Multi-mode child-mother cooperative type load adjusting boiler

Abstract

The invention provides a multi-mode child-mother cooperative type load adjusting boiler and a power generation system. The multi-mode child-mother cooperative type load adjusting boiler comprises at least two sets of boiler systems, a steam pocket system and a main steam pipeline. Wherein the boiler system comprises a boiler, a superheater and a water-cooling circulating pipe, the superheater is arranged in the boiler, and the water-cooling circulating pipe is arranged in the boiler and extends to the top from the bottom of the boiler; the steam pocket system comprises at least one steam pocket, the steam pocket is connected with an external water supply source, the first output end of the steam pocket is connected with an inlet of the water-cooling circulating pipe, the first input end of the steam pocket is communicated with an outlet of the water-cooling circulating pipe, the second output end of the steam pocket is communicated with an inlet of the superheater, and the second output end of the steam pocket is communicated with an outlet of the superheater. And an outlet of the superheater is communicated with the main steam pipeline. According to the load adjusting boiler, by adjusting the number of the boiler systems participating in operation, the load adjusting requirement of a power grid is met, the stability and adaptability of steam supply under different loads are guaranteed, and efficient power generation of a unit is guaranteed.

Description

Technical Field

[0001] The embodiments of the present invention belong to the field of power generation system technology, specifically relating to a multi-mode master-slave cooperative load-regulating boiler and power generation system. Background Technology

[0002] With the increasing proportion of clean energy sources such as photovoltaic, solar thermal, and wind power, and the successive construction and commissioning of high-parameter, large-capacity thermal power generating units, both large and small capacity units are participating in the deep peak shaving of the power grid, and this form will gradually become the norm.

[0003] However, the operating parameters of thermal power units under deep peak shaving deviate significantly from those under high-efficiency and high-economic operation, leading to a continuous decrease in the economic efficiency of the main and auxiliary equipment, potentially increasing coal consumption for power generation, insufficient hydropower, and a decline in the safety of key components (water-cooled walls, turbine rotor, main steam pipes, furnace tubes, etc.) under deep peak shaving conditions. Simultaneously, environmental pollutant indicators required by standards become more difficult to control, and the control technologies and costs for sulfur dioxide, nitrogen oxides, and other emissions require corresponding increases. Furthermore, during deep peak shaving adjustments of coal-fired power units, the boiler's heat load is relatively low under low-load operating conditions, resulting in insufficient adaptability to load changes. Additionally, high moisture content and low volatile matter in coal during combustion often cause delayed combustion and ignition difficulties, leading to unstable and deteriorated combustion. Therefore, an adjustable-load boiler is urgently needed. Summary of the Invention

[0004] The embodiments of the present invention aim to solve at least one of the technical problems existing in the prior art, and provide a multi-mode master-slave cooperative load-adjusting boiler and power generation system.

[0005] This invention provides a multi-mode mother-daughter cooperative load-adjusting boiler, comprising: At least two boiler systems, steam drum systems, and main steam pipelines; The boiler system includes: a boiler, a superheater, and a water-cooled circulation pipe. The superheater is located inside the boiler, and the water-cooled circulation pipe is located inside the boiler and extends from the bottom to the top of the boiler. The steam drum system includes: at least one steam drum, which is connected to an external water supply source; a first output end of the steam drum is connected to the inlet of the water-cooled circulation pipe; a first input end of the steam drum is connected to the outlet of the water-cooled circulation pipe; a second output end of the steam drum is connected to the inlet of the superheater; and the outlet of the superheater is connected to the main steam pipeline.

[0006] In some embodiments of the present invention, the boiler system further includes: an economizer, wherein the cold-side inlet of the economizer is connected to an external water supply source, the cold-side outlet of the economizer is connected to a second input end of the steam drum, and the hot-side inlet of the economizer is connected to the exhaust port of the boiler.

[0007] In some embodiments of the present invention, the boiler system further includes an air preheater, the hot-side inlet of which is connected to the hot-side outlet of the economizer. The hot-side inlet of the air preheater is connected to the exhaust port of the boiler.

[0008] In some embodiments of the present invention, the hot-side inlet of the air preheater is connected to the exhaust port of the boiler.

[0009] In some embodiments of the present invention, the multi-mode mother-daughter cooperative load-adjusting boiler further includes: A smoke exhaust system is provided, which is connected to the hot-side outlet of the air preheater.

[0010] In some embodiments of the present invention, the smoke exhaust system includes a dust collector, an induced draft fan and a chimney connected in sequence, wherein the dust collector is connected to the hot-side outlet of the air preheater.

