DK177438B3

DK177438B3 - Electronically controlled burner

Info

Publication number: DK177438B3
Application number: DKPA201200052A
Authority: DK
Inventors: Kjell Thomsen
Original assignee: Decoflame Aps
Priority date: 2012-01-19
Filing date: 2012-01-19
Publication date: 2017-10-02
Also published as: WO2013107455A3; EP2807424B1; EP2807424A2; WO2013107455A2; DK177438B1; DK2807424T3; PL2807424T3

Abstract

An electronic burner (2) configured to combust bioethanol is disclosed. The electronically controlled burner (2) comprises a fuel tank (6) being in fluid communication with an evaporation accelerator (10) being in thermal contact with a heatin.g element (12) configured to heat and hereby evaparate fuel in the evaporation accelerator (10). The electronically controlled burner (2) comprises further a flame tray (4) having an ignition member (36) configured to ignite vapour delivered from the evaporation accelerator (10). The electronically controlled burner (2) comprises a fuel pump (8) configured to pump fluid fuel between the fuel tank (6) and the evaporation accelerator (10), where the fuel pump (8) is configured to maintain an essentially constant fuel level in the evaporation accelerator (10). The flame tray (4) is provided with a plurality of flame holes (34, 34') having varying hole sizes and/or shapes.

Description

Electronically Controlled Burner

Description

Field o f the Invention l|e invention generally reiates to an electronically controlled burner. The invention more particuiårly reiates to an electronically controlled burner adapted for combustion of iiquld fue! such as ethanoi, prefer-ably liquid fuel comprislng at least 96% bioethanol.

Backgrounå of the Invention

Electronically controlled burners that combustethanol and in particu-iar bioethanol are used for various purposes, Bioethanof is an alcobol producibfe from fermentation of wheat, sugars, potatoes, other sult-able agricultural crops and organlc household waste. Combustmg of bioethanol will only emit water vapour, carbon dloxide and heat. Bio-ethanot fireplaces or burners burn cleanly with an orange/blue flame and are eonsidered to be decorative and completely environmentally friendiy. The colour of the flame depends on the purity of the bioeth-anoL Furthermøre, installation of bioethanol fireplaces does not re~ quire any chimney or flue, They are smoke and odour-free and do not emit harmfui gases,

Several types of electronically controlled ethanoi burners are avallas ble. US 2011 0171587 Al disciosesan electronically controlled ethanoi burner that comprlses an electric heater configured to heat the fuel and hereby evaporate the fuel before the vapour Is ignited. The fue! is pøured into a fuel tank, wherefrom it flows Into an evaporation piate that Is brought into thermal contact with a set of heaters. The evåpdfated fuel (vapouf) is hereåftér guided through a magnetic val ve to a vapour distribution piate.

The fuel level in the evaporation piate is; determined by the lusitlevei of the fuel tank due to the faet that the fue! is guided from the fuel tank to the evaporation piate by gravlty. Therefore, the fuel evapora- tion rate is heaviiy infiuenced by the fuei level in the fuel tank, Since the evaporation rate is one of the main determinants of the magni-tude of the fiames, it is difficuit to con tro i the magnitude of the flame by using an eiectronicaily controiied burner iike the one described in US 2001 0171587 Al. US 4614493 Al disdoses an oil burner having an oii tank, an oii reservoir and an oii suppiy pipe for suppiying fuei oi! to a pot, The oii reservoir is adapted to aiiow the tank to be supported thereon in an inverted man ner and keep fuei oi! to be suppiied from the reservoir to the pot at a constant level. This oil burner is not suitable for burn-ing bioethanol since the burner canrvot be ctosed down as long as there is fuei In the pot. WO 2012000562 Al discloses an ethanoi burner comprising a burner cartridge that has a burner base and wails that extend from the bumer base and which surround the burner base. The burner comprising a feed for feeding ethanoi to the base and a fuei quantity suppiy is connected to the feed and configured to maintaining a con-stant iiquid level on the base during a burning process. The burner can however, not be shot down automatically. WO 8303459 Al discloses a bumer system, where fuei is intended via an iniet to be suppiied into a combustion space. The burner system comprises a giowing filament configured to ignite the evaporated fuei. The bumer system comprises means for suppiy of air to the combustion space. The burner system moreover has at ieast one tur-buience generating member that divides the combustion space into a iower space and an upper space.

None of these burners are capabie of controliing and adjusting the magnitude of the fiames in a desired manner.

Accordingiy, there is need for an eiectronicaily controiied ethanoi burner in which the magnitude of the fiame is both controiSabie and adjustable. There is especiaily need for an eieetronicaliy controiied ethanoi burner in which the magnttude of the flame may be kept constant when set to a predefined ievei (ffame height) - inde-pendentiy of the fuel level in the fuel tank.

