597 results about "Air flow control" patented technology

An airflow controller (100) in a pneumatic vacuum elevator is disclosed. The airflow controller includes a bottom portion (102) and an upper portion (110). The bottom portion is adapted as a hollow stepped cylindrical structure (104) and includes a plurality of plates (108) disposed on a bottom surface of the hollow stepped cylindrical structure. The upper portion includes a cylindrical protrusion (112) configured substantially at a centre portion of the top portion with a projection on an outer face of the cylindrical protrusion, a metal plate (114) incorporated by the upper portion, and a disc (116) including a hollow circular structure (118) with an upper face (116a) and a bottom face (116b) and includes a plurality of extensions (120) positioned on the upper face at predetermined positions and a solenoid valve (122) accommodated by the hollow circular structure (118) and configured to open based on a timer.

The invention discloses a device and method for improving the laser welding quality of a large cylindrical battery tab, belongs to the technical field of new energy automobile battery welding, and aims to solve the problems of low material absorption rate, poor welding protection effect and the like in the prior art. The device comprises a fastening pressing block, the fastening pressing block fixes a battery cell and a collector plate, the fastening pressing block is provided with an internal gas passage, a blowing nozzle of the fastening pressing block is sequentially connected with a plasma activator, a gas heating device, a gas flow controller and a protective gas cylinder, and an exhaust nozzle of the fastening pressing block is connected with an exhaust device. Nitrogen blown out through the blowing nozzle sweeps over the surface of a to-be-welded area of the collector plate, a protective air curtain is formed in the to-be-welded area, the plasma activator conducts ionization activation on the nitrogen, formed nitrogen free radicals and the to-be-welded surface form a nitride layer in a chemical mode, and the laser absorption rate of the material can be remarkably improved. The reaction between the preheated workpiece surface and nitrogen free radicals can be accelerated, and a dual synergistic mechanism of physical preheating and chemical activation is formed.

The invention belongs to the technical field of gas detection, particularly relates to a harmful gas concentration detection device for environmental monitoring, and solves the problems of insufficient airflow control and insufficient detection precision in the prior art. The spiral air flow guide plate, the servo motor and other structures are arranged, the air flow guide plate is designed to be of a right-handed spiral structure, gas enters the barrel in a laminar flow state through a gradually-shrunk channel of the air flow guide plate, turbulence interference is effectively reduced, and the air flow guide effect is improved. The rotating circular plate drives the sliding straight block to move in the radial direction through the inner spiral limiting block, the organ moving block is driven to form a dynamic sealing cavity, sucked airflow is compressed to a detection area, the collision frequency of target gas molecules and the detection assembly is remarkably improved, and therefore the capturing capacity of the device for trace gas is enhanced.

The invention discloses a production line spraying processing system based on Internet of Things, which comprises a state identification module, a dynamic airflow compensation analysis module and a spraying cabin airflow control module, and is characterized in that the state identification module is used for monitoring and judging whether a spraying cabin is in an ideal working state in real time; the dynamic airflow compensation analysis module is used for calculating the airflow requirement of a dead angle area in real time according to a three-dimensional model of a sprayed part, and the spraying cabin airflow control module is used for dynamically adjusting parameters of a vortex generator according to a monitoring analysis result so as to optimize airflow distribution and a paint mist adhesion effect. The state recognition module, the dynamic airflow compensation analysis module and the spraying cabin airflow control module are electrically connected with one another, intelligent management of the spraying process is achieved, the paint mist deposition efficiency and the coating uniformity are remarkably improved, and the over-spraying and dissipation phenomena are reduced.

The invention discloses an air-fuel ratio control method for a high-pressure direct injection engine in a diesel-natural gas dual-fuel cylinder, and relates to the technical field of engine control, and the air-fuel ratio control method comprises the following steps: collecting diesel mass flow, natural gas volume flow and natural gas component data, and determining a diesel-natural gas mixing ratio; a basic target air-fuel ratio is obtained by combining the real-time rotating speed of an engine, the load and the diesel oil-natural gas mixing proportion; based on the pressure and temperature of the intake manifold and the rotating speed of the engine, the target air-fuel ratio after model correction is obtained; the working condition load change rate is detected, the pre-optimized air-fuel ratio trajectory MAP is called, and a transient correction target value is generated; calculating the deviation between the transient correction target value and the measured value of the air-fuel ratio sensor and the deviation change rate, and outputting an air-fuel ratio correction value; and the final target air-fuel ratio is calculated and sent to an air flow control valve to execute air inlet adjustment. The method is suitable for engine application scenes requiring high-precision and self-adaptive control to improve combustion efficiency and reduce emission.

