CN-121995999-A - Digital twinning-based real-time monitoring method for multiple physical fields of temperature and humidity verification box

CN121995999ACN 121995999 ACN121995999 ACN 121995999ACN-121995999-A

Abstract

The invention relates to the technical field of digital twin simulation, in particular to a digital twin-based real-time monitoring method for multiple physical fields of a temperature and humidity verification box, which comprises the steps of constructing a digital twin grid index system, and solving an empty current field by utilizing CFD simulation to obtain reference turbulence energy; the method comprises the steps of obtaining geometric data of equipment to be detected, mapping the equipment to be detected to a digital twin grid index system by utilizing a voxelization algorithm, calculating a thermal inertia correction coefficient, iteratively solving a flow field based on the thermal inertia correction coefficient, generating a source item by applying virtual resistance density and turbulence energy, calculating to obtain real-time correction turbulence energy, calculating credibility weight according to the ratio of the real-time correction turbulence energy of a grid unit where a sensor is positioned to the reference turbulence energy, wherein the credibility weight is inversely related to the ratio, and weighting monitoring data by utilizing the credibility weight to realize closed-loop control. The invention effectively solves the problem of monitoring misalignment caused by topology change of the flow field, and improves the monitoring accuracy.

Inventors

XU ZHENZHEN
ZHANG KAIXING
WANG PEIYU
GAO LEI

Assignees

山东磐然仪器集团有限公司
山东农业大学

Dates

Publication Date: 20260508
Application Date: 20260128

Claims (10)

