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.

中文翻译：

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水温对滴灌系统中压力补偿发射器的水力性能的影响*

正确测试和评估压力补偿（PC）发射器的水力性能是滴灌系统正常运行的基础。但是，环境条件和系统运行的影响通常会导致水温不稳定。量化水温对流量和水力性能的影响对PC排放器至关重要。在本文中，使用了六种广泛使用的PC发射器进行实验室测试，并在15-45°C的水温范围内测量了它们的流速。结果表明，随着水温的升高，PC排放源的流量和温度排放比（TDR）均显着降低（p<0.05），平均下降率分别为7.52％和7.32％。同时，水温较高时，流量系数（k _d）呈下降趋势（p <0.05，平均12.0％），但对PC发射器的流量指数（x）的影响可以忽略。这可能是由于较高的水温导致弹性膜片的硬度降低，该研究将为校正由温度变化引起的压力补偿喷头的性能偏差提供理论参考。