阅读说明：本技术 一种烟气处理系统 (Flue gas treatment system ) 是由 谢庆亮 黄举福 王正阳 许一凡 陈嘉检 于 2019-10-16 设计创作，主要内容包括：本发明公开了一种烟气处理系统,该烟气处理系统使烟气依次流经脱硝反应器、空预器、烟冷器、低低温电除尘器、湿法脱硫塔、冷凝器、除雾器、湿式电除尘器、再热器；该烟气处理系统还设有暖风器,暖风器用于预热即将进入空预器的空气；该烟气处理系统还设有凝结水管路,烟冷器、再热器、暖风器依次串联在凝结水管路上,使凝结水依次流经烟冷器、再热器、暖风器。该烟气处理系统利用凝结水回收烟气余热,以回收了烟气余热的凝结水作为再热器和暖风器的热源,使烟气余热得以充分利用,如此,节约了蒸汽用量、提升了系统运行效率、简化了系统结构、降低了系统的建设成本和运行成本。(The invention discloses a flue gas treatment system, which enables flue gas to sequentially flow through a denitration reactor, an air preheater, a flue gas cooler, a low-temperature electric dust remover, a wet desulphurization tower, a condenser, a demister, a wet electric dust remover and a reheater; the flue gas treatment system is also provided with a fan heater, and the fan heater is used for preheating air to be introduced into the air preheater; the smoke treatment system is also provided with a condensed water pipeline, and the smoke cooler, the reheater and the air heater are sequentially connected on the condensed water pipeline in series, so that the condensed water sequentially flows through the smoke cooler, the reheater and the air heater. This flue gas processing system utilizes the condensate water to retrieve the flue gas waste heat to the condensate water of having retrieved the flue gas waste heat makes the flue gas waste heat can make full use of as the heat source of reheater and heater, so, has practiced thrift the steam quantity, has promoted system operation efficiency, has simplified the system architecture, has reduced the construction cost and the running cost of system.)

1. The flue gas treatment system is characterized in that the flue gas treatment system (1) enables flue gas to sequentially flow through a denitration reactor (11), an air preheater (12), a flue gas cooler (13), a low-low temperature electric precipitator (14), a wet desulfurization tower (16), a condenser (17), a demister (18), a wet electric precipitator (19) and a reheater (110); the flue gas treatment system (1) is also provided with a warm air device (112), and the warm air device (112) is used for preheating air to be fed into the air preheater (12);

the flue gas treatment system (1) still is equipped with condensate pipe way (113), cigarette cold ware (13) reheater (110) fan heater (112) are established ties in proper order on condensate pipe way (113), make the condensate flow through in proper order cigarette cold ware (13) reheater (110) fan heater (112).

2. The flue gas treatment system according to claim 1, wherein the flue gas treatment system (1) is further provided with a flue gas cooler bypass line connected in parallel with the flue gas cooler (13), and the flue gas cooler bypass line is provided with a flue gas cooler bypass valve set (121).

3. The flue gas treatment system according to claim 2, wherein the flue gas treatment system (1) is further provided with a reheater bypass line connected in parallel with the reheater (110), the reheater bypass line being provided with a reheater bypass valve bank (122).

4. The flue gas treatment system (1) of claim 3, wherein the flue gas treatment system (1) is further provided with a heater bypass pipeline connected in parallel with the heater (112), and the heater bypass pipeline is provided with a heater bypass valve set (123).

5. The flue gas treatment system (1) according to any of claims 1 to 4, wherein the inlet of the condensate line (113) is connected to a condensate low-pressure heating system (2) of a steam turbine for introducing condensate from the condensate low-pressure heating system (2).

6. The flue gas treatment system according to claim 5, wherein the inlets of the condensed water pipeline (113) are respectively communicated with a first position and a second position of the condensed water low-pressure heating system (2) through a first inflow branch (114) and a second inflow branch (115), and the first position is located at the upstream of the second position so as to introduce the condensed water with relatively low temperature through the first inflow branch (114) and introduce the condensed water with relatively high temperature through the second inflow branch (115); a first valve group (118) is arranged on the first inlet branch (114), and a second valve group (119) is arranged on the second inlet branch (115).

