Buildings on campus generally consume a large amount of energy

of which heating energy accounts for a large proportion. Under the background of carbon reduction

it is of great importance to apply renewable energy system for heating purpose on campus. In order to achieve the desired carbon reduction effect

optimal system scheduling

of which energy flow analysis is the basis

should be paid special attention to. However

carbon and exergy flow were seldom considered with energy flow in previous studies

resulting in inaccurate and infeasible scheduling results. Thus

based on energy-exergy-carbon flow coupling analysis

a solar-air source heat pump heating system on campus in Xi’an

China was optimally scheduled in this study

under scenarios of considering time-of-use electricity pricing (Scenario 1)

node carbon intensity (Scenario 2)

and both (Scenario 3). The results indicate: 1) The outdoor temperature

efficiency of solar collector

and COP of heat pump all exhibited significant negative correlation with the node carbon intensity. 2) Compared to Scenario 1

the system carbon emissions decreased by 6.13% and renewable energy consumption increased by 2.56% in Scenario 2

but the system operation cost increased by 1.05% simultaneously. 3) Compared to Scenario 1

Scenario 3 reduced carbon emissions by 5.11% but increased system operating cost by 0.6%

while compared to Scenario 2

Scenario 3 reduced system operating cost by 1.29% and increased carbon emissions by 1.09%.