Auxiliary power grid peak shaving and heat supply device and method for double-reheat unit

Abstract

The application is a kind of secondary reheat unit auxiliary power grid peak shaving and heating device and method, aiming at the problem of low efficiency caused by unreasonable use of existing bypass system, a kind of secondary reheat unit auxiliary power grid peak shaving and heating device, comprising: a steam turbine system, an ultrahigh pressure bypass utilization system, including a boiler system, a main steam pipeline is arranged at the outlet of the boiler system, the main steam pipeline is connected with a main steam branch pipeline and an ultrahigh bypass, the ultrahigh bypass is connected with an ultrahigh bypass auxiliary road;The high pressure bypass utilization system includes a primary reheating system, the primary reheating system is connected with the boiler system through the ultrahigh bypass and the main steam pipeline;The low pressure bypass utilization system includes a secondary reheating system, the secondary reheating system is connected with the primary reheating system, the secondary reheating system is connected with a medium pressure cylinder through a medium pressure cylinder inlet steam pipeline, a heating system, a feedwater system, a heat exchange system and a condensate system.The application uses bypass technology for heating, which meets peak shaving and heating at the same time, and achieves multiple purposes at once.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of coal machines, and particularly relates to a secondary reheat unit auxiliary power grid peak shaving and heat supply device and method. BACKGROUND

[0002] In order to achieve the goal of carbon peak and carbon neutralization, the State Energy Administration clearly requires that coal-fired units be upgraded and modified. This indicates that thermal power units need to change from power supply type to clean energy supply type. In order to stabilize the power grid safety, the unit needs to be more deeply peak shaved, but there are many difficulties in the process of unit peak shaving, such as how the steam quantity of the steam turbine changes and the boiler combustion.

[0003] The existing steam turbine bypass control system is a component of the modern unit thermal system. Its function is to coordinate the imbalance between the steam production of the boiler and the steam consumption of the steam turbine. When the operation of the boiler and the steam turbine does not match, when the steam quantity generated by the boiler is greater than the steam quantity required by the steam turbine under the load transient transition condition, the excess part can not enter the steam turbine but be directly introduced into the condenser after being reduced in temperature and pressure through the bypass, thereby maintaining the stability of the boiler operation and reducing or even avoiding the action of the boiler safety valve.

[0004] When the steam turbine starts or sheds load, the reheater may be overheated and burned out due to no steam flow or insufficient steam flow. By sending steam into the reheater through the bypass system, dry burning of the reheater can be effectively prevented, and the reheater can be protected from being damaged.

[0005] Although the steam turbine bypass system has significant advantages in protecting equipment, adjusting load and adapting to different working conditions, the steam turbine bypass system has problems of low turbine efficiency and increased energy consumption in use. At the same time, sudden changes in steam quantity during key periods such as unit startup or load change may cause fluctuations in system parameters, which threatens the safe operation of the unit. In actual application, various factors need to be considered comprehensively to seek a more reasonable and efficient steam utilization scheme. SUMMARY

[0006] In view of the problems existing in the prior art, the application designs a secondary reheat unit auxiliary power grid peak shaving and heat supply device and method, which realizes unit peak shaving, maintains steam turbine no-load operation or brings auxiliary power operation at low load of the unit, allows shutdown without stopping the boiler in case of steam turbine accident, and keeps the boiler in a hot standby state so that the unit can quickly restore grid power generation after troubleshooting, thereby reducing downtime and being conducive to the stability of the entire system. In addition, the bypass system is used to assist heat supply, and energy efficiency is maximized.

[0007] The secondary reheat unit auxiliary power grid peak shaving and heat supply device of the application comprises:

[0008] A steam turbine system for generating steam to drive a steam turbine to work, comprising an ultra-high pressure cylinder, a high pressure cylinder, a medium pressure cylinder and a low pressure cylinder;

[0009] An ultra-high pressure bypass utilization system, comprising a boiler system, wherein an outlet of the boiler system is provided with a main steam pipeline, the main steam pipeline is connected with a main steam branch pipeline and an ultra-high pressure bypass, the boiler system is connected with the ultra-high pressure cylinder through the main steam branch pipeline for delivering steam to the ultra-high pressure cylinder, and the ultra-high pressure bypass is connected with an ultra-high pressure bypass branch pipeline;

[0010] A high pressure bypass utilization system, comprising a primary reheating system, wherein the primary reheating system is connected with the boiler system through the ultra-high pressure bypass and the main steam pipeline, and the boiler system provides steam to the primary reheating system, the primary reheating system is connected with the ultra-high pressure cylinder through an ultra-high pressure cylinder exhaust pipeline, and the steam generated by the ultra-high pressure cylinder is discharged into the primary reheating system, and the primary reheating system is connected with the high pressure cylinder through a high pressure cylinder inlet pipeline, and the steam of the primary reheating system enters the high pressure cylinder to drive the high pressure cylinder to rotate;

