JP5873379B2 - Steam turbine plant and operation method thereof - Google Patents

Description

  Embodiments described herein relate generally to a steam turbine plant and a method for operating the same.

  A first example of a conventional steam turbine plant is shown in FIG. In the steam turbine plant of the first example, the feed water 6 is supplied to the boiler 1 by the feed water pump 7 and is changed to the steam 2 by being heated by the boiler 1. The boiler 1 heats the feed water 6 with combustion exhaust gas generated with coal as fuel or solar heat, for example. The steam 2 generated in the boiler 1 flows into the steam turbine 3 and expands, and generates shaft power that rotates the rotating shaft of the steam turbine 3. At this time, the steam 2 decreases in pressure and temperature inside the steam turbine 3 and becomes exhaust. Exhaust gas 4 from the steam turbine 3 flows into the condenser 5. The exhaust 4 is usually partly condensed and liquid, but most is in a gaseous state. The exhaust 4 is cooled by the cooling water 8 in the condenser 5 and returns to the water supply 6. The feed water 6 changes to steam, and then returns to the water while returning to the upstream of the feed water pump 7 and circulates. The cooling water 8 is conveyed to the condenser 5 by the cooling water pump 9 and often uses seawater or river water. In the case of the first example shown in FIG. 11, the cooling water 8 is heated by the condenser 5 and then discharged to the sea or river. That is, in the first example shown in FIG. 11, the system of the cooling water 8 is a non-circulating system. The rotating shaft of the steam turbine 3 that is rotated by the expanding steam is connected to the generator 30, and power is generated by the generator 30 using the generated shaft power.

  Next, a second example of a conventional steam turbine is shown in FIG. In the steam turbine plant of this second example, the system of the cooling water 8 of the condenser 5 is different from the steam turbine plant of the first example shown in FIG. In the second example shown in FIG. 12, the cooling water 8 of the condenser 5 is circulating water and is conveyed to the condenser 5 by the condensate pump 9. The cooling water 8 is heated by the condenser 5 and then cooled by the atmosphere 10 in the cooling tower 11. The air 10 may be forcibly blown, but in the second example shown in FIG. 12, the cooling tower 11 does not forcibly blow the air 10. Although a blower that conveys the air 10 is not shown, a cooling tower that forcibly blows the air may be used. In that case, a blower is required. The cooling water 8 cooled by the cooling tower 11 is circulated by the condensate pump 9.

  In FIG. 11 and FIG. 12, although the steam turbine is drawn as one unit, a plurality of units may be used, and a reheat cycle or a regeneration cycle may be configured.

JP 2000-64813 A

  Electricity demand varies depending on the season and time of day. During summer daytime, demand is large and power is scarce. Since the temperature of seawater and river water is high during the summer daytime, the cooling water 8 becomes higher in the first example shown in FIG. In the summer daytime, the temperature of the atmosphere 10 is high, and particularly in Japan, the relative humidity is also high. Therefore, in the second example shown in FIG. 12, the cooling capacity in the cooling tower 11 is reduced, and the cooling water 8 becomes higher. In the second example shown in FIG. 12 in which the cooling water 8 is cooled by the atmosphere 10, it is particularly preferable to secure the cooling water 8 at a lower temperature than in the first example shown in FIG. 11 in which seawater or river water is used as the cooling water 8. Have difficulty. When the temperature of the cooling water 8 of the condenser 5 becomes higher, the pressure at the outlet of the steam turbine 3 becomes higher, so that the enthalpy of steam that can be used as the shaft power of the steam turbine 3 (enthalpy difference between the inlet and outlet) becomes smaller. . In the present specification, when there are a plurality of steam turbines 3, the outlet pressure of the steam turbine 3 refers to the outlet pressure of the steam turbine 3 connected to the condenser 5. The output of the steam turbine 3 decreases, and the generated power output decreases during the summer daytime when it is desired to increase the power generation amount.

  Even in summer, there is a surplus of power at night. Although some power plants do not need to generate electricity at night, the boiler 1 cannot be easily stopped or started, and needs to continue to operate. Therefore, at some power plants, the amount of power generation is reduced by operating the boiler 1 and the steam turbine 3 at a partial load at night.

  Therefore, it is desired to increase the power generation output during a time period when the power demand is large such as summer daytime, or to perform power leveling for one day when the power demand changes sufficiently depending on the time period such as summer daytime.

  The present embodiment provides a steam turbine plant capable of leveling the power generation output even when the power output increases during a time period when the power demand is large, or the power demand changes depending on the time period, and an operating method thereof.

  The steam turbine plant according to the present embodiment converts a supplied water into steam, a steam turbine driven by steam from the boiler, and cools the exhaust of the steam turbine with cooling water to change into water. A condenser, a pump for supplying water changed from exhaust gas by the condenser to the boiler, a refrigerator driven by using a part of the steam as a heat source to cool the refrigerant, and a heat storage tank for storing the refrigerant And a cooler that directly or indirectly cools the cooling water with the refrigerant, and flows out the fluid after a part of the steam has passed through the refrigerator, the condenser and the pump, It is made to flow in between.

