A method for intelligent temperature control of a high-efficiency and energy-saving electric heater

Abstract

This invention belongs to the field of electric heater temperature control technology, specifically disclosing a high-efficiency and energy-saving intelligent temperature control method for electric heaters. By constructing a multi-point temperature measurement array inside the liquid heating container, real-time temperature time-series data from each measurement location during the heating process is collected to generate corresponding temperature rise curves. Furthermore, feature points representing thermal dynamic changes are extracted from the curves, effectively capturing the temporal differences and spatial evolution characteristics of different regions within the liquid during the heating process. This allows for a complete reconstruction of thermal dynamic behavior in both spatiotemporal dimensions, providing a high-fidelity and comprehensive decision-making basis for temperature control strategy formulation. Simultaneously, after extracting the curve feature points, the heating process is divided into continuous physical stages, and targeted heating control is performed for each stage. This achieves a shift from deviation feedback control to process state control, making the control actions targeted and forward-looking, which helps reduce energy loss during the transition process.

Description

Technical Field

[0001] This invention belongs to the field of electric heater temperature control technology, and specifically discloses a high-efficiency and energy-saving intelligent temperature control method for electric heaters. Background Technology

[0002] Electric heaters, as a common liquid heating device, are widely used in kettles, water dispensers, and other fields. Traditional temperature control methods mostly rely on a single temperature sensor, comparing the temperature at a single point with a target temperature to switch the heating power on or off. While this method is simple and reliable, it is prone to causing localized areas to overheat before the main liquid reaches the target temperature, thus forcing continuous heating to meet the temperature control criteria. This process not only wastes heat energy but also reduces the system's thermal efficiency due to the extended ineffective heating time.

[0003] To overcome the aforementioned limitations, multi-point temperature monitoring schemes have been introduced in existing technologies. For example, the Chinese invention patent publication number CN121050512A proposes a heating control method and system for an electric kettle based on intelligent temperature control. This method sets multiple temperature sensors inside the electric kettle, assigns a "contribution index" to the temperature sensors at different locations based on the real-time water volume, and weights and fuses the temperatures at each point into a representative temperature value. Then, this fused temperature is compared with the target temperature set by the user, and the heating power is calculated and adjusted in real time based on a PID algorithm.

[0004] Although the scheme improves the spatial representativeness of temperature sensing to some extent, it weights the temperature information of multiple points in space into a single value by using a fixed "contribution index" during temperature sensing. While it integrates data, it masks the temporal differences in the temperature evolution inside the liquid and cannot characterize the thermal dynamics of different stages of the heating process, resulting in distorted temperature control data.

[0005] Furthermore, the temperature control of this scheme is based on PID regulation of the deviation between the fused single temperature value and the target temperature. Since the fused temperature itself is a static compressed representation of the spatial state, the deviation between it and the target temperature is often smooth and lags behind the actual thermal field changes, making it difficult to identify the state transition nodes in the heating process. This results in lagging control actions, a lack of pertinence and foresight, and increased energy consumption during the transition process.

[0006] In addition, existing technologies typically use a single threshold logic to stop heating when the fusion temperature reaches the target value, without considering the completeness of temperature coverage in space. Therefore, they cannot ensure that the liquid reaches the standard uniformly throughout the entire area, which can easily lead to insufficient outlet water temperature or local dry burning risks. Summary of the Invention

[0007] To solve the above-mentioned technical problems, or at least partially solve them, the present invention provides a method for intelligent temperature control of a high-efficiency and energy-saving electric heater.

[0008] The objective of this invention can be achieved through the following technical solution: a method for intelligent temperature control of a high-efficiency and energy-saving electric heater, comprising the following steps: deploying a multi-point temperature measuring array inside a liquid heating container and synchronously collecting time-series temperature data of each measuring point during the heating process.

[0009] Based on time-series temperature data, temperature rise curves for each temperature measurement point are plotted, and curve feature points characterizing thermal dynamic changes are extracted.

[0010] Based on the order of appearance and relative position of the characteristic points, the heating process is divided into four stages: bottom heat accumulation stage, middle heat penetration stage, top acceleration stage, and steady-state maintenance stage, based on the temperature rise curves of different temperature measurement points.

[0011] For each defined stage, based on the type of feature point that triggers that stage and the curve comparison results, a set of directional control commands for adjusting heating power and fluid circulation state are generated and executed.

[0012] During the heating process, a heating stop determination is performed based on both the time stability of the temperature at the measuring point reaching the target temperature and the spatial coverage status. When the determination conditions are met, a heating stop command is triggered.

