Column oven centralized control method and system and column oven control circuit

Abstract

The invention relates to the technical field of liquid chromatographs, in particular to a column oven centralized control method and system and a control circuit of a column oven. The method comprises the following steps: an upper computer obtains current temperature values of column temperature boxes in a plurality of liquid chromatographs in each group in real time through the Internet of Things; the upper computer determines a difference value distribution mode between the current temperature values of all the column temperature boxes in the current group and a preset target temperature value based on the current temperature values of the column temperature boxes in the plurality of liquid chromatographs in each group; if the difference value distribution mode meets a first preset condition, the upper computer starts a centralized cooperative control mode; and if the difference value distribution mode meets a second preset condition, the upper computer starts a decentralized autonomous control mode. According to the invention, the temperature control efficiency of a plurality of liquid chromatographs can be improved, and the energy consumption cost can be effectively reduced and controlled; meanwhile, the device also has an over-temperature protection function; in addition, when liquid leakage is detected, heating can be automatically stopped, and an alarm is given to ensure safety.

Description

Technical Field

[0001] The present invention relates to the technical field of liquid chromatographs, and particularly to a centralized control method and system for a column oven and a control circuit of the column oven. Background Art

[0002] In the field of traditional (liquid) chromatograph technology, heating modules and refrigeration modules are provided in chromatographs to make the temperature of the column oven reach the target temperature, and the heating power of the heating module is dynamically adjusted according to the difference between the actual temperature value and the target temperature value in combination with the PID strategy.

[0003] For example, the patent application with the publication number CN121090739A proposes a chromatograph temperature control method, system, intelligent terminal and storage medium, which relates to the technical field of chromatograph sample separation, including obtaining the sample type of a preset sample; analyzing the sample type to determine the window heating rate and the window target temperature; obtaining the initial temperature of a preset chromatographic column; analyzing the initial temperature of the chromatographic column and the window target temperature to determine the temperature that the chromatographic column needs to be raised; analyzing the temperature that the chromatographic column needs to be raised and the window heating rate to determine the chromatographic column heating time; and controlling a preset chromatographic column temperature control device to control the temperature of the chromatographic column according to the chromatographic column heating time and the window target temperature. This application has the effect of improving the accuracy of the temperature retention time.

[0004] For another example, the patent application with the publication number CN120009452A proposes a temperature adjustment method and device for an ion chromatograph column oven. First, a temperature change model is constructed based on Newton's law of cooling; after the heat source in the column oven starts heating, three time points t<subgt;1< / subgt>, t<subgt;2< / subgt>, t<subgt;3< / subgt> are selected, and t<subgt;3< / subgt> t<subgt;2< / subgt; = t<subgt;2< / subgt> At time \(t_1\), record the chamber temperatures \(T_1\), \(T_2\), and \(T_3\) corresponding to the temperature sensors in the column oven at these three moments, and construct a temperature model for each moment; take the logarithm of the model formulas of the chamber temperature values \(T_1\), \(T_2\), and \(T_3\) at the three moments \(t_1\), \(t_2\), and \(t_3\) and calculate to obtain a prediction model for the final chamber temperature value \(T_{final}\); establish an equilibrium state equation and directly adjust the heat source according to the calculated heat source temperature. This method reduces the waiting time after adjustment and shortens the time required for the temperature control system; and directly obtains the temperature that the heating body needs to be set, and the operation can be completed through one adjustment without repeated adjustment, thereby reducing energy consumption and improving work efficiency.

[0005] For another example, the patent application with the publication number CN114280183A proposes a temperature control device and method for the column oven of a liquid chromatograph, which relates to the technical field of liquid chromatography. By respectively setting two temperature sensors inside and outside the temperature control area of the column oven, the temperature inside the temperature control area and the ambient temperature are detected in real time. For the ambient temperature, the temperature inside the column oven and the target temperature are used as inputs, and the output of the Peltier is controlled using the control parameters and control methods corresponding to the ambient temperature by the PID algorithm. During the use of the column oven, based on the ambient temperature and the stabilized state, the control parameters and control methods are adaptively updated. This invention improves the currently commonly used temperature control method for column ovens, increases the temperature control efficiency, reduces the time to reach the temperature stable state, increases the flexibility of control, and can adjust the temperature with the optimal PID parameters and control methods under various ambient temperatures to make it reach the best working state.

[0006] Although these methods can make the temperature of the column oven reach the target temperature to a certain extent, however, the above-mentioned solutions are all for the control of a single chromatograph and are not suitable for the centralized management and control of a large number of chromatographs running simultaneously in the same space, such as the same detection and analysis center. Summary of the Invention

[0007] The purpose of the present invention is to provide a centralized control method and system for column ovens and a control circuit for column ovens, which partially solve or alleviate the above deficiencies in the prior art, and can effectively reduce the control energy consumption cost while improving the temperature control efficiency of column ovens in multiple liquid chromatographs.

[0008] To solve the aforementioned technical problems, the present invention specifically adopts the following technical solution: A first aspect of the present invention is to provide a centralized control method for a column oven based on the Internet of Things, wherein multiple sets of liquid chromatographs are arranged in a first space; correspondingly, the method further includes the following steps: S101, the host computer obtains the current temperature value of the column oven in each group of multiple liquid chromatographs in real time through the Internet of Things; S102, the host computer determines the difference distribution pattern between the current temperature value of all column ovens in the current group and the preset target temperature value based on the current temperature value of the column ovens in the multiple liquid chromatographs in each group; if the difference distribution pattern meets the first preset condition, step S103 is executed; if the difference distribution pattern meets the second preset condition, step S104 is executed. S103, the host computer starts the centralized collaborative control mode; the centralized collaborative control mode includes: the host computer generates a first PWM signal based on the maximum difference therein, and sends it down to each of the column temperature chambers in the corresponding group, so that all the column temperature chambers in the corresponding group drive the corresponding heating module to heat based on the first PWM signal. S104, the host computer starts the distributed autonomous control mode; the distributed autonomous control mode includes: the host computer sends a control command, so that each of the column temperature chambers in the corresponding group generates its own second PWM signal according to the difference between its current temperature value and the preset target temperature value, so as to drive the corresponding heating module to perform heating.

[0009] In some embodiments, the first preset condition includes: the difference between the current temperature value and the preset target temperature value of all the column ovens in the same group is less than or equal to a first preset difference.

[0010] In some embodiments, the second preset condition includes: the number N of the number of the difference between the current temperature value and the preset target temperature value of the same group of internal column temperature chambers being greater than or equal to the second preset difference is greater than or equal to the preset number threshold M; wherein, the second preset difference is greater than the first preset difference.

