Chapters authored
Novel OTEC Cycle Using Efficiency Enhancer
The ocean thermal energy conversion (OTEC) plant is designed to improve the efficiency of the existing plants. Various researches are being conducted to increase the plant’s efficiency and output with the use of an enhancer, and studies for performance improvement are also in progress from the Kalina and Uehara cycles to ejector pump OTEC (EP-OTEC). Their performance can be improved by increasing the evaporation pressure using an unused heat source and reducing the heat consumption using a reheating system and a regenerator. In the case of EP-OTEC, an ejector is installed near the turbine-exit to reduce the pressure and therefore increase the power output. In simulations and experiments conducted in this study, EP-OTEC showed 38% efficiency improvement from the basic cycle, which is due to the power output volume increase. The optimum ratio was derived by adjusting the pressure ratio. The demonstration plant to be developed in the future is expected to be applied to the high-efficiency OTEC demonstration plant with improved performance, and new technologies will be continuously developed considering economics and commercial viability.
Part of the book: Ocean Thermal Energy Conversion (OTEC)
Perspective Chapter: Ultra-Low Temperature Chillers for Semiconductor Manufacturing Process
The growth of the semiconductor market and advancement of manufacturing technology have led to an increase in wafer size and highly integrated semiconductor devices. The temperature of the supplied cooling medium from the chiller that removes the heat produced in the semiconductor manufacturing process is required to be at a lower level because of the high integration. The Joule-Thomson cooling cycle, which uses a mixed refrigerant (MR) to produce the cooling medium at a level of −100°C required for the semiconductor process, has recently gained attention. When a MR is used, the chiller’s performance is heavily influenced by the composition and proportions of the refrigerant charged to the chiller system. Therefore, this paper introduces a cooling cycle that uses an MR to achieve the required low temperature of −100°C in the semiconductor manufacturing process and provides the results of simple experiments to determine the effects of different MR compositions.
Part of the book: Latest Research on Energy Recovery