A method, system and device for controlling the temperature of a freeze-dryer shelf

Abstract

The application discloses a freeze-drying machine plate layer temperature control method, system and device, and relates to the temperature control field. The method comprises the following steps: acquiring the ambient temperature around the plate layer of the current freeze-drying machine, the inlet temperature and outlet temperature of the silicone oil in the silicone oil pipeline in the freeze-drying box; generating a temperature control signal based on the ambient temperature, the inlet temperature and the outlet temperature; and sending the temperature control signal to the heater or the refrigerator, so that the heater heats the silicone oil in the silicone oil pipeline, and the silicone oil heats or the refrigerator cools each plate layer in the freeze-drying box. The inlet temperature and the outlet temperature of the silicone oil pipeline in the freeze-drying box can represent the heating degree of the silicone oil for the plate layer, and the temperature control signal can be determined in combination with the ambient temperature. Based on the temperature control signal, it is determined whether the plate layer needs to be heated or cooled at present, and the temperature of the plate layer of the freeze-drying machine is more accurately controlled.

Description

Technical Field

[0001] This invention relates to the field of temperature control, and in particular to a method, system and device for controlling the temperature of the plates in a freeze dryer. Background Technology

[0002] Products freeze-dried in a freeze dryer first undergo cooling and freezing into a solid state. Then, they are heated under vacuum, causing the water in the product to sublimate from a solid state to a gaseous state. The heat transfer during this process is primarily achieved through temperature changes in the plates supporting the product. Freeze-drying requires extremely strict temperature control, especially during the sublimation stage. Insufficient heat leads to prolonged drying time, while excessive heat causes product collapse. Therefore, freeze dryers demand high precision in plate temperature control, maintaining stable temperatures over extended periods. Since the pre-freezing and sublimation temperatures are generally below 0°C, and some special products even require temperatures below -50°C, while the desorption drying temperature must be above 0°C, sometimes even above 40°C, accurate temperature control directly impacts the quality of the product processed by the freeze dryer. However, due to the wide temperature range that freeze dryers need to control, precise temperature control is quite challenging. Summary of the Invention

[0003] The purpose of this invention is to provide a method, system, and device for controlling the temperature of the freeze dryer's plates, which determines whether the plates need to be heated or cooled based on temperature control signals, thereby controlling the temperature of the freeze dryer's plates more accurately.

[0004] To solve the above-mentioned technical problems, the present invention provides a method for controlling the temperature of the freeze dryer plates, comprising:

[0005] The ambient temperature around the current freeze dryer's plates, the inlet temperature and outlet temperature of the silicone oil in the silicone oil pipeline in the freeze dryer are obtained. The silicone oil flows along the silicone oil pipeline from the inlet of the freeze dryer through each plate of the freeze dryer and the outlet of the freeze dryer to heat or cool the product on the plate. The difference between the inlet temperature and the outlet temperature is positively correlated with the temperature change of the product.

[0006] A temperature control signal is generated based on the ambient temperature, inlet temperature, and outlet temperature.

[0007] The temperature control signal is sent to the heater or the cooler so that the heater heats the silicone oil in the silicone oil pipeline, the silicone oil heats each plate in the freeze-drying chamber, or the cooler cools each plate in the freeze-drying chamber.

[0008] On the other hand, the freeze dryer also includes an ambient temperature probe, which is disposed on the outside of the plate layer, with its front end suspended and its rear end disposed on the fixing plate of the freeze dryer.

[0009] Obtain the ambient temperature around the current plate layer, including:

[0010] The ambient temperature around the current plate layer is obtained from the ambient temperature probe.

[0011] On the other hand, the freeze dryer also includes a plate outlet temperature probe and a plate inlet temperature probe. The plate outlet temperature probe is located in the silicone oil pipeline near the outlet of the freeze dryer, and the plate inlet temperature probe is located in the silicone oil pipeline near the inlet of the freeze dryer.

[0012] Obtaining the inlet and outlet temperatures of the silicone oil in the freeze-drying chamber includes:

[0013] The inlet temperature detected by the plate inlet temperature probe and the outlet temperature detected by the plate outlet temperature probe are obtained.

[0014] On the other hand, the silicone oil pipeline includes blind pipes;

[0015] The plate temperature probe is placed at the bottom of the blind tube, and the blind tube is placed at the center of the silicone oil pipeline.

