Related Technical Field:

The present invention relates to a method for controlling the energy consumption of an oven during baking.

The invention relates to a novel method for deactivating components such as cooling fan affecting negatively the heating course, turbo fan increasing the energy consumption of the oven as well as lamps in certain periods so as to reduce the energy consumption and improve the energy efficiency in the course of baking in built-in ovens.

The invention, particularly, relates a method for turning on/off heating elements comprised of a primary baking section, a main baking section and a stable baking section, wherein they are operated so as to optimize the energy consumption, when the target temperature determined by a user is reached.

State of the Art

A conventional baking oven comprises a series of heating elements arranged in or near or over an oven baking chamber. In general, the baking ovens comprise at least an annular heating element, an upper heating element, a lower heating element, a cooling fan, turbo fan and lamp.

In household type of ovens, it constitutes nowadays a great importance to take precautions towards keeping the energy consumption values at lower levels and providing energy savings in oven, in which electrical heaters are employed. Ovens comprises elements, whose lid and walls' insulating properties are improved, and which reflect heat in the oven. Different types of heating elements may be employed in the oven to allow heater in the oven to emit the heat. The energy consumption in ovens may vary according to how long heating elements are kept on in the course of baking. Heating elements are turned on/off my means of the thermostat for certain periods during or at the end of the baking process, thereby ensuring that the heat stored in the oven is to be employed so as to use the energy efficiently.

Baking cycle in built-in ovens providing fan-based baking is initialized upon the activation of heaters and fans and is continued along with the operation of heating elements depending on the thermostat, when the temperature of oven reaches the determined target temperature. In static/grill ovens without a fan support, the cycle is yet continued by only the heat. In ovens providing fan-supported baking, when the oven reaches the target temperature determined by a user, heating elements start to de/activate depending on the thermostat. Meanwhile, cooling and oven-chamber turbo fan continue to operate constantly. Oven heating elements are controlled by the thermostat. That only the thermostat provides controlling causes to consume more energy than the energy that is to be consumed during the cycle. In modes designed for energy savings, if operation periods of the heater is kept low, desired baking quality cannot be ensured and the baking time takes longer.

Cooling fan employed in ovens discharges efficiently the moisture and vapor occurring during the baking process as well as ensures the baking process to be completed. The cooling fan required for an efficient baking must be kept active constantly during the baking process in ovens. However, the desired heated air occurring in the baking chamber is discharged to the outside together with the vapor due to the cooling fan employed. This causes a certain amount of loss of the heat energy obtained in the oven due to the cooling fan. Oven causes more energy consumption so as to compensate for the lost heat energy in its chamber with its general operation principle.

Ovens, generally, are heated up to desired baking temperatures in advance before foods positioned therein to be baked are located. The energy and passed time used in the pre-heating process of an oven cause an energy consumption increase.

The energy efficiency in built-in ovens is measured by means of a specific method according to Standard EN 60350-1 (House-hold electric cooking appliances; Method for measuring furnaces, ovens, vapor ovens and grills' performance) . Purpose of the test is to determine and measure the energy consumption and time required to heat the load, which is a water-logged brick simulating the thermal property and water content of foods.

A number of studies have been conducted so as to reduce the energy consumption in oven, wherein there are experimental studies presenting positive solutions resulting in that the insulation thickness of the oven and the number of glasses in the front lid are increased. Although results of those studies in question are in a satisfying state such that they reduce the energy consumption, they could not be implemented in the industry due to material costs employed therein.

In the course of the baking process, the heating elements and cooling fan are activated/deactivated according to a per- determined algorithmic schema. There are a large number of schemas to activate/deactivate the heating elements and fan. According to those types of schemas, one or more heating elements are activated simultaneously in an alternative and/or serial manner. In addition to this, many methods so as to activate/deactivate the heating elements and fan result in a relative more energy consumption. The patent document numbered "2008/06605" has been examined within the result of the preliminary survey conducted in the state of the art. The abstract section subjected to the application states that "the invention relates to an electric oven comprising an infrared resistance positioned at its upper portion so as to reduce the baking time, while allowing the energy consumed in the grill mode to be used more efficiently".

The patent document numbered "2016/00456" has been examined within the result of the preliminary survey conducted in the state of the art. The abstract section subjected to the application stated that "A system for aiming to keep the food product in the oven cold until starting the cooking function and when the oven is on the cooking mode, supporting the heating by means of a low power consumption by functioning as an auxiliary heater and thereby providing the energy efficiency".

