CAJ | 학술논문

应用圆柱绕流的基本理论,研制了一种新型绕流管差压流速流量计.用特制绕流管作取压元件,通过测定正对来流全压孔与特定偏角侧压孔流体压差来测定点流速或断面平均流速和流量.在一定绕流角度范围内,绕流压强系数不随雷诺数变化而变化,使得绕流管流速流量计的应用方便可靠,可在流道外标定而非原位标定,并且系统不确定度可控制在±1.0%以内.将绕流管流速流量计应用于南水北调东线工程解台泵站的1号和3号机组,并分别进行了流量现场测试.测试结果表明,现场实测的流量与经模型试验数据换算的流量之间,误差均在0.78 m3/s以内.在大型低扬程泵站的单泵流量现场测试中,绕流管插入泵叶轮前吸水室取压差,即可实现无等径直管条件水泵流速、流量测定.
응용원주요류적기본이론,연제료일충신형요류관차압류속류량계.용특제요류관작취압원건,통과측정정대래류전압공여특정편각측압공류체압차래측정점류속혹단면평균류속화류량.재일정요류각도범위내,요류압강계수불수뢰낙수변화이변화,사득요류관류속류량계적응용방편가고,가재류도외표정이비원위표정,병차계통불학정도가공제재±1.0%이내.장요류관류속류량계응용우남수북조동선공정해태빙참적1호화3호궤조,병분별진행료류량현장측시.측시결과표명,현장실측적류량여경모형시험수거환산적류량지간,오차균재0.78 m3/s이내.재대형저양정빙참적단빙류량현장측시중,요류관삽입빙협륜전흡수실취압차,즉가실현무등경직관조건수빙류속、류량측정.
A new differential pressure flow-meter is developed by using the theory of flow around a circular cylinder. The special designed cylinder tube is used to obtain fluid pressure in the flow-meter. By measuring the fluid pressure difference between the total pressure hole against the flow and the side hole at specified angles, the point velocities and the average flow rate of cross-section are determined. In a certain range of flow angle around the cylinder tube, the flow pressure coefficient does not change with the Reynolds number, so the new flow-meter can be calibrated outside conduit but not in situ. The application is convenient and reliable, and the system uncertainty can be controlled within ±1.0%. The new flow-meters are applied to the single-pump flow test at the scene of No. 1 and No. 3 unit of Xietai Pumping Station in South-North Water Transfer East Route Project. The errors between the results of field test and conversion from model test were within 0.78 m3/s. The cylinder tubes of the flow-meters were inserted into the suction chamber before the pump impeller, and the flow measurement of large pump was achieved on the condition of no straight pipes.