348results about How to "Shorten defrosting time" patented technology

An air conditioner for a vehicle includes a vapor compression refrigeration cycle switchable between a heat pump cycle and a cooler cycle, a heat core configured to heat air to be blown into a vehicle compartment by using coolant of an engine of the vehicle as a heat source, and a controller configured to control operation of the vapor compression refrigeration cycle. The controller controls the vapor compression refrigeration cycle to be operated as the cooler cycle so as to perform a defrosting control of the outdoor heat exchanger, and outputs an operation request signal to the engine, when the controller determines that the outdoor heat exchanger is frosted.

The invention provides a defrosting control method for an air conditioner. The air conditioner comprises a compressor, a four-way valve, an indoor heat exchanger, a first throttling device, outdoor heat exchangers, a refrigerant pipeline, a second throttling device, a first two-way valve and a second two-way valve. When defrosting begins, the second two-way valve is closed, and the first two-way valve is opened, a refrigerant sprayed by the compressor is divided into two branches at the second connecting point of the first two-way valve, wherein the main branch comprises the large part of refrigerant which flows to the first part heat exchanger of the outdoor heat exchangers to be used for defrosting, flows to the second part heat exchanger through the second throttling device to absorb heat and finally flows through the four-way valve to return into the compressor; the auxiliary branch comprises the other small part of refrigerant which flows through the indoor heat exchanger to exchange heat and flows through the first throttling device to join the main branch. In the defrosting process, the small part of the refrigerant flows to the indoor heat exchanger, an indoor unit has certain heat and does not have cold radiation, the problem that the indoor unit releases the refrigerating capacity to an indoor unit in the defrosting process of the air conditioner is solved, and the comfortable feeling of a user is improved.

A refrigerant cycle device having an ejector includes a first evaporator for evaporating refrigerant flowing out of the ejector, a first passage portion for guiding refrigerant to a refrigerant suction port of the ejector, a throttle unit located in the first passage portion, a second evaporator located in the first passage portion downstream of the throttle unit, a bypass passage portion for guiding hot gas refrigerant from a compressor into the second evaporator, a bypass opening and closing unit provided in the bypass passage portion. Furthermore, a second passage portion is branched from the bypass passage portion downstream of the bypass opening and closing unit, and a flow control unit is provided in the second passage portion to prevent a flow of refrigerant from the first evaporator to the second evaporator through the second passage portion. Therefore, defrosting of both the first and second evaporators can be suitably performed.

The invention relates to an air conditioner control method, and provides the air conditioner control method by using a booster heater to shorten defrosting time and cold air prevention time. The air conditioner control method in an indoor heating state comprises the following steps: driving the booster heater during the cold air prevention of an air conditioner, and judging whether temperature of an indoor heat exchanger is higher than a first set temperature, if yes, driving an indoor fan; if not, keeping halted state of the indoor fan until the temperature of the indoor heat exchanger is higher than the first set temperature; and setting an indoor unit into a refrigeration cycle during the defrosting of the air conditioner, turning off the indoor fan, and driving the booster heater. The booster heater is arranged below the indoor heat exchanger. The method aims at the air conditioner containing the electric booster heater, and the electric booster heater is started during the air conditioner heating operation, the cold air prevention and the defrosting so as to shorten the cold air prevention time and the defrosting time, and extends the usage of the booster heater.

The invention discloses a defrosting method for a heat-pump type air conditioner, which decides whether the defrosting operation mode, namely setting environment determination temperature t<1> and t<2> and three constants a, b and c, is carried out by combination of coil tube temperature T of an outdoor heat exchanger, outdoor temperature T, actual heating time H and set heating time h; under the following conditions, the unit starts the defrosting operation mode: 1. when T is less than or equal to t<1> and more than or equal to t<2>, if the coil tube temperature T of the outdoor heat exchanger meets the condition of T less than a, T plus c and H larger than h in a continuous M minutes, the unit starts to defrost; 2. when T is less than t<2>, if the coil tube temperature T of the outdoor heat exchanger meets the conditions of T less than b, T plus c and H larger than h in a continuous M minutes, the unit starts to defrost. The defrosting method has the advantages of shortening defrosting time, improving defrosting efficiency, leading to thorough defrosting and greatly improving heating efficiency.

