Improvement of pinch technology for the possibility of integration of non-stationary thermal processes, taken into account of their localization

Abstract

RELEVANCE. Designing a network of heat exchangers for heat recovery and integration of thermal processes in general is a very urgent task of energy saving. Such a powerful and widely used tool for the synthesis and design of a network of heat exchangers as pinch technology has a number of limitations, and this study is aimed at expanding its capabilities. Pinch technology can only work effectively with stationary heat flows. In practice, cyclic and periodic processes are encountered, which limits the possibilities of using pinch technology. This was the reason for this study with the aim of expanding the boundaries of application of pinch technology. THE PURPOSE. Improving the pinch technology method to expand the possibilities for integrating cyclic and periodic thermal processes, as well as taking into account their localization. METHODS. When solving the problem, the principle of determining heat exchange connections was analyzed, other algorithms for their selection were proposed, and new optimization criteria were synthesized. RESULTS. A criterion for the structural perfection of a system is proposed, which is the ratio of the heat regenerated in the system to its theoretically possible value. The theoretical results are the proposed criterion of structural perfection and a generalized indicator of the structural-parametric perfection of the system. The practical result of the study was the proposed technical device for converting an unsteady flow into a series of stationary flows. Also, the practical result of this scientific research is a program for the synthesis of heat exchange networks. The proposed conversion device expands the capabilities of pinch technology, and the introduced criteria will make it possible to synthesize or design a system based on new target indicators. The program created during the work allows for the synthesis of a heat exchange network in automatic and semi-automatic modes. CONCLUSION. Thanks to the research carried out, it was possible to improve such a powerful tool as pinch technology and significantly expand its capabilities. An improvement of pinch technology has been proposed to enable the integration of non-stationary thermal processes and take into account their localization. To enable the integration of non-stationary thermal processes, a technical device has been proposed that allows converting a non-stationary flow into several stationary ones, and to take into account the localization of heat flows, a software product has been proposed that allows for the synthesis of a heat exchange network in automatic and semi-automatic modes. In addition, two indicators have been introduced that characterize the structural and structural-parametric perfection of the system.

Keywords

• pinch technology
• integration of thermal processes
• heat
• criterion of structural perfection
• heat exchanger