Patent Application
20050287253
This patent application claims priority from German application DE 10 2004 020 365.2, which was filed on Apr. 23, 2004, the entire disclosure of which is hereby expressly incorporated herein by reference.
The present application concerns a method for adjusting the performance of gas-operated cooking equipment as a function of the geodetic height at the site of the cooking equipment.
In the unprepublished application DE 103 01 526.4 of the applicant, cooking equipment is described, which is equipped with a satellite-supported location system, so that the site and/or the elevation at the site of the cooking equipment can be determined. Depending on the site detected by the location system and/or depending on the site elevation determined by the location system, the parameters of the cooking equipment can be adapted to the local conditions at the site of the cooking equipment, such as different eating habits, special properties of local foods, or physical parameters such as air pressure, density, mean ambient temperature, humidity in the air, boiling point of the water, water composition, water temperature, water availability, gas quality, electrical energy supply and similar.
On the other hand, a combustion system is known from WO 02/10648 A1 of the applicant, which has an air inlet with a fan, a fuel inlet opening through at least one nozzle opening into the air inlet, with at least one valve, an ignition device for igniting an air/fuel mixture downstream of the nozzle and a control and/or regulating device for adjusting the air/fuel mixture in the region of the ignition device via the speed of the fan, bringing this in working connection with a sensor device in such a way that, depending on the values of air quantities detected with the sensor device, such as air volume flow, air flow-through and/or air pressure, the valve in the fuel inlet can be adjusted.
The present system provides a method for setting at least one parameter of gas-operated cooking equipment as a function of its site, in as simple and cost-effective manner as possible, in which, without adding new equipment components, adjustment of the heat output of a combustion system of the cooking equipment at the site can be done automatically during initialization of the cooking equipment.
The present system operates by determining the geodetic height at the site during an initialization step through determination of at least one physical parameter, such as air pressure, density, the mean outside temperature, the humidity in the air and/or the boiling point of water, and/or at least of a difference of two such physical parameters by starting up at least one functional group of the cooking equipment. The system then adjusts the heat output of at least one combustion system of the cooking equipment by adjusting the air/fuel; mixture in the region of an ignition device of the combustion system.
Hereby, preferably the heat output is adjusted by setting the speed of a fan of the combustion system.
Furthermore, it is proposed that the physical parameter be determined under different operating states of the cooking equipment, where the operating states are determined especially by the temperature in a cooking chamber of the cooking equipment and/or by the speed of a fan wheel for circulation of cooking medium, including air and/or steam, especially in the cooking chamber, where preferably a determination is carried out at a cooking chamber temperature of approximately 30°, 100° and 170° for several speeds, especially for five speeds.
It can be provided that the physical parameter for preadjustment of the cooking equipment is determined in the plant and that for adjustment of the cooking equipment the physical parameter is determined at the site. In the adjustment at the site, a comparison is made between the physical parameters determined in the plant and at the site and the result of the comparison is taken into consideration in the adjustment of the air/fuel mixture.
It is proposed that the physical parameter be determined at the site in the cold cooking equipment in which the cooking medium is present at ambient temperature.
Preferred practical examples are characterized by the fact that the boiling point, especially the boiling temperature of water, is determined in a steam generator of the cooking equipment as a physical parameter for the determination of the geodetic height.
Hereby it can be provided that the water is heated until its temperature no longer increases.
Other practical examples are preferably characterized by the fact that the moisture, a differential pressure and/or the density of a cooking medium, including air and/or steam is determined in the cooking chamber and/or fan chamber of the cooking equipment as a physical parameter for the determination of the geodetic height.
It can be provided that the differential pressure between two measured points in the space between a fan wheel in the fan chamber and the wall of the cooking equipment, which faces away from the cooking chamber and is bordering the fan chamber, be determined during operation of the fan wheel.
Finally, it is proposed that the heat output of the combustion system for operation of a steam generator be utilized for heating a cooking medium and/or for charging a heat accumulator.
