Effects of vapor injection modes on the heating performance of heat pumps Bin Liu, Lin Chai, Aiqiang Chen, Fuhui Tang, Khellil Sefiane and Georges E.I. Achkar Eur. Phys. J. Appl. Phys., 86 3 (2019) 30902 Published online: 29 July 2019 DOI: 10.1051/epjap/2019190126