The patent document numbered "EP3051210" has been examined within the result of the preliminary survey conducted in the state of the art. In the invention subjected to the application, the cooking process comprises a pre-heating phase and arrangement step. The pre-heating phase performs that the oven reaches up to desired temperature, and the upper heater and annular heater operate alternately while the fan is on. There is no information on the operation of the cooling fan therein.

The patent document numbered "US2009250451" has been examined within the result of the preliminary survey conducted in the state of the art. In the invention subjected to the application, it is mentioned that the fan uses heating cycles so as to adjust the temperature changes until it is reached to the heating temperature at the pre-heating section and the lower heater is active meanwhile.

The patent document numbered "WO2008118639" has been examined within the result of the preliminary survey conducted in the state of the art. In the invention subjected to the application, the upper heating and lower heating elements may operate alternately by means of controller, while the conventional baking element is active. Considering the operation rate of these element, it can be seen that the conventional cooking baking element is the most active element. The fan operates in every moment in which the conventional baking element is active. However, this system applies for only the pre-heating step. There is a circuit preventing the upper heating and lower heating elements from operating together and a removeable panel turning off the lower heating element.

In algorithms of built-in ovens performing fan-supported baking, which are used in the state of art, the time in which the baking cycle reaches up to the target temperature determined by a user too long along with the negative effect of the cooling fan on the heating. Furthermore, that the oven-chamber fan and lamp operate constantly during the cycle increases the energy consumption of the oven.

When the oven reaches the target, temperature determined by a user, heating elements start to de/activate depending on the thermostat. Meanwhile, cooling and oven-chamber turbo fan continue to operate constantly. This period is too long along with the negative effect of the cooling fan on the heating time. Furthermore, that the oven-chamber fan and lamp operate constantly during the cycle increases the energy consumption of the oven.

Oven heating elements are controlled by the thermostat. That only the thermostat provides controlling causes to consume more energy than the energy that is to be consumed during the cycle.

As a result, due to the aforementioned drawbacks and insufficiency of the existing solutions regarding the subject matter, the need for a development in the related technical field has arisen.

Obj ect of the Invention :

The most important object of the invention is to reduce the energy consumption during a baking function and thereby to increase the energy efficiency. To this end, it is surveyed how different heating algorithms affect the energy efficiency and the most appropriate heating algorithm is determined so as to reduce the energy consumption and thereby to increase the energy efficiency.

Another important object of the invention is to ensure that the oven is heated in the fastest manner and reaches up to the target temperature through deactivating the cooling and (if present) oven-chamber (turbo) fan in the primary baking section. Therefore, there will be decrease in the energy consumption in the primary heating section because the time of reaching up to the target temperature is shorter.

Further object of the invention is to ensure more energy saving by means of preferably turning off the oven lamp because the time of the primary baking section is shorter.

Further object of the invention is to simulate different heating and operating types for every adjustment temperature in accordance with the definition of "static" or "Fan-supported" functions in the standard EN60350-1 so as to reduce the energy consumption and determine the most appropriate algorithm together with the time of the oven reaching up to the target temperature determined by a user.

The structural and characteristic aspects and all the advantages of the present invention will be more clearly understood by means of following figures and the detailed description written with references to these figures. Therefore, while making an evaluation, these figures and the detailed description should be taken into account.

Description of the Invention:

In the method developed so as to increase the energy efficiency according to the present invention, it is ensured that the baking process is performed in three steps in a baking oven comprising at least an upper and/or annular (Turbo) heating element, a lower heating element, a cooling fan, a lamp and a turbo fan (if present) .

It is ensured by the invention to increase the energy efficiency by means of a control unit activating/deactivating different heating elements for every adjustment temperature according to the definition of related functions so as to reduce the energy consumption and determine the most appropriate algorithm together with the time of the oven reaching up to the target temperature (T _set ) determined by a user.

In the inventive method, the oven is comprised of a three-phase baking section. These sections are; a primary baking section (instant heating) in which the oven is heated in the fastest manner and reaches up to the target temperature (T _set ) in a minimum time, a main baking section in which the energy saving is performed at a maximum level after reaching up to the desired target temperature (T _set ) and a stable baking section after reaching up to the desired temperature in the brick center at the main baking section.

In the implementation of the invention, the activation/deactivation time of the baking oven elements to be used as active/passive ( activation/deactivation) and the target temperature are determined by the control unit by using a functional relation set in advance and the instruction in question are applied by switching elements comprised by every oven element. The activation and deactivation time of baking oven elements are determined in accordance with the desired target temperature.

