A flexible air duct precise temperature control system and control method thereof

Abstract

The present invention relates to the field of agricultural product preservation technology, which discloses a flexible air duct precision temperature control system and its control method. The temperature control system refrigeration component includes a flexible air duct component connected to the top of a cold storage through an air cooler, the flexible air duct component includes a flexible air duct, and a plurality of cold storage plates are arranged in different areas in the flexible air duct; a sensor component is used to collect temperature signals and pressure difference signals in the cold storage and the refrigeration component; a controller controls the refrigeration component to process the cold storage plates in three working modes: refrigeration, cold storage and defrosting, and improves the temperature uniformity of the cold storage through the flexible air duct component and the cold storage plates, and reduces the temperature fluctuation in the cold storage during defrosting. The present invention uses flexible air ducts and cold storage plates to improve the temperature uniformity of the cold storage; adopts two exchangers, the air cooler and the cold storage plate, and controls the cold capacity in the cold storage plates when the refrigeration equipment defrosts, so as to significantly reduce the temperature fluctuation in the storage during defrosting.

Description

Technical Field

[0001] The present invention relates to the field of agricultural product preservation, and in particular to a flexible air duct precise temperature control system and a control method thereof. Background Art

[0002] Refrigeration and preservation of agricultural products at the production site is the most crucial link in the entire cold chain. It is the first step in creating an ideal temperature environment for preserving fruits and vegetables, and represents the "first mile" of cold chain logistics. Refrigeration and preservation not only address the conflict between the concentrated market demand and short harvest periods for fruit and vegetables, but also effectively alleviate the constraints on fruit exports caused by a shortage of refrigerated trucks and high freight costs.

[0003] Because traditional refrigeration and fresh-keeping equipment uses finned evaporators and air coolers to achieve forced convection within the cold storage, its heat exchange method is simple, resulting in drastic fluctuations in storage temperature during the defrosting process. Furthermore, the air temperature is inevitably lower near the air cooler and higher farther away. Traditional refrigerated fresh-keeping storage facilities struggle to meet optimal temperature control requirements for refrigeration and fresh-keeping.

[0004] Temperature fluctuations and poor temperature uniformity can lead to condensation, drying out fruit stems and pedicles, causing dents and wrinkles on the skin, and even rotting. These conditions can also cause disease and severely damage economic returns. The more precisely the temperature control for refrigerated agricultural products is controlled, the smaller the upper and lower temperature differences are, and the closer the temperature is to the optimal storage temperature for the produce, the better the preservation effect. However, the temperature of agricultural products is regulated by the storage temperature, and this method of controlling the temperature of agricultural products through storage temperature brings special requirements to the cold storage structure, cooling method, and control method.

[0005] The existing technology has technical defects that the heat exchanger of the fresh-keeping equipment is single, the temperature fluctuation in the warehouse is large, and the temperature control accuracy is low. Summary of the Invention

[0006] In order to overcome or alleviate one or more of the above technical problems, the present invention aims to provide a flexible air duct precise temperature control system and a control method thereof.

[0007] The present invention provides the following technical solutions:

[0008] In one aspect, the present invention provides a flexible air duct precise temperature control system, comprising:

[0009] A refrigeration assembly comprises a flexible air duct assembly connected to the top of the cold storage via a cold air blower (1), wherein the flexible air duct assembly comprises a flexible air duct (704), and a plurality of cold storage plates are arranged in different areas within the flexible air duct (704);

[0010] A sensor component, used to collect temperature signals and pressure difference signals in the cold storage and the refrigeration component;

[0011] The controller is electrically connected to the refrigeration component and the sensor component respectively, and is used to receive the temperature signal and pressure difference signal collected by the sensor component in real time. After analysis and judgment, the controller controls the refrigeration component to process the cold storage plate in three working modes: refrigeration, cold storage and defrosting. The flexible air duct component and the cold storage plate are used to improve the temperature uniformity of the cold storage and reduce the temperature fluctuation in the cold storage during defrosting.

[0012] According to some embodiments, the refrigeration component further comprises a four-way valve (115), which is respectively connected to the compressor (100), the fin condenser (114), the gas-liquid separator (101), the air cooler outlet solenoid valve (108) and the cold storage outlet solenoid valve (106) through a refrigerant pipeline; the inlet and outlet of the air cooler (1) and the cold storage plate are respectively connected to the air cooler inlet solenoid valve (109), the cold storage inlet electronic valve (102), the air cooler outlet solenoid valve (108) and the cold storage outlet solenoid valve (106), One end of the two-way liquid reservoir (110) is connected to the defrost electronic expansion valve (112), the two-way drying filter (113) and the fin condenser (114) in sequence through a refrigerant pipeline; the other end of the two-way liquid reservoir (110) is connected to the filter (111) through a refrigerant pipeline and then divided into two paths, one path is connected to the multi-zone cold storage plate through the refrigerant pipeline and the cold storage inlet electronic valve (102) and the cold storage electronic expansion valve (103), and the other path is connected to the cold air machine (1) through the refrigerant pipeline and the cold air machine inlet electromagnetic valve (109) and the refrigeration electronic expansion valve (107).

[0013] According to some embodiments, a plurality of the cold storage plates are arranged in parallel via a refrigerant pipeline, and a solenoid valve and a one-way valve are respectively provided at the inlet and outlet of each cold storage plate.

[0014] According to some embodiments, the sensor assembly includes a micro-pressure difference sensor (3), a storage temperature sensor (4), a multi-channel temperature sensor (5) and an energy consumption sensor, all of which are electrically connected to the controller; the micro-pressure difference sensor (3) is arranged at the air outlet of the air cooler (1); the storage temperature sensor (4) is arranged at the return air outlet of the air cooler (1); the multi-channel temperature sensors (5) are arranged at various locations in the cold storage, the air outlet of the air cooler (1), the outer surface of the cold storage plate and the air outlet (707) at the end of the air duct; and the energy consumption sensor is arranged at the power supply line end of the flexible air duct precision temperature control system.