Thus, the advantage is based on the surprising finding that an automatic adjustment of the combustion system of a cooking equipment can take place at its site especially at the geodetic height at the site, by using at least one functional group of the cooking equipment, whereby, for example, a steam generator or a moisture-measuring device of the cooking equipment can be selected as a functional group in order to determine the geodetic height via the boiling temperature of the water in the steam generator or via the moisture determined in the cooking chamber and/or fan chamber. The determined geodetic height is then used specifically for the adjustment of the speed of the fan of the combustion system.
Details of the moisture-measuring device which can be used in a method according to the invention can be taken, for example, from DE 42 06 845 C2 of the applicant.
Other characteristics and advantages of the invention follow from the description below in which two practical examples are explained in detail with the aid of a schematic drawing. The following are shown.
As can be seen from
The combustion system 1 in turn includes in its air inlet a fan 2 as well as two pressure-measuring sensors 3a, 3b upstream of a fuel nozzle 4, which can be fed through a fuel source 6 with a valve 5 in-between. Downstream of the fuel nozzle 4 there is an igniter which is not shown, and finally a burner 7 for providing heat to a cooking chamber of the cooking equipment, which is not shown. The pressure-measuring sensors 3a, 3b and the valve are connected to a control device 8, to which control quantities can be introduced through a control quantity line 9 from steam generator 100, while the control device 8 in turn outputs a manipulated variable through the manipulated variable line 10 to the fan 2 and ensures the opening and closing of valve 5, so that a desired heating output can be introduced to the cooking chamber through a heat inlet line 11.
The steam generator 100 in turn includes a housing 101, into which a heating device 102 protrudes for the evaporation of water 103, whereby the boiling temperature of the water 103 can be determined with the aid of a boiling temperature measuring sensor 104 and evaporated water can be introduced to the cooking chamber through a steam line.
When a cooking equipment just described is set up for the first time at a given site, at a specific geodetic height, then the output or rather the heat output of the cooking equipment is adjusted automatically, which, as it is well known, depends on the said height in gas-driven cooking equipment. For this purpose, directly after turning on the cooking equipment, the steam generator 100 is activated, in order to determine the boiling temperature, using the boiling-temperature-measuring sensor 104. From the boiling temperature, which decreases with increasing height above sea level, the geodetic height of the site of the cooking equipment can be calculated. From this, a control quantity is derived which is introduced to the control device 8 via the control quantity line 9 through which then, as a function of the geodetic height, a manipulated variable is calculated, which then again is introduced to the manipulated variable line 10 to fan 2 to adjust its speed.
Naturally, the valve 5 can also be adjusted using the control device 8. However, for reasons of safety, it is preferred that the valve 5 be open only when the speed of the fan 2 has exceeded a previously determined value, which can be determined, for example, with the aid of pressure-measuring sensor 3a, 3b.
Moreover,
Thus, with the method described herein, for the first time, automatic adjustment of the heat output of a gas-operated cooking equipment to a geodetic height is possible without having to introduce any new functional groups in the cooking equipment. Rather, a corresponding adjustment can take place exclusively by carrying out a certain method, preferably within the framework of a software solution. As a result of this, considerable cost and effort is saved.
It was found to be especially advantageous to pre-adjust cooking equipment in the plant, that is, at a known geodetic height and thus at a known air pressure. In this case, the boiling temperatures but also pressure differences under various operating conditions of a cooking equipment can be detected. The operating conditions can differ by different temperatures in the cooking chamber as well as different speeds of the fan wheel in the fan chamber. The different temperatures in the cooking chamber provide a determination with different cooking media, whereby, for example, at 30° C. essentially air is present, while at 100° C. it should be assumed that essentially steam is present. Then adjustment to the geodetic height can take place at the site, after the electricity, gas and water supply has been connected to the cooking equipment. For this purpose then either determination of the boiling temperature or a pressure difference determination can be performed, and then the determined values can be compared with the values obtained in the plant, in order to determine the geodetic height. After determination of the geodetic height, the cooking equipment is then adjusted, especially the speed of the fan of the combustion system of the cooking equipment. Then, as customary, hygienic combustion must be adjusted so that orderly operation of the cooking equipment is ensured.
The characteristics of the invention disclosed in the above description, in the claims, as well as in the drawing can be essential individually or in any arbitrary combination for the realization of the invention in its various embodiments.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2004 020 365.2 | Apr 2004 | DE | national |
