Temperature control method and device for freeze dryer, freeze dryer and computer readable storage medium

Abstract

The invention relates to the technical field of freeze dryer control, and discloses a temperature control method for a freeze dryer, which comprises the following steps: acquiring the current actually measured temperature of a drying chamber; according to the deviation value of the current actually-measured temperature of the drying chamber and the target temperature, the target duty ratio of a refrigeration electromagnetic valve is determined; and the refrigeration electromagnetic valve is controlled according to the target duty ratio. Thus, an integration link in a conventional PID algorithm does not need to be adopted, the hysteresis problem of temperature control is effectively avoided, and then extra heat output generated due to the fact that the heating requirement is misjudged by the PID algorithm is reduced. The energy waste is obviously reduced, and the time required for adjusting the temperature to the target range is shortened. Meanwhile, by accurately controlling switching of the refrigeration valves, the refrigeration depth of the system is not affected while the temperature stability is ensured, and the efficient, energy-saving and stable temperature control effect is achieved. The invention further discloses a temperature control device for the freeze dryer, the freeze dryer and a computer readable storage medium.

Description

Technical Field

[0001] The present application relates to the field of freeze dryer control technology, for example, to a temperature control method and device for a freeze dryer, a freeze dryer, and a computer-readable storage medium. Background Art

[0002] The existing pilot-scale freeze dryer is an important equipment for realizing vacuum freeze drying process in the food and pharmaceutical industries. The equipment is mainly composed of a drying chamber, a cold trap and a corresponding temperature control system. The drying chamber is provided with a partition for placing the items to be freeze-dried, while the cold trap is responsible for collecting and condensing the water sublimated during the freeze drying process. During the freeze drying process, the items are first frozen to a solid state, and then the water is directly sublimated from the solid state to a gas state by heating under near-vacuum conditions, and finally the gaseous water is captured and condensed by the cold trap. Since the freeze dryer has strict requirements for temperature control, a refrigerant with a large specific heat capacity such as silicone oil is usually used for temperature transfer.

[0003] At present, the relevant technology discloses a temperature control method for a freeze dryer, including: when the temperature control system detects that the current temperature is lower than the target range and there is excess cold, the heater is automatically started and its power output is adjusted using a PID algorithm to release an appropriate amount of heat energy to compensate for the cold until the system temperature stably reaches and is maintained within the target range.

[0004] In the process of implementing the embodiments of the present disclosure, it is found that there are at least the following problems in the related art:

[0005] Although the related technology can maintain the system temperature within the target range to a certain extent, the limited thermal conductivity of the coolant with a large specific heat capacity such as silicone oil slows down the response speed of temperature control. This hysteresis makes it easy for the PID algorithm to misjudge during the temperature control process. Therefore, when the PID algorithm misjudges that heating is required due to hysteresis, the heater will output extra heat, resulting in energy waste.

[0006] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present application, and therefore may include information that does not constitute the prior art known to ordinary technicians in the field. Summary of the invention

[0007] In order to provide a basic understanding of some aspects of the disclosed embodiments, a brief summary is given below. The summary is not an extensive review, nor is it intended to identify key / critical components or delineate the scope of protection of these embodiments, but rather serves as a prelude to the detailed description that follows.

[0008] The embodiments of the present disclosure provide a temperature control method and device for a freeze dryer, a freeze dryer, and a computer-readable storage medium to overcome the technical problem of energy waste when the temperature control response is delayed due to the use of silicone oil coolant.

[0009] In some embodiments, the temperature control method for a freeze dryer includes: obtaining the current measured temperature of the drying chamber; determining the target duty cycle of the refrigeration solenoid valve based on the deviation value between the current measured temperature of the drying chamber and the target temperature; and controlling the refrigeration solenoid valve according to the target duty cycle.

[0010] In some embodiments, the temperature control method for a freeze dryer includes: calculating an incremental algorithm output value based on an incremental PID algorithm; determining a target duty cycle of the refrigeration solenoid valve based on a deviation between a current measured temperature of the drying chamber and a target temperature and the incremental algorithm output value.

[0011] In some embodiments, the temperature control method for a freeze dryer comprises:

[0012] Y n =Y n-1 +K p ×(e n -e n-1 )+K i ×e n +K d ×(e n -2×e n-1 +e n-2 )

[0013] Among them, Y n is the output value of this incremental algorithm, Y n-1 is the output value of the last incremental algorithm, K p is the proportionality coefficient, K i is the integration coefficient, K d is the differential coefficient, e n is the deviation between the current measured temperature of the drying chamber and the target temperature, e n-1 is the deviation value of the last control cycle, e n-2 It is the deviation value of the previous control cycle.