[0015] According to some embodiments, the flexible air duct assembly includes an inlet tightener (701), the inlet tightener (701) connects the inlet air duct (702) to the air cooler (1), a static pressure box (703) is provided at the rear end of the inlet air duct (702), and the lining of the static pressure box (703) is made of sound-absorbing material; the outlet of the static pressure box (703) is connected to the flexible air duct (704), and the flexible air duct (704) is provided with a uniform air blower (705) and multi-area distributed cold storage plates; the top strip air outlet (706) of the air duct, the end air outlet (707) of the air duct and the air outlet micropores (708) of the air duct are respectively provided at the top, end and bottom of the flexible air duct (704), wherein the top strip air outlet (706) of the air duct and the end air outlet (707) of the air duct are provided with a blocking cover.

[0016] On the other hand, the present invention also provides a control method for the flexible air duct precise temperature control system as described above, wherein the flexible air duct precise temperature control system includes two cold storage plates, namely a first cold storage plate (21) and a second cold storage plate (22), and comprises the following steps:

[0017] S0: Start the device, select a mode through the controller: preset mode or controller mode, and set the maximum temperature t0h of the cold storage, the minimum temperature t0l of the cold storage, the maximum temperature t1h of the first cold storage plate (21), the minimum temperature t1l of the first cold storage plate (21), the maximum temperature t2h of the second cold storage plate (22), the minimum temperature t2l of the second cold storage plate (22), the maximum pressure difference ph of the air cooler, and the minimum pressure difference pl of the air cooler;

[0018] S1: judging whether it is a preset mode through the controller, if yes, directly proceeding to step S2, if not, it is a controller mode, the controller collects temperature, pressure, and energy consumption parameters through the sensor component, and after inference calculation, optimizes the parameters of the maximum temperature t1h of the first cold storage plate (21), the minimum temperature t1l of the first cold storage plate (21), the maximum temperature t2h of the second cold storage plate (22), the minimum temperature t2l of the second cold storage plate (22), the maximum pressure difference ph of the cold air machine, and the minimum pressure difference pl of the cold air machine, and then proceeds to step S2;

[0019] S2: The controller obtains the real-time temperature T0 of the cold storage and determines whether T0 ≥ t0h. If so, proceed to step S2-1; if not, proceed to step S3;

[0020] S2-1: The controller controls the refrigeration component to perform a refrigeration cycle, the inlet and outlet solenoid valves of the air cooler are opened, and the process proceeds to step S2-2;

[0021] S2-2: The controller obtains the real-time temperature T0 of the cold storage and determines whether T0≤t01. If so, the controller controls the refrigeration component to stop refrigeration and closes the inlet and outlet solenoid valves of the air cooler, and then proceeds to step S2. If not, proceeds to step S2-1.

[0022] S3: The controller obtains the real-time temperature T1 of the first cold storage plate (21), and determines whether T1≥t1h. If so, proceed to step S3-1; if not, proceed to step S4;

[0023] S3-1: The controller controls the cold storage cycle of the refrigeration component, the first cold storage plate solenoid valve (104) and the cold storage outlet solenoid valve (106) are opened, and step S3-2 is continued;

[0024] S3-2: The controller obtains the real-time temperature T1 of the first cold storage plate (21) and determines whether T1≤t11. If so, the controller controls the refrigeration component to stop cold storage, closes the first cold storage plate solenoid valve (104) and the cold storage outlet solenoid valve (106), and enters step S3. If not, enters step S3-1.

[0025] S4: The controller obtains the real-time temperature T2 of the second cold storage plate (22), and determines whether T2≥t2h. If so, proceed to step S4-1; if not, proceed to step S5;

[0026] S4-1: The controller controls the cold storage cycle of the refrigeration component, the second cold storage plate solenoid valve (105) and the cold storage outlet solenoid valve (106) are opened, and step S4-2 is continued;

[0027] S4-2: The controller obtains the real-time temperature T2 of the second cold storage plate (22) and determines whether T2≤t21. If so, the controller controls the refrigeration component to stop cold storage, closes the second cold storage plate solenoid valve (105) and the cold storage outlet solenoid valve (106), and enters step S4. If not, enters step S4-1.

[0028] S5: The controller obtains the real-time differential pressure P of the air cooler transmitted by the micro differential pressure sensor (3), and determines whether pl<P<ph and time≥5min, that is, the real-time differential pressure P of the air cooler (1) is between the set minimum differential pressure value pl of the air cooler and the maximum differential pressure value ph of the air cooler and the duration is greater than or equal to 5 minutes. If so, proceed to step S5-1; if not, proceed to step S1;

[0029] S5-1: The controller controls the defrost cycle of the refrigeration component, the inlet and outlet solenoid valves of the cooling fan are opened, the fan (1) is turned on, and step S5-2 is continued;

[0030] S5-2: The controller obtains the real-time pressure difference P of the air cooler and determines whether P≥ph and time≥3min. If so, the controller controls the refrigeration component to stop defrosting, closes the inlet and outlet solenoid valves of the air cooler, and stops the fan (705) after 5 minutes, and enters S5. If not, enter step S5-1.

[0031] According to some embodiments, in the controller mode of step S1, the controller performs optimization control by an expert control method, and the expert control method includes the following steps:

[0032] S10: Information acquisition and processing, performing analog-to-digital conversion and data processing on the real-time collected data acquired by the sensor component;

[0033] S11: Inference operation: The controller performs inference operation according to a certain inference strategy based on the current input real-time collected data through the interaction of the inference mechanism and the knowledge base retrieval results to obtain the inference results of the t1h, t1l, t2h, t2l, ph, and pl parameters;

[0034] S12: Knowledge base retrieval. The knowledge base is used to categorize and store relevant knowledge and experience information. It receives the real-time data obtained in step S10, searches within the knowledge base, interacts with the inference mechanism, performs parameter matching, and sends the matching structure to the inference mechanism. The knowledge base includes but is not limited to knowledge and experience related to the temperature control system, dynamic information, and target information. Data parameters are filled in and managed in real time, and historical data is screened and eliminated. The knowledge base stores relevant knowledge and experience information for access by the control rule library.

