CN-121978164-A - Quantification method of dynamic consistency of temperature field based on thermal field analysis

CN121978164ACN 121978164 ACN121978164 ACN 121978164ACN-121978164-A

Abstract

The invention discloses a method for quantifying the dynamic consistency of a temperature field based on thermal field analysis, which comprises the steps of respectively arranging temperature measuring points at the upstream and downstream of a filter, applying set disturbance at a constant temperature stage, collecting a multipoint temperature sequence, removing trend and bandpass filtering to obtain preprocessed temperature data, calculating the average value of the phases of the upstream and downstream temperature sequences in a preset frequency band by adopting frequency domain analysis, classifying the result into a main value area to form a downstream phase set, calculating the average absolute value of the phase and a circle statistical parameter according to the set, comprehensively obtaining the killing effect score reflecting the temperature uniformity by calculating the complementary value of the average absolute value of the phase and the exponential decay result of the circle statistical parameter, and realizing the quantitative evaluation of the dynamic consistency of the killing temperature field.

Inventors

ZANG QIANG
SUN JUNFENG
TIAN YE
FANG QIAN
HAN GUOFENG
DUAN ENZE
WANG HUIXIN
BAI ZONGCHUN

Assignees

南京信息工程大学
淄博市张店区疾病预防控制中心
江苏省农业科学院

Dates

Publication Date: 20260505
Application Date: 20260403

Claims (8)

