Steam oven moisture removal control method based on dynamic airflow mixing and steam oven
By using a dynamic airflow mixing dehumidification control method, combined with humidity and air pressure sensors and a PID algorithm, the humidity and air pressure inside the steam oven are precisely controlled. This solves the problem of inaccurate humidity and temperature control in existing technologies, improves cooking results and safety, and reduces energy consumption.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-04
- Publication Date
- 2026-03-10
AI Technical Summary
Existing steam ovens do not have precise humidity and temperature control during the dehumidification process, which affects the cooking effect of food and has high energy consumption.
A dynamic airflow mixing dehumidification control method is adopted. Data is acquired through humidity and air pressure sensors, and a PID algorithm is used to control the pulse duty cycle of the air pump, the speed of the hot air blower, and the opening of the exhaust valve to dynamically adjust the humidity and air pressure of the inner tank and achieve precise humidity control.
It improves the accuracy of humidity control, prevents food surface dehydration, reduces energy consumption, and enhances the safety and cooking effect of the steam oven.
Smart Images
Figure CN121621780A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of cooking equipment, and in particular to a method for controlling the dehumidification of a steam oven based on dynamic airflow mixing, and a steam oven. Background Technology
[0002] With the increasing demand for diverse kitchen appliances, cooking equipment with only steam oven or oven functions can no longer meet current needs. As a steam kitchen appliance that combines the functions of steam oven and oven, the steam oven has emerged.
[0003] Related methods use air pumps and hot air blowers to remove moisture from inside the steam oven. However, in pursuit of rapid dehumidification, the air pump or hot air blower speed is usually fixed at a high level, causing the humidity and temperature inside the oven to drop rapidly during the dehumidification process. This makes it impossible to accurately control the dehumidification accuracy, thus affecting the cooking results. Summary of the Invention
[0004] Therefore, it is necessary to provide a steam oven dehumidification control method based on dynamic airflow mixing and a steam oven to address the above-mentioned technical problems.
[0005] In a first aspect, embodiments of the present invention propose a dehumidification control method for a steam oven based on dynamic airflow mixing. The steam oven includes an inner cavity, an air pump connected to the inner cavity, an exhaust valve, and a hot air blower, a humidity sensor, and a pressure sensor disposed within the inner cavity. The method is applied to the steam oven's steam function mode, and the method includes: The remaining cooking time of the steam oven, the humidity collected by the humidity sensor, and the air pressure collected by the air pressure sensor are obtained. When the remaining cooking time is less than or equal to the first time threshold, the steam oven is controlled to enter the dehumidification mode; When the steam oven is in dehumidification mode, the dry air flow rate in the inner cavity is calculated based on the humidity, and the pulse duty cycle of the air pump is controlled by a PID algorithm based on the dry air flow rate. The speed of the hot air blower is controlled based on the humidity, and the opening degree of the exhaust valve is controlled based on the pulse duty cycle, until the humidity is less than or equal to a humidity threshold, the difference between the air pressure and atmospheric pressure is less than or equal to a first air pressure threshold, and the rate of decrease of humidity is less than or equal to a rate threshold.
[0006] In some embodiments, the formula for calculating the dry air flow rate in the inner liner based on the humidity is: Q_air=K1×(H_max-H_real)+K2×dH / dt Where Q_air represents the dry air flow rate, K1 represents the humidity compensation coefficient, K2 represents the humidity decrease rate compensation coefficient, H_max represents the maximum humidity, H_real represents the humidity, and dH / dt represents the humidity decrease rate.
[0007] In some embodiments, controlling the pulse duty cycle of the air pump using a PID algorithm based on the dry air flow rate includes: If the dry air flow rate is greater than or equal to the flow rate threshold, the pulse duty cycle of the air pump is reduced using a PID algorithm; otherwise, the pulse duty cycle of the air pump is increased using a PID algorithm.
[0008] In some embodiments, the rotational speed of the hot air blower is positively correlated with the humidity.
[0009] In some embodiments, the opening degree of the exhaust valve is negatively correlated with the pulse duty cycle.
[0010] In some embodiments, the method further includes: The humidity compensation coefficient is adjusted according to the humidity, and the humidity decrease rate compensation coefficient is adjusted according to the humidity decrease rate.
[0011] In some embodiments, the humidity compensation coefficient is positively correlated with the humidity, and the humidity decrease rate compensation coefficient is negatively correlated with the humidity decrease rate.
