CN107060922B - Auxiliary steam system of thermal power plant and steam supply method thereof - Google Patents
Auxiliary steam system of thermal power plant and steam supply method thereof Download PDFInfo
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- CN107060922B CN107060922B CN201710296563.3A CN201710296563A CN107060922B CN 107060922 B CN107060922 B CN 107060922B CN 201710296563 A CN201710296563 A CN 201710296563A CN 107060922 B CN107060922 B CN 107060922B
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01K—STEAM ENGINE PLANTS; STEAM ACCUMULATORS; ENGINE PLANTS NOT OTHERWISE PROVIDED FOR; ENGINES USING SPECIAL WORKING FLUIDS OR CYCLES
- F01K17/00—Using steam or condensate extracted or exhausted from steam engine plant
- F01K17/04—Using steam or condensate extracted or exhausted from steam engine plant for specific purposes other than heating
Abstract
The invention relates to the technical field of thermal power generation, in particular to an auxiliary steam system of a thermal power plant and a steam supply method of the auxiliary steam system of the thermal power plant. The auxiliary steam system comprises an auxiliary steam main pipeline of a whole plant and one or more unit auxiliary steam systems, wherein the unit auxiliary steam systems comprise a unit auxiliary steam main pipeline arranged on the auxiliary steam main pipeline of the whole plant and a low-pressure main steam extraction pipeline arranged on the unit auxiliary steam main pipeline, a first valve is arranged between the auxiliary steam main pipeline of the whole plant and the low-pressure main steam extraction pipeline on the unit auxiliary steam main pipeline, and a second valve and a first drainage pipeline arranged in front of the second valve are arranged on the low-pressure main steam extraction pipeline. When the unit operates normally, auxiliary steam in the unit auxiliary steam main pipeline of the unit is supplied by the low-pressure main steam extraction pipeline of the unit, and auxiliary steam in the whole plant auxiliary steam main pipeline is supplied by the unit auxiliary steam main pipeline of one unit of all the operation units. The running time of the starting boiler is shortened, and the safety and reliability of the auxiliary steam running are improved.
Description
Technical Field
The invention relates to the technical field of thermal power generation, in particular to an auxiliary steam system of a thermal power plant and a steam supply method of the auxiliary steam system of the thermal power plant.
Background
Thermal power plants are typically provided with one or more gas-steam combined cycle generator sets, and the functions of the auxiliary steam system of the thermal power plant include providing auxiliary steam for the shaft seal system of the unit, deoxidizing condensate during the start-up phase of the unit, and improving the yield of desalted water. At present, a whole plant auxiliary steam main pipe of an auxiliary steam system of a thermal power plant is provided with two paths of steam sources: one way is used for starting the boiler to supply steam, and the other way is used for extracting and supplying steam for cold reheat steam of the running unit.
The capacity of extracting cold reheat steam of the unit just deactivated to supply auxiliary steam main pipes of the whole plant is only about 1-4 hours, the time depends on the number of units which are put into shaft seal vacuum and the tightness of auxiliary steam systems of the whole plant, and the auxiliary steam operation of the unit needs to be ensured for about 2 hours after the unit is deactivated, so that the steam source of the auxiliary steam main pipes of the whole plant can only be switched to start the boiler for supplying steam after the unit is completely deactivated. Because the arrangement position of the starting boiler is far away from the auxiliary steam main pipe of the whole plant, when the auxiliary steam main pipe steam source of the whole plant is used for extracting steam and supplying steam by the cold reheat steam of the running unit, the starting boiler is converted into a small fire mode to run, namely the outlet door of the starting boiler is closed, and the internal pressure of the boiler is maintained by intermittent start and stop. At this time, the steam pipeline between the boiler and the auxiliary steam main pipe of the whole plant is in a non-circulation state, and the temperature of the steam pipeline is gradually reduced to the saturation temperature under the pressure. When the starting boiler is required to supply steam to the auxiliary steam main pipe of the whole plant, 30 minutes are required from the small fire mode to the big fire mode of the starting boiler, so that the response is slower, and the energy consumption utilization efficiency of the starting boiler is poorer.
Therefore, in order to ensure the safe operation of the auxiliary steam system, the steam source of the auxiliary steam main pipe of the whole plant is only supplied by the starting boiler in most cases, and the steam source of the auxiliary steam main pipe of the whole plant is only supplied by the cold re-extraction steam of the operation unit when the long-time continuous operation of the organic unit is confirmed.
