N. Nishida

Bio: N. Nishida is an academic researcher from Auburn University. The author has contributed to research in topics: Nonlinear system & Piecewise. The author has an hindex of 4, co-authored 4 publications receiving 114 citations.

Studies in chemical process design and synthesis: III. A Simple and practical approach to the optimal synthesis of heat exchanger networks

Abstract: An algorithmic-evolutionary approach to the systematic synthesis of minimum cost networks of exchangers, heaters, and coolers is proposed. The new approach is easy to apply by hand calculations, requiring no special mathematical background and computational skill from the user. In addition to generating many cheaper networks for sample problems ranging in size from 4 to 10 streams as compared to previous studies, the proposed method provides an explicit theoretical guidance on the optimal exchange among hot and cold streams and on the optimal locations of heating and cooling utilities in the network. It also has a provision for the use of stream splitting and for generating a cyclic network. The new method is particularly effective in the synthesis of minimum cost networks for industrial crude unit preheat recovery.

Studies in chemical process design and synthesis II. Optimal synthesis of dynamic process systems with uncertainty

Abstract: The concept of the optimal synthesis of dynamic process systems with uncertain parameters is introduced. A structure parameter approach is used to theoretically derive the necessary condition for the optimal performance system structure, and an effective algorithm for implementing the synthesis method is presented. The results are applied to the optimal synthesis of a reactor-separator system for the dynamic start-up of two reaction systems.

An effective computational algorithm for suboptimal singular and/or bang-bang control I. Theoretical developments and applications to linear lumped systems

Abstract: A new and simple computational algorithm for obtaining suboptimal singular and/or bang-bang solutions of typical lumped and distributed parameter control problems is proposed. The algorithm is based on the piecewise maximization of the Hamiltonian and a limiting process utilizing a penalty function of the control variables. Theoretical developments and computational applications of the algorithm to several linear lumped parameter control problems are presented. Extensions and applications of the algorithm to nonlinear and distributed parameter systems are given in Part II.

An effective computational algorithm for suboptimal singular and/or bang‐bang control II. Applications to nonlinear lumped and distributed systems

Abstract: A new and simple algorithm based on the piecewise maximization of the Hamiltonian and a limiting process utilizing a penalty function of the control variables for the computation of suboptimal singular and/or bang-bang control, previously developed and applied to linear lumped systems in Part I, is tested on four typical nonlinear lumped and distributed systems of particular chemical engineering interest. The computational results have shown that the proposed algorithm is a very effective method for solving singular and/or bang-bang control problems with high state dimensionality, extreme nonlinearity, and multiple controls.

Automatic synthesis of optimum heat exchanger network configurations

Abstract: This paper addresses the problem of automatically generating heat exchanger network configurations that feature minimum investment cost subject to minimum utility cost and fewest number of units. Based on the linear programming and the mixed-integer linear programming (MILP) transshipment models for heat integration, a superstructure that has embedded many alternative configurations is proposed. This superstructure, which has as units the matches predicted by the MILP transshipment model, includes options for series and parallel matching, as well as stream splitting, mixing, and bypassing. Many of the implied stream connections in the superstructure are reduced to zero flow with a nonlinear programming formulation that leads to realistic and practical designs. Theoretical properties as well as the implementation aspects of the proposed procedure for the automatic generation of networks are presented. The method is illustrated with three example problems.

Forty years of Heat Integration: Pinch Analysis (PA) and Mathematical Programming (MP)

Abstract: Process Integration (PI) supporting Process Design, Integration, and Optimisation has been around from the early 1970s. PI was developed originally from Heat Integration, which remains the cornerstone for PI continuous advance. It has been closely related to the development of Chemical, Mechanical and Power Engineering supported by the extended implementation of mathematical modelling, simulation and optimisation, and by the application of information technology. Its development has accelerated over the years as its methodology has been able to provide answers and support for important issues regarding economic development — better utilisation and savings regarding energy, water, and other resources. This contribution is targeting towards providing at least a short overview of its historical development, achievements, and future challenges.