40results about How to "Improve air supply efficiency" patented technology

The utility model relates to the technical field of hairdressing devices, in particular to a handle wiring structure and a hairdressing device.The handle wiring structure comprises a handle shell, a front side fixing frame and a rear side fixing frame, the handle shell is provided with an installation cavity, and the front side fixing frame and the rear side fixing frame are arranged in the installation cavity and assembled and fixed together; the front side fixing frame and / or the rear side fixing frame are / is provided with a notch for a cable to penetrate through. Compared with the prior art, the front side fixing frame and the rear side fixing frame are arranged, and the front side fixing frame and / or the rear side fixing frame are / is provided with the notches, so that when each assembly is assembled, a cable can penetrate through the wire passing holes to be arranged on the outer sides of the front side fixing frame and the rear side fixing frame, and the cable is prevented from being clamped by the assembly in the assembly process; and therefore, the assembly difficulty of each component is reduced. Meanwhile, the cables are arranged on the outer sides of the front side fixing frame and the rear side fixing frame through the notches, the cables can be prevented from invading the air duct, and the air volume and the air supply efficiency of the air duct are improved.

The air return valve comprises an air valve outer frame, a fixing frame is fixedly arranged at an air outlet of the air valve outer frame, non-return partition plates are evenly distributed on the fixing frame along the circumference, the rotating side of each non-return partition plate is fixedly connected with a rotating shaft in the radial direction, and the rotating shaft is fixedly connected with an air inlet of the air valve outer frame. The two ends of the rotating shaft are correspondingly connected to the fixing frame or the air valve outer frame and the fixing frame through bearings respectively. An angle limiting plate is fixedly arranged on a bearing seat of the bearing away from the axis of the fixing frame. According to the non-return air valve, the flowing angle of airflow can be close to or the same as the opening angle of the non-return partition plate, the resistance when the airflow flows out is greatly reduced, and the exhaust efficiency is improved.

The utility model provides a kind of hanging air purifier, relate to air purifier technical field.A kind of hanging air purifier, comprising: shell, air inlet and air outlet are provided on shell;Support frame, support frame is set in shell, and first accommodating space is provided in support frame;Filter element, filter element is set in first accommodating space;Plasma generating device, plasma generating device is set in first accommodating space, and filter element is set between plasma generating device and air inlet;Wherein, plasma generating device includes first frame and multiple plasma generating modules set in first frame.By being provided with plasma generating device in hanging air purifier, air is further treated by sterilization, deodorization etc. after passing through physical filtration, improve purification efficiency, and plasma generating device uses modular design to use multiple plasma generating modules, facilitate flexible configuration.

The application discloses a kind of gas interference simulation device and method for gas alarm testing, belong to gas detection technical field, including detection box, gas alarm is placed in detection box, first gas inlet is opened in the top surface of detection box, exhaust port and the sealing plug that is adapted to the exhaust port are arranged in the side surface of detection box, multifunctional gas analyzer is fixedly installed in detection box, further including: interference device, interference device is fixedly installed in detection box, interference device is used to detect whether the alarm sound of gas alarm is emitted in each specified concentration under interference gas environment, methane is transported from first gas inlet to suction box, cylinder pushes first piston plate to extrude gas into first gas pipe and into detection box, multifunctional gas analyzer detects that methane concentration reaches (5000±50) ppm, whether gas alarm emits alarm signal is observed, then whether stop alarm after two minutes of emptying methane gas through exhaust port, to determine whether gas alarm is qualified.

The utility model relates to a ventilation equipment field provides a kind of air duct assembly, air conditioning system and vehicle.Wind channel component includes air supply device, air supply device includes wind box, and wind box is opened with air inlet and air outlet, air inlet is provided with filter piece, and the position corresponding with air inlet in wind box is provided with air guide piece;Distribution box, fluid communication is in air outlet, and distribution box is provided with valve group, and distribution box includes first air duct, second air duct and third air duct, first air duct is fluid communication with the driver's room of vehicle, second air duct is fluid communication with the traction motor cabin of vehicle, third air duct is fluid communication with the passenger room of vehicle, and valve group is used to distribute the air intake of first air duct, second air duct and third air duct.The air duct assembly can make the airflow output of each air duct stable, avoid the air supply fluctuation caused by external wind pressure variation, ensure the comfort of driver's room, passenger room and the heat dissipation effect of traction motor cabin, improve the reliability of vehicle operation, simplify the structure of air duct assembly.

