الفهرس 
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Abstract
This research addresses the problem of controlling the air temperature leaving a chilled-water air-cooling and dehumidifying coil. Two control strategies are adopted; namely,the fuzzy logic controls (FLC) and the PlD control. The design of the fuzzy controller comprises the error in the desired air temperature and the velocity and acceleration of that error as antecedents. The rule base is developed using the general dynamics of the process. The cooling coil was interfaced to a PC computer where software’s (in HP VEE language) for both FLC and PlD were built in.Experiments were conducted upon changing the coil surface area the inlet-air temperature, the desired exit-air temperature, air velocity, and the inlet chilled-water temperature. For the same operating conditions, as the coil surface area increases the maximum cooling capacity increases and the apparatus dew point decreases nonlinearly. The results show that FLC is capable of handling a wide range of uncertainties. At full outside load, the PlD and the FLC controls can achieve the desired temperature and 100% relative humidity but the PID results in larger downshoot than the FLC. At part loads, FLC is robust It can adapt itself quickly and its performance is satisfactory Meanwhile, a hunting problem is experienced in the three-way control valve operated according to the PID control. The downshoot in the exit-air temperature increases and the response is slower for the PlD control than the FLC. For two cooling steps operations, both controllers can adjust the desired dew point accurately. The settling time for PlD control is longer than that for the FLC.