Modelling of latent heat storage by phase change materials for solar drying processes

近年来，虽然对潜热蓄热的研究和应用日益增多，但将其应用于太阳能农产品干燥系统的研究还不多，实现对太阳辐射的大波动的蓄热，将使太阳能农业干燥技术的进一步开发成为可能。潜热储存可以减少干燥温度中不可避免的昼夜差异，从统一过程控制的角度来看，这是不可取的，并且通常对产品质量有负面影响。在这个研究项目中，它的目的是模拟如何与潜热存储的太阳能干燥器的行为相比，传统的系统，只包括一个太阳能空气加热器和干燥单元。通过仿真可以确定各种设计参数对整个系统性能的影响。为此，将在MATLAB环境下的仿真程序中实现主要系统组件（即太阳能空气加热器、潜热存储器和干燥器）的数值模型。然后，这些可以用于进行不同配置的参数研究，并比较它们的特性，例如关于预期的干燥时间，比能量需求，太阳能利用率和产品质量。预期的结果和模拟程序的开发，使知识的实质性扩展有关利用太阳能在农业干燥技术，也形成了技术和经济评价的基础用于干燥过程的潜热储存。

Although there has been increasing research in the area of latent heat storage and its use in a wide variety of areas in recent years, there has hardly been little work on the implementation of this storage technology in solar drying systems for agricultural products.Realizing such storage of the strongly fluctuating solar radiation would make it possible to further exploit the use of solar energy for agricultural drying technology. Latent heat storage can reduce the unavoidable day/night differences in drying temperatures, which are undesirable from the point of view of uniform process control and generally have a negative impact on product quality. In this research project, it is aimed to model how a solar dryer equipped with latent heat storage behaves in comparison to a conventional system that only consists of a solar air heater and a dryer unit. A simulation allows the determination of the influence of various design parameters on the overall system performance.For this, numerical models for the main system components, namely solar air heater, latent heat storage and dryer will be implemented in simulation programs in a MATLAB environment. These can then be used to carry out parametric studies of the different configurations and compare their characteristics, for example regarding expected drying time, specific energy requirement, solar fraction and product quality.The expected results and the simulation programs to be developed enable a substantial expansion of knowledge about the use of solar energy in agricultural drying technology and also form the basis of the technical and economic evaluation of latent heat storage for drying processes.