Wind and light hydrogen production system utilizing flue gas of coal-fired unit to lift water
By using condensation and water extraction towers and heat pump technologies in the wind and light hydrogen production system, water vapor is extracted from the flue gas of the coal-fired unit, which solves the problem of water shortage in hydrogen production projects in areas with abundant wind and light resources but water shortage, and achieves efficient utilization of water resources and efficient operation of electrolytic cells.
Patent Information
- Application Number
- CN202422556396.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-23
- Publication Date
- 2025-08-15
- Estimated Expiration
- 2034-10-23
AI Technical Summary
In areas with abundant wind and light resources but lack of water, wind and light power hydrogen generation projects face the problem of lack of raw material water, and the existing technology is difficult to effectively utilize the water resources in the flue gas of coal-fired units.
A wind-ray hydrogen production system is designed, and a condensation water extraction tower is used to extract water vapor from the flue gas of the coal-fired unit. The water vapor in the flue gas is condensed into condensed water through the condensation heat exchange system. After processing it, it is supplied to the electrolytic cell as raw material water to produce hydrogen. At the same time, the heat pump and indirect air cooling tower are used to recover the flue gas heat, providing heat backup for the electrolytic cell and achieving efficient utilization of water and heat.
It effectively solves the problem of water shortage, provides sufficient raw material water supply to hydrogen production projects, and reduces the energy consumption of the electrolytic cell, improves the flexibility and green electricity utilization rate of the electrolytic cell, and achieves efficient utilization and conservation of water resources.
Smart Images
Figure CN223226191U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the field of renewable energy hydrogen production and coal-fired power generation, and specifically relates to a wind-solar hydrogen production system that utilizes flue gas from coal-fired units to extract water. Background Art
[0002] Using electricity-generated green hydrogen as a medium, on the one hand, it can achieve large-scale absorption of renewable energy and improve the dispatchability of the power grid; on the other hand, replacing highly polluting and high-emission coal-based hydrogen with clean and efficient green hydrogen can promote the green and low-carbon transformation of industries such as steel and chemical industry.
[0003] The water source required for hydrogen production by water electrolysis is a key issue that most projects need to solve. Utility Model Content
[0004] The technical problem to be solved by the present invention is to provide a wind-solar hydrogen production system that utilizes the flue gas of coal-fired units to extract water, so as to solve the difficulties faced by the construction of wind-solar power generation and hydrogen production projects in areas with abundant wind and solar resources but insufficient water. The water vapor in the flue gas of coal-fired units is used to provide raw water for electrolysis of water to produce hydrogen, thereby achieving water saving and efficient utilization.
[0005] According to the technical solution of the present invention, the present invention provides a wind-solar hydrogen production system that utilizes flue gas from a coal-fired unit to extract water, including a condensing water extraction tower, which is connected to the chimney at the top through a smoke exhaust pipe, and is connected to the coal-fired unit at the bottom through a flue gas input pipe; a water reservoir is provided below the condensing water extraction tower, which is connected to the electrolyzer of the hydrogen production system through a water treatment pipeline, and a chemical water treatment device is provided in the water treatment pipeline; the electrolyzer is connected to a wind power system and / or a photovoltaic system.
[0006] Furthermore, a turbulator, a spray layer and a tube bundle demister are arranged in sequence from bottom to top in the condensation water extraction tower. The condensation water extraction tower is connected to the chimney through a smoke exhaust pipe above the tube bundle demister, and is connected to the coal-fired unit through a flue gas input pipe below the turbulator.
[0007] Furthermore, the water reservoir is connected to an indirect air cooling tower through a high-temperature circulating water pipeline, a circulating water pump is provided in the high-temperature circulating water pipeline, and the indirect air cooling tower is connected to the spray water input end of the spray layer through a low-temperature circulating water pipeline.
[0008] Furthermore, the high-temperature circulating water pipeline is also connected to a heat pump.
[0009] Furthermore, a hot water storage tank is included, and the heat pump, the hot water storage tank, and the electrolytic cell are connected in sequence through a hot water pipeline.
[0010] Furthermore, the water reservoir is connected to the power plant water system through a recycling pipeline.
