面向低碳供暖的城市中水余热跨季节储热系统性能分析

Performance analysis of seasonal thermal energy storage system with urban reclaimed water waste heat for low-carbon heating

为促进跨季节储热技术在寒冷地区的推广应用,以实现北方低碳清洁供暖,提出一种城市中水余热跨季节储热系统。基于TRNSYS建模仿真研究系统长期运行性能,结合建筑供暖需求和运行成本对中水流量与储热体体积进行优化匹配分析,并从环保与经济性角度论证系统可行性。研究结果表明:所述系统可以高效稳定用于区域供暖,连续运行10 a土壤温升为2.84℃,相比传统地源热泵能效比可提升2.80%~18.22%。适当增大储热体体积有利于提高系统储热效率及最大供热能力,在进行系统设计时可按照“大体积、小流量”的原则对储热体体积及中水流量进行匹配,以实现在相同供热能力下最佳经济性。优化匹配后的系统碳排放量与太阳能跨季节储热系统接近,相比于传统供暖系统可减少59.10%,供热费用年值相比太阳能系统与传统供暖系统可分别降低36.51%和24.64%。

In order to promote the application of seasonal thermal energy storage technology in cold regions to realize low-carbon and clean heating in northern China,a seasonal thermal energy storage system with urban reclaimed water waste heat was proposed.The long-term operation characteristics of the system were studied through numerical simulation based on TRNSYS.The volume of heat storage unit and the flow of reclaimed water in the system were optimized considering the heating demand and operation cost,and the feasibility of the system was demonstrated from the perspective of environment and economy.The results show that the system can be applied to district heating efficiently and stably.The soil temperature rises by 2.84℃after 10 a of continuous operation,and the coefficient of performance of the heat pump is 2.80%−18.22%higher than that of the traditional ground source heat pump system.Increasing the volume of heat storage unit is conducive to improving the storage efficiency and maximum heating capacity of the system.Selecting a large volume of heat storage unit and a small flow of reclaimed water can achieve better economic benefits with the same heating capacity.The carbon emission of the system is close to that of the solar seasonal thermal energy storage system,it can reduce by 59.10%compared with the traditional heating system,and the annual heating cost can reduce by 36.51%and 24.64%respectively compared with the solar system and the traditional heating system.