222 results about "Frost (temperature)" patented technology

The invention relates to a defrosting control method for a heat pump unit and the air conditioner heat pump unit adopting the defrosting control method. The situations such as inaccurate judgment of the frosting condition, conduction of defrosting operation under the frostless condition and incomplete defrosting are avoided, the comfort level of an air conditioner is improved, and energy is saved. The real-time temperature of an external coil pipe is monitored, the thickness of a frost layer is judged according to change conditions of the temperature of the external coil pipe and the duration, defrosting is performed when the frost layer has the certain thickness, and defrosting conditions can be adjusted in real time according to temperature and humidity change after running of the unit, so that the unit is adapted to different actual environments.

The invention relates to a control method and control system for adjusting the frosting of an air conditioner and an air conditioner. The control method for adjusting the frosting of the air conditioner comprises the steps that when the air conditioner is in a heating mode, the outdoor environment temperature T1 is detected; the relationship between the outdoor environment temperature T1 and the first temperature preset value is judged; and when the outdoor environment temperature T1 is greater than the first temperature preset value, the air conditioner enters an adjusting frosting mode. According to the control method, the situation that the outdoor environment temperature meets certain conditions is set, the heating operation of the air conditioner does not stop, the air conditioner enters the heating and defrosting or heating and anti-frosting mode, a frost layer is prevented from weakening the heating capacity of the air conditioner, and the situation that in a traditional methodof refrigerating and defrosting, the reliability and service life of a compressor are affected because the compressor accumulates too much refrigerants is avoided; and defrosting or anti-defrosting isconducted in the process of heating, the reduction of indoor temperature cannot be caused, the comfort of a room is improved, and the user experience is improved.

The invention relates to a frost preventing and removing system and a frost preventing and removing method of a heat pipe type air conditioner. A compressor waste heat recovery channel is separated from an outdoor machine through a partition plate; a compressor and an exhaust pipeline are positioned in the compressor waste heat recovery channel; the compressor waste heat recovery channel is internally provided with a waste heat recovery fan and a horizontal heat pipe; and the horizontal heat pipe is parallel to the heat transfer pipe of an outdoor heat exchanger and closely coupled with the heat transfer pipe of the outdoor heat exchanger through a heat exchange fin. According to the frost preventing and removing method which is disclosed by the invention, heat pipe technology compressor waste heat recovery based frost removal and hot gas bypass based frost removal are effectively combined. The frost preventing and removing system disclosed by the invention can realize a winter heating frost preventing mode, a winter heating periodical double-effect frost removing mode and a winter heating optimizing operation mode when operated for winter heating, has dual functions, namely frost prevention and removal, and the outstanding advantages of prolonging the frosting time, shortening the frost removing time, realizing the continuous heat supply of an indoor machine, and the like, and can be used for reducing the condensing temperature by realizing the double-effect cooling of the outdoor heat exchanger by adopting a heat pipe technology when operating for summer cooling, thereby reducing the power consumption of the compressor and enhancing the work property of a machine set.

The invention discloses a control method and device of an air conditioner, a storage medium and the air conditioner. The method includes the steps that the frosting amount of an outdoor heat exchangerof the air conditioner is determined, wherein the frosting amount of the outdoor heat exchanger comprises the frost layer thickness of the outdoor heat exchanger; if the frost layer thickness of theoutdoor heat exchanger belongs to a set defrosting frost layer thickness range, the air conditioner is controlled to be switched into a defrosting manner from a heating manner; if the frost layer thickness of the outdoor heat exchanger belongs to a set non-defrosting frost layer thickness range, the heat comfort state of an indoor environment of the air conditioner is determined; and the air conditioner is controlled to continue to be subjected to heating operation in the heating manner according to the heat comfort state of the indoor environment or be switched into the defrosting manner fromthe heating manner. By means of the scheme, the problems that whether defrosting is carried out or not is judged according to the temperature of the outdoor heat exchanger or the difference between the temperature of the outdoor heat exchanger and the temperature of an outdoor environment, when defrosting exists, the indoor temperature drop is large, and therefore the defrosting heat comfort is poor can be solved, and the effect of improving the defrosting heat comfort is achieved.