[0011] In some embodiments, multiple liquid chromatographs within the same group perform the same detection and analysis task.

[0012] In some embodiments, before activating the centralized collaborative control mode, the following steps are further included: If the deviation between the current temperature value and the preset target temperature value of P column temperature chambers in the same group and the average difference exceeds a preset threshold, based on the current location of the P column temperature chambers, it is determined whether the ambient temperature of all column temperature chambers in the same group is the same. If the ambient temperature is the same and P is greater than or equal to A / 2, the entire group switches to the decentralized autonomous control mode and prompts that P column ovens need maintenance. If the ambient temperature is the same and P is less than A / 2, it indicates that P column temperature chambers need maintenance, and the entire group adopts the centralized collaborative control mode described above. If the ambient temperatures are different, and the ambient temperatures in the P column temperature chambers are all lower or higher than the average ambient temperature of the other column temperature chambers in the same group, then the P column temperature chambers are divided into one subgroup, and the remaining column temperature chambers are in another subgroup, and the subgroup centralized collaborative control mode is activated. If the ambient temperatures are different, and the ambient temperature of P1 of the P column temperature chambers is lower than the average ambient temperature of the other column temperature chambers in the same group, and the ambient temperature of P-P1 of the column temperature chambers is higher than the average ambient temperature of the other column temperature chambers in the same group, then P1 column temperature chambers form a subgroup, P-P1 column temperature chambers form a subgroup, and the other column temperature chambers in the same group form a subgroup, and each subgroup activates the subgroup centralized collaborative control mode.

[0013] In some embodiments, the subgroup centralized collaborative control mode includes: the host computer generating a third PWM signal based on the maximum difference in each subgroup to drive the heating module of the column temperature chamber in the subgroup to heat.

[0014] A second aspect of the present invention is to provide a control circuit for a column oven in a liquid chromatograph, comprising: a first temperature sensor for detecting the temperature of the column oven, a controller, a heater drive circuit electrically connected to the controller, and an Ethernet communication module. The controller is configured to acquire the current temperature value of the column oven from the first temperature sensor in real time; and to send the first PWM signal received by the Ethernet communication module from the host computer to the heater drive circuit to drive the corresponding heating module to heat; or, to generate a corresponding second PWM signal based on the difference between the current temperature value and the preset target temperature value according to the control command received by the Ethernet communication module from the host computer, and send it to the heater drive circuit to drive the corresponding heating module to heat. The first PWM signal is generated by the host computer based on the maximum difference between the current temperature distribution pattern of all column ovens in the current group and the preset target temperature value, which is determined by the host computer based on the current temperature values ​​of the column ovens in the current group. The control command is generated by the host computer based on the current temperature values ​​of the column ovens in the current group and the second preset condition, which is determined by the host computer based on the current temperature values ​​of the column ovens in the current group and the second preset condition, which is determined by the host computer based on the current temperature values ​​of the column ovens in the current group and the preset target temperature value.

[0015] In some embodiments, the system further includes a leakage detection module, the output of which is connected to the controller via a third amplifier; when the controller determines that a leakage has occurred based on the data detected by the leakage detection module, the controller controls the heater drive circuit to stop driving the heater to heat.

[0016] In some embodiments, a second temperature sensor for detecting pipeline temperature is also included. When the controller determines that an abnormal temperature has occurred based on the temperature data from the second temperature sensor, the controller controls the over-temperature protection switch to open, thereby cutting off the power supply to the heater; at the same time, it triggers an alarm from the leakage detection module. And / or, both the first temperature sensor and the second temperature sensor are PT100.

[0017] A third aspect of the present invention is to provide a centralized monitoring system for a multiphase liquid chromatograph, comprising: Multiple liquid chromatographs, wherein the liquid chromatographs include control circuitry as described in any embodiment of the present invention; The host computer is configured to acquire the current temperature values ​​of the column ovens in multiple liquid chromatographs in real time; and determine the distribution pattern of the difference between the current temperature value and the preset target temperature value of all column ovens in the current area based on the current temperature values ​​of the column ovens in the current group; if the difference distribution pattern meets a first preset condition, a centralized collaborative control mode is activated; the centralized collaborative control mode includes: the host computer generates a first PWM signal based on the largest difference and sends it to each column oven in the corresponding group, so that all column ovens in the corresponding group drive the corresponding heating module to heat based on the first PWM signal; if the difference distribution pattern meets a second preset condition, the host computer activates a decentralized autonomous control mode; the decentralized autonomous control mode includes: the host computer sends control commands so that each column oven in the corresponding group generates its own second PWM signal according to the difference between its current temperature value and the preset target temperature value, so as to drive the corresponding heating module to heat.

[0018] Beneficial technical effects: This invention is particularly suitable for scenarios requiring centralized management of a large number of liquid chromatographs (such as a single testing center). Specifically, this invention can manage by grouping and matching different control modes based on the temperature difference distribution pattern within each group. For example, if the temperature difference meets a first preset condition, that is, the chromatographs within the same group with small temperature differences use the same control signal for heating, and if the temperature difference meets a second preset condition, that is, the temperature differences of a large number of chromatographs within the same group are large, then the groups are further subdivided. The subgroups with large temperature differences generate PWM signals to control the heating modules based on their respective current temperature values, while the remaining subgroups with small temperature differences are controlled by a host computer that generates a unified control signal based on the largest temperature difference (currently, these chromatographs also report their corresponding control signals and temperature data to the host computer for centralized management). In this way, while ensuring that the column ovens of each chromatograph reach or approach the preset target temperature, the... Compared to the host computer generating corresponding control signals (such as PWM signals) based on the current temperature value of each chromatograph, this method can reduce the difficulty and complexity of centralized management to a certain extent. Compared to each chromatograph independently generating corresponding control signals based on its current temperature value and then reporting them to the host computer, this method greatly reduces the power consumption of the entire space (as mentioned earlier, part of which is centrally managed by the host computer and adopts a group collaborative control mode, while another part is independently managed by the chromatographs and reported to the host computer). On the other hand, this management method greatly reduces the workload of centralized management by monitoring personnel. For example, through group collaborative management, the amount of control data that needs to be displayed on the monitoring interface at the same time is greatly reduced, so that monitoring personnel can quickly focus on instruments with abnormal temperatures or those that need special attention, reducing information overload and troubleshooting difficulties caused by massive amounts of data on the display interface.

