Method and system for on-line detection of temperature and flow during fermentation broth sterilization process

Abstract

The application discloses a fermentation liquid sterilization process temperature flow online detection method and system, relates to the technical field of process detection, and comprises the following steps: carrying out benchmark detection on a holding pipe in a sterile water full state to obtain a detection benchmark result; discriminating near-infrared transmission signals and along-path temperature distribution during sterilization operation according to the detection benchmark result, determining a continuous liquid phase effective period, and locking a real along-path temperature zone to obtain an effective detection result; controlling a heat pulse loading ring to continuously apply two short-time heat pulses to fermentation liquid entering the holding pipe in the continuous liquid phase effective period, and tracking a temperature rise propagation zone formed by the two short-time heat pulses along the real along-path temperature zone to lock a heat pulse actual propagation path, a lowest temperature section and a local retention section to obtain a propagation analysis result. The application establishes a corresponding relationship among a temperature position, a propagation position and a flow position in the same holding pipe section by continuously applying two short-time heat pulses and tracking a double-pulse temperature rise propagation zone.

Description

Technical Field

[0001] This invention relates to the field of process detection technology, and in particular to a method and system for online detection of temperature and flow rate during the sterilization process of fermentation broth. Background Technology

[0002] With the continuous development of processes in bio-fermentation, enzyme preparation, functional microbial culture, and bio-based material production, the sterilization of fermentation broth has gradually shifted from single endpoint control to online monitoring and process verification throughout the entire process. Existing technologies typically revolve around the holding tube, heat exchange section, and flow detection unit. Temperature sensors, flow meters, and transmission or contact detection elements are used to collect data in real time during the sterilization process to determine the thermal state, flow state, and operational stability of the fermentation broth within the holding tube. In engineering applications, common practices include temperature monitoring at key locations within the holding tube, continuous acquisition of outlet flow rate, and process evaluation of sterilization conditions based on the operational status during heat exchange. Furthermore, with the development of distributed temperature measurement, clamp-on flow detection, and online transmission detection technologies, these detection methods have achieved high continuity and field adaptability, providing a technological foundation for refined monitoring of the fermentation broth sterilization process.

[0003] However, existing technologies still have significant limitations. First, current methods mostly rely on single-point or a small number of discrete temperature signals to determine the sterilization status, making it difficult to accurately reflect the true temperature distribution within the holding tube, especially in identifying the lowest temperature segment consistent with the flow path, thus resulting in insufficient identification of unfavorable sterilization locations. Second, existing methods typically process flow rate and temperature separately, lacking a joint discrimination mechanism based on the actual propagation process. This makes it difficult to accurately characterize the actual flow state under conditions of entrained bubbles in the fermentation broth, discontinuous liquid phase, local stagnation, or delayed propagation, thus resulting in a lack of reliable correlation between flow rate results, residence conditions, and sterilization determination. Summary of the Invention

[0004] In view of the aforementioned existing problems, the present invention is proposed.

[0005] Therefore, this invention provides an online temperature and flow rate detection method for the sterilization process of fermentation broth, which solves the problem of limited accuracy in sterilization determination caused by continuous liquid phase discrimination distortion and insufficient temperature and flow rate coupled detection during the sterilization process of fermentation broth.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0007] In a first aspect, the present invention provides a method for online detection of temperature and flow rate during the sterilization process of fermentation broth, comprising,

[0008] A baseline test is performed on the holding tube filled with sterile water. The baseline test is completed by a near-infrared transmission detection channel set at the upstream and end of the holding tube, a distributed temperature measuring optical fiber spirally wound along the outer wall of the holding tube, a heat pulse loading ring set at the outer periphery of the holding tube inlet, and a clamp-on flow meter set at the holding tube outlet, and the test baseline result is obtained.

[0009] Based on the detection benchmark results, the near-infrared transmission signal and temperature distribution along the sterilization process are judged to determine the effective time period of the continuous liquid phase and lock the true temperature band along the process, so as to obtain effective detection results;

[0010] During the effective period of continuous liquid phase, the thermal pulse loading ring is controlled to continuously apply two short thermal pulses to the fermentation broth entering the holding tube, and the temperature rise propagation band formed by the two short thermal pulses is tracked along the actual temperature band. The actual propagation path of the thermal pulse, the lowest temperature section and the local retention section are locked to obtain the propagation analysis results.

[0011] Based on the propagation analysis results, the continuous flow rate output of the clamp-on flow meter is calibrated to determine the actual flow rate, the actual residence conditions in the lowest temperature section, and the propagation hysteresis in the local stagnation section, thereby obtaining the operating results of the retention section.

[0012] The sterilization results of the holding period operation within the effective time period of continuous liquid phase are used to determine the sterilization status and obtain the online sterilization detection conclusion.

[0013] As a preferred embodiment of the online temperature and flow rate detection method for the sterilization process of fermentation broth described in this invention, the step of performing benchmark detection on the holding tube filled with sterile water specifically includes:

[0014] Fill the holding tube with sterile water and keep the upstream and downstream near-infrared transmission detection channels in a stable transmission state to obtain the full liquid reference state.

[0015] The continuous temperature distribution along the entire length of the holding tube is collected along the distributed temperature measurement optical fiber to form a temperature reference band along the tube.

[0016] Verify the output stability of the clamp-on flow meter under sterile water circulation conditions, and determine the continuous flow output status of the clamp-on flow meter during sterilization operation;

[0017] The full liquid reference state is used as the near-infrared transmission discrimination reference, the friction temperature reference band is used as the friction temperature discrimination reference, and the continuous flow output state is used as the operating reference of the clamp-on flow meter to obtain the detection reference result.

[0018] As a preferred embodiment of the online temperature and flow rate detection method for the sterilization process of fermentation broth described in this invention, the step of discriminating between the near-infrared transmission signal and the temperature distribution along the sterilization process specifically includes:

[0019] The real-time transmission status collected by the upstream and downstream near-infrared transmission detection channels during sterilization operation is compared with the full liquid reference status hour by hour to form the upstream full liquid judgment result and the downstream full liquid judgment result;

[0020] The running period in which both the upstream and downstream full liquid determination results satisfy the full liquid determination condition is defined as the effective continuous liquid phase period.

[0021] The temperature distribution along the process collected by the distributed temperature measurement fiber during sterilization is compared with the temperature reference band along the process segment by segment. The overall temperature rise segment caused by the initial heating and steam switching is eliminated, and the continuous temperature change segment formed by the fermentation broth through the holding tube is retained to obtain the true temperature band along the process.

[0022] By limiting the effective time period of continuous liquid phase to the operating section corresponding to the actual temperature zone along the pipeline, effective detection results can be obtained.

[0023] As a preferred embodiment of the online temperature and flow rate detection method for the fermentation broth sterilization process described in this invention, the step of tracing the temperature rise propagation band formed by two consecutive short-duration heat pulses along the actual temperature band specifically includes:

[0024] During the effective period of continuous liquid phase, the thermal pulse loading ring is activated to send a first short thermal pulse and a second short thermal pulse with a fixed interval to the fermentation broth entering the holding tube;

[0025] Along the distributed temperature measurement optical fiber, within the operating section defined by the effective detection results, the continuous temperature rise trajectory caused by the first short-time thermal pulse and the second short-time thermal pulse on the outer wall of the holding tube is recorded, forming the first temperature rise propagation zone and the second temperature rise propagation zone respectively;

[0026] The first and second temperature rise propagation zones are arranged sequentially along the flow direction of the holding tube to form a double-pulse temperature rise propagation zone.

