JP2012189008A - Thermal power generating plant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermal power generation system including an auxiliary steam system that collects solar heat to generate steam and uses the steam as an auxiliary steam for the thermal power plant in order to suppress the decrease of output or efficiency of a steam turbine.SOLUTION: The thermal power generating plant includes: a primary boiler 1 for generating the steam by burning a fossil fuel; a steam turbine driven by the steam generated by the boiler 1; a steam condenser 5 for condensing the steam that drives the steam turbine; a water supply system for supplying the condensed water discharged from the steam condenser 5 to the primary boiler 1; a steam turbine facility having an auxiliary device that is driven by the steam extracted from the steam turbine; and a solar heat concentrator for heating a heat medium using the solar heat. An auxiliary steam is generated by heating some supplied water extracted from the water supply system using the solar heat concentrator and the auxiliary steam is supplied to the auxiliary device as steam used for driving.

Description

  The present invention relates to a thermal power plant, and more particularly to a thermal power plant having a boiler, a steam turbine, and a solar heat collector.

  Generally, a thermal power plant has, as main components, a fossil fuel such as coal to heat feed water and generate steam, a steam turbine driven by steam generated by the main boiler, and a steam turbine Steam having a condenser that condenses the steam that has driven the steam, a water supply system that supplies the condensate condensed by the condenser as feed water to the main boiler, and a generator that generates electric power using power extracted from the steam turbine Turbine equipment is provided.

  Moreover, in the conventional steam turbine equipment described above, a feed water heater for heating the feed water is provided in the feed water system, the extracted steam extracted from the steam turbine is guided to the feed water heater, and the feed water is heated with the extracted steam.

  Furthermore, a thermal power plant in which a solar heat collecting device is provided in addition to steam turbine equipment has been proposed (see Patent Document 1). This thermal power plant has a solar heat collecting device attached to a feed water heater of a steam turbine facility. In other words, the solar heat collection device heats the heat medium with solar heat, and heat exchange of the heated heat medium with a part of the feed water supplied to the main boiler makes it possible to incorporate solar heat into the heat cycle of the steam turbine. is there.

  On the other hand, in a thermal power plant equipped with the steam turbine equipment as described above, a wide variety of auxiliary equipment is required to operate the steam turbine equipment. Some of these auxiliary devices are driven using steam, for example, steam-type air that extracts the air in the condenser to the outside of the condenser in order to maintain the vacuum of the condenser at all times. An extractor (also called an ejector or a jet pump) is widely used (see Patent Document 2 as an example).

Japanese Patent Laid-Open No. 51-4429 Japanese Patent No. 4579479

  In a conventional power generation system using solar heat, water is preheated by exchanging heat with a heat medium of a solar heat collector, and the water whose temperature has increased is returned to the water supply system of the steam turbine facility and supplied to the main boiler. According to this configuration, the amount of extraction steam supplied to the feed water heater can be reduced, and the output and efficiency can be improved.

  However, in the conventional method, the use of solar thermal energy is limited to preheating of feed water, so the use of solar thermal energy for steam turbine equipment is limited, and the effect of improving output and efficiency is also limited.

  In addition, in the steam turbine heat cycle, where the conventional water supply is preheated by exchanging heat with the heat medium of the solar heat collector and the temperature-increased water supply is directly returned to the water supply system of the steam turbine equipment, the amount of heat recovered by solar heat fluctuates due to weather changes. However, there is a problem that steam turbine output control becomes difficult due to a change in the flow rate of recovered steam to the steam turbine cycle.

  Furthermore, when power is transmitted to an area where the power system is weak, it is difficult to control the grid frequency at the same time as the steam turbine output control.

  Accordingly, an object of the present invention is to expand the range of application of solar thermal energy in steam turbine equipment, improve the output and efficiency of the steam turbine, and reduce fluctuations in the output of the steam turbine due to weather changes.