[0019] Furthermore, by subdividing the same group into smaller subgroups and employing a combination of centralized and decentralized control, a better balance can be struck between the efficiency of unified management and the accuracy required to address individual differences. Specifically, this invention provides a restrictive centralized temperature control mechanism. Before initiating centralized system control (applying the same PWM signal to all column ovens in the same group), column ovens with larger temperature deviations are regrouped based on ambient temperature (i.e., subgroups with larger temperature deviations and subgroups with smaller temperature deviations), and different subgroup control modes are applied to different subgroups. This approach ensures, to a certain extent, that multiple column ovens can reach the preset target temperature in complex laboratory environments, while avoiding or reducing energy consumption (such as the management costs associated with independently assigning PWM signals to each column oven, or the heating energy consumption of applying a uniform PWM signal to all devices), thereby reducing the difficulty of temperature management in scenarios with multiple column ovens. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. The elements or parts in the drawings are not necessarily drawn to scale. Obviously, the drawings described below are some embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0021] Figure 1 A flowchart illustrating a centralized control method for a column temperature chamber provided by the present invention; Figure 2 This is a schematic diagram of a centralized monitoring system for column temperature chambers provided by the present invention; Figure 3 Example diagram of the preset difference provided by the present invention; Figure 4 An example diagram of the liquid chromatograph provided by the present invention; Figure 5 This is a structural example diagram of a column temperature chamber control system provided by the present invention; Figure 6 A schematic block diagram of the structure of a computer device provided by the present invention; Figure 7 This is a schematic diagram of the column temperature chamber grouping provided by the present invention; Figure 8 A schematic diagram of the control circuit of a liquid chromatograph provided by the present invention; Figure 9 This is a schematic diagram illustrating the subgrouping based on ambient temperature provided by the present invention.

[0022] Summary of reference numerals in the attached diagram: 1. First preset difference; 2. Second preset difference. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0024] In this document, suffixes such as "module," "part," or "unit" used to denote elements are used only for the purpose of illustrative purposes and have no specific meaning in themselves. Therefore, "module," "part," or "unit" may be used interchangeably.

[0025] In this document, the terms "upper," "lower," "inner," "outer," "front," "rear," "one end," and "the other end," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the present invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0026] In this document, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, a direct connection, or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0027] In this document, "and / or" includes any and all combinations of one or more of the listed related items.

[0028] In this article, "multiple" means two or more, that is, it includes two, three, four, five, etc.

[0029] As used in this specification, the term "about" typically means + / -5% of the value, more typically + / -4% of the value, more typically + / -3% of the value, more typically + / -2% of the value, even more typically + / -1% of the value, and even more typically + / -0.5% of the value.

[0030] In this specification, certain embodiments may be disclosed in a range-bound format. It should be understood that this "range-bound" description is merely for convenience and brevity and should not be construed as a rigid limitation on the disclosed range. Therefore, the description of a range should be considered as having specifically disclosed all possible subranges and the individual numerical values ​​within those ranges. For example, a description of the range 1-6 should be considered as having specifically disclosed subranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and the individual numbers within those ranges, such as 1, 2, 3, 4, 5, and 6. This rule applies regardless of the breadth of the range.

[0031] Definition of noun: The host computer can be a device used to centrally monitor the temperature of the column oven in the chromatograph, and can perform data analysis and issue control commands (such as to control the heating module in the chromatograph to heat up).

[0032] A liquid chromatograph is an instrument that uses the difference in the distribution ratio of a mixture between a liquid and a solid or between two immiscible liquids to separate the mixture first, and then analyze and identify it.

[0033] In other words, a liquid chromatograph is an instrument that uses the difference in the distribution ratio of a mixture between a mobile phase and a stationary phase to first separate the mixture, and then analyze and identify it. Please see [link to relevant documentation]. Figure 4 A liquid chromatograph mainly consists of an injector, a pump, a column oven (hereinafter referred to as the column oven), and a detector, all connected by pipelines. The column oven is equipped with corresponding heating and cooling modules, temperature sensors, etc.

[0034] The column oven, also known as a chromatographic column temperature control chamber, is a key component of a high-performance liquid chromatograph (HPLC). It is primarily used to precisely control the operating temperature of the chromatographic column to meet the requirements of pharmacopoeia and modern analytical methods, thereby improving column efficiency, peak resolution, and the repeatability of analytical results. Its applications span laboratory settings in biochemistry, environmental science, and food testing.

[0035] PWM (Pulse Width Modulation) is a technique that simulates different voltages or currents by adjusting the width (duty cycle) of pulses. A PWM signal is a periodic square wave containing alternating high-level (On-Time) and low-level (Off-Time) pulses. In some embodiments, the PWM signal can be used to control a heating module to heat a column oven.

[0036] Example 1: In some embodiments, see Figure 1 This invention provides a centralized control method for a column oven based on the Internet of Things, wherein multiple sets of liquid chromatographs are installed in a first space; correspondingly, the method further includes the following steps: S101, the host computer obtains the current temperature value of the column oven in each group of multiple liquid chromatographs in real time through the Internet of Things; S102, the host computer determines the difference distribution pattern between the current temperature value of all column ovens in the current group and the preset target temperature value based on the current temperature value of the column ovens in the multiple liquid chromatographs in each group; if the difference distribution pattern meets the first preset condition, step S103 is executed; if the difference distribution pattern meets the second preset condition, step S104 is executed.

[0037] S103, the host computer starts the centralized collaborative control mode; the centralized collaborative control mode includes: the host computer generates a first PWM signal based on the maximum difference therein, and sends it down to each of the column temperature chambers in the corresponding group, so that all the column temperature chambers in the corresponding group drive the corresponding heating module to heat based on the first PWM signal. S104, the host computer starts the distributed autonomous control mode; the distributed autonomous control mode includes: the host computer sends a control command, so that each of the column temperature chambers in the corresponding group generates its own second PWM signal according to the difference between its current temperature value and the preset target temperature value, so as to drive the corresponding heating module to perform heating.

[0038] In some embodiments, the first space may refer to a space containing multiple liquid chromatographs that can communicate with the same host computer via the Internet of Things, thereby enabling centralized group control, such as multiple instruments in one or more rooms of a laboratory or testing center.

[0039] In some embodiments, the preset target temperature value can be set by the operator according to their actual needs.

[0040] In some embodiments, obtaining the difference distribution pattern may include the steps of: comparing multiple temperature differences of a group of column oven devices with a preset difference (such as a first preset difference) to obtain the relative magnitude of the multiple temperature differences, which is used to characterize the difference distribution pattern. Generally speaking, the temperature difference refers to the difference between the preset target temperature and the actual temperature of the column oven.

