Energy recovery device (ERD) plays a vital role in reducing the energy consumption of seawater reverse osmosis (SWRO) desalination process. Numerous investigations have been conducted for large scale ERDs, yet few studies for small scale ERDs (capacity less than 50 m³/d) have been reported. In this paper, a newly invented piston type integrated high pressure pump-energy recovery device (HPP-ERD), which synchronously pressurizes the raw seawater and recovers hydraulic energy from the concentrated brine, is introduced. The structure and working principle of the HPP-ERD is offered. Three versions of HPP-ERD prototypes are tested in a laboratory emulate platform and the test results can manifest the energy-saving feasibility of the HPP-ERD. A practical small scale SWRO project with a capacity of 50 m³/d using the HPP-ERD is surveyed. A performance analysis of the proposed project is implemented for one-month operating duration, which reveals the acceptable energy-saving capability and durability of the HPP-ERD under actual working circumstances. An economic analysis is finally performed and the analysis consequence indicates that the utilization of the HPP-ERD instead of a single high pressure pump can diminish both the payback period and the desalinated water cost of the proposed project remarkably.

能量回收装置（ERD）在降低海水反渗透（SWRO）淡化工艺的能耗中起着至关重要的作用。对大型ERD进行了大量研究，但对于小型ERD（容量小于50 m ³ / d）的研究却很少。本文介绍了一种新发明的活塞式一体化高压泵浦能量回收装置（HPP-ERD），该装置同步地对原海水加压，并从浓缩盐水中回收水力能。提供了HPP-ERD的结构和工作原理。在实验室仿真平台上测试了三种版本的HPP-ERD原型，测试结果可以证明HPP-ERD的节能可行性。容量为50 m ^3的实用小型SWRO项目/ d使用HPP-ERD进行调查。对拟议项目的性能分析进行了一个月的运行时间，这表明HPP-ERD在实际工作环境下具有可接受的节能能力和耐用性。最终进行了经济分析，分析结果表明，使用HPP-ERD代替单个高压泵可以显着减少拟建项目的投资回收期和淡化水成本。