Refrigeration plant defrosting control method and system guided by system comprehensive performance

Abstract

A cold storage defrosting control method and system guided by system comprehensive performance to image recognition, the method comprises collecting real-time running state pictures of cold air fans in a cold storage refrigeration system, calculating frost density coefficient, if greater than frost determination standard value ρ0, it is determined that frost has formed; taking the time when COP starts to change as the time starting point, taking the time when the defrosting process is completed until the storage temperature returns to the set value as the time ending point, calculating the average performance coefficient in the time period; taking the frost density coefficient ρ 01 as the second frost determination standard value ρ 02 , performing the second defrosting control; taking the median value of ρ 01 and ρ 02 as the third frost determination standard value ρ 03 ; after the fourth defrosting, the bisection method is used to determine the frost determination standard value, and the average performance coefficient is used as the target value to obtain the subsequent frost determination standard value. The present application can effectively improve the unit energy efficiency by continuously optimizing the defrosting judgment standard.

Description

Technical Field

[0001] This invention relates to the field of cold storage defrosting technology, specifically to a cold storage defrosting control method and system based on image recognition guided by the overall system performance. Background Technology

[0002] During the operation of a cold storage refrigeration system, frost buildup on the air coolers can reduce their heat exchange performance, leading to decreased refrigeration efficiency and increased energy consumption. Therefore, it is necessary to periodically assess the frost buildup and implement defrosting control measures during long-term operation of the cold storage facility.

[0003] In current cold storage defrosting control strategies, temperature-time or temperature-humidity-time control methods are typically used for ease of operation. These methods determine defrosting needs based on the temperature and humidity at the evaporative cooler outlet. However, in practice, inaccurate judgment criteria often lead to "false defrosting" or "frost not being removed," impacting unit performance. Some studies on defrosting control use grayscale recognition of images of the evaporative cooler surface to determine defrosting needs, but these criteria are applied only to specific refrigeration systems and cannot be universally applied to all cold storage facilities. Summary of the Invention

[0004] The purpose of this invention is to address the problems in the prior art by providing a cold storage defrosting control method and system based on image recognition guided by the overall system performance. The method uses the average COP (Coefficient of Performance) of the cold storage system as the target value and continuously optimizes the defrosting judgment criteria during operation to find the optimal defrosting time. It is applicable to cold storage facilities with different cooling capacities and layouts, effectively improving the unit's energy efficiency.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A cold storage defrosting control method guided by image recognition based on overall system performance includes:

[0007] Collect real-time images of the operating status of the air coolers in the cold storage refrigeration system;

[0008] The frost density coefficient ρ was calculated from real-time operating images of the air cooler. t And the frosting density coefficient ρ t Compare with the frost judgment standard value ρ0. If it is greater than the frost judgment standard value ρ0, the air cooler is judged to have frosted.

[0009] The time when the coefficient of performance (COP) begins to change is taken as the starting point, and the time from the completion of the defrosting process until the temperature returns to the set value is taken as the ending point. The average coefficient of performance is calculated for the period between the starting point and the ending point.

[0010] The frosting density coefficient ρ corresponds to the moment when the coefficient of performance (COP) is at its maximum during the first defrosting process. 01 ρ, as the second standard value for determining frost formation 02 A second defrosting control is performed; during the third defrosting process, ρ 01 and ρ 02 The median value was used as the third frost determination standard value ρ. 03 A third defrosting control is performed; after the fourth defrosting, the frost judgment standard value is determined by the dichotomy method, and the average performance coefficient is used. As the target value, after two consecutive defrosting processes, if the average performance coefficient is... If the difference is less than the set value, then the last frosting judgment standard value will be used as the frosting judgment standard value for the future.

[0011] As a preferred approach, the frost density coefficient ρ is calculated using real-time operating status images of the evaporative cooler. t The expression is as follows:

[0012]

[0013] In the formula: f t (x, y) and f0(x, y) represent the gray levels at coordinates (x, y) at time t and the initial time, respectively; S represents the area involved in the calculation; Δf represents the gray level change per unit area; ρ t Let be the frost density coefficient at time t.