[0013] Combining all the above technical solutions, the positive effects of this invention are as follows: 1. This invention constructs a multi-point temperature measurement array inside the liquid heating container, collects the temperature time series data of each temperature measurement position in real time during the heating process to generate the corresponding temperature rise curve, and further extracts the curve feature points that characterize the thermal dynamic changes. This effectively captures the time difference and spatial evolution characteristics of different regions inside the liquid during the heating process, thereby completely restoring the thermal dynamic behavior in the spatiotemporal dimension and providing a high-fidelity, full-coverage decision basis for the formulation of temperature control strategies.

[0014] 2. After extracting the feature points of the curve, this invention divides the heating process into continuous physical stages based on the order of appearance and relative position of the feature points, and performs directional heating control for each stage. This realizes the transformation from deviation feedback control to process state control, making the control action targeted and forward-looking. It can adjust the strategy in advance when the stage changes, avoid overshoot and repeated adjustments, and help reduce energy loss during the transition process and optimize energy efficiency.

[0015] 3. In the heating process, the present invention introduces the dual criteria of time stability and spatial coverage to jointly determine the timing of heating termination, which effectively avoids false stops caused by local overheating or single-point achievement, and significantly improves the accuracy and reliability of heating endpoint determination. Attached Figure Description

[0016] The present invention will be further described with reference to the accompanying drawings, but the embodiments in the drawings do not constitute any limitation on the present invention. For those skilled in the art, other drawings can be obtained based on the following drawings without creative effort.

[0017] Figure 1 This is a diagram illustrating the implementation steps of the method of the present invention.

[0018] Figure 2 This is a flowchart illustrating the feature point extraction process for a single temperature rise curve in this invention.

[0019] Figure 3 This is a flowchart illustrating the feature point extraction process for multiple temperature rise curves in this invention. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] See Figure 1 As shown, the present invention proposes an intelligent temperature control method for a high-efficiency and energy-saving electric heater, including the following steps: S1, a multi-point temperature measuring array is set up inside the liquid heating container to synchronously collect the time-series temperature data of each measuring point during the heating process.

[0022] A typical liquid heating container consists of a bottom-embedded heating element, sidewall insulation, and a top water outlet area. Its working principle involves energizing the bottom heating element, which then transfers heat energy to the liquid inside the container via conduction and convection, gradually raising its temperature to the set target temperature. Due to uneven heating of the liquid during the heating process, the internal temperature field exhibits unsteady characteristics. Therefore, to accurately assess whether the heating state has reached the set temperature and avoid misjudging the completion of heating, it is necessary to monitor the liquid temperature inside the container in real time.

[0023] To achieve the above objectives, temperature measurement points need to be set up inside the heating container. However, considering that the structure of the heating container causes a significant vertical stratification tendency in the internal fluid space, a single temperature measurement point cannot capture the temperature gradient distribution of the liquid in space. This invention aims to achieve refined perception of the liquid temperature field inside the container by constructing a multi-point temperature measurement array covering the vertical height direction and the horizontal radial direction inside the heating container.

[0024] In a preferred embodiment of the present invention, a multi-point temperature measuring array is arranged inside the liquid heating container as follows: multiple temperature measuring points are arranged in the vertical direction and the horizontal radial direction in the internal space of the liquid heating container.

[0025] Temperature measurement points are arranged vertically along the height of the container in layers, covering the bottom heating zone, the middle main liquid zone, and the top outlet zone.

[0026] Within the central main liquid zone, at least two temperature measuring points at different radial positions are set on the same height plane.

[0027] The instructions for the above operations state that the temperature measuring points arranged vertically are used to sense the unsteady temperature stratification of the liquid along the height direction, and the temperature measuring points arranged horizontally are used to identify the lateral temperature non-uniformity caused by the asymmetry of fluid flow on the same height section.

[0028] By constructing a three-dimensional distributed multi-point temperature measurement array within the liquid heating container through step S1, it is possible to simultaneously acquire temperature data from multiple spatial locations and with continuous time. Subsequent extraction of thermal dynamic features and division of heating stages provide high-resolution time-series temperature data.

[0029] S2. Based on time-series temperature data, plot the temperature rise curves of each temperature measurement point with time as the horizontal axis and temperature as the vertical axis, and extract the curve feature points that characterize the thermal dynamic changes.