The conceptual diagram which shows the steam turbine plant by 1st Embodiment. The conceptual diagram which shows the steam turbine plant by 2nd Embodiment. The conceptual diagram which shows the steam turbine plant by 3rd Embodiment. The conceptual diagram which shows the steam turbine plant by 4th Embodiment. The conceptual diagram which shows the steam turbine plant by 5th Embodiment. The conceptual diagram which shows the steam turbine plant by 6th Embodiment. The conceptual diagram which shows the steam turbine plant by 7th Embodiment. The conceptual diagram which shows the steam turbine plant by 8th Embodiment. The conceptual diagram which shows the steam turbine plant by 9th Embodiment. The conceptual diagram which shows the steam turbine plant by 10th Embodiment. The conceptual diagram which shows the 1st example of the conventional steam turbine plant. The conceptual diagram which shows the 2nd example of the conventional steam turbine plant.

  Embodiments will be described below with reference to the drawings.

(First embodiment)
A steam turbine plant according to a first embodiment is shown in FIG. The steam turbine plant of the first embodiment includes a boiler 1, a steam turbine 3, a condenser 5, a feed water pump 7, a cooling water pump 9, a cooling tower 11, a flow rate adjusting valve 15, and a pressure reducing valve. 16, the refrigerator 18, the pressure reducing valve 20, the refrigerant pump 21, the cooling material pump 23, the heat storage tank 24, the flow rate control valve 26, the cooler 27, the generator 30, and the flow rate control valve 31. And an on-off valve 46. The refrigerator 18 is, for example, an absorption refrigerator or an adsorption refrigerator.

  In the steam turbine plant according to the first embodiment, the operation pattern mode of the entire steam turbine plant in a time zone with a large power demand is referred to as an operation pattern A. In order to realize the mode of the operation pattern A, the operation pattern mode of the operation of the steam turbine plant that is performed in a time zone where the power demand is not large is assumed to be the operation pattern B in advance. Further, an operation pattern mode in a time zone in which the operation patterns A and B are not performed is an operation pattern C. The operation pattern mode is the operation pattern C when the operation pattern mode according to the operation pattern A is not performed, that is, when there is no time zone in which the power demand is large. For example, the entire steam turbine plant is operated in the operation pattern A during the summer day, in the operation pattern B during the summer night, in the time zone between the operation patterns A and B even in the summer, or in the operation pattern C during the non-summer season.

  These operation pattern B, operation pattern A, and operation pattern C will be described in order below.

(Driving pattern B)
In the operation pattern B, the steam turbine plant is operated as follows. The feed water 6 is supplied to the boiler 1 by the feed water pump 7 and is changed to steam 2 by being heated by the boiler 1. The boiler 1 heats the feed water 6 with combustion exhaust gas generated with coal as fuel or solar heat, for example. The steam 2 generated in the boiler 1 flows into the steam turbine 3 as the turbine inlet steam 12 and expands to generate shaft power that rotates the rotating shaft of the steam turbine 3. At this time, the turbine inlet steam 2 decreases in pressure and temperature inside the steam turbine 3 and becomes exhaust. Exhaust gas 4 from the steam turbine 3 flows into the condenser 5. The exhaust 4 is usually partly condensed and liquid, but most is in a gaseous state. The exhaust 4 is cooled by the cooling water 8 in the condenser 5 to become the condensed water 13. This condensate 13 merges with a fluid 19 output from a refrigerator 18 to be described later, becomes water supply 6, and returns upstream of the water supply pump 7.

  In this operation pattern B, the steam 2 output from the boiler 1 is branched into a turbine inlet steam 12 and a branch steam 14. The branch flow rate at this time is adjusted by the flow rate control valve 15. The branch steam 14 is decompressed to an appropriate pressure by the decompression valve 16 and becomes a refrigerator inlet steam 17 that flows into the inlet of the refrigerator 18. The refrigerator 18 is a refrigerator that is driven by using the refrigerator inlet steam as a heat source, and is, for example, an absorption refrigerator or an adsorption refrigerator. The refrigerator 18 also includes a cooling water for the refrigerator, a cooling tower for air-cooling the cooling water for the refrigerator, and the like, and a part excluding the refrigerant 25 and the refrigerant pump 21 from the entire refrigeration system including them. Is shown as a refrigerator 18. The refrigerator 18 is driven using the refrigerator inlet steam 17 as a heat source, generates cold and cools the refrigerant 25. The flow rate of the refrigerant 25 is adjusted by the flow rate adjustment valve 31 and is conveyed to the heat storage tank 24 by the refrigerant pump 21. A cooling substance 22 is stored in the heat storage tank 24. The refrigerant 25 cools the cooling substance 22. Then, the temperature of the refrigerant 25 rises, and then flows into the refrigerator 18. The cooling substance 22 is liquid at room temperature, but a part or all of it may change into a solid phase by cooling. The cooling substance 22 is, for example, water, and becomes ice when the phase changes. In the operation pattern B, the flow rate control valve 26 is fully closed, and the cooling material pump 23 is not driven.