[0016] On the other hand, before generating the temperature control signal based on the ambient temperature, inlet temperature, and outlet temperature, the method further includes:

[0017] Determine the deviation parameter between the plate entry temperature and the set temperature, wherein the relationship of the deviation parameter is Tp = Tin - Tsp;

[0018] Determine the rate of change parameter of the deviation, the relationship of which is Td = Tin - Tin0;

[0019] Determine the temperature difference parameter of the plate layer itself, and the relationship of the temperature difference parameter of the plate layer itself is Ts=Tin-Tout;

[0020] The temperature difference parameters of the plate layer environment are determined, and the relationship of the temperature difference parameters of the plate layer environment is Te = Ten -

[0021] (Tin+Tout) / 2;

[0022] Wherein, Tp is the deviation parameter, Tin is the inlet temperature of the current cycle, Tsp is the set temperature, Td is the rate of change parameter, Tin0 is the inlet temperature of the previous cycle, Ts is the plate layer's own temperature difference parameter, Tout is the outlet temperature, Te is the plate layer's ambient temperature difference parameter, and Ten is the ambient temperature.

[0023] A temperature control signal is generated based on the ambient temperature, inlet temperature, and outlet temperature, including:

[0024] A temperature control signal is generated based on the deviation parameter, the rate of change parameter, the plate layer's own temperature difference parameter, and the plate layer's ambient temperature difference parameter.

[0025] On the other hand, the temperature control signal is a PWM signal, generated based on the deviation parameter, the rate of change parameter, the plate layer's own temperature difference parameter, and the plate layer's ambient temperature difference parameter, including:

[0026] The duty cycle of the temperature control signal is generated based on the deviation parameter, the rate of change parameter, the plate layer's own temperature difference parameter, and the plate layer's ambient temperature difference parameter. The expression for the duty cycle is P = p * Tp + d * Td + s * Ts + e * Te.

[0027] Wherein, P is the duty cycle, p is the deviation coefficient, d is the rate of change coefficient, s is the plate coefficient, and e is the environmental coefficient;

[0028] The temperature control signal is determined based on the duty cycle.

[0029] On the other hand, sending the temperature control signal to the heater or cooler includes:

[0030] Determine whether the duty cycle is greater than 0;

[0031] If the duty cycle is greater than 0, then the duty cycle of the temperature control signal is set to P and sent to the cooler;

[0032] If the duty cycle is less than 0, the duty cycle of the temperature control signal is set to |P| and sent to the heater.

[0033] On the other hand, after generating the duty cycle of the temperature control signal based on the ambient temperature, inlet temperature, and outlet temperature, the method further includes:

[0034] Determine whether the deviation parameter is greater than a first preset value or less than a second preset value, wherein the first preset value and the second preset value are opposite numbers;

[0035] If the deviation parameter is greater than the first preset value or less than the second preset value, the duty cycle of the temperature control signal is adjusted to a preset threshold, and the process proceeds to the step of sending the temperature control signal to the heater or cooler.

[0036] To solve the above-mentioned technical problems, the present invention also provides a control system for the temperature of the freeze dryer's plates, comprising:

[0037] The temperature acquisition unit is used to acquire the ambient temperature around the current freeze dryer's plates, the inlet temperature and outlet temperature of the silicone oil in the silicone oil pipeline in the freeze dryer, the silicone oil being used to flow along the silicone oil pipeline from the inlet of the freeze dryer through each plate of the freeze dryer and the outlet of the freeze dryer to heat or cool the product on the plate, and the difference between the inlet temperature and the outlet temperature is positively correlated with the temperature change of the product.

[0038] A temperature control signal generation unit is used to generate a temperature control signal based on the ambient temperature, inlet temperature and outlet temperature;

[0039] A transmitting unit is used to send the temperature control signal to a heater or a cooler, so that the heater heats the silicone oil in the silicone oil pipeline, the silicone oil heats each plate in the freeze-drying chamber, or the cooler cools each plate in the freeze-drying chamber.

[0040] To address the aforementioned technical problems, the present invention also provides a device for controlling the temperature of the freeze dryer's plates, comprising:

[0041] Memory, used to store computer programs;

[0042] A processor is used to implement the steps of the freeze dryer plate temperature control method described above when executing the computer program.

[0043] This application provides a method, system, and apparatus for controlling the temperature of freeze dryer plates, relating to the field of temperature control. The method includes acquiring the ambient temperature surrounding the freeze dryer plates, and the inlet and outlet temperatures of the silicone oil in the silicone oil pipeline within the freeze-drying chamber; generating a temperature control signal based on the ambient temperature, inlet temperature, and outlet temperature; and sending the temperature control signal to a heater or a cooler, so that the heater heats the silicone oil in the silicone oil pipeline, and the silicone oil heats each plate in the freeze-drying chamber, or the cooler cools each plate in the freeze-drying chamber. The inlet and outlet temperatures of the silicone oil pipeline within the freeze-drying chamber characterize the degree of heating of the silicone oil, and combined with the ambient temperature, the temperature control signal can be determined. Based on the temperature control signal, it is determined whether to heat or cool the plates, thus more accurately controlling the temperature of the freeze dryer plates. Attached Figure Description

[0044] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the prior art and embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0045] Figure 1 A flowchart of a method for controlling the temperature of a freeze dryer plate provided by the present invention;

[0046] Figure 2 This invention provides a schematic diagram of the structure of a freeze dryer;

[0047] Figure 3 A schematic diagram of the structure of a control system for the plate temperature of a freeze dryer provided by the present invention;

[0048] Figure 4 This is a schematic diagram of a device for controlling the temperature of a freeze dryer plate, provided by the present invention.

