众所周知，我国是世界上水资源严重缺乏的国家之一，尤其是北方地区的大中城市，水资源更为紧缺。以北京为例，一般年平均降水量为630 mm左右，人均水资源占有量不到300 m3，是全国平均水平的1/8，世界的1/32。水资源缺乏已成为我国经济建设的一个亟待解决的问题。 电厂用水 As we all know, our country is one of the countries with serious water shortage in the world. Especially in large and medium-sized cities in the north, water resources are more scarce. Taking Beijing as an example, the average annual average precipitation is about 630 mm, and the per capita water resources occupy less than 300 m3, which is 1/8 of the national average and 1/32 of the world. The lack of water resources has become an urgent issue for economic construction in our country. Power plant water