An active frost warning system for the forecasting and / or detection of active frost conditions by determining the surface or skin temperature of an active frost sensor and comparing the surface or skin temperature with outside ambient temperature and frost point temperature is provided. The system predicts active frost conditions when the surface or skin temperature of the sensor is less than frost point temperature or when the rate of cooling of the surface or skin temperature indicates that the surface or skin temperature of the senor will be less than the frost point temperature in the future.

The invention discloses a defrosting control system and method for an air source heat pump. According to the defrosting control system, based on an original system structure for the air source heat pump, a temperature sensor and cameras for camera-shooting the frosting condition of the surface of an outdoor side heat exchanger are arranged on the outer portion of the outdoor side heat exchanger, the surface of the outdoor side exchanger is coated with underlying color significantly different from frost color, the temperature of accessories of the outdoor heat exchanger is detected by the temperature sensor, the system defrosting function is enabled when the set temperature is reached, meanwhile the cameras are activated and opened automatically, and the frosting condition of the surface of the outdoor heat exchanger can be monitored in real time.

The invention discloses an air conditioning system and an anti-freezing control method thereof. According to the system and the method, an external environment temperature, an internal environment temperature, an inner fan wind grade and an outer fan wind grade are detected, corresponding detection values are distributed in corresponding sections An, Bn, Cn and Dn, the An, the Bn, the Cn and the Dn are permutated and combined to obtain N kinds of results, En is used for representing each result value, and the En values correspond to a corresponding different first preset low-pressure value Px,a corresponding different first preset time value Tm, a corresponding different second preset low-pressure value Py and a corresponding different second preset time value Ta. The optimal Px value, Tmvalue, Py value and Ta value are confirmed after a lot of experiments, so that the condition that the system enters an anti-freezing condition and the condition that the system exits from the anti-freezing condition are confirmed, the good anti-freezing effect can be achieved, and the problem that the system carries out defrosting in the situation that frost does not exist can be avoided.

Disclosed is a heat pump heating / cooling system that uses a hybrid heat source that may include air heat, groundwater heat, brine and in-line heaters. The heat pump includes 1) a device for compressing, condensing, gasifying, and circulating cooling / heating media and exchanging heat with water refrigerant; 2) a device for storing heat energy in a storage tank; 3) a device for loading a load through a four-way fan coil unit; and 4) a control panel. To remove frost on the exterior of an evaporator, the evaporator is temporarily stopped, and brine at a temperature of 15° C. to 20° C., which receives groundwater heat from a brine heat exchanger and receives heat from an in-line heater, is supplied to a brine supply pipe installed around the evaporator to melt and remove the frost on the exterior of the evaporator and then is discharged at a temperature of −3° C. to 5° C.

The invention discloses a self-cleaning method and device of an air conditioner, the air conditioner and electronic equipment. The self-cleaning method comprises the steps that the response to a self-cleaning instruction for the air conditioner is achieved, and the air conditioner is controlled to enter a condensate water forming stage; the situation that the temperature of an indoor coil pipe isreduced to the first preset temperature in the condensate water forming stage is detected, and then the air conditioner is controlled to enter a refrigeration frosting stage; the temperature reductionspeed of the process that the temperature of the indoor coil pipe is reduced to the second preset temperature from the first preset temperature in the refrigeration frosting stage is obtained; the target rotating speed of an indoor fan in the air conditioner in the refrigeration frosting stage is determined according to the temperature reduction speed; and the situation that the temperature of the indoor coil pipe is reduced to the first target temperature of an evaporator in the air conditioner is recognized, and then the air conditioner is controlled to enter a defrosting stage. According to the self-cleaning method, the target rotating speed of the indoor fan in the refrigeration frosting stage can be determined according to the temperature reduction speed, and therefore the problem that due to the fact that the frosting speed is high, the formed frost is not uniform can be solved, the situation that the enough frosting quantity is generated by an indoor heat exchanger is guaranteed, and the cleaning effect of the indoor heat exchanger is enhanced.