The utility model relates to a double-chamber furnace burner gas energy-saving device which comprises a gas inlet pipeline, the gas inlet pipeline is provided with an air flow sensor and an air flow control valve, and a gas pipe is provided with a gas flow sensor and a gas flow control valve. The output end of the air flow sensor and the output end of the gas flow sensor are electrically connected with the input end of the controller, and the output end of the controller is connected with the air flow control valve and the gas flow control valve. The controller is provided with a master controller, the master controller is provided with a double-cross control module, and the master controller controls the air flow control valve and the gas flow control valve through the double-cross control module and the controller. The controller and the master controller are arranged, the controller transmits detection parameters of the air flow sensor and the gas flow sensor to the master controller, the master controller achieves double-cross control through the double-cross control module, and the controller adjusts the valve opening degree of the air flow control valve and the valve opening degree of the gas flow control valve through the double-cross control. And thus, energy-saving control is realized.

The invention discloses a cooling device and glass fiber production equipment, and relates to the technical field of glass fiber production, and the cooling device comprises a spray pipe, an air supply pipeline, a control valve and a control system. Wherein the spray pipe is provided with a plurality of air nozzles distributed at intervals along the longitudinal direction, the plurality of air nozzles are used for spraying air flow towards one side deviating from the bushing so as to form an air vortex capable of reducing the temperature of the bushing and the root of the glass fiber on one side deviating from the bushing of the spray pipe, and the air supply pipeline is connected with the spray pipe and is used for supplying the air flow to the spray pipe; the control valve is arranged on the air supply pipeline and used for controlling the flow of airflow in the air supply pipeline, and the control system is in communication connection with the control valve and used for controlling the opening degree of the control valve according to the wire drawing operation state. The cooling device can stabilize the temperature of the bushing plate when the wire drawing operation is interrupted or the machine head is switched, reduces the number of waste products, and meets the cooling requirement of the bushing plate with high hole number for producing small-diameter fibers, so that the productivity and the economic benefit of a wire drawing operation unit are improved.

The invention discloses an electronic industry clean workshop air circulation function self-adaptive adjusting system and method. The adjusting system comprises a three-dimensional grid monitoring module, a data processing module, a visualization module, a computer vision module, an intelligent decision module and an air circulation control module. The adjusting method comprises the steps of three-dimensional grid sensing arrangement and monitoring, data processing, data visualization, image feature extraction, abnormal area early warning, air circulation parameter decision making, self-adaptive adjusting execution and closed-loop feedback optimization. A continuous space distribution model is constructed through real-time monitoring data of a three-dimensional grid sensor and is converted into a dynamic visual three-dimensional heat map, correlation between environment characteristics and air circulation control quantity is further established, and air flow control parameters are output based on local pollution abnormal conditions. The adjusting accuracy of the system on complex working conditions can be remarkably improved, and self-adaptive adjustment and sustainable evolution of the air circulation function are achieved.

The invention relates to the field of physiotherapy, in particular to a condition control type moxibustion support and a control method. According to the device, the output end of a valve system is connected to a pneumatic push rod, a first air inlet pipe and a second air inlet pipe, and a thermometer inserted into a shielding cylinder and located below a grid is arranged on a thermometer mounting position; according to the condition control type moxibustion support and the control method, the main height and the combustion state of a moxa stick and the secondary medicine mist guiding-out strength are controlled, and the sealing effect of the shielding cylinder provides a basis for airflow control of the first air inlet pipe and the second air inlet pipe; after a height signal of a moxa stick is obtained through a shielding sensor, adjustment is achieved through a pneumatic push rod, the height of the moxa stick is appropriate, and it is guaranteed that the infrared effect and the heat effect of a moxa stick burning point are correctly applied to the skin position; after the height is correctly set, the combustion state of a moxa stick combustion point can be adjusted according to the thermometer and through work adjustment of the second air inlet pipe.

