EP3772618A1 - Method for operating a cooking device and cooking device - Google Patents

Abstract

Method for operating a cooking appliance (1), in which the food to be cooked is prepared by means of a treatment device (2) in a heating chamber (3) that can be closed by a cooking chamber door (13). A cooling device (4) is used to rapidly cool the cooking space (3). To control the rapid cooling, a surface temperature of the food to be cooked is determined with a sensor device (5). The determined surface temperature is regulated with the cooling device (4) to a predetermined target surface temperature.

Description

The present invention relates to a method for operating a cooking appliance, in which a product to be cooked is prepared by means of at least one treatment device in at least one heating chamber that can be closed by at least one cooking chamber door. At least one rapid cooling of the cooking chamber takes place with at least one cooling device.

Such rapid cooling offers the possibility of quickly cooling down the cooking space at the end of the cooking process and preventing unwanted further cooking of the food in the heated up cooking space. This means that the food does not have to be removed directly after the cooking process, but can remain in the cooking space and be kept warm there, for example. Usually, the temperature sensor of the oven is used to regulate the rapid cooling, so that the oven is then cooled down to a target temperature.

The known rapid cooling works reliably in itself. However, better accuracy and control of the process is desirable, on the one hand to enable faster cooling and on the other hand to prevent undesired overcooking or cooling of the food.

In contrast, it is the object of the present invention to improve the rapid cooling of the cooking space and preferably to enable improved control of the process.

This object is achieved by a method with the features of claim 1 and by a cooking appliance with the features of claim 10. Preferred features are the subject of the subclaims. Further advantages and features emerge from the general description of the invention and the description of the exemplary embodiments.

The method according to the invention is used to operate a cooking appliance. A product to be cooked is prepared by means of at least one treatment device in at least one heatable cooking chamber that can in particular be closed by at least one cooking chamber door. At least one rapid cooling of the cooking chamber is carried out with at least one cooling device. In this case, at least one surface temperature of the food to be cooked is determined with at least one sensor device to control and preferably regulate the rapid cooling. The determined surface temperature is regulated with the cooling device to a given target surface temperature.

The method according to the invention offers many advantages. Monitoring the surface temperature of the food during rapid cooling offers a significant advantage. Because, as has been shown, whether the food continues to be cooked and the core temperature of a meat dish, for example, continues to rise, is much more dependent on the surface temperature of the food than on the previously used cooking space temperature. It is therefore particularly advantageous to regulate the ascertained surface temperature for rapid cooling to a predetermined target surface temperature. This ensures that the target temperature for rapid cooling and also for keeping warm is reached much more quickly and, at the same time, considerably better accuracy and better uniformity of the cooking result. Due to the improved controllability, overcooking or cooling of the food can be reliably prevented.

The surface temperature of the item to be cooked is preferably determined repeatedly and in particular continuously during rapid cooling. It is preferred that the determined surface temperature is repeatedly and in particular continuously regulated with the cooling device to the predefined setpoint surface temperature. This offers a particularly targeted rapid cooling and enables particularly tasty cooking results.

The target surface temperature is in particular stored in at least one operating program. It is also possible that the target surface temperature can be preset. For example, the target surface temperature can be preselected through a user input. For example, the target surface temperature is stored in a preselectable operating program or automatic program. This enables the target surface temperature to be adapted to the respective recipe, the food being cooked and / or the type of food being cooked or to other parameters of the automatic program. It is also possible for the target surface temperature to be preset using at least one auxiliary parameter. For example, the type of food to be cooked and / or a degree of cooking and / or at least one other preparation parameter can be specified as an auxiliary parameter. A corresponding target surface temperature is then assigned to such a specification. This enables optimal rapid cooling for many different recipes.