[0035] S13: Control rule base, which stores several rules for organizing the inference results obtained by the inference mechanism with the stored relevant knowledge and experience information output by the knowledge base in step S12. If the control rule base conditions are met, the calculation and reasoning are performed according to the strategy to obtain the final parameter optimization ratio;

[0036] S14: Parameter optimization, used to optimize the parameters of t1h, t1l, t2h, t2l, ph, and pl stored in the controller to achieve intelligent switching of the refrigeration cycle, cold storage, and defrost cycle of the refrigeration component.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] The present invention provides a flexible air duct precise temperature control system and control method thereof, which adopts the method of placing the flexible air duct on the top and arranging cold storage plates in multiple areas of the flexible air duct, and utilizes the characteristics of uniform air supply of the flexible air duct and good heat transfer uniformity of the cold storage to improve the temperature uniformity of the cold storage; adopts two exchangers, the cold air blower and the cold storage plate, to realize forced convection of air in the cold storage through the cold air blower, and when the refrigeration equipment defrosts, the control of the cooling capacity in the cold storage plate and the control of the wind speed of the uniform fan are utilized to greatly reduce the temperature fluctuation in the cold storage during defrosting; the flexible air duct precise temperature control system has two control modes to choose from, namely, preset mode and controller mode. In the preset mode, the temperature control system is adjusted for overall temperature control through the preset pressure difference parameters of the cold storage, cold storage plate and air cooler; in the controller mode, the temperature control system collects input parameters such as the temperature, pressure and energy consumption of the cold storage in real time. By arranging wired or wireless temperature sensors in the cold storage, the average temperature, temperature deviation, fluctuation and uniformity of the cold storage can be calculated, and then the output parameters are optimized and set through expert control methods, thereby realizing intelligent control of the refrigeration cycle, cold storage and defrost cycle, further improving the temperature control accuracy and comprehensive performance of the device, and thus meeting the optimal refrigeration and preservation temperature control requirements of agricultural products. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 This is a schematic diagram of the installation of the air cooler, cold storage plate and sensor assembly in the cold storage provided by an embodiment of the present invention.

[0040] Figure 2 This is a schematic block diagram of the refrigeration process of the refrigeration component in the cold storage provided by an embodiment of the present invention.

[0041] Figure 3 This is a flow chart of a control method for a flexible air duct precise temperature control system provided by an embodiment of the present invention.

[0042] Figure 4 A control process block diagram of an expert control method in a controller mode provided by a controller provided by an embodiment of the present invention.

[0043] In the picture:

[0044] Air cooler 1; first cold storage plate 21; second cold storage plate 22; micro-pressure differential sensor 3; storage temperature sensor 4; temperature sensor 5; inlet tightener 701; inlet air duct 702; static pressure box 703; flexible air duct 704; air balancing fan 705; strip air outlet 706 at the top of the air duct; air outlet 707 at the end of the air duct; air outlet micropores 708 of the air duct; compressor 100; gas-liquid separator 101; cold storage inlet electronic valve 102; cold storage electronic expansion valve 103; first cold storage plate solenoid valve 104; second cold storage plate solenoid valve 105; cold storage outlet solenoid valve 106; refrigeration electronic expansion valve 107; air cooler outlet solenoid valve 108; air cooler inlet solenoid valve 109; two-way liquid reservoir 110; filter 111; defrost electronic expansion valve 112; two-way drying filter 113; fin condenser 114; four-way valve 115. DETAILED DESCRIPTION

[0045] The present invention is described in detail below with reference to the embodiments and accompanying drawings. However, it should be understood that the embodiments and accompanying drawings are merely exemplary descriptions of the present invention and do not constitute any limitation on the scope of protection of the present invention. All reasonable variations and combinations within the scope of the inventive concept of the present invention fall within the scope of protection of the present invention.

[0046] The present invention adopts a method of placing flexible air ducts on the top and arranging cold storage plates in multiple areas of the flexible air ducts, adopts two exchangers, namely, cold air blowers and cold storage plates, and realizes the release of cold and heat absorption of the finned evaporator in the cold air blower and forced convection of air in the cold storage through the blowing of the cold air blower. When the refrigeration equipment defrosts, the control of the cold capacity in the cold storage plates and the control of the wind speed of the averaging fan are utilized to greatly reduce the temperature fluctuation in the storage during defrosting.

[0047] The present invention will be further described below with reference to the accompanying drawings.

[0048] Example 1

[0049] like Figure 1 As shown, this embodiment provides a flexible air duct precision temperature control system, hereinafter referred to as the temperature control system, which includes a controller, a refrigeration component and a sensor component. The refrigeration component is used to cool the cold storage, and the sensor component is used to collect temperature signals and pressure difference signals in the cold storage and at various locations of the refrigeration component; the controller is electrically connected to the refrigeration component and the sensor component, respectively, and is used to receive the temperature signals and pressure difference signals collected by the sensor component in real time, and after analysis and judgment, control the refrigeration of the refrigeration component.

[0050] like Figure 1 The refrigeration component includes an air cooler 1, a flexible air duct component, and a cold storage plate. The sensor component includes a micro-pressure difference sensor 3, a storage temperature sensor 4, a multi-channel temperature sensor 5, and an energy consumption sensor.

[0051] The flexible air duct assembly includes an inlet tightener 701, an inlet air duct 702, a static pressure box 703, a flexible air duct 704, an air balancing fan 705, a strip air outlet 706 at the top of the air duct, an air outlet 707 at the end of the air duct and air outlet micropores 708 of the air duct. The inlet tightener 701 connects the inlet air duct 702 to the air cooler 1. A static pressure box 703 is set at the rear end of the inlet air duct 702. The lining of the static pressure box 703 is made of sound-absorbing material to reduce noise; the outlet of the static pressure box 703 is connected to the flexible air duct 704. The flexible air duct 704 is top-mounted and has a uniform fan 705 and multi-zone cold storage plates inside; the flexible air duct air outlet includes three types, namely, the air duct top strip outlet 706, the air duct end outlet 707 and the air duct outlet micropore 708. Among them, the air duct top strip outlet 706 and the air duct end outlet 707 are provided with a cover, and the air outlet area can be adjusted according to the actual situation on site.

[0052] A micro-pressure difference sensor 3 is provided at the air outlet of the air cooler 1 for judging the frosting state of the air cooler 1; a storage temperature sensor 4 is provided at the return air outlet of the air cooler 1; a plurality of temperature sensors 5 are provided inside the cold storage, which are respectively provided at the air outlet of the air cooler 1, the outer surface of the first cold storage plate 21, the outer surface of the second cold storage plate 22 and the air outlet 707 at the end of the air duct, for detecting the internal temperature of the cold storage and the cold storage temperature of the cold storage plate. In addition, by arranging multiple wired or wireless temperature sensors in the cold storage, the average temperature, temperature deviation, fluctuation and uniformity of the cold storage can be calculated after collection; an energy consumption sensor is provided at the power input end of the temperature control system for monitoring energy consumption; the micro-pressure difference sensor 3, the storage temperature sensor 4, the multiple temperature sensors 5 and the energy consumption sensor are respectively electrically connected to the controller, and multiple wired or wireless temperature sensors are arranged in the cold storage to be connected to the controller.

