The online monitoring methods for carbon emissions of domestic coal-fired power units in the short and medium term are still mainly based on accounting methods

and the online monitoring methods for carbon emissions are not yet fully developed. An online carbon emission accounting method for large coal-fired power plants is explored based on routine monitoring data from the units' fuel management system

leading to the formation of a rapid carbon emission accounting method. Additionally

five direct online monitoring approaches for carbon emissions are designed to measure volume fraction

flow velocity and humidity of CO_2. Building upon the rapid accounting method

the calculation deviations of different carbon emission calculation methods within different calculation periods are compared. The results show that

as the time span of the calculation period increases

the calculation deviations for carbon emissions tend to stabilize. Results from a 60-day monitoring period indicate that the computational deviations for the system method

monitoring method

modified monitoring method

oxygen balance method

modified oxygen balance method

and calorific value method are –11.5%

7.7%

4.6%

9.7%

7.1%

and 17.0%

respectively. After long-term comparative corrections

all these methods are viable for online monitoring of carbon emissions from coal-fired power plants

providing support for managing and controlling carbon emissions and carbon asset management within these facilities.