  The cooling water 8 used in the condenser 5 is cooled by the atmosphere 10 in the cooling tower 11, and then passes through the cooler 27 by the cooling water pump 9 and flows into the condenser 5. However, in the operation pattern B, since the cooling substance 22 does not flow through the cooler 27, the cooling water 8 is not cooled by the cooler 27. The refrigerator inlet steam 17 that has flowed into the refrigerator 18 decreases in temperature in the refrigerator 18 and becomes fluid 19 at the refrigerator outlet. The fluid 19 is depressurized to an appropriate pressure by the pressure reducing valve 20, and then merges with the condensate 13 to become the water supply 6. The on-off valve 46 is fully open. The point where the fluid 19 merges with the condensate 13 is between the condenser 5 and the feed pump 7, but if a plurality of feed pumps 7 are arranged in series, the join point is the most downstream. It may be anywhere between the feed water pump 7 and the condenser 5 that are arranged. The fluid 19 output from the refrigerator 18 is often only water at the time of confluence with the condensate 13, but is mixed with the condensate 13 even if it is in a mixed state of water and steam or only steam. After that, since a small amount of gas is condensed to be in a liquid-only state, there is no problem in the water supply pump 7.

  In this operation pattern B, since the flow rate of the steam flowing into the steam turbine 3 is reduced, the power generation output by the steam turbine 3 is reduced. In addition, the refrigerant pump 21 and the transporting machine included in the refrigerator 18 consume power, but there is no problem because the power is surplus at night. Further, much of the energy that does not flow into the steam turbine 3 is stored in the heat storage tank 24 in the form of cold heat, and little energy is wasted.

(Driving pattern A)
With respect to the operation pattern B, the operation pattern A operates the steam turbine plant as follows. The flow control valve 15, the flow control valve 20, the flow control valve 31, and the on-off valve 46 are fully closed, and the refrigerant pump 21 is stopped. The steam 2 flowing out from the boiler 1 does not diverge, but flows into the steam turbine 3 as the turbine inlet steam 12, and there is no fluid 19 that joins the condensate 13, and the condensate 13 becomes the feed water 6 as it is. The cooling substance 22 stored in a cooled state in the heat storage tank 24 is conveyed to the cooler 27 by the cooling substance pump 23 while the flow rate is adjusted by the flow rate adjusting valve 26. The cooling water 8 is cooled by the cooling substance 22 in the cooler 27 and then flows into the condenser 5. After the temperature of the cooling substance 22 rises in the cooler 27, it flows into the heat storage tank 24 and circulates. When the cooling substance 22 is, for example, water, the heat storage tank 24 may have phase-change ice, and a small amount of ice particles may be mixed even when it is conveyed to the cooling substance pump 23. Since the cooling substance 22 returned from the cooler 27 is hotter than the ice in the heat storage tank 24, the ice melts into water and can be transported by the cooling substance pump 23.

  The cooling water 8 has a lower temperature due to cooling by the cooler 27 with the cooling substance 22. For this reason, the exhaust 4 from the steam turbine 3 is cooled to a lower temperature by the cooling in the condenser 5 by the cooling water 27. Therefore, the condensation temperature in the condenser 5 that condenses the exhaust 4 becomes lower. Therefore, the condensing pressure becomes lower, that is, the degree of vacuum becomes higher. Thereby, the outlet pressure of the steam turbine 3 becomes lower. As a result, the enthalpy drop of steam that can be used by the steam turbine 3 increases, the output of the steam turbine 3 increases, and the amount of power generation increases.

  Although the cooling material pump 26 is operated in the operation pattern A, the power consumption of the cooling material pump 26 is very small compared to the increasing power generation amount.

(Driving pattern C)
In the operation pattern C, the flow rate control valve 15, the flow rate control valve 26, and the on-off valve 46 are fully closed, the refrigerant pump 21 and the cooling material pump 26 are stopped, and the conventional steam turbine plant of the second example shown in FIG. And substantially the same state.

  According to the first embodiment, since the operation is performed in any one of the three types of operation patterns corresponding to the power demand, the power demand is increased depending on the increase in the power generation output during the time when the power demand is large such as summer daytime and the time zone such as summer daytime and nighttime. It is possible to achieve power leveling in a day when the power supply changes sufficiently.

  In FIG. 1, the steam turbine 3 is illustrated as one unit, but a plurality of units may be used, and a reheat cycle or a regeneration cycle may be configured.

(Second Embodiment)
Next, a steam turbine plant according to a second embodiment is shown in FIG. The steam turbine plant according to the second embodiment has a configuration in which one steam turbine 3 is replaced with two steam turbines 3a and 3b connected in series in the steam turbine plant according to the first embodiment shown in FIG. It has become.

  In the second embodiment, the steam turbine 3 is composed of an upstream turbine 3a and a downstream turbine 3b connected in series. The steam 2 output from the boiler 1 flows into the upstream turbine 3a as the turbine inlet steam 12.

  In the operation pattern B of the second embodiment, the upstream turbine exhaust 34 that is the exhaust of the upstream turbine 3a is branched into the downstream turbine inlet steam 35 and the branch steam 14 that are the inlet steam of the downstream turbine 3b. The branch flow rate is adjusted by the flow rate control valve 15. The downstream turbine inlet steam 35 flows into the downstream turbine 3 b, and the exhaust 4 of the downstream turbine 3 b flows into the condenser 5. The operation patterns A, B, and C in the second embodiment are performed in the same manner as the patterns A, B, and C described in the first embodiment.

  In the second embodiment, the steam turbine 3 includes two steam turbines 3a and 3b connected in series. However, the steam turbine 3 may include three or more steam turbines 3 connected in series or connected in parallel. May be present.

  In the first embodiment, the pressure difference between the branch steam 14 and the refrigerator inlet steam 17 is large, and the pressure reduction amount at the pressure reducing valve 16 is large. Therefore, high steam pressure is wasted.

