Experimental investigation on constant temperature and relative humidity control for cigar storage cabinet utilizing a water immersion evaporator

Temperature and humidity are critical factors influencing the quality of cigar storage, and maintaining these interrelated parameters within a specified range poses a common challenge in cigar preservation. A unique approach for controlling temperature and relative humidity in the cigar cabinet is proposed, integrating immersion cooling technology with the proportional-integral-derivative (PID) control method to minimize fluctuations. The chilled water circulates in the traveling water evaporator located in the cigar cabinet, while the cold storage procedure is executed by the immersion evaporator in the water tank. The temperature and relative humidity in the cigar cabinet are regulated by the PID control method, which manages the operation of the circulating water pump, the speed of the evaporator fan, and the current of the positive temperature coefficient (PTC) heater in the system. The control performance is assessed in a JC275 L cigar cabinet. The stability of the cigar cabinet storage is evaluated under four extreme and normal operational conditions, with the temperature rise between the inlet and outlet of the water-flow evaporator restricted to 0.5 °C, the temperature differential maintained at 1.25 °C, and the relative humidity controlled within 2% throughout the cabinet. Moreover, the chilled water storage method effectively mitigates the impact of compressor cycling on temperature and humidity fluctuations within the cabinet. Consequently, the aforementioned approach can maintain cigars under optimal storage conditions.