EP1366323B1 - Array for an automatic firing device for a gas or oil burner - Google Patents

Description

The invention relates to an arrangement of a fan burner and automatic control with an automatic burner control according to the preamble of claim 1.

Automatic firing machines are used to control and monitor a fan burner for liquid and / or gaseous fuels in order to ensure safe and optimal combustion of the fuel and are arranged on a housing part of the fan burner.

The forced-draft burner, or burner for short, requires a comprehensive control device, the automatic burner control, for safe operation, with all controlled systems being monitored by the automatic burner control system in order to detect a malfunction of a component of the burner immediately.

An arrangement of the type mentioned is from the EP 0 556 694 A1 known. The automatic burner is housed separately from the other parts of the burner in a separate housing and connected by means of a variety of electrical control and signal lines to the burner. The firing machines are characterized by a reset button. In a fault detected by the burner control unit, the operation of the burner is interrupted immediately and the fuel supply is turned off. The reset button lights up red to indicate the fault. The red illuminated reset button prompts you to reset the burner control to the initial state.

Out US Pat. No. 4,375,950 an arrangement of a forced air burner and automatic control with a furnace for monitoring the operation of a suitable for liquid and / or gaseous fuels blower burner is known. The fan burner has a combustion chamber with controlled supply of an air quantity predetermined for combustion of the fuel, wherein the amount of air flowing in an air channel leading to the combustion chamber can be regulated by a throttling device which changes the channel cross section. The size of the channel cross-section is determined by the position of an outside on the air duct, mechanically the channel cross-section changing actuator determined.

From the DE-OS 27 53 520 It can be seen that for optimal combustion of the fuel, the amount of air supplied depending on the amount of fuel must be regulated. An arranged in the air supply passage of the burner and rotatable about an axis throttle valve controls the amount of air according to the angular position of the throttle. An actuator determines the angular position of the throttle in the air supply passage, wherein the actuator receives from a control device corresponding command signals during burner operation to adjust the air supply to the burner power. Further improvement to reduce the generation of pollutants in burners are in the EP 0 644 376 A1 described.

Further information on the control of burners with liquid and / or gaseous fuel are the DE 39 00 151 C1 and in the DE 198 39160 A1 refer to.

The regulations on operational safety and environmental protection require the burner to be equipped with the automatic burner control to reduce the risk of fire or explosion and to regulate the air supply to reduce the pollutants released into the environment.

It is also known that actuators, control devices and burner control systems are generally offered as separate components on the market by different manufacturers. Unfortunately, the devices are not fully compatible, so that when equipping the burner with the automatic burner control and the actuator for regulating the amount of air at least a matching pairing must be selected from the offer. Since the life of the burner is very high at 10 years and more, ensuring the supply of spare parts, such as the like, is also very important. the Feuerungsautomaten, the actuators, etc., consuming.

The invention has for its object to provide a simplified, inexpensive equipment for forced air burners.

The above object is achieved by the features specified in the characterizing part of claim 1 according to the invention. Advantageous embodiments of the invention will become apparent from the dependent claims.

Embodiments of the invention are illustrated in the drawings and will be described in more detail below.

Figur 1

einen Ofen mit einem Gebläsebrenner,

Figur 2

einen Stell-Automaten,

Figur 3

einen Aufbau des Stell-Automaten und

Figur 4

der Stell-Automat mit einem externen Stellantrieb.

Show it:

FIG. 1

an oven with a blower burner,

FIG. 2

a parking automat,

FIG. 3

a construction of the Stell-Automaten and

FIG. 4

the automatic control with an external actuator.

In the FIG. 1 1 is an oven, 1A is an oven control, 2 is a water tank, 3 is a supply line and 4 is a routing line, 5 is a forced draft burner, hereafter referred to as burner 5, and 6 is an exhaust gas channel. The oven 1 is used for heating water in Water tank 2. By means of the supply line 3 cold water is supplied to the water tank 2, while heated by the guide line 4 heated water for heating a building and / or for heating domestic water. The temperature of the water in the water tank 2 is monitored by the furnace controller 1A. At the furnace 1, the burner 5, arranged and projects with its combustion chamber 7 in a furnace chamber 8 of the furnace 1. As soon as the temperature of the water drops, the furnace control 1A from the burner 5 requests thermal energy. By burning liquid and / or gaseous fuels, the heat energy is generated by the burner 5. Hot combustion gases from the combustion chamber 7 flow around the water tank 2 in the firing chamber 8 and release their heat energy there. A large part of the heat energy generated is used to heat the water. Thereafter, the combustion gases escape through the exhaust duct 6 to the outside.

