集中空调工况多温域相变蓄冷介质及协同强化传热的研究

At present, the abundant and extensive use of conventional central air-conditioning leads to an increase in continuous energy consumption, creating a gap between on-peak and off-peak electrical load periods. The objective of this project is to solve the problem of pitch peak of chiller unit. A new idea of improving phase change temperature which matches with air-conditioning working condition equivalent temperature is proposed, broadening the temperature window of air-conditioning working condition match with cool storage medium. This paper carries out the investigation of the efficient phase change materials (PCMs) of multi-temperature and enhanced heat transfer of synergism for use in cool thermal energy storage system and presents a model which suit for thermal coupling of chemical composition of PCM as cool thermal energy storage media, and determining the thermo-chemical conversion rule of cool storage material under the working condition of air-conditioning temperature, improving the method of multiple eutectic mixture and strengthen modification. The influence of the phase change latent heat of the organic materials and intermolecular forces was used to investigated, and the construct method of the PCM which has a large latent heat of phase change is obtained. Nanometer composite technology is adopted to enhance the thermal conductivity of organic phase change cool storage media and solve the stability problem with the combination of space steric hindrance and electrostatic potential resistance effect. It can obtain a new-style efficient organic phase change cool storage medium based nanofluid; construct a multi-temperature range and strengthen heat transfer method of different phase change cool storage medium based on nanofluid combination, design new-style cool storage tank to improve the heat transfer model with study on the composite cooperation with enhanced heat transfer condition and coupling effect of multi-temperature range combination phase change cool storage medium based on nanofluid charging process, finally seek out ways for improving enhance the heat transfer effect. The bottleneck problem of the chiller units pitch peak is worked out to lay a theoretical foundation and provide technical support for the application of air-conditioning cool storage technology.

针对集中空调使电力系统峰谷差急剧增加，亟需解决冷水机组的调峰等难题。提出蓄冷介质的相变温度与等效空调工况温度相匹配的思想，开展集中空调高潜热多温域相变蓄冷介质及强化换热研究，建立相变蓄冷介质的热化学组分耦合表征模型，揭示在空调工况温度下介质相变的热化学转化规律，提出有机多元共晶混合与强化改性的方法, 分析有机材料相变潜热与分子间作用力等影响，获得相变潜热大的相变材料构筑方法；研究采用纳米复合技术提高有机相变蓄冷介质的导热率，以空间位阻和静电位阻效应相结合解决纳米粒子稳定性问题,获得新型高效有机相变蓄冷介质基纳米流体；构建不同相变蓄冷介质基纳米流体组合的多温域协同强化换热方法，设计新型蓄冷器，改进了蓄冷器传热模型，研究多温域组合相变蓄冷介质基纳米流体蓄冷过程的复合协同强化问题及耦合关系，找到提高强化换热效果的途径。解决了冷水机组的调峰的瓶颈问题，为空调蓄冷技术的应用提供理论依据和技术支持。

针对集中空调使电力系统峰谷差急剧增加，亟需解决空调冷水机组的调峰问题，急需发展高效蓄冷技术。本项目从高效多温域相变蓄冷介质制备及性能优化、相变蓄冷机理、相变蓄冷过程强化换热及蓄冷器整体优化等方面，开展集中空调工况相变蓄冷系统的性能强化研究。制备了性能优异适合集中空调工况有机相变蓄冷介质基纳米流体、无机共晶盐基纳米流体两类复合相变蓄冷介质，开展了热性能表征及优化研究，采用氧化、酯化、接枝改性方法和纳米复合技术提高有机相变材料的相变潜热和导热系数，揭示了有机碳链接枝产物的分子结构对相变潜热影响规律，以及纳米粒子添加对宏观蓄冷性能的影响规律。研究相变蓄冷介质基纳米流体稳定性机理，以空间位阻解决纳米粒子稳定性问题，确定空调工况纳米相变蓄冷介质适合的稳定机制及化学分散剂类型。开展空调工况多温域组合相变材料蓄冷系统运行及协同强化传热特性的研究，分别建立内翅片套管、圆管及球形堆积床内封装多温域组合相变材料蓄冷系统蓄冷/释冷过程动态仿真数学模型，研究传热流体入口流量、翅片、通道尺寸等因素协同作用对强化换热的影响规律、新型蓄冷器的能量存储与释放规律以及相变蓄冷系统运行蓄/释冷动态特性。构建空调工况多温域组合相变蓄冷介质基纳米流体的匹配原则, 优化蓄冷器的结构。提出了强化内翅片传热套管封装多温域组合相变材料蓄冷单元的复合强化方案, 研制新型蓄冷器，可以同时提升蓄冷速率、蓄冷量和缩短蓄冷完成时间。为空调蓄冷技术的应用提供理论依据和技术支持。截止目前,研究成果已发表论文20篇，其中国际期刊论文11篇(SCI检索)，EI检索2篇，专利3项。