Centrifugal compressors are used in a large number of different compression applications. This tutorial addresses applications for centrifugal compressors in the upstream and midstream sector, such as LNG compression, refrigeration, pipeline compression, compression for gas injection, gas lift, gas gathering, export compression, air compression, and others. The focus is on the specific compress...

Refrigerant mass flow rate is an important measurement for monitoring equipment performance and enabling fault detection and diagnostics. However, a traditional mass flow meter is expensive to purchase and install. A virtual refrigerant mass flow sensor (VRMF) uses a mathematical model to estimate flow rate using low-cost measurements and can potentially be implemented at low cost. This study e...

This thesis addresses modeling and active surge control of a simple compression system, using only the drive system of the compressor for actuation. Theoretical results are validated by experiments on a test rig that was built as a part of this work. Control laws are derived in two stages. First all system states, such as pressure mass ‡ow and impeller speed, are assumed as available signals. A...

turbocharging an engine boosts its power by increasing the amount of input air. this task is accomplished by using the exhaust gas to power a turbine which is engaged with a compressor. the variable geometry turbocharger, vgt is a unique turbocharger that the diffuser vane angle can be changed over a wide range of positions. the mathematics of turbomachinery flow analysis is intensive and uses ...

Simulation models for unitary air conditioners and heat pumps usually can not provide accurate predictions in the case of two-phase refrigerant entering the compressor or fixed-area expansion device. This paper focuses on improving modeling methods in these situations. The study utilized extensive laboratory tests and detailed modeling of two unitary air conditioners, one using R-410A and the o...

determination of the starter torque-speed diagram is a major task in the design or selection of a proper gas turbine starter. in this paper, the maximum power of the mgt-40 gas turbine starter was calculated based on the dynamics of the rotor, start-up logic, and compressor map. in a recent research, the pressure ratio was assumed as a linear function of the rotor speed and the required starter...

A stage-by-stage wet-compression theory and algorithm have been developed for overspray and interstage fogging in the compressor. This theory and algorithm are used to calculate the performance of an 8-stage compressor under both dry and wet compressions. A 2D compressor airfoil geometry and stage setting at the mean radius are employed. Six different cases with and without overspray have been ...

A novel method for introducing a back-up system to an active compressor surge control system is presented in this paper. Active surge control is a promising method for extending the compressor map towards and into the unstable area at low mass flow by stabilizing the surge phenomenon. The method also has potential for allowing operation at higher efficiencies. However, a failure in the active s...