SOME ENERGY-EFFICIENT TECHNOLOGIES IN JAPAN

（EXECUTIVE SESSION）

November, 2007

JAPAN EXTERNAL TRADE ORGANIZATION JAPAN CONSULTING INSTITUTE

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SOME ENERGY-EFFICIENT TECHNOLOGIES IN JAPAN

1. Power Generation Technologies

1.1 Advanced Supercritical Coal-Fired Power Plant

1.2. Integrated Coal Gasification Combined Cycle

2. Heat Pump

2.1 Absorption Heat Pump

2.2 Compression Heat Pump

2.3 Vapor compression

3. Refinery

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1. Ultra supercritical pressure coal–fired power generation system

1000MW High temperature ultra supercritical pressure coal–fired power plant

(Source: HP of MHI)

2. Pressurized fluidized bed boiler combined cycle plant system

360MW Pressurized fluidized bed boiler combined cycle plant system

(Source: HP of Kyushu EPC)

Coal-fired Power Generation - 1

1ry & 2ry Cyclones Pressure vessel Electrostatic precipitator

Fluidized bed boiler

Coal bunker

DeNOx equipment

Exhaust gas feedwater heater

Gas turbine

Cal slurry pump

Steam turbine

(Source: HP of Toshiba)

(Source: Catalogue of IHI)

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3. Integrated coal gasification combined cycle system

(Source: HP of MHI)

250MW Integrated coal gasification combined cycle plant

(Source: HP of MHI)

4. Coal gasification SOFC combined cycle

Coal gasification SOFC (Solid Oxide Fuel Cell) combined cycle (Source: HP of MHI)

Coal gasification SOFC (Solid Oxide Fuel Cell) combined cycle plant

(Source: HP of MHI)

Coal-fired Power Generation – 2 (for very near future use)

Pulverizer

Coal bunker

Coal gasifier Heat exchange

Oxygen/air

Slag Char

Filter

Sulfur removal device

Inverter Steam turbine

Condenser

Exhaust gas

Compressor

Gas turbine HRSG

Coal

Coal gasifier Filter

Gas turbine

Steam turbine

HRSGChimney

Coal gasifier

Coal feed system

Coal gas

Porous filter

Combustor

Gypsum Wet DeSOx

AirStack

N2

O2

Char

Air Air separating unit

Air compressor

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1. Natural gas-fired combined cycle plant system

(Source: HP of Toshiba)

Gas turbine for 455MW single-shaft Natural gas-fired combined cycle plant

(Source: HP of MHI)

2. SOFC-GT combined cycle (being developed)

(Source: HP of MHI)

SOFC-gas turbine combined cycle package for DPHC

(Source: HP of MHI)

Natural Gas-fired Power Generation

SOFC module SOFC cell tube

Recirculation device

Inverter

Combustor

Gas turbine

Heat exchanger

Fuel

Air

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1. Diesel Engine power generation

(Model: Mitsubishi 18KU34)

2. Gas engine power generation

(Model: Mitsubishi)

3. Gas turbine cogeneration (heat/power ratio controllable type)

(Source: HP of Hitz)

4. PEFC cogeneration

(Source: HP of MHI)

Process steam

Feedwater

Fuel

Superheated t

Generator

Compressor

Turbine

Gas turbine

Power Air

Heat recovery boiler

Stack

Exhaust gas

Combustor

Distributed Power & Heat Cogeneration

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Wind turbine power generation

(Model: Mitsubishi Heavy Industries MWT95/2.4)

Photovoltaic cell power generation

1,000kW Photovoltaic power generation plant

(Model: Mitsubishi Heavy Industries MA100)

Hydraulic power generation

412MW Pump turbine generator (Francis type pump turbine supplied by Mitsubishi Heavy Industries)

Refuse incineration power generation

132.6MW Refuse incineration power plant

(Singapore Tuas South incineration plant constructed by Mitsubishi Heavy Industries)

Renewable Energy Power Generation

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1.1 Advanced Supercritical Pressure Coal-fired Power Plant Power generation Coal-firing Supercritical pressure plant

1. Function and features (1) High efficiency power generation

By applying high temperature supercritical steam condition such as 25MPa 600/600°C to steam cycle, much higher thermal efficiency of plant than subcritical pressure plant is obtainable. Applicable to 300MW and larger.

