Multi-stage flash distillation seawater desalination system of low-temperature multi-effect steamer vapor compression distillation

Abstract

The invention discloses a multi-stage flash distillation seawater desalination system of low-temperature multi-effect steamer vapor compression distillation. The system comprises a back presser, a compressor, a low-temperature multi-effect evaporator, a multi-stage flash distillation device, a final stage flash distillation chamber, a heater, a heat source steam pipeline, a feed seawater pipeline and a fresh water outlet pipeline. In the system, the heat source steam is taken into the back presser to act so as to drive the compressor to work; all the finally acted secondary steam in the low-temperature multi-effect evaporator is regarded as the firstly acted heating steam after being compressed by the compressor; the exhaust steam of the back presser is regarded as the heat source steam of the multi-stage flash distillation device; the waste heat in the fresh water of the multi-stage flash distillation device and the low-temperature multi-effect evaporator is recycled and used in final stage flash distillation chamber; and the cooling water in the final stage flash distillation chamber is respectively regarded as the feed seawater of the low-temperature multi-effect evaporator and the multi-stage flash distillation device. By providing different steam parameters suitable for power plants, the multi-stage flash distillation seawater desalination system of low-temperature multi-effect steamer vapor compression distillation disclosed by the invention has the advantages of high energy utilization rate, high thermal efficiency, high yield of the desalted water, little dosage of the feed seawater, and the like, and is widely applied to the field of seawater desalination.

Description

technical field [0001] The invention belongs to the technical field of seawater desalination, and in particular relates to a low-temperature multi-effect steam turbine steam distillation-multistage flash seawater desalination in which heat source steam is driven by a steam turbine to drive a compressor to compress steam (referred to as "turbine steam") for distillation. system. Background technique [0002] my country is a country with serious shortage of water resources. Water shortage has become a major bottleneck restricting the sustainable development of my country's economy and society. Seawater desalination is an effective strategic approach to solve the shortage of freshwater resources in our country. There are many types of seawater desalination technologies, but the ones suitable for industrialization mainly include distillation and membrane methods. Distillation has the advantages of using low-grade heat sources and large device production capacity, and is curre...

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Problems solved by technology

However, this method has the following disadvantages: First, only part of the low-pressure steam can be injected, and the remaining steam is finally cooled into fresh water by the condenser, and part of the heat is taken away by the cooling water, resulting in heat loss; second, the injected low-pressure steam Mixed with heat source steam, it can only be used as power plant feed water after condensation, but loses the original output of this part of fresh water; third, with the increase of heat source steam pressure, more available energy is consumed in the ejector , only a small part is used to increase water production, and as a result, the water production ratio increases gradually, while the exergy efficiency of the ejector decreases, and the energy utilization rate of the system decreases

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