[0049] Figure label:

[0050] 1-Freeze-drying chamber; 2-Plate; 3-Circulation pump; 4-Heater; 5-Refrigerator; 6-Plate inlet temperature probe; 7-Plate outlet temperature probe; 8-Ambient temperature probe; 11-Processor; 14-Solid-state relay; 21-Refrigeration compressor; 22-Electromagnetic on / off refrigeration valve; 23-Mechanical expansion valve. Detailed Implementation

[0051] The core of this invention is to provide a method, system, and device for controlling the temperature of the freeze dryer's plates, which determines whether the plates need to be heated or cooled based on temperature control signals, thereby more accurately controlling the temperature of the freeze dryer's plates.

[0052] 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 embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0053] Figure 1 A flowchart of a method for controlling the temperature of a freeze dryer plate provided by the present invention. Figure 2 This invention provides a schematic diagram of the structure of a freeze dryer;

[0054] The methods for controlling the plate temperature of this freeze dryer include:

[0055] S11: Obtain the ambient temperature around the current freeze dryer plate 2, the inlet temperature and outlet temperature of the silicone oil in the silicone oil pipeline in the freeze dryer 1. The silicone oil is used to flow along the silicone oil pipeline from the inlet of the freeze dryer 1 through each plate 2 of the freeze dryer 1 and the outlet of the freeze dryer 1 to heat or cool the products on the plate 2. The difference between the inlet temperature and the outlet temperature is positively correlated with the temperature change of the product.

[0056] S12: Generates a temperature control signal based on ambient temperature, inlet temperature, and outlet temperature;

[0057] S13: Send a temperature control signal to heater 4 or cooler 5 so that heater 4 heats the silicone oil in the silicone oil pipeline, and silicone oil heats each plate 2 in freeze-drying chamber 1 or cooler 5 cools each plate 2 in freeze-drying chamber 1.

[0058] The plate layer 2 inside the freeze-drying chamber 1 has a hollow structure. The inlet and outlet of the plate layer 2 are connected to silicone oil pipelines. A circulation pump 3 is installed on the circulation pump 3 pipeline. The circulation pump 3 drives the silicone oil to flow through the electric heater 4 and the cooler, and then into the plate layer 2. The control circuit of the heater 4 is directly controlled by the switch output port on the processor 11 to control the on / off state of the solid-state relay 14. The low-temperature side of the cooler 5 is connected to the compressor refrigeration circuit, which has only one route consisting of an electromagnetic on / off refrigeration valve 22 and a mechanical expansion valve 23.

[0059] The temperature around the plate 2 will affect the temperature inside the plate 2. For example, if the ambient temperature is higher than the set temperature, the control amount can be reduced when heating the plate 2. Similarly, the control amount needs to be increased when cooling the plate 2.

[0060] The silicone oil in the silicone oil pipeline will experience temperature changes after flowing through plate 2. These changes represent the cooling or heating capacity of plate 2. Therefore, collecting the inlet and outlet temperatures can reflect the current heating or cooling status of plate 2.

[0061] Based on the current ambient temperature, inlet temperature, and outlet temperature, the temperature control signal can be determined using algorithms such as PID. Based on the temperature control signal, heater 4 and cooler 5 can heat and cool the silicone oil pipeline.

[0062] Specifically, the temperature control signal can indicate whether heating or cooling is needed. When heating is needed, the heater 4 is controlled to heat and the cooler 5 is not cooled; when cooling is needed, the cooler 5 is controlled to cool and the heater 4 is not heated.

[0063] Furthermore, the temperature control signal can be a PWM signal, which is sent to the heater 4 and the cooler 5 respectively. When the heater 4 does not need to heat, the duty cycle of the PWM signal sent to the heater 4 can be controlled to be 0. When the cooler 5 does not need to cool, the duty cycle of the PWM signal sent to the cooler 5 can be controlled to be 0.

