EP1563228A1

EP1563228A1 - High-performance heating apparatus

Info

Publication number: EP1563228A1
Application number: EP03776683A
Authority: EP
Inventors: Rudy Cyris
Original assignee: Thermic Investments SA
Current assignee: Thermic Investments SA
Priority date: 2002-11-20
Filing date: 2003-11-14
Publication date: 2005-08-17
Anticipated expiration: 2023-11-14
Also published as: WO2004046615A1; CA2498289A1; DE60313486T2; ATE360785T1; ES2285212T3; US20050279344A1; CA2498289C; DE60313486D1; EP1563228B1; EP1426691A1; AU2003286009A1

Abstract

The multiple fuel heater has the combustion chamber (1) forming the main support for the heater. The combustion chamber is made of bent and welded (2) sheet metal. The welded structure provides sealing for the combustion chamber. The combustion chamber supports cover panels which are attached by fasteners which do not pass through the chamber walls. Claims include use of the combustion chamber in a heater.

Description

HIGH EFFICIENCY HEATING APPARATUS

OBJECT OF THE INVENTION The present invention relates to a new concept of high-efficiency multi-fuel domestic heating appliance comprising a sealed (or almost sealed) heating body and the operating regime of which can be controlled at distance. The term “sealed heating body” means a heating body whose only communications with the outside consist of a cold primary air inlet and a burnt gas outlet.

Technological background and state of the art

In recent years, significant efforts have been made to produce so-called "modular" domestic heating devices, which may have the same shape, the same design or the same covering, whatever the fuel used or the nominal power required. . These different devices are distinguished by a combustion chamber (or a heating body) of specific dimensions for a solid, liquid or gaseous fuel, or a given power. Thus, the rear wall of the combustion chamber can consist of an intermediate piece having a discharge orifice adapted to each predetermined situation (see US Pat. Nos. 6,209,535 and EP-B-0 883 782). This type of design has notably enabled productivity gains and a rationalization of the storage of intermediate parts among mass-produced manufacturers. Another trend observed is to benefit the field of stoves and household inserts of technological innovations allowing to increase the comfort of use and the user-friendliness of these devices. Thus, the Applicant has also proposed a double-envelope heater for the circulation of air, having on its front face a plate obstructing the free space between the two envelopes and provided with calibrated perforations of air inlet and outlet. to simultaneously optimize the temperature and the speed of the outgoing air flow (patent application EP-A-1,111,307).

At present, heating devices such as stoves are made up of the hybrid assembly of a combustion chamber, possibly rationalized as mentioned above, which can for example be made of sheet steel, with structural parts and / or a decorative covering comprising, for example, cast iron, ceramic or even refractory stone elements such as soapstone (soapstone). The fixing of the parts is carried out by complex and unproductive techniques involving tie rods, grooves and puttying. This complexity is justified by the need to guarantee the best possible seal at the combustion chamber to obtain the minimum desired output. In fact, the combustion chamber can be considered as a closed prismatic form only open on its front face comprising a door, possibly causing flames to appear through a window, and / or on its face. upper to allow the provision of a cooking plate.

In addition to the lack of productivity, this method of assembly has drawbacks related to puttying. Indeed, during the drying of the sealant, it can shrink or have micro-cracks, which causes the entry of air into the chamber, thus adversely affecting the performance of the device. The presence of putty makes it difficult to obtain the required seal according to the different standards in force in different countries (eg USA: EPA standards).

In addition, during transport of the device after manufacture, mastic flows can occur on visible surfaces, which requires the costly intervention of the after-sales service.