  In order to solve the above problems, the present invention is directed to a boiler that generates steam by fossil fuel, a steam turbine that is driven by the steam generated by the boiler, and a condenser that condenses the steam that has driven the steam turbine. And steam turbine equipment having a water supply system for supplying condensate from the condenser to the boiler, auxiliary equipment driven using steam extracted from the steam turbine, and solar heat for heating the heat medium using solar heat In a thermal power plant equipped with a heat collector, auxiliary steam is generated by exchanging heat between part of the feed water extracted from the water supply system and the heat medium heated by the solar heat collector, and the auxiliary steam is used as auxiliary equipment. It is characterized by being supplied as driving steam.

  According to the present invention, steam is generated from a part of feed water extracted from a water supply system using solar thermal energy, and the generated steam is used as auxiliary steam for the steam turbine equipment, thereby using solar thermal energy in the steam turbine equipment. Can be expanded. As a result, the ratio of using a part of the steam generated by the main boiler or the generated steam of the in-house boiler as auxiliary steam is greatly reduced, and accordingly, the output of the steam turbine can be increased and the power generation efficiency can be improved.

  The present invention also provides steam indirectly to the steam turbine heat cycle. That is, boiler feed water is heated by solar heat, and steam derived from solar heat is indirectly used in the steam turbine heat cycle as auxiliary steam for the steam turbine heat cycle. Thereby, the fluctuation | variation of the amount of auxiliary steam generation derived from a solar heat by the change of a weather can be compensated by adjustment of the amount of auxiliary steam extraction derived from a boiler main body. As a result, fluctuations in the steam turbine output can be reduced.

  Therefore, according to the present invention, the range of utilization of solar thermal energy for steam turbine equipment can be expanded, the output and efficiency of the steam turbine can be improved, and fluctuations in the output of the steam turbine due to changes in weather can be reduced.

It is the schematic explaining the system system | strain of the thermal power plant which concerns on the Example of this invention. It is the schematic explaining the control system of the thermal power plant of FIG.

  Generally, in a thermal power plant equipped with a steam turbine facility, a wide variety of auxiliary equipment is required to operate the steam turbine facility. Some of these auxiliary devices are driven using steam. Conventionally, a part of the steam generated by the main boiler or the steam generated in the in-house boiler has been used as the driving steam.

  By the way, in the method of using the conventional solar thermal energy for preheating boiler feedwater, it is necessary to return the preheated water to the water supply system. Therefore, since water supply remains in a liquid state, it cannot be used as a drive source for auxiliary equipment driven using steam. As a result, the range of utilization of solar thermal energy for steam turbine equipment is limited.

  The present invention is not limited to preheating water supply, and a part of the water supply is positively converted into steam by using solar thermal energy, and further, steam is used as auxiliary steam for the steam turbine equipment. It expands the range of use. Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 shows a schematic diagram of a system system of a thermal power plant according to the present embodiment. The thermal power plant according to the present embodiment includes a steam turbine facility and a solar heat collector as main components.

  The steam turbine equipment includes, as main components, a main boiler 1 that generates fossil fuel such as coal and heats feed water to generate steam, a steam turbine that is rotationally driven by steam generated by the main boiler 1, and a steam turbine. A condenser 5 for condensing and condensing steam that has been rotationally driven, a water supply system for supplying the main boiler 1 with the condensate discharged from the condenser 5, and a generator for converting the rotational force of the steam turbine into electric power 4. The steam turbine includes a high-pressure turbine 2 and a medium-low pressure turbine 3. The intermediate / low pressure turbine 3 may be configured separately for the intermediate pressure turbine and the low pressure turbine.

  The condenser 5 takes out the cooling water from the circulating water intake tank 90 using the circulating water pump 91. The cooling water passes through the circulating water inlet pipe 92 and is sent to the condenser 5 to cool the low-pressure turbine exhaust steam and return it to the condensate. The cooling water exiting the condenser 5 passes through the circulating water outlet pipe 93 and flows into the circulating water drainage tank 94.

