Thermochemical heat storage uses a reversible chemical reaction to store thermal energy. This thermal energy storage method has high energy density and allows long-term thermal energy storage. MgO/Mg(OH)₂ is a promising reversible reaction for thermochemical heat storage systems. The performance of this reversible reaction inside a reactor plays a key role in its practical applications. The direct type heat transfer reactor is a novel design compared with an indirect powder bed reactor. It allows the gaseous heat transfer fluid to flow through the powder in order to break the heat transfer limitation from the heat exchanger between the MgO/Mg(OH)₂ powder and the heat transfer fluid. In this study, we evaluated the performance of a direct type MgO/Mg(OH)₂ reactor under various operating conditions. Parametric analyses indicated that the heat output is limited by the reaction rate rather than the heat transfer efficiency. Results also showed the best bed thickness in order to achieve the highest temperature output. Material characterization indicated that the MgO/Mg(OH)₂ particles did not agglomerate with each other after 15 heat charging and discharging cycles.

热化学储热使用可逆化学反应来存储热能。这种热能存储方法具有高能量密度，并且可以长期存储热能。MgO / Mg（OH）₂是用于热化学储热系统的有希望的可逆反应。反应器内部这种可逆反应的性能在其实际应用中起着关键作用。与间接粉末床反应器相比，直接型传热反应器是一种新颖的设计。它允许气态的传热流体流过粉末，以便打破MgO / Mg（OH）₂粉末与传热流体之间的热交换器传热限制。在这项研究中，我们评估了直接型MgO / Mg（OH）_2的性能反应器在各种运行条件下。参数分析表明，热量输出受反应速率的限制，而不是传热效率的限制。结果还显示了最佳的床层厚度，以实现最高的温度输出。材料表征表明，MgO / Mg（OH）₂颗粒在15个热充放电循环后没有彼此凝聚。