Research On Ionic Wind Technology For Indoor Air Purification

In recent years,indoor air pollution has been an increasing serious problem with the rapid development of national economy.Ionic wind technology has a long history of more than 200 years.In the efforts of researchers,people gradually unveiled its mysterious veil.Ionic wind is a kind of plasma jet movement generated from the collision between charged particles of electrode discharge and neutral gas molecules,which can be applied in the fields of air flow control and propulsion,heat dissipation,air purification and so on.Combined with the characteristics of plasma adsorption of particulate matter,decomposition of organic matter and inactivation of microorganisms,the ionic wind technology can achieve silent air purification.A coupling electrode structure is proposed in this dissertation based on the glow discharge characteristics of carbon fiber spiral electrode and the DC ionic wind characteristics of wire-to-bar electrode.On this basis,the ionic wind speed is increased by means of constructing the electric field between electrodes.An ionic wind generator is designed complying with the principle of ionic wind formation,and its air purification performance is tested.Firstly,the glow discharge characteristics of carbon fiber spiral electrode are studied by electric field simulation and experiment.The DC ionic wind characteristics of the wire-to-bar electrode are discussed.Considering about these,a coupled electrode structure has been proposed so as to realize the ionic wind generation under the condition of glow discharge.In this structure,the carbon fiber spiral electrode serves as the cathode and the metal plate electrode serves as the anode.The discharge characteristics and ionic wind characteristics of the coupled electrode structure under DC voltage and AC/DC coupling voltage are discussed respectively.The experimental results show that the ionic wind speed of the coupled electrode structure at AC/DC coupling voltage is 85%higher than that at DC voltage alone.Secondly,the ionic wind speed is increased from plasma generation and DC electric field acceleration.The idea of adding a third electrode to the coupling electrode structure is proposed.Simulations and experiments show that the addition of the third electrode enlarges the area of the collision ionization zone of the coupled electrode structure,increases the number of charged particles used to form the ionic wind,and finally increases the ionic wind speed.The maximum speed of ionic wind is 2.98m/s.On the basis of the third electrode,the effects of the spiral electrode array arrangement and the metal anode laminated arrangement on the ionic wind speed are analyzed by the electric field simulation and the flow field simulation.It is concluded that the array arrangement of spiral electrodes is conducive to the improvement of ionic wind volume and wind speed stability,while the laminated arrangement of metal anode is conducive to the further improvement of ionic wind speed,thus promoting the air purification efficiency.Finally,a prototype is designed and made according to the principle that ionic wind is formed by the glow-discharge plasma of coupled electrode structure.It consists of a primary filter,carbon fiber spiral electrodes and a metal plate collector.The air purification experiment of ionic wind generator was carried out in standard air purification chamber.The experimental results show that the prototype can effectively remove TVOC,with a nine-minute removal rate of 59.7%and a CADR of 196.2m~3/h.The prototype has a less effective effect on the removal of formaldehyde,approximately 39.9%an hour with the CADR of 16.2m~3/h.During the purification process,the by-product ozone production is low,increasing by 2?3ppb every 10minutes.Thus,with the glow discharge plasma as carrier,the ionic wind technology can play a good role in the purification of organic pollutants.The treatment effect of formaldehyde can be improved by multi-layer electrode arrangement and air duct design.And the existence of ionic wind can replace the fan,thus eliminating the noise pollution in the purification process.The application of ionic wind technology in indoor air purification can truly achieve silent purification.It is very suitable for bedrooms,hospital wards,meeting rooms and other places.