1135 results about "Defrosting" patented technology

The invention discloses a defrosting control method and device, refrigeration equipment and a storage medium, and belongs to the technical field of defrosting. According to the defrosting control method, in the first stage, the heater is controlled to defrost the evaporator; entering a second stage when the defrosting state of the first stage meets a first condition; and in the second stage, a compressor exhaust pipe of the refrigerating system is controlled to communicate with the evaporator to conduct hot gas defrosting, and when hot gas defrosting is conducted under the first condition, the heat exchange medium flowing out of the evaporator is in a gaseous state. According to the defrosting control method disclosed by the invention, the heater is firstly controlled to defrost, and then the compressor is controlled to defrost by hot gas, so that staged defrosting is realized; the defrosting state of the first stage is controlled, so that the surface temperature of the evaporator is not too low when hot gas defrosting is carried out, heat exchange media flowing out of the evaporator are prevented from being liquefied, and liquid impact is prevented; and meanwhile, the heater is turned off in the second stage, and excessive heat generated by the heater can be prevented from overflowing to the compartment.

The invention discloses a defrosting control method and system based on the COP attenuation rate, an air conditioner and a medium. The method comprises the steps that the rotating speed of an indoor fan, the temperature of an indoor coil pipe and consumption power are collected; according to the rotating speed of the indoor draught fan, the temperature of the indoor coil pipe and the consumption power, a COP mean value and a COP maximum value are obtained through calculation; according to the COP mean value and the COP maximum value, calculating to obtain a COP attenuation rate; and according to the COP attenuation rate, the air conditioner is controlled to enter a first-stage frost restraining mode, a second-stage frost restraining mode or a reversing defrosting mode. The defrosting opportunity can be accurately determined, the problem that hysteresis exists in defrosting and the comfort degree of a user is affected is solved, and the method can be widely applied to the technical field of air conditioners.

The invention discloses a loading lap joint device for cold chain transportation and sorting and a using method thereof, and relates to the technical field of cold chain transportation, the loading lap joint device comprises a drawing cold storage module, a cold storage module, a cold storage module, a cold storage module, a cold storage module, a cold storage module and a cold storage module, the drawing cold storage module is slidably mounted on a sliding groove in the bottom of a cold chain vehicle compartment, and a cold storage cavity is formed in the drawing cold storage module; the linkage defrosting mechanism comprises a frame type defrosting scraping plate arranged above the drawing cold storage module, a frost collecting groove is formed in the side edge of the cold storage cavity, and scraped frost water is guided into the frost collecting groove through the defrosting scraping plate; the lap joint interface module is arranged at the front end of the drawing cold storage module and comprises a conveying plate and a temperature adjusting air curtain which are movably hinged, and the temperature adjusting air curtain communicates with the cold storage cavity and the frost collecting groove through an air duct and releases cold air; the control unit is used for monitoring the temperature in the compartment and the platform position and adjusting the air speed of the air curtain to control the cold air circulation amount. The system not only can automatically remove the frost layer in the carriage and effectively reduce the environment temperature during loading, but also can be flexibly butted with a sorting line, so that energy conservation, high efficiency and temperature control guarantee of a cold chain loading link are realized.

The invention provides a heat pump non-stop defrosting control method and system based on double-evaporator cooperative control, and the method comprises the steps: building a temperature difference response change rate index by collecting the refrigerant inlet and outlet temperatures of two groups of fin heat exchangers in real time, and recognizing a side needing to be defrosted and a heating side; an electronic expansion valve, a fan and an electromagnetic valve are dynamically configured, so that the side needing to be defrosted enters a static defrosting mode, and the heating side continuously supplies heat; the frequency rising of the compressor and the switching of the four-way valve are cooperatively adjusted, and small-flow pre-balancing is executed before reversing so as to restrain pressure impact; and after defrosting is completed, it is judged that defrosting is finished based on the thermal response state and the heat change trend, the side needing defrosting is controlled to be reset, and heating is started again. Uninterrupted heat supply of the user side in the defrosting process is achieved, water temperature fluctuation and energy consumption are remarkably reduced, and the operation stability and energy efficiency of the heat pump in the low-temperature and high-humidity environment are improved.

