Two-phase optimizing approach to design assessments of long distance heat transportation for CHP systems. (15th November 2016)

• Record Type: Journal Article
• Authors: Hirsch, Piotr; Duzinkiewicz, Kazimierz; Grochowski, Michał; Piotrowski, Robert
• Is Part Of: Applied energy. Volume 182(2016)
• Page Start: 164
• Page End: 176
• Publication Date: 2016-11-15
• Subjects: Pipeline optimization -- Heat transportation -- Decision-making problem -- Life cycle cost modeling; Power (Mechanics) -- Periodicals; Energy conservation -- Periodicals; Energy conversion -- Periodicals; 621.042
• DOI: 10.1016/j.apenergy.2016.08.107
• Languages: English
• ISSNs: 0306-2619

Abstract

Highlights: New method for long distance heat transportation system effectivity evaluation. Decision model formulation which reflects time and spatial structure of the problem. Multi-criteria and complex approach to solving the decision-making problem. Solver based on simulation-optimization approach with two-phase optimization method. Sensitivity analysis of the optimization procedure elements. Abstract: Cogeneration or Combined Heat and Power (CHP) for power plants is a method of putting to use waste heat which would be otherwise released to the environment. This allows the increase in thermodynamic efficiency of the plant and can be a source of environmental friendly heat for District Heating (DH). In the paper CHP for Nuclear Power Plant (NPP) is analyzed with the focus on heat transportation. A method for effectivity and feasibility evaluation of the long distance, high power Heat Transportation System (HTS) between the NPP and the DH network is proposed. As a part of the method the multi-criteria decision-making problem, having the structure of the mathematical programming problem, for optimized selection of design and operating parameters of the HTS is formulated. The constraints for this problem include a static model of HTS, that allows considerations of system lifetime, time variability and spatial topology. Thereby variation of annual heat demand within the DH area, variability of ground temperature, insulation and pipe aging and/or terrain elevation profile can be taken into account in the decision-making process. The HTS construction costs, pumping power, and heat losses are considered as objective functions. In general, the analyzed optimization problem is multi-criteria, hybrid and nonlinear. The two-phase optimization based on optimization-simulation framework is proposed to solve the decision-making problem. The solver introduces a number of assumptions concerning the optimization process. Methods for problem decomposition, scalarization and relaxation are proposed and optimization procedures for the decomposed problem are discussed. The methodology is tested on a sample case study of the NPP planned to be built in Northern Poland. The sensitivity analysis of the problem is also provided.