湿饱和蒸汽计量仪表检测装置分析与优化

Analysis and Optimization of the Detection Devices for Wet Saturated Steam Metering Devices

利用全分离法建立了一套用于实流检定湿饱和蒸汽计量仪表性能的检测装置,通过汽水分离器将移动锅炉输出的湿饱和蒸汽进行分离,分离出饱和蒸汽和饱和水,分别对其进行参数计量,经过计算得出湿饱和蒸汽的流量、干度等参数。按照能量守恒计算出的不确定度为1%,与实验数据进行对比分析,实验数据的不确定度远大于计算不确定度。为此对装置入口与出口温度、压力值进行分析,发现该装置热量损失、压力损失严重,造成不确定度损失。需严格按照GB/T 14416—2010中锅炉蒸汽的采样方法将采样装置改为等速采样装置,同时按照标准调节取样流量,以保证等速取样;须将手持电导率仪测量方式更换为精度更高的化学法——氯根法(硝酸银容量法)来测定干度;系统数据采集设备以及算法的优化同样需要重新审视。

The Full separation method is used to establish a set of actual flow performance detection device for the actual flow calibration of wet saturated steam metering devices.The wet saturated steam produced by mobile boilers is separated by the steamwater separator,and parameter calculation is carried out on the separated saturated steam and saturated water.After calculation,parameters such as flow rate and dryness of wet saturated steam are obtained.The uncertainty calculated according to the conservation of energy is 1%.Compared with the experimental data,the uncertainty reflected by the experimental data is much greater than that of the computational uncertainty.Therefore,through the analysis of the temperature and pressure value of the inlet and outlet of the device,it is found that the heat loss and pressure loss of the device are serious,resulting in the loss of uncertainty.The sampling device should be changed to the isokinetic sampling device according to the sampling method of boiler steam in GB/T14416-2010.Meanwhile,the sampling flow should be adjusted to ensure the isokinetic sampling.The measuring method with the handheld conductivity meter also should be changed to a more precise chemical method,namely,the chlorine root method(silver nitrate volumetric method)to measure dryness.The optimization of the data acquisition device of the system and the algorithm is needed to be reexamined as well.