JP5526219B2 - Thermal power generation system and operation method thereof, thermal power generation system modification method, steam turbine equipment used in thermal power generation system, carbon dioxide separation and recovery device, overheat reducer - Google Patents

Description

  The present invention relates to a fossil fuel-fired thermal power generation system including a carbon dioxide separation and recovery device.

As a fossil fuel-fired thermal power generation system equipped with a carbon dioxide separation and recovery device according to the present invention, a device (PCC: Post Combustion CO ₂ Capture) that separates and recovers carbon dioxide from fossil fuel, for example, exhaust gas from a coal fired boiler. There is a system with.

  Generally, in a carbon dioxide recovery device that recovers carbon dioxide from boiler exhaust gas, the absorption liquid is circulated between the absorption tower and the regeneration tower by driving the absorption liquid circulation pump, and is contained in the boiler exhaust gas in the absorption tower. The absorbed carbon dioxide is absorbed in the absorption liquid, and the carbon dioxide absorbed in the absorption liquid is separated and recovered by the regeneration tower.

  That is, the carbon dioxide component in the boiler exhaust gas is brought into contact with the absorption liquid in the absorption tower, and the absorption liquid at about 40 ° C. absorbs carbon dioxide through a chemical reaction (exothermic reaction) with the carbon dioxide in the gas.

  At this time, the rich absorption liquid rich in carbon dioxide of about 70 ° C. by the chemical reaction between the absorption liquid and carbon dioxide exits the absorption tower, and is then regenerated about 120 ° C. absorption liquid supplied from the regeneration tower ( This is called lean absorption liquid) and heated to about 100 ° C., and the rich absorption liquid after the heat exchange is further heated to about 120 ° C. to 130 ° C. in the regeneration tower and absorbed into the rich absorption liquid. Separate carbon dioxide. The absorption liquid from which carbon dioxide has been separated in the regeneration tower becomes a lean absorption liquid and is again introduced into the absorption tower to absorb the carbon dioxide in the boiler exhaust gas.

  At this time, in order to heat the absorption liquid in the regeneration tower so as to separate carbon dioxide into a lean absorption liquid, the reboiler that supplies the heating steam to the regeneration tower needs to generate a large amount of heating steam.

  Therefore, Japanese Patent No. 4274646 discloses a fossil fuel-fired thermal power generation system equipped with a carbon dioxide separation and recovery device for generating a steam turbine having a high-pressure turbine, an intermediate-pressure turbine, and a low-pressure turbine, and steam for driving them. Boiler, a carbon dioxide absorption tower having a carbon dioxide absorption liquid for absorbing and removing carbon dioxide from the combustion exhaust gas of the boiler, and a regeneration tower for regenerating the carbon dioxide absorption liquid that has absorbed carbon dioxide are removed. A compressor for compressing the carbon dioxide, a compressor turbine driven by a part of the exhaust steam of the high pressure turbine, an auxiliary turbine driven by a part of the exhaust steam of the intermediate pressure turbine, a compressor turbine, A supply pipe for supplying the exhaust steam of the auxiliary turbine to the reboiler of the regeneration tower as a heating source; System having is disclosed.

Japanese Patent No. 4274646

  In the above prior art, in order to compensate for the decrease in turbine efficiency by using the exhaust steam of the intermediate pressure turbine for use as a reboiler heating source, excess energy of the exhaust steam is introduced into the back pressure turbine. It is recovered as power.

  However, when the reboiler stops for an emergency for some reason, it is necessary to install a check valve or stop valve in the air supply system to the reboiler in order to prevent the turbine from accelerating due to the backflow steam from the reboiler. Further, considering the pressure loss of the air supply pipe and the flow meter, the exhaust pressure of the back pressure turbine becomes high, and the amount of power recovery in the back pressure turbine decreases, so that the efficiency improvement is limited.

  In view of this, the present invention provides a carbon dioxide separation that can improve the efficiency including the boiler by recovering more excess superheat energy of the extracted steam sent from the steam turbine to the reboiler and collecting it in the water supply system of the steam turbine. It aims at providing the thermal power generation system provided with the collection | recovery apparatus.

  To achieve the above object, a boiler, a steam turbine driven by steam generated by the boiler, a condenser that cools and condenses the steam that drives the steam turbine, and water that is condensed by the condenser is supplied to the boiler. In a thermal power generation system equipped with a water supply system to be sent to a boiler and a carbon dioxide separation and recovery device for separating carbon dioxide from boiler exhaust gas generated in the boiler, the steam is extracted from the steam turbine and sent to the reboiler of the carbon dioxide separation and recovery device Heat exchange between the extracted steam and the feed water sent from the condenser to the boiler.

  According to the present invention, in a thermal power generation system equipped with a carbon dioxide separation and recovery device, more excess superheat energy of the extracted steam sent from the steam turbine to the reboiler is recovered in the water supply system of the steam turbine, and the boiler is The efficiency improvement including it can be aimed at.

  In addition, the amount of fuel used by the boiler can be significantly reduced, the amount of exhaust gas from the boiler can be reduced, and the amount of carbon dioxide emitted from the boiler can be reduced.

It is a schematic block diagram of the steam turbine equipment side system of the thermal power generation system which concerns on a 1st Example. It is a schematic block diagram of the carbon dioxide separation and recovery apparatus side system of the thermal power generation system which concerns on a 1st Example. It is a schematic block diagram of the steam turbine equipment side system of the thermal power generation system provided with the carbon dioxide separation and recovery device concerning the 2nd example. It is a schematic block diagram of the steam turbine equipment side system of the thermal power generation system provided with the carbon dioxide separation-and-recovery apparatus which concerns on a 3rd Example.

