EP2589871A1 - Method and device for controlling or monitoring an atomisation device for the atomisation of liquid fuels in a modulating burner - Google Patents

Abstract

The method involves determining an air supply-parameter and a fuel supply-parameter, where the fuel supply-parameter is set according to the air supply-parameter for controlling a fuel-air mixture for controlling the power of the burner. A deviation of another fuel supply-parameter is determined by a target value of a characteristic line (30) of a relationship between the both fuel supply-parameters. Another deviation of the latter fuel supply-parameter is determined by the target value of another characteristic line of dependency between latter fuel supply-parameter and air supply-parameter. An independent claim is included for a device for controlling or monitoring a sputtering apparatus for the atomization of liquid fuels, particularly oil, in a modulating burner.

Description

The invention relates to a method and a device for controlling and / or monitoring a sputtering device for sputtering liquid fuels, in particular oil, in a modulating burner according to claims 1 and 10, respectively.

In the prior art so-called Druckölzerstäubungsbrenner are known. Such pressurized oil atomizing burners include a sputtering device that atomizes liquid fuel (eg, oil) to mix the fuel with air as fine droplets. By the atomization, a comparatively large reactive liquid surface can be produced, wherein the most uniform and fine distribution of the droplets in the combustion mixture should be present. The atomizing devices usually include a spray nozzle through which the fuel is passed under the application of high pressure.

The known atomizing devices should enable (as far as possible) stoichiometric combustion of the liquid fuel and, on the exhaust gas side, minimize the proportions of carbon monoxide and nitrogen oxides.

With a modulating burner, the burner output can be varied. An essential factor in addition to the injection of the fuel is the combustion air supply. It is important for an energy-saving handling of the fuel that the burner output can be reduced to low values if necessary. In the prior art, a control or adjustment of a fuel-air mixture for controlling the power of the burner takes place. Overall, the reliability of the control of Druckölzerstäubungsbrennern is perceived as unsatisfactory.

In general, there is a trend in the art that oil burners are formed as evaporative burners. However, these are relatively expensive in terms of production and operation, require a large amount of space, are relatively prone to failure. The energy required for operation (auxiliary energy or additional energy for an oil preheating) is comparatively high.

It is an object of the present invention to propose a method and a device for controlling and / or monitoring a sputtering device, which enables a reliable control of the sputtering of liquid fuels. This object is achieved by a method according to claim 1 and an apparatus according to claim 10.

• Bestimmung mindestens eines Luftzufuhr-Parameters (z.B. Gebläsedrehzahl) sowie eines ersten und mindestens eines zweiten Brennstoffzufuhr-Parameters,
• Einstellung des ersten Brennstoffzufuhr-Parameters (z.B. Pumpendruck) in Abhängigkeit vom Luftzufuhr-Parameter zur Regelung eines Brennstoff-Luft-Gemisches zur Regelung der Leistung des Brenners,
• Bestimmung einer ersten Abweichung des zweiten Brennstoffzufuhr-Parameters (z.B. Pumpendrehzahl) von einem Sollwert einer ersten Kennlinie einer Abhängigkeit zwischen erstem Brennstoffzufuhr-Parameter und zweitem Brennstoffzufuhr-Parameter, und/oder
• Bestimmung einer zweiten Abweichung des zweiten Brennstoffzufuhr-Parameters von einem Sollwert einer zweiten Kennlinie einer Abhängigkeit zwischen zweitem Brennstoffzufuhr-Parameter und Luftzufuhr-Parameter.

According to a first aspect, the object is achieved by a method for controlling and / or monitoring a sputtering device for the atomization of liquid fuels, in particular oil, in a modulating burner, with the steps:

• Determining at least one air supply parameter (eg blower speed) and a first and at least one second fuel supply parameter,
• Setting the first fueling parameter (eg pump pressure) as a function of the air supply parameter for controlling a fuel-air mixture for regulating the output of the burner,
• Determining a first deviation of the second fueling parameter (eg, pump speed) from a setpoint of a first Characteristic of a relationship between the first fuel supply parameter and the second fuel supply parameter, and / or
• Determining a second deviation of the second fueling parameter from a desired value of a second characteristic of a relationship between the second fueling parameter and the airing parameter.

