A full-load peak shaving coal-fired power generation system

Abstract

The present invention relates to a full-load peak shaving coal-fired power generation system, which includes a coal-fired power generation system and a water electrolysis hydrogen production system. Among them, the coal-fired power generation system includes a coal-fired boiler, a steam turbine, a generator, and a step-up substation; the water electrolysis hydrogen production system includes a water electrolysis system, a hydrogen purification system, an oxygen purification system, a hydrogen storage system, and an oxygen storage system; and, the step-up substation is electrically connected to the water electrolysis system. This solution matches the scale of the water electrolysis hydrogen production system with the coal-fired power generation system to reduce the power supply load of the coal-fired power generation unit, improve the operation flexibility of the coal-fired power generation unit, realize the full-load peak shaving function of the coal-fired power generation unit, and at the same time can provide reliable and high-quality hydrogen to the cities and chemical plants around the power plant; in addition, the by-product oxygen generated by water electrolysis hydrogen production can be sent into the coal-fired boiler to realize the oxy-fuel combustion of the boiler, which can stabilize the combustion to a certain extent, improve the boiler efficiency, and reduce carbon emissions.

Description

Technical Field

[0001] The present invention belongs to the field of coal-fired power generation systems, and particularly relates to a full-load peak shaving coal-fired power generation system. Background Art

[0002] At present, the demand for coal-fired power generation units to participate in the deep peak shaving of the power system and the accommodation of renewable energy is becoming increasingly prominent.

[0003] The peak shaving capacity of coal-fired power generation units is mainly restricted by the minimum stable combustion capacity of boilers. At present, the minimum stable combustion load of boilers in large coal-fired power generation units is generally 30% - 50% of the rated load. Through technological upgrading and transformation, the minimum stable combustion load of boilers can be reduced to 20% - 30% of the rated load. If the unit load continues to decline, a series of technical risks such as unstable boiler combustion, flameout, hydrodynamic and heating surface insecurity will be faced. Therefore, it is extremely difficult to achieve deep, even full-load peak shaving through the technological upgrading of coal-fired power generation units themselves.

[0004] Therefore, the defect of the existing coal-fired power generation system is that it is difficult to achieve full-load peak shaving through the technological upgrading of the coal-fired power generation system itself, and the existing coal-fired power generation system and the electrolytic water hydrogen production system are often independent of each other. Summary of the Invention

[0005] The present invention provides a full-load peak shaving coal-fired power generation system, which reasonably matches the scale of the electrolytic water hydrogen production system through the coal-fired power generation system to reduce the power supply load of the coal-fired power generation unit, improve the operation flexibility of the coal-fired power generation unit, realize the full-load peak shaving function of the coal-fired power generation unit, and at the same time can provide high-quality hydrogen and oxygen outside the plant.

[0006] The technical means adopted by the present invention are as follows:

[0007] A full-load peak shaving coal-fired power generation system includes a coal-fired power generation system and an electrolytic water hydrogen production system. Among them, the coal-fired power generation system includes a coal-fired boiler, a steam turbine connected to the coal-fired boiler, a generator connected to the steam turbine, and a booster station connected to the generator; the electrolytic water hydrogen production system includes an electrolytic water system, a hydrogen purification system and an oxygen purification system connected to the electrolytic water system, and a hydrogen storage system and an oxygen storage system respectively connected to the hydrogen purification system and the oxygen purification system; and the booster station is electrically connected to the electrolytic water system.

[0008] Preferably, the electrolytic water system includes an electrolytic cell, a power supply system, and a water replenishment system. The electrolytic cell is respectively connected to the output end of the power supply system and the output end of the water replenishment system, and the input end of the power supply system is connected to the output end of the booster station.

[0009] Preferably, the power supply system includes a transformer and a rectifier. The input end of the transformer is connected to the output end of the booster station. The output end of the transformer is connected to the input end of the rectifier. The output end of the rectifier is connected to the electrolytic cell.

[0010] Preferably, the water replenishing system includes a water tank and a water replenishing pump. The water tank stores demineralized water connected from the coal-fired power generation system. The input end of the water replenishing pump is connected to the water tank. The output end of the water replenishing pump is connected to the electrolytic cell.