[0011] Compared with the prior art, the beneficial technical effects of the present invention are as follows:
[0012] my country's "Three Norths" region boasts abundant coal resources and numerous large-capacity coal-fired power plants. Currently, the flue gas temperature at the inlet of the desulfurization towers of most large and medium-sized coal-fired power plants is between 90°C and 120°C. After entering the desulfurization towers, the flue gas temperature drops to around 55°C. At this point, the flue gas is saturated and contains significant amounts of water vapor. For example, for two 660MW coal-fired power plants, the desulfurization water consumption for two units can reach over 100 tons / hour. Without appropriate measures, this water would be discharged into the atmosphere along with the flue gas, resulting in significant water waste. This solution utilizes flue gas cooling and condensation to extract water, lowering the saturated, wet flue gas temperature from 55°C to around 50°C. This allows for significant water extraction from the flue gas. A typical flue gas water extraction rate for two 660MW coal-fired power plants exceeds 250 tons / hour. This represents a significant increase in water extraction, in addition to covering the water carried away by the flue gas in the desulfurization towers. After treatment, this condensed water can be supplied as feedwater for wind-solar hydrogen production projects, or partially reused in coal-fired units, thereby conserving water and effectively utilizing water resources. For example, a 700MW wind-to-hydrogen project with an annual hydrogen production capacity of 30,000 tons requires approximately 300,000 tons of feedwater per year. Flue gas water extraction from two 660MW coal-fired units, in addition to being reused for the coal-fired units themselves, leaves approximately 300,000 tons of surplus water per year, precisely the feedwater required for the 700MW wind-to-hydrogen project. Therefore, if flue gas water extraction is prioritized for use within the coal-fired units, approximately 300,000 tons of surplus water can be used annually for the 30,000 tons / year wind-to-solar hydrogen production project, thus addressing the water shortage challenge commonly faced by wind-to-solar hydrogen production projects in northern China.
[0013] 2. At the same time, the temperature of flue gas condensate is generally around 50°C, which is significantly higher than the 30°C temperature of the desalted water entering the electrolyzer. Therefore, entering the electrolyzer as raw water can reduce the energy consumption required to raise the temperature of conventional raw water from room temperature to around 90°C, which helps to reduce the electricity consumption of hydrogen production in the electrolyzer.
[0014] 3. In addition, the heat released by flue gas condensation is discharged into the atmosphere through an indirect air-cooling tower. Some of the condensed water in the reservoir is then indirectly cooled by air cooling before entering the condensation water extraction tower to spray the flue gas for cooling. A heat pump can also be used to extract some of the heat from the condensed water and store it in a hot water storage tank. When wind and solar power generation is insufficient, some electrolyzers may shut down. In this case, the hot water storage tank can be used to supply heat to the shut-down electrolyzers, thereby achieving hot standby operation. This in turn accelerates the startup of these electrolyzers, improving their flexibility and green electricity utilization. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Figure 1 It is a schematic diagram of the system structure provided by the utility model.
[0016] Description of reference numerals in the accompanying drawings:
[0017] 1. Electrolyzer; 2. Wind power system; 3. Photovoltaic system; 4. Condensation water extraction tower; 5. Tube bundle demister; 6. Spray layer; 7. Turbulator; 8. Water reservoir; 9. Circulating water pump; 10. Indirect air cooling tower; 11. Heat pump; 12. Chemical water treatment device; 13. Chimney; 14. Hot water storage tank; 15. Flue gas input pipeline; 16. Water treatment pipeline; 17. High-temperature circulating water pipeline; 18. Low-temperature circulating water pipeline; 19. Power plant water system. DETAILED DESCRIPTION
[0018] The utility model provides a wind-solar hydrogen production system that utilizes coal-fired unit flue gas to extract water. More specifically, it is a system that utilizes coal-fired generator unit flue gas to extract water and waste heat to supply water and heat for wind-solar hydrogen production projects. It solves the problem faced by the construction of wind-solar power generation and hydrogen production projects in areas with abundant wind and solar resources but water shortage. It utilizes the water vapor in the flue gas of the coal-fired unit to provide raw water for electrolysis of water to produce hydrogen, thereby achieving water saving and efficient utilization.
[0019] See also Figure 1 The present invention provides a wind-solar hydrogen production system that utilizes flue gas from coal-fired units for water extraction. The system includes a condensing water extraction tower 4, which houses a condensing heat exchange system. The tower 4 is connected to a chimney 13 at the top via a flue gas exhaust pipeline and to the desulfurized flue gas output of the coal-fired units at the bottom via a flue gas input pipeline 15. A water reservoir 8 is located below the tower 4. This reservoir 8 is connected to the electrolyzer 1 of the hydrogen production system via a water treatment pipeline 16, which contains a chemical water treatment device 12. The electrolyzer 1 is connected to a wind power system 2 (wind power generation system) and / or a photovoltaic system 3 (photovoltaic power generation system). Thus, the flue gas after the desulfurization tower of the coal-fired unit enters the condensation and water extraction tower 4 and is sprayed for cooling. A large amount of water vapor originally in the flue gas condenses and falls into the water reservoir 8. The condensed water is finely treated by the chemical water treatment device 12 and then supplied to the electrolyzer 1 as raw water for hydrogen production. The cooled flue gas enters the chimney 13 and is discharged into the atmosphere.