A core idea of the invention is that a setpoint deviation of the first fuel supply parameter (for example, the pump pressure) or the second fuel supply parameter (for example, the pump speed) from a (possibly previously determined, for example stored or stored in the control) setpoint Is determined to check the control of the atomizer or the performance of the burner on their plausibility. By determining the first or second deviation, information is provided which allows a statement about the plausibility, in particular of the first fuel supply parameter. The smaller the deviation, the more - in general - the atomized fuel-air mixture will correspond to a desired composition and quantity. As a result, the control or monitoring of the atomization is improved in a simple manner.

In a particularly preferred embodiment, the first fueling parameter is a fuel pressure, in particular between a pump outlet (24) and a fuel nozzle (12), preferably at a pump outlet (24), and / or the second fueling parameter is a pump speed of a feed pump (15). is. In general, the first or second fueling parameter may be a pump speed of a feed pump or a fuel supply flow or fuel pressure, in particular between a pump outlet and a fuel nozzle, preferably at a pump outlet. In a specific embodiment, the first fueling parameter is the fuel pressure (at the pump outlet) and the second fueling parameter is the pump speed. These parameters can be determined easily and allow a particularly simple check of the plausibility of the control.

In general, it should be noted that an air supply parameter is to be understood as a parameter that directs the air supply either directly or indirectly indicates at least indirectly, such that the air supply (at least approximately) can be determined (in a known geometry or structure of the sputtering device).

Correspondingly, a fuel supply parameter should be understood as meaning a parameter which permits the determination of the fuel supply either directly or at least indirectly (with known geometry or structure of the atomizing device).

If, for example, the pump pressure is comparatively high (possibly above a tolerance range around the characteristic curve), it is possible, for example, to deduce a blockage of the nozzle. If the pump pressure is comparatively low, it is possible, for example, to conclude that there is a leaky suction line or high pressure losses in an oil feed line. In general, therefore, damages or defects within the sputtering apparatus can be easily detected.

The sputtering apparatus can in principle - apart from the additional control technical aspects of the present invention - as in the not yet published German patent application with the file number DE 10 2011 075 409.1 described, be trained.

In a development of the method according to the invention, it is determined whether the first and / or second deviation is outside or within a predetermined tolerance. The tolerance is preferably at least +/- 1%, more preferably +/- 5%, and / or preferably at most +/- 20, more preferably +/- 12%, even more preferably +/- 2%. This improves the monitoring of the control.

A detected deviation from the tolerance can be used, for example, to issue a warning message.

In preferred embodiments, a deviation from the characteristic curve, in particular an exceeding of the tolerance, for example, be displayed on a display or a screen and / or when the tolerance is exceeded, a signal and / or a shutdown of the atomizing device. Thereby the safety during operation of the atomizing device or the burner is further increased.

The air supply parameter may be an air supply amount or a fan speed (which in turn determines or at least co-determines the air supply amount). This also simplifies the regulation.

The pump speed can be determined via a control signal, in particular a pulse width modulation signal. If the rotational speed of the pump is controlled, for example via a pulse width modulation signal, the corresponding control signal can be determined in a simple manner via a rotational speed feedback of the pump motor. A setpoint deviation in the negative and positive range can be detected by means of a possibly dependent (for example in an optionally electronic storage means) mutual dependence of engine speed and pump pressure.

In a preferred development, the air supply is (immediately) increased by a predetermined offset amount before an increase in the output of the burner, for which purpose preferably a blower speed is increased by a predetermined offset amount, for example by at least 50, more preferably at least 90 revolutions per Minute and / or preferably at most 200, more preferably at most 110 revolutions per minute. This training is also claimed as an independent thought. By defining such an offset amount, combustion with excess fuel can be easily avoided.

