WO2023128907A1

WO2023128907A1 - An oven temperature control method

Info

Publication number: WO2023128907A1
Application number: PCT/TR2021/051639
Authority: WO
Inventors: Fatih ZUNGOR; Metin OZTURK; Mustafa BOZTAS; Zubeyde GONULLU
Original assignee: Mamur Teknoloji Sistemleri Sanayi AS
Current assignee: Mamur Teknoloji Sistemleri Sanayi AS
Priority date: 2021-12-30
Filing date: 2021-12-30
Publication date: 2023-07-06
Anticipated expiration: 2024-06-30
Also published as: EP4457463A4; EP4457463A1

Abstract

Performing a heating operation (41) in a cooking chamber (12) with one or more electrically operable heating elements (32, 34); opening and closing (66) of a mechanical thermostat (26) in a band around the set temperature value during the heating operation (41); switching (68) the heating elements (32, 34) on and off with a mechanically switched switch (30) connected (304) by being controlled from the mechanical thermostat (26); an electronic control connected on a temperature control system (11) that performs the heating process (41), which includes controlling (70) the heating elements (32, 34) with a mechanical thermostat (26) and providing (72) heating control according to the set temperature value. the unit (18) receiving feedback (44) from an oven door (16); It is related to an oven temperature control method (72), which provides heating control by controlling (66) of the mechanical thermostat, which provides the feedback (44) to open and close (68) the heating elements (32, 34).

Description

AN OVEN TEMPERATURE CONTROL METHOD

TECHNICAL FIELD

The invention relates to a method for controlling the temperature of a domestic oven, which determines the most accurate duration for turning on and off the heating element and controls the on/off control of the heating element by using an electronic control unit to regulate the operation of the mechanical thermostat.

BACKGROUND OF THE ART

A domestic oven is a device that uses energy sources to cook, melt, reheat, or dry a substance within a closed space. There are many types of ovens, ranging from those used for cooking food in daily life to those used in industry. Some main types of ovens include drying ovens, home ovens, pottery kilns, coal production ovens, blast ovens, industrial kitchen ovens, bread ovens, and so on.

In the literature, efforts are being made to improve oven performance in terms of more efficient use of energy. The most critical factors determining oven performance are energy consumption and cooking quality. The use of a mechanical thermostat that provides temperature control to reduce energy consumption and a timer card that sets a duration of time can be employed. Mechanical thermostats operate by turning on and off within a set temperature range. Generally, ovens that use this device are not controlled by electronic products. Additionally, constantly turning on and off within a temperature range can negatively affect the cooking quality of the oven. Solutions for energy-efficient cooking in ovens while maintaining cooking quality are being developed in the literature.

EP3250002 discloses a domestic cooking device. The domestic cooking device includes several electric heating elements that heat a cooking compartment, a mechanically switched mode switch that opens and closes at least one heating element depending on a set operating mode and a mechanical thermostat that controls the connected heating element according to the selected operating mode. Here, there is at least one additional consumer that can be switched on and off by an electronic circuit relay and an operating mode switch in the heating circuit, where the thermostat is electrically connected in series with the heating elements of the cooking compartment, and the electronic circuit and the additional consumer. BRIEF DESCRIPTION OF THE INVENTION

The object of the invention is to develop an oven temperature control method that increases energy efficiency for ovens by controlling the mechanical thermostat with an electronic control unit.

In order to achieve the above objective, The invention relates to a method for controlling the temperature of an oven comprising heating a cooking chamber with one or more electrically operated heating elements; opening and closing a mechanical thermostat within a band around a set temperature value during heating; controlling the on/off state of the heating elements with a mechanically switched switch connected to the mechanical thermostat; controlling the heating according to the set temperature value by controlling the heating elements with the mechanical thermostat and providing heating control characterized by comprising the steps of receiving feedback from an oven door by an electronic control unit connected to a temperature control system that performs the heating process, and adjust the heating by controlling the mechanical thermostat to enable feedback and heating control opens and closes the heating elements. In this way, the mechanical thermostat is controlled via an electronic control unit, activated without the mechanical thermostat being activated. Here, the electronic control unit can also be controlled by a knob.

In a preferred embodiment of the invention, the feedback received from the oven door has an open state or a closed state of the oven door. In this way, an opening status of the oven door can be followed. In addition, depending on the opening and closing state of the oven door, the heating element can be turned on and off.

