Comparative study of hydrophilic materials for air-to-air heat/mass exchanger

摘要

The paper aimed to investigate the performance of several hydrophilic materials, namely metals, fibres, ceramics, zeolite and carbons, and to select the materials that are most suitable for performing heat and mass transfer between the incoming and outgoing airstreams associated with buildings. Heat and mass transfers within the dry and wet channel airstreams were investigated, and this has provided useful suggestions on the selection of the materials for heat and mass transfer membranes. It has showed that a material's thermal conductivity has less impact on heat transfer than its porosity and pore size do. Besides, hardness, durability and cost of the material are also important in material selection. To enable an effective heat/mass transfer, the porosity of the material would be higher than 3.82 × 10~2, and the pore size would be in the range from 2.75 × 10~(-10) to 3.2 × 10~(-7)m. The material should also be easy of shaping and durable in long-term operation. Of the selected materials, fibre and carbons indicated a higher performance in heat and mass transfer. But fibre would suggest a cheap solution to this process.