The present invention belongs to the technical field of ventilation and air conditioning, and relates to a wall-attached air supply device of an integrated air purification system, including a column, a pre-buried air duct, a mushroom head baffle, an air outlet plate and an annular air guide plate; the upper end of the column is connected to the air outlet plate, and the mushroom head baffle cover is arranged above the air outlet plate; a circular air outlet is opened in the center of the air outlet plate, and an annular air outlet is opened at the outer edge of the air outlet plate; the annular air guide plate is placed between the circular air outlet and the annular air outlet; a pre-filter, an activated carbon filter and a medium efficiency filter are arranged in sequence from bottom to top inside the column. The air supply method is also disclosed, which combines the advantages of the air supply system and the attached jet, and the air supply airflow adheres to the column wall and enters the working area after hitting the floor, forming an air lake airflow distribution on the ground, that is, the airflow with low wind speed and small temperature difference is evenly diffused along the ground, thereby improving the air supply efficiency; by setting a filtering system, the problem of dust in the floor interlayer flowing with the air supply airflow causing the indoor air quality to decrease can be effectively solved.

The utility model relates to a multi-fan type air leakage detection device which comprises an air leakage detection module and a plurality of fans. The draught fan comprises a draught fan body and a base with a first inner cavity, one face of the base is open, the other face of the base is provided with an air side air opening communicated with the first inner cavity, the draught fan body comprises an impeller cover with a second inner cavity, an impeller arranged in the impeller cover and a driving unit connected with the impeller, and the impeller cover covers the open face of the base. The first inner cavity and the second inner cavity are oppositely communicated to form an air cavity; an opening is formed in the side wall of the base to form pipeline side air openings, and all the pipeline side air openings communicate with the air leakage amount detection module. The air supply efficiency and the detection efficiency can be improved by adopting the multiple fans, and after the pressure of the to-be-detected pipeline is stable, part of the fans are selected to work, so that the detection precision can be improved; a conventional fan structure is designed into a structure that the base and the impeller cover are connected in a split mode, the situation that a large fan shell is adopted is avoided, and miniaturization design of the air leakage detection device is facilitated.

The utility model discloses an air purifier belongs to air purification equipment technical field. It includes: air inlet pipe and air outlet pipe, both upside down and connect, and both the top surface, bottom surface of air purifier structure formed after connecting are closed surface, the top surface of air outlet pipe is provided with the communicating port, and the inner chamber of air inlet pipe is communicated with the air outlet pipe through the communicating port, the circumferential side wall of air inlet pipe is provided with a plurality of air inlet face, and every air inlet face is provided with air inlet, the air outlet face is formed on the opposite setting two sides of air outlet pipe respectively, and every air outlet face is provided with air outlet, the filter screen is set in air inlet pipe and covers in communicating port. Set up air inlet and air outlet on every side wall of air inlet pipe and air outlet pipe respectively, can handle the air in larger range fast, realizes the uniform suction and high -efficient discharge of air, effectively promotes the air circulation times in unit time, thereby significantly enhances purification efficiency.

This invention provides a refrigerator control method, including acquiring the working state and / or working level of the refrigerator's storage compartment corresponding to a first air outlet; acquiring the working state and / or working level of the refrigerator's storage compartment corresponding to a second air outlet; determining the preset position reached by each air distributor and the corresponding opening degree of the first and second air outlets based on the working state and / or working level; rotating the two air distributors so that each air distributor rotates to its corresponding preset position, while simultaneously controlling the opening degree of the first and second air outlets by a channel opening and closing device. This invention utilizes the preset position of the rotating air distributors and the corresponding opening degrees of the first and second air outlets, adhering to the principle of on-demand allocation, to specifically adjust the cold air delivery volume and deliver it to the first and second air outlets.

