CN103071369B - Seawater desulfurization system suitable for frequency change of coal quality - Google Patents

Abstract

The present invention provides a seawater desulfurization system adapted to variable coal quality, including an absorption system and a water quality recovery system; by setting an annular spray layer on the uppermost layer of the absorption tower and spraying high-concentration boiler sewage (steam drum furnace) or Alkali-doped seawater (DC furnace) can significantly improve the mass transfer power of the upper layer and the desulfurization efficiency near the wall, thereby improving the overall desulfurization efficiency; by setting a liquid redistributor under the spray layer, the spray near the wall can be redistributed. The spray liquid makes the spray liquid near the wall redisperse into small droplets, increases the specific surface area, enhances the absorption capacity, absorbs SO ₂ near the wall again, and further enhances the desulfurization ability near the wall. When the coal quality changes, the present invention correlates with the second _SO2 measuring point to control the amount of sprayed seawater in the spray layer (steam drum furnace) or the concentration of lye (direct flow furnace), and controls the concentration of sulfur dioxide at the outlet, thereby adapting to Variations in coal quality.

Description

A Seawater Desulfurization System Adapting to Changeable Coal Quality

technical field

The invention relates to the technical field of desulfurization control of coal-fired power stations, in particular to a seawater desulfurization system adaptable to variable coal quality.

Background technique

my country's coal-based energy structure will not change for a long time in the future, but the burning of coal will cause serious environmental problems, such as acid rain caused by the emission of sulfur oxides. With the introduction of the "Emission Standards for Air Pollution from Thermal Power Plants" GB13223-2011, the emission limits of air pollutants from thermal power plants have been reduced by 4 times compared with the previous standards. On the one hand, we can see my country's determination in acid rain control. On the one hand, it is also a great test for desulfurization technology.

Seawater flue gas desulfurization mainly uses the natural alkalinity of seawater to absorb SO ₂ . The seawater desulfurization process has a small investment, no waste, simple process, convenient operation and maintenance, and no scaling and blockage problems. It has a bright development prospect.

Although flue gas seawater desulfurization technology has many advantages, engineering practice has proved that there are still some key technical problems to be solved. The main problem is that seawater desulfurization is performed by using the natural alkalinity of seawater. Desulfurization technology is only applicable to the desulfurization of medium and low-sulfur coal, and with the further stringent emission standards at present, the scope of application of seawater desulfurization technology will be further narrowed. However, the quality of coal in my country varies greatly. Thermal power plants often need to determine the type of coal to operate according to the level of coal prices, and often use low-quality coal. In this context, the application range of seawater desulfurization technology is very small, and how to adapt to my country's changing coal quality is the key point for the implementation of seawater desulfurization technology.

Contents of the invention

The purpose of the present invention is to provide a seawater desulfurization system adaptable to variable coal quality, thereby increasing the coal type adaptability range of the seawater desulfurization technology.

In order to achieve the above object, the present invention adopts the following technical solutions:

A seawater desulfurization system adapted to variable coal quality, including an absorption system and a water quality restoration system;

The absorption system includes a flue gas system and a seawater system;

The flue gas system includes a FGD inlet baffle, a booster fan, an absorption tower, an FGD outlet baffle and a wet chimney; the outlet end of the FGD inlet baffle is connected to the inlet end of the booster fan, and the outlet end of the booster fan is connected to the absorption tower The inlet end of the absorption tower is equipped with a pre-aeration tank, a liquid redistributor, a spray layer, an annular spray layer and a demister from bottom to top, and the outlet end of the top of the absorption tower is connected to the inlet end of the FGD outlet baffle, The outlet end of the FGD outlet baffle is connected to the wet chimney;

The seawater system includes a water distribution well, a pumping tank, a first seawater booster pump and a second seawater booster pump; the outlet of the water distribution well is connected to the inlet of the pumping tank, and the outlet of the pump is connected to the first seawater booster pump The inlet port of the pump and the second seawater booster pump; the outlet port of the first seawater booster pump is connected to the pre-aeration tank of the absorption tower; the outlet port of the second seawater booster pump is connected to the spray layer spray inlet port of the absorption tower ;