[0053] When the temperature control system is in a refrigeration cycle, cold air is blown out through the air cooler 1 and reaches the static pressure box 703 through the inlet air duct 702. The static pressure box 703 can convert part of the dynamic pressure into static pressure to make the cold air blow farther. The cold air passes through the flexible air duct 704 and the flexible air duct outlet, thereby achieving uniform air volume distribution.

[0054] Flexible duct performance verification test: According to GB 50072-2021 Cold Storage Design Standard" and "GB / T30103.1-2013 Cold Storage Thermal Performance Test Method Part 1: Temperature and Humidity Detection" require verification of the temperature distribution of the cold storage (with or without flexible ducts). The test equipment uses a combined cold storage, a low-resistance uniform air supply system with a flexible composite duct on the top, and the temperature control set value is 2.0±0.5℃. The comparative test conclusions of the cold storage (with or without flexible ducts) are: when there is no flexible duct, the average temperature deviation is -0.3℃, the average fluctuation is ±0.4℃, the uniformity is 1.2℃, and the average temperature of all measuring points is 2.3℃; when there is a flexible duct, the average temperature deviation is 0.2℃, the average fluctuation is ±0.4℃, the uniformity is 1.1℃, and the average temperature of all measuring points is 1.8℃; that is, after the installation of the overhead flexible duct, the average temperature deviation, uniformity and the average temperature of all measuring points of the cold storage have improved, indicating that the use of overhead flexible ducts can improve the temperature uniformity of the cold storage. After arranging and analyzing the collected temperature field data, it was found that the average temperature of the area near the outlet of the cold air blower, i.e., the front end of the flexible air duct, was 0.8°C lower than the average temperature of the area far from the outlet of the cold air blower, i.e., the end of the flexible air duct. In order to further improve the uniformity of the cold storage temperature, multiple cold storage plates (a first cold storage plate 21, a second cold storage plate 22) and an equalizing fan 705 were set at the end of the flexible air duct. Taking this flexible air duct performance verification test as an example, different temperature settings of the cold storage plates can be achieved by adjusting the cold storage capacity in the cold storage plates. The temperature of the second cold storage plate 22 is set slightly lower than the temperature of the first cold storage plate 21, so as to reduce the 0.8°C temperature difference between the average temperature of the front end area of ​​the flexible air duct and the average temperature of the end area of ​​the flexible air duct. By setting multiple cold storage areas at the end of the flexible air duct, the uniformity of the temperature in the cold storage can be further improved, and precise temperature control can be achieved.

[0055] like Figure 2 This is a block diagram of the refrigerant transfer structure of the refrigeration component.

[0056] The refrigeration assembly also includes a compressor 100, a gas-liquid separator 101, a cold storage inlet electronic valve 102, a cold storage electronic expansion valve 103, a first cold storage plate solenoid valve 104, a second cold storage plate solenoid valve 105, a cold storage outlet solenoid valve 106, a refrigeration electronic expansion valve 107, an air cooler outlet solenoid valve 108, an air cooler inlet solenoid valve 109, a two-way liquid receiver 110, a filter 111, a defrost electronic expansion valve 112, a two-way drying filter 113, a fin condenser 114, a four-way valve 115 and refrigerant pipes therebetween, and the refrigerant is transported to the various components of the refrigeration assembly through the refrigerant pipes.

[0057] The fin condenser 114 is arranged outside the cold storage, while the air cooler 1, the first cold storage plate 21, and the second cold storage plate 22 are arranged inside the cold storage. The four-way valve 115 is used to switch the flow direction of the refrigerant. It is connected to the compressor 100, the fin condenser 114, the gas-liquid separator 101, the air cooler outlet solenoid valve 108, and the cold storage outlet solenoid valve 106 through the refrigerant pipeline. The two-way liquid reservoir 110 is used to store the refrigerant liquid condensed in the fin condenser 114 or in the air cooler 1, and to manage an appropriate amount to regulate and replenish the liquid circulation volume of each part of the equipment in the refrigeration system. One end of the two-way liquid reservoir 110 is connected to the defrost electronic expansion valve 112, the two-way drying filter 113, and the fin condenser 114 in sequence through the refrigerant pipeline. The other end of the two-way liquid storage tank 110 is connected to the filter 111 through a refrigerant pipe and is divided into two paths. One path is connected to the multi-zone cold storage plate through the refrigerant pipe and the cold storage inlet electronic valve 102 and the cold storage electronic expansion valve 103, and the other path is connected to the cold air fan 1 through the refrigerant pipe and the cold air fan inlet solenoid valve 109 and the refrigeration electronic expansion valve 107.

[0058] The first cold storage plate 21 and the second cold storage plate 22 are arranged in parallel through the refrigerant pipeline. The inlet and outlet of the first cold storage plate 21 and the second cold storage plate 22 are respectively provided with the first cold storage plate solenoid valve 104, the second cold storage plate solenoid valve 105, the cold storage outlet solenoid valve 106 and the one-way valve to realize separate cold storage or joint cold storage in different areas.

[0059] The temperature control system uses two exchangers: an air cooler 1 and a cold storage plate. The air cooler 1 and the cold storage plate are connected in parallel via a refrigerant pipe. The inlet and outlet of the air cooler 1 and the cold storage plate are respectively provided with an air cooler inlet solenoid valve 109, a cold storage inlet electronic valve 102, an air cooler outlet solenoid valve 108, and a cold storage outlet solenoid valve 106 to achieve refrigeration or cold storage. When the temperature control system is cooling, air is blown by the air cooler 1 to achieve the release of cold and heat absorption by the finned evaporator in the air cooler 1 and forced convection of air in the cold storage. When the temperature control system is defrosting, the control of the cooling capacity in the cold storage plate and the wind speed control of the fan 705 are used to significantly reduce the temperature fluctuation in the storage during defrosting. The temperature control system is divided into three working states: refrigeration cycle, cold storage cycle, and defrost cycle.