[0011] Preferably, the hydrogen purification system includes a hydrogen scrubber, a hydrogen cooler, and a hydrogen water separator. The input end of the hydrogen scrubber is connected to the hydrogen output end of the electrolytic cell. The output end of the hydrogen scrubber is connected to the input end of the hydrogen cooler. The output end of the hydrogen cooler is connected to the input end of the hydrogen water separator.

[0012] Preferably, the hydrogen storage system includes a hydrogen buffer tank, a hydrogen compressor, a hydrogen storage tank, and a hydrogen dispenser. The input end of the hydrogen buffer tank is connected to the output end of the hydrogen cooler. The output end of the hydrogen buffer tank is connected to the input end of the hydrogen compressor. The output end of the hydrogen compressor is connected to the input end of the hydrogen storage tank. And the output end of the hydrogen storage tank is connected to the input end of the hydrogen dispenser. The output end of the hydrogen dispenser is connected to a hydrogen transmission system and in-plant hydrogen users.

[0013] Preferably, the output end of the hydrogen dispenser is connected to the hydrogen transmission system and the generator in the plant. And the hydrogen transmission system includes a hydrogen transmission pipeline and a hydrogen transport trailer arranged between the hydrogen storage dispenser and off-plant hydrogen users.

[0014] Preferably, the oxygen purification system includes an oxygen scrubber, an oxygen cooler, and an oxygen water separator. The input end of the oxygen scrubber is connected to the oxygen output end of the electrolytic cell. The output end of the oxygen scrubber is connected to the input end of the oxygen cooler. The output end of the oxygen cooler is connected to the input end of the oxygen water separator.

[0015] Preferably, the oxygen storage system includes an oxygen storage tank and an oxygen pressure regulating device. The input end of the oxygen storage tank is connected to the output end of the oxygen water separator. The output end of the oxygen storage tank is connected to the input end of the oxygen pressure regulating device. The output end of the oxygen pressure regulating device is connected to in-plant oxygen users and off-plant oxygen users.

[0016] Preferably, the coal-fired boiler is provided with an oxy-fuel burner and an oxygen heater. The output end of the oxygen pressure regulating device is connected to the oxy-fuel burner through the oxygen heater.

[0017] Compared with the prior art, the beneficial technical effects of the present invention are as follows:

[0018] 1. This solution enables the coal-fired power generation system to achieve deep peak shaving or even full-load peak shaving by matching an appropriate scale of the electrolyzed water system, which is more conducive to the power grid's consumption of new energy.

[0019] 2. The power plant in this solution produces hydrogen through the electrolyzed water hydrogen production system, which has high purity and is green and environmentally friendly, and can provide reliable and high-quality hydrogen for the cities and chemical plants around the power plant.

[0020] 3. The by-product oxygen generated by electrolyzing water is sent into the coal-fired boiler to achieve oxygen-enriched combustion of the boiler, which can stabilize combustion to a certain extent, improve the boiler efficiency, and reduce carbon emissions. Description of the Drawings

[0021] Figure 1 It is a schematic structural diagram of the full-load peak shaving coal-fired power generation system of the present invention.

[0022] Figure 2 It is a schematic structural diagram of the electrolyzed water system.

[0023] Figure 3 It is a schematic structural diagram of the hydrogen purification system and the oxygen purification system.

[0024] Figure 4 It is a schematic structural diagram of the hydrogen storage system and the hydrogen transmission system.

[0025] Figure 5 It is a schematic structural diagram of the oxygen storage system.

