EP1450102A1 - Heating apparatus and corresponding operation method - Google Patents

Abstract

Process for operating a heating device (1) comprises a fan (10) for producing a combustion air stream and a control unit (15) for operating the fan depending on at least one control parameter. The control unit has a characteristic field with an operating characteristic line in which a fan revolution number is produced depending on the control parameter so that a fan revolution number is assigned to each value of the control parameter. The control unit is attached to an oscillation recognition unit (38) which recognizes unreliable oscillation behavior of the heating device during operation of the heating device. An independent claim is also included for a heating device used in the above process. Preferred Features: The operating characteristic line is varied so that the control unit is pushed within the characteristic field parallel to the rotational axis.

Description

State of the art

The present invention relates to a heater, in particular a heating device of a central building heating system and / or a building water heating system. Operational Such a heater can be used in certain Operating conditions lead to undesirable vibrations, which is the flame formation of a burner of the heater can adversely affect. For example, the Flames excited to vibrate in a resonance range be what the goodness of combustion, in particular with regard to emission values and efficiency, deteriorated. In extreme cases, the flame can pass through the Natural vibrations.

The vibration behavior of such a heater becomes one depending on the operating state of the heater, e.g. Speed of a fan and / or fuel volume flow, determined, on the other hand, the structure of the heater also have a significant impact on the Vibration behavior. The structure includes in particular the Design of the supply air and exhaust air routing e.g. with regard on pipe length, pipe cross sections, number and type of Flow deflections. It can also be important whether the heater is an external wall unit and / or is a condensing boiler. Since the device structure from depends on the respective application, can be in operation possible vibration conditions occurring at the factory are not taken into account. In addition, too Ambient conditions of the heater, e.g. Fresh air temperature and air pressure, the vibration behavior of the heater.

Advantages of the invention

The present invention with the features of independent Claims has the advantage that the heater is impermissible Automatically recognizes vibration states and by a Change in fan speed automatically eliminated. The adverse effects of any occurring Vibrations can thus be independent of each Installation situation, regardless of the periphery of the Heater, regardless of environmental conditions and regardless of the operating status of the heater be effectively reduced or avoided. Factory Presettings are therefore unnecessary.

By changing the fan speed, especially effectively in the vibration system or in that Vibration behavior of the heater can be intervened, so that any self-resonance behavior that may occur effective by changing the fan speed can be eliminated.

A major advantage of the present invention is also seen in that the change in fan speed achieved with the help of a variation of the operating characteristic is so that in the actual control algorithm for No control or regulation of the fan speed must be intervened. By changing the The operating characteristic is adjusted accordingly Fan speed using the control algorithm from itself. The invention can thus be based on an existing one Control algorithm, so here no special effort is required.

In an expedient embodiment, the variation the operating characteristic by the control the operating characteristic within the map parallel to Speed axis shifts. In other words, the zero position the speed axis becomes relative to the operating characteristic adjusted. This shift can basically be stepless or in speed steps, which results in correspondingly a stepless or stepped Increased speed of the fan speed results.

In another embodiment, the map can have several essentially parallel to the operating characteristic Have characteristic curves. The variation of the operating characteristic can then preferably take place in that the control to a characteristic curve adjacent to the operating characteristic switches. Because neighboring characteristics are different distinguish from each other that they are the same Control parameters different fan speeds assign, there is also a result of this procedure Change in fan speed.

In an alternative embodiment, the Operating characteristic curve have several speed levels that each assigned to a range of values of the control parameter are, the respective within each speed level Fan speed is constant and being adjacent Speed levels have different fan speeds. at In such an embodiment, the variation of Operational characteristic curve expediently take place in that the Control the the current value of the control parameter assigned speed level with an adjacent one Speed level summarizes, so that the on this Value ranges of the control parameter summarized in this way the fan speed of the adjacent speed level assigned. Through this measure, the quasi current value of the control parameter Fan speed assigned to the current value of the Control parameter adjacent value range of Control parameter is assigned. That is, the The speed level of the neighboring value range is set to Range of values of the current value of the control parameter extends. This procedure essentially corresponds a shift in the operating characteristic within the Map parallel to the control parameter axis. As the The aforementioned embodiments can also do this, in particular through appropriate software, relatively simple will be realized.