1. The digital twinning-based real-time monitoring method for the multiple physical fields of the temperature and humidity verification box is characterized by comprising the following steps of: Constructing a digital twin grid index system, and performing steady-state solution on an empty flow field of the verification box by using computational fluid dynamics simulation to obtain reference turbulence energy of each grid unit; Obtaining geometric data of equipment to be detected, mapping the equipment to be detected to the digital twin grid index system by utilizing a ray casting voxelization algorithm, and calculating a thermal inertia correction coefficient of each grid unit; Based on the thermal inertia correction coefficient, carrying out iterative solution on the digital twin flow field by utilizing a preset momentum-turbulence energy bidirectional injection operator, and respectively applying virtual resistance density, turbulence energy generation source items and unsteady thermal inertia items in a momentum equation, a turbulence equation and an energy equation to obtain real-time correction turbulence energy and real-time temperature estimated values of each grid unit; Determining grid units where the sensors are positioned, and calculating the credibility weight of each sensor by utilizing the ratio of the real-time correction turbulence energy to the reference turbulence energy and the deviation of the temperature measured value of the sensor and the real-time temperature estimated value; and carrying out weighted calculation on the sensor measured value by using the credibility weight, and carrying out closed-loop control on the verification box by using the obtained weighted monitoring value.
2. The digital twinning-based real-time monitoring method for multiple physical fields of a temperature and humidity verification box according to claim 1, wherein the relation formula for calculating the thermal inertia correction coefficient of each grid unit is: in the formula, Characterization of the first embodiment Thermal inertia correction coefficients of the individual grid cells; Characterizing the placeholder mask, as The value of the center of each grid unit is 1 when the center of each grid unit is positioned in the equipment to be detected, and the value of each grid unit is 0 otherwise; And Respectively representing the specific heat capacity and the density of the material of the equipment to be detected; And The specific heat capacity and density of the air medium are characterized separately.
3. The digital twinning-based real-time monitoring method for multiple physical fields of a temperature and humidity verification box according to claim 1, wherein the method for acquiring the real-time corrected turbulence energy and the real-time temperature estimated value comprises the following steps: The method comprises the steps of constructing a momentum conservation equation containing momentum sink source items, solving the momentum conservation equation to obtain new flow velocity vectors of grid cells, constructing a discretized turbulence transportation equation, calculating resistance power density by using the new flow velocity vectors and virtual resistance density, converting the resistance power density into turbulence energy to generate source items by using vortex conversion efficiency factors and substituting the turbulence energy into the turbulence transportation equation, constructing the discretized energy conservation equation, correcting non-steady-state item coefficients in the energy conservation equation by using thermal inertia correction coefficients, and alternately and circularly solving the momentum conservation equation, the turbulence transportation equation and the energy conservation equation containing the source items by using a SIMPLE algorithm until residual errors are converged to obtain real-time corrected turbulence energy and real-time temperature estimated values.
4. The digital twinning-based real-time monitoring method for multiple physical fields of a temperature and humidity verification box according to claim 3, wherein the virtual resistance density satisfies a relation: in the formula, Characterization of the first embodiment Virtual resistance density experienced by the individual grid cells; Characterization of the first embodiment Space occupying masks of the grid units; Characterizing hydrodynamic viscosity; characterizing a virtual permeability constant; characterizing an inertial resistance coefficient; Characterization of the first embodiment Real-time flow velocity vectors for the individual grid cells; A module characterizing a real-time flow velocity vector; The density of the air medium was characterized.
5. The digital twinning-based real-time monitoring method for multiple physical fields of a temperature and humidity verification box according to claim 3, wherein the turbulence energy generation source term satisfies a relation: in the formula, Characterization of the first embodiment The turbulence energy of the grid cells generates a source term; Characterizing a vortex conversion efficiency factor; Characterization of the first embodiment Virtual resistance density of the individual grid cells; Characterization of the first embodiment Real-time flow velocity vectors for the individual grid cells; the absolute value of the resistive power density is characterized.
6. The digital twinning-based real-time monitoring method for multiple physical fields of a temperature and humidity verification box according to claim 4, wherein the method for acquiring the virtual permeability constant and the inertial resistance coefficient comprises the following steps: Acquiring the porosity and the characteristic diameter of the equipment to be detected, and calculating to obtain a virtual permeability constant and an inertial resistance coefficient by using an Ergun empirical equation; or calculating to obtain a virtual permeability constant and an inertial resistance coefficient based on the porosity and the characteristic diameter by using an Ergun empirical equation; and acquiring pressure drop data through a wind tunnel experiment, fitting to obtain an empirical formula, and reversely calculating the empirical formula to obtain a virtual permeability constant and an inertial resistance coefficient.
7. The digital twinning-based real-time monitoring method for multiple physical fields of a temperature and humidity verification box according to claim 5, wherein the process for obtaining the vortex conversion efficiency factor comprises the following steps: acquiring wake flow temperature decay length of an entity load in a wind tunnel by using a thermal imager; calculating the analog temperature decay length under the corresponding working condition in the digital model; constructing an objective function taking the difference value of the wake flow temperature decay length and the simulated temperature decay length as a target; And searching a numerical value minimizing the objective function by using an optimization algorithm as the vortex conversion efficiency factor.
8. The digital twinning-based real-time monitoring method for multiple physical fields of a temperature and humidity verification box according to claim 1, wherein the calculating of the confidence weights of the sensors uses the following relation: in the formula, Characterization of the first embodiment Confidence weights of the individual sensors; characterizing a blocking ratio correlation factor; characterizing a sensitivity index; Characterization of the first embodiment Grid cell indexes corresponding to the sensors; Characterization of the first embodiment Temperature measurements of the grid cell in which the individual sensors are located, Characterization of the first embodiment Real-time temperature estimates of the grid cells where the individual sensors are located, The consistency penalty factor is characterized as such, Characterization of the first embodiment Position orientation factors of the individual sensors; Characterization of the first embodiment Real-time turbulence energy correction is carried out on grid units where the sensors are positioned; Characterization of the first embodiment The reference turbulence energy of the grid unit where the sensors are positioned; The anti-zero parameter is characterized in that, The target set temperature of the assay chamber is characterized.
9. The digital twinning-based real-time monitoring method for multiple physical fields of a temperature and humidity verification box according to claim 8, wherein the position and direction factors satisfy the relation: in the formula, Characterization of the first embodiment Physical coordinate vectors of the individual sensors; Characterizing the geometric center coordinate vector of the device under inspection, Characterizing a sensitivity index; Characterization of the first embodiment Real-time flow velocity vectors of the grid cells where the individual sensors are located, Characterization of the first embodiment Position orientation factors of the individual sensors; A module characterizing a real-time flow velocity vector; characterizing the anti-zero parameter.
10. The digital twinning-based real-time monitoring method for multiple physical fields of a temperature and humidity verification box according to claim 8, wherein the acquiring process of the sensitivity index comprises the following steps: Acquiring temperature data of each historical moment acquired by the high-precision standard platinum resistor as a true value; Acquiring temperature data of all sensors at each historical moment, calculating reliability weights under different sensitivity index combinations, and carrying out weighted calculation on the historical temperature data of all the sensors at each historical moment by using the reliability weights to obtain weighted monitoring values; Calculating a root mean square error between the weighted monitoring value and the true value; And selecting a sensitivity index combination which minimizes the root mean square error as a set value of the sensitivity index.

