An energy efficiency control strategy for a building-oriented dehumidification system

In industrial or commercial buildings, the working components and energy sources of a Liquid Desiccant Dehumidification System (LDDS) are usually in different locations, which increases the difficulties of system operation and maintenance. This paper presents a control strategy on the outlet air humidity for a dehumidifier with distributed operating scheme to improve the performance of a large-scale LDDS. A new Fuzzy-PID controller is implemented to fine tune the outlet air humidity by manipulating the solution inlet temperature at a stable desiccant concentration ranges. This Fuzzy-PID controller is developed from a T-S fuzzy model, with varied parameters according to previous and current input and output variables. Control performances of the cooperation between concentration regulation module and General-PID, Cascade-PID or Fuzzy-PID controller have been compared in simulations. Different indices are used to evaluate the control performances of different controllers. The simulation results show that the method proposed in this paper can solve the control issues raised by distributed operation, which is an appropriated choice to be applied in a multiple-terminal LDDS in buildings.