Urban Waste Water For Thermal Power Plant Circulating Cooling Water

In the day water resource is short increasingly. It can be used as the secondary source of water entirely the municipal sewage treated secondarily by the sewage treating plant. The thermal power plant is the big consumer, and the circulating cooling water in it doesn't contract with people, require lower water quality and higher water quantity. Then, the power plant is the biggest potential consumer.The paper is supported by the project of the reusing waste water treated secondarily from the Sewage treating Plant of Gaobeidian in Beijing as the circulating cooling water in the Huaneng cent-company in Beijing. It summarizes the change of water quality in the process of sewage treating and of being used as the circulating cooling water in the thermal power plant, analyzes the relation between water quality and some common matters, in the end comes to some conclusions that are guides to the municipal sewage reusing as the circulating cooling water in the thermal power plant.Reviewing the entire reusing project, we grasp the key factors influencing the reusing engineering and the changing process of water quality. After secondary treating, the water quality is steady. Because NH4-N do special harm to the circulating water system, the removal of NH4-N is inquired. After pre-treating, the quality of the water bysecondary treating improves greatly. Through reviewing two ways, the cut corrosion and scale and sterilization, the paper raises the effective measures to immune metal from corrosion and to stop the scale come forth. In the part, the water quality change and its corresponding cause are*proposed in cooling water system.Then, the paper analyzes the key factors affecting reusing and suggests the methods. The common matters during sewage reusing as circulating cooling water are the scale, metal corrosion and microbe development. It is concluded that the water after pre-treating is caustic in many ways. The control to condense multiple, organism and NH4-N are the key factors. Through metal hanging slice test, the connection between organic pollutants and NH4-N and metal corrosion is raised.Following on, the paper analyzes the cost of the sewage reusing object. The cost of circulating water pre-treating is 0.83 yuan/m3 in 2003, and 0.81 yuan/m3 in 200land 2002. In it, the cost of chemicals is the highest, about 35%. The cost of circulating treating for water quality steady is 0.53 yuan/m3 in 2003, but is about 0.1 yuan/m3 in the past two years. Using the chlorine ingot is the cause'of the increase in the cost.At last, it is summed up the outcomes of the paper in entire research.