However, for a unit with a running mode of day start and night stop, the unit is frequently started and stopped, the demand quantity of auxiliary steam in the unit running stage and the stopping stage is larger, and particularly under the condition that a plurality of units are started and stopped day and night, the demand quantity of auxiliary steam in the system is larger, so that the boiler needs to be started and the running mode is frequently converted. And moreover, a large amount of natural gas can be consumed when the boiler is started for auxiliary steam of the whole plant, and the cost is high. Especially, the safety of starting the boiler and supplying auxiliary steam is relatively poor, when the starting boiler in the big fire mode trips, and under the condition that the auxiliary steam users of the whole plant are more, the auxiliary steam main pipe pressure of the whole plant can rapidly drop due to the small heat capacity of the starting boiler, so that the auxiliary steam supply of a unit shaft seal system is easily interrupted suddenly, and the safety of the unit is influenced.
The heat capacity of the waste heat boiler is much larger than that of the starting boiler, if the steam of the waste heat boiler is used for supplying the auxiliary steam of the unit, even if the unit trips, the residual steam of the waste heat boiler can still be maintained for a long time for supplying the auxiliary steam of the unit, thereby being beneficial to the switching of the auxiliary steam sources. Therefore, how to put the steam of the waste heat boiler into use as the steam source of the auxiliary steam system becomes a problem to be solved urgently.
Disclosure of Invention
The invention aims to provide an auxiliary steam system and a steam supply method for a thermal power plant, which take low-pressure main steam of a waste heat boiler as a steam source of the auxiliary steam system to be used, so as to overcome the defects in the prior art.
In order to solve the technical problems, the invention adopts the following technical scheme:
the utility model provides a thermal power factory's auxiliary steam system, including the whole factory auxiliary steam female pipeline and with the whole factory auxiliary steam female pipeline be connected one or more unit auxiliary steam system, every unit auxiliary steam system all is including locating on the whole factory auxiliary steam female pipeline and leading to the unit shaft seal system the unit auxiliary steam female pipeline and locate the unit auxiliary steam female pipeline on and with the low pressure main steam extraction pipeline that exhaust-heat boiler is linked together, be equipped with first valve on the unit auxiliary steam female pipeline between whole factory auxiliary steam female pipeline and low pressure main steam extraction pipeline, be equipped with the second valve on the low pressure main steam extraction pipeline and be located the first drainage pipeline before the second valve, be equipped with first steam trap on the first drainage pipeline.
Preferably, the unit auxiliary steam bus pipeline is provided with second drain pipelines respectively in front of and behind the first valve, and the second drain pipelines are provided with second steam traps.
Preferably, a cold reheat steam extraction pipeline is arranged between the first valve and the unit shaft seal system on the unit auxiliary steam bus pipeline, the cold reheat steam extraction pipeline is communicated with a steam exhaust port of the unit high pressure cylinder, and a third valve is arranged on the cold reheat steam extraction pipeline.
Preferably, the auxiliary steam main pipeline of the unit is connected with the unit shaft seal system through a shaft seal electric heater, the shaft seal electric heater is connected with a bypass pipeline in parallel, and a bypass valve is arranged on the bypass pipeline.
Preferably, the unit shaft seal system comprises a high-medium pressure shaft seal system, the high-medium pressure shaft seal system is connected with the unit auxiliary steam main pipeline through a high-medium pressure shaft seal steam inlet valve, and the high-medium pressure shaft seal steam inlet valve is connected with an electric valve in parallel.
Preferably, the auxiliary steam parent pipeline of the whole plant is also provided with a starting boiler steam supply pipeline communicated with the starting boiler, and the starting boiler steam supply pipeline is provided with a fourth valve.
The auxiliary steam in the auxiliary steam main pipeline of the unit is supplied by the low-pressure main steam in the low-pressure main steam extraction pipeline of the unit, and the auxiliary steam in the auxiliary steam main pipeline of the whole plant is supplied by the auxiliary steam main pipeline of one unit of all the units.
Preferably, when the running unit is deactivated, the unit auxiliary steam main pipeline of the unit stops supplying steam to the whole plant auxiliary steam main pipeline, a low-pressure main steam pressure preset value is set, and when the low-pressure main steam pressure of the unit is reduced to the low-pressure main steam pressure preset value, the cold reheat steam extraction pipeline of the unit starts to supply cold reheat steam to the unit auxiliary steam main pipeline.
Preferably, after all units of the whole plant are completely deactivated, the auxiliary steam in the auxiliary steam mother pipeline of the whole plant is supplied by the start-up boiler.
Preferably, when the unit is started in a cold state, auxiliary steam in the unit auxiliary steam main pipeline of the unit is supplied by the whole plant auxiliary steam main pipeline.
Compared with the prior art, the invention has obvious progress:
the low-pressure main steam of the waste heat boiler is used as a steam source of the auxiliary steam system, and the auxiliary steam system is not required to be supplied with steam by the starting boiler when the organic units of the whole plant normally operate, so that the operation time of starting the boiler is shortened, the consumption of natural gas of the starting boiler is reduced, and the cost is reduced. The low-pressure main steam of the running unit is fully utilized to supply auxiliary steam of the unit, the advantages of short steam supply distance and small heat loss are achieved, and due to the advantages of large heat capacity of the running unit, even if the unit trips, the low-pressure main steam of the waste heat boiler can still be maintained for a long time to continuously supply auxiliary steam of the unit, the auxiliary steam source is favorably switched, and therefore the safety and reliability of auxiliary steam running of the unit are greatly improved.
