Hot flue gas waste heat recovery water-saving system for dry coal powder gasification process
Through the combination of a two-stage cooling system and a gas-liquid separator, the problem of high water content of hot flue gas in the coal dry powder gasification process is solved, and the effective recovery of water vapor in the flue gas and the improvement of hot air drying capacity is achieved, so as to achieve water saving and Energy-saving effect.
Patent Information
- Application Number
- CN202323328239.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-06
- Publication Date
- 2025-01-07
- Estimated Expiration
- 2033-12-06
AI Technical Summary
In the coal dry powder gasification process, the high water content of hot flue gas causes the hot air to heat up to a large amount of energy, reducing the drying capacity of hot air.
Using a two-stage cooling system, including an air cooler and a flue gas condenser, the flue gas temperature is reduced to 50-60℃ through the water circulation pipeline, condensate is precipitated, and the water vapor is further separated through the gas-liquid separator to reduce the heated flue gas in the hot air furnace. The load of the water vapor is used to heat exchange and preheat the combustion air with an air cooler.
It achieves water and energy saving effects, improves the drying capacity of hot air and the energy efficiency of the system.
Smart Images
Figure CN222317041U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to a water-saving system for hot flue gas waste heat recovery in a coal pulverized gasification process, belonging to the technical field of waste heat recovery. Background Art
[0002] In the pulverized coal gasification process, coal enters the pulverizer from the raw coal bin and is ground into carbon powder. Since the process requires the moisture content of the pulverized coal to be less than 2%, it is necessary to connect the hot air furnace to the hot flue gas for drying and blow it to the pulverized coal collector. The hot air and pulverized coal are separated in the pulverized coal collector, and the pulverized coal enters the gasification process. The hot flue gas returns to the hot air furnace for heating. At this time, the moisture content of the hot flue gas reaches about 25%. Due to the high moisture content, the energy required for hot air heating is large, and the drying capacity of the hot air is reduced. Utility Model Content
[0003] In view of the above deficiencies in the prior art, the problem to be solved by the utility model is to provide a coal pulverized gasification process hot flue gas waste heat recovery and water-saving system with a reasonable structural design that can not only improve the drying capacity of hot air, but also achieve energy and water saving.
[0004] The technical solution adopted by the utility model to solve its technical problems is:
[0005] The coal pulverized gasification process hot flue gas waste heat recovery and water-saving system comprises a raw coal bunker, the coal outlet of the raw coal bunker is connected to the coal inlet of a coal mill, the air inlet of the coal mill is connected to the air outlet of a hot blast furnace, the discharge port of the coal mill is connected to the feed port of a coal powder collector, the smoke outlet of the coal powder collector is connected to the smoke inlet of an air cooler, the air inlet of the air cooler is connected to an air inlet pipe, the air outlet of the air cooler is connected to the air inlet of the hot blast furnace, the smoke outlet of the air cooler is connected to the smoke inlet of a smoke condenser, the smoke condenser is connected to a cooling tower via a water circulation pipeline, the smoke outlet of the smoke condenser is connected to the air inlet of a gas-liquid separator, and the air outlet of the gas-liquid separator is connected to the air inlet of the hot blast furnace.
[0006] The hot flue gas waste heat recovery and water-saving system of the coal dry powder gasification process can reduce the flue gas temperature to 50-60℃ through a two-stage cooling system of an air cooler and a flue gas condenser. After the flue gas after cooling passes through the condenser and the gas-liquid separator, a large amount of condensed water can be precipitated, and the condensed water can be recycled to achieve the purpose of saving water; after the flue gas enters the hot blast furnace, it can also reduce the load of water vapor in the hot blast furnace heating flue gas, achieve energy-saving effects, and improve the drying capacity of hot air. At the same time, using the air that exchanges heat with the flue gas through the air cooler as the combustion-supporting air of the hot blast furnace can also further improve the drying capacity of the hot air and improve the energy-saving effect.
[0007] Further preferably, the dry coal powder outlet of the coal powder collector cooperates with the coal powder transfer device, and the condensate water outlet of the gas-liquid separator is connected to the condensate water collecting device.
[0008] Further preferably, the air cooler adopts a metal plate heat exchanger made of 304 stainless steel. The air cooler can also adopt a metal tube heat exchanger or a cast iron plate heat exchanger.
[0009] Further preferably, the flue gas condenser adopts a metal tube heat exchanger made of 304 stainless steel, and a condensate discharge port is provided at the flue gas outlet reducer of the flue gas condenser. The flue gas condenser can also adopt a metal plate heat exchanger, a cast iron plate heat exchanger structure, a corrosion-resistant non-metallic plate heat exchanger, or a corrosion-resistant non-metallic tube heat exchanger.
