变量喷洒喷头性能指标建立及模糊评价

针对全圆喷洒喷头性能评价指标不能充分反映变量喷洒喷头各参数连续变化特点的问题,该文加入了时间变量参数,初步建立了变量喷洒喷头的评价指标,主要包括:喷头射程降低系数、喷头喷洒形状系数、喷洒均匀性系数、喷洒打击强度变化系数及喷灌强度变化系数。采用模糊数学的方法,以上述5个性能评价指标,分别对BPXH20变量喷洒全射流喷头,BPY120变量喷洒摇臂式喷头和BPY220变量喷洒摇臂式喷头进行综合评价,并根据不同应用场合,探索性能指标权重值变化±20%对评价结果的影响。结果表明:喷洒均匀性系数、喷洒强度变化系数及打击强度变化系数对权重变化较为敏感,但不影响评价喷头的性能。说明权重值选取合理,可为今后其它变量喷洒喷头评价提供参考。

Fuzzy evaluation and performance index of variable-rate sprinklers

The parameters of variable-rate sprinkler changed continuously when it is rotating, and the evaluation index of commonly sprinklers can not reflect the characteristics adequately. To overcome this problem, indexes of rotating time and the sprinkler evaluation index for variable spraying were proposed. The indexes mainly included the wetted radius reduced coefficient, the spraying shape coefficient, the uniformity coefficient, the variations of intensity coefficient and the variations of hit intensity coefficient. The fuzzy mathematics method was adopted, and the fluidic sprinkler typed BPXH20, BPY120 and BPY220 were evaluated with the five evaluation index factors. According to different applications of the sprinklers, the results of evaluation weights value changed by ±20% show that the evaluation weight values of the uniformity coefficient, the variations of intensity coefficient and the variations of hit intensity coefficient were very sensitive but would not impact results of the quality evaluation. It can be concluded that weight values were suitable for evaluating the variable-rate sprinklers in this paper, and the methods may be provided references for other variable-rate sprinklers.