The water quality recovery system includes an oxidation fan, a mixing tank, an aeration tank, a drainage tank, and an aeration fan; the inlet of the pre-aeration tank is connected to the outlet of the oxidation fan, and is connected to the outlet of the first seawater booster pump. The outlet of the aeration tank is connected to the inlet of the mixing tank, the inlet of the mixing tank is connected to the outlet of the pumping tank, the outlet of the mixing tank is connected to the inlet of the aeration tank, and the inlet of the aeration tank is connected to the aeration tank The outlet of the fan and the outlet of the aeration tank are connected to the drainage tank;

The spray liquid in the annular spray layer is boiler sewage or alkali-doped seawater; the bottom of the annular spray layer is provided with a number of nozzles to spray towards the wall, and the sprayed wall flow enters the liquid redistributor for redistribution, making the wall The nearby spray liquid redisperses into small droplets to further absorb SO ₂ near the wall.

The further improvement of the present invention is: when the seawater desulfurization system is connected to the steam drum furnace, the absorption system also includes a sewage system for providing boiler sewage, and the sewage system includes a boiler drum, a sewage expansion vessel, a sedimentation tank and Heat exchanger; the outlet of the boiler drum is connected to the inlet of the blowdown expander, the outlet of the blowdown expander is connected to the inlet of the sedimentation tank, the outlet of the sedimentation tank is connected to the inlet of the heat exchanger, and the outlet of the heat exchanger Connect to the spray inlet port of the annular spray layer in the absorption tower.

The further improvement of the present invention is that: the heat exchanger adopts a casing type heat exchanger, the inner pipe is passed into the sewage, and the outer pipe is passed into the demineralized water; the inlet end of the inner pipe is connected with the outlet end of the sedimentation tank, and the outlet end of the inner pipe is It is connected with the spray inlet end of the annular spray layer in the absorption tower.

The further improvement of the present invention is: the outlet end of the FGD outlet baffle and the wet chimney are provided with a second SO _measuring point; the absorption tower is adjusted by adjusting the amount of sprayed seawater in the spray layer under the annular spray layer The absorption efficiency; the amount of spray seawater in the spray layer is controlled by the second SO ₂ measuring point correlation.

The further improvement of the present invention is that: when the seawater desulfurization system is connected with a direct current furnace, the absorption system also includes an alkali liquor system for providing alkali liquor; the alkali liquor system includes an alkali liquor tank, an alkali adding pump and a third seawater pressurization pump; the outlet of the pump suction pool is connected to the inlet of the third seawater booster pump, while the outlet end of the lye tank is connected to the inlet end of the alkali-adding pump, and the seawater mixed with the outlet of the alkali-adding pump and the outlet of the third seawater booster pump Mix together and enter the spray inlet end of the annular spray layer in the absorption tower to provide alkali-doped seawater for the annular spray layer.

The further improvement of the present invention is: the outlet end of the FGD outlet baffle and the wet chimney are provided with the second SO _measuring point; the absorption efficiency of the absorption tower is adjusted by adjusting the concentration of the spray liquid in the annular spray layer; The liquid concentration is controlled by the second _SO2 measuring point correlation.

The further improvement of the present invention is that: the desulfurized absorption liquid enters the pre-aeration tank at the bottom of the absorption tower, and at the same time, fresh seawater is mixed in the pre-aeration tank for pre-aeration, and the mixture of the absorption liquid and fresh sea water enters the mixing tank It is mixed with another part of fresh seawater, and then enters the aeration tank for aeration to restore water quality, and is discharged through the drainage tank after aeration.

The further improvement of the present invention is that: the mixing ratio of the fresh seawater introduced into the pre-aeration tank and the desulfurized absorption liquid is 0.8; that is, the ratio of the volume of fresh seawater to the volume of the desulfurized absorption liquid is 0.8:1.

The further improvement of the present invention is that: the liquid redistributor is located under the spray layer and above the inlet of the absorption tower; the liquid redistributor includes two layers of staggered stops; the stoppers are in the shape of oblique triangular prisms, including The top surface, the first bottom surface, the second bottom surface, the first baffle plate and the second baffle plate, wherein the top surface and the wall surface of the absorption tower are arranged obliquely downward at 45°, and the top surface is a flat plate or a corrugated plate, which is arranged below the top surface The included angle between the first bottom surface and the second bottom surface is less than 90°, and the first baffle plate and the second baffle plate are vertically fixed on both sides of the top surface.