[0030] After completing the comprehensive perception of the liquid temperature field inside the heating container, considering that the liquid heating process is a non-steady-state process driven by multiple physical mechanisms such as heat conduction, natural convection, and heat stratification formation and dissipation, its macroscopic performance will show obvious stage characteristics over time. The heating control requirements are different at different stages. If only the original temperature value is relied upon for control, these inherent state transition nodes cannot be identified, which can easily lead to a one-size-fits-all control strategy, resulting in response lag and increased energy consumption.

[0031] To address the aforementioned issues, it is necessary to extract structured feature points from the temperature rise curves that can indicate stage transitions. Given that the thermal dynamics of the liquid heating process are reflected not only in the temperature evolution of a single temperature measurement point but also in the temperature coordination and relative evolution relationship between multiple temperature measurement points, this invention employs a dual-dimensional strategy targeting both single and multiple temperature rise curves during feature point extraction.

[0032] In a specific embodiment, the extraction of curve feature points representing thermal dynamic changes is described in the following process: S21, feature point extraction for a single temperature rise curve.

[0033] Given that different physical stages in the liquid heating process have different heat transport efficiencies, the rate of temperature rise per unit time, i.e., the heating rate, changes. When the physical stage switches, the heating rate will experience acceleration, deceleration, or directional adjustment, which manifests as local extremes or step jumps in the heating rate time series. These two types of changes indicate that the internal state of the thermal system has evolved. Therefore, the original temperature rise curve corresponding to it is marked as the inflection point, which serves as a characteristic of the thermal dynamic stage transition.

[0034] See Figure 2 As shown, based on the above considerations, the feature point extraction process is as follows: S211, perform first-order numerical differentiation on the temperature rise curve generated for each temperature measurement point to generate the corresponding heating rate time series.

[0035] S212. For the heating rate time series, calculate the change in heating rate between the current point and the previous moment point by point, and at the same time determine the local monotonicity of the current point. If the monotonicity reverses or the change in heating rate exceeds the rate change threshold at a certain moment, the rate change threshold is used to distinguish between real thermal dynamic events and measurement noise. For example, it can be limited to a heating rate change of no more than 0.3°C / s per second. The monotonicity reversal corresponds to the local extreme value of the heating rate, and the change in heating rate exceeding the rate change threshold corresponds to a step jump. Mark the point on the temperature rise curve corresponding to that moment as an inflection point.

[0036] See Figure 3 As shown in Figure S22, feature point extraction is performed on multiple temperature rise curves.

[0037] In the initial heating phase, the area near the heat source heats up rapidly, while the area farther from the heat source heats up more slowly. Therefore, the temperature rise curve at the bottom measuring point remains above that at the top measuring point, exhibiting an upward-downward relationship. As heating continues, heat is transferred upwards through conduction and convection, and the heating rate in the top region gradually accelerates. When the temperature rise rate at the top exceeds that at the bottom, the relative positions of the two temperature curves will reverse, and they will intersect at a certain point. This intersection point reflects that heat has penetrated to the distant region, and the thermal influence range has completed a phased expansion.

[0038] During the heating process, if the regions where the two temperature measuring points are located are still in a non-equilibrium stage of heat conduction, a temperature gradient will usually be observed due to the difference in distance between the heat sources, resulting in separate temperature rise curves. When heat is fully transferred and convection mixing is sufficient, the temperature evolution at different locations tends to be synchronized, manifested as parallel and overlapping temperature rise curves within a certain period. Therefore, the parallel overlapping segment is temporal evidence of the achievement of spatial homogeneity in the thermal field.

[0039] Based on the above explanation, the feature point extraction process is as follows: S221. When comparing two temperature rise curves, monitor the relative position changes of the two curves on the temperature coordinate axis. When the two curves change from an upper and lower position relationship to an intersection, identify the intersection moment as an intersection point of the two curves.

[0040] S222. When comparing two temperature rise curves, the instantaneous temperature difference between the two curves is calculated point by point for a continuous time interval. If all instantaneous temperature differences between the two curves are less than or equal to the temperature consistency tolerance within the entire interval and the duration of the interval is greater than the effective duration, then the time interval is determined to be a parallel overlapping segment.

[0041] In the above operations, the temperature consistency tolerance constitutes the amplitude convergence condition for determining the parallel overlap segment, such as ±0.3°C, to ensure that the temperatures of the two temperature measurement points are basically equal in an engineering sense, and to eliminate false overlap caused by sensor noise. The effective duration constitutes the time persistence condition for determining the parallel overlap segment, such as 5s, to eliminate instantaneous crossover and to ensure that the synchronization state has physical persistence rather than accidental fluctuations.