[0014] As a preferred option, the frost density coefficient ρ t In the step of comparing the frost determination standard value ρ0 with the value obtained when the evaporative air cooler is determined to be frosted, if the value is greater than the frost determination standard value ρ0, the fluctuation amplitude ξ obtained in the case of no frost is also compared:

[0015] ρ t -ρ0>ξ.

[0016] As a preferred approach, the average performance coefficient over the time period from the start to the end of the time is calculated using the following formula.

[0017] Q t1 =q t1 (h out -h in )

[0018]

[0019] wherein Q t1 represents the refrigerating capacity at time t1, W t1 represents the compressor power at time t1, q t1 is the refrigerant flow rate, h out and h in are the refrigerant enthalpy at the outlet and inlet of the air cooler, respectively, Q t2 , Q t3 ... represent the refrigerating capacity at time t2, t3,..., respectively, and are calculated in the same way as Q t1 , W t2 , W t3 ... represent the compressor power at time t2, t3,..., respectively.

[0020] As a preferred scheme, the coefficient of performance COP takes into account the fluctuation amplitude β during measurement, and the average coefficient of performance COP is calculated. The time starting point of the average coefficient of performance COP

[0021] |COP t -COP0|>β

[0022] wherein COP t represents the coefficient of performance COP at time t, and COP0 represents the coefficient of performance COP during stable operation.

[0023] As a preferred scheme, after the fourth defrosting, the frost determination criterion value is determined by bisection, and the average coefficient of performance COP is taken as the target value. After the end of two successive defrosting processes, if the difference between the average coefficients of performance COP is less than a set value, the last frost determination criterion value is taken as the frost determination criterion value thereafter, and the following expression is satisfied:

[0024]

[0025] wherein: represents the difference between the two calculated average coefficients of performance COP , and ε is the set fluctuation range of the difference between the average coefficients of performance COP ; when the above expression is satisfied, the last frost determination criterion value is taken as the final frost determination criterion value ρ0.

[0026] A cold storage defrosting control system guided by image recognition based on system comprehensive performance, comprising a defrosting PTC heater, a pressure sensor, a temperature sensor, a flow meter, a power meter, a camera and an upper computer arranged in a cold storage refrigeration system; a first pressure sensor and a first temperature sensor are arranged at the inlet of the cold air fan of the cold storage refrigeration system to monitor the inlet refrigerant state of the cold air fan, and a second pressure sensor and a second temperature sensor are arranged at the outlet of the cold air fan to monitor the outlet refrigerant state of the cold air fan; a flow meter is arranged at the inlet of the compressor of the cold storage refrigeration system to monitor the refrigerant flow of the cold air fan, and a power meter is arranged on the compressor to monitor the power of the compressor; the camera collects real-time running state pictures of the cold air fan; the upper computer receives the data collected by the pressure sensor, the temperature sensor, the flow meter, the power meter and the camera, and controls the defrosting PTC heater to defrost the cold air fan.

[0027] As a preferred scheme, the cold storage refrigeration system comprises a compressor, an oil-gas separator, a condenser, a liquid storage tank, an economizer and a cold air fan connected in sequence through pipelines; the outlet pipeline of the compressor is connected with the condenser through the oil-gas separator, a pressure maintaining valve is arranged between the oil-gas separator and the condenser, and the liquid condensed by the condenser is input into the liquid storage tank; the outlet of the liquid storage tank is connected with the economizer through two parallel branches, an economizer branch electronic expansion valve and an economizer branch ball valve are arranged in series on one of the branches; the outlet of the economizer is connected with the compressor through two branches, a one-way valve is arranged on one of the branches, the other branch is connected with the compressor through the cold air fan, and a main pipeline electronic expansion valve is arranged between the economizer and the cold air fan.

[0028] An electronic device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to realize the cold storage defrosting control method guided by image recognition based on system comprehensive performance.

[0029] A computer readable storage medium storing a computer program, wherein the computer program is executable by a processor to realize the cold storage defrosting control method guided by image recognition based on system comprehensive performance.