The invention discloses a method for controlling an air conditioner. The method is carried out during the defrosting operation and / or in the early stage of the reentering heating operation after finishing defrosting; according to the judgment of the room temperature, the directions of a left blade and a right blade are controlled by utilizing a result detected through a human induction sensor in order that the swinging directions of the left blade and the right blade point to a peopleless region judged by a detection result. During the defrosting, an indoor fan can operate at high rotational speed, improve heat-exchange efficiency in the indoor side and shorten defrosting time; and in the early stage of reentering the heating operation after finishing defrosting, the indoor fan can operate at high rotational speed and improve the heating effect, avoid cold wind from directly blowing on people and improve comfortableness.

The invention discloses an air-conditioner defroster. The defroster comprises a compressor, a four-way valve, an evaporator and a condenser. The defroster also comprises a first pipeline for connecting a liquid inlet of the evaporator with a liquid outlet of the condenser; a second pipeline for connecting an air return inlet of the evaporator with a first port of the four-way valve; a third pipeline for connecting an air inlet of the condenser with a second port of the four-way valve; a fourth pipeline for connecting an air outlet of the compressor with a third port of the four-way valve; a fifth pipeline for connecting a suction inlet of the compressor with a fourth port of the four-way valve; a bypass pipeline with one end communicated with the first pipeline and the other end communicated with the fourth pipeline; a bypass control valve arranged on the bypass pipeline for starting / closing the bypass pipeline; a throttle valve arranged on the first pipeline for regulating the flow of refrigerant in the first pipeline through adjusting the openness of the throttle valve. The invention combines the advantages of heat pump defrosting and hot gas bypass defrosting and can achieve the most effective defrosting.

The invention discloses an air-cooled refrigerator which comprises a refrigeration system, an electrical control device, a sensing device and an air duct system, wherein the sensing device comprises a refrigerating chamber temperature sensor, a freezing chamber temperature sensor and an evaporator temperature sensor; and a timing part arranged in the electrical control device comprises a compressor operation timer, a defrosting pre-preparation timer, an air return defrosting timer and an electrical-heated defrosting timer. The invention also provides an energy-saving defrosting control method of the air-cooled refrigerator. The energy-saving defrosting control method comprises the following steps of: entering a defrosting program; performing defrosting pre-preparation; performing air return defrosting; performing electrical-heated defrosting; and finishing defrosting. According to the air-cooled refrigerator and the air return defrosting control method thereof provided by the invention, signals of each sensor can be received by the electrical control device, the state of each timer can be monitored, fine control over a compressor, a fan and the like can be realized, over-high temperature of a refrigerating chamber, caused by air return defrosting, is prevented, a preservation effect of the refrigerator is reduced, and meanwhile, a closed-loop type poor working process is prevented.

The invention discloses a defrosting method of a multi-combination type air conditioning unit. The defrosting method comprises that starting operation is carried out, temperature T0 of a frosted side of a coil pipe of an outdoor heat exchanger (1) of each outdoor machine is measured, when T0 of a certain outdoor machine is judged to be lower than -12 degrees, an air conditioning main controller sends a defrosting command to start to defrost the outer machine, reversing direction is carried out on a four-way reversing valve (2) and rotation of an outdoor fan is stopped at the same time, the outer fan is operated in an inverted mode, when a defrosting temperature sensor of the outdoor machine for carrying out defrosting detects temperature of a defrosting side of the coil pipe of the outdoor heat exchanger (1) of the outdoor machine to be larger than or equal to 12 degrees, defrosting is finished, after frequency of an inverter compressor (3) of the outdoor machine is reduced to reversing frequency, the frequency is kept being operated for 10 seconds, then the four-way reversing valve (2) is reversed in direction, and the whole air conditioning unit is switched back to be operated in a heating mode. The defrosting method is short in defrosting time, high in defrosting efficiency and rapid in defrosting speed.

The invention provides a VRV (Varied Refrigerant Volume) air conditioning system. The VRV air conditioning system comprises a heat accumulator working pipeline respectively communicated with a VRV liquid refrigerant pipeline and a VRV gaseous refrigerant pipeline; a heat accumulator, a heat accumulator electronic expansion valve and a heat accumulator electromagnetic valve are arranged on the heat accumulator working pipeline. A first four-way valve is arranged among the gaseous refrigerant pipeline, an air suction port and an exhaust port of a compressor and a communicating pipe, a second four-way valve is arranged between an outdoor unit heat exchanger and the communicating pipe, and meanwhile a first defrosting pipeline and a second defrosting pipeline are respectively arranged between the second four-way valve and the heat accumulator working pipeline and between the second four-way valve and the gaseous refrigerant pipeline. When frosting of the system needs defrosting, the heat for defrosting is supplied by an indoor unit and the heat accumulator together so as to reduce the influence of defrosting process on the indoor side, so that the defrosting time is shortened, and the heating effect of the indoor side is guaranteed. The invention further provides a VRV air conditioning defrosting control method.