Drawings
Fig. 1 is a schematic structural diagram of an auxiliary steam system of a thermal power plant according to an embodiment of the present invention.
In the figure:
100. auxiliary steam bus duct 200 of whole plant, auxiliary steam bus duct 300 of unit and low-pressure main steam extraction duct
401. First hydrophobic conduit 402, second hydrophobic conduit 403, and third hydrophobic conduit
404. Fourth hydrophobic conduit 405, fifth hydrophobic conduit 406, sixth hydrophobic conduit
500. Cold reheat steam extraction line 600, bypass line 700, and start-up boiler steam supply line
1. First valve 2, second valve 3, third valve
41. First steam trap 411, first inlet isolation valve 412, first outlet isolation valve
42. Second steam trap 421, second inlet isolation valve 422, second outlet isolation valve
43. Third steam trap 431, third inlet isolation valve 432, third outlet isolation valve
44. Hydrophobic isolation valve 45, hydrophobic pneumatic valve 4 and regulating valve
5. Regulating valve 6, shaft seal electric heater 7 and bypass valve
8. High-medium pressure shaft seal system 9, low-pressure shaft seal system 10 and high-medium pressure shaft seal steam inlet valve
11. Electric valve 12, fourth valve 13 and check valve
Detailed Description
The following describes the embodiments of the present invention in further detail with reference to the accompanying drawings. These embodiments are merely illustrative of the present invention and are not intended to be limiting.
In the description of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the apparatus or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.
In the description of the present invention, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.
Furthermore, in the description of the present invention, unless otherwise indicated, the meaning of "a plurality" is two or more.
Example 1
An embodiment provides an embodiment of a steam supply method of a steam auxiliary system of a thermal power plant. The thermal power plant is provided with one or more units, the auxiliary steam system comprises a whole plant auxiliary steam main pipeline and unit auxiliary steam main pipelines of all units, and all the unit auxiliary steam main pipelines are connected with the whole plant auxiliary steam main pipeline.
The auxiliary steam supply method of the auxiliary steam system of the thermal power plant of the first embodiment is that when the unit operates normally, auxiliary steam in the unit auxiliary steam main pipeline of the operating unit is supplied by low-pressure main steam in the low-pressure main steam extraction pipeline of the unit, and auxiliary steam in the whole-plant auxiliary steam main pipeline is supplied by unit auxiliary steam main pipelines of one unit of all operating units.
According to the auxiliary steam system steam supply method of the thermal power plant, low-pressure main steam of the waste heat boiler is used as a steam source of the auxiliary steam system, the auxiliary steam system is not required to be started for steam supply when the whole plant organic unit normally operates, the operation time of starting the boiler is shortened, the consumption of natural gas of the starting boiler is reduced, and the cost is reduced. The low-pressure main steam of the running unit is fully utilized to supply auxiliary steam of the unit, the advantages of short steam supply distance and small heat loss are achieved, and due to the advantages of large heat capacity of the running unit, even if the unit trips, the low-pressure main steam of the waste heat boiler can still be maintained for a long time to continuously supply auxiliary steam of the unit, the auxiliary steam source is favorably switched, and therefore the safety and reliability of auxiliary steam running of the unit are greatly improved.
Further, in the first embodiment, when the operation unit is deactivated, if the auxiliary steam in the auxiliary steam main pipeline of the whole plant is supplied by the auxiliary steam main pipeline of the unit, the auxiliary steam main pipeline of the unit stops supplying steam to the auxiliary steam main pipeline of the whole plant. When the operation unit is stopped and started, the low-pressure main steam extraction pipeline of the unit continues to supply steam to the auxiliary steam main pipeline of the unit, but as the unit stops operating, the pressure of the low-pressure main steam of the stopped unit continuously drops. The embodiment sets a low-pressure main steam pressure preset value, the low-pressure main steam pressure preset value is not lower than the minimum value of auxiliary steam pressure required by the auxiliary steam main pipeline of the unit when the unit is stopped, and when the low-pressure main steam pressure of the unit is reduced to the low-pressure main steam pressure preset value, the cold reheat steam extraction pipeline of the unit starts to supply cold reheat steam to the auxiliary steam main pipeline of the unit, and an auxiliary steam source in the auxiliary steam main pipeline of the unit is switched from the low-pressure main steam of the unit to the cold reheat steam of the unit so as to meet the requirement of the auxiliary steam pressure required by the auxiliary steam main pipeline of the unit. The cold reheat steam of the unit is independently used for supplying steam to the unit auxiliary steam main pipeline of the unit, and the steam supply range is greatly reduced, so that the time for the cold reheat steam to supply the unit auxiliary steam is greatly increased, the requirement of the unit on auxiliary steam operation time when the unit is stopped can be met, and the steam supply by starting a boiler is not needed. And the switching response speed between the low-pressure main steam supply and the cold reheat steam supply of the unit is high, so that the safety of auxiliary steam operation of the unit can be ensured.