[0060] When the refrigeration component is in refrigeration cycle: the controller sends a refrigeration cycle control signal, and the refrigerant starts to circulate in the refrigeration component. After the low-temperature and low-pressure liquid refrigerant absorbs heat in the air cooler 1, it vaporizes into a low-temperature and low-pressure gaseous refrigerant, is sucked into the compressor 100 through the four-way valve 115 and compressed into a high-pressure and high-temperature steam and then discharged into the fin condenser 114. In the fin condenser 114, it is cooled by the cooling medium and condensed into a high-pressure and medium-temperature liquid refrigerant. It passes through the two-way drying filter 113, the filter 111 and the two-way liquid storage tank 110, and then enters the refrigerant pipeline of the air cooler 1, that is, it passes through the air cooler inlet solenoid valve 109 and the refrigeration electronic expansion valve 107 to become a low-temperature and low-pressure liquid refrigerant, and enters the air cooler 1 again to absorb heat and vaporize, thereby achieving circulation and refrigeration of the cold storage.

[0061] When the refrigeration component is in cold storage cycle: the cold storage process is that the refrigeration component receives the cold storage control signal from the controller, and the refrigerant starts to circulate in the refrigeration component. After the low-temperature and low-pressure liquid refrigerant absorbs heat in the cold storage plate, it vaporizes into a low-temperature and low-pressure gaseous refrigerant, is sucked into the compressor 100 through the four-way valve 115 and compressed into high-pressure and high-temperature steam and then discharged into the fin condenser 114. In the fin condenser 114, it is cooled by the cooling medium and condensed into a high-pressure and medium-temperature liquid refrigerant. It passes through the two-way drying filter 113, the filter 111 and the two-way liquid storage tank 110, and then enters the refrigerant pipeline of the cold storage plate, that is, it passes through the cold storage inlet solenoid valve 106 and the cold storage electronic expansion valve 103 to become a low-temperature and low-pressure liquid refrigerant, and then enters the cold storage plate again to absorb heat and vaporize, thereby achieving circulation to store cold in the cold storage. Among them, the first cold storage plate 21 and the second cold storage plate 22 are connected in parallel through the first cold storage plate solenoid valve 104, the second cold storage plate solenoid valve 105 and the one-way valve. Cold can be stored separately or in combination, and the refrigerant flow rate can be adjusted through the cold storage electronic expansion valve 103 to achieve temperature control. The wind speed of the equalizing fan 705 can be adjusted through the controller to achieve different heat exchange rates, thereby further improving the uniformity of the cold storage temperature.

[0062] During the defrost cycle of the refrigeration component: the process of the defrost cycle of the refrigeration component is that the refrigeration component receives the defrost cycle control signal from the controller, and the refrigerant starts to circulate in the refrigeration component. After the low-temperature and low-pressure liquid refrigerant absorbs heat in the fin condenser 114, it is vaporized into a low-temperature and low-pressure gaseous refrigerant, and is sucked into the compressor 100 through the four-way valve 115 and compressed into a high-pressure and high-temperature steam and then discharged into the air cooler 1. Heat is released and defrosted in the air cooler 1, and condensed into a high-pressure and medium-temperature liquid refrigerant. It passes through the filter 111, the two-way liquid storage tank 110, the defrost electronic expansion valve 112 and the two-way drying filter 113, and then enters the refrigerant pipeline of the fin condenser 114. The high-pressure and medium-temperature liquid refrigerant is converted into a low-temperature and low-pressure liquid refrigerant through the defrost electronic expansion valve 112, and enters the fin condenser 114 again to absorb heat and vaporize, thereby realizing cyclic defrosting.

[0063] like Figure 3 Figure 1 shows a flow chart of a control method for a flexible duct precision temperature control system. A micro-pressure differential sensor 3, a storage temperature sensor 4, multiple wired or wireless temperature sensors 5, and an energy consumption sensor are electrically connected to a controller. The multiple wired or wireless temperature sensors 5 are connected to the controller either wired or wirelessly. The controller output signals are used to control the three operating states of the refrigeration component: the refrigeration cycle, the cold storage cycle, and the defrost cycle.

[0064] A control method for a flexible air duct precise temperature control system has two control modes in the initial stage, a preset mode and a controller mode, and specifically includes the following steps:

[0065] S0: Start the device and select the mode through the controller: preset mode or controller mode, and set the maximum temperature t0h of the cold storage, the minimum temperature t0l of the cold storage, the maximum temperature t1h of the first cold storage plate 21, the minimum temperature t1l of the first cold storage plate 21, the maximum temperature t2h of the second cold storage plate 22, the minimum temperature t2l of the second cold storage plate 22, the maximum pressure difference ph of the air cooler, and the minimum pressure difference pl of the air cooler.

[0066] S1: The controller determines whether the preset mode is selected. If so, the process proceeds directly to step S2. If not, the process enters the controller mode. The control system collects parameters such as device temperature, pressure, and energy consumption, and optimizes the parameters of the first cold storage plate 21 (t1h), the first cold storage plate 21 (t1l), the second cold storage plate 22 (t2h), the second cold storage plate 22 (t2l), the maximum pressure difference ph of the air cooler, and the minimum pressure difference p1 of the air cooler based on the knowledge base, database, inference mechanism, and control rule base, and then proceeds to step S2.

[0067] S2: The controller obtains the real-time temperature T0 of the cold storage and determines whether T0 ≥ t0h. If so, proceed to step S2-1; if not, proceed to step S3;

[0068] S2-1: The controller controls the refrigeration component to perform a refrigeration cycle, the inlet and outlet solenoid valves of the air cooler are opened, and the process proceeds to step S2-2;

[0069] S2-2: The controller obtains the real-time temperature T0 of the cold storage and determines whether T0≤t01. If so, the controller controls the refrigeration component to stop refrigeration and closes the inlet and outlet solenoid valves of the air cooler, and then proceeds to step S2. If not, proceeds to step S2-1.

[0070] S3: The controller obtains the real-time temperature T1 of the first cold storage plate 21 and determines whether T1 ≥ t1h. If so, proceed to step S3-1; if not, proceed to step S4;

[0071] S3-1: The controller controls the cold storage cycle of the refrigeration component, the first cold storage plate solenoid valve and the cold storage outlet solenoid valve are opened, and step S3-2 is continued;

[0072] S3-2: The controller obtains the real-time temperature T1 of the first cold storage plate 21 and determines whether T1≤t11. If so, the controller controls the refrigeration assembly to stop cold storage, closes the first cold storage plate solenoid valve and the cold storage outlet solenoid valve, and proceeds to step S3. If not, proceeds to step S3-1.

