1. Summary of thermal power generation in Japan

Transcription

1 1. Summary of thermal power generation in Japan 1.1 History of companies in Japan ity supply in Japan is carried out by independent regional companies, which require close communication to operate efficiently. In 1952, the nine major companies established the Federation of Power Companies (FEPC) to promote smooth operations within the industry. Since then, the FEPC has played an important role as a base for communication between the power companies and as a forum for exchanging ideas on the evolution of the environment in the electricity industry. The FEPC undertakes various activities aimed at ensuring operations of the electricity industry in keeping with the development of the country as a whole. With the restoration of Okinawa to Japan in 1972, the Okinawa Power Company resumed its participation in Japan's industry, becoming a full FEPC member in March Fig Service Areas by Company 1.2 History of the power plant and the role of thermal power generation in Japan ity consumption in Japan has expanded almost consistently after the world war. Further, in recent years, the need has intensified for a comfortable life as seen in the progression of computerization and the proliferation of air conditioners, and even though the Japanese economy has entered a stable growth period, shows no signs of slowing down. In addition, new problems are starting to appear as the increases. Let consider the current situation and future of electricity consumption. Due to the betterment of people's living standards, comfortable living is sought and the role of electricity in living starting with air conditioning is growing increasingly. Moreover, due to the progression of a highly intelligent community as a result of IT innovation including the computer and communication, the role of electricity is increasing in all aspects of industry and living. From these facts, over the course of time, the percentage of electricity consumption among consumption of other energies (electrification ratio) is running high. Although the is dependent on the trends in the business climate and those in politics and the community, even in recent years when the Japanese economy has entered a stable growth period, it continues to increase due to the progression of computerization and the proliferation of air conditioners. power in Japan is supplied mainly by thermal (oil, LNG, coal, etc.), hydro, and nuclear power generation. There are 1,300 or more power plants in all parts of Japan to meet the 1

2 growing steadily due to an upsurge in the desire to seek comfortable living, computerization, graying, etc. PJ (Petajoules=10 15 J) Ratio of accounting for primary energies (electrification ratio) Domestic supply of primary energies denotes the percentage that accounts for (Note) 1PJ equals a heating value of about 25,800 kl of crude oil. (Fiscal ) Source: Comprehensive Energy Statistics (2003 version) Fig.1.2-1: Ratio of accounting for primary energies (electrification ratio) The role of electric energy, being useful and easy to use, is intensifying year after year, and the ratio of electric energy to the consumption of all energies has now reached about 40%. 2

3 Track record and outlook of power generated by source. (Hundred million kwh) Nuclear power Oil, etc. Coal Natural gas (LNG) Hydro Geothermal power generation and new Power generated yearly (Note) 1. Oil, etc. includes LPG, other gases and bituminous mixtures. 2. Due to rounding off, there may be cases where the total value does not equal 100%. 3. Total of 10 companies. Power received is included. 4. The numeric values in the graph represent the segment share (%). Source: (Fiscal) Outline of Fiscal 2005 Supply Program (March 2005) and others Fig.1.2-2: Track record and outlook of power generated by Source. Power generated increases with each passing year, and we cope with the for increasing while planning departure from the use of oil through the use of nuclear energy, natural gas (LPG), etc. As our lives become convenient and rich, the role of electricity serving in our lives continues to expand. The amount of electricity usage varies significantly depending on the time period of the day and the season. When we look at the electric consumption on an annual basis, in recent years, the growth in the summer season is significant due to air conditioning, and when we look at it on a daily basis, the maximum consumption is marked at about 2:00 p.m. when the heat in midsummer reaches its peak. The difference between the maximum and the minimum values of electricity consumption is more and more on an increasing trend. The increase in home air conditioners has a significant effect on this. On the other hand, electricity is an energy that is impossible to be stored. Although a plant that generates is built to the peak of (maximum ), when the varies significantly according to season and time period, efficiency in the utilization of the power plant lowers, and as a result, the cost to deliver the electricity will be comparatively high. 3

