Workshop Geothermal Energy: Opportunities and Challenges

Workshop Geothermal Energy: Opportunities and Challenges

Coating testing and demonstration and hybrid cooling for low temperature geothermal platns: results of the H2020-project MATChING

Johan Van Bael, Project Manager, VITO

TWI, Cambridge, 10th of October 2019

PAG 2 GRANT AGREEMENT 686031DATE 10/10/2019

The project in summary

Within the project novel technologies are developed to optimise cooling with particular reference to geothermal and fossil fuel cooling systems.

Nevertheless most of the technologies are applicable for nuclear plants or even in other sectors different from the electric one

Reduce evaporative losses and plume visibility in

geothermal power plants to increment the geo-fluid re-

injected fraction;

Increase the robustness of cooling equipments to allow the use of

non-traditional waters;

Increase the heat exchange efficiency of condenser and cooling

equipments;

Promote the use of alternative water sources (low quality waters,

blow down waters, municipal waters)

Geothermal Power Plant Thermal Power Plant

OB

JEC

TIV

ES

MATChING is the acronym of a project titled: “Materials & technologies for performance improvement of cooling systems in

power plants” which has been submitted for the call NMP-15 of H2020 EU funding program: Materials innovations for the

optimisation of cooling in power plants”

To improve electricity production processes from Low-T

geothermal sources (100–175°C) optimizing ORC cycle

trough the use of Ground Water Cooling


Consortium, quick facts and main outcomes

Overall reduction of geothermal steam emitted into the atmosphere up to 15% and extension of production wells life

up to 10% using hybrid solutions for cooling towers and advanced materials and coatings for dry modules

Overall plant efficiency increase up to 0.4-0.5%, enhancing the heat transfer efficiency in the condenser both on the

steam side and water side via the use of advanced nano-engineered coatings and surfaces..

Overall reduction of fresh water abstraction in fossil fuelled power plants of about 30% validating a set of solutions

(6) for the recovery and treatment of cooling water in CT equipped plants.

Expected Outcomes

Starting Date First of March 2016

Duration: 42 months

Partners: 16

Overall Budget € 11.847.291,75

Grant Amount € 9.706.413,77


Overview of technologies

WP5

Steam condenser and cooling

water circuit

WP6

Water treatment and Recovery

WP3 and WP4:

Use of GWC for optimization of ORC for low T geothermal source

Hybrid CT in steam dominated geothermal plants


ENEL-Torrevaldaliga Nord Power Plant

ENGIE – Merades Pilot Plant

EDF– Bugey Power Plant

Demonstration program

Coatings for geothermal

heat exchangers

Membranes for water

recovery from FGDHybrid CT for geothermal

application

Coatings/materials for

steam condenser and

membranes for cooling

water treatment

Coatings/materials for

steam condenser Membrane condensor

Membranes and

technologies for

cooling water

treatment

Balmatt in Mol,

Belgium

Torrevaldaliga Nord

Italy

Nuova San Martino,

Italy

As Pontes,

Spain

Chatou,

France

Bugey,

France

Bruxelles,

Belgium


Coating demonstration for low T geothermal plants



Exotic expensive materials (inconels, hestealloys etc) are able to perform very well in

highly corrosive environments, but economic aspects have to be taken into account. To

reduce the installation costs, we investigate the application of coatings for upgrading

the corrosion resistance of cheaper materials in place of expensive, corrosion

resistant alloys.

Material Group Tested Metals PRE % Cost (relative to steel)

Carbon steel P265G - 1

Stainless steels

& Alloys

316L

318LN

904L

Alloy 31 (Super-Duplex)

27

34

36

52

8.3

7.1

19.4

33

Titanium Grade 2: 99.9%Ti - 16.2

Selected alternative substrates:

P265G: Carbon steel with specified

elevated temperature properties intended

for pressure purposes.

