Study on thermal and energy-saving performances of pipe-embedded wall utilizing low-grade energy

Abstract

Building energy performance improvement has received much attention in recent years. In this paper, the pipe-embedded wall integrated with low-grade energy was reported, which can be used to reducing the energy consumption effectively on space heating and cooling. The computational fluid dynamics (CFD) method was adopted to study the thermal performance of the pipe-embedded wall. An indoor experiment was conducted to verify the accuracy of the numerical model. The simulation data was agreed very well with the experimental result. The influence of inlet water temperature, mass flow rate and location of the embedded pipe has been evaluated under steady state. The results show that the pipe-embedded wall could achieve the best cooling or heating performance, when the pipes are in the middle location of the wall. The mass flow rate has little effect on the heat loss of the wall, but has a significant effect on the heat transfer of the circulating fluid. In the transient analysis, the pipe-embedded wall can reduce 13% of total heat gain in cooling season and 33% of heat loss in winter. The results indicate that the pipe-embedded wall has the advantages to utilize directly low-grade energy for reducing building cooling/heating load. The study also provides guidance for the design and optimization of low-energy buildings.