The invention provides a method and device for controlling ultrasonic defrosting, a storable medium and an air conditioner. Based on features like a high frequency, a short wave length and effective energy centralization of ultrasonic waves and the proper control method, defrosting is realized by the ultrasonic waves; effects of frost restraining and defrosting are reached; comfort demands of users in defrosting are satisfied; and efficient frost-free running of a heat pump air-conditioning unit can be expected. The control method comprises the steps that the air conditioner is started for heating, an outdoor environment temperature T<outer ring>, an outdoor heat exchanger coil temperature T<outer coil> and an outdoor environmental relative air humidity h are detected after normal runningfor first preset time t1; when the T<outer ring>, the T<outer coil> and h satisfy preset defrosting working conditions, the air conditioner starts an ultrasonic defrosting mode; and when the preset defrosting working conditions are not satisfied, the air conditioner can keep running under an original working mode, and the pre-set defrosting working conditions are judged for a time at an interval of second preset time t2.

The invention relates to the technical field of defrosting of air source heat pump water chilling units, in particular to frost restraining and defrosting equipment for an air source heat pump water chilling unit for different humidities and a frost restraining and defrosting control method. The air source heat pump water chilling unit and a frost restraining and defrosting device are arranged. The frost restraining and defrosting equipment is characterized in that an outdoor temperature sensor, an outdoor air relative humidity sensor, an evaporator temperature sensor, a video camera monitor,a surface air cooler fin photoelectric frost measuring sensor and a controller are arranged on the air source heat pump water chilling unit; the outdoor temperature sensor, the outdoor air relative humidity sensor, the evaporator temperature sensor, the video camera monitor and the surface air cooler fin photoelectric frost measuring sensor are connected with the frost restraining and defrosting device through the controller, and the frost restraining and defrosting device is controlled to work through the controller after detection numerical analysis of all the sensors. The frost restrainingand defrosting equipment and the frost restraining and defrosting method have the advantages that the method is simple, frost inhibition control has pertinence, the defrosting efficiency is high, andthe defrosting effect is good.

The invention discloses an air source heat pump defrosting device based on a multi-effect synthetic action at an initial frosting stage. The air source heat pump defrosting device comprises a refrigerant circuit, an air circuit and a defrosting speed regulation system. At the initial frosting stage, a frost layer is sparse and short or is in a non-frozen liquid drop state, thereby being easy to remove. According to the air source heat pump defrosting device, the growing characteristics of the frost layer at the initial frosting stage are fully utilized, high-temperature, high-pressure and dry air directly acts on the finned surface of a second heat exchanger through air supply nozzles, and therefore quick defrosting with the multi-effect synthetic action including blowdown, thawing and evaporation is achieved. Meanwhile, the defrosting speed regulation system can control the acting time of the high-temperature and high-pressure air on the finned surface by changing the vertical movement speed of the air supply nozzles along the second heat exchanger so as to achieve the effect that the frost layer at different frosting degrees is completely removed. The air source heat pump defrosting device is low in defrosting energy consumption, normal heating running of a heat pump system is not influenced in the defrosting process, the heat supply time of the heat pump system is prolonged, and the heat supply efficiency of the heat pump system is improved.

The invention relates to a low-temperature environment anti-freeze anti-frost refrigeration house monitoring device. The low-temperature environment anti-freeze anti-frost refrigeration house monitoring device comprises a monitor, a protective cover, a lighting lamp and a heating lamp; the monitor comprises a pan / tilt holder, a spherical bracket and a camera; the spherical bracket is connected with the camera and the pan / tilt holder; the pan / tilt holder is installed on the ceiling of a refrigeration house; the protective cover is arranged outside the monitor; the protective cover is hemispherical; the protective cover comprises two layers of glass cover bodies; space between the two layers of glass cover bodies is vacuum; the edges of the glass cover bodies at two sides are sealed through sealing bars; the edge of the protective cover is fixed onto the ceiling of the refrigeration house; the lighting lamp is ring-shaped; the lighting lamp is arranged inside the protective cover; the heating lamp is ring-shaped; and the heating lamp is arranged inside the protective cover. According to the low-temperature environment anti-freeze anti-frost refrigeration house monitoring device of the invention, the two-layer glass protective cover can isolate temperature so as to protect the monitor and enable an anti-frost effect; the heating lamp is arranged in the protective cover so as to remove frost on the protective cover, and therefore, the monitoring device can work properly.

