Retrofit of heat exchanger networks with pressure recovery of process streams at sub-ambient conditions

This paper presents a new mathematical programming model for the retrofit of heat exchanger networks (HENs), wherein the pressure recovery of process streams is conducted to enhance heat integration. Particularly applied to cryogenic processes, HENs retrofit with combined heat and work integration is mainly aimed at reducing the use of expensive cold services. The proposed multi-stage superstructure allows the increment of the existing heat transfer area, as well as the use of new equipment for both heat exchange and pressure manipulation. The pressure recovery of streams is carried out simultaneously with the HEN design, such that the process conditions (streams pressure and temperature) are variables of optimization. The mathematical model is formulated using generalized disjunctive programming (GDP) and is optimized via mixed-integer nonlinear programming (MINLP), through the minimization of the retrofit total annualized cost, considering the turbine and compressor coupling with a helper motor. Three case studies are performed to assess the accuracy of the developed approach, including a real industrial example related to liquefied natural gas (LNG) production. The results show that the pressure recovery of streams is efficient for energy savings and, consequently, for decreasing the HEN retrofit total cost especially in sub-ambient processes.

Highest return farming systems for Tama and Muscatine soils: an application of linear programming to 240- and 480- acre farms operated by two men/

Cover title.

Highest return farming systems for Drummer-Flanagan soils : an application of linear programming to farm planning /

Cover title.

Adaptive linear classifier by linear programming,

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A linear programming code to determine whether a Boolean function is a threshold function,

Bibliography: p. 14.

An error analysis of solutions to sparse linear programming problems,

"Supported in part by the Advanced Research Projects Agency ... contract no. US AF 30(602) 4144."

Simplex method and theory; notes on linear programming and extension-----part 62.

"Contract no. AF 49(638)-700."

Regional adjustments in grain production : a linear programming analysis /

"U.S. Dept. of Agriculture, in cooperation with Iowa Agriculture and Home Economics Experiment Station Center for agricultural and economic adjustment."

Regional adjustments in grain production : a linear programming analysis : mathematical models, proofs, methods of data collection and estimation, and supplementary tables /

Cover title.

Regional analysis of production adjustments in the major field crops : historical and prospective : an application of spatial linear programming /

Literature cited and selected references: p. 38-41.

Aggregate economic effects of alternative land retirement programs : a linear programming analysis /

Includes bibliographical references (p. 53-54).

Interregional adjustments in crop and livestock production; a linear programming analysis,

Prepared in cooperation with the Center for Agricultural and Economic Development. Iowa Agriculture and Home Economics Experiment Station, Iowa State University.

CDM3/linear programming.

On cover: Control data, 1604/1604-A computer.

Introduction to linear programming.

Mode of access: Internet.