[0012] In some embodiments, the method further includes: If the difference between the air pressure and atmospheric pressure is greater than the second air pressure threshold, the air valve is controlled to be fully opened until the difference between the air pressure and atmospheric pressure is less than or equal to the first air pressure threshold.
[0013] In some embodiments, the method further includes: If the steam oven is in dehumidification mode for a longer period than the second time threshold, the air pump will be controlled to continue working, and the hot air blower will be controlled to operate at its maximum speed.
[0014] In a second aspect, embodiments of the present invention provide a steam oven, including an inner cavity, an air pump communicating with the inner cavity, an exhaust valve, a hot air blower disposed in the inner cavity, a humidity sensor, and a pressure sensor, and further including a controller electrically connected to the air pump, the exhaust valve, the hot air blower, the humidity sensor, and the pressure sensor. When the steam oven is in steam function mode, the controller executes the steps of the method described in the first aspect.
[0015] Compared with existing technologies, this technical solution has the following advantages: 1. In the baking function mode, when the steam oven is in dehumidification mode, the dry air flow rate in the inner cavity is calculated based on the humidity. The pulse duty cycle of the air pump is controlled using a PID algorithm based on the dry air flow rate. The speed of the hot air blower is also controlled based on the humidity, and the opening degree of the exhaust valve is controlled based on the pulse duty cycle. The dehumidification control strategy adopted in this application dynamically adjusts the humidity in the inner cavity, improving the accuracy of humidity control, enhancing cooking performance, and reducing the energy consumption of the steam oven.
[0016] 2. By controlling humidity and the rate of humidity decrease, severe dehydration of food surfaces can be avoided; 3. By controlling the difference between air pressure and atmospheric pressure, the safety of using the steam oven is improved. Attached Figure Description
[0017] Figure 1 This is a schematic diagram of the module connection of a steam oven in one embodiment; Figure 2 This is a flowchart of a steam oven dehumidification control method based on dynamic airflow mixing in one embodiment; Figure 3 This is a flowchart illustrating a specific method for controlling the dehumidification of a steam oven based on dynamic airflow mixing in an example embodiment. Detailed Implementation
[0018] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are merely some examples or embodiments of the present invention. For those skilled in the art, the present invention can be applied to other similar scenarios based on these drawings without creative effort. Unless obvious from the context or otherwise specified, the same reference numerals in the drawings represent the same structures or operations.
[0019] As indicated in this invention and the claims, unless the context clearly indicates otherwise, the words "a," "an," "an," and / or "the" do not specifically refer to the singular and may also include the plural. Generally speaking, the terms "comprising" and "including" only indicate the inclusion of explicitly identified steps and elements, which do not constitute an exclusive list, and the method or apparatus may also include other steps or elements.
[0020] While this invention makes various references to certain modules in an apparatus according to embodiments of the invention, any number of different modules can be used and run on a computing device and / or processor. Modules are merely illustrative, and different aspects of the apparatus and methods may use different modules.
[0021] It should be understood that when a unit or module is described as "connected" or "coupled" to other units, modules, or blocks, it may refer to a direct connection or coupling, or communication with other units, modules, or blocks, or the presence of intermediate units, modules, or blocks, unless the context explicitly indicates otherwise. The term "and / or" as used herein may include any and all combinations of one or more of the related listed items.
[0022] Figure 1 This is a schematic diagram of the module connections of a steam oven according to an embodiment of the present invention. Figure 1 As shown, the steam oven includes an inner cavity, an air pump 102 communicating with the inner cavity, an exhaust valve 104, a hot air blower 106 disposed in the inner cavity, a humidity sensor 108, and a pressure sensor 110, and also includes a controller 112 electrically connected to the air pump 102, the exhaust valve 104, the hot air blower 106, the humidity sensor 108, and the pressure sensor.
[0023] The air pump is used to introduce dry air into the inner liner, the exhaust valve is used to exhaust air out of the inner liner, and the hot air blower is used to mix the hot steam in the inner liner with the dry cold air, and to make the temperature field in different areas inside the inner liner more uniform.
[0024] The air pump is connected to the inner liner via a hose.
[0025] The air pump is a diaphragm type.
[0026] Figure 2 This is a flowchart of a steam oven dehumidification control method based on dynamic airflow mixing, according to an embodiment of the present invention. The method is applied to the steam oven's steam function mode. Figure 1 As shown, the process includes the following steps: S202: Obtain the remaining cooking time of the steam oven, the humidity collected by the humidity sensor, and the air pressure collected by the air pressure sensor.