[0011] In some embodiments of the present invention, the multi-mode mother-daughter cooperative load-adjusting boiler further includes: A coal supply system comprising a raw coal hopper, a coal mill, and a pulverizer connected in sequence, wherein the pulverizer is connected to each of the boilers.

[0012] In some embodiments of the present invention, the number of boiler systems is the same as the number of steam drums, and the boiler systems are connected in a corresponding manner to the first steam drum.

[0013] In some embodiments of the present invention, a multi-way valve is provided on the main steam pipeline, and the outlet of each superheater is connected to a different interface of the multi-way valve.

[0014] A second aspect of the present invention provides a power generation system comprising the multi-mode master-slave cooperative load-adjusting boiler described in any of the above embodiments.

[0015] According to embodiments of the present invention, a multi-mode, master-slave cooperative load-regulating boiler and power generation system is provided, comprising at least two boiler systems. When grid dispatch requires the unit to reduce output, one boiler system can be controlled to operate while the remaining boiler systems are shut down, thereby reducing the operating time of some boiler systems, reducing equipment wear and tear, extending equipment lifespan, and avoiding problems such as incomplete combustion and unstable flames in a single boiler caused by large load fluctuations, thus improving combustion efficiency and stability. When grid dispatch requires increasing unit output, two or more boiler systems can be controlled to operate to meet electricity demand, improving the unit's responsiveness to grid dispatch. The load-regulating boiler of the present invention can adjust the number of boiler systems participating in operation according to the grid's needs, meeting the grid's load regulation requirements, ensuring the stability and adaptability of steam supply under different loads, and guaranteeing efficient power generation. In addition, when some boiler systems are involved in power supply, the remaining boiler systems that are not shut down can be inspected or repaired, avoiding the power generation interruption problem caused by the traditional need to shut down a single boiler for maintenance, ensuring continuous and stable operation of the power plant, and improving the unit's operational reliability and availability. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of the multi-mode mother-daughter cooperative load-adjusting boiler according to the first embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of the multi-mode mother-daughter cooperative load-adjusting boiler according to the second embodiment of the present invention.

[0017] The labels in the attached diagram are as follows: 1. First boiler; 2. Second boiler; 3. Raw coal hopper; 4. Coal mill; 5. Pulverizer; 6. First steam drum; 7. Water-cooled circulating pipe; 8. First downcomer; 9. Dust collector; 10. Induced draft fan; 11. Chimney; 12. Air preheater; 13. Superheater; 14. Economizer; 15. Main steam pipe; 16. Multi-way valve; 17. Cold ash hopper; 18. Second steam drum; 19. Third steam drum; 20. Second downcomer; 21. Third water inlet pipe; 22. Second water inlet pipe; 23. First water inlet pipe. Detailed Implementation

[0018] To enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only for explaining the present invention and are not intended to limit the invention. The described embodiments are some, but not all, of the embodiments of the present invention. Based on the described embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention.

[0019] like Figure 1 , Figure 2 As shown, a first aspect of the present invention provides a multi-mode, mother-daughter cooperative load-adjusting boiler, comprising: at least two boiler systems, a steam drum system, and a main steam pipeline 15; wherein, the boiler system comprises: a boiler, a superheater 13, and a water-cooled circulation pipe 7, the superheater 13 being disposed inside the boiler, and the water-cooled circulation pipe 7 being disposed inside the boiler and extending from the bottom to the top of the boiler; the steam drum system comprises: at least one steam drum, the steam drum being connected to an external water supply source, the first output end of the steam drum being connected to the inlet of the water-cooled circulation pipe 7, the first input end of the steam drum being connected to the outlet of the water-cooled circulation pipe 7, the second output end of the steam drum being connected to the inlet of the superheater 13, and the outlet of the superheater 13 being connected to the main steam pipeline 15.

[0020] According to an embodiment of the present invention, the multi-mode master-slave cooperative load-adjusting boiler is equipped with at least two boiler systems. When the grid dispatch requires the unit to reduce its output, one boiler system can be controlled to operate while the remaining boiler systems are shut down. This reduces the operating time of some boiler systems, lowers equipment wear, extends equipment lifespan, and avoids problems such as incomplete combustion and unstable flames in a single boiler caused by large load fluctuations, thereby improving combustion efficiency and stability. When the grid dispatch requires the unit to increase its output, two or more boiler systems can be controlled to operate to meet electricity demand, improving the unit's responsiveness to grid dispatch. The load-adjusting boiler of the present invention can adjust the number of boiler systems participating in operation according to the grid's needs, meeting the grid's load adjustment requirements, ensuring the stability and adaptability of steam supply under different loads, and guaranteeing efficient power generation. In addition, when some boiler systems are involved in power supply, the remaining boiler systems that are not shut down can be inspected or repaired, avoiding the power generation interruption problem caused by the traditional need to shut down a single boiler for maintenance. This ensures the continuous and stable operation of the power plant and improves the unit's operational reliability and availability.