[0064] This application provides a method, system, and apparatus for controlling the temperature of a freeze dryer's plates, relating to the field of temperature control. The method includes acquiring the ambient temperature surrounding the current plate 2 of the freeze dryer, and the inlet and outlet temperatures of the silicone oil in the silicone oil pipeline within the freeze-drying chamber 1; generating a temperature control signal based on the ambient temperature, inlet temperature, and outlet temperature; and sending the temperature control signal to a heater 4 or a cooler 5, so that the heater 4 heats the silicone oil in the silicone oil pipeline, thereby heating each plate 2 in the freeze-drying chamber 1, or the cooler 5 cools each plate 2 in the freeze-drying chamber 1. The inlet and outlet temperatures of the silicone oil pipeline within the freeze-drying chamber 1 characterize the degree of heating of the plate 2 by the silicone oil, and the temperature control signal can be determined by combining this with the ambient temperature. Based on the temperature control signal, it is determined whether to heat or cool the plate 2, thus more accurately controlling the temperature of the plate 2 in the freeze dryer.

[0065] Based on the above embodiments:

[0066] In some embodiments, the freeze dryer further includes an ambient temperature probe 8, which is disposed on the outside of the plate layer 2, with its front end suspended and its rear end disposed on the fixing plate of the freeze dryer 1.

[0067] Obtain the ambient temperature around the current layer 2, including:

[0068] Acquire the ambient temperature around the current plate layer 2 sent by ambient temperature probe 8.

[0069] An ambient temperature probe 8 is installed near plate 2. The probe 8 is mounted on a fixed plate between plate 2 and freeze-drying chamber 1, with its front end suspended and its rear end secured to the fixed plate by a latch. The front end of the ambient temperature probe 8 can detect the ambient temperature near plate 2, thus facilitating subsequent calculations.

[0070] The rear end of the ambient temperature probe 8 is fixed on the fixing plate between the plate 2 and the freeze-drying chamber 1. It is relatively close to the freeze-drying chamber 1 and the plate 2, so the ambient temperature obtained is more accurate compared to other locations.

[0071] In some embodiments, the freeze dryer further includes a plate outlet temperature probe 7 and a plate inlet temperature probe 6. The plate outlet temperature probe 7 is disposed in the silicone oil pipeline near the outlet of the freeze dryer 1, and the plate inlet temperature probe 6 is disposed in the silicone oil pipeline near the inlet of the freeze dryer 1.

[0072] Obtain the inlet and outlet temperatures of the silicone oil in freeze-drying chamber 1, including:

[0073] The inlet temperature detected by the plate inlet temperature probe 6 and the outlet temperature detected by the plate outlet temperature probe 7 are obtained.

[0074] A plate outlet temperature probe 7 is installed near the outlet of the silicone oil pipeline at the location of plate 2, and a plate inlet temperature probe 6 is installed near the inlet of the silicone oil pipeline at the location of plate 2. The plate inlet temperature probe 6 can detect the temperature of the silicone oil in the silicone oil pipeline before heating or cooling plate 2, and the plate outlet temperature probe 7 can detect the temperature of the silicone oil in the silicone oil pipeline after heating or cooling plate 2. By using the inlet temperature probe 6 and the outlet temperature probe 7, the amount of silicone oil used for heating or cooling plate 2 can be determined, which facilitates subsequent calculations.

[0075] Placing a temperature probe in the silicone oil pipeline allows for a more accurate determination of the silicone oil temperature, leading to more accurate subsequent calculations.

[0076] In some embodiments, the silicone oil pipeline includes a blind pipe;

[0077] The plate temperature probe 7 is placed at the bottom of the blind tube, which is placed in the center of the silicone oil pipeline.

[0078] The plate temperature probe 7 should be inserted into the bottom of the blind tube welded to the silicone oil pipeline. The opening of the blind tube should face upwards, and the bottom should be in the center of the silicone oil pipeline. Silicone oil should be added inside the blind tube. There is a threaded locking device at the opening of the blind tube to constrain the probe lead.

[0079] Considering that the temperature at the center of the silicone oil pipeline is more consistent with the actual silicone oil temperature, a blind tube inserted into the silicone oil pipeline was added. The temperature probe 7 is connected to the bottom of the silicone oil blind tube, so the actual silicone oil temperature can be detected by placing the bottom of the blind tube at the center of the silicone oil pipeline.