In a preferred embodiment of the invention, a first time, a second time, and a third time are recorded in the controller when the mechanical thermostat operates in the closed state of the oven door. As a result, the electronic control unit calculates the opening and closing time of the heating process as small time differences by receiving feedback and controls the heating process's opening and closing by controlling the mechanical thermostat's operation control in a way that the mechanical switch operates before the heating process done by the mechanical thermostat.

In a preferred application of the invention, in the open state of the oven door, the first-time, second-time, and third-time records are deleted in the controller, and the heating process is interrupted. In this way, the heating process is interrupted when the oven door is open to save energy.

A preferred embodiment of the invention is an oven temperature control method, comprising activating a predetermined algorithm from a controller connected to the electronic control unit for providing electric current; defining an opening time and a closing time of a heating process based on a first-time, a second time, and a third-time record and a hysteresis time that varies depending on the feedback received from the mechanical thermostat after the activation of the algorithm; providing heating control by the defined opening time and closing time; and terminating the algorithm if the inequality condition is not met. In this way, the electronic control unit, which is activated before the mechanical thermostat and controls the operation of the mechanical thermostat, also provides energy-efficient control by reducing the set temperature value of the mechanical thermostat. In other words, thanks to the electronic control unit, the oven saves energy without significantly reducing the cooking quality.

In a preferred application of the invention, the opening and closing of heating elements are provided on a relay on which electrical switching is electrically connected in the electronic control unit in accordance with the calculated opening and closing times and the electrical transmission from the mechanical thermostat to the electronic control unit. In this way, current control can be provided in the electronic control unit with the relay on the electronic control unit. In addition, the electronic control unit can perform a calculation process per the algorithm and work as a timer.

In a preferred application of the invention, the operation of a limit thermostat that is electrically connected to the temperature control system and measures heating during the heating process to stop working at a predetermined specific temperature threshold value. In this way, malfunctions due to overheating in the temperature control system can be prevented.

BRIEF DESCRIPTION OF THE FIGURES

Figure 1 is a general perspective view of the oven.

Figure 2 is the schematic representation of the oven temperature control system.

Figure 3 is the schematic representation of the electronic control unit in the oven temperature control system. Figure 4 is the analysis graph of the system providing oven temperature control.

Figure 5 is a schematic illustration of an oven temperature control method according to the invention.

Figure 6 is the analysis graph of an operating state of an oven temperature control method according to the invention.

Figure 7 is the continuation of the analysis graph illustration of an operating state of an oven temperature control method of the invention.

DETAILED DESCRIPTION OF THE INVENTION

In this detailed explanation, the invention is explained without any limitation and only concerning examples to better explain the subject matter.