  On the other hand, in the second embodiment, the pressure difference between the upstream turbine exhaust 34 and the refrigerator inlet steam 17 is smaller. For this reason, the degree to which the high pressure of steam is wasted is smaller in the second embodiment than in the first embodiment. In addition, the refrigerator inlet steam 17 has an upper temperature limit due to the restrictions of the refrigerator 18, and the operation pattern B may not be possible in the first embodiment depending on the temperature of the steam 2 from the boiler 1. The upstream turbine exhaust 34 is lower in temperature than the steam 2 from the boiler 1 and is likely to be lower than the upper limit value of the temperature. For this reason, in the second embodiment, the operation pattern B is more easily established than in the first embodiment.

  Similarly to the first embodiment, the second embodiment can also increase the power generation output during a time period when the power demand is large, and can achieve power leveling on a day when the power demand changes sufficiently.

(Third embodiment)
Next, a steam turbine plant according to a third embodiment is shown in FIG. The steam turbine plant according to the third embodiment is configured by replacing one steam turbine 3 with two steam turbines 3c and 3d arranged in parallel in the steam turbine plant according to the first embodiment shown in FIG. It has become.

  In this 3rd Embodiment, the steam turbine 3 is comprised from the steam turbine 3c and the steam turbine 3d which are arrange | positioned in parallel, and generator 30a, 30b is connected to each steam turbine 3c, 3d. Yes. The steam 2 from the boiler 1 is branched into a second turbine inlet steam 37 which is an inlet steam of the steam turbine 3d, a first turbine inlet steam 43 which is an inlet steam of the steam turbine 3c, and a branch steam 14. A flow rate adjusting valve 36 is provided on the inlet side of the steam turbine 3d, and the flow rate adjusting valve 36 is used together with the flow rate adjusting valve 15 to adjust the flow rate of the inlet steam of the steam turbines 3c and 3d.

  The second exhaust 40, which is the exhaust of the steam turbine 3d, and the first exhaust 44, which is the exhaust of the steam turbine 3c, merge to become the exhaust 4. In the third embodiment, the steam turbine 3 is composed of two steam turbines arranged in parallel. However, three or more steam turbines may be provided, or a portion connected in series may exist. An on-off valve 38 is provided on the exhaust side of the steam turbine 3d.

  The operation pattern B in the third embodiment is performed in the same manner as the operation pattern B in the first embodiment except that the branch flow rate is adjusted by the flow rate control valve 15 and the flow rate control valve 36. When the flow control valve 36 is fully closed, the on-off valve 38 is fully closed, and the steam turbine 3d and the generator 30b are not operated. When there are three or more steam turbines 3 arranged in parallel, the number of steam turbines 3 that are not operated may be greater than one if there are one or more steam turbines that are operating.

  The operation pattern A in the third embodiment is the same as the operation pattern A in the first embodiment except that the flow rate control valve 15 and the flow rate control valve 20 are fully closed and the flow rate control valve 36 and the on-off valve 38 are fully opened. Do. In this case, the two steam turbines 3c and 3d are operated.

  Further, the operation pattern C in the third embodiment is performed in the same manner as the operation pattern C in the first embodiment.

  In the first embodiment, the flow rate of the turbine inlet steam 12 is secured to some extent, and in the second embodiment, if the flow rate of the downstream turbine inlet steam 35 is not secured to some extent, sound turbine operation cannot be maintained, and the inlet steam of the refrigerator 18 Cannot increase 17 In contrast, in the third embodiment, the flow rate of the second turbine inlet steam 37, which is the inlet steam of the steam turbine 3d, can be made zero, and the refrigerator inlet steam 17 can be increased.

  Similarly to the first embodiment, the third embodiment can also increase the power generation output during a time period in which the power demand is large, and can achieve power leveling on a day when the power demand changes sufficiently.

(Fourth embodiment)
Next, a steam turbine plant according to a fourth embodiment is shown in FIG. In the steam turbine plant of the fourth embodiment, the extracted steam 29 is extracted from the middle stage of the turbine blade row of the steam turbine 3 as branch steam to the refrigerator 18 in the steam turbine plant of the first embodiment shown in FIG. It has become the composition. The branch flow rate is adjusted by the flow rate control valve 15. After the flow rate is adjusted by the flow rate control valve 15, the extraction steam 29 is decompressed to an appropriate pressure by the pressure reducing valve 16, becomes the refrigerator inlet steam 17, and flows into the refrigerator 18.

  The operation pattern B in the fourth embodiment is performed in the same manner as the operation pattern B in the first embodiment, except that the extracted steam 29 extracted from the middle stage of the turbine blade row of the steam turbine 3 is used as the branched steam. Further, the operation patterns A and C in the fourth embodiment are performed in the same manner as the operation patterns A and C in the first embodiment, respectively.