[0011] A low pressure bypass utilization system, comprising a secondary reheating system, wherein an outlet of the secondary reheating system is connected with a medium pressure cylinder inlet pipeline;

[0012] The secondary reheating system is connected with the primary reheating system through a high pressure bypass, and the secondary reheating system is connected with the medium pressure cylinder through the medium pressure cylinder inlet pipeline for providing steam to the medium pressure cylinder;

[0013] A heat supply system, comprising a low temperature hot water user, an industrial hot water user and a high temperature hot water user, wherein the low temperature hot water user is connected with the secondary reheating system through a low pressure bypass steam stabilizing tank;

[0014] A feedwater system, connected with the boiler system, the industrial hot water user and the high temperature hot water user;

[0015] A heat exchange system, connected with the boiler system, the primary reheating system and the secondary reheating system, wherein the heat exchange system is used for water and steam heat exchange with the primary reheating system and the secondary reheating system respectively, and provides water for the boiler system;

[0016] A condensate water system, connected with the secondary reheating system and the feedwater system.

[0017] In the application, the steam is used multiple times by setting the primary reheat system and the secondary reheat system, the utilization efficiency is high, and the combustion of the boiler can be ensured and the operation of the steam turbine can be stabilized, the bypass system controls the boiler steam temperature, when the unit is cold started, the steam quantity generated by the boiler is larger than the steam quantity required by the steam turbine when the steam turbine is started, the speed is increased or the load is started, at this time, the bypass system can be used as a starting exhaust. When hot state is started, after using the bypass system, the boiler can operate at a larger combustion rate and a higher evaporation quantity, the steam temperature is accelerated to match the metal temperature of the steam turbine, so that the starting time is shortened. When the power grid is peak-regulated, the bypass system can assist heating, maintain stable combustion parameters, and the boiler is stopped due to a large amount of steam adjustment. When the load is increased, the steam turbine can be quickly switched to maintain the steam supply, prevent the steam turbine speed from being reduced due to insufficient steam supply. The unit peak regulation can also be realized, the steam turbine is maintained in an idle operation or a plant power operation at a low load, the steam turbine is allowed to be stopped without stopping the boiler in an accident, the boiler is in a hot standby state, so that the unit can quickly restore grid power generation after troubleshooting, thereby reducing the downtime and being beneficial to the stability of the whole system.

[0018] Further, the heat exchange system comprises a first steam heat exchanger, a second steam heat exchanger, a third steam heat exchanger, a first steam cooler, a second steam cooler, a third steam cooler and a steam header, wherein the first steam heat exchanger is connected with the first steam cooler, the second steam heat exchanger is connected with the second steam cooler, the third steam heat exchanger is connected with the third steam cooler, the first steam heat exchanger, the second steam heat exchanger and the third steam heat exchanger are connected with the steam header, the first steam heat exchanger, the second steam heat exchanger and the third steam heat exchanger are connected with a water supply pipeline for conveying water for the boiler system, and the steam header supplies heat to a high-temperature hot water user.

[0019] Further, the first steam heat exchanger is connected with the boiler system through an ultrahigh bypass auxiliary road, the second steam heat exchanger is connected with the primary reheat system through a high bypass auxiliary road connected with a high-pressure bypass, and the third steam heat exchanger is connected with the secondary reheat system through a low bypass auxiliary road.

[0020] Further, the feedwater system comprises a water storage tank, a water pump, a deaerator and a feedwater pump turbine, the water storage tank is connected with the water supply pipeline through a water storage pipeline, the water storage tank sends water to the boiler system and an industrial hot water user through the water pump, and a feedwater pump preposition system is arranged between the deaerator and the feedwater pump turbine.

[0021] Further, the condensate water system comprises a low-pressure heater, a multi-stage heat exchanger and a condenser, the low-pressure heater is connected with the low-pressure bypass steam stabilizing tank through a condensate water bypass, the low-pressure heater is connected with the condenser through a condensate water pump, the low-pressure heater is connected with the multi-stage heat exchanger through a condensate water pipeline heat exchange pipeline, and the secondary reheat system is connected with the condenser through a condenser pipeline.

[0022] Further, the ultra-high-pressure cylinder, the high-pressure cylinder, the medium-pressure cylinder and the low-pressure cylinder are coaxially arranged and connected through a shaft coupling.

[0023] The method comprises a unit starting preparation stage, a unit starting stage, a unit regulating stage and a unit load increasing stage.

