausgestattet ist, um die Temperaturdarstellungen zu verarbeiten, um basierend auf den Temperaturdarstellungen eine Ausgabe bereitzustellen, und
wobei die Ausgabevorrichtung dafür eingerichtet ist, einem Benutzer der Ausgabevorrichtung verbrennungsbezogene Information zu präsentieren,

dadurch gekennzeichnet, dass

die verbrennungsbezogene Information eine geschätzte Zeitspanne für eine optimale Nachbefüllung der Verbrennungskammer mit einem festen Brennstoff, wie etwa Holz, umfasst.

6. Holzverbrennender Ofen (1) nach Anspruch 5, wobei das Verbrennungs-Überwachungssystem außerdem einen Startschalter (25) umfasst, der vorzugsweise mit einer primären Luftklappe (14) und/oder einer primären Luftregelung (19) und/oder einer Türe (15) des holzverbrennenden Ofens (1) mechanisch gekoppelt ist.

7. Verfahren zum Bereitstellen von verbrennungsbezogener Information oder der holzverbrennende Ofen nach einem der vorhergehenden Ansprüche, wobei der Temperatursensor derart angeordnet ist, dass er keinem Ruß und Abgas ausgesetzt ist.

8. Verfahren zum Bereitstellen von verbrennungsbezogener Information oder der holzverbrennende Ofen nach einem der vorhergehenden Ansprüche, wobei das Verbrennungs-Überwachungssystem eine Zeitgebereinheit umfasst, um den Temperaturdarstellungen Zeitstempel zuzuordnen.

9. Verfahren zum Bereitstellen von verbrennungsbezogener Information oder der holzverbrennende Ofen nach einem der vorhergehenden Ansprüche, wobei die vom Temperatursensor gemessene Temperatur, während der Verbrennung des festen Brennstoffs, niedriger ist als die innere Temperatur im oberen Teil der Verbrennungskammer.

10. Verfahren zum Bereitstellen von verbrennungsbezogener Information oder der holzverbrennende Ofen nach einem der vorhergehenden Ansprüche, das oder der das Vorausberechnen der Entwicklung der Verbrennung umfasst, um dadurch einen optimalen Zeitpunkt für eine Nachbefüllung abzuschätzen.

11. Verfahren zum Bereitstellen von verbrennungsbezogener Information oder der holzverbrennende Ofen nach einem der vorhergehenden Ansprüche, wobei die verbrennungsbezogene Information Vorschläge für den Benutzer umfasst, um die Luftzufuhr zur Verbrennungskammer anzupassen.

12. Verfahren zum Bereitstellen von verbrennungsbezogener Information oder der holzverbrennende Ofen nach einem der vorhergehenden Ansprüche, wobei die Ausgabe und/oder verbrennungsbezogene Information wenigstens teilweise vom speziellen Typ des holzverbrennenden Ofens abhängt, in dem die Verbrennung stattfindet.

13. Verfahren zum Bereitstellen von verbrennungsbezogener Information oder der holzverbrennende Ofen nach einem der vorhergehenden Ansprüche, wobei die verbrennungsbezogene Information wenigstens teilweise auf empirischer Information basiert, die eine Temperaturentwicklung in einem vorgegebenen Typ von holzverbrennendem Ofen in Abhängigkeit von der Menge an festem Brennstoff, der für die Verbrennung verwendet wird, betrifft.

14. Verfahren zum Bereitstellen von verbrennungsbezogener Information oder der holzverbrennende Ofen nach einem der vorhergehenden Ansprüche, wobei die verbrennungsbezogene Information Information umfasst, die den Kaminzug betrifft.

15. Verfahren zum Bereitstellen von verbrennungsbezogener Information oder der holzverbrennende Ofen nach Anspruch 12 oder 13, wobei der spezielle Typ des holzverbrennenden Ofens aus einer vorgegebenen Liste von verschiedenen Holzöfen ausgewählt ist.

Revendications

1. Procédé de fourniture d'informations liées à la combustion liées à une combustion de combustible solide, tel que le bois, dans un poêle à bois (1), le poêle à bois comprenant une chambre de combustion (11) définie par un poêle interne (12), le poêle interne ayant un extérieur (121),
le poêle à bois comprenant en outre un système de surveillance de combustion (2),
le système de surveillance de combustion comprenant

un capteur de température (22) agencé sensiblement au niveau dudit extérieur (121) du poêle interne (12), et

un agencement de traitement et de communication (21) couplé audit capteur de température (22) et fournissant en outre un couplage de communication (23) pour permettre une connexion à un dispositif de sortie (24),

dans lequel le capteur de température, lors de la combustion dudit combustible solide, fournit une donnée de capteur de température,

dans lequel l'agencement de traitement et de communication accepte une connexion depuis le dispositif de sortie et transmet des représentations de température concernant la combustion de combustible solide à l'intérieur de ladite chambre de combustion, les représentations de température étant dérivées de la donnée de capteur de température,
dans lequel le dispositif de sortie traite lesdites représentations de température pour fournir une donnée sur la base desdites représentations de température, et
dans lequel ledit dispositif de sortie présente des informations liées à la combustion à un utilisateur dudit dispositif de sortie, caractérisé en ce que
lesdites informations liées à la combustion comprennent un temps estimé pour remplir de manière optimale la chambre de combustion d'un combustible solide tel que le bois.

