Full capacity long life peak shaving technology for thermal power units based on SOEC-OEC dual-process coupling
The existing thermal power flexibility renovation plan is difficult to eliminate the thermal system life loss and unit safety operation risks caused by frequent and rapid load changes.In order to effectively ensure the safety,economy,and health of thermal power units participating in grid peak shaving,a full capacity and long life peak shaving technology scheme for thermal power units based on the coupling of solid oxide electrolysis cell hydrogen production technology(SOEC)and burner local oxygen enriched combustion technology(OEC)is proposed and constructed.Taking an ultra supercritical 1 000 MW secondary reheat unit as an example,energy efficiency calculation is conducted on the SOEC-OEC system participating in power grid peak shaving at a depth of 70%~100%,and the results are compared with that of the conventional alkaline water electrolysis hydrogen production(ALK)system.The results show that,the energy efficiency of the extraction electrolysis hydrogen production system in SOEC-OEC is as high as 49.86%,which is about 26.40%higher than that of the ALK system.The oxygen enriched combustion system can reduce the boiler exhaust gas by up to 23.7%,reduce the unit coal consumption by 2.83 g/(kW·h),and reduce the carbon emissions by about 2.82 t/h.In addition,the SOEC-OEC system can also bring excess peak shaving subsidy benefits,hydrogen sales revenue,oxygen enrichment and coal saving and carbon reduction revenue,as well as equipment life extension benefits to the unit,fully ensuring the economic efficiency,safety,and environmental protection of the thermal power peak shaving process.