47results about How to "Low operating and management costs" patented technology

The invention discloses a method for utilizing high-load earthworm biological filter to treat decentralized sewage in countries, and relates to a sewage treatment method. The treatment method comprises the following steps: the decentralized sewage in the countries is firstly collected; suspended matter and floating matter are removed by a pretreatment tank; BOD5 is led to be 110 to 160mg / L, COD is 120 to 150mg / L and SS is 90 to 130mg / L; then the obtained mixture is pumped into the high-load earthworm biological filter according to hydraulic loading of 4 to 6m<3>(m<2> question mark d); after passing through a first earthworm biological filtering layer and a second earthworm biological filtering layer which are filled with light shale spherical porcelain granules (7) filtering media with the diameter of 3 to 7mm and 15000 to 28000 eisenia foetidas (8) are added on the surface of the filtering media per square meter, the water which is discharged from a settling tank (6) and has BOD5 of less than 15mg / L, COD of less than 60mg / L and SS of less than 15mg / L reaches the national water quality standard for field irrigation; little amount of residue sludge which is collected by the settling tank (6) and contains wormcast is used for improving the soil or is used as fertilizers. The method has large hydraulic loading, small occupy area, is hard to be blocked, has simple process and operation, good water outlet quality and low construction cost and operating cost and can be widely used for treatment of the waste water in rural areas.

The invention discloses an exhaust gas waste heat steam producing system of a marine diesel generating set. The exhaust gas waste heat steam producing system comprises a hot well, a boiler water-feeding pump, a steam pocket, an exhaust boiler, an evaporator and a preheater, wherein the evaporator and the preheater are installed in the exhaust boiler, and the hot well is sequentially connected with the boiler water-feeding pump, the preheater, a steam pocket first inlet, a steam pocket first outlet, the evaporator, a steam pocket second inlet, a steam pocket second outlet and a fuel auxiliary boiler. Exhaust gas produced by the marine diesel generating set is led into the exhaust boiler. The exhaust gas waste heat steam producing system can effectively recover exhaust gas waste heat of the marine diesel generating set, save fuel cost and improve ship environment friendliness.

The invention relates to a technology for processing indissolvable and nondegradable organic waste gas by integrated composite organisms, and the technology is applicable to the purification of low-density, indissolvable and nondegradable organic waste gas. A high-density low-speed air suction way and a domestication way of low flow-rate circuiting liquid are adopted; and during the domestication process, a fungus-bacteria composite organism system with pseudomonas as a dominant bacterium is constructed by use of a pH changing way. A composite organism tower combines two microorganisms of fungus and bacteria, and the diversity of microorganisms can be effectively applicable to the requirements of various indissolvable and nondegradable organics on different bacteria; system resistance is reduced by the introduction of a fungus system; water film resistance is reduced effectively and the mass transfer process of the organic waste gas is accelerated by means of low circuiting flow-rate; an integrated type technological structure is adopted to the fungus and the bacteria, so the processing technology is simplified and the investment cost and operating cost are reduced. The system is high in efficiency of removing the indissolvable and nondegradable organic waste gas and load, and has an extensive applicability.

The invention discloses a capillary infiltration ditch system for treating the domestic sewage, consisting of a surface soil layer, a sand-soil layer, an artificial soil layer and a water-guiding layer from the top to bottom in sequence; wherein, plants are planted on the surface soil layer, wherein, the soil layer of the surface is planted with the plants; in the surface soil layer and the artificial soil layer, a surface water distribution pipe and an inner water distribution pipe are respectively provided with surface cloth tube and deep cloth tube communicated with a hydrolysis acidification unit or a septic tank; the periphery of the water distribution pipe is the green pebble encapsulated with an earthwork cloth; the water-guiding layer is provided with a water-discharging pipe communicated with the water-discharging pool and an air-drawing duct for naturally forcing the ventilation with an air-drawing principle. With higher water-force load, the invention has a higher removal efficiency of the COD, BOD5, total phosphorus, NH4<+>-N, TN in the domestic sewage. The effluent achieves the national sewage comprehensive discharge standard. The invention has the advantages of low cost in the basic construction and an operation management, small impact by the environment, no public health problems as well as vegetables and economic plants- planting. The invention is particularly applied to treat the distribution sewage with a high cost pipe building and a high requirement of the nitrogen and phosphorus removal.