Further, in the first embodiment, after all units of the whole plant are deactivated, the auxiliary steam in the auxiliary steam main pipe of the whole plant is supplied from the start-up boiler. Therefore, the auxiliary steam system steam supply method of the thermal power plant of the embodiment supplies steam to the auxiliary steam system by the starting boiler only after all units of the whole plant are completely deactivated, thereby avoiding the need of frequently switching the operation mode of the starting boiler due to frequent start and stop of each unit when the starting boiler is only adopted to supply auxiliary steam of the whole plant, and greatly reducing the operation time of the starting boiler and the consumption of natural gas.
Further, in the first embodiment, when the unit is started in a cold state, the auxiliary steam in the unit auxiliary steam main pipeline of the unit is supplied by the whole plant auxiliary steam main pipeline. If the whole plant inorganic group runs before, the auxiliary steam in the auxiliary steam main pipeline of the whole plant is the auxiliary steam supplied by the starting boiler; if the organic unit normally operates before, the auxiliary steam in the auxiliary steam main pipeline of the whole plant is the auxiliary steam supplied by the auxiliary steam main pipeline of the unit.
Example two
Embodiment two provides an embodiment of the auxiliary steam system of the thermal power plant, wherein the thermal power plant is provided with one or more units. The auxiliary steam system of the thermal power plant of the second embodiment can realize the auxiliary steam system steam supply method of the thermal power plant of the first embodiment.
As shown in fig. 1, the auxiliary steam system of the thermal power plant of the second embodiment includes a whole plant auxiliary steam bus duct 100 and one or more unit auxiliary steam systems (only one is shown in fig. 1) connected to the whole plant auxiliary steam bus duct 100. Each unit auxiliary steam system comprises a unit auxiliary steam parent pipeline 200 and a low-pressure main steam extraction pipeline 300. The auxiliary steam main pipeline 200 is arranged on the auxiliary steam main pipeline 100 of the whole plant, and the auxiliary steam main pipeline 200 of the unit is led to the unit shaft seal system and is used for conveying auxiliary steam to the unit shaft seal system. The low-pressure main steam extraction pipeline 300 is arranged on the auxiliary steam main pipeline 200 of the unit, and the low-pressure main steam extraction pipeline 300 is communicated with the waste heat boiler and is used for extracting low-pressure main steam in the waste heat boiler and conveying the extracted low-pressure main steam into the auxiliary steam main pipeline 200 of the unit. A first valve 1 is arranged on the auxiliary steam main pipeline 200 of the unit between the auxiliary steam main pipeline 100 of the whole plant and the low-pressure main steam extraction pipeline 300. The low-pressure main steam extraction pipeline 300 is provided with a second valve 2 and a first drain pipeline 401, and the first drain pipeline 401 is positioned in front of the second valve 2. The first drain pipe 401 is provided with a first steam trap 41, and the first drain pipe 401 is provided with a first inlet isolation valve 411 and a first outlet isolation valve 412 respectively in front of and behind the first steam trap 41. The first drainage pipe 401 is used for timely draining drainage before the second valve 2 in the low-pressure main steam extraction pipe 300 when the second valve 2 is opened, so that water impact is avoided when the low-pressure main steam extraction pipe 300 supplies steam to the auxiliary steam main pipe 200 of the unit, and operation safety of an auxiliary steam system is ensured.
In the second embodiment, a check valve 13 is further disposed on the low-pressure main steam extraction pipe 300 downstream of the second valve 2 to prevent steam in the auxiliary steam main pipe 200 from entering the low-pressure main steam extraction pipe 300. To further ensure that the low pressure main steam extraction pipeline 300 does not generate water impact when supplying steam to the auxiliary steam main pipeline 200 of the unit, a fifth drain pipeline 405 is further provided in the present embodiment before and after the check valve 13.
In the auxiliary steam system of the thermal power plant of the second embodiment, when the unit operates normally, the second valve 2, the first inlet isolation valve 411 and the first outlet isolation valve 412 of the operating unit are opened, and the first steam trap 41 is started, so that normal steam supply to the auxiliary steam main pipeline 200 of the unit through the low-pressure main steam extraction pipeline 300 can be realized; at the same time, the first valve 1 can be opened, and the auxiliary steam main pipeline 200 of the running unit supplies steam to the auxiliary steam main pipeline 100 of the whole plant. Therefore, the low-pressure main steam of the waste heat boiler is used as a steam source of the auxiliary steam system, the auxiliary steam system is not required to be started for supplying steam when the organic units of the whole plant normally operate, the operation time for starting the boiler is shortened, the consumption of natural gas for starting the boiler is reduced, and the cost is reduced. The low-pressure main steam of the running unit is fully utilized to supply auxiliary steam of the unit, the advantages of short steam supply distance and small heat loss are achieved, and due to the advantages of large heat capacity of the running unit, even if the unit trips, the low-pressure main steam of the waste heat boiler can still be maintained for a long time to continuously supply auxiliary steam of the unit, the auxiliary steam source is favorably switched, and therefore the safety and reliability of auxiliary steam running of the unit are greatly improved.
