Preliminary design and thermal analysis of a liquid metal heat pipe radiator for TOPAZ-II power system

Isothermal Performance of Heat Pipes: A Review

Heat pipes transfer heat via phase transformation of the working fluid, where the working fluid will keep the temperature constant and absorb or release a large amount of latent heat during phase transformation. With the development of heat pipe technology, the isothermal performance of heat pipes has been gradually emphasized in many application fields. Most studies focused on the average temperature characteristics of one heat pipe or several heat pipes with the same type, and lacked a comprehensive analysis on the isothermal performance of different heat pipes. In this paper, previous studies on the application fields of the isothermal performance of heat pipes, the isothermal level of heat pipes used in different fields, and the methods to improve the isothermal performance of heat pipes are summarized. The parameters of the wick have little effect on the temperature uniformity of the heat pipe, while the arrangement of the wick has more influence on the uniformity of the heat pipe. The most suitable charge rate is 15% to 30% of the total inner volume, and the best start-up performance and isothermal performance is at approximately 45°.

An IVTIFN–TOPSIS Based Computational Approach for Pipe Materials Selection

This paper proposes a multicriteria decision-making (MCDM) approach, coupling intervalued trapezoidal intuitionistic fuzzy number (IVTIFN) with the technique for order preference by similarity to ideal solution (TOPSIS) to facilitate the selection of pipe materials. Their integration can maximize the advantage in better expressing decision maker’s preference on the proposed evaluation criteria by using a bounded limit instead of an exact value, to rank material alternatives based upon their functional, economic and environmental attributes. To reduce possible information overlapping resulted from the criteria, Mahalanobis distance is incorporated into IVTIFN–TOPSIS to improve the selection results. An illustrative example is provided to verify the proposed approach and demonstrate its practical application, in which four common alternative materials, including carbon steel, galvanized steel, polyvinyl chloride (PVC) and high-density polyethylenes (HDPE), are subject to precise selection to determine their adaptability in waste-water piping. The selection result indicates that the plastic materials are superior to the metal materials. In particular, HDPE is the optimal material alternative for waste-water collection and transport.