A refrigeration cycle apparatus 100 includes a first compressor 101, a second compressor 102 provided in parallel with the first compressor 101, a radiator 103 for cooling a refrigerant compressed by the compressors 101 and 102, an expander 104 for recovering power while expanding the refrigerant cooled by the radiator 103, an evaporator 105 for evaporating the refrigerant expanded by the expander 104, a rotation shaft 123 connecting the first compressor 101 to the expander 104 so that the first compressor 101 uses the power recovered by the expander 104, a controller 112 for executing a control including a step of increasing a flow rate of the refrigerant gradually during a defrosting operation in which frost formed on the evaporator 105 is melted by allowing the refrigerant having a high temperature to flow through the evaporator 105.

The invention provides an air-conditioner and a control method of the air-conditioner. By means of the air-conditioner, heating capacity of low-temperature heating and outdoor frosting state of the air-conditioner can be improved and defrosting time can be shortened, therefore, indoor room temperature fluctuation can be decreased when the air-conditioner is defrosted, operating reliability of a compressor can be improved when the air-conditioner is defrosted, cost is reduced, and the conventional air-conditioner can be refitted. The invention has the technical scheme that: the air-conditioner is provided with a refrigerant circulating system, wherein the refrigerant circulating system comprises the compressor, a four-way valve, an outdoor heat exchanger, an indoor heat exchanger, a refrigerant pipeline and a refrigerant heater, and the refrigerant heater is arranged on a section of an E pipe of the four-way valve. The refrigerant heater in the invention is directly installed on the section of the E pipe of the four-way valve or a section of a refrigerant pipe between the four-way valve and a wind pipe stop valve, and components with mutually interferential control modes are reduced by the refrigerant heater. The system control is reliable, mutually interferential phenomenon is avoided, operating reliability of the whole air-conditioner is improved, the structure is simple and the cost is reduced.

The invention relates to an air conditioner, aiming at shortening the time for defrosting while defrosting and heating are simultaneously proceeded to ensure the indoor comfort. In case of starting the defrosting for an outdoor heat exchanger during the heating, a part of a main loop switch valve (713) and a bypass switch valve (715) is under switch control, other outdoor heat exchangers (732,733, 734) are used to implement defrosting and heating operation while a part (713) of the outdoor heat exchanger (73) is defrosted, and heating operation is resumed subsequent to repeatedly implementing defrosting and heating operation on all the outdoor heat exchanger sequentially by means of control, in addition, upon the ending of the defrosting and the heating operation, the outdoor exchanger with large frost-covering amount is detected and judged, the main loop switch valve and the bypass switch valve of this outdoor exchanger are subjected to switch control, and other outdoor heat exchangers are used to implement restrictive defrosting and heating operation while the defrosting only for this outdoor heat exchanger is implemented.

The invention provides a defrosting control method for an air conditioner. The air conditioner comprises a compressor, a first four-way valve, an indoor heat exchanger, a throttling device, an outdoor heat exchanger, a refrigerant pipeline, a second four-way valve, an electromagnetic valve and a heat storage device. When the air conditioner is in heating operation, the first four-way valve and the second four-way valve are both converted into a heating mode, a heat storage mode for the heat storage device is controlled to be started and stopped by controlling the on-off state of the electromagnetic valve, and heat stored by the heat storage device is used for achieving a heat source provided when heating and defrosting are simultaneously conducted. When the air conditioner is in defrosting operation, the first four-way valve is kept in the heating mode, the second four-way valve is converted into a refrigerating mode, the electromagnetic valve is opened, refrigerant gas sprayed by the compressor is divided into two branches, the refrigerant gas exhausted by the compressor simultaneously flows to the indoor heat exchanger and the outdoor heat exchanger, in the defrosting process, refrigerant simultaneously flows to the indoor heat exchanger and the outdoor heat exchanger, certain heat exists on the indoor side, cold radiation is not generated, and user comfort is greatly improved.