[0010] The beneficial effects of the utility model are:
[0011] The hot flue gas waste heat recovery and water-saving system of the coal pulverized gasification process described in the utility model has a reasonable structural design. It can not only condense a large amount of condensed water by condensing the flue gas for recycling and utilization, thereby achieving the purpose of saving water, but also reduce the load of water vapor in the hot blast furnace heating flue gas, thereby achieving the effect of energy saving. At the same time, in conjunction with the preheating of the combustion-supporting air, the drying capacity of the hot air is greatly improved. BRIEF DESCRIPTION OF THE DRAWINGS
[0012] Figure 1 It is a structural schematic diagram of the utility model;
[0013] In the figure, 1. raw coal bin; 2. coal mill; 3. coal powder collector; 4. hot air furnace; 5. coal powder transfer device; 6. air cooler; 7. gas-liquid separator; 8. flue gas condenser; 9. cooling tower; 10. air inlet pipe; 11. water circulation pipeline. DETAILED DESCRIPTION
[0014] The following is a further description of the embodiments of the present invention in conjunction with the accompanying drawings:
[0015] like Figure 1 As shown, the hot flue gas waste heat recovery and water-saving system for the coal dry powder gasification process described in the utility model includes a raw coal bunker 1, the coal outlet of the raw coal bunker 1 is connected to the coal inlet of the coal mill 2, the air inlet of the coal mill 2 is connected to the air outlet of the hot blast furnace 4, the discharge port of the coal mill 2 is connected to the feed port of the coal powder collector 3, the dry coal powder outlet of the coal powder collector 3 cooperates with the coal powder transfer device 5, the smoke outlet of the coal powder collector 3 is connected to the smoke inlet of the air cooler 6, the air inlet of the air cooler 6 is connected to the air inlet pipe 10, the air outlet of the air cooler 6 is connected to the air inlet of the hot blast furnace 4, the smoke outlet of the air cooler 6 is connected to the smoke inlet of the smoke condenser 8, the smoke condenser 8 is connected to the cooling tower 9 through the water circulation pipeline 11, the smoke outlet of the smoke condenser 8 is connected to the air inlet of the gas-liquid separator 7, the air outlet of the gas-liquid separator 7 is connected to the air inlet of the hot blast furnace 4, and the condensate outlet of the gas-liquid separator 7 is connected to the condensate collecting device.
[0016] The air cooler 6 is a metal plate heat exchanger made of 304 stainless steel. The flue gas condenser 8 is a metal tube heat exchanger made of 304 stainless steel. A condensate discharge port is provided at the flue gas outlet diameter change of the flue gas condenser 8.
[0017] The working principle and use process of this utility model:
[0018] When in use, the coal in the raw coal bin 1 is transported to the coal mill 2, and the coal mill 2 is working. At the same time, the hot blast furnace 4 blows hot flue gas into the coal mill 2 to dry the coal powder, and the dried coal powder is blown into the coal powder collector 3. The qualified dry coal powder in the coal powder collector 3 enters the coal powder transfer device 5 through the dry coal powder outlet and is transported to the next process. The flue gas in the coal powder collector 3 is discharged through the flue gas outlet and enters the air cooler 6 through the flue gas inlet of the air cooler 6. The flue gas in the air cooler 6 is cooled by the air entering the air cooler 6. After the air enters the air cooler 6, it exchanges heat with the flue gas inside it. The heated air is transported to the hot blast furnace 4 through the pipeline as combustion air. At this time, the heat of the flue gas is converted to the combustion air, which can reduce the energy consumption of the hot blast furnace. After the flue gas in the air cooler 6 is cooled by the first stage, the temperature drops to about 100°C. The cooled flue gas enters the flue gas condenser 8 through the flue gas inlet of the flue gas condenser 8 for secondary cooling. The flue gas in the flue gas condenser 8 After being cooled by circulating water, the temperature is further reduced to about 50°C, and about 8%-9% of condensed water can be precipitated, and the condensed water is discharged from the condensation outlet of the flue gas condenser 8; the flue gas after the secondary cooling enters the gas-liquid separator 7 again, and the flue gas and the condensed water are separated by the gas-liquid separator 7, wherein the flue gas returns to the hot blast furnace 4 for heating and then enters the coal mill 2. When the flue gas with reduced water content enters the hot blast furnace for heating, it can achieve energy-saving effects and improve the drying capacity of the hot air. At the same time, the condensed water is recycled and reused, which can achieve the purpose of saving water.
[0019] The present invention is not limited to the above-mentioned specific implementation modes. Changes, modifications, additions or substitutions made by ordinary technicians in this field within the essential scope of the present invention should also fall within the protection scope of the present invention.
Claims
1. A hot flue gas waste heat recovery and water-saving system for a pulverized coal gasification process, comprising a raw coal bunker (1), the coal outlet of the raw coal bunker (1) being connected to the coal inlet of a coal mill (2), the air inlet of the coal mill (2) being connected to the air outlet of a hot blast furnace (4), and the material outlet of the coal mill (2) being connected to the material inlet of a pulverized coal collector (3), characterized in that: The smoke outlet of the coal powder collector (3) is connected to the smoke inlet of the air cooler (6), the air inlet of the air cooler (6) is connected to the air inlet pipe (10), the air outlet of the air cooler (6) is connected to the air inlet of the hot blast furnace (4), the smoke outlet of the air cooler (6) is connected to the smoke inlet of the smoke condenser (8), the smoke condenser (8) is connected to the cooling tower (9) through the water circulation pipeline (11), the smoke outlet of the smoke condenser (8) is connected to the air inlet of the gas-liquid separator (7), and the air outlet of the gas-liquid separator (7) is connected to the air inlet of the hot blast furnace (4).
2. The hot flue gas waste heat recovery and water-saving system of the pulverized coal gasification process according to claim 1 is characterized by: The dry coal powder outlet of the coal powder collector (3) cooperates with the coal powder transfer device (5), and the condensate water outlet of the gas-liquid separator (7) is connected to the condensate water collection device.
3. The hot flue gas waste heat recovery and water-saving system of the pulverized coal gasification process according to claim 1 is characterized by: The air cooler (6) is a metal plate heat exchanger made of 304 stainless steel.
4. The hot flue gas waste heat recovery and water-saving system of the pulverized coal gasification process according to claim 1 is characterized by: The flue gas condenser (8) is a metal tube heat exchanger made of 304 stainless steel, and a condensate discharge port is provided at the flue gas outlet diameter change point of the flue gas condenser (8).