  The water supply system includes, in order from the condenser 5 toward the main boiler 1, a condensate pump 6, an intercooler 97 and an aftercooler 98 installed in parallel with each other, a low-pressure feed water heater 18, and a deaerator. 44, boiler feed water pump 50, and high-pressure feed water heaters 51a, 51b, 51c. The low-pressure feed water heater 18 and the deaerator 44 are supplied with extracted steam extracted from the medium-low pressure turbine 3 as a heating source. Further, the extracted steam extracted from the high-pressure turbine 2 is supplied to the high-pressure feed water heater 51 as a heating source. The number of low-pressure and high-pressure feed water heaters installed is not limited to that shown.

  The feed water supplied to the main boiler 1 from the feed water system is heated when it sequentially passes through the boiler primary superheater 57 and the boiler secondary superheater 58 installed in the main boiler 1, and is vaporized into steam. The steam generated in the main boiler 1 flows down the main steam pipe 80 and is supplied to the high-pressure turbine 2 to drive the high-pressure turbine 2 to rotate. The steam that rotationally drives the high-pressure turbine 2 is returned again to the main boiler 1, heated by the boiler reheater 82, flows down through the high-temperature reheat steam pipe 83 as reheated steam, and is supplied to the intermediate / low pressure turbine 3. The steam supplied to the intermediate / low pressure turbine 3 rotates and drives the intermediate / low pressure turbine 3, and then is guided to the condenser 5, cooled, condensed, and condensed. The condensate condensated in the condenser 5 is supplied to the condensate pump 6 and pressurized, and then flows down through the main air extractor inlet condensate piping 7. The main air extractor inlet condensate pipe 7 is branched into an intercooler inlet air pipe 7a and an aftercooler inlet air pipe 7b on the way, and the condensate flowing down the main air extractor inlet condensate pipe 7 is The air flows into the intercooler inlet air pipe 7a and the aftercooler inlet air pipe 7b, respectively, and is supplied to the intercooler 97 and the aftercooler 98 to be heated. The condensate that has exited the intercooler 97 and the aftercooler 98 merges, flows down the low pressure feed water heater inlet condensate piping 17, and is introduced into the low pressure feed water heater 18 and the deaerator 44. The condensate that has been sequentially heated by the low-pressure feed water heater 18 and the deaerator 44 is introduced into the high-pressure feed water heaters 51a, 51b, and 51c as feed water, and is heated in order to increase the temperature, and then introduced into the main boiler 1 as feed water. The

  Furthermore, the steam turbine equipment of the present embodiment includes an in-house boiler 107 that generates auxiliary steam necessary for the operation of the steam turbine equipment.

  Moreover, the steam turbine equipment of the present embodiment is a first stage main air extractor 13, a second stage main air extractor 15, and an activation air extractor 12 as auxiliary devices that are driven using steam extracted from the steam turbine. With.

  The first-stage main air extractor 13 and the second-stage main air extractor 15 allow the air in the condenser 5 to be moved out of the condenser by the ejector effect in order to maintain the degree of vacuum in the condenser 5. This is the equipment to be extracted. The first stage main air extractor 13 and the second stage main air extractor 15 are supplied with main steam generated by the main boiler 1 or auxiliary steam generated by the in-house boiler 107 as driving steam. A part of the main steam flowing down the main steam pipe 80 flows down the main air extractor-driven steam take-out pipe 85 and the pressure reducing valve inlet pipe 7c branched from the main steam pipe 80, and is decompressed by the pressure reducing valve 79. It is supplied to the stage main air extractor 13 and the second stage main air extractor 15, respectively.

  The auxiliary steam generated in the in-house boiler 107 flows down the in-house boiler outlet valve 108 and the auxiliary steam pipe 109 and is once supplied to the auxiliary steam mother pipe 110, and then the pipe 38 and the pressure reducing valve from the auxiliary steam mother pipe 110. It flows down the inlet pipe 7c and the pressure reducing valve 79 and is supplied to the first-stage main air extractor 13 and the second-stage main air extractor 15, respectively.