[0030] Compared with the prior art, the present application has at least the following beneficial effects:

[0031] Existing image recognition and defrosting control methods based on specific unit parameters have limitations and lack universality in their evaluation criteria. These limitations can lead to misjudgments in practical applications, causing the unit to defrost when defrosting is unnecessary or delaying the optimal defrosting time, thus reducing the performance of the cold storage refrigeration system and increasing energy consumption. The cold storage defrosting control method proposed in this invention, which uses image recognition guided by comprehensive system performance, addresses this issue. Since the coefficient of performance (COP) of the system always exhibits a trend of first increasing and then decreasing during the frosting process, a first frosting criterion is established based on past experience. The second frosting criterion uses the frosting density coefficient corresponding to the maximum COP during the first process as the standard. The median value of the first two standards is then used as the third frosting criterion. This process is iterated using a binary method until the average COP of the two defrosting processes is reached. If the difference is less than a preset value, the final frost determination criterion is used as the final determination criterion. This invention uses the average coefficient of performance of the cold storage refrigeration system... As a target value, the frosting judgment criteria used for image recognition are continuously optimized until an average coefficient of performance is achieved during the frosting process and the refrigeration system returns to normal storage temperature. By using the image recognition standard at its optimal performance as the future standard, this invention ensures that the entire defrosting control process is compatible with current cold storage refrigeration systems, significantly improving the accuracy and reliability of the defrosting control method and enhancing unit energy efficiency. This invention also increases the applicability of the defrosting control method in cold storage facilities with different cooling capacities and layouts, making it more universally applicable. Attached Figure Description

[0032] Figure 1 A schematic diagram of the structure of a cold storage defrosting control system based on image recognition guided by the overall system performance, as described in this embodiment of the invention;

[0033] Figure 2 Flowchart of a cold storage defrosting control method guided by system comprehensive performance based on image recognition, according to an embodiment of the present invention;

[0034] Figure 3 A schematic diagram illustrating the optimization of the defrosting determination criteria based on COP changes in this embodiment of the invention. Detailed Implementation

[0035] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0036] The cold storage defrosting control method guided by system comprehensive performance and image recognition provided by the embodiment of the present application enables the cold storage system to continuously optimize the defrosting judgment standard through the given program during the operation process until the result converges, and the optimal defrosting time is obtained, and in the subsequent operation process, the standard is taken as the defrosting judgment standard to ensure the normal operation of the unit.

[0037] Please refer to Figure 1 The cold storage defrosting control system guided by system comprehensive performance and image recognition provided by the embodiment of the present application comprises a defrosting PTC heater 18, a pressure sensor, a temperature sensor, a flow meter 16, a power meter 17, a camera 19 and an upper computer 20 arranged in the cold storage refrigeration system. The cold storage refrigeration system comprises a compressor 1, an oil-gas separator 2, a condenser 4, a liquid storage tank 5, an economizer 8 and a cold air fan 11 connected in sequence through pipelines. The outlet pipeline of the compressor 1 is connected with the condenser 4 through the oil-gas separator 2, and a pressure maintaining valve 3 is arranged between the oil-gas separator 2 and the condenser 4. The liquid condensed by the condenser 4 is input into the liquid storage tank 5. The outlet of the liquid storage tank 5 is connected with the economizer 8 through two parallel branches. An economizer branch electronic expansion valve 6 and an economizer branch ball valve 7 are arranged in one of the branches in series, and the other branch is directly connected with the economizer 8. The outlet of the economizer 8 is connected with the compressor 1 through two branches. A one-way valve 9 is arranged in one of the branches, and the other branch is connected with the compressor 1 through the cold air fan 11. A main road electronic expansion valve 10 is arranged between the economizer 8 and the cold air fan 11.

[0038] The first pressure sensor 12 and the first temperature sensor 13 are arranged at the inlet of the cold air fan 11 of the cold storage refrigeration system to monitor the inlet refrigerant state of the cold air fan 11. The second pressure sensor 14 and the second temperature sensor 15 are arranged at the outlet of the cold air fan 11 to monitor the outlet refrigerant state of the cold air fan 11. The flow meter 16 is arranged at the inlet of the compressor 1 of the cold storage refrigeration system to monitor the refrigerant flow of the cold air fan 11. The power meter 17 is arranged on the compressor 1 to monitor the power of the compressor 1. The real-time running state picture of the cold air fan 11 is collected through the camera 19. The upper computer 20 receives the data collected by the pressure sensor, the temperature sensor, the flow meter 16, the power meter 17 and the camera 19, and controls the defrosting PTC heater 18 to defrost the cold air fan 11.