7. The flue gas treatment system according to claim 6, wherein the outlet of the condensed water line (113) communicates via a first outflow branch (116) to a third location of the condensed water low-pressure heating system (2), which third location is downstream of the second location.

8. The flue gas treatment system according to claim 7, wherein the condensate low-pressure heating system (2) comprises a main conduit (21) and a plurality of low-pressure heaters (22) connected in series in the main conduit (21), the first position being upstream of the most upstream low-pressure heater (22), and the second position being between the two low-pressure heaters (22).

9. The flue gas treatment system according to claim 8, wherein the flue gas treatment system (1) is further provided with a power door bypass pipeline, the power door bypass pipeline is connected in parallel with the power door (23) on the main pipeline (21), and the power door bypass pipeline is provided with a power door bypass valve set (124).

10. The flue gas treatment system of claim 7, wherein the outlet of the condensed water pipeline (113) is further communicated with the inlet position of the condensed water pipeline (113) through a second outflow branch (117), and a third valve set (120) is arranged on the second outflow branch (117).

Technical Field

The invention relates to the technical field of coal-fired boiler flue gas treatment, in particular to a flue gas treatment system.

Background

The flue gas treatment system of the existing coal-fired boiler realizes flue gas denitration, dust removal, desulfurization and whitening elimination by enabling flue gas to sequentially flow through a denitration reactor, an air preheater, a flue gas cooler, a low-temperature electric precipitator, a wet desulfurization tower, a condenser, a demister, a wet electric precipitator and a reheater. And in order to relieve the blockage of the air preheater, a fan heater is arranged to heat air which is about to enter the air preheater.

Wherein, the flue gas heat is retrieved to the smoke cooler utilization condensate water, and the condensate water of having retrieved the flue gas heat is carried back to steam turbine's backheat system.

Wherein the reheater heats the flue gas with low pressure steam.

Wherein, the air heater utilizes steam turbine steam extraction or steam heating air for the factory, and this type of steam is superheated steam, and the heat release coefficient is low, leads to the heat transfer ability of air heater general, in order to improve the heat transfer ability of air heater, needs to make superheated steam earlier through the temperature reduction water cooling rethread air heater.

The existing flue gas treatment system has the defects of large steam consumption, long pipeline, high operation pressure, low operation reliability, high system construction cost, high operation cost and the like.

In view of the above, overcoming some or all of the above-mentioned disadvantages of existing flue gas treatment systems is a technical problem that needs to be solved by those skilled in the art.

Disclosure of Invention

In order to solve the technical problems, the invention provides a flue gas treatment system, which enables flue gas to sequentially flow through a denitration reactor, an air preheater, a flue gas cooler, a low-temperature electric precipitator, a wet desulfurization tower, a condenser, a demister, a wet electric precipitator and a reheater; the flue gas treatment system is also provided with a fan heater, and the fan heater is used for preheating air to be introduced into the air preheater;

the flue gas processing system still is equipped with the condensate pipe way, the cigarette cooler the re-heater the fan heater is established ties in proper order on the condensate pipe way, makes the condensate flow through in proper order the cigarette cooler the re-heater the fan heater.

According to the arrangement, the condensed water is used for recovering the flue gas waste heat, and the condensed water for recovering the flue gas waste heat is used as the heat source of the reheater and the heater, so that the flue gas waste heat is fully utilized, the steam consumption is saved, the system operation efficiency is improved, the system structure is simplified, and the construction cost and the operation cost of the system are reduced.

Further, the flue gas treatment system is further provided with a flue gas cooler bypass pipeline connected with the flue gas cooler in parallel, and a flue gas cooler bypass valve group is arranged on the flue gas cooler bypass pipeline.

Furthermore, the flue gas treatment system is also provided with a reheater bypass pipeline connected with the reheater in parallel, and a reheater bypass valve bank is arranged on the reheater bypass pipeline.