  The air extracted from the condenser 5 by the ejector effect of the first stage main air extractor 13 flows down the pipe 9 and is guided to the first stage main air extractor 13. It becomes a mixed gas with water vapor, and further flows down the pipe 95 and flows into the intercooler 97. The mixed gas that has flowed into the intercooler 97 is cooled by heat exchange with the condensate, then passes through the pipe 14 through the intercooler 97 and is guided to the second-stage main air extractor 15. The mixed gas guided to the second-stage main air extractor 15 is mixed with water vapor, and then passes through the pipe 96 and flows into the aftercooler 98. The water vapor content of the mixed gas flowing into the aftercooler 98 is cooled by heat exchange with the condensate, becomes drainage, passes through the pipe 105, and is collected by the condenser 5. On the other hand, the air extracted from the condenser 5 is returned to the atmosphere from the aftercooler 98 through the aftercooler outlet air pipe 16.

  The startup air extractor 12 is an auxiliary device that takes out the air in the condenser 5 to the outside of the condenser 5 by the ejector effect when the steam turbine is started up. The starting air extractor 12 is connected to the auxiliary steam mother pipe 110 via the auxiliary steam pipe 71 and the pipe 39, and the auxiliary steam generated by the in-house boiler 107 is supplied as driving steam.

  When the steam turbine is started, the auxiliary steam generated by the in-house boiler 107 is supplied to the starting air extractor 12, and the starting air extractor 12 is driven. Due to the ejector action of the activated starter air extractor 12, the air in the condenser 5 sequentially passes through the condenser air extractor pipe 9, the starter air extractor inlet air extractor pipe 10, and the starter air extractor 12. It is sent to the air extractor outlet silencer 69 and discharged into the atmosphere. Thereby, the vacuum degree of the condenser 5 at the time of steam turbine starting increases.

  In addition, auxiliary steam is taken out from the auxiliary steam mother pipe 110 through a turbine auxiliary steam branch pipe 37, and the auxiliary steam passes through the turbine auxiliary steam valve 45 and is supplied to the turbine auxiliary steam pressure adjusting valve 46. After passing through, it flows to the turbine auxiliary steam system. Thereafter, the auxiliary steam is used as auxiliary steam for each turbine device, for example, turbine auxiliary steam such as turbine ground seal or steam for regeneration of a condensate demineralizer.

  Similarly, auxiliary steam is taken out from the auxiliary steam mother pipe 110 through the boiler auxiliary steam branch pipe 36, and the auxiliary steam passes through the boiler auxiliary steam valve 65 and passes through the boiler auxiliary steam pressure adjusting valve 66 and then the boiler auxiliary steam. It flows into the system. Thereafter, the auxiliary steam is used as auxiliary steam for boiler equipment, for example, boiler auxiliary steam such as boiler soot blower steam, burner atomized steam, or heavy oil heating steam.

  Similarly, auxiliary steam for heating the deaerator 44 required for starting the thermal power plant is taken out from the auxiliary steam mother pipe 110 using the deaerator auxiliary steam branch pipe 40, and the deaerator auxiliary steam valve 42 is installed. It flows down and then passes through the deaerator auxiliary steam pressure regulating valve 43 and is supplied to the deaerator 44.

  Auxiliary steam is supplied from the main boiler 1 to the auxiliary steam mother pipe 110 in addition to the in-house boiler 107. The main boiler 1 is connected to an auxiliary steam mother pipe 110 via a boiler auxiliary steam take-out pipe 74 and a boiler auxiliary steam supply pipe 77. During normal operation of the thermal power plant, auxiliary steam is supplied from the main boiler 1 to the auxiliary steam mother. Supplied to the tube 110.

  Next, the solar heat collecting apparatus of a present Example is demonstrated.

  The solar heat collecting apparatus of the present embodiment includes a solar heat collecting apparatus main body 22, a heat medium heat exchanger 20, a heat medium cooler 26, and a heat medium circulation system 113 as main components.

  The solar thermal collector main body 22 has a solar thermal collector mirror as a main component, and there are several types of solar thermal collector mirrors such as trough type, tower type, and Fresnel type. Can also be used with a heat collecting mirror. The example in FIG. 1 models a Fresnel type. The heat medium flowing through the heat medium circulation system 113 includes a molten salt or oil as a component.

