2212results about "Noise suppression" patented technology

The invention discloses an air conditioning system and a control method thereof. The air conditioning system comprises an air conditioning outdoor unit; the air conditioning outdoor unit comprises a compressor, an outdoor heat exchanger and an outdoor fan; the outdoor fan is at least provided with a first working mode and a second working mode; and when the outdoor fan runs in the first working mode, a wind gear is higher than that when the outdoor fan runs in the second working mode. The control method comprises the following steps that S1, the air conditioning system is controlled to enter arefrigeration mode; S2, according to the outdoor environment temperature and / or preset hours, the outdoor fan is controlled to enter the first working mode or the second working mode. According to the control method of the air conditioning system, the air conditioning system can control the outdoor fan to enter the first working mode or the second working mode according to the outdoor environmenttemperature and / or the preset hours, and when the outdoor fan runs in the second working mode, the wind gear of the outdoor fan is lowered, so that the use reliability the air conditioning system cannot be affected, and the requirement of a user on comfortableness can be met.

The invention provides an intelligent adjustment method for distributed air treatment equipment, and belongs to the technical field of air treatment equipment, and the method comprises the steps: inputting a personnel distribution image into an airflow field reconstruction model based on a graph neural network, outputting three-dimensional space flow field distribution data, calculating a personnel intensity index, and predicting an average thermal sensation index value; an air supply adjustment double-layer game model is established based on the data, the air supply angle and the air supply speed of an electric side supply nozzle and the air supply quantity of a lower air supply outlet are solved, an actuator is controlled to adjust air supply parameters, and the target air outlet temperature and the refrigerant flow of the heat exchanger are calculated through a thermodynamic entropy production minimization heat exchange optimization algorithm; and feedback correction is performed according to the actually predicted average thermal sensation index deviation to form closed-loop control, so that the technical problem that the distributed air treatment equipment is difficult to adjust the air supply parameters in real time according to the personnel distribution dynamic change so as to ensure the thermal comfort and the energy efficiency at the same time is solved.

The utility model relates to an air duct structure and a cabinet machine in the technical field of air conditioners, the air duct structure comprises a main air duct, a fan, an air outlet frame and a grating, the grating is installed between the air outlet end of the main air duct and the air outlet frame, airflow in the main air duct contacts with the grating in the flowing process, the grating scatters eddy current, and the air outlet end of the main air duct is connected with the air outlet frame. Air flow blown out of the main air duct passes through the grille and then is blown to the air outlet frame, the pressure difference between the air flow and the air outlet frame is reduced, air outlet is smoother, and therefore abnormal sound is effectively eliminated. The installation position of the grille can effectively scatter the vortex area, meanwhile, installation operation of the grille is more convenient, the installation position is easy to operate, additional positioning pieces do not need to be added in the air duct to fix the grille, the grille only needs to be directly connected to the lower side of the air outlet frame or the upper side of the air outlet end, and the installation operation is convenient. The additional positioning piece is omitted, so that the smoothness of the air cavity of the main air duct is further improved, and the air resistance of the air cavity is reduced.

The invention relates to the technical field of household appliances, and discloses a refrigeration range hood which comprises an air conditioner assembly, a refrigeration assembly and a control assembly. The range hood assembly is arranged below the air conditioner assembly and comprises an air cabinet and a range hood fan, a condensation air opening is formed in the air cabinet, and the condensation fan is connected with the condensation air opening; the range hood fan is arranged in the air cabinet; the flow guide partition plate is arranged in the air cabinet, the flow guide partition plate is matched with the inner wall of the air cabinet to form a flow guide cavity, the air inlet end of the flow guide cavity is communicated with the condensate air opening, the air outlet end of the flow guide cavity is communicated with an air inlet of the range hood fan, and the flow guide partition plate comprises an extension section and an air guide section which are sequentially arranged from top to bottom; the air guide section extends to the side wall of the air cabinet from the bottom edge of the extension section. According to the refrigeration range hood, wind resistance can be reduced, the air volume can be increased, and noise reduction is facilitated.

