Multi-layer circulating type pig trotter stewing control system based on intelligent temperature control

Abstract

The present application relates to the technical field of industrial temperature control, and particularly relates to a multi-layer circulation type stewing control system for stewing pork trotters based on intelligent temperature control, which vertically divides a pot body into five temperature control structures, and isolates a hollow interlayer between inner and outer walls of the pot body by a heat insulation plate; a capillary tube is configured for steam heating; detection temperatures of different temperature control structures are obtained; in a stewing process, the pot is divided into a gas zone and a liquid zone by a liquid level sensor configured in the pot; in the liquid zone, a layer height correction coefficient is determined according to a layer height of each temperature control structure; combined with a detection temperature value in a heating process of each layer and the layer height correction coefficient, an adjustment proportional term and an adjustment integral term are obtained; temperature control adjustment of the liquid zone is realized; in the gas zone, a temperature loss rate is analyzed combined with a temperature difference between a top layer temperature and a liquid level temperature, and temperature compensation is realized. The present application can improve uniformity of temperature distribution in a stewing process, optimize a heating strategy, and improve energy utilization efficiency.

Description

Technical Field

[0001] This invention relates to the field of industrial temperature control technology, specifically to a multi-layer circulating braising control system for pig's trotters based on intelligent temperature control. Background Technology

[0002] The steam vertical braising pot is a widely used braising equipment in the food processing industry, especially suitable for braising meat, poultry, seafood, and other foods. Its main feature is that it uses steam as a heating medium. Through a steam circulation system in the pot's jacket, heat is transferred to the inner wall of the pot, thereby heating and braising the ingredients. In actual heating, temperature control is a crucial aspect to consider for this type of equipment.

[0003] In the relevant equipment, a layered temperature control system is used for temperature control. This system is based on an empirical three-zone model (upper, middle, and lower), but its thermodynamic zoning deviates significantly from the actual operating conditions of the equipment. This unsteady heat conduction environment leads to a mismatch between the traditional three-zone temperature control architecture and the actual thermodynamic distribution characteristics of the equipment. During temperature control, because the equipment contains gas and liquid regions, the temperature regulation requirements of different regions are inconsistent. This results in poor uniformity of temperature regulation by the traditional PID temperature control algorithm, leading to heat waste and insufficient energy utilization efficiency. Summary of the Invention

[0004] To address the technical problems of poor uniformity, heat waste, and insufficient energy utilization efficiency in traditional PID temperature control algorithms, this invention provides a multi-layer circulating braising control system for pig's trotters based on intelligent temperature control. The specific technical solution adopted is as follows:

[0005] This invention proposes a multi-layer circulating braising control system for pig's trotters based on intelligent temperature control. The system features a hollow interlayer between the inner and outer walls of the pot. Based on temperature loss at different heights when the pot is empty, the pot is vertically divided into five temperature control layers. The interlayers of different temperature control layers are isolated by heat insulation plates. Each layer has capillary tubes distributed within its isolated area for steam heating. Temperature sensors are installed at different heights within the pot to acquire the detected temperatures of each temperature control layer. During the cooking process, a liquid level sensor within the pot divides the pot into gas and liquid zones, and different control effects are applied to these zones, including:

[0006] In the liquid zone, according to the layer height of each layer temperature control architecture compared with the layer height of the bottom layer, the layer height correction coefficient of each layer is determined; according to the detection temperature and the target temperature during cooking, the initial proportional adjustment item is determined; combined with the numerical increase rate of the detection temperature in the heating process of each layer and the layer height correction coefficient, the initial proportional adjustment item is adjusted to obtain the adjusted proportional item; according to the temperature difference between the current target temperature and the detection temperature and the layer height correction coefficient, the integral item is adjusted to determine the adjusted integral item; combined with the adjusted proportional item and the adjusted integral item, the liquid zone is controlled and adjusted.

[0007] In the gas zone, the temperature loss rate is analyzed combined with the temperature difference between the top layer temperature and the liquid surface temperature, and the temperature compensation of each layer in the gas zone is determined combined with the temperature loss rate.