[0024] The unit regulating stage comprises a rapid peak regulation, a unit load reduction and a unit load sudden reduction process,

[0025] The rapid peak regulation process specifically comprises that the boiler system generates steam into the ultra-high-pressure cylinder and the primary reheat system, the steam is heat exchanged in the heat exchange system to form heat exchange water, and then enters the boiler system, when heat supply is needed, the heat exchange system provides steam, when high-temperature hot water is needed, the heat exchange water is delivered;

[0026] The unit load reduction process specifically comprises that the boiler system generates steam into the ultra-high-pressure cylinder and the primary reheat system, the steam generated by the primary reheat system enters the high-pressure cylinder, the steam after the primary reheat system does work enters the secondary reheat system, when the steam quantity is large, the steam enters the heat exchange system to be heat exchanged to form heat exchange water;

[0027] The unit load sudden reduction process specifically comprises that the boiler system generates steam into the ultra-high-pressure cylinder, the primary reheat system and the secondary reheat system, and the heat exchanged water enters the low-temperature hot water user.

[0028] Further, the unit starting preparation stage specifically comprises that the feedwater system delivers water to the boiler system, and then the boiler system generates steam, at this time, the steam does not enter the ultra-high-pressure cylinder, enters the primary reheat system and the secondary reheat system, when the heat supply system needs to work, the steam is heat exchanged in the heat exchange system and enters the heat supply system.

[0029] Further, the unit starting stage specifically comprises that the steam generated by the boiler system enters the ultra-high-pressure cylinder, the primary reheat system and the secondary reheat system, when the heat supply system needs to work, the steam enters the heat exchange system to form heat exchange water, and then enters the heat supply system;

[0030] Further, the unit load increasing stage specifically comprises that the heat exchange system is closed, and when the water quantity required by the boiler system 13 is insufficient, the feedwater system is started to supply water.

[0031] The application discloses a device and method for auxiliary grid peak shaving and heat supply of a double-reheat unit. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 A structural schematic diagram of an embodiment 1;

[0033] 1, an ultra-high pressure cylinder; 1-1, a main steam pipeline; 1-2, an ultra-high bypass; 1-3, an ultra-high bypass auxiliary pipeline; 1-4, an ultra-high pressure cylinder exhaust pipeline;

[0034] 2, a high pressure cylinder; 2-1, a high pressure cylinder inlet pipeline; 2-2, a high pressure bypass; 2-3, a high pressure bypass auxiliary pipeline; 2-4, a high pressure cylinder exhaust pipeline;

[0035] 3, a medium pressure cylinder; 3-1, a communication pipeline;

[0036] 4, a low pressure cylinder;

[0037] 5, a primary reheat system;

[0038] 6, a secondary reheat system; 6-1, a medium pressure cylinder inlet pipeline; 6-2, a low pressure bypass to a condenser pipeline; 6-3, a low pressure bypass auxiliary pipeline; 6-4, a condenser pipeline;

[0039] 7, a first steam heat exchanger; 7-1, a first steam-water heat exchange pipeline; 7-2, a first steam bypass; 7-3, a first heat exchange water pipeline;

[0040] 8, a second steam heat exchanger; 8-1, a second steam-water heat exchange pipeline; 8-2, a second heat exchange water pipeline; 8-3, a second steam bypass;

[0041] 9, a third steam heat exchanger; 9-1, a third steam-water heat exchange pipeline; 9-2, a third steam bypass; 9-3, a third heat exchange water pipeline;

[0042] 10, a first steam cooler; 11, a second steam cooler; 12, a steam cooler;

[0043] 13, a boiler system; 13-1, a main steam pipeline; 13-2, a water storage pipeline; 13-3, a bypass water supply pipeline; 13-4, a water supply pipeline;

[0044] 14, a steam header; 14-1, a connecting pipeline;

[0045] 15, a water storage tank; 15-1, a high pressure water pump; 15-2, a heat supply water pipeline;

[0046] 16. Auxiliary steam header; 16-1. Auxiliary steam pipeline; 16-2. Auxiliary steam to small turbine pipeline; 16-3. Auxiliary steam to deaerator heating pipeline;

[0047] 17. Deaerator;

[0048] 18. Feedwater pump turbine; 18-1. Feedwater pipeline; 18-2. Feedwater pump and booster pump system; 18-3. Feedwater intermediate tap desuperheating water pipe; 18-4. Steam cooler water supply pipeline;

[0049] 19. Low-pressure heater; 19-1. Condensate pump; 19-2. Condensate bypass piping; 19-3. Condensate heat exchange piping; 19-4. Steam cooler piping;

[0050] 20. Low-pressure bypass steam pressure stabilizing tank; 20-1. Low-pressure bypass heat exchange pipeline;

[0051] 21. Low-temperature hot water users;

[0052] 22. Multistage heat exchanger;

[0053] 23. Condenser;

[0054] 24. Users of high-temperature hot water;

[0055] 25. Industrial steam users. Detailed Implementation

[0056] The technical solutions of the embodiments of the present invention will be explained and described below with reference to the accompanying drawings. However, the following embodiments are only preferred embodiments of the present invention and not all of them. Other embodiments obtained by those skilled in the art based on the embodiments in the implementation methods without creative effort are all within the protection scope of the present invention.