Finally, the approval standards for the marketing of the aforementioned heating devices are manifold, the technical requirements generally varying from one country to another (American, French, DIN +, European, Norwegian, etc. standards. .). Thus, it is often necessary to carry out successive modifications of a given device in order to obtain an approval in several countries (adjustment of the combustion air opening, device for bringing the hot air into the flame, etc. .). Document DE-A-30 09 251 describes a solid fuel heating appliance, the combustion chamber of which is delimited by stainless steel sheets in the form of concave flanges, which are fixed to the external walls to form channels allowing the delivery of secondary air into said chamber, via air inlet orifices provided in its upper part. The flanges are arranged at the rear and on both sides of the chamber. The front junction is made by a grid. Air intake slots practiced at the foot of the flanges allow the diversion of part of the primary air into secondary air. The external walls, which constitute the main supporting structure of the stove, and the flanges are provided with flanges allowing to apply the sheets one on the other in a peripheral zone to form a lining where they will be fixed by welding or screwing. The assembly of the different walls is therefore difficult and the tightness of the combustion chamber is not guaranteed. The secondary air supply can be controlled manually or automatically.

Document WO-A-99 64789 describes a heating device for solid fuel comprising adjustment means, associated with sensors and controlled automatically, for example by a motor, at the level of three types of air intake: primary, secondary and tertiary. The appliance is provided with a programmable control unit for selective control of the adjustment means with a view to optimizing combustion under different operating conditions, in particular during the ignition phase, a "high" and "low" regime. ", a re-ignition phase and the extinction phase. Primary air is supplied to the fireplace at the base of the combustion chamber. Secondary air is supplied through a channel adjoining the chamber, where it heats up, on top of the fireplace, along the glass, to reduce the deposition of soot. Finally, the tertiary air is brought to the center of the chamber by another channel to ensure total combustion of the unburnt gases. Preferably, the opening of these air inlets is regulated by a valve or a register controlled by an actuator such as a stepping motor, controlled by the programmable unit. The control unit can be connected to a clock or to a thermostat. The setpoint parameter on which the regulation is based is the temperature of combustion. The different operating conditions are displayed on a control console also presenting indicator lights and push-buttons allowing the user to select the speed. The reaction times to the air inlet controls in terms of combustion temperature reached are of the order of several minutes at least.

Aims of the Invention The present invention aims to provide a solution which makes it possible to overcome the drawbacks of

1 state of the art.

In particular, the invention aims to provide a heating device designed to allow the achievement of significant productivity gains during assembly in series.

In addition, the invention aims to provide a heating device whose combustion chamber is almost perfectly sealed. The invention further aims to provide a home heating device ensuring the user the comfort of being able to adjust remotely, precisely and automatically, its operating regime.

The invention finally aims to provide a home heating device with great adaptability for the performance of approval tests in different countries.

Main characteristic features of the invention A first object of the present invention relates to a multi-fuel heating device comprising:

a combustion chamber made of sheet metal of a weldable metal, preferably steel, obtained by assembling a rear wall, two side walls, a bottom wall and an upper wall, said chamber having predetermined standard dimensions as a function of a nominal power required, - at least one outlet device for burnt gases connected to said chamber, an outer cover fixed to said chamber, comprising elements such as cast iron, ceramic, enamel or refractory stone plates, - a front access door, optionally provided with a window, connected to the combustion chamber, characterized in that: the combustion chamber constitutes the main supporting structure of the heating appliance and is made of folded sheet metal and welded so as to be completely sealed, possibly except at the joint with said door, said elements forming the outer cover are fixed to the combustion chamber, without the fasteners passing through the chamber and without said elements being necessarily fixed between them.

The invention relates to any gas heater of the chimney or suction cup type, with liquid fuel, in particular with evaporation under pressure or gasification under atmospheric pressure, with wood, coal or other solid fuel.

Particularly advantageously, the outer cover is produced by the combustion chamber itself. The tightness of the combustion chamber of the apparatus according to the invention allows it to be given a particularly high efficiency, even being of the order of 80% for wood heating, which is an advantage. appreciable for the skilled person and / or for the user (reduced consumption).

Preferably, the cover elements are fixed to the combustion chamber by screws, rivets, by gluing or by puttying.