Other important features and advantages of the present Invention result from the dependent claims, from the Drawings and from the associated figure description based on the drawings.

drawings

Embodiments of the invention are in the drawings are shown and are explained in more detail below.

Fig. 1

eine stark vereinfachte Prinzipdarstellung eines Heizgeräts nach der Erfindung,

Fig. 2

eine diagrammartige Darstellung eines Kennfelds.

Each shows schematically

Fig. 1

a greatly simplified schematic diagram of a heater according to the invention,

Fig. 2

a diagrammatic representation of a map.

Description of the embodiments

1 includes a heater 1 according to the Invention a burner 2 in a combustion chamber 3rd is arranged. An air supply leads to the combustion chamber 3 4, via which the combustion air is fed to the burner 2. In the embodiment shown here, the Air supply 4 coaxially with an exhaust gas discharge 5 Exhaust pipe, not shown, is connected to To discharge combustion gases into the atmosphere. The Air supply 4 with air pipe and the exhaust gas discharge 5 with Exhaust pipe form an air / exhaust system. If the Air supply 4, the combustion air from the environment Building sucks, in which the heater 1 is arranged, the heater 1 is an external wall unit. The heater 1 usually forms part of a Building central heating and / or one Building water heating system.

The heater 1 can be designed as a condensing boiler, at which the combustion gases are below the dew point of water be cooled. It is preferably the Heater 1, however, a conventional heater 1, at which the exhaust gases do not cool below the dew point of water become.

The burner 2 acts on its hot Combustion gases a heat exchanger 6, which has a Flow line 7 and a return line 8 for example with a radiator arrangement, not shown Building central heating is connected. About that Heat exchanger 6, an exhaust gas hood 9 is arranged, the passes to exhaust gas discharge 5. The one shown here Embodiment is in the exhaust gas discharge 5 above the Exhaust collector 9, a blower 10 arranged, the exhaust gas sucked out of the combustion chamber 3 and one through the suction corresponding volume flow or air mass flow Combustion air via air supply 4 to burner 2 supplies. In another embodiment, the blower can 10 can also be arranged in the air supply 4.

Furthermore, the burner 2 is via a fuel line 11 and a fuel control device 12 with a Fuel supply 13 connected. As fuel usually used natural gas or heating oil. The Fuel control device 12 can with a Modulation magnet 14 may be equipped for the suitable adjustment of the fuel control device 12 provides.

The heater 1 also has a controller 15 that serves to actuate the modulation magnet 14, what the controller 15 via a control line 16 with the Modulation magnet 14 is connected. The modulation magnet 14 and the fuel control device 12 form one Fuel dosing. The controller 15 contains expediently a so-called fuel burner control, with which the operation and monitoring of the burner 2 with fully automatic ignition.

In this context, the heater 1 is also with a flame control device 35 equipped by means of a corresponding sensor 36, for example is designed as an ionisensor, the presence and / or the absence, preferably the intensity of a flame of the Brenners 2 sensed and a corresponding Communicates signal line 37 to the controller 15. This Flame control device 35 can with a corresponding Design used as a vibration detection device are referred to below as 38. With help this vibration detection device 38 can Control 15 determine whether a for heater 1 impermissible vibration condition is present or not. For example, the flame of burner 2 oscillates when such a vibration behavior occurs. The The flame can oscillate or flicker with the help of Sensor 36 can be detected, making it the controller 15 is possible, an impermissible vibration behavior of the Determine heater 1.

A speed n (see FIG. 2) of the fan 10 can be from one Speed sensor 17, for example a Hall sensor, is detected become. The speed sensor 17 stands over a Signal line 18 with a blower control unit 19 in Connection, which in turn via a control line 20 with the controller 15 and via a power supply line 21 is connected to the blower 10.

In the embodiment shown here is in the Air supply 4 also has a differential pressure measuring point 22 a differential pressure switch 23 arranged at Gives a switching signal when a certain pressure is reached and this via a signal line 24 of the controller 15 feeds. It is also possible to use the differential pressure measuring point 22 with the differential pressure switch 23 in the exhaust gas discharge 5 to arrange.