4 Movements in how electricity is used over one day in midsummer (Million kw) (Merging of 10 companies) July 20, 2004 July 24, 2001 August 25, 1995 August 7, 1990 August 29, 1995 July 31, 1975 (Note) Merging of 9 companies only in 1975 (Time) Survey conducted by the Federation of Power Companies of Japan Fig Movements in how the electricity is used over one day in midsummer For, there is a significant difference between daytime and nighttime in one day. This reflects the fact that while a good amount of electricity is used by plants and offices in the daytime, industrial activities are not performed much at night. In addition, even in the daytime, the amount of electricity used decreases from 12:00 to 13:00 p.m. when plants and offices are in a lunch break. During the day on a hot summer day, for air conditioning increases. The consumption at the peak in the daytime reaches about 2 times that in the time period in a day when the consumption is lowest. 4

5 Movements in how the electricity is used over one year (Million kw) (Merging of 10 companies) (All-time maximum) Fiscal 2001 Fiscal 2004 Fiscal 1995 Fiscal 1990 Fiscal 1985 Fiscal 1975 Fiscal 1968 Fiscal 1967 (Note) Merging of 9 companies before (Month) Survey conducted by the Federation of Power Companies of Japan Fig.1.2-4: Movements in how the electricity is used over one year When we look at on a month-by-month basis, there is a big change in how the electricity is used even through one year. ity registered its peak during the summer season of fiscal 1968, and currently, there are 2 peaks in the summer and the winter in conjunction with the upsurge in used for heating in winter. In particular, the increase in the peak in summer is remarkable, showing a big gap compared with spring and autumn when there is low for air conditioning. The gap in due to the season will cause the efficiency of the utilization rate of plant to lower together with scale-up of the gap due to the time period, and will contribute to increasing the cost to deliver the electricity to the consumer. [Combination in response to the characteristics of the source] Although the amount of electricity usage varies, as it is impossible to store the electricity, and it is necessary to adjust the amount of electricity to be generated with reference to the. power companies combine a variety of generation systems for the purpose of meeting that varies every moment. Efforts to cope with peak During the day when electricity is used in large amounts, a power plant must generate high-volume electricity. Provision for peak is made by an oil-fired thermal power and pumped-storage hydro generation, which are excellent in coping with that can vary. Supplying base On the other hand, base is supplied by nuclear power generation and hydro power generation (run-off river type) taking the power generation cost and environment load into account. Combined use of sources Further, in Japan, most energy resources rely on imports from abroad. To supply electricity with stability in the

6 future as well, taking the limited fossil resources, global environmental issues, further economics, etc. into account, we intend to combine the resources in well-balanced way making use of characteristics of each type of power generation including hydro, thermal, and nuclear, thereby dispersing the risk by not relying on one source. ity varies during the day or at night even in one day. In electric utilities, the features of hydro, thermal, and nuclear power generation such as operation characteristics, economics, and efforts to cope with global environmental issues are judged comprehensively to combine various kinds of sources in an optimum balance. cope with peak Equalizing pool-type hydro Water reservoir-type hydro Pumped-storage hydro Oil cope with middle electric power LNG, LPG, and other gases Coal Nuclear power cope with base Run-off river-type hydro/geothermal power generation (Time) Fig.1.2-5: Combination of sources for Table 1.2-1: Characteristics of respective sources and optimum combination Power generation Supply capacity Characteristics system Pumped-storage hydro Equalizing pool-type hydro Water reservoir-type hydro Oil-fired thermal power LNG, LPG, and other gas-fired thermal power Coal-fired thermal power cope with peak cope with peak cope with peak cope with middle cope with base and middle s Finds application as a supply capacity to cope with sudden fluctuation in and peak because it copes very easily with fluctuation in. Although the initial cost is high, this is excellent economically from the viewpoint of average service life, and because it copes extremely easily with fluctuation in electric power, this type finds application as a supply capacity for peak. Although the running cost is relatively high, the capital cost is low and it is excellent in coping with fluctuation in electric power, thereby finding application as a supply capacity for peak. The running cost is low, and with respect to the capital cost as well, it is cheaper than a coal-fired thermal power and it is excellent in coping with fluctuation in, thereby finding application as a supply capacity for middle. Although the capital cost is high, it copes more easily than nuclear power with fluctuation in, thereby finding application as a supply capacity for intermediate between that for base and that for middle. 6