1. A method for quantifying temperature field dynamic consistency based on thermal field analysis, comprising: (1) At least one temperature measuring point is arranged at the upstream of a filter of the microorganism incubator, and a plurality of temperature measuring points are arranged at the downstream of the filter; (2) In the constant temperature stage of the killing process, setting disturbance is applied to the incubator, and the temperature sequence of each temperature measuring point is acquired according to preset sampling parameters; (3) Trend removal and band-pass filtering treatment are respectively carried out on each temperature sequence to obtain a pretreated temperature sequence; (4) Calculating the average value of the phase of the preprocessed temperature sequence of the upstream temperature measuring point and the average value of the phase of the preprocessed temperature sequence of each downstream temperature measuring point in a preset frequency band by adopting a frequency domain analysis method, and classifying each average value of the phase into a preset main value area to form a downstream phase set; (5) Calculating to obtain a phase average absolute value and a circle statistical parameter based on the downstream phase set; (6) And calculating the complementary value of the average absolute value of the phase, carrying out attenuation treatment on the round statistical parameter, and calculating to obtain a killing effect score reflecting the temperature uniformity according to the complementary value and the attenuation treatment result, thereby completing the quantification of the dynamic consistency of the killing temperature field.
2. The method for quantifying the dynamic uniformity of a temperature field based on thermal field analysis according to claim 1, wherein in the step (1), the direction in which air flows downstream from the filter is set to be forward with reference to the neutral plane of the filter; the directional distance from the temperature measuring point to the neutral plane is defined as the shortest signed distance, positive values are positioned on the forward side, and negative values are positioned on the reverse side; If the directional distance from the temperature measuring point to the neutral plane is a negative value, the temperature measuring point is taken as an upstream temperature measuring point, and if the directional distance from the temperature measuring point to the neutral plane is a positive value, the temperature measuring point is taken as a downstream temperature measuring point.
3. The method for quantifying the dynamic consistency of a temperature field based on thermal field analysis according to claim 2, wherein step (2) is specifically as follows: Determining a sampling time interval and a sampling point number; the total sampling duration is not less than three times of a preset disturbance period; the preset disturbance period is a period which changes according to the sine law; applying a set temperature at a constant temperature stage; determining each discrete sampling time according to the sampling time interval; the total number of the temperature measuring points is the sum of the number of the upstream temperature measuring points and the number of the downstream temperature measuring points; And respectively acquiring the temperature of each temperature measuring point at each discrete sampling moment to form a temperature sequence corresponding to each temperature measuring point.
4. The method for quantifying thermal field analysis-based temperature field dynamic consistency according to claim 3, wherein step (3) is specifically as follows: Performing polynomial least square fitting for three times on the temperature sequence corresponding to each temperature measuring point to obtain a trend term, and subtracting the corresponding trend term from the temperature sequence to obtain a temperature sequence with trend removed; setting a band-pass lower limit frequency, a band-pass upper limit frequency and a filter order, and processing the temperature sequence after trending by adopting a zero-phase bidirectional Butterworth band-pass filtering mode to obtain a preprocessed temperature sequence.
5. The method for quantifying thermal field analysis-based temperature field dynamic consistency according to claim 4, wherein in step (4), a frequency domain analysis method is used to calculate a phase average value of the pre-processed temperature sequence of the upstream temperature measurement point and the pre-processed temperature sequence of each downstream temperature measurement point within a preset frequency band, and the method is specifically as follows: Determining an upstream temperature measuring point set and a downstream temperature measuring point set according to the positive and negative direction distances from the temperature measuring points to the neutral plane of the filter; Calculating the average value of the preprocessed temperature sequences corresponding to all upstream temperature measuring points to obtain an upstream reference preprocessed temperature sequence; Performing discrete Fourier transform on the upstream reference pre-processed temperature sequence and the pre-processed temperature sequence corresponding to each downstream temperature measuring point respectively; Obtaining a cross spectrum corresponding to each downstream temperature measuring point through conjugate operation, and extracting the argument of each cross spectrum as the phase of the corresponding downstream temperature measuring point; Determining a preset frequency band according to the band-pass lower limit frequency and the band-pass upper limit frequency; Screening out a discrete frequency point set in the preset frequency band; and averaging all phases of each downstream temperature measuring point in the discrete frequency point set to obtain a phase average value corresponding to each downstream temperature measuring point.
6. The method for quantifying thermal field analysis-based temperature field dynamic consistency according to claim 5, wherein in step (4), each phase average value is classified into a preset main value region to form a downstream phase set, specifically as follows: the preset main value area is an interval from negative circumference rate to positive circumference rate, and comprises positive circumference rate; The method comprises the steps of (1) carrying out downward rounding on a phase average value corresponding to each downstream temperature measuring point, dividing the sum of the phase average value and the positive circumference ratio by the double circumference ratio, and subtracting the product of the double circumference ratio and the downward rounding result from the phase average value to obtain a result mapped to a preset main value area; if the mapped result is a negative circumference ratio, the result is adjusted to be a positive circumference ratio, and a main valued phase corresponding to each downstream temperature measuring point is obtained; and collecting main valued phases corresponding to all downstream temperature measuring points to form a downstream phase set.
7. The method for quantifying thermal field analysis-based temperature field dynamic consistency according to claim 6, wherein step (5) is specifically as follows: Calculating the average value of the absolute values of all the main valued phases to obtain the average absolute value of the phases; calculating the average value of cosine values of each main valued phase to obtain a circular statistical cosine average value; Calculating the average value of the sine values of each main valued phase to obtain a round statistic sine average value; Adding the square of the round statistical cosine average value and the square of the round statistical sine average value, and taking the square root to obtain the round statistical consistency; And subtracting the round statistical consistency from one to obtain the round statistical dispersion.
8. The method for quantifying thermal field analysis-based temperature field dynamic consistency according to claim 7, wherein step (6) is specifically as follows: calculating the complementary value of the average absolute value of the phase, carrying out attenuation treatment on the round statistics related parameters, and calculating the killing effect score reflecting the temperature uniformity according to the complementary value and the attenuation treatment result, wherein the method comprises the following steps: Subtracting the ratio of the average absolute value of the phase to the peripheral rate to obtain the complementary value of the average absolute value of the phase; calculating by taking a natural constant as a base and taking a negative value of the circle statistical dispersion as an index to obtain a result after applying exponential decay to the circle statistical dispersion; and multiplying the complementary value of the average absolute value of the phase with the result of exponential decay to obtain a killing effect score reflecting the temperature uniformity, and completing the quantification of the dynamic consistency of the killing temperature field.