A temperature sensor 25 is located in the flow line 7 arranged, the signal via a signal line 26th is also supplied to the controller 15. By means of the Flow temperature, the burner output can be adjusted via a Modulation current i (see also FIG. 2) for controlling the Modulation magnet 14 depending on a predetermined Setpoint are regulated. This setpoint can Controller 15 e.g. via an outside temperature sensor weather-dependent and / or via a fixed setting according to the required room temperature.

A further temperature sensor 27 is located in the exhaust gas discharge 5 arranged, the signal via a signal line 28 of the Control 15 is supplied. With the help of this Temperature sensor 27, which is also in another embodiment can be arranged in the air supply 4, it is basically possible, a temperature-related change in the Air mass flow through numerical adjustment to compensate for what, for example, in DE 195 10 425 C2 is described.

The controller 15 has access to one shown in FIG Map 29, the several curves 30,31,32 and 33 for one Fan speed n depending on a control parameter contains. One is expediently used as the control parameter Burner output Q or a correlating one Heat request used. The individual characteristics 30,31,32,33 run essentially parallel to each other and are in the direction of the speed axis from each other spaced, i.e. for the same value of the control parameter Q (Burner output / heat requirement) results for each Characteristic 30,31,32,33 another fan speed n.

From the characteristic curves 30, 31, 32, 33, a characteristic curve which is most suitable for the present installation state or for the present air / exhaust gas system 4, 5 is selected in the course of the installation of the heater 1 and is referred to below as the operating characteristic curve K _x , In the present case, this operating characteristic curve K _x is formed by the characteristic curve 32. A method for determining the operating characteristic K _x is described, for example, in DE 102 03 798 from January 31, 2002.

2 is a characteristic curve 34 for the Modulation current i as a function of the control parameter Q located.

In the present embodiment, the characteristics have 30,31,32,33 speed levels, each of which has a range of values of the control parameter Q is assigned. Within the The respective speed level is the corresponding one Range of values assigned fan speed n constant. As well An embodiment is possible in which the characteristic curves 30 to 33 the fan speed n continuously Assign control parameter Q.

The heater 1 according to the invention works as follows:

In normal operation, the fan 10 is actuated with respect to its fan speed n as a function of the operating characteristic K _x , ie a specific normal fan speed n is assigned to the current value of the control parameter Q using the operating characteristic K _x . The blower control unit 19 then tries to set or regulate the blower speed n specified in this way on the blower 10.

In the proper operation of the heater 1, it can Burner 2 switched on in certain operating states In addition, there are 1 vibrations in the heater train in the natural resonance frequency range of Heater 1 lie and thereby reinforce. Once a there is such an impermissible vibration behavior this is recognized by the vibration detection device 38 become. The controller 15 then directs suitable ones Countermeasures.

According to the invention, the control 15 is designed such that it varies the operating characteristic K _x as soon as it detects the presence of an impermissible vibration behavior by means of the vibration detection device 38. The aforementioned variation of the operating characteristic curve K _x takes place in such a way that an alternative fan speed n 'is assigned to the current value of the control parameter Q. The alternative fan speed n 'deviates from the normal fan speed n, which results from the operating characteristic K _x .

The alternative fan speed n 'determined by the variation of the operating characteristic K _x is then supplied by the controller 15 to the fan control unit 19, so that it accordingly sets the alternative fan speed n' on the fan 10. By changing the fan speed n at the operating point at which the impermissible vibrations have been determined, the volume flow through the heater 1 changes, as a result of which the vibration behavior changes considerably. In particular, the vibration system is moved out of the natural resonance frequency range. The impermissible vibration behavior can be effectively suppressed.

An embodiment is preferred in which the control 15 varies the operating characteristic K _x such that the alternative fan speed n 'is greater than the normal fan speed n provided for this control parameter. Accordingly, the air volume flow increases, so that there is always a lean combustion with low pollutants. In principle, however, a lowering of the fan speed is also conceivable.

The controller 15 can vary the operating characteristic K _x, for example, by shifting the operating characteristic K _x within the characteristic diagram 29 parallel to the speed axis, that is to say upwards (or downwards) according to FIG. 2. Correspondingly, the assigned fan speed n increases (or decreases) for the respective control parameter Q.