[0042] S23. The identified inflection points, intersection points, and parallel overlapping segments are all taken as curve feature points.

[0043] S3. Based on the order of appearance and relative position of the characteristic points, the heating process is divided into the bottom heat accumulation stage, the middle heat penetration stage, the top acceleration stage, and the steady-state maintenance stage for the temperature rise curves of different temperature measurement points.

[0044] After extracting the feature points of the curve, the entire heating process can be divided into stages based on the extracted feature points. However, if the stage division is based solely on the presence or absence of feature points, while ignoring their order of appearance on the time axis and their relative positional relationship among multiple curves, it may lead to blurred stage boundaries, misjudgments, or logical conflicts.

[0045] Therefore, when dividing the heating stage using feature points, this invention introduces a feature comparison order and time constraint mechanism. The comparison order defines the reasonable evolution logic that different feature points should follow physically. The time constraint limits the time interval that feature points must meet in order to exclude abnormal sequences that do not conform to the heat transfer law.

[0046] The following describes the specific process of dividing the heating stage in conjunction with the preferred embodiment: S31. Considering that the bottom temperature measuring point is closest to the heat source and has the earliest and most sensitive temperature response, it can reflect the heating first. The temperature rise curve of the bottom heating element near the temperature measuring point is set as the reference curve, which can effectively anchor the time starting point of the entire heating process and provide a unified time reference system for subsequent multi-point comparison.

[0047] S32. Given that in the initial stage of heating, heat accumulates rapidly in the bottom region through thermal conduction, when the temperature of the bottom liquid rises to a certain level, the heating rate slows down or even plateaus. This change is represented by the first inflection point on the temperature rise curve. Based on this, within a preset time window, when the first inflection point is detected on the reference curve, this inflection point indicates that the bottom thermal energy has accumulated to a level sufficient to drive fluid movement, and the heating process is determined to have entered the bottom heat accumulation stage.

[0048] S33. After entering the bottom heat accumulation stage, heat begins to diffuse longitudinally towards the central region. This invention selects at least two temperature measuring points at different heights within the central main liquid zone and compares their temperature rise curves. When these curves are identified as entering a parallel overlapping segment, it indicates that the heating process at each point within the selected central vertical range has reached dynamic equilibrium, and heat has been transmitted within that vertical range. This indicates that the heating process has entered the central heat transmission stage.

[0049] S34. After entering the middle heat penetration stage, the heat flow continuously transports the high-temperature liquid to the top region. When the heat flow stably reaches the top region, the heating rate will surpass that of the middle region due to continuous heat input. Based on this, the instantaneous heating rate of the temperature rise curves of the temperature rise point in the top outlet area and the temperature rise point in the middle main liquid area is continuously compared. The temperature rise point in the middle main liquid area refers to the temperature rise point located at the middle height of the liquid main area of ​​the container. Its physical meaning is to reflect the average thermal state of the middle volume of the liquid. When the instantaneous heating rate of the top curve is continuously exceeded by the instantaneous heating rate of the middle curve, it indicates that the heat penetration has been completed, and the heating process is judged to have entered the top acceleration stage.

[0050] S35. After entering the top acceleration stage, continuously monitor the temperature of the top outlet area temperature measuring point and simultaneously compare the temperature of the top temperature measuring point with the temperature of the middle temperature measuring point closest to the top temperature measuring point. When the temperature of the top outlet area temperature measuring point reaches the target temperature, and the real-time temperature difference between it and the closest middle temperature measuring point drops to the set temperature difference range for the first time (for example, the set temperature difference range is 0.5°C), it indicates that the top and middle have achieved thermal synchronization, the entire liquid body is close to the thermal equilibrium state, and it is determined that the heating process has entered the steady-state maintenance stage.

[0051] The explanation applied to the above heating stage division introduces a preset time window as a time constraint in determining the bottom heat accumulation stage. This is mainly because, in the early stages of liquid heating, the bottom temperature measurement point may produce a false inflection point due to sensor noise. Therefore, by setting a time window, and limiting the inflection point to appearing within this window as valid, early abnormal signals can be effectively eliminated.

[0052] In one feasible approach, considering that the bottom heat accumulation stage is essentially a process of injecting and accumulating heat energy into the adjacent liquid, its duration should not exceed the time required to directly heat the local area to the target temperature. This is because once the target temperature is reached, the system has entered thermal equilibrium and is no longer in the accumulation category. Therefore, the length of the preset time window can be set as the theoretical time required to heat the liquid in the bottom heating zone from the initial temperature to the target temperature under the rated heating power of the liquid heating container.

