Natural gas (NG) is delivered to homes and businesses through a complex pipeline network that mainly consists of high-pressure main feed lines and many low-pressure local distribution lines. To date, throttling valves have been employed to reduce the NG pressure between the two types of pipeline, leading to the loss of the work potential generated by the expansion of pressurized NG in the NG supply chain. As a result, research is currently underway to replace throttling valves with turbo expander generators (TEGs) to obtain additional work power. In this study, a multi-energy hub system consisting of phosphoric acid fuel cell (PAFC) and TEG modules is proposed and analyzed using ASPEN-HYSYS® modeling and simulations. The key concept underlying the system configuration is to maximize overall system efficiency through the integration of exothermic PAFC and endothermic TEG operations. When the TEG system is combined with four 460kW_e PAFC stacks, the simulation results show that roughly 1.73 MW_e of power can be produced in the TEG system via the expansion of a 28,000 kg/h NG stream. However, when the PAFC stack runs under hydrogen production mode (which requires high voltage operation), an additional heating source is required to fully deliver the expansion work generated by the NG flow within the TEG system. This study clearly illustrates the beneficial features of the proposed multi-energy hub system in terms of thermal integration and overall efficiency but also reveals that the system configuration and operation need to be carefully optimized in order to advance the technology.

天然气（NG）通过复杂的管道网络输送到家庭和企业，该网络主要由高压主进水管和许多低压本地配电管组成。迄今为止，节流阀已被用于降低两种类型的管道之间的天然气压力，从而导致天然气供应链中由于压缩天然气的扩张而产生的工作潜力的损失。因此，目前正在进行研究，以用涡轮膨胀器发电机（TEG）替代节流阀以获得更多的工作动力。在这项研究中，提出了一种由磷酸燃料电池（PAFC）和TEG模块组成的多能源枢纽系统，并使用ASPEN-HYSYS®建模和仿真进行了分析。系统配置的关键概念是通过放热PAFC和吸热TEG操作的集成来最大化整体系统效率。当TEG系统与四个460kW结合使用时_在PAFC烟囱中，仿真结果表明，通过扩大28,000 kg / h NG流，可以在TEG系统中产生大约1.73 MW _e的功率。但是，当PAFC堆在制氢模式下运行（这需要高压操作）时，需要一个额外的热源来完全输送TEG系统中NG流产生的膨胀功。这项研究清楚地说明了所提出的多能源枢纽系统在热集成和整体效率方面的有益功能，但同时也揭示了需要仔细优化系统配置和运行以提高技术水平。