[0041] For example, the decision to activate centralized collaborative control mode or decentralized autonomous control mode can be made based on the magnitude of all temperature differences within the current group (e.g., all are very large, or all are very small).

[0042] For example, because the actual temperature of the column oven is lower than the preset target temperature, the heating module needs to heat the column oven to gradually increase the temperature to the preset target temperature. Therefore, the centralized collaborative control mode can refer to the unified temperature regulation of the same group of column ovens, thereby controlling the heating modules of the column ovens of all chromatographs in the same group to uniformly heat the column ovens through a single instruction (such as a PWM signal), so that the temperature of the column ovens in all chromatographs in the same group approaches the preset target temperature.

[0043] Preferably, the present invention generates a first PWM signal based on the largest difference in the same group (i.e., the largest difference between the current temperature value and the preset target temperature value), which can ensure to a certain extent that all column temperature chambers can be fully heated (or reach the target temperature).

[0044] In other words, the present invention preferably generates the first PWM signal based on the maximum difference within the same group. Compared with the host computer configuring an independent PWM signal for each column temperature chamber, this greatly reduces the computational load and communication energy consumption cost of the host computer (i.e., each time a PWM signal is generated, network bandwidth and communication power are consumed).

[0045] Furthermore, the centralized control mechanism can improve the efficiency of temperature management of a large number of column ovens and reduce the difficulty of centralized management to a certain extent.

[0046] In some embodiments, whether a centralized collaborative control mode or an autonomous decentralized control mode is adopted, a PID (proportional-integral-derivative control) algorithm can be used to generate a PWM signal.

[0047] For example, the duty cycle of the PWM signal can be dynamically adjusted by calculating the temperature difference (i.e., target temperature - current actual temperature) between the target temperature (i.e., preset target temperature value) and the current actual temperature (i.e., current temperature value), and the maximum temperature difference can be selected, thereby precisely controlling the heating power.

[0048] In some embodiments, regardless of whether a centralized collaborative control mode or an autonomous decentralized control mode is used, even within the same group, the temperature difference between each column temperature chamber and the preset target temperature is not entirely the same. Therefore, different PID control strategies can be adopted according to the different magnitudes of the temperature difference. For example, different difference thresholds can be set to classify different temperature control modes, thereby matching different PID control strategies to different temperature control modes.

[0049] For example, when the temperature difference is greater than or equal to the third preset difference, the temperature difference is considered to be large (for example, in the decentralized autonomous control mode, the current temperature of a column temperature chamber is 25℃, and the user presets the target temperature to 40℃. At this time, the temperature difference is 15℃, which is greater than the third preset difference, such as 10℃, so the temperature difference can be considered to be large). Proportional (P) control can be used to make the actual temperature of the column temperature chamber approach the target value as soon as possible.

[0050] In some embodiments, the output of the PID controller depends primarily on the proportional (P) term.

[0051] For example, P_output = Kp * e(t), where Kp is the proportionality coefficient. The larger the deviation (i.e., the temperature difference) e(t), the larger the calculated P_output value.

[0052] In some embodiments, a duty cycle mapping table for the PWM signal can be preset. For example, a larger P_output value can be mapped to a PWM signal with a high duty cycle (e.g., 80%-100%), causing the system to heat up quickly.

[0053] For example, if e(t) = 15℃ and Kp = 5, then P_output = 5 * 15 = 75. Through a preset mapping table, P_output = 75 may correspond to a 90% PWM duty cycle.

[0054] For example, when the temperature difference is less than or equal to the third preset difference, the temperature difference is considered small (for example, in the decentralized autonomous control mode, the current temperature of a certain column oven is 38.5℃, and the temperature difference e(t) = 1.5℃ between it and the target temperature of 40℃ is less than the third preset difference, which is a small deviation). At this time, it can be determined by three terms: (1) Proportional (P) term: Kp*e(t). It provides basic regulation, but its contribution is also small at this time because e(t) is small. (2) Integral (I) term: Ki*∫e(t)dt. The integral term will accumulate historical deviations. Even if the current temperature difference is small, if there has been a small deviation in the past, the integral term will gradually increase, thereby completely eliminating the steady-state error (i.e., finally making the temperature accurately stabilize at 40℃). (3) Differential (D) term: Kd*de(t) / dt. The differential term reflects the trend (rate) of temperature change. If the temperature rises too fast, the differential term will generate a negative feedback, suppress the heating power, and prevent overshoot. Specifically, the selection of the third preset difference can be determined based on actual experience values, or it can be the intermediate difference between the maximum and minimum temperature differences in the same group.

[0055] In some embodiments, based on a preset PWM signal duty cycle mapping table, the comprehensively calculated PID_output value can be mapped to a low duty cycle PWM signal (e.g., the duty cycle fluctuates between 10% and 30%), so that the heating module can perform fine (or slower) power regulation.

[0056] For example: e(t) = 1.5℃, and the temperature rises rapidly de(t) / dt = 0.5℃ / s. Assume Kp = 5, Ki = 0.1, Kd = 10. P_output = 5 * 1.5 = 7.5; I_output = 0.1 * (cumulative of historical small deviations) = 2 (assumed value); D_output = 10 * (-0.5) = -5 (negative sign to suppress heating); the calculated PID_output = 7.5 + 2 - 5 = 4.5. This smaller PID_output value will be mapped to a 15% PWM duty cycle to achieve a smoother (or slower) temperature rise.

[0057] In some embodiments, the decentralized autonomous control mode may refer to generating corresponding PWM signals based on the temperature difference of each column temperature box in the current group, so as to heat multiple column temperature boxes in a decentralized manner.

[0058] In some embodiments, the first preset condition includes: the difference between the current temperature value and the preset target temperature value of all column temperature chambers in the same group is less than or equal to a first preset difference. When the temperature difference of all column temperature chambers in the same group is less than or equal to the first preset difference, it can be said to a certain extent that the equipment status of the column temperature chambers in the current group is relatively similar, and it can be considered that the difference distribution pattern of the column temperature chambers in the group conforms to the centralized collaborative control mode, thereby uniformly heating the column temperature chambers in the same group.

[0059] Meanwhile, when the temperature difference of all column ovens in the same group is small, the first PWM signal generated based on the maximum difference can reduce the heating energy cost to a certain extent for column ovens with smaller temperature differences (i.e., less than the maximum difference) by combining it with the PID adjustment strategy.