[0026] Wherein:

[0027] 1 Coal-fired power generation system;

[0028] 11 Coal-fired boiler; 11a Oxygen-enriched burner; 11b Oxygen heater;

[0029] 12 Steam turbine;

[0030] 13 Generator;

[0031] 14 Step-up substation;

[0032] 2 Electrolyzed water hydrogen production system;

[0033] 21 Electrolyzed water system; 21a Electrolytic cell; 21b Power supply system; 21b-1 Transformer; 21b-2 Rectifier; 21b-3 Switch; 21b-4 Cable; 21c Make-up water system; 21c-1 Water tank; 21c-2 Make-up water pump; 21c-3 Make-up water pipeline; 21c-4 Make-up water valve;

[0034] 22 Hydrogen purification system; 22a Hydrogen scrubber; 22b Hydrogen cooler; 22c Hydrogen water separator; 22d Hydrogen purification pipeline; 22e Hydrogen purification valve;

[0035] 23 Hydrogen storage system; 23a Hydrogen buffer tank; 23b Hydrogen compressor; 23c Hydrogen storage tank; 23d Hydrogen dispenser; 23e Hydrogen storage pipeline; 23f Hydrogen storage valve;

[0036] 24 Hydrogen transmission system; 24a Hydrogen transmission pipeline; 24b Hydrogen transmission valve; 24c Hydrogen transportation trailer;

[0037] 25 Oxygen purification system; 25a Oxygen scrubber; 25b Oxygen cooler; 25c Oxygen water separator; 25d Oxygen purification pipeline; 25e Oxygen purification valve;

[0038] 26 Oxygen storage system; 26a Oxygen storage tank; 26b Oxygen pressure regulating device; 26c Oxygen storage pipeline; 26d Oxygen storage valve. Detailed implementation mode

[0039] The present invention provides a full-load peak-shaving coal-fired power generation system, as Figure 1 shown, including a coal-fired power generation system 1 and a water electrolysis hydrogen production system 2. By matching the coal-fired power generation system 1 with a suitable water electrolysis hydrogen production system 2, the coal-fired power generation system 1 realizes full-load peak shaving.

[0040] Among them, the coal-fired power generation system 1 includes a coal-fired boiler 11, a steam turbine 12 connected to the coal-fired boiler 11, a generator 13 connected to the steam turbine 12, and a booster station 14 connected to the generator 13; the steam generated by the coal-fired boiler 11 enters the steam turbine 12, the steam turbine 12 drives the generator 13 to generate electricity, and after being boosted by the booster station 14, it is sent to the power grid and the water electrolysis hydrogen production system 2.

[0041] The water electrolysis hydrogen production system 2 includes a water electrolysis system 21, a hydrogen purification system 22 and an oxygen purification system 25 connected to the water electrolysis system 21, and a hydrogen storage system 23 and an oxygen storage system 26 respectively connected to the hydrogen purification system 22 and the oxygen purification system 25; and, the booster station 14 is electrically connected to the water electrolysis system 21, a part of the electricity boosted by the booster station 14 is connected to the water electrolysis system 21 for producing hydrogen and oxygen, the hydrogen enters the hydrogen storage system 23 through the hydrogen purification system 22, and then is sent to users through the hydrogen transmission system 24, while the oxygen enters the oxygen storage system 26 through the oxygen purification system 25, and then enters the burner of the coal-fired boiler 11 after being pressure-regulated and heated.

[0042] Among them, the electricity load of the water electrolysis hydrogen production system 2 is comprehensively selected according to factors such as the peak shaving depth demand of the coal-fired power generation system 1, the hydrogen consumption demand, and the plant electricity load; and the water electrolysis system 21 can adopt alkaline water electrolysis, proton exchange membrane water electrolysis, solid polymer anion exchange membrane water electrolysis or solid oxide water electrolysis technology.

[0043] Specifically, as Figure 2As shown in the figure, the electrolyzed water system 21 includes an electrolytic cell 21a, a power supply system 21b, and a water replenishment system 21c. The electrolytic cell 21a is respectively connected to the output terminals of the power supply system 21b and the water replenishment system 21c, and the input terminal of the power supply system 21b is connected to the output terminal of the booster station 14.

