Refrigeration house defrosting method and device, electronic equipment and storage medium

Abstract

The embodiment of the invention provides a refrigeration house defrosting method and device, electronic equipment and a storage medium. Operation parameters of a refrigeration house are obtained and comprise at least one of the refrigeration house temperature, the evaporation temperature, the air supply temperature and the operation time of a compressor; according to the operation parameters, whether preset defrosting conditions are met or not is judged; and when the preset defrosting condition is met, according to the temperature of the refrigeration house, a fan is controlled to conduct defrosting, and / or a compressor is controlled to conduct defrosting. Whether defrosting is needed or not can be detected according to the numerical values of multiple parameters such as the temperature of the cold storage and the evaporation temperature, intelligent defrosting is achieved, the defrosting energy efficiency is improved, different defrosting modes such as fan defrosting and high-evaporation-temperature defrosting are used in combination with different temperature ranges of the cold storage, and the unit defrosting energy efficiency and the temperature stability of the cold storage are further improved.

Description

Technical Field

[0001] The present invention relates to the field of refrigeration technology, and in particular to a cold storage defrosting method, a cold storage defrosting device, a cold storage and a computer-readable storage medium. Background Art

[0002] Cold storage is a facility used to store and preserve refrigerated or frozen items. It is widely used in food, medicine, chemical and other industries. The cold storage maintains an internal low-temperature environment through a refrigeration system to ensure the quality and safety of the stored items. In the cold storage refrigeration system, the refrigeration air cooler (commonly known as the air cooler) is used as an evaporator. Due to the relatively low temperature of the cold storage, the evaporation temperature in the air cooler is often below 0°C. When the air in the cold storage contacts the coil under the drive of the fan, the moisture contained in the air will precipitate and adhere to the surface of the coil to form a frost layer. With the excessive thickening of the frost layer, the performance of the unit will decline, the working conditions will deteriorate, and the reliability will decrease. Therefore, the surface of the air cooler often needs to be defrosted. At present, the cold storage market generally adopts timed defrosting, which consumes a lot of power. Frost-free defrosting also causes the temperature of the cold storage to fluctuate, which is energy-consuming and inefficient. Summary of the invention

[0003] In view of the above problems, embodiments of the present invention are proposed to provide a cold storage defrosting method, a cold storage defrosting device, a cold storage and a computer-readable storage medium that overcome the above problems or at least partially solve the above problems.

[0004] In order to solve the above problems, an embodiment of the present invention discloses a cold storage defrosting method, comprising:

[0005] Acquire operating parameters of the cold storage, wherein the operating parameters include at least one of the cold storage temperature, the evaporation temperature, the air supply temperature, and the operating time of the compressor;

[0006] According to the operating parameters, determining whether a preset defrosting condition is met;

[0007] When the preset defrosting condition is met, defrosting is performed by controlling the fan according to the cold storage temperature, and / or defrosting is performed by controlling the compressor.

[0008] Optionally, judging whether a preset defrosting condition is met according to the operating parameters includes:

[0009] Determining whether the temperature difference between the cold storage temperature and the evaporation temperature satisfies a first preset condition;

[0010] Determining whether the temperature difference between the supply air temperature and the cold storage temperature satisfies a second preset condition;

[0011] determining whether the evaporation temperature satisfies a third preset condition;

[0012] It is determined whether the compressor operation time satisfies a fourth preset condition.

[0013] Optionally, the defrosting is performed in one of the following defrosting modes according to the temperature of the cold storage: defrosting is performed by controlling a fan according to the temperature of the cold storage, and / or defrosting is performed by controlling a compressor, including:

[0014] When the temperature of the cold storage is greater than a first cold storage temperature threshold, turning off the refrigeration function of the compressor and turning on the fan for defrosting;

[0015] Get the defrost time and evaporator pipe temperature;

[0016] When the defrosting time exceeds the first operating time and the evaporator pipeline temperature is greater than the first pipeline temperature threshold, the defrosting is stopped.

[0017] Optionally, the defrosting is performed by controlling a fan according to the temperature of the cold storage, and / or the defrosting is performed by controlling a compressor, further comprising:

[0018] When the cold storage temperature is less than or equal to the first cold storage temperature threshold and greater than the second cold storage temperature threshold, proportional integral derivative control is performed on the compressor frequency based on the target evaporation temperature to perform defrosting, and the fan is controlled to perform defrosting;

[0019] When the defrosting time exceeds the second running time, the defrosting is stopped.

[0020] Optionally, the defrosting is performed by controlling a fan according to the temperature of the cold storage, and / or the defrosting is performed by controlling a compressor, further comprising:

[0021] When the temperature of the cold storage is less than or equal to the second cold storage temperature threshold, controlling the compressor to perform a thermal fluorination defrosting mode;

[0022] When the evaporator pipeline temperature is greater than the second pipeline temperature threshold, defrosting is stopped.

[0023] Optionally, the first preset condition is that the difference between the cold storage temperature and the evaporation temperature is greater than a temperature difference threshold.

[0024] Optionally, the second preset condition is that the difference between the supply air temperature and the cold storage temperature is less than a temperature difference threshold.

[0025] Optionally, the third preset condition is: the evaporation temperature is less than an evaporation temperature threshold.