The invention discloses a method for determining defrosting of an air source heat pump unit. The method comprises the following steps of acquiring the ambient temperature, ambient humidity, and fin temperature by a sensor detection module of the heat pump unit; judging that the ambient humidity is greater than or equal to the predetermined defrosting humidity, determining the first defrosting timeby checking a relationship table of the ambient temperature and the ambient humidity, and acquiring the compressor running time; and judging that the compressor running time is greater than the firstdefrosting time, judging that the fin temperature is smaller than or equal to the preset defrosting chip temperature, judging that the ambient temperature is smaller than or equal to the preset defrosting ambient temperature, judging that the difference between the ambient temperature and the fin temperature is less than or equal to a preset defrosting ring fin difference, and entering a defrostprocedure. According to the method for determining the defrosting of the air source heat pump unit provided by the invention, by acquiring the ambient humidity, judging the ambient temperature, the problem that the that the energy efficiency of the unit is reduced caused by defrosting or excessive frosting of the unit due to the phenomenon that the ambient humidity is too low and the unit enters defrosting without frosts, and the phenomenon that the ambient humidity is too high and the unit does not enter defrosting when the frosting is serious is solved.

The invention provides an air conditioner and a control method thereof. The control method comprises the steps that outdoor temperature prediction information of the position where the air conditioneris located is obtained; according to the outdoor temperature prediction information, a condensation condition required to be reached when a frost and dew condensation event occurs in an indoor environment where an indoor unit of the air conditioner is located is determined; whether the indoor environment is about to reach the condensation condition is judged; if yes, the air conditioner is controlled to adjust the running state so as to prevent the indoor environment from the frost and dew condensation event. By means of the method, the air conditioner can automatically prevent the frost anddew condensation event from occurring, the intelligent degree is improved, and the air conditioner is particularly suitable for viewing buildings with large glass doors and windows.

The invention discloses a control method for defrosting without shutdown and a refrigeration device. The control method comprises the steps that a conventional refrigeration mode is executed, a refrigerant sequentially flows through at least two evaporators, and throttling is carried out through a throttling device before the refrigerant flows into the first evaporator; operation parameters of theconventional refrigeration mode are detected, and whether the operation parameters meet preset defrosting conditions or not is judged; and if yes, a defrosting refrigeration mode is executed, the refrigerant flows into the first evaporator from a bypass pipeline, and throttling is carried out through the throttling device before the refrigerant flows into the remaining evaporators. According to the control method for defrosting without shutdown and the refrigeration device, the high-temperature refrigerant which is not throttled is directly fed into the first evaporator, so that a frost layeron the surface of the refrigerant is melted, the refrigerant is throttled through the throttling device before flowing into the remaining evaporators, compensation refrigeration is carried out on circulating air, low-temperature air supply is maintained, and therefore the temperature in the refrigeration device is kept at a low temperature.

The invention relates to a frosting and dewing preventing device special for a low-temperature blackbody radiation source. A heating device, a three-way electromagnetic valve, a refrigerating device,a solid-state relay and the like are installed in a shell, moisture in air is evaporated through a furnace body, a humidity sensor measures the humidity value in gas and then sends the humidity valueto the three-way electromagnetic valve, when the humidity value is greater than a set value, the electromagnetic valve is in a closed state, and the gas is exhausted into the environment through an exhaust pipe; when the humidity value reaches a set value, the electromagnetic valve is switched on to enable gas to enter the condenser for cooling; the obtained dry gas is enabled to pass through a filter; impurity particles in the dry gas are removed and then the dry gas enters the low-temperature blackbody radiation source cavity. The pressure of dry gas in the cavity space is greater than the ambient pressure, gas containing moisture is effectively prevented from entering the cavity to be condensed into frost and dew, and the device is safe, reliable, good in temperature stability, low in cost, high in working efficiency, beneficial to measurement of infrared optical instrument and meter equipment and more beneficial to use in narrow and small space.