[0014] In some embodiments, the temperature control method for a freeze dryer includes: when the deviation value between the current measured temperature of the drying chamber and the target temperature is greater than the second threshold and less than the first threshold, and the output value of the incremental algorithm is greater than the lower limit threshold of the duty cycle, determining the target duty cycle of the refrigeration solenoid valve to be the first duty cycle; or, when the deviation value between the current measured temperature of the drying chamber and the target temperature is greater than the second threshold and less than the first threshold, and the output value of the incremental algorithm is equal to the lower limit threshold of the duty cycle, determining the target duty cycle of the refrigeration solenoid valve to be the second duty cycle; wherein the first duty cycle is greater than the second duty cycle.

[0015] In some embodiments, the temperature control method for a freeze dryer includes: when the deviation value between the current measured temperature of the drying chamber and the target temperature is greater than a first threshold value, determining the target duty cycle of the refrigeration solenoid valve to be an upper limit threshold value of the duty cycle; or, when the deviation value between the current measured temperature of the drying chamber and the target temperature is less than a second threshold value, determining the target duty cycle of the refrigeration solenoid valve to be a lower limit threshold value of the duty cycle; wherein the first threshold value is greater than the second threshold value.

[0016] In some embodiments, the temperature control method for a freeze dryer includes: obtaining a target temperature of a drying chamber set by a freeze dryer user; and obtaining a current measured temperature of the drying chamber when the target temperature of the drying chamber is lower than a refrigeration temperature threshold.

[0017] In some embodiments, the temperature control method for a freeze dryer includes: obtaining an expected maintenance time of the target temperature; when the temperature of the drying chamber reaches the target temperature and the time the temperature of the drying chamber is maintained within the target temperature range reaches the expected maintenance time, stopping the control of the refrigeration solenoid valve.

[0018] In some embodiments, the temperature control method for a freeze dryer includes: a processor and a memory storing program instructions, and the processor is configured to execute the aforementioned temperature control method for a freeze dryer when running the program instructions.

[0019] In some embodiments, the freeze dryer includes: a freeze dryer body; and the aforementioned temperature control device for the freeze dryer, installed on the freeze dryer body.

[0020] In some embodiments, the computer-readable storage medium stores program instructions, and when the program instructions are executed, the computer is used to execute the aforementioned temperature control method for a freeze dryer.

[0021] The temperature control method, device, freeze dryer and computer-readable storage medium provided in the embodiments of the present disclosure can achieve the following technical effects:

[0022] This solution obtains the current measured temperature of the drying room in real time, compares it with the preset target temperature, and calculates the deviation value. Based on the deviation value, the target duty cycle of the refrigeration solenoid valve is directly determined, which is used as the basis for controlling the switching of the refrigeration valve, so as to accurately adjust the cold distribution and achieve precise control of the temperature in the drying room. With this solution, there is no need to use the integral link in the conventional PID algorithm, which effectively avoids the temperature control lag problem caused by the limited thermal conductivity of the silicone oil refrigerant, thereby reducing the additional heat output caused by the PID algorithm misjudging the heating demand. It not only significantly reduces energy waste, but also shortens the time required to adjust the temperature to the target range, improving the efficiency and accuracy of the overall temperature control. At the same time, by accurately controlling the switching of the refrigeration valve, it is possible to ensure temperature stability while keeping the system's refrigeration depth unaffected, achieving efficient, energy-saving and stable temperature control effects.

[0023] The above general description and the following description are exemplary and explanatory only and are not intended to limit the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] One or more embodiments are exemplarily described by corresponding drawings, which do not limit the embodiments. Elements with the same reference numerals in the drawings are shown as similar elements, and the drawings do not constitute a scale limitation, and wherein:

[0025] Figure 1 is a structural schematic diagram of a freeze dryer provided in an embodiment of the present disclosure;

[0026] Figure 2 is a schematic diagram of a temperature control method for a freeze dryer provided in an embodiment of the present disclosure;

[0027] Figure 3 is a schematic diagram of a method for determining a target duty cycle provided by an embodiment of the present disclosure;

[0028] Figure 4 is a schematic diagram of another temperature control method for a freeze dryer provided by an embodiment of the present disclosure;

[0029] Figure 5 is a schematic diagram of another temperature control method for a freeze dryer provided by an embodiment of the present disclosure;

[0030] Figure 6 It is a schematic diagram of a temperature control device for a freeze dryer provided in an embodiment of the present disclosure.

[0031] Reference numerals:

[0032] 1: Drying chamber; 2: Circulation pump; 3: Heater; 4: Heat exchanger; 5: Compressor unit; 6: Cold trap; 7: Refrigeration solenoid valve; 8: Cold trap valve. DETAILED DESCRIPTION

[0033] In order to be able to understand the features and technical contents of the embodiments of the present disclosure in more detail, the implementation of the embodiments of the present disclosure is described in detail below in conjunction with the accompanying drawings. The attached drawings are for reference only and are not used to limit the embodiments of the present disclosure. In the following technical description, for the convenience of explanation, a full understanding of the disclosed embodiments is provided through multiple details. However, one or more embodiments can still be implemented without these details. In other cases, to simplify the drawings, well-known structures and devices can be simplified for display.