The invention provides a flow guide ring structure, a fan assembly, an air conditioner and a noise reduction control method thereof.The flow guide ring structure comprises a flow guide ring, a noise reduction unit is arranged on the periphery of the flow guide ring, the noise reduction unit comprises a first sound absorption assembly, and the first sound absorption assembly comprises a first shell cover, a first partition plate and a first movable plate; the first shell cover covers the peripheral face of the flow guide ring to form a first cavity, the first cavity is divided by the first partition plate into a first sound absorption cavity and a second sound absorption cavity, the first sound absorption cavity and the second sound absorption cavity are different in size, and a plurality of first communicating holes are formed in a first perforated plate section of the first partition plate in a penetrating mode. The first movable plate is movably arranged on the first perforated plate section so as to adjust the number of the shielded first communicating holes. According to the flow guide ring structure, self-adaptive adjustment and noise reduction can be carried out according to the change of the operating parameters, so that noise of different frequencies generated under different operating parameters is effectively reduced, the frequency range of effective noise reduction is widened, the noise reduction effect is improved, and the mute experience comfort of a user is improved.

The invention provides an attenuator for ducted air flow systems such as heating, ventilation and air conditioning systems arranged to direct the airflow into the attenuator by reducing the airflow path geometry into a central channel surrounded by absorbing material to damp resonant modes to reduce noise more uniformly across the desired frequency spectrum than resistive attenuators.

The utility model provides a humidifying device and an air purifier. The humidifying device comprises a water tank, a wet curtain assembly and a water level monitoring and water path module, the water level monitoring and water path module comprises a separation cover arranged in the water tank and provided with a separation cavity extending from the bottom of the separation cover to the top of the separation cover, and a water inlet used for communicating the separation cavity with the water tank is formed in the bottom of the separation cover; a water return port communicated with the separation cavity is formed in the top of the separation cover, so that redundant water of the wet curtain assembly flows back to the separation cavity through the water return port; the water level monitoring assembly is arranged in the separation cavity and used for monitoring the water level in the separation cavity; the water pump is arranged in the partition cavity and used for feeding water in the partition cavity into the wet curtain assembly. According to the humidification device, redundant water of the wet curtain assembly flows back into the separation cover, due to the fact that the space in the separation cover is small, the redundant water can flow along the inner wall of the separation cover more easily, water surface fluctuation caused by splashing is avoided, and then the monitored water level is accurate.

A fan assembly has a substantially centrifugal outlet, an axial intake, an airflow channel extending substantially perpendicular to the axial intake, and a guide element for redirecting airflow adjacent the axial intake. The axial intake is spaced apart from a back wall of the airflow channel by a first distance, and the guide element is positioned between the axial intake and the back wall of the airflow channel, or the guide element comprises a back surface of the fan assembly. The airflow from the airflow channel then passes through the guide element to enter the axial intake.

The utility model provides an obliquely-installed air duct of a mobile air conditioner, which comprises a shell serving as an installation carrier, and the shell is hollow and forms an installation cavity; the volute assembly is obliquely arranged in the mounting cavity, the volute assembly comprises an upper volute assembly and a lower volute assembly located below the upper volute assembly, an upper volute cavity and a lower volute cavity are formed in the upper volute assembly and the lower volute assembly respectively, the upper volute cavity and the lower volute cavity are coaxially arranged, and the axis of the upper volute cavity and the axis of the lower volute cavity incline to the horizontal plane; the side wall of the upper volute cavity is provided with an exhaust channel, the exhaust channel extends upwards, is in butt joint with a first air outlet in the top of the shell and is used for discharging air, an evaporator is arranged on an air inlet path of the upper volute cavity, and a condenser is arranged on an air inlet path of the lower volute cavity. The inclined air duct of the mobile air conditioner is compact in structure, small in size, low in manufacturing cost and use cost, convenient to assemble, high in air outlet speed, long in air supply distance, low in working noise and good in use effect.

The invention discloses a silencer, an air conditioner and a design method of the silencer, the silencer comprises a shell and a plurality of acoustic units arranged in the shell, and the shell is mounted on the outer wall of an air duct and provided with a mounting surface facing the air duct; the acoustic unit comprises a plurality of half-wavelength pipes, each half-wavelength pipe is provided with an extended first acoustic channel, and a first inlet and a first outlet of each half-wavelength pipe are formed in the mounting surface; wherein the first acoustic channel lengths of the plurality of half-wavelength tubes are set based on different target noise reduction frequencies so as to cover a predetermined noise reduction frequency band. The silencer is installed outside the air duct through the shell, it is guaranteed that the original circulation area and shape of the air duct are not affected at all, and therefore the 100% ventilation rate is achieved, and the core contradictions that the air volume is sacrificed and the performance of an air conditioner is reduced when a traditional noise reduction device is additionally installed are solved. Secondly, according to the scheme, the resonance sound absorption principle of a series of half-wavelength tubes is utilized, and the principle has an excellent control effect on low-frequency noise.

