Method for operating a cooking process for food using a cooking appliance

Description

2. The actual temperature in the cooking chamber must be present, and at least one heating element must be present to achieve the actual temperature corresponding to the target temperature. The method according to the invention is characterized in that at the start of the cooking process, at least one target temperature value is specified, wherein at least one heating element is controlled to achieve the actual temperature value according to this target temperature value, and after a predetermined time after the start of the cooking process, at least one further, lower target temperature value is automatically specified. The at least one heating element is controlled to achieve the actual temperature according to this lower target temperature value such that the actual temperature corresponds to the lower target temperature value. By lowering the actual temperature to the lower target temperature value, less heating energy is required. The inventive method thus enables simple implementation in standard operating modes (e.g.Top heat, bottom heat, hot air or convection) provides automatic and simple energy savings when cooking food, thus offering a practical everyday solution without the user having to select cooking programs with special energy-saving modes beforehand. The user simply selects their desired standard operating mode in the usual way and sets a target temperature for the cooking chamber or accepts a target temperature suggested by the cooking appliance. With the start of the cooking process, this target temperature is then active, whereby at least one heating element is controlled via a control unit to achieve the actual temperature according to this target temperature. After a heating phase, the actual temperature then reaches the initially set or specified target temperature.The control unit then maintains the actual temperature at the level of the setpoint temperature set after the start of the cooking process until, according to the invention, a new, lower setpoint temperature is automatically set after a predetermined time 25 after the start of the cooking process. Now, at least one heating element is controlled by the control unit to lower the actual temperature to the lower setpoint temperature value, such that after a control-related transition period until the cooking process is switched off, the actual temperature corresponds to the lower setpoint temperature value 30. This allows for a reduction in the power output without negatively affecting the cooking result. The time until the actual temperature drops to the new, lower target temperature is preferably determined in such a way that the cooking results are generally no longer fundamentally affected. For example, browning, searing, or crust formation still occurs before the actual temperature drops, i.e.,In BE2025 / 7039 3, an actual temperature corresponds to the initial (start) target temperature. The subsequent phase with a reduced actual temperature serves to "cook through" larger foods, while at the same time preventing the food from "burning" due to the reduced actual temperature. As a rule, there is no fixed end time for the cooking process, so the actual temperature in the cooking chamber is continuously maintained at the lower setpoint temperature until the user switches off the cooking process or the cooking appliance. According to the procedure described in EP2251607A2, the temperature reduction occurs during a reduction period before the defined end of the cooking program. After the end of the cooking program, the heating elements are switched off. Thus, the reduced temperature level is not maintained indefinitely. Rather, the cooking chamber cools down to room temperature during prolonged use. In general, however, it is necessary to maintain the reduced cooking temperature for a longer period for a good cooking result.The end of the cooking process is usually unknown; therefore, a blanket shutdown leads to poor results if the timing does not happen to match the food being cooked. According to the invention, the time at which the further, lower setpoint temperature is specified can depend on a user-selected operating mode (e.g., top heat, bottom heat, hot air, or convection) for the cooking process or on the first, higher setpoint temperature, i.e., the initial (start) setpoint temperature. In an advantageous embodiment, a differentiation of the residual heat utilization according to the invention is provided, taking into account the heating phase at the beginning of the cooking process, in which the actual temperature is increased to the initial (start) setpoint temperature. The distinction is made depending on whether the heating phase was carried out by means of a rapid heating control of at least one heating element or without rapid heating control.In a first variant of this embodiment, the time after the reduction of the actual temperature to the new, lower target temperature value according to the invention, and thus the energy-saving use of residual heat, depends on whether a rapid heating control was present or not. If the initial target temperature was reached by means of rapid heating, then the actual temperature is lowered to the lower target temperature value relatively soon after a first predetermined time (t1). If, on the other hand, the initial target temperature was reached without rapid heating, then the actual temperature is lowered to the lower target temperature value later after a second predetermined time (t2). Experimentally determined, advantageous time values ​​for the temperature reduction are, for example: BE2025 / 7039 4 a) 20 to 50 minutes if the heating was carried out with rapid heating, b) 50 to 60 minutes if the heating was carried out without