Study on the heat transfer characteristics of a moderate-temperature heat pipe heat exchanger

Experimental and numerical investigation of a cross flow air-to-water heat pipe-based heat exchanger used in waste heat recovery

“…A representation of the heat pipe working cycle can be seen in Figure 2. Due to the high effective thermal conductivity of these devices at essentially constant temperature throughout its length [8,9], heat pipes have been referred as superconductors. Their effective conductivity can easily be several orders of magnitude greater than pure conduction through a solid metal [5,10,11] Figure 2: Schematic of a working heat pipe…”

“…For low to medium grade heat, consisting of temperatures above 150°C, Noie [24] presents an analytical method of characterising the HPHX using the Effectiveness (ε-NTU method) to predict the performance of the heat exchanger. The same approach is taken by Danielewicz et al [25], Jouhara & Merchant [26] and Han & Zou [8] with the aid of a computer coding that predicts the effectiveness depending on different inlet conditions. All the surveyed papers refer to air-to-air HPHX even if it is mentioned by Noie that the ε-NTU method theory applies even if different fluids are used on the shell side.…”

“…The expression chosen to predict the heat transfer in nucleate pool boiling is that of Rohsenow & Hartnett [44], found to be the most comprehensive correlation as it holds remarkably well and has been reported by many researchers in the literature; Reay & Kew [7], Hagens et al [13], Mroué et al [37] and Ramos et al [45] reported the use of Rohsenow & Hartnett's expression [46] to predict the heat transfer from nucleate pool boiling in thermosyphons. Rohsenow & Hartnett's expression for nucleate pool boiling has the form shown in equation (8).…”

Numerical Analysis of Liquid–Liquid Heat Pipe Heat Exchanger Based on a Novel Model

“…Experimental and theoretical studies on HPHEXs were conducted by many scholars [5,15,16]. For the experimental study of HPHEXs, Ma et al [5] investigated a HPHEX used for recovering the waste heat in a slag cooling process in the steel industry, and the influence of the change of waste water mass flow rate on the performance of HPHEX was also studied.…”

“…For the experimental study of HPHEXs, Ma et al [5] investigated a HPHEX used for recovering the waste heat in a slag cooling process in the steel industry, and the influence of the change of waste water mass flow rate on the performance of HPHEX was also studied. For the theoretical calculation of HPHEXs, the mathematical model in the moderate-temperature HPHEX system was established by Han et al [15] to study the temperature distribution inside and outside each HP. There were also scholars who combined experiments and theories to analyze HPHEXs.…”