The invention relates to the technical field of air conditioners, and discloses a noise reduction method for a multi-connected air conditioning system, which comprises the following steps: acquiring high pressure and low pressure of the air conditioning system under the condition that a compressor is started according to a preselected frequency; and the opening degree of an indoor electronic expansion valve corresponding to the started indoor unit is controlled according to the high pressure and the low pressure of the air conditioning system. According to the method, the pressure difference before and after the indoor electronic expansion valve can be adjusted to a proper range, so that the refrigerant turbulence degree is reduced, the noise generated in the starting stage of the air conditioning system is reduced, and the noise reduction effect of the air conditioning system is improved. The invention further discloses a noise reduction device for the multi-connected air conditioning system, the multi-connected air conditioning system and a computer readable storage medium.

The utility model relates to the technical field of air conditioning, and discloses a volute assembly for an air conditioner and the air conditioner. The air conditioner comprises a cross-flow fan and a heat exchanger, the volute assembly for the air conditioner comprises a volute, an air outlet channel is defined, an inlet of the air channel is suitable for communicating with the cross-flow fan, and an outlet of the fan is suitable for communicating with the heat exchanger; the volute tongue is arranged in the air duct; wherein the volute tongue is detachably connected with the volute. The volute tongue is detachably connected with the volute, so that the volute tongue can be independently detached, installed and replaced, the volute and the volute tongue can be independently produced and machined, the situation that the whole volute cannot be used due to machining errors of the volute tongue can be avoided, the machining complexity and difficulty are reduced, and the machining cost of the volute and the volute tongue is also reduced.

The invention provides an air conditioner control method, an air conditioner and a storage medium. The method comprises the steps that thermal data, user state data and air quality data of a current indoor space are obtained in real time; according to the heating power data, the user state data and the air quality data, air supply grade area division is conducted on the current indoor space, and air supply grade area data are obtained; obtaining a computational fluid dynamics simulation model database matched with the current indoor space; predicting based on a computational fluid dynamics simulation model database by utilizing a preset air supply strategy model according to the thermal data, the user state data, the air quality data and the air supply grade area data, and generating a current air supply strategy; and the air conditioner is controlled according to the current air supply strategy. By applying the air conditioner control method, the precision of the air supply strategy can be improved, and the air supply effect is optimized.

The utility model relates to the field of air conditioner air outlet devices, in particular to a central air conditioner air outlet noise reduction device which comprises an air receiving barrel, a bucket-shaped air expanding cover, an air outlet cover, a noise reduction frame, an air direction guiding frame and a protection frame. A hopper-shaped air expanding cover is arranged at the lower end of the air receiving barrel, an air outlet cover is arranged at the lower end of the hopper-shaped air expanding cover, an embedded groove is formed in the end, away from the hopper-shaped air expanding cover, of the air outlet cover, and a noise reduction frame, an air direction guiding frame and a protection frame are sequentially arranged in the embedded groove. According to the air conditioner air outlet device, noise generated by airflow resonance is effectively reduced through the air expansion flow guide design of the hopper-shaped air expansion cover and the sound absorption cotton plate filling of the sound attenuation and noise reduction frame, airflow can be evenly and softly blown to a room through the design of the air direction guide frame, and the problems that airflow in a traditional air conditioner air outlet device is too strong and uneven in distribution are solved.

The invention relates to the technical field of air conditioner noise reduction, in particular to a combined type noise reduction device suitable for electromechanical air conditioner equipment, which comprises a noise reduction component, the noise reduction component comprises an outer noise reduction cover and an inner noise reduction cover, and a flow guide channel is arranged between the outer noise reduction cover and the inner noise reduction cover. The noise reduction inner cover is composed of a plurality of deformable noise reduction plates. The flow guide channel is divided into a plurality of resonant cavities through the silencing parts; the following rotation assembly and the linkage piece are connected, the linkage piece is connected to a rotating shaft of the cooling fan, and the following rotation assembly rotates reversely through the linkage piece. The following rotation assembly changes along with the rotating speed of the fan, the extrusion piece is driven by centrifugal force to generate gradient type radial displacement, the noise reduction inner cover is dynamically extruded, and the size of a resonant cavity is changed; and when the fan runs at a high speed, the resonant cavity becomes smaller so as to adapt to the high-frequency noise.