The invention discloses an energy-saving type airflow cooperative control system of an impact type tunnel instant freezer and an optimization method. The system obtains multi-source data of materials, environment and equipment in real time through a data sensing and collecting module; the collaborative optimization decision module generates a global control instruction for coordinating the air supply subsystem, the refrigeration subsystem and the conveying subsystem based on an optimization model with the lowest total energy consumption of the system as a target; the airflow dynamic execution module and the refrigeration conveying cooperative execution module respectively drive the adjustable airflow generation unit, the refrigerating unit and the conveying chain to generate a dynamic airflow field matched with the freezing load and adjust the cooling capacity and the speed; the intelligent defrosting scheduling module optimally triggers defrosting based on the prediction model; according to the method, the steps of data collection, decision optimization, airflow dynamic adjustment, refrigeration conveying cooperation and intelligent defrosting are synchronously executed. According to the invention, deep collaboration and dynamic optimization of multiple subsystems are realized, the energy consumption of the instant freezer can be obviously reduced, and the freezing uniformity and the continuous production efficiency are improved.

The invention relates to the technical field of heat pump control, and discloses a defrosting method and device of a heat pump system and the heat pump system.The defrosting method comprises the steps that the temperature and humidity of gaps of a fin type heat exchanger are monitored in real time; and when the temperature is lower than or equal to the threshold value of the dynamic dew point temperature plus the safety margin and the humidity is higher than or equal to the threshold value, it is judged that the frosting prevention condition is met, the gap temperature is increased by adjusting the refrigerant bypass valve, the gap humidity is reduced by adjusting the airflow adjusting valve, and therefore frosting is actively prevented. And if the frost layer appears, short-time refrigeration interruption or low-power heating is started for defrosting according to the thickness of the frost layer or a pressure difference signal. And the formed ice layer is forcibly removed by switching the flow direction of the refrigerant and heating. By means of three-level linkage control, accurate defrosting in the whole process from prevention to removal is achieved, energy waste is effectively avoided, the defrosting efficiency and operation stability of the system are improved, and the user experience is improved.

The invention relates to the technical field of air source heat pump unit control, and discloses a control method for an air source heat pump unit. The method comprises the following steps: acquiring environment temperature and humidity data in real time, and performing noise filtering and time synchronization; generating a temperature prediction sequence based on the sliding window and the LSTM model; fluctuation characteristics are extracted through an optimization algorithm, and compressor control signals are generated; estimating the thickness of a frost layer in combination with a thermodynamic model and dynamically generating a defrosting instruction; closed-loop control parameters are generated through normalization processing and weight distribution; and finally, a system execution command is generated through multi-objective optimization, and compressor regulation and control and system health monitoring are achieved. The unit operation efficiency can be improved, the energy consumption can be reduced, and the defrosting control accuracy and the system stability can be enhanced.

A HVAC&R system includes a heat pump configured to selectively circulate a working fluid. The heat pump includes an outdoor heat exchanger, an indoor heat exchanger, a compressor, a reversing valve configured to direct the working fluid from the compressor to the outdoor heat exchanger or to the indoor heat exchanger, and a controller. The controller is configured to determine whether a pressure of the working fluid exiting the compressor exceeds a pressure threshold, and, in response to determining that the pressure of the working fluid exiting the compressor exceeds the pressure threshold, control the reversing valve to block the working fluid from flowing from the compressor through the reversing valve to the outdoor heat exchanger.