[0039] Please refer to Figure 2 The cold storage defrosting control method guided by system comprehensive performance and image recognition provided by the embodiment of the present application comprises the following steps.

[0040] A given frosting judgment standard value ρ0 is given. The value can be obtained through experience. From the aspect of the operation safety of the unit, the value can be defined to be slightly larger, and it is determined that the unit has been seriously frosted when the system performs defrosting for the first time;

[0041] During the operation of the cold storage unit, the image acquisition device takes a picture of the surface of the air cooler 11 every 10 seconds (the value is only exemplary) and transmits the picture to the host computer 20 for sharpening and grayscale processing. At the same time, the host computer 20 collects and records the main operating parameters of the unit, including but not limited to the suction flow of the compressor 1, the inlet and outlet pressures and temperatures of the air cooler 11, and the power of the compressor 1. It should be noted that the sensor arrangement mentioned in the embodiment of the present application is the arrangement of conventional sensors in the normal operation of the refrigeration system, and no additional sensors are added to increase the cost of the unit.

[0042] The expression for calculating the frosting density coefficient pt of the real-time running state picture of the air cooler (11) is as follows:

[0043]

[0044] In the formula, f t (x, y), f0(x, y) represent the gray scale at coordinates (x, y) at time t and initial time, respectively, S represents the area participating in the calculation, Δf represents the gray scale change per unit area, and pt t is the frosting density coefficient at time t. When pt t is greater than the frosting determination standard value p0, it is considered that the air cooler 11 has frosted.

[0045] Further, after the image recognition result exceeds the frosting determination standard, the defrosting operation is performed. It should be noted that due to the influence of air flow, light conditions, image acquisition equipment, etc., even if the frosting state does not change, the image recognition result may also fluctuate. Therefore, in the normal non-frosting working state, the host computer 20 also calculates the fluctuation amplitude ξ for the fluctuation condition, and when the following formula is satisfied, the defrosting stage is entered:

[0046] pt t -p0> ξ

[0047] Further, the values of pressure, temperature, and power measured by the sensor may also fluctuate, and the host computer 20 calculates the fluctuation amplitude β of the system performance coefficient COP in the normal operation process, and when the following formula is satisfied, the timing starts, and it is considered that the performance of the system has changed due to external factors:

[0048] |COP t -COP0|> β

[0049] In the formula, COP tCOPt represents the performance coefficient COP at time t, COP0 represents the performance coefficient COP at stable operation; it should be noted that through the experimental process, it is proved that during the frosting process, the system performance coefficient COP is not directly reduced, but shows a trend of first rising and then falling, and the possible reason for this situation is that in the initial stage of the frosting process, the frost layer thickness is very small, and the influence on the thermal resistance and air flow rate can be ignored, but it brings the air side of the cold air fan from dry to wet, which increases the air side heat transfer coefficient, resulting in the increase of the system performance coefficient COP, with the extension of the frosting time, the frost layer thickness increases, the influence on the thermal resistance and air flow rate becomes larger, and then the heat exchange effect of the cold air fan becomes worse, and the system performance coefficient COP begins to decrease.

[0050] Further, after the defrosting start is determined by the host computer 20, since the defrosting process will cause the warehouse temperature to fluctuate for a short time, the warehouse temperature returns to the set value as the end time of the single control cycle, the time during which the performance coefficient COP starts to change until the single control cycle ends is defined as the total single control time T, and the average performance coefficient is calculated in the T time period.

[0051] Further, in the second frosting control cycle, the frosting density coefficient corresponding to the maximum system performance coefficient COP is selected by the host computer 20 as the frosting determination standard p of the control cycle 01 , the same operation as the first cycle is recorded, and the average performance coefficient of the control cycle is recorded.

[0052] Further, in the third frosting control cycle, the median of the frosting density coefficients of the previous two times is taken as the frosting determination standard p of the control cycle 02 , and the average performance coefficient of the control cycle is recorded.