[0034] The terms "first", "second", etc. in the specification and claims of the embodiments of the present disclosure and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchanged where appropriate, so that the embodiments of the embodiments of the present disclosure described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions.

[0035] Unless otherwise stated, the term "plurality" means two or more.

[0036] In the embodiment of the present disclosure, the character " / " indicates that the preceding and following objects are in an "or" relationship. For example, A / B indicates: A or B.

[0037] The term "and / or" is a description of the association relationship between objects, indicating that three relationships can exist. For example, A and / or B means: A or B, or, A and B.

[0038] The term "correspondence" may refer to an association relationship or a binding relationship. The correspondence between A and B means that there is an association relationship or a binding relationship between A and B.

[0039] Figure 1 is a schematic diagram of the structure of a freeze dryer provided in an embodiment of the present disclosure; Figure 1 As shown, the embodiment of the present disclosure discloses a freeze dryer, including core components such as a drying chamber 1, a circulating pump 2, a heater 3, a heat exchanger 4, a compressor unit 5, a cold trap 6, a refrigeration solenoid valve 7, and a cold trap valve 8. These components are interconnected by pipelines to form a closed-loop freeze drying system.

[0040] Specifically, in the working process of the freeze dryer, the drying chamber 1, as the main place for material drying, works closely with the circulating pump 2, the heater 3 and the heat exchanger 4. The circulating pump 2 is responsible for driving the working medium to flow in the system to ensure the transfer of energy and the working medium. The heater 3 provides the heat energy required for drying, while the heat exchanger 4 is used to adjust the temperature of the working medium to meet the drying requirements at different stages. At the same time, the compressor unit 5 and the cold trap 6 constitute a refrigeration system, which realizes a low-temperature environment through the circulation of the working medium to capture the sublimated water vapor. The refrigeration solenoid valve 7 and the cold trap valve 6 accurately control the flow path of the refrigerant and the working state of the cold trap 6 to ensure the stability and efficiency of the freeze-drying process.

[0041] Figure 2 is a schematic diagram of a temperature control method for a freeze dryer provided in an embodiment of the present disclosure; Figure 2 As shown, optionally, the embodiment of the present disclosure provides a temperature control method for a freeze dryer, comprising:

[0042] S21, the freeze dryer obtains the current measured temperature of the drying chamber.

[0043] S22, the freeze dryer determines a target duty cycle of the refrigeration solenoid valve according to a deviation between the current measured temperature of the drying chamber and the target temperature.

[0044] S23, the freeze dryer controls the refrigeration solenoid valve according to the target duty cycle.

[0045] In one example, a temperature sensor can be directly installed in the drying chamber of the freeze dryer, and the temperature sensor can be used to capture the temperature changes in the drying chamber in real time, so as to directly obtain the current measured temperature of the drying chamber. In another example, it is also possible to rely on the monitoring of other parameters inside the freeze dryer, combined with known physical relationships and mathematical models, to indirectly obtain the measured temperature of the drying chamber by calculation or inference. Here, other parameters include but are not limited to shelf temperature, pressure, humidity, etc. With this solution, the current measured temperature of the drying chamber can be obtained in a variety of ways.

[0046] Furthermore, the freeze dryer can determine the target duty cycle of the refrigeration solenoid valve according to the deviation between the current measured temperature of the drying chamber and the target temperature, so that the freeze dryer can control the refrigeration solenoid valve according to the target duty cycle. In this way, the determination of the target duty cycle in combination with the deviation value can ensure that the temperature of the drying chamber approaches the target value quickly and stably, effectively avoiding the problem of oversupply or undersupply of cold in traditional temperature control methods, thereby significantly improving the temperature control accuracy of the freeze dryer and realizing the on-demand supply of cold.

[0047] The temperature control method for a freeze dryer provided by the embodiment of the present disclosure is adopted, and the current measured temperature of the drying chamber is obtained in real time, and compared with the preset target temperature to calculate the deviation value. Therefore, based on the deviation value, the target duty cycle of the refrigeration solenoid valve is directly determined, and this is used as the basis for controlling the switching of the refrigeration valve, so as to accurately regulate the cold distribution and achieve accurate control of the temperature in the drying chamber. With this scheme, there is no need to adopt the integral link in the conventional PID algorithm, which effectively avoids the temperature control lag problem caused by the limited thermal conductivity of the silicone oil refrigerant, thereby reducing the additional heat output caused by the PID algorithm misjudging the heating demand. Not only does it significantly reduce the waste of energy, but it also shortens the time required for the temperature to be adjusted to the target range, and improves the efficiency and accuracy of the overall temperature control. At the same time, by accurately controlling the switching of the refrigeration valve, it is possible to ensure temperature stability while keeping the refrigeration depth of the system unaffected, and achieve efficient, energy-saving and stable temperature control effects.

[0048] Figure 3 is a schematic diagram of a method for determining a target duty cycle provided by an embodiment of the present disclosure; Figure 3 As shown, optionally, in S22, the freeze dryer determines a target duty cycle of the refrigeration solenoid valve according to a deviation between the current measured temperature of the drying chamber and the target temperature, including:

[0049] S31, the freeze dryer calculates an incremental algorithm output value according to the incremental PID algorithm.

