©2017 Tecumseh Products Company LLC

Modeling a Rotary Compressor in GT-SUITE

Dr. Eng Sidnei OliveiraGT Conference 2017

Refrigeration Cycle

HeatAbsorbed

HeatRejected

Compressor Tasks:- Fluid circulation- Gas compression

PressureEnthalpy Diagram

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Rotary Compressor

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Vane

Block

Roller

Rotary Mechanism

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Rotary Mechanism

GT Conference 2017

Rotary Mechanism

GT Conference 2017

Rotary Mechanism

GT Conference 2017

Rotary Mechanism

GT Conference 2017

Rotary Mechanism

GT Conference 2017

Rotary Mechanism

GT Conference 2017

Rotary Mechanism

GT Conference 2017

Rotary Mechanism

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COVERED IN THIS PRESENTATION

REGULAR TEMPLATESFROM

GT LIBRARY

Model Development

▪Regular Templates: Flow (Refrigerant, Lubrication Oil)

Thermal

Bearings

▪Customizations Implemented: Friction Losses

Refrigerant Leakage• Roller/Block

• Roller Top/Bottom

• Vane Top/Bottom

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Leakage Model - Motivation

6.3%

(*) Source: N. E. Woldman, Machinability and Machining of Metals. McGraw-Hill Book Co. 1951 GT Conference 2017

(*)

Model Development - Leakages Considered

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Roller/Block Leakage

d

Vane Top/Bottom Leakage

Roller Top/Bottom Leakage

Mixture: R410A and Oil

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v R410A

Lubricating Oil

Pcc

Psc

ሶ𝑚

CompressionChamber

SuctionChamber

PccPsc

Roller/Block Leakage

Mixture Concentration: R410A & Oil

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Mixture Density: R410A and Oil

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Mixture Viscosity: R410A and Oil Lubricant

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Leakage Equation – Roller Top/Bottom

ሶ𝑚𝑚 =൯𝜋. ҧ𝜌𝑚(𝛿𝑠𝑢𝑝

3 + 𝛿𝑖𝑛𝑓3)(𝑃𝑐 − 𝑃𝑠

)6. ҧ𝜇𝑚. l n( Τ𝑅𝑟 𝑅𝑖

ሶ𝑚𝑔𝑎𝑠 = 𝑤 ሶ.𝑚𝑚

WORKING CONDITION

Pressure Drop

Source: Brancher, R. D. (2013). Desenvolvimento e Validacao Experimental de um Modelo para Previsao do Desempenhode Compressores Rotativos de Pistao Rolante. Florianopolis. Master Thesis – Federal University of Santa Catarina. Brazil.

Clearance (sup. & inf.)

DIMENSIONS & CONSTANTS

Roller Diam. (ext. & int.)Constants)

RESULTS

Mixture Leakage

Gas Leakage Dynamic viscosity

Density

Concentration

MIXTUREPROPERTIES

FUNCTION OF

TemperaturePressure

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Leakage Equation – Roller/Block

ሶ𝑚𝑚 = 0,0162. 𝜇𝑚. 𝛿𝑚(𝑃𝑐 − 𝑃𝑠)𝜌𝑚𝛿𝑚𝜇𝑚

2ℎ𝑟𝛿𝑚

0,504

ሶ𝑚𝑔𝑎𝑠 = 𝑤 ሶ.𝑚𝑚

WORKING CONDITION

Pressure Drop

Source: Brancher, R. D. (2013). Desenvolvimento e Validacao Experimental de um Modelo para Previsao do Desempenhode Compressores Rotativos de Pistao Rolante. Florianopolis. Master Thesis – Federal University of Santa Catarina. Brazil.

RESULTS

Mixture Leakage

Refrigerant Leakage

Roller height

Clearance

DIMENSIONS & CONSTANTS

Constant

Dynamic viscosity

Density

Concentration

MIXTUREPROPERTIES FUNCTION OF

TemperaturePressure

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Leakage Equation – Vane Top/Bottom

Source: Brancher, R. D. (2013). Desenvolvimento e Validacao Experimental de um Modelo para Previsao do Desempenhode Compressores Rotativos de Pistao Rolante. Florianopolis. Master Thesis – Federal University of Santa Catarina. Brazil.

ሶ𝑚 = 𝛿𝑠𝑢𝑝 + 𝛿𝑖𝑛𝑓 . 𝑙𝑣 . 𝑃𝑐𝑐2𝑘

)𝑅. 𝑇𝑐𝑐 (𝑘 − 1𝑟𝑝

2𝑘 − 𝑟𝑝

𝑘+1𝑘

Vane Height

DIMENSIONS & CONSTANTS

Clearance (sup. & inf.)

Pressure Ratio

WORKING CONDITION

Temperature Compr. Chamber

Pressure Compr. Chamber

Gas Constant

Cp/Cv

IDEAL GASPROPERTIES

RESULT

Gas Leakage

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“FlowMap” Template

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“FlowMap” Template

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DIMENSIONS&

CONSTANTS

Temperature

Pressure

MIXTUREPROPERTIES

WORKING CONDITIONPressure Drop RESULT

Leakage Flow

Results

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Results

0.8%

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Conclusions

▪ The leakage was explained by the model accordingly,

▪ The leakage model reduced from 6.8 to 0.8% the mass flow error estimate,

▪ Tolerance levels could be evaluated based on the leakage estimative,

▪Good agreement was observed between simulated and experimental PV Diagram.

GT Conference 2017

GT Conference 2017

Thank You for your Attention