[0057] Example 1

[0058] A secondary reheat unit auxiliary power grid peak shaving and heating device, such as Figure 1 As shown, it includes:

[0059] A steam turbine system is used to generate steam to drive the steam turbine; it includes an ultra-high pressure cylinder 1, a high pressure cylinder 2, an intermediate pressure cylinder 3, and a low pressure cylinder 4; a connecting pipe 3-1 is provided between the intermediate pressure cylinder 3 and the low pressure cylinder 4;

[0060] The ultra-high pressure bypass utilization system includes a boiler system 13. The boiler system 13 is provided with a main steam pipeline 13-1 at its outlet. The main steam pipeline 13-1 is connected to a main steam branch pipeline 1-1 and an ultra-high pressure bypass 1-2. The boiler system 13 is connected to the ultra-high pressure cylinder 1 through the main steam branch pipeline 1-1 for supplying steam to the ultra-high pressure cylinder 1.

[0061] The high pressure bypass utilization system comprises a primary reheat system 5, the primary reheat system 5 is connected with a boiler system 13 through an ultra-high pressure bypass 1-2 and a main steam pipe 13-1, and the boiler system 13 provides steam to the primary reheat system 5;

[0062] The primary reheat system 5 is connected with the ultra-high pressure cylinder 1 through an ultra-high pressure cylinder exhaust pipe 1-4, and the steam generated by the ultra-high pressure cylinder 1 is discharged into the primary reheat system 5; the primary reheat system 5 is connected with the high pressure cylinder 2 through a high pressure cylinder inlet pipe 2-1, and the steam of the primary reheat system 5 enters the high pressure cylinder 2 to drive the high pressure cylinder 2 to rotate;

[0063] The low pressure bypass utilization system comprises a secondary reheat system 6, the secondary reheat system 6 is connected with a medium pressure cylinder inlet pipe 6-1 at an outlet; the secondary reheat system 6 is connected with the primary reheat system 5 through a high pressure bypass 2-2, and the secondary reheat system 6 is connected with the medium pressure cylinder 3 through the medium pressure cylinder inlet pipe 6-1 to provide steam to the medium pressure cylinder 3; wherein the high pressure bypass 2-2 is connected with the high pressure cylinder inlet pipe 2-1, and a high pressure cylinder exhaust pipe 2-4 is connected with the high pressure bypass 2-2, so that the high pressure cylinder 2 discharges steam to the secondary reheat system 6;

[0064] The heat supply system comprises a low temperature hot water user 21, an industrial hot water user 25 and a high temperature hot water user 24, the low temperature hot water user 21 is connected with the secondary reheat system 6 through a low pressure bypass steam stabilizing tank 20; the low pressure bypass steam stabilizing tank 20 is connected with the secondary reheat system 6 through a low bypass to condenser pipe 6-2, and the low bypass to condenser pipe 6-2 is connected with the medium pressure cylinder inlet pipe 6-1;

[0065] The water supply system is connected with the boiler system 13, the industrial hot water user 25 and the high temperature hot water user 24;

[0066] The heat exchange system is connected with the boiler system 13, the primary reheat system 5 and the secondary reheat system 6, and is used for water and steam heat exchange with the primary reheat system 5 and the secondary reheat system 6 respectively, and provides water for the boiler system 13;

[0067] The condensate water system is connected with the secondary reheat system 6 and the water supply system.

[0068] The heat exchange system comprises a first steam heat exchanger 7, a second steam heat exchanger 8, a third steam heat exchanger 9, a first steam cooler 10, a second steam cooler 11, a third steam cooler 12 and a steam header 14, wherein the first steam heat exchanger 7 is connected with the first steam cooler 10, the second steam heat exchanger 8 is connected with the second steam cooler 11, the third steam heat exchanger 9 is connected with the third steam cooler 12, the first steam heat exchanger 7 is connected with the steam header 14 through a first steam bypass 7-2, the second steam heat exchanger 8 is connected with the steam header 14 through a second steam bypass 8-3, the third steam heat exchanger 9 is connected with the steam header 14 through a third steam bypass 9-2, and the steam header 14 supplies heat to a high-temperature hot water user 24. The steam header 14 is connected with an auxiliary steam header 16 through a connecting pipe 14-1, the first steam heat exchanger 7 is connected with a first heat exchange water pipeline 7-3, the second steam heat exchanger 8 is connected with a second heat exchange pipeline 8-2, the third steam heat exchanger 9 is connected with a third heat exchange pipeline 9-3, the boiler system 13 is connected with a water supply pipeline 13-4, and the first heat exchange water pipeline 7-3, the second heat exchange pipeline 8-2 and the third heat exchange pipeline 9-3 are connected with the water supply pipeline 13-4.

[0069] The water is sequentially sent to the third steam cooler 12, the second steam cooler 11 and the first steam cooler 10, and then is divided into three branches of a first steam water heat exchange pipeline 7-1, a second steam water heat exchange pipeline 8-1 and a third steam water heat exchange pipeline 9-1, and then is respectively sent to the first steam heat exchanger 7, the second steam heat exchanger 8 and the third steam heat exchanger 9.

