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| Small-scale furnaces |
 In particular, heating devices used in apartments and other residential dwellings can have a major and adverse impact on the quality of life if they prove to be subject to thermoacoustic oscillations. We develop cost-effective and easy-to-install methods to help prevent problems of this kind. We define small-scale furnaces as combustion systems used at the lower end of the kW range, e.g. various kinds of gas thermal value equipment, oil burners etc. in apartments, detached homes and multiple occupancy homes. We also include in this category gas ovens, e.g. gas heaters used for camping and similar systems with a defined combustion chamber geometry in which acoustic oscillations can become established, and which also contain a burning flame. .
Especially in the heating device sector, efficient low-pollution operation and smooth combustion are all important features because direct or indirect noise originating from the combustion system can, to a greater or lesser extent, have a profound and adverse impact on the quality of home life, and therefore on general quality of life. Large-scale systems share common features with small-scale systems. For example, combustion oscillations can be caused by apparently minor changes in ambient conditions (gas composition, installation conditions, operating point, ambient temperature etc.). The impact of these changes can cover a very wide range: low-frequency buzzing with fixed or variable frequency when starting, sudden brief occurrence of instabilities caused by, e.g. the closing of a door (and its associated pressure impulse), high-frequency whistling (approx. 800Hz, 120dB) when operating at a defined operating point, etc. It is understandable that this kind of behaviour in combustion systems is not acceptable for the manufacturer. In most cases, during the planning and development phase, little attention is paid to the optimisation of the thermoacoustic properties of a device and this can mean that any inherent tendency towards combustion instabilities may remain undetected until the prototype stage, or even until the test stage prior to market launch. It is then necessary to develop passive measures rapidly which can be installed quickly and cost-effectively without modifying the overall concept of the burner. In several projects, IfTA GmbH has developed successful solutions for various renowned manufacturers and these solutions have proven capable of damping the combustion instabilities in these various devices. Following an experimental and numerical investigation of the system in our laboratory and/or on the computer during which we gained a detailed understanding of the causes of instability problems, passive measures were developed which x91detuned' the acoustics in such a way that it was no longer possible for combustion and acoustics to establish a feedback loop. In most cases, various different measures were devised (dampers, resonators etc.) which equipped manufacturers with a range of different options to prevent unstable system characteristics. As well as developing efficient "quick solutions", we do of course also offer expert consultancy and guidance support during the planning and development stage, thus ensuring that problems of this kind will not occur in the test phase. Given the sensitivity of this topic, it goes without saying that we treat all such investigations and information as absolutely confidential. We therefore quite deliberately avoid quoting any specific examples, or naming our customers at this stage. We are sure that you will understand our position. |