利用电厂余热的大温差长输供热模式

Long-distance heat-supply mode with large temperature difference using waste heat ofpower plants

针对电厂余热利用存在的余热输送距离远、余热品位低、回收成本高等难点,提出了以低回水温度为特征的大温差长输供热模式,大幅提高热网输送能力,显著降低回收余热成本,使大规模利用电厂余热的清洁供热方式经济可行。考虑我国北方地区城镇未来供热面积达200亿㎡的发展规模,提出了以利用电厂余热的长输供热模式为基础的清洁供热规划方案,与以煤改气和煤改电为主的参考方案相比,规划方案可节能50%,减少大气污染排放80%,减少碳排放2亿t,降低综合供热成本25%。由于长输供热投资大且涉及多方,建议国家进一步明确电厂余热是我国北方城镇清洁供暖主力热源的地位,并出台相应政策和措施,鼓励这一清洁高效供热模式的发展。

Targeting at the problems of long-distance heat transportation,low heat grade and high recovery cost existing in waste heat utilization of power plants,a large-temperature difference long-distance heat-supply mode characterized by low return water temperature was proposed.The mode has greatly improved the transmission capacity of the heat-supply network and significantly reduced the cost of waste heat recovery.It made the large-scale waste heat utilization of power plants economic and feasible as well.Considering the potential heating area of cities and towns in northern China which will reach 20 billion square meters,a clean heat-supply scheme was made based on the long-distance heating mode utilizing waste heat from power plants.Compared with the reference scheme replacing coal with gas or electricity,this scheme can save 50%energy consumption,reduce 80%air pollution emission,reduce carbon emission by 200 million tons,and save the comprehensive heating cost by 25%.Since the long-distance heat-supply mode is of large investment and complex relationships with multiple parties,waste heat from power plants should be further stated as the dominant heating source for the clean heating in northern cities and towns in China,and corresponding policies and measures should be carried out to encourage the development of this clean and efficient heating mode.