[0080] In some embodiments, before generating the temperature control signal based on the ambient temperature, inlet temperature, and outlet temperature, the method further includes:

[0081] Determine the deviation parameter between the plate inlet temperature and the set temperature. The relationship of the deviation parameter is Tp = Tin - Tsp;

[0082] Determine the rate of change parameter of the deviation. The relationship of the rate of change parameter is Td = Tin - Tin0;

[0083] Determine the temperature difference parameter of the plate layer itself. The relationship of the temperature difference parameter of the plate layer itself is Ts=Tin-Tout;

[0084] The temperature difference parameters of the plate layer environment are determined by the formula Te = Ten -

[0085] (Tin+Tout) / 2;

[0086] Where Tp is the deviation parameter, Tin is the inlet temperature of the current cycle, Tsp is the set temperature, Td is the rate of change parameter, Tin0 is the inlet temperature of the previous cycle, Ts is the temperature difference parameter of the plate itself, Tout is the outlet temperature, Te is the temperature difference parameter of the plate environment, and Ten is the ambient temperature.

[0087] Temperature control signals are generated based on ambient temperature, inlet temperature, and outlet temperature, including:

[0088] Temperature control signals are generated based on deviation parameters, rate of change parameters, plate temperature difference parameters, and plate environment temperature difference parameters.

[0089] In some embodiments, the temperature control signal is a PWM signal, generated based on deviation parameters, rate of change parameters, the temperature difference parameters of the plate itself, and the temperature difference parameters of the plate environment, including:

[0090] The duty cycle of the temperature control signal is generated based on the deviation parameter, the rate of change parameter, the temperature difference parameter of the plate itself and the temperature difference parameter of the plate environment. The expression of the duty cycle is P=p*Tp+d*Td+s*Ts+e*Te.

[0091] Where P is the duty cycle, p is the deviation coefficient, d is the rate of change coefficient, s is the slab coefficient, and e is the environmental coefficient;

[0092] The temperature control signal is determined based on the duty cycle.

[0093] The control process needs to take into account the relationship between the current set temperature and the inlet and outlet temperatures, as well as the relationship between the ambient temperature and the inlet and outlet temperatures. In addition, it is necessary to determine the relationship between the two cycles of the inlet temperature.

[0094] Solid-state relay 14 and electromagnetic on / off cooling valve 22 can be controlled by the switching output of processor 11 to perform periodic opening and closing actions. The opening time To and closing time Tc are determined based on the output percentage P calculated by comprehensively considering the PLC's set temperature Tsp, the collected board inlet temperature Tin, board outlet temperature Tout, and board ambient temperature Ten. Table 1 shows the correspondence between the absolute value of the output percentage P and the opening and closing times. (t is the unit time coefficient):

[0095] Table 1

[0096] Output percentage P absolute value Start Time To Closure time Tc 0 0 10t 0<|P|<＝10 1t 9t 10<|P|<＝20 2t 8t 20<|P|<＝30 3t 7t 30<|P|<＝40 4t 6t 40<|P|<＝50 5t 5t 50<|P|<＝60 6t 4t 60<|P|<＝70 7t 3t 70<|P|<＝80 8t 2t 80<|P|<＝90 9t 1t 90<|P|<＝100 10t 0

[0097] Based on the performance of the solid-state relay 14, its on / off unit time coefficient t can be selected in the range of (0.1, 0.2) seconds, and the unit time coefficient of the electromagnetic on / off cooling valve 22 can be selected in the range of (1, 2) seconds.

[0098] In some embodiments, sending a temperature control signal to the heater 4 or the cooler 5 includes:

[0099] Determine if the duty cycle is greater than 0;

[0100] If the duty cycle is greater than 0, the duty cycle of the temperature control signal is set to P and sent to the cooler 5;

[0101] If the duty cycle is less than 0, the duty cycle of the temperature control signal is set to |P| and sent to heater 4.

[0102] If the duty cycle is greater than 0, it is determined that the temperature inside the freeze dryer 1 is higher than the set temperature and refrigeration is required. The obtained P is used as the duty cycle of the temperature control signal, that is, the temperature control signal is a PWM signal with a duty cycle of P% sent to the cooler 5.

[0103] If the duty cycle is less than 0, it is determined that the temperature inside the freeze dryer 1 is lower than the set temperature and heating is required. Considering that the duty cycle cannot be negative, the obtained |P| is used as the duty cycle of the temperature control signal, that is, the temperature control signal is a PWM signal with a duty cycle of |P|% sent to the heater 4.

[0104] In some embodiments, after generating the duty cycle of the temperature control signal based on the ambient temperature, inlet temperature, and outlet temperature, the method further includes:

[0105] Determine whether the deviation parameter is greater than the first preset value or less than the second preset value, where the first preset value and the second preset value are opposite numbers;

[0106] If the deviation parameter is greater than the first preset value or less than the second preset value, the duty cycle of the temperature control signal is adjusted to the preset threshold, and the step of sending the temperature control signal to the heater 4 or the cooler 5 is initiated.