[0053] For example, the formula for calculating the length of the preset time window is: ,in This indicates the mass of the liquid in the bottom heating zone. Indicates the specific heat capacity of a liquid. Indicates the initial temperature of the liquid. Indicates the target temperature. Indicates thermal efficiency. This indicates the rated heating power.

[0054] The heating process is divided into continuous physical stages by the S3 step, providing directional control commands that match the current thermodynamic state for subsequent temperature control strategies.

[0055] S4. For each stage, based on the type of feature point that triggers the stage and the curve comparison results, generate and execute a set of directional control commands to adjust the heating power and fluid circulation state.

[0056] Since each stage is defined by specific characteristic points and multi-curve comparison results, it corresponds to different thermodynamic behaviors. Heating requirements differ under different heat transfer mechanisms.

[0057] Therefore, this invention provides targeted heating control for different heating stages. In the heating control, based on the traditional heating power adjustment, a circulating pump is introduced as a thermal management execution unit. The heating power is used to adjust the intensity of heat energy input to the heating container per unit time. The circulating pump, as a forced convection drive device, controls the fluid flow intensity by adjusting the rotation speed, thereby actively intervening in the heat transport efficiency and mixing uniformity within the container.

[0058] In an optional embodiment of the present invention, the control command for the heating stage is generated as follows: (1) When it is determined that the bottom heat accumulation stage has been entered, the bottom liquid heats up rapidly in this stage, but effective convection has not yet been formed, and there is a risk of local overheating or even dry burning. The command triggered at this time includes: reducing the heating power to avoid the bottom heat flux being too high and causing the temperature to rise too quickly, and starting the circulation pump to run at a low speed. By introducing weak forced convection, the bottom thermal boundary layer is disturbed in advance to suppress extreme thermal stratification and prepare for the subsequent transition from natural convection to forced convection, while avoiding energy waste caused by high-speed disturbance.

[0059] (2) When it is determined that the central heat penetration stage has been entered, the central region has entered the convection-dominated heat transfer stage. It is necessary to accelerate the horizontal and vertical heat mixing to eliminate the temperature gradient. The triggered instructions include: switching the circulation pump to high speed and dynamically fine-tuning the heating power according to the temperature difference between the top and bottom temperature measurement points to achieve dynamic matching of power and heat transfer capacity.

[0060] During the central heat transfer stage, the bottom region is warmer due to its proximity to the heat source, while the top region is not yet fully heated and is relatively cooler, resulting in a temperature difference between the top and bottom. During heat transfer, the change in the temperature difference between the top and bottom reflects the state of thermal stratification. The temperature control objective at this stage is to reduce thermal stratification and promote temperature field homogenization.

[0061] In one specific embodiment, the heating power is dynamically fine-tuned based on the temperature difference between the top and bottom temperature measuring points as follows: the temperature difference between the current top and bottom temperature measuring points is calculated with a fixed sampling period.

[0062] Compare the temperature difference between the current top and bottom temperature measuring points with the configured allowable temperature difference range, which is usually 1 to 3°C.

[0063] If the current temperature difference is greater than the upper limit of the allowable temperature difference range, it indicates that the thermal stratification is significant. At this time, an instruction to reduce the heating power by one step is generated to weaken the heat source intensity at the bottom, slow down the bottom temperature rise rate, and provide more sufficient thermal response time for the top area, thereby suppressing the further expansion of the temperature difference.

[0064] Conversely, if the current temperature difference falls within the allowable range, it indicates that the thermal stratification is within an acceptable range, and the overall heat transfer is basically matched with the heat input. At this time, the current heating power is kept unchanged to maintain a stable heat penetration process.

[0065] If the current temperature difference is less than the lower limit of the allowable temperature difference range, it indicates that the bottom heating is insufficient. In this case, an instruction to increase the heating power by one step can be generated to enhance the heat input, increase the heating rate while ensuring uniformity, and avoid unnecessary extension of the heating cycle due to excessive power suppression.

[0066] The step size mentioned above refers to the smallest controllable adjustment unit used in the heating power adjustment process, which can be set manually.

[0067] (3) When the top acceleration phase is determined, the top heating rate surpasses that of the middle, indicating that the heat flow has reached the upper part and the system enters the heating sprint period. At this time, the triggered instructions include: switching the circulation pump to high speed, strengthening forced convection, and increasing the heating power. Using the convection channel, the overall temperature is quickly pushed to the target temperature.