  In the first embodiment, the pressure difference between the branch steam 14 and the refrigerator inlet steam 17 is large, and the pressure reduction amount at the pressure reducing valve 16 is large. Therefore, high steam pressure is wasted. In the fourth embodiment, since the pressure difference between the extracted steam 29 and the refrigerator inlet steam 17 is smaller, the degree of wasting of the high pressure of steam is smaller than in the first embodiment. In some cases, there is no need for decompression, and there is no waste in using steam pressure. Moreover, since the temperature of the refrigerator inlet steam 17 has an upper limit due to the restriction of the refrigerator 18, the operation pattern B may not be established in the first embodiment depending on the temperature of the steam 2 output from the boiler 1. . On the other hand, in the fourth embodiment, the extracted steam 29 is lower in temperature than the steam 2 output from the boiler 1, and therefore is likely to be lower than the upper limit value of the temperature of the refrigerator inlet steam 17, and the plant is more than in the first embodiment. It is easy to establish driving.

  Similarly to the first embodiment, the fourth embodiment can also increase the power generation output in a time zone where the power demand is large, and can achieve power leveling on a day when the power demand changes sufficiently.

(Fifth embodiment)
Next, a steam turbine plant according to a fifth embodiment is shown in FIG. The steam turbine plant of the fifth embodiment is the same as that of the conventional second example in the system of the cooling water 8 used in the condenser 5 in the steam turbine plant of the fourth embodiment shown in FIG. The configuration is changed to a non-circular system similar to the first example. For this reason, the cooling tower 11 that cools the cooling water 8 used in the first to fourth embodiments is unnecessary.

  In the fifth embodiment, for example, seawater or river water is used as the cooling water 8. The cooling water 8 is taken from the sea or river by the cooling water pump 9, cooled by the cooler 27, and then flows into the condenser 5. After the heat is exchanged with the exhaust 4 in the condenser 5 and the temperature rises, it is discharged to the sea or river. When the steam turbine plant is not close to the sea or river, the cooling water 8 is cooled by the cooling tower 11 as in the first to fourth embodiments, and thus the cooling water 8 is circulated. On the other hand, when the steam turbine plant is close to the sea or river, since the seawater or river water is used as the cooling water 8 as in the fifth embodiment, the cooling water 8 is often a non-circulating type. .

  Also in the first to third embodiments, the system of the cooling water 8 may be a non-circulation type as in the fifth embodiment, and it is selectively used depending on whether the steam turbine plant is close to the sea or river.

  Similarly to the fourth embodiment, the fifth embodiment can increase the power generation output during a time period when the power demand is large, and can achieve power leveling in a day when the power demand changes sufficiently.

(Sixth embodiment)
Next, a steam turbine plant according to a sixth embodiment is shown in FIG. The steam turbine plant according to the sixth embodiment is the same as the steam turbine plant according to the fourth embodiment shown in FIG. 4, except that the confluence of the refrigerator outlet fluid 19 to the water supply system is changed from the outlet side of the condenser 5 to the inlet side. It has become the composition.

  That is, in the operation pattern B of the fourth embodiment, the refrigerator outlet fluid 19 joins the condensate 13 flowing out of the condenser 5 to become the water supply 6, but in the operation pattern B of the sixth embodiment, The refrigerator outlet fluid 19 merges with the exhaust 4 to become a condenser inlet steam 28 that is an inlet steam of the condenser 5. The condenser inlet steam 28 is cooled by the cooling water 8 in the condenser 5 and becomes the feed water 6.

  The operation patterns A and C of the sixth embodiment are performed in the same manner as the operation patterns of the fourth embodiment.

  In general, the refrigerator outlet fluid 19 is often only water when it passes through the pressure reducing valve 20, but there may be a mixed state of water and steam or a state of only steam. For this reason, depending on the operation state of the plant, there is a possibility that after the merging, the liquid is not completely reached. If gas is mixed in the water supply 6, the operation of the water supply pump 7 may not be sound. However, in 6th Embodiment, since the fluid which gas mixed into the feed water pump 7 does not flow in, there exists an effect which can ensure the soundness of the feed water pump 7. FIG.

  In the sixth embodiment, the condenser inlet steam 28 has a higher flow rate and higher temperature than the exhaust 4. Therefore, in the sixth embodiment, the vacuum degree of the condenser 5 in the operation pattern B is lower than that in the fourth embodiment, and the output of the steam turbine 3 is lower, but in the operation pattern B, the demand power is excessive. There is no problem because it is in a state.

  The sixth embodiment can also be applied to the first to third embodiments.

  Further, in the sixth embodiment, a method in which the cooling water 8 is circulated as in the first to fourth embodiments is adopted. However, as in the fifth embodiment, the system of the cooling water 8 is a non-circulation method. It may be.

  Similarly to the fourth embodiment, the sixth embodiment can increase the power generation output during a time period when the power demand is large, and can achieve power leveling in a day when the power demand changes sufficiently.

(Seventh embodiment)
Next, a steam turbine plant according to a seventh embodiment is shown in FIG. The steam turbine plant according to the seventh embodiment is the same as the steam turbine plant according to the fourth embodiment shown in FIG. 4, except that the refrigeration machine outlet fluid 19 is branched and a branch flow path toward the inlet of the condenser 5 is provided. An opening / closing valve 47 is provided in the flow path. The on-off valve 47 branches the refrigerant outlet fluid 19 that has passed through the pressure reducing valve 20 upstream of the flow regulating valve 46, and the second branched fluid 45, which is one of the branched fluids, enters the condenser 5. On the side, it merges with the exhaust 4. The first branched fluid 39, which is the other branched fluid, passes through the flow rate adjustment valve 46 and then merges with the condensate 13 flowing out from the condenser 5 to become the water supply 6.