(2) High thermal efficiency over whole operating load range As the boiler is designed suitable for variable pressure operation, high plant efficiency over whole load range is obtainable owing to sliding pressure operation.

(3) Excellent dynamic performance Owing to once-through boiler design with less heat storage capacity of water and metal, excellent dynamic performance is obtained.

(4) Environmentally friendly operation Owing to state of the art combustion technology, environmentally friendly operation in addition to CO2 emission reduction is assured.

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2. Plant system

Supercritical coal-fired power generation plant

Conde -nser

Electrostatic precipitator

Low NOx burner

Boiler

Lime stone

Unloader Dust net

Coal carrier

Stacker

Reclaimer Coal conveyer

Electricity Transmission cable

Switch -gear Transformer

Generator

Building DeNOx reduction measures

Coalbunker

Steam turbine Catalytic DeNOx

Air preheater

Induced draft fan

Desulphurization plant

Stack 200m height

Flue gas analyzer

Gypsum

Coal ash

Useful ashAsh pond To DeSOx

Forced draft fanRaw water

Water purifier

Ocean

Pulvelizer

Steam

Boi

ler f

eedw

ater

pum

p

Feed

w

ater

Coo

ling

wat

er Ash

Circ

ulat

ing

wat

er p

ump

Indu

stria

l wat

er

Dis

char

ge w

ater

Coal

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3. Performance advantage

4. System and structure

Steam Pressure & Temperature

0 25 50 75 100 107

Unit load %

0

50

100

150

200

250

300

350

400

450

500

550

600

650

Tem

pera

ture

℃

SC Pressure MPa

SC Main steam temp °C

SC Reheat steam temp °C

Sub PressureMPa

Sub Mainsteam

Sub RH Steam temp °C

SC steam temp.

Sub steam temp

SC steam pressure

Sub steam pressure

30

25

20

15

10

5

Pre

ssur

e M

Pa

Improvement of plant efficiency

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(1) Boiler

The main difference of supercritical sliding pressure boiler from subcritical pressure drum type boiler with regard to structure is furnace water wall construction due to once-through flow in the former furnace water wall and recirculation flow in the latter.

High reliability of furnace water wall is assured with vertical tube structure with rifled tubes or spirally-wound structure with smooth or rifled tubes.

(2) Turbine generator

The structure of steam turbine for supercritical plant is basically same as that for subcritical plant except for the alteration material and physical dimensions.

(3) Plant

•Distributed Digital Control system is installed for better dynamic performance.

• Demineralizer is provided for better boiler feedwater quality control.

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5. FWW mass velocity & FWW structure

Furnace water wall (FWW) flow Furnace water wall structure

Vertical tube wall with rifled tube Spirally-wound tube wall with smooth tubes

Critical mass velocity

0

500

1000

1500

2000

2500

3000

3500

0 25 50 75 100 107

Unit load %

Mas

s ve

loci

ty k

g/m

2 /s

Massvelocity(MV)in verticaltube kg/m2/s

MV in 60deginclinedtube kg/m2/s

Critical MVfor smoothtube kg/m2/s

Critical MVfor insiderifled tube kg/m2/s

60deg. Inclined tube wall

Vertical tube wall

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6. Energy Saving /CO2 Emission Reduction More than 5% to (8%) reduction of fuel consumption and CO2 emission are

achievable compared with the conventional plant with steam condition of

16.7MPa×538°C /538°C.