Moreover, there is need for an eleetfonicaliy controiied efchanol burner that can be closed down fast,

Object of the Invention

Accordingly, it is an object of the present invention to provide an eieetronicaliy controiied ethanoi burner in which the magnitude of the fiame can be kept constant independentiy of the fuel leve! in the fuei tank,

It is aiso an object to provide an eieetronicaliy controiied ethanoi burner in which the heating of the ethanoi can be carried out in a controiied manner and in which the fuel consumption rate is control-iable (e.g. so that a fuel consumption rate below 500 mi /hour can be achieved),

Summary of the Invention

The object of the present invention can be achieved by an electronj-caliy controiied burner ha ving the features defined in ciaim 1, Pre-ferred embodiments are defined in the dependant sub claims and ex-piained in the following description and iliustrated in the accompany- ing drawings,

The eieetronicaliy controiied burner accordmg to the invention is con-figured to combust bioethanoi, which eieetronicaliy controiied burner comprises a fuei tank being in fluid communication with an evaporation accelerator being in thermal contact with a heating element configured to heat and hereby evaporate fuel In the evaporation accelerator, a fiame tray having an ignition member configured to ignite vi-pour deilvered from the evaporation accelerator. The burner comprises a fuel pump configured to pump fluid fuel between the fuei tank and the evaporation accelerator, where the fuei pump is config-ured to maintain an essentiaiiy constant fuel ievel in the evaporation accelerator, The fiame tray is provided with a piuraiity of flame hoies having varying hole sties and/or shapes. ipreby, it is achieved that the magnitude of the flame can be kept constant. The magnitude of the flame can be kept at a constant leve! due to the faet that the evaporation rate is maintained at an essentiaiiy constant level because the constant fuel ievei in the evaporation accelerator is maintained essentiaiiy constant,

It is preferred that the electronicaiiy controlled burner is configured tø set the magnitude of the fiame to a piuraiity ofpredefined leveis so that the user of the eiectronicaliy controiied burner can set the heat generation rate (heat output) and the fuei consumption rate ac-cording to specific requirements. It is especiaiiy preferred that the user of the electronicaiiy controlled burner can set the fuei consumption rate to a ievel that is lower than or equal to 500 mi/hour,

By maintaining a constant fuel ievel in the evaporation accelerator, it is possibie to maintain a basicaiiy constant evaporation rate so that the heating of the ethanoi can be carried out in a controfled manner.

The term "electronicaiiy controiied burner" means that the burner comprises an eiectricai heater configured to heat and hereby evapo-rate fuei in the evaporation accelerator.

The evaporation acceierator is a member adapted to faciiitate evaporation of the fuei. In an electronicaiiy controiied burner evaporation faciiitation is preferabiy carried out by using an eiectrie heating element configured to generate a predeflned amount of heat to evapo-rate the fuel at a defined rate. This is crucial when applying bioetha-no! as a fuel under low temperature conditions, since on ly the blo-ethanol vapour is ignitabie and the evaporation temperature of bio-ethanoi is around 17°C,

The evaporation accelerator may be any suitable member capabfe of vaporising the fuel, The evaporation accelerator may be a tank com-prising an eiectric heating element,

It is preferred that the electronlcaSly controiied bumeraccording to the invention is configured to combust bioethanol, since bioethanol has severa! advantages over conventional fueis for electronicaiiy controiied burners,

Bioethanol has a number of advantages over conventional fueis.

Since bioethanol comes from a renewable resource such as crops and not from a fin'ste resource it is an environmentally friendiy fuei.

The fuei tank may be an Integrated part of the electronicaiiy controlled burner, however, it is also possible to arrange the tank in a distance from the remaining parts of the electronicaiiy controiied burner. The tank may be arranged outside of the bullding in whlch the remaining parts of the eiectronicafly controiied burner are arranged.

By having a tank being in fluid communication with the evaporation accelerator, fuei can be pumped from the tank to the evaporation accelerator and a constant fuei ieve! can be maintained. Besides the evaporation accelerator can be emptied by pumping fuei from the evaporation accelerator to the tank, which may be a huge advantage for safety reasons,

The heating element may be any suitabie type of electrlcal heating element. It is essentiai that the heating element is configured to heat and hereby evaporate fuei in the evaporation accelerator.

