Steam water recovery device for waste heat boiler blow-off

Abstract

The utility model belongs to the technical field of boiler blow-off, and particularly relates to a steam water recovery device for waste heat boiler blow-off. Comprising a continuous drainage tank, an inlet of the continuous drainage tank is connected with a boiler drum, a liquid phase outlet of the continuous drainage tank is connected with a sewage tank, a gas phase outlet of the continuous drainage tank is connected with a steam pipeline of an air preheater, a steam pipeline outlet of the air preheater is connected with a fixed drainage tank, and an outlet of the fixed drainage tank is connected with the sewage tank. An outlet of the sewage tank is connected with a working medium pipeline of the heat exchanger; flash steam generated in the blow-down process exchanges heat with combustion air, steam condensate and boiler blow-down water after heat exchange are subjected to heat exchange with demineralized water, and the blow-down water after heat exchange enters a circulating water return system, so that daily consumption of circulating water is supplemented, the utilization efficiency of energy is improved, the operation cost is reduced, and the service life of the boiler is prolonged. Meanwhile, the safety and stability of system operation are ensured, and the development trend of energy conservation and environmental protection is met.

Description

Technical Field

[0001] The utility model belongs to the technical field of boiler sewage discharge, and in particular relates to a steam-water recovery device for sewage discharge of a waste heat boiler. Background Art

[0002] During the operation of high-pressure steam boilers, in order to ensure the steam quality and the heat exchange efficiency of the waste heat boiler, the content of silicon dioxide and sodium in the high-pressure steam and the conductivity of the boiler water must be strictly controlled. To this end, it is necessary to discharge the impurities such as slag and scale generated during the operation of the boiler in a timely manner through continuous blowdown of the steam drum and regular blowdown of the boiler, so as to ensure the cleanliness of the boiler and the heat exchange efficiency.

[0003] In the existing boiler blowdown technology, the continuous blowdown volume of the drum is generally controlled at about 2% of the boiler feed water volume. In the blowdown process of the high-pressure boiler drum, after the high-temperature and high-pressure boiler water (9.8MPa, 320℃) enters the continuous discharge tank, a large amount of flash evaporation will occur, generating a large amount of steam. However, these flashed steams are usually vented directly, and the blowdown water is directly discharged into the ditch, and finally merged into the sewage treatment plant, and treated together with the sewage from other devices before being discharged outside the factory. This treatment method not only fails to effectively recycle and utilize flash steam and blowdown water, but also increases the treatment load of the sewage treatment plant and increases the cost of sewage treatment. Utility Model Content

[0004] According to the above deficiencies in the prior art, the purpose of the utility model is to provide a steam-water recovery device for waste heat boiler sewage discharge, which exchanges heat between the flash steam generated in the sewage discharge process and the combustion air, and the steam condensate and sewage after the heat exchange are exchanged with the desalted water, while taking away the heat of the sewage, it also increases the temperature of the desalted water, and the cooled sewage enters the circulating water return system to supplement the daily consumption of circulating water. It not only improves the utilization efficiency of energy and reduces the operating cost, but also ensures the safety and stability of the system operation, conforms to the development trend of energy conservation and environmental protection, and has significant economic and social benefits.

[0005] The utility model is realized by adopting the following technical solutions:

[0006] The steam-water recovery device for waste heat boiler sewage discharge comprises a continuous row tank, the inlet of the continuous row tank is connected to the boiler drum through a pipeline, the liquid phase outlet at the bottom of the continuous row tank is connected to the inlet of the sewage tank through a pipeline, the gas phase outlet at the top of the continuous row tank is connected to the steam pipe inlet of the air preheater through a pipeline, the steam pipe outlet of the air preheater is connected to the inlet of the fixed row tank through a pipeline, the outlet of the fixed row tank is connected to the inlet of the sewage tank through a pipeline, the outlet of the sewage tank is connected to the working fluid pipe inlet of the heat exchanger through a pipeline, filters and sewage pumps are respectively provided on the pipelines for filtering impurities in the sewage, and the working fluid pipe outlet of the heat exchanger is connected to a circulating water pool through a pipeline.