It is possible that the target surface temperature is set as a function of at least one parameter for the food to be cooked and preferably as a function of the type of food to be cooked. The parameter is queried in particular by at least one user input. The parameter can also be determined at least partially automatically by the cooking appliance using sensors. For example, the sensor device and in particular a camera device or an IR sensor can be used for this purpose. Significantly less expensive than an IR camera are IR sensors with a few, for example 16, pixels.

It is preferred that the surface temperature of the item to be cooked is detected without contact with the sensor device. Such a configuration is particularly convenient and user-friendly. The sensor device preferably comprises at least one camera device for detecting thermal radiation. In particular, the surface temperature of the item to be cooked is determined with such a camera device. In particular, the surface temperature of the item to be cooked is determined by evaluating the detected thermal radiation. For this purpose, the camera device can be designed as an infrared camera and / or thermal imaging camera. Such a camera device offers an inexpensive and at the same time reliable option for determining the surface temperature. It is also possible that the sensor device comprises at least one radiation thermometer and / or at least one other suitable thermal radiation sensor.

The surface temperature of the food to be cooked can also be recorded in contact with the food. In particular, the surface temperature is determined with at least one penetration thermometer. The surface temperature is preferably determined with a penetration thermometer with at least one measuring point near the surface. In particular, the penetration thermometer comprises several measuring points. At least one measuring point is in particular in the food. At least one measuring point is located outside of the food to be cooked. The surface temperature of the item to be cooked is then derived, in particular, from a temperature profile over the individual measuring points. It is also possible that at least one measuring point of the penetration thermometer is specifically arranged close to the surface. The temperature measured at this measuring point is then preferably viewed as the surface temperature of the item to be cooked. It is also possible for the sensor device to include at least one sensor which is arranged in contact with the surface of the item to be cooked and for the surface temperature to be detectable above it.

In an advantageous development it is provided that at least one internal temperature, preferably the core temperature, of the food to be cooked is determined. In particular, at least one penetration thermometer is used for this purpose. Rapid cooling is preferably started when the food to be cooked has reached a predefined setpoint internal temperature. The target internal temperature corresponds in particular to the desired core temperature at the time the food is finished. Since the completion time of the item to be cooked can be reliably identified from the core temperature, such a configuration allows rapid cooling to be started at an optimal point in time, for example directly after the completion time has been reached. The set internal temperature is in particular stored in at least one preselectable operating program and / or can be set using at least one user input.

It is possible and preferred for the target surface temperature for rapid cooling to be equal to a target internal temperature of the item to be cooked that is predetermined for the cooking process. It has proven to be very advantageous for the cooking result if, in automatic programs with a penetration thermometer, the target internal temperature for regulation with the penetration thermometer is the same as the target surface temperature for rapid cooling and preferably also for keeping warm. For example, the set internal temperature or core temperature of 60 ° C is provided for a piece of meat. Then, the target surface temperature for the rapid cooling is also preferably set to 60 ° C. It is possible that a deviation of a maximum of +/- 10 ° C and preferably a deviation of a maximum of +/- 5 ° C is provided between the target surface temperature and the target internal temperature. It is also possible that a higher deviation is provided between the target surface temperature and the target internal temperature. It is also possible for the target surface temperature for rapid cooling to be set independently of the target internal temperature.

In a particularly preferred embodiment, the surface temperature of the item to be cooked continues to be determined after rapid cooling. The determined surface temperature is preferably regulated with the treatment device to a given target surface temperature. Such a control can, for example, be used to keep the food warm. The regulation takes place in particular with at least one heating device of the treatment device. This is particularly advantageous since the surface temperature, which is already determined to regulate rapid cooling, can also be used for further regulation and, for example, for keeping warm. It is also possible for the determined surface temperature of the food to be cooked to be regulated to a predetermined target surface temperature with the treatment device during the cooking process. This is advantageous, for example, for specific cooking and / or browning. In such embodiments, an internal temperature and, in particular, the core temperature of the item to be cooked can additionally or alternatively be used, which is determined, for example, with a penetration thermometer.

