Electricity-assisted thermochemical sorption system for seasonal solar energy storage
Electricity-assisted thermochemical sorption system for seasonal solar energy storage
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DOI：
10.1016/j.enconman.2020.112659
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发表时间：
2020-04
影响因子：
10.4
通讯作者：
Zhiwei Ma;Huashan Bao;A. Roskilly
中科院分区：
文献类型：
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作者：
Zhiwei Ma;Huashan Bao;A. Roskilly
利用具有热泵和储能双重功能的固气热化学吸附技术对季节性太阳能蓄热进行了研究。可以在较高温度下放热的热化学反应，通常在充电过程中需要相对较高的解吸温度，在英国等高纬度地区，使用最成熟、最经济的太阳能集热器（平板或真空管型）时，太阳能的有效回收可能会出现问题。本研究研究了两种混合概念，即在可用太阳热量不够高的情况下，分别引入电动压缩机或电加热器来补充热化学解吸过程的压力上升和温度上升。srcl2 -8/ 1nh3化学吸附由于其适宜的吸附/解吸温度和较大的储能密度，从230个氨化学吸附反应中选择了srcl2 -8/ 1nh3化学吸附。对srcl2 -8/ 1nh3化学吸附两种混合体系的性能进行了评价和比较，确定了最优方案。结果表明，与电加热器相比，压缩机混合热化学吸附显著提高了储气容量。在泰恩河畔纽卡斯尔天气条件下，配置20 m2太阳能集热器的SSTES系统在压缩比为4的情况下，夏季可通过充电4465.4 kWh太阳能热和848.2 kWh电力，存储3226.8 kWh化学吸收热，存储效率为60.7%；按系统整体容积计算，对应的能量密度为147.3 kWh/m3。由于采用了可再生的太阳能热能和夏季低碳强度的电力，与燃气锅炉和传统热泵相比，所提出的混合SSTES系统在碳排放上有明显的减少。
The present paper investigated the seasonal solar thermal energy storage (SSTES) using solid-gas thermochemical sorption technology that has inherently combined function of heat pump and energy storage. The thermochemical reactions that can discharge heat at a higher temperature usually requires a relatively higher desorption temperature during charging process, which could be problematic to efficiently recover solar energy in high-latitude regions like the UK when using the most mature and economic solar thermal collector (flat-plate or evacuated tube type). The present work studied two hybrid concepts where an electric-driven compressor or an electric heater was introduced to supplement the thermochemical desorption process in terms of pressure rise and temperature lift, respectively, when the available solar heat was not sufficiently high. The SrCl2-8/1NH3chemisorption was selected from 230 ammonia-chemisorption reactions due to its suitable adsorption/desorption temperature and large energy storage density. The performance of two hybrid systems using SrCl2-8/1NH3chemisorption were evaluated and compared to determine the optimal solution. The results revealed that the hybrid thermochemical sorption with a compressor substantially improved the storage capacity compared to that with electric heater. With a compression ratio of 4, the SSTES system with 20 m2solar collector under the weather condition of Newcastle upon Tyne can store 3226.8 kWh chemisorption heat in summer by charging 4465.4 kWh solar heat and 848.2 kWh electricity, indicating 60.7% storage efficiency; the corresponding energy density based on the overall system volume is 147.3 kWh/m3. Because of using the renewable solar heat and low carbon intensity electricity in summer, the proposed hybrid SSTES system has noteworthy reduction on carbon emission compared to gas boiler and conventional heat pump.