[0073] S4: The controller obtains the real-time temperature T2 of the second cold storage plate 22 and determines whether T2 ≥ t2h. If so, proceed to step S4-1; if not, proceed to step S5;

[0074] S4-1: The controller controls the cold storage cycle of the refrigeration component, opens the second cold storage plate solenoid valve and the cold storage outlet solenoid valve, and proceeds to step S4-2;

[0075] S4-2: The controller obtains the real-time temperature T2 of the second cold storage plate and determines whether T2 ≤ t21. If so, the controller controls the refrigeration assembly to stop cold storage, closes the second cold storage plate solenoid valve and the cold storage outlet solenoid valve, and proceeds to step S4. If not, proceeds to step S4-1.

[0076] S5: The controller obtains the real-time differential pressure P of the cooling fan transmitted by the micro-pressure differential sensor 3, and determines whether pl < P < ph and time ≥ 5 min, that is, the real-time differential pressure P of the cooling fan is between the set minimum differential pressure value pl of the cooling fan and the maximum differential pressure value ph of the cooling fan and the duration is greater than or equal to 5 minutes. If so, step S5-1 is performed; if not, step S1 is performed;

[0077] S5-1: The controller controls the defrost cycle of the refrigeration component, opens the inlet and outlet solenoid valves of the cooling fan, turns on the fan, and proceeds to step S5-2;

[0078] S5-2: The controller obtains the real-time pressure difference P of the air cooler and determines whether P≥ph and time≥3min. If so, the controller controls the refrigeration component to stop defrosting, closes the inlet and outlet solenoid valves of the air cooler, and stops the fan after 5 minutes, and enters S5. If not, enter step S5-1.

[0079] like Figure 4 As shown, in the controller mode, that is, through the schematic diagram of the controller's intelligent autonomous control principle, the controller performs optimal control through the expert control method, which includes the following steps:

[0080] S10: Information acquisition and processing: acquiring real-time data collected by various sensors and performing analog-to-digital conversion and data processing; real-time data collected is the detection value of sensors collected from the cold storage control site, including but not limited to storage temperature sensors, wired or wireless temperature sensors, micro-pressure differential sensors, and energy consumption sensors;

[0081] S11: Inference operation: The controller performs inference operation according to a certain inference strategy based on the current input data through the interaction of the inference mechanism and the knowledge base retrieval results to obtain the inference results of the parameters t1h, t1l, t2h, t2l, ph, and pl;

[0082] S12: Knowledge base retrieval. The knowledge base is used to classify and store relevant knowledge and experience information. It receives the real-time data obtained in step S10, searches within the knowledge base and interacts with the reasoning mechanism to match parameters, and sends the matched structure to the reasoning mechanism. The knowledge base includes but is not limited to the knowledge and experience, dynamic information, and target information corresponding to the temperature control system, and can fill in data parameters in real time and manage them, and filter and eliminate historical data. The knowledge base stores relevant knowledge and experience information for the control rule library to retrieve.

[0083] S13: Control rule base. This base stores several rules. For example, each production rule is a statement expressed in the form of "if this condition is met, this action should be taken." This base is used to combine the inference results obtained by the inference mechanism with the stored knowledge and experience information output by the knowledge base in step S12. If the control rule base conditions are met, the inference is performed according to the strategy to obtain the final parameter optimization ratio.

[0084] S14: Parameter optimization, used to optimize the parameters of t1h, t1l, t2h, t2l, ph, and pl stored in the controller to achieve intelligent switching of the refrigeration cycle, cold storage, and defrost cycle of the refrigeration component.

[0085] By acquiring and organizing control domain knowledge, such as prior experience, dynamic information, and goals, appropriate rules are selected and reasoned and output in a timely manner according to the strategy to achieve control of the device's refrigeration cycle, cold storage cycle, and defrost cycle, further improving the device's temperature control accuracy and overall performance. The system collects sensor detection values ​​from the cold storage control site, including but not limited to storage temperature sensors, wired or wireless temperature sensors, micro-pressure differential sensors, and energy consumption sensors; acquires and processes information, converts the collected data into analog and digital form, processes it, and sends the values ​​to the knowledge base; through the interaction between the knowledge base and the reasoning mechanism, determines the control algorithm, and based on the control rule base, derives the optimal parameters, thereby automatically adjusting the temperature control device's set parameters and issuing corresponding instructions for precise, real-time control, achieving the functions of refrigeration, cold storage, and defrost, and ensuring the control accuracy and overall performance of the temperature control device.

[0086] The knowledge base includes, but is not limited to, relevant knowledge and experience, dynamic information, and target information of the temperature control system. It can also fill in data parameters in real time and manage them, and filter and eliminate historical data. The knowledge and experience include, but are not limited to, algorithms for obtaining the average temperature, temperature deviation, fluctuation, and uniformity of the cold storage, and the relationship between the pressure difference of the air cooler and the frosting state of the air cooler evaporator. The control rule base includes, but is not limited to, controlling the working state of the device and the air cooler inlet and outlet solenoid valves based on the real-time temperature of the cold storage, controlling the device and the working state of the cold plate solenoid valve and the cold storage outlet solenoid valve based on the real-time temperature of the cold storage, and controlling the device and the working state of the cold plate solenoid valve and the cold storage outlet solenoid valve based on the real-time temperature of the cold storage. The device controller can make independent, real-time automatic decisions, and by modifying and adding control rules, it can continuously accumulate knowledge and improve control performance.

[0087] In this embodiment, a temperature control system with precise temperature control of dual exchangers is formed through the flexible duct uniform air supply technology, multi-zone cold storage technology and refrigeration technology through automatic control and intelligent control integration: the flexible duct is placed on the top and cold storage plates are arranged in multiple zones within the flexible duct; two exchangers, air coolers and cold storage plates, are used, and forced convection of air in the cold storage is achieved by blowing air from the air coolers. When the refrigeration equipment defrosts, the temperature is controlled by controlling the cooling capacity in the cold storage plates and controlling the wind speed of the uniform fan.