[0021] In some embodiments of the present invention, the multi-mode, mother-daughter coordinated load-adjusting boiler further includes a coal supply system, comprising a raw coal hopper 3, a coal mill 4, and a pulverizer 5 connected in sequence, with the pulverizer 5 connected to each boiler. Coal raw material enters the coal mill 4 from the raw coal hopper 3, where it is ground and refined to form pulverized coal. The pulverized coal is discharged into the boiler of each boiler system through the pulverizer 5 to supply raw materials for boiler combustion.

[0022] An external water source supplies cold water to the steam drum. The steam drum delivers the cold water to the water-cooled circulation pipe 7 through the first output end. The cold water flows along the water-cooled circulation pipe 7 from the bottom to the top of the boiler and absorbs the heat generated by combustion in the boiler. When the cold water flows to the position of the cold water circulation pipe near the top of the boiler, it becomes a mixture of water and steam. The mixture of water and steam enters the steam drum through the first input end of the steam drum via the water-cooled circulation pipe 7. The mixture of water and steam undergoes water-steam separation in the steam drum. The steam enters the superheater 13 through the second output end of the steam drum. The superheater 13 reheats the steam to make it superheated steam. The superheated steam enters the main steam pipe 15 through the outlet of the superheater 13, and is then delivered to the steam turbine through the main steam pipe 15.

[0023] like Figure 1 As shown, in the first embodiment of the present invention, the steam drum system may include a first steam drum 6, at least two sets of boiler systems are respectively connected to the first steam drum 6, an external water source supplies cold water to the first steam drum 6 through a first water inlet pipe 23, the first output end of the first steam drum 6 supplies water to the water-cooled circulation pipes 7 of at least two boilers through a first downcomer 8, the outlet of the water-cooled circulation pipes 7 of at least two boilers is connected to the first input end of the first steam drum 6, the second output end of the first steam drum 6 is connected to the superheater 13 of at least two boilers, and the output end of the superheater 13 of at least two boilers is connected to the main steam pipe 15.

[0024] like Figure 2 As shown, in the second embodiment of the present invention, the steam drum system includes a second steam drum 18 and a third steam drum 19, and the first boiler 1 system is connected to the second steam drum 18, and the second boiler 2 system is connected to the third steam drum 19. An external water source supplies cold water to the second steam drum 18 through the second water inlet pipe 22. The first output end of the second steam drum 18 supplies water to the water-cooled circulation pipe 7 in the first boiler 1 through the first downcomer 8. The outlet of the water-cooled circulation pipe 7 in the first boiler 1 is connected to the first input end of the second steam drum 18. The second output end of the second steam drum 18 is connected to the superheater 13 in the first boiler 1. The output end of the superheater 13 in the first boiler 1 is connected to the main steam pipe 15. An external water source supplies cold water to the third steam drum 19 through the third inlet pipe 21. The first output end of the third steam drum 19 supplies water to the water-cooled circulation pipe 7 in the second boiler 2 through the second downcomer 20. The outlet of the water-cooled circulation pipe 7 in the second boiler 2 is connected to the first input end of the third steam drum 19. The second output end of the third steam drum 19 is connected to the superheater 13 in the second boiler 2. The output end of the superheater 13 in the second boiler 2 is connected to the main steam pipe 15.

[0025] When using separate second steam drums 18 and third steam drums 19, the first boiler 1 and the second boiler 2 can achieve independent water circulation control. During load adjustment, the hydrodynamic state of components such as the water-cooled circulation pipes 7 in each boiler is more stable, avoiding hydrodynamic imbalance caused by large changes in flow rate. Even if a common first steam drum 6 is used, its design size is adapted to the total capacity of the mother and daughter boilers. The first downcomer 8 is divided into two and leads to the water-cooled circulation pipes 7 of the first boiler 1 and the second boiler 2 respectively, which can also ensure relatively stable hydrodynamic circulation under different loads.

[0026] In other embodiments of this disclosure, the steam drum system may include three, four, five, or six or seven steam drums, corresponding to three, four, five, or six boiler systems, and the steam drums and boiler systems are connected in a one-to-one correspondence.