The cooking appliance according to the invention is suitable and designed to be operated according to the method described above. In particular, the cooking appliance comprises the components described above for carrying out the method according to the invention.

When regulating the cooling device or rapid cooling, the surface temperature determined with the sensor device corresponds in particular to the actual surface temperature for regulation to the setpoint surface temperature. In particular, when the specified target surface temperature is reached, rapid cooling is ended. The rapid cooling takes place in particular at a defined point in time during the cooking process or at the end of the cooking process. The timing can be in a Be stored in the operating program and / or determined as a function of at least one sensor-recorded parameter. Rapid cooling can also be started manually. The treatment device and / or the cooling device and / or the sensor device are in particular operatively connected to one another and are preferably controlled by at least one control device.

Further advantages and features of the present invention emerge from the exemplary embodiments, which are explained below with reference to the accompanying figures.

Figur 1

eine rein schematische Darstellung eines erfindungsgemäßen Gargeräts in einer Vorderansicht;

Figur 2

eine rein schematische Skizze mit einem Kerntemperaturverlauf bei einem Schnellabkühlen nach dem Stand der Technik;

Figur 3

eine rein schematische Skizze mit einem Kerntemperaturverlauf bei einem Schnellabkühlen nach dem erfindungsgemäßen Verfahren; und

Figur 4

eine rein schematische Skizze mit einem Oberflächentemperaturverlauf bei einem Schnellabkühlen nach dem erfindungsgemäßen Verfahren.

In the figures show:

Figure 1

a purely schematic representation of a cooking device according to the invention in a front view;

Figure 2

a purely schematic sketch with a core temperature profile during rapid cooling according to the prior art;

Figure 3

a purely schematic sketch with a core temperature profile during rapid cooling according to the method according to the invention; and

Figure 4

a purely schematic sketch with a surface temperature profile during rapid cooling according to the method according to the invention.

In Figure 1 a cooking device 1 according to the invention is shown, which is designed here as an oven 100. The cooking appliance 1 is operated according to the method according to the invention. The cooking appliance 1 has a heatable cooking chamber 3 which can be closed by a cooking chamber door 13. The cooking device 1 is provided here as a built-in device. It can also be designed as a stand-alone device.

For the preparation of food or food, a treatment device 2 is provided, which is not visible in the view shown here in the cooking space 3 or behind the cooking space door 13. The treatment device 2 comprises a thermal heating device with several heating sources for heating the cooking space 3. For example, an upper heat, a lower heat, a hot air heat source and / or a grill heat source can be provided as heat sources. The oven 100 can be equipped with a steam cooking function and / or a microwave function.

The cooking appliance 1 here comprises a control device 103 for controlling or regulating appliance functions and operating states. Via the control device 103 are preselectable Operating settings and preferably also various automatic programs or program operating modes and other automatic functions can be executed. To this end, the control device 103 controls the treatment device 2 as a function of a preselected automatic program.

An operating device 101 is provided for operating the cooking appliance 1. For example, an operating mode or an automatic program or a program operating mode or other automatic functions can be selected and set via this. Further user inputs can also be made via the operating device 101 and, for example, menu control can be performed. The operating device 101 also includes a display device 102 via which user instructions and z. B. Prompts can be displayed. The operating device 101 can comprise operating elements and / or a touch-sensitive display device 102 or a touchscreen.

The cooking appliance 1 is equipped with a cooling device 4, not visible here, for rapid cooling of the cooking space 3. For example, the cooling device 4 includes an actuator, not shown here, which can automatically open and close the cooking chamber door 13. It can be provided that the air is actively blown out of the cooking space 3 through the opened door 13. It is also possible that the cooling device 4 rinses the cooking chamber 3 and thus cools it by means of its own fan device or one that is already provided for heating the cooking chamber 3. As a result of the rapid cooling, the cooking space 3 is cooled so quickly after the cooking process that the food does not have to be removed, but can remain in the cooking space 3 and, for example, be kept warm there without overcooking.