[0008] Further, according to the temperature loss at different heights in the full steam state in the pot, the pot body interlayer is vertically divided into five layers of temperature control architecture, including:

[0009] The pot is filled with steam, and the temperature values at different heights in the pot after a preset period of time are obtained;

[0010] According to the difference between the bottom temperature value and the top temperature value, the temperature loss value is obtained; according to the temperature loss value and the temperature value at different heights, the pot body height is divided into five layers of temperature architecture, and the temperature loss of each layer of temperature architecture is the same.

[0011] Further, according to the layer height of each layer temperature control architecture compared with the layer height of the bottom layer, the layer height correction coefficient of each layer is determined, including:

[0012] The square value of the ratio of the layer height of each layer to the layer height of the bottom layer is taken as the layer height correction coefficient.

[0013] Further, according to the detection temperature and the target temperature during cooking, the initial proportional adjustment item is determined, including:

[0014] The difference between the target temperature and the detection temperature is calculated as the initial proportional adjustment item.

[0015] Further, the initial proportional adjustment item is adjusted combined with the numerical increase rate of the detection temperature in the heating process of each layer and the layer height correction coefficient to obtain the adjusted proportional item, including:

[0016] The temperature values of the corresponding layer temperature control architecture at different times are counted, and the temperature growth straight line is obtained by arranging in time sequence and linear fitting, and the slope of the temperature growth straight line is taken as the numerical increase rate;

[0017] The product of the numerical increase rate, the layer height correction coefficient and the initial proportional adjustment item is calculated, and the sum of the product value and the initial proportional adjustment item is taken as the adjusted proportional item.

[0018] Further, the integral term is adjusted according to the temperature difference between the target temperature and the detected temperature at the current time and the layer height correction coefficient, and the adjusted integral term is determined, comprising:

[0019] The difference between the target temperature and the detected temperature at the current time is calculated, and the heating hysteresis coefficient is normalized as a heating hysteresis coefficient.

[0020] The initial integral adjustment term is obtained based on the PID algorithm; the product of the heating hysteresis coefficient, the initial integral adjustment term and the corresponding layer height correction coefficient is calculated as the adjusted integral term.

[0021] Further, the liquid zone is controlled and adjusted by combining the adjusted proportional term and the adjusted integral term, comprising:

[0022] The adjusted proportional term and the adjusted integral term are taken as the input of the PID algorithm to realize the PID control and adjustment of the corresponding temperature control architecture in the liquid zone.

[0023] Further, the temperature loss rate is analyzed by combining the temperature difference between the top layer temperature and the liquid surface temperature, comprising:

[0024] The difference between the top layer temperature and the liquid surface temperature is taken as the gas temperature difference; the ratio of the gas temperature difference to the liquid surface temperature is taken as the temperature loss rate.

[0025] Further, the temperature compensation of each layer of the gas zone is determined by combining the temperature loss rate, comprising:

[0026] The product value of the temperature loss rate and the preset power is calculated as the compensation power corresponding to the gas zone temperature control architecture;

[0027] The capillary of the gas zone temperature control architecture interlayer is steam heated based on the compensation power.

[0028] Further, when the liquid zone and the gas zone are simultaneously included in the height range corresponding to any temperature control architecture, the height proportion of the liquid zone and the gas zone is determined, and the corresponding temperature control architecture belongs to the side with a larger height proportion value.

