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To minimize the water absorption and to improve the thermal insulated properties of the insulation materials used for the cargo containment systems (CCSs) of LNG carrier, a kind of expanded water-repellent perlite has been developed by coating hydrophobic membrane onto the outer surface of the expanded perlite to change its physical and chemical characteristics. Considering the CCSs operated in a wide temperature range from environmental temperature to cryogenic temperature, the thermal analysis has been conducted to quantitatively determine the thermal insulted properties of the insulation materials. Furthermore, a double-sided guarded hot plate apparatus (GHP) is specifically designed and fabricated for the measurement of the thermal conductivities of the insulation specimens operated down to liquid nitrogen temperature. The breakage ratio associated with the water absorption and the thermal conductivity of the expanded water-repellent perlite is firstly proposed, and then a series of experiments are carried out to determine the thermal conductivity of the expanded water-repellent perlite ranging from room temperature to cryogenic temperature based on the different breakage ratios.

A simulation model of chiller system containing four sets of chillers is built in Energyplus 7.0 simulation software. Based on the simulation data of chiller system, a data-mining tool − hierarchical cluster method is applied in chiller system to analyze the operation performance of chiller system. Using a built-in analytical tool in SPSS v17.0, hierarchical cluster method is made on the five main operating variables of chiller system over a year. There are three clusters produced by hierarchical cluster method, which represent three typical operating conditions of chiller system of a whole year. Through the analysis of the characteristics of clusters of main operating variables, the operating conditions of each chiller can be illustrated, which matches with the control strategy implemented in the chiller system. By the analysis of COPs of each chiller in different clusters, the potential of energy saving for the chiller system under different clusters can be illustrated. Besides, it is found that the Refrigeration Operation Energy Efficiency Ratio (ROEER) of one chiller over one year can be represented by the COPs of one chiller in different cluster centers, which demonstrates that the cluster results are reasonable.

A double-sided guarded hot plate apparatus (GHP) is specifically designed, fabricated, and constructed for the measurement of thermal conductivities of insulation specimens operated down to liquid nitrogen temperature (-196 °C), at different controlled pressures from 0.005 Pa to 0.105 MPa. The specimens placed in this apparatus are 300 mm in diameter at various thicknesses ranging from 4 mm to 40 mm. The apparatus is different from traditional GHP in terms of structure, supporting and heating method. The details of the design and construction of the hot plate, the cold plates, the suspensions, the clampings, and the vacuum chamber of the system are presented. The measurement methods of the temperatures, the input power, the meter area, and the thickness of the specimens are given. The apparatus is calibrated with teflon plates as sample and the maximum deviation from the published data is about 6% for thermal conductivity. The uncertainties for the measurement are also discussed in this paper.