经过三十五年的建设,北京已发展成为具有550万城市人口的大城市。全市能源消费近两千万吨标准煤,其中煤炭消费量占74％。冬季30％的煤炭用于取暖,占全年耗煤量的12.5％,大部分房屋建筑是采用落后方式——小火炉和小锅炉取暖。全市锅炉二万多台,平均市区每平方公里有六十多台。随着近几年大量兴建住宅,全市锅炉台数以每年四五百台的速度剧增。每逢冬季,煤厂、灰 After 35 years of construction, Beijing has grown into a large city with a population of 5.5 million. The city’s energy consumption is nearly 20 million tons of standard coal, of which coal consumption accounts for 74%. In winter, 30% of coal is used for heating, which accounts for 12.5% ​​of the annual coal consumption. Most houses are built in backward ways—small stoves and small boilers for heating. The city has more than 20,000 boilers, with an average of more than 60 units per square kilometer. With the large number of residential buildings built in recent years, the number of boilers in the city has increased rapidly at a rate of 400 to 500 units per year. Every winter, coal plants, ash