[0027] S204: When the remaining cooking time is less than or equal to the first time threshold, control the steam oven to enter the dehumidification mode.
[0028] S206: When the steam oven is in dehumidification mode, the dry air flow rate in the inner cavity is calculated based on the humidity, and the pulse duty cycle of the air pump is controlled by a PID algorithm based on the dry air flow rate, the speed of the hot air blower is controlled based on the humidity, and the opening degree of the exhaust valve is controlled based on the pulse duty cycle, until the humidity is less than or equal to a humidity threshold, the difference between the air pressure and atmospheric pressure is less than or equal to a first air pressure threshold, and the rate of decrease of humidity is less than or equal to a rate threshold.
[0029] Based on steps S202-S206 above, in the baking function mode, when the steam oven is in dehumidification mode, the dry air flow rate in the inner cavity is calculated based on the humidity, and the pulse duty cycle of the air pump is controlled by a PID algorithm based on the dry air flow rate. The speed of the hot air blower is also controlled based on the humidity, and the opening degree of the exhaust valve is controlled based on the pulse duty cycle. The dehumidification control strategy adopted in this application dynamically adjusts the humidity in the inner cavity, improving the accuracy of humidity control, enhancing cooking performance, and reducing the energy consumption of the steam oven.
[0030] Furthermore, this embodiment avoids severe dehydration of the food surface by controlling humidity and the rate of humidity decrease.
[0031] Furthermore, this embodiment improves the safety of using the steam oven by controlling the difference between air pressure and atmospheric pressure.
[0032] In a specific embodiment, the formula for calculating the dry air flow rate in the inner liner based on the humidity is as follows: Q_air=K1×(H_max-H_real)+K2×dH / dt Where Q_air represents the dry air flow rate, K1 represents the humidity compensation coefficient, K2 represents the humidity decrease rate compensation coefficient, H_max represents the maximum humidity, H_real represents the humidity, and dH / dt represents the humidity decrease rate.
[0033] In a specific embodiment, if the dry air flow rate is greater than or equal to the flow rate threshold, the pulse duty cycle of the air pump is reduced by a PID algorithm; conversely, the pulse duty cycle of the air pump is increased by a PID algorithm.
[0034] When the dry air flow rate is too high, it indicates that the humidity in the inner tank is low and dehumidification is not required. In this case, the PID algorithm is used to reduce the pulse duty cycle of the air pump to reduce the dehumidification speed. Conversely, the PID algorithm is used to increase the pulse duty cycle of the air pump to increase the dehumidification speed.
[0035] In a specific embodiment, the rotational speed of the hot air blower is positively correlated with the humidity; the opening degree of the exhaust valve is negatively correlated with the pulse duty cycle.
[0036] The speed of the hot air blower is dynamically adjusted according to the humidity. The higher the humidity, the higher the speed, in order to improve the dehumidification speed.
[0037] The smaller the pulse duty cycle of the air pump, the faster its dehumidification speed. In this case, the opening of the exhaust valve needs to be increased to speed up the dehumidification. Conversely, the larger the pulse duty cycle, the slower its dehumidification speed. In this case, the opening of the exhaust valve needs to be decreased to reduce the dehumidification.
[0038] For example, the rotational speed of the hot air blower = base value + 20 × (H_real - 50).
[0039] For example, the opening degree of the exhaust valve = 100% - (pulse duty cycle of the air pump × 80).
[0040] In one embodiment, the method further includes: adjusting the humidity compensation coefficient according to the humidity, and adjusting the humidity decrease rate compensation coefficient according to the humidity decrease rate.
[0041] Specifically, the humidity compensation coefficient is positively correlated with the humidity, and the humidity decrease rate compensation coefficient is negatively correlated with the humidity decrease rate.
[0042] When the actual humidity in the inner tank is greater than the set value, the humidity compensation coefficient is increased to enhance the humidity compensation effect; when the humidity decrease rate is too slow, the humidity decrease rate compensation coefficient is increased to strengthen the correction of the humidity decrease rate.
[0043] In this embodiment, an inner-loop control strategy is employed to dynamically control humidity by controlling the pulse duty cycle of the air pump using a PID algorithm based on the dry air flow rate, controlling the speed of the hot air blower based on the humidity, and controlling the opening degree of the exhaust valve based on the pulse duty cycle. An outer-loop control strategy is used to further refine the humidity control by adjusting the humidity compensation coefficient based on the humidity and the humidity decrease rate compensation coefficient based on the humidity decrease rate. This embodiment utilizes a dual-loop control strategy to improve the accuracy of dehumidification control and enhance cooking performance.