  In the operation pattern B of the seventh embodiment, normally, the flow rate adjustment valve 46 is fully opened and the on-off valve 47 is fully closed. Then, the entire amount of the refrigerator outlet fluid 19 joins the condensate 13. In many cases, the refrigerator outlet fluid 19 is only water when it passes through the pressure reducing valve 20, but there may be a mixed state of water and steam or only steam. For this reason, depending on the operation state of the plant, there is a possibility that after mixing with the exhaust 4, the state of liquid alone cannot be obtained. If gas is mixed in the water supply 6, the operation of the water supply pump 7 may not be sound. In such a case, in the seventh embodiment, the refrigerator outlet fluid 19 is branched while adjusting the degree of branching according to the opening degree of the flow rate adjustment valve 47. At this time, the on-off valve 46 does not have to be fully opened, and the pressure reduction degree of the pressure reducing valve 20 is changed if necessary. The second branch fluid 45, which is a part of the refrigerator outlet fluid 19, merges with the exhaust 4 to become a condenser inlet steam 28 that is an inlet steam of the condenser 5, and is cooled by the cooling water 8 in the condenser 5. It is cooled and becomes condensed water 13.

  In the operation patterns A and C of the seventh embodiment, the same operation as that of the fourth embodiment is performed except that the flow rate adjustment valve 47 is also fully closed.

  In the seventh embodiment, it is possible to prevent a fluid mixed with gas from flowing into the feed water pump 7, and to ensure the soundness of the feed water pump 7. When the flow rate of the second branch fluid 45 is not zero, the condenser inlet steam 28 has a higher flow rate and higher temperature than the exhaust 4, and therefore the vacuum degree of the condenser 5 in the operation pattern B is lower than in the fourth embodiment. Although the output of the steam turbine 3 is lower, the operation pattern B often has no problem because of the surplus power. Even if there is a problem, in the sixth embodiment, the entire amount of the chiller outlet fluid 19 is always joined with the exhaust 4, whereas the steam turbine 3 is partially in terms of time and flow rate. Since the exhaust gas 4 is joined, the degree of decrease in the output of the turbine 3 is smaller than that in the sixth embodiment.

  The seventh embodiment can also be applied to the first to third embodiments.

  Further, in the seventh embodiment, a method in which the cooling water 8 is circulated as in the first to fourth embodiments and the sixth embodiment is adopted. However, as in the fifth embodiment, the cooling water 8 The system may be non-circulating.

  Similarly to the fourth embodiment, the seventh embodiment can also increase the power generation output during a time period when the power demand is large, and can achieve power leveling in a day when the power demand changes sufficiently.

(Eighth embodiment)
Next, a steam turbine plant according to an eighth embodiment is shown in FIG. In the steam turbine plant of the eighth embodiment, the cooler 27 used for cooling the cooling water 8 of the condenser 5 in the steam turbine plant of the fourth embodiment shown in FIG. And the inlet side of the condenser 5 are used for cooling the exhaust 4. For this reason, in the eighth embodiment, the cooling water 8 of the condenser 5 is cooled by the cooling tower 11.

  In the operation pattern B of the eighth embodiment, the cooling substance 22 in the fourth embodiment cools the cooling water 8 by the cooler 27, but in the eighth embodiment, the cooler 27 cools the exhaust 4 of the steam turbine 3. Cooling. The exhaust 4 is cooled by the cooling substance 22 and then flows into the condenser 5. The cooling water 8 is cooled by the cooling tower 11 and circulates through the loop of the cooling pump 9, the condenser 5 and the cooling tower 11.

  Note that the sixth embodiment or the seventh embodiment may be applied to the eighth embodiment. In this case, the point where the refrigerator outlet fluid 19 or the second branch fluid 45 joins the exhaust 4 may be upstream or downstream of the cooler 27.

  In the operation patterns A and C of the eighth embodiment, since the cooling substance 22 does not flow as in the fourth embodiment, the condensate 4 flows into the condenser 5 without being cooled by the cooler 27.

  In the eighth embodiment, the exhaust 4 of the steam turbine 3 is cooled in the cooler 27 by the cooling substance 22 and then cooled in the condenser 5 by the cooling water 8. Therefore, the condensation temperature in the condenser 5 that condenses the exhaust 4 in the eighth embodiment is lower than in the conventional steam turbine plants of the first and second examples. Therefore, the condensing pressure becomes lower, that is, the degree of vacuum becomes higher. Thereby, since the outlet pressure of the steam turbine 3 becomes lower, the enthalpy drop of the steam that can be used by the steam turbine 3 increases. The output of the steam turbine 3 increases and the amount of power generation increases. As described above, it is possible to increase power generation output during a time period during which there is a large power demand such as summer daytime, and to achieve power leveling for a day when the power demand changes sufficiently depending on the time period such as summer daytime.

  The eighth embodiment can also be applied to the first to third embodiments. The technique of the sixth or seventh embodiment can be applied to the eighth embodiment. At this time, the refrigerator outlet fluid 19 or the second refrigerator outlet fluid 39 is connected to the steam turbine 3 and the cooler 27. Or may be merged between the cooler 27 and the condenser 5.

  Further, in the eighth embodiment, a system in which the cooling water 8 is circulated is adopted as in the first to fourth embodiments, but the system of the cooling water 8 is a non-circulating system as in the fifth embodiment. It may be.