The invention discloses an embedded ceramic wear-resistant structure petal leather cup, and particularly relates to a pipe cleaner, the embedded ceramic wear-resistant structure petal leather cup comprises a pipe body framework, a top cover is fixedly installed in a top port of the pipe body framework, the pipe body framework is sleeved with a plurality of petal leather cup bodies, and a plurality of composite beads which are close to a cup opening and are distributed in a circumferential array mode are movably arranged on the outer side faces of the petal leather cup bodies; the outer side wall of the petal leather cup body is provided with flow channel grooves penetrating to the section of a cup opening, and each flow channel groove is located between the two composite beads and distributed in the middle. The flow channel grooves are distributed in an inclined mode and fixedly communicated with a flow channel formed in the petal leather cup body and an air hole formed in the pipe body framework. Through the combined design of the runner grooves and the composite beads, the wear resistance and the cleaning efficiency are improved, self-rotation and intelligent airflow control are achieved through airflow guiding and dynamic adjustment, and the self-rotation intelligent airflow cleaning device is suitable for complex pipeline cleaning scenes.

The invention discloses a hollow-core optical fiber microstructure size dynamic nondestructive measurement and control system, which is characterized in that a spectral confocal detection module acquires spectral signals reflected by each interface of the cross section of a hollow-core optical fiber from the side surface of the hollow-core optical fiber by using a dispersion confocal principle in a hollow-core optical fiber drawing process, and converts the spectral signals into spectral data; the data analysis module outputs an axial peak value calculated value by using a neural network model according to the spectral data, and converts the axial peak value calculated value into the diameter of a nested glass tube in the nested structure unit; the regulation and control module outputs an airflow regulation instruction according to the difference between the diameter of the nested glass tube and a preset value; the airflow control module adjusts the size of airflow entering the hollow-core optical fiber according to the airflow adjusting instruction, and then the diameter of the nested glass tube is adjusted. According to the invention, the diameter of the nested structure unit in the hollow-core optical fiber can be accurately measured in the production process, and the technological parameters can be adjusted in time according to the product state.

The invention discloses an air filtering system and method, and relates to the technical field of vehicle engineering.The air filtering system comprises an air inlet module, an air inlet flow control module, an air filtering module and a temperature detection module, and the air inlet module comprises a high-temperature air guiding pipe and a normal-temperature air guiding pipe; the normal-temperature air guide pipe is used for sucking normal-temperature air in the external environment; the high-temperature air guide pipe is used for sucking high-temperature air generated in an engine cabin; the air filtering module is used for filtering the mixed air; the filtered mixed air enters the engine; the temperature detection module is used for detecting the mixed air temperature of the mixed air; the air inlet flow control module is used for controlling the air flow proportion between the normal-temperature air and the high-temperature air sucked by the air inlet module according to the mixed air temperature so that the mixed air temperature can be within the standard temperature interval. The filtering effect of the air filtering module can be improved, the service life of the air filtering module can be prolonged, and the maintenance cost of the air filtering module is reduced.

To provide an air conditioning system enabling an air humidity in a living room to be closer to a target humidity while making an air temperature in a living room close to a target temperature.SOLUTION: A control part in an air conditioning system includes: a temperature conditioning and air quantity control mode for controlling an air quantity of a carrying fan and an aperture of a damper on the basis of a temperature conditioning operation where an air conditioning device conditions an air temperature in a living room so as to have a target temperature; and a humidity conditioning and air quantity control mode for controlling the air quantity of the carrying fan and the aperture of the damper on the basis of a humidity conditioning operation where the air conditioning device conditions an air humidity in the living room so as to have a target humidity. The control part performs control for switching the temperature conditioning and air quantity control mode and the humidity conditioning and air quantity control mode on the basis of a first control capability value set on the basis of temperature difference between the air temperature in the living room and the target temperature and a second control capability value set on the basis of humidity difference between the air humidity in the living room and the target humidity.SELECTED DRAWING: Figure 3

The invention discloses a gas environment regulation and control system and method for a clean laboratory. The gas environment regulation and control system comprises an air treatment unit and a gas monitoring unit, and the air treatment unit and the gas monitoring unit are connected with an intelligent control unit; the control unit is connected with an execution mechanism; the air treatment unit comprises a three-stage filtering module, an activated carbon adsorption module, a variable refrigerant flow air conditioning system and a heat recovery device; the gas monitoring unit comprises a multi-dimensional sensor network, a movable sampling device and a rail type gas suction hood; the intelligent control unit comprises an edge computing node and a cloud management platform; the execution mechanism comprises an airflow control assembly and a temperature and humidity regulation and control assembly. The gas environment regulation and control system of the clean laboratory adopts a composite purification technology and has a real-time monitoring and purifying function.