It may be an advantage that the heating eiement is Integrated in the evaporation accel erator,

The flame tray may be any suitable type of flame tray eapabie of dis-tributing and burnlng the vaporised fuei,

It may be beneflcia! that the fiame tray has an elongate shape e.g, a rectangular box-tike shape, The ferne tray may, høwever, aiso have another geometric shape {a elrcuiar arced shape or an elliptic shape by way of exampie),

It is essentlat that the fiame tray is having an Ignition member con-figured to ighite vapour deiivered from the evaporation accelerator,

The eiectronicaily controiled burner comprlses a fuef pump config-ured to pump between the fuei tank and che evaporation acceierator. The pump may be configured to provlde pulsatlng fuei pumping,

It is preferred that the pump is an electric pump adapted to be controiled by a controi unit in a way such that the pump is configured to maintain an essentiaSiy constant fuei level in the evaporation ae-ceie ra tor it is an advantage that the pump has two pumping directions so that the pump can be used to pump fuei both between the fue! tank and the evaporation acceierator and between the evaporation accelerator and the fuei tank,

It is preferred that vapour is delivered from the evaporation accelerator via a vapour diffuser to the fiame tray. Ibis preferred that the vapour diffuser comprlses a pipe member ciosed at the top and fea-turing a number of holes and being in fluid communlcation with the fiame tray.

The electronicaliy controfied burner according to the invention Is preferabiy adapted for combusting of bioethanoi.

It is preferred that the ignition member is a filament, Using a filament as ignition member is beneficiai because a filament is capable of igniting the vaporised fuet as soon as the vapour gets in contact with the filament. When a spark is used to ignite the vaporized fuel in an eiectnc borner there is a risk of ignition of a rather large vol-ume of vapour which may cause a minor expiosion. Another disad-vantage of a spark ignition is the constant "clicking noise" which may be perceived as disturbing because it takes a considerabie period of time before a sufficient amount of bioethanol vapour has been dis-tributed to the flame tray, These draw backs are soived by using a filament as ignition member.

The fiiament may have any suitabie size, iength and shape, and goes into operation as soon as the vapour starts to rise into the flame tray in order to avoid expiosive ignition of a buiid-up of vapour.

It is preferred that the fuei pump is configured to pump fuel from the fue! tank into the evaporation accelerator in a first mode and to pump fuel from the evaporation accelerator into the fuei tank in another mode. Hereby, it is achieved that a feguired amount of fuei can be deiivered to the evaporation accelerator by using the pump whiie the pump is operated in the first mode. On the other hånd, the pump can be used to empty the evaporation accelerator by pumping fuei from the evaporation accelerator into the fuei tank while the pump is operated in another mode.

It is important to underline that it is possibie to operate the pump in a pluraSity of modes in order to meet varlous operation require-ments. In case of detection of a malfunction it may be an ad vantage to be abie to empty the evaporation accelerator as fast as possibie, in order to extinguish the fire by interrupting the vapour supplies to the fiame tray.

It may be an advantage that the burner comprises a controi unit configured to controi the fuei pump. Preferably, the controi unit is configured to recesve input from one or more sensors Integrated in the electronicaiiy controlled burner or in proximity to the electroni-caiiy controiied bumer, Hereby the controi unit can be used to con-troi the electronicaiiy controiied burner accordsng to received inputs and hereby provide a more specific controi of the electronicaiiy controiied burner,

It may be an advantage that the eiectronicaliy controiied burner comprises a controi unit and a temperature sensor being in thermai contact with the evaporation acceierator, In this way, the controi urt ft can controi the eiectronicaiiy controiied burner according to the temperature of the evaporation acceierator.

Preferabiy, the controi unit is configured to controi the heating element on the basis of temperature detected by a temperature sensor, preferabiy a temperature sensor being in thermai contact with evaporation acceierator and hereby the fuel.

It is preferred that the electronicaiiy controiied burner comprises a controi unit and a temperature sensor being in thermai contact with the evaporation acceierator, where the controi unit is configured to controi the heating element on the basis of temperature detected by the temperature sensor, where the controi unit is configured to switch off the ignition member when the detected temperature ex-ceeds a defined up per temperature ievei Ta, and/or where the controi unit is configured to switch off the burner when the detected temperature is beiow a defined iower temperature ievei Ti.

Hereby it is achieved that the controi unit can be configured to switch off the ignition member in a situation where a certain temperature is reached. When the temperature exceeds a defined upper temperature dames are present in the fiame tray and thus the filament can be switched off. In another situation when the temperature in the flame tray does not rise during a pre-defned time penod (in-dicating that no fiames are burning) the filament may be switched offtogether with the rematning part of the eiectronicaliy controiled burner, Therefore, an automatic switch offi procedure of the eiectron-icaliy controiled burner (the entire firepiace installation) can be con-ducted when a detected temperature (of the flame tray or an area close to the flame tray) is below a defined temperature level.

