“Development of a Nelium Turbo-Brayton cryogenic ......“Development of a Nelium Turbo-Brayton cryogenic refrigerator for the ... - Participation in experiments on the neon-helium

“Development of a Nelium Turbo-Brayton cryogenic refrigerator for the

FCC-hh”EASITrain project status overview

EASITrain – European Advanced Superconductivity Innovation and Training. This Marie Sklodowska-Curie Action (MSCA) Innovative Training Networks (ITN) has received funding from the

European Union’s H2020 Framework Programme under Grant Agreement no. 764879

EASITrain project status overview

Technical University Dresden

Bitzer Chair of Refrigeration, Cryogenics and Compressor Technology // Sofiya Savelyeva

FCC Week 2019, Brussels // 27.06.2019

Slide 2

Outline

Motivation

Work performed:

- Former cycle baseline

- Limiting factors

- Improved design

Secondments & Trainings & Dissemination events

Next steps





Slide 3

Motivation

Cryogenic system for the FCC-hh

Total power consumption:

~σ 200 MW : 20 MW // 10 Plants // 100 km

Cooling capacity per plant:

- from 60 to 40 K

thermal shields – 78 kW

beam screens – 504 kW

- from 300 to 40 K

pre-cooling of the helium cycle – 270 kW

C

T

T

C

Quenchbuffer

BCE F D

CM

Qcm

Shaft

C

Qts

Tunnel

Qcl

Cavern

T

T

T

C CC

C

Qbs Qts

Cryoplant layout

(L. Tavian)

Ring layout (L. Tavian)

Nelium cycle





Slide 4

Baseline cryogenic cycle

Key components:

- multi-stage centrifugal compressor (~10 MW range)

- turbo-expander ~700 kW → power recovery in compressor

Previously considered Nelium composition: 33 vol. % of neon

Nelium Turbo-Brayton cycle: former

baseline cycle layout

Image courtesy: MAN Diesel and Turbo

Image courtesy: SKF





Slide 5

Limiting factors

1. Turbo-compressor design

Currently developed 1-tandem design:

- up to 40 vol. % He;

- total compressor isentropic efficiency: ~73 %

0

2

4

6

8

0 0.2 0.4 0.6 0.8 1Nu

mb

er o

f co

mp

ress

or

casi

ng

s

Helium content (vol.)

Number of required compressor casings depending

on the helium content

(M. Podeur, University of Stuttgart; MAN)

0

2

4

6

8

10

0 0.2 0.4 0.6 0.8 1

Re

lati

ve g

as

ma

ss


Theoretical relative gas mass compared to a pure helium cycle

(excluding the buffer)

Total

Neon

Helium

1

1.5

2

2.5

3

0 0.2 0.4 0.6 0.8 1

Re

lati

ve v

olu

me


Relative heat exchanger sizes

2. System size and gas mass





Slide 6

Compared cycle arrangements

Cycle A (baseline) Cycle B Cycle C





Slide 7

2 inner heat exchangers reduced pressure ratio reduced pressure ratio

easier pressure control higher volumetric flow to the second

compressor casing

reduced pressure ratio of pre-cooling turbine

compared to cycle B

higher pressure ratio additional heat exchanger additional heat exchanger

high speed of the pre-cooling turbine (high

pressure ratio)


Chosen arrangement

Cycle A (baseline) Cycle B Cycle C





Slide 8

5.3

5.4

5.5

5.6

5.7

5.8

5.9

6

6.1

6.2

0.3 0.4 0.5 0.6 0.7

Pre

ssu

rera

tio


Required pressure ratio depending on the gas mixture

composition

Cycle C Cycle A


Cycle C - > new baseline

Advantages:

- Reduced pressure ratio

- Higher volumetric flow on the inlet of the second casing

Thus, for 40 % helium:

Cicle A: 𝑉1 𝑐𝑎𝑠𝑖𝑛𝑔

𝑉2 𝑐𝑎𝑠𝑖𝑛𝑔~2,4

Cycle C: 𝑉1 𝑐𝑎𝑠𝑖𝑛𝑔

𝑉2 𝑐𝑎𝑠𝑖𝑛𝑔~1,9 (var)

Increase helium content up to 60 vol. % He - 1 compressor impeller → +4..5 % to the total

compresor ηs↑

or





Slide 9

Improved cycle concept

Case study (under progress): matching the turbo-compressor middle pressure with the

cycle parameters

Estimated total power for the chosen case: ~9.7 MW

New baseline cycle flow diagram

7500

7600

7700

7800

7900

8000

8100

8200

11 13 15 17 19

Isen

tro

pic

wo

rk o

f co

mp

ress

ion

, kW

Inlet pressure to the 2nd compressor casing, bar

Total isentropic power of the compressor depending on the middle

pressure (for NTU1=18)

26.06.2019: “Improved concept of the Nelium Turbo-Brayton cycle

for the FCC-hh beam screen cooling”,

S. Savelyeva, S. Klöppel, Ch. Haberstroh, H. Quack





Slide 10

Upper heat exchanger design

Reduction of the heat exchanger cross-

section area and the cold box diameter

IHX1

IHX2

New baseline cycle flow diagram

Cold box cross section

Length: 5.6…6 m;

Diameter: 3.6..3.8 m





Slide 11

Natural Nelium concept

- Corresponds to the neon-helium ratio in the air:

Natural Nelium: (Ne:He) ~(3:1) + (3…8 %) H2

- Economically advantageous

- Current target composition: 60 % neon, 40 % helium → cheaper helium can be added

Crude nelium mixture production flow

diagram

- Hydrogen presence in the mixture: good

thermophysical properties

- Problem: instability of composition





Slide 12

Secondments & Trainings & Dissemination events

- Secondment – Linde Kryotechnik, Pfungen, Switzerland (29.04.-14.06.2019)

- Scientific cooperation with ESR 15 – University of Stuttgart, Germany (18.03.-05.04.19)

- Cryogenics conference 2019, Prague, Czech Republic (07.04.-11.04.19)





Slide 13

Next steps

- Case study for the cycle design matching with the turbo-compressor design

- Part-load operation and buffer optimisation for the new cycle baseline

- Compander designReview of the cycle performance calculation

- Cool-down operation of the new cycle baseline

- Further study of the Natural Nelium concept

- Participation in experiments on the neon-helium turbo-compressor test rig (University

of Stuttgart)

- Secondment 2





Slide 14

Thank you for your attention!

EASITrain – European Advanced Superconductivity Innovation and Training. This Marie Sklodowska-Curie Action (MSCA) Innovative Training Networks (ITN) has received funding from the European Union’s H2020 Framework

Programme under Grant Agreement no. 764879

“Development of a Nelium Turbo-Brayton cryogenic refrigerator for the FCC-hh”

EASITrain project status overviewS. Savelyeva, Ch. Haberstroh

Documents

“Development of a Nelium Turbo-Brayton cryogenic ......“Development of a Nelium Turbo-Brayton cryogenic refrigerator for the ... - Participation in experiments on the neon-helium