rapid heating.In a second variant, depending on whether the heating was performed with or without rapid heating, different setpoint temperatures are used for the reduction of the actual temperature. If the initial setpoint temperature was reached by means of rapid heating, the reduction of the actual temperature to a first setpoint temperature value occurs. If, on the other hand, the initial setpoint temperature was reached without rapid heating, the reduction of the actual temperature to a second setpoint temperature value occurs, whereby the second setpoint temperature value is higher than the first setpoint temperature value. As a further variant, it is also planned to combine the two variants mentioned above, i.e., reduction of the actual temperature after different times and the use of different setpoint temperatures to which the actual temperature is reduced. The temperature is lowered. The variants described above take into account the fact that, in the case of rapid heating, a greater energy input into the food already occurs during the heating phase.In one implementation, the reduction of the initial setpoint temperature, active at the start of the cooking process, to the subsequent, lower setpoint temperature corresponds to a fixed temperature difference value (ΔT). This temperature difference value could, for example, be 20 Kelvin. An initial setpoint temperature of 1800°C would then be reduced to 1600°C, while an initial setpoint temperature of 1500°C would be reduced to 1300°C. In an alternative implementation, a fixed value is always defined for the subsequent, lower setpoint temperature. This value is chosen so that it lies below the setpoint temperatures at which a cooking process is usually started. For example, 1300°C could be defined as the lower setpoint temperature value.In a further embodiment, the reduction of the first setpoint temperature value, active at the start of the cooking process, to the subsequent, lower setpoint temperature value depends on the level of the setpoint temperature value at the start of the cooking process, 30 whereby the reduction is greater the higher the setpoint temperature value at the start of the cooking process, in particular a percentage reduction (e.g. by 10%) is provided, i.e., with an initial setpoint temperature value of 1500°C, a reduction of 15 Kelvin takes place. BE2025 / 7039 5 Furthermore, it is provided that the timing and temperature level of the reduction can be individually adjusted by the user. If, during the operation of the cooking process, the user manually adjusts the target temperature via a setting element, one embodiment provides that the reduction of the actual temperature to the further, 5 lower target temperature value is prevented or reversed.Instead, the manually set target temperature is activated, and at least one heating element is controlled to bring the actual temperature to this target temperature value. The invention is subsequently illustrated and described in more detail with reference to drawings. Figure 1 shows an actual temperature profile over time in the cooking chamber according to a first embodiment, Figure 2 shows an actual temperature profile over time in the cooking chamber according to a second embodiment, Figure 3 shows an actual temperature profile over time in the cooking chamber according to a further embodiment, Figure 4 shows a block diagram of a cooking appliance, and Figure 5 shows a flowchart for a variant of the method according to the invention. Before explaining the actual temperature profiles shown in Figures 1 to 3, 20 essential components of a cooking appliance (1) with which the inventive method is carried out will be briefly described with reference to the block diagram in Figure 4.The cooking appliance (1) has at least one temperature sensor (2) for determining the actual temperature in the cooking chamber and at least one heating element (3A, 3B, 3C, 3D) for achieving the actual temperature according to the set temperature. The two heating elements are preferably a top heating element (3A), a ring heating element (3B), a hot air blower (3C), and a bottom heating element (3D). To achieve / set the actual temperature, one of these heating elements (3A, 3B, 3C, 3D), a combination of heating elements, or all heating elements simultaneously can be used. The heating element(s) (3A, 3B, 3C, 3D) are controlled by a control unit (4). The control unit (4) receives the signal from the temperature sensor (2) as an input. Target temperature values ​​(Tset, Tset1, Tset2, Tred, Tred1, Tred2) are also received as inputs to the control unit. The target temperature values ​​can be set, for example, by the user via a manual setting element (5).However, it is also intended to select and confirm the setpoint temperature values ​​suggested by the cooking appliance (1) via the confirmation element (35). Furthermore, it is also intended to store corresponding setpoint temperature values ​​already saved in the control unit (4). Figures 1 to 3 show the actual temperature profile in the cooking chamber in diagrams, with time plotted on the horizontal axis and temperature on the vertical axis. The actual temperature profile with rapid heating is represented by a dotted line. The actual temperature profile without rapid heating (5) is represented by a dashed line. Figure 1 shows a time-based actual temperature profile in the cooking chamber according to a first design variant. At the start of the cooking process, a first target temperature value (Tset) is specified.In a heating phase immediately following the start of the cooking process, at least one heating element (3A, 3B, 3C, 3D) is controlled to bring the actual temperature value up to the target temperature value (Tset), whereby the actual temperature is raised to the target temperature value (Tset). The