The present invention to an energy-storing phase change material and energy-stored air source heat pump defrosting system, belonging to the field of refrigeration equipment technology. The chemical component of said energy-storing phase change material is formed from CaCl2.6H2O and nucleating agent. Said invention also provides the concrete structure of said system. Said system can implement the function conversion from system heat production, waste heat energy storage, energy-releasing defrosting and heat production.

The invention provides a multi-unit defrosting control method which comprises steps as follows: firstly, whether an indoor unit is in a starting up state is judged; whether the indoor unit executes a topspeed defrosting function is judged during starting up, if yes, an auxiliary electric heating function is started, a fan of the indoor unit is controlled to work, and otherwise, treatment is performed in a conventional defrosting manner; and whether the topspeed defrosting function is started and executed during shutdown is judged, if yes, the auxiliary electric heating function is started, the fan of the indoor unit is controlled to work, and otherwise, treatment is performed in a conventional defrosting manner. With the adoption of the control method of multiple units, when an air conditioning system operates for heating, if an outdoor unit meets the defrosting condition, the system enters the topspeed defrosting mode, heat is continuously obtained by starting electric heating and the fan, the defrosting time is shortened, and the thermal comfort experience of a user is guaranteed. The invention further provides a multi-unit defrosting control system and a multi-unit air conditioner.

The invention relates to a stepped refrigerating system for recovering oil gas, which comprises a primary refrigerating system, a secondary refrigerating system and a tertiary refrigerating system, wherein the primary refrigerating system is connected with the secondary refrigerating system connected with the tertiary refrigerating system. The invention has the benefits that a refrigerant in a hot steam manner is directly used for performing the phase change defrosting (hot freon defrosting), and the energy efficiency ratio is high. Since the hot freon defrosting is carried out in a heat exchanger, so that the heat transfer speed and the defrosting speed are high, the defrosting time of a primary oil gas condenser and a secondary oil gas condenser is within 15 minutes, and the defrosting time of a tertiary oil gas condenser can also be within 30 minutes. The defrosting time is saved greatly.

A refrigerator in which evaporators for refrigerating a plurality of compartments are integrally formed and pipes are easily connected with the evaporator. The refrigerator includes a main body including a first compartment disposed at an upper side thereof and a second compartment disposed at a lower side thereof and separated from the first compartment, and an evaporator in which a first refrigerating part installed in the first compartment is integrally connected with a second refrigerating part installed in the second compartment by a connection pipe. An inlet pipe and an outlet pipe of the evaporator are disposed to one of the first refrigerating part and the second refrigerating part, and the connection pipe extends from the lower side of the second refrigerating part and is connected with the upper side of the first refrigerating part.

The invention discloses a defrosting control method of an air conditioning system. The method comprises the following steps: when a defrosting mode of the air conditioning system is operated, an outdoor environment temperature and a coil temperature of an outdoor heat exchanger are obtained; and a defrosting operation frequency of a compressor of the air conditioning system is dynamically adjusted according to the outdoor environment temperature and the coil temperature of the outdoor heat exchanger. The invention further discloses an air conditioning system and a computer readable storage medium. When the defrosting mode of the air conditioning system is operated, the operation frequency of the compressor is dynamically adjusted according to the outdoor environment temperature and the coil temperature of the outdoor heat exchanger, so that the defrosting time is shortened, and the heating comfort of the air conditioning system is improved.

The invention relates to a fin type evaporator which comprises a fixed plate, single column or multiple columns of refrigerant coil pipes mounted on the fixed plate and a plurality of fins sheathed on the refrigerant coil pipes, wherein a groove is formed on each fin, a heater pipe clamp for defrosting is mounted in each groove, and each fin is provided with a hem for stably clamping a heater pipe along the edge of the groove. The invention further relates to a refrigerator using the evaporator. The fins of the evaporator are provided with the hems for clamping the heater pipes along the edges of the grooves, and the arrangement of the hems change the traditional line contact to the surface contact, thereby reducing the heat transfer resistance between the heater pipes and the fins, shortening the defrosting time, saving the defrosting energy consumption of the evaporator and mounting the heater pipes on the evaporator more firmly.

