自流发油液面高度的确定

Determination of the Level for Artesian Discharge

为了保证在临时失去动力的情况下也能付油,就必须做到部分自流付油。要实现自流付油,油品就必须有一定的液面高度,也就是要求储存油品液面与发油鹤管出口具有足够的高度差。这个高度差取决于流量、管道及管件的阻力。以冯村油库扩建2×3000m^3内浮顶罐及付油系统为例,建立自流发油系统模型,给出液面与鹤管出口高度差的计算公式。通过计算,得出最小工作高度。指出速度水头对同一液面高度的实际流量的影响及不同液面高度下的自流发油流量。通过分析研究得知,如果一满罐油在保证流量表准确的情况下,全部实现自流发油,可付油品量占全部油品的79％,既可节约电能,又可在临时失去动力的情况下不影响正常发油。

Partial artesian discharge is essential to automatic oil supply under temporary loss of power. To realize artesian discharge, there must be a certain height of liquid level, or an adequate level difference between the liquid stored and the outlet of unloading arm. The level difference depends upon flowrate and resistance in pipes and fittings. Taking as an example the 2×3,000 m3 inner floating roof tanks and oil unloading system in Fengcun, this paper develops a model for artesian discharge system, giving the calculation formula for level difference between liquid and arm outlet. Minimum operation level can be deduced from the formula. Described are the influence of velocity head on the actual flows with same level and the artesian flows for different liquid levels. Analysis shows that, with the flowmeter having sufficient precision, 79% of the oil stored in a full tank can be artesian, so not only can energy be saved, but normal oil supply be guarranteed under temporary loss of power.