The invention relates to the technical field of air source heat pumps, and discloses a wind-solar complementary air source heat pump integrated system which comprises a hardware device, an active frost suppression module and a predictive optimization scheduling control system. The control system can collect internal and external state data of the system and quantitatively calculate frosting risk indexes of the evaporator in all time periods in the future based on future environment temperature and humidity predicted values. According to the method, the hardware device is connected with the active frost suppression module, a dynamic decision is made according to the frosting risk index, when it is judged that the future frosting risk exceeds a preset threshold value, the active frost suppression module is started in advance, photovoltaic heat recovery warm water stored in the hardware device is used for preheating air entering an evaporator, and frosting is actively suppressed from the source. By means of predictive active frost suppression, a traditional passive and high-energy-consumption defrosting mode is replaced, the operation efficiency and heating stability of the heat pump system in the wet and cold environment are remarkably improved, and comprehensive and efficient utilization of energy is achieved.

The invention discloses a fan power consumption estimation method and refrigeration equipment. The method for estimating the power consumption of the fan comprises the following steps of: sampling operation parameters of the refrigeration equipment for calculating the power of the fan by taking a time step as a unit, calculating the real-time power of the fan, and performing integral accumulation on the real-time power at each sampling moment to obtain the power consumption of the fan; if the heat exchanger corresponding to the fan at the current sampling moment is in a non-defrosting state, obtaining previous defrosting operation time and current defrosting interval time, and inputting the previous defrosting operation time and the current defrosting interval time into a frosting grade evaluation model to obtain a current frosting grade; meanwhile, the real-time environment temperature and the fan rotating speed are obtained, and the fan reference power is obtained through calculation; and based on the frosting grade and the fan reference power, compensation power is obtained through calculation, and the sum of the fan reference power and the compensation power serves as the real-time power of the fan at the current sampling moment. According to the method, more accurate real-time power and power consumption of the fan can be estimated.

The invention relates to a low-temperature efficient heating air energy heat pump unit, discloses a low-temperature efficient heating air energy heat pump unit, and belongs to the technical field of heat pump air conditioners. The unit is composed of a compressor, an evaporator, a condenser, a throttling valve, a defrosting module, a refrigerant adjusting module and a control unit. The surfaces of fins of the evaporator are coated with polytetrafluoroethylene modified hydrophobic frost-resistant coatings, and the frosting amount can be inhibited by 60% or above; the defrosting module adopts a bypass coupling scheme of a 500-800W electric heating wire and a high-temperature refrigerant, and the defrosting time is less than or equal to 8min and is shortened by 30% compared with a traditional scheme; the refrigerant adjusting module dynamically adjusts the refrigerant temperature of an inlet of the evaporator through the bypass electromagnetic valve and the refrigerant mixing cavity, so that the compressor still maintains 100% of the rotating speed at-25 DEG C without frequency reduction, the COP is larger than or equal to 2.0, and the heating capacity is kept 75% or above of the normal temperature value. The system solves the industrial problems of frequent frosting, high defrosting energy consumption and large heating attenuation under the low-temperature and high-humidity working conditions, and can be widely applied to heating systems in household, commercial and high-humidity and low-temperature areas.

The invention provides a heat pump intelligent control method and system for hierarchical defrosting, and the method comprises the steps: collecting the temperature of an inlet and an outlet of a fin, calculating the temperature difference and the change rate thereof, and evaluating the initial state of frosting; and the influence of the frost layer on the system performance is further analyzed in combination with the water side heat exchange efficiency and the attenuation rate thereof. Based on the information, the controller accurately judges mild, moderate and severe frosting states by using a frosting grade scoring function, and automatically matches corresponding defrosting strategies: when the frosting state is mild, the heating mode is maintained, and online defrosting is carried out; when the temperature is moderate, a progressive bypass is adopted for defrosting; and switching to a refrigeration mode and dynamically adjusting the opening degree of the expansion valve to strengthen the defrosting effect when the temperature is heavy. The defrosting precision and the system stability are improved, and the operation efficiency and the user experience of the heat pump equipment in the low-temperature environment are improved.