The heating device according to the invention further comprises a first register or valve to adjust the entry of cold outside air into the room, which can be opened at an intermediate position between a fully closed position and a completely open, operated by a remotely controlled motor, the remote control being a wireless remote control, preferably infrared or ultrasonic. This ability to control the heating device according to the invention by remote control is not a simple application obvious to those skilled in the art of techniques known elsewhere. Its interest stems directly from the almost perfect seal of the chamber and its very high efficiency. In fact, it is only under these conditions that rapid, efficient and reproducible combustion control is possible. The reaction time on the remote control is indeed a few seconds. Advantageously, the aforementioned remote control is equipped with a thermostat and / or a digital programmer, and possibly with display means, preferably with liquid crystal or electroluminescent.

The opening or closing of the first register is advantageously controlled by a timer, the opening or closing of the first register can also be carried out at a value preprogrammed by a presence detector in a volume, preferably an infrared sensor. .

According to a preferred embodiment of the invention, the heater comprises a duct for heating the outside air in contact with the chamber combustion, before penetration therein, said conduit being terminated by a narrowing and terminating in the upper part of the chamber near its front face. According to another preferred embodiment of the invention, the heating device further comprises a duct provided with a second register or valve for bringing secondary air from the outside to the chamber, said register adjustable by the user. This additional air supply advantageously improves the elimination of solid particle residues in the flue gases at low operating speeds (idle). Another object of the present invention relates to a combustion chamber intended to be integrated into a multi-fuel heater, constituting the main support structure of the heater, only open on its front face and produced in folded and welded sheet metal. Advantageously, this combustion chamber has extensions making it possible to fix there external covering elements of the appliance such as plates, feet or cooking plates in cast iron, ceramic, enamel or refractory stone.

Brief description of the figures

Figure 1 shows a perspective view of the combustion chamber of the heater according to the present invention.

Figure 2 schematically shows the air circuit of a heating device according to a first embodiment of the present invention.

Figure 3 schematically shows the air circuit of a heating device according to a second embodiment of the invention. Description of a preferred embodiment of the invention ^• As described in FIG. 1, the present invention consists in proposing a combustion chamber 1 made of folded and welded steel sheets 2. One could alternatively use another weldable metal. A prismatic combustion chamber is thus produced, produced according to the "thermos" principle. The only opening provided on the part to be heated is that allowing the provision of a door 3, for example also made of steel or decorative cast iron, on the front face.

The principle of a closed combustion chamber according to the invention is extremely advantageous insofar as the latter can be produced in an almost perfectly sealed manner. Low losses ¹ sealing can indeed occur, inevitably, at the door seal. It follows therefore obtaining an exceptionally high yield (of the order of 80%). In addition, the stove or the heating appliance can be constituted solely by said combustion chamber and have compact dimensions, depending only on the desired nominal power. Advantageously the heating device described above can be extended by structural elements upwards 4 'or downwards 4 "for example. The downward extensions 4" can allow the fixing of feet. These elements can generally allow the attachment of decorative pieces 20, for example cast iron, enamel or ceramic plates. The fixing means are all the fixing means known to those skilled in the art, such as screws, glue, putty, rivets, etc. According to the invention, it is not required that the decorative elements are additionally fixed or assembled together, which avoids the productivity losses linked to such generally complicated fasteners or assemblies. The attachments of decorative elements 20 to the steel combustion chamber are such that they respect the tightness of the chamber. In no case will there therefore be fasteners perforating the wall of the combustion chamber.

The combustion chamber according to the invention will of course benefit from the advantageous characteristics described in American patent US-B-6, 209, 535, such as for example an interchangeable rear face depending on the fuel and / or the power. This rear face will advantageously include an air inlet orifice and a burnt gas discharge orifice. This latter orifice 30 can also be provided in the upper face of the chamber. The fuel used can be solid (wood, coal), liquid (diesel) or gaseous (natural gas, propane). A grid or a valve is provided at the bottom of the chamber to generate a small additional air inlet allowing to give a starting aid ("ignition booster") which is optional for wood and essential for coal.

