A METHOD OF STARTING A BURNER DEVICE AND HEATING DEVICE HAVING A BURNER DEVICE

Abstract

Example embodiments relate to a method of starting a burner device. The temperature of the combustion air is measured, and a temperature-dependent set value of the heating energy of a glow element is specified. Example embodiments also relate to a heating device having a burner device.

Claims

1. A method of starting a burner device-, wherein a mixture of combustion air and a fuel is burnt in the burner device, wherein a burning process of the burner device is started by a glow element, and the method comprising: measuring a temperature of the combustion air, and determining a set value of the heating energy of the glow element as a function of the measured temperature.

2. The method according to claim 1, further comprising: determining a scaled set value of the heating energy as a function of the measured temperature, wherein the scaled set value is smaller than the set value, wherein the combustion air is conveyed into the burner device in the event that the scaled set value of the heating energy of the glow element is reached, and wherein the fuel is conveyed into the burner device in the event that the set value of the heating energy of the glow element is reached.

3. The method according to claim 1, further comprising: monitoring, in the burner device, whether a flame is present, determining a delay time, and operating the glow element during the delay time after a time at which the presence of a flame has been determined.

4. The method according to claim 1, further comprising: switching the glow element on at the beginning of the starting process and operating at a rated power, purging a path passing the combustion air in the burner device with combustion air at the beginning of the starting process, and measuring the temperature of the combustion air after the purging of the path.

5. The method according to claim 1, further comprising: determining a stabilization time, and starting a regulation of the burner device only after the stabilization time has elapsed after switching off of the glow element.

6. A heating device for heating air and/or heating a liquid, comprising: a burner device which generates thermal energy by the combustion of a fuel-air mixture, a heat exchanger which transfers the thermal energy generated by the burner device to the air and/or liquid, and a control device, wherein the burner device includes a glow element, a combustion air fan, a fuel pump, and a temperature sensor for measuring the temperature of the combustion air, and wherein the control device is configured so as to perform the method according to claim 1.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0016] The aforementioned and the following configurations and embodiments as to the method also apply accordingly to the heating device which implements the method. To avoid repetitions, reference is thus made to the remaining description.

[0017] Specifically, there are a large number of possibilities for designing and further developing the method according to the present disclosure and the heating device. To this end, reference is made, on the one hand, to the claims subordinate to the independent claims, and, on the other hand, to the description below of example embodiments in conjunction with the drawing, in which:

[0018] FIG. 1 shows a schematic representation of the heating device,

[0019] FIG. 2 shows a schematic representation of the burner device, and

[0020] FIG. 3 shows a schematic representation of the course of the starting process of the burner device.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

[0021] FIG. 1 shows a heating device very schematically. A fuel-air mixture is burnt in a burner device 1, and the thermal energy thus released is transferred to air or a medium such as raw water in a heat exchanger 2. In particular, the flue gas generated in the burner device 1 is supplied to the heat exchanger 2. The starting process of the burner device 1 described below is controlled by the control device 3.

[0022] The burner device schematically represented in FIG. 2 has a combustion chamber in which the fuel-air mixture is burnt and the resulting flue gas (see arrow on the right side) is here evacuated to the right to be transferred to room air or raw water, for example, via the heat exchanger. The combustion process is started by the glow element 100. It is indicated here that a pulse-modulated electrical voltage is applied to the glow element 100. The temperature thus resulting at the glow element 100 causes the vaporization of a fuel, a Diesel fuel for example, and thus to the generation of a fuel-air mixture. The required combustion air (indicated by the left arrow) is supplied via the combustion air fan 101. The fuel is introduced into the combustion chamber via a fuel pump 102. This takes place in particular in the immediate vicinity of the glow element 100 such that the liquid fuel vaporizes in the temperature environment generatedby the glow element 100. A self-sustaining flame (here indicated symbolically) has formed after a certain period of time, and the glow element 100 can be switched off. The sensor 104 in the combustion chamber is used to detect the flame.

[0023] A temperature sensor 103 measuring the temperature of the supplied combustion air is provided for the starting process described below. Signals from the sensors for the flame 104 and for the temperature of the combustion air 103 are fed to the control device 3 illustrated in FIG. 1. In addition, the control device 3 controls the glow element 100more precisely the driving of the glow element 100, the fuel pump 102 and the combustion air fan 101.

[0024] FIG. 3 schematically shows an example of the course of the starting of the burner device. The starting phase takes place between times 1 and 7.

[0025] The top line a) shows the rated power of the glow element plotted against time t. At the beginning of the method, the glow element is switched on at time 1 and is operated at its rated power, which is regulated by measuring the current and the voltage and by setting a PWM-voltage (an electrical voltage regulated by pulse width modulation). The glow element is switched off at time 6, i.e. before the end of the starting phase.