7 Nuclear power Run-off river-type hydro power generation cope with base cope with base Supply capacity for peak : Supply capacity for middle : Supply capacity for base : Although the capital cost is high, the running cost is low, whereby this can perform the operation at a high utilization rate as a supply capacity for base. Although the initial cost is high, it is excellent economically from the viewpoint of average service life, and it finds application as a supply capacity for base. A source whose amount of electricity to be generated can easily be adjusted A source that has the two features of peak and base A source that supplies a constant volume of electricity 1.3 Movements in thermal efficiency of thermal power plants in Japan and outlook for thermal power generation technology in the future Since the first Rankine cycle-based thermal (steam) power generation plant (Steam pressure: 0.59MPa (gage) (6atg), 7.5kW (10HP) was manufactured by Charles A. Persons in 1884, the thermal efficiency of steam power generation plants has improved significantly together with improvement of steam conditions (higher temperature/higher pressure) and larger capacity. In Japan as well, LNG-fired supercritical pressure (SC) plants whose main steam pressure was 24.3 MPa (gage) (246 atg) and whose main/reheat steam temperature was 538/566 C came into operation in the form of Tokyo Power Company's Anegasaki thermal plant Unit No.1 in Subsequently, similar steam conditions were adopted for coal-fired plants, and in 1989, 2-stage reheat LNG-fired Ultra Supercritical pressure (USC) thermal power generation whose main steam pressure was 31.0 MPa (gage) (316atg) and whose ultrasupercritical-pressure/high-pressure/middle-pressure steam temperature was 566/566/566 C came into operation at CHUBU Power Company's Kawagoe thermal power plant Unit No.1. As described earlier, improvement of steam conditions has been planned steadily. However, in recent years, the growth of steam conditions has become relatively slow, and as shown in the figure, the thermal efficiency of steam power generation moves at little over 40%. Slowdown trends in rise of thermal efficiency of thermal (steam) power generation achieved a significant change through the introduction of LNG combined cycle power generation using a full-scale exhaust heat recovery system with a turbine inlet temperature (TIT) of the C-class gas turbine as a core at TOHOKU Power Company's Higashi Niigata Unit group No.3 in As shown in the figure, through the adoption of combined cycle power generation system combining the Brayton cycle (gas turbine) and the Rankine cycle (steam turbine), the thermal efficiency of the thermal power plant rose in a stroke to about 44%. TIT of gas turbines for commercial use has risen at a rate of about 20 C/year on average due to progression of cooling technology and development of heat-resistant materials. In November 1999, the advanced combined cycle power generation cycle (ACC) consisting mainly of a 1,450- C-class gas turbine begun commercial operation at TOHOKU Power Company's Higashi Niigata Unit group No.4-1, and 50% thermal efficiency, having which had been a dream for a long time in the thermal power generation sector, was attained. During this period, a number of LNG combined cycle power generation plants were introduced one after another, and attained an excellent track record of operation with high thermal efficiency, load change, etc. The installed capacity of LNG combined cycle power generation at the end of 2001 reached 22 million kw in total across the 6 Power Companies & 21 groups, coming to account for 17% of the installed capacity of all commercial-use thermal power generation. Currently, in addition, TOKYO Power Company's Futtsu thermal power plant Unit group 3 & group 4, Shinagawa thermal power plant Unit group No.1, Kawasaki thermal power plant Unit group No.1, TOHOKU Power Company's Unit group No.4-2, etc. are in the advanced stage of construction, and the thermal efficiency of ACC under construction is planned to be 50 to 53%. On the other hand, with respect to coal-fired thermal power, improvement in the steam condition of coal-fired USC thermal power generation continues steadily such as at CHUBU Power Company's Hekinan thermal power plant Unit No.3 (main steam pressure: 24.1 MPa (gage) (246 atg), main/reheat steam temperature: 538/593 C), Power Development Company's Matsuura thermal power plant Unit No.2, HOKURIKU Power Company's Nanao Ohta thermal power plant Unit No.2 (main steam pressure: 24.1 MPa (gage) (246 atg), main/reheat steam temperature: 593/593 C), TOHOKU Power Company's Haramachi thermal power plant Unit No.2, CHUGOKU Power Company's Misumi power plant Unit No.1 (main steam pressure: 24.5 MPa (gage) (250atg), main/reheat steam pressure: 600/600 C), Power Development Company's Tachibanawan thermal power plant Unit No. 1 & No.2 (main steam pressure: 25 Mpa (gage) (255atg), 7

