Seawater desalination device and composite system utilizing temperature difference drive

Abstract

The invention discloses a seawater desalination device and composite system utilizing temperature difference drive. The device comprises a reverse osmosis membrane system, a first pressure maintainingsystem and a drive system, the drive system comprises a first phase-change cylinder and a first drive cylinder, and the first phase-change cylinder is provided with a phase change working medium anda temperature regulating system; the first drive cylinder is provided with a first seawater inlet and a first seawater outlet, the interior of a cylinder body is provided with a drive piston, and thefirst seawater outlet and the first pressure maintaining system are separately connected with a water inlet of the reverse osmosis membrane system; and temperature of the first phase-change cylinder is adjusted to make a phase change working medium have phase change, and the phase change working medium drives the drive piston to enter seawater raw water, and after pressurizing is performed, seawater desalination is performed. According to the device provided by the invention, the multi-stage drive system and an energy recovery system are added in the composite system, the energy recovery system absorbs and utilizes residual pressure of reverse osmosis concentrated brine and partial heat of the concentrated brine by combining temperature difference drive, supplements seawater to the reverseosmosis membrane system, and better solves the problem of high energy consumption costs in seawater reverse osmosis desalination.

Description

technical field [0001] The invention relates to the technical field of reverse osmosis seawater desalination, in particular to a seawater desalination device driven by temperature difference and a composite system thereof. Background technique [0002] Reverse osmosis seawater desalination is one of the mainstream technologies for seawater desalination at present. Traditional reverse osmosis seawater desalination uses high-pressure pumps to increase the inlet water pressure (about 5.8-6.8MPa) to overcome the osmotic pressure of water. The concentrated brine discharged from the reverse osmosis membrane remains The pressure is as high as 5.5-6.5MPa, and then the residual pressure energy of the concentrated brine is recovered through the energy recovery device, and the energy recovery is converted into water intake energy, which reduces the energy consumption of reverse osmosis seawater desalination. Such a seawater desalination process requires a large amount of In underdevelo...

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Problems solved by technology

[0004] Aiming at the problem of low-cost seawater reverse osmosis desalination in countries or regions with low-temperature heat sources, the present invention provides a seawater desalination device driven by temperature difference and its composite system, which makes full use of low-temperature heat sources and solves the problem of seawater reverse osmosis desalination projects. high cost problem

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