A New Strategy to Synthesis an Optimum Controllable HEN by using Fuzzy Analogical Gates

Abstract

This paper presents a new strategy to synthesis optimum controllable heat exchanger networks; the proposed strategy consists of four sequential steps: i) Quantification of index of structural controllability. ii) Exergy analysis and normalized irreversibility. iii) Thermal effectiveness of network. iv) Fuzzy analogical gates network and selection of the best weight index. Two analogical gates (symmetric and asymmetric) are employed. The symmetric gate (AND gate) inputs are the index controllability and thermal effectiveness. The asymmetric gate (Invoke gate) inputs are the output of the AND gate and the normalized irreversibility. The proposed method has been applied for two problems well-known in published literature. The results of these case studies show that the present strategy is both robust and accurate when the index of controllability is the same for different networks and it's to hard to decide the optimum controllable network, also, from the view point of exergy and thermal effectiveness.

Controllability robustness of heat exchanger network based on complex network theory

“…According to the concept of "down-stream paths," with "down-stream path length" as the standard, the interference transmission in the heat exchanger network can be divided into four different modes, 17 according to this, the severity of interference transmission is divided into four levels, which are used as the weight e ij of the network. The "down-stream path length" is determined by the number of heat exchangers involved in the path.…”

Fuzzy Analogical gates Technique for Heat Integration between Areas

“…The first gate is selected to be symmetric and the second gate is asymmetric. A fuzzy analogical -AND gate will be followed by a fuzzy invoke gate Hussein [18]. The symmetric gate inputs are normalized savings in energy requirement µ 1 and the number of inter-zonal transfer µ 2 .…”