This paper presents a study carried out as part of commissioning and testing of world’s first grid-scale 150 kW_e Pumped Heat Energy Storage (PHES) demonstration system. The system employs two novel layered packed-bed thermal stores. The present study experimentally investigates one of the stores designated as “hot thermal store”, which has an energy storage density of 1072 MJ/m³ and stores heat at 500 °C and 12 bar. The layered store is an enhancement of a normal packed-bed store and offers a higher degree of thermal stratification. Experiments show that layering results in about 64 % reduction in pressure loss along with yielding considerably narrower thermocline. Round-trip efficiency, storage capacity and utilisation were calculated based on 1st Law analysis considering both simple and layered mode operation at nominal design conditions. Two cycle control scenarios were considered: time-based and temperature-based. In the time-based scenario, the store shows nearly similar performance in both modes. However, in temperature-based scenario, layered mode outperforms. During cyclic operation, layered mode outperforms as it reaches steady-state in merely 3rd cycle, without any loss in efficiency, capacity and utilisation; simple mode yields competitive efficiency but capacity and utilisation deteriorate after each successive cycle and steady-state is achieved in 20th cycle. 2nd Law analysis was additionally performed to gain insight into various losses and their impact on the performance.

本文介绍了作为世界上第一个电网规模 150 kW _e泵热储能 (PHES) 示范系统调试和测试的一部分进行的研究。该系统采用两个新型分层填充床热库。本研究通过实验调查了指定为“热热库”的其中一个库，其能量存储密度为 1072 MJ/m ³并在 500 °C 和 12 bar 下储存热量。分层商店是普通填充床商店的增强版，提供更高程度的热分层。实验表明，分层导致压力损失减少约 64%，同时产生相当窄的温跃层。往返效率、存储容量和利用率是根据第一定律分析计算的，同时考虑了标称设计条件下的简单模式和分层模式操作。考虑了两种循环控制方案：基于时间和基于温度。在基于时间的场景中，商店在两种模式下表现出几乎相似的性能。然而，在基于温度的场景中，分层模式表现更好。在循环运行期间，分层模式的性能优于它，因为它仅在第 3 个循环中就达到稳态，而没有任何效率、容量和利用率的损失；简单模式产生有竞争力的效率，但容量和利用率在每个连续循环后都会下降，并在第 20 个循环中达到稳态。另外执行第二定律分析以深入了解各种损失及其对性能的影响。