Further, in the second embodiment, the unit auxiliary steam bus pipeline 200 is provided with a second drain pipeline 402 respectively before and after the first valve 1, the second drain pipeline 402 is provided with a second steam trap 42, and the second drain pipeline 402 is provided with a second inlet isolation valve 421 and a second outlet isolation valve 422 respectively before and after the second steam trap 42. The second drain pipe 402 is used for timely draining the drain water before and after the first valve 1 in the auxiliary steam bus pipe 200 of the unit when the first valve 1 is opened, so that water impact is prevented, and the operation safety of an auxiliary steam system is ensured.
Further, in the second embodiment, a cold reheat steam extraction pipe 500 is disposed between the first valve 1 and the shaft seal system of the unit on the auxiliary steam bus 200 of the unit, and the cold reheat steam extraction pipe 500 is connected to the steam outlet of the high pressure cylinder of the unit for extracting the cold reheat steam exhausted from the high pressure cylinder and delivering the extracted cold reheat steam to the auxiliary steam bus 200 of the unit. A third valve 3 is provided on the cold reheat steam extraction pipe 500. When the running unit is in a stop state, if the unit auxiliary steam main pipeline 200 of the running unit supplies steam to the whole plant auxiliary steam main pipeline 100, the first valve 1 is closed first, so that the unit auxiliary steam main pipeline 200 of the running unit stops supplying steam to the whole plant auxiliary steam main pipeline 100. When the operation unit is stopped, the low-pressure main steam extraction pipeline 300 of the unit continues to supply steam to the auxiliary steam main pipeline 200 of the unit, when the low-pressure main steam pressure of the unit is reduced to a preset value which is not lower than the low-pressure main steam pressure of the minimum auxiliary steam pressure required by the auxiliary steam main pipeline 200 of the unit when the unit is stopped, the third valve 3 is opened, and then the supply of auxiliary steam sources in the auxiliary steam main pipeline 200 of the unit is switched from the supply of the low-pressure main steam extraction pipeline 300 to the supply of the cold reheat steam extraction pipeline 500. The cold reheat steam of the unit is used for independently supplying steam to the unit auxiliary steam main pipeline 200 of the unit, and the steam supply range is greatly reduced, so that the time for the cold reheat steam to supply the unit auxiliary steam is greatly increased, the requirement of the unit on auxiliary steam operation time when the unit is stopped can be met, and the steam supply by starting a boiler is not needed. And the switching response speed between the low-pressure main steam supply and the cold reheat steam supply of the unit is high, so that the safety of auxiliary steam operation of the unit can be ensured.
In the second embodiment, the cold reheat steam extraction pipe 500 is located between the first valve 1 and the low pressure main steam extraction pipe 300, and in order to further ensure that no water impact phenomenon occurs in the unit auxiliary steam bus 200, a sixth drain pipe 406 is further disposed between the cold reheat steam extraction pipe 500 and the low pressure main steam extraction pipe 300 on the unit auxiliary steam bus 200.
Further, in the second embodiment, a third drain pipe 403 is disposed on the cold reheat steam extraction pipe 500 after the third valve 3, a third steam trap 43 is disposed on the third drain pipe 403, and a third inlet isolation valve 431 and a third outlet isolation valve 432 are disposed on the third drain pipe 403 before and after the third steam trap 43, respectively. The third drain pipe 403 is used for timely discharging drain water after the third valve 3 in the cold reheat steam extraction pipe 500 when the third valve 3 is opened, so that water impact is avoided, and operation safety of the auxiliary steam system is ensured.
