Introducing a proper hydrogen liquefaction concept for using wasted heat of thermal power plants-case study: Parand gas power plant

摘要

A hydrogen liquefaction concept with an innovative configuration and a capacity of 4 kg·s^(-1)(345.6 t·d^(-1))is developed.The concept involves an ammonia absorption refrigeration system for the pre-cooling of hydrogen and MR streams from 25℃ to-30℃.The ammonia absorption refrigeration system is fed by exhaust gases of the Pa rand gas power plant that are normally dissipated to the environment with a temperature of 546℃.The simulation is performed by Aspen HYSYS V9.0,using two separate equations of state for simulating hydrogen and MR streams to gain more accurate results especially for ortho-para conversion.Results show that conversion enthalpy estimated by Aspen HYSYS,fits very well to the experimental data.Determining the important independent variables and composition of MRs are done using trial and error procedure,a functional and straightforward method for complicated systems.The minimum temperature limit in the cooling section is lowered,and an ortho-para converter is implemented in this section.The proposed concept performs well from energy aspects and leads to COP and SEC equal to 0.271 and 4.54 kW·h·kg^(-1),respectively.The main advantage of this study is in the low SEC,eliminating the losses of the distribution network,and improving the ability of the hydrogen liquefaction for energy storage in off-peak times.