[0026] Optionally, the fourth preset condition is: since the last defrost, the accumulated running time of the compressor exceeds the third running time, and the current startup running time of the compressor exceeds the fourth running time.

[0027] A second aspect of the embodiments of the present invention discloses a cold storage defrosting device, comprising:

[0028] An acquisition module, used to acquire operating parameters of the cold storage, wherein the operating parameters include at least one of the cold storage temperature, the evaporation temperature, the air supply temperature, and the operating time of the compressor;

[0029] A judgment module, used for judging whether a preset defrosting condition is met according to the operating parameters;

[0030] The control module is used to control the fan to perform defrosting according to the cold storage temperature when the preset defrosting conditions are met, and / or control the compressor to perform defrosting.

[0031] Optionally, the judging module includes:

[0032] A first judgment submodule, used to judge whether the temperature difference between the cold storage temperature and the evaporation temperature meets a first preset condition;

[0033] A second judgment submodule is used to judge whether the temperature difference between the supply air temperature and the cold storage temperature meets a second preset condition;

[0034] A third judgment submodule, used to judge whether the evaporation temperature meets a third preset condition;

[0035] The fourth judgment submodule is used to judge whether the compressor operation time meets a fourth preset condition.

[0036] Optionally, the control module includes:

[0037] A first control submodule is used to turn off the refrigeration function of the compressor and turn on the fan for defrosting when the temperature of the cold storage is greater than a first cold storage temperature threshold;

[0038] The acquisition submodule is used to obtain the defrost time and the evaporator pipe temperature;

[0039] The first stop submodule is used to stop defrosting when the defrosting time exceeds the first operating time and the evaporator pipeline temperature is greater than a first pipeline temperature threshold.

[0040] Optionally, the control module further includes:

[0041] A second control submodule is used for performing proportional-integral-differential control on the compressor frequency to perform defrosting based on the target evaporating temperature when the cold storage temperature is less than or equal to the first cold storage temperature threshold and greater than the second cold storage temperature threshold, and controlling the fan to perform defrosting;

[0042] The second stopping submodule is used for stopping defrosting when the defrosting time exceeds a second running time.

[0043] Optionally, the control module further includes:

[0044] A third control submodule, used for controlling the compressor to perform a thermal defrosting mode when the cold storage temperature is less than or equal to the second cold storage temperature threshold;

[0045] The third stopping submodule is used to stop defrosting when the evaporator pipeline temperature is greater than a second pipeline temperature threshold.

[0046] Optionally, the first judgment submodule includes:

[0047] The first preset condition is that the difference between the cold storage temperature and the evaporation temperature is greater than a temperature difference threshold.

[0048] Optionally, the second judgment submodule includes:

[0049] The second preset condition is that the difference between the supply air temperature and the cold storage temperature is less than a temperature difference threshold.

[0050] Optionally, the third judgment submodule includes:

[0051] The third preset condition is that the evaporation temperature is less than an evaporation temperature threshold.

[0052] Optionally, the fourth judgment submodule includes:

[0053] The fourth preset condition is that the accumulated running time of the compressor exceeds the third running time since the last defrosting, and the running time of the compressor at the current startup exceeds the fourth running time.

[0054] According to a third aspect of an embodiment of the present invention, an electronic device is disclosed, comprising: a processor, a memory, and a computer program stored in the memory and capable of running on the processor, wherein the computer program implements the steps of the cold storage defrosting method as described above when executed by the processor.

[0055] According to a fourth aspect of the embodiments of the present invention, a computer-readable storage medium is disclosed, on which a computer program is stored. When the computer program is executed by a processor, the steps of the cold storage defrosting method as described above are implemented.

[0056] The embodiments of the present invention include the following advantages:

[0057] The present invention introduces a cold storage defrosting method, which obtains the operating parameters of the cold storage, including at least one of the cold storage temperature, evaporation temperature, air supply temperature, and the operating time of the compressor; determines whether the preset defrosting conditions are met according to the operating parameters; when the preset defrosting conditions are met, defrosting is performed by controlling the fan according to the cold storage temperature, and / or the compressor is controlled to defrost. The present invention can detect whether defrosting is required by the numerical values ​​between multiple parameters such as the cold storage temperature and the evaporation temperature, realize intelligent defrosting, improve defrosting energy efficiency, and use different defrosting methods such as fan defrosting and high evaporation temperature defrosting in combination with different temperature ranges of the cold storage, thereby improving the unit defrosting energy efficiency and the temperature stability of the cold storage. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Figure 1 This is a flow chart of the steps of a cold storage defrosting method provided by an embodiment of the present invention;

[0059] Figure 2 It is a flowchart of another method for defrosting a cold storage provided by an embodiment of the present invention;

[0060] Figure 3 The present invention is a block diagram of a cold storage defrosting device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0061] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0062] The refrigeration system of the cold storage usually adopts a vapor compression refrigeration cycle. The basic principle is as follows: the compressor sucks in low-pressure, low-temperature refrigerant gas and compresses it into high-pressure, high-temperature gas; the high-pressure, high-temperature gas passes through the condenser, releases heat and becomes a high-pressure, room-temperature liquid; the high-pressure liquid is reduced in pressure through the expansion valve and becomes a low-pressure, low-temperature liquid; the low-pressure, low-temperature liquid absorbs heat inside the cold storage in the evaporator, becomes a low-pressure, low-temperature gas, and returns to the compressor to complete a cycle.