The invention relates to a method for removing antibiotics resistance gene in sewage, and belongs to the technical field of sewage purification treatment. According to the method, the relevance between membrane surface pollutant components and the antibiotics resistance gene is inspected, a biological treatment and membrane technology combined process is adopted, biological treatment, membrane technology and membrane surface pollutant adsorption intercepting effects are organically coupled, adjustment and control and operating parameters during a membrane bioreactor biological process are fixed and optimized, and the optimum concentration of membrane surface organic pollutant required by the enhanced removal of the antibiotics resistance gene in the sewage is fixed, so that removal rate of the antibiotics resistance gene in the sewage reaches 93.7 percent. The method has the advantages that chemical agents are not required to be additional cast, secondary pollution is reduced, operation management costs are reduced, the significant requirements on economical, social and environmental sustainable development are met, the technology is simple and reasonable, industrialized application requirements on sewage advanced treatment and recycling are met, and a scientific and reliable novel technology is provided for controlling the spreading of the antibiotics resistance gene in the sewage.

The dispersed in-site ecological sewage purifying process belongs to the field of sewage treating technology. Pond in countryside used as sewage treating apparatus is separated with water separating barricading into a purifying stuffing zone and a purifying plant zone. In the purifying stuffing zone, bionic water weed stuffing is set; and in the purifying plant zone, submergent plant is planted. Under the guide of the barricading, sewage is made to pass through the purifying stuffing zone and the purifying plant zone successively, so that organic matters and trophic salts are eliminated. The treated water is returned with a reflux pump to aerate and raise the treating effects of purifying water, beautifying environment and preventing water eutrophication.

The invention relates to a treatment process of sludge from a turbid circulating system of a steel enterprise hot rolling factory, and the process comprises the following steps: directly pumping sludge generated during water treatment of a turbid circulating system of a steel enterprise hot rolling factory into an oxide scale pit by a sludge pump, performing natural filtration to separate water from the sludge, mixing the sludge with coarse-grained oxide scale for outward transport together, allowing the water obtained after filtration to enter a whirling well at a low position in a gravity flow mode. Water in sludge is removed by the natural filtration of the oxide scale pit; the process is simple; the operation and management are very convenient; no mechanical equipment such as a filter press, a high-lift sludge pump, and the like is required; intermittent operation can be adopted, which saves a lot of water resources; a certain number of project construction land are saved; a lot of civil construction and equipment investment is saved; a lot of operation management cost is saved; a lot of energy consumption is saved; labor intensity of operators is greatly reduced; and secondary pollution caused in sludge treatment is prevented.

The invention relates to an underground comprehensive pipe gallery. The underground comprehensive pipe gallery comprises a high-position gallery body and a low-position gallery body which are constructed under the ground. The high-position gallery body is divided into ventilating rooms, an escape channel, a power distribution room and a feeding room through first partition walls. A plurality of first inlets and outlets are formed in the first partition walls and communicate the ventilating rooms, the escape channel, the power distribution room and the feeding room. The top of each ventilating room is provided with a ventilating opening and a ventilating structure which are exposed out of the ground. The top of the escape channel is provided with an escape opening and an escape well cover which are exposed out of the ground. The top of the feeding room is provided with upper feeding openings and feeding cover plates which are exposed out of the ground. Second inlets and outlets communicating with the low-position gallery body are formed in the bottoms of the ventilating rooms, the escape channel and / or the feeding room. The low-position gallery body is internally provided with a pipeline cabin and a cable cabin. A drainage structure is arranged at the bottoms of the pipeline cabin and the cable cabin. The pipeline cabin is divided into a plurality of sub pipeline cabin bodies. The cable cabin is divided into a plurality of sub cable cabin bodies. The underground comprehensive pipe gallery is small in occupied area, convenient to install and maintain and high in management efficiency.

The invention provides a solar snow melting system, which is characterized in that a heat conduction oil pipe is coiled with the inner wall of an underground thermal insulating heat exchange pit, and a water pipe is connected with the underground thermal insulating heat exchange pit in a vertical spliced manner; a light source type magnifying lens is mounted outside a heat collection box; a heat conduction oil pipeline is mounted inside the heat collection box and an energy storage chamber; the oil conduction oil pipeline is connected with the heat conduction oil pipe inside the underground thermal insulating heat exchange pit to form a circulating oil pipe; a water pipeline inside the underground thermal insulating heat exchange pit is connected with an evaporator end of a ground source heat pump unit; low-condensation-point heat conduction oil pipelines are paved under the earth surface, and a thermal insulating layer is paved under the low-condensation-point heat conduction oil pipeline; heat pipes are fixed among the low-condensation-point heat conduction oil pipelines; and the low-condensation-point heat conduction oil pipelines are connected with one side of a heat exchange, and the other side of the heat exchange is connected with a condenser end of the ground source heat pump unit. The solar snow melting system provided by the invention has the advantages that the solar snow melting system has no corrosion on a road and no denudation damage on the road surface, uses solar energy and geothermal energy, and has the advantages of small energy consumption, low operation management cost, fuel saving, no secondary pollution, small occupied area, simplicity for operation and maintenance, little investment and long service life.

