HYGROSCOPIC CYCLE

INNOVATION

Francisco Javier Rubio Serrano Head of Engineering/Energy Division

Index

1. Background

2. Innovative Technology

3. Applications

4. Commercial Plants

5. Hygroscopic Cycle VS Rankine Cycle

6. Conclusions

HYGROSCOPIC CYCLE

1. BACKGROUND (1)

HYGROSCOPIC CYCLE

"If the wars of the XX century were fought over oil, the wars of XXI century will be fought over water”. Ismail Serageldin

1. BACKGROUND (2) Rankine cycle mainly application is to generate electricity in thermal power

stations.

Rankine cycles are large consumers of water, used as replacement cycle itself, for cleaning and cooling system, being the latest consumer the most important of the three. This consumption depends on the type of technology used, cooling system selected, the weather conditions and cycle performance.

Main improvements developed to increase the efficiency of the Rankine Cycle are the following:

Overheating steam at the beginning of the expansion (Hirn Cycle).

Pressure and temperature modifications at the initial and final phase of expansion

Overheating

Regeneration Cycle

Binary Vapour Cycle

HYGROSCOPIC CYCLE

Hygroscopic Cycle

2. INNOVATIVE TECHNOLOGY (1) The technology is being developed since 2008 and is located in the state of the art

since 2010, as “Rankine cycle with absorption step using hygroscopic compounds". In 2012 IMASA, ENGINEERING AND PROJECTS, S.A, acquired the rights to use it.

Hygroscopic cycle is a power cycle which is characterized by working with hygroscopic compounds which optimize condensation of the steam at the output turbine. It can work under high vacuum to the outlet with good cooling conditions.

Hygroscopic cycle is compatible with all the improvements of the conventional Rankine Cycle.

Main advantages are a significant improvement in technical, environmental and economical. “Rankine Cycle Revolution”.

Improve the electrical performance around 1%. (From 0,3% to 1% net electrical efficiency improves).

Savings in cooling water intakes above 85%.

O&M costs decreased by 25%.

Steam cycle investment costs are reduced around 5% (space reduction (civil works)).

Increases the life of the plant, the reliability and the availability.

HYGROSCOPIC CYCLE

2. INNOVATIVE TECHNOLOGY (2)

Hygroscopic cycle uses a steam absorber where the steam turbine output current is in contact with hygroscopic compounds, increasing the condensation temperature.

There is a thermal and chemical recovery of boiler blowdown.

The increase of performance implies:

• Reduce of fuel consumption

• Carbon dioxide (C02) reduction per kWh produced

• Increased competitiveness

HYGROSCOPIC CYCLE

2. INNOVATIVE TECHNOLOGY (3)

Improved cooling conditions imply:

• Replace cooling towers or air condensers by air coolers

• Decrease or cancel the water consumption

• Environmental impact reduction

HYGROSCOPIC CYCLE

3. APPLICATIONS

HYGROSCOPIC cycle has several applications. The main and more interesting

ones are the following:

• Power plants

Combined cycles

Nuclear plants

Thermoelectric plants (coal ant other fuels)

Biomass power plants

CSP Plants

Cogeneration plants

Applicable to new and existing plants.

In all cases, the application of Hygroscopic cycle technology would mean a

significant increase of competitiveness.

HYGROSCOPIC CYCLE

4. COMMERCIAL PLANT

Hygroscopic cycle can be applied commercially to

power plants that use a Rankine cycle for any power.

Most of the equipment and materials are the same as

on a conventional Rankine cycle (turbine, boiler,

deaerator, pumps, etc ...).

The novelty is the incorporation of a steam absorber,

regenerative heat exchanger, air cooler and internal

recirculation to recover thermally and chemically

boiler blowdown.

All equipment and materials of the Hygroscopic cycle

are commercials and 100% guaranteed by the

different manufacturers.

HYGROSCOPIC CYCLE

5. HYGROSCOPIC CYCLE VS RANKINE CYCLE (1)

5.1 ANNUAL PRICE AND CONSUMPTION OF COOLING WATER

HYGROSCOPIC CYCLE

5. HYGROSCOPIC CYCLE VS RANKINE CYCLE (2)

HYGROSCOPIC CYCLE

PARAMETERS RANKINE CYCLE WITH COOLING TOWERS

RANKINE CYCLE WITH AIR CONDENSER

HYGROSCOPIC CYCLE

INVESTMENT PRICE (€) 35.500.000 37.070.000 33.700.000

ELECTRICAL NET OUTPUT (MW) 15,00 14,19 15,23

ANNUAL ELECTRICAL PRODUCTION (MWh)

117.000 110.682 118.794

NET PERFORMANCE STEAM CYCLE (%)

28,74 27,18 29,19

ANNUAL CONSUMPTION COOLING WATER(m3)

550.000 - 52.500

ANNUAL COOLING TOWER BLOWDOWN PRODUCTION(m3)

180.000 - -

ANNUAL CONSUMPTION OF INPUT WATER TO THE STEAM CYCLE (m3)

15.000 15.000 12.000

ANNUAL COST OF COOLING WATER (€)

1.100.000 - 105.000

ANNUAL MAINTENANCE COST (€)

1.200.000 1.050.000 900.000

ANNUAL SELF CONSUMPTION (MWh)

11.700 11.595 11.525

6. CONCLUSIONS

Increases the electrical performance around

1%.

Savings in cooling water consumptions above

85%.

Steam cycle investment costs are reduced

around 5%.

O&M costs are decreased by 25%.

Applicable to all power plants that use a

Rankine or steam cycle: power plants,

combined cycle, nuclear, biomass,

thermosolar, cogeneration ...

HYGROSCOPIC CYCLE

EFFICIENCY AND SAVINGS

Thanks for your attention Francisco Javier Rubio Serrano

Head of Engineering/Energy Division Móv: +34 683 66 19 69

fj.rubio@imasa.com www.imasa.com