[0063] The mainstream defrosting methods currently used in the cold storage market include electric defrosting, water defrosting, hot air bypass defrosting, and thermal fluorine defrosting. Among them, heat pump defrosting has the advantages of high energy efficiency, fast defrosting, and easy installation.

[0064] One of the core concepts of the embodiments of the present invention is that the present invention optimizes the cold storage refrigeration unit using hot fluorine frost. The present invention uses parameter detection to intelligently determine the defrosting state and thus enter defrosting; through detection technology and control technology, it is determined to enter different defrosting modes, thereby optimizing defrosting power consumption and reducing storage temperature fluctuations.

[0065] Reference Figure 1, shows a flow chart of the steps of a cold storage defrosting method provided by an embodiment of the present invention, and the method may specifically include the following steps:

[0066] Step 101, obtaining operating parameters of the cold storage, wherein the operating parameters include at least one of the cold storage temperature, the air supply temperature, the evaporation temperature, and the operating time of the compressor;

[0067] During the operation of the cold storage, frost or ice will form on the surface of the evaporator due to the condensation of moisture in the air. As time goes by, the frost layer will become thicker and thicker, affecting the heat transfer efficiency of the evaporator and causing a decrease in the refrigeration effect. Therefore, defrosting operations need to be performed regularly. Cold storage defrosting refers to the removal of frost or ice on the surface of the evaporator by a specific method in the cold storage refrigeration system to restore the heat transfer efficiency of the evaporator. The cold storage is roughly composed of the following parts and components: a compressor and a low-pressure pressure sensor installed in the compressor pipeline, a condenser and an electronic expansion valve connected to the condenser, an evaporator and a cold storage temperature sensor package, an air supply temperature sensor package, an evaporator pipeline temperature sensor package, and a fan inside the evaporator, and a four-way valve connecting the compressor, condenser, evaporator and the external environment.

[0068] The defrosting temperature of the cold storage refers to the temperature inside the cold storage during the defrosting process, which is detected by the cold storage temperature sensing package installed on the evaporator. The supply air temperature refers to the temperature of the air delivered to the cold storage by the evaporator during the refrigeration process. This temperature directly affects the temperature control and refrigeration effect inside the cold storage; the supply air temperature is detected by the supply air sensing package installed on the evaporator.

[0069] The evaporation temperature refers to the temperature reached by the refrigerant in the evaporator of the refrigeration system during the evaporation process. The evaporation temperature is a key parameter in the design and operation of the cold storage refrigeration system, which directly affects the efficiency and performance of the system. The lower the evaporation temperature, the more heat the refrigerant absorbs from the inside of the cold storage, and the better the refrigeration effect. At the same time, the more energy the compressor needs to consume, the energy consumption of the system will also increase. Too low evaporation temperature may cause frost on the evaporator surface, affecting the heat transfer efficiency and requiring frequent defrosting. The evaporation temperature can be measured by the low-pressure sensor installed on the compressor connecting pipeline. The low pressure pressure is converted to the evaporation temperature, and one low pressure corresponds to one evaporation temperature.

[0070] The compressor is the core component of the cold storage refrigeration system. Its main function is to compress the refrigerant and circulate it in the system to achieve the refrigeration effect. The low-pressure and low-temperature refrigerant gas is sucked in and then compressed into a high-pressure and high-temperature gas through mechanical compression. This process increases the energy of the refrigerant, allowing it to release heat in the condenser; the refrigerant absorbs heat in the evaporator and becomes a gas, which is then sucked in and compressed by the compressor, and then releases heat and becomes a liquid through the condenser. Finally, it returns to the evaporator after the pressure is reduced by the expansion valve, forming a complete cycle; modern cold storage compressors usually have an adjustable cooling capacity function, which can automatically adjust the cooling capacity according to the load changes inside the cold storage; the efficient operation of the compressor can improve the efficiency of the entire refrigeration system. The running time of the compressor, that is, the length of time the compressor is turned on, is the length of time the compressor works.

[0071] Step 102, judging whether a preset defrosting condition is met according to the operating parameters;

[0072] The cold storage temperature, air supply temperature, evaporation temperature, and compressor operation time are closely related to determining whether to turn on defrosting and which defrosting method to choose. The setting of evaporation temperature and air supply temperature needs to comprehensively consider the refrigeration effect, energy consumption and frosting risk. These are key parameters in the refrigeration system and directly affect the refrigeration effect, energy consumption and frosting risk. Through reasonable design, selection of suitable refrigerants, control systems and real-time monitoring, the evaporation temperature and air supply temperature can be optimized to ensure the efficient operation of the cold storage and the quality of refrigerated items. Usually, the evaporation temperature is set within a range of 5-10℃ lower than the target temperature inside the cold storage. For example, if the target temperature of the cold storage is -18℃, the evaporation temperature may be set between -23℃ and -28℃, etc. Different specific cold storage temperatures have different corresponding cold storage temperature and evaporation temperature temperature difference corresponding ranges. Only when both conditions are met at the same time, the cold storage unit will determine that it has successfully entered the defrosting mode.