[0029] The present application has the following advantages:

[0030] In this embodiment of the invention, a five-layer vertical temperature control architecture is adopted, with each layer separated by heat-insulating partitions, to achieve layered temperature monitoring and control. Different temperature control strategies are employed for the liquid and gas zones based on their thermal conductivity characteristics. In the liquid zone, the initial proportional adjustment term is adjusted based on the temperature difference between the layer height and the target temperature of each layer, resulting in an adjusted proportional term. The integral term is adjusted based on the temperature difference between the current target temperature and the detected temperature, and the layer height correction coefficient, to determine the adjusted integral term. The liquid zone is controlled and regulated by combining the adjusted proportional and integral terms. That is, in PID control, the proportional and integral terms are enhanced by considering the temperature characteristics and layer height characteristics of the liquid zone itself, thereby improving response speed, enhancing the temperature stability of the liquid inside the pot, and achieving a more stable braising process. For the gas zone, the temperature loss rate is analyzed based on the temperature difference between the top layer temperature and the liquid surface temperature, and the temperature compensation for each layer in the gas zone is determined based on the temperature loss rate. Thus, different temperature control methods are used for different areas to ensure the uniformity of the overall temperature distribution. In summary, the embodiments of the present invention significantly reduce the temperature gradient inside the equipment and improve the uniformity of temperature distribution during the braising process through a five-layer vertical temperature control architecture and a layered control strategy. Furthermore, the heating strategy is optimized for the temperature loss characteristics of the gas and liquid zones, reducing heat waste, improving energy utilization efficiency, and achieving intelligent and automated temperature control. Attached Figure Description

[0031] To more clearly illustrate the technical solutions and advantages in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a structural diagram of a multi-layer circulating braising control system for pig's trotters based on intelligent temperature control, provided in one embodiment of the present invention.

[0033] The markings in the diagram are: 11: Inner wall; 12: Outer wall; 13: Heat insulation plate; 14: Liquid level sensor; 15: Capillary tube; Z1-Z5: Temperature control architecture. Detailed Implementation

[0034] To further illustrate the technical means and effects adopted by the present invention to achieve its intended purpose, the following, in conjunction with the accompanying drawings and preferred embodiments, details the specific implementation, structure, features, and effects of a multi-layer circulating braised pig's trotters control system based on intelligent temperature control proposed according to the present invention. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics in one or more embodiments can be combined in any suitable form.

[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0036] The following description, in conjunction with the accompanying drawings, details the specific solution of a multi-layer circulating braised pig's trotters braising control system based on intelligent temperature control provided by the present invention.

[0037] Please see Figure 1 The diagram illustrates a multi-layer circulating braising control system for pig's trotters based on intelligent temperature control, according to an embodiment of the present invention, comprising:

[0038] There is a hollow interlayer between the inner wall 11 and the outer wall 12 of the pot; according to the temperature loss at different heights when the pot is empty, the pot body is vertically divided into five temperature control structures (Z1-Z5), and the interlayers of different temperature control structures are isolated by heat insulation plates 13; each layer of temperature control structure has capillary tubes 15 distributed in the interlayer isolation area, and steam heating is carried out through the capillary tubes 15; temperature sensors are installed in the pot at different temperature control structure heights to obtain the detection temperature of different temperature control structures; during the cooking process, the pot is divided into gas zone and liquid zone by liquid level sensor 14 installed in the pot.

[0039] The pot body is typically a vertical cylindrical or hemispherical structure, made of high-quality stainless steel or carbon steel, with a large internal volume to hold a significant amount of ingredients and braising liquid. The pot body is divided into an outer wall 12 and an inner wall 11, with a hollow interlayer between them. Capillary tubes 15 are distributed within this interlayer, allowing for steam heating. The steam temperature is set to a constant 100 degrees Celsius.

[0040] Based on the temperature loss at different heights under full steam conditions inside the pot, the pot body jacket is vertically divided into five temperature control structures, including: filling the pot with steam and obtaining the temperature values ​​at different heights inside the pot after a preset time period; using the difference between the temperature value at the bottom and the temperature value at the top as the temperature loss value; and dividing the pot body height into five temperature structures based on the temperature loss value and the temperature values ​​at different heights, with each temperature structure having the same temperature loss.

[0041] The preset time period can be a fixed time period, such as one minute, or it can be the time when the pot temperature is constant, and the corresponding constant time is used as the preset time period. There are no restrictions on this.