[0050] S32, the freeze dryer determines the target duty cycle of the refrigeration solenoid valve according to the deviation value between the current measured temperature of the drying chamber and the target temperature and the output value of the incremental algorithm.

[0051] It is understandable that the traditional PID algorithm accumulates historical deviation values ​​through the integral term when eliminating static errors, but it is easy to cause excessive integration in the early stage of system response or when there is a lot of external interference, causing over-adjustment and frequent operation of the refrigeration solenoid valve. In contrast, the incremental PID algorithm does not rely on deviation accumulation, but calculates the control increment based on the current deviation and its rate of change, avoiding the problem of excessive integration and reducing energy consumption and equipment wear. At the same time, the incremental PID algorithm in this embodiment only considers the deviation between the current measured temperature and the target temperature in the integral term, which simplifies the calculation, improves the real-time performance and response speed of the system, and enables the system to adjust the solenoid valve duty cycle faster to keep the drying chamber temperature stable.

[0052] Furthermore, since the output value of the incremental algorithm directly represents the adjustment amount of the current control cycle relative to the previous cycle, this determination method also makes the determination of the duty cycle more accurate and flexible. Therefore, by calculating the output value of the incremental algorithm, the duty cycle of the solenoid valve can be adjusted more accurately to achieve accurate control of the drying chamber temperature.

[0053] With this scheme, the incremental algorithm is used to obtain the incremental algorithm output value, which can not only avoid the problem of excessive integration and improve the stability and response speed of the system, but also more accurately and flexibly determine the duty cycle of the refrigeration solenoid valve, thereby facilitating the precise control of the drying chamber temperature.

[0054] Optionally, in S31, the freeze dryer calculates an incremental algorithm output value according to the incremental PID algorithm, including:

[0055] Y n =Y n-1 +K p ×(e n -e n-1 )+K i ×e n +K d ×(e n -2×e n-1 +e n-2 )

[0056] Among them, Y n is the output value of this incremental algorithm, Y n-1 is the output value of the last incremental algorithm, K p is the proportionality coefficient, K i is the integration coefficient, K d is the differential coefficient, e n is the deviation between the current measured temperature of the drying chamber and the target temperature, e n-1 is the deviation value of the last control cycle, e n-2 It is the deviation value of the previous control cycle.

[0057] In this scheme, the freeze dryer can obtain the proportional coefficient, the integral coefficient and the differential coefficient. And obtain the output value of the last incremental algorithm, the deviation value of the last control cycle and the deviation value of the last control cycle. Among them, the deviation value of the last control cycle refers to the difference between the actual temperature of the drying chamber and the target temperature at the end of the control cycle immediately before the current control cycle. The deviation value of the last control cycle refers to the difference between the actual temperature of the drying chamber and the target temperature at the end of a cycle before the last control cycle. For example, if this cycle is the fifth cycle, the deviation value of the last control cycle refers to the deviation value between the actual temperature of the drying chamber in the fourth cycle and the target temperature, and the deviation value of the last control cycle refers to the deviation value between the actual temperature of the drying chamber in the third cycle and the target temperature.

[0058] Optionally, the proportionality factor K p The determination of K is usually based on the response speed and stability requirements of the freeze dryer system. For example, an initial value can be set through experience or preliminary testing. Then, K is gradually increased. pWhen the freeze dryer system responds quickly and has a small overshoot, a better K can be determined. p This allows the system to quickly eliminate errors while avoiding excessive fluctuations.

[0059] Optionally, the integration coefficient K i The purpose of determining is to eliminate the static error of the system. In one example, when K is initially set p After the value is set, you can start adjusting K i Usually, the integral constant is set to a larger value first to avoid excessive impact of the integral action on the system. Then, the integral constant is gradually reduced to observe the response of the system. When the system can stably eliminate static errors and no instability occurs, a better K can be determined. i In this way, the system can maintain a stable output during long-term operation.

[0060] Optionally, the differential coefficient K d The main purpose of determining K is to improve the dynamic performance of the system and reduce overshoot and oscillation. p and K i Based on the value, a smaller K can be initially set d Then, gradually increase K d When the system dynamic performance is improved, such as the overshoot is reduced and the oscillation is weakened, a better K can be determined. d This allows the system to adjust its output quickly and smoothly in response to input changes.

[0061] In this way, the obtained proportional coefficient, integral coefficient, differential coefficient, the output value of the last incremental algorithm, the deviation value of the last control cycle, and the deviation value of the last control cycle are input into the incremental PID algorithm to obtain the incremental algorithm output value. In this scheme, the incremental PID algorithm is used to calculate the incremental algorithm output value, which can avoid the over-adjustment problem caused by the accumulation of integral terms in the traditional PID algorithm. By considering the current deviation and its rate of change in real time, the system response speed is improved, and energy consumption and equipment wear are effectively reduced. It is ensured that the system can quickly adjust the solenoid valve duty cycle when facing temperature fluctuations, thereby maintaining the stability of the drying chamber temperature.