  A thermal power generation system according to an embodiment of the present invention will be described below with reference to the drawings. In addition, the same code | symbol is attached | subjected to the equivalent component through each drawing.

  A thermal power generation system according to a first embodiment of the present invention will be described with reference to FIGS. 1 and 2. Of the thermal power generation system of this embodiment, the schematic configuration of the steam turbine equipment side system is shown in FIG. 1, and the schematic configuration of the carbon dioxide separation and recovery device side system is shown in FIG. In addition, a present Example shows the case where the steam turbine equipment 100 and the carbon dioxide separation and recovery apparatus 200 are newly installed.

  The steam turbine equipment 100 of the thermal power generation system according to the present embodiment will be described. As shown in FIG. 1, the steam turbine facility 100 includes a boiler 1 that generates fossil fuel and generates steam, and a high-pressure turbine 2 and an intermediate-pressure turbine 3 that constitute a steam turbine that is rotationally driven by the steam generated by the boiler 1. , And a low-pressure turbine 4, a generator 5 that converts the rotational force of the steam turbine into electric power, a condenser 20 that condenses and condenses the steam that has rotationally driven the steam turbine, and condensate in the condenser 20. The water supply system 101 which sends the converted water supply to the boiler 1 is provided.

  The boiler 1 heats feed water supplied from the condenser 20 with heat obtained by burning fossil fuel, and generates high-temperature and high-pressure steam. The steam generated in the boiler 1 is sent to the high-pressure turbine 2, and power is generated in the high-pressure turbine 2 to reduce the pressure. The steam that has driven the high-pressure turbine 2 is returned again to the boiler 1 and is heated again by the boiler 1 to become high-temperature reheated steam. The reheated steam heated again by the boiler 1 is sent from the boiler 1 to the intermediate pressure turbine 3, and the intermediate pressure turbine 3 generates power to reduce the pressure. The steam that has driven the intermediate-pressure turbine 3 flows down the crossover pipe 48 and is sent to the low-pressure turbine 4. The low-pressure turbine 4 generates power and is further depressurized. The steam that has driven the low-pressure turbine 4 is sent to the condenser 20, where it is cooled, condensed, and condensed. The condensate condensated by the condenser 20 flows down the water supply system 101 as water supply, and is supplied to the boiler 1 again.

  The high-pressure turbine 2, the intermediate-pressure turbine 3, the low-pressure turbine 4, and the generator 5 are connected via a turbine rotor, and the power of the turbine is taken out as electric power by the generator 5.

  The water supply system 101 is a condenser pump 21, a ground condenser 22, a first low-pressure feed water heater 24, a second low-pressure feed water heater 25, and a third low-pressure feed water heater in this order from the condenser 20 toward the boiler 1. 26, a fourth low-pressure feed water heater 27, a deaerator 8, a boiler feed pump inlet booster pump 9, a boiler feed pump 10, and a high-pressure feed water heater 11.

  The first low pressure feed water heater 24, the second low pressure feed water heater 25, the third low pressure feed water heater 26, and the fourth low pressure feed water heater 27 are respectively connected to the first extraction pipe 44 and the second extraction pipe from the low pressure turbine 4. 43, extraction steam is sent as a heating source through the third extraction pipe 42 and the fourth extraction pipe 41.

  The feed water condensed by the condenser 20 is sent to the condensate pump 21 to be boosted and sent to the ground condenser 22. The feed water that has passed through the ground condenser 22 flows down the first low-pressure feed water heater 24, the second low-pressure feed water heater 25, the third low-pressure feed water heater 26, and the fourth low-pressure feed water heater 27 sequentially. Heat is exchanged with extracted steam in each feed water heater.

  The drain of the second low-pressure feed water heater 25 flows down the second low-pressure feed water heater drain pipe 35 and is sent to the first low-pressure feed water heater 24. The drain of the first low-pressure feed water heater 24 flows down the first low-pressure feed water heater drain pipe 36 and is collected in the condenser 20. On the other hand, the drain of the fourth low-pressure feed water heater 27 flows down the fourth low-pressure feed water heater drain pipe 33 and is sent to the third low-pressure feed water heater 26. The drain of the third low-pressure feed water heater 26 is sent to the third low-pressure feed water heater drain pump 37 to be pressurized, and flows down the third low-pressure feed water heater drain pipe 34 to constitute the feed water system 101. It returns to the heater drain pump outlet condensate pipe 38. The third low-pressure feed water heater drain pump outlet condensate pipe 38 is a pipe connected to the third low-pressure feed water heater 26 and the fourth low-pressure feed water heater 27.

  Next, the carbon dioxide separation and recovery apparatus 200 will be described. As shown in FIG. 2, the carbon dioxide separation and recovery apparatus 200 includes an absorption tower 65 that absorbs carbon dioxide contained in boiler exhaust gas discharged from the boiler 1 of the steam turbine equipment 100 with an absorption liquid, and a carbon dioxide that is absorbed by the absorption tower 65. The regenerator 72 separates carbon dioxide from the absorbing liquid that has absorbed carbon, and the reboiler 17 that generates steam and supplies the steam to the regenerating tower 72 as a heat source for separating carbon dioxide from the absorbing liquid.

  The boiler 1 generates boiler exhaust gas containing carbon dioxide when fossil fuel is burned. The boiler exhaust gas generated in the boiler 1 flows down from the boiler 1 through the boiler exhaust pipe 60 and is sent to the boiler exhaust gas booster fan 61 where the pressure is increased. The boiler exhaust gas boosted by the boiler exhaust gas booster 61 is sent to the boiler exhaust gas cooler 62 and cooled, and then sent to the absorption tower 65.

