| Water flow standard device is the device of liquid flow meter test and verification, andthe research and application of it is the important part of the test technology development andflow metering, also provides the guarantee for the healthy development of the relatedindustries. As the highest standard of the water flow measurement in hebei province, its maintask is to ensure that the waters flow metering accuracy in hebei province, on a regular basisto calibration of flow meters, the type evaluation to instruments of the newly developed oruse, quality inspection, verification and calibration, which requires the flow unit should havea high enough accuracy, reliability and efficiency of verification, and on the market widelyused type of flow meter with high coverage rate. Therefore, in order to meet the needs of themarket, on the basis of the original water flow standard device, technical personnel upgradeit。The new device adopts and the structure of the standard table and the static weightmethod,which is more mature now. It has the characteristics of two test patternscomplementary, improves the unit price, its higher verification efficiency and automationdegree, realizes the online verification standard table, as well as the verification andcalibration to the special-shaped flowmeterthe whose application on the market is widelyranged (flow meter and the elbow type differential pressure flowmeter). In addition, the newplant construction details on mature technology has also carried on the thorough and expand：1) The vertical and horizontal test line of elaborate design of the new device enables theeffective combination of standard table method and weighing method which was adopted torealize the calibration function of flow meter and the elbow flowmeter,which makes up thedefects of the original device in this aspect;2) The use of pneumatic open commutator:the flow capacity of the pneumatic opencommutator is very big, when switching water flow on the system pressure is affectedunconspicuously, the structure is compact, when its reversing the noise is small; In thisdevice, the upstream of each nozzle commutator duck-billed add the gas storage bag of thegas power source, which provides enough power for nozzle quick reversing, ensure thecommutation time10ms or less,and make it have better symmetry;3) The standard intensive configuration, the parallel use of many sets of high precision electromagnetic flowmeter,and the use of the new1/12000three standard electronic scale,namely, the accuracy in the full range,1/2,1/4range is1/12000, the scale can shiftautomatically according to the weight shift, without human intervention;4) adding rectifier,which adjusts the flow model on the road at the pipe ofDN(65-200)mm, by using CFD software to simulate and verify the necessity of addingrectifier,and study the feasibility of the rectifier equivalent straight pipe,to cost savings,reduce the occupied space.The work mode of the standard table method and quality standard method, both meet theneed of scientific research and finalize the design appraisal high measurement accuracy, andcan meet the compulsory verification test efficiency. This device is developed, and ensuresthe effective implementation of water meter in our country national standard and the watermeter metrological verification procedures that is equal adoption of international standardsand the equivalent international suggestion, meets the requirements of national legal systemfor the measurement of the water meter products management. |
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