[0107] The preset value can be set to 100% to accelerate the heating or cooling speed. The specific value can be adjusted according to actual needs, and this application does not impose further limitations here. The deviation parameter represents the difference between the plate inlet temperature and the set temperature. If the difference between the plate inlet temperature and the set temperature is greater than 1℃, it indicates that the difference is large. Continuing to use a PWM signal with a duty cycle of P% to control the cooler 5 or a PWM signal with a duty cycle of |P|% to control the heater 4 will affect the heating or cooling progress and the output quality of the freeze dryer. Therefore, the duty cycle is adjusted to 100% to increase the heating or cooling speed. Subsequent control based on the calculated P value will continue when the deviation parameter is less than 1℃.

[0108] Figure 3This is a schematic diagram of a control system for the plate temperature of a freeze dryer provided by the present invention. The control system for the plate temperature of the freeze dryer includes:

[0109] Temperature acquisition unit 31 is used to acquire the ambient temperature around the plate 2 of the freeze dryer, the inlet temperature and outlet temperature of the silicone oil in the silicone oil pipeline in the freeze dryer 1. The silicone oil flows along the silicone oil pipeline from the inlet of the freeze dryer 1 through each plate 2 of the freeze dryer 1 and the outlet of the freeze dryer 1 to heat or cool the product on the plate 2. The difference between the inlet temperature and the outlet temperature is positively correlated with the temperature change of the product.

[0110] Temperature control signal generation unit 32 is used to generate temperature control signals based on ambient temperature, inlet temperature and outlet temperature;

[0111] The transmitting unit 33 is used to send a temperature control signal to the heater 4 or the cooler 5, so that the heater 4 heats the silicone oil in the silicone oil pipeline, and the silicone oil heats each plate 2 in the freeze-drying chamber 1, or the cooler 5 cools each plate 2 in the freeze-drying chamber 1.

[0112] The freeze dryer also includes an ambient temperature probe 8, which is located on the outside of the plate 2. The front end of the ambient temperature probe 8 is suspended, and the rear end of the ambient temperature probe 8 is mounted on the fixed plate of the freeze drying chamber 1.

[0113] The temperature acquisition unit 31 is specifically used to acquire the ambient temperature around the current plate layer 2, the inlet temperature and the outlet temperature of the silicone oil pipeline in the freeze dryer 1, which are sent by the ambient temperature probe 8.

[0114] The freeze dryer also includes a plate outlet temperature probe 7 and a plate inlet temperature probe 6. The plate outlet temperature probe 7 is located in the silicone oil pipeline near the outlet of the freeze dryer 1, and the plate inlet temperature probe 6 is located in the silicone oil pipeline near the inlet of the freeze dryer 1.

[0115] The temperature acquisition unit 31 is specifically used to acquire the ambient temperature around the freeze drying chamber 1 of the current freeze dryer, the inlet temperature detected by the plate inlet temperature probe 6, and the outlet temperature detected by the plate outlet temperature probe 7.

[0116] Silicone oil pipelines include blind pipes;

[0117] The plate temperature probe 7 is placed at the bottom of the blind tube, which is placed in the center of the silicone oil pipeline.

[0118] Also includes:

[0119] The deviation parameter determination unit is used to determine the deviation parameters between the plate entry temperature and the set temperature. The relationship between the deviation parameters is Tp = Tin - Tsp.

[0120] The rate of change parameter determination unit is used to determine the rate of change parameter of the deviation. The relationship of the rate of change parameter is Td = Tin - Tin0.

[0121] The plate layer self-temperature difference parameter determination unit is used to determine the plate layer self-temperature difference parameter. The relationship of the plate layer self-temperature difference parameter is Ts=Tin-Tout;

[0122] The plate environment temperature difference parameter determination unit is used to determine the plate environment temperature difference parameter. The relationship of the plate environment temperature difference parameter is Te=Ten-(Tin+Tout) / 2;

[0123] Where Tp is the deviation parameter, Tin is the inlet temperature of the current cycle, Tsp is the set temperature, Td is the rate of change parameter, Tin0 is the inlet temperature of the previous cycle, Ts is the temperature difference parameter of the plate itself, Tout is the outlet temperature, Te is the temperature difference parameter of the plate environment, and Ten is the ambient temperature.

[0124] The temperature control signal generation unit 32 is specifically used to generate a temperature control signal based on the deviation parameter, the rate of change parameter, the temperature difference parameter of the plate itself, and the temperature difference parameter of the plate environment.

[0125] The temperature control signal is a PWM signal;

[0126] The temperature control signal generation unit 32 is specifically used to generate the duty cycle of the temperature control signal based on the deviation parameter, the rate of change parameter, the temperature difference parameter of the plate itself and the temperature difference parameter of the plate environment. The expression of the duty cycle is P=p*Tp+d*Td+s*Ts+e*Te.