[0088] Taking the storage of berry agricultural products as an example, berries are thin-skinned and juicy, making them suitable for ice storage. The temperature of ice storage needs to be controlled within the temperature range between 0°C and the biological freezing point of the fruit cells to keep the fruit tissue cells alive and maintain a low metabolic level. In order to prevent damage to the fruit cell tissue caused by freezing, the more precise the temperature control, the smaller the upper and lower temperature difference, and the closer the temperature is to the biological freezing point of the fruit, the better the preservation effect. The flexible air duct precision temperature control system and its control method provided in this embodiment can meet the refrigeration and preservation requirements of such agricultural products at the production site. The flexible air duct is placed on the top and cold storage plates are arranged in multiple areas within the flexible air duct to avoid the cold air from the air cooler blowing directly onto the stored agricultural products, improve the uniformity of the cold storage temperature, reduce the temperature fluctuation range to achieve precise control of small temperature differences in the cold storage, and reduce a series of problems caused by temperature fluctuations, such as condensation in fruit bags, easy breeding of microorganisms, increased aging and corruption of fruits, significantly reduced evaporator cooling efficiency, and increased power consumption. The flexible air duct precision temperature control system provided in this embodiment has two mode options: preset mode and controller mode. In controller mode, the device control system collects input parameters such as the temperature, pressure and energy consumption of the cold storage in real time. By arranging wired or wireless temperature sensors in the cold storage, the average temperature, temperature deviation, fluctuation and uniformity of the cold storage can be calculated, and then the output parameters are optimized and set based on the knowledge base, database, inference mechanism and control rule library, thereby realizing intelligent control of the refrigeration cycle, cold storage and defrost cycle.

[0089] In actual production applications, the optimal cold storage parameter settings vary due to varying cold storage sizes, storage temperature settings, and product types, quantities, and stacking methods. Users often rely on experience when setting parameters, resulting in significant discrepancies between the cold storage temperature settings and the actual temperature of the stored products. This can lead to inappropriate parameter settings, resulting in product quality issues and increased energy consumption.

[0090] When the flexible duct precise temperature control system is controlled in controller mode, the user only needs to set the maximum and minimum temperatures of the cold storage. The device control system collects input parameters such as temperature, pressure and energy consumption of the cold storage in real time, and optimizes the output parameters through the expert control system to achieve precise control of the actual temperature of the stored products, realize intelligent control of the refrigeration cycle, cold storage and defrost cycle, and further improve the temperature control accuracy and comprehensive performance of the device, thereby meeting the refrigeration and preservation temperature control requirements under different conditions.

[0091] When the flexible duct precise temperature control system is controlled in the preset mode, the cold storage capacity of the cold storage plate can be adjusted by setting the parameter of the cold storage plate temperature. When the cold storage capacity of the cold storage plate is increased during the low peak electricity consumption at night, the electricity consumption of the cold storage during the peak electricity consumption during the day can be reduced, which has certain economic and social benefits.

[0092] The above embodiments are merely preferred embodiments of the present invention, and the scope of protection of the present invention is not limited to the above embodiments. All technical solutions that fall within the scope of protection of the present invention are within the scope of protection of the present invention. It should be noted that improvements and modifications that can be made by a person skilled in the art without departing from the principles of the present invention are also considered to be within the scope of protection of the present invention.

Claims

1. A flexible air duct precise temperature control system, characterized in that: include: A refrigeration assembly comprises a flexible air duct assembly connected to the top of a cold storage via a cold air blower (1), the flexible air duct assembly comprising a flexible air duct (704), a uniform air blower (705) and multi-region distributed cold storage plates arranged inside the flexible air duct (704), and a top strip-shaped air outlet (706) and air duct air outlet micropores (708) arranged on the flexible air duct (704); A sensor component, used to collect temperature signals and pressure difference signals in the cold storage and the refrigeration component; The controller is electrically connected to the refrigeration component and the sensor component respectively, and is used to receive the temperature signal and pressure difference signal collected by the sensor component in real time. After analysis and judgment, the controller controls the refrigeration component to process the cold storage plate in three working modes: refrigeration, cold storage and defrosting. The flexible air duct component and the cold storage plate are used to improve the temperature uniformity of the cold storage and reduce the temperature fluctuation in the cold storage during defrosting.

2. The flexible air duct precise temperature control system according to claim 1 is characterized in that: The refrigeration assembly further comprises a four-way valve (115), which is connected to the compressor (100), the finned condenser (114), the gas-liquid separator (101), the air cooler outlet solenoid valve (108) and the cold storage outlet solenoid valve (106) respectively through a refrigerant pipeline; the inlet and outlet of the air cooler (1) and the cold storage plate are respectively connected to the air cooler inlet solenoid valve (109), the cold storage inlet electronic valve (102), the air cooler outlet solenoid valve (108) and the cold storage outlet solenoid valve (106), and the two-way liquid reservoir One end of the two-way liquid storage device (110) is connected to the defrost electronic expansion valve (112), the two-way drying filter (113) and the fin condenser (114) in sequence through a refrigerant pipeline; the other end of the two-way liquid storage device (110) is connected to the filter (111) through a refrigerant pipeline and is then divided into two paths, one path is connected to the multi-zone cold storage plate through a refrigerant pipeline and the cold storage inlet electronic valve (102) and the cold storage electronic expansion valve (103), and the other path is connected to the cold air machine (1) through a refrigerant pipeline and the cold air machine inlet electromagnetic valve (109) and the refrigeration electronic expansion valve (107).

3. The flexible air duct precise temperature control system according to claim 2, characterized in that: A plurality of cold storage plates are arranged in parallel through a refrigerant pipeline, and an electromagnetic valve and a one-way valve are respectively provided at the inlet and outlet of each cold storage plate.

4. The flexible air duct precise temperature control system according to claim 3, characterized in that: The sensor assembly comprises a micro-pressure difference sensor (3), a storage temperature sensor (4), a multi-channel temperature sensor (5) and an energy consumption sensor, all of which are electrically connected to the controller; the micro-pressure difference sensor (3) is arranged at the air outlet of the air cooler (1); the storage temperature sensor (4) is arranged at the return air outlet of the air cooler (1); the multi-channel temperature sensors (5) are arranged at various locations in the cold storage, the air outlet of the air cooler (1), the outer surface of the cold storage plate and the air outlet (707) at the end of the air duct; and the energy consumption sensor is arranged at the power supply line end of the flexible air duct precision temperature control system.

