Method for the recovery of process wastewaters of a fossil-fueled steam power plant and fossil-fueled steam power plant

Abstract

A fossil-fueled steam power plant and method, the plant has a water-steam circuit, cooling water circuit, flue gas cleaning system and cooling tower. A fossil-fueled steam generator, steam turbine and condenser are connected to the water-steam circuit. In the cooling water circuit, a cooling tower and condenser are connected such that expanded steam is condensed by the exchange of heat with the cooling water circuit. The flue gas from the generator is cleaned in the flue gas cleaning system, and the cleaning system is supplied with process water. Process wastewater leaves the cleaning system. The cleaning system is connected to the cooling water circuit such that process water required for cleaning system is drawn from the cooling water circuit. To remove contaminated process wastewater, the cleaning system is connected to a wastewater treatment system having an evaporator, where system purified process wastewater is generated.

1 . A fossil fuel-fired steam power plant, comprising
 a water-steam circuit into which are connected a fossil fuel-fired steam generator, a steam turbine, and a condenser,   a cooling water circuit, into which are connected a cooling tower and the condenser, wherein expanded steam from the water-steam circuit is condensable in the condenser by heat exchange with the cooling water circuit, and   a flue gas purification plant, in which flue gas from the fossil fuel-fired steam generator is purified, wherein the flue gas purification plant is supplied with a process water and a process wastewater is discharged therefrom,   wherein the flue gas purification plant is connected to the cooling water circuit, such that the process water required for the flue gas purification plant is drawn from the cooling water circuit, and the flue gas purification plant is connected for discharge of contaminated process wastewater to a wastewater treatment plant comprising an evaporator and by which a purified process wastewater is produced.   
     
     
         2 . The fossil fuel-fired steam power plant as claimed in  claim 1 ,
 wherein the flue gas purification plant is connected to the cooling water circuit downstream of the cooling tower, such that cooling tower blowdown water is used as process water for the flue gas purification plant.   
     
     
         3 . The fossil fuel-fired steam power plant as claimed in  claim 1 ,
 wherein the flue gas purification plant is connected to the cooling water circuit upstream of the cooling tower and upstream of a cooling tower make-up water treatment plant, such that an as yet untreated cooling tower water for use in the cooling tower is used as process water for the flue gas purification plant.   
     
     
         4 . The fossil fuel-fired steam power plant as claimed in  claim 1 ,
 wherein the flue gas purification plant is connected to the cooling water circuit upstream of the cooling tower and to a cooling tower make-up water treatment plant, such that a cooling tower water treated for use in the cooling tower is used as process water for the flue gas purification plant.   
     
     
         5 . The fossil fuel-fired steam power plant as claimed in  claim 1 ,
 wherein the wastewater treatment plant is connected to a deionization plant connected into the water-steam circuit, such that a purified process wastewater from the wastewater treatment plant is passed into the deionization plant.   
     
     
         6 . The fossil fuel-fired steam power plant as claimed in  claim 1 ,
 wherein the wastewater treatment plant is connected to a cooling tower make-up water treatment plant connected into the water-steam circuit, such that a purified process wastewater from the wastewater treatment plant is passed into the cooling tower make-up water treatment plant.   
     
     
         7 . The fossil fuel-fired steam power plant as claimed in  claim 1 ,
 wherein the wastewater treatment plant is furthermore additionally connected to the condensate purification plant, the evacuation system and the sampling point for introduction of contaminated process wastewaters from the water-steam circuit into the wastewater treatment plant.   
     
     
         8 . A method for operating a fossil fuel-fired steam power plant, comprising
 a water-steam circuit, into which are connected a fossil fuel-fired steam generator, a steam turbine, and a condenser, wherein steam is generated in the steam generator, and said steam is expanded in the steam turbine, and passed into the condenser,   a cooling water circuit, into which are connected a cooling tower and the condenser, wherein the expanded steam from the water-steam circuit is condensed in the condenser by heat exchange with the cooling water circuit, and   a flue gas purification plant, in which flue gas from the fossil fuel-fired steam generator is purified,   
       the method comprising:
 drawing the process water required for the flue gas purification plant from the cooling water circuit, which water is contaminated by flue gas purification, wherein contaminated process wastewater is formed, and 
 supplying the contaminated process wastewater to a wastewater treatment plant comprising an evaporator, in which a purified process wastewater is formed by evaporation. 
 
     
     
         9 . The method for operating a fossil fuel-fired steam power plant as claimed in  claim 8 ,
 wherein the flue gas purification plant is supplied with a cooling tower blowdown water as process water which is drawn from the cooling water circuit downstream of the cooling tower.   
     
     
         10 . The method for operating a fossil fuel-fired steam power plant as claimed in  claim 8 ,
 wherein the flue gas purification plant is supplied with an as yet untreated cooling tower water as process water which is drawn from the cooling water circuit upstream of the cooling tower and upstream of a cooling tower make-up water treatment plant.   
     
     
         11 . The method for operating a fossil fuel-fired steam power plant as claimed in  claim 8 ,
 wherein the flue gas purification plant is supplied with a treated cooling tower water as process water which is drawn from the cooling water circuit upstream of the cooling tower of a cooling tower make-up water treatment plant.   
     
     
         12 . The method for operating a fossil fuel-fired steam power plant as claimed in  claim 8 ,
 wherein the purified process wastewater from the wastewater treatment plant is passed into a deionization plant connected into the water-steam circuit.   
     
     
         13 . The method for operating a fossil fuel-fired steam power plant as claimed in  claim 8 ,
 wherein the purified process wastewater from the wastewater treatment plant is passed into a cooling tower make-up water treatment plant connected into the water-steam circuit.   
     
     
         14 . The method for operating a fossil fuel-fired steam power plant as claimed in  claim 8 ,
 wherein contaminated process wastewaters from the water-steam circuit, from the condensate purification plant, from the evacuation system and the sampling point are furthermore additionally introduced into the wastewater treatment plant.