[0060] In other embodiments, for column ovens with temperature differences less than the maximum difference, the insulation / cooling stage can be switched in advance to avoid overheating of column ovens with small temperature differences.

[0061] It should be understood that in some embodiments, even if applying the same first PWM signal to some column ovens with small temperature differences may cause slight overheating, the slight overheating is still within an acceptable range because the temperature differences of the column ovens that meet the first preset conditions are all small.

[0062] In some embodiments, the second preset condition includes: the number N of the difference between the current temperature value and the preset target temperature value of the same group of internal column temperature chambers being greater than or equal to the second preset difference is greater than or equal to the preset quantity threshold M; wherein, the second preset difference is greater than the first preset difference.

[0063] In some embodiments, when the temperature difference of most of the column temperature chambers in the group (e.g., N≥M) is large, that is, greater than or equal to the second preset difference, it may indicate that there are serious differences in the state of the equipment in the group (e.g., different equipment wear levels, and / or different environmental parameters such as ambient temperature). In this case, it is preferable to use a distributed autonomous control mode, so that each device can use a PWM signal generated based on its actual temperature difference, in order to ensure to a certain extent that all column temperature chambers can accurately reach the target temperature.

[0064] In other words, for most column temperature chambers with large temperature differences, this invention preferably applies a decentralized autonomous control mode, which can avoid the problem of excessive overheating of equipment with small temperature differences or insufficient heating of equipment with large temperature differences that may be caused by applying a uniform PWM signal.

[0065] In some embodiments, see Figure 3 When the temperature difference of all devices is less than the first preset difference 1, the centralized collaborative control mode is applicable; when the temperature difference of most devices is greater than or equal to the second preset difference 2, the decentralized autonomous control mode is applicable.

[0066] It should be understood that Figure 3 In this paper, the relative magnitudes of the first preset difference 1 and the second preset difference 2 on the temperature axis are merely illustrative, and the present invention does not limit the numerical values ​​of the first preset difference 1 and the second preset difference 2. Preferably, the second preset difference is greater than the first preset difference.

[0067] In some embodiments, multiple liquid chromatographs within the same group perform the same detection and analysis task. Key parameters such as column type, mobile phase flow rate, and run time are typically similar for the same monitoring and analysis task, which may indicate that the preset target temperatures of these column ovens are the same or very close. This invention groups devices performing the same detection and analysis task together, significantly reducing the difficulty of temperature control and management for multiple chromatographic column devices.

[0068] Example 2: In some embodiments, before activating the centralized collaborative control mode, the following steps are further included: If the deviation between the current temperature value and the preset target temperature value of P column temperature chambers in the same group and the average difference exceeds a preset threshold, based on the current location of the P column temperature chambers, it is determined whether the ambient temperature of all column temperature chambers in the same group is the same. If the ambient temperature is the same and P is greater than or equal to A / 2, the entire group switches to the decentralized autonomous control mode and prompts that P column ovens need maintenance. If the ambient temperature is the same and P is less than A / 2, it indicates that P column temperature chambers need maintenance, and the entire group adopts the centralized collaborative control mode described above. If the ambient temperatures are different, and the ambient temperatures in the P column temperature chambers are all lower or higher than the average ambient temperature of the other column temperature chambers in the same group, then the P column temperature chambers are divided into one subgroup, and the remaining column temperature chambers are in another subgroup, and the subgroup centralized collaborative control mode is activated. If the ambient temperatures are different, and the ambient temperature of P1 of the P column temperature chambers is lower than the average ambient temperature of the other column temperature chambers in the same group, and the ambient temperature of P-P1 of the column temperature chambers is higher than the average ambient temperature of the other column temperature chambers in the same group, then P1 column temperature chambers form a subgroup, P-P1 column temperature chambers form a subgroup, and the other column temperature chambers in the same group form a subgroup, and each subgroup activates the subgroup centralized collaborative control mode.

[0069] The applicant noted that in practical applications, although the same group of devices performs the same detection and analysis tasks, individual biases still exist due to differences in the environment and the operating status of each device (e.g., differences in the attenuation characteristics or aging degree of the heating module).

[0070] In this regard, for the Q column ovens that are divided into the same group (i.e., the difference between the current temperature value of each of the Q column ovens and the preset target temperature value is less than or equal to the first preset difference), the average temperature difference is used to represent the overall temperature situation of this group of equipment. If the difference between the current temperature value of a column oven in a certain chromatograph and the preset target temperature value deviates significantly from the average temperature difference, it indicates that the individual's performance relative to the group average of the column ovens in the same group is highly discrete.

[0071] If P (1≤P<A) of the Q column ovens have deviations from the average difference exceeding a preset threshold (i.e., the dispersion of each of the P devices is greater than a preset value), determine whether the difference between the maximum and minimum ambient temperatures in the Q column ovens (i.e., the ambient temperature difference) meets the third preset condition: ambient temperature difference < preset difference threshold ΔT (e.g., 1.0°C). If so, it indicates that the ambient temperatures of all column ovens (temperature sensors for acquiring ambient temperature can be installed on the chromatograph) are not significantly different or are the same, suggesting that the large dispersion may be due to different degrees of decay characteristics or aging of the P column ovens. Therefore, if the number of column ovens whose deviations from the average difference exceed the preset threshold is greater than or equal to a preset proportion, such as P greater than or equal to A / 2, the entire group switches to decentralized autonomous control mode, and P column ovens are prompted that maintenance may be required; if P is less than A / 2, the equipment is prompted that maintenance is required, and the Q column ovens adopt centralized collaborative control mode.

[0072] Please see Figure 9 If P (1≤P<A) of the Q column temperature chambers deviate from the average difference value beyond the preset threshold, and the difference between the maximum and minimum ambient temperatures in the Q column temperature chambers is greater than or equal to the preset difference threshold ΔT (e.g., 1.0°C), it indicates that the ambient temperatures of all column temperature chambers are significantly different (or the ambient temperatures are different). In other words, the degree of dispersion is large due to the coupling effect of the differences in the column temperature chambers themselves and the ambient temperature. Therefore, it is necessary to determine whether the ambient temperatures of the P column temperature chambers are all higher or lower than the average ambient temperature of the AP column temperature chambers (±δ, where δ is an empirical value). If they are all higher or lower, the entire group adopts a subgroup distributed collaborative control mode, that is, the P column temperature chambers are divided into one subgroup, and the remaining AP column temperature chambers are another subgroup, and each subgroup adopts a subgroup centralized collaborative control mode. If the ambient temperature of P1 column temperature chambers (P1 < P) is lower than the average ambient temperature of AP column temperature chambers (±δ, where δ is an empirical value), and the ambient temperature of P-P1 column temperature chambers is higher than the average ambient temperature of AP column temperature chambers (±δ, where δ is an empirical value), then the Q column temperature chambers are divided into three subgroups: P1 column temperature chambers form one subgroup; P-P1 column temperature chambers form another subgroup; and AP column temperature chambers form another subgroup. Each subgroup generates a unique PWM signal based on the maximum temperature difference within the group (i.e., the maximum difference between the current temperature value and the preset target temperature within the subgroup). In other words, each subgroup adopts a subgroup centralized cooperative control mode.