[0044] The power supply system 21b includes a transformer 21b-1 and a rectifier 21b-2. The input terminal of the transformer 21b-1 is connected to the output terminal of the booster station 14, the output terminal of the transformer 21b-1 is connected to the input terminal of the rectifier 21b-2, and the output terminal of the rectifier 21b-2 is connected to the electrolytic cell 21a. The transformer 21b-1 is used to step down the high-voltage electricity taken out from the booster station 14 of the coal-fired power generation system 1 to a voltage level matching the electrolyzed water hydrogen production system 2; the rectifier 21b-2 is used to convert the alternating current generated by the transformer 21b-1 into qualified direct current to supply power to the electrolytic cell 21a; and it also has a switch 21b-3 and a cable 21b-4. The switch 21b-3 is used to connect and disconnect the booster station 14 and the transformer 21b-1; the cable 21b-4 is used to connect the above-mentioned devices.

[0045] The water replenishment system 21c includes a water tank 21c-1 and a water replenishment pump 21c-2. The water tank 21c-1 stores the demineralized water introduced from the coal-fired power generation system 1. The input terminal of the water replenishment pump 21c-2 is connected to the water tank 21c-1, and the output terminal of the water replenishment pump 21c-2 is connected to the electrolytic cell 21a. It is used to pressurize the demineralized water sent from the water tank 21c-1 and then send it into the electrolytic cell 21a; and the water replenishment system 21c also has a water replenishment pipeline 21c-3 and a water replenishment valve 21c-4. The water replenishment pipeline 21c-3 is used to connect the above-mentioned devices; the water replenishment valve 21c-4 is used to open and cut off the above-mentioned devices.

[0046] And, in this solution, the hydrogen purification system 22 and the oxygen purification system 25 are respectively used to purify hydrogen and oxygen and improve their purity.

[0047] As Figure 3As shown, the hydrogen purification system 22 includes a hydrogen scrubber 22a, a hydrogen cooler 22b, and a hydrogen water separator 22c. The input end of the hydrogen scrubber 22a is connected to the hydrogen output end of the electrolyzer 21a. The output end of the hydrogen scrubber 22a is connected to the input end of the hydrogen cooler 22b. The output end of the hydrogen cooler 22b is connected to the input end of the hydrogen water separator 22c. The hydrogen scrubber 22a is used to wash the hydrogen generated by the electrolyzer 21a. The hydrogen cooler 22b is used to cool the hydrogen washed by the hydrogen scrubber 22a. The hydrogen water separator 22c is used to separate the gas and liquid of the hydrogen discharged by the hydrogen cooler 22b, and then send it to the hydrogen storage system 23. And the hydrogen purification system 22 further includes a hydrogen purification pipeline 22d and a hydrogen purification valve 22e. The hydrogen purification pipeline 22d is used to connect the above-mentioned devices, and the hydrogen purification valve 22e is used to open and cut off the above-mentioned devices.

[0048] As Figure 4 As shown, the hydrogen storage system 23 includes a hydrogen buffer tank 23a, a hydrogen compressor 23b, a hydrogen storage tank 23c, and a hydrogen dispenser 23d. The input end of the hydrogen buffer tank 23a is connected to the output end of the hydrogen cooler 22b. The output end of the hydrogen buffer tank 23a is connected to the input end of the hydrogen compressor 23b. The output end of the hydrogen compressor 23b is connected to the input end of the hydrogen storage tank 23c. And the output end of the hydrogen storage tank 23c is connected to the input end of the hydrogen dispenser 23d. The output end of the hydrogen dispenser 23d is connected to a hydrogen transmission system 24 and hydrogen users in the factory. The hydrogen buffer tank 23a is used to buffer the hydrogen sent by the hydrogen purification system 22 and play a role in stabilizing the pressure. The hydrogen compressor 23b is used to pressurize the hydrogen discharged by the hydrogen buffer tank 23a. The hydrogen storage tank 23c is used to store the pressurized hydrogen. The hydrogen dispenser 23d is used to distribute the hydrogen sent by the hydrogen storage tank 23c to the hydrogen transmission system 24 and hydrogen users in the factory. And the hydrogen storage system 23 further includes a hydrogen storage pipeline 23e and a hydrogen storage valve 23f. The hydrogen storage pipeline 23e is used to connect the devices of the hydrogen storage system 23 above, and the hydrogen storage valve 23f is used to open and cut off the above-mentioned devices.