The utility model relates to a Fab clean room hot exhaust air recovery processing emergency linkage system, which belongs to the technical field of clean room gas circulation and comprises a fresh air inlet pipe, a fresh air supply outlet, a fan filter unit and an exhaust pipe communicated with the outside of a clean room. The recovery pipe is sequentially provided with a circulating fan capable of pumping away hot exhaust air, a cooling mechanism and an air return pipe, the cooling mechanism is a dry coil cooler or a gas-gas heat exchanger or a cold clean gas mixing type cooler, and the system further comprises an automatic control device. The clean air is conveniently recycled, the burden of supplementing fresh air in a clean room is reduced through the recycled clean air, the operation cost of humidity control of a heating ventilation air conditioner is reduced, the cost of cleaning treatment on air is also reduced, and then the production cost is greatly reduced.

The utility model discloses an air duct structure and an air curtain machine. The air curtain machine comprises a shell, an air duct structure and a wind wheel structure. The shell is provided with an air inlet and a wind wheel chamber, and the air inlet is communicated with the wind wheel chamber. The air duct structure is provided with an air inlet end and an air outlet end, and the air inlet end communicates with the wind wheel chamber; the air duct structure comprises two air duct side plates which are arranged in a spaced mode. The air duct side plate comprises a protruding part and two connecting parts, the connecting parts are fixed relative to the shell, the protruding part is arranged between the two connecting parts, the protruding part protrudes towards the inner side of the air duct structure, and the protruding part and the connecting parts are in arc smooth transition. The wind wheel structure is rotationally installed in the wind wheel chamber and used for driving air to flow from the air inlet to the air duct structure. According to the air duct side plate, by arranging the protruding parts, air can be guided, transition of air flow is smoother, the air can be prevented from directly colliding with the inner side wall of the air duct side plate, after collision is reduced, vortex generation can be restrained, and therefore noise generation can be reduced.

The invention discloses an air conditioner indoor unit, and belongs to the technical field of air conditioners. The air conditioner indoor unit comprises a shell, an impeller, a heat exchanger, a volute and a volute tongue, an air inlet channel is formed between the volute tongue and the shell, and an impeller mounting cavity and an air outlet channel are formed between the volute and the volute tongue; the impeller is arranged at the impeller mounting cavity, the impeller is used for driving airflow to sequentially pass through the air inlet duct and the impeller mounting cavity to form outlet airflow, and the outlet airflow comprises backflow airflow which flows back to the impeller after being shunted at the volute tongue and air outlet airflow flowing to the air outlet duct; the air outlet airflow exchanges heat with the heat exchanger; a gap flow channel is formed in a gap between the volute tongue windward side of the volute tongue and the impeller; the volute tongue is provided with a drainage channel, and the drainage channel is used for guiding a part of backflow airflow to the gap flow channel. According to the air conditioner indoor unit, the pressure resistance of the cross-flow fan can be improved.

The invention discloses a muffling device, an air conditioner and a muffling control method.The muffling device comprises a shell, an acoustic metamaterial structure and a sound conduction interface, the acoustic metamaterial structure is arranged in a muffling cavity of the shell and is constructed to be a continuous swirling flow channel capable of prolonging a sound wave propagation path in the muffling cavity, and the sound conduction interface is arranged in the shell; the sound conduction interface is arranged at the joint of the shell and the valve pipe. Noise firstly enters the shell through the sound conduction interface, so that sound wave reflection loss is avoided; in the silencing cavity, the continuous swirling flow channel of the acoustic metamaterial structure forces the propagation path of sound waves to be greatly prolonged in a limited space, so that low-frequency resonance noise is effectively inhibited; meanwhile, a physical closed environment provided by the shell isolates external aging factors, and the problems that a traditional rubber damping material loses efficacy due to hardening and the performance of sound insulation cotton is degraded are solved; according to the invention, the risk of new resonance caused by frequency deviation is fundamentally avoided, and synchronous control and long-term reliable noise elimination of low-frequency noise are realized.