[0044] In one embodiment, the method further includes: if the difference between the air pressure and atmospheric pressure is greater than a second air pressure threshold, then controlling the air valve to be fully open until the difference between the air pressure and atmospheric pressure is less than or equal to a first air pressure threshold.
[0045] If the difference between the air pressure and atmospheric pressure is greater than the second air pressure threshold, it indicates that the air pressure in the inner cavity is too high. If dehumidification is stopped at this point, steam will blow onto the user's face when the user opens the steam oven. In this embodiment, the difference between the air pressure and atmospheric pressure is controlled to be less than or equal to the first air pressure threshold to avoid steam blowing onto the face.
[0046] In one embodiment, the method further includes: if the time the steam oven is in dehumidification mode is greater than a second time threshold, then controlling the air pump to continue working and controlling the hot air blower to operate at its maximum speed.
[0047] In some special cases, the dehumidification time of the steam oven may be too long. If the dehumidification mode ends too early, the dehumidification will be incomplete, resulting in steam blowing onto the face. In this embodiment, if the steam oven is in dehumidification mode for a longer period than a second time threshold, the air pump is controlled to continue working, and the hot air blower is controlled to operate at its maximum speed to perform secondary dehumidification and avoid steam blowing onto the face.
[0048] Figure 3 This is a control flowchart for the steam oven in the first example embodiment when it is in steam function. Figure 3 As shown, the steam oven is in steam function mode. It acquires the remaining cooking time T_remain, the humidity H_real from the humidity sensor, and the air pressure P_real from the air pressure sensor. When the remaining cooking time T_remain is less than or equal to the first time threshold T_set (3min~5min), the steam oven enters dehumidification mode. At this time, the air pump's pulse duty cycle is: 5s on / 3s off, the hot air blower's base speed is 1300RPM, and the exhaust valve opening is 30%. Then, the dry air flow rate Q_air in the inner cavity is calculated based on the humidity H_real. Based on the dry air flow rate Q_air, the air pump's pulse duty cycle is controlled using a PID algorithm, the hot air blower's speed is controlled based on the humidity H_real, and the exhaust valve opening is controlled based on the pulse duty cycle. During the dehumidification process, the difference between air pressure and atmospheric pressure ΔP and the humidity decrease rate dH / dt are acquired in real time. Then, adjust the humidity compensation coefficient K1 according to the humidity H_real, and adjust the humidity decrease rate compensation coefficient K2 according to the humidity decrease rate dH / d, until the humidity H_real is less than or equal to the humidity threshold (35%RH), the difference between air pressure and atmospheric pressure ΔP is less than or equal to the first air pressure threshold (50Pa), and the humidity decrease rate dH / dt is less than or equal to the rate threshold (1%RH / s), at which point the dehumidification mode ends. If the above conditions are not met, the dehumidification mode remains in operation, and the above process is repeated continuously. After the dehumidification mode ends, the exhaust valve is fully open for 10 seconds, and the air pump and hot air blower are turned off. If the time T_real in the dehumidification mode of the steam oven is greater than the second time threshold (6 minutes), the air pump is controlled to continue working, and the hot air blower is controlled to operate at maximum speed.
[0049] It should be understood that although the steps in the flowchart above are shown sequentially as indicated by the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowchart above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages in other steps.
[0050] This invention also proposes a steam oven, including an inner cavity, an air pump communicating with the inner cavity, an exhaust valve, a hot air blower disposed in the inner cavity, a humidity sensor, and a pressure sensor, and further including a controller electrically connected to the air pump, the exhaust valve, the hot air blower, the humidity sensor, and the pressure sensor. When the steam oven is in steam function mode, the controller executes the steps of the method described in the above embodiments.
[0051] In some embodiments, the formula for calculating the dry air flow rate in the inner liner based on the humidity is: Q_air=K1×(H_max-H_real)+K2×dH / dt Where Q_air represents the dry air flow rate, K1 represents the humidity compensation coefficient, K2 represents the humidity decrease rate compensation coefficient, H_max represents the maximum humidity, H_real represents the humidity, and dH / dt represents the humidity decrease rate.
[0052] In some embodiments, if the dry air flow rate is greater than or equal to a flow rate threshold, the pulse duty cycle of the air pump is reduced using a PID algorithm; conversely, the pulse duty cycle of the air pump is increased using a PID algorithm.
[0053] In some embodiments, the rotational speed of the hot air blower is positively correlated with the humidity.
