A heat pump driven and hollow fiber membrane-based liquid desiccant air dehumidification system: A transient performance study

• Heat pump driven and hollow fiber membrane based liquid desiccant air dehumidification system is proposed.
• A transient model is given.
• Load and output responses to weather are analyzed.
• Compressor speed is adjusted to meet the load change.

Heat pump driven and hollow fiber membrane based liquid desiccant systems have been adopted for air dehumidification because of their capabilities to prevent liquid desiccant droplets from crossing over into the process air and to achieve high energy efficiencies. Due to the transient operating conditions like load and weather conditions, a transient model for the novel system is proposed in this study. Based on experiments and model simulations, the transient behaviors of the system are analyzed both at the start-up and in the normal operation periods. It is found that the initial concentration of the liquid desiccant and the volume of solution stored in the container play key roles at the start-up period, while the initial temperature has less influences. Adjusting the compressor speed is a feasible way to track the load and weather fluctuations. The model developed in this work is necessary for the control and optimization of the air dehumidification technology.