[0073] Before using a unified PWM signal to centrally control the heating modules in each chromatograph, this invention preferably further groups and manages the equipment based on differences in ambient temperature. Subgroups with small ambient temperature differences (i.e., temperature deviations in the same direction, such as all high or all low) are managed uniformly, while subgroups with large ambient temperature differences (i.e., temperature deviations in different directions, such as some high and some low) are managed separately. This approach retains the efficiency advantages of unified management (such as synchronous startup and unified benchmarks) while also considering the individual differences between the equipment.

[0074] For example, if there is a temperature difference of 3°C between P column ovens in the same group, and the deviation between the temperature difference and the average difference of 1°C is 2°C, and the deviation exceeds a preset threshold (e.g., 1°C), then it is possible to further determine how to control the temperature based on whether the ambient temperature of the column ovens in the same group is the same.

[0075] For example, if all column ovens in the same group have the same ambient temperature, it may indicate that the dispersion of the P column ovens is not primarily driven by environmental factors, but rather by malfunctions or individual differences within the ovens themselves. In this case, it is preferable to issue an alarm signal to prompt operators to investigate. Furthermore, if P is greater than or equal to A / 2, the entire group switches to the decentralized autonomous control mode; if P is less than A / 2, the entire group adopts the centralized collaborative control mode.

[0076] For example, see Figure 7 If the ambient temperature of P column temperature chambers in the same group is higher or lower than the average ambient temperature of other column temperature chambers in the same group (e.g., the ambient temperatures of column temperature chambers a, b, and c are all higher than the average ambient temperatures of d, e, and f), or if the temperature deviation of the column temperature chambers is in the same direction, then the P column temperature chambers with larger deviation values ​​can be divided into a separate group, and the subgroup centralized collaborative control mode can be activated. That is, the same PWM signal (i.e., the third PWM signal) is applied to the P column temperature chambers with larger deviation values ​​(e.g., they are all at the cold air vent), thus activating the subgroup centralized collaborative control mode; at the same time, another identical PWM signal (i.e., the third PWM signal) can be applied to the remaining column temperature chambers with smaller deviation values.

[0077] In some embodiments, the subgroup centralized cooperative control mode includes: generating a third PWM signal based on the maximum difference in each subgroup to drive the heating modules of all column temperature chambers in that subgroup to heat.

[0078] Alternatively, if the ambient temperature of P1 of the P column temperature chambers is lower than the average ambient temperature of the other column temperature chambers in the same group (e.g., the ambient temperature of column temperature chamber a is lower than the average ambient temperature of d, e, and f), and the ambient temperature of the other group, namely P-P1, is higher than the average ambient temperature of the other column temperature chambers in the same group (e.g., the ambient temperature of column temperature chambers b and c is higher than the average ambient temperature of d, e, and f), it can be said that the ambient temperature deviation direction of the column temperature chambers is inconsistent. In this case, it is preferable to divide the column temperature chambers into subgroups based on the direction of the ambient temperature deviation (e.g., dividing the column temperature chambers into a subgroup with higher ambient temperatures and a subgroup with lower ambient temperatures), and applying different PWM signals to each subgroup, that is, each subgroup starts the subgroup centralized cooperative control mode.

[0079] In this embodiment, the present invention provides a restrictive centralized temperature control mechanism. Before initiating centralized system control (applying the same PWM signal to all column ovens in the same group), column ovens with large temperature deviations are secondary-grouped based on ambient temperature (i.e., subgroups with consistent temperature deviation directions and subgroups with inconsistent temperature deviation directions), and different subgroup control modes are applied to different subgroups. This approach ensures, to a certain extent, that multiple column ovens can reach the preset target temperature in complex laboratory environments, while avoiding or reducing energy consumption (such as the management costs associated with independently assigning PWM signals to each column oven, or the heating energy consumption of applying a uniform PWM signal to all devices), thereby reducing the difficulty of temperature management in scenarios with multiple column ovens.

[0080] In other words, this invention is particularly suitable for scenarios requiring centralized management of a large number of liquid chromatographs (such as a single testing center). Specifically, this invention can achieve a good balance between the efficiency of unified management and the accuracy of individual differences by managing groups and matching different control modes and subgroup control modes based on the temperature difference distribution pattern within the same group.

[0081] Example 3: Please see Figure 8 The present invention also provides a control circuit for a liquid chromatograph, comprising: a first temperature sensor for detecting the temperature of a column oven, a controller, a heater drive circuit and an Ethernet communication module electrically connected to the controller; The controller is configured to acquire the current temperature value of the column oven from the first temperature sensor in real time; and to send the first PWM signal received by the Ethernet communication module from the host computer to the heater drive circuit to drive the corresponding heating module to heat; or, to generate a corresponding second PWM signal based on the difference between the current temperature value and the preset target temperature value according to the control command received by the Ethernet communication module from the host computer, and send it to the heater drive circuit to drive the corresponding heating module to heat. The first PWM signal is generated by the host computer based on the maximum difference between the current temperature distribution pattern of all column ovens in the current group and the preset target temperature value, which is determined by the host computer based on the current temperature values ​​of the column ovens in the current group. The control command is generated by the host computer based on the current temperature values ​​of the column ovens in the current group and the second preset condition, which is determined by the host computer based on the current temperature values ​​of the column ovens in the current group and the second preset condition, which is determined by the host computer based on the current temperature values ​​of the column ovens in the current group and the preset target temperature value.

[0082] In some embodiments, the control circuit of the column oven in the liquid chromatograph further includes: a leakage detection module, the output of which is connected to the controller via a third amplifier; when the controller determines that a leakage has occurred based on the data detected by the leakage detection module, the controller controls the heater drive circuit to stop driving the heater to heat.

[0083] In some embodiments, the control circuit of the column oven in the liquid chromatograph further includes a second temperature sensor for detecting the temperature of the tubing. When the controller determines that an abnormal temperature has occurred based on the temperature data from the second temperature sensor, the controller controls the over-temperature protection switch to open, thereby cutting off the power supply to the heater; at the same time, it triggers an alarm from the leakage detection module.