[0027] As a preferred embodiment of the online temperature and flow rate detection method for the fermentation broth sterilization process described in this invention, the method of locking the actual propagation path of the heat pulse specifically includes:

[0028] In the double-pulse temperature rise propagation band, the positions where the temperature rise response first appears and the positions where the temperature rise response last appears along the flow direction are extracted and used as the starting response position and the ending response position, respectively.

[0029] The starting and ending response positions are connected along the holding tube to form the actual propagation path of the thermal pulse, and the actual propagation path of the thermal pulse is limited to the holding tube section corresponding to the true temperature band along the path in the effective detection results.

[0030] As a preferred embodiment of the online temperature and flow rate detection method for the fermentation broth sterilization process described in this invention, the locking of the lowest temperature range specifically includes:

[0031] Search for continuous temperature valleys along the actual temperature zone and in the direction of the holding tube flow to form a temperature valley sequence;

[0032] Select consecutive temperature valleys from the temperature valley sequence whose temperature values ​​are lower than those of the adjacent valleys on both sides to form the lowest temperature valleys;

[0033] The lowest temperature range is limited to the holding tube section corresponding to the valid detection result, and spatial location is mapped with the holding tube section corresponding to the actual propagation path of the heat pulse to determine the lowest temperature range located in the same holding tube section as the actual propagation path of the heat pulse.

[0034] As a preferred embodiment of the online temperature and flow rate detection method for the fermentation broth sterilization process described in this invention, the locking of the local stagnation zone specifically includes:

[0035] The temperature rise propagation time difference between the first and second temperature rise propagation zones at adjacent temperature measurement positions was measured along the double-pulse temperature rise propagation zone according to the flow direction of the holding tube, and the local propagation time of each section was calculated to form the local propagation distribution results;

[0036] Search along the flow direction of the holding tube for sections where the local propagation time increases or the local propagation speed decreases, and form local stagnation sections where local propagation anomalies occur at corresponding positions in both the first and second temperature rise propagation zones.

[0037] The localized retention section is mapped along the flow direction of the holding tube to the actual propagation path of the heat pulse, thus obtaining the localized retention section corresponding to the actual propagation path of the heat pulse;

[0038] By correlating the actual propagation path of the heat pulse, the lowest temperature segment, and the local stagnation segment corresponding to the actual propagation path of the heat pulse, the propagation analysis results are obtained.

[0039] As a preferred embodiment of the online temperature and flow rate detection method for the fermentation broth sterilization process described in this invention, the step of calibrating the continuous flow rate output by the clamp-on flow meter based on the propagation analysis results specifically includes:

[0040] The actual propagation path of the thermal pulse across the holding tube and the propagation time of the double-pulse temperature rise propagation band across the cross section are determined to form the true through speed.

[0041] Based on the correspondence between the actual flow velocity and the apparent flow velocity output by the clamp-on flow meter, the continuous flow output of the clamp-on flow meter under the continuous flow output state in the detection benchmark result is proportionally corrected to form the actual flow result.

[0042] The actual residence conditions in the lowest temperature section are determined based on the actual flow rate results, and the propagation lag in the local stagnation section is determined based on the actual flow rate results.

[0043] By mapping the actual flow rate, the actual residence time in the lowest temperature section, and the propagation lag in the local stagnation section to the same holding pipe section, the operating results of the holding section are obtained.

[0044] As a preferred embodiment of the online temperature and flow rate detection method for the sterilization process of the fermentation broth described in this invention, the step of determining the sterilization status of the holding period operation results within the effective time period of the continuous liquid phase specifically includes:

[0045] The results of the holding phase operation are limited to the effective time period of the continuous liquid phase to form the sterilization judgment zone results;

[0046] Extract the actual flow rate and actual residence time of the lowest temperature section from the sterilization determination section results to form the section determination results;

[0047] The results of the section determination are compared with the target requirements to form a test conclusion on whether the target requirements have been met;

[0048] The positional relationship between the lowest temperature section and the local retention section on the holding tube is verified. When the lowest temperature section and the local retention section are located at the same holding position, a key focus section is formed.

[0049] The results of the lowest temperature range, the actual flow rate corresponding to the lowest temperature range, the actual residence time corresponding to the lowest temperature range, the test conclusions, and the key areas of concern are summarized into the online sterilization test conclusions.

[0050] Secondly, the present invention provides an online temperature and flow rate detection system for the sterilization process of fermentation broth, including a reference detection module for performing reference detection on a holding tube filled with sterile water. The reference detection is completed by a near-infrared transmission detection channel set at the upstream and end of the holding tube, a distributed temperature measuring optical fiber spirally wound along the outer wall of the holding tube, a heat pulse loading ring set at the outer periphery of the holding tube inlet, and a clamp-on flow meter set at the holding tube outlet, thereby obtaining the detection reference result.

[0051] The liquid phase discrimination module, based on the detection benchmark results, discriminates the near-infrared transmission signal and temperature distribution along the sterilization process, delineates the effective time period of the continuous liquid phase and locks the actual temperature band along the process, and obtains effective detection results.

[0052] The pulse propagation module controls the thermal pulse loading ring to continuously apply two short thermal pulses to the fermentation broth entering the holding tube during the effective period of continuous liquid phase. It also tracks the temperature rise propagation band formed by the two short thermal pulses along the actual temperature band, locks the actual propagation path of the thermal pulse, the lowest temperature section and the local stagnation section, and obtains the propagation analysis results.

[0053] The operation analysis module calibrates the continuous flow rate output by the clamp-on flow meter based on the propagation analysis results, determines the actual flow rate, the actual residence conditions in the lowest temperature section, and the propagation hysteresis in the local stagnation section, and obtains the operating results of the retention section.

[0054] The sterilization determination module performs sterilization determination on the holding period operation results within the effective time period of the continuous liquid phase and outputs the sterilization online detection conclusion.

[0055] The beneficial effects of this invention are as follows: By first performing benchmark testing on the holding tube filled with sterile water, and then simultaneously identifying the near-infrared transmission signal and temperature distribution along the flow path during sterilization, the effective period of continuous liquid phase can be screened out in advance, and the true temperature band along the flow path can be locked, reducing the interference of bubbles, foam, steam switching, and overall temperature rise on subsequent analysis from the source. By continuously applying two short-duration thermal pulses and tracking the double-pulse temperature rise propagation band, combined with the controllable pulse loading parameters of the thermal pulse loading loop and the ability of distributed temperature measurement optical fiber to collect the continuous temperature rise response of the entire holding tube, not only can the actual propagation path of the thermal pulse be obtained, but also the lowest temperature section and the local stagnation section can be identified simultaneously. The local stagnation section is determined by the increased propagation time of the thermal pulse in the local section, the decreased local propagation speed, and the consistent propagation anomaly of the double pulse recurring in the corresponding section, so that the temperature position, propagation position and flow position are established in the same holding tube section. By calibrating the continuous flow rate output of the clamp-on flowmeter using propagation analysis results, the actual flow rate result no longer relies solely on a single flow rate detection, but can reflect the true passage state of the thermal pulse. This improves the accuracy of determining the actual residence conditions in the lowest temperature section and the propagation lag in local stagnation sections. Simultaneously, since the thermal pulse loading duration, the interval between adjacent thermal pulse transmissions, and the spatial resolution, temperature resolution, and sampling period of the distributed temperature sensing fiber are all within a controllable range, the stability of thermal pulse propagation identification and the reliability of identifying local abnormal sections are enhanced. Attached Figure Description

[0056] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. 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.

[0057] Figure 1 This is a flowchart of an online method for detecting temperature and flow rate during the sterilization process of fermentation broth.

[0058] Figure 2 This is a flowchart for determining the effectiveness of liquid phase chromatography.

[0059] Figure 3 This is a flowchart for tracking the propagation of a dual-pulse temperature rise.