It is preferred that the eiectronicaliy controiled bumer comprises an overflow sensor configured to detect fuel overflow of the tank, Here-by it is possible to monitor the tank, It is preferred that the eiectronicaliy controiled burner is configured in such a way that fuel overflow detection information is being sent to the control unit and that the control unit is adapted to generate an action when fuel overflow detection information is being recelved.

It is preferred that the eiectronicaliy controfied burner comprises an overflow sensor configured to detect fuel overflow of the tank and to generate an aiert in the case of an overflow condition, It is beneficiai that the control unit is configured to generate an aiert that may inform the user of the burner about the overflow situation, The alert may be any suitabie type of alert such as a visua! alert (e,g, a warn-ing fight) ør an acoustic aiert (e.g. a warning noise). It is aiso possible to have a control unit that is configured to send a signal wireiess-iy to an extern device (a wireless receiver Integrated in a watch, a mobiie phone or a computer) or to send a signal via the internet e.g, to a server that may be configured to send a text massage or an email to one or more recipients,

It may be an advantage that the eiectronicaliy controlied burner is configured to set the evaporation rate from the evaporation accefera-tor. By the term "set" is meant that the evaporation rate is main-tained essentialiy constant. When an essentiaily constant evaporation rate is maintained the evaporation rate oniy vanes slightiy, pref-erably less than 25% or even more preferred iess than 10%, It is preferred the eiectronicaliy controiled burner is configured to set the evaporation rate from the evaporation accelerator to a number of re- defined levels, Hereby, a number of flamé height levels can be achieved, Moreover, it is possibie to control the fuef consumption rate inciuding keeping the fuel consumption rate to a leve! below e.g, 500 ml/hour.

By hiving a constant evaporation rate a constant flame "dispiay" can be achieved. This means that each flame in the flame tray (there may be several flame holes) wiil keep an essentialty constant flame height - independently of the fuel ieve! in the fue! tank. In this way, the generated heat wiil also be basicaily constant and the electroni-cally controiied burner wiil be controliable to a high degree.

The fiame tray is provided with a plurality of flame holes having varying hole sizes and/or shapes. By having a plurality of varying hole sizes and/or shapes is achieved that a different vapour flow is guided through the different holes. Due to the faet that the flame height depends heavily on the vapour flow, different flame heights are achieved by a fiame tray having a plurality of flame holes with varying hole sizes. The shape of the holes influences the vlsual char-acteristics of the flame and thus the shape of the fiame holes may be chosen in order to achieve desired visuai flame characteristics (e.g. a wide or narrow fiame).

It may be an advantage that the eleetrohicaliy controiied by f her comprises a carbon monoxide (CO) sensor and/or a CO2 (carbon di-oxide) sensor. CO and/or CO2 may be detected by the sensor(s) and information from the sensor(s) may preferabiy be send to the control unit. Since CO can be toxic to humans and animals is preferred that the electronically controiied burner is configured to switch off auto-maticaliy when a high level of CO (higher than a defined critical iev-el) is detected, Preferably, the control unit is adapted to switch off the eiectronically controiied burner and empty the evaporation accelerator by activating the fuel pump when a high level of CO and/or CO2 Is detected by ane or more sensors.

It is preferred thatthe electroniealiy controiied burnér domprises a tilt sensor, A titt sensor may be any suitabie type of tiit sensor capa- bie of detecting change of orientation of the eiectronicaiiy controiied burner. By having a tiit sensor it is possible to switch off the burner in case that undesirable tiit conditions occur (e.g. when the eiectroo-iealiy controiied burner is tiited unintended under operation).

It is preferred that the eiectronicaiiy controiied burner comprises a ieakage detection sensor. The ieakage detection sensor may be any suitabie type of Ieakage sensor and preferabiy, the ieakage detection sensor is configured to detect ieakage in the area below the fuel tank so that Ieakage of the fuel tank or ieakage from the fuel pump or from one of the connections to either the fuei pump, the tank or the evaporation accelerator, may be detected by using the Ieakage detection sensor. It is, however, aiso possible to have a Ieakage sensor arranged eisewhere In the eiectronicaiiy controiied burner.

It is preferred that the controi unit is configured to communicate wireiessiy with a remote Control. It may be an advantage to use a mobile phone, e.g. a smart phone as a remote controi.

