Technique And Economy Comparison Of Schemes On The Seawater Desalinization And Combination Application

With the continuous development of desalination technology, power plant joint with water plant can optimize utilization of resources to achieve efficient use of energy. In order to solve local water resource problems, this project uses the model of conjoint power plant and water plant to build 10 million ton/day water plant. Combined with engineering construction conditions, four desalination schemes were designed, compare technical and economic performance. Setting filters in the reverse osmosis process to achieve the desired effect for seawater pretreatment system. MED-TVC and SWRO coupling schemes, two desalination processes independent of each other, not to reduce the quantity of water and other resource sharing purposes, but increased The complexity of water intake and pretreatment system, the tedious nature. Economy is relatively poor. After comprehensive comparison, scheme one is recommended in the project, the first phase of station will construct 25000t/d of MED-TVC.Analysis cost factors affecting of desalination, operational costs to four schemes are obtained. Steam and electricity price changes caused by fluctuations coal prices. Steam price accounted for about 45% of the unit cost of making water, great influenced by the coal operation cost. In the reverse osmosis process, electricity accounts for about 23% of the unit cost of making water, moderate influenced by the coal operation cost. The repair and maintenance costs account for 35% of unit cost of water created. The unit cost of making water of reverse osmosis process is mainly affected by the film life and film price and coal price and freshwater production. In this paper, proposed how to reduce operating costs and risks of desalination. It laid basis to choosing the right technical schemes.This Article will propose design optimization for the recommended desalination scheme. Such as MED-TVC process, separating the raw seawater and cooling seawater can reduce the amount of seawater pretreatment system; Salt concentration ratio increased to 2.2, the amount of raw water can reduce the 6930t/h, the seawater pretreatment significantly reduced the scale; Under certain conditions, enhance GOR can reduce the cost of making water,in the project made GOR of Medium pressure steam greater than equal to 13 Kg/Kg, low-pressure steam GOR greater than equal to 12 Kg/Kg; steam from low press cylinder of steam turbine of which steam price are cheap can reduce the cost of seawater desalination and thermal coal consumption. A set of MED-TVC devices use steam from low press cylinder of steam turbine in the project; the amount of steam can be reduced when raw seawater of MED-TVC use fresh seawater, it is advantage for economic operations of MED-TVC and reducing coal consumption;In the construction of the first phase desalination of sea water, try to use the facilities of a power plant to share resources and reduce the project cost, will not affect a unit operation.