  Similarly to the fourth embodiment, the eighth embodiment can also increase the power generation output in a time zone where the power demand is large, and can achieve power leveling in a day when the power demand changes sufficiently.

(Ninth embodiment)
Next, a steam turbine plant according to a ninth embodiment is shown in FIG. The steam turbine plant of the ninth embodiment has a configuration in which a cooler 27 is provided inside the condenser 5 in the steam turbine plant of the eighth embodiment shown in FIG.

  In the eighth embodiment, the cooler 27 is disposed upstream of the condenser 5 and cools the exhaust 4. However, in the ninth embodiment, the cooler 27 is disposed inside the condenser 5.

  In the ninth embodiment, the exhaust 4 of the steam turbine 3 is cooled by the condenser 5 by the cooling water 8 while being cooled by the cooling substance 22 in the cooler 27 in the condenser 5. Therefore, in the ninth embodiment, the condensing temperature in the condenser 5 that condenses the exhaust 4 is lower than that of the conventional steam turbine plants of the first and second examples. For this reason, as in the eighth embodiment, an increase in power generation output during a time period in which the power demand is large such as summer daytime, and a one-day power leveling in which the power demand changes sufficiently depending on the time period such as summer daytime and nighttime are achieved.

  Note that the sixth embodiment or the seventh embodiment may be applied to the ninth embodiment, and in that case, the point at which the refrigerator outlet fluid 19 or the second branch fluid 45 joins the exhaust 4 is the cooler 27. It may be upstream or downstream.

  The ninth embodiment can also be applied to the first to fourth embodiments. The ninth embodiment can also apply the technology of the sixth or seventh embodiment.

  Further, in the ninth embodiment, a system in which the cooling water 8 is circulated as in the first to fourth embodiments is adopted. However, as in the fifth embodiment, the system of the cooling water 8 is a non-circulating system. It may be.

  Similarly to the eighth embodiment, the ninth embodiment can also increase the power generation output during a time period in which the power demand is large, and can achieve power leveling on a day when the power demand changes sufficiently.

(10th Embodiment)
Next, a steam turbine plant according to a tenth embodiment is shown in FIG. The steam turbine plant of the tenth embodiment has a configuration in which a cooler 27 is provided downstream of the condenser 5 in the steam turbine plant of the eighth embodiment shown in FIG. In the eighth embodiment, the cooler 27 is disposed upstream of the condenser 5 and cools the exhaust 4. However, in the tenth embodiment, the cooler 27 is disposed downstream immediately after the condenser 5.

  In the tenth embodiment, the exhaust 4 of the steam turbine 3 is cooled in the condenser 5 by the cooling water 8 and then cooled in the cooler 27 by the cooling substance 22. At this time, the cooler 27 behaves as if it is a part of the condenser 5 and the condensation temperature of the exhaust 4 is lower than that of the conventional steam turbine plants of the first and second examples. For this reason, the tenth embodiment is similar to the eighth embodiment in that the power output increases in the time zone where the power demand is large such as summer daytime, or the power level of the day when the power demand changes sufficiently depending on the time zone such as summer daytime. Is achieved. The same effect as in the eighth and ninth embodiments can be obtained.

  The tenth embodiment can also be applied to the first to fourth embodiments. In the tenth embodiment, the technology of the sixth or seventh embodiment can be applied. At this time, the refrigerator outlet fluid 19 or the second refrigerator outlet fluid 39 is the steam turbine 3 and the condenser. May be merged between the condenser 5 and the condenser 27.

  Further, in the tenth embodiment, a system in which the cooling water 8 is circulated as in the first to fourth embodiments is adopted. However, as in the fifth embodiment, the system of the cooling water 8 is a non-circulation system. It may be.

  Similarly to the eighth embodiment, the tenth embodiment can also increase the power generation output during a time period in which the power demand is large, and can achieve power leveling on a day when the power demand changes sufficiently.

(Eleventh embodiment)
Next, an eleventh embodiment will be described. The eleventh embodiment is a method for operating the steam turbine plant of any of the first to tenth embodiments. In the operation method of the eleventh embodiment, the operation of the steam turbine plant of any of the first to tenth embodiments is performed as follows. The electric power demand increases during the summer daytime, but when the electric power demand is larger than the first predetermined value, the steam turbine plant is operated in the operation pattern A mode. In order to realize the operation of the steam turbine plant in the operation pattern A mode, the steam turbine plant is operated in the operation pattern B mode in advance in a time zone in which the electric power demand is smaller than the second predetermined value. When the operation patterns A and B are not performed, the steam turbine plant is operated in the operation pattern C mode. The second predetermined value is less than or equal to the first predetermined value. A set value is provided for the power demand and used as an index for switching the operation pattern mode.

(Twelfth embodiment)
Next, a twelfth embodiment will be described. The twelfth embodiment is a method for operating the steam turbine plant of any of the first to tenth embodiments. In the operation method of the twelfth embodiment, the operation of the steam turbine plant of any of the first to tenth embodiments is performed as follows.