The invention discloses a warm air device suitable for special-shaped columns and having an air purification function, including an L-shaped baffle located at a right-angled gap of a column, a supporting plate is provided on the column at the bottom of the L-shaped baffle, a dust collecting plate close to the side wall of the column is placed on the supporting plate, and an L-shaped chamber surrounded by the L-shaped baffle and the dust collecting plate close to the two side walls of the column constitutes a hot air flow channel: the dust collecting plate is composed of a plate frame, a cooling plate embedded in the inner side of the plate frame, and an activated carbon plate on the outer side, and the cooling plate close to the side wall of the column is a coil structure connected to an external refrigeration device through a connecting water pipe; a semi-elliptical heat source is provided in the L-shaped baffle below the dust collecting plate, and an air inlet is provided on the L-shaped baffle close to the semi-elliptical heat source; a fan-shaped wind slot with a height of 10 to 15 cm is extended outward in the horizontal direction at the top of the L-shaped baffle with a side length of the column as a radius, and an air outlet is provided on the outer side of the fan-shaped wind slot. The invention is simple in structure and practical, making the indoor airflow organization more reasonable.

The utility model relates to a fan with a magnetic screen, which comprises a main frame, a mounting groove is arranged in the main frame, the main frame comprises a fan upper cover and a fan lower cover, a clamping groove is arranged on the inner side of the fan lower cover, a clamping block is arranged at the bottom of the fan upper cover, a hollow plate is connected to the inner side of the fan lower cover, and the top of the hollow plate extends upwards to be provided with a first mounting cylinder. And a main control board is mounted on the first mounting cylinder. The magnetic screen is tightly attached to the magnetic mounting plate through magnetism and is positioned through the buckles and the clamping rods, so that the magnetic screen can be quickly positioned and mounted and only needs to be pulled out during disassembly, operation is simple, a user can easily replace the screen according to own preferences or requirements, and flexibility is high; due to the design of the hollow shaft, the fan blades can be detached very conveniently, the magnetic attraction mounting plate on the hollow shaft can not abut against the positions above the fan blades any more by rotating the nut at the bottom of the hollow shaft, then the fan blades are taken out, and a circuit cannot be affected.

The utility model provides a shell device and an air conditioner with the same. The shell device comprises a shell provided with a ventilation opening; the filter screen assembly is arranged on the shell, and the position of the filter screen assembly can be adjusted so as to avoid or shield the ventilation opening; and the bearing assembly is arranged on the shell, and the filter screen assembly is in sliding fit with the bearing assembly, so that the filter screen assembly is guided through the bearing assembly in the moving process of the filter screen assembly. The reversible air supply air conditioner effectively solves the problem that in the prior art, experience is poor when a user uses the reversible air supply air conditioner.

The invention discloses a thin freezing air duct and a design method thereof. The thin freezing air duct comprises an air duct front cover, a thin fan and an air duct rear cover. According to the invention, the thickness of the thin freezing air duct is reduced by adopting the thin fan, so that the use volume of the freezing upper-layer drawer is increased. Meanwhile, the fluid domain and the computational domain of the thin freezing air duct are analyzed and calculated in a mode of combining CFD software simulation and air duct fluid domain visual simulation, so that the use volume of a freezing upper layer drawer of the thin freezing air duct is increased, the molded line of the fluid domain and the position and size of each air supply outlet are optimized, and the reliability of the thin freezing air duct is improved. Parameters such as the diameter of the air inlet of the fan are determined, the design problem is predicted and avoided in advance, the design quality and the design efficiency are improved, and the optimal matching effect is achieved.

The utility model relates to the technical field of portable fans, in particular to a handheld fan which comprises a shell, a fixing support, a high-speed fan, a control panel and a power source, the shell is provided with a holding portion and an air blowing portion, an included angle is formed between the holding portion and the air blowing portion, and an air blowing channel and an air guiding channel which are communicated with each other are arranged in the shell. The air guide channel is arranged in the holding part, and the air blowing channel is arranged on the air blowing part; the shell is provided with a first air inlet on one side of the blowing channel; the fixing support is installed in the air blowing channel and provided with an air outlet groove. The high-speed fan is installed on the fixing support and used for guiding air of the first air inlet and the air guiding channel to the air outlet groove. The control panel is installed on one side of the air guide channel. The design of the fan conforms to the human engineering principle, so that a user can hold the fan more comfortably, and the hand fatigue feeling is relieved. Meanwhile, due to the included angle design, the fan is more stable, and a user can better control the wind direction and the wind power.

The present invention discloses an air guide structure, an indoor air supply device and an air supply method. The air guide structure comprises a shell having a hollow air guide chamber therein; an air inlet structure arranged on a side wall of the shell for connecting the hollow air guide chamber with outdoor air; and an air outlet structure arranged on the same side as the air inlet structure for connecting the hollow air guide chamber with indoor air. The indoor air supply device provided by the present invention can blow the wind introduced from the outdoors toward the wall by adopting the above-mentioned air guide structure, thereby preventing the wind from blowing directly on the human body, and the wind speed is gentler, thereby improving the comfort of the air outlet of the indoor air supply device and enhancing the user experience.