According to a preferred embodiment (which, however, is claimed independently), the fuel pressure is checked before commissioning a feed pump, preferably a warning or shutdown occurs when the fuel pressure is greater than a predetermined value (for example, 1 bar), preferably greater than 0 bar is. It should be made clear at this point that the pressure data are to be understood as differential pressure with respect to a surrounding normal pressure. Alternatively or additionally, it may also be provided that a warning signal or a shutdown takes place if no signal is present at all. This could be traceable, for example, to a malfunction of a pressure sensor.

In a further alternative, the fuel pressure can be checked after commissioning a feed pump, wherein preferably a warning signal or a shutdown takes place when the fuel pressure is less than a predetermined value, in particular 0 bar. Again, it depends on a differential pressure to a surrounding normal pressure. A warning or a shutdown can alternatively or additionally be done if no pressure signal is present. In any case, the control of the atomizer in safety terms is further improved.

The above object is achieved independently by a device for controlling and / or monitoring a sputtering device for atomizing liquid fuels in a modulating burner, comprising an air supply line for supplying air to the burner, a fuel supply line for supplying liquid to the burner an air supply parameter determining device for determining an air supply parameter (eg fan speed), a first fuel supply parameter determining device for determining a first fuel supply parameter (eg pump pressure), a second fuel supply parameter determining device for determining a second fuel supply parameter (eg pump speed), a control device for setting the first fuel supply parameter in dependence on the air supply parameter for controlling a fuel mixture for controlling the burner, a storage means, on the parameter Kennli a deviation determination device for determining a deviation of the second fuel supply parameter from a first desired value of a first characteristic of a relationship between the first fuel supply parameter and the second fuel supply parameter and / or for determining a deviation of the second Fuel supply parameter from a second setpoint value of a second characteristic of a relationship between the first second fuel supply parameter and the air supply parameter.

With regard to the advantages, reference is made to the above method. In terms of the device, an essential idea is that a characteristic is stored in the control (for example for the pump pressure as a function of an engine speed or pump speed).

In a preferred embodiment, a fan for providing the air flow and / or a, in particular speed-controlled, pump, optionally comprising a fuel supply, is provided, wherein the air supply parameter determining means preferably comprises a fan speed determining means and / or the first fuel supply parameter determining means preferably a pump pressure determining device. These measures can be done in a simple manner a reliable control.

In a specific embodiment, a pressure sensor is provided for determining a fuel pressure in the fuel supply line as the first or second fuel supply parameter, in particular between the pump outlet and a fuel nozzle, preferably at the pump outlet. By providing the pressure sensor, a fuel supply parameter can be easily determined, which simplifies the control. A further fuel supply parameter may then be provided, for example, by a device configured to evaluate the pump speed of a pump, for example via a PWM signal (pulse width modulation signal). Overall, the scheme is reliably simplified.

In a concrete embodiment, the pump drive, in particular electronically, is speed-controlled or speed-controllable. Furthermore, the pump drive can include an EC motor (EC motor = Electronically Commuted Motor = brushless DC motor or electronic motor). In combination with the other features, a reliable operation of the pump can thereby be enabled, which improves the efficiency of the atomizing device.

The device according to the invention can comprise, for example, a display or a screen and / or a warning signal device, for example a light or a sound generating device. As a result, the control is also further improved in terms of safety.

In general, the device for regulating and / or monitoring may comprise devices or means which allow structurally already mentioned method steps.