[0049] Preferably, the output end of the hydrogen dispenser 23d is connected to the hydrogen transmission system 24 and the generator 13 in the factory to send hydrogen into the hydrogen-cooled generator 13 of the power plant. And the hydrogen transmission system 24 includes a hydrogen transmission pipeline 24a, a hydrogen transmission valve 24b, and a hydrogen transport trailer 24c arranged between the hydrogen storage dispenser and hydrogen users outside the factory. Among them, the hydrogen transmission pipeline 24a is used to send the hydrogen stored in the hydrogen storage system 23 to users by pipeline. The hydrogen transmission valve 24b is used to open and cut off the hydrogen transmission pipeline 24a. The hydrogen transport trailer 24c is used to send the hydrogen stored in the hydrogen storage system 23 to users by road transportation.

[0050] And as Figure 3As shown in the figure, the oxygen purification system 25 includes an oxygen scrubber 25a, an oxygen cooler 25b, and an oxygen water separator 25c. The input end of the oxygen scrubber 25a is connected to the oxygen output end of the electrolytic cell 21a. The output end of the oxygen scrubber 25a is connected to the input end of the oxygen cooler 25b. The output end of the oxygen cooler 25b is connected to the input end of the oxygen water separator 25c. Among them, the oxygen scrubber 25a is used to scrub the oxygen generated by the electrolytic water system 21; the oxygen cooler 25b is used to cool the oxygen after the oxygen scrubber 25a; the oxygen water separator 25c is used to separate the gas and liquid of the oxygen discharged from the oxygen cooler 25b; and then it is sent to the oxygen storage system 26. And the oxygen purification system 25 further includes an oxygen purification pipeline 25d and an oxygen purification valve 25e. The oxygen purification pipeline 25d is used to connect the equipment of the above-mentioned oxygen purification system 25; the oxygen purification valve 25e is used to open and cut off the above-mentioned equipment.

[0051] The oxygen storage system 26 includes an oxygen storage tank 26a and an oxygen pressure regulating device 26b. The input end of the oxygen storage tank 26a is connected to the output end of the oxygen water separator 25c. The output end of the oxygen storage tank 26a is connected to the input end of the oxygen pressure regulating device 26b. The output end of the oxygen pressure regulating device 26b is connected to the in-plant oxygen users and off-plant oxygen users. Among them, the oxygen storage tank 26a is used to store the oxygen sent by the oxygen purification system 25; the oxygen pressure regulating device 26b is used to adjust the oxygen in the oxygen storage tank 26a to an appropriate pressure and flow rate and deliver it to the users. And the oxygen storage system 26 further includes an oxygen storage pipeline 26c and an oxygen storage valve 26d. The oxygen storage pipeline 26c is used to connect the equipment of the above-mentioned oxygen storage system 26; the oxygen storage valve 26d is used to open and cut off the above-mentioned equipment.

[0052] Preferably, as Figure 1 shown, the in-plant oxygen user is a coal-fired boiler 11. The coal-fired boiler 11 is provided with an oxygen-enriched burner 11a and an oxygen heater 11b. The output end of the oxygen pressure regulating device 26b is connected to the oxygen-enriched burner 11a through the oxygen heater 11b, so as to connect the oxygen of the oxygen storage system 26 to the oxygen-enriched burner 11a of the coal-fired boiler 11 through the oxygen heater, which can stabilize the combustion to a certain extent, improve the boiler efficiency, and reduce carbon emissions.

