멜트블로운 부직포로 제조된 평막형 전열교환소자

Abstract

Enthalpy Exchanger is an advanced ventilator which typically controls the temperature in exchange of two different air inside through air supply and exhaust also controls the humidity at the same time, reduce the difference in temperature and humidity inside and out, and hence realizes energy. Two distinct characteristics of paper material used in today's exchanger are porous surface structure and excellent high- and low-air permeability. However, there are problems such as decomposition of materials by mold spread after absorbing moisture many hours of use, reverse contamination during the ventilation, and high exchange costs due to its low durability from washing. Melt-blown manufacture method that manifestly similar structure as a paper was used to resolve those problems of paper material energy recovery mentioned above. Its replaceability was based on filtering efficiency comparison of surface structure, air-permeability, absorbability, and mechanical properties by the use of two polymers, Polypropylene (PP) and polyamide (PA, Nylon). In the beginning, the properties of paper materials that used in energy recovery and many other thermoplastic polymers were examined. The melt-blown manufacture method was chosen after examining the structure and properties of paper material and many non-woven manufacture methods that make similar structure as paper material. In chapter 2, the optimum process condition of PP and PA polymers suggested after examining the melt-blown of non-woven manufacture system and the conditions per each process. In addition, the previous studies and trends of Enthalpy Exchanger were analyzed and the meaning of its replacement was explained In chapter 3, two types of polymers, PP and PA were treated with additives such as hydrophilic and absorbent agents. A variety of experiments, including chemical and physical processes such as UV treatment and calendering process were conducted. In results, the changes in surface structure, moisture movement, air permeability, tensile strength, and thermal characteristics of PP and PA were investigated. In chapter 4, critical properties of moisture and air permeability were gained after hydrophilic treatment and calendering process of hydrophobic PP polymer. Even after hydrophilic treatment of low-melting and hydrophobic PP polymer, it was difficult to higher moisture permeability than 5,000 (g/m²/day). In such condition as 100℃, 2.0-2.5m/min, 4,000 (g/m²/day), the highest moisture permeability was obtained. However, its low air permeability, 2000 sec was far less than 5,000 g/m²/day and 5,000 sec, air permeability and permeate time of paper material. Therefore, this test concluded its replaceability of the paper material low. After conducting the same tests on PA polymer, the similar properties of paper materials were gained by hydrophobic properties itself and changes in surface structure after calendering process. In such condition as 2.0m/min at 124℃ calender temperature, higher moisture permeability, 6,000 g/²m²/day and air permeate time 8,000 sec were yielded and these values are considered to be excellent properties of Enthalpy Exchanger that could replace paper materials. In conclusion, the comparative analysis of the surface and performance of PP and PA polymers non-woven and computer simulation of ventilation system in Enthalpy Exchanger were conducted. With paper element and equal method, valid energy recovery efficiency of summer and winter condition was measured and it is concluded that PA melt-blown polymer non-woven is an outstanding material for an Enthalpy Exchanger.