  The boiler exhaust gas sent to the absorption tower 65 is absorbed into the absorption liquid in the absorption tower 65 and becomes a processing gas containing no carbon dioxide. The processing gas flows down from the absorption tower 65 through the absorption tower outlet boiler exhaust gas pipe 66, is sent to the chimney 67, and is discharged from the chimney 67 to the atmosphere.

  On the other hand, of the boiler exhaust gas sent from the boiler 1, the boiler exhaust gas that has not undergone the carbon dioxide separation and recovery process flows down the bypass gas pipe 64 branched from the boiler exhaust gas pipe 60 upstream of the boiler exhaust gas booster fan 61, and the absorption tower It joins the outlet boiler exhaust gas pipe 66 and is led to the chimney 67. The bypass gas pipe 64 is provided with a bypass butterfly valve 63 that controls the flow rate of the bypass gas pipe 64. By controlling the opening degree of the bypass butterfly valve 63, the flow rate of the boiler exhaust gas that bypasses the carbon dioxide separation and recovery device 200 is controlled.

  The rich absorbing liquid containing a large amount of carbon dioxide is absorbed in the boiler tower exhaust gas in the absorption tower 65 and sent to the rich absorbing liquid transfer pump 68 to be pressurized, and then the absorbing liquid heat exchanger 69. And heated to about 100 ° C. The rich absorbent heated by the absorbent heat exchanger 69 is sent to the regeneration tower 72 and further heated to about 120 ° C. to 130 ° C. in the regeneration tower 72 to separate carbon dioxide gas absorbed from the boiler exhaust gas.

  The carbon dioxide gas separated from the rich absorbent is sent from the regeneration tower 72 to the outlet gas cooler 73 and cooled. The carbon dioxide gas cooled by the outlet gas cooler 73 is sent to the reflux drum 77, and moisture contained in the gas is separated. The carbon dioxide gas from which moisture has been separated in the reflux drum 77 flows down the carbon dioxide exhaust pipe 78 and is supplied to a liquefied carbon dioxide storage facility (not shown).

  The water separated from the carbon dioxide separation / recovery device in the reflux drum 77 is sent from the reflux drum 77 to the reflux drum pump 76, pressurized, and returned to the regeneration tower 72.

  A part of the absorption liquid in the regeneration tower 72 is extracted through the regeneration tower absorption liquid extraction pipe 74 and sent to the reboiler 17. The absorption liquid sent to the reboiler 17 is heated in the reboiler 17 to become steam. The absorbing liquid that has become steam in the reboiler 17 flows down the reboiler outlet steam pipe 75 and is returned to the regeneration tower 72.

  As will be described later, extracted steam extracted from the intermediate pressure turbine 3 is supplied to the reboiler 17 as a heating source via the extracted steam supply system 102. In the reboiler 17, the absorbing liquid is heated by the supplied extracted steam to generate steam.

  The absorption liquid from which the carbon dioxide gas is separated in the regeneration tower 72 is sent from the regeneration tower 72 to the absorption liquid heat exchanger 69, and is cooled by exchanging heat with the rich absorption liquid in the absorption liquid heat exchanger 69. The absorption liquid cooled in the absorption liquid heat exchanger 69 is sent to the lean absorption liquid transfer pump 71 to be pressurized, and sent to the lean absorption liquid cooler 70. The absorption liquid sent to the lean absorption liquid cooler 70 is returned to the absorption tower 65 after being cooled. As described above, the absorption liquid is configured to circulate between the absorption tower 65 and the regeneration tower 72.

  Returning to the description of the steam turbine equipment 100. As shown in FIG. 1, the steam turbine equipment 100 according to the thermal power generation system of the present embodiment is an extraction steam supply system that supplies extracted steam extracted from the intermediate pressure turbine 3 to the reboiler 17 of the carbon dioxide separation and recovery device 200. 102.

  The extraction steam supply system 102 is connected to an extraction mechanism (not shown) provided in an intermediate stage of the intermediate pressure turbine 3 and the reboiler 17.

  The extraction steam supply system 102 performs an extraction check valve 12, an extraction steam superheat reducer inlet valve 54, and an extraction steam superheat reduction process for preventing the backflow of the extraction steam in order from the intermediate pressure turbine 3 toward the reboiler 17. The extraction steam superheat reducer 14, the extraction steam superheat reducer outlet valve 15, the reboiler heating steam inlet output control valve 16 that controls the amount and pressure of the extraction steam supplied to the reboiler 17, and the pressure of the steam supplied to the reboiler 17 are detected. A reboiler heating steam pressure detector 58 is provided.

  A part of the steam flowing down the intermediate pressure turbine 3 is extracted by the extraction mechanism provided in the intermediate stage, flows down the extraction steam supply system 102 as extraction steam, and is sent to the extraction steam superheat reducer 14. The extracted steam sent to the extracted steam superheat reducer 14 is cooled to near the saturation temperature of the pressure of the air supply system by exchanging heat with the feed water sent from the water supply system 101 in the extracted steam superheat reducer 14. .

  The extracted steam cooled and reduced in temperature in the extracted steam superheat reducer 14 passes through the reboiler heating steam inlet output control valve 16 and is sent to the reboiler 17.

  The reboiler heating steam inlet output control valve 16 is controlled to open and close based on the detection signal of the reboiler heating steam pressure detector 58 installed at the inlet of the reboiler 17. By controlling the opening and closing of the reboiler heating steam inlet output control valve 16, the pressure and steam flow rate of the extracted steam supplied to the reboiler are controlled.