The invention relates to 'a compound vegetation wetland sewage treatment system that has comprehensive benefits' which belongs to the field of sewage treatment. The invention is characterized in that: the compound vegetation includes cattail, wild rice stem, water shallot, calamus (dominated by cattail). Two rows of the cattail are spaced by a row of wild rice stem, water shallot or calamus. The invention adopts the cattail, the wild rice stem, the water shallot and the calamus that are easy to be obtained and survive, low in cost and needs no care and gravel base to construct an undercurrent type artificial wetland system, which can not only purge the domestic sewage from urban and rural areas efficiently but also achieve a high overall benefit of compound vegetation and can enhance the landscape effect of the wetland, and develop the application in food, medicine and braiding product. The wetland system provided by the invention can keep a long-term and stable decontaminating effect and is characterized in that the purifying effect is prominent, the construction project is easy, the operation cost is low and the weed invasion is less, the landscape effect is good, the overall benefit is good and the development potential is large, which meets the practical conditions of the country and is suitable for being generalized in a large scale.

The invention relates to a connection system for an air-cooled split air conditioner. Aiming at the problems that the pipeline has large resistances and the return oil blockage happens to the pipeline when the existing air conditioner has long distance and high fall, the invention provides a connection system for the air conditioner. An exhaust rising pipeline (4) of the invention is a pipeline which is uniformly upward and an oil separator (5) is arranged at the lower end of the exhaust rising pipeline (4). The exhaust inlet (5-1) of the oil separator (5) is connected with an exhaust horizontal pipeline (3) which is extended out from an indoor-machine (1) and the exhaust outlet (5-2) of the oil separator (5) is connected with the exhaust rising pipeline (4) connected to an outdoor-machine (2); the oil return pipe port (5-3) of the oil separator (5) is connected with one end of an oil return pipeline (6) while the other end of the oil return pipeline (6) is connected to the air return pipeline (1-2) of a compressor (1-1) in the indoor-machine (1). The invention has the advantages of small resistance, smooth oil return, simple system structure, easy implementation, easy installation, low cost, small investment, low running and management fees, few occupied building spaces and is beneficial for popularization and utilization.

The invention relates to a method for recycling non-radioactive production wastewater of a nuclear power plant. The method comprises the following steps: firstly classifying non-radioactive production wastewater in a plant area according to main pollutant characteristics, and adopting the same type of treatment facility for the same type of wastewater or wastewater similar in water quality; and transporting the collected and treated non-radioactive production wastewater to a seawater pretreatment plant forebay of a circulating water system by virtue of a pipeline, carrying out seawater treatment, and then taking the treated wastewater as supplementary water of a cooling water system. The method provided by the invention is firstly applied to the nuclear power plant, and the problem of discharge of the non-radioactive production wastewater is solved by applying the method. The method provided by the invention reduces the intake quantity of the cooling water system on raw water, improves the water reuse rate of the whole plant, saves the operation management cost, and also can reduce the discharge of the non-radioactive production wastewater of the nuclear power plant and reduce the influence of the discharged water on the environment. The non-radioactive production wastewater recycling way provided by the invention can provide a reference for nuclear power project design adopting a seawater cooling tower in future.

The invention discloses a high-efficiency aerobic granular sludge continuous flow reactor and a running method. The reactor comprises a reactor main body, a water inlet system, an aeration system and a drainage system. The reactor main body consists of an aerobic granular sludge biotreatment part and a built-in high-efficiency precipitation tube, the bottom of the built-in high-efficiency precipitation tube is designed to be like a spherical surface upward protruding, the opening below the tube wall is designed to a sawtoothed arc-shaped slot, and the inner surface of the arc-shaped slot is an inclined surface upward inclining by 45 degrees. A special hemming aeration cake of the aeration system is positioned on one side of the bottom of a reactor inner cavity, and the built-in high-efficiency precipitation tube is fixedly arranged on the wall of the reactor main body. The running method comprises the following steps: 1) inoculating aerobic granular sludge; 2) injecting domestic sewage into the reactor and starting the device; and 3) after three weeks of cultivation, maturing aerobic granular sludge, and stably running the aerobic granular sludge reactor. The invention provides an integrated reactor capable of treating sewage under the continuous flow running condition.