The invention relates to a defrosting control method and device, refrigeration equipment and a storage medium. The method comprises the steps that when the refrigeration equipment is in a defrosting mode, whether defrosting is completed or not is comprehensively judged based on the defrosting temperature of an evaporator in an evaporator bin and the heating humidity of a heater, and it is accurately determined that defrosting is completed only when the defrosting temperature reaches the preset temperature and the heating humidity reaches the preset humidity; compared with a traditional defrosting strategy depending on timing control or based on the time interval, the defrosting ending moment can be more accurately determined based on the defrosting temperature and the heating humidity so that the refrigerating equipment can quit the defrosting mode when defrosting is just completed, excessive defrosting or insufficient defrosting can be avoided, and the refrigerating equipment can be controlled to quit the defrosting mode. The problem of excessive defrosting or insufficient defrosting caused by an existing defrosting method is solved.

The utility model discloses a carbon dioxide internal defrosting system which comprises a carbon dioxide circulation loop and an internal defrosting liquid return pipeline, the carbon dioxide circulation loop and the internal defrosting liquid return pipeline are formed by connecting pipelines, the carbon dioxide circulation loop conducts compression refrigeration circulation, and the internal defrosting liquid return pipeline conducts low-temperature defrosting circulation. The internal defrosting liquid return pipeline further comprises a second electromagnetic valve, a third electromagnetic valve and a check valve on the basis of the carbon dioxide circulation loop, the second electromagnetic valve is arranged on the connecting pipeline and connected with the electronic expansion valve in parallel, and a liquid return pipeline connected with the carbon dioxide liquid storage device through the third electromagnetic valve and the check valve is arranged at an outlet of the low-temperature air cooler. The device does not consume electric energy, and is energy-saving and environment-friendly; no risk exists in long-time defrosting, and safety and reliability are achieved; and the defrosting time is short, the defrosting heating area is large, and the defrosting efficiency is high.

The invention discloses a refrigerator and a fault maintenance method of a defrosting heater of the refrigerator, n pieces of operation data of a refrigerating system are input into a trained fault diagnosis model to output a fault diagnosis result of the defrosting heater, whether the defrosting heater breaks down or not does not need to be checked in a manual troubleshooting mode, and the fault diagnosis efficiency is improved. The refrigerator fault can be automatically diagnosed in real time. Besides, when the fault diagnosis result is that the defrosting heater breaks down, the chamber temperature of the storage chamber is reduced to the preset lowest temperature, food materials are prevented from being damaged due to the fact that the temperature rises too high during defrosting, the refrigerating system is controlled to stop refrigerating, a refrigerating air door is opened, air blowing defrosting operation is conducted on the evaporator, and the refrigerating efficiency is improved. The intelligent defrosting mode is started after the fault of the defrosting heater is diagnosed, so that the refrigerator can be normally defrosted when the fault of the defrosting heater is diagnosed, and the stable operation of the refrigerator can be maintained.

The invention discloses an intelligent commercial refrigerator in an energy-saving mode based on an AI technology. The intelligent commercial refrigerator comprises an AI intelligent control module, a multi-dimensional sensor network module, a dynamic refrigeration adjusting module, an intelligent defrosting control module, a monitoring management module, a diagnosis correction module and an energy-saving module. The problems that a traditional commercial refrigerator is high in energy consumption, inflexible in refrigeration adjustment, not timely in fault diagnosis and incapable of achieving remote monitoring are solved. According to the invention, through specific algorithms of the improved sparrow algorithm module and the over-temperature calculation module in the AI intelligent control module, multi-dimensional data in the operation process of the refrigerator are evaluated and processed, and the accuracy and efficiency of data processing are improved. And through an improved time sequence analysis module and a cooling capacity demand prediction algorithm module in the dynamic refrigeration adjustment module, the refrigeration demand of the refrigerator is evaluated and optimized, and real-time adjustment of the refrigeration intensity and the operation state is achieved.

