| The trend of the centrifugal compressors applications now, is to use a small and light unit with high pressure ratio and efficiency. To achieve this, the rotational speed of the compressor must be very high, over 30,000 rpm, to increase tip speed. These characteristics of such compressors reduce the manufacturing and operating costs and improve, in general, the performance of the system.; The objective of the present work is to design a test rig for small centrifugal compressors for studying the performance, including efficiency and operating range (surge and choke). The design of the test rig takes into account safety, flexibility of use, reliability and uncertainty analysis. The design also takes into consideration the American Society of Mechanical Engineering, Performance Test Codes 10 (ASME PTC 10). The study contains the following major results: (1) Aero-thermodynamics analysis of the impeller to estimate the power requirement for different compressors geometries, as well as torque and total pressure and temperature ratios estimation. This analysis was used to develop three codes. The results of these codes help to select the proper driver and instrumentation for the test facility. The results of the codes indicate the need for a driver with 500 kW to run the compressor for a given impeller tip radius ranged from .0286 to 0.1143 m to satisfy the objective. Also, the maximum expected total pressure ratio is over 8 and the maximum expected mass flow rate is 3.35 kg/s. (2) The design of the test rig including general layout and selection of the driver unit. (3) Measuring techniques, with consideration to ASME PTC 10 including single sample uncertainty analysis of the instrumentation. The uncertainty analysis helps to recommend some correlation terms. |