The burner 5 has a fan 9, an air duct 10 with a throttle device 11, a conveying and metering device 12 for the fuel and an atomizer nozzle 13 arranged in the combustion chamber 7. The conveying and metering device 12 conveys the fuel in the direction of an arrow 14 by means of a fuel pump 15 or by means of a corresponding gas pressure. A metering valve 17, which is switched on between the fuel pump 15 and the atomizer nozzle 13 into a fuel line 16, regulates or interrupts the flow of the fuel. The fuel is metered via the fuel line 16 to the atomizer nozzle 13, where by means of compressed air, the fuel is finely distributed, so that the fuel-air mixture can be ignited by means of an electric spark between ignition electrodes 18 and 19. An air compressor 20 sucks air from the air duct 10 and pushes the compressed air through an air line 21 into the atomizer nozzle 13. The necessary for the combustion air is pressed by the fan 9 through the air duct 10 to the combustion chamber 7, wherein the throttle device 11 by changing the Cross-section of the air duct 10, the amount of air in accordance with the required heat output dosed so that the supplied from the delivery and metering device 12 of the atomizer nozzle 13 optimally burned fuel. A flame probe 22 monitors the burning process in the combustion chamber 7. The flame probe 22 represents, for example, in the combustion of fuel oil in a form of a photocell, the intensity of the emission of ultraviolet or infrared light of a flame 23 or in the combustion of natural gas in an ionization probe training increased by the flame 23 electrical conductivity of the gases in the combustion chamber 7 fixed. In the exhaust duct 6, the oxygen content and / or by means of a sensor 25, the temperature of the exhaust gases can be measured in addition by means of an exhaust gas probe 24 ("λ-probe").

According to the amount of heat requested by the furnace 1, the burner 5 must be set in motion, the heat output changed or turned off. So that these complicated processes take place automatically in the burner 5, the burner is equipped with a monitoring circuit, an automatic burner 26. It controls the timing of switching on and off the pumps 9, 11, 15 and the correct ratio of the amounts of air and fuel, taking into account the signals transmitted by the probes 22, 24, 25 and monitors the presence of the flame 23. At least the amount of air adjusted by means of the throttle device 11 via an actuator 27. For reasons of safety engineering, the automatic burner control 26 checks the function of each component of the controlled systems as well as the position of the actuator 27. For the sake of clarity, the drawing of FIG FIG. 1 Electrical wires for electrical signals and power supply not shown.

The automatic burner 26 and the actuator 27 are housed in a common housing 29 with a power supply 28 for the power supply of the automatic burner 26 and the actuator 27 and the other electrical and electronic components. A wall of the housing 29 has an externally manually operated reset button 30 of the automatic burner 26.

The actuator 27 is mechanically connected to the throttle device 11 of the air duct 10. The actuator 27 changes under the control of the automatic burner 26 by means of the throttle device 11, the cross section of the air duct 10 and thus controls the air flow, so that the combustion process for the requested by the furnace control 1 A heat output proceeds under optimal conditions. In one embodiment, the actuator 27 equipped with an electric drive changes the channel cross-section by means of a throttle flap 32 rotatably mounted in the air duct 10 about an axis 31. The position of the actuator is transmitted mechanically to the throttle flap 32 by means of a linkage 33.

In the execution after FIG. 2 engages an actuator axis 34, for example with a mandrel directly into a groove of the axis 31 so that the position of the throttle valve 32 in Air duct 10 directly corresponds to the angle of rotation or the position of the actuator axis 34 of the actuator 27. In both embodiments, the position of the throttle valve 32 and the actuator axis 34 is the furnace 26 continuously transmitted.

