Energy and economic evaluation of the air source hybrid heating system driven by off-peak electric thermal storage in cold regions

The widely used coal-fired boilers are polluted and inefficient, the single-stage air source compression or absorption heat pumps suffer from poor applicability in low temperature. In order to overcome the above shortcomings and achieve efficient heating in cold regions, the novel air source hybrid heating system driven by off-peak electric thermal storage is proposed. In this work, the thermodynamic models of the hybrid system are developed and validated. Using these models, the energy and economic advantages of the system in the research cities can be determined by formulating rational operation strategies. The results show compared with reference heating systems, the coefficient of performance of the proposed system can be increased by 62%∼125%, and the heating cost can be reduced by 37.30%∼55.48% when applied in Shenyang. When the ratio of centralized heating price to off-peak electricity price is less than 51.2 kW h/m2, 54.9 kW h/m2, 76.9 kW h/m2, the economic advantage of the hybrid system over centralized heating will disappear in Beijing, Shenyang, and Harbin, respectively. Only when the ratio of natural gas price to off-peak electricity price is greater than 6.0 kW h/m3, 6.2 kW h/m3, 6.7 kW h/m3 in the above three cities respectively, the economic advantage over distributed gas-fired heating can be reflected.