Cascade heating development of direct heating water heater with gas and heat pump

GUO Yanlong, GUAN Jiangyong, YAN Wei, HE Zikun, MO Fanlong

Journal of Appliance Science & Technology . 2021, (zk): 19 -22 . DOI: 10.19784/j.cnki.issn1672-0172.2021.99.005