[0073] Step 103, when the preset defrosting condition is met, defrosting is performed by controlling the fan according to the cold storage temperature, and / or controlling the compressor to perform defrosting.

[0074] When the key parameters such as the cold storage temperature, air supply temperature, evaporation temperature, and compressor operation time meet the corresponding defrosting conditions, the cold storage unit begins to defrost. Cold storage defrosting refers to the removal of frost or ice on the surface of the evaporator in the cold storage refrigeration system by a specific method to restore the heat transfer efficiency of the evaporator. It is an essential maintenance operation during the operation of the cold storage, because the accumulation of frost will seriously affect the refrigeration effect and system efficiency. Common cold storage defrosting methods include: electric heating defrosting, heating the surface of the evaporator by an electric heater to melt the frost layer; hot fluorine defrosting, using the high temperature and high pressure gas discharged by the compressor to directly or indirectly heat the evaporator to melt the frost layer; water defrosting, directly flushing the evaporator surface by spraying water, so that the frost layer melts and is discharged with the water flow; fan defrosting, using a fan to blow hot air to the surface of the evaporator to melt the frost layer. Through reasonable defrosting control and system design, the efficient operation of the cold storage and the quality of refrigerated items can be ensured.

[0075] In one embodiment of the present invention, different defrosting methods are selected for different cold storage temperatures, which can improve defrosting efficiency and save energy. However, no matter which defrosting method is used, it needs to be achieved by controlling the compressor or the fan or both.

[0076] The embodiment of the present invention introduces a cold storage defrosting method, by obtaining the operating parameters of the cold storage, including at least one of the cold storage temperature, evaporation temperature, air supply temperature, and the operation time of the compressor; judging whether the preset defrosting conditions are met according to the operating parameters; when the preset defrosting conditions are met, defrosting is performed by controlling the fan according to the cold storage temperature, and / or the compressor is controlled to defrost. The present invention can detect whether defrosting is needed by the numerical values ​​between multiple parameters such as the cold storage temperature and the evaporation temperature, realize intelligent defrosting, improve defrosting energy efficiency, and use different defrosting methods such as fan defrosting and high evaporation temperature defrosting in combination with different temperature ranges of the cold storage, thereby improving the unit defrosting energy efficiency and the temperature stability of the cold storage.

[0077] Reference Figure 2 , shows a flow chart of another method for defrosting a cold storage provided by an embodiment of the present invention, the method may specifically include the following steps:

[0078] Step 201, obtaining operating parameters of the cold storage, wherein the operating parameters include at least one of the cold storage temperature, evaporation temperature, air supply temperature, and compressor operation time;

[0079] Step 202, judging whether the temperature difference between the cold storage temperature and the evaporation temperature satisfies a first preset condition; judging whether the temperature difference between the supply air temperature and the cold storage temperature satisfies a second preset condition; judging whether the evaporation temperature satisfies a third preset condition; judging whether the compressor operation time satisfies a fourth preset condition;

[0080] Cold storage defrosting is an essential maintenance operation during the operation of the cold storage. Common conditions for triggering automatic defrosting of the cold storage include: when the surface temperature of the evaporator is lower than the set value, defrosting is triggered; or defrosting is triggered once every certain period of time (such as 8 hours, 12 hours, etc.); or defrosting is triggered when the internal temperature of the cold storage fluctuates beyond the set range. Similarly, the conditions for starting defrosting of the cold storage are also set in this embodiment, so that defrosting can be more efficient and energy-saving. To determine whether the defrosting conditions are met, it is necessary to determine whether the following four preset conditions are met at the same time.

[0081] In one embodiment, step 202 may include the following sub-steps:

[0082] The first preset condition is that the difference between the cold storage temperature and the evaporation temperature is greater than a temperature difference threshold.

[0083] The cold storage temperature has a wide range of values ​​according to the actual situation. For different ranges of cold storage temperatures and different evaporation temperatures, there are corresponding different differences between the cold storage temperature and the evaporation temperature. Only when the difference is greater than the corresponding temperature difference threshold of the cold storage temperature, the defrosting condition is met.

[0084] Referring to Table 1, the corresponding relationship between the temperature difference between the evaporation temperature and the storage temperature in the defrosting limiting conditions of a cold storage defrosting method provided by an embodiment of the present invention is shown:

[0085] Storage temperature / ℃ (Storage temperature - evaporation temperature) / ℃ When the storage temperature is greater than 15℃ Storage temperature - evaporation temperature > t1 15℃≥Storage temperature>7℃ Storage temperature - evaporation temperature > t2 7℃≥Storage temperature>0℃ Storage temperature - evaporation temperature > t3 0℃≥Storage temperature>-7℃ Storage temperature - evaporation temperature > t4 -7℃≥Storage temperature>-15℃ Storage temperature - evaporation temperature > t5 -15℃≥Storage temperature Storage temperature - evaporation temperature > t6

[0086] Among them, the default value of t1 is 16℃, the default value of t2 is 13℃, the default value of t3 is 11℃, the default value of t4 is 9℃, the default value of t5 is 8℃, and the default value of t6 is 7℃.