Description

Quantification method of dynamic consistency of temperature field based on thermal field analysis Technical Field The invention relates to the technical field of thermal field analysis, in particular to a quantification method of dynamic consistency of a temperature field based on thermal field analysis. Background Microbial incubators are widely used in laboratory and biopharmaceutical environments for microbial cultivation, preservation and periodic sterilization. Typically, the kill cycle includes modes such as high Wen Ganre sterilization (e.g., 140-180 degrees), wet-hot decontamination (about 90 degrees), chemical gas decontamination (e.g., hydrogen peroxide vapor), and the like. The temperature control of the existing equipment mostly adopts a single-point sensor and a cavity circulating heating system, and the stability of temperature distribution is maintained through a heater, a fan and an air deflector. However, there are significant differences in the internal air flow rates, humidity, pressure, and thermal boundary conditions of the system under different kill modes. In particular in systems with filter devices, the direction of air flow and the heat exchange efficiency are not constant, resulting in complex time-variations of the temperature field within the thermostatic segment. Temperature uniformity is typically assessed by arranging a plurality of stations and calculating the instantaneous temperature difference at each point. This static evaluation method is suitable for steady state heating equipment, but its reliability is significantly reduced in incubators where air circulation and filtration devices are present. When the fan is started or stopped or the filter unit is disassembled, the air flow direction and the heat transfer path are changed, so that the temperature distribution is delayed and fluctuated in time. Since conventional uniformity tests only record instantaneous temperature, without taking such dynamic delays into account, it is common for the measured value to be uniform in surface and for the local area not to reach the kill temperature, resulting in a misdetermination. The existing incubator killing temperature analysis method ignores the influence mechanism of the air filtering unit on the temperature field under different working conditions. The filter device not only changes the circulation amount of the air flow, but also has certain heat capacity and hygroscopicity, and the physical state of the filter device can be changed along with the switching of the killing mode. For example, in a wet and hot decontamination mode, the filter material absorbs moisture and then slowly responds to the conduction and release of hot air, and in a high temperature dry and hot mode, the filter material is removed or in an inert state, and a completely different heat transfer path is formed in the cavity. These state changes make the temperature response of each area in the box body no longer synchronous, so that the temperature uniformity index measured by the traditional method cannot reflect the heat distribution condition of the actual killing stage. Disclosure of Invention The invention aims to provide a quantification method for the dynamic consistency of a temperature field based on thermal field analysis, which is used for quantifying the dynamic consistency of the temperature field in the process of killing a microbial incubator. The method for quantifying the dynamic consistency of the temperature field based on the thermal field analysis comprises the following steps: (1) At least one temperature measuring point is arranged at the upstream of a filter of the microorganism incubator, and a plurality of temperature measuring points are arranged at the downstream of the filter; (2) In the constant temperature stage of the killing process, setting disturbance is applied to the incubator, and the temperature sequence of each temperature measuring point is acquired according to preset sampling parameters; (3) Trend removal and band-pass filtering treatment are respectively carried out on each temperature sequence to obtain a pretreated temperature sequence; (4) Calculating the average value of the phase of the preprocessed temperature sequence of the upstream temperature measuring point and the average value of the phase of the preprocessed temperature sequence of each downstream temperature measuring point in a preset frequency band by adopting a frequency domain analysis method, and classifying each average value of the phase into a preset main value area to form a downstream phase set; (5) Calculating to obtain a phase average absolute value and a circle statistical parameter based on the downstream phase set; (6) And calculating the complementary value of the average absolute value of the phase, carrying out attenuation treatment on the round statistical parameter, and calculating to obtain a killing effect score reflecting the temperature uniformity according to the comple