Flash evaporation and freezing united seawater desalination system for thermal power plant

Abstract

The invention discloses a flash evaporation and freezing united seawater desalination system for a thermal power plant, which consists of a water supply system, a multilevel flash evaporation system, a freezing system, a heat pump system and a thermal system of the thermal power plant. The water supply system is connected with the multilevel flash evaporation system, the freezing system and the thermal system of the thermal power plant respectively through pipelines; and the freezing system is connected with the thermal system of the thermal power plant through the heat pump system and the multilevel flash evaporation system. Through the structural design of a final level flash evaporation chamber of the multilevel flash evaporation system, the heat release of the freezing system and the residual heat of desalination water of the multilevel flash evaporation system are effectively recovered and utilized, water steam required by ice crystal melting is also provided for the freezing system, so that the output of desalination water of the multilevel flash evaporation system is increased, and the desalination water of the freezing system is enabled not to be contaminated. Based on theoptimized design of the water supply system and the heat source selection of the multilevel flash evaporation system, the whole system obtains high integrity and integral optimization, therefore, theflash evaporation and freezing united seawater desalination system has the characteristics that the output of desalination water is high, the quality of desalination water is high, the comprehensive utilization of energy is more complete.

Description

technical field [0001] The invention belongs to the technical field of desalination of seawater, in particular to a seawater desalination system for thermal power plants with combined production of flash evaporation and refrigeration. Background technique [0002] At present, seawater desalination methods mainly include multi-stage flash evaporation, multi-effect distillation, reverse osmosis, and freezing. Today's seawater desalination devices still use the multi-stage flash method with the largest water yield, the most mature technology, and high operational safety. It is mainly built in conjunction with thermal power plants and is suitable for large and super large desalination devices. However, the multi-stage flash method still has the disadvantages of high energy consumption and high cost of seawater desalination. How to effectively reduce energy consumption and further improve the water production capacity of the device is very important to reduce the cost of multi-st...

AI Technical Summary

Problems solved by technology

But in the technological process of this method, the step of using n-butane vapor to melt ice crystals not only does not efficiently utilize the heat of n-butane vapor, but also must use a separator to carry out a separation process to obtain fresh water, because water is inevitably subjected to a small amount of n-butane The pollution of n-butane makes the obtained fresh water difficult to drink directly, which greatly limits the use of this method. How to improve the process flow of n-butane refrigeration method to obtain high-quality fresh water is directly related to the future development prospects of this method

In addition, the current seawater desalination devices jointly built with thermal power plants generally use steam turbine low-pressure extraction steam as the power heat source, and the extracted steam will cause insufficient work in the steam turbine, so the thermal economy of thermal power plants will be reduced

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