[0127] Where P is the duty cycle, p is the deviation coefficient, d is the rate of change coefficient, s is the slab coefficient, and e is the environmental coefficient;

[0128] The signal generation unit is used to determine the temperature control signal based on the duty cycle.

[0129] The first judgment unit is specifically used to determine whether the duty cycle is greater than 0;

[0130] The transmitting unit 33 is specifically used to set the duty cycle of the temperature control signal to P and send it to the cooler 5 if the duty cycle is greater than 0.

[0131] If the duty cycle is less than 0, the duty cycle of the temperature control signal is set to |P| and sent to heater 4.

[0132] The first judgment unit is specifically used to determine whether the deviation parameter is greater than a first preset value or less than a second preset value, wherein the first preset value and the second preset value are opposite numbers;

[0133] The duty cycle adjustment unit is used to adjust the duty cycle of the temperature control signal to a preset threshold if the deviation parameter is greater than the first preset value or less than the second preset value, and to trigger the sending unit 23.

[0134] The description of the control system for the plate temperature of the freeze dryer provided in this application is given in the above embodiments and will not be repeated here.

[0135] Figure 4 This is a schematic diagram of a freeze dryer plate temperature control device provided by the present invention. The freeze dryer plate temperature control device includes:

[0136] Memory 41 is used to store computer programs;

[0137] The processor 11 is used to execute a computer program to implement the steps of the freeze dryer plate temperature control method described above.

[0138] The description of the freeze dryer plate temperature control device provided in this application is similar to that in the above embodiments and will not be repeated here.

[0139] It should also be noted that, in this specification, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, 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. Without further limitations, 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 said element.

[0140] Those skilled in the art will further recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0141] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for controlling the temperature of the plates in a freeze dryer, characterized in that, include: The ambient temperature around the current freeze dryer's plates, the inlet temperature and outlet temperature of the silicone oil in the silicone oil pipeline within the freeze dryer are obtained. The silicone oil flows along the silicone oil pipeline from the inlet of the freeze dryer through each plate of the freeze dryer and to the outlet of the freeze dryer to heat or cool the product on the plate. The difference between the inlet temperature and the outlet temperature is positively correlated with the temperature change of the product. A temperature control signal is generated based on the ambient temperature, inlet temperature, and outlet temperature. The temperature control signal is sent to the heater or the cooler so that the heater heats the silicone oil in the silicone oil pipeline, the silicone oil heats each plate in the freeze-drying chamber, or the cooler cools each plate in the freeze-drying chamber. Before generating a temperature control signal based on the ambient temperature, inlet temperature, and outlet temperature, the method further includes: Determine the deviation parameter between the plate entry temperature and the set temperature, wherein the relationship of the deviation parameter is as follows: ; The rate of change parameter of the deviation is determined, and the relationship of the rate of change parameter is as follows: ; The temperature difference parameters of the plate layer itself are determined, and the relationship of the temperature difference parameters of the plate layer itself is as follows: ; The temperature difference parameters of the plate layer environment are determined, and the relationship of the temperature difference parameters of the plate layer environment is as follows: ; in, The deviation parameter is... The inlet temperature for the current cycle, To set the temperature, The rate of change parameter, The inlet temperature mentioned in the previous cycle. The temperature difference parameter of the plate layer itself. The outlet temperature is... The temperature difference parameter of the plate layer environment. The ambient temperature; A temperature control signal is generated based on the ambient temperature, inlet temperature, and outlet temperature, including: A temperature control signal is generated based on the deviation parameter, the rate of change parameter, the plate layer's own temperature difference parameter, and the plate layer's ambient temperature difference parameter. The temperature control signal is a PWM signal, generated based on the deviation parameter, the rate of change parameter, the plate layer's own temperature difference parameter, and the plate layer's ambient temperature difference parameter, including: The duty cycle is generated based on the deviation parameter, the rate of change parameter, the plate layer's own temperature difference parameter, and the plate layer's ambient temperature difference parameter. The expression for the duty cycle is: ; Wherein, P is the duty cycle, p is the deviation coefficient, d is the rate of change coefficient, s is the plate coefficient, and e is the environmental coefficient; The temperature control signal is determined based on the duty cycle; Sending the temperature control signal to the heater or cooler includes: Determine whether the duty cycle is greater than 0; If the duty cycle is greater than 0, then the duty cycle of the temperature control signal is set to P and sent to the cooler; If the duty cycle is less than 0, then the duty cycle of the temperature control signal is set to... And send it to the heater.

