液压驱动压裂泵液压系统设计及其脉动的抑制

Hydraulic System Design and Pulse Suppression of Hydraulic Drive Fracturing Pumps

针对传统机械式压裂泵冲次高、易损件寿命短等缺点,提出了液压驱动式压裂泵,设计了"半开半闭式液压系统",建立了仿真模型,搭建了试验样机,结果表明:仿真模型准确,液压驱动式压裂泵也可以实现高压输出,受液压缸泄露、魏氏效应、系统固有换向时间的影响,压裂泵存在压力和流量脉动,且随负载压力的增大而增大。根据压力和流量脉动特点,设计了一套由柱塞缸、气缸和蓄能器组等构成的气缸式蓄能器脉动抑制装置,结果表明:该装置能显著抑制压力和流量脉动;且脉动随蓄能器容积或预充气压力的增大而减小;在该装置的作用下,液压驱动式三缸压裂泵的压力脉动等效于机械式五缸压裂泵。

Aimed at the disadvantage that the traditional fracturing pumps have high frequency of stroke and short lifespan, the hydraulic drive fracturing pump is proposed. The half-open and half-close circuit hydraulic system is designed.Its simulation model and test prototype are built. The results show that the model is accurate. And the hydraulic drive fracturing pump can also achieve high pressure output. Because of the leakage of hydraulic cylinders, Westphal Phenomena and the natural switch time of the system, there exists pressure and flow pulsation in the fracturing pump. This pulsation increases with increasing of load pressure. According to the characteristics of the pressure and flow pulsation, the pulse suppression device, which consists of the piston cylinder, pneumatic cylinder and accumulator groups, is designed. The test results show that this device can significantly suppress the pressure and flow pulsation. And this pulsation decreases with the increase of the volume or pre- charged pressure of the accumulator. With the help of this device, the pulsation of the hydraulic drive fracturing pump with three cylinders is equivalent to the traditional fracturing pump with five cylinders.