Staged power generation system and staged power generation method by salt difference energy

Abstract

The invention discloses a staged power generation system by salt difference energy. The staged power generation system comprises a multistage osmosis device serially formed by a plurality of osmosis devices and a plurality of water turbines, each osmosis device comprises osmosis stages, the osmosis stage is formed by a plurality of osmosis membrane elements in parallel and used for dividing solutions different in concentration into a high-concentration side and a low-concentration side, the high-concentration side of each osmosis device corresponds to a water turbine, and the water turbines are coaxially connected to be used for driving a generator to operate; after a high-solubility solution and a low-solubility solution are respectively fed into the high-concentration side and the low-concentration side of each osmosis stage respectively, the osmosis stage can convert osmotic pressure difference into high-concentration side hydrostatic pressure, and the water turbines can be driven to rotate to drive the generator to operate by the aid of corresponding-size back pressure exerted to the osmosis stages. The invention further discloses a staged power generation method by the salt difference energy. Since different back pressure is exerted to different stages, system output power is enabled to be close to the maximum value, and power density of membranes is increased. Meanwhile, the osmotic membranes are fully utilized.

Description

technical field [0001] The invention belongs to the technical field of salt difference energy, and in particular relates to a system and method for generating electricity by salt difference energy. Background technique [0002] With the deepening of human understanding, the energy crisis and environmental pollution are becoming more and more prominent. The development and utilization of new energy sources is the only way to solve these problems without delay. Salt difference energy is the chemical potential difference energy between seawater and freshwater or between two solutions of different concentrations, and it is a renewable energy with the highest energy density in ocean energy. It is estimated that the reserves of coastal salt energy resources in my country are about 3.9×10 15 J, the theoretical power is about 1.25×10 8 kW. At present, there are mainly three types of seawater salinity energy generation technologies: osmotic pressure method, vapor pressure method a...

AI Technical Summary

Problems solved by technology

At present, the cost of power generation using these two methods is very high, and the equipment investment is large; the energy conversion efficiency is low, and the energy density is small

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