Water temperature effects on hydraulic performance of pressure‐compensating emitter in a drip irrigation system<sup>*</sup>
Peng Hou, Shuqin Li, Zeyuan Liu, Hongxu Zhou, Tahir Muhammd, Wu Ruonan, Wenchao Liu, Li Yunkai
Abstract
Abstract Accurate testing and evaluation of the hydraulic performance of pressure‐compensating (PC) emitters are basic for proper operation of drip irrigation systems. However, the impacts of environmental conditions and system operation usually result in unstable water temperature. Quantifying the effects of water temperature on flow rate and hydraulic performance are of vital importance to PC emitters. In this paper, six types of widely used PC emitters were used for laboratory testing, and their flow rates in the water temperature range of 15–45 °C were measured. The results showed that both the PC emitters' flow rate and temperature discharge ratio (TDR) decreased significantly with increase of water temperature ( p < 0.05), with average decreasing rates of 7.52 and 7.32%, respectively. Meanwhile, the flow coefficient ( k d ) showed a downward trend with higher water temperature ( p < 0.05, 12.0% in average), but the effects on the flow index ( x ) of the PC emitter could be ignored. This may be due to the decrease in hardness of the elastic diaphragm caused by higher water temperature, the research would provide theoretical references for correcting the performance deviation of pressure‐compensating emitters caused by temperature variation.