水合盐热化学反应器参数优化与供暖应用案例分析

Parameter optimization of a thermochemical reactor using salt hydrates:A case study of heating application

水合盐热化学储热技术具有储热密度高、长期储存几乎无热损失等优点,对可再生能源高效利用具有重要意义。其中热化学反应器的设计和运行控制对水合盐热化学储热的性能十分关键,目前有关反应器的模拟通常采用多物理场仿真软件,无法开展动态工况下的长时间尺度研究。因此,本工作建立了热化学反应器动态仿真模型,并对模型进行了验证;利用该模型,对入口空气温度、水蒸气分压力、流速和反应器尺寸等因素对出口参数的影响进行了敏感性分析。结果表明,空气流速对响应时间、稳定输出时间和放热功率的影响较大,水蒸气分压力对温升有较大影响但对总放热量几乎没有影响。最后本工作以长沙某住宅建筑为例,在冬季典型日气象参数条件下开展了反应器放热供暖工况研究。与无控制策略相比,采用合适的控制策略可将反应器放热功率与热负荷之间的偏差从69.21%降低到9.89%,从而提高放热功率与热负荷的匹配度。本工作研究结果对热化学反应器的设计与控制策略的确定具有指导意义。

Thermochemical energy storage with salt hydrates has the advantages of high heat-storage density and nearly zero heat loss in the long storage process;these are of great significance for the efficient utilization of renewable energy.The design and operation control of reactors are crucial for the performance of thermochemical heat storage of salt hydrates.However,multiphysical field-simulation software is widely used for modeling,which is not suitable for long-term research under dynamic conditions.Therefore,in this study,we establish a dynamic simulation model for thermochemical reactors.In addition,sensitivity analysis was conducted to determine the effects of factors such as inlet air temperature,water-vapor partial pressure,flow rate,and reactor size on the outlet parameters.The results show that the airflow rate significantly affected the response time,stable output time,and heat release power.In addition,the partial pressure of water vapor greatly affected the temperature rise,while displaying almost no effect on the total heat release.Finally,by considering a residential building in Changsha as an example,we studied the charging process of the reactor under typical daily meteorological parameters during winter.Compared with the condition without control strategies,the adoption of appropriate control strategies could effectively improve the matching between the heat release power of the reactor and its heat load.The findings of this study could provide a guide for the design and control strategy determination of thermochemical reactors.