Secondary reheating unit auxiliary power grid peak regulation and heat supply device and method

Abstract

The invention relates to a secondary reheating unit auxiliary power grid peak regulation and heat supply device and method, and aims to solve the problem of low efficiency caused by unreasonable use of an existing bypass system, the secondary reheating unit auxiliary power grid peak regulation and heat supply device comprises a steam turbine system, an ultrahigh pressure bypass utilization system and a boiler system, a main steam pipeline is arranged at an outlet of the boiler system, the main steam pipeline is connected with a main steam branch pipeline and an ultrahigh bypass, and the ultrahigh bypass is connected with an ultrahigh auxiliary bypass; the high-pressure bypass utilization system comprises a primary reheating system, and the primary reheating system is connected with the boiler system through an ultrahigh bypass and a main steam pipeline; the low-pressure bypass utilization system comprises a secondary reheating system, the secondary reheating system is connected with a primary reheating system, and the secondary reheating system is connected with an intermediate-pressure cylinder, a heat supply system, a water supply system, a heat exchange system and a condensation water system through an intermediate-pressure cylinder steam inlet pipeline. The bypass technology is used for heat supply, peak regulation and heat supply are met, and multiple purposes are achieved.

Description

Technical Field

[0001] The present invention belongs to the field of coal-fired machinery, and in particular relates to a secondary reheat unit auxiliary power grid peak regulation and heat supply device and method. Background Art

[0002] In order to achieve the goal of carbon peak and carbon neutrality, the National Energy Administration explicitly requires coal-fired power units to be upgraded. This indicates that thermal power units need to be transformed from power supply to clean energy supply. In order to stabilize the safety of the power grid, the units carry out more in-depth peak regulation, but the peak regulation process faces many difficulties. How to change the steam volume of the turbine and the combustion of the boiler are urgent problems to be solved.

[0003] The existing turbine bypass control system is an integral part of the thermal system of modern unit units. Its function is to coordinate the imbalance between the boiler steam production and the turbine steam consumption. When the operation of the boiler and the turbine do not match, under the transient load condition, when the amount of steam generated by the boiler is greater than the amount of steam required by the turbine, the excess can be directly introduced into the condenser after bypass temperature and pressure reduction without entering the turbine, so as to maintain the stability of the boiler operation and reduce or even avoid the action of the boiler safety valve.

[0004] When the turbine is started or load is dumped, the reheater may overheat and burn out due to lack of steam flow or insufficient steam flow. Sending steam to the reheater through the bypass system can effectively prevent the reheater from dry burning and protect the reheater from damage.

[0005] Although the turbine bypass system has significant advantages in protecting equipment, adjusting loads and adapting to different working conditions, there are problems with low turbine efficiency and increased energy consumption in the use of the turbine bypass system. At the same time, during critical periods such as unit startup or load changes, sudden changes in steam volume may cause fluctuations in system parameters, posing a threat to the safe operation of the unit. In practical applications, it is necessary to comprehensively consider various factors and seek a more reasonable and efficient steam utilization solution. Summary of the invention

[0006] In view of the problems existing in the prior art, the present application designs a secondary reheat unit auxiliary power grid peak load regulation and heat supply device and method, which realizes the peak load regulation of the unit, maintains the turbine to run at no load or with factory power when the unit is under low load, and allows the turbine to be shut down without stopping the boiler in case of a turbine accident. The boiler is in a hot standby state, so that the unit can quickly resume grid-connected power generation after the fault is eliminated, thereby reducing downtime and facilitating the stability of the entire system. In addition, the bypass system is used to assist in heating to maximize energy efficiency.

[0007] A secondary reheat unit auxiliary power grid peak load regulation and heat supply device of the present invention comprises:

[0008] The steam turbine system is used to generate steam to drive the steam turbine; it includes an ultra-high pressure cylinder, a high pressure cylinder, an intermediate pressure cylinder and a low pressure cylinder;

[0009] The ultra-high pressure bypass utilization system includes a boiler system, wherein a main steam pipeline is provided at the outlet of the boiler system, wherein the main steam pipeline is connected to a main steam branch pipeline and an ultra-high pressure bypass, and the boiler system is connected to the ultra-high pressure cylinder through the main steam branch pipeline for conveying steam to the ultra-high pressure cylinder; the ultra-high pressure bypass is connected to an ultra-high pressure bypass auxiliary pipeline;