[0042] See Figure 1 The corresponding temperature control architecture is Z1-Z5; Z1 is the top layer and Z5 is the bottom layer. It can be understood that the height of different temperature control architectures can be different. In this embodiment of the invention, the basis for dividing the temperature control architecture is the temperature loss, that is, determining the temperature loss of the entire pot body, and dividing the temperature architecture according to the temperature loss. In other embodiments of the invention, the temperature control architecture can also be divided into multiple layers, and there is no limitation on this.

[0043] It should be noted that in this embodiment of the invention, steam heating is achieved through a Kirchhoff array resistance wire layout, and the pot body is heated by introducing hot steam into the capillary tube 15, which is then transported to the corresponding jacketed layers. In this embodiment, the steam flow rate can be controlled by a piezoelectric ceramic proportional valve at the inlet of each capillary tube 15 to control the heating temperature. It is understood that a corresponding vent valve also needs to be configured on the other side to allow steam to flow out of the jacket. These are all conventional braising equipment structures, and will not be described further.

[0044] Modern steam-powered vertical braising pots are often equipped with advanced control systems that enable automated control of the braising process. These control systems typically include temperature sensors, pressure sensors, and time controllers, automatically adjusting steam flow and braising time according to preset process parameters to ensure stable braising processes and consistent product quality. In this embodiment of the invention, temperature sensors can be configured within the pot at different heights of the temperature control architecture to obtain the detected temperature for each architecture. Specifically, the detected temperature is the temperature value within the pot at each temperature control architecture level during the braising process. Three sets of temperature sensors can be deployed at the corresponding height of each temperature control architecture level (which can be the midpoint of the corresponding architecture height), arranged in a 120° ring. These sensors measure the temperature at different locations within the equipment in real time, and the average temperature of the three sets of sensors at the same height of the same temperature control architecture is taken as the detected temperature for that architecture. It should be noted that since this solution includes both gas and liquid zones, the corresponding temperature sensors need to be capable of detecting temperature in both gas and liquid environments simultaneously.

[0045] In this embodiment of the invention, the liquid level sensor 14 can be a piezoresistive liquid level sensor, which can measure the liquid level height inside the pot and divide the gas zone and liquid zone. When both liquid and gas zones are included within the height range corresponding to any temperature control architecture, the height ratio of the liquid zone to the gas zone is determined, and the temperature control architecture with the larger height ratio is selected.

[0046] For example, if the total height of the temperature control architecture of a certain layer is 5cm, with liquid occupying 3cm and gas occupying 2cm, then the temperature control architecture of that layer is the temperature control architecture corresponding to the liquid area.

[0047] It should be noted that this invention aims to achieve overall temperature coordination by controlling the liquid and gas zones differently. Since the equipment heats through steam heat exchange, the steam and the pot change temperature through this exchange. Different temperatures at the detection and heating ends directly affect the efficiency of heat transfer, resulting in different adjustment effects even with the same heating section at different detection temperatures. Therefore, adjustment needs to be based on the temperatures at both the detection and heating ends. Furthermore, during braising, the temperature distribution above and below the liquid surface in the pot differs. In the subsurface layer, forced convection and conduction result in significant heating; however, in the surface layer, heat transfer is primarily through natural convection and radiation, leading to slower efficiency and weaker heating. Therefore, it is necessary to use the liquid level sensor 14 to categorize the layers into liquid and gas zones and implement two targeted temperature control strategies.

[0048] In the liquid zone, the layer height correction coefficient for each layer is determined by comparing the layer height of each temperature control structure with that of the bottom layer. An initial proportional adjustment term is determined based on the detected temperature and the target temperature during cooking. The initial proportional adjustment term is adjusted by combining the rate of increase of the detected temperature during heating of each layer with the layer height correction coefficient, resulting in an adjustment proportional term. The integral term is adjusted based on the temperature difference between the current target temperature and the detected temperature, along with the layer height correction coefficient, to determine the adjustment integral term. The liquid zone is then controlled and regulated by combining the adjustment proportional term and the adjustment integral term. In the gas zone, the temperature loss rate is analyzed by combining the temperature difference between the top layer temperature and the liquid surface temperature, and the temperature compensation for each layer in the gas zone is determined based on the temperature loss rate.