2. Procédé de fourniture d'informations liées à la combustion selon la revendication 1, dans lequel ledit capteur de température est attaché audit extérieur du poêle interne, de préférence à une partie supérieure ou à une partie arrière supérieure dudit extérieur, de manière encore davantage préférée adjacent à une ouverture d'échappement (18) dudit poêle interne.

3. Procédé de fourniture d'informations liées à la combustion selon la revendication 1 ou 2, dans lequel le système de surveillance de combustion comprend en outre un commutateur de démarrage (25) couplé électriquement à un circuit de l'agencement de traitement et de communication, et dans lequel l'agencement de traitement et de communication démarre une session de mesure de température sur la base d'un événement lié au commutateur de démarrage, le commutateur de démarrage étant de préférence couplé mécaniquement à un registre d'air primaire (14) et/ou à un régulateur d'air primaire (19) et/ou à une porte (15), et dans lequel l'événement lié au commutateur de démarrage qui concerne donc également le registre d'air primaire, le régulateur ou la porte.

4. Procédé de fourniture d'informations liées à la combustion selon l'une quelconque des revendications précédentes, dans lequel le capteur de température est exposé à des températures inférieures à 450 °C, de préférence inférieures à 400 °C, de manière encore davantage préférée inférieures à 350 °C.

5. Poêle à bois (1) comprenant une chambre de combustion (11) définie par un poêle interne (12), le poêle interne ayant un extérieur (121),
le poêle à bois comprenant en outre un système de surveillance de combustion (2),
le système de surveillance de combustion comprenant

un capteur de température (22) agencé sensiblement au niveau dudit extérieur (121) du poêle interne (12), et

un agencement de traitement et de communication (21) couplé audit capteur de température (22) et fournissant en outre un couplage de communication (23) pour permettre la connexion à un dispositif de sortie (24),

dans lequel le capteur de température est agencé pour fournir une sortie de capteur de température pendant la combustion dudit combustible solide,
dans lequel l'agencement de traitement et de communication est agencé pour transmettre des représentations de température concernant la combustion du combustible solide à l'intérieur de ladite chambre de combustion au dispositif de sortie, les représentations de température étant dérivées de la sortie de capteur de température,
dans lequel le dispositif de sortie est agencé avec une application logicielle pour traiter lesdites représentations de température afin de fournir une donnée basée sur lesdites représentations de température, et
dans lequel ledit dispositif de sortie est agencé pour présenter des informations liées à la combustion à un utilisateur dudit dispositif de sortie, caractérisé en ce que lesdites informations liées à la combustion comprennent un temps estimé pour remplir de manière optimale la chambre de combustion d'un combustible solide tel que le bois.

6. Poêle à bois (1) selon la revendication 5, dans lequel le système de surveillance de combustion comprend en outre un commutateur de démarrage (25), de préférence couplé mécaniquement à un registre d'air primaire (14) et/ou à un régulateur d'air primaire (19) et/ou une porte (15) du poêle à bois (1).

7. Procédé de fourniture d'informations liées à la combustion ou poêle à bois selon l'une quelconque des revendications précédentes, dans lequel le capteur de température est agencé de sorte qu'il ne soit pas exposé à la suie et aux gaz de fumée.

8. Procédé de fourniture d'informations liées à la combustion ou poêle à bois selon l'une quelconque des revendications précédentes, dans lequel ledit système de surveillance de combustion comprend une unité de synchronisation pour associer lesdites représentations de température à des horodatages.

9. Procédé de fourniture d'informations liées à la combustion ou poêle à bois selon l'une quelconque des revendications précédentes, dans lequel la température mesurée par ledit capteur de température, pendant la combustion de combustible solide, est inférieure à la température intérieure dans la partie supérieure de ladite chambre de combustion.

10. Procédé de fourniture d'informations liées à la combustion ou poêle à bois selon l'une quelconque des revendications précédentes, comprenant la prédiction de la progression de la combustion de manière à estimer un temps optimal pour le ravitaillement.

11. Procédé de fourniture d'informations liées à la combustion ou poêle à bois selon l'une quelconque des revendications précédentes, dans lequel lesdites informations liées à la combustion comprennent des suggestions à l'utilisateur pour ajuster le débit d'air dans la chambre de combustion.

12. Procédé de fourniture d'informations liées à la combustion ou poêle à bois selon l'une quelconque des revendications précédentes, dans lequel ladite sortie et/ou les informations liées à la combustion dépendent au moins en partie du type spécifique de poêle à bois dans lequel ladite combustion est effectuée.

13. Procédé de fourniture d'informations liées à la combustion ou poêle à bois selon l'une quelconque des revendications précédentes, dans lequel lesdites informations liées à la combustion sont moins en partie basées sur des informations expérimentales concernant une progression de température dans un type prédéfini de poêle à bois dépendant de la quantité du combustible solide utilisé pour la combustion.

14. Procédé de fourniture d'informations liées à la combustion ou poêle à bois selon l'une quelconque des revendications précédentes, dans lequel lesdites informations liées à la combustion comprennent des informations liées au tirage de cheminée.

15. Procédé de fourniture d'informations liées à la combustion ou poêle à bois selon la revendication 12 ou 13, dans lequel ledit type spécifique de poêle à bois est sélectionné à partir d'une liste prédéfinie de différents poêles à bois.

Drawing