500MW coal-fired power plant (load factor 0.75)

Plant Conventional plant Supercritical plant

Coal consumption Base - (50,000 to 90,000) ton/year CO2 emission Base - (140,000 to 230,000) ton/year

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1.2 Integrated Coal Gasification Combined Cycle Plant Power Generation Coal gasification IGCC 1. Function (1) Integrated coal gasification and power generation (2) High efficiency power generation with coal (3) Environmentally friendly coal-used power generation

2. Plant system

Integrated coal gasification combined cycle

Coal gasifier

Coal feed system

Coal gas

Porous filter

Combustor

GypsumWet DeSOx

AirStack

N2

O2

Char

Air Air separating unit

Air compressor

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3. Features

(1) High efficiency (< 50% LHV base) power generation with coal is obtainable,

resulting in less coal consumption and less CO2 emission.

Presently 250MW air-blown IGCC is being demonstrated for performance and

operability.

(2) Wide range of coal can be used for fuel.

A wide range coal is gasified in gasifier, transforming into coal gas suitable for

combustor of gas turbine.

(3) Less emission of SOx, NOx and particulate emission per kWh.

In addition, SOx is recovered as gypsum with DeSOx equipment and NOx

formation is minimized by reducing atmosphere in gasifier and low NOx

combustor of gas turbine. Dust is removed with porous filter before entering

into combustor of gas turbine.

(4) Useful byproduct-slag

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250MW IGCC demonstration plant at Nakoso PS in Japan Source: HP of Mtsubishi Heavy Industries, Ltd.

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2.1 Absorption Heat Pump / Refrigerator Air conditioning & refrigeration Waste heat utilization Absorption heat pump

1. Types of heat pump There are two types of heat pump, one is mechanical type (vapor compression

type) and the other is absorption type.

2. System (1) Mechanical type (vapor compression type)

The main components in the system are compressor (usually driven by electric

motor), condenser (heat discharger), expansion valve and evaporator (heat

absorber). The working fluid (gaseous refrigerant) from the evaporator

compressed to a high pressure and cooled in the condenser (to liquid) is

expanded to the low pressure of the evaporator by the expansion valve

evaporating and absorbing the heat from outside (cooling the outside fluid).

So, much electrical power is consumed by the compressor.

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(1) Mechanical (vapor compression) heat pump

(2) Absorption heat pump

(2) Absorption type

Heat in

Input Electricity

Engine

Heat out

Compressor

2. Compression

3. Condensation1. Evaporation

4. Expansion

Expansion valveEvaporator CondenserExpansion valve

Heat in

Evaporator Condenser

Heat outAbsorber

Heat

Regenerator

Pump

Expansionvalve

2

3

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• Main components The main components in the system are refrigerant absorber, pump, heater

(regenerator), condenser, expansion valve of working fluid, expansion valve of

absorbent and absorber cooler.

• Cycle

Absorbent (water or lithium bromide) absorbs the working medium (ammonia or

water), then the pressure of the liquid is raised by the pump. The liquid is, then

heated for boiling off the gaseous working media from the absorbent of liquid

state. The gaseous working fluid is cooled in the condenser to liquid state

dissipating heat, then, it is expanded to the evaporator pressure by the

expansion valve absorbing the outside heat. Thus the driving force of the cycle is

basically produced thermally resulting in much less electrical power requirement

than the mechanical (vapor compression) type but heat.

3. Energy saving and less GHG (CO2) emission with absorption type As absorption type requires less electrical energy or mechanical though

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requires heat for regeneration, it is higher in efficiency especially when waste

heat is available for regeneration.

Comparison of electrical power consumption

Type of HP Mechanical HP Absorption type HP

Electrical power consumption (kWh)

Large Small

Fossil fuel required None None (waste heat)

CO2 emission Large

CO2 is produced when the electricity for compressor use

is generated.