8 main/reheat steam pressure: 600/610 C), which have started operation. In addition, pressurized fluidized bed combustion (PFBC) combined cycle generation plants combining expansion and steam turbines started operation at HOKKAIDO Power Company's Tomatoh Atsuma Unit No.3 in 1998, CHUGOKU Power Company's Oosaki Unit No.1-1 in 2000, and KYUSHU Power Company's Kanda Unit No.1 in Through these, the thermal efficiency of coal-fired thermal power plants reached about 43%. Gross thermal efficiency [%] HHV Chiba#2 Chiba#1 Kanda#1 Shinkokura#2 Combined cycle power generation (Gas/Steam turbine) Anesaki#1 Kashima#5 Steam power generation (Boiler/Steam turbine) Higashiniigata#3 Kawagoe#1 Himeichi#5 Kawasaki Higashiniigata#4 Yokohama #7, 8 Hitachinaka#1 Fiscal year Fig.1.3-1: Developments in thermal efficiency of thermal power generation 8

9 Table 1.3-1: Major coal-fired thermal power generation plants in Japan ( ) Era Before 1975 From 1976 to 1985 No. 1 power company Sumitomo joint electric power co., Ltd Power plant Unit Approved Manufacturer Steam conditions output Boiler Turbine Generator Niihamanishi Unit No MPa-538 C/538 C MHI MHI GE, Hitachi, Ltd. Niihamanishi Unit No MPa-538 C/538 C MHI MHI 2 Tohoku Sendai Unit No MPa-566 C/538 C 3 Kyushu Minato Unit No MPa-566 C/538 C MHI MHI 4 Tohoku Sendai Unit No MPa-566 C/538 C 5 Chugoku Mizushima Unit No MPa-538 C/538 C 6 Tohoku Sendai Unit No MPa-566 C/538 C 7 Sumitomo joint electric power co., Ltd 8 Chugoku Mizushima Unit No MPa-566 C/538 C 9 Kyushu Omura Unit No MPa-566 C/538 C MHI MHI 10 Shikoku Saijo Unit No MPa-566 C/538 C MHI 11 Chugoku Shimonoseki Unit No MPa-566 C/538 C MHI MHI 12 J-POWER Takehara Unit No MPa-566 C/538 C 13 Hokkaido Naie Unit No MPa-566 C/538 C IHI 14 J-POWER Takasago Unit No MPa-566 C/538 C MHI MHI 15 J-POWER Takasago Unit No MPa-566 C/538 C MHI MHI Operation started from Hitachi, Ltd Hitachi, Ltd. Hitachi, Ltd Hitachi, Ltd. Hitachi, Ltd Hitachi, Ltd. Hitachi, Ltd Hitachi, Ltd. Hitachi, Ltd Hitachi, Ltd. Hitachi, Ltd Hokkaido Naie Unit No MPa-566 C/538 C IHI Hitachi, Ltd. Hitachi, Ltd Shikoku Saijo Unit No MPa-566 C/538 C IHI Hitachi, Ltd. Hitachi, Ltd Jyoban Joint Power Co. Tobata Co-operative Thermal Power Company, Inc. Nakoso Unit No MPa-566 C/538 C MHI Hitachi, Ltd. Hitachi, Ltd Tobata Cooperative Thermal Power Company, Inc. Unit No MPa-566 C/538 C MHI MHI Toyama Kyodo Toyamashinko Unit No MPa-566 C/538 C Hitachi, Ltd. Hitachi, Ltd Toyama Kyodo Toyamashinko Unit No MPa-566 C/538 C Hitachi, Ltd. Hitachi, Ltd Sumitomo joint electric Mibugawa Unit No MPa-566 C/538 C MHI MHI power co., Ltd Hokkaido Sagawa Unit No MPa-538 C/538 C MHI Fuji Fuji Sakata kyodo power company, Ltd. Sakata kyodo power company, Ltd. 26 Hokkaido Sakata kyodo power company, Ltd. Sakata kyodo power company, Ltd. Tomatoh Atsuma Unit No MPa-566 C/538 C MHI Unit No MPa-566 C/538 C MHI Hitachi, Ltd. Hitachi, Ltd Unit No MPa-566 C/538 C J-POWER Matsushima Unit No MPa-538 C/538 C MHI Hitachi, Ltd. Hitachi, Ltd J-POWER Matsushima Unit No MPa-538 C/538 C MHI Hokkaido Sagawa Unit No MPa-538 C/538 C KHI Fuji Fuji J-POWER Takehara Unit No MPa-538 C/538 C Jyoban Joint Power Co. Jyoban Joint Power Co. 33 Hokkaido Hitachi, Ltd. Hitachi, Ltd Nakoso Unit No MPa-538 C/566 C MHI Hitachi, Ltd. Hitachi, Ltd Nakoso Unit No MPa-538 C/566 C IHI Tomatoh Atsuma Unit No MPa-538 C/566 C IHI Hitachi, Ltd. Hitachi, Ltd