The utility model discloses refrigeration equipment which comprises a freezing inner container, a refrigerating chamber, a refrigerating device and a control device, wherein a refrigerating chamber is formed in the freezing inner container; the freezing partition plate divides the freezing chamber into a freezing chamber and a refrigerating chamber, and a freezing return air inlet is formed in the freezing partition plate; an evaporator; the first partition plate is provided with a freezing air supply outlet; a refrigeration liner; the second partition plate divides the refrigerating chamber into a refrigerating air supply channel and a refrigerating storage chamber, and a refrigerating air outlet is formed in the second partition plate; a refrigeration air supply part; a refrigeration air return part; the refrigeration air supply part is used for communicating the refrigeration chamber with the refrigeration air supply channel, and the refrigeration air return part is used for communicating the refrigeration chamber with the refrigeration storage chamber. Cold air in the refrigeration chamber upwards flows back to the refrigeration chamber through a freezing air supply channel, a freezing air supply port, a freezing storage chamber and a freezing air return port; and the other path downwards flows back to the refrigeration chamber from the refrigeration air supply part, the refrigeration air supply channel, the refrigeration air outlet, the refrigeration storage chamber and the refrigeration air return part, so that the circulation length of the refrigeration air path of the upper-freezing and lower-hiding type refrigerator is shortened, and the circulation resistance of the refrigeration air path is reduced.

This application provides a leak-proof ventilation structure and manufacturing method for irregular cross-section tunnel intersections. The structure utilizes an irregularly shaped adaptable duct connection assembly comprising multiple splicing units and irregularly shaped adjustment units. The irregularly shaped adjustment units are configured as bendable metal plate structures, allowing their shape to be adjusted on-site according to the actual contour of the irregular cross-section at the intersection of the inclined shaft and the main tunnel. This achieves adaptation between the irregularly shaped adaptable duct connection assembly and the irregular cross-section. Compared to existing technologies where standard-specification connection assemblies cannot adapt to irregular cross-sections, resulting in gaps at the connection points, this application structurally eliminates the root cause of gaps, effectively reducing air leakage channels and improving the air supply efficiency of the ventilation system. Because the irregularly shaped adjustment units adapt to the shape of the irregular cross-section, the connection between the irregularly shaped adaptable duct connection assembly and the main ventilation duct is smoothly transitioned, significantly reducing local ventilation resistance, reducing air pressure loss, and improving the overall delivery efficiency of the ventilation system.

The utility model relates to the technical field of air feeders, in particular to a centrifugal air feeder which is efficient in conversion, stable in air flow, high in adjustability and adaptability and easy to maintain. Comprising a driving mechanism, a reverser is arranged at the output end of the driving mechanism, an impeller is arranged at the output end of the reverser, and the driving mechanism drives the reverser and the impeller to rotate; the impeller comprises a main plate, a plurality of wings are arranged on the main plate, the wings are distributed on the edge of the main plate in the circumferential direction, a certain angle is formed between the chord lines of the wings and the plane of the main plate, side plates corresponding to the wings are arranged on the main plate, and the side plates are connected with the wings. The outer side of the impeller is provided with a volute, the volute is provided with an air suction port and an air blowing port, and the volute forms a flow path of air flow generated by rotation of the impeller.

This utility model discloses a vehicle air conditioning duct, belonging to the technical field of air conditioning systems for three-wheeled motorcycle canopies. It mainly includes a duct base, with a first and a second duct connection cover sealed to the base for distributing airflow. The first duct connection cover is sealed to a first and a second duct for connecting to a surface air vent. The second duct connection cover is sealed to a defrost transition duct. A main defrost outlet is located at the end of the defrost transition duct furthest from the duct base. Side defrost ducts are connected to both sides of the defrost transition duct, with a side defrost outlet at the end of each side duct. This utility model, by optimizing the duct structure, significantly reduces wind resistance, increasing airflow by 15%-20% without changing the fan power. It also reduces the severe impact and turbulence between the airflow and the duct wall, effectively reducing aerodynamic noise generated by the duct system and improving driving comfort. This utility model is mainly used in three-wheeled low-speed motorcycle canopies.