  The extracted steam sent to the reboiler 17 exchanges heat with the absorbing solution sent from the regeneration tower 72 in the reboiler 17 and is cooled and drained. On the other hand, the absorbing liquid is heated to become vapor. Since the absorption liquid in the regeneration tower 72 is heated to about 120 ° C. to 130 ° C. by the amount of heat supplied to the reboiler 17, carbon dioxide is separated from the absorption liquid, and at the same time carbon dioxide is recovered, the absorption liquid is regenerated and again. Water is sent to the absorption tower 65.

  The extracted steam that has been cooled and drained by the reboiler 17 is sent to the reboiler drain pump 18 as a hot water drain to be pressurized. The hot water drain boosted by the reboiler drain pump 18 flows down the reboiler drain pump outlet water supply pipe 19 and is sent to the third low-pressure feed water heater 26. The hot water drain sent to the third low-pressure feed water heater 26 is heat-recovered by exchanging heat with the feed water, and flows down through the third low-pressure feed water heater drain pipe 34 and returned to the feed water system 101.

  The water supply system 101 includes a water supply branch system 103 that guides part of the water supply to the extraction steam superheat reducer 14, exchanges heat with the extraction steam in the extraction steam superheat reduction apparatus 14, and then returns to the deaerator 8.

  The feed water branch system 103 branches from the feed water system 101 between the fourth low-pressure feed water heater 27 and the deaerator 8 and adjusts the distribution amount of the feed water from the upstream side to the downstream side in the feed water flow direction. Condensate flow distribution valve 29, extraction steam superheat reducer inlet condensate pipe 30 connected from condensate flow distribution valve 29 to extraction steam superheat reducer 14, and extraction extracted from extraction steam heating reducer 14 to deaerator 8 A steam superheat reducer outlet condensate pipe 31.

  Further, the water supply system 101 includes an overheat reducer bypass water supply system 104 that is connected to the deaerator 8 from the condensate flow distribution valve 29 and bypasses the extracted steam superheat reducer 14 with a part of the water supply. The overheat reducer bypass water supply system 104 is configured by an extraction steam overheat reducer bypass condenser pipe 32.

  The first to fourth low-pressure feed water heaters of the feed water system 101 are sequentially flowed down and heated, and the heated feed water is divided into the extracted steam superheat reducer 14 side and the deaerator 8 side by the condensate flow rate distribution valve 29. Is done.

  The feed water distributed to the extraction steam superheat reducer 14 by the condensate flow distribution valve 29 flows down the extraction steam superheat reducer inlet condensate pipe 30 and is supplied to the extraction steam superheat reducer 14. The feed water supplied to the extraction steam superheat reducer exchanges heat with the extraction steam, recovers excess superheat energy of the extraction steam, and raises the temperature. The feed water that has recovered the superheat energy of the extracted steam by the extracted steam superheat reducer 14 flows down the extracted steam superheat reducer outlet condensate pipe 31 and is sent to the deaerator 8.

  On the other hand, the feed water distributed to the deaerator 8 side by the condensate flow distribution valve 29 flows down the extraction steam superheat reducer bypass condensate pipe 32, bypasses the extraction steam superheat reducer 14 and directly enters the deaerator 8. Sent.

  The feed water divided into the extracted steam superheat reducer 14 side and the deaerator 8 side is joined again by the deaerator 8, flows down the feed water system 101, and is sent to the boiler 1.

  On the other hand, the extraction steam supply system 102 includes an overheat reducer bypass extraction steam system 105 that branches from the extraction steam supply system 102 upstream of the extraction steam superheat reducer inlet valve 54 and is connected to the deaerator 8.

  The superheat reducer bypass extraction steam system 105 bypasses the reboiler 17 of the carbon dioxide separation / recovery device 200 and directly leads a part of the extraction steam flowing down the extraction steam supply system 102 to the water supply system 101 of the steam turbine facility.

  The extracted steam led to the deaerator 8 is used as a heating source of feed water in the deaerator. The feed water temperature at the deaerator inlet, that is, the outlet of the fourth low-pressure feed water heater is an optimum temperature for exchanging heat with the extracted steam, and guides the extracted steam to the deaerator 8.

  The carbon dioxide separation and recovery apparatus 200 adjusts the amount of carbon dioxide recovered from the boiler exhaust gas by opening and closing control of the bypass butterfly valve 63 provided in the bypass gas pipe 64. The amount of extracted steam required by the reboiler 17 also varies due to the variation in the amount of carbon dioxide recovered from the boiler exhaust gas. There may be a case where a part of the extracted steam becomes redundant in accordance with the fluctuation of the extracted steam amount required by the reboiler 17.

  In the present embodiment, surplus extracted steam is caused to flow through the superheat reducer bypass extracted steam system 105 and returned to the water supply system 101 in accordance with fluctuations in the amount of extracted steam requested by the reboiler 17.

  On the other hand, the amount of water supplied to the extraction steam superheat reducer 14 needs to be changed in accordance with the change in the extraction steam amount required by the reboiler 17.

  In the present embodiment, the water supply distribution amount to the water supply branch system 103 and the overheat reducer bypass water supply system 104 is adjusted by the condensate flow rate distribution valve 29 in accordance with the fluctuation of the amount of extracted steam required by the reboiler 17.

  According to this configuration, it is possible to operate flexibly corresponding to fluctuations in the required amount of the reboiler 17 while suppressing the influence on main components such as a turbine. Moreover, since excess extraction steam returns to the water supply system 101, the fall of thermal efficiency can be suppressed.