[0060] Figure 4 Flowchart for flow calibration and sterilization determination. Detailed Implementation

[0061] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0062] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0063] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0064] Reference Figures 1-4 As one embodiment of the present invention, this embodiment provides a method for online detection of temperature and flow rate during the sterilization process of fermentation broth, comprising the following steps:

[0065] S1. A baseline test is performed on the holding tube in a sterile water-filled state. The baseline test is completed by a near-infrared transmission detection channel set at the upstream and end of the holding tube, a distributed temperature measuring optical fiber spirally wound along the outer wall of the holding tube, a heat pulse loading ring set at the outer periphery of the holding tube inlet, and a clamp-on flow meter set at the holding tube outlet, so as to obtain the test baseline result.

[0066] S1.1. After the main sterilization pipeline of the fermentation broth is installed, first confirm the installation of the near-infrared transmission detection channel set at the upstream and downstream of the holding tube, the distributed temperature measuring optical fiber spirally wound along the outer wall of the holding tube, the heat pulse loading ring set at the outer periphery of the holding tube inlet, and the clamp-on flow meter set at the holding tube outlet. Ensure that the near-infrared transmission detection channel set at the upstream and downstream of the holding tube is in normal transmission state, the distributed temperature measuring optical fiber spirally wound along the outer wall of the holding tube is continuously distributed along the entire length of the holding tube, the heat pulse loading ring set at the outer periphery of the holding tube inlet is in contact with the outer wall of the holding tube, and the clamp-on flow meter set at the holding tube outlet is located at the measurement position at the holding tube outlet.

[0067] In this embodiment, the sampling period of the near-infrared transmission detection channels located upstream and downstream of the holding tube is 0.2s to 1s, which is used to continuously identify the full liquid transmission state at the inlet and outlet sides of the holding tube; the clamp-on flow meter located at the outlet of the holding tube has continuous output capability, with a minimum measurable flow rate of 0.07μL / min and a flow response time of no more than 1s, which is used to characterize the continuous output state under low flow conditions during the sterilization operation phase; the thermal pulse loading ring adopts a controllable short-time heating method, with a single thermal pulse loading duration of 0.2s to 2s and an emission interval of 3s to 20s between two adjacent thermal pulses, in order to ensure that a distinguishable temperature rise propagation response is formed subsequently.

[0068] After installation confirmation, sterile water is introduced into the holding tube until the sterile water is continuously discharged from the end of the holding tube and the gas inside the holding tube is exhausted. During the continuous flow of sterile water through the holding tube, the transmission signals output by the near-infrared transmission detection channels set at the upstream and downstream ends of the holding tube are continuously recorded. When the near-infrared transmission detection channels set at the upstream and downstream ends of the holding tube maintain a stable transmission state, the transmission state corresponding to the sterile water filling condition is recorded as the full liquid reference state.

[0069] Preferably, when the near-infrared transmission detection channels located at the upstream and downstream ends of the holding tube have a transmission fluctuation amplitude that does not exceed ±2% of their respective reference average values ​​over 10 or more consecutive sampling cycles, it is determined that a stable transmission state has been reached.

[0070] It should be noted that, in order to avoid the impact of residual local air bubbles on the accuracy of the full liquid reference state when the sterile water is full, the end of the holding tube can be continuously drained for a period of time before the transmission signal is recorded. When the transmission signal output by the near-infrared transmission detection channel set at the upstream and end of the holding tube shows obvious fluctuations, the sterile water continues to flow and the residual gas in the holding tube is discharged until the near-infrared transmission detection channel set at the upstream and end of the holding tube returns to a stable transmission state, and then the corresponding transmission state is recorded as the full liquid reference state.

[0071] S1.2. During the period of maintaining the full liquid reference state, the temperature distribution of the entire holding tube is continuously collected along the distributed temperature measurement fiber, and the temperature value of the corresponding temperature measurement position is recorded in sequence according to the flow direction of the holding tube, so that a continuous temperature distribution sequence is formed from the inlet to the end of the holding tube; when the temperature distribution sequence remains stable in multiple consecutive collection cycles, the continuous temperature distribution corresponding to the entire holding tube under the state of sterile water full is recorded as the temperature reference zone along the path.

[0072] In this embodiment, the spatial resolution of the distributed temperature measurement fiber is 5mm~50mm, the temperature resolution is 0.05℃~0.2℃, and the sampling period is 0.5s~2s. It is used to identify the natural temperature distribution of the entire holding tube and the local temperature rise propagation process caused by subsequent thermal pulse loading.

[0073] Preferably, when the temperature deviation of the corresponding temperature measurement position does not exceed ±0.1℃ within five or more consecutive acquisition cycles, the temperature distribution sequence is determined to be stable.

[0074] It should be noted that, to reduce the impact of short-term changes in the external ambient temperature of the holding tube on the temperature baseline along the flow path, temperature data acquisition was conducted under conditions of continuous flow of sterile water and the absence of a thermal pulse loading ring located around the inlet of the holding tube. This ensures that the temperature distribution obtained along the distributed temperature-measuring fiber corresponds to the natural temperature distribution of the entire holding tube under sterile water-filled conditions. By establishing a temperature baseline along the flow path, it is possible to distinguish between the overall synchronous temperature rise, steam switching disturbances, and the actual temperature changes that occur along the flow path of the fermentation broth during subsequent sterilization operations. This provides a unified basis for the extraction of the actual temperature band along the flow path.

[0075] S1.3. During the temperature reference zone acquisition along the pipeline, the flow rate value output by the clamp-on flow meter set at the outlet of the retention tube is recorded synchronously, and the sterile water circulation state is kept unchanged; when the flow rate value is continuously output in multiple consecutive acquisition cycles without interruption, jump or abnormal return to zero, the output state of the clamp-on flow meter set at the outlet of the retention tube under the sterile water circulation state is recorded as the continuous flow output state.

[0076] In this embodiment, the clamp-on flow meter can maintain continuous output above 0.07 μL / min and is used for flow monitoring under sterilization conditions in the holding section within the range of 0.07 μL / min to 50 mL / min.

[0077] Preferably, when the flow rate value fluctuates within ±3% of the current average value for more than 10 consecutive sampling periods and no abnormal return to zero occurs, it is determined to be in a continuous flow output state.

[0078] It should be noted that, to avoid the instantaneous fluctuations during the initial startup phase of the clamp-on flowmeter located at the outlet of the holding tube affecting the accuracy of the continuous flow output, the flow rate is preferably recorded after the clamp-on flowmeter has been continuously outputting for a period of time. The absence of abnormal interruptions within multiple consecutive acquisition cycles is used as the criterion for judging the continuous flow output status. The continuous flow output status is not used solely to characterize the improvement in the accuracy of the clamp-on flowmeter itself, but rather serves as an operational benchmark for subsequent calibration of the flow output based on the actual propagation results of the thermal pulse. This ensures that the actual flow results more accurately reflect the operating status of the fermentation broth through the holding tube under conditions of low flow rate, bubble disturbance, or localized propagation anomalies.

[0079] After acquiring the full liquid reference state, the friction temperature reference band, and the continuous flow output state, the full liquid reference state is used as the near-infrared transmission discrimination reference, the friction temperature reference band is used as the friction temperature discrimination reference, and the continuous flow output state is used as the operating reference of the clamp-on flow meter. The detection reference result is formed by the near-infrared transmission discrimination reference, the friction temperature discrimination reference, and the operating reference of the clamp-on flow meter.

[0080] S2. Based on the detection benchmark results, the near-infrared transmission signal and temperature distribution along the sterilization process are judged to determine the effective time period of the continuous liquid phase and lock the true temperature band along the process to obtain effective detection results.