In one embodiment according to the present invention, the burner is configured to communicate through the Internet or through a wired or wireiess network. In this way, the eiectronicaiiy controiied burner may receive information (e.g. software updates) through the Internet or a wired or wireiess network, The eiectronicaiiy controiied burner may also be configured to send information via the Internet or alternative!'/ through a wired or wireiess network,

It may be an advantage that the eiectronicaiiy controiied bumer is configured to be started (switched on) by using an interface, prefer-ably an interface provided on the controi unit. It is however, also possible to have an eiectronicaiiy controiied burner that is configured to be started by using a remote controi. It is preferred that once the electronicaiiy controlled burner has been powered on by presstng an on/off button, the remofce control can be used to change the flame size ievels and to start up the ignition.

It is preferred that the electronicaiiy controlled burner comprises a safety chamber arranged below the evaporation accelerator. Pref-erably, the burner comprises a fuel tank arranged below the evaporation accelerator and a safety chamber arranged beiow the fuel tank.

It is preferred that a leakage detection sensor is arranged in the safety chamber and that the leakage detection sensor is arranged so that it is adapted to detect leakage from the fuel tank or leakage from the fuel pump or from one of the connections to either the fuei pump, the tank or the evaporation accelerator.

Descriptton of the Drawings

The invention wii! become more fuiiy understood from the detatied descriptton given herein beiow. The accompanying drawings are given by way of illustration only, and thus, they are not limitative of the present invention. In the accompanying drawings:

Fig. i shows a schematic cross-sectionai view of an electronicaiiy controlled burner according to the invention;

Fig. 2 shows a schematic top vtew of a fiame tray according to the invention;

Fig. 3 shows a schematic side vtew of the fiame tray shown in Fig. 2;

Fig. 4 shows schematic side views of a flame tray tn three differ-ent States of operation; and

Fig. 5 shows the fiame tray with burning flames in two different fiame level modes,

Detailed Description of the Invention

Referring how in detail to the drawings for the purpose of iilustrating preferred embodiments of the present invention, an eiectronicaiiy controiled burner 2 of the present invention is illustrated in Fig, 1.

In Fig. i a schematic side view of an eiectronicaiiy controHed burner 2 according to the invention is illustrated. The eiectronicaiiy con-troiied burner 2 is configured to combust bioethanoi and thus no chimney is needed.

The elecferooicaify controiled burner 2 comp rises an eiongate basicaiiy boxed-shaped fiame tray 4 mecbanlcaliy attached to a number of connection members 26 shaped as rods. The connection members extend perpendicular to the longitudinal axis X of the eiectronicaiiy controiled burner 2. The dame tray 4 is provided with a piurality of flame openings 34, 34', 34" through which vaporised fuei can be dis-tributed. It is intended a fiame F is buming from dame opening 34, 34', 34" as iong as vapour is suppiied through the fiame opening 34, 34', 34".

The fiame tray 4 is surrounded by a fiame stabiliser 42 that also function as a heat transfer piate 42, The fiame stabiiiser/heat transfer piate 42 is eapabie of distributing the heat generated by the dames F back to an evaporation accelerator 10 that is mechanicaliy and thermaiiy connected to the flame tray 4. A temperature sensor 14 is arranged in the top portion of the evaporation acceierator 10 above a heating eiement 12 that is arranged centraliy in the evaporation accelerator 10. A fuel level sensor 16 is provided at the tower side of the evaporation acceierator 10, The fuei level sensor 16 is configured to detect the fuel level in the evaporation accelerator 10. Fuei is being suppiied to the evaporation accelerator 10 through a pipe 38 that is connected tb an electric fuel pump 8 that is further connected to fuel tank 6, The connection members 26 are mechanicaliy attached to the upper side of the fuei tank 6. A fuei overflow return pipe 41 is connected to the evaporation accelerator 10 and the fuei tank δ. A safety chamber 46 is arranged below the fuei tank 6, At the central part of the safety chamber 46 an indentation 50 is prcvided. A liquid sensor 48 is arranged at the bottom of the indentation 50. The liquid detection sensor 48 is configured to detect ieakage from the fuei tank 6, from the fuei pump 8 or from one of the connections between the pipe 38 and the evaporation acceierator 10, the pipe 38 and the fuei pump 8, the pipe 38' and the fuei pump 8 or the pipe 38' and the fuei tank 6.

The temperature sensor 14 is electrically connected to a control unit 20 via a cabie 30 and the fuei level sensor 16 is electricaiiy connected to the control unit 20 by a wire 30'"". The control unit 20 is equlpped with a display 22 configured to provide visuai information to the user of the eiectronicaiiy controlied burner 2. The controi unit 20 moreover comprises an interface 24 consistlng of a number of buttons that can be used to sefcup (e.g. by entering values) the controi unit 20. The controi unit 20 is suppiied with eiectriclty from a power supply 44.