Furthermore, the flue gas treatment system is also provided with a fan heater bypass pipeline connected with the fan heater in parallel, and a fan heater bypass valve group is arranged on the fan heater bypass pipeline.

Furthermore, the inlet of the condensed water pipeline is communicated with a condensed water low-pressure heating system of the steam turbine so as to introduce condensed water from the condensed water low-pressure heating system.

Furthermore, inlets of the condensed water pipeline are respectively communicated with a first position and a second position of the condensed water low-pressure heating system through a first inflow branch and a second inflow branch, the first position is located at the upstream of the second position, so that the condensed water with relatively low temperature is introduced through the first inflow branch, and the condensed water with relatively high temperature is introduced through the second inflow branch; and a first valve bank is arranged on the first inlet branch, and a second valve bank is arranged on the second inlet branch.

Further, an outlet of the condensed water pipeline is communicated with a third position of the condensed water low-pressure heating system through a first outflow branch, and the third position is located at the downstream of the second position.

Furthermore, the condensed water low-pressure heating system comprises a main pipeline and a plurality of low-pressure heaters which are sequentially connected in series on the main pipeline, the first position is located at the upstream of the most upstream low-pressure heater, and the second position is located between the two low-pressure heaters.

Furthermore, the flue gas treatment system is also provided with an electric door bypass pipeline, the electric door bypass pipeline is connected with an electric door on the main pipeline in parallel, and the electric door bypass pipeline is provided with an electric door bypass valve group.

Furthermore, the outlet of the condensed water pipeline is communicated with the inlet position of the condensed water pipeline through a second outflow branch, and a third valve bank is arranged on the second outflow branch.

Drawings

FIG. 1 is a schematic diagram of an embodiment of a flue gas treatment system according to the present invention.

The reference numerals are explained below:

1, a flue gas treatment system, 11 denitration reactors, 12 air pre-heaters, 13 flue gas coolers, 14 low-low temperature electric dust collectors, 15 induced draft fans, 16 wet desulfurization towers, 17 condensers, 18 demisters, 19 wet electric dust collectors, 110 reheaters, 111 chimneys, 112 air heaters, 113 condensed water pipelines, 114 first inlet branches, 115 second inlet branches, 116 first outlet branches, 117 second outlet branches, 118 first valve banks, 119 second valve banks and 120 third valve banks; 121 smoke cooler bypass valve group, 122 reheater bypass valve group, 123 heater bypass valve group, 124 electric door bypass valve group, 125 circulation valve group, 126 circulation pump group.

2, a condensed water low-pressure heating system, 21 a main pipeline, 22 a low-pressure heater and 23 an electric door.

Detailed Description

In order to make those skilled in the art better understand the technical solution of the present invention, the technical solution of the present invention is further described in detail below with reference to the accompanying drawings and the detailed description.

First, in the description of the present invention, the terms "upstream" and "downstream" refer to the direction of the condensed water flow, and the position through which the condensed water flows first is the upstream and the position through which the condensed water flows later is the downstream.

Please refer to fig. 1.

The flue gas treatment system 1 is provided with a denitration reactor 11, an air preheater 12, a flue gas cooler 13, a low-low temperature electric dust remover 14, an induced draft fan 15, a wet desulphurization tower 16, a condenser 17, a demister 18, a wet electric dust remover 19, a reheater 110, a chimney 111 and a heater 112.

The flue gas is discharged from the coal-fired boiler, sequentially flows through a denitration reactor 11, an air preheater 12, a flue gas cooler 13, a low-low temperature electric dust remover 14, an induced draft fan 15, a wet desulfurization tower 16, a condenser 17, a demister 18, a wet electric dust remover 19 and a reheater 110, and then is discharged from a chimney 111.

The air preheater 12 is used to preheat air to the coal-fired boiler.

The smoke cooler 13 is used for reducing the temperature of the smoke, so that the smoke enters the low-low temperature electric dust remover 14 at a lower temperature.