[0053] Further, with reference to Figure 3 , starting from the fourth frosting control cycle, the frosting determination standard of the system is changed to the following mode: the median of the determination standards of the first and third defrosting cycles and the median of the determination standards of the second and third defrosting cycles are taken as the determination standards of the fourth and fifth frosting control cycles. During the frosting process, the frosting density coefficient obtained by image recognition also increases with time, but due to the influence of the two periods of defrosting process and warehouse temperature drop to the set value, the change trend of the average performance coefficient is not completely the same as the change trend of the system performance coefficient COP with time. Therefore, in order to obtain the optimal average performance coefficient , the bisection method is used to continuously find the optimal defrosting determination standard, such as Figure 3As shown, if the frost density coefficient corresponding to the four points in the figure is used as the criterion for judging the average performance coefficient in the defrost cycle... If the result is greater than 4', then the optimal defrosting criterion will be narrowed down to between 4 and 3, and this process will continue in a loop until the average performance coefficient is reached. The change is small enough to satisfy the following equation:

[0054]

[0055] In the formula: This represents the average performance coefficient obtained from two calculations. The difference, ε, is the set average performance coefficient. The allowable fluctuation range of the difference; when the above formula is satisfied, the last frosting judgment standard value is taken as the final frosting judgment standard value ρ0.

[0056] Calculate the average performance coefficient over the time period from the start to the end of the time period using the following formula.

[0057] Q t1 =q t1 (h out -h in )

[0058]

[0059] In the formula: Q t1 W represents the cooling capacity at time t1. t1 q represents the compressor power at time t1. t1 h is the refrigerant flow rate. out and h in These are the enthalpy values ​​of the refrigerant at the air cooler outlet and inlet, respectively, Q. t2 Q t3 ...represent the cooling capacity at times t2, t3... respectively, calculated in the same way as Q. t1 Same, W t2 W t3 ...represent the compressor power at times t2, t3... respectively. Where q... t1 The flow rate can be read via flow meter 16, h out and h in The refrigerant status at the inlet and outlet of the air cooler 11 can be determined by the data collected from the first pressure sensor 12, the second pressure sensor 14, the first temperature sensor 13, and the second temperature sensor 15.

[0060] Since the host computer collects and stores all monitoring values ​​during the communication process, and the time interval between each collection is very short, it can be assumed that the cooling capacity and compressor power of the system do not change within this interval.

[0061] The average performance coefficient from the start of the change in the performance coefficient COP caused by frosting to the time when the library temperature returns to the set temperature after the defrosting is completed is calculated by the host computer 20 The next image recognition frost determination criterion is corrected accordingly; the average performance coefficient The defrosting is determined by guiding image recognition, the false defrosting phenomenon caused by unrealistic determination criteria is avoided, the performance of the unit is improved, and the application has wide applicability because the specific determination criteria are not given according to the unit condition in the control logic.

[0062] Another embodiment of the application also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to realize the cold storage defrosting control method guided by system comprehensive performance and image recognition.

[0063] Another embodiment of the application also provides a computer readable storage medium, which stores a computer program, wherein the computer program is executed by a processor to realize the cold storage defrosting control method guided by system comprehensive performance and image recognition.

[0064] For example, the instructions stored in the memory can be divided into one or more modules / units, which are stored in the computer readable storage medium and executed by the processor to complete the cold storage defrosting control method guided by system comprehensive performance and image recognition. The one or more modules / units can be a series of computer readable instruction segments capable of completing a specific function, which are used to describe the execution process of the computer program in the server.

[0065] The electronic device can be a smart phone, a notebook, a palm computer, a cloud server and other computing devices. The electronic device can include, but is not limited to, a processor, a memory. Those skilled in the art can understand that the electronic device can also include more or less components, or combine certain components, or different components, for example, the electronic device can also include an input / output device, a network access device, a bus, etc.

[0066] The processor can be a central processing unit (CPU), and can also be other general-purpose processors, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic device, discrete hardware component, etc. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor.

