Economics and exergy analysis for heating system based on the parameters of water temperature

Taking a residential quarter in Changchun as an example, analyses the economics and exergy for heating system with different heating medium parameters. The results show that the water temperature greatly affects economics of the heating system, and the higher supply/return water temperatures, the lower the initial investment. Proposes the method defining optimum return water temperature, which is 41.6 ℃ in the condition of supply water temperature of 60 ℃ for end users. The exergy loss of boiler heating systems takes about 78％ of the total exergy loss, and for different heating medium parameters, the exergy loss has little variance, while the initial investment for heating system is greatly different. For either primary network or secondary network, increasing supply water temperature is reasonable for utilizing energy and reducing initial investment of heating system.