带级间热回收的太阳能分级溶液集热/再生临界性能特性及热力学优化

A solar grading solution collector/regenerator system with inter-grade heat recovery is established in this project in which the analysis of critical performance characteristics and thermodynamic optimization will be conducted. The main study contents are listed as: 1) Based on the balances of material flow and energy flow of solution in packing reservoir, the model of solar grading solution collector/regenerator system will be built and the effects of heat recovery efficiency on the energy efficiency of system are studied and the application scope of surrounding air relative humidity, solar radiation intensity and solution concentration are given when the performances of solar grading collector/ regenerator are better than solar single collector/ regenerator. 2) Based on the heat exergy model as well as the models of enthalpy exergy and diffusion exergy both of solution and air at their inlet and outlet, the exergy analysis method in second law of thermodynamics will be used to get the working graphs of exergy efficeincy and the distribution of exergy loss ratio for the system optimization. 3) Establishing the experimental units of solar grading solution collector/regenerator system with inter-grade heat recovery and studying critical environmental parameters, critical solution concentration and flow-rate when the performances of grading collector/regenerator are better than the single collector/regenerator. The applicant of this project has completed theoretical modeling, numerical simulations and experimental studies on the single collector/regenerator and has published twenty five papers cited by SCI, EI etc. including eight papers in the WEB of SCIENCE and achieved four authorizations of invention patents. The applicant has the working basis for accomplishing the project successfully.

项目构建一套带级间热回收的太阳能分级溶液集热/再生系统，进行系统临界性能特性分析及热力学优化。主要内容为：1）基于填料储液槽内溶液的物质流和能量流平衡，建立太阳能分级溶液集热/再生系统数学模型，研究热回收效率对系统能源效率影响，给出分级集热/再生性能优于单级集热/再生所适用的室外环境湿度、太阳辐射强度及溶液浓度范围；2）基于溶液再生过程热量火用、溶液和空气进出口焓火用及扩散火用模型，采用热力学第二定律中的火用分析方法进行系统优化，得到系统火用效率作用图线及火用损率分布；3）搭建带级间热回收的太阳能分级溶液集热/再生试验装置，研究分级集热再生优于单级集热再生的临界环境参数、临界溶液浓度及流量参数。申请人已对单级太阳能溶液集热/再生进行理论建模、数值模拟及实验研究，发表与本项目相关的三大检索论文25篇，包括8篇国际期刊SCI论文，获得发明专利授权4项，已具备完成本项目的工作基础。

针对我国夏热冬冷地区高温高湿及中低太阳辐射条件下高浓度除湿溶液较难进行有效再生的问题，项目提出一种带级间热回收的太阳能分级集热/再生系统。主要研究内容为：1）基于带级间热回收的太阳能分级溶液集热/再生系统数学模型，研究该种分级溶液集热/再生在溶液浓度及环境参数上临界性能特性；2）基于系统热力学㶲分析模型及方法，分析分级溶液集热/再生系统各影响参数对系统㶲效率及㶲损系数的影响；3）基于焓火积耗散数模型，提出预测溶液除湿再生过程性能的简化解析模型；4）设计一种自预热太阳能集热/再生器，对其性能优化进行研究；对内冷/内热型除湿/再生性能特性进行研究；实验研究外表面蒸发式溶液除湿器的热湿传递特性。重要研究结果：1）相比单级再生，分级再生在室外环境状态上存在临界值；室外环境温度和相对湿度高于临界点、太阳辐射辐射强度低于临界点，分级再生优于单级再生；2）随着集热/再生板长增加，临界空气流量越低，临界溶液流量越高；3）在溶液浓度较高、温度较低及环境空气相对潮湿的情况下，采用自预热C/R比传统C/R更合适；4）实验研究表明外表面蒸发冷却的除湿性能确实要高于绝热除湿；5）通过系统㶲损率分析得知热回收型分级再生系统中的薄弱环节在于一、二级太阳能集热/再生器以及填料式除湿器。关键数据：1）采用1~3m分级集热/再生对0.4浓度的氯化锂水溶液进行再生，热回收型分级再生的临界环境相对湿度是78%，临界太阳辐射强度是800W/m2，临界空气和溶液流量是220-260kg/h和17- 42kg/h；2）相比传统C/R，自预热C/R再生效率提高2%到5.6%；3）实验研究表明外表面蒸发冷却的除湿性能要高于绝热除湿20%；4）热回收型分级再生系统中㶲损一级再生器（REG1）的㶲损率为32.2%。项目的研发成功将有助于太阳能分级集热/再生方法在溶液除湿空调系统上的推广应用。