[0062] Optionally, in S32, the freeze dryer determines a target duty cycle of the refrigeration solenoid valve according to a deviation value between the current measured temperature of the drying chamber and the target temperature and an output value of the incremental algorithm, including:

[0063] When the deviation between the current measured temperature of the drying chamber and the target temperature is greater than the second threshold and less than the first threshold, and the output value of the incremental algorithm is greater than the duty cycle lower limit threshold, the freeze dryer determines that the target duty cycle of the refrigeration solenoid valve is the first duty cycle. Or,

[0064] When the deviation between the current measured temperature of the drying chamber and the target temperature is greater than the second threshold and less than the first threshold, and the output value of the incremental algorithm is equal to the duty cycle lower limit threshold, the freeze dryer determines that the target duty cycle of the refrigeration solenoid valve is the second duty cycle.

[0065] The first duty cycle is greater than the second duty cycle.

[0066] In this solution, the first threshold, the second threshold, the first duty cycle and the second duty cycle can be preset according to the actual situation. For example, the first threshold is 2°C, the second threshold is -2°C, the first duty cycle is the output value of the incremental algorithm, and the second duty cycle is 0. In addition, the lower limit threshold of the duty cycle can be determined based on the cooling demand, which is closely related to the cooling rate. Specifically, when the cooling rate is set to 1°C / min, by analyzing the relationship between the system cooling capacity and the target cooling rate, and taking into account the balance between energy efficiency and safe operation of the equipment, the minimum solenoid valve opening time required to achieve the cooling rate is determined, that is, the lower limit threshold of the duty cycle is 20%. With this solution, it can be ensured that the system can not only effectively meet the cooling demand, but also avoid unnecessary energy consumption and equipment wear.

[0067] In this way, when the deviation between the current measured temperature of the drying chamber and the target temperature is greater than -2°C and less than 2°C, and the output value of the incremental algorithm is greater than 20%, the freeze dryer determines the target duty cycle of the refrigeration solenoid valve to be the output value of the incremental algorithm. With this solution, the accuracy of temperature control and the sensitivity of system response are comprehensively considered, ensuring that the determination of the target duty cycle is not only based on the real-time temperature deviation, but also incorporates the dynamic adjustment capability of the incremental algorithm, thereby effectively improving the accuracy of the duty cycle setting and optimizing the temperature control effect during the freeze drying process.

[0068] In this way, when the deviation between the current measured temperature of the drying chamber and the target temperature is greater than -2°C and less than 2°C, and the output value of the incremental algorithm is equal to 20%, the freeze dryer determines that the target duty cycle of the refrigeration solenoid valve is 0. This solution not only reflects the high attention to the temperature control accuracy, but also ensures the accuracy of the duty cycle setting by combining the output of the incremental algorithm, effectively avoiding unnecessary refrigeration operations when approaching the target temperature, and improving the control performance and energy efficiency of the freeze dryer in the temperature fine-tuning stage.

[0069] S22, the freeze dryer determines the target duty cycle of the refrigeration solenoid valve according to the deviation between the current measured temperature of the drying chamber and the target temperature, including:

[0070] When the deviation between the current measured temperature of the drying chamber and the target temperature is greater than the first threshold, the freeze dryer determines that the target duty cycle of the refrigeration solenoid valve is the duty cycle upper limit threshold.

[0071] When the deviation between the current measured temperature of the drying chamber and the target temperature is less than the second threshold, the freeze dryer determines that the target duty cycle of the refrigeration solenoid valve is the duty cycle lower limit threshold.

[0072] The first threshold is greater than the second threshold.

[0073] In this solution, the first threshold and the second threshold can be pre-set according to the actual situation. For example, the first threshold is 2°C, the second threshold is -2°C, and the duty cycle lower limit threshold can be determined based on the cooling demand, which is closely related to the cooling rate. Specifically, when the cooling rate is set to 1°C / min, by analyzing the relationship between the system cooling capacity and the target cooling rate, and considering the balance point between energy efficiency and safe operation of the equipment, the minimum solenoid valve opening time required to achieve the cooling rate is determined, that is, the duty cycle lower limit threshold is 20%. With this solution, it can be ensured that the system can effectively meet the cooling demand while avoiding unnecessary energy consumption and equipment wear. At the same time, the determination of the duty cycle upper limit threshold is based on a comprehensive consideration of the maximum cooling capacity of the refrigeration system, the urgency of the cooling demand, and the durability and service life of the equipment. As an example, the duty cycle upper limit threshold is 90%. In this way, it can be ensured that the system maintains stable operation while efficiently cooling, avoiding overload and excessive wear, thereby optimizing overall performance and extending equipment life.