The further improvement of the present invention is that: the width of the top surface of the upper block is greater than or equal to the width of the gap between the ends of the adjacent lower blocks fixed on the inner wall of the absorption tower.

There are SO ₂ measuring points at the entrance of the absorption tower and the pipeline before entering the wet chimney, and the measuring point before entering the wet chimney has a control function. For the seawater desulfurization system corresponding to the drum boiler, this control point is related to the amount of seawater sprayed into the absorption tower. For the seawater desulfurization system that the once-through furnace is used for, this control point is related to the amount of alkali in seawater.

Compared with the prior art, the main advantages of the system of the present invention are:

1. The uppermost spray layer of the present invention adopts an annular spray layer, which can significantly improve the desulfurization efficiency. The reason is as follows: As the flue gas rises, its sulfur content gradually decreases, so the mass transfer power also decreases. In order to improve the mass transfer power of the upper layer, on the one hand, the alkalinity of seawater can be increased, and on the other hand, the spray volume can be increased. In fact, the seawater in the center of the absorption tower covers a large area and the absorption efficiency is high, but the desulfurization efficiency is low in the surrounding area due to the influence of the wall. The annular spray layer used in the present invention sprays high-concentration alkali-doped seawater (including boiler blowdown water or alkali-doped seawater) and sprays it toward the wall surface, thereby greatly improving the desulfurization efficiency near the wall surface, and further improving overall desulfurization efficiency.

2. The present invention is provided with a liquid redistributor above the entrance of the absorption tower under the spray layer, which can redistribute the spray liquid near the wall surface, so that the spray liquid near the wall surface redisperses into small droplets, and the specific surface area increases. The absorption capacity is enhanced, absorbing SO ₂ near the wall again, and further enhancing the desulfurization capacity near the wall; the two bottom surfaces of the liquid redistributor form a wedge shape, which can significantly reduce the flow resistance of the flue gas; it is arranged on both sides of the top surface of the liquid redistributor The two baffles can effectively prevent the collected liquid from flowing out from both sides.

3. In the present invention, a pre-aeration tank is added to the bottom of the absorption tower, thereby reducing the pressure of the subsequent aeration, improving the aeration effect, and saving the occupied area of the seawater desulfurization system. Adding fresh seawater into the pre-aeration tank with a mixing ratio of 0.8 can effectively prevent the overflow of absorbed SO ₂ on the one hand, and on the other hand, the way of mixing while aerating can reduce the dilution of the absorption liquid and improve the The power of mass transfer achieves a better oxidation effect than directly mixing fresh liquid in the mixing tank and then aerating.

4. Corresponding to the drum boiler, the complete utilization of boiler sewage can achieve the purpose of treating waste with waste. By adjusting the amount of seawater sprayed in the spray layer under the annular spray layer, the absorption efficiency of the absorption tower can be adjusted to adapt to the coal quality. Variety. Corresponding to the once-through furnace, it is necessary to add alkali to the seawater sprayed in the annular spray layer, so that the absorption efficiency of the absorption tower can be adjusted by changing the concentration of the alkali solution to adapt to the change of coal quality.

Description of drawings

Fig. 1 is the seawater desulfurization system diagram corresponding to the drum boiler of the present invention;

Fig. 2 is the seawater desulfurization system diagram corresponding to the once-through furnace of the present invention;

Figure 3 is a schematic diagram of a liquid redistributor.

In the figure: 1. FGD inlet baffle, 2. Booster fan, 3. First SO ₂ measuring point, 4. Absorption tower, 5. FGD outlet baffle, 6. Second SO ₂ measuring point, 7. Wet chimney , 8. Boiler steam drum, 9. Sewage expansion vessel, 10. Sedimentation tank, 11. Heat exchanger, 12. Softened water booster pump, 13. Water distribution well, 14. Pump suction tank, 151. First seawater booster Pump, 152, second seawater booster pump, 153, third seawater booster pump, 16, oxidation fan, 17, mixing tank, 18, aeration tank, 19, drainage tank, 20, aeration fan, 21, seawater , 22, softened water, 23, absorption liquid, 24, sewage, 25, flue gas after dust removal, 26, air, 27, valve, 28, sea, 29, to deaerator, 30, to low temperature heater, 31 , pre-aeration tank, 70, liquid redistributor, 701, top surface, 702, first bottom surface, 703, second bottom surface, 704, first baffle plate, 705, second baffle plate, 32, spray layer, 33, annular spray layer, 34, mist eliminator, 80, lye tank, 90, alkali adding pump.