[0070] The first steam heat exchanger 7 is connected with the boiler system 13 through an ultrahigh bypass auxiliary pipeline 1-3, the ultrahigh bypass auxiliary pipeline 1-3 is connected with an ultrahigh bypass 1-2, the second steam heat exchanger 8 is connected with the primary reheating system 5 through a high bypass auxiliary pipeline 2-3 connected with a high pressure bypass 2-2, and the third steam heat exchanger 9 is connected with the secondary reheating system 6 through a low bypass auxiliary pipeline 6-3.

[0071] The water supply system comprises a water storage tank 15, a water pump 15-1, a deaerator 17 and a water supply pump turbine 18, the water storage tank 15 is connected with the water supply pipeline 13-4 through a water storage pipeline 13-2, when the water quantity of the boiler water supply system is sufficient, the water storage pipeline 13-2 is opened to enter the water storage tank 15 for storage. The boiler system 13 is connected with a bypass water supply pipeline 13-3, an industrial hot water user 25 is connected with a hot water supply pipeline 15-2, the water pump 15-1 is connected with the bypass water supply pipeline 13-3 and the hot water supply pipeline 15-2, the water storage tank 15 sends water to the boiler system 13 and the industrial hot water user 25 through the water pump 15-1, and a water supply pump pre-system 18-2 is arranged between the deaerator 17 and the water supply pump turbine 18.

[0072] The condensate water system comprises a low-pressure heater 19, a multi-stage heat exchanger 22 and a condenser 23, the low-pressure heater 19 is connected with the low-pressure bypass steam stabilizing tank 20 through a condensate water bypass 19-2, the low-pressure heater 19 is connected with the condenser 23 through a condensate water pump 19-1, the condensate water bypass 19-2 is connected with a condensate water pipeline heat exchange pipeline 19-3, the low-pressure heater 19 is connected with the multi-stage heat exchanger 22 through the condensate water pipeline heat exchange pipeline 19-3, and the secondary reheat system 6 is connected with the condenser 23 through a condenser pipeline 6-4.

[0073] The auxiliary steam header 16 supplies heat to the high-temperature hot water user 24 through an auxiliary steam pipeline 16-1, the auxiliary steam header 16 is connected with the deaerator 17 through an auxiliary steam to deaerator heating pipeline 16-3 and connected with the feed water pump turbine 18 through an auxiliary steam to small machine pipeline 16-2, and the feed water pump preposition system 18-2 supplies water to the boiler system through a feed water pipeline 18-1.

[0074] The low-temperature heat supply user 21 is provided with the multi-stage heat exchanger 22 between the low-pressure bypass steam stabilizing tank 20, a steam cooler pipeline 19-4 is connected between the third steam cooler 12 and the multi-stage heat exchanger 22, a steam cooler pipeline 18-4 is connected between the feed water pump preposition system 18-2 and the third steam cooler 12, water is supplied to the third steam cooler 12 through the steam cooler pipeline 18-4, and a feed water intermediate tap desuperheating water pipe 18-3 is connected to the steam cooler pipeline 18-4, so that water is supplied to the steam header 14 through the feed water intermediate tap desuperheating water pipe 18-3.

[0075] The superhigh-pressure cylinder 1, the high-pressure cylinder 2, the medium-pressure cylinder 3 and the low-pressure cylinder 4 are coaxially arranged and connected through a shaft coupling.

[0076] Embodiment 2

[0077] A secondary reheat unit auxiliary power grid peak shaving and heat supply method, comprising a unit starting preparation stage, a unit starting stage, a unit regulating stage and a unit load increasing stage;

[0078] In the unit starting preparation stage:

[0079] The condenser 23 is filled with water, and the water in the condenser 23 enters the low-pressure heating system 19 through the condensate pump 19-1, and enters the deaerator 17. At this time, the valve on the condensate bypass pipeline 19-2 is closed. When the water level in the deaerator 17 meets the requirements, the water in the deaerator 17 enters the feedwater pump and pre-pump system 18-2, and the feedwater pump turbine 18 is started. The feedwater pump turbine 18 drives the feedwater pump and pre-pump system 18-2 to rotate, and water is transported to the feedwater pipeline 18-1 and enters the boiler system 13. The boiler system burns to generate steam, and the steam enters the main steam pipeline 1-1. When the steam parameters do not meet the requirements, the main steam does not enter the super-high-pressure cylinder 1, but enters the super-high bypass 1-2. At this time, the super-high-pressure cylinder exhaust pipeline 1-4 and the super-high bypass auxiliary pipeline 1-3 are closed. The steam enters the primary reheating system 5. After being heated in the primary reheating system 5, the steam enters the high-pressure cylinder inlet pipeline 2-1. Due to the fact that the parameters do not meet the requirements, the steam enters the high-pressure bypass 2-2. At this time, the high-pressure cylinder exhaust pipeline 2-4 and the high-pressure bypass auxiliary pipeline 2-3 are closed. The steam enters the secondary reheating system 6, and similarly, the steam does not enter the medium-pressure cylinder inlet pipeline 6-1, but directly enters the low-pressure bypass to condenser pipeline 6-2. When the heating system needs to work, the condensate pipeline heat exchange pipeline 19-3 is opened. The steam enters the low-pressure bypass steam stabilizing tank 20, enters the multi-stage heat exchanger 22, and enters the condenser 23. The heat-exchanged water enters the low-temperature hot water user 21. When the steam does not need to be heated, the steam enters the condenser pipeline 6-4 and is discharged into the condenser 23.

