Economic comparison of low-temperature and ultra-low-temperature district heating for new building developments with low heat demand densities in Germany

District heating risks to lose competitiveness the lower the linear heat density of a district is. The distribution network needs to be highly efficient in order to ensure economic feasibility. The heat distribution temperatures are crucial to keep distribution heat losses as low as possible. For a new development in Germany consisting mainly of single family houses, two district heating networks at different supply temperature levels are examined in terms of economic and efficiency aspects. Depending on the required temperature level and temperature difference between supply and return the needed volume flow differ. Consequently also the required pipe diameter is affected. The impact of design temperature and operating strategy on the economic feasibility of the district heating network is investigated.

区域供热 (district heating) 的竞争力会随着区域线性热密度的降低而逐渐丧失。为保障其经济可行性，供热管网需具备极高的运行效率。供热输送温度对于将管网热损失控制在最低水平至关重要。针对德国以独栋住宅为主的新建开发片区，本文针对两种不同供水温度等级的区域供热管网，从经济性与能效维度展开评估分析。所需的供水温度及供回水温差不同，所需的流体体积流量也会有所差异，进而对所需管道管径造成影响。本研究分析了设计温度与运行策略对区域供热管网经济可行性的影响。