Session: 19-05: Design, control, and testing.

Submission Number: 175078

Oil-Free Heat Pump Development With Drop-in Refrigerant 

The global push toward sustainable heating solutions has accelerated the adoption of heat pump technology across both comfort and industrial applications. This study presents the development of an oil-free heat pump system based on the existing Danfoss Turbocor compressor platforms—TGH285 and TGS380—originally designed for R1234ZE. To meet the high lift requirements of heat pump operation while minimizing development time and cost, a drop-in refrigerant strategy was pursued. Through high-fidelity computational fluid dynamics (CFD) analysis, R1234yf was selected as the optimal refrigerant candidate.

Both compressors were evaluated on a gas test rig. TGH285 demonstrated the ability to achieve a pressure ratio of up to 9 within its power envelope at a saturated suction temperature (SST) of −21°C. A comprehensive performance map was generated, and additional testing under comfort cooling conditions confirmed the dual-function capability of the TGH285 for both heating and cooling applications.

The results support the feasibility of designing a reversible chiller system utilizing a single compressor unit, significantly reducing system complexity and cost. The use of magnetic bearings eliminates the need for oil lubrication, thereby removing the challenges associated with high- and low-temperature oil management. This advancement underscores the potential of oil-free, high-efficiency heat pump systems in next-generation HVAC applications.

Presenting Author: Jin Yan Danfoss Turbocor Inc

Presenting Author Biography: Dr. Jin Yan is the VP of technology and the Director of Aero-thermal Engineering in Danfoss Turbocor. He manages the new compressors designs and technology development activities in Danfoss. His team has developed many compressors such as TGS490, TGS380, and VTCA400 for low GWP refrigerants. TGS490 and VTCA400 both won AHR Expo Innovation awards. TGS380 and TGS490 are used to cool the chips in most of the AI and mega data centers around the world. Before he joined Danfoss, Dr. Yan was the manager of combustion aero in GE. His team developed aircraft engine/Gas turbine designs and prototypes for GE aviation, GE power, and GE Oil & Gas. He worked as the worldwide turbomachinery expert for Ansys before GE. He got his PhD in turbomachinery from Durham University in England

Authors:

Yintao Wang Danfoss Turbocor
Ryan Dingman Danfoss Turbocor
Milan Panthi Sharma Danfoss Turbocor
Jin Yan Danfoss Turbocor Inc