In Taiwan, huge amount of LNG was imported each year where it was evaporated into NG using sea water to provide for household and facility usage, such as power generation. During this conversion process, tremendous cold energy had been wasted and dissipated to the sea. It is the main goal of this research to reclaim the cold energy for another engineering application to conserve energy. Research efforts has been focused on Nitrogen Separation process, where pure Nitrogen should be produced in low temperature, and is thus suitable to use LNG cold energy. It is estimated that among the 20 million kW-h power devoted into N2 separation each year, 48% can be saved from reclaiming LNG cold energy, presenting significant energy-savings potential. Based on 3 processes proposed in this study, the payback years were all ranked within 5 years, indicating promising feasibility for engineering applications.

Yes / In this work, a novel concept in freeze desalination (FD) was introduced. Nowadays the total liquefied natural gas (LNG) production capacity has reached 290 Megatons per year. Its enormous cold energy released from re-gasification can be used in the freeze desalination process to minimize the overall energy consumption. A process of FD on flake ice maker utilizing LNG cold energy was designed and simulated by HYSYS software. An ice bucket on flake ice maker was chosen as seawater crystallizer mainly due to its continuous ice making and removing ice without heat source. A dynamic model of the freezing section has been developed and simulated through gPROMS software. The results show that the consumption of 1 kg equivalent LNG cold energy can obtain about 2 kg of ice melt water. In addition, it is shown that the power consumption of this LNG/FD hybrid process is negligible.

The import of the vegetable has prevailed in the long run over the own production. In connection with this reality and increasing demand for the food with higher quality the production greenhouse is more often built. The providing heat, cold and electricity for the year-round operation is related to the construction and working of these objects. The theoretical part of this theses describes possible ways how to cover energy consumption for the model greenhouse in Kožichovice, Třebíč region. The heat losses and the year-round heat consumption were stated for the selected model and compared with the exact values from Kožichovice. The following method of energy supply was selected based on the calculated energy consumption - the separate cogeneration unit, cooperation of several cogeneration units, a biogas station, a heat pump and central heating system. These methods of energy supply were subjected to technical and economical comparison.