[0081] S2.1. After the detection baseline result is formed, maintain the main sterilization path of the fermentation broth in normal sterilization operation and continuously record the real-time transmission signals output by the near-infrared transmission detection channels located upstream and downstream of the holding tube; compare the real-time transmission signals output by the near-infrared transmission detection channel located upstream of the holding tube with the transmission signals corresponding to the full liquid baseline state according to the sampling sequence. When the real-time transmission signal output by the near-infrared transmission detection channel located upstream of the holding tube maintains a stable transmission characteristic consistent with the full liquid baseline state during continuous sampling, it is recorded as the upstream full liquid establishment result; when the real-time transmission signal output by the near-infrared transmission detection channel located upstream of the holding tube shows obvious fluctuations, continuous deviations, or intermittent changes, it is recorded as the upstream non-full liquid establishment result; compare the real-time transmission signals output by the near-infrared transmission detection channel located downstream of the holding tube with the transmission signals corresponding to the full liquid baseline state according to the sampling sequence. The real-time transmission signal output by the measurement channel is compared with the transmission signal corresponding to the full liquid reference state in the same way. When the real-time transmission signal output by the near-infrared transmission detection channel at the end of the holding tube maintains a stable transmission characteristic consistent with the full liquid reference state during continuous sampling, it is recorded as the end full liquid established result. When the real-time transmission signal output by the near-infrared transmission detection channel at the end of the holding tube shows obvious fluctuations, continuous deviations, or intermittent changes, it is recorded as the end non-full liquid established result. The upstream full liquid establishment result or the upstream non-full liquid establishment result corresponding to the near-infrared transmission detection channel at the upstream of the holding tube is used to form the upstream full liquid discrimination result. The end full liquid establishment result or the end non-full liquid establishment result corresponding to the near-infrared transmission detection channel at the end of the holding tube is used to form the end full liquid discrimination result.

[0082] When the upstream full liquid determination result and the end full liquid determination result remain consistent with the full liquid reference state within the same operating period, the corresponding operating period is recorded as the continuous liquid phase effective period. In this embodiment, the continuous liquid phase effective period refers to the operating period in which the fermentation broth continuously fills the area from the inlet to the end of the holding tube, and the near-infrared transmission detection channels located at the upstream and end of the holding tube do not exhibit significant devitrification, fluctuation instability, or intermittent changes.

[0083] It should be noted that, in order to avoid the impact of air bubbles, foam, or steam switching disturbances in the fermentation broth on the accuracy of determining the effective period of the continuous liquid phase, when the real-time transmission signal output from either of the near-infrared transmission detection channels located upstream and downstream of the holding tube shows a sudden change, periodic fluctuation, or continuous deviation from the full liquid reference state, the corresponding running period will not be recorded in the effective period of the continuous liquid phase. Instead, the recording will continue until the near-infrared transmission detection channels located upstream and downstream of the holding tube return to the transmission state consistent with the full liquid reference state, and then it will be re-classified as the effective period of the continuous liquid phase.

[0084] S2.2. During the effective period of continuous liquid phase formation, the temperature distribution along the entire holding tube during sterilization is continuously collected along the distributed temperature-measuring optical fiber, and the temperature values ​​at each measurement position are recorded according to the flow direction of the holding tube, forming a temperature sequence along the path during sterilization. The temperature sequence along the path is compared segment by segment with the temperature reference band along the path. First, temperature change segments that rise synchronously, fall synchronously, or rise overall for a short time along the entire holding tube are identified. Then, the overall temperature rise segments caused by the initial heating and steam switching are removed from the temperature sequence along the path. Only the continuous temperature change segments that unfold locally along the holding tube and are consistent with the process of the fermentation broth passing through are retained, and the continuous temperature change segments are recorded as the true temperature band along the path. In this embodiment, the true temperature band along the path represents the continuous temperature distribution formed at the corresponding position along the distributed temperature-measuring optical fiber when the fermentation broth actually passes through the holding tube. It does not include the synchronous temperature rise caused by the overall heating of the holding tube, nor does it include non-flow-through temperature disturbances caused by steam switching, external environmental fluctuations, and the failure of the heat pulse loading loop to be triggered.

[0085] It should be noted that, in order to avoid the impact of local environmental changes outside the holding tube on the identification of the actual temperature zone along the flow path, the temperature reference zone along the flow path is used as the reference for the natural temperature distribution of the holding tube when comparing segments, and the continuous change relationship between adjacent temperature measurement positions obtained along the distributed temperature measurement fiber is used as the criterion; when a certain temperature change is only manifested as a simultaneous increase in the entire section of the holding tube and not as a sequential expansion along the flow direction of the holding tube, the corresponding temperature change is regarded as the overall temperature rise segment and is not included in the actual temperature zone along the flow path.

[0086] S2.3. The effective time period of the continuous liquid phase is limited to the operating segment corresponding to the actual temperature band along the flow path, ensuring that the effective time period of the continuous liquid phase and the actual temperature band along the flow path are consistent within the same sterilization operating segment. The limited operating segment is recorded as the effective detection result. In this embodiment, the effective detection result is used to characterize the operating segment that meets both the continuous liquid phase conditions and reflects the actual process of the fermentation broth passing through the holding tube, thereby ensuring that the temperature rise propagation band formed by the subsequent heat pulse loading ring is tracked only within the operating segment corresponding to the effective detection result.

[0087] In this embodiment, a one-to-one conversion relationship between the near-infrared transmission detection channel and the thermal pulse loading ring is not established between the transmission value and the thermal pulse temperature rise value. Instead, the near-infrared transmission detection channel first provides the effective time period of the continuous liquid phase, and then the thermal pulse loading ring triggers thermal pulse propagation tracking within the effective time period of the continuous liquid phase. The distributed temperature measurement fiber records the propagation position of the thermal pulse along the holding tube, thereby establishing a time period constraint relationship and a spatial position registration relationship between the near-infrared transmission discrimination result and the thermal pulse propagation result within the same operating period and the same holding tube segment.

[0088] It should be noted that, in order to ensure the feasibility of valid test results, when a continuous liquid phase effective time period exists but a true friction temperature band is not formed in the corresponding section, the corresponding operating section will not be recorded as a valid test result; when a true friction temperature band exists but the corresponding section does not belong to the continuous liquid phase effective time period, the corresponding operating section will also not be recorded as a valid test result, until the continuous liquid phase effective time period and the true friction temperature band are simultaneously satisfied in the same operating section, then the corresponding operating section will be recorded as a valid test result.

[0089] S3. During the effective period of continuous liquid phase, the thermal pulse loading ring is controlled to continuously apply two short thermal pulses to the fermentation broth entering the holding tube, and the temperature rise propagation band formed by the two short thermal pulses is tracked along the actual temperature band. The actual propagation path of the thermal pulse, the lowest temperature section and the local stagnation section are locked to obtain the propagation analysis results.

[0090] S3.1. The operating section defined by the effective detection results is used as the thermal pulse loading and temperature rise tracking section. The thermal pulse loading ring is started during the effective period of continuous liquid phase, so that the thermal pulse loading ring continuously applies the first short-time thermal pulse and the second short-time thermal pulse to the fermentation broth entering the holding tube along the outer periphery of the holding tube inlet. The first short-time thermal pulse and the second short-time thermal pulse maintain a fixed time interval.

[0091] Preferably, the fixed time interval between the first short-term thermal pulse and the second short-term thermal pulse can remain unchanged after the main sterilization circuit of the fermentation broth is running stably, so that the dual-pulse temperature rise propagation band has a clear correspondence within the same continuous liquid phase effective time period; when the time interval between the first short-term thermal pulse and the second short-term thermal pulse is too short and the first temperature rise propagation band overlaps with the second temperature rise propagation band, the fixed time interval between the first short-term thermal pulse and the second short-term thermal pulse can be extended and the dual-pulse temperature rise propagation band can be re-recorded.