2. The method for controlling the temperature of the freeze dryer plates as described in claim 1, characterized in that, The freeze dryer also includes an ambient temperature probe, which is disposed on the outside of the plate layer. The front end of the ambient temperature probe is suspended, and the rear end of the ambient temperature probe is disposed on the fixing plate of the freeze dryer. Obtain the ambient temperature around the current plate layer, including: The ambient temperature around the current plate layer is obtained from the ambient temperature probe.

3. The method for controlling the temperature of the freeze dryer plates as described in claim 1, characterized in that, The freeze dryer also includes a plate outlet temperature probe and a plate inlet temperature probe. The plate outlet temperature probe is located in the silicone oil pipeline near the outlet of the freeze dryer, and the plate inlet temperature probe is located in the silicone oil pipeline near the inlet of the freeze dryer. Obtaining the inlet and outlet temperatures of the silicone oil in the freeze-drying chamber includes: The inlet temperature detected by the plate inlet temperature probe and the outlet temperature detected by the plate outlet temperature probe are obtained.

4. The method for controlling the temperature of the freeze dryer plates as described in claim 3, characterized in that, The silicone oil pipeline includes blind pipes; The plate temperature probe is placed at the bottom of the blind tube, and the blind tube is placed at the center of the silicone oil pipeline.

5. The method for controlling the temperature of the freeze dryer plates as described in claim 1, characterized in that, After generating the duty cycle of the temperature control signal based on the ambient temperature, inlet temperature, and outlet temperature, the method further includes: Determine whether the deviation parameter is greater than a first preset value or less than a second preset value, wherein the first preset value and the second preset value are opposite numbers; If the deviation parameter is greater than the first preset value or less than the second preset value, the duty cycle of the temperature control signal is adjusted to a preset threshold, and the process proceeds to the step of sending the temperature control signal to the heater or cooler.

6. A control system for the temperature of the freeze dryer's plates, characterized in that, include: The temperature acquisition unit is used to acquire the ambient temperature around the current freeze dryer's plates, the inlet temperature and outlet temperature of the silicone oil in the silicone oil pipeline in the freeze dryer. The silicone oil is used to flow along the silicone oil pipeline from the inlet of the freeze dryer through each plate of the freeze dryer and the outlet of the freeze dryer to heat or cool the product on the plate. The difference between the inlet temperature and the outlet temperature is positively correlated with the temperature change of the product. A temperature control signal generation unit is used to generate a temperature control signal based on the ambient temperature, inlet temperature and outlet temperature; A transmitting unit is used to send the temperature control signal to a heater or a cooler, so that the heater heats the silicone oil in the silicone oil pipeline, the silicone oil heats each plate in the freeze-drying chamber, or the cooler cools each plate in the freeze-drying chamber. Also includes: The deviation parameter determination unit is used to determine the deviation parameter between the plate entry temperature and the set temperature. The relationship between the deviation parameter is as follows: ; The rate of change parameter determination unit is used to determine the rate of change parameter of the deviation, wherein the relationship of the rate of change parameter is as follows: ; A plate-layer self-temperature difference parameter determination unit is used to determine the plate-layer self-temperature difference parameters, the relationship of which is: ; A plate layer environmental temperature difference parameter determination unit is used to determine the plate layer environmental temperature difference parameters, the relationship of which is: ; in, The deviation parameter is... The inlet temperature for the current cycle, To set the temperature, The rate of change parameter, The inlet temperature mentioned in the previous cycle. The temperature difference parameter of the plate layer itself. The outlet temperature is... The temperature difference parameter of the plate layer environment. The ambient temperature; The temperature control signal generation unit is specifically used to generate a temperature control signal based on the deviation parameter, the rate of change parameter, the plate layer's own temperature difference parameter, and the plate layer's ambient temperature difference parameter. The temperature control signal is a PWM signal; The temperature control signal generation unit is specifically used to generate a duty cycle based on the deviation parameter, the rate of change parameter, the plate layer's own temperature difference parameter, and the plate layer's ambient temperature difference parameter. The expression for the duty cycle is: ; Wherein, P is the duty cycle, p is the deviation coefficient, d is the rate of change coefficient, s is the plate coefficient, and e is the environmental coefficient; A signal generation unit is used to determine the temperature control signal based on the duty cycle; The first judgment unit is specifically used to determine whether the duty cycle is greater than 0; The transmitting unit is specifically used to set the duty cycle of the temperature control signal to P and send it to the cooler if the duty cycle is greater than 0. If the duty cycle is less than 0, then the duty cycle of the temperature control signal is set to... And send it to the heater.

7. A device for controlling the temperature of the freeze dryer's plates, characterized in that, include: Memory, used to store computer programs; A processor, configured to execute the computer program to implement the steps of the freeze dryer plate temperature control method as described in any one of claims 1 to 5.

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