[0026] Line b) illustrates the course of the heating energy of the glow element as a function of time t. The energy is calculated, for example, by numerical integration of the power. The ramp-shaped course which is formed up to a maximum at time 6 can be seen. If the power of the glow element is constantly regulated between times 3 and 4, it can be assumed that the increase in energy is linear. A scaled set value and a set value of the heating energy are also plotted.

[0027] Line c) shows the driving of the combustion air fan in relation to the set rotational speed. The fan is first operated between times 1 and 2 and is then switched off. The fan is only switched on again at time 3 to then be operated permanently. It is indicated that the rotational speed and thus the speed of the fan between times 1 and 2 is higher than after time 3, i.e. during normal operation of the burner device. A set rotational speed is specified for normal operation. In one configuration, the set rotational speed is specified as a function of the measured temperature of the combustion air.

[0028] Line d) shows the activation of the fuel supply. The fuel is introduced into the combustion chamber as from time 4 and also beyond the end of the starting phase.

[0029] Line e) relates to the sensor for detecting the flame. The time at which the flame and thus the beginning of the combustion phase are detected is referred to as time 5. From time 5, the combustion therefore takes place permanently or a flame is permanently present.

[0030] The cooperation of the individual components or events when starting the combustion process is described below.

[0031] Simultaneously with the switching on of the glow element at time 1, the combustion air fan is started and operated until the combustion path, i.e. in particular the combustion chamber has been purged with fresh air. The fan is therefore switched off at time 2. The duration between times 1 and 2 can be set such that it is ensured that fresh air reaches the temperature sensor. The specified time therefore depends on how long it takes to convey the fresh air. The duration can therefore be measured on the basis of the conditions of the burner device installed in the heating device, for example. Alternatively, the duration is specified as a function of a maximum exhaust gas or fresh air path, as a function of the respective line cross-sections and the characteristics of the fresh air fan, for example the fan speed and/or the volume flow which can be generated.

[0032] After the fan is switched off, the temperature of the combustion air is determined based on the measurement of the temperature sensor. This is realized at time 2. Based on the temperature, three set values are determined for driving the glow element, i.e. calculated by interpolationpreferably using a data table and/or for example a relationship described by mathematical formulae: these are, on the one hand, a set value for the heating energy and, on the other hand, a scaled set value preferably between 50% and 100%. Finally, this is the set value for the delay time which is shorter as the measured temperature increases (see further explanations). The set value of the heating energy or the energy set value depends on the temperature of the combustion air, if a higher temperature is associated with a lower set value and a lower temperature is associated with a higher set value. The warmer the combustion air is, the less thermal energy has to be provided by the glow element. The relationships between the set value and the temperature of the combustion air are determined from comparative measurements, for example. The scaled set value is for example determined from a scaling value between 0.5 and 1 and the set value. The time required by the combustion air fan to reach the set rotational speed necessary for operation is relevant to the scaling value. If the fan accelerates quickly, the time can be shorter. If the fan increases its rotational speed only slowly, the delay time is to be set longer. As can be seen in line b), the glow element is driven such that the heating energy thereof increases continuously. The power and energy are continuously monitored based on the measuring of the voltage and the current.

[0033] The fan for the combustion air is switched on at the time at which the scaled set value of the heating energy has been reached, i.e. here at time 3. If the set value is then reached at time 4, the pump device is started such that combustion air and fuel are present in the combustion chamber. Furthermore, the fan has preferably reached its set number of revolutions at time 4. In one configuration, the heating energy of the glow element is no longer determined after this time 4. The calculation of the energy from the measured values for the current and the voltage is for example stopped. The heating energy of the glow element is increased by the further driving, starting from the rated or set power beyond the set value.

[0034] At time 5, it is recognized that there is a flame, i.e. that the mixture of combustion air and fuel has ignited. The glow element which is still active supports the development of the flame during a delay time from time 5 to time 6. The glow element is switched off at time 6.

[0035] A stabilization time extends up to time 7 after which it is assumed that a combustion state has been reached which permits normal operation of the burner device or the heating apparatus.

[0036] While the disclosure has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the disclosure. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the disclosure without departing from the essential scope thereof. While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.

LIST OF REFERENCE NUMERALS

[0037] 1 Burner device [0038] 2 Heat exchanger [0039] 3 Control device [0040] 100 Glow element [0041] 101 Combustion air fan [0042] 102 Fuel pump [0043] 103 Temperature sensor [0044] 104 Sensor for detecting a flame