Abstract
Improving the performance of MSF (multi stage flash) desalination plants is a major challenge for desalination industry. High feed temperature in summer shortens the evaporation range of MSF plants and limits their yield. Installing a cooler at the feed intake expands the evaporation range of MSF plants and increases their yield. Adding a cooler and a mixing chamber increases the capital and operational costs of MSF plants. This paper presents thermal and economic analysis of installing a feed cooler at the plant intake. The profit of selling the additionally produced water must cover the cost of the cooling system. The selling prices for a reasonable breakeven depend on the selected cooling temperature. The cost of installing coolers capable of maintaining feed–brine mixture temperatures of 18–20 °C shows breakeven selling prices of 0.5–0.9 $/m3. These prices fall within the current range of potable water selling prices.
•Thermo-economic analysis for MSF plant with brine mixing and cooling is presented.•Analysis is based on first and second laws of thermodynamics.•The profit gained from producing additional water covers the cooling cost.•The suggested modification is a promising technique for plants in hot climates.