Process for improving thermal efficiency while producing power and desalinating water

A process for improving the thermal and energy efficiency of an existing steam turbine power generation plant having a high-pressure boiler with a combustion exhaust of known temperature and dewpoint, comprising the steps of:

• adding a secondary economizer in a combustion exhaust path of an existing high-pressure boiler to be heated by the combustion exhaust of said high-pressure boiler, said secondary economizer connected with a flash tank and having a conduit passing through a condenser condensate collection tank connected with the steam exhaust of the steam turbine;
• adding a multi-effect desalination train connected with said flash tank and said condenser condensate collection tank to circulate low-pressure steam from said flash tank, through consecutive effects of said desalinization train, through said condenser condensation collection tank, and back into said flash tank;
• condensing the steam exhausted from a turbine and collecting it in said condenser condensate collection tank;
• passing fresh water condensate through said secondary economizer and flashing said fresh water condensate in said flash tank to produce low-pressure steam;
• introducing salinous water or water containing minerals, salts, and dissolved solids into said consecutive effects of said desalinization train;
• heat exchanging said low-pressure steam from said flash tank against said collected condenser condensate to initially heat said condenser condensate and to condense said low-pressure steam into said fresh water condensate such that said fresh water condensate has a temperature about the same or greater than the dewpoint of said combustion exhaust of said high-pressure boiler;
• conducting said low-pressure steam from said flash tank through a last effect of said desalinization train to heat and desalinize said salinous water or water containing minerals, salts, and dissolved solids and to condense said low-pressure steam into fresh water, mixing it with said fresh water condensate, and conducting the mixture back into said flash tank;
• preheating said initially heated condenser condensate in a high-pressure preheater and passing said preheated condenser condensate through a high-pressure deareator to remove dissolved gases;
• reheating said preheated and deareated condenser condensate by passing it through a primary economizer heated by the combustion exhaust of said high-pressure boiler and utilizing said reheated and deareated condenser condensate as feedwater for said high-pressure boiler;
• and
• utilizing said fresh water condensate having a temperature about the same or greater than the dewpoint of said combustion exhaust of said high-pressure boiler to recover waste heat from said combustion exhaust.

A process for improving the thermal and energy efficiency of a steam turbine power generation plant having a high-pressure boiler with a combustion exhaust of known temperature and dewpoint, comprising the steps of:

• connecting a secondary economizer in a combustion exhaust path of an existing high-pressure boiler to be heated by the combustion exhaust of said high-pressure boiler, said secondary economizer further connected with a flash tank and having a conduit passing through a condenser condensate collection tank connected with the steam exhaust of the steam turbine;
• providing a multi-effect desalination train connected with said flash tank and said condenser condensate collection tank to circulate low-pressure steam from said flash tank, through consecutive effects of said desalinization train, through said condenser condensation collection tank, and back into said flash tank;
• condensing the steam exhausted from said turbine and collecting it in said condenser condensate collection tank;
• passing fresh water condensate through said secondary economizer and flashing said fresh water condensate in said flash tank to produce low-pressure steam;
• introducing salinous water or water containing minerals, salts, and dissolved solids into said consecutive effects of said desalinization train;
• heat exchanging said low-pressure steam from said flash tank against said collected condenser condensate to initially heat said condenser condensate and to condense said low-pressure steam into said fresh water condensate such that said fresh water condensate has a temperature about the same or greater than the dewpoint of said combustion exhaust of said high-pressure boiler;
• conducting said low-pressure steam from said flash tank through a last effect of said desalinization train to heat and desalinize said salinous water or water containing minerals, salts, and dissolved solids and to condense said low-pressure steam into fresh water, mixing it with said fresh water condensate, and conducting the mixture back into said flash tank;
• preheating said initially heated condenser condensate in a preheater and passing said preheated condenser condensate through a deareator to remove dissolved gases;
• and
• utilizing a portion of said deareated condenser condensate as feedwater for said high-pressure boiler.