Theoretical calculation and experimental analysis on humidification performance of high-performance water-absorbing porous fiber plates

Abstract

In order to improve the indoor relative humidity in winter, a high-performance water-absorbing porous fiber plate was introduced in this paper, which absorbed water and infiltrated through capillary action, and an experimental system with porous plates arranged in parallel as humidifying elements was designed and constructed to explore the humidifying performance of porous plates and to expand its application field. The experimental results showed that the humidification effect of porous plates was excellent. At a relative humidity of 15 %, mainstream air velocity of 3.5 m/s, and air temperature of 45 °C, the maximum humidification capacity of the system reached 266.4 g/h. The humidification capacity was proportional to the air temperature and mainstream air velocity, and inversely proportional to the relative humidity of the air. The mainstream air velocity increased by 0.5 m/s, the humidification capacity increased by about 20 g/h. The change trend of humidification capacity and heat transfer quantity calculated through the criterion correlation was consistent with the measured values, and the relative errors between the theoretical and experimental values for most of the conditions were within 20 %. One of the reasons for the errors might be that the mainstream air velocity in the gaps between the porous plates was greater than the mainstream air velocity of the experimental air duct used in the theoretical calculation. Due to the difficulty in measuring the air velocity in the gaps between porous plates, CFD simulations were conducted. The relative errors between the theoretical corrected values calculated with the simulated air velocities and the experimental values were within 10 % for most of the conditions, and between 10 % and 15 % for very few conditions.