[0087] In one embodiment, step 202 may further include the following sub-steps:

[0088] The second preset condition is that the difference between the supply air temperature and the cold storage temperature is less than a temperature difference threshold.

[0089] The second preset condition that must be met when the cold storage enters defrost mode is that the temperature difference between the supply air temperature and the storage temperature must satisfy the following condition: supply air temperature - storage temperature < to, where the default value of to is 3°C.

[0090] In one embodiment, step 202 may further include the following sub-steps:

[0091] The third preset condition is that the evaporation temperature is less than an evaporation temperature threshold.

[0092] The third preset condition that the cold storage needs to meet when entering defrost mode is that the evaporation temperature must meet the following conditions: evaporation temperature < tz, and the default value of tz is generally -25°C.

[0093] In one embodiment, step 202 may further include the following sub-steps:

[0094] The fourth preset condition is that the accumulated running time of the compressor exceeds the third running time since the last defrosting, and the running time of the compressor at the current startup exceeds the fourth running time.

[0095] The fourth preset condition that the cold storage needs to meet when entering the defrost mode is that the running time must be met: first, the compressor has been running for more than 30 minutes since the last defrost mode ended; second, the compressor has been running for more than 3 minutes since it started.

[0096] Step 203, when the preset defrosting condition is met, defrosting is performed by controlling the fan according to the cold storage temperature, and / or controlling the compressor to perform defrosting.

[0097] In one embodiment, step 203 may include the following sub-steps:

[0098] Sub-step S11, when the cold storage temperature is greater than a first cold storage temperature threshold, turning off the refrigeration function of the compressor and turning on the fan for defrosting;

[0099] When the defrosting conditions are met, the unit enters different defrosting modes according to different cold storage temperatures. According to the range of cold storage temperatures from high to low, when the cold storage temperature is greater than >7℃, it enters the fan defrosting mode. Fan defrosting is a common cold storage defrosting method. The basic principle of fan defrosting is to use the fan to blow the hot air inside the cold storage to the surface of the evaporator, and melt the frost layer on the surface of the evaporator through the heat of the hot air. The usual steps are as follows: the fan starts. During the defrosting process, the fan starts and blows the hot air inside the cold storage to the evaporator; the hot air is heated, and the hot air contacts the surface of the evaporator, transferring heat to melt the frost layer; drainage, the melted frost water is discharged through the drainage system.

[0100] In this embodiment, the control step is to control the refrigeration compressor to stop running, control the fan in the evaporator to start, and use the fan with a higher cold storage temperature to blow hot air to defrost the unit.

[0101] Sub-step S12, obtaining the defrosting time and the evaporator pipe temperature;

[0102] The defrosting process of the cold storage only needs to last for a period of time, and the defrosting can be stopped after the defrosting is completed. In this embodiment, the specific judgment condition for stopping the defrosting of the fan needs to be determined according to the time of this defrosting and the temperature of the evaporator pipeline. The defrosting time can be obtained by the timer, and the evaporator pipeline temperature is detected by the pipeline temperature sensing package set in the evaporator pipeline.

[0103] Sub-step S13, when the defrosting time exceeds the first operating time and the evaporator pipeline temperature is greater than the first pipeline temperature threshold, stopping the defrosting.

[0104] When the defrosting operation time exceeds 10 minutes and the evaporator pipe temperature detection temperature is higher than 5°C, the cold storage defrosting is completed and the defrosting is exited.

[0105] In another embodiment, step 203 may further include the following sub-steps:

[0106] Sub-step S21, when the cold storage temperature is less than or equal to the first cold storage temperature threshold and greater than the second cold storage temperature threshold, proportional integral derivative control is performed on the compressor frequency based on the target evaporation temperature to perform defrosting, and the fan is controlled to perform defrosting;

[0107] When 7℃≥cold storage temperature>3℃, defrosting is performed by controlling the evaporation temperature and fan. The evaporation temperature is determined by the low pressure measured by the low pressure sensor on the compressor intake pipe. Therefore, the actual operation of controlling the evaporation temperature is to control the compressor frequency. The specific control method is to use the PID (proportional integral differential) control method to calculate the compressor operating frequency, adjust the compressor operating frequency through the PID controller, change the flow and pressure of the refrigerant, and indirectly control the temperature of the evaporator to melt the frost layer.

[0108] The basic principle of PID control is that the PID controller calculates the control signal through the combination of three parts: proportional (P), integral (I) and differential (D). In PID (proportional-integral-differential) control, OUTPUT refers to the control signal calculated by the control system based on the current error (the difference between the set value and the actual value) to adjust the state of the controlled object. OUTPUT is the final output of the PID controller and is usually used to drive actuators (such as valves, motors, heaters, etc.) to achieve precise control of the controlled object. OUTPUT is the final output of the PID controller and is used to adjust the state of the controlled object. For example, in a temperature control system, OUTPUT can control the power of the heater so that the temperature gradually approaches the set value; through the combination of the three parts of proportional, integral and differential, OUTPUT can quickly respond to changes in the error and gradually eliminate the steady-state error; the adjustment of OUTPUT can keep the system stable and avoid oscillation and overshoot.