[0010] The high-pressure bypass utilization system includes a primary reheat system, wherein the primary reheat system is connected to the boiler system through an ultra-high bypass and a main steam pipeline, and then the boiler system provides steam to the primary reheat system; the primary reheat system is connected to the ultra-high pressure cylinder through an ultra-high pressure cylinder exhaust pipeline, and then the steam generated by the ultra-high pressure cylinder is discharged into the primary reheat system; the primary reheat system is connected to the high-pressure cylinder through a high-pressure cylinder air intake pipeline, and then the steam of the primary reheat system enters the high-pressure cylinder to drive the high-pressure cylinder to rotate;

[0011] A low-pressure bypass utilization system, including a secondary reheat system, wherein the outlet of the secondary reheat system is connected to a medium-pressure cylinder steam inlet pipeline;

[0012] The secondary reheat system is connected to the primary reheat system via a high-pressure bypass, and the secondary reheat system is connected to the intermediate pressure cylinder via an intermediate pressure cylinder steam inlet pipeline, for providing steam to the intermediate pressure cylinder;

[0013] The heating system includes low-temperature hot water users, industrial hot water users and high-temperature hot water users, wherein the low-temperature hot water users are connected to the secondary reheat system via a low-pressure bypass steam pressure regulating tank;

[0014] A water supply system connected to the boiler system, industrial hot water users, and high-temperature hot water users;

[0015] A heat exchange system connected to the boiler system, the primary reheat system and the secondary reheat system, the heat exchange system being used to perform water and steam heat exchange with the primary reheat system and the secondary reheat system respectively, and to provide water for the boiler system;

[0016] The condensate system is connected to the secondary reheat system and the feed water system.

[0017] In the present application, by setting a primary reheat system and a secondary reheat system, steam is used multiple times with high utilization efficiency, and it can ensure the combustion of the boiler and stabilize the operation of the steam turbine. The bypass system controls the boiler steam temperature. When the unit is started in a cold state, the amount of steam generated by the boiler when the turbine is running, speeding up or starting to carry load is larger than the amount of steam required by the steam turbine. At this time, the bypass system can be used as a startup exhaust. During hot start, after using the bypass system, the boiler can operate at a higher combustion rate and higher evaporation rate, accelerate the increase of steam temperature, and quickly match it with the metal temperature of the steam turbine, thereby shortening the startup time. When the power grid is running at peak load, the bypass system can assist in heating, keep the combustion parameters stable, and the boiler steam is greatly adjusted to cause shutdown. When the load is increased, it can be quickly switched to maintain the steam supply to the steam turbine to prevent insufficient steam supply from causing the steam turbine speed to drop. It can also achieve peak load regulation of the unit, maintaining the turbine running at no load or running with plant power when the unit is under low load. In the event of a turbine accident, it is allowed to shut down without stopping the boiler, and the boiler is in hot standby mode, so that the unit can be quickly restored to grid-connected power generation after the fault is eliminated, thereby reducing downtime and benefiting the stability of the entire system.

[0018] Furthermore, the heat exchange system includes 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 manifold, wherein the first steam heat exchanger is connected to the first steam cooler, the second steam heat exchanger is connected to the second steam cooler, the third steam heat exchanger is connected to the third steam cooler, the first steam heat exchanger, the second steam heat exchanger and the third steam heat exchanger are all connected to the steam manifold, the first steam heat exchanger, the second steam heat exchanger and the third steam heat exchanger are all connected to the water supply pipeline for transporting water to the boiler system, and the steam manifold supplies heat to high-temperature hot water users.

[0019] Furthermore, the first steam heat exchanger is connected to the boiler system through an ultra-high bypass auxiliary line, the second steam heat exchanger is connected to the primary reheat system through a high bypass auxiliary line connected to the high-pressure bypass, and the third steam heat exchanger is connected to the secondary reheat system through a low bypass auxiliary line.

[0020] Furthermore, the water supply system includes a water storage tank, a water pump, a deaerator and a feed water pump turbine. The water storage tank is connected to the water supply pipeline through a water storage pipe. The water storage tank sends water to the boiler system and industrial hot water users through a water pump. A feed water pump pre-system is provided between the deaerator and the feed water pump turbine.

[0021] Furthermore, the condensate system includes a low-pressure heater, a multi-stage heat exchanger and a condenser, the low-pressure heater is connected to the low-pressure bypass steam pressure regulating tank through a condensate bypass, the low-pressure heater is connected to the condenser through a condensate pump, the low-pressure heater is connected to the multi-stage heat exchanger through a condensate pipeline heat exchange pipeline, and the secondary reheat system is connected to the condenser through a condenser pipeline. The low-pressure heater is connected to a deaerator.

