The energy recovery device (ERD) plays an important role in reducing energy consumption of seawater reverse osmosis (SWRO) system. However, for reciprocating-switcher energy recovery device (RS-ERD), stroke switching will cause flowrate and pressure pulsations of high and low pressure fluids, which will affect the operation stability of SWRO system. In this paper, we develop a three-cylinder energy recovery device (TC-ERD) and a matching control strategy with instantaneous overlap function to simultaneously reduce the flowrate and pressure pulsations of high and low pressure fluids. Under design capacity (30 m³/h) and 5.0 MPa operating pressure, the pressure pulsation amplitude of HP brine is only 0.0675 MPa, which is 86.5% lower than that of RS-ERD. The flowrate pulsation amplitude (0.954 m³/h) of LP seawater decreases by 68.2% compared with RS-ERD, while that (1.336 m³/h) of HP brine is approximately doubled. The doubling of HP brine flowrate pulsation arises from the fact that the actual operating point of the boost pump is much lower than its rated operating point, which can be improved by optimizing pump selection in future work. The energy recovery efficiency of the TC-ERD is as high as 97.1% at design capacity and 5.0 MPa operating pressure.

能量回收装置（ERD）在降低海水反渗透（SWRO）系统的能耗方面起着重要作用。但是，对于往复式开关能量回收装置（RS-ERD），行程开关会引起高低压流体的流量和压力脉动，从而影响SWRO系统的运行稳定性。本文中，我们开发了一种三缸能量回收装置（TC-ERD）和具有瞬时重叠功能的匹配控制策略，以同时减少高低压流体的流量和压力脉动。在设计容量（30 m ³ / h）和5.0 MPa的工作压力下，HP盐水的压力脉动幅度仅为0.0675 MPa，比RS-ERD降低86.5％。流量脉动幅度（0.954 m ³与RS-ERD相比，LP海水/ h）降低了68.2％，而HP盐水的（1.336 m ³ / h）大约增加了一倍。HP盐水流量脉动加倍的原因是增压泵的实际工作点远低于其额定工作点，这可以通过在以后的工作中优化泵的选择来改善。在设计容量和5.0 MPa的工作压力下，TC-ERD的能量回收效率高达97.1％。