In Figure 1 , oven connections are shown from a general perspective view. There is a muffle (13) that protects the oven (10) from external influences and supports the oven parts to be held together. Inside a cavity that opens inward from the front wall of the muffle (13), there is a cooking chamber (12) surrounded by the muffle (13). A front wall (14) in the frame shape at the opening of the sleeve (13) is provided on the outer wall of the cooking chamber (12). An oven door (16) is pivoted to the edge of the front wall (14) with a hinge so as to cover the front wall. There is a first heating element (32) and a second heating element (34) inside the cooking chamber (12) that are heated by an electrical connection to ensure the cooking of the food. n Figure 2, the system that provides temperature control for the oven is shown schematically. Feedback is provided from a connection line (162) in the oven door (16) to an electronic control unit (18) in the oven temperature control system (11 ). Feedback to the electronic control unit (18) is also provided from the output pin (264) of a mechanical thermostat (26) via a feedback line (182) from a thermostat coming from the mechanical thermostat (26). Here, the mechanical thermostat (26) performs an on-off operation within a band around a set temperature value. The on-off operation is performed by controlling the first and second heating elements (32, 34) through electrical cutting or transmission. A connection is made from the output pin of the mechanical thermostat (264) to the conductive wire connection pin (282) of a lamp (28). The negative wire connection pin (284) of the lamp (28) is connected to a negative wire connection end (384) of a first terminal (38) via a negative conductive wire (22). The grounding wire connection end (386) of the first terminal (38) is connected to the grounding wire connection end (406) of a second terminal (40). Thus, the lamp (28) is kept in working condition, and the inside of the cooking chamber (12) is illuminated. The terminals (38, 40) ensure the connection of connection lines (20, 22, 24) to each other in a working principle towards one another in two or more parts. A connection is made from a thermostat connection line (183) on the electronic control unit (18) to the input pin (262) located on the mechanical thermostat (26) through the first terminal (38). Thus, energy flow is provided from the electronic control unit (18) to the mechanical thermostat (26) and the operation of the mechanical thermostat (26) is controlled by the connections (182, 183, 262, 264) made. A connection is made from an external conductive wire connection line (184) on the electronic control unit (18) to a positive conductive wire (20) of the temperature control system (11). In addition, there is a negative conductive wire (22) and a grounding wire (24) on the temperature control system (11). There is also a mechanically switched switch (30) connected (304) in a manner controlled by the mechanical thermostat (26) to turn on or off the cooking chamber heating element (32, 34) in the temperature control system (11 ). The switch (30) can be in transmission or cutting mode with its first leg connection pin (301 ) and its sixth leg connection pin (306) connected to each other. The switch (30) can be in transmission or cutting mode with its second leg connection pin (302) and its fifth leg connection pin (305) connected to each other. In addition, the switch (30) can be in transmission or cutting mode with its third leg connection pin (303) and its fourth leg connection pin (304) connected to each other. A second-leg connection pin (302) and a fifthleg connection pin (305) of the switch (30) provide a mutual connection for transmission or cutting. In addition, a mutual connection between a third-leg connection pin (303) and a fourth-leg connection pin (304) of the switch (30) for transmission or cutting. The first leg connection pin (301 ) of the switch (30) is connected to a conductor line connection pin (322) of the first heater (32); the second leg connection pin (302) is connected to a conductor line connection pin (342) of the second heater (34); the third leg connection pin (303) is connected to an external conductor connection line end (402) of the second terminal (40) and is connected to the external conductor connection line (184) of the electronic control unit (18) via a positive conductor line (20). Additionally, the fourth leg connection pin (304) of the switch (30) is connected to an output pin (364) of a limit thermostat (36), and the fifth leg connection pin (305) is connected to an output pin (264) of a mechanical thermostat. Here, the limit thermostat (36) cuts off the electrical transmission and stops operation in case of overheating during cooking. The sixth leg connection pin (306) has no connection to any line. The negative line connection pin (324) of the first heater (32) and the negative line connection end (404) of the second terminal (40) are connected to each other. Furthermore, the negative line connection pin (324) of the first heater (32) is connected to a negative line connection pin (344) of the second heater (34) via a negative conductor line (22). The grounding line pin (326) of the first heater (32) is unconnected. The grounding line pin (346) of the second heater (34) is also unconnected. The input pin (362) of the limit thermostat (36) is connected to the external conductor line connection end (382) of the first terminal (38) via the positive conductor line (20). Additionally, the negative line connection end (404) of the second terminal (40) is connected to the negative line connection end (384) of the first terminal (38).

In Figure 3, the electronic control unit of the system that controls the oven temperature is shown schematically. The connection lines (181 , 182, 183, 184) of the electronic control unit (18) mentioned in Figure 2 are shown here. Additionally, during cooking in the cooking chamber (12), the on/off time of the heating element can be calculated by a controller (185) located on the electronic control unit (18) that receives feedback from the mechanical thermostat (26) and the oven door (16). The controller (185) contains an algorithm that calculates the on/off time. The electronic control unit (18) also acts as a unit that interrupts or conducts electrical transmission to heaters (32, 34) by the on/off times calculated by the controller (185), as it controls the operation of the mechanical thermostat (26). The controller

(185) works both as a calculator and as a timer. The electrical transmission and control of the heating elements (32, 34) are provided through a mechanical switch (30). The operation is arranged as follows: feedback is received, the optimal on/off times are calculated, the electronic control unit (18) controls the mechanical thermostat (26) connected to the heaters (32, 34) via the switch (30) to ensure the control of the heating elements (32, 34) as hysteresis and the heating on/off cycles are performed. The electronic control unit (18) reduces the temperature value band set by the mechanical thermostat (26) and thus provides energy efficiency in the oven (10) without compromising cooking quality. Additionally, a relay

(186) on the electronic control unit (18) provides current switching.

Figure 4 shows the analysis graph of the system providing oven temperature control. In the analysis graph given here, a power comparison was made with an oven center. According to the analysis graph, it has been determined that the electronic control unit (18) and the system (11) control the energy by acting before the mechanical thermostat (26) when necessary, and as a result, the oven (10) works more efficiently, that is, provides energy efficiency.