[0092] The fixed time interval is fixed for the same double-pulse detection sequence, but can be reset between different double-pulse detection sequences based on the apparent flow rate output by the clamp-on flow meter, the propagation time of the previous double pulse, or the flow stability in the corresponding section of the effective detection result.

[0093] Preferably, when the apparent flow rate fluctuation during the effective period of the continuous liquid phase exceeds ±5% of the current average, or when there is a significant change in flow state during the propagation of two consecutive thermal pulses, the double-pulse detection sequence is not recorded in the propagation analysis results. Instead, the first short-time thermal pulse and the second short-time thermal pulse are re-emitted after the flow stabilizes, so as to avoid the second short-time thermal pulse falling into a different flow dynamics segment than the first short-time thermal pulse.

[0094] After the first and second short-duration thermal pulses are applied sequentially to the fermentation broth entering the holding tube, the temperature change trajectory of the outer wall of the holding tube is continuously recorded along the distributed temperature measurement optical fiber within the operating section defined by the effective detection results. The continuous temperature rise trajectory corresponding to the first short-duration thermal pulse is recorded as the first temperature rise propagation zone, and the continuous temperature rise trajectory corresponding to the second short-duration thermal pulse is recorded as the second temperature rise propagation zone. The first and second temperature rise propagation zones are arranged sequentially according to the flow direction of the holding tube, with the first temperature rise propagation zone in front and the second temperature rise propagation zone behind, to obtain the double-pulse temperature rise propagation zone.

[0095] It should be noted that, in this embodiment, the dual-pulse temperature rise propagation band refers to the continuous temperature rise band formed on the outer wall of the holding tube when the first short-time thermal pulse and the second short-time thermal pulse propagate along the flow direction of the holding tube, which is used to subsequently lock the actual propagation path of the thermal pulse and the local stagnation section.

[0096] Considering the axial thermal diffusion during the propagation of the heat pulse along the holding tube, the first and second temperature rise propagation bands are allowed to exhibit pulse broadening, peak attenuation, or waveform boundary blunting during propagation. Therefore, this embodiment does not use the unchanged shape of the complete pulse waveform as a criterion. Instead, it prioritizes extracting the response time when the temperature rise front first reaches the preset temperature rise threshold, the local temperature rise centroid time, or the arrival time difference between adjacent temperature measurement positions as propagation features to reduce the impact of axial thermal diffusion on the identification of the heat pulse propagation path and local propagation analysis.

[0097] To avoid temperature disturbances outside the effective continuous liquid phase period from being included in the dual-pulse temperature rise propagation band, the first and second temperature rise propagation bands are recorded only within the operating range defined by the effective detection results. When the thermal pulse loading loop is not in operation, the temperature changes along the distributed temperature measurement fiber are not recorded in the first and second temperature rise propagation bands. When the temperature rise waveform at a certain temperature measurement location becomes indistinguishable due to diffusion superposition or external disturbances, or when it is discontinuous with adjacent temperature measurement locations, the abnormal waveform corresponding to that location is not directly used for local propagation time calculation. Instead, it is combined with the continuous response results of adjacent temperature measurement locations for elimination or interpolation correction.

[0098] S3.2. Search sequentially along the double-pulse temperature rise propagation zone according to the flow direction of the holding tube for the positions where the temperature rise response first and last appears. Record the position where the temperature rise response first appears as the starting response position and the position where the temperature rise response last appears as the ending response position. Connect the starting response position and the ending response position along the holding tube to form the actual propagation path of the heat pulse. Limit the actual propagation path of the heat pulse to the holding tube section corresponding to the actual temperature zone along the effective detection results.

[0099] It should be noted that, in this embodiment, the actual propagation path of the thermal pulse refers to the propagation section that the first short-time thermal pulse and the second short-time thermal pulse actually pass through along the holding tube during the effective period of continuous liquid phase. The starting response position indicates the position where the dual-pulse temperature rise propagation band first appears to continuously heat up in the flow direction of the holding tube, and the ending response position indicates the position where the dual-pulse temperature rise propagation band last maintains continuous heating in the flow direction of the holding tube.

[0100] S3.3. After the actual propagation path of the heat pulse is formed, continuously search for temperature valleys along the actual temperature band in the direction of the holding tube. First, record the temperature changes where the temperature value is continuously lower than the adjacent sections as a temperature valley sequence. Then, select the temperature valley with the lowest temperature value that is continuously distributed along the direction of the holding tube from the temperature valley sequence, and record the corresponding section as the lowest temperature section. Limit the lowest temperature section to the holding tube section corresponding to the effective detection result, and perform spatial location mapping with the holding tube section corresponding to the actual propagation path of the heat pulse. When the lowest temperature section and the actual propagation path of the heat pulse are located in the same holding tube section, retain the corresponding lowest temperature section as the lowest temperature section in the propagation analysis process. The lowest temperature section in the direction of the holding tube flow will be judged to coincide with the actual propagation path of the heat pulse. When the lowest temperature section is located in the holding tube section covered by the actual propagation path of the heat pulse, retain the corresponding lowest temperature section as the lowest temperature section in the propagation analysis process.

[0101] It should be noted that, in this embodiment, the lowest temperature segment refers to the holding tube segment with the lowest temperature within the actual temperature band along the flow path, and whose spatial location corresponds to the same effective detection segment as the actual propagation path of the heat pulse. This segment characterizes the lowest temperature position of the fermentation broth as it passes through the holding tube. To avoid bias in identifying the lowest temperature segment due to overall temperature fluctuations in the holding tube, the temperature valley segment sequence is judged based on the actual temperature band along the flow path, not on the overall temperature rise segment that has already been eliminated. When two or more temperature valley segments have the same temperature value and are all located within the same effective detection segment corresponding to the actual propagation path of the heat pulse, the temperature valley segment with a longer continuous coverage along the holding tube flow direction is recorded as the lowest temperature segment.

[0102] It should be noted that, in this embodiment, the lowest temperature segment refers to the holding tube segment with the lowest temperature within the actual temperature band along the flow path, which coincides with the actual propagation path of the heat pulse. This segment is used to characterize the lowest temperature location of the fermentation broth as it passes through the holding tube. To avoid bias in identifying the lowest temperature segment due to overall temperature fluctuations in the holding tube, the temperature valley segment sequence is based on the actual temperature band along the flow path, not on the overall temperature rise segment that has already been eliminated. When two or more temperature valley segments have the same temperature value and both coincide with the actual propagation path of the heat pulse, the temperature valley segment with a longer continuous coverage along the flow direction of the holding tube is recorded as the lowest temperature segment.

[0103] S3.4. After the actual propagation path of the heat pulse and the lowest temperature section are formed, the temperature rise propagation time difference between adjacent temperature measurement positions is measured along the first and second temperature rise propagation zones according to the flow direction of the holding tube. Based on this, the local propagation time of each section is calculated to form the local propagation distribution result. The local propagation distribution result is searched along the flow direction of the holding tube for sections where the local propagation time increases or the local propagation speed decreases. The sections where local propagation anomalies occur at corresponding positions in both the first and second temperature rise propagation zones are recorded as local stagnation sections. The local stagnation sections are mapped along the flow direction of the holding tube to the actual propagation path of the heat pulse to obtain the local stagnation sections corresponding to the actual propagation path of the heat pulse.