  Next, the function and effect of the present invention will be described.

  The steam required by the reboiler 17 of the carbon dioxide separation and recovery apparatus 200 is not superheated steam but saturated steam of about 3 atg, and its saturation temperature is 143 ° C. On the other hand, the pressure / temperature of the extracted steam extracted from the intermediate pressure turbine 3 is about 9 atg / 370 ° C. Accordingly, since the degree of superheat of the extracted steam is high and the temperature difference from the required temperature 143 ° C. of the reboiler 17 is as large as 227 ° C., if the extracted steam is supplied to the reboiler 17 as it is, the temperature of both cannot be matched.

  On the other hand, when the temperature of the extracted steam is reduced by the spray, the temperature is lowered, but the superheat energy possessed by the extracted steam is not effectively utilized.

  In this embodiment, the steam extracted from the steam turbine is cooled by heat exchange with the feed water of the steam turbine, and the cooled steam is sent to the reboiler. It is possible to return the overheated energy to the heat cycle of the steam turbine, and it is possible to suppress a decrease in efficiency due to extraction.

  In this embodiment, an extraction steam superheat reducer 14 for exchanging heat between the extraction steam of the intermediate pressure turbine 3 and the feed water before entering the deaerator 8 is provided to effectively recover the heat of the extraction steam. Yes. By means of recovering the superheated energy of the extracted steam again in the steam turbine cycle, it becomes possible to suppress the output and efficiency of the steam turbine.

  In addition, by recovering the superheated energy of the extracted steam with the feed water before supplying the boiler, the feed water temperature rises, so that the boiler fuel can be reduced and the efficiency including the boiler can be improved.

  According to the system configuration of the present embodiment, the steam turbine efficiency is improved by 2% to 3% (absolute value) as compared with a system in which the back pressure turbine is driven by extracted steam and the power is recovered and then supplied to the reboiler. There is an example. Due to this effect, the amount of fuel used by the boiler is greatly reduced, the amount of exhaust gas from the boiler is reduced, and the effect of reducing not only the economic effect but also the amount of carbon dioxide emitted from the boiler can be obtained.

  In the present embodiment, the steam itself supplied to the reboiler may be superheated steam of 3 atg or more. Therefore, it is not always necessary to extract air from the intermediate pressure turbine if the pressure and temperature conditions are satisfied.

  However, the turbine has a characteristic that when the partial load operation is performed, the extraction pressure of all the turbines is substantially proportionally decreased. Therefore, when the turbine is operated at a partial load, if the air is extracted from the low-pressure turbine, a required pressure of about 3 atg or more required by the reboiler cannot be secured. Therefore, even if the turbine is partially loaded, in order to ensure the minimum extraction pressure of about 3 atg or more required by the reboiler, the extraction is performed from the intermediate pressure turbine exhaust section where the extraction pressure is higher than that of the low pressure turbine. Note that when the air is extracted from the high-pressure turbine, it is too higher than the required pressure, so that the throttle pressure reduction width of the extracted steam pressure increases and the turbine efficiency is lowered.

  Therefore, it is desirable to extract from the intermediate pressure turbine in order to secure the minimum extraction pressure even during the partial load operation and suppress the decrease in turbine efficiency.

A second embodiment of the present invention will be described with reference to FIG. FIG. 3 is a schematic configuration diagram of the steam turbine equipment side system of the thermal power generation system according to the second embodiment of the present invention. In addition, the same code | symbol is attached | subjected to the component equivalent to a 1st Example, and description is abbreviate | omitted. Also, the carbon dioxide separation and recovery device is the same as that of the first embodiment, and the description thereof is omitted.

  This embodiment differs from the embodiment shown in FIG. 1 in that the extraction steam supply system 102 is downstream of the superheat reducer bypass extraction steam system 105 and upstream of the extraction steam superheat reducer inlet valve 54. On the side, an extraction steam escape system 106 branched from the extraction steam supply system 102 and connected to the condenser 20 is provided.

  The extraction steam relief system 106 has an emergency pressure relief extraction pressure detector 57, an emergency pressure relief stop valve 52, and an emergency pressure relief adjustment valve 55 from the upstream side toward the downstream side where the condenser 20 is located. .

  When the carbon dioxide separation and recovery device 200 is urgently stopped for some reason, the reboiler heating steam inlet output control valve 16 that controls the amount and pressure of the extracted steam supplied to the reboiler 17 is closed, and the air supply from the intermediate pressure turbine 3 to the reboiler 17 is performed. And the extraction steam superheat reducer inlet valve 54 and the extraction steam superheat reducer outlet valve 15 are closed to isolate the extraction steam superheat reducer 14 from the extraction steam supply system 102. Along with the stoppage of the air supply, an operation is performed to switch the amount of water supply passing through the main valve to the entire amount superheat reducer bypass water supply system 104 side through the extraction steam superheat reducer bypass condensate pipe 32 using the condensate flow distribution valve 29.

  In addition, the bleed steam surplus due to the stop of the air supply to the reboiler 17 is operated by opening the emergency pressure relief valve 52 and adjusting the opening of the emergency pressure relief regulating valve 55 to adjust the pressure. To the condenser 20.

  The abnormal pressure rise of the extracted steam is detected by the emergency pressure relief extraction pressure detector 57, and the emergency pressure relief regulating valve 55 is opened.