  In the present embodiment, the heat medium flowing in the heat medium circulation system 113 is heated by solar heat collected by the solar heat collecting mirror. The heat medium heated by the solar heat collector main body 22 and heated to high temperature is introduced into the heat medium heat exchanger 20 through the pressure regulating valve 23 and the valve 24a. The heat medium introduced into the heat medium heat exchanger 20 is cooled by exchanging heat with condensate or a part of the water supply supplied from the water supply system.

  In the present embodiment, a bypass system 114 that bypasses the heat medium heat exchanger 20 is provided in the heat medium circulation system 113 in case the abnormality occurs in the heat medium heat exchanger 20. A heat medium cooler 26 is provided on the downstream side of the bypass system 114. When the heat medium heat exchanger 20 is bypassed, the bypass valve 25 provided in the bypass system 114 is opened, and the valve provided in the heat medium circulation system 113 upstream and downstream of the heat medium heat exchanger 20 is opened. 24a and valve 24b are closed. Next, the valve 27 is opened to supply cooling water to the heat medium cooler 26, and the valve 28 is opened to discharge solar thermal energy out of the system.

  The heat medium that has passed through the heat medium cooler 26 is sent to the solar heat collector main body 22 by the heat medium circulation pump 21. The above is the main configuration of the solar heat collecting apparatus of the present embodiment.

  The thermal power plant of the present embodiment introduces a part of the condensate or feed water extracted from the water supply system of the steam turbine equipment to the solar heat collector, generates the auxiliary steam by heating, and uses this auxiliary steam as auxiliary equipment. An auxiliary steam supply system for supplying operating steam is provided.

  The auxiliary steam supply system connects a water supply pipe 8 for extracting a part of the condensate whose pressure has been increased by the condensate pump 6 from the main air extractor inlet condensate pipe 7, and the water supply pipe 8 and the heat medium heat exchanger 20. A water supply pipe 112, a water supply pipe 111 that extracts a part of the water supply boosted by the boiler water supply pump 50 from the water supply system and joins the water supply pipe 112, the heat medium heat exchanger 20, and the solar heat generation auxiliary steam brackish water separator 100. A part of steam that flows down the auxiliary steam supply pipe 34, a steam pipe 102 that introduces steam from the solar heat generation auxiliary steam brack separator 100, a steam pipe 102 that introduces steam into the auxiliary steam mother pipe 110, and an auxiliary steam supply pipe 34. The water separated by the steam pipe 63 that joins the high pressure steam turbine bleed pipe 61 for supplying the bleed steam from the high pressure turbine 2 to the high pressure feed water heater 51 and the solar heat generation auxiliary steam brackish water separator 100 The and a drain pipe 104 to be introduced into the condenser 5. As a method for feeding the boiler feed water taken out from the deaerator 44 to the heat medium heat exchanger 20, a small dedicated feed pump (not shown) may be installed in parallel with the boiler feed pump 50. Alternatively, a boiler booster pump (not shown) of the boiler feed pump 50 installed on the suction side of the boiler feed pump 50 can be installed to supply boiler feed water from the pump to the heat medium heat exchanger 20.

  FIG. 2 is an explanatory diagram of auxiliary steam local control of the thermal power plant according to the present embodiment shown in FIG. The first stage main air extractor 13 and the second stage main air are controlled by controlling the outlet pressure of the main air extractor driven steam pressure reducing valve 79 based on the pressure signal detected by the main air extractor driven steam detector 79p. Drive steam pressure control of the extractor 15 is performed.

  The turbine auxiliary steam pressure detector 46p detects the turbine auxiliary steam pressure, controls the degree of turbine auxiliary steam pressure adjustment valve 46, and adjusts the outlet pressure of the turbine auxiliary steam pressure adjustment valve 46 to the turbine. The pressure control required by the auxiliary steam system is performed.