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

[0023] A secondary reheat unit auxiliary power grid peak regulation and heat supply method, including a unit start-up preparation stage, a unit start-up stage, a unit adjustment stage and a unit load increase stage;

[0024] The unit regulation stage includes rapid peak regulation, unit load reduction and unit load sudden drop processes.

[0025] The rapid peak-shaving process is specifically as follows: the boiler system generates steam that enters the ultra-high pressure cylinder and the primary reheat system, the steam is heat-exchanged in the heat exchange system to form hot water, and then enters the boiler system. When heat supply is required, the heat exchange system provides steam, and when high-temperature hot water is required, the hot water is delivered;

[0026] The load reduction process of the unit is specifically as follows: the steam generated by the boiler system enters the ultra-high pressure cylinder and the primary reheat system, the steam generated by the primary reheat system enters the high pressure cylinder, the excess steam of the primary reheat system and the steam after the high pressure cylinder has done work enter the secondary reheat system, and when the steam volume is large, the steam enters the heat exchange system for heat exchange to form hot water for exchange;

[0027] The specific process of unit load drop is as follows: the boiler system generates steam which enters the ultra-high pressure cylinder, the primary reheat system and the secondary reheat system, and the water after heat exchange enters the low-temperature hot water users.

[0028] Furthermore, the start-up preparation stage of the unit is specifically as follows: the water supply system transports 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, but enters the primary reheat system and the secondary reheat system. When the heating system needs to work, the steam exchanges heat at the heat exchange system and enters the heating system.

[0029] Furthermore, the unit startup phase is specifically as follows: the steam generated by the boiler system enters the ultra-high pressure cylinder, the primary reheat system and the secondary reheat system. When the heating system needs to work, the steam enters the heat exchange system to form hot water, and then enters the heating system;

[0030] Furthermore, the load increase stage of the unit is specifically as follows: the heat exchange system is shut down, and when the amount of water required by the boiler system 13 is insufficient, the water supply system is started to supply water.

[0031] The beneficial effects of the present invention are as follows: the present application is a secondary reheat unit auxiliary power grid peak shaving and heating device and method, which adopts high and low bypass heating and peak shaving technology, extracts steam from main steam and reheat steam for heating, adjusts the steam volume to reduce the steam entering the steam turbine, and reduces the work. The system can both ensure the combustion of the boiler and stabilize the operation of the steam turbine. In addition, the bypass technology is used for heating, which can meet both peak shaving and heating, achieving multiple goals at one stroke. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a structural schematic diagram of Example 1;

[0033] 1. Ultra-high pressure cylinder; 1-1. Main steam pipeline; 1-2. Ultra-high bypass; 1-3. Ultra-high bypass auxiliary pipeline; 1-4. Ultra-high pressure cylinder exhaust pipeline;

[0034] 2. High-pressure cylinder; 2-1. High-pressure cylinder intake pipe; 2-2. High-pressure bypass; 2-3. High-pressure bypass auxiliary pipe; 2-4. High-pressure cylinder exhaust pipe;

[0035] 3. Medium pressure cylinder; 3-1. Connecting pipe;

[0036] 4. Low pressure cylinder;

[0037] 5. Primary reheat system;

[0038] 6. Secondary reheat system; 6-1. Medium pressure cylinder steam inlet pipeline; 6-2. Low bypass to condenser pipeline; 6-3. Low bypass auxiliary pipeline; 6-4. Condenser pipeline;

[0039] 7. First steam heat exchanger; 7-1. First steam-water heat exchange pipeline; 7-2. First steam bypass; 7-3. First hot water exchange pipeline;

[0040] 8. Second steam heat exchanger; 8-1. Second steam-water heat exchange pipeline; 8-2. Second hot water exchange pipeline; 8-3. Second steam bypass;

[0041] 9. The third steam heat exchanger; 9-1. The third steam-water heat exchange pipeline; 9-2. The third steam bypass; 9-3. The third hot water exchange pipeline;

[0042] 10. First steam cooler; 11. Second steam cooler; 12. Steam cooler;

[0043] 13. Boiler system; 13-1. Main steam pipeline; 13-2. Water storage pipeline; 13-3. Bypass water supply pipeline; 13-4 Water supply pipeline;

[0044] 14. Steam header; 14-1 connecting pipe;

