For this consultancy summary, the customer, one of the world’s leading HVAC manufacturers, required the design of a new range of chillers using R1234ze(E) refrigerant. The chiller uses a 2-stage in-line compressor. Both compressors and the return channel need to be designed.
What are the design targets? The scope of this project is to design a 2-stage inline chiller compressor for HVAC application. The refrigerant adopted is R1234ze(E), which is a low GWP (~6) alternative to R134a. High-efficiency level is required in a range of flowrates (20% around design condition).
The deliverables are the design of a 2 stage inline compressor that achieves high COP at most frequent operating points, but also meets the partload conditions, with specially designed tandem return channel to be used as inlet guide vane for the second stage compressor.
TURBOdesign Pre (refrigeration cycle coupled with compressor meanline design) was used for the initial cycle analysis and compressor stage sizing. Both the cycle and the compressor performance were available from the simulation results. The compressor map could also be produced to evaluate the operating range. A parametric study was carried out to find the optimum rpm and pressure ratio split between 1st and 2nd stage compressor.
Based on the customer’s feedback from rotor dynamics, a proper design rpm was chosen to balance the requirement from aerodynamic performance and mechanical integrity.
To discover the 3D design and optimization of the compressor stage, we invite you to download the complete consultancy summary below.