In order to have a particularly targeted control over the energy consumption of the food to be cooked during rapid cooling, the invention provides for direct control of the surface temperature of the food to be cooked for rapid cooling. For this purpose, the surface temperature is determined with a sensor device 5 during the cooking process and during rapid cooling. The surface temperature determined in this way is then regulated with the cooling device to a given target surface temperature, which z. B. is stored in an automatic program. Such a direct regulation is more meaningful, less error-prone and can be done in a shorter time. For rapid cooling, the invention offers a considerably faster and more controlled achievement of the target temperature and a considerably better accuracy and at the same time a considerably better uniformity of the cooking result.

The sensor device 5 here comprises a camera device 15 for detecting thermal radiation, which is designed, for example, as an infrared camera or thermal imaging camera is. The camera device 15 is not visible here in the interior of the cooking space 3 above the food. In an embodiment not shown here, the surface temperature can also be determined by means of a suitable penetration thermometer.

It has proven to be particularly advantageous to adapt the target surface temperature of the item to be cooked for rapid cooling to the target core temperature of the item to be cooked, or to equate it with this. This allows the cooking process to be stopped particularly quickly and reliably. This is because the surface temperature of the food is usually higher than the core temperature. How quickly and whether the core of the item to be cooked heats up further after rapid cooling is therefore essentially determined by the temperature difference between the surface temperature and the core temperature of the item to be cooked. As a result, the cooking process can be stopped particularly quickly if, during rapid cooling, the surface of the food to be cooked is regulated or cooled to the target core temperature as quickly as possible. In the case of automatic programs with a roasting thermometer, it is also advantageous to use the target core temperature directly as the keeping temperature.

The Figure 2 shows a sketch in which a core temperature profile of a product to be cooked, here for example roast beef, was determined and applied during a cooking process. For this purpose, the core temperature 200 is plotted against the time 201. Here, at the end of the cooking process, rapid cooling was carried out according to the prior art, in which the cooking space temperature is used for regulation.

For preparation, the food was cooked to a core temperature of 60 ° C using a roasting thermometer. As soon as this core temperature has been reached, the rapid cooling function with automatic door opening is started and the cooking space 3 is heated to e.g. B. 70 ° C cooled to prevent overcooking when remaining in the oven 3. It is also possible to start at a lower temperature (e.g. 45 ° C) and only jump to 70 ° C when it is reached, which leads to a shorter overall cooling time for the system. The time dt1 is required to cool down the food and the cooking space 3 and leads to an unfavorable increase in the core temperature of dT1. For food, e.g. B. pastries that are cooked to just before 100 ° C, this additional energy consumption means an undesirable increase in browning or z. B. further drying out.

The Figure 3 shows the sketch of another core temperature profile in which the core temperature 200 was plotted over time 201. To determine the core temperature, the same conditions and the same food as for the core temperature curve were used here Figure 2 used. However, the rapid cooling takes place here according to the invention Method or with the inventive cooking device 1. For this purpose, the temperature of the food on the surface is used for temperature control during rapid cooling.

The food is cooked to a core temperature of 60 ° C using a roasting thermometer. As soon as this core temperature is reached, the rapid cooling function with automatic door opening is started and the cooking space 3 is brought to a target food temperature of z. B. 70 ° C controlled cooled. During this cooling process, the surface temperature of the food (OTLM) is measured continuously. For the regulation is z. B. a PI or PID controller or other control instruments. Since the OTLM follows the cooking cabinet temperature (BMT) in time, the BMT is also the target temperature of z. B. go well below 70 ° C in order to reach the target temperature Tz in the shortest possible time. The time dt2 required for this is shorter than that of the indirectly controlled process dt1, so that the overcooking dT2 <dT1 is also lower. In this direct way of regulation, you can significantly reduce overcooking and the additional energy input, as in the Fig. 4 clearly visible.