See Table 1 for the meanings of the instrument codes in Figure 1 and Figure 2.

Table 1

the code code meaning the code code meaning T temperature P pressure f flow SO ₂ Sulfur dioxide concentration pH pH value I show C control

Detailed ways

Referring to Figure 1, the seawater desulfurization system corresponding to the drum boiler and adapting to variable coal quality mainly includes an absorption system and a water quality recovery system, and the basic process connection is as follows:

The connection mode of the flue gas process of the absorption system: After dust removal, the flue gas 25 enters the inlet port of the FGD inlet baffle 1, the outlet port of the FGD inlet baffle 1 is connected to the inlet port of the booster fan 2, and the outlet port of the booster fan 2 is connected to the One SO ₂ The inlet end of the measuring point 3, the outlet end of the first SO ₂ Measuring point 3 is connected to the inlet end of the absorption tower 4, and the flue gas passes through the liquid redistributor 70 in the absorption tower 4 successively, the spray layer 32, the annular spray Drench layer 33, demister 34, arrive at the outlet end of absorption tower 4, the outlet end of absorption tower 4 connects the inlet end of FGD outlet baffle plate 5, the outlet end of FGD outlet baffle plate 5 connects the second _SO2Measuring point 6 The inlet end and the outlet end of the second SO ₂ measuring point 6 are connected to the wet chimney 7 for smoke exhaust operation.

The connection mode of the seawater process of the absorption system: seawater 21 enters the inlet section of the water distribution well 13, the outlet end of the water distribution well 13 is connected to the valve 27 and then connected to the inlet end of the pumping pool 14, and the outlet end of the pumping pool 14 is connected to the first seawater booster The inlet port of the pump 151 and the second seawater booster pump 152 , and the outlet port of the second seawater booster pump 152 are connected to the spray inlet port of the spray layer 32 of the absorption tower 4 .

The connection mode of the sewage flow process of the absorption system: the outlet end of the boiler drum 8 is connected to the inlet end of the sewage expansion vessel 9, the outlet end of the sewage expansion vessel 9 is connected to the inlet end of the sedimentation tank 10, and the outlet end of the sedimentation tank 10 is connected to the heat exchanger The inlet end of heat exchanger 11 and the outlet end of heat exchanger 11 are connected to the spray inlet end of annular spray layer 33 in absorption tower 4 .

The connection mode of the water quality recovery system: the absorption liquid 23 enters the pre-aeration tank 31, the inlet of the pre-aeration tank 31 is connected to the outlet of the oxidation fan 16, and is connected to the outlet of the first seawater booster pump 151, and the pre-aeration tank The outlet of 31 is connected to the inlet of mixing tank 17, the inlet of mixing tank 17 is connected to the outlet of pumping tank 14 at the same time, the outlet of mixing tank 17 is connected to the inlet of aeration tank 18, and the inlet of aeration tank 18 At the same time, the outlet end of the aeration fan 20 is connected, and the outlet end of the aeration tank 18 is connected to the drainage pool 19 to connect to the sea 28 for drainage.

The heat exchanger 11 adopts a sleeve-and-tube heat exchanger, the inner pipe carries the sewage 24, and the outer pipe carries the demineralized water 22. The spray inlet ends of the annular spray layer 33 are connected. The demineralized water 22 enters the outer tube of the heat exchanger 11 to be heated.

Referring to Figure 2, the seawater desulfurization system corresponding to the once-through furnace that adapts to variable coal quality is mainly divided into an absorption system and a water quality recovery system. The basic process connection is as follows:

The flue gas flow of the absorption system corresponding to the once-through furnace, the connection method of the seawater flow of the absorption system, and the connection method of the water quality restoration system are the same as those corresponding to the drum boiler. Because the once-through furnace does not have boiler continuous sewage, there is no connection method for the sewage flow of the absorption system, but there is a connection method for the lye flow of the absorption system.