Description

Digital twinning-based real-time monitoring method for multiple physical fields of temperature and humidity verification box Technical Field The invention relates to the technical field of digital twin simulation. More particularly, the invention relates to a digital twinning-based real-time monitoring method for multiple physical fields of a temperature and humidity verification box. Background The temperature and humidity verification box is used as key basic equipment in the metering detection field and is mainly used for carrying out magnitude tracing and calibration on various temperature and humidity sensors, recorders and environment monitoring equipment. Existing assay-box control systems are generally based on the physical assumption of a steady-state uniform field, i.e., that the flow rate, temperature, and humidity distribution of the fluid medium is considered uniform and stable over the active operating area. Based on this assumption, in the prior art, a sensor with a fixed position is mostly used to collect an environmental parameter, and the parameter is regarded as an average state value of the whole working area, so that the output power of the heater and the humidifier is adjusted through a PID controller. Under the working condition of no load or tiny load, the control logic can meet the requirements of national metering calibration standards on temperature and humidity fluctuation degree and uniformity. However, in an actual industrial metering scenario, the inside of the calibration box often needs to be placed with physical entities to be tested, which have different forms, different materials and a certain volume. The presence of these physical loads breaks the physical assumption of a steady-state uniform field. From a microfluidic mechanical perspective, when a fluid flows through a non-streamlined solid load, boundary layer separation occurs at the tail of the fluid, thereby inducing wake, vortex shedding, and a recirculation zone. At this time, the topology structure of the flow field is fundamentally changed, the area originally in a laminar flow state may be converted into a turbulent flow area with high turbulence, and the area originally in the main flow channel may be changed into a dead water area due to load shielding. Such distortion of the flow field topology can lead to a significant deviation between the sensor readings and the real environmental conditions of the work area. If the fixed sensor is just positioned in a wake flow backflow area generated by a load, the acquired temperature and humidity data are mainly influenced by the thermal inertia of the load, obvious hysteresis exists, the change of a central main flow area of the box body cannot be responded in time, and if the sensor is positioned in a slit acceleration area, the heat convection coefficient of the sensor is increased suddenly, so that transient overshoot occurs in a measured value. Existing control systems still use preset arithmetic average weights to process sensor data due to lack of perceptibility of such flow field and load coupling effects. The processing mode of calculating the non-ideal state dynamic turbulence process by using the ideal state static operator constitutes the fundamental contradiction of parameter space-time mismatch. This mismatch is macroscopically manifested by the controller receiving a distorted feedback signal, resulting in a system that is subject to tuning oscillations, overshoot, or extended settling time. Particularly, when the precise detection is carried out in multiple physical fields, the fluctuation of the wet bulb temperature caused by local turbulence can lead to the severe jump of the relative humidity reading, so that the detection box is difficult to reach the specified metering index under the loaded working condition. Although some prior art attempts to increase sampling density by increasing the number of sensors, if abnormal distortion data severely interfered by turbulence cannot be identified and removed, only increasing the data volume can introduce more noise, and the physical contradiction between flow field topological distortion and fixed monitoring points caused by load intervention cannot be fundamentally solved. Disclosure of Invention In order to solve the problem that monitoring data cannot accurately represent the environment of an effective working area due to topological change of a flow field in the prior art under a loaded working condition, the invention provides a digital twinning-based real-time monitoring method for a plurality of physical fields of a temperature and humidity verification box, which comprises the following steps: Constructing a digital twin grid index system, and performing steady-state solution on an empty flow field of the verification box by using computational fluid dynamics simulation to obtain reference turbulence energy of each grid unit; Obtaining geometric data of equipment to be detected, mapping the equi