5. The flexible air duct precise temperature control system according to claim 1, characterized in that: The flexible air duct assembly comprises an inlet tightener (701), wherein the inlet tightener (701) connects the inlet air duct (702) with the air cooler (1); a static pressure box (703) is provided at the rear end of the inlet air duct (702), and the lining of the static pressure box (703) is made of a sound-absorbing material; the outlet of the static pressure box (703) is connected to the flexible air duct (704), and a uniform air blower (705) and multi-region distributed cold storage plates are provided inside the flexible air duct (704); a strip-shaped air outlet (706) at the top end of the air duct, an air outlet (707) at the end end of the air duct, and air outlet micropores (708) at the air duct are respectively provided at the top end, the end end, and the bottom surface of the flexible air duct (704), wherein the strip-shaped air outlet (706) at the top end of the air duct and the air outlet (707) at the end end of the air duct are provided with a blocking cover.

6. A control method for a flexible air duct precise temperature control system according to any one of claims 2 to 4, characterized in that The flexible air duct precise temperature control system includes two cold storage plates, namely a first cold storage plate (21) and a second cold storage plate (22), and includes the following steps: S0: Start the device, select a mode through the controller: preset mode or controller mode, and set the maximum temperature t0h of the cold storage, the minimum temperature t0l of the cold storage, the maximum temperature t1h of the first cold storage plate (21), the minimum temperature t1l of the first cold storage plate (21), the maximum temperature t2h of the second cold storage plate (22), the minimum temperature t2l of the second cold storage plate (22), the maximum pressure difference ph of the air cooler, and the minimum pressure difference pl of the air cooler; S1: judging whether it is a preset mode through the controller, if yes, directly proceeding to step S2, if not, it is a controller mode, the controller collects temperature, pressure, and energy consumption parameters through the sensor component, and after inference calculation, optimizes the parameters of the maximum temperature t1h of the first cold storage plate (21), the minimum temperature t1l of the first cold storage plate (21), the maximum temperature t2h of the second cold storage plate (22), the minimum temperature t2l of the second cold storage plate (22), the maximum pressure difference ph of the cold air machine, and the minimum pressure difference pl of the cold air machine, and then proceeds to step S2; S2: The controller obtains the real-time temperature T0 of the cold storage and determines whether T0 ≥ t0h. If so, proceed to step S2-1; if not, proceed to step S3; S2-1: The controller controls the refrigeration component to perform a refrigeration cycle, the inlet and outlet solenoid valves of the air cooler are opened, and the process proceeds to step S2-2; S2-2: The controller obtains the real-time temperature T0 of the cold storage and determines whether T0≤t01. If so, the controller controls the refrigeration component to stop refrigeration and closes the inlet and outlet solenoid valves of the air cooler, and then proceeds to step S2. If not, proceeds to step S2-1. S3: The controller obtains the real-time temperature T1 of the first cold storage plate (21), and determines whether T1≥t1h. If so, proceed to step S3-1; if not, proceed to step S4; S3-1: The controller controls the cold storage cycle of the refrigeration component, the first cold storage plate solenoid valve (104) and the cold storage outlet solenoid valve (106) are opened, and step S3-2 is continued; S3-2: The controller obtains the real-time temperature T1 of the first cold storage plate (21) and determines whether T1≤t11. If so, the controller controls the refrigeration component to stop cold storage, closes the first cold storage plate solenoid valve (104) and the cold storage outlet solenoid valve (106), and enters step S3. If not, enters step S3-1. S4: The controller obtains the real-time temperature T2 of the second cold storage plate (22), and determines whether T2≥t2h. If so, proceed to step S4-1; if not, proceed to step S5; S4-1: The controller controls the cold storage cycle of the refrigeration component, the second cold storage plate solenoid valve (105) and the cold storage outlet solenoid valve (106) are opened, and step S4-2 is continued; S4-2: The controller obtains the real-time temperature T2 of the second cold storage plate (22) and determines whether T2≤t21. If so, the controller controls the refrigeration component to stop cold storage, closes the second cold storage plate solenoid valve (105) and the cold storage outlet solenoid valve (106), and enters step S4. If not, enters step S4-1. S5: The controller obtains the real-time differential pressure P of the air cooler transmitted by the micro differential pressure sensor (3), and determines whether pl<P<ph and time≥5min, that is, the real-time differential pressure P of the air cooler (1) is between the set minimum differential pressure value pl of the air cooler and the maximum differential pressure value ph of the air cooler and the duration is greater than or equal to 5 minutes. If so, proceed to step S5-1; if not, proceed to step S1; S5-1: The controller controls the defrost cycle of the refrigeration component, the inlet and outlet solenoid valves of the cooling fan are opened, the equalizing fan (705) is turned on, and step S5-2 is continued; S5-2: The controller obtains the real-time pressure difference P of the air cooler and determines whether P≥ph and time≥3min. If so, the controller controls the refrigeration component to stop defrosting, closes the inlet and outlet solenoid valves of the air cooler, and stops the fan (705) after 5 minutes, and enters S5. If not, enter step S5-1.

7. A control method for the flexible air duct precise temperature control system according to claim 6, characterized in that: In the controller mode of step S1, the controller performs optimization control by an expert control method, and the expert control method includes the following steps: S10: Information acquisition and processing, performing analog-to-digital conversion and data processing on the real-time collected data acquired by the sensor component; S11: Inference operation: The controller performs inference operation according to a certain inference strategy based on the current input real-time collected data through the interaction of the inference mechanism and the knowledge base retrieval results to obtain the inference results of the t1h, t1l, t2h, t2l, ph, and pl parameters; S12: Knowledge base retrieval. The knowledge base is used to categorize and store relevant knowledge and experience information. It receives the real-time data obtained in step S10, searches within the knowledge base, interacts with the inference mechanism, performs parameter matching, and sends the matching structure to the inference mechanism. The knowledge base includes but is not limited to knowledge and experience related to the temperature control system, dynamic information, and target information. Data parameters are filled in and managed in real time, and historical data is screened and eliminated. The knowledge base stores relevant knowledge and experience information for access by the control rule library. S13: Control rule base, which stores several rules for organizing the inference results obtained by the inference mechanism with the stored relevant knowledge and experience information output by the knowledge base in step S12. If the control rule base conditions are met, the calculation and reasoning are performed according to the strategy to obtain the final parameter optimization ratio; S14: Parameter optimization, used to optimize the parameters of t1h, t1l, t2h, t2l, ph, and pl stored in the controller to achieve intelligent switching of the refrigeration cycle, cold storage, and defrost cycle of the refrigeration component.

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