Thar Energy, LLC © 2016│ All Rights ReservedFor additional information contact:

Marc Portnoff, marc.portnoff@tharenergyllc.com

sCO2 Brayton Power Cycle Heat Exchanger Test Facility

AbstractThe supercritical carbon dioxide (sCO2) Brayton power cycle is

adaptable to a variety of heat sources and has higher cycle

efficiency compared to traditional power cycles. As such, it is

being considered for multiple power generation applications such

as waste heat recovery, fossil, concentrated solar power,

geothermal and nuclear.

A key determinant on power cycle efficiency and profitability is

heat exchanger (HX) performance and cost.

To evaluate heat exchanger performance, Thar Energy, with

funding support from U.S. DOE NETL, has designed a test loop

simulating a simple recuperated Brayton cycle. The test facility,

under construction, is being sized to evaluate innovative ideas in

HX design.

PSV

PSV

0.141 kg/s

8.46 kg/min

RecuperatorsCO2 -sCO2

MFM

Flue Gas

255 bar

30 C

87 bar, 370 C

254 bar

390 C

86 bar, 567 C

85 bar, 80 C

84 bar,

30 C

Manual

E Stop

Combustion

Air-sCO2

Heater HX

HX H1

TE_B1 PT_B2

TE_B2

Flow

VFD

BPR

High Pressure

Control

Large

Surge

Tank

PT_02

TE_02

PT_03

TE_03

PT_01

TE_01

CO2 Supply

45 bar

V--14

PT_04

TE_04

PT_05

TE_05

Burner

PT_B1Blower

CO2

Pump

& VFD

P1

V--1

4

Vent

Booster

Pump

P2

Outside

Water-sCO2

Cooler HX

Manual

BPR

Low

Pressure

ControlBaffle

Pres.

Vessel

PT_07

TE_07

PT_06

TE_06

PT_07

TE_07

PT_05

TE_05

Thar Energy manufactures Microchannel Recuperators,

Heaters & Coolers for the sCO2 Power Cycle.

The test loop’s focus is on collecting performance

measurements to evaluate prototype recuperator,

heater HX, and cooler HX.

• Heat transfer coefficient • Surface density

• Fluid flow pressure drop • Friction factor

The system also allows for the evaluation of

individual auxiliary sCO2 Power Cycle components

including pumps, filters, valves, sensors and material

properties such as corrosion resistance.

The main components of the loop include a variable

speed sCO2 pump with mass flow monitor, gas fired

heater, and a chiller. A pressure control valve has been

incorporated as a substitute for the performance of a

turbine, thereby enhancing the system’s operating

flexibility at reasonable costs.

Reconfigurable Test Loop

• Pressures to 275 bar

• Temperatures to 700 C

• sCO2 mass flow to 10 kg/min

Test Loop Flow Diagram

• Test thermal performance over

a range of operating conditions

• Compare actual to predicted

performance

Test Loop Layout

Thar Energy Manufactures sCO2 Power Cycle

Recuperators, Heater HXs & Cooler HXs for

Generator

Primary

Heater

Precooler

High Temp

Recuperator

Low Temp

Recuperator

Compressor Recompressing

Compressor

Cooling

Air

Turbine

Heat Input

Counter-Current

Microtube

5.5 MW

2.5 MW Hot Gas–sCO2 HX

Heaters

Recuperators

Microchannel

sCO2

Gas

Cooler

Gas Coolersor Water Coolers

316 Stainless & Inconel 625

Inconel

740H

Aluminum,

Low Carbon or

Stainless Steel

Typical sCO2 Recuperated

Recompression Brayton Cycle

40 kW Inconel 625

Microtube Heater

100 kW Inconel 625

Microtube Recuperator

Tube Bundle

4,500 m2/m3

1,800 m2/m3

Work supported by US DOE NETL under:

DE-FE0024012: Seth Lawson, Program Officer

DE-FE0025348: Mark Freeman, Program Officer

Virginia Tech,

Blacksburg, VA

November 1-3, 2016

Lalit Chordia, PhD, Ed Green, Marc Portnoff