A numerical example should serve to explain: In a certain operating state, an impermissible vibration behavior occurs. This operating state is characterized, among other things, by the control parameter Q, which has a value of 15, for example. N the normal fan speed is obtained from the operating characteristic curve K _x and amounts to about 1,900 rpm ^-1. By a shift of the operating characteristic K _x corresponding to an arrow 39 upward, ie in the direction of greater speeds, results in an alternate blower speed n 'of about 2,300 rpm ^-1. The shift in the operating characteristic K _{x can} then be changed continuously or in predetermined steps until the critical oscillation state is eliminated. Likewise, a certain speed jump can be specified, in which experience has shown that the impermissible vibration state passes.

If - as here - there are several characteristic curves 30 to 33 in the characteristic diagram 29, which also run essentially parallel to one another, the controller 15 can also be designed such that it varies the operating characteristic curve K _x by switching over to an adjacent characteristic curve 31 or 33 , For example, the current control parameter Q again has a value of 15; n the corresponding normal fan speed is then about 1,900 rpm ^-1. The change of the operating characteristic curve K _x to the adjacent upward curve 33 then leads to an alternate blower speed n 'of about 2,100 rpm ^-1.

Furthermore, it is possible to design the controller 15 in such a way that, in order to vary the operating characteristic K _x , it combines the speed level assigned to the current value of the control parameter Q, here the speed level with n = 1,500 rpm ^-1 , with an adjacent speed level. For example, the mentioned speed level (n = 1,900 rpm ^-1 ) is combined with the speed level adjacent in the direction of larger control parameters Q, i.e. here with the speed level with n = 2,300 rpm ^-1 . The consequence of this is that the current value of the control parameter Q (here Q = 15) is assigned the fan speed n of this adjacent speed level as an alternative fan speed n ', so that it then has the value n' = 2,300 rpm ^-1 .

This procedure corresponds to a shift of the operating characteristic K _x parallel to the axis of the control parameter Q according to FIG. 2 to the left.

The controller 15 is expediently designed such that, after the variation of the operating characteristic K _{x has been} carried out, it further checks whether there is an impermissible oscillation state, adaptation times being taken into account. If the impermissible vibration condition is still present or if a new, impermissible vibration condition has occurred, the controller 15 changes the operating characteristic K _{x again} . However, as soon as the controller 15 can determine that the impermissible oscillation state is no longer present, it can, particularly after a predetermined period of time, undo the previous variation or the previous variations until the blower 10 returns to normal according to its operating characteristic K _x is operated.

In a special embodiment, the controller 15 can also be designed in such a way that it gradually adapts the operating characteristic K _x to impermissible vibration states, in particular to those that occur repeatedly. This means that the controller 15 remembers a control parameter Q in which the operating characteristic curve K _{x was} varied once or several times. As soon as this noted control parameter Q occurs again later, the controller 15 can carry out the variation of the operating characteristic K _x that was carried out earlier, even before the vibration detection device 38 detects the presence of an impermissible vibration state. The heater 1 then shows a particularly stable operating behavior.

LIST OF REFERENCE NUMBERS

1

heater

2

burner

3

combustion chamber

4

air supply

5

flue gas discharge

6

heat exchangers

7

supply line

8th

Return line

9

Exhaust gas collection hood

10

fan

11

fuel line

12

Fuel control device

13

fuel supply

14

modulating magnetic

15

control

16

control line

17

Speed sensor

18

signal line

19

Blower controller

20

control line

21

Power line

22

Differenzdruckmeßstelle

23

Differential Pressure Switch

24

signal line

25

temperature sensor

26

signal line

27

temperature sensor

28

signal line

29

map

30

curve

31

curve

32

curve

33

curve

34

curve

35

Flame control device

36

sensor

37

signal line

38

Vibration detection device

39

Characteristic curve shift

Claims (15)