[0045] 15. Water storage tank; 15-1. High-pressure water pump; 15-2. Hot water supply pipe;

[0046] 16. Auxiliary steam header; 16-1. Auxiliary steam pipeline; 16-2. Auxiliary steam to small machine 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 pre-pump system; 18-3. Feedwater intermediate tap cooling water pipe; 18-4. Steam cooler water supply pipeline;

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

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

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

[0052] 22. Multi-stage heat exchanger;

[0053] 23. Condenser;

[0054] 24. High temperature hot water users;

[0055] 25. Industrial steam users. DETAILED DESCRIPTION

[0057] The following is an explanation and description of the technical solutions of the embodiments of the present invention in conjunction with the accompanying drawings of the present invention, but the following embodiments are only preferred embodiments of the present invention, not all. Based on the embodiments in the implementation mode, other embodiments obtained by those skilled in the art without creative work are all within the protection scope of the present invention.

[0058] Example 1

[0059] A secondary reheat unit auxiliary power grid peak load regulation and heating device, such as Figure 1 As shown, including:

[0060] The steam turbine system is used to generate steam to drive the steam turbine to work; 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;

[0061] The ultra-high pressure bypass utilization system includes a boiler system 13, wherein a main steam pipeline 13-1 is provided at the outlet of the boiler system 13, wherein the main steam pipeline 13-1 is connected to a main steam branch pipeline 1-1 and an ultra-high pressure bypass 1-2, and the boiler system 13 is connected to the ultra-high pressure cylinder 1 through the main steam branch pipeline 1-1, and is used to transport steam to the ultra-high pressure cylinder 1;

[0062] A high-pressure bypass utilization system, comprising a primary reheat system 5, wherein the primary reheat system 5 is connected to a boiler system 13 via an ultra-high bypass 1-2 and a main steam pipeline 13-1, and the boiler system 13 provides steam to the primary reheat system 5;

[0063] The primary reheat system 5 is connected to the ultra-high pressure cylinder 1 through the ultra-high pressure cylinder exhaust pipeline 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 to the high pressure cylinder 2 through the high pressure cylinder intake pipeline 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;

[0064] The low-pressure bypass utilization system includes a secondary reheat system 6, wherein the outlet of the secondary reheat system 6 is connected to an intermediate-pressure cylinder steam inlet pipeline 6-1; the secondary reheat system 6 is connected to the primary reheat system 5 via a high-pressure bypass 2-2, and the secondary reheat system 6 is connected to the intermediate-pressure cylinder 3 via an intermediate-pressure cylinder steam inlet pipeline 6-1, so as to provide steam to the intermediate-pressure cylinder 3; wherein the high-pressure bypass 2-2 is connected to the high-pressure cylinder air inlet pipeline 2-1, and the high-pressure cylinder exhaust pipeline 2-4 is connected to the high-pressure bypass 2-2, so that the high-pressure cylinder 2 exhausts steam to the secondary reheat system 6;

[0065] The heating system includes 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 to the secondary reheat system 6 through a low-pressure bypass steam surge tank 20; the low-pressure bypass steam surge tank 20 is connected to the secondary reheat system 6 through a low bypass to condenser pipeline 6-2, and the low bypass to condenser pipeline 6-2 is connected to the medium-pressure cylinder steam inlet pipeline 6-1;

[0066] A water supply system connected to the boiler system 13, industrial hot water users 25, and high-temperature hot water users 24;

[0067] A heat exchange system connected to the boiler system 13, the primary reheat system 5 and the secondary reheat system 6, wherein the heat exchange system is used to perform water and steam heat exchange with the primary reheat system 5 and the secondary reheat system 6, respectively, and provide water for the boiler system 13;

[0068] The condensate system is connected to the secondary reheat system 6 and the water supply system.

[0069] 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 manifold 14, wherein 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, the third steam heat exchanger 9 is connected to the third steam cooler 12, the first steam heat exchanger 7 is connected to the steam manifold 14 through a first steam bypass 7-2, the second steam heat exchanger 8 is connected to the steam manifold 14 through a second steam bypass 8-3, the third steam heat exchanger 9 is connected to the steam manifold 14 through a third steam bypass 9-2, and the steam manifold 14 supplies heat to a high-temperature hot water user 24. The steam header 14 is connected to the auxiliary steam header 16 through a connecting pipe 14-1, the first steam heat exchanger 7 is connected to the first heat exchange water pipeline 7-3, the second steam heat exchanger 8 is connected to the second heat exchange pipeline 8-2, the third steam heat exchanger 9 is connected to the third heat exchange pipeline 9-3, and the boiler system 13 is connected to 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 all connected to the water supply pipeline 13-4.