[0104] In this embodiment, the local stagnation segment refers to the location where the thermal pulse exhibits a reduced propagation speed or prolonged transit time within a local section of the holding tube, used to characterize the location where the propagation lag of the fermentation broth within the holding tube is more pronounced. If a segment exhibits isolated temperature rise fluctuations only during a single thermal pulse propagation, without showing consistent local propagation anomalies in the corresponding segment of another thermal pulse, the corresponding segment is not recorded as a local stagnation segment. If the comparison segment corresponding to the first and second temperature rise propagation bands is not within the same continuous liquid phase effective time period, or if a flow fluctuation exceeding a preset threshold occurs during the two thermal pulse propagations, this segment is not used as a dual-pulse consistency comparison segment; instead, the dual-pulse temperature rise propagation band is re-acquired before identifying the local stagnation segment.

[0105] After identifying the actual propagation path of the heat pulse, the lowest temperature segment, and the local stagnation segment corresponding to the actual propagation path of the heat pulse, the actual propagation path of the heat pulse, the lowest temperature segment, and the local stagnation segment corresponding to the actual propagation path of the heat pulse are correlated to obtain the propagation analysis results.

[0106] S4. Based on the propagation analysis results, calibrate the continuous flow output of the clamp-on flow meter, determine the actual flow results, the actual residence conditions in the lowest temperature section, and the propagation hysteresis in the local stagnation section, and obtain the operating results of the retention section.

[0107] S4.1. After the propagation analysis results are formed, first determine the holding tube section between the initial response position and the final response position along the actual propagation path of the thermal pulse, and record the holding tube section between the initial response position and the final response position as the crossing section; then record the propagation process of the first temperature rise propagation band passing through the crossing section and the propagation process of the second temperature rise propagation band passing through the crossing section along the double pulse temperature rise propagation band, and determine the time when the first temperature rise propagation band enters the crossing section, the time when the first temperature rise propagation band leaves the crossing section, the time when the second temperature rise propagation band enters the crossing section, and the time when the second temperature rise propagation band leaves the crossing section according to the flow direction of the holding tube.

[0108] Preferably, the span between the initial response position and the final response position is selected as a holding tube section through which both temperature rise propagation bands continuously pass, so that both the first and second temperature rise propagation bands have a complete entry and exit process within the same span. With the above method, the propagation time distance can simultaneously reflect the actual passage of the first and second temperature rise propagation bands within the actual propagation path of the heat pulse.

[0109] After the above time is determined, the propagation time of the first temperature rise propagation zone and the second temperature rise propagation zone through the crossing section is compared. When the propagation time of the first temperature rise propagation zone and the second temperature rise propagation zone through the crossing section is consistent, the corresponding propagation time is recorded as the propagation time distance, and the actual passing speed is formed based on the crossing section and the propagation time distance.

[0110] In this embodiment, the actual flow rate represents the actual flow state of the fermentation liquid along the holding tube within the section corresponding to the actual propagation path of the heat pulse, and is used to correct the continuous flow rate output by the clamp-on flow meter.

[0111] S4.2. After the actual flow rate is established, the continuous flow rate output by the clamp-on flow meter under the continuous flow output state in the detection benchmark result is recorded synchronously. The continuous flow rate output by the clamp-on flow meter in the same time period is calibrated with the flow change corresponding to the actual flow rate. Based on the correspondence between the actual flow rate and the apparent flow rate output by the clamp-on flow meter, the flow correction coefficient is obtained. The flow correction coefficient is used to proportionally correct the continuous flow rate output by the clamp-on flow meter so that the continuous flow rate output by the clamp-on flow meter is consistent with the actual flow state corresponding to the actual propagation path of the heat pulse. The calibrated continuous flow rate is recorded as the actual flow rate result.

[0112] In this embodiment, the actual flow rate result represents the flow rate result formed after the continuous flow rate output by the clamp-on flow meter is corrected for the actual passing speed. It is used to subsequently determine the actual residence time in the lowest temperature section and the propagation hysteresis in the local stagnation section.

[0113] The apparent velocity is the velocity value calculated based on the continuous flow rate output by the clamp-on flow meter and the corresponding flow cross-sectional area of ​​the holding tube. The flow correction factor is the ratio of the actual velocity to the apparent velocity. The actual flow result is the product of the continuous flow rate and the flow correction factor.

[0114] To ensure that the actual flow rate and propagation analysis results are within the same operating period, the continuous flow rate output by the clamp-on flow meter is based on the continuous flow rate output state in the detection benchmark results and maintains a time correspondence with the propagation time interval corresponding to the crossed section. When the continuous flow rate output by the clamp-on flow meter is interrupted, jumps, or abnormally returns to zero within the same time period, the corresponding flow rate value is not recorded as the actual flow rate result, but continuous recording continues until the clamp-on flow meter resumes the continuous flow rate output state, and then the continuous flow rate within the same operating period is calibrated.

[0115] Preferably, the continuous flow rate output by the clamp-on flow meter is preferably sampled at the same time interval as the propagation time of the first and second temperature rise propagation zones through the crossing section, so that the continuous flow rate, actual passing velocity, actual residence in the lowest temperature section, and propagation lag in the local stagnation section output by the clamp-on flow meter are consistent on the same time axis and in the same holding tube flow direction. After adopting the above method, the operating results of the holding section can directly reflect the actual flow state of the fermentation broth through the holding tube during the same operating period.

[0116] S4.3. After the actual flow rate results are obtained, first determine the starting and ending positions of the lowest temperature section along the flow direction of the holding tube. Then, according to the coverage area of ​​the lowest temperature section on the holding tube, map the actual flow rate results to the section where the lowest temperature section is located, and form the actual residence situation of the lowest temperature section based on the passage of fermentation broth in the section where the lowest temperature section is located. Then, determine the starting and ending positions of the local stagnation section along the flow direction of the holding tube. Then, according to the coverage area of ​​the local stagnation section on the holding tube, map the actual flow rate results to the section where the local stagnation section is located, and combine the abnormal propagation characteristics of the local stagnation section in the propagation analysis results, such as increased local propagation time, decreased local propagation speed, or prolonged passage time, to form the propagation lag situation of the local stagnation section.

[0117] In this embodiment, the actual residence status of the lowest temperature section represents the actual flow state of the fermentation broth when it passes through the lowest temperature section, and the propagation stagnation status of the local stagnation section represents the propagation slowdown status of the fermentation broth when it passes through the local stagnation section.

[0118] It should be noted that, in order to avoid affecting the accuracy of judgment when the lowest temperature section and the local stagnation section partially overlap in the direction of the holding tube, the actual residence of the lowest temperature section is recorded separately according to the coverage area of ​​the holding tube corresponding to the lowest temperature section, and the propagation lag of the local stagnation section is recorded separately according to the coverage area of ​​the holding tube corresponding to the local stagnation section. When the lowest temperature section and the local stagnation section are located in the same holding tube position, the actual residence of the lowest temperature section and the propagation lag of the local stagnation section remain independent and do not substitute for each other.

[0119] S4.4. The actual flow rate results are assigned to the holding tube section covered by the actual propagation path of the heat pulse. The actual residence status of the lowest temperature section is assigned to the section containing the lowest temperature section, and the propagation lag status of the locally stagnant section is assigned to the section containing the locally stagnant section. This ensures that the actual flow rate results, the actual residence status of the lowest temperature section, and the propagation lag status of the locally stagnant section maintain a corresponding relationship in the same holding tube flow direction. The results of the sections maintaining this correspondence are recorded as the holding section operation results. In this embodiment, the holding section operation results represent the flow rate status, residence status, and propagation lag status corresponding to the actual propagation path of the heat pulse, the lowest temperature section, and the locally stagnant section within the same operating period, used for subsequent sterilization determination.