[0080] When the unit is in the starting stage: when the steam parameters meet the requirements, the boiler system burns to generate steam, and the steam enters the main steam pipeline 1-1. According to the starting requirements, it enters the super-high-pressure cylinder 1, and part of it enters the super-high bypass 1-2. At this time, the super-high-pressure cylinder exhaust pipeline 1-4 is opened, and the super-high bypass auxiliary pipeline 1-3 is closed. The steam enters the primary reheating system 5.

[0081] After being heated in the primary reheating system 5, the steam enters the high-pressure cylinder inlet pipeline 2-1. Part of the steam enters the high-pressure bypass 2-2. At this time, the high-pressure cylinder exhaust pipeline 2-4 is opened. The high-pressure bypass auxiliary pipeline 2-3 is closed.

[0082] The steam enters the secondary reheating system 6, and similarly, part of the steam enters the medium-pressure cylinder inlet pipeline 6-1, and part of it enters the low-pressure bypass to condenser pipeline 6-2. The low-pressure bypass auxiliary pipeline 6-3 is also closed.

[0083] When the heating system needs to work, the condensate pipeline heat exchange pipeline 19-3 is opened. The steam enters the low-pressure bypass steam stabilizing tank 20, enters the multi-stage heat exchanger 22, and enters the condenser 23. The heat-exchanged water enters the low-temperature hot water user 21.

[0084] When the steam does not need to be heated, the steam enters the condenser pipeline 6-4 and is discharged into the condenser 23.

[0085] In the unit regulation stage, the unit regulation stage includes fast peak regulation, unit load drop and unit load sudden drop process, the fast peak regulation process is as follows: the boiler system burns to generate steam, the steam enters the main steam pipeline 1-1. The steam enters the super-high pressure cylinder 1 according to the starting demand. The super-high bypass 1-2 and the super-high bypass auxiliary road 1-3 are opened. The super-high pressure cylinder exhaust pipeline 1-4 and the super-high bypass 1-2 steam are combined and then enter the primary reheating system 5. The steam cooler pipeline 18-4 is opened, water enters three steam coolers. Through the super-high bypass auxiliary road 1-2, the first steam heat exchanger 7 is opened. The first steam water heat exchanger pipeline 7-1 is opened, and the heat-exchanged water enters the boiler system 13-4 through the water supply pipeline 13-4. When the water quantity is sufficient, the water storage pipeline 13-2 is opened to enter the water storage tank 15 for storage. When the steam quantity of the super-high bypass auxiliary road 1-3 is large, the steam bypass 7-2 is opened, and the steam enters the steam header 14. The intermediate tap feed water pump 18-3 is opened, and the steam in the steam header 14 is cooled. When the steam quantity in the steam header 14 is sufficient, the steam enters the auxiliary steam header 16. Part of the steam in the auxiliary steam header 16 enters the deaerator 17, and when the temperature of the deaerator 17 is low, heating is performed. Another way enters the small machine steam pipeline through the heating water pipeline 15-2, to provide steam source for the feed water pump turbine 18. When the steam parameter is sufficient, the heating water pipeline 15-2 serves as the main driving steam source, and the steam extraction and high exhaust serve as backup. If heating is required at this time, part of the steam in the auxiliary steam header 16 enters the industrial steam user 25. If high-temperature hot water is required at this time, the high-pressure water pump 15-1 is started, water enters the heating water pipeline 15-2, and then enters the industrial hot water user 25. The bypass feed water pipeline 13-3 is closed.

[0086] The unit load drop process is as follows: in addition to the previous operation of the super-high bypass. The primary reheating steam enters the high-pressure cylinder pipeline 2-1. The high-pressure bypass 2-2 and the high-pressure bypass auxiliary road 2-3 are opened. The high-pressure cylinder exhaust pipeline 2-4 and the high-pressure bypass 2-2 steam are combined and then enter the secondary reheating system 6. When the steam quantity of the high-pressure bypass auxiliary road 2-3 is large, the steam enters the second steam heat exchanger 8, and the second steam water heat exchanger pipeline 8-1 is opened and then enters the second heat exchange water pipeline 8-2. The heat-exchanged water enters the water supply pipeline 13-4. In addition, when the steam quantity is sufficient, the steam enters the steam bypass 8-3 and enters the steam header 14. The steam in the steam header 14 enters the auxiliary steam header 16. The steam in the auxiliary steam header 16 enters the heating water pipeline 15-2 to provide steam source for the feed water pump turbine. Steam extraction and high exhaust serve as backup.