To provide an outdoor unit of an air conditioner capable of effectively suppressing stagnation and diffusion of a flammable refrigerant in a machine chamber for a long period of time when the flammable refrigerant leaks.SOLUTION: An outdoor unit 100 of an air conditioner comprises a compressor 2 that compresses a refrigerant, a heat exchanger 4 that exchanges heat between the refrigerant and outside air, and a blower fan 8 that blows outside air to the heat exchanger. The refrigerant is a flammable refrigerant (for example, propane, ethane, isobutane, or the like). A machine chamber 120 in which the compressor 2 is installed, comprises a removable or replenishable adsorbent (for example, activated carbon, zeolite, or the like) that adsorbs the flammable refrigerant. The adsorbent may be integrated with a soundproof material surrounding the compressor 2, housed in a removable container installed in the machine chamber 120, or applied onto an inner surface of the machine chamber 120.SELECTED DRAWING: Figure 3

The invention relates to the technical field of air purification equipment, in particular to an unpowered public place air directional flow purification structure. The problems that in the prior art, the natural ventilation principle and the multi-stage purification function cannot be fused on the structural design level, and consequently inherent defects exist in the aspects of energy consumption, noise, maintenance cost, airflow organization stability and the like are solved. The unpowered public place air directional flow purification structure is arranged on a wall unit and comprises a micropore physical pre-filtering structure, a multi-layer labyrinth type physical filtering structure and an adsorption / deposition structure which are integrally arranged in a closed mounting cavity in the wall unit. In the operation process of the structure, no fan or motor or external power supply is needed in the whole process, air circulation is driven by completely depending on the thermal characteristics of the wall and weak thermal buoyancy formed by an indoor environment heat source, no mechanical moving part exists in the operation process, the noise level is low, and the noiseless requirement of a hospital ward area at night is met.

The invention relates to the field of intelligent environment control, in particular to a method and system for controlling operation of air conditioning equipment and a storage medium. The method comprises the following steps: acquiring external sound; based on a voiceprint library of the air conditioning equipment, air conditioning equipment noise and environment noise are separated from the external sound in a frequency domain; setting, for each frequency in the spectrum of the external sound, a weight indicating a corresponding tolerance of noise at that frequency; on the basis of the set weight, whether the noise of the air conditioning equipment at the frequency affects the user experience or not is determined for each frequency; and when the noise of the air conditioning equipment at any frequency affects the user experience, operation of the air conditioning equipment is adjusted.

The disclosure relates to the field of ventilation systems, specifically to ventilation systems in residential and non-residential (commercial) buildings. Specifically, the invention relates to decentralized supply and extract units with waste heat recovery and can be used for transmitting heat and power from an extraction air flow, i.e. from a flow of air extracted from a building, to a supply air flow, i.e. a flow of fresh air being drawn into a building, for the purpose of replacing spent air from the building.

Disclosed in the present application are an indoor air-conditioning unit, and heating, ventilation and air-conditioning equipment. The indoor air-conditioning unit comprises a housing, a heat exchanger and an electric control box, wherein an air duct is provided in the housing, and the housing has a return air vent and an air outlet which are in communication with the air duct; the heat exchanger is arranged in the air duct and has an air intake face; and the electric control box is arranged in the air duct and located between the air intake face and the return air vent, and the electric control box has a first flow guide face configured such that at least part of the airflow in the air duct blowing towards an outer edge of the heat exchanger is directed to the air intake face. The indoor air-conditioning unit thus has reduced noise.

The invention discloses a fan noise control method, device and system and an air conditioner, and belongs to the field of fan noise control. The draught fan noise control method comprises the steps that when it is determined that the noise of a draught fan is unqualified, the noise peak frequency of the noise is obtained; determining the noise type of the noise based on the noise peak frequency; and the fan blade angle is adjusted based on the noise type. According to the scheme, when the fan noise is unqualified, different types of noise can be determined based on the noise peak frequency, and then the fan blade angle is adjusted by adopting different adjusting modes according to the different types of noise, so that when the noise is unqualified, the fan blade angle can be adjusted in a targeted manner based on the different types of noise, adjustment can be performed in time, and the fan blade angle adjusting efficiency is improved. And a sound wave generator is not needed, the cost is low, the method can be suitable for various use scenes, and the use experience of a user is not affected.

