Simulation study on the reaction process based single stage metal hydride thermal compressor

The reasonable use of waste heat has been one of the promising ways in increasing the utilization ratio of energy, while a metal hydride-based single stage thermal compressor shows great potential in recycling power from low grade heat. As the core part of a metal hydride-based hydrogen compressor, the reactor integrating reaction and heat transfer deserves in-depth investigation. In order to analyze the dynamic working process of a reactor, a numerical simulation based on a non-local thermal equilibrium model was conducted at 50 × 20 grid. Under the given conditions, the dynamic characteristics of both absorption and desorption were examined, and it was found that the reaction fraction X reaches 0.9 after 450 s during the absorption, while the reverse process of desorption takes about 300 s. The largest bed temperature differences during absorption and desorption are 11 K and 25 K, respectively. A pronounced asymmetry between absorption and desorption was observed, which is not desirable in the working of MHTC. However, by changing the transport conditions properly, it is possible to improve the situation, which was shown in the simulation results.