In general, a fuel boiler (for example oil condensing boiler) is proposed, in which a fuel-air network (or oil-air network) is implemented, whereby a modulating operation of a burner is made possible within a specified power range. The combustion ratio λ is preferably constant in the modulation range. The sputtering device can, as in the not yet published German patent application with the file number DE 10 2011 075 409.1 be executed. With such a spraying device or such a mixing system with a fuel nozzle (oil nozzle) a (possible) stoichiometric, low-emission combustion with very low levels of carbon monoxide and nitrogen oxides can be realized. As a modulation range, a range of about 30 to 100% of a maximum power is proposed. As a result, the heating requirement in heated buildings can be provided in an efficient manner even with comparatively large seasonal fluctuations. In general, needs-based control and thus energy-saving operation is possible. At the same time, safe and stable combustion should be ensured even at a lower power limit.

A fundamental idea of the invention is that for a reliable control in the predetermined operating range of the fuel-air network (oil-air network; oil-air) the relation of a first fuel supply parameter (in particular pump pressure) to a second fuel supply parameter (in particular a speed of the oil pump) is used.

A variable speed fuel pump (oil pump) is preferred. Required auxiliary power for a pump drive can be kept low by using a (highly efficient) EC motor. In particular, in a partial load range, a power consumption (strong) can be reduced. In particular, by the speed control of the pump, the pump drive can work with a relatively high efficiency.

Overall, efficient combustion is achieved by comparison with a predetermined characteristic within adjustable tolerance limits. For (continuous) monitoring, a plausibility criterion is introduced in order to be able to rule out or at least reduce the likelihood of a defective combustion, or to provide fault images for the to recognize the entire operating area and to be able to take appropriate measures.

The above object is achieved independently by a sputtering apparatus or a burner or boiler with the above-mentioned device for controlling and / or monitoring or designed to carry out the above method for controlling and / or monitoring.

Further details emerge from the subclaims.

Fig. 1

eine schematische Ansicht einer Zerstäubungsvorrichtung 10 mit einem Brenner 11; und

Fig. 2

ein Diagramm.

The invention will also be described in terms of further features and advantages based on embodiments, which are explained in more detail with reference to the drawings. Hereby show:

Fig. 1

a schematic view of a sputtering apparatus 10 with a burner 11; and

Fig. 2

a diagram.

In the following description of the figures, the same reference numerals are used for identical or identically acting parts.

The atomizing device 10 comprises a fuel nozzle 12 for injecting fuel into a combustion chamber 13. The fuel is supplied via a fuel supply line 14 from a (speed-controlled) pump or oil pump 15. The pump 15 is driven by a pump drive 16. The speed of the pump drive 16 is determined via a speed-determining device 17.

By means of a blower 18 with a blower drive 19, air 20 is supplied to the combustion chamber 13 via an air supply line 21, wherein the air supply line 21 is formed at an air supply line end 22 which is provided adjacent to the combustion chamber 13 in such a way that it surrounds the fuel nozzle 12. With respect to further advantageous embodiments of the fuel nozzle or the atomizing device is to the unpublished German patent application with the file number DE 10 2011 075 409.1 directed.

The pump 15 is connected to a fuel supply 23 (possibly with a fuel reservoir or an oil reservoir). A pressure at an outlet 24 of the pump 15 is measured by a pressure sensor 25. A speed of the drive 19 of the blower 18 is determined by a speed-determining device (Hall sensor) 26.

In the following embodiment, thus, the fuel pressure at the output 24 (= first fuel supply parameter) of the pump 15 is measured and the speed of the pump drive 16 (= second fuel supply parameter) and the speed of the fan drive 19 (= air supply parameters).

For the combustion air monitoring a speed feedback of the fan drive 19 can be exploited. The speed signal can be generated by a Hall sensor.