The invention belongs to the technical field of organically polluted groundwater treatment, and especially relates to a system for restoring organically polluted groundwater through supersonic wave combined photo-Fenton oxidation, and a method thereof. The main body of an apparatus is a supersonic wave combined photo-Fenton oxidation reaction tower, parts comprising a supersonic generator, an ultraviolet lamp, a TiO2 catalyst coating, a pH-t monitor and a mixer are arranged in the tower, and the tower, the parts, a gas recovery and purification treatment device, a condenser, a Fenton reagent box, an acid-alkali tank, a water storage box, pipelines and various pumps form the complete restoration apparatus. The synergistic effect of the supersonic waves, ultraviolet lights and Fenton oxidation substantially improves the oxidation degrading treatment efficiency of organic matters, and realizes the second pollution-free, efficient and thorough restoration of organic matter polluted groundwater.

The invention discloses a waste water purifying system of artificial marshland composite vegetation, which comprises the following steps: including water green onion, fragrant flag, water willow; interlineating fragrant flag line and water willow line in the water green onion line. This invention adopts low cost water green onion, fragrant flag, water willow and gravel base material to constitute hidden flow artificial marshland system, can either remove contaminant of water body effectively, or increase landscape of marshland distinctively.

The invention provides a bottom edge aerification system of a water delivery valve of a high lift lock. The bottom edge aerification system comprises a water delivery valve, a water gallery, a first vent pipe, a rotary joint and a second vent pipe. The water delivery valve adopts a slot-free anti-arc valve, and comprises a valve support hinge, a valve panel, and a valve support arm connecting the valve support hinge and the valve panel. The first vent pipe is buried in concrete when a valve chamber is poured, and an inlet end of the first vent pipe is positioned at the top of the valve chamber and connected with atmosphere. The second vent pipe communicated with the outside is led out of the bottom edge of the water delivery valve, and enters the valve support hinge along the valve support arm, and the rotary joint connecting the first vent pipe to the second vent pipe is arranged at the valve support hinge. The system can improve a water flow cavitation problem of a valve section of the lock, avoids cavitation erosion damage, can improve the operational safety of the lock, reduce the burial depth of the valve section and simplify a gallery body of the valve section, avoids a new cavitation source formed due to the excessively complicated body of the valve section, and can reduce the construction difficulty and construction cost of the gallery of the valve section.

The invention discloses a method for utilizing high-load earthworm biological filter to treat decentralized sewage in countries, and relates to a sewage treatment method. The treatment method comprises the following steps: the decentralized sewage in the countries is firstly collected; suspended matter and floating matter are removed by a pretreatment tank; BOD5 is led to be 110 to 160mg / L, COD is 120 to 150mg / L and SS is 90 to 130mg / L; then the obtained mixture is pumped into the high-load earthworm biological filter according to hydraulic loading of 4 to 6m<3>(m<2> question mark d); after passing through a first earthworm biological filtering layer and a second earthworm biological filtering layer which are filled with light shale spherical porcelain granules (7) filtering media with the diameter of 3 to 7mm and 15000 to 28000 eisenia foetidas (8) are added on the surface of the filtering media per square meter, the water which is discharged from a settling tank (6) and has BOD5 of less than 15mg / L, COD of less than 60mg / L and SS of less than 15mg / L reaches the national water quality standard for field irrigation; little amount of residue sludge which is collected by the settling tank (6) and contains wormcast is used for improving the soil or is used as fertilizers. The method has large hydraulic loading, small occupy area, is hard to be blocked, has simple process and operation, good water outlet quality and low construction cost and operating cost and can be widely used for treatment of the waste water in rural areas.