10 Table 1.3-2: Major coal-fired thermal power generation plants in Japan ( ) Era From 1986 to 1995 From 1996 to 2005 No. power company Power plant Unit Approved output Steam conditions 34 Chugoku Shinonoda Unit No MPa-538 C/566 C IHI Manufacturer Boiler Turbine Generator Operation started from J-POWER Ishikawa Unit No MPa-566 C/566 C KHI Fuji Fuji Chugoku Shinonoda Unit No MPa-538 C/566 C IHI J-POWER Ishikawa Unit No MPa-566 C/566 C KHI Fuji Fuji Kyushu Matsuura Unit No MPa-538 C/566 C MHI Hitachi, Ltd. Hitachi, Ltd J-POWER Matsuura Unit No MPa-538 C/566 C 40 Chubu Hekinan Unit No MPa-538 C/566 C MHI 41 Hokuriku Tsuruga Unit No MPa-566 C/566 C MHI 42 Chubu Hekinan Unit No MPa-538 C/566 C MHI 43 Chubu Hekinan Unit No MPa-538 C/593 C IHI MHI 44 Tohoku Noshiro Unit No MPa-538 C/566 C Hitachi, Ltd. Hitachi, Ltd Fuji Fuji Okinawa Gushikawa Unit No MPa-566 C/538 C KHI Hitachi, Ltd. Hitachi, Ltd Soma Kyodo Shinchi Unit No MPa-538 C/566 C Hitachi, Ltd. Hitachi, Ltd Tohoku Noshiro Unit No MPa-566 C/593 C IHI Hokuriku Nanao Ohta Unit No MPa-566 C/593 C MHI Okinawa Gushikawa Unit No MPa-566 C/538 C MHI J-POWER Takehara Unit No MPa-566 C/538 C Hitachi, Ltd. Hitachi, Ltd Soma Kyodo Shinchi Unit No MPa-538 C/566 C MHI Kyushu Reihoku Unit No MPa-566 C/566 C IHI J-POWER Matsuura Unit No MPa-593 C/593 C MHI Tohoku Haramachi Unit No MPa-566 C/593 C MHI Hokkaido Tomatoh Unit No MPa-566 C/538 C MHI MHI Atsuma Chugoku Misumi Unit No MPa-600 C/600 C MHI MHI Hokuriku Nanao Ohta Unit No MPa-593 C/593 C IHI Tohoku Haramachi Unit No MPa-600 C/600 C Hitachi, Ltd. Hitachi, Ltd Shikoku Tachibana wan Unit No MPa-566 C/593 C J-POWER Tachibana wan Unit No MPa-600 C/610 C IHI GE , GE 61 Hokuriku Tsuruga Unit No MPa-593 C/593 C MHI J-POWER Tachibana wan Unit No MPa-600 C/610 C MHI Chugoku Osaki Unit No MPa-566 C/593 C Hitachi, Ltd. Hitachi, Ltd New Unit GT: ALSTOM 64 Kyushu Kanda MPa-566 C/593 C IHI No.1 ST: TOSHIBA 65 Chubu Hekinan Unit No MPa-566 C/593 C IHI Okinawa Kin Unit No MPa-566 C/566 C MHI Hitachi, Ltd. Hitachi, Ltd J-POWER Isogo Unit No MPa-600 C/610 C IHI 68 Hokkaido Tomatoh Atsuma Fuji SIEMENS Fuji Unit No MPa-600 C/600 C IHI Hitachi, Ltd. Hitachi, Ltd Chubu Hekinan Unit No MPa-566 C/593 C IHI Okinawa Kin Unit No MPa-566 C/566 C MHI Hitachi, Ltd. Hitachi, Ltd Kyushu Reihoku Unit No MPa-593 C/593 C MHI 72 Tokyo Hitachinaka Unit No MPa-600 C/600 C 73 Tokyo Hirono Unit No MPa-600 C/600 C MHI MHI 74 Kansai Maizuru Unit No MPa-595 C/595 C MHI MHI Hitachi, Ltd. Hitachi, Ltd