[0027] In some embodiments of the present invention, a multi-way valve 16 is provided on the main steam pipeline 15, and the outlet of each superheater 13 is connected to a different interface of the multi-way valve 16. The multi-way valve 16 can control the opening and closing of the superheater 13 and the main steam pipeline 15 to coordinate with the operation or shutdown of the boiler corresponding to the superheater 13. That is, when the boiler is running, the multi-way valve 16 between the corresponding superheater 13 and the main steam pipeline 15 is in a connected state, and when the boiler is shut down, the multi-way valve 16 between the corresponding superheater 13 and the main steam pipeline 15 is in a closed state.

[0028] In some embodiments of the present invention, the boiler system further includes: an economizer 14, the cold-side inlet of which is connected to an external water supply source, the cold-side outlet of which is connected to the second input end of the steam drum, and the hot-side inlet of which is connected to the boiler exhaust port. The boiler flue gas flows through the economizer 14 and is heated before entering the water supply of the economizer 14. The heated water then enters the steam drum through the second input end to provide the steam drum with water at a certain temperature. Utilizing the heat from the high-temperature flue gas to heat the external water supply can improve resource utilization and increase the efficiency of the boiler's steam supply.

[0029] In some embodiments of the present invention, the boiler system further includes an air preheater 12, the hot-side inlet of which is connected to the hot-side outlet of the economizer 14. The hot-side inlet of the air preheater 12 is connected to the boiler exhaust port. After the high-temperature flue gas is heated by water in the economizer 14, it enters the air preheater 12 and heats the air inside the air preheater 12, further improving the energy utilization rate of the high-temperature flue gas.

[0030] In some embodiments of the present invention, the hot-side inlet of the air preheater 12 is connected to the exhaust port of the boiler. The high-temperature flue gas discharged from the boiler can also directly enter the air preheater 12 and heat the air flowing through the air preheater 12.

[0031] In some embodiments of the present invention, the multi-mode mother-daughter cooperative load-adjusting boiler further includes a flue gas system connected to the hot-side outlet of the air preheater 12. After releasing heat through the economizer 14 and the air preheater 12, the high-temperature flue gas enters the flue gas system and is discharged after being treated by the exhaust system.

[0032] In some embodiments of the present invention, the flue gas exhaust system includes a dust collector 9, an induced draft fan 10, and a chimney 11 connected in sequence. The dust collector 9 is connected to the hot-side outlet of the air preheater 12. The flue gas entering the flue gas exhaust system is first treated by the dust collector 9 to reduce the dust in the flue gas, and then introduced into the chimney 11 by the induced draft fan 10, and finally discharged through the chimney 11.

[0033] In some embodiments of the present invention, a cold ash hopper 17 is provided below each boiler to discharge the coal slag produced by combustion in the boiler.

[0034] A second aspect of the present invention provides a power generation system comprising the multi-mode master-slave cooperative load-adjusting boiler described in any of the above embodiments.

[0035] According to an embodiment of the present invention, the power generation system is equipped with at least two boiler systems. When the grid dispatch requires the unit to reduce its output, one boiler system can be controlled to operate while the remaining boiler systems are shut down. This reduces the operating time of some boiler systems, lowers equipment wear, extends equipment lifespan, and avoids problems such as incomplete combustion and unstable flames in a single boiler caused by large load fluctuations, thereby improving combustion efficiency and stability. When the grid dispatch requires the unit to increase its output, two or more boiler systems can be controlled to operate to meet electricity demand, improving the unit's responsiveness to grid dispatch. The load-regulating boiler of the present invention can adjust the number of boiler systems participating in operation according to the grid's needs, meeting the grid's load-regulating requirements, ensuring the stability and adaptability of steam supply under different loads, and guaranteeing efficient power generation. Furthermore, when some boiler systems are involved in power supply, the remaining boiler systems that are not shut down can be inspected or repaired, avoiding the power generation interruption problem caused by the traditional need to shut down a single boiler for maintenance. This ensures the continuous and stable operation of the power plant and improves the unit's operational reliability and availability.