[0068] (4) When the steady-state maintenance phase is determined, the top has reached the target temperature and the temperature difference with the middle has entered the tolerance, indicating that the system is close to thermal equilibrium. The triggered instructions include: switching the heating mode to the low-power pulse maintenance mode, using intermittent small energy input to avoid continuous heating leading to overall overheating, and switching the circulation pump back to low speed. Since the temperature field is already uniform, there is no need for strong convection to maintain mixing, thus reducing the power consumption of the circulation pump.

[0069] Through step S4, this invention abandons the traditional crude mode of constant high-power heating control and instead adopts a coordinated regulation strategy of heating power and circulating pump speed. The two are coupled on demand at different stages to achieve coordinated optimization of heat distribution. This not only improves heating uniformity and response speed, but also effectively reduces total energy consumption by supplying energy on demand and stirring on demand.

[0070] The innovative implementation of the above steps also includes a stage judgment anomaly handling mechanism: if no corresponding feature point is detected within a preset time window during the heating stage division process, the stage judgment anomaly is determined.

[0071] At this time, the directional heating control command is not executed, triggering an alarm.

[0072] The above operations can identify stage-specific anomalies. If the control strategy is switched according to the original plan under abnormal conditions, safety risks such as local overheating, dry burning, or incorrect energy input may occur because the actual thermal state does not match the control expectations.

[0073] Therefore, the anomaly handling mechanism essentially constitutes a state verifier based on the consistency of physical processes, ensuring that all directional heating control commands are activated only when the system is in a verifiable and expected thermodynamic state, effectively avoiding misoperation caused by abnormal operating conditions.

[0074] S5. During the heating process, a heating stop determination is performed based on the dual conditions of the time stability state and the spatial coverage state of the temperature at the measuring point reaching the target temperature. When the determination conditions are met, a heating stop command is triggered.

[0075] The heating process is not unconditionally continuous. To maximize energy efficiency by cutting off energy input in a timely manner when the liquid as a whole reaches the expected thermal state, a termination determination mechanism is needed. Traditional heating termination determination usually relies solely on whether the temperature of a single measuring point has reached the target value. Due to the obvious thermal stratification and dynamic non-uniformity within the liquid, a single point may have already exceeded the temperature limit while the main body or distant areas have not yet reached the target. If the machine is stopped prematurely, it will result in insufficient heating. If heating continues to wait for the single point to stabilize, it is very easy to cause local overheating or even dry burning. This approach cannot guarantee overall thermal uniformity and makes it difficult to balance energy efficiency and safety.

[0076] To address the aforementioned issues, this invention considers the evolution characteristics of the temperature field within a liquid heating container in both time and space dimensions. It proposes a dual termination criterion based on temporal stability and spatial coverage, which can accurately determine whether the liquid has truly achieved overall, uniform, and stable thermal compliance, thereby triggering a heating stop command at the optimal time.

[0077] The heating stop determination process is described below with reference to the following embodiments: S51, compare the measured temperature of each temperature measuring point in the liquid heating container with the target temperature in real time.

[0078] S52. When the temperature of a certain temperature measuring point first reaches or exceeds the target temperature, the duration of temperature maintenance is continuously monitored. If the duration of the temperature measuring point at or above the target temperature is not less than the temperature stabilization time, where the temperature stabilization time is used to filter out false compliance signals caused by instantaneous temperature fluctuations, for example, 3 to 5 seconds, then the temperature measuring point is marked as a valid compliance point.

[0079] S53. Based on the known spatial layout topology of the multi-point temperature measurement array inside the container, all effective compliant points are used as geometric nodes, and the compliant temperature coverage area is constructed in three-dimensional space through geometric construction.

[0080] In a specific example, the convex hull method is used to construct the compliant temperature coverage area in three-dimensional space. The construction process is as follows: S531, construct a point set by corresponding to the position of each valid compliant point in the container.

[0081] S532. Call the 3D convex hull algorithm to calculate the point set and output a convex polyhedron. The convex polyhedron is enclosed by a set of triangular facets. Each facet is defined by three vertices, and all valid qualifying points are located inside or on the surface of the polyhedron.

[0082] The implementation logic of the 3D convex hull algorithm is as follows: First, select four non-coplanar extreme points from the point set to form an initial tetrahedron. This tetrahedron serves as the initial approximation of the convex hull, and its four triangular facets divide the 3D space into internal and external regions.

[0083] Secondly, all the remaining points not included in the initial tetrahedron vertices are classified according to their spatial position relative to each facet: for each facet, if a point is located outside a facet, it is added to the external point set corresponding to that facet.