AISI 316L: Austenitic stainless steel

Ref: N. Mundhenk “Laboratory and in-situ corrosion studies in geothermal environments” GRC Transactions vol. 36, 2012



Coating ID

MATChINGProducer/Supplier Material tested

1 DTI-1 AISI 316L

2 DTI-2 AISI 316L

3 DTI-3 AISI 316L

4 Commercial-1 AISI316L/P265G



7 Commercial-4 AISI316L/P265


9 DTI-4 AISI316L/P265G*


11 AIMEN-1 AISI316L/P265G

12 AIMEN-2 AISI316L/P265G

13 DTI-5 P265G



Laboratory Validation

Basic Characterization and application if needed

• Coating thickness

• Dry Adhesion

• Surface Energy

Test Inks

Dynamic and Static contact angle

Ethanol break test

Basic information about the coating characteristics


laboratory tests are indicators but no “guarantors” of

performance in either positive or negative sense.

However, if the coating is user-friendly, and the laboratory

tests are positive, it is worthwhile to subject the coatings to

real exposure tests.

1-“Wet adhesion”

Adhesion

Blistering

Rusting

OK performance

2-“Mock-up Test”

Selection of 6

candidates for the

demo phase

Poor

performance

Discarded




1-Screening test “Wet Adhesion”

Adhesion failure is often the first step in the corrosion of coated metal. We inspired in the “hot water test” ASTM D870.

Testing procedure: The samples are immersed for 72 h at 90C in a NaCl solution (3.5% wt.). After that, the samples are first

evaluated visually, and then rated for adhesion, blistering, rusting. If the samples perform well they are reimmersed for additional

72h and evaluated again. In the second step, the goal is to assess performance in conditions that simulates damages (cuts) in

the coating.OK performanceFail Fail




2-Screening test Mock Up (LOTU test)

Immersion tests at the maximum temperature and pressure operating conditions is the best qualification test to ensure long-term

reliability of the coatings. the ASTM E 1068-85 “standard test method for testing nonmetallic sealing materials by

immersion in a simulated geothermal test fluid” establish a test duration of 570 h (24 days) for temperatures of 140C or less

LOTU (mock-up) In situ Balmatt

Temperature 125-135 C 125-130 C

Pressure 30-40 bars ̴ 40 bars

Partial

pressure of

CO2

-CO2 in the gas

mixture76,5 Vol. %

pH 5.55 ̴ 5.50

Stirring 600 rpm Flow rate

Flow velocity

100-200 m3 h-1

1 m s-1Exposure time ̴ 24 days (570h)

At the end of the test, the samples are sent to AIMEN for EIS evaluation.

PAG 13 GRANT AGREEMENT 686031CONFIDENTIALDATE 14/03/2019

13


AISI 316L

Coat 4 Coat 6 Coat 10 Coat 12 Coat 13

Rp / ᾪ

cm

2

Rp / ᾪ

cm

2

Pass Condition

Rp>10E+7

Benchmark

P265G (CS)



Demonstration and on site evaluation of the selected coatings




Design of the corrosion sensor

Flange and structure

Working Electrodes

Isolation rings

Counterelectrode

Ref. Electrode


16



Monitored rings

Non Monitored


17




18


Coating 6 > Coating 8 > Coating 10 > Coating 4 >>> Coating 13




Conceptual design of hybrid cooling systems based on GWC

What is ATES?

ATES = Aquifer Thermal Energy Storage

More than 1,000 sites, mostly in NL and Scandivia, but also in the North of

Belgium

Seasonal storage system based on a ‘hot well’ and a ‘cold well’ = doublet



Low-enthalpy geothermal power plants high sensitivity of performance to

ambient temperature (especially CHP plants

Reduced electrical efficiency of ORC



Aquifer temperature is constant no seasonal effect on Power production

Groundwater is used in a closed loop no water consumption



Aquifer temperature is constant no seasonal effect on Power production

Groundwater is used in a closed loop no water consumption

Constraint : no thermal pollution of the aquifer recooling



System modelling and optimisation

Optimization problem identify best policy for hybrid cooling operation.

Objective function: max 𝑃𝑛𝑒𝑡

Constraint: σ ሶ𝑚𝑖𝑛𝑗𝑒𝑐𝑡𝑒𝑑 = σ ሶ𝑚𝑒𝑥𝑡𝑟𝑎𝑐𝑡𝑒𝑑

Time horizon: 1 year

Technique: Approximated DP

Surrogate model for the plant

performance = f(actions)


Future developments - GeoSmart


Thank you

Johan Van Bael

Project manager @ VITO

[email protected]

Workshop Geothermal Energy: Opportunities and Challenges

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