To address the influence of multi-scale complex loads on the deep-sea mining transport system during operations, the Failure Modes and Effects Analysis (FMEA) method is improved based on the α-cut fuzzy numbers, resulting in an α-cut based Fuzzy FMEA model ( α-FFMEA). The evaluation criteria of failure modes, including occurrence ( O), severity ( S), and detectability ( D), are described by using linguistic terms, effectively overcoming the limitations of traditional methods in dealing with uncertainty. Analytic Hierarchy Process (AHP) and entropy theory are used to assign the weights of O, S, and D reasonably and objectively, ensuring the scientificity and accuracy of the risk assessment. The α-cut fuzzy numbers and centroid method are then used to calculate the risk priority number of each failure mode across different α-cuts, providing a quantitative basis for system failure prevention and optimization. Finally, the transport system in the deep-sea linkage system is analyzed to validate the effectiveness and applicability of the model, offering important theoretical basis and practical guidance for the optimization and failure prevention of the deep-sea mining transport system.

The air conditioning system is an important component of the service system for the ship safety area. The function of the air conditioning water system is to transport chilled/hot medium water from the cold or heat source to the air treatment equipment. The air conditioning water system includes the chilled water system and the hot water system. The current study researches the impact of Safe Return to Port (SRtP) requirements on the design of the air conditioning water systems of large cruise ships, addressing the design ability for the SRtP of cruise ships. Firstly, the purpose of the design of the air conditioning systems for the SRtP of large cruise ships is presented based on the SRtP rules, and the basic design method of the air conditioning water systems for the SRtP of large cruise ships is also proposed. The configuration scheme, system principle and valve operation of the air conditioning water system for the SRtP of a large cruise ship are analyzed and studied to provide the design method of the air conditioning system of the activated safe area and the machinery space supporting SRtP. The results indicate that different design methods should be flexibly selected to simplify the design of SRtP. The research can provide references for the design of the air conditioning water system for large cruise ships in the future.

Large passenger ships usually have multiple galleys to meet the needs of different passengers for delicious food. And each galley demands to be equipped with one or more exhaust fans. The galley therefore requires high exhaust air volume, correspondingly with high energy consumption of the exhaust fan. The galley hood is an important component of the galley exhaust system, which is used to collect water vapor and oil smoke generated by various equipment in the galley. At present, the galley on large passenger ships generally uses the hood for centralized local ventilation. This study analyzes the control technology of the exhaust system of the traditional galley hood on large passenger ships. A new design method of energy-saving exhaust control system is proposed for the galley hood based on the frequency conversion control technology and variable air volume control technology for fans, in order to address the disadvantages of high exhaust air volume and high energy consumption. Through experimental verification on a Ro-ro passenger ship, the air volume data of the galley exhaust fan in the traditional exhaust system are compared and analyzed with those in the energy-saving exhaust system. It is verified that the new galley hood exhaust system has significant energy-saving effect and can be popularized in other ship types.

The polar region has great economic and technological value, and helicopters have played an important role in China’s previous scientific expeditions in the North and South Pole. In order to lead the development of helicopter technology for polar environment, the helicopter usage scenarios and key technical requirements are established by analyzing the geographical and meteorological environment of polar region and the mission profile, and the connotation of each key technology and future development are studied and analyzed. It is the future development that the helicopter can adapt to the complex geographical, meteorological and extreme low temperature environment in polar regions, and achieve autonomous support in polar depopulated zone by focusing on the development of key technologies such as take-off and landing in ice and snow, flight in complex environments, anti-ice and rainproof, low temperature use, heating and insulation in the cabin.

For the marine power plant with the side exhaust system cooled by water spraying, the opening of the water spray cooling device will cause significant change of the temperature in the system. The properties of the flue gas in the exhaust system will therefore change, which accordingly affects the acoustic performance of the side exhaust silencer system. This paper firstly calculates the hydrodynamics of the side exhaust system before and after the water spraying through Fluent, and then the temperature distribution of the side exhaust silencer system at the different water spray flow by changing the cooling water flow. The CFD results are then used as the input to calculate the transmission loss of the exhaust system in order to obtain the acoustic performance of the side exhaust system before and after water spraying. It concludes that the water spry cooling can improve the acoustical behavior of the whole system at the low frequency range. The results can provide reference for the design of the side exhaust system in the future.