[0070] After passing through the third steam cooler 12, the second steam cooler 11 and the first steam cooler 10 in sequence, the water is divided into three branches, namely the first steam-water heat exchange pipeline 7-1, the second steam-water heat exchange pipeline 8-1 and the third steam-water heat exchange pipeline 9-1, and then transported to the first steam heat exchanger 7, the second steam heat exchanger 8 and the third steam heat exchanger 9 respectively.

[0071] The first steam heat exchanger 7 is connected to the boiler system 13 through the ultra-high bypass auxiliary line 1-3, and the ultra-high bypass auxiliary line 1-3 is connected to the ultra-high bypass 1-2. 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.

[0072] 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 pipe 13-4 through a water storage pipe 13-2. When the water volume of the boiler water supply system is sufficient, the water storage pipe 13-2 is opened to enter the water storage tank 15 for storage. The boiler system 13 is connected to the bypass water supply pipe 13-3, the industrial hot water user 25 is connected to the hot water supply pipe 15-2, the water pump 15-1 is connected to the bypass water supply pipe 13-3 and the hot water supply pipe 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 feedwater pump pre-system 18-2 is provided between the deaerator 17 and the feedwater pump turbine 18.

[0073] 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 regulating 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 condensate bypass 19-2 is connected to a condensate pipeline heat exchange pipeline 19-3. The low-pressure heater 19 is connected to the multi-stage heat exchanger 22 through the condensate pipeline heat exchange pipeline 19-3. The secondary reheat system 6 is connected to the condenser 23 through a condenser pipeline 6-4.

[0074] The auxiliary steam header 16 supplies heat to the high-temperature hot water user 24 through the auxiliary steam pipeline 16-1. The auxiliary steam header 16 is connected to the deaerator 17 through the auxiliary steam to deaerator heating pipeline 16-3, and is connected to the feed water pump turbine 18 through the auxiliary steam to small machine pipeline 16-2. The feed water pump pre-system 18-2 supplies water to the boiler system through the feed water pipeline 18-1.

[0075] A multi-stage heat exchanger 22 is provided between the low-temperature heating user 21 and the low-pressure bypass steam stabilizing tank 20, and a steam cooler pipeline 19-4 is connected between the third steam cooler 12 and the multi-stage heat exchanger 22. The steam cooler pipeline 18-4 is connected between the feed water pump pre-system 18-2 and the third steam cooler 12, and water is supplied to the third steam cooler 12 through the steam cooler pipeline 18-4. The feed water intermediate tap cooling water pipe 18-3 is connected to the steam cooler pipeline 18-4, and water is supplied to the steam manifold 14 through the feed water intermediate tap cooling water pipe 18-3.

[0076] The ultra-high pressure cylinder 1, the high pressure cylinder 2, the medium pressure cylinder 3 and the low pressure cylinder 4 are coaxially arranged and connected via a coupling.

[0077] Example 2

[0078] A secondary reheat unit auxiliary power grid peak regulation and heat supply method, including a unit start-up preparation stage, a unit start-up stage, a unit adjustment stage and a unit load increase stage;

[0079] When the unit is in the startup preparation stage:

[0080] The condenser 23 is filled with water. After the water in the condenser 23 passes through the condensate pump 19-1, it enters the low-pressure heating system 19 and the deaerator 17. At this time, the valve on the condensate bypass pipe 19-2 is closed. When the water level of the deaerator 17 meets the requirements, the water in the deaerator 17 enters the feedwater pump and the pre-pump system 18-2, and the feedwater pump turbine 18 is started. The feedwater pump turbine 18 drives the feedwater pump and the pre-pump system 18-2 to rotate, and transports water to the feedwater pipeline 18-1 and enters the boiler system 13. Combustion in the boiler system produces 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 ultra-high pressure cylinder 1, but enters the ultra-high bypass 1-2. At this time, the ultra-high pressure cylinder exhaust pipeline 1-4 and the ultra-high bypass auxiliary road 1-3 are closed. The steam enters the primary reheat system 5. After being heated in the primary reheat system 5, the steam enters the high-pressure cylinder intake pipeline 2-1. Because the parameters do not meet the requirements. Steam enters the high-pressure bypass 2-2. At this time, the high-pressure cylinder exhaust pipeline 2-4 and the high-bypass auxiliary pipeline 2-3 are closed. Steam enters the secondary reheat system 6. Similarly, the steam does not enter the medium-pressure cylinder steam 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 pressure regulating tank 20, enters the multi-stage heat exchanger 22, and enters the condenser 23. The water after heat exchange enters the low-temperature hot water user 21. When the steam does not need to provide heating, the steam enters the condenser pipeline 6-4 and is discharged into the condenser 23.

