Thermal and exergetic performance evaluation of an absorption type desiccant dehumidifier

In this article, a mathematical model for rotary-shaped liquid desiccant dehumidifier has been developed for its parametric and feasibility analysis. The dehumidifier has a cylindrical shape with a number of circular channels, distributed uniformly over the rotor cross section. This type of dehumidifier is commonly known as desiccant wheel. The energy and exergetic performance of the dehumidifier has been discussed under different operating conditions. The performance curves which help to optimize the performance of the dehumidifier are drawn for a wide range of rotational speeds (0.5–7 rpm), wheel width (0.1–0.6 m), air mass flux (1–8 kg/m².s), and regeneration temperature (50–90°C). A reduction of about 25% in humidity ratio is observed with an increase in the wheel width from 0.1 to 0.2 m. Furthermore, a feasibility analysis of the proposed dehumidification system has been presented for climatic conditions of Dhahran. The computed results show that better supply air conditions can be obtained to provide human comfort in the hot and humid climate with effectiveness of the system largely dependent on air flow rate, wheel width, and humidity ratio of the process air. The annual average value of dehumidification performance is found to be 0.55 which shows that system can control the latent load efficiently throughout the year.