  According to the present embodiment, the same effects as those of the first embodiment can be obtained, and the reliability of the thermal power generation system can be improved. That is, when the carbon dioxide separation / recovery device 200 is urgently stopped for some reason, it is possible to prevent unnecessary inflow of condensate to the extracted steam superheat reducer 14 as soon as possible. Further, by stopping the supply of air to the reboiler 17, surplus extracted steam is released to the condenser 20 via the extracted steam escape system 106, thereby preventing a rapid increase in the flow rate of the inflow steam to the low-pressure turbine 4, A rapid load increase of the low-pressure turbine 4 can be suppressed, and the reliability of the system can be improved.

  A third embodiment of the present invention will be described with reference to FIG. FIG. 4 is a schematic configuration diagram of the steam turbine equipment side system of the thermal power generation system according to the third embodiment of the present invention. In addition, the same code | symbol is attached | subjected to the component equivalent to 1st and 2nd Example, and description is abbreviate | omitted. Also, the carbon dioxide separation and recovery device is the same as that of the first embodiment, and the description thereof is omitted.

  The present embodiment shows a case where a carbon dioxide separation and recovery device is newly installed in the existing steam turbine equipment.

  When the carbon dioxide separation and recovery device 200 is additionally installed in the existing steam turbine equipment 100, the extraction steam supply system 102, the feed water branch system 103, the overheat reducer bypass feed water system 104, and the overheat reducer bypass extraction steam system 105 are combined. To be added. A bleed steam escape system 106 may also be installed.

  An extraction steam superheat reducer 14 is provided in the extraction steam supply system 102 for exchanging heat between the extraction steam supplied to the reboiler 17 and the feed water supplied to the boiler 1.

  In addition, the extraction steam supply system 102 is additionally installed, and the extraction steam cooled and drained by the reboiler 17 is recovered by the third low-pressure feed water heater 26, so that the reboiler drain pump outlet water supply pipe 19 is additionally installed. A reboiler drain pump 18 is installed in the reboiler drain pump outlet water supply pipe 19.

  Further, if necessary, the third low-pressure feed water heater 26 and the third low-pressure feed water heater drain pump 37 are replaced to increase the capacity in order to collect the drained extracted steam.

  In the feed water system 101, the pipe between the fourth low-pressure feed water heater 27 and the deaerator 8 is replaced with a third low-pressure feed water heater outlet condensate pipe 28 and a condensate flow distribution valve 29, and the feed water branch system 103, An overheat reducer bypass water supply system 104 is additionally installed.

  As necessary, the deaerator 8 is connected to the feed water branch system 103, the overheat reducer bypass feed water system 104, and the overheat reducer bypass bleed steam system 105, so that the capacity is increased by replacement.

  Moreover, when installing the extraction steam escape system | strain 106, the condenser 20 is replaced and the capacity | capacitance is increased as needed. Alternatively, if a simple heat exchanger 79 is installed in the extraction steam escape system 106 and a part of the water supply of the water supply system 101 is used as a cold heat source, the condenser 20 is not required to be replaced, and the modification cost can be reduced.

  Further, in the present embodiment, unlike the embodiment shown in FIG. 1 or FIG. 3, an existing modified intermediate pressure turbine exhaust pressure regulating valve 40 and a crossover pipe pressure detector 59 are additionally provided in the crossover pipe 45. There is a feature in the point.

  In the case where a carbon dioxide recovery device is provided in the existing steam turbine equipment and the extraction steam of the intermediate pressure turbine is supplied to the reboiler, securing the steam supply pressure from the intermediate pressure turbine to the reboiler 17 becomes a problem.

  Therefore, the detected value of the crossover pipe pressure detector 59 is set so that the pressure of the exhaust section of the intermediate pressure turbine 3 when the carbon dioxide recovery device is not installed and the pressure of the exhaust section of the intermediate pressure turbine 3 after installation are the same pressure. Based on the above, the intermediate pressure turbine exhaust pressure regulating valve 40 is throttled through a control device (not shown).

  Control is performed to increase the pressure on the upstream side of the intermediate pressure turbine exhaust pressure adjustment valve to reduce the amount of steam to the low pressure turbine 4 and prevent an excessive decrease in the exhaust pressure of the existing intermediate pressure turbine.

  According to the present embodiment, even when a carbon dioxide separation and recovery device is newly installed in the existing steam turbine equipment, the same effect as in the first embodiment can be obtained. In addition, when a carbon dioxide separation and recovery device is newly installed and the supply steam is extracted for the newly installed reboiler, the exhaust pressure of the existing medium pressure turbine is prevented from being significantly reduced, and the extraction steam to the extraction steam supply system 102 is extracted. The pressure required for steam supply can be secured.