Small

The electrical power for the pump is small

4. Utilization of waste heat (cogeneration) As waste heat is effectively utilized in absorption type heat pump / refrigerator,

the combination of power generation and refrigeration (cogeneration) is

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preferable from view point of higher energy efficiency, cheaper operating cost

and less CO2 (GHG) emission (No increase of fuel consumption and CO2

emission).

5. Application of heat pump (1) Air (atmosphere) conditioning of room such as small space to large building

(2 ) Temperature control of various industrial process

(3) Temperature control of manufacturing process of food beverage

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2.2 Compression Type Heat Pump-Ecocute Hot water production Effective use of

Electricity Compression heat pump

1. Function (1) Economical hot water production with cheaper electricity at night and its

storage for daytime use.

(2) Clean hot water production.

(3) Energy(electricity) storage as hot water (temperature < 90°C).

2. Features (1) Refrigerant

Environmentally much more friendly substance CO2 than commonly used

materials previously such as CFC (R12) and HCFC (R22) is used as

refrigerant. Refrigerant, CO2, is stable natural substance, not manufactured

chemically.

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(2) Coefficient of performance It is as high as about 5, which means “5” times energy (heat) is obtainable with

“1” input of energy (electricity to drive compressor).

The energy of “4” times of the input energy is absorbed from ambient air, a kind

of solar energy.

(3) Environmentally friendly hot water supply equipment

As the energy consumption is much less than fossil fuel combustion type, CO2

emission is much less also.

As electricity is used, no combustion gas is emitted being suitable for inside

installation.

(4) High economic performance

As the amount of electricity consumed is small and it is operated when the

electricity charge rate is low such as at night, the economic performance is

excellent. The investment is recoverable within a few years.

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Hot water Temperature－ 90℃

Heat

Atmospheric heat

Heat exchanger Heat

exchanger

Compressor

Expansion valve

Heat pump unit Heat storage unit

Hot water

Cold water

Tem

pera

ture

lay

ered

heat

sto

rage

tank

Pump

Power input : 1

Energy output －

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2.3 Vapor Compression Heat Pump Food industry Waste heat utilization Vapor recompression

1. Function (1) Utilization of waste or used low temperature vapor (steam in most cases) for

producing higher temperature vapor required for concentration and volume reduction of commodity in production process.

(2) By recompressing low temperature vapor, steam in most cases, higher temperature steam is obtained with much less energy consumption, resulting in no fuel consumption and CO2 emission except for the power for compressor.

2. Features (1) Steam supply from outer source for heating of product for concentration and

volume reduction is not required resulting in simple compact plant system. (2) Waste energy contained in low temperature vapor is effectively utilized

resulting in energy saving for producing high temperature vapor. (3) Vapor recompression technology is useful for various manufacturing industries

including food and beverage, semiconductor, plating and others where waste liquid is discharged.

(4) Investment for installation of vapor compression equipment will be recovered within a few years or less.

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3. Example of a system

Concentration system of liquid product

Evaporated steam at 100°C

Compressor

Motor

Heatingsteam at 110°C

Air

Condensed waterLow concentration solution tank

Concentrated product tank

Pre-heater

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3. Rotary Heat Storage Burner for heating Furnace Refinery Heat recovery Heat storage burner

1. Function (1) Heat recovery by combustion air from exhaust gas from heating furnace for

highly efficient combustion performance of burner

(2) Continuous operation with single rotary type burner

2. Features (1) High thermal efficiency

Owing to the excellent combustion, very high thermal efficiency is obtained

(≥ 90%) only with radiant furnace.

(2) Heat recovery equipment is minimized owing to the efficient heat absorption by

radiant furnace.

(3) NOx emission is reduced owing to reduced combustion air.

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3. System /structure

Heat storage rotary burner Heating furnace system with heat storage rotary burner

Air

Heat storage body

Ambient air High temperature exhaust gas

Exhaust gas passage

Combustion air passage

Low temperature exhaust gas

Process fluid

Exhaust gas

Exhaust gas Steam