Abstract
Refrigeration systems are required in most chemical industries in order to maintain the temperature in process equipments, production line, air-conditioned environments or rooms, etc. The main drawback of the refrigeration systems is the great energy requirement. Aiming at minimizing these costs, several works have been reported in the literature using variable speed compressors. This study applied the commercial software ASPEN PLUS® and ASPEN PLUS DYNAMICS® to simulate an experimental chiller prototype. The first software was used to simulate the steady state condition, while the latter one was used to evaluate the open loop and closed loop dynamics of the cooling process. The geometries of heat exchangers were obtained from the software EXCHANGER DESIGN AND RATING®, also included in the package ASPEN®. Once validated with experimental data, the simulator was used to the performance assessment of the classical control strategies application using variable speed compressor. It was also proposed the use of fuzzy logic-based control. It was used a two-term fuzzy control, that is suitable for nonlinear processes and is based on the plant expert knowledge. The fuzzy controller proved to be effective in controlling the system under different operating conditions.
