某地源热泵机组能效测试不确定度分析

Uncertainty analysis for COP measurement of a GSHP unit

为保证某地源热泵机组制冷系数(COP)测试的科学性和真实性,用间接测量不确定度的计算方法对测量数据进行处理。首先对所得到数据进行有效性分析,在保证数据没有粗大误差的前提下,运用不确定度理论对间接测量得到的数据进行分析处理,并通过分析各个因素的相对不确定度来探讨是否需要通过提高仪器的精度来提高结果精度。计算结果表明:合成不确定度评定COP的结果为COP=4.87,Uc=0.19;扩展不确定度评定COP的结果为(4.87±0.36),置信度为95%;在极端情况下,温度计和功率表还有提高精度的潜力,而超声波流量计没有必要提高精度。

To ensure the validity of COP testing of a GSHP system,a method was proposed to measure the degree of uncertainty to deal with statics in the survey when applying for the demonstrative project of renewable energy.Firstly,the collected data were tested for the validity.The data of the indirect measurement were analyzed with the theory of uncertainty on the premise of no distinct error exiting in the process.Meanwhile,it was also discussed that whether it was necessary to improve the accuracy of the instruments to mend the result just by means of analyzing the relative uncertainty of various factors.The results show that the computed COP is equal to 4.87,but combined uncertainty is 0.19 and expanded uncertainty is 0.36 at the level of 95% of confidence probability.Two conclusions can be drawn： One is that it is very important to analyze the collected data in a scientific method;the other is that there is great potential to improve the accuracy of mercurial thermometer and power meter at extreme situation,while there is no need for ultrasonic flowmeter.