The regulation of the fuel-air mixture via a predetermined relationship (fixed characteristic) between the fan speed as a measure of the amount of air and the pump pressure. The pump pressure (which may correspond to the nozzle pressure) is a measure of the amount of fuel (amount of oil). For a given geometry and structure of the sputtering apparatus 10, the pump pressure is in turn firmly related to the pump speed or the speed of the (electric) pump drive 16 of the pump 15. In this respect, it is possible to determine a characteristic curve for a given geometry and structure of the sputtering apparatus 10 (either experimental or theoretical or calculatory). This characteristic can be stored, for example, in a memory 27 of a control device 28. The control device 28 can communicate with the other components of the atomizing device 10 (or also the burner 11), in particular with the speed-determining device 26, the pressure sensor 25 and the speed-determining device 17 (wired or wireless, for example via radio or infrared). Furthermore, for example, in the memory 27, an upper and a lower tolerance band can be set, so that a total of a tolerance range 29 (see FIG. Fig. 2 ) is defined around the characteristic 30 around. The tolerance range 29 according to Fig. 2 In this case, it separates an upper region 31 from a lower region 32, in which the deviation from the characteristic is no longer accepted, so that a warning and in the extreme case even a fault shut-off takes place. The plausibility check is carried out here in particular between pump speed and pump pressure, but can also be done indirectly between fan speed and pump speed.

About the relationship between pump speed (which can be done via a feedback via a PWM signal, ie pulse width modulation signal) and the pressure, which is determined by the pressure sensor 25 can be deduced faulty images that affect the operation of the burner. For example, a deviation outside the (predetermined) tolerance range 29 may be attributed to the use of an incorrect nozzle, damage to a nozzle, an unacceptable pressure loss in an oil supply, an improper inlet pressure in a supply line, and / or pump wear. Possible errors and the result of the combustion mixture are illustrated again in the following table: possible error result Pressure too high and speed OK Nozzle clogged Burn too thin inadmissibly high form Burn too fat Pressure too low and Drezhahl OK Nozzle too big / wrong burning too fat Suction line leaking Burn too thin too high pressure losses in oil supply Burn too thin

In Fig. 2 the areas 31 and 32 are also described as niO areas (where niO stands for "not okay"). Correspondingly, OK means "okay".

Outside the tolerance band 33, the combustion is increasingly incomplete and it is to be expected with a higher CO-formation and an unstable flame. Outside the (in Fig. 2 right) tolerance band 34 takes place a combustion under air deficiency (rich mixture).

In order to avoid the combustion with excess fuel in a scheme, during the control process from a smaller power to a larger power, a fan offset, for example, to (about or at least) 100 U / min, take place.

The pressure sensor 25 (oil pressure sensor) can be realized via an external pressure sensor with an output signal of for example 4 to 20 mA. A short circuit and an interruption can be detected. The pressure can be checked when the device starts up (and not when the engine is switched on). If a pressure signal is present, a lockout can occur. In a further (regular) startup, the pump drive 16 can be released. If no pressure signal is present at this time, a lockout occurs. An optionally calculated (for example, via the pulse width modulation signal) speed feedback of the pump drive 16 is detected by a possibly deposited dependence of engine speed to pump pressure a setpoint deviation in the negative and positive range (plausibility check, see above).

It should be noted at this point that all the above-described parts taken alone and in any combination, in particular the details shown in the drawings, are claimed as essential to the invention. Changes are familiar to the person skilled in the art.

Reference numerals:

10

atomizer

11

burner

12

fuel nozzle

13

combustion chamber

14

Fuel supply line

15

Pump (oil pump)

16

pump drive

17

Speed determining means

18

fan

19

fan drive

20

air

21

Air supply line

22

Air supply line end

23

Fuel supply

24

output

25

pressure sensor

26

Speed determining means

27

Storage

28

control device

29

tolerance

30

curve

31

upper area

32

lower area

33

tolerance band

34

tolerance band

Claims (14)