[0074] In this way, when the deviation between the current measured temperature of the drying chamber and the target temperature is greater than 2°C, the target duty cycle of the refrigeration solenoid valve is determined to be 90%. This solution effectively ensures that the system can respond quickly when facing a large temperature deviation, and achieves rapid refrigeration through a high duty cycle. This strategy not only takes into account the direct impact of temperature deviation on refrigeration demand, but also reflects the importance of system response speed and refrigeration efficiency, thereby optimizing the overall efficiency and performance of the freeze-drying process while ensuring the accuracy of temperature control.

[0075] In this way, when the deviation between the current measured temperature of the drying chamber and the target temperature is less than -2°C, the freeze dryer determines the target duty cycle of the refrigeration solenoid valve to be 20%. With this solution, the relationship between temperature deviation and refrigeration demand is effectively balanced to avoid over-refrigeration. This strategy not only considers the direct impact of temperature deviation on the system's refrigeration demand, but also reflects the careful consideration of energy efficiency and equipment wear, thereby optimizing the energy efficiency of the freeze dryer and the durability of the equipment while ensuring the accuracy of temperature control.

[0076] Figure 4 is a schematic diagram of another temperature control method for a freeze dryer provided by an embodiment of the present disclosure; Figure 4 As shown, the embodiment of the present disclosure provides another temperature control method for a freeze dryer, comprising:

[0077] S41, the freeze dryer obtains the target temperature of the drying chamber set by the freeze dryer user.

[0078] S42, when the target temperature of the drying chamber is lower than the refrigeration temperature threshold, the freeze dryer obtains the current measured temperature of the drying chamber.

[0079] S43, the freeze dryer determines a target duty cycle of the refrigeration solenoid valve according to a deviation between the current measured temperature of the drying chamber and the target temperature.

[0080] S44, the freeze dryer controls the refrigeration solenoid valve according to the target duty cycle.

[0081] It can be understood that a refrigeration system is also configured inside the freeze dryer, and the refrigeration system includes but is not limited to a compressor, a condenser, an expansion valve, an evaporator, etc. In practical applications, the system needs to be responsible for the cooling task of the two key physical spaces of the drying chamber and the cold trap at the same time. When the target temperature is set to be low, the refrigeration capacity of the refrigeration system is fixed. How to efficiently and reasonably allocate this part of the cold capacity becomes the key to improving the performance of the freeze dryer. Therefore, by accurately calculating and dynamically adjusting the duty cycle of the refrigeration solenoid valve, the optimal allocation of cold capacity is achieved, so that the freeze dryer can reach and stably maintain the set low temperature target value more quickly, especially in the range of below -20°C to the refrigeration limit. This advantage is particularly obvious. Therefore, in this embodiment, the freeze dryer obtains the target temperature of the drying chamber set by the freeze dryer user. And when the target temperature of the drying chamber is lower than the refrigeration temperature threshold, the temperature control process of this case is started to control the refrigeration solenoid valve. Here, the refrigeration temperature threshold is -20°C. In this way, when the target temperature of the drying chamber is lower than -20°C, the freeze dryer obtains the current measured temperature of the drying chamber, compares it with the target temperature, and calculates the deviation value between the two. Based on this deviation value, the freeze dryer dynamically determines the target duty cycle of the refrigeration solenoid valve. Then, the freeze dryer will accurately control the refrigeration solenoid valve according to the calculated target duty cycle to ensure that the refrigeration system can operate efficiently and stably.

[0082] With this scheme, the temperature control scheme based on this embodiment has higher applicability in low-temperature environments, and can more accurately obtain the current measured temperature of the drying chamber under the limitation of low-temperature scenarios, and make more detailed adjustments to the duty cycle of the refrigeration solenoid valve based on the deviation value from the target temperature. This control method not only improves the stability of temperature control, but also significantly reduces energy consumption. Since the distribution of cooling capacity is more reasonable, unnecessary waste of cooling capacity is avoided, so that the drying chamber can maintain a stable temperature for a longer time after reaching the target temperature, reducing the frequent start and stop of the refrigeration system, thereby extending the service life of the freeze dryer.

[0083] Figure 5 is a schematic diagram of another temperature control method for a freeze dryer provided by an embodiment of the present disclosure; Figure 5 As shown, the embodiment of the present disclosure provides another temperature control method for a freeze dryer, comprising:

[0084] S51, the freeze dryer obtains the current measured temperature of the drying chamber.

[0085] S52, the freeze dryer determines a target duty cycle of the refrigeration solenoid valve according to a deviation between the current measured temperature of the drying chamber and the target temperature.

[0086] S53, the freeze dryer controls the refrigeration solenoid valve according to the target duty cycle.

[0087] S54, the freeze dryer obtains the expected maintenance time of the target temperature.

[0088] S55, the freeze dryer determines whether the temperature of the drying chamber has reached the target temperature and whether the time for which the temperature of the drying chamber has been maintained within the target temperature range has reached the expected maintenance time.