The invention discloses a self-adaptive defrosting air energy heat pump unit and relates to the technical field of air energy heat pumps, the self-adaptive defrosting air energy heat pump unit comprises an evaporator body, the evaporator body comprises a copper pipe, a shell and a fin whole arranged on the outer side of the copper pipe in a sleeving mode, a magnetic sheet is embedded in the fin whole, and an adjusting mechanism is arranged at one end of the fin whole in the axial direction of the fin whole. A cleaning mechanism is arranged at the center, close to each other, of the whole fins; according to the invention, through the design of rotationally sleeving the fins, the fins can be conveniently cleaned by the cleaning mechanism, an electric field and a magnetic field which are perpendicular to each other are generated by using the conductive cleaning head and the magnetic sheets embedded in the fins, heat can be gradually generated on the surface of the cleaning head according to the Nernst-Andern Hawson effect, and thicker frost layers on the surface layers of the fins are removed; compared with a traditional defrosting mode, the defrosting method has the advantages that a large amount of energy does not need to be additionally consumed to melt a frost layer, energy consumption is reduced, meanwhile, large indoor temperature fluctuation caused by defrosting is avoided, and the comfort level of a user is improved.

The invention relates to an equipment defrosting method and device, air conditioning equipment and a storage medium. The method comprises the steps that multiple environment parameter values of the environment where target equipment is located and the surface temperature value of the target equipment are collected; determining a freezing point temperature value corresponding to the current environment according to the plurality of environment parameter values; and under the condition that it is determined that the target equipment meets a preset defrosting condition based on the surface temperature value and the freezing point temperature value, defrosting operation is conducted on the target equipment. Therefore, whether the equipment meets the frosting condition or not can be efficiently and accurately judged, and the defrosting efficiency of the equipment is improved.

A refrigerator is disclosed. The refrigerator may include a compressor which compresses a refrigerant; a condenser which condenses the refrigerant compressed by the compressor; a switching valve which is connected to an outlet of the condenser; an evaporator; a first flow path which connects one branched side of the switching valve to the evaporator; a defrosting heater for removing frost formed on the evaporator; a memory; and a processor. The processor controls the switching valve to shut off the first flow path if a defrosting start condition is satisfied while the refrigerant circulates through the first flow path, and operates the defrosting heater if a first condition is satisfied in a state while the first flow path is shut off.

The utility model belongs to the technical field of heating ventilation air conditioners, and particularly relates to a defrosting device and an air source heat pump device. The defrosting device comprises a hot air pipe, the hot air pipe is arranged around the fin type heat exchanger, and air holes facing one side of the fin type heat exchanger are formed in the hot air pipe. The vortex tube comprises a vortex chamber, an air inlet, a cold air section and a hot air section, the air inlet, the cold air section and the hot air section are communicated with the vortex chamber, the air inlet is used for introducing compressed air, the hot air section is connected with the hot air pipe, and the air outlet direction of the cold air section faces the outer side of the fin heat exchanger. According to the defrosting device, compressed air is used for defrosting, so that the air source heat pump device can stably heat and supply heat for a long time in a low-temperature environment, sufficient compressed air resources of a plant are reasonably utilized to be matched with the defrosting device, non-stop defrosting of a heat pump unit can be achieved, and the heat exchange performance of the heat pump unit is effectively improved.

The application provides an electric vehicle heat storage defrosting heat pump system, wherein the first medium A pumped by a compressor is sequentially returned to the compressor through a condenser, an expansion valve and an evaporator, the condenser is provided with a first medium A bypass branch, the first medium A bypass branch passes through a heat storage device, a second medium B bypass branch passes through the heat storage device, the second medium B flowing through the second medium B bypass branch exchanges heat with a motor system, and a defrosting heat exchanger is arranged close to the evaporator. The system can ensure normal defrosting operation when the motor, the battery and the inverter and other power electrical equipment cannot provide effective heat energy during non-working or initial working.