[0020] In this embodiment, the condensation heat exchange system of the condensation water extraction tower 4 employs a direct condensation heat exchange system, in other words, a hybrid condensation water extraction method. This system includes, in order from bottom to top, a turbulator 7, a spray layer 6, and a tube bundle demister 5. Above the tube bundle demister 5, the condensation water extraction tower 4 is connected to the chimney 13 via a flue gas exhaust line. Below the turbulator 7, the condensation water extraction tower 4 is connected to the coal-fired unit via a flue gas input line 15.
[0021] The incoming flue gas first flows through turbulator 7, which mixes and evenly distributes the flue gas. The turbulent flow increases the subsequent contact area and uniformity between the flue gas and the spray water, enhancing the spray cooling and demisting effects. The spray layer 6, primarily a spray device, evenly sprays water through, for example, a nozzle structure, allowing the cooler water to directly contact and mix with the flue gas, lowering the flue gas temperature. The saturated water vapor in the flue gas condenses and falls into the water reservoir 8. The cooled flue gas continues upward through the tube bundle demister 5, removing mist droplets and dust from the flue gas and reducing mist carryover. It ultimately enters the chimney 13 and is discharged into the atmosphere.
[0022] Furthermore, water reservoir 8 is connected to indirect air-cooling tower 10 via high-temperature circulating water pipeline 17. High-temperature circulating water pipeline 17 is equipped with a circulating water pump 9. Indirect air-cooling tower 10 is connected to the spray water input of spray layer 6 via low-temperature circulating water pipeline 18. This allows some of the condensed water (still relatively high) in water reservoir 8 to be pressurized by circulating water pump 9 and then enter indirect air-cooling tower 10 for cooling, forming low-temperature circulating water. This water then flows as spray water to spray the flue gas at spray layer 6 of condensation water extraction tower 4, thereby cooling the flue gas.
[0023] The high-temperature circulating water pipeline 17 is also connected to a heat pump 11, which can extract some of the circulating water's heat for utilization. For example, it also includes a hot water storage tank 14. The heat pump 11, hot water storage tank 14, and electrolytic cell 1 are sequentially connected via a hot water pipeline. This allows the heat extracted by the heat pump 11 to be transferred to and stored in the hot water storage tank 14, where it can be supplied to the electrolytic cell 1 for hot standby operation when needed. The heat pump 11 can utilize steam from the unit or direct electricity as a high-level energy source to raise the temperature of the waste heat from the condensed water to a temperature suitable for hot standby operation of the electrolytic cell. More specifically, the heat pump's inlet is connected to the high-temperature circulating water pipeline, and its outlet is connected to the hot water storage tank. A portion of the high-temperature circulating water enters the heat pump, which, using external steam, electricity, or other energy sources as input, further raises the temperature of the high-temperature circulating water, converting it into hot water that is then fed into the hot water storage tank. The heat in the hot water storage tank provides the heat source for hot standby operation of the electrolytic cell. Most of the high-temperature circulating water from the water reservoir 8 enters the indirect air-cooling tower 10, and the rest enters the heat pump 11 for heating when needed and then enters the hot water storage tank 14; when the hot water storage tank 14 is full of water, all the high-temperature circulating water enters the indirect air-cooling tower 10.
[0024] The water reservoir 8 is also connected to the power plant water system 19 through a recycling pipeline, so that the condensed water in the water reservoir 8 can be directly recycled to the desulfurization system of the coal-fired unit, or used for other water facilities in the power plant such as boiler water replenishment and dry ash humidification after treatment.
[0025] It is understood that in this solution, the condensation water extraction tower 4 is used to lower the temperature of the saturated net flue gas after desulfurization, thereby condensing a large amount of water vapor therein as condensed water. In addition to the aforementioned hybrid condensation water extraction method, the condensation heat exchange system in the condensation water extraction tower 4 can also adopt an indirect condensation water extraction method. For example, a shell-and-tube heat exchanger structure is provided, in which the flue gas is transported through the shell side of the heat exchanger and the coolant (such as water) is transported through the tube side. The flue gas and coolant do not directly contact each other, but rather exchange heat indirectly. In addition, the connection of the pipelines in this system and the setting of the corresponding valves and pumps can be adjusted according to needs. The specific structure of the hydrogen production system can continue to use existing technologies or other feasible solutions, and is not the focus of improvement in this solution. These specific details are easy to implement based on existing technologies and are not elaborated here.