In the primary baking section, only the upper or annular (turbo) heating element of the baking oven elements or any two of the lower heating elements are kept constantly active by the control unit. While the lamp may be active alternatively, the cooling fan and turbo fan (if present) are kept passive by the control unit in this section. Therefore, an instant heating is provided due to the fact that the oven chamber reaches up to the desired target temperature ( _set ) in the fastest manner.

The control unit in the oven ensures that the oven is heated in the fastest manner and reaches up to the target temperature. It is ensured that the cooling and turbo fan is kept passive with the help of switching elements existing separately for each cooling and turbo fan on the control unit. In this section, only heating elements are active, however the cooling and turbo fans are passive. It takes shorter for the oven to reach up to the target temperature because it ensured that there is constantly a temperature increase and is only two heating elements being active, thereby causing decrease in the energy consumption in the primary heating section. In addition to this, since the time of the primary baking section is short, the upper heating element or annular heating element or the lower heater is activated alternative to the lamp through the heating step in the primary baking section. Because the oven lamp is deactivated in the primary baking section, more than targeted energy saving can be achieved .

When the oven reaches up to the target temperature determined by a user, the main baking section starts to operate. In the main baking section, in order to decrease energy consumption; only one of the upper or annular (turbo) heating elements and the lamp and preferably the cooling fan and the turbo fan are kept active by the control unit, wherein the lower heating element is kept passive. Depending on which one of the upper or annular heating elements is preferred, the cooling fan and/or turbo fan is activated by the control unit together with the activation of said heating element. The heating element employed in the main baking section is active/passive in parallel with the cooling fan and/or turbo fan.

The heating element operating in the main baking section may be an upper resistance or annular (turbo) resistance based on the oven property.

In the main baking section, considering the baking performance, so as to optimize the energy consumption, the on/off time of the heating element (upper or annular heater) and the cooling and/or turbo fan being active/passive in parallel with the heating element chosen according to the oven type in the main baking section is calculated according to Equation 1.

3T _on £ T _off £ 5T _on (Equation 1)

T _on : activation time

T _off : deactivation time

In determining their activation and deactivation times; structural factors such as oven-chamber volume, resistance power values, fan motor power values, interior structure of the oven firebox are taken into consideration.

In the main baking section, when the brick center temperature reaches up to the desired value, the stable baking section is initialized. In this section, until the oven reaches up to the target temperature chosen by a user, the turbo fan is activated alternatively, while the upper heater and/or annular heater and the cooling fan are adjusted by the control element in a constantly-active manner. When it is reached up to the target temperature (T _set ) , the upper heater and/or annular heater and the turbo fan, if active, are operated according to the thermostat-controlled on-off instructions and the oven is maintained at the target temperature. In this section, while the cooling fan is constantly kept active, the lower heater is in a passive state.

The baking time and energy consumption are decreased by means of the inventive 3-phase baking function. The method can be controlled by an electronic control element comprised by every oven element or a computer program or a combination thereof.

In the method comprising at least a three-phase baking process, the baking process is performed by way of activating/deactivating every one of the oven elements through the control unit throughout the process. In the beginning of the baking process, a target temperature defined by a user is defined. The primary baking section being a first phase is carried out at a temperature defined by a user in the beginning of baking, wherein the main baking section being a second phase is carried out at a second temperature that is lower than the temperature in the primary baking section and is calculated by the control unit according to the temperature in the primary baking section, wherein the stable baking section being a third phase carried out at a third temperature that is calculated by the control unit according to the temperature in the primary baking section and is greater than the second temperatures and equals to the targeted temperature value.

Thanks to the operation of only one of the upper or annular heating elements and the lamp, the lower heating element being passive, and the controlled operation of the cooling fan and/or turbo fan according to the operation of the heating elements, which is disclosed in Equation 1, because less power is transmitted to only one heating element, it is possible to continue to bake at a stable temperature so as to improve the baking quality in the third phase and to decrease the energy consumption at every three sections through the completion of the minimum time by means of the instant heating in the primary baking section.

The control unit comprises switching elements existing separately for an upper heating element or annular (turbo) heating element, a lower heating element, a cooling fan, a turbo fan and a lamp, and controlling whether each of said oven elements is active/passive and their active/passive time.

Due to the baking function comprising the inventive three section, the time of the primary baking section (instant heating) , in which the baking process is carried out at a higher temperature, gets shorter and the time of the main baking section, in which the baking process is carried out at a lower temperature compared to the temperature of the primary baking section. As a result, the energy consumption of oven will be decreased .