[0087] When the unit load drops: When the unit load drops, in addition to the operation of opening the super-high bypass and the high bypass, the low bypass needs to be opened. The secondary reheat system 6 steam part enters the intermediate pressure cylinder 3 along the intermediate pressure cylinder inlet pipe 6-1. Another part enters the low pressure bypass steam stabilizing tank 20. Then quickly open the condensate bypass pipe 19-2, open the condensate pipe heat exchange pipe 19-3 to the multi-stage heat exchanger 22, and the heat exchanged water is stored in the water tank in the low temperature heating user 21 in time. If the low bypass steam quantity is large, open the condenser pipe 6-4, and discharge into the condenser 23 to ensure the safe operation of the unit. If the water level in the condenser 23 is high, open the steam cooler pipe 19-4 to send part of the water into and reduce the water level.

[0088] When the unit load drops: When the unit load drops, in addition to the operation of opening the super-high bypass and the high bypass, the low bypass needs to be opened. The secondary reheat system 6 steam part enters the intermediate pressure cylinder 3 along the intermediate pressure cylinder inlet pipe 6-1. Another part enters the low pressure bypass steam stabilizing tank 20. Then quickly open the condensate bypass pipe 19-2, open the condensate pipe heat exchange pipe 19-3 to the multi-stage heat exchanger 22, and the heat exchanged water is stored in the water tank in the low temperature heating user 21 in time. If the low bypass steam quantity is large, open the condenser pipe 6-4, and discharge into the condenser 23 to ensure the safe operation of the unit. If the water level in the condenser 23 is high, open the steam cooler pipe 19-4 to send part of the water into and reduce the water level.

[0089] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited to this. Those skilled in the art should understand that the present application includes but is not limited to the contents described in the above specific embodiments and the drawings. Any modification that does not deviate from the functional and structural principles of the present application will be included in the scope of the claims.

Claims

1. A secondary reheat unit auxiliary power grid peak shaving and heating device, characterized in that, include: A steam turbine system is used to generate steam to drive a steam turbine. It includes an ultra-high pressure cylinder (1), a high pressure cylinder (2), a medium pressure cylinder (3), and a low pressure cylinder (4); The ultra-high pressure bypass utilization system includes a boiler system (13), the boiler system (13) is provided with a main steam pipeline (13-1) at the outlet, the main steam pipeline (13-1) is connected to the main steam branch pipeline (1-1) and the ultra-high pressure bypass (1-2), the boiler system (13) is connected to the ultra-high pressure cylinder (1) through the main steam branch pipeline (1-1) for supplying steam to the ultra-high pressure cylinder (1); The high-pressure bypass utilization system includes a primary reheat system (5), which is connected to a boiler system (13) via an ultra-high pressure bypass (1-2) and a main steam pipeline (13-1), thereby the boiler system (13) supplies steam to the primary reheat system (5); the primary reheat system (5) is connected to an ultra-high pressure cylinder (1) via an ultra-high pressure cylinder exhaust pipeline (1-4), thereby the steam generated by the ultra-high pressure cylinder (1) is discharged into the primary reheat system (5); the primary reheat system (5) is connected to a high-pressure cylinder (2) via a high-pressure cylinder inlet pipeline (2-1), thereby the steam from the primary reheat system (5) enters the high-pressure cylinder (2) to drive the high-pressure cylinder (2) to rotate; The low-pressure bypass utilization system includes a secondary reheat system (6), the outlet of which is connected to a medium-pressure cylinder steam inlet pipe (6-1); the secondary reheat system (6) is connected to the primary reheat system (5) through a high-pressure bypass (2-2), and the secondary reheat system (6) is connected to the medium-pressure cylinder (3) through the medium-pressure cylinder steam inlet pipe (6-1) for supplying steam to the medium-pressure cylinder (3); The heating system includes low-temperature hot water users (21), industrial hot water users (25) and high-temperature hot water users (24), wherein the low-temperature hot water users (21) are connected to the secondary reheat system (6) through a low-pressure bypass steam pressure stabilizing tank (20); The water supply system is connected to the boiler system (13), industrial hot water users (25), and high-temperature hot water users (24); A heat exchange system is connected to the boiler system (13), the primary reheat system (5), and the secondary reheat system (6). The heat exchange system is used to exchange water and steam heat with the primary reheat system (5) and the secondary reheat system (6) respectively, and to provide water to the boiler system (13). The heat exchange system includes a first steam heat exchanger (7), a second steam heat exchanger (8), a third steam heat exchanger (9), a first steam cooler (10), a second steam cooler (11), a third steam cooler (12), and a steam header (14). The first steam heat exchanger (7) is connected to the first steam cooler (10), the second steam heat exchanger (8) is connected to the second steam cooler (11), and the third steam heat exchanger (9) is connected to the third steam cooler (12). The first steam heat exchanger (7), the second steam heat exchanger (8), and the third steam heat exchanger (9) are all connected to the steam header (14). The first steam heat exchanger (7), the second steam heat exchanger (8), and the third steam heat exchanger (9) are all connected to the water supply pipeline (13-4) for the boiler system 13 to transport water. The steam header (14) supplies heat to the high-temperature hot water user (24). The first steam heat exchanger (7) is connected to the boiler system (13) through the ultra-high bypass auxiliary line (1-3). The second steam heat exchanger (8) is connected to the primary reheat system (5) through the high bypass auxiliary line (2-3) connected to the high pressure bypass (2-2). The third steam heat exchanger (9) is connected to the secondary reheat system (6) through the low bypass auxiliary line (6-3). The condensate system is connected to the secondary reheat system (6) and the feedwater system.

