Optimal layout of multi-floor process plants using MILP

Abstract

In this work, a new mixed integer linear programming (MILP) model is proposed for the multi-oor process plant layout problem with additional considerations. Multi-oor process plant layout determines the spatial arrangement of process plant units considering their connectivity amongst other factors and aects the cost of constructing the plant, the ease of plant operation and expansion, general safety levels within the plant and its neighbouring environment, as well as operational costs. Over the past years, mathematical programming models have been developed to describe the layout problem considering connectivity costs, pumping costs, installation of safety devices, and piping, in single and multiple oors. Features such the representation of irregularly shaped items, tall equipment spanning multiple oors and others have been successfully modelled. This work builds on such past considerations with additional features that allow multi-oor equipment items extend above the maximum potential number of oors, and the selection of an available number of oors less than the maximum number required by any equipment item. Integer cuts are also developed for the proposed model to enhance its eciency. The performance and limitations of the proposed model are demonstrated with industry-relevant case studies of up to 25 units, and results show a potential cost savings when compared to existing models with additional computational benets of the integer cuts in all of the cases explored.

Factory Manufactured Modular Construction of Process Plants

“…Automated design techniques were highlighted [29] and a method to arrange modules in a process plant developed [30]. Layout optimisation models have been applied for optimising construction, safety, operational costs [31] in the industrial process plant research.…”

An MILP model for safe multi-floor process plant layout using the domino hazard index

“…From an optimisation point of view, safety factors in layout designs have been considered in the past. A great deal of research have focused on the economic aspects -piping, construction and operational costs -associated with a layout conguration in single and multi-oor scenarios (Barbosa-Póvoa et al, 2002, Ejeh et al, 2018a2019b, Georgiadis and Macchietto, 1997, Guirardello and Swaney, 2005, Hwang and Lee, 2014, Papageorgiou and Rotstein, 1998, Park et al, 20112018, Patsiatzis andPapageorgiou, 2002;2003). However, an ideal plant layout design ought to establish a balance between risks and cost savings.…”

“…In this section, the proposed mathematical model is presented in detail. The proposed model is an extension of the MILP model in Ejeh et al (2019b) -model OPTL -which determines the optimal multi-oor process plant layout conguration for a set of process plant equipment items with considerations for piping, horizontal and vertical pumping, area-dependent land purchase, and xed and area-dependent oor construction costs. Additional constraints are included to evaluate equipment separation distances, aside from connection distances, for safety metric calculations, hazard scenarios as outlined in Step 4 (section 3), and the purchase and installation of protection devices.…”

“…In addition to the oor constraints by Ejeh et al (2019b) outlined in the appendix, the following are introduced. To ensure that the value of the binary variable N ij is 1 only when two items are assigned to the same oor, equation (A.4) is replaced by ( 14) -(20).…”

Coupling Layout Optimization of Key Plant and Industrial Area

“…Additionally, pipeline network design plays a more important role in the area-wide layout because of the long distance, which brings more solving difficulties as well. Therefore, at present, more attention is paid to the study of plant layout [28][29][30][31], and unfortunately, only a small number of researchers have focused on the area-wide layout [32,33] due to its complexity. The coupling optimization of both is even rarer.…”