[0067] The memory can be an internal storage unit of the server, such as a hard disk or a memory of the server. The memory can also be an external storage device of the server, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. Further, the memory can also include both the internal storage unit and the external storage device of the server. The memory is used to store the computer readable instructions and other programs and data required by the server. The memory can also be used to temporarily store data that has been output or will be output.

[0068] It should be noted that the information interaction and execution process between the above module units are based on the same concept as the method embodiments, and the specific functions and technical effects brought by them can be referred to the method embodiment part, which will not be repeated here.

[0069] Those skilled in the art can clearly understand that, for the convenience and brevity of description, only the division of the above functional units and modules is taken as an example for illustration, and in actual application, the above functions can be completed by different functional units and modules according to needs, that is, the internal structure of the device is divided into different functional units or modules to complete all or part of the functions described above. Each functional unit or module in the embodiment can be integrated in one processing unit, or each unit can exist physically, or two or more units can be integrated in one unit. The integrated unit can be realized in the form of hardware or in the form of software functional unit. In addition, the specific names of each functional unit or module are only for easy distinction, and do not limit the protection scope of the present application. The specific working process of the unit or module in the system can refer to the corresponding process in the foregoing method embodiment, which will not be repeated here.

[0070] The integrated unit, if implemented in the form of a software function unit and sold or used as an independent product, can be stored in a computer readable storage medium. Based on such understanding, all or part of the processes in the above-mentioned embodiment methods can be completed by a computer program instructing related hardware, and the computer program can be stored in a computer readable storage medium. When the computer program is executed by a processor, the steps of the above-mentioned various method embodiments can be implemented. The computer program includes computer program code, which can be in the form of source code, object code, executable files or some intermediate forms. The computer readable medium at least includes any entity or device capable of carrying the computer program code to the photographing device / terminal equipment, recording medium, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signal, telecommunication signal and software distribution medium. For example, U disk, mobile hard disk, magnetic disk or optical disk, etc.

[0071] In the above embodiments, the description of each embodiment has its own focus, and the parts not described or recorded in a certain embodiment can be referred to the relevant description of other embodiments.

[0072] The above-described embodiments are only used to illustrate the technical solutions of the present application, rather than limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application.

Claims

1. A cold storage defrosting control method based on image recognition guided by overall system performance, characterized in that, include: Collect real-time operating status images of the air cooler (11) in the cold storage refrigeration system; The frost density coefficient ρ was calculated from the real-time operating status images of the air cooler (11). t And the frosting density coefficient ρ t Compare with the frost judgment standard value ρ0. If it is greater than the frost judgment standard value ρ0, then the air cooler (11) is judged to be frosted. The frost density coefficient ρ was calculated from the real-time operating status images of the air cooler (11). t The expression is as follows: In the formula: f t (x,y) and f0(x,y) represent the gray levels at coordinates (x,y) at time t and the initial time, respectively; S represents the area involved in the calculation; Δf represents the gray level change per unit area; ρ t The frost density coefficient at time t; The time when the coefficient of performance (COP) begins to change is taken as the starting point, and the time from the completion of the defrosting process until the temperature returns to the set value is taken as the ending point. The average coefficient of performance is calculated for the period between the starting point and the ending point. The frosting density coefficient ρ corresponds to the moment when the coefficient of performance (COP) is at its maximum during the first defrosting process. 01 ρ, as the second standard value for determining frosting 02 A second defrosting control is performed; during the third defrosting process, ρ 01 and ρ 02 The median value was used as the third frost determination standard value ρ. 03 A third defrosting control is performed; after the fourth defrosting, the frost judgment standard value is determined by the dichotomy method, and the average performance coefficient is used. As the target value, after two consecutive defrosting processes, if the average performance coefficient is... If the difference is less than the set value, then the last frosting judgment standard value will be used as the frosting judgment standard value for the future.

2. The cold storage defrosting control method based on image recognition guided by the overall system performance according to claim 1, characterized in that, The frost density coefficient ρ t In the step of determining that the air cooler (11) has been frosted, the fluctuation amplitude ξ obtained under the condition of no frosting is compared with the frost determination standard value ρ0. r t -ρ0>ξ.