A respirator has a shell that defines a breathable air zone for a user wearing the respirator. An air flow control system for the respirator has an air delivery conduit within the shell of the respirator, a valve member moveable relative to the air delivery conduit and within the shell to vary the amount of air flow through the air delivery conduit, and a valve actuator outside of the shell of the respirator. The valve actuator is manipulatable by a user of the respirator while wearing the respirator to control movement of the valve member.

An extraction cleaner may include a base, an upright body pivotally coupled to the base, a supply tank removably coupled to the upright body and a recovery tank removably coupled to the upright body. The base may include a non-removable door and a removable suction nozzle. At least one fluid dispensing nozzle may be provided on the door. The door may be pivotally coupled to the base for providing access to an agitator. The cleaner may include and auto-spray configuration. The cleaner may include a support on the upright portion for the recovery tank. The cleaner may include an additive tank received in a receptacle of the supply tank. The recovery tank may include a float and / or an airflow management configuration. The cleaner may include a cleaning tool and a suction changeover valve and / or a fluid changeover valve. The cleaner may include a mixing valve for supplying fluid to a fluid changeover valve. A cleaning composition including an aqueous based cleaning solution mixed, on demand, with an aqueous based oxidizing solution is also provided.

Air flow control insertable into an air opening for controlling air flowing along an air flow direction, with a closure device including a cloth or fabric adjustable between an opening position releasing the air opening and a closing position at least partially closing the air opening by means of an adjustment device for selectively releasing and closing the air opening to change the air resistance and / or for thermal management of a downstream unit in the air flow direction. Various solutions are proposed to integrate the air control system in or behind an air grille, especially in very limited installation space.

The invention discloses a high-temperature-resistant maintenance-free nano dust filtration system and method, and belongs to the technical field of dust filtration systems. The system comprises a dust filtering main body, a nano ceramic filter element assembly, an automatic blowback system and a control system. The nano ceramic filter element is sequentially provided with an outer coarse filter layer, a middle medium filter layer and an inner fine filter layer from outside to inside, so that a radial gradient aperture structure is formed, and graded interception of dust is realized. The automatic blowback system is configured in a way that double electromagnetic pulse valves are connected in series to form double-peak collaborative blowback airflow which is firstly subjected to high-pressure impact stripping and then is subjected to high-flow removal. The control system continuously collects pressure difference data and calculates the pressure difference change rate, the remaining time for reaching a pressure difference threshold value is predicted according to the pressure difference change rate, the back flushing triggering opportunity is judged, self-adaptive dust removal control is achieved, meanwhile, the pressure difference recovery rate before and after back flushing is calculated, and back flushing parameters are automatically adjusted. According to the invention, high-efficiency purification of high-temperature dust-containing gas and long-term maintenance-free operation of the system are realized, and the service life of the filter element is remarkably prolonged.

The invention belongs to the field of pipeline airflow control, and discloses a gas flow self-balancing valve mechanism, which can realize self-balancing of gas flow in a gas path by a simple structure, so that the production cost of equipment connected with the gas path can be further reduced on the premise of avoiding sudden change of the gas flow, and the production efficiency is improved. Comprising a flow control pore plate and a pair of opening control assemblies located on the two sides of the flow control pore plate respectively, the flow control pore plate is provided with flow control through holes, and airflow flows in an air path through the flow control through holes; the opening degree control assembly is provided with an airflow driving fan, a fan blade linkage shaft and a driven rotating part which are sequentially arranged in the direction of the flow control pore plate, the airflow driving fan is rotationally coupled with the driven rotating part through the fan blade linkage shaft, the driven rotating part is coaxially and rotationally arranged on the flow control pore plate and provided with shielding blades, and when the driven rotating part rotates, the shielding blades are arranged on the flow control pore plate. And the shielding blade is driven to rotate to shield the flow control through hole, so that the opening degree of the flow control through hole relative to the gas path is adjusted.

