高寒地区供暖的多能协同互补机理及系统优化方法研究

Tibetan Plateau is a particular district, with extremely harsh cold climate, scarce natural resources but abundant renewable energy resources such as solar, air and ground energy. Therefore, the fuel-combustion-based heating systems widely used in northern China cannot be applied to meet the heating demands in this particular area. Instead, making full use of the local renewable energy resources and developing sustainable heating systems is of high necessity in energy saving and environment protection. However, there are some limitations in heating system design for plateau buildings. For one thing, there exist a time mismatch between the heat supply and demand, due to the instability of renewable energy and the fluctuation of user loads. Moreover, the influence mechanism among different energy grades remains unclear, leading to relatively low overall energy efficiency of the whole system. For another, for such a heating system containing heat work conversion and heat transfer process simultaneously, available system design methods almost rely on forward problem approach, rather than inverse problem approach, making it hard to find the optimal solutions for certain systems. To solve the aforementioned problems, the main objective of this program is to clarify the internal mechanism of different coupled energies and develop high efficiency renewable energy based integrated heating system for plateau buildings, through both theoretical analysis and experiment. For integrated heating system containing solar energy collection, air-source heat pump and thermal energy storage, ideal system form and optimal design parameters are to be determined via inverse problem and variation method. Furthermore, the proposed approach is about to be utilized for practical system design in plateau area. This research is important for not only enriching thermodynamic optimization theory and method, but also effectively addressing the heating problem in plateau area, which is of both high academic significance and great application prospects.

青藏高原称为地球第三极，气候寒冷，在国家“十三五”期间被划入供暖区域。该地区化石能源匮乏且生态脆弱，因此不能照搬北方供暖模式。充分利用该地区丰富的可再生能源以满足供暖需求是其根本出路，但需解决以下问题：可再生能源的不稳定性与用户负荷的波动性使现有供暖系统在能量供需间存在时序不匹配问题，且不同能态间品位耦合关系不清晰，系统整体能效存在提升空间；现有设计大都根据工程经验，采用“正向”思路得到“可行解”，缺乏“反向”寻求“最优解”的分析方法。为此，本项目拟采用理论分析与实验测试相结合的研究方法，探索高寒地区可再生能源供暖的多能互补、品位耦合与时序匹配机理，以太阳能集热、空气源热泵、蓄能相结合的供暖系统为例，采用反问题与变分方法，提出其理想系统确定方法，求得系统最佳设计与运行参数，为实际工程提供指导。本研究有益于深化拓展热学优化理论与有效解决高寒地区供暖问题，具有较高的学术价值与广泛的应用前景。

青藏高原称为地球第三极，气候寒冷，在国家“十三五”期间被划入供暖区域。该地区化石能源匮乏且生态脆弱，因此不能照搬北方供暖模式。充分利用该地区丰富的可再生能源以满足供暖需求是其根本出路，但需解决以下问题：可再生能源的不稳定性与用户负荷的波动性使现有供暖系统在能量供需间存在时序不匹配问题，且不同能态间品位耦合关系不清晰，系统整体能效存在提升空间；现有设计大都根据工程经验，采用“正向”思路得到“可行解”，缺乏“反向”寻求“最优解”的分析方法。为此，本项目旨在采用理论分析与实验测试相结合的研究方法，探索高寒地区可再生能源供暖的多能互补、品位耦合与时序匹配机理，以太阳能集热、空气源热泵、蓄能相结合的供暖系统为例，采用反问题与变分方法，提出其理想系统确定方法，求得系统最佳设计与运行参数，为实际工程提供指导。项目主要从以下三方面开展工作：（1）高原寒冷地区用户负荷特性与供暖设备性能及变工况模型研究；（2）多能互补供暖系统中能量供需间的品位耦合与时序匹配机理研究；（3）太阳能、空气能、蓄能相结合的供暖系统反问题优化设计方法研究。主要研究成果及科学意义如下：（1）文献调研了高寒地区太阳能、空气能等可再生能源利用系统及其关键设备，整理了其部件模型，建立了各供暖子系统的解析模型。分析了现有建筑热工设计规范与方法在用于高原建筑负荷计算存在的局限性，提炼了影响其建筑热工计算的主要气象因素，修正并建立了高寒地区建筑围护结构非稳态传热模型。（2）调研了高原城镇建筑供暖系统现状，实测了高寒地区典型太阳能平板集热型热水供暖设备与空气源热泵的性能参数。结合理论分析，拟合了系统热性能与气象参数间的动态响应规律。定义了系统能量供需的时序不匹配度，推导了太阳能热水、空气源热泵、蓄能三者的热量供应与建筑热负荷需求间的在时序上动态匹配的定量关系。（3）将反问题与变分方法相结合，提出太阳能、空气能、蓄能相结合的供暖系统整体热性能优化方法，求得理想系统形式与系统最佳设计参数根据优化设计方案，搭建小型“太阳能平板集热型热水系统+空气源热泵+水/相变蓄能”供暖系统实验台，并进行了初步的运行调试。（4）以第一作者发表学术期刊论文12篇，其中SCI收录论文9篇，EI收录论文3篇，获批国家发明专利2项。