[0049] It is understandable that the processing flow of braised pig's trotters typically includes steps such as ingredient selection, cleaning, preparation of spices and brine, braising, cooling, and packaging. The braising equipment in this embodiment of the invention is the equipment used in the braising process of braised pig's trotters. During the braising process, brine and the ingredients to be braised need to be added to the pot. That is, after the contents are added, the liquid level in the pot is measured by a piezoresistive liquid level sensor.

[0050] It should be noted that the temperature distribution above and below the liquid surface in the pot is also different. In the layer below the liquid surface, the heating effect is significant due to the forced convection and conduction of the liquid; while in the layer above the liquid surface, heat conduction is mainly through natural convection and radiation, so the heat conduction efficiency is slower and the heating effect is weaker. Using a piezoresistive liquid level sensor, the layers of the equipment are classified into liquid and gas zones. Two corresponding temperature control strategies are then implemented.

[0051] First, let's analyze the liquid region:

[0052] In the liquid zone, the layer height correction coefficient for each layer is determined by comparing the layer height of each temperature control structure with that of the bottom layer. An initial proportional adjustment term is determined based on the detected temperature and the target temperature during cooking. The initial proportional adjustment term is then adjusted using the rate of increase of the detected temperature during heating of each layer and the layer height correction coefficient, resulting in an adjustment proportional term. The integral term is then adjusted based on the temperature difference between the current target temperature and the detected temperature, along with the layer height correction coefficient, to determine the adjustment integral term. Finally, the liquid zone is controlled and regulated by combining the adjustment proportional term and the adjustment integral term.

[0053] The bottom layer, the one closest to the bottom of the pot in terms of temperature control architecture, responds to temperature changes most rapidly. Because of the steam heating effect at the bottom, it has a larger overall heating area and faster heat feedback. Therefore, this layer allows for initial correction of the temperature control architecture of different layers. For example... Figure 1 In this context, the lowest layer is the Z5 layer.

[0054] Among them, the floor height correction coefficient is an index data for temperature control analysis based on the floor height of different temperature control architectures. Since the floor heights of different floors are different, the heat exchange efficiency is also different. In general temperature control, linear control is directly performed based on different floors without considering the impact of floor height on heat exchange efficiency, which leads to problems in temperature control. In this embodiment of the invention, the impact of floor height is analyzed to realize the influence of temperature control.

[0055] Furthermore, in some embodiments of the present invention, the layer height correction coefficient for each layer is determined by comparing the layer height of each temperature control structure with the layer height of the bottom layer. This includes using the square of the ratio of the layer height of each layer to the layer height of the bottom layer as the layer height correction coefficient, and the corresponding calculation formula is as follows:

[0056]

[0057] In the formula, This represents the layer height correction coefficient of the i-th layer temperature control architecture; This represents the height of the i-th layer of the temperature control architecture; This indicates the height of the Z5 layer.

[0058] Since the different layers have different heights and require different volumes of liquid to be deheated, the actual temperature adjustment also needs to be adjusted in conjunction with the layer height. The smaller the layer height, the smaller the liquid volume within the layer, the smaller the contact area between the layers, and the smaller the required temperature adjustment. In this embodiment of the invention, the bottom layer Z5 is used as the benchmark, and the temperature adjustment is corrected in conjunction with the layer height of different layers to calculate the layer height correction coefficient.

[0059] The present invention aims to achieve temperature stability through PID control. When adjusting directly through the proportional control term, the temperature transfer is slow. That is, the process of the resistance wire heating to generate steam, the steam input into the corresponding jacket, and the heat transfer from the steam to the pot in the jacket has a certain delay. Therefore, it is necessary to enhance the proportional term to allow it to over-adjust, thereby improving the timeliness of temperature regulation.

[0060] In this embodiment of the invention, the PID algorithm includes a proportional term, an integral term, and a derivative term. The initial proportional adjustment term, the initial integral adjustment term, and the derivative term are obtained directly using the traditional PID algorithm.