The connection mode of the lye flow process of the absorption system: the outlet of the pumping pool 14 is connected to the inlet of the third seawater booster pump 153, and the outlet of the lye tank 80 is connected to the inlet of the alkali-adding pump 90, and the outlet of the alkali-adding pump 90 is connected to each other. The seawater 21 from the outlet and the outlet of the third seawater booster pump 153 is mixed and enters the spray inlet port of the annular spray layer 33 in the absorption tower 4 .

Referring to Fig. 3, the liquid redistributor 70 is located under the spray layer 32 and above the inlet of the absorption tower 4; the liquid redistributor 70 includes two layers of staggered blocks; surface 701, the first bottom surface 702 and the second bottom surface 703, the first baffle plate 704 and the second baffle plate 705, wherein the top surface 701 is arranged obliquely downward at 45° with the wall surface of the absorption tower 4, and the top surface 701 can be a flat plate or a For the corrugated plate, the angle between the first bottom surface 702 and the second bottom surface 703 arranged under the top surface 701 is less than 90°, and the first baffle plate 704 and the second baffle plate 705 are vertically fixed on both sides of the top surface 701 . The spray liquid 23 near the wall of the absorption tower 4 can fall to the top surface 701 of the liquid redistributor 70 for redistribution and absorption. The width of the top surface 701 of the upper block is greater than or equal to the width of the gap between the ends of the adjacent lower block fixed on the inner wall of the absorption tower, so that the liquid on the inner wall of the absorption tower can flow to the upper block or the lower block , and then flow down along the front end of the upper block or the lower block, so that the spray liquid near the wall redisperses into small droplets and further absorbs the SO ₂ near the wall.

The working principle of the seawater desulfurization system for changing coal quality corresponding to the drum furnace shown in Figure 1 is as follows:

1) After heat exchange between the boiler sewage 24 and the demineralized water 22, the temperature drops from 157°C to 50°C, and the temperature of the boiler sewage 24 decreases, which is beneficial to improve the desulfurization efficiency. The boiler blowdown water 24 is sprayed after entering the annular spray layer 33 , and the annular spray layer 33 can significantly improve the absorption efficiency near the wall surface of the absorption tower 4 . At the same time, the pH value of the boiler blowdown 24 can reach 10-14, which is higher than the pH value of the seawater 21. Therefore, when the annular spray layer 23 uses the boiler blowdown water 24 as the absorption liquid 23, the upper part of the absorption tower 4 can be avoided because the sulfur content of the flue gas is reduced. The resulting weakening of the mass transfer power with the seawater can significantly increase the mass transfer power of the absorption process at the upper part of the absorption tower 4 . Since the application of boiler blowdown water 24 can reflect the idea of treating waste with waste, boiler blowdown water is all applied no matter how the coal quality changes. When the coal quality changes, such as when the sulfur content increases, the desulfurization efficiency can be improved by increasing the amount of spraying of seawater 21, and the specific method is: link the control of the second _SO2 measuring point 6 with the second seawater booster pump 152 , by adjusting the second seawater booster pump 152 to adjust the amount of seawater spraying to adapt to the change of coal quality.

2) A pre-aeration tank 31 is installed at the bottom of the absorption tower 4, and at the same time, the pre-aeration adopts the method of aeration while mixing fresh seawater (the blending ratio is 0.8), and the absorption liquid undergoes a pre-aeration process, and the pH increases 1.5 or so. If the absorption liquid 23 does not carry out a pre-aeration process in advance, but the absorption liquid 23 directly enters the mixing tank 17 and then enters the aeration tank 18 similar to the traditional seawater desulfurization system, there will be the following disadvantages: when first entering the mixing tank, due to the absorption liquid The pH value of 23 is very low, and it is very easy to overflow acid gas in the mixing tank 17. Secondly, the absorption liquid 23 enters the mixing tank 17 for mixing. In fact, the absorption liquid 23 is diluted to a large extent, which will reduce the subsequent aeration The oxidation effect of the process increases the aeration investment in the subsequent aeration process.

