Heat-pipe low-temperature multi-effect sea water desalinating system and process flow

Abstract

The invention discloses a heat-pipe low-temperature multi-effect sea water desalinating system which comprises a plurality of groups of heat-pipe multi-effect evaporators, a steam injector TVC (Thermal Vapor Compressor), a cooler, an air water release device, a steam-water separator, a water ring vacuum pump, a raw water pump, a fresh water pump, a turbine intermediate pressure cylinder and a turbine low pressure cylinder and also comprises the distribution of steam, product water and strong brine between heat-pipe multi-effect evaporators. The invention also discloses a process flow of the heat-pipe low-temperature multi-effect sea water desalinating system, comprising the steps of: extracting steam through the turbine intermediate pressure cylinder, ejecting circulation steam in the cooler and exhaust steam of the turbine low pressure cylinder through the steam injector TVC to ensure that the circulation steam and the exhaust steam of the turbine low pressure cylinder are changed into higher-quality steam to enter the heat-pipe evaporators, condensing and releasing heat of the steam at a heat absorption end through a heat pipe, transferring the heat to heating and atomized sea water at the other end; heating next-stage sea water through taking the heated and vaporized sea water as the heat source of the next multi-effect evaporator while cooling the heated and vaporized sea water to generate fresh water; heating the sea water which cools the last-stage steam entering the cooler and exhausting the generated non-condensable gas through the air water release device; pumping the non-condensable gas of the multi-effect evaporators through the water ring vacuum pump to ensure that the system runs in a negative-pressure state; and discharging concentrated water out of the system through a pipeline and pumping the fresh water to a fresh water tank through a permeated water pump.

Description

technical field [0001] The present invention relates to thermal desalination of seawater, in particular to a heat pipe type low-temperature multi-effect evaporator to improve seawater evaporation efficiency and low-quality steam turbine low-pressure cylinder exhaust to improve energy utilization and power plant efficiency . The steam produced by heating the seawater through the heat pipe is used as the heat source of several groups of evaporators in the future to improve the utilization rate of the steam. Background technique [0002] Low-temperature multi-effect distillation refers to steam with a heat source below 70°C. It was applied to industrial seawater desalination systems around 1981. It is characterized by connecting a series of horizontal tube spray falling film steamers in series, using a certain amount of steam The input passes through multiple evaporation and condensation, and the evaporation temperature of the latter effect is lower than that of the previous e...

AI Technical Summary

Problems solved by technology

However, since the maximum operating temperature of the concentrated seawater of the device is about 110°C, it is highly corrosive to the heat transfer tube and the equipment body, and expensive copper-nickel alloy, special stainless steel and titanium must be used, so the equipment cost is high

In addition, in order to reduce scaling and corrosion, add acid and degas (remove CO2 and O2) to the seawater entering the device, thus increasing the cost of water production

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