An energy storage system for reducing the electricity consumption of a coal-fired boiler induced draft fan

Abstract

The present application relates to a kind of energy storage systems for reducing the power consumption of coal-fired boiler induced draft fan, comprising air compression energy storage device and flue gas injection device, flue gas injection device includes boiler induced draft fan and with the air compression energy storage device connection flue gas injector, the input end of flue gas injector is connected flue gas input by first flue gas pipeline, the input end of boiler induced draft fan is connected flue gas input by second flue gas pipeline, the output of flue gas injector and boiler induced draft fan is all connected with desulfurizing tower by flue gas output pipeline;Air compression energy storage device drives flue gas injector to be injected to flue gas output pipeline by first flue gas pipeline with the flue gas mixed by the operation of boiler induced draft fan and output into flue gas output pipeline, into desulfurizing tower and release to atmosphere in processing.Compared with prior art, the present application can directly reduce the load of boiler induced draft fan, can effectively reduce the power consumption of induced draft fan and then reduce the plant power rate, improve the peak shaving capability of unit.

Description

Technical Field

[0001] This invention relates to the field of coal-fired power generation equipment technology and energy storage system technology, and in particular to an energy storage system for reducing the power consumption of induced draft fans in coal-fired boilers. Background Technology

[0002] With increasing pressure on power grid peak shaving, energy storage systems have attracted widespread attention as an important regulatory resource for mitigating peak-valley differences in the power grid. Existing compressed air energy storage systems typically operate during off-peak hours, compressing air to high pressure and storing it in a storage chamber, converting electrical energy into the internal energy of the air. During peak hours, the high-pressure air is released from the storage chamber, heated, and then used to drive a turbine to generate electricity. This energy release process involves multiple energy conversion steps, resulting in relatively low overall system efficiency and high equipment investment.

[0003] In coal-fired power plants, boiler induced draft fans operate continuously for extended periods and are among the major energy-consuming devices. However, existing energy-saving retrofit solutions for boiler induced draft fans primarily focus on the fan's operational phase, utilizing frequency conversion regulation under varying loads to reduce its power consumption. Research on reducing the operating load of boiler induced draft fans is scarce, thus limiting the upper limit of energy savings for these fans. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the existing technology and provide an energy storage system for reducing the power consumption of induced draft fans in coal-fired boilers. This invention can directly reduce the operating load of the boiler induced draft fan and the energy loss during the power generation process of the air compression energy storage device, effectively reduce the power consumption of the induced draft fan, thereby reducing the plant power consumption rate, improving the peak-shaving capacity of the unit, achieving the purpose of energy saving and consumption reduction, reducing operating costs, and bringing significant economic benefits.

[0005] The objective of this invention can be achieved through the following technical solutions:

[0006] This invention provides an energy storage system for reducing the power consumption of induced draft fans in coal-fired boilers, comprising an air compression energy storage device and a flue gas ejector device. The flue gas ejector device includes a boiler induced draft fan and a flue gas ejector connected to the air compression energy storage device. The input end of the flue gas ejector is connected to a flue gas inlet through a first flue gas pipe, and the input end of the boiler induced draft fan is connected to the flue gas inlet through a second flue gas pipe. The output ends of both the flue gas ejector and the boiler induced draft fan are connected to a desulfurization tower through flue gas output pipes.

[0007] The air compression energy storage device serves as the driving steam source for the flue gas ejector, driving the flue gas ejector to eject the flue gas through the first flue gas pipe to the flue gas output pipe, where it mixes with the flue gas output to the flue gas output pipe by the boiler induced draft fan, enters the desulfurization tower for treatment, and is then released into the atmosphere.

[0008] Preferably, the air compression energy storage device includes a back pressure unit, a compressor, and an air storage tank connected in sequence. The output end of the air storage tank is connected to the flue gas ejector, the input end of the back pressure unit is connected to a steam turbine, and the steam turbine is connected to a boiler.