Further, in the second embodiment, the cold reheat steam extraction pipe 500 is further provided with a tuning valve 4 and a tuning valve 5 in sequence from upstream to downstream, the tuning valve 5 is located upstream of the third valve 3, a fourth drain pipe 404 is provided after the tuning valve 4, and the fourth drain pipe 404 is provided with a drain isolation valve 44 and a drain pneumatic valve 45 in sequence from upstream to downstream. When the low-pressure main steam pressure of the unit is reduced to a preset low-pressure main steam pressure value and the cold reheat steam extraction pipeline 500 of the unit is started to supply cold reheat steam to the auxiliary steam main pipeline 200 of the unit in the operation unit shutdown process, the tuning valve 4 is slightly opened, and meanwhile, the drainage isolating valve 44 and the drainage pneumatic valve 45 on the fourth drainage pipeline 404 are opened, so that the pipeline after the tuning valve 4 is warmed; after the heating pipe is completed, the adjusting valve 5 is slightly opened, and the pipeline behind the adjusting valve 5 is heated; after the heating pipe is completed, the adjusting valve 5 is closed, the foot adjusting valve 4 is opened, the foot third valve 3 is opened, the third inlet isolation valve 431 and the third outlet isolation valve 432 are opened, and the third steam trap 43 is started. And (3) adjusting the pressure of the cold reheat steam in the cold reheat steam extraction pipeline 500 to a required preset value, and when the auxiliary steam pressure value in the auxiliary steam main pipeline 200 of the unit is reduced to the preset value, opening the adjusting valve 5, and starting to supply steam to the auxiliary steam main pipeline 200 of the unit through the cold reheat steam extraction pipeline 500. Thereby realizing that the auxiliary steam source in the auxiliary steam main pipeline 200 of the unit is switched from being supplied by the low-pressure main steam extraction pipeline 300 to being supplied by the cold reheat steam extraction pipeline 500 when the unit is deactivated.
Further, in the second embodiment, the auxiliary steam main pipeline 100 of the whole plant is further provided with a start-up boiler steam supply pipeline 700, and the start-up boiler steam supply pipeline 700 is communicated with the start-up boiler and is used for conveying steam in the start-up boiler to the auxiliary steam main pipeline 100 of the whole plant. A fourth valve 12 is provided on the start-up boiler steam supply line 700. When all units in the whole plant are completely deactivated, the fourth valve 12 can be opened, and the starting boiler supplies steam to the auxiliary steam main pipeline 100 of the whole plant through the starting boiler steam supply pipeline 700 so as to prepare for cold starting of the units. The auxiliary steam system of the thermal power plant supplies steam to the auxiliary steam main pipeline 100 of the whole plant by the starting boiler only after all units of the whole plant are completely stopped, so that the situation that the starting boiler needs to frequently switch operation modes due to frequent starting and stopping of each unit when the starting boiler is only adopted for supplying auxiliary steam of the whole plant is avoided, and the operation time of the starting boiler and the consumption of natural gas are greatly reduced.
In the second embodiment, the first valve 1, the second valve 2, the third valve 3, the tuning valve 4 and the fourth valve 12 are all electric valves, and the first steam trap 41, the second steam trap 42 and the third steam trap 43 are all automatic steam traps. The automatic control of the operation of the auxiliary steam system can be realized.
Further, in the second embodiment, the unit shaft seal system includes a high-medium pressure shaft seal system 8 and a low-pressure shaft seal system, wherein the high-medium pressure shaft seal system 8 has a certain requirement on the temperature of the shaft seal steam. The auxiliary steam main pipeline 200 of the unit is connected with a shaft seal system of the unit through the shaft seal electric heater 6, and low-pressure main steam in the low-pressure main steam extraction pipeline 300 is heated by the shaft seal electric heater 6 and then is sent to the shaft seal system of the unit, so that the temperature requirement of the shaft seal system of the unit on shaft seal steam is met.
When the unit normally operates, the high and medium pressure shaft seal system 8 is in a self-sealing state, namely, the high and medium pressure shaft seal system 8 does not need to supply shaft seal steam outside at the moment, and the sealing of the high and medium pressure shaft seal system 8 can be maintained by steam leaked from the inside of the high and medium pressure cylinder. At this time, if the shaft seal electric heater 6 fails, the sealing of the high and medium pressure shaft seal system 8 is not affected. However, when the unit is in a non-use state, because no steam exists in the high-medium pressure cylinder, the shaft seal steam of the high-medium pressure shaft seal system 8 needs to be switched to the external steam supply, and if the shaft seal electric heater 6 is in a fault state at this time, the temperature of the steam entering the high-medium pressure shaft seal system 8 is inevitably reduced rapidly, so that the normal operation of the steam turbine is affected. To avoid this problem, in the second embodiment, the shaft seal electric heater 6 is connected in parallel with a bypass pipe 600, and a bypass valve 7 is provided in the bypass pipe 600. When the unit is in a non-use state, an auxiliary steam source in the auxiliary steam main pipeline 200 of the unit is switched from low-pressure main steam to cold reheat steam, and the temperature of the cold reheat steam can meet the temperature requirement of the high-medium-pressure shaft seal system 8 on shaft seal steam. At this time, even if the shaft seal electric heater 6 is in a fault state, cold reheat steam in the unit auxiliary steam parent pipeline 200 can still be sent into the unit shaft seal system through the bypass valve 7 on the bypass pipeline 600, so that the shaft seal steam supply and temperature requirements of the shaft seal system are met, and meanwhile, the shaft seal electric heater 6 in the fault state is isolated from the system for overhauling. In order to prevent leakage of the bypass valve 7 on the bypass pipe 600 from causing low temperature at the outlet of the shaft seal electric heater 6, it is preferable that two bypass valves 7 are connected in series on the bypass pipe 600 in the second embodiment.