[0061] In this embodiment of the invention, an initial proportional adjustment term is determined and enhanced to obtain an adjusted proportional term. The initial proportional adjustment term is determined based on the detected temperature and the target temperature during cooking, including: calculating the difference between the target temperature and the detected temperature as the initial proportional adjustment term. The initial proportional adjustment term is adjusted by combining the numerical increase rate of the detected temperature and the layer height correction coefficient during the heating process of each layer, resulting in an adjusted proportional term. This includes: statistically analyzing the temperature values ​​of the corresponding layer's temperature control architecture at different times, arranging them chronologically, and linearly fitting them to obtain a temperature growth line, using the slope of the temperature growth line as the numerical increase rate; calculating the product of the numerical increase rate, the layer height correction coefficient, and the initial proportional adjustment term, and using the sum of the product and the initial proportional adjustment term as the adjusted proportional term.

[0062] Understandably, the difference between the target temperature and the detected temperature represents the temperature to be adjusted, which can be used as the initial proportional adjustment term. However, due to the actual temperature delay effect, a stronger adjustment stimulus is needed to achieve the desired temperature change. That is, when the initial proportional adjustment term value is greater than 0, the actual adjustment term needs to be larger, and when the initial proportional adjustment term value is less than 0, the actual adjustment term needs to be smaller. This is to react more quickly to temperature changes. The greater the rate of increase in the value, the greater the temperature change, and the more drastic the adjustment term needs to be. Similarly, the larger the floor height correction coefficient value, the more complicated the heat transfer, and the more drastic the adjustment term needs to be. In other words, when the initial proportional adjustment term value is greater than 0, the actual adjustment term needs to be larger, and when the initial proportional adjustment term value is less than 0, the actual adjustment term needs to be smaller.

[0063] In this embodiment of the invention, the feature is perfectly achieved by calculating the product of the numerical increase rate, the floor height correction coefficient, and the initial proportional adjustment term, and then using the sum of the product and the initial proportional adjustment term as the adjustment proportional term. After determining the proportional term, the integral term also needs to be determined.

[0064] When performing integral temperature regulation on equipment, it takes a certain amount of time for the target temperature and the actual detected temperature to reach equilibrium, resulting in a hysteresis heating effect. Therefore, the corresponding integral regulation effect should be reduced to avoid overlap between the integral regulation term and the hysteresis heating effect of heat transfer.

[0065] Furthermore, in some embodiments of the present invention, the integral term is adjusted based on the temperature difference between the target temperature and the detection temperature at the current moment and the floor height correction coefficient to determine the adjustment integral term, including: calculating the difference between the target temperature and the detection temperature at the current moment and normalizing it as a heating hysteresis coefficient; obtaining an initial integral adjustment term based on a PID algorithm; and calculating the product of the heating hysteresis coefficient, the initial integral adjustment term, and the corresponding floor height correction coefficient as the adjustment integral term.

[0066] The greater the difference between the target temperature and the detected temperature at the current moment, the greater the corresponding heating lag effect. In this case, the integral term needs to be increased to improve the adjustment speed. Similarly, a larger layer height correction coefficient also requires an increased integral term. Therefore, the product of the heating lag coefficient, the initial integral adjustment term, and the corresponding layer height correction coefficient is used as the adjustment integral term. The derivative adjustment is not adjusted. This achieves the adjustment of the liquid zone.

[0067] Secondly, the analysis of the gas region:

[0068] During the brining process, due to the high fluidity of the gas, combined with the steam depressurization device and sealing in the gas zone, there is a significant temperature loss in the gas zone compared to the liquid zone, and the rate of heat loss is faster closer to the top of the device. Therefore, we will directly analyze the temperature loss in the gas zone.

[0069] Furthermore, in some embodiments of the present invention, the temperature loss rate is analyzed by combining the temperature difference between the top layer temperature and the liquid surface temperature, including: taking the difference between the top layer temperature and the liquid surface temperature as the gas temperature difference; and taking the ratio of the gas temperature difference to the liquid surface temperature as the temperature loss rate.