heating phase can occur with or without a rapid heating control. During rapid heating, a configuration of several heating elements (3A, 3B, 3C, 3D), e.g., a top heating element, a ring heating element, and a hot air blower, is preferably used simultaneously. Additionally, during rapid heating, the heating elements (3A, 3B, 3C, 3D) are preferably continuously switched on and operated at full load during the heating phase (also called the booster phase). If the actual temperature value is raised to the setpoint temperature (Tset) "normally," i.e., without rapid heating, fewer or different heating elements (3A, 3B, 3C, 3D) are used and / or the heating elements (3A, 3B, 3C, 3D) are not controlled at full load, but rather intermittently.In pulsed operation, the heating elements (3A, 3B, 3C, 3D) are switched on and off periodically, with the ratio of the on-time to the off-time determining the average heating power. The heating phase until the setpoint temperature (Tset) is reached is correspondingly shorter in rapid heating mode than in the heating phase without rapid heating. After the heating phase, when the actual temperature reaches the setpoint temperature (Tset), the overall heating power is reduced, whereby the heating elements (3A, 3B, 3C, 3D) are controlled via the control unit (4) so ​​that the actual temperature remains as constant as possible to the first setpoint temperature (Tset). This can be achieved through a corresponding configuration of the Controlled heating elements (3A, 3B, 3C, 3D) and / or via a corresponding clocking of the same. According to the invention, after a predetermined time (tred1, tred2) after the start of the cooking process, a further setpoint temperature value (Tred) is automatically specified, which is lower than the first setpoint temperature value (Tset).In this process, at least one heating element (3A, 3B, 3C, 3D) is controlled to achieve the actual temperature according to this lower / reduced setpoint temperature value (Tred) so that the actual temperature corresponds to the lower setpoint temperature value (Tred). Here too, the adjustment of the actual temperature is achieved via a corresponding configuration of the controlled five heating elements (3A, 3B, 3C, 3D) and / or via a corresponding clocking of the same. The transition of the actual temperature from the first setpoint temperature value (Tset) to the new, lower setpoint temperature value (Tred) occurs within a control-related transition time. After the actual temperature has been lowered to the lower target temperature (Tred), this value is maintained continuously until the end of the cooking process.10 As can be seen in Figure 1, the new, lower target temperature (Tred) is set at two different, predetermined times (tred1, tred2).In the case of rapid heating, the new, lower setpoint temperature (Tred) is set after time (tred1), whereas without rapid heating, the new, lower setpoint temperature is set later after time (tred2).15 The different times of the temperature reduction take into account the fact that, in the case of rapid heating, a greater energy input into the food being cooked already occurs during the heating phase. Figure 2 shows a time-based actual temperature profile in the cooking chamber according to a second design variant. As in Figure 1, two temperature profiles are shown – with and without rapid heating. In contrast to Figure 1, however, only one time point (tred) is provided for the temperature reduction. However, two further, lower target temperature values ​​(Tred1, Tred2) are provided. The first value (Tred1), which is used for both reduced target temperature values ​​(Tred1, Tred2), is used in the case of rapid heating, while the second target temperature value (Tred2) is used in the case without rapid heating.The second target temperature value (Tred2) is preferably higher than the first target temperature value (Tred1). In this way, the actual temperature is reduced more significantly in the case of rapid heating, because the rapid heating already results in a greater energy input into the food during the heating phase, and more residual heat can be utilized. Figure 3 shows a time-dependent actual temperature profile in the cooking chamber according to a third design variant. There is no differentiation in the heating phase. The profile shown in the heating phase can refer to a profile with or without rapid heating. However, the two temperature profiles differ with regard to the initial (start) target temperature values ​​(Tset1, Tset2), which are set at the start of the cooking process. The temperature is specified. Corresponding to the two different initial setpoint temperatures (Tset1, Tset2), there are two different reduced setpoint temperatures (Tred1, Tred2). The time (tred) for the temperature reduction, i.e.The setting / activation of these reduced target temperature values ​​(Tred1, Tred2) for controlling at least one heating element (3A, 3B, 3C, 3D) is, however, the same.5 If the target temperature value (Tset1) is initially set, the temperature is reduced to the target temperature value (Tred1). If a lower target temperature value (Tset2) is initially set, the temperature is reduced to the target temperature value (Tred2). As can be seen, the target temperature value (Tred2) is higher than the target temperature value (Tred1). This takes into account the fact that in the case of a higher initial target temperature value, a temperature reduction occurs. Greater energy input into the food being cooked occurs, and more residual heat can be utilized. The time sequences shown in Figures 1 to 3 are only schematic and not to scale. Figure 5 shows a schematic flow diagram for a variant of the inventive process 15, differentiating between whether the heating phase was carried out with or without rapid heating (see Figure 1).