[0081] During the unit startup phase: 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 startup requirements, it enters the ultra-high pressure cylinder 1, and part of it enters the ultra-high bypass 1-2. At this time, the ultra-high pressure cylinder exhaust pipeline 1-4 is opened and the ultra-high bypass auxiliary pipeline 1-3 is closed. The steam enters the primary reheat system 5.

[0082] After being heated in the primary reheat system 5, the steam enters the high-pressure cylinder steam inlet pipe 2-1. The steam part enters the high-pressure bypass 2-2. At this time, the high-pressure cylinder exhaust pipe 2-4 is opened. The high-pressure bypass auxiliary line 2-3 is closed.

[0083] The steam enters the secondary reheat system 6. Similarly, part of the steam enters the intermediate pressure cylinder steam inlet pipeline 6-1, and part of the steam enters the low bypass to condenser pipeline 6-2. The low bypass auxiliary pipeline 6-3 is also closed.

[0084] When the heating system needs to work, the condensate pipe heat exchange pipeline 19-3 is opened. The steam enters the low-pressure bypass steam pressure regulating tank 20, enters the multi-stage heat exchanger 22, and enters the condenser 23. The water after heat exchange enters the low-temperature hot water user 21.

[0085] When the steam does not need to provide heat, the steam enters the condenser pipe 6 - 4 and is discharged into the condenser 23 .

[0086] When in the unit regulation stage, the unit regulation stage includes rapid peak regulation, unit load reduction and unit load sudden drop processes. The rapid peak regulation process is specifically as follows: combustion in the boiler system generates steam, and the steam enters the main steam pipe 1-1. Steam enters the ultra-high pressure cylinder 1 according to the startup requirements. The ultra-high bypass 1-2 and the ultra-high bypass auxiliary road 1-3 are opened. The ultra-high pressure cylinder exhaust pipeline 1-4 merges with the steam of the ultra-high bypass 1-2 and enters the primary reheat system 5. Open the steam cooler pipeline 18-4, and water enters the three steam coolers. Enter the first steam heat exchanger 7 through the ultra-high bypass auxiliary road 1-2. Open the first steam-water heat exchange pipeline 7-1, and the water after heat exchange enters the water supply pipeline 13-4 and enters the boiler system 13. When the water volume is sufficient, open the water storage pipeline 13-2 to enter the water storage tank 15 for storage. When the steam volume of the ultra-high bypass auxiliary road 1-3 is large, open the steam bypass 7-2, and the steam enters the steam manifold 14. Open the middle tap cooling water pipe 18-3 of the water supply pump to cool the steam in the steam header 14. When the amount of steam 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 is heated when the temperature of the deaerator 17 is low. Another way enters the hot water supply pipe 15-2 to the small machine steam pipeline to provide a steam source for the feed water pump turbine 18. When the steam parameters are sufficient, the hot water supply pipe 15-2 serves as the main driving steam source, and the extraction steam 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, start the high-pressure water pump 15-1, and the water enters the hot water supply pipe 15-2 and then enters the industrial hot water user 25. The bypass water supply pipe 13-3 is closed.

[0087] The load reduction process of the unit is specifically as follows: In addition to the previous super high bypass operation. The primary reheat steam enters the high-pressure cylinder pipeline 2-1. The high-pressure bypass 2-2 and the high bypass auxiliary road 2-3 are opened. The high-pressure cylinder exhaust pipeline 2-4 merges with the high-pressure bypass 2-2 steam and enters the secondary reheat system 6. When the steam volume of the high bypass auxiliary road 2-3 is large, the steam enters the second steam heat exchanger 8, and at the same time opens the second steam-water heat exchange pipeline 8-1 and enters the second hot water exchange pipeline 8-2. The water after heat exchange enters the water supply pipeline 13-4. In addition, when the steam volume is sufficient, the steam enters the steam bypass 8-3 and enters the steam manifold 14. The steam in the steam manifold 14 enters the auxiliary steam manifold 16. The steam in the steam manifold 16 enters the hot water supply pipe 15-2 to provide a steam source for the feedwater pump turbine. The extraction steam and high exhaust are used as backup.

