This document is the Accepted Manuscript version of the following article: D. Zhuo, Y. tian, Y. Qu, and Y. K. Chen, ???Thermal analysis of phase change material board (PCMB) under weather conditions in the summer???, Applied Thermal Engineering, Vol. 99, pp. 690-702, February 2016. Under embargo. Embargo end date: 3 February 2018. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/. The final, published version is available online at DOI: https://doi.org/10.1016/j.applthermaleng.2016.01.121.Phase Change Material Board (PCMB) has been considered as an effective way to improve the thermal comfort in either new or existing buildings. In this work, firstly the optimal melting temperatures of internal and external PCMB are given, and the optimal heat storage capacities are obtained under the idealised circumstance of considering sinusoidal changes of the room and outdoor temperatures during a day. Secondly, to study the potential energy saving from applying a PCMB, a case study of a lightweight office with real environmental conditions is carried out. The air conditioning is switched on in the model to keep the indoor temperature within thermal comfort. Using the daily energy consumption and daily thermal comfort rate as the performance criteria, the effects of major influencing factors including melting temperature, latent heat and thermal conductivity of PCMB are studied parametrically. The results show that both the external and internal PCMB can achieve better performance when the melting temperature is chosen to be slightly higher than the average indoor air temperature. In the summer, the external PCMB has a better performance than the internal PCMB because the external PCMB works not only as a heat storage system whose function is similar to the internal PCMB, but also as a thermal connection between the outdoor and indoor environment due to its thermal insulation function, which reduces the influence of the changing outdoor environment
The nanofluid forced convection heat exchange in a porous channel within three heated blocks was numerically investigated using the Nonorthogonal multiple-relaxation time lattice Boltzmann method (MRT-LBM). The effects of various parameters such as nanoparticle volume fraction (ϕ), Darcy number (Da) on heat exchange performance and flow phenomena were analyzed when the Pecklel number (Pe), the Prandtl number (Pr), and porosity (ε) were 25, 5.829 and 0.3, respectively. The outcome showed that the mean Nusselt number (Nu) on the surface of heated sources remarkably improved by adding nanoparticles. Furthermore, the forced convection heat exchange of the fluid flow in the mainstream area and the heat conduction in the liquid retention zone had a conspicuous influence on the heat-transfer properties. It is worth noting that the forced convection heat transfer of the fluid flow dominates heat exchange. The simulation showed that the average surface Nusselt number on the heated blocks and the heat exchange performance declined with the increase of the Darcy number.