The control unit 20 is electrically eonheeted to the temperature sensor 14 by a cabie 30. Thus, the controi unit 20 is configured to re~ ceive temperature measurements (detected by the temperature sensor 14). The control unit 20 is electrically connected to the heating element 12 In the evaporation accelerator 10 by a cabie 30'. The control unit 20 is configured to controi the heating element 12 on the basis of the detected temperature and control unit settlngs.

The control unit 20 may be configured to switch off an ignition mem-ber formed as a filament 36 when the detected temperature exceeds a defined upper temperature levei T^ since there is no need for the fiiament to be switched on when the temperature has reached a cer-tain ievel where flames F are burning perfectly without assistance from the filament 36. The control unit 20 may be configured to switch off the electronicaify controlied burner 2 when the detected temperature is beiow a defined iower temperature leve! Ti,

The control unit 20 is efectricaliy connected to the fuei pump 8 by a cable 30". The controi unit 20 is configu red to controi the pump (turn the fuei pump 8 on, switch off the fuel pump S orchange the pump-ing direction or speed of the fuel pump 8).

The control unit 20 is furfcher electncalfy connected to a fuel levei sensor 16 that is adapted to send fuel level information to the control unit 20. By using the fuel level sensor 16 it is posstbie to provide information about the fuel level in the evaporation accelerator 10 and send the information to the controi unit 20 so that the control unit 20 can use these data to regutate or controi the fuel pump 8, the heat-ing element 12 or another device being adapted to be controlied by the control unit 20, A fuel level sensor 18 is arranged at the side of the fuel tank beiow the control unit 20, The fuel level sensor 18 is eiectrlcally connected to the control unit 20 by a cable 30"" and configured to send fuel level information to the control unit 20. Du ring fllling up the tan k 6 with fuel the fuel leve! sensor 18 may be configured to indicate when a predefined percentage of the tank volume, 75% by way of exam-ple, has been reached. The controi unit 20 can preferably, be adapted to generate an acoustic indication (e.g, one or more loud beeps) so that the user of the eiectronically controlied burner 2 Is aware that the tank 6 is close to being filled up. It is also possible to use the control unit 20 generate an alert when a low fuel level (e.g. 25% or 10% of the tank volume) is detected by the fuei level sensor 18. A temperature sensor 45 is arranged at the flame tray 4 and configured to communlcate wireiessly with the control unit 20. It is aiso possibie to have a wired electricaiiy connection between the flame tray 4 and the control unit 20.

The tank 6 has a tank intet 32 and a ild 28 for the tank intet 32. The lid 28 is conflgured to be mechantcally attached to the intet 32 e.g. by a screwed connection. The ifd 28 and the intet 32 may be provid-ed with corresponding threads. A fuel spiliage tray 52 is arranged around the iniet 32 and is adapted to accumuiate fuel that is spilied when filiing fuel into the tank 6. A vapour diffuser 43 is arranged inside the flame tray 4, The vapour diffuser 43 is pipe-shaped and closed at the top. The pipe-shaped vapour diffuser 43 is provided with a piurality of apertures 58 configured to distribute the vapour from the evaporation accelerator 10 irs-to the fiame tray 4.

The apertures 58 in the evaporation diffuser 43 will guide vapour to the sides whiie a pipe-shaped evaporation diffuser 43 without apertures 58 woufd guide aii of the vapour straight upwards to die fiame opening next to the filament 36. A bal! 56 is arranged inside the vapour diffuser 43. When vapour is guided upwards through the vapour diffuser 43 the bal! 5| will be dispiaced verticaiiy by the rising vapour. When no vapour is generat-ed (e.g. when the evaporation accelerator 10 is empty, the temperature in the evaporation accelerator 10 is faiiing or the pump 8 starts reversing thus emptying the evaporation acceierator 10} the bal! 56 will piug the evaporation diffuser 43. Accordingly, the evaporation diffuser 43 functions as a bai! valve that can be used to facilitate a fast switch down procedure of the eiectronicaiiy controlied burner 2, A liquid sensor (an overflow detection sensor) 54 is arranged in the fue! spillage tray 52. The liquid sensor 54 is iiSpied to detect when overflow occurs. When overflow occurs the liquid sensor 54 (e.g. constructed as a humidity sensor) sends information to the control unit 20 via a cabie 30"', The contra! unit 20 generates an alert (e.g. a beep) and prevents a start-up of the eiectronicaily controiied burner 2 until the iiquid sensor 54 no longer indicates the present of an overflow condstion. The Iiquid sensor 54 prevents that the tank 6 is fiiied to overfiowing. A tilt sensor (not shown) is Integrated in the eiectronicaliy controiied burner 2. The tiifc sensor is configured to send information about the orientation of the electronicaiiy controiied burner 2 (e.g. measured as the angle between the longitudinal axis X of the electronicaiiy controiied bumer 2 and the horizontal direction) to the controi unit 20.