In the housing 29 ( Fig. 1 ), at least the automatic burner 26, the actuator 27 and the power supply 29 are housed and form a positioning machine 35. A connection socket 36 (FIG. Fig. 2 ) on the housing 35 forms passages of electrical lines 37 for the electrical signals and / or the power supply for the components to be controlled of the burner 5 (FIG. Fig. 1 ). The components to be controlled include, for example, the blower 9, the conveying and metering device 12, the air compressor 20, an ignition device 38 for the ignition electrodes 18 (FIG. Fig. 1 ), 19 ( Fig. 1 ) and monitoring probes 39. Of the monitoring probes 39, at least the flame probe 22 (FIG. Fig. 1 ) connected. Depending on the design of the burner 5, the exhaust gas probe 24 ( Fig. 1 ) and / or the temperature sensor 25 ( Fig. 1 ) additionally connected. Furthermore, the furnace control 1A is connected to the line 37 with the automatic control 35. The leads 37 contact the socket 36 by means of plugs 40 and / or by means of terminals, so that the electrical connections are easily separable when replacing one of the components.

The described arrangement of the automatic burner 26 and the actuator 27 in the automatic control 35 has a number of advantages. The installation of the automatic control 35 is more cost-effective compared to the installation of a conventional, composed of completely independent devices pair consisting of the burner control 26 and the actuator 27. In addition, electrical connections 41 between the burner control 26 and the actuator 27 within the automatic control 35 very short and optimally installed in every application. The effort to achieve the electromagnetic compatibility is lower because less electrical lines 37 are guided in and out of the automatic control 35 in comparison with the conventional arrangement. Last but not least, further savings result from the sharing of assemblies, e.g. the power supply 28, and logic elements of the controller.

In another embodiment, in the automatic control 35 of the automatic burner 26 is connected as a module pluggable with the power supply 28 and the actuator 27. This is after the removal of the module of the automatic control 35 also used as an external actuator 42. The external actuator 42 is, for example, in the drawing of FIG. 2 not shown electrical lines connected to the socket 36 of the equipped with the module of the automatic burner 26 automatic control 35 and controlled.

An inexpensive version of the automatic control 35 is in the FIG. 3 shown. On a printed circuit board 43 in the housing 29 ( Fig. 1 ) are the circuits of the automatic burner 26 ( Fig. 2 ) and the actuator 27, the power supply 28 and the connection socket 36 are arranged. A logic unit 44 (eg, a microprocessor 44 ') is arranged to perform the functions of the automatic burner 26 and to drive and monitor a servomotor 45 of the actuator 27 via the connections 41. An interface 46 between the logic unit 44 and the connections 41 or the connection socket 36 adapts the levels of the internal electrical signals to the levels of the servomotor 45 or the external components connected via the connection socket 36. Likewise, necessary protective devices 47 are arranged on the printed circuit board 43 for the electromagnetic compatibility (EMC). In one embodiment of the automatic control 35 ( Fig. 2 ), the microprocessor 44 'is used as the logic unit 44. All parameters and functions are stored in a programmable memory 48 accessed by the microprocessor 44 '. This arrangement has the advantage that the setting machine 35, by changing parameters or program parts in the memory 48, to the respective type of burner 5 (FIG. Fig. 1 ).

A switch 49 is additionally arranged in another embodiment inside the automatic control 35. The switch 49 is set in the one position for blocking the functions of the automatic burner 26 and for directly connecting control circuits of the servomotor 45 to the connector 36. This allows the use of the automatic control 35 as an external actuator 42 ( Fig. 2 ).

In another embodiment according to the FIG. 4 the adjusting machine 35 additionally includes at least one control module 50 for controlling a further external actuator 42. The electrical lines 37 for transmitting the drive power for the external actuator 42 and signals for the feedback of the state of the external actuator 42 are on the Terminating bush 36 led to the automatic control 35. The external actuator 42 is powered by the power supply 28, for example.

The control module 50 is, for example, a pluggable to the circuit board 43 separate circuit part that fulfills all functions of the control module 50 or only an actuator interface 51 with the EMC protection circuits 47 for the external actuator 42 contains, the functions of the control module 50 as software in Program of the microprocessor 44 'or in the form of parameters in the memory 48 are included. The control module 50 is configured to receive and process the feedback signals to control and monitor the position of the external actuator 42 such that the instantaneous position of the external actuator 42 is a function dependent on the instantaneous position of the internal actuator 27 following a predetermined function. The automatic control 35 with the external actuator 42 forms an electronic composite control device. The predetermined function of this composite electronic control device may be input to the memory 48 of the microprocessor 44 'in the form of a table, for example.