The invention relates to the technical field of fresh air system control, and discloses a self-adaptive fresh air adjusting method and device based on an air quality fusion model.The method comprises the steps that indoor air quality parameters, outdoor air quality parameters, personnel activity data and user operation records are obtained, normalization processing is conducted on original data, and time sequence characteristic data are extracted; inputting the time sequence characteristic data into an air quality fusion model based on a DBN network and an LSTM network, and predicting future indoor air quality through the air quality fusion model; user operation records are subjected to clustering analysis through a DBSCAN algorithm, output of the air quality fusion model is combined, and a personalized adjustment strategy is generated through a multi-target optimization algorithm; the personalized adjusting strategy is sent to a controller of the fresh air system, and the controller adjusts the fresh air system according to a received fresh air volume instruction; according to the method, the air quality prediction and adjustment precision is remarkably improved, and the personalized requirements of different users are better met.

The invention relates to air conditioning equipment and a control method of the air conditioning equipment, and relates to the field of air conditioners. The controller is configured to obtain throttling device configuration information of the air conditioning equipment under the conditions that refrigerant leakage happens to the air conditioning equipment and an initial risk frequency exists in a preset frequency range, the initial risk frequency is a compressor operation frequency which causes the abnormal state of the air conditioning equipment, and the compressor operation frequency is a compressor operation frequency which causes the abnormal state of the air conditioning equipment. The throttling device configuration information is used for representing whether the air conditioning equipment is provided with a throttling device or not; a refrigerant leakage detection strategy matched with the throttling device configuration information is determined; based on the refrigerant leakage detection strategy, the refrigerant leakage degree of the air conditioner equipment is detected; under the condition that the refrigerant leakage degree meets the refrigerant leakage condition, the initial risk frequency is adjusted to obtain a target risk frequency; and the operation duration of the compressor under the target risk frequency is controlled to be lower than a preset duration threshold value. According to the technical scheme, stable operation of the air conditioning equipment can be guaranteed.

An embedded filtering ventilator for a curtain wall relates to the technical field of indoor ventilation and comprises an adapting part, a filtering part arranged in the adapting part and a protection part arranged on the outer side of the adapting part. The equipment can adapt to preset spaces with different sizes of the curtain wall, and the utilization rate of the equipment is improved while the overall and smooth visual effect of the curtain wall is prevented from being damaged by the externally-hung ventilator; the equipment is installed indoors, installation is simple, indoor replacement and maintenance can be achieved, manpower is effectively saved, and the safety of workers is guaranteed; the equipment can effectively absorb noise, and the happiness in use is improved.

The invention relates to the field of air purification control, in particular to a mobile air purifier operation control method, system and equipment and a medium. The method comprises the following steps: acquiring environmental parameters through a multi-source sensor, generating a multi-dimensional operation parameter matrix by using a fuzzy control algorithm, planning an optimal moving path by using an improved AI algorithm according to spatial topology sensing data, and cooperatively adjusting related components through a PID controller. A night low-noise operation strategy, a specific algorithm calculation parameter, sleep stage identification, corresponding control and the like are provided, and a look-ahead control instruction set can be generated; the invention further comprises a corresponding operation control system, electronic equipment and a computer readable storage medium. The technical effects that the ambient air quality and the user state are accurately perceived, global coverage purification and multi-system parameter joint debugging of the air purifier are achieved, low-noise operation at night is achieved, the function is dynamically adjusted according to the sleep stage, and the air purification effect and the user use experience are improved are achieved.

The utility model discloses an air conditioner which comprises an indoor unit, the indoor unit comprises a machine shell, an indoor heat exchanger and a heat exchange fan, the heat exchange fan is arranged in a containing cavity and comprises a heat exchange fan, a first driving motor and a first buffering piece, and the first driving motor comprises a first stator and a first rotor. The first rotor is rotatably arranged on the outer side of the first stator, the heat exchange fan is located on one side, in the axial direction of the first rotor, of the first rotor, the first rotor is used for driving the heat exchange fan to rotate, and the first buffer part is connected to the heat exchange fan and the first rotor; the first buffering piece is located between the heat exchange fan and the first rotor in the axial direction of the first rotor. By the adoption of the scheme, the first buffering piece is arranged, the first buffering piece can transmit the rotating power of the first rotor to the heat exchange fan, meanwhile, the damping effect can be achieved between the first rotor and the heat exchange fan, and therefore noise generated when the heat exchange fan works can be reduced.