| In contemporary society,the increase of the number of city office,together with people more and more requirement of indoor decoration,aggravates the problem of indoor environment pollution,and the indoor air condition is closely related to people’s health,but also the most easily neglected problems.Therefore,this article is aiming at the most common organic indoor air pollution gas--formaldehyde degradation experiment research,designing a set of equipment which can put into the central air conditioning and ventilation system of building,guaranteeing the drive ability and will not affect the ventilation system capable.By comparing the conventional way of formaldehyde degradation method,this paper chose to use DC corona reactor to produce low temperature plasma to degrade formaldehyde method,so the design of single-stage cylinder needle-net electrode as basic electrode structure of corona reactor on account that the supply situation can not affect the ventilation ducts.Following discussion for the reactor are taken through a large number of experiments:Firstly,the single-stage cylinder needle-net electrode corona reactor are designed,and various electrode structure parameters on the discharge characteristics of the system are explored through the control variable method.It is found that in the normal corona discharge voltage range,for the tubular needle-net type electrode reactor,the discharge current decreases with decreases of the diameter of the needle electrode,decreases with the decreases of drum net electrode diameter,and increases with the increase of discharge voltage,increases with the increase of net electrode wire mesh density,and under the condition that other conditions unchanged,negative corona current is higher than that of positive corona current;It is found that the maximum current is 0.371 m A in the experiment In addition,the relationship between circuit equivalent conductance I/U and the discharge voltage U also satisfies the classical Thomson relations which is commonly used in corona discharge.In the second,explore the driving effect of corona reactor.Research shows that the corona reactor can produce low temperature plasma ion wind,therefore this paper experiments to explore the ion wind features of cylinder needle-net electrode,in order to ensure that it will not affect the overall ventilation effect,also has certain drive effect on the air inside of the original system.The results of experiment showed that the wind speed of ion wind can reach 0.810m/s.Thirdly,explore the characteristics of degradation of formaldehyde in this coronareactor.The degradation of formaldehyde experiment system is designed,design a generator which can produce a uniform concentration of formaldehyde and link it into,using control variable method to explore the relationship between electric voltage,system of gas flow rate,reaction length,inlet concentration of formaldehyde and formaldehyde degradation rate and the absolute purification of formaldehyde.It was found that: degradation rate of formaldehyde and absolute purification increase with the increase of the discharge voltage,with the increase of the length of corona reactor,and decreased with the increase of unit inlet air intake flow;Thus,the formaldehyde degradation rate increased as the entrance to the formaldehyde concentration decreases,but at the same time,the amount of absolute purification formaldehyde was increased.In the experiment,the maximum formaldehyde degradation rate is 36.83%,the maximum amount of absolute purification formaldehyde is 3.23 ppm.It is concluded that the order of factor that affect the degradation rate of formaldehyde is the reaction length,gas flow,and inlet concentration and discharge voltage.Finally,the corona discharge characteristics of reactor cylinder needle-net,driving characteristics and degradation of formaldehyde features are concluded,it is proved that this device can be used in building ventilation systems,this paper laid a good theoretical basis for the further practical research. |
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