Turbo Machinery & Energy Conversion LAB 팽창과정에서의 터보엑스펜더 영향에 관한연구 Effect of a Turbo Expander for Regeneration in the Expansion Process Chong-Hyun

Turbo Machinery & Energy Conversion LAB

팽창과정에서의 터보엑스펜더 영향에 관한연구팽창과정에서의 터보엑스펜더 영향에 관한연구Effect of a Turbo Expander for Regeneration in thEffect of a Turbo Expander for Regeneration in th

e Expansion Processe Expansion Process

Chong-Hyun Cho(Gyeongsang National University, Korea)

2006. 12. 062006. 12. 06


Introduction of Introduction of LaboratoryLaboratory

Directe ProfessorDirecte ProfessorSOO YOUNG CHOSOO YOUNG CHO

A Field of StudyA Field of StudyTurbomachinery and Energy ConversionTurbomachinery and Energy ConversionOptimization using CFDOptimization using CFDMicro Rotating MachinesMicro Rotating Machines Wind Tunnel testWind Tunnel testNoise and Vibration MeasurementNoise and Vibration Measurement

LocationLocation403-410, 403-408, 404-203, 403-410, 403-408, 404-203, Wind Tunnel buildingWind Tunnel building


MotiveMotive

Using a turbo expanderUsing a turbo expander


Expansion (R134a)Expansion (R134a)

Before expansionBefore expansion

After expansionAfter expansionTwo-phase state


Expander analysisExpander analysis

Basic configurations- Matching with nozzle exit velocity- Tip diameter by the rotational speed- Number of blades- Decide turbine efficiency- Optimum hub diameter (flow quality is changed within the passage) etc.

Blade design- Impulse blade- Internal flow analysis


• an axial type small turbine and single stage• nozzle angle was a 74°

Parameters Nozzle Rotor

Blade height (H:mm) 3.37 3.5

Axial chord (cx:mm) - 12.5

Pitch (s:mm) - 7.3

Number of blade (N)

9 72

Mean dia. (Dm:mm) 96.16 96.16

Aspect ratio (H/cx) - 0.28

Solidity (s/cx) - 0.58

Experiment (Verneau)Experiment (Verneau)


Expander Analysis : Expander Analysis : 50RT50RT

Output power : 2.30 kW(heating), 1.81kW(cooling)Torque : 2.50 Nm(heating), 2.46 Nm(cooling)Outer Dia. : 103.3mmInner Dia. : 67.3mmPartial Admission : 19.96%Rate Rotational Speed : 8763 RPM(heating),

7041 RPM(cooling)


9.25RT (DBC 503T-28,000kcal/hr)50RT model : 1/5-1/6 SizeMass flowrate : 0.25kg/secExpansion (low RPM) : 11~16bar, 4~6barExpansion (high RPM) : 16~18bar, 4~7bar

Operating condition : Operating condition : Exp. Exp.


실험장치실험장치


Exp. Apparatus Exp. Apparatus


Assumptions : 1-D, homogenous flow

Nozzle Design Nozzle Design

02

1 2

D

dxfVVdVdp

VAm

Assumptions : nozzle flow isentropic

0

)(2

VdVdh

pa s

Pressure eq.

]2

)(){([)1(2

22

12

D

f

T

VT

sV

dx

dA

A

VM

dx

dp

dpTdsdh


Assumptions : Al nozzle, roughness 0.2mm

Nozzle Design Nozzle Design

2)74.1)log(2( sk

Rf

Location chock

02

1])()[( 2

T

Ts

Vdx

dA

A

Pressure gradient at chock location

0})(1

{

)}()(1

)()({}3

)(3

)](12

))((1

)()(2

)(2[{)]()(22

[

2

22

2

2

2

22

2

222

2

32

22

2

dx

Ad

A

a

dx

sdT

sAm

dx

ds

sAm

s

T

s

T

dx

dA

dx

dA

A

a

dx

ds

sAm

dx

dp

dx

dA

Adx

dA

Adx

ds

spAm

p

T

a

T

s

a

asdx

dp

p

a

aa

p

pp

psp

pps


Inlet Diameter : 8.0mmThroat Diameter : 3.6mmExit Diameter : 5.8mmNozzle Length : 57.8mm

Nozzle Nozzle


Design of Turbo Design of Turbo Expander Expander

U/C1

0.0 0.2 0.4 0.6 0.8 1.0

E (

util

izat

ion

fact

or)

0.0

0.2

0.4

0.6

0.8

1.0

- Supersonic turbineSupersonic turbine:: Min. Min. shocklossshockloss Max. utilization factorMax. utilization factor Impulse turbine Impulse turbine


Turbine DesignTurbine Design


Turbo Expander Turbo Expander


Rotor SpecificationsRotor Specifications Types Parameters

A B

No. of blades (N) 29 29

Mean dia. (Dm: mm) 71.85 70.46

Pitch at mean dia. (s : mm) 7.78 7.63

Chord (c: mm) 15.0 15.0

Solidity (σ : c/s) 1.93 1.97

Blade height (ht: mm) 11 8

Aspect ratio (ht/c) 0.73 0.53

Blade angle at suction (βs) 65.0° 65.0°

Blade angle at pressure (βp) 65.0° 65.0°

Blade thickness (t: mm) 4.70 4.70

Leading edge thick. (tle: mm) 1.0 1.0

Trailing edge thick. (tte: mm) 1.0 1.0


Manufacturing EXManufacturing EX












Manufacturing EXManufacturing EXEnjoy R/C helicopter air showEnjoy R/C helicopter air show


A turbo expander is installed in the expansion process instead of expansion V/V. It recovered 0.37kJ/kg on the 9.25RT experimental utility.Efficiency increases according to the pressure ratioEfficiency drops linearly 3.7% between shroud and un-shroud rotor Experimental study is very important exact manufacturing of test systemSpecially, micro rotating machine required manufacturing quality is 0.001mm

SummarySummary


Thank you for your attentions

Documents

Turbo Machinery & Energy Conversion LAB 팽창과정에서의 터보엑스펜더 영향에 관한연구 Effect of a Turbo Expander for Regeneration in the Expansion Process Chong-Hyun