Development of a gaseous and solid-state hybrid system for stationary hydrogen energy storage

Hydrogen can serve as a carrier to store renewable energy in large scale.However,hydrogen storage still remains a challenge in the current stage.It is difficult to meet the technical requirements applying the conventional storage of compressed gaseous hydrogen in high-pressure tanks or the solid-state storage of hydrogen in suitable materials.In the present work,a gaseous and solid-state(G-S)hybrid hydrogen storage system with a low working pressure below 5 MPa for a 10 kW hydrogen energy storage experiment platform is developed and validated.A Ti-Mn type hydrogen storage alloy with an effective hydrogen capacity of 1.7 wt%was prepared for the G-S hybrid hydrogen storage system.The G-S hybrid hydrogen storage tank has a high volumetric hydrogen storage density of 40.07 kg H_(2)m^(-3) and stores hydrogen under pressure below5 MPa.It can readily release enough hydrogen at a temperature as low as-15C when the FC system is not fully activated and hot water is not available.The energy storage efficiency of this G-S hybrid hydrogen storage system is calculated to be 86.4%-95.9%when it is combined with an FC system.This work provides a method on how to design a G-S hydrogen storage system based on practical demands and demonstrates that the G-S hybrid hydrogen storage is a promising method for stationary hydrogen storage application.

A review of validation methods for building energy modeling programs

Building energy simulation analysis plays an important supporting role in the conservation of building energy.Since the early 1980s,researchers have focused on the development and validation of building energy modeling programs(BEMPs)and have basically formed a set of systematic validation methods for BEMPs,mainly including analytical,comparative,and empirical methods.Based on related papers in this field,this study systematically analyzed the application status of validation methods for BEMPs from three aspects,namely,sources of validation cases,comparison parameters,and evaluation indicators.The applicability and characteristics of the three methods in different validation fields and different development stages of BEMPs were summarized.Guidance were proposed for researchers to choose more suitable validation methods and evaluation indicators.In addition,the current development trend of BEMPs and the challenges faced by validation methods were investigated,as well as the existing progress of current validation methods under this trend was analyzed.Subsequently,the development direction of the validation method was clarified.