  The power generation amount decreases during the summer daytime, but when the power generation amount of the entire steam turbine plant is smaller than the third predetermined value, the steam turbine plant is operated in the operation pattern A mode. In order to realize the operation in the operation pattern A mode, the steam turbine plant is operated in the operation pattern B mode in advance in a time zone in which the power generation amount is larger than the fourth predetermined value. When the operation patterns A and B are not performed, the steam turbine plant is operated in the operation pattern C mode. The fourth predetermined value is greater than or equal to the third predetermined value. A set value is provided for the power generation amount and used as an indicator for switching the operation pattern mode.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the invention described in the claims and equivalents thereof as well as included in the scope and gist of the invention.

DESCRIPTION OF SYMBOLS 1 Boiler 2 Steam 3 Steam turbine 4 Exhaust 5 Condenser 6 Feed water 7 Feed water pump 8 Cooling water 9 Cooling water pump 10 Air | atmosphere 11 Cooling tower 12 Turbine inlet steam 13 Condensate 14 Branch steam 15 Flow control valve 16 Pressure reducing valve 17 Refrigerator Inlet steam 18 Refrigerating machine 19 Refrigerating machine outlet fluid 20 Pressure reducing valve 21 Refrigerant pump 22 Cooling material 23 Cooling material pump 24 Heat storage tank 25 Refrigerant 26 Flow control valve 27 Cooler 28 Condenser inlet steam 29 Extracted steam 30 Generator 31 Flow control valve 46 On-off valve 47 Flow control valve

Claims (14)

A boiler that changes the supplied water into steam;
A steam turbine driven by steam from the boiler;
A condenser for cooling the exhaust of the steam turbine with cooling water to change it into water;
A pump for supplying the boiler with water changed from the exhaust by the condenser;
A refrigerator that is driven by using a part of the steam as a heat source and cools the refrigerant;
A heat storage tank for storing the refrigerant;
A cooler that directly or indirectly cools the cooling water with the refrigerant;
With
The effluent fluid after a part of the steam has passed through the refrigerator is caused to flow between the condenser and the pump ,
A first operation pattern in which steam flows into the refrigerator to drive the refrigerator and the refrigerant does not flow from the heat storage tank, and the refrigerant flows from the heat storage tank without flowing steam into the refrigerator A steam turbine plant configured to switch between a second operation pattern and a third operation pattern in which steam does not flow into the refrigerator and the refrigerant does not flow from the heat storage tank . A boiler that changes the supplied water into steam;
A steam turbine driven by steam from the boiler;
A condenser for cooling the exhaust of the steam turbine with cooling water to change it into water;
A pump for supplying the boiler with water changed from the exhaust by the condenser;
A refrigerator that is driven by using a part of the steam as a heat source and cools the refrigerant;
A heat storage tank for storing the refrigerant;
A cooler that directly or indirectly cools the cooling water with the refrigerant;
With
An outflow fluid after a part of the steam passes through the refrigerator is caused to flow between the steam turbine and the condenser ,
A first operation pattern in which steam flows into the refrigerator to drive the refrigerator and the refrigerant does not flow from the heat storage tank, and the refrigerant flows from the heat storage tank without flowing steam into the refrigerator A steam turbine plant configured to switch between a second operation pattern and a third operation pattern in which steam does not flow into the refrigerator and the refrigerant does not flow from the heat storage tank . Wherein a part or all of the effluent, steam turbine plant according to claim 1, wherein a that can be made to flow between the condenser and the steam turbine. The cooler steam turbine plant according to any one of claims 1 to 3, characterized in that you cool the cooling water for cooling the exhaust in the condenser. The cooler steam turbine plant according to any one of claims 1 to 3, characterized in that you cool the exhaust disposed between the condenser and the steam turbine. The cooler steam turbine plant according to any one of claims 1 to 3, characterized in that you cool the exhaust provided inside the condenser. The cooler steam turbine plant according to any one of claims 1 to 3, characterized in that you cool the effluent fluid from said condenser disposed between the condenser and the pump. The refrigerator, steam turbine plant according to any one of claims 1 to 7, characterized in that that will be driven by using a branched vapor branched from an upstream of the steam turbine. Wherein comprises a steam turbine plurality of steam turbines connected in series, the refrigerator according to claim 1 to 7, characterized in that that will be driven by using a branched vapor branched from the exhaust steam of the steam turbine is not a most downstream The steam turbine plant according to any one of the above. The steam turbine includes a plurality of steam turbine arranged in parallel, characterized in that that comprise an adjustment mechanism to a state which does not flow through the vapor to one or more turbines among the steam turbine arranged in parallel The steam turbine plant according to any one of claims 1 to 9. The refrigerator, steam turbine plant according to any one of claims 1 to 7, characterized in that that will be driven by using the extraction steam bled from the middle stage of the steam turbine. Steam turbine plant according to any one of claims 1 to 11 wherein the cooling water is equal to or that will be cooled by the cooling tower using atmosphere. A method for operating a steam turbine plant according to any one of claims 1 to 12 ,
When the power demand is greater than a first predetermined value, the vehicle is operated in the second operation pattern, and when the power demand is smaller than a second predetermined value during the time period before the operation of the second operation pattern, the method of operating a steam turbine plant, characterized in that you operated in the first operation pattern. A method for operating a steam turbine plant according to any one of claims 1 to 12 ,
When the power generation amount is smaller than the first predetermined value, the second operation pattern is used for operation, and when the power demand is larger than the second predetermined value during the time period before the operation of the second operation pattern, the second operation pattern is used. An operation method for a steam turbine plant, wherein the operation is performed with one operation pattern.

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