Optimised Solar Thermal Storage System for Delivering Process Heat at Temperatures Above 160 C

该研究的核心目标是利用相变材料（PCM）开发一种新型太阳能热能储存系统。相变材料是一类吸收或释放能量时发生相变的材料。它们通常在吸收热量时进入液态，在热量被提取时凝固。由于材料的潜热容量（材料发生相变时吸收或释放的能量）的特性，pcm具有很高的热能储存潜力。该系统旨在利用聚光太阳能热收集器技术的发展，该技术提供高温并将其与PCM储热相结合。本研究旨在利用潜热蓄热能力，储存相对大量的太阳能热能，并在需要时释放。该研究将特别关注提供适合中温范围工业过程的温度和加热剖面。详细的科学目标：PCM的发展，提高理想的性能，如导热性和熔化温度。该活动将采用计算机模拟，然后进行实验验证。确定影响PCM热循环稳定性和长期（季节性）储存能力的因素，并采取措施减轻热循环和长期储存的负面影响。热循环稳定性定义为材料在保持其热性能的同时可以经历加热和冷却循环的次数。初步调查将通过标准材料特性测试进行，然后使用扫描电子显微镜（SEM）进行显微镜检查。降解因素将被识别，随后采取纠正措施，材料将被重新测试。开发了一个模型来解释熔化和凝固过程中的相变边界运动，并开发了热交换器设计，通过从熔化和凝固模型中获得的知识进行优化。新颖的模型，以了解，量化和可视化的熔融和固化过程的PCM。PCM经过优化，可以进行更多的热循环，并且在用于长期储能时降解更少。一种新型热交换器的设计利用了PCM的熔化和凝固特性。一个工业规模的系统设计，用于存储和输送热量，使用优化的PCM作为存储介质。由于工业过程占英国全国能源使用量的近16%，其中一半以上的能源来自不可再生能源，因此本研究的希望是通过改进存储技术和提供更高温度的能力，使太阳能热能成为工业环境中可行的替代能源。该研究的潜在应用包括食品加工业、茶叶工业和聚合物制造。

The core aim of the study is the development of a novel solar thermal energy storage system using phase change materials (PCM). PCM are a class of material which change phase when absorbing or releasing energy. They typically enter a liquid form when absorbing heat and solidify when the heat is extracted. PCMs have high thermal energy storage potentials due to the material property of latent heat capacity, the amount of energy absorbed or released when a material undergoes a phase change. The system aims to take advantage of the developments in concentrating solar thermal collector technology which deliver high temperatures and couple it with PCM heat storage. This study aims to use latent heat storage capability to store a relatively large amount of solar thermal energy and release the energy at the point of demand. The research will give specific attention to delivering temperatures and heating profiles suitable for mid-temperature range industrial processes.Detailed scientific objectivesDevelopment of PCM which enhances desirable properties such as thermal conductivity and melting temperatures. This activity will be carried out using computer simulation followed by experimental verification.Identify the factors affecting the thermal cycle stability and long-term (seasonal) storage capability of PCM and incorporate measures to mitigate the negative effects of thermal cycling and long-term storage. Thermal cycling stability is defined as the number of times a material can undergo heating and cooling cycles while maintaining its thermal properties. Initial investigation will be carried out through standard material characterisation tests followed by microscopy using scanning electron microscope (SEM). Degradation factors will be identified, followed by the application of corrective measures and the material will be re-tested. Development of a model to explain the phase change boundary movement during melting and solidifying and development of heat exchanger design with optimisations led by knowledge gained from the melting and solidifying model.NoveltyModel to understand, quantify and visualise the melting and solidifying process of PCM.PCM optimised to undergo more thermal cycles and degrade less when used for long-term energy storage.Development of a novel heat exchanger designed to take advantage of the melting and solidifying profile of PCM.An industrial scale, system design for storage and delivery of heat, using an optimised PCM as the storage medium.Benefit to societyWith industrial processes accounting for nearly 16% of national energy usage in the United Kingdom and over half of that energy coming from non-renewable sources, it is the hope of this study, to make solar thermal energy a viable alternative in an industrial setting, through improvements in storage technology and capability to deliver higher temperatures. The potential applications of the proposed work include processes in the food processing industry, tea industry and polymer manufacture.