[0120] S5. Sterilize the results of the holding period operation within the effective time period of the continuous liquid phase and obtain the sterilization online detection conclusion.

[0121] S5.1. Limit the operating results of the holding section to the operating section corresponding to the effective time period of the continuous liquid phase along the flow direction of the holding pipe, so that the operating results of the holding section only retain the actual flow rate, the actual residence of the lowest temperature section and the propagation lag of the local retention section within the effective time period of the continuous liquid phase, and record the section results corresponding to the effective time period of the continuous liquid phase as the sterilization judgment section results.

[0122] It should be noted that, in order to avoid the impact of flow fluctuations, temperature disturbances, or propagation lag changes outside the effective period of the continuous liquid phase on the accuracy of sterilization determination, when the operating section corresponding to the holding section operation result does not belong to the effective period of the continuous liquid phase, the result of the corresponding section is not recorded in the sterilization determination section result. Instead, the section limitation along the flow direction of the holding tube is maintained until the operating result of the holding section is consistent with the effective period of the continuous liquid phase within the same operating section, and then the result of the corresponding section is recorded as the sterilization determination section result.

[0123] S5.2. Extract the actual flow rate and actual residence time of the lowest temperature section from the sterilization judgment section results along the flow direction of the holding tube, and record the actual flow rate and actual residence time of the lowest temperature section as the section judgment results; compare the section judgment results with the target requirements. When the actual flow rate and actual residence time of the lowest temperature section meet the target requirements, it is recorded as a test conclusion that the target requirements have been met. When the actual flow rate or actual residence time of the lowest temperature section does not meet the target requirements, it is recorded as a test conclusion that the target requirements have not been met.

[0124] It should be noted that the target requirement in this embodiment represents the judgment requirements that the flow state and residence state corresponding to the lowest temperature section should meet in the main circuit of fermentation broth sterilization during the sterilization operation stage. The target requirement can be determined according to the setting of the flow state of the holding tube in the fermentation broth sterilization process.

[0125] S5.3. After the test results are formed, the positional relationship between the lowest temperature section and the local stagnation section on the holding tube is verified along the flow direction of the holding tube. When the lowest temperature section and the local stagnation section are located at the same holding position, the corresponding holding position is recorded as a key focus section. When the lowest temperature section and the local stagnation section are located at different holding positions, no key focus section is formed. In this embodiment, the key focus section refers to the position where the lowest temperature section and the local stagnation section coincide on the holding tube, used to characterize the holding tube section where the lowest temperature position and the propagation hysteresis position occur simultaneously.

[0126] It should be noted that, in order to avoid the accuracy of the key concern section being affected by the fact that the lowest temperature section and the local stagnation section only come into contact briefly at the boundary, the continuous coverage range of the lowest temperature section and the local stagnation section in the direction of the holding tube is used as the basis for judgment when verifying the positional relationship; when the lowest temperature section and the local stagnation section only meet at a single boundary temperature measurement position and do not form a continuous overlapping section, the corresponding position will not be recorded as the key concern section.

[0127] S5.4. Along the flow direction of the holding tube, configure the lowest temperature section, the actual flow rate corresponding to the lowest temperature section, the actual residence status corresponding to the lowest temperature section, the detection conclusion, and the key focus section into the same operating section. This ensures that the lowest temperature section, the actual flow rate corresponding to the lowest temperature section, the actual residence status corresponding to the lowest temperature section, the detection conclusion, and the key focus section remain consistent within the same sterilization operating period. The results of the sections that maintain consistency are recorded as the online sterilization detection conclusion. In this embodiment, the online sterilization detection conclusion represents a comprehensive judgment result of the flow rate status, residence status, and achievement of target requirements corresponding to the lowest temperature section within the effective period of continuous liquid phase. It also reflects whether the lowest temperature section and the local stagnation section appear at the same holding position.

[0128] This embodiment also provides an online temperature and flow rate monitoring system for the fermentation broth sterilization process, including:

[0129] The benchmark detection module performs benchmark detection on the holding tube in a sterile water-filled state. The benchmark detection is completed by a near-infrared transmission detection channel set at the upstream and end of the holding tube, a distributed temperature measuring optical fiber spirally wound along the outer wall of the holding tube, a heat pulse loading ring set at the outer periphery of the holding tube inlet, and a clamp-on flow meter set at the holding tube outlet, and obtains the benchmark detection result.

[0130] The liquid phase discrimination module, based on the detection benchmark results, discriminates the near-infrared transmission signal and temperature distribution along the sterilization process, delineates the effective time period of the continuous liquid phase and locks the actual temperature band along the process, and obtains effective detection results.

[0131] The pulse propagation module controls the thermal pulse loading ring to continuously apply two short thermal pulses to the fermentation broth entering the holding tube during the effective period of continuous liquid phase. It also tracks the temperature rise propagation band formed by the two short thermal pulses along the actual temperature band, locks the actual propagation path of the thermal pulse, the lowest temperature section and the local stagnation section, and obtains the propagation analysis results.

[0132] The operation analysis module calibrates the continuous flow rate output by the clamp-on flow meter based on the propagation analysis results, determines the actual flow rate, the actual residence conditions in the lowest temperature section, and the propagation hysteresis in the local stagnation section, and obtains the operating results of the retention section.

[0133] The sterilization determination module performs sterilization determination on the holding period operation results within the effective time period of the continuous liquid phase and outputs the sterilization online detection conclusion.

[0134] In summary, this invention, by first performing baseline testing on the holding tube filled with sterile water, and then simultaneously identifying the near-infrared transmission signal and temperature distribution along the flow path during sterilization, can pre-screen out the effective period of continuous liquid phase and lock the true temperature band along the flow path, reducing the interference of bubbles, foam, steam switching, and the overall temperature rise section on subsequent analysis from the source. By continuously applying two short-duration thermal pulses and tracking the double-pulse temperature rise propagation band, combined with the controllable pulse loading parameters of the thermal pulse loading loop and the ability of distributed temperature-measuring optical fiber to collect the continuous temperature rise response of the entire holding tube section, it can not only obtain the actual propagation path of the thermal pulse, but also simultaneously identify the lowest temperature section and the local stagnation section. The local stagnation section is determined by the increased propagation time of the thermal pulse in the local section, the decreased local propagation speed, and the consistent propagation anomaly of the double pulse recurring in the corresponding section, thus establishing a correspondence between temperature position, propagation position, and flow position within the same holding tube section. By calibrating the continuous flow rate output of the clamp-on flowmeter using propagation analysis results, the actual flow rate result no longer relies solely on a single flow rate detection, but can reflect the true passage state of the thermal pulse. This improves the accuracy of determining the actual residence conditions in the lowest temperature section and the propagation lag in local stagnation sections. Simultaneously, since the thermal pulse loading duration, the interval between adjacent thermal pulse transmissions, and the spatial resolution, temperature resolution, and sampling period of the distributed temperature sensing fiber are all within a controllable range, the stability of thermal pulse propagation identification and the reliability of identifying local abnormal sections are enhanced.

