一、前言热力系统在整个能源消费系统中占有重要的地位。发展集中供热、热电结合可以促进热力系统总体水平的升级进步,提高能源利用率,节省能源,改善环境,创造更多的经济效益和社会效益。南京地处长江岸边,冬季受北方冷空气影响,气候相当寒冷,累年日平均温度低于和等于5℃的日数达80天左右,每年在较长的时间内,人们的生活、工作和学习都非常需要一个 I. Introduction The thermodynamic system occupies an important position in the entire energy consumption system. The development of central heating and thermal power combined can promote the upgrade of the overall level of thermal systems, improve energy efficiency, save energy, improve the environment, and create more economic and social benefits. Nanjing is located on the bank of the Yangtze River. In winter, it is affected by the cold air in the north. The climate is very cold. The number of days with an average daily temperature below 5°C is approximately 80 days. Every year, people live and work for a longer period of time. It takes a lot to study