[0026] In summary, the flue gas temperature at the desulfurization tower entrance of most large and medium-sized coal-fired units currently ranges from 90°C to 120°C. After entering the desulfurization tower, the flue gas temperature drops to around 55°C. At this point, the flue gas is saturated and contains a large amount of water vapor. For example, for a 660MW coal-fired unit, the water consumption for desulfurization of two units can reach over 100 tons / hour. If no measures are taken, this water will be discharged into the atmosphere along with the flue gas, resulting in a significant waste of water resources. This solution utilizes flue gas cooling and condensation to extract water, lowering the saturated, wet flue gas temperature from 55°C to around 50°C. This allows for the extraction of a significant amount of water from the flue gas. A typical flue gas water extraction rate for two 660MW coal-fired units exceeds 250 tons / hour. This means that, in addition to covering the water carried away by the flue gas in the desulfurization tower, over 100 tons / hour of additional water can be extracted. This condensed water, after treatment, can be supplied as feedwater to wind and solar hydrogen production projects or partially reused in the coal-fired units, thereby saving water and efficiently utilizing water resources. For example, a 700MW wind power hydrogen production project, with an annual hydrogen production capacity of 30,000 tons, requires approximately 300,000 tons of raw water per year. Flue gas water extraction from two 660MW coal-fired units, in addition to being reused for the coal-fired units themselves, leaves approximately 300,000 tons of surplus water per year, precisely the right amount for the raw water required by the 700MW wind power hydrogen production project. Therefore, if flue gas water extraction is prioritized for use within the coal-fired units, approximately 300,000 tons of surplus water can be used annually for the 30,000-ton wind-solar hydrogen production project, thus addressing the water shortage challenge commonly faced by wind-solar hydrogen production projects in northern China. Furthermore, flue gas condensate is typically around 50°C, significantly higher than the 30°C temperature of desalted water entering the electrolyzer. Therefore, using flue gas condensate as raw water in the electrolyzer reduces the energy required to heat the raw water from room temperature to approximately 90°C, thereby reducing electricity consumption for hydrogen production. In addition, the heat released by flue gas condensation is discharged into the atmosphere through an indirect air-cooling tower. Some of the condensed water in the reservoir is then indirectly cooled by air cooling before being sprayed onto the flue gas in a condensation water extraction tower. A heat pump can also be used to extract some of the heat from the condensed water and store it in a hot water storage tank. When wind and solar power generation is insufficient, some electrolyzers may shut down. In this hot standby mode, the hot water storage tank can be used to supply heat to the downtime electrolyzers, enabling them to operate in hot standby mode. This in turn accelerates the startup of these electrolyzers, improving their flexibility and green electricity utilization.
[0027] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; obviously, the embodiments described are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention; for ease of description, only the parts related to the relevant utility model are shown in the accompanying drawings. In the absence of conflict, the embodiments and features in the embodiments of the present invention can be combined with each other; modifying the technical solutions described in the aforementioned embodiments, or equivalently replacing some of the technical features therein, does not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.
Claims
1. A wind-solar hydrogen production system that uses flue gas from coal-fired units to extract water, characterized by: The invention comprises a condensation water extraction tower (4), wherein the condensation water extraction tower (4) is connected to a chimney (13) at the top through a smoke exhaust pipeline, and is connected to a coal-fired unit at the bottom through a smoke input pipeline (15); a water reservoir (8) is provided below the condensation water extraction tower (4), and the water reservoir (8) is connected to an electrolyzer (1) of a hydrogen production system through a water treatment pipeline (16), wherein a chemical water treatment device (12) is provided in the water treatment pipeline (16); and the electrolyzer (1) is connected to a wind power system (2) and / or a photovoltaic system (3).
2. The wind-solar hydrogen production system utilizing coal-fired unit flue gas water extraction according to claim 1 is characterized in that: A turbulator (7), a spray layer (6) and a tube bundle demister (5) are sequentially arranged in the condensation water extraction tower (4) from bottom to top. The condensation water extraction tower (4) is connected to the chimney (13) above the tube bundle demister (5) through a smoke exhaust pipeline, and the condensation water extraction tower (4) is connected to the coal-fired unit through a smoke input pipeline (15) below the turbulator (7).
3. The wind-solar hydrogen production system utilizing water extraction from coal-fired unit flue gas according to claim 2 is characterized in that: The water reservoir (8) is further connected to an indirect air cooling tower (10) via a high-temperature circulating water pipeline (17), a circulating water pump (9) is provided in the high-temperature circulating water pipeline (17), and the indirect air cooling tower (10) is connected to the spray water input end of the spray layer (6) via a low-temperature circulating water pipeline (18).
4. The wind-solar hydrogen production system utilizing coal-fired unit flue gas water extraction according to claim 3 is characterized in that: The high-temperature circulating water pipeline (17) is also connected to a heat pump (11).
5. The wind-solar hydrogen production system utilizing water extraction from coal-fired unit flue gas according to claim 4 is characterized in that: It also includes a hot water storage tank (14), and the heat pump (11), the hot water storage tank (14), and the electrolytic cell (1) are connected in sequence via a hot water pipeline.
6. The wind-solar hydrogen production system utilizing water extraction from coal-fired unit flue gas according to any one of claims 1 to 5, characterized in that: The water reservoir (8) is also connected to the power plant water system (19) via a recycling pipeline.