[0070] The temperature compensation for each layer of the gas zone is determined by combining the temperature loss rate, including: calculating the product of the temperature loss rate and the preset power as the compensation power corresponding to the gas zone temperature control architecture; and steam heating the capillary 15 of the gas zone temperature control architecture interlayer based on the compensation power.

[0071] The preset power can be a preset power value under full load operation, or it can be a fixed value that can be preset and adjusted according to the actual situation, such as 3 kilowatts, and there is no restriction on this.

[0072] The higher the temperature loss, the higher the compensation power should be in the corresponding gas zone. In this embodiment of the invention, the product of the temperature loss rate and the preset power is directly calculated as the compensation power corresponding to the temperature control architecture of the gas zone.

[0073] In the embodiments of the present invention, the compensation power is mainly the power of the resistance wire used for steam heating. The higher the power, the faster the steam heating speed, and the more quickly and sufficiently energy-rich the temperature compensation can be achieved.

[0074] In this embodiment of the invention, a five-layer vertical temperature control architecture is adopted, with each layer separated by heat-insulating partitions, to achieve layered temperature monitoring and control. Different temperature control strategies are employed for the liquid and gas zones based on their thermal conductivity characteristics. In the liquid zone, the initial proportional adjustment term is adjusted based on the temperature difference between the layer height and the target temperature of each layer, resulting in an adjusted proportional term. The integral term is adjusted based on the temperature difference between the current target temperature and the detected temperature, and the layer height correction coefficient, to determine the adjusted integral term. The liquid zone is controlled and regulated by combining the adjusted proportional and integral terms. That is, in PID control, the proportional and integral terms are enhanced by considering the temperature characteristics and layer height characteristics of the liquid zone itself, thereby improving response speed, enhancing the temperature stability of the liquid inside the pot, and achieving a more stable braising process. For the gas zone, the temperature loss rate is analyzed based on the temperature difference between the top layer temperature and the liquid surface temperature, and the temperature compensation for each layer in the gas zone is determined based on the temperature loss rate. Thus, different temperature control methods are used for different areas to ensure the uniformity of the overall temperature distribution. In summary, the embodiments of the present invention significantly reduce the temperature gradient inside the equipment and improve the uniformity of temperature distribution during the braising process through a five-layer vertical temperature control architecture and a layered control strategy. Furthermore, the heating strategy is optimized for the temperature loss characteristics of the gas and liquid zones, reducing heat waste, improving energy utilization efficiency, and achieving intelligent and automated temperature control.

[0075] It should be noted that the order of the above embodiments of the present invention is merely for descriptive purposes and does not represent the superiority or inferiority of the embodiments. The processes depicted in the accompanying drawings do not necessarily require a specific or sequential order to achieve the desired result. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0076] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

Claims

1. A multi-layer circulating braising control system for pig's trotters based on intelligent temperature control, characterized in that, The inner and outer walls of the pot have a hollow interlayer. Based on the temperature loss at different heights when the pot is empty, the pot body is vertically divided into five temperature control layers, with the interlayers of different temperature control layers isolated by heat insulation plates. Each temperature control layer has capillary tubes distributed within its interlayer isolation area, through which steam is heated. Temperature sensors are installed within the pot at different heights of the temperature control layers to acquire the detected temperatures. During the cooking process, a liquid level sensor inside the pot divides the pot into gas and liquid zones, and different control effects are applied to these zones, including: In the liquid zone, the layer height correction coefficient for each layer is determined by comparing the layer height of each temperature control structure with that of the bottom layer. An initial proportional adjustment term is determined based on the detected temperature and the target temperature during cooking. The initial proportional adjustment term is then adjusted using the rate of increase of the detected temperature during heating of each layer and the layer height correction coefficient, resulting in an adjustment proportional term. The integral term is then adjusted based on the temperature difference between the current target temperature and the detected temperature, along with the layer height correction coefficient, to determine the adjustment integral term. Finally, the liquid zone is controlled and regulated by combining the adjustment proportional term and the adjustment integral term. In the gas zone, the temperature loss rate is analyzed by combining the temperature difference between the top layer temperature and the liquid surface temperature, and the temperature compensation of each layer in the gas zone is determined by combining the temperature loss rate. The analysis of temperature loss rate by combining the temperature difference between the top layer temperature and the liquid surface temperature includes: The difference between the top layer temperature and the liquid surface temperature is taken as the gas temperature difference; the ratio of the gas temperature difference to the liquid surface temperature is taken as the temperature loss rate. The temperature compensation for each layer in the gas region is determined based on the temperature loss rate, including: The product of the temperature loss rate and the preset power is calculated and used as the compensation power corresponding to the gas zone temperature control architecture. Steam heating is performed on the capillary tubes of the gas zone temperature control architecture sandwiched by compensated power.