The present disclosure provides a multi-split air conditioning system and a control method thereof, comprising a compressor, an outdoor heat exchanger, a first gas side pipe, a second gas side pipe and a liquid side pipe, the first gas side pipe, the second gas side pipe and the liquid side pipe are all communicated between the indoor side and the outdoor side, and the first gas side pipe is communicated with the exhaust end of the compressor; further comprising at least one indoor unit, at least one heat storage module, at least one constant temperature dehumidification indoor unit, at least one hot water module, at least one floor heating module, and a photovoltaic module capable of absorbing solar energy and generating electric energy for supply to the multi-split air conditioning system. According to the present disclosure, the effects of constant temperature dehumidification, heat storage defrosting, air conditioning demand, floor heating demand, domestic hot water demand and photovoltaic application can be realized simultaneously through a set of system, the actual needs of users are solved, and each module can be selected to be connected to the system or not according to actual needs.

To provide a refrigerator capable of suppressing unnecessary temperature rise of a member around a defrosting heater due to light emission of the defrosting heater in a defrosting process.SOLUTION: Refrigerator 10 includes refrigerating compartment 12 and the like as a storage compartment, cooling compartment 27 in which air blown into the storage compartment is cooled by evaporator 26, defrosting heater 30 disposed below evaporator 26 inside cooling compartment 27, return air passage 24 through which air returning from the storage compartment to cooling compartment 27 is blown, and light shielding portion 43 disposed between air outlet 42 of return air passage 24 and defrosting heater 30.SELECTED DRAWING: Figure 3

The utility model discloses an evaporator defrosting device and a refrigerator, the evaporator defrosting device comprises a heating plate and a heat conducting fin, and the heating plate is used for being arranged on one side of an evaporator; one end of the heat-conducting fin is connected with one side, facing the evaporator, of the heating plate, and the other end of the heat-conducting fin is configured to be far away from the heating plate, so that the heat-conducting fin can extend into the evaporator; when the heating plate is arranged on one side of the evaporator, at least part of the heat-conducting fins extend into the evaporator, so that heat of the heating plate can be transferred into the evaporator, and the defrosting efficiency of the evaporator is improved.

The application discloses an air conditioner and relates to the technical field of air conditioners. The air conditioner comprises a high-pressure pressure sensor configured to detect the exhaust pressure of a compressor; and a controller configured to periodically acquire the exhaust pressure of the compressor and the change rate thereof when the air conditioner operates in a reverse defrosting mode; determine whether the exhaust pressure reaches a first threshold P1 and the change rate reaches a first set value; if yes, control the compressor to operate at a reduced frequency and the frequency reduction amplitude is △H1; if no, when the exhaust pressure reaches a second threshold P2 and the change rate reaches a second set value, control the compressor to operate at a reduced frequency and the frequency reduction amplitude is △H2; wherein P1>P2 and △H1>△H2. By setting two different frequency reduction nodes and combining real-time judgment of the change rate of the exhaust pressure, a dynamic and conditional hierarchical frequency reduction control strategy is constructed, so that the dual optimization of defrosting efficiency and noise control is simultaneously realized under the premise of ensuring the defrosting effect.

The hot fluorine defrosting valve for the refrigerating unit comprises a valve body, a main pipe, a first branch pipe and a second branch pipe are arranged on the valve body, a connecting plate is fixedly connected to the top of the valve body, a servo motor is installed on the top of the connecting plate, a rotating shaft of the servo motor penetrates through the top of the valve body, and the rotating shaft of the servo motor is fixedly connected with the main pipe. The first branch pipe is fixedly connected with a valve element, a rotor is installed in the first branch pipe, and a Hall sensor and a temperature sensor are installed on the inner wall of the first branch pipe. According to the utility model, the microcontroller receives a temperature signal monitored by the temperature sensor, and precisely controls the servo motor to adjust the position of the valve core by combining with the rotating speed of the rotor detected by the Hall sensor, so that high-temperature and high-pressure hot fluorine enters the evaporator for defrosting, the Hall sensor ensures the stability of flow, and the temperature sensor monitors the temperature of a pipeline in real time; the microcontroller automatically controls the servo motor to adjust the state of the valve element according to sensor data and preset data.

