Abstract:
When DRA is used in oil pipeline, the throughput of the line can be improved or pressure can be decreased. How to evaluate the DRA's performance is an important problem to be discussed. This paper discusses the principle that utilizes the simulative loop to evaluate DRA, and gives out a detailed evaluation apparatus. The components, design specifications and hydraulics characteristics are introduced. The
m value of No. 0 diesel, No. -10 diesel and kerosent bave been determined and their values are 0.08. 0.08 and 0.18 respectively. A series of DRAs named EP have been synthesized in laboratory and their drag reduction efficieneies have been determined under different conditions. Comparative tests have shown that the performance of some EP samples have reached or exceeded the DRAs imported from foreign countries. Besides, the interaction law between DRAs and fluids have been examined. The test results have shown that the drag reduction efficiency will reach the maximum when Reynolds number touches approximately 9 000 (relatively to shear rate 1 276 s
-1), and with the Re's increment, the drag reduction efficiency will decrease due to shear and degradation. When the concentration of DRA in the fluid is 15 mg/L, the drag reduction efficiency will get to a maximum of 74%. For those DRAs that have the same molecule structure, the drag reduction efficiency can be predicted through the measurement of the DRA samples' apparent viscosity. Changing fluid's type only influences Re under a certain flow pressure, which will result in the variation of the drag reduction efficiency.