2. The multi-layer circulating braising control system for pig's trotters based on intelligent temperature control as described in claim 1, characterized in that, Based on the temperature loss at different heights under full steam conditions inside the boiler, the boiler jacket is vertically divided into a five-layer temperature control structure, including: Fill the pot with steam and obtain the temperature values ​​at different heights inside the pot after a preset time period. The temperature loss value is calculated based on the difference between the bottom temperature and the top temperature. Based on this temperature loss value and the temperature values ​​at different heights, the height of the pot is divided into five temperature structures, with each temperature structure having the same temperature loss.

3. The multi-layer circulating braising control system for pig's trotters based on intelligent temperature control as described in claim 1, characterized in that, Based on a comparison between the height of each layer of the temperature control architecture and the height of the bottom layer, a height correction coefficient for each layer is determined, including: The square of the ratio of the height of each floor to the height of the bottom floor is used as the floor height correction coefficient.

4. The multi-layer circulating braising control system for pig's trotters based on intelligent temperature control as described in claim 1, characterized in that, Based on the detected temperature and the target temperature during cooking, determine the initial proportion adjustment items, including: The difference between the target temperature and the detection temperature is calculated and used as the initial proportional adjustment term.

5. A multi-layer circulating braising control system for pig's trotters based on intelligent temperature control as described in claim 1, characterized in that, The initial proportional adjustment term is adjusted by combining the rate of temperature increase detected during the heating process of each layer and the layer height correction coefficient, resulting in an adjusted proportional term, including: The temperature values ​​of the corresponding layer temperature control architecture at different times are statistically analyzed, arranged in time sequence, and a linear fitting is performed to obtain a temperature growth line. The slope of the temperature growth line is used as the rate of increase in value. Calculate the product of the numerical increase rate, the floor height correction coefficient, and the initial proportional adjustment term, and use the sum of the product and the initial proportional adjustment term as the adjustment proportional term.

6. A multi-layer circulating braising control system for pig's trotters based on intelligent temperature control as described in claim 1, characterized in that, The integral term is adjusted based on the temperature difference between the target temperature and the detected temperature at the current moment and the floor height correction coefficient. The adjusted integral term includes: Calculate the difference between the target temperature and the detected temperature at the current moment, and normalize it to obtain the heating hysteresis coefficient; The initial integral adjustment term is obtained based on the PID algorithm; the product of the heating hysteresis coefficient, the initial integral adjustment term and the corresponding floor height correction coefficient is calculated as the adjustment integral term.

7. A multi-layer circulating braising control system for pig's trotters based on intelligent temperature control as described in claim 1, characterized in that, The liquid region is controlled and adjusted by combining the proportional adjustment term and the integral adjustment term, including: By adjusting the proportional and integral terms as inputs to the PID algorithm, PID control regulation of the corresponding temperature control architecture within the liquid region is achieved.

8. A multi-layer circulating braising control system for pig's trotters based on intelligent temperature control as described in claim 1, characterized in that, When a temperature control architecture contains both liquid and gas zones within its corresponding height range, the height ratio of the liquid zone to the gas zone is determined, and the temperature control architecture with the larger height ratio is considered to be the one with the larger height ratio.

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