[0036] The multi-mode mother-daughter cooperative load-adjusting boiler and power generation system of the present invention also have the following beneficial effects: This invention enables the coordinated operation of a mother and daughter boiler, i.e., the first boiler and the second boiler work together. When it is necessary to reduce the load, the daughter boiler can be shut down, and only the mother boiler operates under relatively stable conditions. This reduces the frequency of frequent adjustments to the combustion state of a single boiler, avoids problems such as incomplete combustion and unstable flame caused by large load fluctuations, and improves combustion efficiency and stability. Frequent load changes in a single boiler can lead to turbulent hydrodynamic conditions and affect water circulation safety. In this invention, when independent second steam drums 18 and third steam drums 19 are used, the mother and daughter boilers can achieve independent water circulation control. During load adjustment, the hydrodynamic state of components such as water-cooled circulation pipes 7 and downcomers in each boiler is more stable, avoiding hydrodynamic imbalance caused by large changes in flow rate. Even if a common first steam drum 6 is used, its design size is adapted to the total capacity of the mother and daughter boilers. The first downcomer 8 is divided into two and leads to the mother and daughter boilers respectively, which can also ensure relatively stable hydrodynamic circulation under different loads. When existing boilers frequently change loads, many components need to operate under non-design conditions, which can easily accelerate wear and reduce lifespan. This invention achieves load adjustment by starting and stopping sub-boilers. The main boiler can operate under or near-design conditions in most cases, while the sub-boilers are started and stopped according to load demand, reducing the operating time of equipment under non-design conditions, reducing equipment wear and tear, and extending equipment lifespan. Compared to a single boiler, this invention can quickly adjust the load between the design working fluid flow rate of 100 and 70 by controlling the start and stop of the sub-boilers, meeting the needs of deep peak shaving of the power grid. Moreover, the adjustment process is simpler and faster, without the need for complex parameter adjustments to a single boiler, thus improving the unit's response capability to power grid dispatch. When the sub-boiler is shut down, maintenance, spare parts replacement, and inspection can be carried out simultaneously without affecting the normal operation of the main boiler. This avoids the power generation interruption problem caused by the need to shut down a single boiler for maintenance, ensuring the continuous and stable operation of the power plant and improving the operational reliability and availability of the unit.

[0037] It is understood that the above embodiments are merely exemplary implementations used to illustrate the principles of the present invention, and the present invention is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A multi-mode, mother-daughter cooperative load-adjusting boiler, characterized in that, include: At least two boiler systems, steam drum systems, and main steam pipelines; The boiler system includes: a boiler, a superheater, and a water-cooled circulation pipe. The superheater is located inside the boiler, and the water-cooled circulation pipe is located inside the boiler and extends from the bottom to the top of the boiler. The steam drum system includes: at least one steam drum, which is connected to an external water supply source; a first output end of the steam drum is connected to the inlet of the water-cooled circulation pipe; a first input end of the steam drum is connected to the outlet of the water-cooled circulation pipe; a second output end of the steam drum is connected to the inlet of the superheater; and the outlet of the superheater is connected to the main steam pipeline.

2. The multi-mode mother-daughter cooperative load-adjusting boiler according to claim 1, characterized in that, The boiler system further includes an economizer, the cold-side inlet of which is connected to an external water supply source, the cold-side outlet of which is connected to the second input end of the steam drum, and the hot-side inlet of which is connected to the exhaust port of the boiler.

3. The multi-mode mother-daughter cooperative load-adjusting boiler according to claim 2, characterized in that, The boiler system further includes an air preheater, the hot-side inlet of which is connected to the hot-side outlet of the economizer. The hot-side inlet of the air preheater is connected to the exhaust port of the boiler.

4. The multi-mode mother-daughter cooperative load-adjusting boiler according to claim 3, characterized in that, The hot-side inlet of the air preheater is connected to the exhaust port of the boiler.

5. The multi-mode mother-daughter cooperative load-adjusting boiler according to claim 4, characterized in that, The multi-mode mother-daughter cooperative load-adjusting boiler also includes: A smoke exhaust system is provided, which is connected to the hot-side outlet of the air preheater.

6. The multi-mode mother-daughter cooperative load-adjusting boiler according to claim 5, characterized in that, The exhaust system includes a dust collector, an induced draft fan, and a chimney connected in sequence, and the dust collector is connected to the hot-side outlet of the air preheater.

7. The multi-mode mother-daughter cooperative load-adjusting boiler according to claim 1, characterized in that, The multi-mode mother-daughter cooperative load-adjusting boiler also includes: A coal supply system comprising a raw coal hopper, a coal mill, and a pulverizer connected in sequence, wherein the pulverizer is connected to each of the boilers.

8. The multi-mode mother-daughter cooperative load-adjusting boiler according to claim 1, characterized in that, The number of boiler systems is the same as the number of steam drums, and each boiler system is connected to a corresponding first steam drum.

9. The multi-mode mother-daughter cooperative load-adjusting boiler according to claim 1, characterized in that, The main steam pipeline is equipped with a multi-port valve, and the outlet of each superheater is connected to a different interface of the multi-port valve.

10. A power generation system, characterized in that, The power generation system includes a multi-mode mother-daughter cooperative load-adjusting boiler as described in any one of claims 1 to 9.

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