11 Technical development, in general, aims at higher efficiency of power generation for the purpose of reducing the environmental load and CO2 emission; however, concrete issues include the following: (1) High-temperature gas turbine aiming at further improvement of thermal efficiency of combined cycle power generation (2) Making coal utilization technology starting with coal gasification combined cycle power generation system more sophisticated Thermal power plants consist of a boiler, turbine, and generator, and the efficiency of power generation was increased through the larger capacity of the configuration of the basic equipment and sophistication of running conditions (mainly higher temperature and pressure of the stem cycle system). Gross thermal efficiency was increased from about 30% 40 years ago to 40% currently. This 40% was achieved by the ultra-supercritical pressure power generation system. For the purpose of increasing the efficiency further, the development of combined cycle power generation technology is in progress. Through this development, we can aim at 50% efficiency. This technology aims, in addition to the conventional steam cycle, to combine the gas turbine cycle to improve the efficiency of power generation comprehensively through power generation from both cycles. Combined cycle power generation using natural gas is becoming mainstream in new thermal power generation technology as combined cycle power generation. Further, the development of a ceramic turbine blade is in progress to improve the efficiency by causing higher temperature. With respect to the use of coal related to the reduction of CO2 emission, although the pulverized coal combustion system has been adopted in recent years for the purpose of improving efficiency, the integrated coal gratification combined cycle (IGCC) is the target of development to improve efficiency further. The fluidized bed generation system is a generation system that uses fluidized bed combustion. The commercialization of fluidized bed combustion was propelled as a combustion system of flame-resistant materials. However, in recent years, the excellent environmental characteristics of fluidized bed combustion, such as desulfurization in furnace and low NOx combustion, are receiving attention. From the viewpoint of improving efficiency, the development and commercialization of the pressurized fluidized bed combined cycle generation system (PFBC) are in progress. In light of its intrinsic characteristics, it is also considered that it will pave the way for mixed fuel power generation with coal and biomass (especially waste). 11