The invention subject of a cooking temperature control method is shown schematically in Figure 5. During the heating process (41 ) in the cooking chamber (12), feedback (182) from a mechanical thermostat (26) is applied to the controller (185) through a predefined algorithm (42). Upon execution of the algorithm (42), the duration of the thermostat's active periods, which consist of three consecutive time periods during the operation of the mechanical thermostat (26), is recorded as a first time period (48), a second time period (52), and a third time period (56), while the oven door remains closed. The first time period (48) is denoted as T1 , the second time period (52) is designated as T2, and the third time period (56) is designated as T3. These recorded time periods (48) (52) (56) are valid not only for the first three time periods but also for the three consecutive time periods taken during the heating process. The recorded T1 , T2, and T3 values (50) (54) (58) are also stored in the controller (60). Subsequently, feedback (44) is received through the oven door to monitor its status (45) during the heating process (41). Based on the feedback (44), the oven door control (45) is performed, and the status of the door (16) being open or closed (46) (74) is determined. If the oven door is found to be open (74), the previously recorded time periods (50) (54) (58) in the controller (60) are cleared (78), and the heating process is terminated. Afterwards, the oven door control (45) is repeatedly performed within a certain period, and if the oven door is found to be open (74) again, the recorded time periods (50) (54) (58) in the controller (60) are cleared (78) again, and the process is repeated until the door is found to be continuously closed (46). If the closed state (46) of the oven door is detected after the oven door open state (74) is detected and the oven door control (45) is performed again, recording of time records (50) (54) (58) is ensured on the controller (60). In the oven door control (45), the closed door state (46) detections are repeated continuously to record the time records (50) (54) (58) of when the mechanical thermostat operates on the controller (60). Then, a time record check (61) is performed to determine if there are three consecutive time records (50) (54) (58) recorded in the controller during the closed door state (46). If there are no at least three consecutive time records (50) (54) (58) recorded (60) on the controller (185), the process returns to recording the operating times of the mechanical thermostat (26) (60). If there are at least three consecutive time records (50) (54) (58) recorded (60) on the controller, a hysteresis time interval (A (51 )) that varies depending on the first time, second time, third time records (50, 54, 58) and the first time record (T1) is checked against a predetermined inequality condition formula to see if the inequality is satisfied (84) (86). Information about the pre-determined inequality condition for T1 , T2, T3 and AT(T1 ) (50, 51 , 54, 58) time values is provided below;

,T1 : Duration of the 1st time interval when the thermostat is active

,T2: Duration of the 2nd time interval when the thermostat is active

,T3: Duration of the 3rd time interval when the thermostat is active

,AT(T 1 ): A different hysteresis time depending on the T 1 time Whether the inequality situation is provided or not (84) (86)

is checked with the inequality formula.

After the inequality condition is not satisfied (86), the algorithm activated by the controller (185) is terminated (43). In other words, heating control (72) can be performed by opening and closing the heating elements (68) and controlling the heating elements (70) by ensuring the opening and closing (66) of the mechanical thermostat (26), and the algorithm is terminated (43). When the inequality condition is satisfied (84), a opening time (TON(T1 )) (62) and a closing time (TOFF (T1 )) (64) are defined for the relay (186) according to the T1 time (48), and approximately the heating element control (70) is provided by the relay (186) based on the defined times (62, 64). While the relay (186) provides this heating element control (70), oven door checks (45) are made according to the feedback received (182). In other words, oven door checks (45) are made in accordance with the feedback received (182) from the door during heating process (41 ) and heating control (72). By detecting the closed door state (46) again through oven door checks (45), the maximum open-close repetition time control (88) is performed, and thus, the opening-closing operation (68) can be performed not only when the door is opened (74) but also when the maximum opening-closing repetition is reached (90). If the maximum opening-closing repetition has not been reached (92), the flow process (42) of the algorithm continues by returning to the step of starting the relay's (186) heating element control (70). When the maximum repetition number (90) is reached, heating control (72) can be performed by opening and closing the heating elements (68) and controlling the heating elements (70) by ensuring the opening and closing (66) of the mechanical thermostat (26). If the open door status (74) is detected again, heating element control (70) is provided again with the mechanical thermostat (26) and heating control (72) can be performed. In the temperature control method of the oven according to the present invention, the algorithm (42) activated takes feedback from the output of the mechanical thermostat (26) and the oven door (182), and finds the most accurate method (the most accurate on/off time) while ensuring maximum efficiency without significantly reducing cooking quality.