Any of the sensors 45, 14, 54, 18, 48, 16 rrtay be configured to communicate wireiessiy or by means of cabies with the controi unit 20. A remote controi 40 is configured to communicate wireiessiy with the controi unit 20. The remote controi 40 may be used to change set-ting in the controi unit 20, to read a log or to gravide any øther form of communication with the controi unit 20. It is possibie to use a mobile phone (smart p'honé) as remote controi.

Fig. 2 iilustrates a top view of a flame tray 4 according to the invention. The flame tray 4 has a rectanguiar cross section and comprises a piuraiity of small fiame openings 34, medium sized flame openings 34' and larger flame openings 34". The flame tray 4 is provided with a piuraiity of fiame openings having varying opening slzes. In this way, the vapour flow being guided through openings of different siz-es wiii differ and thus a more natura! flame Image (varying flame height as shown in Fig. 4 c) can be achieved. A vapour diffuser (see Fig. 1) extends basicaliy perpendicuiar to the longitudinal axis Y of the fiame tray 4. A filament 36 Is arranged above the vapour diffuser over a centrai fiame opening at the central portion C of the flame tray 4.

The filament 36 is configured to ignite the vapour that is gu ided to the openings 34, 34', 34" via the vapour diffuser, initially, prior to start-up of the electronicaSly controlled burner 2, fuel will be pumped to the evaporation accelerator i G and the heater 12 will be switched on in order to warm up the fuel. When vapour Is present at the vapour diffuser, the vapour will initially be distributed through the flame openlng provided at the central portion C of the flame tray 4, The filament will be turned on and thus the vapour will be ignited as soon as the filament is in contacfc with vapour.

Compared to the prior art ignition members formed as spark generators, the filament provides a less nossy and safer ignition member«

As the temperature of the flame tray 4 increases from the central portion C of the flame tray 4 towards the end portions E, Έ’ of the flame tray 4 the flames will start spreading from the central portion C of the fiame tray 4 towards the end portions E, E' of the flame tray m when the eiectronicaliy controlled burner 2 is switched off the fuel will be pumped away from the evaporation accelerator 10 by using the fuel pump 8, After a short time, the bal! 56 (see Pig. i) will be sucked downwards and plug the bdttom openlng of the vapour diffuser 43 (see Fig. i). Therefore, no vapour will be sullied to the flame tray 4 and thus the flames F in the fiame tray 4 wiil be put out.

It can be seen that the number and size of the flame openings shown in Fig, 2 correspond to the number and size of flame openings of the flame tray 4 shown in Fig. 1.

Fig. 3 iilustrates a schematic cross-sectional view of the fiame traf 4 shown in Fig. 1 and in Fig. 2. Since no vapour is generated from the evaporation accelerator 10, the baii 56 is arrangsd In a position where it piugs the vapour diffuser 43. In this situation, no vapour can reach the flame tray 4 and be ignited by the filament 36, The number and size of the fiame openings 34, 34', 34" shown in Fig. 3 correspond to the number and size of flame openings 34, 34', 34" of the flame tray 4 shown in Fig. 1 and in Fig. 2. It is possible to use different sizes and shapes of the fiame openings 34, 34', 34".

Fig. 4 iiiustrates three schematic side views of a fiame tray 4 ofan eiectricaiiy controiied burner 2 according to the invention. The fiame tray 4 is enclosed by a fiame stabiliser 42. In Fig. 4 a) one iarge flame F having a height H3 ts burning, This situation wouid occur dur-ing start-up of the eiectricaiiy controiied burner 2,

In Fig. 4 b) the fire has been spread both towards the first end portion E and the second end portion E' of the fiame stabiliser 42. A iarge sized fiame is burning next to the central fiame F in the direc-tlon towards the first end E of the fiame stabiliser 42 while a medium sized fiame with a fiame height H2 is burning next to the central fiame F in the direction towards the second end E' of the fiame stabiliser 42

In Fig, 4 c) a fiame F is burning from each of the fiame openings in the flame tray 4 and the flame stabiliser 42, In this situation, the flame stabiliser 42 transfers heat back to the evaporation accelerator 10. The heatsng element 12 can be switched off because a sufficient amount of heat, generated by the fiames F, is transferred back to the evaporation accelerator 10. In Fig. 4 c) there are smaii flames F with a height Hi, medium sized fiames F with a height Ha and large fiames F with height H3. Whiie the large flames burn from the iarge flame openings (see Fig. 1-3), the medium sized fiames F bum from the medium sized flame openings (see Fig. i-3) and the smaii sized flames F burn from the smallest fiame openings (see Fig. 1-3).

