基于过泵温差的变频输油泵机组效率确定方法

Efficiency Determination for Variable Frequency Oil Pump Assembly Based on Temperature Difference Through Pump

对变频输油泵机组效率的检测,目前还没有成熟的计算和测试方法。分析输油泵进出口处能量守恒关系,根据原油流经输油泵后所产生的温升和焓的特性,将原油流经输油泵过程等效为定熵过程与定压过程,推导变频工况下输油泵效率,计算电动机输出功率,进而得到变频输油泵机组效率,形成了基于过泵温差的变频输油泵机组效率计算方法,并提出相关测试要求。进行变频输油泵机组现场能效测试,比较用该方法与用比例定律法计算的结果,认为前者更可靠。使用该方法无需确定电动机定子和转子的性能参数,为现场测试带来较大便利。

There is no mature testing and calculation method to calculate variable frequency （VF） pump assembly efficiency now. According to the principle of thermodynamics, the energy conservation relationship between the input and output of the pump is analyzed. The oil flowing pump process is equated to the constant entropy process and the constant pressure process because of the property of enthalpy. Based on that analysis, the pump efficiency under VF condition can be determined, and the motor output power and the VF assembly efficiency can be calculated. This procedure is called the VF assembly efficiency calculation method and is based on the temperature difference, which is caused by oil flow through the pump, and then field test was performed to confirm this analytic procedure. Finally, this study compared the new method calculation results with the proportional law. The results show that the former method has a number of advantages including accuracy and convenience, without using motor performance parameters of stator and rotor.