Heat transfer characteristics of straw-core paper honeycomb plates II: Heat transfer mechanism with hot-above and cold-below conditions

• Published in: Applied thermal engineering Vol. 195; p. 117165
• Main Authors: Guo, Zhensheng, Xu, Yuan, Chen, Jinxiang, Wei, Peixing, Song, Yiheng
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.08.2021; Elsevier BV
• Subjects: Cold weather construction; Conduction heating; Conductive heat transfer; Convective heat transfer; Functional honeycomb plate; Heat conductivity; Heat exchangers; Heat transfer; Heat transfer calculation; Heat transfer mechanism; Honeycomb structures; Insulation; Multilayers; Plates (structural members); Radiative heat transfer; Renewable resources; Straw; Studies; Temperature; Thermal conductivity; Functional honeycomb plate; HP; PHP; SHP; Heat transfer mechanism; DLR; BEP; Heat transfer calculation; GHP; Straw; FHP
• ISSN: 1359-4311; 1873-5606
• DOI: 10.1016/j.applthermaleng.2021.117165

•Radiative heat transfer was the primary heat transfer mode in honeycomb plates (HPs).•Local convection occurred in an HP due to weak disturbances when h > 15–20 mm.•Heat insulation performance of an HP could be improved by multilayer substitution.•Fillers prevented radiation and local convection by drastically reducing the cavity.•Foundation was laid for studying the heat transfer of FHPs at normal temperatures. Considering the large amount of cement consumed in construction and that straw and other renewable resources are discarded in considerable amounts every year, the heat transfer mechanism of solid-core functional paper honeycomb plates (FHPs) was investigated by calculating and analyzing the equivalent thermal conductivity λE of honeycomb plates (HPs) to develop functional sandwich plates and realize the utilization of straw as a resource. The results led to the following conclusions: (1) Under normal temperatures and hot-above/cold-below conditions, radiative heat transfer, which is usually neglected under normal temperatures, was the primary heat transfer mode in HPs. (2) Local convection occurred in HPs due to weak disturbances when the plate thickness h was greater than 15–20 mm. Accordingly, a technical approach was proposed for improving the heat insulation performance of HPs through multilayer substitution. (3) The filling materials could effectively prevent radiative and local convective heat transfer by drastically reducing the cavity size in the honeycomb structure. The heat conduction among solid particles had little influence on the λE of the FHPs. This paper lays a theoretical foundation for studying the heat transfer mechanism of FHPs at normal temperatures.