[0084] Then, iteratively for each non-empty patch in the external point set, the point farthest from the patch is selected to form a new patch, and the positions of the remaining points in the original external point set relative to the newly generated patch are recalculated, and the external point set of each new patch is updated.

[0085] Finally, repeat the above process until the external point sets of all patches are empty, and finally output the convex hull surface triangular mesh.

[0086] S533. Define the generated convex polyhedron as the target temperature coverage area, representing the conservative outer boundary of the liquid space that has reliably reached the target temperature.

[0087] S54. Given that the ultimate goal of liquid heating is not localized compliance, but rather the uniformity of the overall thermal field, only when the bottom, middle, and top of the container all achieve stable compliance can it be proven that the heat has effectively penetrated the entire liquid height. Based on this, by checking whether the compliant temperature coverage area simultaneously includes the valid compliant points located in the bottom heating zone, the middle main liquid zone, and the top outlet zone, if all three are included, heating is stopped.

[0088] The S5 process overcomes the limitations of traditional single-point temperature control, which stops once the local temperature reaches the target. At the end of the staged and directional heating control, it achieves accurate and timely determination of the heating endpoint, thus achieving the goal of safe and energy-saving temperature control.

[0089] The above embodiments can be implemented, in whole or in part, by software, hardware, firmware, or any other combination thereof. When implemented using software, the above embodiments can be implemented, in whole or in part, in the form of a computer program product.

[0090] Those skilled in the art will recognize that the modules and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0091] In addition, the functional modules in the various embodiments of this application can be integrated into one processing module, or each module can exist physically separately, or two or more modules can be integrated into one module.

[0092] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

[0093] Finally, the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for intelligent temperature control of a high-efficiency, energy-saving electric heater, characterized in that, include: A multi-point temperature measurement array is deployed inside the liquid heating container to simultaneously collect time-series temperature data of each measurement point during the heating process; Based on time-series temperature data, temperature rise curves for each temperature measurement point are plotted, and curve feature points characterizing thermal dynamic changes are extracted. Based on the order of occurrence and relative position of the characteristic points, the heating process is divided into the bottom heat accumulation stage, the middle heat penetration stage, the top acceleration stage, and the steady-state maintenance stage for the temperature rise curves at different temperature measurement points. For each defined stage, based on the type of feature point that triggers the stage and the curve comparison results, a set of directional control commands for adjusting heating power and fluid circulation state are generated and executed. During the heating process, a heating stop determination is performed based on both the time stability of the temperature at the measuring point reaching the target temperature and the spatial coverage status. When the determination conditions are met, a heating stop command is triggered. The extraction of curve feature points characterizing thermal dynamic changes is described in the following process: The first-order numerical derivative of the temperature rise curve generated at each temperature measurement point is performed to generate the corresponding heating rate time series. For the heating rate time series, calculate the change in heating rate between the current point and the previous moment point point by point, and determine the local monotonicity of the current point. If the monotonicity reverses at a certain moment or the change in the heating rate exceeds the threshold for a sudden change in rate, the point on the temperature rise curve corresponding to that moment is marked as an inflection point. When comparing two temperature rise curves, monitor the change in the relative position of the two curves on the temperature coordinate axis. When the two curves change from an upper and lower position relationship to an intersection, identify the intersection moment as an intersection point of the two curves. When comparing two temperature rise curves, the instantaneous temperature difference between the two curves is calculated point by point over a continuous time interval. If all instantaneous temperature differences between the two curves are less than or equal to the temperature consistency tolerance throughout the entire interval and the duration of the interval is greater than the effective duration, then the time period is determined to be a parallel overlapping segment. The identified inflection points, intersection points, and parallel overlapping segments are all used as curve feature points; The heating process is divided into a bottom heat accumulation stage, a middle heat penetration stage, a top acceleration stage, and a steady-state maintenance stage, as follows: The temperature rise curve near the temperature measuring point of the bottom heating element is set as the reference curve. Within a preset time window, when the first inflection point is detected on the baseline curve, it is determined that the heating process has entered the bottom heat accumulation stage. After entering the bottom heat accumulation stage, select at least two temperature measuring points located in the central main liquid area and at different heights, compare their temperature rise curves, and determine that the heating process has entered the central heat penetration stage when at least two temperature rise curves are identified to enter the parallel overlapping section. After entering the central heat penetration stage, the instantaneous heating rate of the temperature rise curves of the top outlet area temperature measurement point and the central main liquid area temperature measurement point is continuously compared. When the instantaneous heating rate of the temperature rise curve of the top outlet area temperature measurement point continuously exceeds the instantaneous heating rate of the temperature rise curve of the central main liquid area temperature measurement point, it is determined that the heating process has entered the top acceleration stage. Once the top acceleration phase begins, the temperature of the top outlet area temperature measuring point is continuously monitored, and the temperature of the top temperature measuring point is simultaneously compared with the temperature of the middle main liquid area temperature measuring point closest to that top temperature measuring point. When the temperature at the top outlet area reaches the target temperature, and the real-time temperature difference between the top outlet area and the nearest central main liquid area temperature measurement point drops to within the set temperature difference range for the first time, the heating process is determined to have entered the steady-state maintenance phase.