[0109] In the defrost control method of this embodiment, the refrigeration variable frequency compressor runs without stopping, and the compressor frequency runs according to the target evaporation temperature of 1°C. The compressor frequency control method is as follows:

[0110] The operating frequency range of the compressor is [F(l), F(h)],

[0111] Proportional gain OUTPUT(P)n = Kp * ΔTn

[0112] Integral gain OUTPUT(I)n = OUTPUT(I)n-1 + Ki * ΔTn

[0113] Derivative gain OUTPUT(D)n = Kd / 10(ΔTn - ΔTn-1)

[0114] The difference between the compressor's current calculated frequency and the previous calculated frequency:

[0115] ΔF(n) = F(n) - F(n-1)

[0116] = Kp * (ΔTn - ΔTn-1) + Ki * ΔTn + Kd / 10(ΔTn - 2ΔTn-1 + ΔTn-2)

[0117] |ΔF(n)| ≤ the maximum limit of the compressor ΔF(Max) (i.e., the PID adjustment rate Ks)

[0118] Where, ΔTn is the difference between the actual evaporation temperature in the current cycle and the target evaporation temperature by 1°C, and

ΔTn-1

[0119] The period of the compressor frequency is adjusted every 4 seconds. The controller detects the temperature difference of the system (the difference between the actual evaporation temperature and the target evaporation temperature by 1°C) every 1 second, calculates the average value of the temperature differences of each system within the first 5 seconds, and the measured values used for subsequent calculations are all average values.

[0120] F(n) = F(n-1) + Kp * (ΔTn - ΔTn-1) + Ki * ΔTn + Kd / 10(ΔTn - 2ΔTn-1 + ΔTn-2)

[0121] F(n) is the compressor operating frequency calculated for each cycle. When the calculated compressor frequency is within different ranges, the assignment of the compressor frequency satisfies the following conditions:

[0122] If F(l) < F(n) < F(h), then the compressor frequency is directly assigned as the calculated frequency F(n);

[0123] If F(n) ≥ F(h) maximum, then the compressor frequency is assigned as F(h), i.e., the highest compressor frequency;

[0124] If F(n) ≤ F(l) minimum, then the compressor frequency is assigned as F(l), i.e., the lowest compressor frequency;

[0125] Sub-step S22, when the defrosting time exceeds the second operating time, stop defrosting.

[0126] The PID controller is used to control the compressor frequency and then the evaporation temperature and the fan to defrost. The compressor can maintain the evaporation temperature at 1°C. Since this temperature is higher than the melting point of frost, the frost layer begins to melt. The fan keeps running, and the temperature in the warehouse is 3-7°C. The wind blows through the frost, accelerating the melting of the frost. Since the frost temperature and evaporation temperature are lower than the warehouse temperature, the unit is still cooling during the defrosting process, reducing energy consumption while still maintaining a stable warehouse temperature. When the defrosting time exceeds 20 minutes, exit the defrosting.

[0127] In one embodiment, step 203 may further include the following sub-steps:

[0128] Sub-step S31, when the cold storage temperature is less than or equal to the second cold storage temperature threshold, controlling the compressor to perform a thermal fluorination defrosting mode;

[0129] When the temperature of the cold storage is ≤3℃, the cold storage unit enters the hot fluorine defrosting mode. The basic principle of hot fluorine defrosting is to use the high temperature and high pressure gas (hot air) discharged from the compressor to directly or indirectly heat the evaporator to melt the frost layer on the surface of the evaporator. The usual steps are as follows: a) Hot air introduction: During the defrosting process, the high temperature and high pressure gas discharged from the compressor is introduced into the evaporator through the hot air valve; b) Heating the evaporator: The high temperature and high pressure gas flows inside the evaporator, heating the surface of the evaporator to melt the frost layer; c) Hot gas discharge: The melted frost layer becomes liquid, mixed with hot air and discharged from the evaporator, usually through the condenser or a special drainage pipe. The advantages of hot fluorine defrosting are: fast defrosting speed, usually only a few minutes to more than ten minutes to complete defrosting; because the high temperature and high pressure gas discharged from the compressor is directly used, no additional energy is required, and the energy saving effect is good; it can be integrated with the control system to realize automatic control and reduce manual intervention.

[0130] In this embodiment, since the storage temperature is relatively low at this time, the defrosting effect of the fan and the evaporation temperature is not good and the efficiency is low, so thermal fluorine defrosting is adopted. The control steps are: open the electronic expansion valve in the system to the maximum, and open the condenser to the maximum value; adjust the compressor frequency to [Switching Frequency] (the default value is 50Hz); switch the four-way valve, and switch the four-way valve from the cooling state to the heating state. Its main function is to change the flow path of the refrigerant in the system, thereby realizing the switching of the cooling and heating modes; after switching, adjust the compressor frequency to [Defrosting Frequency] (the default value is 70Hz), and the cold storage enters the thermal fluorine defrosting mode.

[0131] Sub-step S32, when the evaporator pipeline temperature is greater than a second pipeline temperature threshold, stopping defrosting.

[0132] When the temperature sensing package of the evaporator heat exchange tube detects that the temperature of the tube rises to 15℃, defrosting is completed and the cold storage unit exits defrosting.

