Abstract: Lowtemperature multieffect seawater desalination device needs to operate in a negative pressure environment, so the design of the vacuum system is crucial for the stable and safe operation of the device. This paper introduces the working principle of the injector and establishes a calculation method for the vacuum system pumping volume and multistage injection. Combined with a practical engineering case, the steam consumption and equipment process parameters under different injection process flows are calculated in detail and analyzed. This provides theoretical and computational basis for the process design and scheme selection of the vacuum system of the lowtemperature multieffect seawater desalination device.

Key words: lowtemperature multieffect, seawater desalination, vacuum system, injector