[0009] The high-temperature steam from the boiler is used as the driving steam source for the back pressure machine after being powered by the steam turbine. The back pressure machine drives the compressor to compress air and inputs the compressed air into the air storage tank for storage as high-pressure air.

[0010] Preferably, the steam turbine is also connected to a generator, and the high-temperature steam from the boiler is used to generate electricity by the steam turbine, which then drives the generator to generate electricity.

[0011] Preferably, the output end of the steam turbine is connected to the boiler in sequence through a condenser, a condensate pump, a low-pressure heater, a feedwater pump, and a high-pressure heater.

[0012] Preferably, the output end of the condenser is connected to a cooling tower and a circulating water pump, and the output end of the circulating water pump is connected to the input end of the condenser to form a circulation loop.

[0013] Preferably, the back pressure machine is also connected to a regenerator.

[0014] Preferably, one or more of the steam turbine, the back pressure machine, and the compressor are provided.

[0015] Preferably, a bypass valve is provided on the first flue gas duct.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] (1) This invention combines an air compression energy storage device and a flue gas ejector device. The air compression energy storage device drives the flue gas ejector to pressurize and eject the flue gas from the first flue gas pipeline to the flue gas output pipeline. The flue gas is mixed with the flue gas output from the boiler induced draft fan to the flue gas output pipeline, enters the desulfurization tower for treatment, and is released into the atmosphere. This directly reduces the operating load of the boiler induced draft fan, effectively reduces the power consumption of the induced draft fan, thereby reducing the plant power consumption rate, improving the peak-shaving capacity of the unit, achieving the purpose of energy saving and consumption reduction, reducing operating costs, and bringing significant economic benefits. At the same time, the flue gas ejector is an energy release component of compressed air, reducing the energy conversion links in the power generation process of the air compression energy storage device, and reducing the energy loss in the power generation process of the air compression energy storage device.

[0018] (2) This invention sets up a back pressure unit, a compressor, and an air storage tank connected in sequence. The back pressure unit is connected to a steam turbine, the steam turbine is connected to a boiler, and the steam turbine is also connected to a generator set. During peak electricity demand, the high-temperature steam from the boiler is used to generate electricity by the steam turbine and then drives the generator to generate electricity. During off-peak or flat-peak electricity demand, a portion of the steam is partially expanded in the steam turbine and then extracted as the driving steam source for the back pressure unit, reducing the operating load of the steam turbine. At the same time, the back pressure unit drives the compressor to compress air and store it in the air storage tank. During peak electricity demand, the high-pressure air is released to drive the ejector to eject flue gas, which improves the energy conversion efficiency and operational flexibility of the system, reduces energy loss during power generation, further taps the peak-shaving potential of coal-fired generator sets and compressed air energy storage systems, and alleviates the peak-shaving pressure of the power grid. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of an energy storage system for reducing the power consumption of induced draft fans in coal-fired boilers, provided by the present invention.

[0020] The following are marked in the diagram: 1. Steam turbine, 2. Generator, 3. Condenser, 4. Back pressure unit, 5. Compressor, 6. Air storage tank, 7. Flue gas ejector, 8. Bypass valve, 9. First flue gas duct, 10. Second flue gas duct, 11. Boiler induced draft fan, 12. Flue gas output duct, 13. Desulfurization tower, 14. Regeneration device. Detailed Implementation

[0021] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. These embodiments are based on the technical solution of the present invention and provide detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0022] refer to Figure 1 As shown, this embodiment provides an energy storage system for reducing the power consumption of induced draft fans in coal-fired boilers, including an air compression energy storage device and a flue gas ejector device. The flue gas ejector device includes a boiler induced draft fan 11 and a flue gas ejector 7 connected to the air compression energy storage device. The input end of the flue gas ejector 7 is connected to the flue gas inlet through a first flue gas pipe 9, and the input end of the boiler induced draft fan 11 is connected to the flue gas inlet through a second flue gas pipe 10. The output ends of both the flue gas ejector 7 and the boiler induced draft fan 11 are connected to a desulfurization tower 13 through a flue gas output pipe 12.