[0007] The air duct inlet of the air preheater is connected to the combustion fan through a pipeline, the air duct outlet of the air preheater is connected to the incinerator through a pipeline, and the incinerator is connected to the waste heat boiler through the flue outlet expansion joint. The saturated steam flashed out from the top of the row tank is introduced into the air preheater to heat the combustion air. The heated combustion air enters the incinerator and is mixed with the fuel gas for combustion, which significantly improves the thermal efficiency of the incinerator and increases the steam production of the waste heat boiler.

[0008] The air pipe outlet of the air preheater is provided with a temperature monitoring device, the steam pipe inlet of the air preheater is connected to the steam pipe from the pipe network, the steam pipe from the pipe network is provided with a No. 1 regulating valve, and the temperature monitoring device is electrically connected to the No. 1 regulating valve through a DCS control system. The valve opening of the No. 1 regulating valve is controlled by feedback from the temperature monitoring device, which can not only reasonably distribute the steam consumption of the pipe network and reduce steam waste, but also stabilize the temperature of the combustion air after heat exchange by the air preheater, and prevent the temperature change of the combustion air entering the incinerator due to the change of the continuous discharge volume, thereby affecting the thermal efficiency of the incinerator.

[0009] The medium pipe inlet of the heat exchanger is connected to the desalted water through a pipeline, and the medium pipe outlet of the heat exchanger is connected to the deaerator through a pipeline. After the sewage enters the sewage tank, it is pumped out through the sewage pump and exchanges heat with the desalted water from the pipe network in the heat exchanger. The desalted water after heat exchange enters the deaerator, which increases the temperature of the desalted water entering the deaerator and saves the consumption of heating steam.

[0010] The deaerator body is provided with a thermometer, and the inlet of the deaerator is also connected to a steam pipeline, and a No. 2 regulating valve is provided on the steam pipeline. The thermometer and the No. 2 regulating valve are electrically connected through a DCS control system. The valve opening of the No. 2 regulating valve is controlled by feedback from the thermometer, and the water temperature of the deoxygenated water is controlled to ensure the working efficiency and deoxygenation effect of the deaerator.

[0011] The continuous tank is provided with a level gauge inside, and a level control valve is provided at the liquid phase outlet at the bottom of the continuous tank. The level gauge and the level control valve are electrically connected through a DCS control system. The valve opening of the level control valve is adjusted by feedback from the level gauge to maintain the sewage in the continuous tank at a certain level, so that the continuous sewage has enough residence time in the tank to ensure its flash evaporation effect.

[0012] The tops of the continuous row tank and the sewage tank are provided with safety valves, and the tops of the fixed row tanks are provided with venting pipelines, which can discharge the gas in time, prevent the equipment from overpressure, and improve the safety of the device.

[0013] A check valve is provided on the gas phase outlet pipeline at the top of the continuous tank to prevent the steam in the steam network from flowing back; a check valve is provided on the working medium pipeline outlet pipeline of the heat exchanger to prevent the circulating water from flowing back after the device is shut down.

[0014] The working principle of the utility model is:

[0015] After the high-temperature and high-pressure boiler water in the boiler drum enters the continuous discharge tank, the boiler water will flash evaporate in large quantities. The flash steam generated in the continuous discharge tank is exchanged with the combustion air through the air preheater, thereby heating the combustion air and recovering the waste heat of the steam. After the heat exchange is completed, the steam condensate and the sewage in the fixed discharge tank are collected in the sewage tank, filtered through the filter, and then the water is sent out by the sewage pump, and then heat exchanged with the desalted water from the pipeline network in the heat exchanger, which increases the temperature of the desalted water and recovers the heat of the sewage. The cooled sewage enters the circulating water return system through the circulating water pool, supplementing the daily consumption of circulating water. The sewage is also effectively recycled and utilized, saving resources, reducing costs and increasing efficiency.