3. The cold storage defrosting control method based on image recognition guided by the overall system performance according to claim 1, characterized in that, The average performance coefficient for the time period from the start to the end of time is calculated using the following formula. Q t1 =q t1 (h out -h in ) In the formula: Q t1 W represents the cooling capacity at time t1. t1 q represents the compressor power at time t1. t1 h is the refrigerant flow rate. out and h in The enthalpy values ​​of the refrigerant at the outlet and inlet of the air cooler (11) are Q, respectively. t2 Q t3 …represent the cooling capacity at times t2, t3… respectively, calculated in the same way as Q. t1 Same, W t2 W t3 …represent the compressor power at times t2, t3… respectively.

4. The cold storage defrosting control method based on image recognition guided by the overall system performance according to claim 3, characterized in that, The coefficient of performance (COP) is calculated by taking into account the fluctuation range β during the measurement process, and the average coefficient of performance is then calculated. The starting point of time is marked as: |COP t -COP0|>β Where: COP t COP represents the performance coefficient at time t, and COP0 represents the performance coefficient COP during stable operation.

5. The cold storage defrosting control method based on image recognition guided by the overall system performance according to claim 4, characterized in that, After the fourth defrost, the frost determination criterion value is determined using a dichotomy method, and the average performance coefficient is used. As the target value, after two consecutive defrosting processes, if the average performance coefficient is... If the difference is less than the set value, then the last frosting judgment standard value will be used as the subsequent frosting judgment standard value, satisfying the following expression: In the formula: This represents the average performance coefficient obtained from two calculations. The difference, ε, is the set average performance coefficient. The allowable fluctuation range of the difference; when the above formula is satisfied, the last frosting judgment standard value is taken as the final frosting judgment standard value ρ0.

6. A cold storage defrosting control system based on image recognition guided by overall system performance, characterized in that, The cold storage defrosting control method based on image recognition guided by the overall system performance, as described in any one of claims 1 to 5, includes a defrosting PTC heater (18), a pressure sensor, a temperature sensor, a flow meter (16), a power meter (17), a camera (19), and a host computer (20) installed in the cold storage refrigeration system; a first pressure sensor (12) and a first temperature sensor (13) are arranged at the inlet of the cold air blower (11) of the cold storage refrigeration system to monitor the refrigerant status at the inlet of the cold air blower (11), and a second pressure sensor (14) and a second temperature sensor (15) are arranged at the outlet of the cold air blower (11). A sensor (15) is used to monitor the refrigerant status at the outlet of the air cooler (11); a flow meter (16) is installed at the inlet of the compressor (1) of the cold storage refrigeration system to monitor the refrigerant flow of the air cooler (11), and a power meter (17) is installed on the compressor (1) to monitor the power of the compressor (1); a real-time operating status image of the air cooler (11) is collected by a camera (19); the host computer (20) receives the data collected by the pressure sensor, temperature sensor, flow meter (16), power meter (17) and camera (19), and controls the defrosting PTC heater (18) to defrost the air cooler (11).

7. The cold storage defrosting control system based on image recognition guided by overall system performance as described in claim 6, characterized in that, The cold storage refrigeration system includes a compressor (1), an oil-gas separator (2), a condenser (4), a liquid storage tank (5), an economizer (8), and a cooler (11) connected in sequence by pipelines. The outlet pipeline of the compressor (1) is connected to the condenser (4) via the oil-gas separator (2). A pressure maintaining valve (3) is installed between the oil-gas separator (2) and the condenser (4). The liquid condensed by the condenser (4) is input into the liquid storage tank (5). The outlet of the liquid storage tank (5) is connected to the economizer (8) via two parallel branches. One branch is equipped with a series economizer branch electronic expansion valve (6) and an economizer branch ball valve (7). The outlet of the economizer (8) is connected to the compressor (1) via two branches. One branch is equipped with a one-way valve (9), and the other branch is connected to the compressor (1) via the cooler (11). A main electronic expansion valve (10) is installed between the economizer (8) and the cooler (11).

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, it implements the cold storage defrosting control method based on image recognition guided by the overall system performance as described in any one of claims 1 to 5.

9. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by the processor, it implements the cold storage defrosting control method based on image recognition guided by the overall system performance as described in any one of claims 1 to 5.

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