[0023] Through the above technical solution, the air compression energy storage device drives the flue gas ejector 7 to pressurize and eject flue gas from the first flue gas duct 9 into the flue gas output duct 12, where it mixes with the flue gas output from the boiler induced draft fan 11 into the flue gas output duct 12. The mixture then enters the desulfurization tower 13 for treatment and is released into the atmosphere. This technical solution reduces the operating load of the boiler induced draft fan 11, thereby effectively reducing the power consumption of the boiler induced draft fan 11 and lowering the power consumption rate, improving the peak-shaving capacity of the unit, achieving the goals of energy saving, consumption reduction, and lower operating costs, resulting in significant economic benefits. Simultaneously, the flue gas ejector 7 is an energy release component for compressed air, reducing the energy conversion steps in the power generation process of the air compression energy storage device.

[0024] As an optional implementation, the air compression energy storage device includes a back pressure unit 4, a compressor 5, and an air storage tank 6 connected in sequence. The output end of the air storage tank 6 is connected to a flue gas ejector 7, and the input end of the back pressure unit 4 is connected to a steam turbine 1, which is connected to a boiler.

[0025] High-temperature steam from the boiler is used as the driving steam source for the back pressure machine 4 after being powered by the steam turbine 1. The back pressure machine 4 drives the compressor 5 to compress air and inputs the compressed air into the air storage tank 6 to store it as high-pressure air.

[0026] As an optional implementation, the steam turbine 1 is also connected to a generator 2. The high-temperature steam from the boiler is used by the steam turbine 1 to generate electricity, which then drives the generator 2 to generate electricity.

[0027] The above technical solution enables high-temperature steam from the boiler to generate electricity through the turbine during peak electricity demand, and then drive the generator to produce electricity. During off-peak or flat-peak periods, a portion of the steam is partially expanded in the turbine and extracted as the driving steam source for the back-pressure turbine, reducing the turbine's operating load. At the same time, the back-pressure turbine drives the compressor to compress air and store it in the air storage tank. During peak electricity demand, the high-pressure air is released to drive the ejector to eject flue gas, improving the system's energy conversion efficiency and operational flexibility, reducing energy loss during power generation, further tapping the peak-shaving potential of coal-fired power generating units and compressed air energy storage systems, and alleviating the peak-shaving pressure on the power grid.

[0028] As an optional implementation, the output end of the steam turbine 1 is connected to the boiler in sequence via a condenser 3, a condensate pump, a low-pressure heater, a feedwater pump, and a high-pressure heater. The exhaust steam from the steam turbine 1 is condensed by the condenser 3 and then flows sequentially through the condensate pump, the low-pressure heater, the feedwater pump, and the high-pressure heater before entering the boiler to absorb heat and become high-temperature steam again before returning to the steam turbine 1 to complete the cycle, thereby reducing energy loss.

[0029] As an optional implementation, the output end of the condenser 3 is connected to a cooling tower and a circulating water pump, and the output end of the circulating water pump is connected to the input end of the condenser 3, forming a circulation loop. After the exhaust steam undergoes heat exchange in the condenser 3, the cooling water passes through the cooling tower and the circulating water pump before re-entering the condenser to complete the circulation.

[0030] As an optional implementation, the back pressure unit 4 is also connected to a regenerator 14. The steam in the back pressure unit 4 expands further and does work before entering the regenerator 14.

[0031] As an optional implementation, a bypass valve 8 is provided on the first flue gas duct 9.

[0032] As an optional implementation, the steam turbine 1, back pressure unit 4 and compressor 5 are provided with one or more units. The specific number can be determined according to the actual capacity of the coal-fired power generation unit and the air energy storage device. The process can be optimized by adopting multi-stage compression, intermediate heat exchange and other methods.

[0033] As an optional implementation, the top of the desulfurization tower 13 is provided with an exhaust port for discharging flue gas into the atmosphere.