[0084] In some embodiments, both the first temperature sensor and the second temperature sensor are PT100.

[0085] Please see Figure 2 Based on the above-described control circuit or a liquid chromatograph having the above-described control circuit, the present invention also provides a centralized monitoring system for column ovens, comprising: Multiple liquid chromatographs, wherein the liquid chromatographs include the control circuitry as described in the embodiments of the present invention; The host computer is configured to acquire the current temperature values ​​of the column ovens in multiple liquid chromatographs in real time; and determine the distribution pattern of the difference between the current temperature value and the preset target temperature value of all column ovens in the current area based on the current temperature values ​​of the column ovens in the current group; if the difference distribution pattern meets a first preset condition, a centralized collaborative control mode is activated; the centralized collaborative control mode includes: the host computer generates a first PWM signal based on the largest difference and sends it to each column oven in the corresponding group, so that all column ovens in the corresponding group drive the corresponding heating module to heat based on the first PWM signal; if the difference distribution pattern meets a second preset condition, the host computer activates a decentralized autonomous control mode; the decentralized autonomous control mode includes: the host computer sends control commands so that each column oven in the corresponding group generates its own second PWM signal according to the difference between its current temperature value and the preset target temperature value, so as to drive the corresponding heating module to heat.

[0086] It should be understood that the system is used to implement the method steps described in any embodiment of the present invention.

[0087] For example, please see Figure 5 The present invention also provides an example of a control circuit for a column oven in a liquid chromatograph.

[0088] Specifically, the control circuit or main control chip is based on a microcontroller (i.e., the controller in the above embodiments), and combines a temperature sensor, an unbalanced bridge, an instrumentation operational amplifier, and a high-precision analog-to-digital converter to measure the temperature signal of the chromatography column oven. The timer module built into the main control chip outputs a PWM signal (for example, the parameters of the PWM signal are sent from the host computer, and then the timer module outputs the corresponding PWM signal, or the microcontroller automatically generates the corresponding PWM signal parameters to control the timer module to output the corresponding PWM signal), and combines it with a PID algorithm to control the heater and / or cooler. The main control chip has a built-in Ethernet MAC layer module, which, combined with an external physical layer chip (such as an Ethernet communication interface), realizes Ethernet communication function. For instruments with low precision requirements, the temperature measurement and leakage detection signals are amplified by the operational amplifier and then acquired by the ADC module built into the main control chip.

[0089] The main control chip is powered by a 24V DC power supply. The power management module includes two isolated DC / DC modules to power the analog circuit and the microcontroller circuit respectively; and a non-isolated DC / DC circuit to power the external I / O interface circuit.

[0090] Among them, the microcontroller is the core of the entire control system, and a high-performance microcontroller (such as the STM32F207 series microcontroller) can be selected.

[0091] The column oven temperature can be acquired using a temperature sensor (i.e., the first temperature sensor, such as PT100, which is a platinum-based resistance temperature sensor) installed inside the column oven. The temperature is measured using an unbalanced bridge circuit with a three-wire connection. The bridge signal is conditioned and amplified by an instrumentation operational amplifier, then converted into a digital signal by a high-precision analog-to-digital converter. The signal is then exchanged with the main control chip via the SPI interface (Serial Peripheral Interface).

[0092] The heater and cooler are controlled by PWM signals generated by the timer module. The control signals are magnetically isolated and then amplified by MOSFETs (Metal Oxide Semiconductor Field Effect Transistors). The heater, powered by AC 220V, is driven by an external solid-state relay, while the cooler, powered by DC 24V, is directly driven by MOSFETs.

[0093] The GPIO signals (General Purpose Input / Output) of the main control chip are connected to the drive circuit via magnetic isolation, and the drive circuit uses MOSFETs for signal amplification.

[0094] The RS-485 (a serial communication standard) interface uses a standard transceiver chip, and the Ethernet interface uses a transceiver chip (such as the DP83848 chip). These are connected to the USART (Universal Synchronous / Asynchronous Receiver / Transmitter) and MII media independent interface of the main control chip, respectively, to realize the communication connection with the computer.

[0095] The instrument uses a temperature sensor (i.e., the second temperature sensor) for temperature detection, and two thermistors to form a detection bridge for leakage detection. The signals are conditioned by operational amplifiers and then connected to the main control chip, which is then used for signal acquisition by the analog-to-digital converter module built into the main control chip.

[0096] In some embodiments, the control circuit can support both heating (e.g., heating to 85°C) and cooling (e.g., cooling to 10°C below room temperature).

[0097] In some embodiments, the column oven transfers heat through contact conduction, resulting in rapid heating. It also features over-temperature protection; if the temperature rises abnormally, the over-temperature protection switch will trip, cutting off the power supply to the heater and triggering an alarm. If a leak occurs in the liquid chromatograph's liquid path, the leak sensor will detect it, and the control circuit system will automatically stop heating and trigger an alarm to ensure safety.

[0098] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0099] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) and includes several instructions to cause a computer terminal (which may be a mobile phone, computer, server, or network device, etc.) to execute the methods described in the various embodiments of the present invention.

[0100] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims. All of these forms are within the protection scope of the present invention.

[0101] In some embodiments, this application also provides a schematic block diagram of the structure of a computer device, please see... Figure 6 Computer programs can be used in situations such as Figure 6 It runs on the computer device shown. Figure 6As shown, the computer device includes a processor, memory, and a network interface connected via a system bus. The memory may include non-volatile storage media and internal memory. The non-volatile storage media may store an operating system and computer programs. The computer programs include program instructions that, when executed, cause the processor to perform arbitrary methods. The processor provides computational and control capabilities to support the operation of the entire computer device. The internal memory provides an environment for the execution of the computer programs in the non-volatile storage media; when executed by the processor, these programs cause the processor to perform arbitrary methods. The network interface is used for network communication, such as sending assigned tasks. Those skilled in the art will understand that... Figure 6 The structures shown are merely block diagrams of a portion of the structure related to the present application and do not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than shown in the figures, or combine certain components, or have different component arrangements. It should be understood that the processor may be a Central Processing Unit (CPU), but it can also be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor.