The invention discloses a labyrinth ultra-low-pressure trickle irrigation emitter. The trickle irrigation emitter is in a tubular structure with a through hole in the middle. The structure is composed of a labyrinth section, a water outlet section and a connecting section sequentially, wherein the maximum sizes of outer tube diameters of the labyrinth section and the connecting section are the same, a water inlet is arranged at the labyrinth section, a water outlet is arranged at the water outer section, the water inlet and the water outlet are connected through a flower type energy dissipation channel, and the flower type energy dissipation channel is disposed in the tubular wall of the labyrinth section. According to the labyrinth ultra-low-pressure trickle irrigation emitter, a dedicated water pump is not needed, the working pressure is low, the operating coat is low, and the emitter can work normally under the water pressure of the water level of 1.5m; walls of used tubes and pipe fittings are thin, requirements for material strength are not high, the construction cost is low, internal connecting type pipe fittings are adopted, and installation is convenient; the emitter is designed into a plug-and-play mode and easy to dismount for washing, and operating and management costs are low; pipe network laying is flexible and convenient; and users can freely change the spacing of emitters according to different crop spacing between rows and lay pipe networks flexibly.

The invention particularly relates to an intelligent pipeline compensator fault alarm device, and solves the problem that monitoring alarm is not timely in an existing pipeline compensator. The intelligent pipeline compensator fault alarm device comprises a compensation tube arranged in a compensation pit, a compensation spring is arranged in the middle of the compensation tube, the two ends of the compensation tube are connected with a water inlet pipe and a water outlet pipe through pipeline flanges respectively to be led out of the compensation pit, liquid level control probes are arrangedat the two ends of the inner bottom of the compensation pit, a temperature and humidity probe is arranged at the upper part of the compensation pit, air pressure displacement detection devices are arranged above the pipeline flanges, and a compensation pit cover plate is arranged on the top of the compensation pit in a covering mode. The device utilizes digitalized and intelligent data acquisitionto realize high-precision detection of the pipeline compensator and real-time alarm record, fault alarm time is greatly shortened, a lot of maintenance cost is saved, scientific management, quantitative management and timely alarm are achieved, and operation management cost is reduced.

The invention discloses a low-consumption biological treatment method of rural sewage, comprising the specific process flows: sending the rural sewage into a three-level septic tank, sending into a collecting tank, sending into a tower type biofilter, sending into wet land and yielding water. The invention fully utilizes rural geographic and geomorphic characteristics to collect sewage, supplies oxygen by a natural ventilation tower biofilter, processes rural domestic sewage by utilizing rural surrounding wet lands, is not provided with a sewage aeration system and a sludge treatment system, has simple process flow, less adopted equipment and small land occupation, obviously reduces one-shot engineering, equipment investment and operation energy loss thereof of sewage treatment, is convenient for farmers to manage, lowers operation management cost, realizes low-carbon operation, accelerates the comprehensive improvement of the rural environment and protects environment.

The invention provides a device system and method for staged water supply and cascade recycling of a wet cooling unit, the device system comprises a first-stage water supply system, a second-stage water supply system and a third-stage water supply system which are connected in sequence, and effluent of a boiler make-up water treatment unit and effluent of a condensed water precision treatment unit in the wet cooling unit are subjected to quality-divided recycling and cascade utilization; the method using the device system is low in operation and management cost, realizes zero water taking of surface source water and zero discharge of waste water of the wet cooling unit thermal power plant, reduces environmental pollution, and has obvious economic benefits and environmental benefits.

The invention provides a bioelectrocatalysis coupled contact oxidation denitrification filtration integrated bio-reactor which is characterized by comprising a bioelectrocatalysis pool, and a first water collection tank, a contact oxidation pool, a denitrification pool, a second water collection tank and a filtering basin which are arranged in sequence around the bioelectrocatalysis pool, whereinthe bioelectrocatalysis pool is used for performing bioelectrocatalysis on pollutants and comprises a hollow columnar electrocatalysis pool body, a cathode and an anode; the cathode is arranged alongan inner wall of the pool body; the anode is positioned in the middle of the pool body; a water inlet is formed in the electrocatalysis pool body; the first water collection tank is communicated withthe upper part of the electrocatalysis pool; the contact oxidation pool is communicated with the lower part of the first water collection tank and is used for performing biological contact oxidation degradation and carrying out a nitrification reaction of nitrogen; a plurality of aerators are arranged at the bottom of the contact oxidation pool; the denitrification pool is communicated with the upper part of the contact oxidation pool and is used for carrying out a denitrification reaction; the second water collection tank is communicated with the upper part of the denitrification pool; and awater outlet is formed in the upper part of the filtering basin.