The working principle of the seawater desulfurization system adapted to the variable coal quality corresponding to the once-through furnace shown in Figure 2 is as follows:

The lye from the lye tank 80 is mixed with the seawater 21 entering the annular spray layer 33 through the alkali-adding pump 90, and the absorption efficiency of the desulfurization tower can be adjusted to adapt to the change of coal quality by adjusting the amount of lye mixed into the seawater . Concrete method: associate the second _SO2 measuring point 6 with the control of the alkali adding pump 90, adjust the pH value of the alkali-doped seawater entering the annular spray layer 33 by adjusting the amount of alkali added to adapt to the change of coal quality.

The working principle of the liquid redistributor shown in Figure 3 is as follows:

After the spray liquid 23 near the wall surface of the absorption tower 4 falls to the top surface 701 of the liquid redistributor 70, due to the flow limiting effect of the first baffle plate 704 and the second baffle plate 705, it flows down along the top surface 701 to form small droplets and then restarts. The SO ₂ in the flue gas near the wall surface is absorbed to further improve the desulfurization efficiency near the wall surface of the absorption tower 4 . Since the first bottom surface 702 and the second bottom surface 703 of the liquid redistributor 70 form a wedge shape, the resistance increases little when the flue gas at the inlet of the absorption tower 4 passes through the liquid redistributor 70 . The system of the present invention considers that the flue gas bypasses are being removed or lead-sealed everywhere, so the seawater desulfurization system does not set up the flue gas bypasses, but the seawater bypasses are set up. The purpose is that when the system fails, the bypass The road drains the sea water.

The seawater in the system of the present invention can be taken from the ocean. If the power plant uses seawater for cooling, the seawater in the system can also be taken from the process cooling water for the condenser. At this time, no special water intake equipment can be provided, saving investment and operating costs.

Claims (8)

1. adapt to the Deuslfurizing system for sea water that ature of coal is changeable, it is characterized in that, comprise absorption system and quality recovery system;

Described absorption system comprises flue gas system and sea water service system;

Described flue gas system comprises FGD inlet baffle (1), booster fan (2), absorption tower (4), FGD outlet damper (5) and wet chimney (7); The port of export of FGD inlet baffle (1) is connected with the arrival end of booster fan (2), booster fan (2) port of export connects the arrival end on absorption tower (4), absorption tower (4) is provided with preaeration tank (31), liquid re-distributor (70), spraying layer (32), annular spraying layer (33) and demister (34) from the bottom to top successively, the port of export at top, absorption tower (4) connects the arrival end of FGD outlet damper (5), and the port of export of FGD outlet damper (5) connects wet chimney (7);

Described sea water service system comprises distribution well (13), pump suction pond (14), the first seawater booster pump (151) and the second seawater booster pump (152); The port of export of distribution well (13) connects pump inhales the arrival end in pond (14), and the port of export of pump absorption (14) connects the arrival end of the first seawater booster pump (151) and the second seawater booster pump (152); The port of export of the first seawater booster pump (151) connects the preaeration tank (31) on absorption tower (4); The port of export of the second seawater booster pump (152) connects spraying layer (32) the spray inlet end on absorption tower (4);

Described quality recovery system comprises oxidation fan (16), mixing pit (17), aeration tank (18), blowoff basin (19) and Aeration fan (20); The arrival end of preaeration tank (31) connects the port of export of oxidation fan (16), connect the port of export of the first seawater booster pump (151) simultaneously, the port of export of preaeration tank (31) connects the arrival end of mixing pit (17), the arrival end of mixing pit (17) connects pump simultaneously and inhales the port of export in pond (14), the port of export of mixing pit (17) connects the arrival end of aeration tank (18), the arrival end of aeration tank (18) connects the port of export of Aeration fan (20) simultaneously, and the port of export of aeration tank (18) connects blowoff basin (19);

Spray liquid in annular spraying layer (33) is boiler blowdown water or mixes Aral Sea water; The bottom of annular spraying layer (33) is provided with (4) the wall direction injection to absorption tower of some spouts, and the wall after injection flows to into liquid re-distributor (70) and distributes;

Described liquid re-distributor (70) is positioned under spraying layer (32), on the entrance of absorption tower (4), liquid re-distributor (70) comprises some blocks of two-layer interlaced arrangement, block is oblique triangular prism shape, comprise end face (701), the first bottom surface (702), the second bottom surface (703), the first baffle plate (704) and second baffle (705), wherein end face (701) and absorption tower (4) wall oblique lower layout at 45 °, end face (701) is flat board or corrugated plating, the angle being arranged between the first bottom surface (702) and the second bottom surface (703) of end face (701) below is less than 90 °, the first baffle plate (704) and second baffle (705) be vertically fixed on end face (701) along absorption tower (4) both sides radially.

