A Method to Estimate the Performance Map of a Centrifugal Compressor Stage

Casey, Michael; Robinson, Chris

doi:10.1115/1.4006590

Cited by 73 publications

(40 citation statements)

References 3 publications

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“…The delivered electric energy from the battery per unit electrode surface area during the discharge process from time 0 to t is calculated from Equation 4, which is the time integration of the cell voltage times the drawn current density from the cell. The total irreversible heat generation per unit electrode surface area during the discharge process from time 0 to t can also be calculated from Equation 5. In this equation, the total rate of irreversible heat generation per unit volume of the cell is integrated along the cell thickness direction over time.…”

Section: Modelingmentioning

confidence: 99%

Introducing the energy efficiency map of lithium-ion batteries

Farhad

Nazari

2018

Int J Energy Res

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Summary The charge, discharge, and total energy efficiencies of lithium‐ion batteries (LIBs) are formulated based on the irreversible heat generated in LIBs, and the basics of the energy efficiency map of these batteries are established. This map consists of several constant energy efficiency curves in a graph, where the x‐axis is the battery capacity and the y‐axis is the battery charge/discharge rate (C‐rate). In order to introduce the energy efficiency map, the efficiency maps of typical LIB families with graphite/LiCoO2, graphite/LiFePO4, and graphite/LiMn2O4 anode/cathode are generated and illustrated in this paper. The methods of usage and applications of the developed efficiency map are also described. To show the application of the efficiency map, the effects of fast charging, nominal capacity, and chemistry of typical LIB families on their energy efficiency are studied using the generated maps. It is shown how energy saving can be achieved via energy efficiency maps. Overall, the energy efficiency map is introduced as a useful tool for engineers and researchers to choose LIBs with higher energy efficiency for any targeted applications. The developed map can be also used by energy systems designers to obtain accurate efficiency of LIBs when they incorporate these batteries into their energy systems.

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Section: Modelingmentioning

confidence: 99%

Introducing the energy efficiency map of lithium-ion batteries

Farhad

Nazari

2018

Int J Energy Res

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“…A multitude of publications deals with the concrete shape of such maps, i.e., the concrete correlations between head, compression work, volume flow, and speed, or respective representatives of this compressor characteristics. In [2], a set of equations is presented that aims to describe the performance map far away from the design point. As in the present contribution, the methodology in [2] is based on a static dependence of the same dimensionless compressor characteristics as they are used here.…”

Section: Introductionmentioning

confidence: 99%

Real-time estimation of a multi-stage centrifugal compressor performance map considering real-gas processes and flexible operation

Gentsch

King

2020

Journal of Process Control

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This paper contributes to modeling and supervision of multi-stage centrifugal compressors coping with real-gas processes and steady to highly transient operating conditions. A novel dynamic model is derived, and the incorporation of the generic Lee-Kesler-Plöcker real-gas equation of state and its derivatives is presented. The model allows for embedding arbitrarily shaped performance maps, based on state-of-the-art polytropic change-of-state compressor characteristics. As the validity of these maps is a key issue for simulation and model-based monitoring, performance maps are treated as time-variant, and their shape is to be identified and monitored during operation. The proposed real-time map estimation scheme comprises an Unscented Kalman Filter and a newly proposed algorithm, referred to as Recursive Map Estimation. The combination yields a novel parameter and state estimator, which is expected to be superior if some parameters are characterized by a distinct operating point dependency. Two additional time-variant parameters are provided for monitoring: The first indicates the level of confidence in the local estimate, and the second points to drastic performance map alterations, which may be further exploited in fault detection. A modified reference simulation of a two-stage supercritical carbon dioxide compressor with known state trajectories, performance maps, and alterations demonstrates the successful application of the entire monitoring scheme, and serves for a discussion of the results.

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“…Finally, based on this understanding, the radial compressor map prediction method of Casey and Robinson [11] is extended to include this parameter in the selection of coefficients to allow stages with matched and mismatched vaned diffusers to be predicted. Some examples of predicted and measured maps are given to demonstrate the capability of the method and to explain the trends observed.…”

Section: Introductionmentioning

confidence: 99%

The Matching of a Vaned Diffuser With a Radial Compressor Impeller and its Effect on the Stage Performance

Casey

Rusch

2014

Volume 2D: Turbomachinery

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The matching of a vaned diffuser with a centrifugal impeller is examined with a one-dimensional (1D) analysis combined with extensive experimental data. A matching equation is derived to define the required throat area of the diffuser relative to the throat area of the impeller at different design speeds and validated by comparison with a wide range of compressor designs. The matching equation is then used to give design guidelines for the throat area of vaned diffusers operating with impellers at different tip-speed Mach numbers. An analysis of test data for a range of high pressure ratio turbocharger compressor stages is presented in which different matching between the diffuser and the impeller has been experimentally examined. The test data includes different impellers with different diffuser throat areas over a wide range of speeds. It is shown that the changes in performance with speed and diffuser throat area can be explained on the basis of the tip-speed Mach number which causes both the diffuser and impeller to choke at the same mass flow. Based on this understanding, a radial compressor map prediction method is extended to include this parameter, so that more accurate maps for matched and mismatched vaned diffusers can be predicted.

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A Method to Estimate the Performance Map of a Centrifugal Compressor Stage

Cited by 73 publications

References 3 publications

Introducing the energy efficiency map of lithium-ion batteries

Introducing the energy efficiency map of lithium-ion batteries

Real-time estimation of a multi-stage centrifugal compressor performance map considering real-gas processes and flexible operation

The Matching of a Vaned Diffuser With a Radial Compressor Impeller and its Effect on the Stage Performance

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