DESCRIPTION OF SYMBOLS 1 Boiler 2 High pressure turbine 3 Medium pressure turbine 4 Low pressure turbine 5 Generator 8 Deaerator 9 Boiler feed pump inlet booster pump 10 Boiler feed pump 11 High pressure feed heater 12 Extraction check valve 13 Extraction steam superheat reducer inlet pipe 14 Extraction Steam superheat reducer 15 Extraction steam superheat reducer outlet valve 16 Reboiler heating steam inlet output control valve 17 Reboiler 18 Reboiler drain pump 19 Reboiler drain pump outlet water pipe 20 Condenser 21 Condensate pump 22 Ground condenser 23 Low pressure first Feed water heater inlet condensate pipe 24 First low pressure feed water heater 25 Second low pressure feed water heater 26 Third low pressure feed water heater 27 Fourth low pressure feed water heater 28 Third low pressure feed water heater outlet condensate pipe 29 Condensate flow distribution valve 30 Extraction steam superheat reducer inlet condensate pipe 31 Extraction steam superheat reducer outlet condensate pipe 32 Extraction steam superheat reducer bypass condensate pipe 3 Fourth low pressure feed water heater drain pipe 34 Third low pressure feed water heater drain pipe 35 Second low pressure feed water heater drain pipe 36 First low pressure feed water heater drain pipe 37 Third low pressure feed water heater drain pump 38 Third low pressure feed water heating Drain pump outlet condensate pipe 40 Medium pressure turbine exhaust pressure adjustment valve 41 Fourth bleed pipe 42 Third bleed pipe 43 Second bleed pipe 44 First bleed pipe 48 Crossover pipe 51 Emergency pressure relief pipe 52 Emergency pressure relief Valve 53 Extraction branch second piping 54 Extraction steam overheat reducer inlet valve 55 Emergency pressure relief adjustment valve 56 Emergency pressure relief condenser inlet pipe 57 Emergency pressure relief extraction pressure detector 58 Reboiler heating steam pressure detector 59 Crossover pipe pressure detector 60 Boiler exhaust gas pipe 61 Boiler exhaust gas booster fan 62 Boiler exhaust gas cooler 63 Bypass butterfly valve 64 Bypass gas Suction pipe 65 Absorption tower 66 Absorption tower outlet boiler exhaust gas pipe 67 Chimney 68 Rich absorption liquid transfer pump 69 Absorption liquid heat exchanger 70 Lean absorption liquid cooler 71 Lean absorption liquid transfer pump 72 Regeneration tower 73 Outlet gas cooler 74 Inside regeneration tower Absorption liquid extraction pipe 75 Reboiler outlet steam pipe 76 Reflux drum pump 77 Reflux drum 78 Carbon dioxide exhaust pipe 100 Steam turbine equipment 101 Water supply system 102 Extraction steam supply system 103 Supply water branch system 104 Superheat reducer Bypass water supply system 105 Superheat reduction Bypass extraction steam system 106 Extraction steam escape system 200 Carbon dioxide separation and recovery device

Claims (15)

