文章基本信息

标题：Reverse flow in natural convection heat pipe solar water heater
本地全文：下载
作者：Kok Seng Ong ; Kevin Osmond ; Wei Li Tong 等
期刊名称：Intl Jnl of Low-Carbon Technologies
印刷版ISSN：1748-1317
电子版ISSN：1748-1325
出版年度：2015
卷号：10
期号：4
页码：430-437
DOI：10.1093/ijlct/ctu017
语种：English
出版社：Oxford University Press
摘要：System performance of a natural convection (thermosyphon) solar water heater depends on design and setup of collector and storage tank as well as environmental factors such as solar intensity, ambient temperature and wind conditions. The relative height separating the tank and collector mainly influences the magnitude of the thermosyphon flow rates, including both forward and reverse flow at night. In this experimental investigation, an array of evacuated tube heat pipe solar collectors was connected to an insulated hot water storage tank. The effect of the separation height between tank and collectors was investigated and reported. Thermosyphon water flow rates were measured using a dye-injection procedure in both forward and reverse flow directions. The results showed that reverse flow always occurred in the evenings and was about 5–11 times less than forward flow. The overnight mean water temperature drop was independent of the height separating the collectors and storage tank and ranged between 2 and 10°C. The temperature drop was greater when the night was cooler.