[0089] S56, when the temperature of the drying chamber reaches the target temperature and the time for which the temperature of the drying chamber is maintained within the target temperature range reaches the expected maintenance time, the freeze dryer stops controlling the refrigeration solenoid valve.

[0090] In this solution, the target temperature range and the expected maintenance time can be preset. In this way, when the temperature of the drying chamber reaches the target temperature and the temperature of the drying chamber is maintained within the target temperature range for the expected maintenance time, the freeze dryer stops controlling the refrigeration solenoid valve. With this solution, the freeze dryer can intelligently stop controlling the refrigeration solenoid valve, thereby avoiding unnecessary energy consumption and improving the overall efficiency and energy utilization of the freeze drying process.

[0091] Figure 6 is a schematic diagram of a temperature control device for a freeze dryer provided in an embodiment of the present disclosure; Figure 6 As shown, the embodiment of the present disclosure provides a temperature control device 300 for a freeze dryer, including a processor 301 and a memory 302. Optionally, the device 300 may also include a communication interface 303 and a bus 304. Among them, the processor 301, the communication interface 303, and the memory 302 can communicate with each other through the bus 304. The communication interface 303 can be used for information transmission. The processor 301 can call the logic instructions in the memory 302 to execute the temperature control method for the freeze dryer of the above embodiment.

[0092] In addition, the logic instructions in the memory 302 described above may be implemented in the form of software functional units and when sold or used as independent products, may be stored in a computer-readable storage medium.

[0093] The memory 302 is a computer-readable storage medium that can be used to store software programs and computer executable programs, such as program instructions / modules corresponding to the method in the embodiment of the present disclosure. The processor 301 executes functional applications and data processing by running the program instructions / modules stored in the memory 302, that is, the temperature control method for the freeze dryer in the above embodiment is implemented.

[0094] The memory 302 may include a program storage area and a data storage area, wherein the program storage area may store an operating system and an application required for at least one function; the data storage area may store data created according to the use of the terminal device, etc. In addition, the memory 302 may include a high-speed random access memory and may also include a non-volatile memory.

[0095] The disclosed embodiment provides a freeze dryer, comprising: a freeze dryer body, and the above-mentioned temperature control device 300 for the freeze dryer. The temperature control device 300 for the freeze dryer is installed on the freeze dryer body. The installation relationship described here is not limited to placement inside the freeze dryer body, but also includes installation connections with other components of the freeze dryer, including but not limited to physical connections, electrical connections or signal transmission connections, etc. Those skilled in the art can understand that the temperature control device 300 for the freeze dryer can be adapted to a feasible freeze dryer body, thereby realizing other feasible embodiments.

[0096] An embodiment of the present disclosure provides a computer-readable storage medium storing computer-executable instructions, wherein the computer-executable instructions are configured to execute the temperature control method for a freeze dryer.

[0097] The technical solution of the embodiment of the present disclosure can be embodied in the form of a software product, which is stored in a storage medium and includes one or more instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in the embodiment of the present disclosure. The aforementioned storage medium may be a non-transient storage medium, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a disk or an optical disk, and other media that can store program codes.

[0098] The above description and the accompanying drawings fully illustrate the embodiments of the present disclosure so that those skilled in the art can practice them. Other embodiments may include structural, logical, electrical, process and other changes. The embodiments represent only possible changes. Unless explicitly required, separate components and functions are optional, and the order of operation may vary. The parts and features of some embodiments may be included in or replace the parts and features of other embodiments. Moreover, the words used in this application are only used to describe the embodiments and are not used to limit the claims. As used in the description of the embodiments and the claims, unless the context clearly indicates, the singular forms of "a", "an" and "the" are intended to include plural forms as well. Similarly, the term "and / or" as used in this application refers to any and all possible combinations of listings containing one or more associated ones. In addition, when used in the present application, the term "comprise" and its variants "comprises" and / or comprising refer to the presence of stated features, wholes, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or groups thereof. In the absence of further restrictions, the elements defined by the sentence "comprising a ..." do not exclude the presence of other identical elements in the process, method or device comprising the elements. In this article, each embodiment may focus on the differences from other embodiments, and the same and similar parts between the various embodiments may refer to each other. For the methods, products, etc. disclosed in the embodiments, if they correspond to the method part disclosed in the embodiments, then the relevant parts can refer to the description of the method part.

[0099] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software may depend on the specific application and design constraints of the technical solution. The technicians may use different methods for each specific application to implement the described functions, but such implementations should not be considered to exceed the scope of the embodiments of the present disclosure. The technicians may clearly understand that, for the convenience and simplicity of description, the specific working processes of the systems, devices and units described above may refer to the corresponding processes in the aforementioned method embodiments, and will not be repeated here.

[0100] In the embodiments disclosed herein, the disclosed methods and products (including but not limited to devices, equipment, etc.) can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units can be only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between each other shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms. The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the units may be selected according to actual needs to implement this embodiment. In addition, each functional unit in the embodiment of the present disclosure may be integrated in a processing unit, or each unit may exist physically alone, or two or more units may be integrated in one unit.