  The boiler auxiliary steam pressure detector 66p detects the boiler auxiliary steam pressure, adjusts the degree of boiler auxiliary steam pressure adjustment valve 66, and the boiler auxiliary steam system needs the outlet pressure of the boiler auxiliary steam pressure adjustment valve 66. Perform pressure control.

  The deaerator auxiliary steam pressure detection meter 43p detects the auxiliary steam pressure required by the deaerator 44, and adjusts the degree of solution of the deaerator auxiliary steam pressure adjustment valve 43 to adjust the deaerator auxiliary steam pressure. The pressure control which the deaerator 44 requires for the outlet pressure of the valve 43 is performed.

  The pressure was detected by the heat medium heat exchanger outlet high-temperature water pressure detector 32p, and the degree of solution of the heat medium heat exchanger outlet high-temperature water pressure adjustment valve 32 was adjusted to suit the solar heat generation auxiliary steam brackish water separator 100. The brackish water separator is controlled by pressure control and separated into saturated steam and drain.

  The auxiliary steam pressure required by the auxiliary steam mother pipe 110 is detected by the solar heat generating auxiliary steam brackish water separator outlet pressure detector 101p, and the degree of excitement of the solar heat generating auxiliary steam brack water separator outlet pressure regulating valve 101 is adjusted. Provide auxiliary steam pressure control.

  The auxiliary steam pressure required by the auxiliary steam mother pipe 110 is detected by a boiler auxiliary steam pressure detector 76p, and the pressure control of the auxiliary steam mother pipe 110 is performed by adjusting the degree of solution of the boiler auxiliary steam pressure adjusting valve 76. .

  The above is the main configuration of the thermal power plant of this embodiment. Next, the effect of the thermal power plant of a present Example is demonstrated.

  When starting the thermal power plant, first, the in-house boiler 107 is activated to generate auxiliary steam, and this auxiliary steam is introduced into the auxiliary steam mother pipe 110 through the in-house boiler outlet valve 108 and the auxiliary steam pipe 109.

  During normal operation of the thermal power plant, the boiler feed water that has passed through the high pressure third feed water heater outlet boiler feed pipe 56 passes through a economizer (not shown), a furnace and a drum, and is introduced into the boiler primary superheater 57. Part of the boiler-generated steam that has passed through the boiler primary superheater 57 is taken out by a boiler auxiliary steam take-out pipe 74, flows down through a boiler auxiliary steam valve 75, passes through a boiler auxiliary steam pressure adjustment valve 76, and is supplied with boiler auxiliary steam. It is supplied to the auxiliary steam mother pipe 110 through the pipe 77.

  In the present invention, in addition to these two auxiliary steam supply sources, steam generated by solar heat is also introduced into the auxiliary steam mother pipe 110 and effectively used as auxiliary steam.

  A part of the condensate whose pressure has been increased by the condensate pump 6 is taken out by the water supply pipe 8, flows down the water supply valve 68, passes through the water supply pipe 112, passes through the valve 29, and is introduced into the heat medium heat exchanger 20. Alternatively, a part of the feed water of the main boiler 1 fed from the boiler feed pump 50 to the main boiler 1 is taken out by the feed pipe 111, flows down the valve 67, passes through the feed water pipe 112, passes through the valve 29, and heat medium heat exchange. Introduced into the vessel 20.

  The feed water is heated by the heat medium that has received heat energy from the solar heat in the heat medium heat exchanger 20 and has become a high temperature, and becomes a high-temperature and high-pressure brackish water mixture that comes out of the heat medium heat exchanger outlet high-temperature water pipe 30. Further, the brackish water mixture flows down the valve 31 and then passes through the pressure regulating valve 32 and flows into the solar heat generation auxiliary steam brackish water separator 100 where the brackish water mixture is depressurized to become a saturated steam component and a saturated drain component. To be separated. The saturated steam component flows down the pressure regulating valve 101, passes through the steam pipe 102, and partly flows down the steam pipe 33, passes through the steam valve 35, and is introduced into the pipe 64 through the steam pipe 63. The heating steam exiting the pipe 64 flows into the high-pressure feed water heater 51b and heats the boiler feed water.