[0133] The embodiment of the present invention introduces a cold storage defrosting method, by obtaining the operating parameters of the cold storage, including at least one of the cold storage temperature, evaporation temperature, air supply temperature, and the operation time of the compressor; judging whether the preset defrosting conditions are met according to the operating parameters; when the preset defrosting conditions are met, defrosting is performed by controlling the fan according to the cold storage temperature, and / or the compressor is controlled to defrost. The present invention can detect whether defrosting is needed by the numerical values ​​between multiple parameters such as the cold storage temperature and the evaporation temperature, realize intelligent defrosting, improve defrosting energy efficiency, and use different defrosting methods such as fan defrosting and high evaporation temperature defrosting in combination with different temperature ranges of the cold storage, thereby improving the unit defrosting energy efficiency and the temperature stability of the cold storage.

[0134] It should be noted that, for the sake of simplicity, the method embodiments are described as a series of action combinations, but those skilled in the art should be aware that the embodiments of the present invention are not limited by the order of the actions described, because according to the embodiments of the present invention, certain steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in the specification are all preferred embodiments, and the actions involved are not necessarily required by the embodiments of the present invention.

[0135] Reference Figure 3 , shows a structural block diagram of a cold storage defrosting device provided by an embodiment of the present invention, which may specifically include the following modules:

[0136] The acquisition module 301 is used to acquire the operating parameters of the cold storage, wherein the operating parameters include at least one of the cold storage temperature, the evaporation temperature, the air supply temperature, and the operating time of the compressor;

[0137] A judgment module 302 is used to judge whether a preset defrosting condition is met according to the operating parameters;

[0138] The control module 303 is used to control the fan to perform defrosting according to the cold storage temperature when the preset defrosting condition is met, and / or control the compressor to perform defrosting.

[0139] In one embodiment, the determination module includes:

[0140] A first judgment submodule, used to judge whether the temperature difference between the cold storage temperature and the evaporation temperature meets a first preset condition;

[0141] A second judgment submodule is used to judge whether the temperature difference between the supply air temperature and the cold storage temperature meets a second preset condition;

[0142] A third judgment submodule, used to judge whether the evaporation temperature meets a third preset condition;

[0143] The fourth judgment submodule is used to judge whether the compressor operation time meets a fourth preset condition.

[0144] In one embodiment, the control module includes:

[0145] A first control submodule is used to turn off the refrigeration function of the compressor and turn on the fan for defrosting when the temperature of the cold storage is greater than a first cold storage temperature threshold;

[0146] The acquisition submodule is used to obtain the defrost time and the evaporator pipe temperature;

[0147] The first stop submodule is used to stop defrosting when the defrosting time exceeds the first operating time and the evaporator pipeline temperature is greater than the first pipeline temperature threshold.

[0148] In one embodiment, the control module further includes:

[0149] A second control submodule is used for performing proportional-integral-differential control on the compressor frequency to perform defrosting based on the target evaporating temperature when the cold storage temperature is less than or equal to the first cold storage temperature threshold and greater than the second cold storage temperature threshold, and controlling the fan to perform defrosting;

[0150] The second stopping submodule is used for stopping defrosting when the defrosting time exceeds a second running time.

[0151] In one embodiment, the control module further includes:

[0152] A third control submodule, used for controlling the compressor to perform a thermal defrosting mode when the cold storage temperature is less than or equal to the second cold storage temperature threshold;

[0153] The third stopping submodule is used to stop defrosting when the evaporator pipeline temperature is greater than a second pipeline temperature threshold.

[0154] In one embodiment, the first determination submodule includes:

[0155] The first preset condition is that the difference between the cold storage temperature and the evaporation temperature is greater than a temperature difference threshold.

[0156] In one embodiment, the second determination submodule includes:

[0157] The second preset condition is that the difference between the supply air temperature and the cold storage temperature is less than a temperature difference threshold.

[0158] In one embodiment, the third determination submodule includes:

[0159] The third preset condition is that the evaporation temperature is less than an evaporation temperature threshold.

[0160] In one embodiment, the fourth determination submodule includes:

[0161] The fourth preset condition is that the accumulated running time of the compressor exceeds the third running time since the last defrosting, and the running time of the compressor at the current startup exceeds the fourth running time.

[0162] The embodiment of the present invention obtains the operating parameters of the cold storage, including at least one of the cold storage temperature, evaporation temperature, air supply temperature, and the operation time of the compressor; determines whether the preset defrosting conditions are met according to the operating parameters; when the preset defrosting conditions are met, defrosting is performed by controlling the fan according to the cold storage temperature, and / or the compressor is controlled to defrost. The present invention can detect whether defrosting is needed by the numerical values ​​between multiple parameters such as the cold storage temperature and the evaporation temperature, realize intelligent defrosting, improve defrosting energy efficiency, and use different defrosting methods such as fan defrosting and high evaporation temperature defrosting in combination with different temperature ranges of the cold storage, thereby improving the defrosting energy efficiency of the unit and the temperature stability of the cold storage.

[0163] As for the device embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment.

[0164] An embodiment of the present invention further provides an electronic device, including:

[0165] It includes a processor, a memory, and a computer program stored in the memory and capable of running on the processor. When the computer program is executed by the processor, the various processes of the above-mentioned cold storage defrosting method embodiment are implemented, and the same technical effect can be achieved. To avoid repetition, it will not be repeated here.

