A ventilation experimental study of thermal performance of an urban underground pipe rack

Abstract

Urban pipe rack is a type of underground tunnel used for centralized laying of municipal pipelines in cities. In this study, the effort of using urban underground pipe rack to preheating or cooling ambient air for building thermal comfort as a new passive energy saving method was made. This is similar with the existing earth to air heat exchanger (ETAHE). In the research, a long-term static air temperature and humidity test and ventilation experiments in summer/winter were carried out in the underground pipe rack located in Guangzhou, the thermal performance of the pipe rack which includes temperature performance, cooling and heating potential was also made. The static air temperature in the pipe rack is lower than ambient temperature in daytime in summer and higher than ambient temperature all day in winter. After air flowed through 200-meter pipe rack, its maximum temperature drop and rise in summer and winter could reach 7.5 °C and 11.2 °C respectively. The daily average cooling potential in summer and heating potential in winter of the 200-meter pipe rack was 467.3 MJ and 1418.6 MJ respectively. The COP of the pipe rack was found to be 2.4 in summer and 2.7 in winter. Results show the potential of pipe rack in providing low energy cooling and heating.