Further, in the second embodiment, the high-medium pressure shaft seal system 8 is connected with the auxiliary steam bus pipeline 200 of the unit through the high-medium pressure shaft seal steam inlet valve 10, and the high-medium pressure shaft seal steam inlet valve 10 is connected with an electric valve 11 in parallel. When the unit is started in a cold state, the high-medium pressure shaft seal steam inlet valve 10 cannot be opened due to logic limiting conditions in the starting stage of the unit shaft seal system, so that the use speed of the unit shaft seal system is affected, and the starting speed of the unit shaft seal system can be accelerated by opening the electric valve 11. When the logic limitation condition of the high-medium pressure shaft seal steam inlet valve 10 is released, the electric valve 11 can be closed. After the unit normally operates, the high-medium pressure shaft seal system 8 is switched to self-sealing steam supply, and external steam supply is stopped, so that the electric valve 11 is required to be opened to maintain the circulation of steam in the pipeline, water accumulation in the pipeline is prevented, and the situation that the high-medium pressure shaft seal system 8 is switched to external steam supply from self-sealing is avoided. After the unit shaft seal system is deactivated, the electric valve 11 is closed to prevent steam from being fed into the high and medium pressure shaft seal system 8. In the process of frequent start and stop of the unit, the unit shaft seal system is frequently switched between the on-off state and the off-off state, and the electric valve 11 is adopted to realize remote control, so that the automatic control level is improved, and the manual work intensity is reduced.
In summary, the auxiliary steam system steam supply method of the thermal power plant and the auxiliary steam system of the thermal power plant fully utilize the low-pressure main steam and the cold reheat steam of the waste heat boiler to maintain auxiliary steam operation of each unit in the operation and the deactivation stage, greatly reduce the operation time of starting the boiler and reduce the consumption and cost of natural gas. And the low-pressure main steam and the cold reheat steam of the unit supply auxiliary steam for the unit, so that the safety and reliability of the auxiliary steam operation of the unit are greatly improved.
The foregoing is merely a preferred embodiment of the present invention, and it should be noted that modifications and substitutions can be made by those skilled in the art without departing from the technical principles of the present invention, and these modifications and substitutions should also be considered as being within the scope of the present invention.
Claims (10)
1. The utility model provides an assist vapour system of thermal power factory, its characterized in that, including whole factory assist vapour female pipeline (100) and with whole factory assist vapour female pipeline (100) be connected one or more unit assist vapour system, every unit assist vapour system all including locating on whole factory assist vapour female pipeline (100) and lead to unit shaft seal system's unit assist vapour female pipeline (200) and locate on unit assist vapour female pipeline (200) and with waste heat boiler be linked together low pressure main steam extraction pipeline (300), be equipped with first valve (1) on unit assist vapour female pipeline (200) with be equipped with between low pressure main steam extraction pipeline (300) in whole factory assist vapour female pipeline (100), be equipped with second valve (2) and be located on low pressure main steam extraction pipeline (300) first hydrophobic pipeline (401) before second valve (2), be equipped with first steam trap (41) on first hydrophobic pipeline (401), first valve (412) are equipped with first steam trap (41) respectively before first water trap (41) and first isolated import.
2. The auxiliary steam system of a thermal power plant according to claim 1, wherein the auxiliary steam main pipeline (200) of the unit is provided with second drain pipelines (402) respectively in front of and behind the first valve (1), and the second drain pipelines (402) are provided with second steam traps (42).
3. The auxiliary steam system of a thermal power plant according to claim 1, wherein a cold reheat steam extraction pipeline (500) is arranged between the first valve (1) and the unit shaft seal system on the unit auxiliary steam main pipeline (200), the cold reheat steam extraction pipeline (500) is communicated with a steam outlet of a unit high pressure cylinder, and a third valve (3) is arranged on the cold reheat steam extraction pipeline (500).
4. The auxiliary steam system of a thermal power plant according to claim 1, wherein the unit auxiliary steam main pipeline (200) is connected with the unit shaft seal system through a shaft seal electric heater (6), the shaft seal electric heater (6) is connected with a bypass pipeline (600) in parallel, and the bypass pipeline (600) is provided with a bypass valve (7).
5. The auxiliary steam system of a thermal power plant according to claim 1, wherein the unit shaft seal system comprises a high-medium pressure shaft seal system (8), the high-medium pressure shaft seal system (8) is connected with the unit auxiliary steam main pipeline (200) through a high-medium pressure shaft seal steam inlet valve (10), and the high-medium pressure shaft seal steam inlet valve (10) is connected with an electric valve (11) in parallel.