[0101] The flowchart and block diagram in the accompanying drawings show the possible architecture, function and operation of the system, method and computer program product according to the embodiment of the present disclosure. In this regard, each box in the flowchart or block diagram can represent a module, a program segment or a part of the code, and the module, the program segment or a part of the code contains one or more executable instructions for realizing the specified logical function. In some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, which can depend on the functions involved. In the description corresponding to the flowchart and the block diagram in the accompanying drawings, the operations or steps corresponding to different boxes can also occur in a different order from the order disclosed in the description, and sometimes there is no specific order between different operations or steps. For example, two consecutive operations or steps can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, which can depend on the functions involved. Each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, may be implemented by a dedicated hardware-based system that performs the specified functions or actions, or may be implemented by a combination of dedicated hardware and computer instructions.

Claims

1. A temperature control method for a freeze dryer, characterized in that: The freeze dryer includes a drying chamber and a refrigeration solenoid valve arranged on a pipeline connecting a heat exchanger and a compressor unit, and the method includes: Get the current measured temperature of the drying chamber; According to the deviation between the current measured temperature of the drying chamber and the target temperature, the target duty cycle of the refrigeration solenoid valve is determined; The refrigeration solenoid valve is controlled according to the target duty cycle.

2. The method according to claim 1, characterized in that According to the deviation between the current measured temperature of the drying chamber and the target temperature, the target duty cycle of the refrigeration solenoid valve is determined, including: According to the incremental PID algorithm, the incremental algorithm output value is calculated; The target duty cycle of the refrigeration solenoid valve is determined according to the deviation between the current measured temperature of the drying chamber and the target temperature and the output value of the incremental algorithm.

3. The method according to claim 2, characterized in that According to the incremental PID algorithm, the incremental algorithm output value is calculated, including: Y n =Y n-1 +K p ×(e n -e n-1 )+K i ×e n +K d ×(e n -2×e n-1 +e n-2 ) Among them, Y n is the output value of this incremental algorithm, Y n-1 is the output value of the last incremental algorithm, K p is the proportionality coefficient, K i is the integration coefficient, K d is the differential coefficient, e n is the deviation between the current measured temperature of the drying chamber and the target temperature, e n-1 is the deviation value of the last control cycle, e n-2 It is the deviation value of the previous control cycle.

4. The method according to claim 2, characterized in that: According to the deviation between the current measured temperature of the drying chamber and the target temperature and the output value of the incremental algorithm, the target duty cycle of the refrigeration solenoid valve is determined, including: When the deviation between the current measured temperature of the drying chamber and the target temperature is greater than the second threshold and less than the first threshold, and the output value of the incremental algorithm is greater than the duty cycle lower limit threshold, the target duty cycle of the refrigeration solenoid valve is determined to be the first duty cycle; or, When the deviation between the current measured temperature of the drying chamber and the target temperature is greater than the second threshold and less than the first threshold, and the output value of the incremental algorithm is equal to the duty cycle lower limit threshold, determining the target duty cycle of the refrigeration solenoid valve to be the second duty cycle; The first duty cycle is greater than the second duty cycle.

5. The method according to claim 1, characterized in that According to the deviation between the current measured temperature of the drying chamber and the target temperature, the target duty cycle of the refrigeration solenoid valve is determined, including: When the deviation between the current measured temperature of the drying chamber and the target temperature is greater than the first threshold, determining the target duty cycle of the refrigeration solenoid valve to be the duty cycle upper limit threshold; or, When the deviation between the current measured temperature of the drying chamber and the target temperature is less than the second threshold, determining the target duty cycle of the refrigeration solenoid valve to be the duty cycle lower limit threshold; The first threshold is greater than the second threshold.

6. The method according to claim 1, characterized in that When the target temperature of the drying chamber is lower than the cooling temperature threshold, the current measured temperature of the drying chamber is obtained, including: Obtaining the target temperature of the drying chamber set by the freeze dryer user; When the target temperature of the drying chamber is lower than the cooling temperature threshold, the current measured temperature of the drying chamber is obtained.

7. The method according to claim 1, characterized in that After controlling the refrigeration solenoid valve according to the target duty cycle, the method further includes: Get the expected maintenance time of the target temperature; When the temperature of the drying chamber reaches the target temperature and the time for which the temperature of the drying chamber is maintained within the target temperature range reaches the expected maintenance time, the control of the refrigeration solenoid valve is stopped.

8. A temperature control device for a freeze dryer, comprising a processor and a memory storing program instructions, characterized in that: The processor is configured to execute the temperature control method for a freeze dryer according to any one of claims 1 to 7 when running the program instructions.

9. A freeze dryer, characterized in that: include: Freeze dryer body; The temperature control device for a freeze dryer according to claim 8, is installed on the freeze dryer body.

10. A computer-readable storage medium storing program instructions, characterized in that: When the program instructions are executed, the computer is used to execute the temperature control method for a freeze dryer according to any one of claims 1 to 7.

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