2. The intelligent temperature control method for a high-efficiency energy-saving electric heater as described in claim 1, characterized in that: The following describes the arrangement of a multi-point temperature measurement array inside the liquid heating container: Multiple temperature measuring points are arranged vertically and radially within the internal space of the liquid heating container. Temperature measurement points are arranged vertically along the height of the container, covering the bottom heating zone, the middle main liquid zone, and the top outlet zone. Within the central main liquid zone, at least two temperature measuring points at different radial positions are set on the same height plane.

3. The intelligent temperature control method for a high-efficiency energy-saving electric heater as described in claim 1, characterized in that: The preset time window is the theoretical time required to heat the liquid in the bottom heating zone from the initial temperature to the target temperature under the rated heating power of the liquid heating container.

4. The intelligent temperature control method for a high-efficiency energy-saving electric heater as described in claim 1, characterized in that: The generated and executed set of directional control commands for adjusting heating power and fluid circulation state are as follows: When it is determined that the bottom heat accumulation stage has been entered, the triggered instructions include: reducing the heating power and starting the circulation pump to run at a low speed; When the system is determined to have entered the central heat penetration stage, the triggered commands include: switching the circulation pump to high speed and dynamically fine-tuning the heating power based on the temperature difference between the top and bottom temperature measuring points. When the system is determined to be entering the top acceleration phase, the triggered commands include: switching the circulation pump to high speed and increasing the heating power; When the steady-state maintenance phase is determined, the triggered commands include: switching the heating mode to low-power pulse maintenance mode and switching the circulation pump back to low speed.

5. The intelligent temperature control method for a high-efficiency energy-saving electric heater as described in claim 1, characterized in that: The division of the heating process into a bottom heat accumulation stage, a middle heat penetration stage, a top acceleration stage, and a steady-state maintenance stage also includes a stage-based abnormality handling mechanism. If no corresponding feature point is detected within the preset time window during the heating stage division process, the stage determination is determined to be abnormal. At this time, the directional heating control command is not executed, triggering an alarm.

6. The intelligent temperature control method for a high-efficiency energy-saving electric heater as described in claim 4, characterized in that: The process of dynamically adjusting the heating power based on the temperature difference between the top and bottom temperature measuring points is as follows: The temperature difference between the current top and bottom temperature measurement points is calculated using a fixed sampling period. Compare the current temperature difference between the top and bottom temperature measuring points with the configured allowable temperature difference range; If the current temperature difference is greater than the upper limit of the allowable temperature difference range, then generate an instruction to reduce the heating power by one step. If the current temperature difference falls within the allowable range, a command to maintain the current heating power is generated. If the current temperature difference is less than the lower limit of the allowable temperature difference range, generate an instruction to increase the heating power by one step.

7. The intelligent temperature control method for a high-efficiency energy-saving electric heater as described in claim 1, characterized in that: The implementation process for determining heating stop based on both the time stability state and spatial coverage state of the temperature at the measuring point reaching the target temperature is as follows: The measured temperature at each temperature measuring point inside the liquid heating container is compared with the target temperature in real time to identify the valid target points; Based on the known spatial layout topology of the multi-point temperature measurement array inside the container, all effective compliant points are used as geometric nodes, and the compliant temperature coverage area is constructed in three-dimensional space through geometric construction. Check whether the area covered by the compliant temperature simultaneously includes valid compliant points located in the bottom heating zone, the middle main liquid zone, and the top outlet zone. If it does, then stop heating.

8. The intelligent temperature control method for a high-efficiency energy-saving electric heater as described in claim 7, characterized in that: The process for identifying valid compliance points is as follows: Once the temperature at a certain temperature measurement point reaches or exceeds the target temperature for the first time, the duration of temperature maintenance is continuously monitored. If the duration of the temperature measurement point at or above the target temperature is not less than the duration of temperature stabilization, then the temperature measurement point is marked as a valid target point.

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