Method for regulating and / or monitoring a sputtering apparatus (10) for sputtering liquid fuels, in particular oil, in a modulating burner (11), comprising the steps: Determination of at least one air supply parameter and of a first and at least one second fuel supply parameter, Setting the first fueling parameter in dependence on the air supply parameter for controlling a fuel-air mixture for controlling the power of the burner, Determining a first deviation of the second fueling parameter from a desired value of a first characteristic of a relationship between the first fueling parameter and the second fueling parameter, and / or Determining a second deviation of the second fuel supply parameter from a desired value of a second characteristic of a relationship between the second fuel supply parameter and the air supply parameter. Method according to claim 1,
characterized in that
the first fueling parameter is a fuel pressure, in particular between a pump outlet (24) and a fuel nozzle (12), preferably at a pump outlet (24), and / or the second fueling parameter is a pump speed of a feed pump (15). Method according to claim 1 or 2,
characterized in that
it is determined whether the first and / or second deviation is outside or within a predetermined tolerance, wherein the tolerance is preferably at least +/- 1%, more preferably +/- 5%, and / or preferably at most +/- 20%, more preferably +/- 12%, even more preferably +/- 2% of the target value. Method according to one of the preceding claims,
characterized in that
a deviation from the characteristic curve, in particular an exceeding of the tolerance, for example on a display or screen, is displayed and / or when the tolerance is exceeded, for example acoustic or optical, signal and / or a shutdown of the sputtering takes place. Method according to one of the preceding claims,
characterized in that
the air supply parameter is a fan speed or an air supply amount. Method according to one of the preceding claims, in particular according to claim 4,
characterized in that
the pump speed is determined via a control signal, in particular a pulse width modulation signal. Method according to one of the preceding claims,
characterized in that before an increase in the power of the burner, the air supply is increased by a predetermined offset amount, for which purpose preferably a blower speed is increased by a predetermined offset amount, for example by at least 50, preferably at least 90 U / min and / or at most 200, preferably at most 110 U / min. Method according to one of the preceding claims,
characterized in that prior to startup of a feed pump (15) the fuel pressure is checked, preferably a warning or shutdown occurs when the fuel pressure is greater than a predetermined value, for example 1 bar, preferably greater than 0 bar. Method according to one of the preceding claims,
characterized in that after commissioning of a feed pump (15) the fuel pressure is checked, preferably a warning signal or a shutdown takes place when the fuel pressure is less than a predetermined value, in particular 0 bar. Apparatus for controlling and / or monitoring a sputtering apparatus (10) for sputtering liquid fuels in a modulating burner (11) an air supply line (21) for supplying air to the burner (11), a fuel supply line for supplying liquid fuel to the burner (11), an air supply parameter determination device for determining an air supply parameter, a first fuel supply parameter determination device for determining a first fuel supply parameter, a second fuel supply parameter determination device for determining a second fuel supply parameter, a control device for setting the first fuel supply parameter as a function of the air supply parameter for controlling a fuel mixture for controlling the burner (11), a memory means on which parameter characteristics can be stored or stored, deviation determining means for determining a deviation of the second fueling parameter from a first desired value of a first characteristic of a relationship between the first fueling parameter and the second fueling parameter and / or a deviation determination device for determining a deviation of the second fuel supply parameter from a second desired value of a second characteristic curve of a relationship between the first fuel supply parameter and the air supply parameter. Device according to claim 10,
marked by
a fan (18) for providing the air flow and / or a particularly speed-controlled pump (15) optionally comprising a fuel supply (23), wherein the air supply parameter determining means preferably comprises a fan speed determining means and / or the first fuel supply parameter Determining device preferably comprises a pump pressure determining device. Device according to claim 10 or 11,
marked by
a pressure sensor (25) for determining a fuel pressure in the fuel supply line as a first or second fuel supply parameter, in particular between the pump outlet and the fuel nozzle (12), preferably at the pump outlet (24). Device according to one of claims 10 to 13, in particular according to one of claims 11 to 13,
characterized in that
the pump drive, in particular electronic, is speed-controlled or comprises an EC motor. Device according to one of claims 10 to 14,
marked by
a display or a screen and / or a warning signal device, such as light or sound signal device.

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