The utility model provides an electronic cigarette with double oil bottles, which comprises a cigarette holder, a shell component, a first atomizing component and a second atomizing component, the cigarette holder is connected to the shell component, the first atomizing component and the second atomizing component are arranged in the shell component side by side, the first atomizing component comprises a first atomizing channel, and the second atomizing component comprises a second atomizing channel. The cigarette holder comprises a suction nozzle part, a cover plate part and an airflow control column, the suction nozzle part and the airflow control column are fixedly connected to the cover plate part, the suction nozzle part and the cover plate part are arranged in a spaced mode, the suction nozzle part is provided with a suction hole, and when the suction hole of the suction nozzle part is communicated with the first atomization channel and the first atomization assembly is in a working state, the airflow control column seals the second atomization channel; when the second atomization assembly is in the working state, the airflow control column seals the first atomization channel. According to the electronic cigarette with the double oil bottles, double tastes can be switched, the cost is reduced, and the electronic cigarette is convenient to use.

A system includes an outlet flowline from an activated carbon bed, a bypass flowline, a furnace, and a control system. The outlet flowline is configured to flow an acid gas stream out of the activated carbon bed after the activated carbon bed has removed benzene, toluene, and xylene from the acid gas stream. The bypass flowline includes a bypass valve and provides an alternative flow path for the acid gas stream exiting the activated carbon bed. The furnace includes a burner configured to combust at least a portion of the acid gas stream. The control system includes a temperature sensor and a controller. The temperature sensor is configured to measure a furnace temperature. The controller is configured to reduce a percent opening of the bypass valve based on the measured furnace temperature.

The invention relates to the related technical field of intelligent equipment, in particular to a row type suction cup mechanical arm for processing and transferring large whole glass, which comprises a mechanical combined arm, a base, a left bracket, a right bracket, a suction cup module, an intelligent sensing module, an air blowing module, a closing switching module and a swing switching mechanism. According to the invention, through multi-mode and self-adaptive airflow control, the problem of glass adhesion caused by atmospheric pressure difference is solved. According to the application, the action combination of small-amplitude translation and overturning is utilized, and the switching of'gentle wind 'and'strong air knife' is matched, so that the generated high-speed air knife is accurately and powerfully blown into a gap, a water film is instantly destroyed, the pressure difference is efficiently eliminated, the adhesion phenomenon between the glass is eliminated at the moment when the glass is overturned to generate the gap, and the transportation work is smoother.

The present invention discloses an electrostatic rotary cup spray gun. The atomizer base assembly, the electrostatic high-voltage generator assembly, and the atomizing rotary air flow control unit have a self-cleaning function for cleaning the rotary cup assembly and the structure that realizes the paint conveying function, thereby ensuring that the color-changing paint switching and the process cleaning are free of impurities; in addition, the shaping air ring assembly, the atomizer base assembly, the electrostatic high-voltage generator assembly, and the atomizing rotary air flow control unit have the function of quantitatively adjusting the cyclone angle and range of the shaping air, thereby achieving the effect of accurately adjusting the spray width of the paint atomized particles; finally, the characteristics of cleaning the inner and outer surfaces of the rotary cup and the paint delivery pipe, accurately switching the paint supply, cleaning the color-changing paint and the process without impurities, and the closed-loop control of the rotary cup rotation speed and the atomizing shaping air intake volume can be precisely regulated.

The application discloses an air intake flow control method and device, electronic equipment and a storage medium. The method comprises the following steps: monitoring the air flow in real time through an air flow sensor and monitoring the pressure difference before and after the filter screen in real time through a pressure difference sensor; determining the pressure difference threshold corresponding to the current air flow based on a preset first corresponding relationship between the air flow and the pressure difference threshold; when the current pressure difference corresponding to the current air flow is less than or equal to the pressure difference threshold, determining the first flow compensation value corresponding to the current pressure difference based on a preset second corresponding relationship between the pressure difference and the flow compensation value, and compensating the current air flow based on the first flow compensation value. Thus, when there is foreign matter in the filter screen in the existing steady flow pipe, the pressure difference changes greatly, the measured air intake flow is less accurate, and the problems of black smoke and insufficient power of the vehicle are caused.

This invention relates to an air flow open-loop control system (20) with the ability to correct for non-linearity in a non-linear actuated damper, resulting in improved precision and less pressure variations when controlling multiple face-dampers (31) and bypass-damper (52) The controller includes a processor that receives data on the damper's position and determines the non-linearity of the damper. The correction module then corrects for this non-linearity so that the damper can be used to steer a linearly proportional air flow based on a linear control signal. The correction module generates a corrected signal for the damper that is indicative of the desired position for the damper that will result in the desired air flow. In operation mode, the processor uses this corrected signal to control the damper and produce a linearly proportional air flow. This invention enables more precise control of HVAC air flow and ensures that non-linearity in the damper does not affect the system's performance.

