| 摘要: |
| 【目的】寻找合适的渠道走向和几何尺寸，优化渠道水温度。【方法】根据渠道增温过程原理，建立了适用于渠道表面水体吸收太阳短波辐射的计算模型，并通过试验验证该模型，在此基础上，利用该模型模拟不同的渠道几何尺寸（宽深比分别为1∶1、1.5∶1、2∶1）和渠道走向（东西走向、南北走向、与东西方向呈45°夹角）下灌溉水的增温效率。【结果】东西走向且宽深比最大的渠道增温效率最高，宽深比为2∶1的渠道的增温效率比1∶1的渠道高42.42%～256%；东西走向的渠道增温效率比南北走向的渠道高58.45%～296%，说明该模型具有一定的精度及准确度。【结论】增大灌溉渠道宽深比并使其走向趋向东西走向，可以有效利用灌溉水输运过程中的自然增温过程提高水温，降低低温灌溉水对农作物生长的影响。 |
| 关键词: 渠道走向；几何尺寸；灌溉水；太阳辐射；水温 |
| DOI：10.13522/j.cnki.ggps.2019019 |
| 分类号: |
| 基金项目: |
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| The Impact of Orientation and Geometrical Dimensions of Channel on Water Temperature Rise |
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GUO Jiawen, PU Xunchi*, HUANG Ruixian
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State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu 610065, China
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| Abstract: |
| 【Background】The growth and development of crops depends on thermal accumulation, and in areas irrigated with groundwater in north China and reservoir water in south China, the water temperature is low. Low irrigation water temperature could reduce photosynthesis and inhibit root uptake of water and minerals, thereby impeding crop growth and ultimately reducing yield. Understanding the change in water temperature in irrigation channels is hence an important design parameter. 【Objective】The objective of this work is to investigate the influence of orientation and physical dimensions of channel on water temperature change within it. 【Method】 Field experiments were conducted, from which we measured the change in water temperature; the measured data were used to derive a model to calculate how water surface temperature rises once it flows into a channel. The model was then used to calculate the change in water surface temperature in channels with a width-depth ratio of 2∶1, 1.5∶1 and 1∶1, respectively, flowing in the north- south, the east-west and the southeast-northeast directions, respectively. 【Result】 The calibration against experimental data revealed that the model is accurate and robust. The simulated results showed that when other conditions were the same, the channel flowing in the east-west direction was most heating efficient, with the width-depth ratio 2∶1 increasing heating efficiency by 42.42%~256% compared to the wide-depth ratio 1∶1. When the width- depth ratio was the same, the channel flowing in the east-west direction was 58.45%~296% more heating efficient than channels flowing in other two directions. 【Conclusion】We can draw the following conclusions: ①The model derived for calculating water temperature change in channel was accurate and robust. ②When other conditions were the same, the bigger the width-depth ratio of the channel is, the more heating efficient it is. Wherever possible, the width-depth ratio of the channel should be maximized. ③When other conditions were the same, the more east-west orientated the channel is, the more heating efficient it is. |
| Key words: channel orientation; geometric dimension; irrigation water; solar radiation; water temperature |
