Packing computing servers into the vessel of an underwater data center considering cooling efficiency.

• A green and sustainable method for packing servers is investigated. • Cooling principles on cooling efficiency and packing capacity are constructed. • The problem is formulated as bin-packing models via segmenting and gridding. • Mathematical analyses and solution strategies help to pack servers efficiently. An Underwater Data Center (UDC) is an underwater vessel full of computing servers and designed with a cooling system using cold water in the ocean. A UDC vessel is composed of cabinets for computing servers, and the cabinets are finally packed into racks that facilitate the installments of the computing servers. We formulate the problem of packing cabinets into the vessel by considering the water volume required for server cooling and the placement of the cabinets of servers. Due to different patterns of racks, a set of mixed-integer linear programs were developed, and they were solved by methods with several stages. As demonstrated by experiments, the proposed models and strategies effectively solve the simulated instances generated by considering the cooling principles. The cabinets with more considerable differences in their width and height are better than single-sized cabinets because the smaller cabinets make the packing process more flexible. Moreover, multi-sized cabinet packing is significantly better than single-sized cabinet packing. Additionally, it is not always appropriate to use racks with large capacities. However, racks with multiple capacities may improve the space and energy utilization degrees when the size and the designed heat power consumption of the data center are fixed. [ABSTRACT FROM AUTHOR]