A boiler, a steam turbine driven by steam generated by the boiler, a condenser that cools and condenses the steam that drives the steam turbine, and feed water that feeds the water condensed by the condenser to the boiler A system, a carbon dioxide separation and recovery device for separating carbon dioxide from boiler exhaust gas generated in the boiler, and an extraction steam supply for supplying extracted steam extracted from the steam turbine to a reboiler of the carbon dioxide separation and recovery device In a thermal power generation system equipped with a system,
An overheat reducer that is provided in the extraction steam supply system and that exchanges heat between the extraction steam supplied to the reboiler and the feed water supplied to the boiler ;
The water supply system includes a water supply branch system that guides the water supply to the superheat reducer, returns the water supply heat-exchanged with the extracted steam by the superheat reducer to the water supply system, and bypasses the water supply to the superheat reducer. A first valve that adjusts the distribution amount of the feed water that flows down to the superheat reducer bypass feed water system that is sent to the boiler, and the feed water branch system and the superheat reducer bypass feed water system,
The extraction steam supply system is a superheat reducer bypass extraction steam system that bypasses the superheat reducer and extracts the extracted steam flowing down the extraction steam supply system to the water supply system, the superheat reducer, and the superheater. A thermal power generation system comprising: a second valve that adjusts a distribution amount of extracted steam to be supplied to the reducer bypass extracted steam system. The extraction steam supply system is
An extraction steam escape system that leads the extraction steam to the condenser on the upstream side of the second valve and on the downstream side of the superheat reducer bypass extraction steam system;
The extraction steam escape system includes a third valve that adjusts the amount of extraction steam that flows down the extraction steam escape system, and a fourth valve that adjusts the pressure of the extraction steam that flows down the extraction steam escape system. The thermal power generation system according to claim 1. The thermal power generation system according to claim 1, wherein the steam extracted from the steam turbine is at least 3 atg and superheated steam. The thermal power generation system according to claim 1, wherein the steam turbine for extracting the extracted steam is an intermediate pressure turbine. A boiler, a steam turbine driven by steam generated by the boiler, a condenser that cools and condenses the steam that drives the steam turbine, and feed water that feeds the water condensed by the condenser to the boiler A steam turbine facility for supplying extracted steam extracted from the steam turbine to a reboiler of a carbon dioxide separation and recovery device that separates carbon dioxide from boiler exhaust gas generated in the boiler,
The water supply system to intake the water was water, the water supply to the heated said extraction steam and by heat exchange with desuperheater over-heat reducer said extraction steam being air to said reboiler shall be the heat source With
The water supply system includes a superheat reducer bypass water supply system that bypasses the superheat reducer and sends the water to the boiler, a water supply amount that is supplied to the superheat reducer, and a water supply that flows down to the superheat reducer bypass water supply system A steam turbine facility comprising: a first valve that adjusts the amount; and a heat exchanger that cools the extracted steam bypassing the superheat reducer with the feed water and condenses the steam. 6. The steam turbine equipment according to claim 5, wherein the condenser takes in the extracted steam bypassing the overheat reducer and the reboiler, and condenses and returns the extracted steam to the water supply system. The steam turbine equipment according to claim 5, wherein the steam extracted from the steam turbine is at least 3 atg and superheated steam. The steam turbine equipment according to claim 5, wherein the steam turbine for extracting the extracted steam is an intermediate pressure turbine. An absorption tower that absorbs carbon dioxide contained in boiler exhaust gas discharged from a boiler of a steam turbine facility with an absorption liquid; a regeneration tower that separates the carbon dioxide from the absorption liquid that has absorbed the carbon dioxide in the absorption tower; A carbon dioxide separation and recovery device for steam turbine equipment, comprising a reboiler that generates steam and supplies the steam to the regeneration tower as a heat source for separating the carbon dioxide from the absorbing liquid,
The reboiler using the extracted steam extracted from the turbine constituting the steam turbine equipment as a heat source,
The extraction steam supplied to the reboiler is subjected to an overheat reduction process by exchanging heat with water supplied to the boiler from a condenser constituting the steam turbine equipment,
An extraction steam supply system for supplying extracted steam extracted from the turbine to the reboiler; and a heat exchange between the extraction steam and the feed water provided in the extraction steam supply system and supplied to the reboiler. An overheat reducer that performs overheat reduction processing;
A superheat reducer bypass bleed steam system that bypasses the superheat reducer and sends the extracted steam flowing down the bleed steam supply system to the water supply system of the steam turbine facility;
A water supply branch system that branches from the water supply system, guides the water supply to the overheat reducer, and returns the water supply heat exchanged with the extraction steam in the overheat reducer to the water supply system;
A first valve that is provided in the water supply system or the water supply branch system, adjusts the amount of water supplied to the boiler by bypassing the overheat reducer, and the distribution amount of the water supply to flow down the water supply branch system;
A carbon dioxide separation and recovery device for steam turbine equipment, comprising: a second valve that adjusts a distribution amount of extracted steam to be supplied to the superheat reducer and the superheat reducer bypass extracted steam system. The extraction steam supply system includes an extraction steam escape system that guides the extraction steam to the condenser upstream of the second valve and downstream of the superheat reducer bypass extraction steam system. The extraction steam escape system includes a third valve that adjusts the amount of extraction steam that flows down the extraction steam escape system, and a fourth valve that adjusts the pressure of the extraction steam that flows down the extraction steam escape system. The carbon dioxide separation and recovery device for a steam turbine facility according to claim 9. The steam extracted from the turbine is 3 atg or more and superheated steam, and the carbon dioxide separation and recovery device for steam turbine equipment according to claim 9. The carbon dioxide separation and recovery device for steam turbine equipment according to claim 9, wherein the turbine for extracting the extracted steam is an intermediate pressure turbine. A boiler, a steam turbine driven by steam generated by the boiler, a condenser that cools and condenses the steam that drives the steam turbine, and feed water that feeds the water condensed by the condenser to the boiler A thermal power generation system comprising a grid,
An absorption tower that absorbs carbon dioxide contained in boiler exhaust gas discharged from the boiler with an absorption liquid, a regeneration tower that separates the carbon dioxide from the absorption liquid that has absorbed the carbon dioxide in the absorption tower, and generates steam A carbon dioxide separation and recovery device comprising a reboiler for supplying the steam to the regeneration tower as a heat source for separating the carbon dioxide from the absorption liquid;
An extraction steam supply system for supplying extracted steam extracted from an intermediate pressure turbine constituting the steam turbine to a reboiler of the carbon dioxide separation and recovery device;
A pressure control valve for adjusting the pressure of the extracted steam flowing through the extracted steam supply system, provided in a crossover pipe for supplying the steam discharged from the intermediate pressure turbine to the low pressure turbine constituting the steam turbine; Thermal power generation system characterized by A boiler, a steam turbine driven by steam generated by the boiler, a condenser that cools and condenses the steam that drives the steam turbine, and feed water that feeds the water condensed by the condenser to the boiler A method for remodeling a thermal power generation system comprising a grid,
An absorption tower that absorbs carbon dioxide contained in boiler exhaust gas discharged from the boiler with an absorption liquid, a regeneration tower that separates the carbon dioxide from the absorption liquid that has absorbed the carbon dioxide in the absorption tower, and generates steam A carbon dioxide separation and recovery device comprising a reboiler for supplying the steam to the regeneration tower as a heat source for separating the carbon dioxide from the absorption liquid;
The extraction steam extracted from the medium pressure turbine constituting the steam turbine is additionally installed with an extraction steam supply system for supplying the reboiler of the carbon dioxide separation and recovery device,
An overheat reducer for exchanging heat between the extracted steam sent to the reboiler and the feed water sent to the boiler is provided in the extracted steam supply system,
A pressure control valve for adjusting a main steam pressure is provided in a crossover pipe for sending main steam discharged from the intermediate pressure turbine to a low pressure turbine constituting the steam turbine;
A feed water branch system for guiding the feed water to the overheat reducer and returning the feed water heat-exchanged with the extracted steam by the overheat reducer to the feed water system; and bypassing the overheat reducer for the feed water. A superheat reducer bypass feed water system to be sent to the boiler, and a first valve for adjusting a distribution amount of feed water flowing down to the feed water branch system and the overheat reducer bypass feed water system,
The superheat reducer bypass bleed steam system, the superheat reducer bypassing the superheat reducer, the superheat reducer bypassing the superheat reducer, and the superheat reducer and the superheat reduction. remodeling process of thermal power system that is characterized in that additionally provided a second valve for adjusting the amount of distribution of extraction steam to air in the vessel bypass extraction steam line. In the extraction steam supply system,
An extraction steam escape system for guiding the extraction steam to the condenser is additionally installed on the upstream side of the second valve and on the downstream side of the superheat reducer bypass extraction steam system;
A third valve for adjusting the amount of extraction steam flowing down the extraction steam escape system and a fourth valve for adjusting the pressure of extraction steam flowing down the extraction steam escape system are provided in the extraction steam escape system. The method for remodeling a thermal power generation system according to claim 14.

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