Techno-economic analysis on frosting and defrosting operations of an air source heat pump unit applied in a typical cold city

In recent years, air source heat pump (ASHP) units have found applications worldwide due to their advantages. For an ASHP unit with a multi-circuit outdoor coil, when the refrigerant distribution adjusted with the valves, system defrosting efficiency could be optimized. Meanwhile, adjusting the refrigerant distribution by using valves located at each circuit could improve the frosting evenness value, and system coefficient of performance and the defrosting efficiency are thereby both optimized. However, in open literature, no tech-economic analysis work on frosting/defrosting performances of ASHP units is reported, which limits the development of innovation technologies in this field. Therefore, a techno-economic analysis on frosting/defrosting operations for an ASHP unit used in typical cold regions is given, basing on previous experimental work and series of assumptions. As concluded, the total running costs of the new ASHP unit could decrease as much as 5,327.99 CNY ($ 798.87), or 7.67%, and the total cost about 5,177.99 CNY ($ 776.36), or 6.68%, in 15 years' service life, compared with a traditional one. The payback period of additional first cost of valves is less than 1 year. Conclusions of this study might provide a new analytical tool for scholars, researchers, product developers, and policy designers, and shed new light on the designing and performance optimization of ASHP units.