Advantageously, the combustion chamber also has a wall 5 for creating a heating duct 6 of the incoming air, as shown schematically in Figure 2. At the outlet 7 of this duct, which has a narrowing to generate a venturi effect and give the heated air an increasing speed (acceleration), it is injected into the chamber proper, at its upper part 10, along the door and more particularly of the window 9 included in this, if applicable. The air entering the room does not have to be "cold": it is the variation between the temperature of this heated air and the temperature prevailing in the room which causes the suction movement of air in the room

(as well as the chimney draft). This variation in temperature must simply be sufficient.

According to the preferred embodiment described here, the temperature of the heated air when it enters the room is about 300 ° C.

A first part of the heated air, endowed with a certain speed, descends along the glass to the bottom of the chamber 11 and will supply the combustion by acting as primary air. A second part of the heated air makes it possible to ignite unburnt or partially burned volatile materials in the upper part 10 of the chamber while acting as secondary air. The fact of preheating the air before entering the combustion chamber makes it possible not to cool the chamber and therefore not to favor the creation of unburnt volatile materials.

An important advantage of the invention lies in the sealing of the combustion chamber. It follows that one can perform an extremely precise control of the operating regime. For example, we can automatically control a damper or air inlet valve 15 located at the rear of the room. This is integral with a motorized device 16 controlled remotely, preferably by infrared or ultrasonic means 17. Thus, the user can adjust the combustion rate without moving from his chair, for example, depending on the thermal or visual comfort desired. The remote control 17 makes it possible to adopt, by push button, an intermediate speed between a maximum speed corresponding to the maximum opening of the air inlet register and a minimum speed, corresponding to the minimum opening of said register. The combustion reaction to the remote control is very rapid, even instantaneous, by virtue the excellent sealing of the chamber. Therefore, the user can advantageously use the wireless remote control to view the instantaneous (or almost instantaneous) response of the variation in combustion which is requested, that is to say a change in the flame rate. In this regard, it would not be interesting or comfortable to use a localized control at the level of the heater, a certain distance being necessary for this visualization. In addition, this type of heater allows continuous heating (> 10 hours with wood).

In an alternative embodiment, provision can also be made for switching on or off at fixed times, controlled by a programmer / timer, or even for lighting the stove by infrared or other detection of people in a volume. given.

Thus, in maximum speed, there is an excess of combustion air (sub-stoichiometric) with the presence of blue flames. Conversely, in minimum regime, we are in sub-stoichiometric conditions with the presence of yellow-orange flames, of more or less "soft" appearance. The air deficit in the latter case is such that there are no longer any flames at the bottom of the chamber, yellow flames still being present at the top of the chamber, as well as small flames which "drip "along the vertical edges of the glass. These are of course supplied by the very light air inlets at the front door. When the air supply is completely cut off, the air already in the heating duct loses its speed and forms a "buffer", the lack of air in the chamber also causes an accumulation of unburnt or partially burnt gases. The configuration of the heating duct, in particular its thickness, has been studied so as to prevent any explosion in the chamber during a brutal recharge of outside air. Indeed, in this case, the buffer plug is gradually eliminated and the flames only reappear gradually in the combustion chamber (5 to 10 seconds after opening the valve).

In order to further improve combustion hygiene during idle operating regimes and to eliminate the last residues of solid particles in the fumes, the combustion chamber according to the invention can be equipped with an additional duct 6 '' secondary air supply (Figure 3). This duct 6 ′ could ideally be provided with a device 18 for adjusting the air flow admitted into the combustion chamber, actuable from the outside by the user. Said device 18 could of course be in the completely closed position at medium and high combustion regimes.