The utility model provides air treatment equipment which can comprise an equipment body, an air inlet and an air outlet. The air guide plate is rotatably arranged at the air outlet so as to open or close the air outlet; the air guide device is arranged on the air guide plate, the air guide device comprises a plurality of air guide blades which are movably arranged, and the air guide blades are used for adjusting the air outlet direction of the air outlet. According to the air treatment equipment, when air is supplied, air supplied out of the air outlet can have a wider coverage space by adjusting the opening angle of the air guide plate and adjusting the relative air guide angle of the air guide blades in two stages, so that the indoor temperature adjusting efficiency is improved, and the comfort degree of a user is improved.

The utility model relates to a refrigerator. The refrigerator comprises a refrigerator body and a refrigerator cover, the first refrigerator container and the second refrigerator container are adjacently arranged in the refrigerator body up and down; a first air supply duct is arranged in the first air duct assembly; a second air supply duct is arranged in the second air duct assembly; an evaporation bin is arranged at the bottom of the first refrigerator container and located below the bottom of the first storage chamber, and the first air supply duct and the second air supply duct communicate with the rear end of the evaporation bin. An air return opening is formed in the top face of the front end of the evaporation bin and communicates with the first storage chamber and the evaporation bin. An air return pipe is arranged between the first refrigerator container and the second refrigerator container and communicates with the front end area of the evaporation bin and the second storage chamber, and therefore an air path circulation path between the first air duct assembly and the first storage chamber can be shortened, and an air path circulation path between the second air duct assembly and the second storage chamber can be shortened. The air supply efficiency in the first storage chamber and the second storage chamber is improved, and the refrigeration efficiency of the whole machine is improved.

The present invention discloses an air supply mechanism, including a base plate and a swing piece, wherein a first limiting gap and a second limiting gap are provided on the base plate, a first action portion is provided at the center of the swing piece, and a second action portion is provided outside the swing piece, the swing piece vertically passes through the first limiting gap and the second limiting gap, and the first action portion is located between the first limiting gap and the second limiting gap, and the first action portion and the second action portion can bend and swing when the first action portion and the second action portion alternately attract and repel. The swing piece used in the air supply mechanism does not need to be fixed at one end, so it can be free from the tearing force generated by fixing one end, can extend the working life of the swing piece, and can swing at both ends under one driving force, so the air supply efficiency is high and the cost is low.

The all-air heat pump system comprises a machine body, an air supply assembly, a first pressure difference sensor and a second pressure difference sensor, an air supply opening is formed in the machine body, the air supply assembly is arranged in the machine body, and an air outlet is opposite to the air supply opening; the first pressure difference sensor and the second pressure difference sensor are both arranged on the lower side of an air inlet of the air supply assembly, and the first pressure difference sensor is used for detecting the air pressure difference value of the air inlet of the air supply assembly and the air supply outlet. The second pressure difference sensor is used for detecting the air pressure difference value between the air supply outlet and the outside of the machine body, and the first pressure difference sensor and the second pressure difference sensor are electrically connected with the air supply assembly. The two sets of sensors monitor the air pressure cooperatively, a comprehensive and accurate air pressure monitoring system is formed, it is ensured that detected data are accurate, and then the air supply amount is accurately adjusted.

The utility model discloses a kind of venturi pneumatic fans, including annular machine base, low pressure air ring and rotating adjusting sleeve. The front end of the annular machine base of venturi fan is provided with diffusion pipe, the annular seat of low pressure air ring, is set in the rear portion of air jet ring, the inside of low pressure air ring is provided with annular air duct, and annular air duct is provided with air inlet pipe. Pressure regulator is provided on low pressure air ring, and the adjusting sleeve of pressure regulator is connected between low pressure air ring by screw thread movable connection. Low pressure air enters air inlet pipe, and air supply work is carried out by being sprayed from the sleeve opening of adjusting sleeve. The opening size of the sleeve opening of rotating adjusting sleeve, the pressure and flow of low pressure air spray are adjusted. The utility model can use high pressure air or low pressure air two kinds of driving air supply work, effectively utilize surplus low pressure air, and energy-saving effect is superior.