2. The auxiliary power grid peak shaving and heating device for a double reheat unit according to claim 1, characterized in that, The water supply system includes a water storage tank (15), a water pump (15-1), a deaerator (17), and a feedwater pump turbine (18). The water storage tank (15) is connected to the water supply pipeline (13-4) through a water storage pipeline (13-2). The water storage tank (15) delivers water to the boiler system (13) and industrial hot water users (25) through the water pump (15-1). A feedwater pump pre-installation system (18-2) is provided between the deaerator (17) and the feedwater pump turbine (18).

3. The auxiliary power grid peak shaving and heating device for a double reheat unit according to claim 1, characterized in that, The condensate system includes a low-pressure heater (19), a multi-stage heat exchanger (22), and a condenser (23). The low-pressure heater (19) is connected to the low-pressure bypass steam pressure stabilizing tank (20) through a condensate bypass (19-2). The low-pressure heater (19) is connected to the condenser (23) through a condensate pump (19-1). The low-pressure heater (19) is connected to the multi-stage heat exchanger (22) through a condensate pipeline heat exchange pipeline (19-3). The secondary reheat system (6) is connected to the condenser (23) through a condenser pipeline (6-4).

4. The auxiliary power grid peak shaving and heating device for a double reheat unit according to claim 1, characterized in that, The ultra-high pressure cylinder (1), high pressure cylinder (2), medium pressure cylinder (3) and low pressure cylinder (4) are coaxially arranged and connected by a coupling.

5. A method for auxiliary power grid peak shaving and heating supply of a double reheat unit, characterized in that, The auxiliary power grid peak shaving and heating device for a double reheat unit as described in any one of claims 1 to 4 includes a unit start-up preparation stage, a unit start-up stage, a unit regulation stage, and a unit load increase stage. The unit regulation phase includes rapid peak shaving, unit load reduction, and sudden unit load drop processes. The rapid peak shaving process is as follows: the boiler system (13) generates steam that enters the ultra-high pressure cylinder (1) and the reheat system (5). The steam exchanges heat at the heat exchange system to form hot water, which then enters the boiler system (13). When heating is needed, the heat exchange system provides steam; when high-temperature hot water is needed, hot water is delivered. The specific process of the unit load reduction is as follows: the boiler system (13) generates steam that enters the ultra-high pressure cylinder (1) and the primary reheat system (5). The steam generated by the primary reheat system (5) enters the high pressure cylinder (2). The excess steam from the primary reheat system (5) and the steam after the high pressure cylinder (2) has done work enter the secondary reheat system (6). When the steam volume is large, the steam enters the heat exchange system to exchange heat and form hot water. The process of sudden load drop of the unit is as follows: the boiler system (13) generates steam that enters the ultra-high pressure cylinder (1), the primary reheat system (5) and the secondary reheat system (6), and the water after heat exchange enters the low temperature hot water user (21).

6. The method for auxiliary power grid peak shaving and heating of a double reheat unit according to claim 5, characterized in that, The specific start-up preparation stage of the unit is as follows: the water supply system delivers water to the boiler system (13), and then the boiler system (13) generates steam. At this time, the steam does not enter the ultra-high pressure cylinder (1), but enters the primary reheat system (5) and the secondary reheat system (6). When the heating system needs to work, the steam exchanges heat at the heat exchange system and enters the heating system.

7. The method for auxiliary power grid peak shaving and heating of a double reheat unit according to claim 5, characterized in that, The specific start-up phase of the unit is as follows: the steam generated by the boiler system (13) enters the ultra-high pressure cylinder (1), the primary reheat system (5) and the secondary reheat system (6). When the heating system needs to work, the steam enters the heat exchange system to form hot water for heat exchange, and then enters the heating system.

8. The method for auxiliary power grid peak shaving and heating of a double reheat unit according to claim 5, characterized in that, The specific steps of the unit's load increase phase are as follows: shut down the heat exchange system, and when the water required by the boiler system (13) is insufficient, start the water supply system to supply water.

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