[0088] When the unit load drops suddenly: When the unit load drops suddenly, in addition to opening the super high bypass and high bypass at the same time. At this time, the low bypass needs to be opened. The steam part of the secondary reheat system 6 enters the medium pressure cylinder 3 along the medium pressure cylinder steam inlet pipe 6-1. The other part enters the low pressure bypass steam pressure regulating 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 water after heat exchange enters the water tank in the low temperature heating user 21 in time for storage. If the low bypass steam volume is large, open the condenser pipe 6-4 and discharge it 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, send part of the water in, and lower the water level.

[0089] When the unit is loaded: When the peak load regulation of the unit is over and the load needs to be increased, first close the condenser pipeline 6-4. The low bypass to condenser pipeline 6-2 enters the multi-stage heat exchanger 22 for heat exchange. If the water volume of the low-temperature user 21 is sufficient at this time, open the steam cooler pipeline 19-4, enter the steam cooler, and use the high water temperature to facilitate rapid load increase. When the unit load continues to rise, close the low bypass to condenser pipeline 6-2, close the low bypass auxiliary road 6-3 and the third steam heat exchanger 6, and cut off the steam heat exchange pipeline 9-1. Then close the condensate bypass pipeline 19-2 and the condensate pipeline heat exchange pipeline 19-3. Ensure the water supply of the deaerator 17. As the unit load increases, close the high bypass auxiliary road 2-3, the second hot water exchange pipeline 8-2, and the super high bypass auxiliary road 1-3. Then close the steam cooler water supply pipeline 18-4. After the super-high bypass and high bypass auxiliary roads are closed, the high-pressure bypass 2-2 and super-high bypass 1-2 are closed. Then the steam source of the water supply pump is switched to extraction steam and cooling. When the boiler water supply is insufficient, the high-pressure water pump 15-1 is started to supply water to the boiler system 13 along the bypass water supply pipeline 13-3. When the boiler water supply is sufficient, the high-pressure water pump 15-1 can continue to supply water to the high-temperature water user 25.

[0090] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that the present invention includes but is not limited to the contents described in the drawings and the above specific embodiments. Any modification that does not deviate from the functional and structural principles of the present invention will be included in the scope of the claims.

Claims

1. A secondary reheat unit auxiliary power grid peak load regulation and heat supply device, characterized in that: include: Steam turbine system, used to generate steam to drive the steam turbine; It comprises an ultra-high pressure cylinder (1), a high pressure cylinder (2), a medium pressure cylinder (3) and a low pressure cylinder (4); An ultra-high pressure bypass utilization system comprises a boiler system (13), wherein a main steam pipeline (13-1) is provided at the outlet of the boiler system (13), wherein the main steam pipeline (13-1) is connected to a main steam branch pipeline (1-1) and an ultra-high pressure bypass (1-2), and wherein the boiler system (13) is connected to the ultra-high pressure cylinder (1) via the main steam branch pipeline (1-1) and is used to transport steam to the ultra-high pressure cylinder (1); The high-pressure bypass utilization system comprises a primary reheat system (5), wherein the primary reheat system (5) is connected to a boiler system (13) via an ultra-high bypass (1-2) and a main steam pipeline (13-1), and the boiler system (13) provides steam to the primary reheat system (5); the primary reheat system (5) is connected to the ultra-high pressure cylinder (1) via an ultra-high pressure cylinder exhaust pipeline (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 to the high-pressure cylinder (2) via a high-pressure cylinder air intake pipeline (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; A low-pressure bypass utilization system comprises a secondary reheat system (6), wherein the outlet of the secondary reheat system (6) is connected to an intermediate-pressure cylinder steam inlet pipeline (6-1); the secondary reheat system (6) is connected to the primary reheat system (5) via a high-pressure bypass (2-2), and the secondary reheat system (6) is connected to the intermediate-pressure cylinder (3) via an intermediate-pressure cylinder steam inlet pipeline (6-1), so as to provide steam to the intermediate-pressure cylinder (3); A heating system, comprising a low-temperature hot water user (21), an industrial hot water user (25) and a high-temperature hot water user (24), wherein the low-temperature hot water user (21) is connected to a secondary reheat system (6) via a low-pressure bypass steam surge tank (20); A water supply system connected to the boiler system (13), industrial hot water users (25), and high-temperature hot water users (24); a heat exchange system connected to the boiler system (13), the primary reheat system (5) and the secondary reheat system (6), wherein the heat exchange system is used to perform water and steam heat exchange with the primary reheat system (5) and the secondary reheat system (6), respectively, and to provide water for the boiler system (13); The condensate system is connected to the secondary reheat system (6) and the water supply system.