6. The auxiliary steam system of a thermal power plant according to claim 1, wherein the auxiliary steam main pipeline (100) of the whole plant is further provided with a starting boiler steam supply pipeline (700) communicated with a starting boiler, and the starting boiler steam supply pipeline (700) is provided with a fourth valve (12).
7. A method for supplying steam by an auxiliary steam system of a thermal power plant, characterized in that the auxiliary steam in the auxiliary steam main pipeline of the unit is supplied by low-pressure main steam in the low-pressure main steam extraction pipeline of the unit when the unit is operating normally, and the auxiliary steam in the auxiliary steam main pipeline of the whole plant is supplied by the auxiliary steam main pipeline of one unit of all units.
8. The method for supplying steam to auxiliary steam system of thermal power plant according to claim 7, wherein when the operation unit is deactivated, the auxiliary steam main pipeline of the unit stops supplying steam to the auxiliary steam main pipeline of the whole plant, a low-pressure main steam pressure preset value is set, and when the low-pressure main steam pressure of the unit is reduced to the low-pressure main steam pressure preset value, the cold reheat steam extraction pipeline of the unit starts to supply cold reheat steam to the auxiliary steam main pipeline of the unit.
9. The method for supplying steam to auxiliary steam system of thermal power plant according to claim 7, wherein after all units of the whole plant are deactivated, the auxiliary steam in auxiliary steam main pipe of the whole plant is supplied by start-up boiler.
10. The method for supplying steam to auxiliary steam system of thermal power plant according to claim 7, wherein the auxiliary steam in the auxiliary steam main pipeline of the unit is supplied by the auxiliary steam main pipeline of the whole plant when the unit is started in cold state.
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| CN111255536B (en) * | 2020-01-22 | 2022-08-30 | 中国能源建设集团广东省电力设计研究院有限公司 | FCB operation method of gas-steam unit power plant |
| CN113591262A (en) * | 2021-03-15 | 2021-11-02 | 西安西热节能技术有限公司 | Method for constructing multi-parameter steam source auxiliary steam header system |
| CN114934817B (en) * | 2022-04-28 | 2023-11-17 | 中国电建集团华东勘测设计研究院有限公司 | Shaft seal steam supply system of middle-low pressure cylinder type steam turbine and operation method |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001090507A (en) * | 1999-09-24 | 2001-04-03 | Hitachi Ltd | Electric power plant |
| CN102996191A (en) * | 2012-12-26 | 2013-03-27 | 北京国电蓝天节能科技开发有限公司 | Double-extraction adjustable heating system of thermal power generating unit |
| CN205480920U (en) * | 2016-03-14 | 2016-08-17 | 西安热工研究院有限公司 | System for power station unit auxiliary steam header utilizes local boiler to supply vapour |
| CN106246245A (en) * | 2016-08-29 | 2016-12-21 | 华能国际电力开发公司铜川照金电厂 | A kind of method shortening unit starting time and energy conservation starting |
| CN206035552U (en) * | 2016-09-06 | 2017-03-22 | 上海电气电站设备有限公司 | Cogeneration vapour turbine system |
| CN206035553U (en) * | 2016-09-06 | 2017-03-22 | 上海电气电站设备有限公司 | Cogeneration system of combined cycle |
| CN206055732U (en) * | 2016-08-30 | 2017-03-29 | 大唐东北电力试验研究所有限公司 | A kind of new heat-supplying unit |
| CN206816311U (en) * | 2017-04-28 | 2017-12-29 | 申能股份有限公司 | The auxiliary vapour system in thermal power plant |
-
2017
- 2017-04-28 CN CN201710296563.3A patent/CN107060922B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001090507A (en) * | 1999-09-24 | 2001-04-03 | Hitachi Ltd | Electric power plant |
| CN102996191A (en) * | 2012-12-26 | 2013-03-27 | 北京国电蓝天节能科技开发有限公司 | Double-extraction adjustable heating system of thermal power generating unit |
| CN205480920U (en) * | 2016-03-14 | 2016-08-17 | 西安热工研究院有限公司 | System for power station unit auxiliary steam header utilizes local boiler to supply vapour |
| CN106246245A (en) * | 2016-08-29 | 2016-12-21 | 华能国际电力开发公司铜川照金电厂 | A kind of method shortening unit starting time and energy conservation starting |
| CN206055732U (en) * | 2016-08-30 | 2017-03-29 | 大唐东北电力试验研究所有限公司 | A kind of new heat-supplying unit |
| CN206035552U (en) * | 2016-09-06 | 2017-03-22 | 上海电气电站设备有限公司 | Cogeneration vapour turbine system |
| CN206035553U (en) * | 2016-09-06 | 2017-03-22 | 上海电气电站设备有限公司 | Cogeneration system of combined cycle |
| CN206816311U (en) * | 2017-04-28 | 2017-12-29 | 申能股份有限公司 | The auxiliary vapour system in thermal power plant |
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