In the Figure 4 a surface temperature 202 is plotted over time 201. The curve 203 shown here of the surface temperature 202 in the with reference to FIG Figure 2 described rapid cooling recorded. The curve 203 thus shows the surface temperature 202 of the food to be cooked during rapid cooling with regulation to the cooking space temperature according to the prior art. The course 204 of the surface temperature 202 was, however, with reference to FIG Figure 3 described rapid cooling according to the invention detected. The curve 204 thus corresponds to the surface temperature 202 during the rapid cooling according to the invention with regulation based on the surface temperature of the item to be cooked. The curves 203, 204 clearly show that the regulation of the surface temperature reliably prevents overcooking and undesired additional energy input into the food after rapid cooling.

If control is based on the OTLM (course 204), the target temperature Tz is reached faster than if control is based on the BMT (course 203). In addition, the deviations between BMT and OTLM depend on the device and the load, so that parameterization attempts are helpful to improve the correlation. Another important advantage is that in the method according to the invention, meaningful temperatures can be selected specifically as the target temperature for rapid cooling. If z. For example, if a roast beef is to be cooked to a core temperature of 60 ° C, 60 ° C should also be used as the target temperature for quick cooling and keeping warm. As long as the surface and core temperature of the food are the same, there is no flow of energy and the food is overcooked or cooled.

It has proven to be a disadvantageous simplification to always cool down to the same oven temperature or to use it for keeping warm. The optimal holding temperature is usually dependent on the food and, in addition to overcooking and cooling, also influences the moisture content or drying out and the visual impression when serving. It is therefore not only important to reach this target temperature quickly, but also to choose sensibly for each food. For this purpose, in the invention, for. B. an assignment of the type of food and the target surface temperature of the food is stored.

List of reference symbols

1

Cooking appliance

2

Treatment facility

3

Cooking space

4th

Cooling device

5

Sensor device

13

Oven door

15th

Camera setup

100

oven

101

Control device

102

Display device

103

Control device

200

Core temperature

201

time

202

Surface temperature

203

course

204

course

Claims (10)

A method for operating a cooking appliance (1), wherein the food to be cooked is prepared by means of at least one treatment device (2) in at least one heatable cooking space (3) that can be closed by at least one cooking space door (13), and with at least one cooling device (4) at least one rapid cooling the cooking space (3) takes place,
characterized,
that to control the rapid cooling, a surface temperature of the item to be cooked is determined with at least one sensor device (5) and that the determined surface temperature is regulated to a predetermined target surface temperature with the cooling device (4). Method according to the preceding claim, characterized in that the surface temperature is determined repeatedly and in particular continuously during the rapid cooling. Method according to one of the preceding claims, characterized in that the target surface temperature is stored in at least one operating program and / or that the target surface temperature can be preset. Method according to one of the preceding claims, characterized in that the target surface temperature is set as a function of a parameter for the food and preferably the type of food. Method according to one of the preceding claims, characterized in that the surface temperature of the food to be cooked is detected without contact with the sensor device (5) and is preferably determined with at least one camera device (15) or an IR sensor for detecting thermal radiation. Method according to one of the preceding claims, characterized in that the surface temperature of the food to be cooked is determined with at least one penetration thermometer with at least one measuring point near the surface. Method according to one of the preceding claims, characterized in that an internal temperature of the food to be cooked is determined, in particular with at least one Penetration thermometer, and that rapid cooling is started when the food has reached a specified target internal temperature. Method according to one of the preceding claims, characterized in that the target surface temperature for rapid cooling is equal to a target internal temperature of the food to be cooked that is predetermined for the cooking process. The method according to any one of the preceding claims, characterized in that after rapid cooling, the surface temperature of the food is further determined and that the determined surface temperature is regulated with the treatment device (2) to a predetermined target surface temperature, so that, for. B. a targeted warming takes place. Cooking appliance (1), suitable and designed to be operated according to the method according to one of the preceding claims.

Images