Multistage flash evaporation seawater desalination-pressure delay osmotic salinity difference power generation coupled system and operation method thereof

Abstract

The invention discloses a multistage flash evaporation seawater desalination-pressure delay osmotic salinity gradient power generation coupled system and an operation method thereof. The system comprises a brine heater, a multistage flash evaporation heat recovery section, a multistage flash evaporation heat discharge section, a pressure exchanger, a booster pump, a pressure delay osmotic membraneassembly, a water turbine, a natural seawater introducing pump, a cooling seawater discharge pump, a product fresh water extracting pump, a CO2 removal device, a deoxygenization device and a vacuumizing device which are connected with one another. According to the invention, strong brine and seawater discharged by a multistage flash evaporation system are respectively introduced into the absorbing liquid side and the feed liquid side of the pressure delay osmotic membrane assembly for osmotic power generation; the flow ratio of absorbing liquid to the feed liquid is adjusted through a feed liquid flow control valve; a pressure difference between the two sides of the pressure delay osmotic membrane assembly is adjusted through the booster pump; and the ratio of flow at the two sides of thepressure exchanger is adjusted through a flow control valve. The energy utilization efficiency of the whole system can be improved, the salinity of strong brine discharged by the system is reduced, and influence on the ecological environment is reduced.

Description

technical field [0001] The invention relates to the technical field of seawater desalination and salinity difference energy, in particular to a multi-stage flash seawater desalination and pressure delayed osmosis salt difference power generation coupling system and an operating method. Background technique [0002] Multi-stage flash desalination technology is a thermal seawater desalination technology capable of producing large quantities of fresh water. However, the multi-stage flash seawater desalination technology has high heat consumption and is an energy-intensive seawater desalination method. At the same time, it will discharge a large amount of concentrated brine with a concentration higher than the environment, which will have a negative impact on the surrounding ecological environment. The pressure-delayed osmosis power generation technology can use the solution concentration difference to generate electricity. It is mainly used in areas rich in salt difference ener...

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Problems solved by technology

However, the difference in the concentration of these salinity energy resources is relatively small, and the cost of pretreatment is relatively high due to the large amount of impurities in natural seawater, river water and lake water

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