Claims

1. A centralized control method for a column temperature chamber based on the Internet of Things, characterized in that, Multiple sets of liquid chromatographs are installed in the first space; correspondingly, the method further includes the following steps: S101, the host computer obtains the current temperature value of the column oven in each group of multiple liquid chromatographs in real time through the Internet of Things; S102, the host computer determines the difference distribution pattern between the current temperature value of all column ovens in the current group and the preset target temperature value based on the current temperature value of the column ovens in the multiple liquid chromatographs in each group; if the difference distribution pattern meets the first preset condition, step S103 is executed; if the difference distribution pattern meets the second preset condition, step S104 is executed. S103, the host computer initiates the centralized collaborative control mode; The centralized collaborative control mode includes: the host computer generates a first PWM signal based on the maximum difference therein, and sends it down to each of the column temperature chambers in the corresponding group, so that all the column temperature chambers in the corresponding group drive the corresponding heating module to heat based on the first PWM signal; S104, the host computer starts the distributed autonomous control mode; the distributed autonomous control mode includes: the host computer sends a control command, so that each of the column temperature chambers in the corresponding group generates its own second PWM signal according to the difference between its current temperature value and the preset target temperature value, so as to drive the corresponding heating module to perform heating.

2. The centralized control method for a column temperature chamber based on the Internet of Things according to claim 1, characterized in that, The first preset condition includes: the difference between the current temperature value and the preset target temperature value of all the column temperature chambers in the same group is less than or equal to the first preset difference.

3. The centralized control method for a column temperature chamber based on the Internet of Things according to claim 2, characterized in that, The second preset condition includes: the number N of the difference between the current temperature value and the preset target temperature value of the same group of internal column temperature chambers being greater than or equal to the second preset difference is greater than or equal to the preset number threshold M; wherein, the second preset difference is greater than the first preset difference.

4. A centralized control method for a column temperature chamber based on the Internet of Things according to any one of claims 1 to 3, characterized in that, Multiple liquid chromatographs within the same group perform the same detection and analysis task.

5. A centralized control method for a column temperature chamber based on the Internet of Things according to claim 4, characterized in that, Before activating the centralized collaborative control mode, the following steps are also included: If the deviation between the current temperature value and the preset target temperature value of P column temperature chambers in the same group and the average difference exceeds a preset threshold, based on the current location of the P column temperature chambers, it is determined whether the ambient temperature of all column temperature chambers in the same group is the same. If the ambient temperature is the same and P is greater than or equal to A / 2, the entire group switches to the decentralized autonomous control mode and prompts that P column ovens need maintenance. If the ambient temperature is the same and P is less than A / 2, it indicates that P column temperature chambers need maintenance, and the entire group adopts the centralized collaborative control mode described above. If the ambient temperatures are different, and the ambient temperatures in the P column temperature chambers are all lower or higher than the average ambient temperature of the other column temperature chambers in the same group, then the P column temperature chambers are divided into one subgroup, and the remaining column temperature chambers are in another subgroup, and the subgroup centralized collaborative control mode is activated. If the ambient temperatures are different, and the ambient temperature of P1 of the P column temperature chambers is lower than the average ambient temperature of the other column temperature chambers in the same group, and the ambient temperature of P-P1 of the column temperature chambers is higher than the average ambient temperature of the other column temperature chambers in the same group, then P1 column temperature chambers form a subgroup, P-P1 column temperature chambers form a subgroup, and the other column temperature chambers in the same group form a subgroup, and each subgroup activates the subgroup centralized collaborative control mode.

6. The centralized control method for a column temperature chamber based on the Internet of Things according to claim 5, characterized in that, The subgroup centralized collaborative control mode includes: the host computer generates a third PWM signal based on the maximum difference in each subgroup to drive the heating module of the column temperature chamber in the subgroup to heat.

7. A control circuit for a column oven in a liquid chromatograph, characterized in that, include: A first temperature sensor for detecting the temperature of the column oven, a controller, a heater drive circuit electrically connected to the controller, and an Ethernet communication module; The controller is configured to acquire the current temperature value of the column oven from the first temperature sensor in real time; and to send the first PWM signal received by the Ethernet communication module from the host computer to the heater drive circuit to drive the corresponding heating module to heat; or, to generate a corresponding second PWM signal based on the difference between the current temperature value and the preset target temperature value according to the control command received by the Ethernet communication module from the host computer, and send it to the heater drive circuit to drive the corresponding heating module to heat. The first PWM signal is generated by the host computer based on the maximum difference between the current temperature distribution pattern of all column ovens in the current group and the preset target temperature value, which is determined by the host computer based on the current temperature values ​​of the column ovens in the current group. The control command is generated by the host computer based on the current temperature values ​​of the column ovens in the current group and the second preset condition, which is determined by the host computer based on the current temperature values ​​of the column ovens in the current group and the second preset condition, which is determined by the host computer based on the current temperature values ​​of the column ovens in the current group and the preset target temperature value.

8. The control circuit for the column oven in a liquid chromatograph according to claim 7, characterized in that, Also includes: A leakage detection module is provided, the output of which is connected to the controller via a third amplifier. When the controller determines that a leakage has occurred based on the data detected by the leakage detection module, the controller controls the heater drive circuit to stop driving the heater to heat.

9. The control circuit for the column oven in a liquid chromatograph according to claim 8, characterized in that, It also includes a second temperature sensor for detecting pipeline temperature. When the controller determines that an abnormal temperature has occurred based on the temperature data from the second temperature sensor, the controller controls the over-temperature protection switch to open, thereby cutting off the power supply to the heater; Simultaneously triggers an alarm from the leakage detection module; And / or, both the first temperature sensor and the second temperature sensor are PT100.

10. A centralized monitoring system for a multiphase liquid chromatograph, characterized in that, include: Multiple liquid chromatographs, said liquid chromatographs including the control circuitry as described in claims 7-9; The host computer is configured to acquire the current temperature values ​​of the column ovens in multiple liquid chromatographs in real time; And based on the current temperature values ​​of the column ovens in multiple liquid chromatographs within the current group, determine the distribution pattern of the difference between the current temperature value and the preset target temperature value of all column ovens in the current area; If the difference distribution pattern meets the first preset condition, the centralized collaborative control mode is activated. The centralized collaborative control mode includes: the host computer generates a first PWM signal based on the maximum difference and sends it to each column temperature chamber in the corresponding group, so that all column temperature chambers in the corresponding group drive the corresponding heating module to heat based on the first PWM signal; if the difference distribution pattern meets the second preset condition, the host computer starts the decentralized autonomous control mode; the decentralized autonomous control mode includes: the host computer sends a control command so that each column temperature chamber in the corresponding group generates its own second PWM signal based on the difference between its current temperature value and the preset target temperature value, so as to drive the corresponding heating module to heat.

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