The invention discloses an energy-saving defrosting system based on a main evaporator and an auxiliary evaporator. The energy-saving defrosting system has a refrigerating mode and a defrosting mode. In the refrigeration mode, the first on-off valve is opened, the second on-off valve and the third on-off valve are closed at the same time, the main evaporator operates to undertake the refrigeration task, meanwhile, the auxiliary evaporator is maintained in a low-temperature state through the bypass flow limiting branch, it is ensured that refrigeration operation can be immediately put into use when the defrosting mode is switched, and temperature rise in the cabinet is restrained. And when frosting of the main evaporator reaches the set thickness, the defrosting mode is switched to, the first on-off valve is closed, and meanwhile the second on-off valve and the third on-off valve are opened. In the mode, the main evaporator stops working, the auxiliary evaporator works, high-temperature refrigerant gas (system waste heat) exhausted by the compressor is used for defrosting the main evaporator through the defrosting loop, meanwhile, the auxiliary evaporator conducts independent refrigeration to maintain the temperature in the cabinet, a traditional electric heating mode is replaced, the energy-saving effect is remarkable, and the defrosting efficiency is greatly improved.

The utility model belongs to the technical field of evaporators, and particularly relates to a freezing evaporator assembly which comprises a base. An evaporator main body is mounted on one side in the base; a blower device shell is fixedly connected to one side of the exterior of the base; a first servo motor is mounted in the blower device shell; the output end of the first servo motor is fixedly connected with fan blades; in the long-term use process of the freezing evaporator, due to the facts that the surface temperature of the freezing evaporator is low, frosting and freezing are likely to occur, too thick frost blocks air circulation, the heat exchange efficiency is reduced, and the refrigerating effect is poor, when frost appears on the surface of the evaporator body, the defrosting effect can be achieved only by opening the heating piece, and the defrosting efficiency is improved. And the influence of thicker frost on the refrigeration effect is reduced.

The application discloses an intelligent defrosting control method, a refrigeration system, a controller and a storage medium, and relates to the technical field of defrosting control. The method comprises the following steps: acquiring first operation parameters and initial reference parameters of a refrigeration unit; performing thickness calculation processing on the first operation parameters and the initial reference parameters based on a frost layer calculation model to obtain a first frost layer thickness; determining a first defrosting control mode according to a first comparison result between the first frost layer thickness and a preset thickness threshold; the first defrosting control mode is one of the following: a thin-frost working condition control mode, a medium-frost working condition control mode and a thick-frost working condition control mode; determining a target defrosting device from the refrigeration unit according to the first defrosting control mode, and controlling the target defrosting device to perform dynamic defrosting control processing on a cold storage, so that intelligent defrosting is realized on the cold storage. The method can reduce the hardware cost, reliably and accurately realize defrosting operation, enhance the defrosting effect and reduce the system energy efficiency.

The application provides a multi-connected air conditioner, which comprises a controller, and the controller is configured to: before the air conditioner performs a defrosting action, judging whether all indoor units are in a starting state; if yes, determining a first type of target indoor unit from the indoor units in the starting state, and controlling the first type of target indoor unit to perform the defrosting action; otherwise, determining a second type of target indoor unit from the indoor units in a starting state and a stopping state, or determining the second type of target indoor unit from the indoor units in the stopping state, and controlling the second type of target indoor unit to perform the defrosting action. In different operation states, the application determines corresponding target indoor units to perform the defrosting action, realizes accurate control of the heat load required during defrosting, effectively avoids the influence on user comfort, realizes accurate control of the number of indoor units participating in defrosting, reduces the waste of the capacity of the multi-connected air conditioner caused by too many indoor units participating in defrosting, and realizes intelligent defrosting.