[0016] Compared with the prior art, the beneficial effects of the utility model are as follows:

[0017] (1) The steam-water recovery device for waste heat boiler blowdown described in the utility model can realize the recovery and reuse of the waste heat of steam flashed out during the boiler blowdown process, effectively improve the energy utilization efficiency, save steam consumption, and at the same time, improve the thermal efficiency of the incinerator and reduce energy consumption;

[0018] (2) The steam-water recovery device for waste heat boiler wastewater of the utility model realizes the recovery and reuse of wastewater heat, which not only reduces water consumption, but also reduces the impact on the environment, and saves water resources and wastewater treatment costs;

[0019] (3) The steam-water recovery device for waste heat boiler wastewater of the utility model realizes precise control of the combustion air and deoxygenated water temperature through the DCS control system, effectively reduces the waste of steam, saves the consumption of heating steam, and ensures the overall efficient and stable operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural schematic diagram of the steam-water recovery device for waste heat boiler sewage discharge according to the utility model;

[0021] In the figure: 1. Continuous row tank; 2. Boiler drum; 3. Sewage tank; 4. Air preheater; 5. Fixed row tank; 6. Heat exchanger; 7. Filter; 8. Sewage pump; 9. Circulating water pool; 10. Combustion fan; 11. Incinerator; 12. Temperature monitoring device; 13. No. 1 regulating valve; 14. Deaerator; 15. Thermometer; 16. No. 2 regulating valve; 17. Liquid level gauge; 18. Liquid level control valve. DETAILED DESCRIPTION

[0022] In order to make the purpose and technical solution of the utility model more clear, the utility model is further described in detail below in conjunction with the accompanying drawings.

[0023] Example 1

[0024] like Figure 1 As shown, the steam-water recovery device for waste heat boiler sewage discharge comprises a continuous row tank 1, the inlet of the continuous row tank 1 is connected to the boiler drum 2 through a pipeline, the liquid phase outlet at the bottom of the continuous row tank 1 is connected to the inlet of the sewage tank 3 through a pipeline, the gas phase outlet at the top of the continuous row tank 1 is connected to the steam pipe inlet of the air preheater 4 through a pipeline, the steam pipe outlet of the air preheater 4 is connected to the inlet of the fixed row tank 5 through a pipeline, the outlet of the fixed row tank 5 is connected to the inlet of the sewage tank 3 through a pipeline, the outlet of the sewage tank 3 is connected to the working fluid pipe inlet of the heat exchanger 6 through a pipeline, a filter 7 and a sewage pump 8 are respectively provided on the pipeline, and the working fluid pipe outlet of the heat exchanger 6 is connected to a circulating water pool 9 through a pipeline.

[0025] The air duct inlet of the air preheater 4 is connected to the combustion fan 10 through a pipeline, the air duct outlet of the air preheater 4 is connected to the incinerator 11 through a pipeline, and the incinerator 11 is connected to the waste heat boiler through a flue outlet expansion joint.

[0026] The air duct outlet of the air preheater 4 is provided with a temperature monitoring device 12, the steam duct inlet of the air preheater 4 is connected to the steam duct from the pipeline network, the steam duct from the pipeline network is provided with a No. 1 regulating valve 13, and the temperature monitoring device 12 is electrically connected to the No. 1 regulating valve 13 through a DCS control system.

[0027] The medium pipeline inlet of the heat exchanger 6 is connected to desalted water through a pipeline, and the medium pipeline outlet of the heat exchanger 6 is connected to the deaerator 14 through a pipeline.

[0028] The body of the deaerator 14 is provided with a thermometer 15. The inlet of the deaerator 14 is also connected to a steam pipeline, on which a No. 2 regulating valve 16 is provided. The thermometer 15 and the No. 2 regulating valve 16 are electrically connected through a DCS control system.

[0029] A liquid level meter 17 is provided inside the continuous tank 1, and a liquid level control valve 18 is provided at the liquid phase outlet at the bottom of the continuous tank 1. The liquid level meter 17 and the liquid level control valve 18 are electrically connected through a DCS control system.

[0030] The tops of the continuous row tank 1 and the sewage tank 3 are provided with safety valves, and the top of the fixed row tank 5 is provided with a venting pipeline.

[0031] A check valve is provided on the gas phase outlet pipeline at the top of the series tank 1, and a check valve is provided on the working medium pipeline outlet pipeline of the heat exchanger 6.