2. a kind of Deuslfurizing system for sea water that ature of coal is changeable that adapts to according to claim 1, it is characterized in that, in the time that described Deuslfurizing system for sea water connects drum boiler, described absorption system also comprises the foul drainage system that boiler blowdown water is provided, and described foul drainage system comprises boiler-steam dome (8), blowdown system (9), sedimentation basin (10) and heat exchanger (11); The port of export of boiler-steam dome (8) connects the arrival end of blowdown system (9), the port of export of blowdown system (9) connects the arrival end of sedimentation basin (10), the port of export of sedimentation basin (10) connects the arrival end of heat exchanger (11), and the port of export of heat exchanger (11) connects the spray inlet end of the annular spraying layer (33) in absorption tower (4).

3. a kind of Deuslfurizing system for sea water that ature of coal is changeable that adapts to according to claim 2, is characterized in that, heat exchanger (11) adopts double pipe heat exchanger, and inner tube passes into sewer (24), and outer tube passes into demineralized water (22); The arrival end of inner tube is connected with the port of export of sedimentation basin (10), and the port of export of inner tube is connected with the spray inlet end of the annular spraying layer (33) in absorption tower (4).

4. a kind of Deuslfurizing system for sea water that ature of coal is changeable that adapts to according to claim 2, is characterized in that, between the port of export of FGD outlet damper (5) and wet chimney (7), is provided with the 2nd SO ₂measuring point (6); By regulating the amount of the sprayed sea water in the spraying layer (32) under annular spraying layer (33) to regulate the absorption efficiency of absorption tower (4); The amount of the sprayed sea water in spraying layer (32) is by the 2nd SO ₂measuring point (6) is associated to be controlled.

5. a kind of Deuslfurizing system for sea water that ature of coal is changeable that adapts to according to claim 1, is characterized in that, in the time that described Deuslfurizing system for sea water connects Once-through Boiler, the alkali lye of the alkali lye system that provides is also provided described absorption system; Described alkali lye system comprises alkali liquid tank (80), adds alkali pump (90) and the 3rd seawater booster pump (153); The entrance that pump is inhaled outlet connection the 3rd seawater booster pump (153) in pond (14) is connected, the port of export of alkali liquid tank (80) is connected with the arrival end that adds alkali pump (90) simultaneously, add the spray inlet end that enters the annular spraying layer (33) in absorption tower (4) together with the outlet of alkali pump (90) and seawater blending that the 3rd seawater booster pump (153) outlet is flowed out, provide to annular spraying layer (33) and mix Aral Sea water.

6. a kind of Deuslfurizing system for sea water that ature of coal is changeable that adapts to according to claim 5, is characterized in that, between the port of export of FGD outlet damper (5) and wet chimney (7), is provided with the 2nd SO ₂measuring point (6); By regulating the interior spray liquid basicity of annular spraying layer (33) to regulate the absorption efficiency of absorption tower (4); Spray liquid basicity is by the 2nd SO ₂measuring point (6) is associated to be controlled.

7. a kind of Deuslfurizing system for sea water that ature of coal is changeable that adapts to according to claim 1, it is characterized in that, absorption liquid after desulfurization enters the preaeration tank (31) of bottom, absorption tower (4), simultaneously blending fresh seawater and carry out preaeration in preaeration tank (31), the mixed liquor of absorption liquid and fresh seawater enters mixing pit (17) again to be mixed with the fresh seawater of another part, enter again aeration tank (18) and carry out aeration recovery water quality, after aeration, discharge by blowoff basin (19).

8. a kind of Deuslfurizing system for sea water that ature of coal is changeable that adapts to according to claim 7, is characterized in that, the blending ratio of the absorption liquid after the fresh seawater passing in preaeration tank (31) and desulfurization is 0.8; Be fresh seawater volume with desulfurization after the ratio of volume of absorption liquid be 0.8:1.