A heat exchanger includes plate assemblies arranged to define airflow gaps between adjacent plate assemblies, allowing air to flow in one airflow direction. Each plate assembly includes a frame having two headers and a center section, a diaphragm disposed on the frame, and two airflow restricting elements disposed at each header of the frame. For each header, a first airflow restricting element is located on a first side of the frame and a second airflow restricting element is located on a second side of the frame.In each pair of adjacent plate assemblies, the central portions are spaced apart to define the airflow gap, and the first airflow restricting elements of a first plate assembly engage the second airflow restricting elements of a second plate assembly to form two airflow restrictors at opposite ends of the airflow gap relative to a direction other than the airflow direction.

The invention relates to the technical field of rice processing, in particular to special flavor rice processing freeze drying equipment which comprises a condensing box and a cuboid material bin arranged in the condensing box. A plurality of sets of turning paired frames are symmetrically installed on the inner walls of the two sides of the material bin, each set of turning paired frame is composed of turning paired frame units oppositely arranged on the two sides, and each turning paired frame unit comprises a supporting building frame, an adjusting frame, a supporting cylinder, a synchronous transmission piece and a spiral turning piece. The top of the condensation box is provided with a box top plate and a top support, the top support is provided with a sliding support section capable of moving transversely, the bottom end is provided with a multilayer porous ceramic water vapor adsorption piece in a hoisting mode, the bottom end is filled with an activated carbon layer and connected with an external vacuum pump, and an adsorption area directly faces a middle working area of the overturning opposite frame. The sliding branch section drives the water vapor adsorption part to transversely move synchronously with throwing of the turning part. Through mechanical-airflow-control multi-dimensional cooperation, oxidation is prevented while water vapor is efficiently captured, flavor components are further locked, and the processing quality of the high-quality flavor rice is guaranteed.

The utility model discloses a transformer winding turntable drying circuit system, which comprises three-phase power supplies L1, L2 and L3 and a grounding wire PE, and is characterized in that the three-phase power supplies are connected into a system through a main circuit breaker QF; the conveyor belt motor control loop comprises a contactor KM1, a contactor KM3, a thermal relay FR1 and a conveyor belt motor M1; the turntable motor control loop comprises a contactor KM2, a thermal relay FR2 and a turntable motor M2; the airflow control loop comprises an electromagnetic valve EV; the conveying control unit is used for controlling the conveying belt motor M1 to rotate forwards so as to convey the transformer winding to the position of the rotating disc. The turntable drying control unit is used for controlling a turntable motor M2 and an electromagnetic valve EV to work to realize turntable rotation and pneumatic drying; and the output control unit is used for controlling the conveyor belt motor M1 to rotate reversely so as to output the dried transformer winding. Uniform drying of all positions of the winding is achieved through rotation of the rotating disc, and the consistency of the drying process of the transformer winding is guaranteed.

This invention discloses a temperature- and humidity-controlled recirculating wind tunnel for sandstorm environments, relating to the field of wind tunnel technology. It includes a wind tunnel structure, an airflow pitch guiding mechanism, a sandstorm control mechanism, and a wind tunnel airflow control mechanism. The wind tunnel structure comprises an experimental section. The right end of the experimental section is connected to the bottom end of the sand control section via a diffusion section. The top end of the sand control section is connected to the right air inlet of a recirculating fan. The left air outlet of the recirculating fan is connected to the top end of a control section via a recirculating section. The bottom end of the control section is connected to the left end of the experimental section via a contraction section. The airflow pitch guiding mechanism is installed at both ends within the experimental section. The sandstorm control mechanism includes a sandstorm filtration component and a sandstorm collection component. The sandstorm filtration component is installed in the middle of the sand control section, and the sandstorm collection component is installed at the bottom of the sand control section. This temperature- and humidity-controlled recirculating wind tunnel for sandstorm environments has good filtration performance, preventing sand particles from clogging the mesh of the filter screen. The airflow within the experimental section can flow from left to right or from right to left.

The HVAC cleaning system comprises an HVAC system and a cleaning structure. The cleaning structure forms a fluidic connection with the HVAC system. The HVAC system controls a flow of air into and out of a chamber. The HVAC system controls the temperature of the air in the chamber. The cleaning structure injects a disinfection solution as a spray into the air flow controlled by the HVAC system. The disinfection solution cleans the ductwork of the HVAC system.