Life cycle climate performance analysis of sewage source heat pump systems.

Sewage source heat pump (SSHP) systems recycle urban wastewater as a heat source, developing a renewable energy utilization pattern in the severe situation of global energy crisis and environmental pollution. Life cycle climate performance (LCCP), is the most comprehensive assessment method to calculate the cradle-to-grave warming impact in a quantitative form of the equivalent CO2 emission. To aid the research on the energy saving and emission reduction potential of SSHP, this paper focused on the energy comparison between SSHP and gas-fired and coal-fired boiler, and engineering data of typical cases in different cities of north China were tested. Accordingly LCCP model of SSHP was established to calculate the greenhouse gases that came from not only the unit but the heating system. Based on the results, indirect emission is dramatically higher than direct emission, and energy consumption especially played a key role. SSHP, substituting conventional heating ways, has remarkable benefits in ecology and economy. Besides, LCCP is supposed to be an index to evaluate refrigerant alternatives in view of the limitation of GWP.