The external actuator 42 actuates, for example, the metering valve 17 in the atomizer 13 of the burner 5 ( Fig. 1 ) leading fuel line 16 for liquid and / or gaseous fuel under the control of the setting machine 35, so that the furnace control 1A ( Fig. 1 ) required amount of heat is generated. The position of the external actuator 42 determines by means of the metering valve 17, the burner 5 supplied amount of fuel. In the electronic composite must over the entire adjustment of the heat output of the burner 5 by means of adjustable with the internal actuator 27 throttle device 11, the air flow in the air duct 10 are adjusted so that the fuel with the predetermined amount of air in the combustion chamber 7 (Fig. Fig. 1 ) is burned optimally.

Since the functional table for the composite electronic control device in the memory 48 is interchangeable, the electronic composite control device has a much greater flexibility than a composite mechanical control device, if the automatic control 35 is to adapt to the characteristics of the various types of burner 7.

For example, in the aforementioned patent DE 39 00 151 C1 a composite mechanical control device described in which a single actuator the Throttle device 11 and the metering valve 17 sets, wherein the throttle device 11 and the metering valve 17 are coupled via adjustable levers and rods so that for the entire power adjustment range of the burner 7, the optimum fuel-air ratio is ensured.

Claims (8)

1. Arrangement of a fan burner (5) and an automatic setting device (35) with an automatic firing apparatus (26) for monitoring the operation of a fan burner (5) suitable for liquid and/or gaseous fuels comprising a combustion chamber (7) with a regulated supply of an amount of air which is predetermined for combustion of the fuel, wherein the amount of air flowing in an air duct (10) leading to the combustion chamber (7) can be regulated by a throttle device (11) which alters the duct cross-section and the size of the duct cross-section is determined by the position of a setting drive (27) arranged externally on the air duct (10) and mechanically altering the duct cross-section, characterised in that the components for performing the functions of the automatic firing apparatus (26) together with the setting drive (27) are disposed in a housing (29) of an automatic setting device (35), that a setting drive shaft (34) of the setting drive (27) projects out of the housing (29) and that the automatic setting device (35) is arranged at the fan burner (5).
2. Arrangement according to Claim 1, characterised in that the throttle device (11) is a throttle flap (32) rotatable about a shaft (31) and arranged in the air duct (10) and that the throttle flap (32) is connected mechanically to a setting drive shaft (34) of the setting drive (27).
3. Arrangement according to Claim 1 or 2, characterised in that circuits of the automatic firing apparatus (26) and the setting drive (27) as well as a setting motor (45) of the setting drive (27) are fed by a common mains unit (28).
4. Arrangement according to Claim 3, characterised in that in the housing (29) the automatic firing apparatus (27) is connected in a pluggable manner as a module to the mains unit (28) and the setting drive (27).
5. Arrangement according to Claim 3, characterised in that a logic unit (44) with the circuits of the automatic firing apparatus (26) and the setting drive (27) with the mains unit (28) are arranged on a printed circuit board (43) in the housing (29).
6. Arrangement according to Claim 5, characterised in that the logic unit (44) is a microprocessor (44'), for example, and that the microprocessor (44') is adapted at least for performing the functions of the automatic firing apparatus (26) and for actuating and monitoring the setting drive (27), wherein parameters and program portions for performing the functions of the automatic firing apparatus (26) and for actuating and monitoring the setting drive (27) are stored in a memory (45) connected to the microprocessor (44').
7. Arrangement according to Claim 3 to 6, characterised in that a switch (49) is arranged in the automatic setting device (35) and that in the one position the switch (49) is adapted to block the functions of the automatic firing apparatus (26) and to directly connect circuits of the setting drive (27) to external connection points of a connecting socket (36).
8. Arrangement according to one of the preceding claims, characterised in that the automatic setting device (35) includes at least one actuation module (50) connected to an external setting device (42) and that the actuation module (50) is adapted to receive and process signals for controlling and monitoring the external setting drive (42), in such a way that the automatic setting device (35) and the external setting drive (42) form an electronic composite control means in which a position of the external setting drive (42), which is predetermined by the actuation module (50), is a predetermined function of the position of the internal setting drive (27) disposed in the automatic setting device (35).

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