Development of a Residential Scale, Economized, Compressor Load Stand to Measure Compressor Performance Using Low GWP, Flammable Refrigerants

The phase-out of legacy refrigerants is currently underway because of their high Global Warming Potential (GWP) in heat pump systems. Many low-GWP flammable refrigerants such as R1234yf, R1234ze(E), R454B, R32, and blends are being explored as replacements of conventional refrigerants. Additionally, proliferation of heat pump systems often requires modifications such as economization. Characterizing the performance of the next generation of compressors with flammable, low-GWP, working fluids requires significant experimental support. This work presents the design and commissioning of a hot-gas bypass compressor load stand to support such an effort. The selection of components and tubing sizes was completed using output from the thermodynamic model of the hot gas bypass cycle developed in Engineering Equations Solver (EES) and constrained by ASHRAE standard 23. The design capacity for the load stand is 1–5 tons (3.5–17.58 kW) compressor capacity. The load stand is capable of testing compressors at saturated suction temperature as low as − 30 ℉ and saturated discharge temperature as high as 140 ℉. This load stands also includes control over the oil recirculation rate and as well as a dedicated economized loop. The load stand is validated using ZP38K5RE-TF5 Copeland scroll compressor datasheet. The aim of the load stand is to collect data and develop datasheets for economized rotary and scroll compressors, which will be used for vapor injected compressors model development.