The wind wheel structure comprises a cylinder, the flow guide cone, a main blade and a stabilizing ring, the flow guide cone is a thin-shell rotary body with the equal wall thickness, and the thin-shell rotary body is formed by rotating an outer contour line around the axis of the cylinder by a circle, and the outer contour line is formed by sequentially and smoothly connecting a first arc section, a second arc section, a straight line section and a third arc section; the outer contour line is gradually away from the axis of the cylinder from the starting end of the first arc section to the end point of the third arc section; the starting end of the first arc section intersects with the inner wall of the thin-shell rotary body forming the flow guide cone and the surface of the column body; a plurality of main blades are uniformly distributed on the circumference of the large end of the flow guide cone and extend towards the column body; the main blades are longitudinally parallel to the axis of the diversion cone; the first arc section is used for forming a gas inlet area with a flaring, and the second arc section forms a gas compression area for increasing the gas flow rate; the linear section and the third arc section form a gas flow guide area; the stabilizing ring is of an annular structure and is formed on the throwing-out side of the main blade in a sleeving mode, and the stabilizing ring is located at the end close to the column body in the axial direction.

The utility model discloses an integrated water-cooling marine temperature-adjusting and dehumidifying air conditioner, and relates to the technical field of marine air conditioners, the integrated water-cooling marine temperature-adjusting and dehumidifying air conditioner comprises a frame, the side wall of the frame is covered with a plurality of fixing plates, and a layering plate is arranged in the frame to divide the inner space of the frame into an upper layer and a lower layer; a heat exchanger, an electric heater and an air feeder communicated with the outside are arranged in the upper layer; a compressor communicated with the heat exchanger through a pipeline, a water-cooling condensation shell tube communicated with the compressor through a pipeline and an electric cabinet are arranged in the lower layer, and the water-cooling condensation shell tube is connected with the heat exchanger through a pipeline; the upper-layer temperature-adjusting air supply system and the lower-layer refrigeration circulation system are separated through upper-layer and lower-layer physical isolation; if a certain system fails, only the corresponding layer parts need to be disassembled, overall disassembly is not needed, the maintenance time is shortened, and the labor cost is reduced; layered design enables the modules to be compact in layout, reduces the overall size of the unit, and is suitable for ship space limited scenes.

The utility model provides an ultrathin FFU unit which comprises an FFU box body and an ultrathin backward-tilting centrifugal fan, the ultrathin backward-tilting centrifugal fan is installed in the FFU box body, an efficient ultrathin filter is installed at the bottom of the FFU box body, an ultrathin air guide ring with a protective net is installed in the middle of the top end of the FFU box body and matched with the ultrathin backward-tilting centrifugal fan, and the ultrathin air guide ring with the protective net is installed in the middle of the top end of the FFU box body. The edge of the ultra-thin backward-tilting centrifugal fan is provided with a backward-tilting ultra-thin impeller attached to the ultra-thin air guide ring with the protective net, and the edge of the ultra-thin air guide ring with the protective net is provided with an arc air guide plate matched with the ultra-thin backward-tilting centrifugal fan. The fan in the unit is high in air supply efficiency, air pressure diffusion is uniform, and the air speed of the air outlet face is average and stable; the structural strength of the FFU box body is high, vibration caused by high-speed rotation of the fan is reduced, and noise is effectively reduced; the structure for connecting the FFU box body and the filter is good in sealing effect, thin in thickness and suitable for being used in equipment and space with height limitation.

The utility model provides a neck hanging fan which comprises a neck wearing part and an air supply mechanism connected to the two ends of the neck wearing part, the air supply mechanism comprises a shell and a fan, the shell comprises an air outlet facing the neck of a human body, and an air supply cavity suitable for installing the fan and an air channel suitable for guiding airflow to the air outlet are formed in the shell. The air channel comprises at least one streamline inner side face which is a smooth and continuous curved face, the end, close to the air supply cavity, of the air channel is a first air supply section which is in butt joint communication with the air supply cavity through a communication opening, and the end, close to the draught fan, of the streamline inner side face participates in forming the first air supply section and has the trend of protruding outwards. The first air supply section is suitable for slow flow guide. Flow field distribution in the air channel is optimized by arranging the streamline inner side face, vortexes are reduced, resistance is reduced, local high air speed is reduced by arranging the first air supply section which tends to protrude outwards for slow flow guide, speed change is more stable, speed distribution is even, noise at the first air supply section, namely the highest flow speed position, is lowered, and noise reduction is facilitated. And user experience is improved.