[0034] The working principle of an energy storage system for reducing the power consumption of induced draft fans in coal-fired boilers, as provided in this embodiment, is as follows:

[0035] During peak electricity consumption, the high-temperature steam from the boiler is used to generate electricity by the turbine 1, which then drives the generator 2 to generate electricity. During off-peak or flat-peak periods, a portion of the steam expands in the turbine 1 and is extracted as the driving steam source for the back pressure compressor 4. The back pressure compressor 4 drives the compressor 5 to compress air, and the compressed air is then stored in the air storage tank 6 as high-pressure air. During peak operation, the high-pressure air stored in the air storage tank 6 is used as the ejector gas source to drive the flue gas ejector 7 to pressurize and eject the flue gas from the first flue gas pipe 9 into the flue gas output pipe 12. The flue gas mixes with the flue gas output from the boiler induced draft fan 11 into the flue gas output pipe 12, enters the desulfurization tower 13 for treatment, and is then released into the atmosphere. This directly reduces the operating load of the boiler induced draft fan 11, thereby effectively reducing the power consumption of the boiler induced draft fan 11 and lowering the plant power consumption rate. At the same time, it reduces energy loss during the power generation process of the compressed air energy storage system, improves the system's energy conversion efficiency and operational flexibility, further taps the peak-shaving potential of coal-fired power generating units and compressed air energy storage systems, and alleviates the peak-shaving pressure on the power grid.

[0036] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. An energy storage system for reducing the power consumption of induced draft fans in coal-fired boilers, characterized in that, It includes an air compression energy storage device and a flue gas ejector device. The flue gas ejector device includes a boiler induced draft fan (11) and a flue gas ejector (7) connected to the air compression energy storage device. The input end of the flue gas ejector (7) is connected to the flue gas inlet through a first flue gas pipe (9). The input end of the boiler induced draft fan (11) is connected to the flue gas inlet through a second flue gas pipe (10). The output ends of the flue gas ejector (7) and the boiler induced draft fan (11) are both connected to a desulfurization tower (13) through a flue gas output pipe (12). The air compression energy storage device serves as the driving steam source for the flue gas ejector (7), driving the flue gas ejector (7) to eject the flue gas through the first flue gas pipe (9) to the flue gas output pipe (12), where it mixes with the flue gas output to the flue gas output pipe (12) by the boiler induced draft fan (11), enters the desulfurization tower (13) for treatment, and is released into the atmosphere; The air compression energy storage device includes a back pressure machine (4), a compressor (5) and an air storage tank (6) connected in sequence. The output end of the air storage tank (6) is connected to the flue gas ejector (7). The input end of the back pressure machine (4) is connected to a steam turbine (1). The steam turbine (1) is connected to a boiler. The high-temperature steam from the boiler is used as the driving steam source for the back pressure machine (4) after being powered by the steam turbine (1). The back pressure machine (4) drives the compressor (5) to compress air and inputs the compressed air into the air storage tank (6) to store it as high-pressure air. The steam turbine (1) is also connected to a generator (2). The high-temperature steam from the boiler performs work and generates electricity through the steam turbine (1), which then drives the generator (2) to generate electricity. The output end of the steam turbine (1) is connected to the boiler in sequence through the condenser (3), condensate pump, low-pressure heater, feedwater pump and high-pressure heater.

2. The energy storage system for reducing the power consumption of induced draft fans in coal-fired boilers according to claim 1, characterized in that, The output end of the condenser (3) is connected to a cooling tower and a circulating water pump. The output end of the circulating water pump is connected to the input end of the condenser (3) to form a circulation loop.

3. The energy storage system for reducing the power consumption of induced draft fans in coal-fired boilers according to claim 1, characterized in that, The back pressure machine (4) is also connected to a regenerator (14).

4. The energy storage system for reducing the power consumption of induced draft fans in coal-fired boilers according to claim 1, characterized in that, The steam turbine (1), the back pressure machine (4), and the compressor (5) are provided with one or more units.

5. The energy storage system for reducing the power consumption of induced draft fans in coal-fired boilers according to claim 1, characterized in that, A bypass valve (8) is provided on the first flue gas duct (9).

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