The invention discloses a two-box type impact testing box. A hanging basket between a high-temperature box and a low-temperature box is moved to transfer a test sample and a room-temperature box does not need to be arranged, so that the defrosting time can be shortened, the consumption of electric quantity is reduced and the testing cost is saved; inner walls of the high-temperature box and the low-temperature box are respectively provided with a heating device and a refrigerating device; the circulation of air flow is driven by an impeller; the air flow rapidly and circularly flows to realize the effect of rapidly heating the test sample or refrigerating the test sample; an impeller, one heating device, an evaporator, a regenerator and the like are all located on the side wall of the high-temperature box or the low-temperature box; a motor drives the impeller to rotate to drive the air flow to flow in the front and rear direction of the box body; the air flow can rapidly flow and the distribution of the air flow is uniform so as to reduce the formation of frost and realize a long-time defrosting-operation-free circulating continuous test; a driving device for moving the hanging basket is arranged in a refrigerator cabinet rather than in the low-temperature box, so as to avoid influences on the driving device by the low temperature and rapidly move the hanging basket; the safety is high.

When using refrigerator running effectively and produces heat is discharged into the external and external of the heat, reduce the required power and defrosting defrosting time. A refrigerator (1) is provided with a cold chamber (2), freezing chambers (4, 5), a cooler (12) which can generate cool air for cooling the cold chamber and the freezing chambers, and refrigeration cycle of a compressor (24). The invention also includes a fan (9) in the refrigerator for transferring cooling air to at least any one of the cold chamber and freezing chambers, an electric heater (22) which is configured below the cooler, the air whose temperature arises through circulation in the cold chamber, antifreeze solution which saves the heat generated by the compressor or the outside air, and a control unit (66) which controls a circulating pump (51) which makes the fan in the refrigerator or the antifreeze solution to circulate. During the process of defrost operation, the control unit utilizes the heat from the circulated air in the cold chamber or the compressor or the outer air to heat the cooler besides using the heater to heat the cooler.

The invention discloses a heat pump system and a defrosting control method thereof. The heat pump system comprises a compressor, a four-way valve, an outdoor heat exchanger, an indoor heat exchanger and a heating device. The outdoor heat exchanger is a micro-channel heat exchanger; and during system defrosting, the heating device can heat at least one header pipe of the micro-channel heat exchanger. According to the heat pump system, defrosting is even, the defrosting efficiency can be improved, the system can still heat the indoor space in the defrosting process, the temperature variation amplitude of the indoor side in the defrosting process is reduced, and the system comfort and the defrosting efficiency are improved.

The invention discloses a defrosting system of an air cooling refrigerator and a defrosting control method of the defrosting system of the air cooling refrigerator. The defrosting system of the air cooling refrigerator comprises an evaporator, electric heating tubes, a controller, an evaporator temperature sensor, a water pan and a freezing chamber temperature sensor, one or more electric heating tubes are fixed to a heat exchange tube of the evaporator and connected with the controller, the evaporator wall face temperature sensor is arranged on the surface of the heat exchange tube of the evaporator and connected with the controller, the freezing chamber temperature sensor is installed on the inner wall of an air cooling refrigerator freezing chamber and connected with the controller, and the water pan is arranged under the evaporator. According to the control method of the defrosting system of the air cooling refrigerator, the controller is adopted to detect the temperature of the wall face of the evaporator and the temperature of the freezing chamber, and the detected temperatures are combined with the accumulated running time of a compressor or the total running time of the compressor to judge whether defrosting should be performed or not; when the temperature of refrigerant in the heat exchange tube T>=T3 or the defrosting time t>=t2, the defrosting process is stopped; when defrosting water is discharged out of the refrigerator, the refrigerator is started again to enter the next refrigerating circulation. According to the defrosting system and the defrosting method, defrosting is uniform, the defrosting time is shortened, the electric heating defrosting efficiency is improved, and energy consumption of the refrigerator is reduced.

The invention relates to an air source heat pump system, which comprises two injection enthalpy-increasing air source heat pump subsystems and two triple-sleeve heat exchangers. A refrigerating loop starts from an outlet of an indoor heat exchanger of each subsystem, runs through a flow regulating valve and enters a suction opening of a compressor via the triple-sleeve heat exchanger, a first throttling valve, an outdoor heat exchanger and a first gas and liquid separator of the subsystem; and an air supplementing loop is branched at the outlet of the indoor heat exchanger of each subsystem and enters an air supplementing opening of the compressor of the subsystem via a second throttling valve, the triple-sleeve heat exchanger and a coupling subsystem triple-sleeve heat exchanger of the subsystem. By the aid of the coupling injection enthalpy-increasing air source heat pump system, problems that heat cannot be supplied continuously during defrosting in a low-temperature environment and defrosting time is long are solved, energy is reasonably utilized, heat required by defrosting is increased, and problems that the quantity of accumulated liquid refrigerating working media generated by an outdoor heat exchanger of a defrosting subsystem is increased, a compressor is impacted by liquid and the like are solved.