[0166] An embodiment of the present invention further provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the various processes of the above-mentioned cold storage defrosting method embodiment are implemented, and the same technical effect can be achieved. To avoid repetition, it will not be repeated here.

[0167] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0168] It will be appreciated by those skilled in the art that the embodiments of the present invention may be provided as methods, devices, or computer program products. Therefore, the embodiments of the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the embodiments of the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.

[0169] The embodiments of the present invention are described with reference to the flowcharts and / or block diagrams of the methods, terminal devices (systems), and computer program products according to the embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of the processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing terminal device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing terminal device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0170] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing terminal device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce a manufactured product including an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0171] These computer program instructions can also be loaded onto a computer or other programmable data processing terminal device so that a series of operating steps are executed on the computer or other programmable terminal device to produce a computer-implemented process, thereby providing instructions for executing on the computer or other programmable terminal device to implement the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0172] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the embodiments of the present invention.

[0173] Finally, it should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or terminal device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or terminal device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or terminal device including the elements.

[0174] The above is a detailed introduction to a cold storage defrosting method and a cold storage defrosting device provided by the present invention. Specific examples are used in this article to illustrate the principle and implementation mode of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea; at the same time, for general technical personnel in this field, according to the idea of ​​the present invention, there will be changes in the specific implementation mode and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. A cold storage defrosting method, characterized in that: include: Acquire operating parameters of the cold storage, wherein the operating parameters include at least one of the cold storage temperature, the evaporation temperature, the air supply temperature, and the operating time of the compressor; According to the operating parameters, determining whether a preset defrosting condition is met; When the preset defrosting condition is met, defrosting is performed by controlling the fan according to the cold storage temperature, and / or defrosting is performed by controlling the compressor.

2. The method according to claim 1, characterized in that: The step of judging whether a preset defrosting condition is met according to the operating parameters includes: Determining whether the temperature difference between the cold storage temperature and the evaporation temperature satisfies a first preset condition; Determining whether the temperature difference between the supply air temperature and the cold storage temperature satisfies a second preset condition; determining whether the evaporation temperature satisfies a third preset condition; It is determined whether the compressor operation time satisfies a fourth preset condition.

3. The method according to claim 1, characterized in that The defrosting is performed in one of the following defrosting modes according to the temperature of the cold storage: defrosting is performed by controlling a fan according to the temperature of the cold storage, and / or defrosting is performed by controlling a compressor, including: When the temperature of the cold storage is greater than a first cold storage temperature threshold, turning off the refrigeration function of the compressor and turning on the fan for defrosting; Get the defrost time and evaporator pipe temperature; When the defrosting time exceeds the first operating time and the evaporator pipeline temperature is greater than the first pipeline temperature threshold, the defrosting is stopped.

4. The method according to claim 3, characterized in that According to the temperature of the cold storage, defrosting is performed by controlling a fan, and / or defrosting is performed by controlling a compressor, and further comprising: When the cold storage temperature is less than or equal to the first cold storage temperature threshold and greater than the second cold storage temperature threshold, proportional integral derivative control is performed on the compressor frequency based on the target evaporation temperature to perform defrosting, and the fan is controlled to perform defrosting; When the defrosting time exceeds the second running time, the defrosting is stopped.

5. The method according to claim 4, characterized in that According to the temperature of the cold storage, defrosting is performed by controlling a fan, and / or defrosting is performed by controlling a compressor, and further comprising: When the temperature of the cold storage is less than or equal to the second cold storage temperature threshold, controlling the compressor to perform a thermal fluorination defrosting mode; When the evaporator pipeline temperature is greater than the second pipeline temperature threshold, defrosting is stopped.

6. The method according to claim 2, characterized in that The first preset condition is that the difference between the cold storage temperature and the evaporation temperature is greater than a temperature difference threshold.

7. The method according to claim 2, characterized in that: The second preset condition is that the difference between the supply air temperature and the cold storage temperature is less than a temperature difference threshold.

8. The method according to claim 2, characterized in that: The third preset condition is that the evaporation temperature is less than an evaporation temperature threshold.

9. The method according to claim 2, characterized in that: The fourth preset condition is that the accumulated running time of the compressor exceeds the third running time since the last defrosting, and the running time of the compressor at the current startup exceeds the fourth running time.

10. A cold storage defrosting device, characterized in that: include: An acquisition module, used to acquire operating parameters of the cold storage, wherein the operating parameters include at least one of the cold storage temperature, the evaporation temperature, the air supply temperature, and the operating time of the compressor; A judgment module, used for judging whether a preset defrosting condition is met according to the operating parameters; The control module is used to control the fan to perform defrosting according to the cold storage temperature when the preset defrosting conditions are met, and / or control the compressor to perform defrosting.

11. An electronic device, characterized in that: include: A processor, a memory, and a computer program stored in the memory and capable of running on the processor, wherein when the computer program is executed by the processor, the steps of the cold storage defrosting method according to any one of claims 1 to 9 are implemented.

12. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the cold storage defrosting method according to any one of claims 1 to 9 are implemented.

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