.ClaRa.Components.HeatExchangers.HEXvle2gas_L3_1ph_BU_ntu.HeatTransferTubes .ClaRa.Components.HeatExchangers.HEXvle2gas_L3_1ph_BU_ntu.HeatTransferTubesmodel HeatTransferTubes = ClaRa.Basics.ControlVolumes.Fundamentals.HeatTransport.Generic_HT.CharLine_L2;