The invention discloses an air conditioner and a defrosting method thereof. The air conditioner comprises a heat exchange system and a control system, wherein the heat exchange system comprises a compressor, a four-way valve, a first indoor heat exchanger, a second indoor heat exchanger, a throttling device, a first outdoor heat exchanger and a second outdoor heat exchanger, wherein an indoor unit adapter of the four-way valve is connected with the inlet pipe of the first indoor heat exchanger and / or the inlet pipe of the second indoor heat exchanger, and an outdoor unit adapter of the four-way valve is connected with the outlet pipe of the first outdoor heat exchanger and / or the outlet pipe of the second outdoor heat exchanger; and the outlet pipe of the first indoor heat exchanger and the outlet pipe of the second indoor heat exchanger are connected with the inlet pipe of the first outdoor heat exchanger and / or the inlet pipe of the second outdoor heat exchanger through the throttling device, the outlet pipe of the first outdoor heat exchanger is connected with the inlet pipe of the second outdoor heat exchanger, and the outlet pipe of the second outdoor heat exchanger is connected with the inlet pipe of the first outdoor heat exchanger. By adoption of the air conditioner and the defrosting method thereof, the indoor comfort degree is guaranteed, and meanwhile, the defrosting efficiency of the air conditioner is improved.

The invention belongs to the field of air conditioners, and relates to an air-conditioner outdoor unit hood with a defrosting structure, in particular to an air-conditioner outdoor unit capable of quickly defrosting. Due to more strong winds in winter, a large amount of heat is brought away by air flow, air-conditioner outdoor units are all mounted on the walls, temperature of one sides of the air-conditioner outdoor units are very low due to air current flow between the outdoor units and the walls, water is enabled to be frosted or frozen again by the strong winds when frost is molten into flow downwards along heat exchangers, consumed electrical energy is increased, and time for defrosting is prolonged. A steady-flow insulation cavity with the upper end closed is arranged on one side of a heat exchanger of an outdoor unit (1), transverse flow of air on two sides of the steady-flow insulation cavity is prevented through air blocking structures, and the rear side and / or the lower side of the steady-flow insulation cavity is provided with an opening serving as an air inlet of the outdoor unit (1). Hot air in a defrosting are is effectively prevented from escaping upwards by the steady-flow insulation cavity, air current flow is reduced, insulation effect is good, defrosting speed is increased, and heating effect and comfort of an air conditioner are improved.

The invention relates to the technical field of an air conditioner defrosting and provides an air conditioner outdoor unit defrosting method. When the refrigeration mode is selected to perform defrosting, firstly an indoor fan stops operating to enable residual heat of an indoor heat exchanger to completely act on a refrigerant recycling back; when the temperature of the indoor heat exchanger is reduced to be lower than the indoor temperature, the indoor fan is started, indoor heater air is utilized to conduct convective heating on the indoor heat exchanger, and the indoor fan stops operating to prevent somatosensory cold air enabling human to obviously feel cold from being produced till the temperature of the indoor heat exchanger is reduced to reach a cold air preventing temperature threshold. In the whole defrosting process, the residual heat of the indoor heat exchanger is fully utilized, the indoor air heat is further properly utilized, accordingly the defrosting time is overall shortened, the defrosting efficiency is improved, and the overall energy efficiency ratio of an air conditioner is also improved.

The invention relates to an air conditioner, comprising indoor unit and outdoor unit. Indoor heat exchanger and air supply apparatus are set in the indoor unit. Thereinto, there is at least a heating device in the indoor device and the heating device runs during defrosting of said air conditioner. The heating device is set at the upstream or downstream of indoor heat exchanger. The invention provides a control method of air conditioner. The method comprises defrosting of air conditioner when achieving the condition of defrosting and running of heating device at least when said air conditioner defrosts. The air conditioner and the control method of invention can shorten the defrosting time and make the indoor temperature not decrease. Furthermore, it can make the temperature in door improve quickly under the low temperature.