[0032] When using, the specific steps are as follows:

[0033] Through the continuous discharge of the boiler drum 2, the high-temperature and high-pressure boiler sewage (9.8MPa, 320℃) is sent to the continuous tank 1, and the sewage flashes in the continuous tank 1. The flashed steam enters the air preheater 4 through the pipeline to heat the combustion air in the air preheater 4. At the same time, the valve opening of the steam pipeline is adjusted by the DCS control system to ensure the temperature of the combustion air entering the incinerator and the efficiency of the incinerator; the liquid level in the continuous tank 1 is adjusted by the DCS control system to ensure the flash effect; the sewage in the continuous tank 1, The steam condensate produced by the air preheater 4 and the sewage discharged into the fixed discharge tank 5 during the regular sewage discharge process are collected into the sewage tank 3 through the pipeline. Under the action of the sewage pump 8, the sewage in the sewage tank 3 is filtered by the filter 7 and then enters the heat exchanger 6. After heat exchange with the desalted water from the pipeline network, it enters the circulating water return pipeline network and is finally merged into the circulating water pool 9; the desalted water heat exchanged by the heat exchanger 6 enters the deaerator 14, and the valve opening of the steam pipeline is adjusted by the DCS control system to ensure the temperature of the deoxygenated water, thereby ensuring the efficiency of the deaerator 14.

Claims

1. A steam-water recovery device for waste heat boiler wastewater, characterized in that: The invention comprises a continuous row tank (1), wherein the inlet of the continuous row tank (1) is connected to a boiler drum (2) through a pipeline, the liquid phase outlet at the bottom of the continuous row tank (1) is connected to the inlet of a sewage tank (3) through a pipeline, the gas phase outlet at the top of the continuous row tank (1) is connected to the steam pipeline inlet of an air preheater (4) through a pipeline, the steam pipeline outlet of the air preheater (4) is connected to the inlet of a fixed row tank (5) through a pipeline, the outlet of the fixed row tank (5) is connected to the inlet of a sewage tank (3) through a pipeline, the outlet of the sewage tank (3) is connected to the working medium pipeline inlet of a heat exchanger (6) through a pipeline, a filter (7) and a sewage pump (8) are respectively provided on the pipeline, and the working medium pipeline outlet of the heat exchanger (6) is connected to a circulating water pool (9) through a pipeline.

2. The steam-water recovery device for waste heat boiler wastewater according to claim 1 is characterized in that: The air duct inlet of the air preheater (4) is connected to the combustion fan (10) through a pipeline, the air duct outlet of the air preheater (4) is connected to the incinerator (11) through a pipeline, and the incinerator (11) is connected to the waste heat boiler through a flue outlet expansion joint.

3. The steam-water recovery device for waste heat boiler wastewater discharge according to claim 2 is characterized in that: The air duct outlet of the air preheater (4) is provided with a temperature monitoring device (12), the steam duct inlet of the air preheater (4) is connected to a steam duct from a pipe network, a No. 1 regulating valve (13) is provided on the steam duct from the pipe network, and the temperature monitoring device (12) and the No. 1 regulating valve (13) are electrically connected via a DCS control system.

4. The steam-water recovery device for waste heat boiler wastewater according to claim 1, characterized in that: The medium pipeline inlet of the heat exchanger (6) is connected to desalted water through a pipeline, and the medium pipeline outlet of the heat exchanger (6) is connected to the deaerator (14) through a pipeline.

5. The steam-water recovery device for waste heat boiler wastewater according to claim 4 is characterized in that: The body of the deaerator (14) is provided with a thermometer (15), the inlet of the deaerator (14) is also connected to a steam pipeline, a second regulating valve (16) is provided on the steam pipeline, and the thermometer (15) and the second regulating valve (16) are electrically connected through a DCS control system.

6. The steam-water recovery device for waste heat boiler wastewater according to claim 1, characterized in that: A liquid level meter (17) is provided inside the continuous tank (1), and a liquid level control valve (18) is provided at the liquid phase outlet at the bottom of the continuous tank (1). The liquid level meter (17) and the liquid level control valve (18) are electrically connected via a DCS control system.

7. The steam-water recovery device for waste heat boiler wastewater according to claim 1, characterized in that: The tops of the continuous row tank (1) and the sewage tank (3) are provided with safety valves, and the top of the fixed row tank (5) is provided with a venting pipeline.

8. The steam-water recovery device for waste heat boiler wastewater according to claim 1, characterized in that: A check valve is provided on the gas phase outlet pipeline at the top of the series tank (1), and a check valve is provided on the working medium pipeline outlet pipeline of the heat exchanger (6).

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