[0135] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for online detection of temperature and flow rate during the sterilization process of fermentation broth, characterized in that: include, Benchmark tests were performed on the holding tube in a sterile water-filled state, specifically including: Fill the holding tube with sterile water and keep the upstream and downstream near-infrared transmission detection channels in a stable transmission state to obtain the full liquid reference state. The continuous temperature distribution along the entire length of the holding tube is collected along the distributed temperature measurement optical fiber to form a temperature reference band along the tube. Verify the output stability of the clamp-on flow meter under sterile water circulation conditions, and determine the continuous flow output status of the clamp-on flow meter during sterilization operation; The full liquid reference state is used as the near-infrared transmission discrimination reference, the friction temperature reference band is used as the friction temperature discrimination reference, and the continuous flow output state is used as the operating reference of the clamp-on flow meter to obtain the detection reference result. Based on the detection benchmark results, the near-infrared transmission signal and temperature distribution along the sterilization process are judged to determine the effective time period of the continuous liquid phase and lock the true temperature band along the process, so as to obtain effective detection results; The real-time transmission status collected by the upstream and downstream near-infrared transmission detection channels during sterilization operation is compared with the full liquid reference status hour by hour to form the upstream full liquid judgment result and the downstream full liquid judgment result. The running period in which both the upstream and downstream full liquid determination results satisfy the full liquid determination condition is defined as the effective continuous liquid phase period. The temperature distribution along the process collected by the distributed temperature measurement fiber during sterilization is compared with the temperature reference band along the process segment by segment. The overall temperature rise segment caused by the initial heating and steam switching is eliminated, and the continuous temperature change segment formed by the fermentation broth through the holding tube is retained to obtain the true temperature band along the process. By limiting the effective time period of continuous liquid phase to the operating section corresponding to the actual temperature zone along the circuit, effective detection results can be obtained. During the effective period of continuous liquid phase, the thermal pulse loading loop continuously applies two short thermal pulses to the fermentation broth entering the holding tube, and tracks the temperature rise propagation band formed by the two short thermal pulses along the actual temperature band to lock the actual propagation path of the thermal pulses, the lowest temperature section, and the local stagnation section, specifically including: The temperature rise propagation time difference between the first and second temperature rise propagation zones at adjacent temperature measurement positions was measured along the double-pulse temperature rise propagation zone according to the flow direction of the holding tube, and the local propagation time of each section was calculated to form the local propagation distribution results; Search along the flow direction of the holding tube for sections where the local propagation time increases or the local propagation speed decreases, and form local stagnation sections where local propagation anomalies occur at corresponding positions in both the first and second temperature rise propagation zones. The localized retention section is mapped along the flow direction of the holding tube to the actual propagation path of the heat pulse, thus obtaining the localized retention section corresponding to the actual propagation path of the heat pulse; By correlating the actual propagation path of the heat pulse, the lowest temperature segment, and the local stagnation segment corresponding to the actual propagation path of the heat pulse, the propagation analysis results are obtained. Based on the propagation analysis results, calibrate the continuous flow rate output of the clamp-on flow meter to determine the actual flow rate, the actual residence time in the lowest temperature zone, and the propagation hysteresis in the local stagnation zone. Specifically, this includes: The actual propagation path of the thermal pulse across the holding tube and the propagation time of the double-pulse temperature rise propagation band across the cross section are determined to form the true through speed. Based on the correspondence between the actual flow rate and the apparent flow rate output by the clamp-on flow meter, the continuous flow rate output by the clamp-on flow meter under the continuous flow output state in the detection benchmark result is proportionally corrected to form the actual flow rate result. The actual residence conditions in the lowest temperature section are determined based on the actual flow rate results, and the propagation lag in the local stagnation section is determined based on the actual flow rate results. By mapping the actual flow rate, the actual residence time in the lowest temperature section, and the propagation lag in the local stagnation section to the same holding pipe section, the operating results of the holding section are obtained. The sterilization determination is performed on the holding period operation results within the effective time period of the continuous liquid phase, specifically including: The results of the holding phase operation are limited to the effective time period of the continuous liquid phase to form the sterilization judgment zone results; Extract the actual flow rate and actual residence time of the lowest temperature section from the sterilization determination section results to form the section determination results; The results of the section determination are compared with the target requirements to form a test conclusion on whether the target requirements have been met; The positional relationship between the lowest temperature section and the local retention section on the holding tube is verified. When the lowest temperature section and the local retention section are located at the same holding position, a key focus section is formed. The results of the lowest temperature range, the actual flow rate corresponding to the lowest temperature range, the actual residence time corresponding to the lowest temperature range, the test conclusions, and the key areas of concern are summarized into the online sterilization test conclusions.

2. The online temperature and flow rate detection method for the fermentation broth sterilization process as described in claim 1, characterized in that: The method of tracing the temperature rise propagation band formed by two consecutive short-duration thermal pulses along the actual temperature band specifically includes: During the effective period of continuous liquid phase, the thermal pulse loading ring is activated to send a first short thermal pulse and a second short thermal pulse with a fixed interval to the fermentation broth entering the holding tube; Along the distributed temperature measurement optical fiber, within the operating section defined by the effective detection results, the continuous temperature rise trajectory caused by the first short-time thermal pulse and the second short-time thermal pulse on the outer wall of the holding tube is recorded, forming the first temperature rise propagation zone and the second temperature rise propagation zone respectively; The first and second temperature rise propagation zones are arranged sequentially along the flow direction of the holding tube to form a double-pulse temperature rise propagation zone.

3. The online temperature and flow rate detection method for the fermentation broth sterilization process as described in claim 1, characterized in that: The actual propagation path of the locked thermal pulse specifically includes: In the double-pulse temperature rise propagation band, the positions where the temperature rise response first appears and the positions where the temperature rise response last appears along the flow direction are extracted and used as the starting response position and the ending response position, respectively. The starting and ending response positions are connected along the holding tube to form the actual propagation path of the thermal pulse, and the actual propagation path of the thermal pulse is limited to the holding tube section corresponding to the true temperature band along the path in the effective detection results.

4. The method for online detection of temperature and flow rate during the sterilization process of fermentation broth as described in claim 1, characterized in that: The locking of the lowest temperature range specifically includes: Search for continuous temperature valleys along the actual temperature zone and in the direction of the holding tube flow to form a temperature valley sequence; Select consecutive temperature valleys from the temperature valley sequence whose temperature values ​​are lower than those of the adjacent valleys on both sides to form the lowest temperature valleys; The lowest temperature range is limited to the holding tube section corresponding to the valid detection result, and spatial location is mapped with the holding tube section corresponding to the actual propagation path of the heat pulse to determine the lowest temperature range located in the same holding tube section as the actual propagation path of the heat pulse.

5. An online temperature and flow rate detection system for the sterilization process of fermentation broth, based on the online temperature and flow rate detection method for the sterilization process of fermentation broth according to any one of claims 1 to 4, characterized in that: include, The benchmark detection module performs benchmark detection on the holding tube in a sterile water-filled state. The benchmark detection is completed by a near-infrared transmission detection channel set at the upstream and end of the holding tube, a distributed temperature measuring optical fiber spirally wound along the outer wall of the holding tube, a heat pulse loading ring set at the outer periphery of the holding tube inlet, and a clamp-on flow meter set at the holding tube outlet, and obtains the benchmark detection result. The liquid phase discrimination module, based on the detection benchmark results, discriminates the near-infrared transmission signal and temperature distribution along the sterilization process, delineates the effective time period of the continuous liquid phase and locks the actual temperature band along the process, and obtains effective detection results. The pulse propagation module controls the thermal pulse loading ring to continuously apply two short thermal pulses to the fermentation broth entering the holding tube during the effective period of continuous liquid phase. It also tracks the temperature rise propagation band formed by the two short thermal pulses along the actual temperature band, locks the actual propagation path of the thermal pulse, the lowest temperature section and the local stagnation section, and obtains the propagation analysis results. The operation analysis module calibrates the continuous flow rate output by the clamp-on flow meter based on the propagation analysis results, determines the actual flow rate, the actual residence conditions in the lowest temperature section, and the propagation hysteresis in the local stagnation section, and obtains the operating results of the retention section. The sterilization determination module performs sterilization determination on the holding period operation results within the effective time period of the continuous liquid phase and outputs the sterilization online detection conclusion.

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