The invention provides a large-scale charging pile-containing regional energy network economic optimization management method based on an MACPSO algorithm, and belongs to the field of energy network management methods. The method comprises the following steps of counting the travel data of regional electric vehicles, and establishing a travel model; counting the working data of the charging pilesin the region to establish a probability distribution model of the electric vehicles, and sampling to calculate an estimator; establishing an electric vehicle response scheduling model through the travel model, the probability distribution model and the estimator; and establishing an energy network economic optimization model through the electric vehicle response scheduling model. According to thepresent invention, the energy network economic optimization model is solved through the MACPSO algorithm, so that on the premise that the regional power generation meets the power consumption load requirement, the optimal economic operation management cost and environmental pollution treatment cost are obtained through calculation, the economic management is conducted on the regional power, and on the premise that the load power consumption requirement in the region is guaranteed, the optimal planned output of the controllable power generation units in the regional energy network is realized.

The invention provides a bioelectrocatalysis coupled contact oxidation denitrification filtration integrated bio-reactor which is characterized by comprising a bioelectrocatalysis pool, and a first water collection tank, a contact oxidation pool, a denitrification pool, a second water collection tank and a filtering basin which are arranged in sequence around the bioelectrocatalysis pool, whereinthe bioelectrocatalysis pool is used for performing bioelectrocatalysis on pollutants and comprises a hollow columnar electrocatalysis pool body, a cathode and an anode; the cathode is arranged alongan inner wall of the pool body; the anode is positioned in the middle of the pool body; a water inlet is formed in the electrocatalysis pool body; the first water collection tank is communicated withthe upper part of the electrocatalysis pool; the contact oxidation pool is communicated with the lower part of the first water collection tank and is used for performing biological contact oxidation degradation and carrying out a nitrification reaction of nitrogen; a plurality of aerators are arranged at the bottom of the contact oxidation pool; the denitrification pool is communicated with the upper part of the contact oxidation pool and is used for carrying out a denitrification reaction; the second water collection tank is communicated with the upper part of the denitrification pool; and awater outlet is formed in the upper part of the filtering basin.

The invention discloses a water purifying system for an artificial wetland. The water purifying system comprises a collection and pretreatment system, a water distribution and collection system, a plant tank and a precipitation system; when the sewage sequentially passes through the step type plant tank under the gravity function, the pollution matters and nutrients are absorbed or desorbed by a plant system, and then the water is purified; a gravel filtering material of different gradation is arranged under a net-shaped separating film, the special soil is put at the upper part of the net-shaped separating film, and the net-shaped separating film is a biological carrier which is prepared according to a certain material proportional ratio, so that the net-shaped separating film is suitablefor the growth of wetland plants and has certain porosity, and the organic matters in the sewage are absorbed in the special soil, collected, and degraded under the action of microorganisms in the soil; nitrogen, phosphor, potassium and other nutrients required by plant growth are absorbed and utilized by the roots of the wetland plant, and the sewage entering the wetland system is effectively purified under the functions of adsorption and degrading by the soil and the microorganisms in the soil, and the functions of percolation by filler and adsorption by plants.

The invention discloses a landscape-type recycled water treatment wetland system suitable for an urban community, which comprises a wetland pool; reed, zizania aquatica, water willow and scirpus validus vahl are planted in the wetland pool; rows of the zizania aquatica, water willow and scirpus validus vahl are mixed among the rows of the reed; and the rows of the zizania aquatica, water willow and scirpus validus vahl mixed among the rows of the reed are single or various. The landscape-type recycled water treatment wetland system has the advantages that: the system has high efficiency for water purification, high yield of vegetation, wide range of application, low construction cost, convenient operation and management, good landscape effect and large wetland evapotranspiration.

The invention provides a fresh air device and a control method thereof. The fresh air device comprises an air draft unit and a dust removal unit. The air draft unit comprises a first cover body, a first filter screen, a controller and an air draft fan electrically connected with the controller, and the first cover body is provided with an air inlet and an air outlet which communicate with the interior and the exterior correspondingly. The dust removal unit comprises a second cover body, a second filter screen and a dust removal fan electrically connected with the controller. The second cover body is provided with an air outlet and an air inlet which are respectively communicated with the indoor and outdoor. During cooling, the air draft fan is started to exhaust indoor air to the outside from the first cover body, so that outdoor cold air is sucked into the indoor space through the second cover body. During dust removal, the dust removal fan is started and blows air to the second filter screen so as to remove dust on the surface of the second filter screen. According to the fresh air device, automatic dust removal can be achieved without additionally arranging a dust removal brush,the dust removal effect is good, the maintenance time and the service life of the fresh air device can be prolonged, and the energy-saving and cooling effects are good.