2. The secondary reheat unit auxiliary power grid peak load regulation and heat supply device according to claim 1, characterized in that: 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 to the first steam cooler (10), the second steam heat exchanger (8) is connected to the second steam cooler (11), 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 a water supply pipeline (13-4) for conveying water to a boiler system 13, and the steam header (14) supplies heat to a high-temperature hot water user (24).

3. The secondary reheat unit auxiliary power grid peak load regulation and heat supply device according to claim 2, characterized in that: The first steam heat exchanger (7) is connected to the boiler system (13) via an ultra-high bypass auxiliary line (1-3), the second steam heat exchanger (8) is connected to the primary reheat system (5) via a high bypass auxiliary line (2-3) connected to the high-pressure bypass (2-2), and the third steam heat exchanger (9) is connected to the secondary reheat system (6) via a low bypass auxiliary line (6-3).

4. The secondary reheat unit auxiliary power grid peak load regulation and heat supply device according to claim 2, characterized in that: The water supply system comprises a water storage tank (15), a water pump (15-1), a deaerator (17) and a feed water pump turbine (18); the water storage tank (15) is connected to a water supply pipeline (13-4) via a water storage pipeline (13-2); the water storage tank (15) delivers water to a boiler system (13) and an industrial hot water user (25) via a water pump (15-1); and a feed water pump pre-system (18-2) is provided between the deaerator (17) and the feed water pump turbine (18).

5. The secondary reheat unit auxiliary power grid peak load regulation and heat supply device according to claim 1, characterized in that: The condensate system comprises a low-pressure heater (19), a multi-stage heat exchanger (22) and a condenser (23); the low-pressure heater (19) is connected to a low-pressure bypass steam pressure regulating tank (20) via a condensate bypass (19-2); the low-pressure heater (19) is connected to the condenser (23) via a condensate pump (19-1); the low-pressure heater (19) is connected to the multi-stage heat exchanger (22) via a condensate pipeline heat exchange pipeline (19-3); and the secondary reheat system (6) is connected to the condenser (23) via a condenser pipeline (6-4).

6. The secondary reheat unit auxiliary power grid peak load regulation and heat supply device according to claim 1, characterized in that: The ultra-high pressure cylinder (1), the high pressure cylinder (2), the medium pressure cylinder (3) and the low pressure cylinder (4) are coaxially arranged and connected via a coupling.

7. A secondary reheat unit auxiliary power grid peak load regulation and heat supply method, characterized in that: The secondary reheat unit auxiliary power grid peak load regulation and heat supply device according to any one of claims 1 to 6 comprises a unit start-up preparation stage, a unit start-up stage, a unit adjustment stage and a unit load increase stage; The unit regulation stage includes rapid peak regulation, unit load reduction and unit load sudden drop processes. The rapid peak load regulation process is specifically as follows: the boiler system (13) generates steam which enters the ultra-high pressure cylinder (1) and the primary reheat system (5); the steam is heat exchanged in the heat exchange system to form hot water, which then enters the boiler system (13); when heat supply is required, the heat exchange system provides steam; when high-temperature hot water is required, the hot water is delivered; The load reduction process of the unit is specifically as follows: the steam generated by the boiler system (13) 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 of the primary reheat system (5) and the steam after work of the high pressure cylinder (2) enter the secondary reheat system (6), and when the steam volume is large, the steam enters the heat exchange system for heat exchange to form hot water for exchange; The unit load sudden drop process is specifically as follows: the boiler system (13) generates steam which 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).

8. The secondary reheat unit auxiliary power grid peak load regulation and heat supply method according to claim 7, characterized in that: The unit startup preparation stage is specifically as follows: the water supply system transports 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 reheating system (5) and the secondary reheating system (6). When the heating system needs to work, the steam exchanges heat at the heat exchange system and enters the heating system.

9. The secondary reheat unit auxiliary power grid peak load regulation and heat supply method according to claim 7, characterized in that: The startup phase of the unit is specifically 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, and then enters the heating system.

10. The secondary reheat unit auxiliary power grid peak load regulation and heat supply method according to claim 7, characterized in that: The unit load increase stage specifically includes: shutting down the heat exchange system, and when the amount of water required by the boiler system (13) is insufficient, starting the water supply system to supply water.

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