Claims

1. A full-load peak shaving coal-fired power generation system, characterized in that, It includes a coal-fired power generation system (1) and a water electrolysis hydrogen production system (2). Among them, the coal-fired power generation system (1) includes a coal-fired boiler (11), a steam turbine (12) connected to the coal-fired boiler (11), a generator (13) connected to the steam turbine (12), and a step-up substation (14) connected to the generator (13); the water electrolysis hydrogen production system (2) includes a water electrolysis system (21), a hydrogen purification system (22) and an oxygen purification system (25) connected to the water electrolysis system (21), and a hydrogen storage system (23) and an oxygen storage system (26) respectively connected to the hydrogen purification system (22) and the oxygen purification system (25); and the step-up substation (14) is electrically connected to the water electrolysis system (21). The water electrolysis system (21) includes an electrolytic cell (21a), a power supply system (21b), and a water replenishing system (21c). The electrolytic cell (21a) is respectively connected to the output end of the power supply system (21b) and the output end of the water replenishing system (21c), and the input end of the power supply system (21b) is connected to the output end of the step-up substation (14). The power supply system (21b) includes a transformer (21b-1) and a rectifier (21b-2). The input end of the transformer (21b-1) is connected to the output end of the step-up substation (14), the output end of the transformer (21b-1) is connected to the input end of the rectifier (21b-2), and the output end of the rectifier (21b-2) is connected to the electrolytic cell (21a). The water replenishing system (21c) includes a water tank (21c-1) and a water replenishing pump (21c-2). The water tank (21c-1) stores demineralized water accessed from the coal-fired power generation system (1). The input end of the water replenishing pump (21c-2) is connected to the water tank (21c-1), and the output end of the water replenishing pump (21c-2) is connected to the electrolytic cell (21a). The hydrogen purification system (22) includes a hydrogen scrubber (22a), a hydrogen cooler (22b), and a hydrogen water separator (22c). The input end of the hydrogen scrubber (22a) is connected to the hydrogen output end of the electrolytic cell (21a), the output end of the hydrogen scrubber (22a) is connected to the input end of the hydrogen cooler (22b), and the output end of the hydrogen cooler (22b) is connected to the input end of the hydrogen water separator (22c). The oxygen purification system (25) includes an oxygen scrubber (25a), an oxygen cooler (25b), and an oxygen water separator (25c). The input end of the oxygen scrubber (25a) is connected to the oxygen output end of the electrolytic cell (21a), the output end of the oxygen scrubber (25a) is connected to the input end of the oxygen cooler (25b), and the output end of the oxygen cooler (25b) is connected to the input end of the oxygen water separator (25c).

2. The full-load peak shaving coal-fired power generation system according to claim 1, characterized in that, The hydrogen storage system (23) includes a hydrogen buffer tank (23a), a hydrogen compressor (23b), a hydrogen storage tank (23c), and a hydrogen dispenser (23d). The input end of the hydrogen buffer tank (23a) is connected to the output end of the hydrogen cooler (22b), the output end of the hydrogen buffer tank (23a) is connected to the input end of the hydrogen compressor (23b), the output end of the hydrogen compressor (23b) is connected to the input end of the hydrogen storage tank (23c), and the output end of the hydrogen storage tank (23c) is connected to the input end of the hydrogen dispenser (23d). The output end of the hydrogen dispenser (23d) is connected to a hydrogen transmission system (24) and in-plant hydrogen users.

3. The full-load peak shaving coal-fired power generation system according to claim 2, wherein The output end of the hydrogen dispenser (23d) is connected to the hydrogen transmission system (24) and the in-plant generator (13), and the hydrogen transmission system (24) includes a hydrogen transmission pipeline (24a) and a hydrogen transport trailer (24c) provided between the hydrogen dispenser (23d) and off-plant hydrogen users.

4. A full-load peak shaving coal-fired power generation system according to claim 1, wherein, The oxygen storage system (26) includes an oxygen storage tank (26a) and an oxygen pressure regulating device (26b). The input end of the oxygen storage tank (26a) is connected to the output end of the oxygen-water separator (25c), the output end of the oxygen storage tank (26a) is connected to the input end of the oxygen pressure regulating device (26b), and the output end of the oxygen pressure regulating device (26b) is connected to in-plant and off-plant oxygen users.

5. A full-load peak shaving coal-fired power generation system according to claim 4, characterized in that, The coal-fired boiler (11) is provided with an oxygen-enriched burner (11a) and an oxygen heater (11b). The output end of the oxygen pressure regulating device (26b) is connected to the oxygen-enriched burner (11a) through the oxygen heater (11b).

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