当前我国的区域供热系统多按质调原理进行设计。从世界范围来看，采用此种供热方式的国家多分布在东欧地区以及前苏联各加盟共和国（如波罗的海的爱沙尼亚等）。所谓质调系指一次网的循环水量在整个供暖季节固定不变，热源处仅根据室外平均温度（有时也考虑风速）来改变供水温 At present, China’s district heating system is designed according to the principle of quality adjustment. From a worldwide perspective, the countries that use this type of heating are mostly distributed in Eastern Europe and the former Soviet republics (such as Estonia in the Baltic Sea). The so-called quality adjustment means that the amount of circulating water in the primary net is constant throughout the heating season, and the heat source only changes the water supply temperature based on the average outdoor temperature (sometimes considering the wind speed).