In this research, a device for injecting condensate-water generated from the evaporator into the distributor on the top of the condenser was fabricated as a method for improving the efficiency of the portable air conditioner. To compare the efficiency, the condensation temperature, blowout air temperature, power consumption, cooling capacity, and COP of the system were measured. As a result of the experiment, the condensation temperature dropped by about 6.2 °C. Also, the power consumption of the compressor was reduced by about 0.16 kW and the cooling capacity increased by 0.2 kW. As a result, it was confirmed that the COP increased by about 16 % when the condensate-water was sprayed on the condenser.

In this study, to investigate the performance characteristics of a seawater ice-making device, using a scraped surface double tube evaporator, experiments were conducted under various operating conditions, including inlet temperature and flow rate of seawater, evaporating temperature, and scraper rotation speed. The main results are summarized as follows: (1) The section where stable ice making is possible, is determined by the inlet temperature and the flow rate range of seawater. By controlling the flow rate of seawater, the ice packing factor (IPF) of the device can be adjusted from 0.3 to 14.7%. (2) The IPF increases in cases where the evaporating temperature decreases linearly, until −13 °C. As the temperature of refrigerant that flows into the evaporator changes, the IPF is changed. Consideration is required for these connections. (3) The IPF increases when speeding up the scraper. The minimum rotating speed of the scraper was 350 rpm in these experiments. Optimum operating conditions for the seawater ice slurry maker are established through experiments. These results will be considered as important data for designing a slurry type seawater ice-making device.