The invention provides a heat pump air conditioner frosting judgment method, a computer readable storage medium and an air conditioner. The method comprises the steps: after the air conditioner is started and enters a heating operation mode, detecting current of a motor of an outer fan in real time to obtain a real-time current value; judging whether frosting conditions are met or not according tothe difference between the real-time current value and the normal operation current value of the motor, and then, judging and analyzing the temperature of an outer pipe; and when the two judgment conditions are met at the same time, judging that an outdoor heat exchanger frosts and enters a defrosting mode. The current value is used as the frosting judgment condition and is not easily influencedby the environment temperature and humidity, so that whether frosting occurs or not can be judged more accurately, and the situations of missed judgment and misjudgment and the like are prevented.

The invention provides an evaporative cooling unit with a frost prevention structure. The evaporative cooling unit comprises an indoor circulating system, an outdoor circulating system, a metal filterscreen, a refrigerating system and a frost prevention system, wherein the indoor circulating system is provided with an indoor return air inlet and an indoor air supply outlet, and indoor air entersthe indoor circulating system by the indoor return air supply inlet and then is sent back to the indoor by the indoor air supply outlet; the outdoor circulating system is provided with an outdoor airinlet and an outdoor air outlet, and outdoor air enters the outdoor circulating system by the outdoor air inlet and then is exhausted to the outdoor by the outdoor air outlet; the metal filter screenis arranged at the outdoor air inlet so as to filter the outdoor air; the refrigerating system can transfer heat of air in the indoor circulating system to air in the outdoor circulating system, so that the temperature of the air in the outdoor circulating system increases; and the frost prevention system is provided with a frost prevention air duct capable of exhausting the air with increased temperature in the outdoor circulating system to the metal filter screen. The outdoor air with increased temperature is exhausted to the metal filter screen through the frost prevention air duct, so thatthe surface temperature of the metal filter screen is increased, and frosting, icing and snow accumulation on the metal filter screen are prevented.

The invention discloses an anti-frosting method with low energy consumption. The anti-frosting method is characterized by comprising the following steps: forming a nanostructure on the surface of a substrate, and modifying a low surface energy substance, so as to obtain a micro-droplet self-release surface capable of delaying frost crystal formation and / or accelerating frost crystal melting, and then realizing a frost-free surface by combining with an auxiliary method with micro-energy consumption under low energy consumption. According to the anti-frosting method disclosed by the invention, by a chemical deposition method, an electrochemical corrosion method and the like, various nanostructures (such as nanocones, nanoneedles, nanoflowers and multi-scale nanostructures) are prepared on the substrate material and the low surface energy substance is modified to obtain the micro-droplet self-release surface, such surface can effectively delay the frost crystal formation under the conditions of high humidity and wall temperature lower than the freezing point, and the frost crystal covering time of the surface is dozens of times that of a smooth surface; by further combining with the auxiliary means with micro-energy consumption, the frost-free surface can be realized for a long time under low energy consumption.

The invention discloses a computer simulation performance computation method of a refrigeration system under a frosting working condition. The computer simulation performance computation method comprises the following steps of respectively establishing a wet air physical property computing module, a coolant physical property computing module, a condenser structure computing module, an evaporator structure computing module and an evaporator frosting computing module; and establishing a refrigeration circulation system computing module. On the basis of simulating the variation of a frost layer of an evaporator, the variation of the whole refrigeration circulation operation situation is caused due to the variation of evaporation temperature. Through the computer simulation performance computation method disclosed by the invention, design can effectively avoid the system abnormal work risk due to frosting; simultaneously, effective geographic data is effectively provided for defrosting control of a refrigeration system, and the refrigerating output and the energy efficiency ratio of the refrigeration system are more effectively improved. Computing time is subjected to uniform step length partition firstly, and complex iteration computation is carried out on the structure and heat exchange parameter in a program by utilizing computer accessory appliances. The method in the invention realizes the dynamic simulation of a whole system under the frosting working condition.