At high combustion regimes, the temperature reached inside the sealed combustion chamber and the high temperature of the primary and secondary air make it possible to burn a maximum of solid particles in the flue gases. In this case, the quantity of secondary air supplied by the existing air valve 15 is sufficient. At lower combustion regimes

(idle), the temperature inside the sealed combustion chamber is lower and the quantity of secondary air passing through the air valve is reduced, since this air intake has itself been reduced to reach idling speed. Although this type of operation still allows, thanks to the sealing of the combustion chamber and. the large preheating area of the incoming air, to obtain good combustion hygiene, so it is possible to improve it by adding an additional quantity of secondary air only as described in FIG. 3. With regard to the approval tests to be carried out for this device, provision will be made, mutatis mutandis, for an adequate range opening the damper or valve 15 as well as the key positions thereof (with or without stop notch) corresponding to the different regimes to be tested, in order to satisfy the different requirements according to the different standards in force. Of course, another advantage of the invention will reside in the possibility of controlling these tests via the abovementioned remote control 17.

Claims

1. Multi-fuel heater comprising:

a combustion chamber (1) made of sheet metal (2) of a weldable metal, preferably of steel, obtained by assembling a rear wall, two side walls, a bottom wall and an upper wall, said chamber having predetermined standard dimensions as a function of a nominal power required, - at least one outlet device (30) for the burnt gases connected to said chamber,

- an outer cover fixed to said chamber, comprising elements (20) such as cast iron, ceramic, enamel or refractory stone plates, - a front access door (3), optionally provided with a window (9), connected to the combustion chamber, characterized in that:

the combustion chamber (1) constitutes the main supporting structure of the heating appliance and is made of folded and welded sheet metal (2) so as to be completely sealed, possibly except at the joint with said door, said elements ( 20) forming the outer cover are fixed to the combustion chamber, without the fasteners passing through the chamber and without said elements being necessarily fixed between them.

2. Heating device according to claim 1, characterized in that the outer cover is produced by the combustion chamber (1) itself.

3. Heating device according to claim 1 or 2, characterized in that the cover elements (20) are fixed to the combustion chamber by screws, rivets, by gluing or by puttying.

4. Heating device according to any one of the preceding claims, characterized in that it comprises a first register or valve (15) for regulating the entry of cold outside air into the chamber (1), which can be opened to at least one intermediate position between a fully closed position and a fully open position and actuated by a remotely controlled motor (16) (17).

5. Heating device according to claim 4, characterized in that the remote control (17) is a wireless remote control, preferably infrared or ultrasonic.

6. Heating device according to claim 4, characterized in that the opening or closing of the first register (15) is controlled by a timer.

7. Heating device according to claim 4, characterized in that the opening or closing of the first register (15) is carried out at a value preprogrammed by a presence detector in a volume, preferably an infrared sensor.

8. Heating appliance according to any one of the preceding claims, characterized in that it comprises a heating duct (6) for the outside air in contact with the combustion chamber (1), before penetration into it , said conduit being terminated by a narrowing (7) and terminating in the upper part (10) of the chamber near its anterior face (9).

9. A heating appliance according to claim 4, characterized in that it further comprises a duct (6 ') provided with a second register or valve (18) for bringing secondary air from the outside to the chamber (1), said register (18) being adjustable by the user, the combustion chamber therefore being almost sealed.

10. Heating appliance according to claim 5, characterized in that the remote control (17) is equipped with a thermostat and / or a digital programmer, and possibly with display means, preferably with liquid crystal or electroluminescent.

11. Combustion chamber (1) intended to be integrated into a multi-fuel heating appliance according to any one of the preceding claims, characterized in that it constitutes the main supporting structure of the heating appliance, open only on its front face (9) and is made of folded and welded sheet (2).

12. Combustion chamber according to claim 11, characterized in that it has extensions (4 ', 4 ") allowing elements to be fixed therein.

(20) external covering of the appliance such as plates, feet or cooking plates in cast iron, ceramic, enamel or refractory stone.

13. Use of a combustion chamber according to claim 11 or 12 in a gas heater of the chimney or suction cup type, with liquid fuel, in particular with evaporation under pressure or with gasification under atmospheric pressure, with wood, coal or other solid fuel.