Research On Energy-saving Renovation Technology Of Urban Central Heating

The central heating system in China's heating area suffers serious corrosion and water leakage,causing heat loss and hydraulic system disorder,which seriously affects operating safety of heating system and heating effect,and increases energy consumption.This dissertation is about the research into the heating system renovation which aims to enhance energy efficiency,safety and stability of urban central heating system.Firstly,the dissertation introduces a survey on the present condition of central heating conducted in 16 provinces in china which shows 25%of the pipe network has the pipe age of over 15 years,and only about 50%of heat transfer stations are automated and intellectualized.The average energy consumption of coal source heating,gas source heating and cogeneration heating is 25.8kgce/m2,14.6m3/m2 and 0.50GJ/m2 respectively.Only 16%of all implements heat metering.The temperature drop of recirculating hot water is 2.4?/km.There has been 509,000 ordinary heating accidents from 2006 to 2011,among which nearly 77%was caused by pipe corrosion and pipe aging.Old pipe network renovation is of great significance and has great potential to save energy.Secondly,the dissertation analyzes technology plan of heating system energy-saving renovation,which includes pipeline and accessory renovation technology,heating regulating technology,multi-source network operating,heating station energy-saving renovation technology,heat metering energy-saving renovation technology and heating monitoring technology.The overall length of of the network reconstruction is estimated at 7941km,which takes up 35%of the whole network.Of all the pipeline to be reconstructed,pipe age of over 15 years takes up about 60%.The overall number of heat meters and flow balancers to be installed is 2470,000 and 1020,000 respectively.The number of heating information managing platforms to be set up is 375.The overall investment in heating system renovation is estimated at 183 billion yuan,the investment in heating station energy-saving renovation is 20.3 billion yuan,the investment in secondary network energy-saving renovation is 22.9 billion yuan,the investment in monitoring capacity is 3.6 billion yuan.The renovation will save 20.46 million tons of heating-coal,reduce 420 million tons of pipeline water provision and save 23 million kwh electricity consumption annually,which will bring the benefit of cutting the cost of 18.4 billion yuan,2.1 billion yuan and 150 million yuan on coal,water and ecletricy respectively and reduce the emission of 56.73 million tons of carbon dioxide,220,000 tons of sulfur dioxide,100,000 tons of citric oxide,50,000 tons of dust and 5.34 million tons of ash annually.Finally,taking the example of a renovation project conducted by a shenyang heating company,the dissertation analyzes the potential of the renovation and the benefits of energy saving and finance it will bring.The amount of annual coal consumption per unit after the renovation was reduced by 10%.The boiler saved 9.8%of the energy after a waste heat recovery device was retrofitted to the boiler.The electricity consumption was reduced by 50%after the frequency conversion technology renovation.The heat station saved 38%of the electricity,and the total electricity consumption saved in 3 months was 400,000 kwh,saving 280,000 yuan on the cost of electricity.The savings on the cost of personnel is 60,000 yuan annually.The loss of water reduced to 80 t/h,saving 1.67 million yuan on the cost of water supply and 16.2 million yuan on the cost of heating during the heating period,which amounts to 18 million yuan all together.After the household heating renovation,users' motivation to pay were promoted.