  On the other hand, the auxiliary steam that has passed through the steam pipe 102 passes through the steam supply pipe 34 and flows into the auxiliary steam mother pipe 110, and serves as auxiliary steam such as a main air extractor, start-up air extractor, turbine auxiliary steam, and boiler auxiliary steam. Be utilized. The drain of the solar heat generation auxiliary steam brack separator 100 flows down the drain valve 103, passes through the drain pipe 104, and flows to the condenser 5.

  In the example shown in FIG. 1, a turbine bleed configuration that heats the high-pressure feed water heater 51 a, the high-pressure feed water heater 51 b, and the high-pressure feed water heater 51 c by the bleed extracted from two places from the high-pressure turbine 2 and one place from the medium- and low-pressure turbine 3. The case of is displayed. The auxiliary steam taken out from the solar heat becomes a drain after exchanging heat in the high-pressure feed water heater 51b, flows down the drain pipe 52, passes through the water level adjustment valve 53, and is introduced into the high-pressure feed water heater 51a. The drain from the high-pressure feed water heater 51 a passes through the water level adjustment valve 54 and is recovered by the deaerator 44. The drain of the low-pressure feed water heater 18 passes through the low-pressure feed water heater drain pipe 59 and is recovered to the condenser 5.

  In a conventional thermal power plant, an in-house boiler dedicated to the power plant is installed to start the thermal power plant. That is, the in-house boiler is started first, auxiliary steam necessary for starting the boiler and the turbine is secured, and when the plant is started, it is switched to its own boiler-generated steam.

  However, the present embodiment is not limited to preheating the feed water by providing an auxiliary steam supply system, and a part of the feed water is actively made steam using solar thermal energy, and the steam is started as auxiliary steam for the steam turbine equipment. Can be used from time to time. Furthermore, even in normal operation after completion of startup, steam can be generated by solar heat recovery, and the steam can be used as auxiliary steam required by a boiler or turbine plant in normal operation of a thermal power plant.

  Auxiliary steam required by the boiler plant during normal plant operation includes boiler soot blower steam, boiler burner atomizing steam, heavy oil heater steam, heating steam for evaporators, and the like. The auxiliary steam required by the turbine plant includes air extractor driven steam, turbine ground seal steam, and steam for heating the deaerator at start-up. If some of the auxiliary steam required by these devices can be covered with steam generated by solar heat recovery, a significant improvement in power generation efficiency and a reduction in the unit price of power generation can be achieved. At the same time, the amount of carbon dioxide generated from thermal power plants Is also lowered.

  Generally, the main steam is decompressed and used as the driving steam for the main air extractor of the condenser used in the thermal power plant. However, in this embodiment, steam generated by solar heat can be used as a driving steam source for the main air extractor, so that the main steam that has been conventionally used as the driving steam source for the main air extractor is not depressurized, and the swallowing steam of the steam turbine is used. Therefore, it is possible to improve the output and performance of the steam turbine. In addition, when a condenser vacuum pump is used instead of the main air extractor, the condenser vacuum pump is replaced with the main air extractor, and steam is generated from solar heat. This saves the driving power of the water pump vacuum pump. Furthermore, the main air extractor using steam generated from solar heat raises the condenser vacuum degree to the vacuum side more than the condenser vacuum pump, thereby increasing the output of the steam turbine and improving the efficiency.

  Therefore, not only the preheating of the water supply during normal operation, but also the range of utilization of solar thermal energy for the steam turbine equipment can be expanded through startup and normal operation, and the output and efficiency of the steam turbine can be improved.

  The auxiliary steam can also be used as part of the extraction steam of the high-pressure feed water heater.

