The utility model discloses an evaporative condensing unit, including evaporation compressor unit and evaporative condenser, wherein, the evaporation compressor unit include: heat exchanger, it is used for supplying refrigerated water and refrigerant to carry out the heat exchange to make refrigerant heat absorption vaporization, the compressor, its refrigerant pressurization liquefaction that is used for making the vaporization, evaporative condenser includes: upper strata heat transfer district, it is used for the warp compressor liquefied refrigerant carries out the precooling through the air, heat transfer district of lower floor, it is used for by freezing water to cool off the refrigerant of precooling and let in the refrigerated refrigerant heat exchanger, cooling water treatment system, it is including being used for throwing the charge device of adding medicament with control recirculated cooling water dirt for recirculated cooling water. The utility model discloses a monitoring devices is used for real -time supervision quality of water through the volume according to water quality information control charge device adding medicament so that the change of real time control quality of water.