基于槽式聚光中温供能的太阳能吸附制冷循环质能传输强化及换能耦合研究

Medium temperature thermal energy, obtained by solar trough concentrating technology, is utilized to provide the steady heat source for the adsorption refrigeration system by using the heat storing devices. The project will build the thermodynamic model of the adsorption refrigeration cycle based on the adsorption bed using concentric tube with fins, achieve the temperature distribution and the pressure distribution in the adsorption bed with the medium temperature thermal source, and discover the flow and heat and mass transfer characteristics of the adsorbate in the adsorption bed. By optimizing the structure of the concentric tube with fins, the thermal energy from the heat source could be transferred to the adsorbent quickly and uniformly, and the adsorbed/ desorbed refrigeration fluid - the adsorbate could be taken away rapidly. By studying the correlations of the desorption amount and the desorption time with the heat source temperature, the optimum driving temperature would be reached. By controlling the energy supply to the adsorption refrigeration system, the adsorbed/ desorbed refrigeration period would be shorted, and multiple adsorbed/ desorbed refrigeration cycles daily would be realized, thereby enhance the overall refrigerating efficiency of the system. To match the solar trough concentrating thermal supply with the adsorption refrigeration energy use, the study on the energy output characteristics of the solar trough concentrating collector as thermal energy provider, and the matching of the solar trough concentrating collector with the thermal energy storing device would be performed. The relative experimental setup would be build to realize the steady adsorption refrigeration cycle in the condition of the unsteady energy source from solar energy.

基于太阳能槽式聚光技术获得中温热能，利用储热装置调控实现对吸附制冷系统的稳定供能。项目将建立翅片同心管吸附床结构吸附制冷热力学模型，获取中温热源条件下吸附床中的温度和压力分布，得到制冷工质在吸附床中的流动及传热传质特性。通过优化吸附床翅片同心管结构，将从外界吸收的热能快速均匀传递至吸附剂，并迅速输运吸附/解吸的制冷工质；研究供热热源温度与制冷工质解吸量和解吸时间的关联关系，获得最佳驱动温度；采用适当供能调控策略，缩短制冷工质的吸附/解吸循环周期，实现每日多次吸附/解吸循环，从而提高系统制冷总效率。针对太阳能聚光集热供能与吸附制冷用能的匹配性，研究槽式聚光集热器作为热能供给装置的能量输出特性；考虑太阳辐射的不连续性和间歇性特点，研究储能部件与聚光集热器的匹配关系。建立相关实验装置，实验研究太阳能不稳定供能条件下，通过储热放热措施和一定供能调节策略，获得稳定的能量输出，实现稳定的吸附制冷循环。

项目围绕吸附制冷循环中质能输运强化及利用太阳能槽式聚光中温供能时的供能、储能、用能匹配开展研究。建立了吸附制冷循环中质能输运的有关数学模型，设计、优化并搭建了工作于不同工作温度范围的水浴式固体吸附制冷系统和导热油浴固体吸附制冷系统。采用水浴/导热油浴吸附床代替太阳直接照射吸附床，有效改善了吸附床内温度分布的均匀性；且水浴/导热油油浴具有储热及调节作用，有助于解决太阳供能不稳定问题。. 研究了水浴/导热油浴温度、脱吸附时间、冷凝温度、吸附床压力等对制冷剂脱吸附及系统制冷性能的影响。提高脱吸附阶段水浴/导热油浴温度和延长加热脱吸附时间均可增加参与循环的制冷剂量，从而在吸附阶段获得更多制冷量；然而更高的水浴/导热油浴温度和更长的加热时间将引起更大散热损失。系统存在一个较佳的加热脱吸附时间，更长加热时间导致系统热利用率及制冷性能下降。在外界输入能量相当的情况下，制冷剂冷凝温度越低，系统日制冰量、直接制冷量和制冷性能系数越大。冷凝器冷凝能力应当与吸附床内制冷剂脱吸附速率匹配，以确保脱吸附的制冷剂蒸汽能够及时冷凝，从而降低吸附床内制冷剂蒸汽压力，促进脱吸附过程。. 构建了以太阳能槽式聚光集热器供能、导热油/水储能、吸附制冷用能的模式，实现能量收集、输运、转换与利用的完整系统。获得了有/无负载（储能）情况下太阳能槽式聚光集热系统中的工质（导热油），及换热与储能装置内的工质（水）的温度变化规律，讨论了聚光集热与换热储能过程中工质温度控制和提高热利用率的方法。研究了可用于系统能量储存的中低温复合相变储能材料。选取相变潜热较大、适合太阳能储热的三种无机水合盐相变储能材料十水合硫酸钠、三水合乙酸钠和八水合氢氧化钡进行改性，即将这些材料添加成核剂后与膨胀石墨进行真空吸附制备复合定型“固-固”相变储能材料。实验结果表明这些复合相变材料具有过冷度小，无相分离、无泄漏、导热率高，性能稳定等优点。