  In addition, in the steam turbine heat cycle, where the conventional water supply is preheated by exchanging heat with the heat medium of the solar heat collector and the temperature-increased water supply is directly returned to the water supply system of the steam turbine equipment, the amount of heat recovered by solar heat fluctuates due to weather changes. However, there is a problem that steam turbine output control becomes difficult due to a change in the flow rate of recovered steam to the steam turbine cycle. Furthermore, when power is transmitted to an area where the power system is weak, it is difficult to control the grid frequency at the same time as the steam turbine output control. On the other hand, the present invention provides steam to the steam turbine heat cycle indirectly to the steam turbine cycle. That is, boiler feed water is heated by solar heat, and steam derived from solar heat is indirectly used in the steam turbine heat cycle as auxiliary steam for the steam turbine heat cycle. For example, this steam is indirectly used as the driving steam for the main air extractor of the condenser. In other words, since the auxiliary steam from the boiler body is also used as the driving steam for the main air extractor of the condenser, the fluctuation in the amount of auxiliary steam generated from the solar heat due to changes in the weather causes the amount of auxiliary steam extraction from the boiler body to increase or decrease. Always compensated by As a result, the vacuum degree of the condenser is maintained and the fluctuation of the steam turbine output can be reduced.

  Utilizes steam extracted from its boiler steam generation system, steam generated from its boiler steam, and steam generated by solar thermal energy from a solar thermal collector as a steam generation source for auxiliary steam at a steam power plant, a form of thermal power generation An example of an auxiliary steam system for a thermal power plant was explained. The same applies to an auxiliary steam system of a combined power plant that uses a gas turbine and a steam turbine instead of a steam power plant. The same applies to a system that uses water supply directly as a heat medium for solar thermal energy recovery and utilizes the heat medium heat exchanger 20 as unnecessary.

DESCRIPTION OF SYMBOLS 1 Main boiler 2 High pressure turbine 3 Medium / low pressure turbine 4 Generator 5 Condenser 6 Condensate pump 12 Startup air extractor 13 First stage main air extractor 15 Second stage main air extractor 18 Low pressure feed water heating 20 Heat medium heat exchanger 21 Heat medium circulation pump 22 Solar heat collector main body 26 Heat medium cooler 44 Deaerator 50 Boiler feed pumps 51a, 51b, 51c High pressure feed water heater 57 Boiler primary superheater 58 Boiler secondary Superheater 69 Start-up air extractor outlet silencer 82 Boiler reheater 97 Intercooler 98 After cooler 107 In-house boiler 110 Auxiliary steam mother pipe 113 Heat medium circulation system 114 Bypass system

Claims (5)

A boiler that generates steam by fossil fuel, a steam turbine that is driven by the steam generated by the boiler, a condenser that condenses the steam that has driven the steam turbine, and a condensate that is discharged from the condenser A steam power plant comprising: a water supply system that supplies the boiler to the boiler; steam turbine equipment having auxiliary equipment that is driven using steam extracted from the steam turbine; and a solar heat collector that heats the heat medium using solar heat A power plant,
Auxiliary steam that generates a supplemental steam by exchanging heat between a part of the feed water extracted from the water supply system and the heat medium heated by the solar heat collector, and supplies the supplemental steam to the supplementary equipment as a drive steam A thermal power plant characterized by comprising a supply system. The thermal power plant according to claim 1,
The said steam turbine equipment is equipped with the main air extractor which extracts the air in the said condenser as the said auxiliary equipment, The thermal power plant characterized by the above-mentioned. The thermal power plant according to claim 2,
The water supply system includes a condensate pump that boosts the condensate discharged from the condenser, a low-pressure feed water heater that heats the condensate with extracted steam extracted from the steam turbine, and a deaerator that degass the condensate A boiler feed water pump that pressurizes the deaerator outlet boiler feed water, and a high-pressure feed water heater that heats the boiler feed pump outlet feed water with the extracted steam extracted from the steam turbine,
The auxiliary steam supply system supplies the auxiliary steam to the high-pressure feed water heater together with extracted steam extracted from the steam turbine. In the thermal power plant according to claim 3,
The steam turbine facility uses the auxiliary steam supplied from the auxiliary steam supply system as boiler auxiliary steam. In the thermal power plant according to claim 3,
The steam turbine facility uses the auxiliary steam supplied from the auxiliary steam supply system as auxiliary steam for turbine equipment.

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