Method for operating a heating device (1), in particular a central building heating and / or a building hot water preparation system, The heater (1) has a blower (10) for generating a combustion air flow and a controller (15) for actuating the blower (10) as a function of at least one control parameter (Q), wherein the controller (15) for speed control of the fan (10) has a map (29) with an operating characteristic (K _x ), in which a fan speed (n) is stored as a function of the control parameter (Q), such that each value of the Control parameter (Q) is assigned a specific fan speed (n), The controller (15) is connected to a vibration detection device (38) which detects inadmissible vibration behavior of the heater (1) during operation of the heater (1), wherein the controller (15) carries out a variation of the operating characteristic curve (K _x ) in the presence of an impermissible vibration behavior, such that the current value of the control parameter (Q) is assigned an alternative fan speed (n ') which is different from that fan speed (n) deviates, which is determined by the non-varied operating characteristic (K _x ). Method according to claim 1,
characterized in that the variation of the operating characteristic (K _x ) takes place in that the control (15) shifts the operating characteristic (K _x ) within the characteristic diagram (29) parallel to the speed axis. Method according to claim 1,
characterized, that the characteristic diagram (29) has a plurality of characteristic curves (30, 31, 32, 33) which run essentially parallel to the operating characteristic curve (K _x ), that the variation of the operating characteristic (K _x ) takes place in that the control (15) switches over to a characteristic (30, 31, 32, 22) adjacent to the operating characteristic (K _x ). Method according to claim 1,
characterized, that the operating characteristic curve (K _x ) has a plurality of speed levels, each of which is assigned to a value range of the control parameter (Q), the respective fan speed (n) being constant within each speed level and adjacent speed levels having different fan speeds (n), that the variation of the operating characteristic (K _x ) takes place in that the controller (15) combines the speed level assigned to the current value of the control parameter (Q) with an adjacent speed level, in such a way that the associated value ranges of the control parameters (Q) the fan speed (n ) is assigned to the neighboring speed level. Method according to one of claims 1 to 4,
characterized in that the control (15) is adaptive and remembers a value of the control parameter (Q), in which the operating characteristic (K _x ) was varied once or several times, and when this value of the control parameter (Q ) performs the same variation of the operating characteristic (K _x ), regardless of whether the vibration detection sensor system (38) detects a permissible vibration behavior. Method according to one of claims 1 to 5,
characterized in that the control (15) reverses this variation after a variation in the operating characteristic (K _x ) as soon as the impermissible vibration behavior is no longer present. Method according to one of claims 1 to 6,
characterized in that the control (15) reverses this variation after a variation of the operating characteristic (K _x ) as soon as the impermissible vibration behavior is no longer present for a predetermined period of time. Method according to one of claims 1 to 7,
characterized in that the controller (15) carries out the variation of the operating characteristic (K _x ) in such a way that an increased fan speed (n) results for the fan (10). Method according to one of claims 1 to 8,
characterized in that the control parameter is formed by a burner output Q or a heat request. Method according to one of claims 1 to 9,
characterized in that the vibration detection device (38) is formed by a flame control device (35) which detects the absence and / or presence of a flame from a burner (2) of the heater (1). A method according to claim 10,
characterized in that the flame control device (35) has at least one ion probe (36). Method according to one of claims 1 to 11,
characterized in that the heater (1) is designed as an outer wall device. Method according to one of claims 1 to 12,
characterized in that the heater (1) is designed such that its combustion exhaust gases in the exhaust line do not cool below the dew point of water in normal operation. Heating device, in particular a central building heating system and / or a building water heating system, with a blower (10) for generating a combustion air flow and with a controller (15) for actuating the blower (10) as a function of at least one control parameter (Q), wherein the controller (15) for speed control of the fan (10) has a map (29) with an operating characteristic (K _x ), in which a fan speed (n) is stored as a function of the control parameter (Q), such that each value of the Control parameter (Q) is assigned a specific fan speed (n), The controller (15) is connected to a vibration detection device (38) which detects inadmissible vibration behavior of the heater (1) during operation of the heater (1), the controller (15) executing a variation of the operating characteristic (K _x ) in the presence of an impermissible vibration behavior, such that the current value of the control parameter (Q) is assigned an alternative fan speed (n ') which is different from that fan speed (n) deviates, which is determined by the non-varied operating characteristic (K _x ). Heater according to claim 14 characterized by the characterizing feature of at least one of claims 2 to 13.

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