The invention relates to the technical field of tension testing equipment, in particular to a high-low temperature tension tester, which comprises a temperature change box, an upper pull rod arrangedin the temperature change box, a lower pull rod movably arranged in the temperature change box in a penetrating mode and a sealing ring. The temperature change box is provided with a through hole, thelower pull rod enters the temperature change box through the through hole, the sealing ring is used for sealing a gap between the lower pull rod and the through hole, and a heating device is arrangedin the lower pull rod. The invention discloses the high-low temperature tension tester, the sealing ring is arranged between the lower pull rod and the temperature change box, the lower pull rod cansmoothly penetrate through the temperature change box, meanwhile, relative sealing of the temperature change box is guaranteed, the heating device is arranged in the lower pull rod, the temperature ofthe lower pull rod can be increased, frost condensed on the surface of the lower pull rod can be dissolved, the pull rod is prevented from being fixed to a box body, and accurate tension testing canbe guaranteed at high temperature and low temperature.

The invention discloses a novel defrosting system and a control method thereof. The novel defrosting system comprises a compressor, a four-way reversing valve, an outdoor heat exchanger, an electronic expansion valve and an indoor heat exchanger, an air outlet and an air inlet of the compressor are connected through a second air return pipeline, and an electromagnetic valve device is arranged on the second air return pipeline. A novel defrosting method of an air conditioner includes the steps of (1) thin frost and thick frost detection and judgment, and (2) defrosting: when judgment is thin frost, adopting a thin frost removal mode, and when judgment is thick frost, adopting a thick frost removal mode. By the novel defrosting system and the control method thereof, the thin frost and the thick frost can be distinguished automatically, different defrosting modes are adopted for the thin and thick frost to allow indoor temperature to be more stable, defrosting effect is better, and waiting time of customers is shortened.

The invention relates to a control method and device for air conditioner defrosting, and an air conditioner. The control method comprises the steps: when the air conditioner meets a frosting temperature condition, the frosting accumulated duration is determined according to the temperature of an outdoor coil pipe and the frosting point temperature of the air conditioner; and when the frosting accumulated duration meets a preset duration condition, the air conditioner is controlled to enter into a defrosting mode. According to the method for determining the frosting accumulated duration based on the temperature of the outdoor coil pipe of the air conditioner and then conducting defrosting judgment control according to the duration condition, the air conditioner can be more accurately controlled to trigger and enter into the defrosting mode, and the problems of false triggering, frequent triggering and the like of a defrosting process in related technologies are reduced.

The invention discloses a high-temperature sterilization control method and device as well as an air conditioner and a storage medium. The high-temperature sterilization control method comprises the following steps: judging a current state of an outdoor heat exchanger according to a frosting reference temperature after a high-temperature sterilization mode is started, wherein the current state comprises a liable-to-frost state, a frosting state and a defrosting state; if the outdoor heat exchanger is in the liable-to-frost state, reducing compressor frequency and / or rotation speed of an indoorfan to enter a high-temperature sterilization state; if the outdoor heat exchanger is in the frosting state, regulating compressor frequency and / or the rotation speed of the indoor fan to keep the high-temperature sterilization rate; and if the outdoor heat exchanger is in the defrosting state, determining the rotation speed of the indoor fan based on a defrosting reference temperature. In this way, the compressor frequency and the rotation speed of the indoor fan are controlled based on the current state of the outdoor heat exchanger after the high-temperature sterilization mode is started,so that high-temperature sterilization of the air conditioner is realized by controlling a defrosting process; and quick defrosting is realized in real time while the outdoor heat exchanger is in thedefrosting state.