Figure 6 and Figure 7 show an analysis graph for an operating condition of the temperature control method of the oven according to the present invention. In Figure 6, the analyses that may occur when the equality condition is met according to the equality formula (84) are given. In Figure 7, the analyses that may occur when the equality condition is not met according to the equality formula (86) are given. Here, the maximum on/off cycle change (90, 92) is given based on the changing temperature (T_set) of the heating temperature (TFmn) of the cooking chamber (12). Additionally, the maximum open-close cycle control (88) shows that heating continues to be turned on and off until the maximum cycle is reached (92), and when the maximum cycle is reached (90), the heating process (41 ) continues. REFERENCE NUMBERS

10 Oven 364 Output pin

11 Temperature control system 38 First terminal

12 Cooking room 382 Outer conductor line terminal

13 Muffle 384 Negative line connector

14 Front wall 386 Ground wire terminal

16 Oven door 40 Second terminal

162 Connecting line 402 Outer conductor line terminal

18 Electronic control unit 404 Negative line terminal

181 Feedback line from the hatch 406 Ground wire terminal

182 Feedback line from thermostat 41 Heating operation

183 Connection line to thermostat 42 Commissioning the algorithm

184 Outer conductor connection line 43 Termination of the algorithm

185 Controller 44 Door feedback

186 Relay 45 Oven door control

20 Positive conductor line 46 Closed lid status

22 Negative conductor line 48 First time (T1 )

24 Earthing line 50 Record of the first time (T 1 )

26 Mechanical thermostat 51 Hysteresis time

262 Thermostat input pin 52 Second time (T2)

264 Thermostat output pin 54 Second time (T2) recording

28 Lamps 56 Third time (T3)

282 conductor line connection pin 58 Record of the third time (T3)

284 Negative line connection pin 60 Save in controller

30 Switches 61 Time register control (T1 ,T2, T3)

301 First leg connection pin 62 Defining the opening time

302 Second leg connection pin 64 Defining shutdown time

303 Third leg connection pin 66 Switching the mechanical thermostat on

304 Fourth connecting pin and off

305 Fifth pin connecting pin 68 Switching the heating elements on and off

306 Sixth leg connecting pin 70 Heating elements control

32 First heating element 72 Ensuring heating control conductor line connection pin 74 Door open status Negative line connection pin 78 Deleting records Ground line pin 80 Interruption of the heating operation Second heating element 84 Ensuring the state of inequality Conductor line connection pin 86 Failure to provide inequality Negative line connection pin 88 Maximum on-off repeat time control Ground line pin Reaching 90 max reps Limit thermostat 92 Maximum reps not reached Input pin

Claims

CLAIMS - A method for controlling the temperature of an oven comprising heating a cooking chamber (12) with one or more electrically operated heating elements (32, 34) (41); opening and closing a mechanical thermostat (26) within a band around a set temperature value during heating (66); controlling the on/off state of the heating elements (32, 34) with a mechanically switched switch (30) connected to the mechanical thermostat (26) (68); controlling the heating according to the set temperature value by controlling the heating elements (32, 34) with the mechanical thermostat (26) (70) and providing heating control (72) characterized by comprising the steps of receiving feedback (44) from an oven door (16) by an electronic control unit (18) connected to a temperature control system (11) that performs the heating process (41 ), and adjust the heating by controlling the mechanical thermostat (66) to enable feedback (44) and heating control (72) opens and closes the heating elements (32, 34). - An oven temperature control method in accordance with Claim 1 , wherein the feedback (44) received from the oven door (16) has an open state (74) or a closed state (46) of the oven door. - An oven temperature control method according to any one of the previous claims, wherein a first time, a second time, and a third time (50, 54, 58) are recorded in the controller when the mechanical thermostat (24) operates in the closed state of the oven door (46). - An oven temperature control method according to any of the previous claims, wherein the first time, second time and third time record (50) (54) (58) in the controller is deleted (78) in the open state of the oven door (74), and the heating process is interrupted (80). - An oven temperature control method according to any of the previous claims, wherein the activation of a predetermined algorithm from a controller (185) connected to the electronic control unit (18) for providing electric current; defining an opening time and a closing time (62, 64) of a heating process (41) based on a first time, a second time, and a third time record (50, 54, 58) and a hysteresis time (51 ) that varies depending on the feedback (182) received from the mechanical thermostat (26) after the activation of the algorithm (42); providing heating control (72) in accordance with the defined opening time (62) and closing time (64); and terminating the algorithm (43) if the inequality condition is not met (86).

6- An oven temperature control method according to any of the previous claims, wherein the opening and closing of heating elements (32, 34) is provided on a relay (186) on which electrical switching is electrically connected in the electronic control unit (18) in accordance with the calculated opening and closing times (62) (64) and the electrical transmission from the mechanical thermostat (26) to the electronic control unit (18). 7- An oven temperature control method according to any of the previous claims, wherein the operation of a limit thermostat (36) that is electrically connected to the temperature control system (11) and measures heating during the heating process (41) to stop working at a predetermined specific temperature threshold value