Fig. 5 iiiustrates the fiame tray 4 shown in Fig. 4 with burning flames F ih two different fiame tevei modes. In Fig. 5 a) the fiames F are smalter fhan in Fig. 5 b). However* the ratio between adjacent flames F is remained the same. This means that the ratio between the smallest fiame H< and the largest flame H3 in Fig. 5 a) equais the ratio between the smallest flame Hfi and the largest flame H'3 in Fig. 5 b). The same goes for the medium sized flames Hz, Ha. According-iy, the following conditions are fulfil led.

(1) (2) (33

List of reference numerals 2 - Electronic Sioethanol Burner 4 ~ Flame Tray 6 - Fuel tank 8 - Fuel pump 10 - Evaporation accelerator 12 - Heating element 14 ~ Temperature sensor 16 - Fuel leve! sensor 18 ~ Fuel tank levet sensor 20 - Control unit 22 ~ Operator display 24 - Interface 26 - Flame tray support 28 - Ud 30, 303 30" - Cable 30"3 30""., 30 ’ - Canie 32 - Tank miet 34,34f, 34" ~ Flame opening 36 - Filament 38, 38' - Fuel pipe 40 - Remote control 41 - Fuel overflow return pipe 42 ~ Flame stabiliser/heat transfer plate 43 - Vapour diffuser 44 - Power supply 45 - Temperature sensor 46 ~ Safety diamber 48 - Leakage detection sensor 50 - Indentation 52 ~ Fuel splliage tray 54 - Liquid sensor 56 - 6a 11 58 - Aperture 60 - Bottom member 62 - Intet 64 ~ Outiet 66 - Fuei X ~ Longitudinal axis of the bumer Y - Longitudinal axis of the fiame tray C ~ Central portion E, E' - End portion F - Fiame

Hj., Ha, Hs - Fiame height H'i, H'3 - Fiame height

Claims

An electronically controlled fireplace (2) configured to burn bio-ethanel, which electronically controlled fireplace (2) comprises a fuel tank (6) connected to an evaporative chamber (10) in thermal contact 5 with a heater (12) configured ten! heating and thereby evaporating fuel In the evaporation chamber (10) a combustion chamber (4) is provided with an ignition element (36) configured for! igniting steam from the evaporator chamber (10), characterized in that the electronically controlled fireplace (2) comprises a fuel pump (8) configured to pump liquid fuel between the fuel tank (6) and evaporator chamber (10), wherein the fuel pump (8) is configured to maintain a substantially constant fuel level in the evaporation chamber (10), wherein the fuel pump (8) is configured to! pumping fuel from the fuel tank (6) into the evaporator chamber (10) in a first state and pumping fuel from the evaporating chamber (10) into the fuel tank (6) in a second state, increasing the fuel chamber (4) with several flame holes (34, 34 '} with different hole sizes and / or shapes.

An electronically controlled fireplace (2) according to claim 1, characterized in that the ignition element (36) is a filament (36).

An electronically controlled fireplace (2) according to one of the preceding claims, characterized in that the electronically controlled fireplace (2) comprises a control unit (20) and a temperature sensor in thermal contact with the evaporating chamber (10), wherein the control unit is configured to control the heater (12) on the basis of the temperature measured by the temperature sensor, wherein the control unit (20) is configured to switch off the ignition element (36) when the measured temperature exceeds a defined upper temperature level T2, and / or where the control unit (20) is configured to turn off the ignition element (36) and the electronically controlled fireplace (2) when the measured temperature is below a defined lower temperature level Ti,

An electronically controlled fireplace (2) according to one of the preceding claims, characterized in that the electronically controlled fireplace (2) comprises an overflow sensor configured to detect fuel overflow at the tank (6) and to generate an alarm in the event of an overflow. .

An electronically controlled fireplace (2) according to one of the preceding claims, characterized in that the electronically controlled fireplace (2) is configured to maintain a set rate of evaporation from the evaporation chamber (10).

An electronically controlled fireplace (2) according to one of the preceding claims, characterized in that the electronically controlled fireplace (2) comprises a CO sensor and / or a CO 2 sensor.

An electronically controlled fireplace (2) according to one of the preceding claims, characterized in that the electronically controlled fireplace (2) comprises a tilt sensor,

An electronically controlled fireplace (2) according to one of the preceding claims, characterized in that the electronically controlled fireplace (2) comprises a leakage sensor and / or one or more fluid sensors.