The invention discloses a method and a device for automatically heating and removing ice, frost and fog for a vehicle-mounted lens, and the method for automatically heating and removing ice, frost and fog for the vehicle-mounted lens. Comprising the following steps: acquiring an actual vehicle-mounted camera view, comparing the vehicle-mounted camera view with a camera image recorded in advance, detecting the environment temperature, and determining the temperature of the vehicle-mounted camera in combination with image comparison information and temperature information. And judging whether the surface of the vehicle-mounted lens is fogged or frosted, calculating the shielded area of the visual field of the vehicle-mounted camera according to the image comparison information, calculating the heat required for melting the shielded fog or frosted, and heating the surface of the vehicle-mounted lens by using the heating module. The invention provides a technology for automatically heating and removing ice, frost and fog on the surface of a camera based on images and temperature feedback of a heating element.

The embodiment of the invention provides a controller, an air conditioner floor heating system and an anti-freezing control method thereof, and relates to the technical field of air conditioners. Theanti-freezing control method for the air conditioner floor heating system includes the steps of obtaining the temperature Tci of a liquid pipe of a water module, obtaining the temperature Tco of an air pipe of the water module, and if Tci is smaller than or equal to a first preset value and Tco is smaller than or equal to a second preset value, controlling the air conditioner floor heating systemto start an anti-freezing mode. The temperature Tci of the liquid pipe of the water module and the temperature Tco of the air pipe of the water module are obtained and compared with the preset values,if Tci is smaller than or equal to the first preset value and Tco is smaller than or equal to the second preset value, it means that an electronic expansion valve has a leakage phenomenon at that time, and if the evaporation temperature is lower than the freezing point after leakage of refrigerants, water in the water module will have a freezing and expansion phenomenon. By controlling the air conditioner floor heating system to start the anti-freezing mode, the temperature of the water in the water module can be improved, and the risk of frost damage to the water module can be lowered.

A refrigeration cycle apparatus includes a low temperature-side refrigeration cycle 110, a high temperature-side refrigeration cycle 120, defrosting detecting means 116 which detects a frost-formed state of a low temperature-side evaporator 114 of the low temperature-side refrigeration cycle 110. When an operation should be shifted to a defrosting operation for thawing frost of the low temperature-side evaporator 114, an operation of the low temperature-side compressor 111 of the low temperature-side refrigeration cycle 110 is continued, an operation of the high temperature-side compressor 121 of the high temperature-side refrigeration cycle 120 is stopped, and the operation is shifted to the defrosting operation. When the operation is shifted to the defrosting operation, heat-accumulated high temperature low temperature-side refrigerant is supplied to the low temperature-side evaporator 114 to defrost. Therefore, it is possible to shorten the defrosting time and to enhance the operation efficiency of a refrigeration cycle.

The invention relates to a control method and device for air conditioner defrosting, and an air conditioner. The control method comprises the steps: when the air conditioner operates in a heating mode, the temperature of an outdoor coil pipe of the air conditioner is obtained; when it is determined that a preset condition is met according to the temperature of the outdoor coil pipe, the air conditioner is controlled to enter into a defrosting mode, wherein the preset condition comprises that the accumulated duration when the temperature of the outdoor coil pipe meets a preset frosting temperature condition meets the preset duration condition. According to the method for performing defrosting judgment control based on frosting temperature condition and the duration condition, the air conditioner can be more accurately controlled to trigger and enter into the defrosting mode, and the problems of false triggering, frequent triggering and the like of the defrosting mode in related technologies are reduced.

A refrigerator including a main body including a storeroom; an evaporator arranged in the back of the storeroom and configured to generate cold air; a defrost heater arranged under the evaporator into which air flows and configured to remove frost or ice formed on the evaporator; a temperature sensor arranged on the top of the evaporator and configured to measure temperature; and a controller configured to stop operation of the defrost heater in a first defrost cycle based on a first measurement measured by the temperature sensor and stop operation of the defrost heater in a second defrost cycle based on a second measurement, which is different from the first measurement.