Discussion on calculation methods of renewable energy utilization rate in district cooling and heating systems

The district cooling and heating system can effectively reduce energy consumption and pollutant emissions in the region through comprehensive and synergistic application of renewable energy. The renewable energy utilization rate is often used as the control or evaluation index in district cooling and heating projects, but the specific algorithm of renewable energy utilization rate is not clear yet. Analyses current two kinds of calculation methods for evaluating the utilization level of renewable energy in energy systems—heat conversion method and exergy conversion method, then clearly defines and quantitatively describes the calculation boundaries and formulas. Recommends the calculation method of renewable energy utilization rate, which avoids the difference of energy grade and attribute in the district cooling and heating system. Gives a calculation example of a river-water-source heat pump project.