[0054] In some embodiments, the opening degree of the exhaust valve is negatively correlated with the pulse duty cycle.
[0055] In some embodiments, the method further includes: adjusting the humidity compensation coefficient according to the humidity, and adjusting the humidity decrease rate compensation coefficient according to the humidity decrease rate.
[0056] In some embodiments, the humidity compensation coefficient is positively correlated with the humidity, and the humidity decrease rate compensation coefficient is negatively correlated with the humidity decrease rate.
[0057] In some embodiments, if the difference between the air pressure and atmospheric pressure is greater than a second air pressure threshold, the air valve is controlled to be fully opened until the difference between the air pressure and atmospheric pressure is less than or equal to a first air pressure threshold.
[0058] In some embodiments, if the steam oven is in dehumidification mode for a period of time longer than a second time threshold, the air pump is controlled to continue working, and the hot air blower is controlled to operate at its maximum speed.
[0059] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes of the embodiments of the above methods. Any references to memory, storage, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, or optical storage, etc. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc.
[0060] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0061] The above embodiments merely illustrate several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.
Claims
1. A method for controlling the dehumidification of a steam oven based on dynamic air mixing, the steam oven comprising an inner container, an air pump in communication with the inner container, an exhaust valve, and a hot air machine, a humidity sensor, and an air pressure sensor provided in the inner container, characterized in that, The method is applied to a steaming function mode of the steaming oven, and the method comprises the following steps: acquiring a remaining cooking time of the steaming oven, a humidity collected by the humidity sensor, and an air pressure collected by the air pressure sensor; when the remaining cooking time is less than or equal to a first time threshold, controlling the steaming oven to enter a dehumidification mode; when the steaming oven is in the dehumidification mode, calculating a dry air flow in the inner container according to the humidity, controlling a pulse duty cycle of the air pump by a PID algorithm according to the dry air flow, controlling a rotating speed of the hot air fan according to the humidity, and controlling an opening degree of the exhaust valve according to the pulse duty cycle, until the humidity is less than or equal to a humidity threshold, a difference between the air pressure and an atmospheric pressure is less than or equal to a first air pressure threshold, and a humidity drop rate is less than or equal to a rate threshold.
2. The method of claim 1, wherein, The calculation formula for calculating the dry air flow in the inner container according to the humidity is: Q_air=K1×(H_max-H_real)+K2×dH / dt wherein Q_air represents the dry air flow, K1 represents a humidity compensation coefficient, K2 represents a humidity drop rate compensation coefficient, H_max represents a maximum humidity, H_real represents the humidity, and dH / dt represents the humidity drop rate.
3. The method of claim 1, wherein, The control of the pulse duty cycle of the air pump by the PID algorithm according to the dry air flow comprises the following steps: if the dry air flow is greater than or equal to a flow threshold, the pulse duty cycle of the air pump is reduced by the PID algorithm; otherwise, the pulse duty cycle of the air pump is increased by the PID algorithm.
4. The method of claim 1, wherein, The rotating speed of the hot air fan is positively correlated with the humidity.
5. The method of claim 1, wherein, The opening degree of the exhaust valve is negatively correlated with the pulse duty cycle.
6. The method of claim 2, wherein, The method further comprises the following steps: adjusting the humidity compensation coefficient according to the humidity, and adjusting the humidity drop rate compensation coefficient according to the humidity drop rate.
7. The method of claim 6, wherein, The humidity compensation coefficient is positively correlated with the humidity, and the humidity drop rate compensation coefficient is negatively correlated with the humidity drop rate.
8. The method of claim 1, wherein, The method further comprises the following steps: if the difference between the air pressure and the atmospheric pressure is greater than a second air pressure threshold, the air valve is controlled to be fully opened until the difference between the air pressure and the atmospheric pressure is less than or equal to the first air pressure threshold.
9. The method according to any one of claims 1 to 8, characterized in that, The method further comprises the following steps: if a time when the steaming oven is in the dehumidification mode is greater than a second time threshold, the air pump is controlled to continuously work, and the hot air fan is controlled to work at a maximum rotating speed.
10. A steam oven, comprising an inner container, an air pump in communication with the inner container, an exhaust valve, a hot air machine arranged in the inner container, a humidity sensor and an air pressure sensor, further comprising a controller electrically connected with the air pump, the exhaust valve, the hot air machine, the humidity sensor and the air pressure sensor, characterized in that, When the steaming oven is in the steaming function mode, the controller performs the steps of the method according to any one of claims 1 to 9.