SOME ENERGY-EFFICIENT TECHNOLOGIES IN JAPAN

Transcription

1 SOME ENERGY-EFFICIENT TECHNOLOGIES IN JAPAN (EXECUTIVE SESSION) November, 2007 JAPAN EXTERNAL TRADE ORGANIZATION JAPAN CONSULTING INSTITUTE

2 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 2

3 Coal-fired Power Generation Ultra supercritical pressure coal fired power generation system 1000MW High temperature ultra supercritical pressure coal fired power plant (Source: HP of Toshiba) (Source: HP of MHI) 2. Pressurized fluidized bed boiler combined cycle plant system 360MW Pressurized fluidized bed boiler combined cycle plant system 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: Catalogue of IHI) (Source: HP of Kyushu EPC) 3

4 Coal-fired Power Generation 2 (for very near future use) 3. Integrated coal gasification combined cycle system 250MW Integrated coal gasification combined cycle plant Coal gasifier Coal gas Coal feed system Porous filter Wet DeSOx Gypsum Combustor Air Stack Char N2 Air O2 Air separating unit Air compressor (Source: HP of MHI) (Source: HP of MHI) 4. Coal gasification SOFC combined cycle Coal gasification SOFC (Solid Oxide Fuel Cell) combined cycle plant Coal Coal bunker Coal gasifier Heat exchange Filter Sulfur removal device Inverter Steam turbine Condenser Steam turbine HRSG Chimney Compressor Gas turbine Slag Char Coal gasifier Filter Pulverizer Oxygen/air Gas turbine HRSG Exhaust gas Coal gasification SOFC (Solid Oxide Fuel Cell) combined cycle (Source: HP of MHI) (Source: HP of MHI) 4

5 Natural Gas-fired Power Generation 1. Natural gas-fired combined cycle plant system Gas turbine for 455MW single-shaft Natural gas-fired combined cycle plant (Source: HP of Toshiba) (Source: HP of MHI) 2. SOFC-GT combined cycle (being developed) SOFC-gas turbine combined cycle package for DPHC SOFC cell tube SOFC module Recirculation device Fuel Inverter Air Combustor Gas turbine Heat exchanger (Source: HP of MHI) (Source: HP of MHI) 5

6 Distributed Power & Heat Cogeneration 1. Diesel Engine power generation 2. Gas engine power generation (Model: Mitsubishi 18KU34) (Model: Mitsubishi) 3. Gas turbine cogeneration (heat/power ratio controllable type) 4. PEFC cogeneration Process steam Fuel Superheated t Exhaust gas Combustor Generator Compressor Turbine Heat recovery boiler Stack Power Air Gas turbine Feedwater (Source: HP of Hitz) (Source: HP of MHI) 6

7 Wind turbine power generation Renewable Energy Power Generation Photovoltaic cell power generation Hydraulic power generation (Model: Mitsubishi Heavy Industries MWT95/2.4) 1,000kW Photovoltaic power generation plant (Model: Mitsubishi Heavy Industries MA100) Refuse incineration power generation 412MW Pump turbine generator (Francis type pump turbine supplied by Mitsubishi Heavy Industries) 132.6MW Refuse incineration power plant (Singapore Tuas South incineration plant constructed by Mitsubishi Heavy Industries) 7

8 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 CO 2 emission reduction is assured. 8

9 2. Plant system Unloader Dust net Reclaimer Coal conveyer Stack 200m height Electricity Coal carrier Transmission cable Switch -gear Industrial water Stacker Transformer Raw water To DeSOx Steam turbine Generator Water purifier Ocean Discharge water Circulating water pump Conde -nser Cooling water Building Steam Boiler feedwater pump Coal Feed water Pulvelizer Low NOx burner DeNOx reduction measures Coal bunker Boiler Ash Ash pond Forced draft fan Desulphurization plant Induced draft fan Catalytic DeNOx Lime stone Electrostatic Flue gas analyzer Air preheater precipitator Coal ash Useful ash Gypsum Supercritical coal-fired power generation plant 9

10 3. Performance advantage Steam Pressure & Temperature SC steam temp. 30 Sub steam temp SC Pressure MPa Improvement of plant efficiency Temperature SC steam pressure Sub steam pressure SC Main steam temp C SC Reheat steam temp C Sub Pressure MPa Sub steam Main Unit load % 5 Pressure MPa Sub RH Steam temp C 4. System and structure 10

11 (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. 11

12 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 3500 Critical mass velocity 3000 Mas s velocity(mv) in vertical tube kg/m2/s Mass velocity kg/m 2 /s deg. Inclined tube wall Vertical tube wall MV in 60deg inclined tube kg/m2/s Critical MV for smooth tube kg/m2/s Critical MV for inside rifled tube kg/m2/s Unit load % 12

13 6. Energy Saving /CO 2 Emission Reduction More than 5% to (8%) reduction of fuel consumption and CO 2 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 CO 2 emission Base - (140,000 to 230,000) ton/year 13

14 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 Coal gasifier Coal gas Coal feed system Porous filter Wet DeSOx Gypsum Combustor Air Stack Char N2 Air O 2 Air separating unit Integrated coal gasification combined cycle Air compressor 14

15 3. Features (1) High efficiency (< 50% LHV base) power generation with coal is obtainable, resulting in less coal consumption and less CO 2 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 15

16 250MW IGCC demonstration plant at Nakoso PS in Japan Source: HP of Mtsubishi Heavy Industries, Ltd. 16

17 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. 17

18 Heat in Engine Input Electricity Heat out Heat in Absorber 2 Heat out Compressor Regenerator 2. Compression 1. Evaporation 3. Condensation Pump 3 4. Expansion Expansion valve Heat Evaporator Expansion valve Condenser Evaporator Expansion valve Condenser (1) Mechanical (vapor compression) heat pump (2) Absorption heat pump (2) Absorption type 18

19 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 (CO 2 ) emission with absorption type As absorption type requires less electrical energy or mechanical though 19

20 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) Fossil fuel required CO 2 emission Large None Large CO 2 is produced when the electricity for compressor use is generated. Small None (waste heat) 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 20

21 preferable from view point of higher energy efficiency, cheaper operating cost and less CO 2 (GHG) emission (No increase of fuel consumption and CO 2 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 21

22 2.2 Compression Type Heat Pump-Ecocute Hot water production 1. Function Effective use of Electricity Compression heat pump (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 CO 2 than commonly used materials previously such as CFC (R12) and HCFC (R22) is used as refrigerant. Refrigerant, CO 2, is stable natural substance, not manufactured chemically. 22

23 (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. 23

24 Power input : 1 Energy output - Hot water Temperature- 90 Compressor Hot water Atmospheric heat Heat exchanger Heat Heat exchanger Temperature layered heat storage tank Cold water Expansion valve Heat pump unit Pump Heat storage unit 24

25 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 CO 2 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. 25

26 3. Example of a system Evaporated steam at 100 C Compressor Heating steam at 110 C Motor Condensed water Low concentration solution tank Air Preheater Concentrated product tank Concentration system of liquid product 26

27 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. 27

28 3. System /structure Combustion air passage Heat storage body Process fluid Ambient air High temperature exhaust gas Exhaust gas passage Low temperature exhaust gas Air Exhaust gas Steam Exhaust gas Heat storage rotary burner Heating furnace system with heat storage rotary burner 28