An ultralow-temperature district heating system that uses neighborhood-scale heat pumps was recently proposed and investigated. Although the system was found more efficient than any existing solution, there is still potential in this concept for achieving better efficiency and cost-effectiveness. One of the main origins of losses here is through the enlarged pipes. In this work, triple-pipes are proposed to be used instead of twin-pipes to have individual domestic hot water and space heating pipes, reducing the size of heat pumps and decreasing thermal loss rates. The proposed concept is designed, sized and thermodynamically analyzed for a case study in Denmark. The performance is compared with the previous version of this concept as well as the low-temperature district heating system, which is another important competitor to the proposed solution. The results prove that the proposed system outperforms both of the competitors in terms of energy efficiency. For three consecutive days in typical warm/moderate/cold weather in the case study, the proposed solution results in the rates of heat loss of 4.5/10.9/16.5%, respectively. The heat loss rates, for the conventional configuration and the low-temperature design, are 4.9/13.8/19.6% and 5.6/17.8/33.1%, respectively.

中文翻译：

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共享动力热泵三联管超低温区域供热系统热力学分析

最近提出并研究了一种使用社区规模热泵的超低温区域供热系统。尽管发现该系统比任何现有解决方案都更有效，但该概念仍有实现更高效率和成本效益的潜力。这里损失的主要来源之一是通过扩大的管道。在这项工作中，建议使用三管代替双管来拥有单独的生活热水和采暖管，从而减小热泵的尺寸并降低热损失率。提议的概念是为丹麦的一个案例研究设计、确定尺寸和热力学分析的。将性能与该概念的先前版本以及低温区域供热系统进行比较，后者是所提出的解决方案的另一个重要竞争对手。结果证明，所提出的系统在能源效率方面优于两个竞争对手。在案例研究中典型的温暖/中等/寒冷天气连续三天，所提出的解决方案导致热量损失率分别为 4.5/10.9/16.5%。常规配置和低温设计的热损失率分别为 4.9/13.8/19.6% 和 5.6/17.8/33.1%。