The condenser 17 is used for cooling and condensing the desulfurized flue gas, the demister 18 recovers the water vapor generated by condensation, the reheater 110 is used for heating the flue gas at the outlet of the demister 18 to heat the flue gas to an unsaturated state, and the condenser 17, the demister 18 and the reheater 110 are matched to realize the white smoke elimination.

The air heater 112 is used to heat air that is about to enter the air preheater 12. In the operation process of the system, more ammonia escaping from the denitration reaction tower exists near the air preheater 12, so that the flue gas reacts with the ammonia to generate ammonium bisulfate when flowing through the air preheater 12, and the air preheater 12 is corroded and blocked due to the deposition of the ammonium bisulfate. The air to be fed into the air preheater 12 is heated by the air heater 112, so that the generation and deposition of ammonium bisulfate can be alleviated, the corrosion and blockage of the air preheater 12 can be alleviated, and the heat exchange capacity and the operational reliability of the air preheater 12 are improved.

With continued reference to fig. 1.

The flue gas treatment system 1 is provided with a condensed water pipeline 113, and the flue gas cooler 13, the reheater 110 and the heater 112 are sequentially connected in series on the condensed water pipeline 113, so that the condensed water sequentially flows through the flue gas cooler 13, the reheater 110 and the heater 112.

When the condensed water flows through the smoke cooler 13, the condensed water exchanges heat with the smoke flowing through the smoke cooler 13 to heat up, the waste heat of the smoke is fully recovered, the temperature of the smoke is reduced, and the dust removal effect of the low-low temperature electric dust remover 14 is ensured. Meanwhile, the problem of high exhaust gas temperature caused by the arrangement of the air heater 112 can be solved by recycling the waste heat of the flue gas through the flue gas cooler 13.

Then, the condensed water flowing out of the flue gas cooler 13 flows through the reheater 110 to heat the flue gas flowing through the reheater 110, so that the flue gas waste heat recovered by the condensed water becomes the heat source of the reheater 110, and compared with the prior art in which low-pressure steam is adopted as the heat source of the reheater 110, the condensed water heating system can greatly save the steam consumption, improve the system operation efficiency and reduce the system operation cost.

Then, the condensed water flowing out from the reheater 110 flows through the air heater 112 to heat the air flowing through the air heater 112, so that the flue gas waste heat recovered by the condensed water also becomes the heat source of the air heater 112, compared with the prior art that steam extracted by a steam turbine or steam for plant use is used as the heat source of the air heater 112, on one hand, the steam consumption can be saved, thereby reducing the system operation cost, on the other hand, since the condensed water flows through the reheater 110 before flowing through the air heater 112, the condensed water is in a non-superheated state when flowing through the air heater 112, thereby not needing to utilize the desuperheating water for cooling in advance, thereby simplifying the system configuration, and further reducing the construction cost of the system.

According to the arrangement, the condensed water is used for recovering the flue gas waste heat, and the condensed water with the recovered flue gas waste heat is used as the heat source of the reheater 110 and the heater 112, so that the flue gas waste heat is fully utilized, the steam consumption is saved, the system operation efficiency is improved, the system structure is simplified, and the construction cost and the operation cost of the system are reduced.

With continued reference to fig. 1.

The flue gas treatment system 1 is further provided with a flue gas cooler bypass pipeline, a reheater bypass pipeline and a heater bypass pipeline, and the flue gas cooler bypass pipeline, the reheater bypass valve bank 122 and the heater bypass valve bank 123 are respectively arranged on the flue gas cooler bypass pipeline, the reheater bypass pipeline and the heater bypass pipeline.

The flue gas cooler bypass line is connected in parallel with the flue gas cooler 13, and in detail, an inlet of the flue gas cooler bypass line is connected to a pipe section of the condensed water pipe 113 located upstream of the flue gas cooler 13, and an outlet of the flue gas cooler bypass line is connected to a pipe section of the condensed water pipe 113 located between the flue gas cooler 13 and the reheater 110. By adjusting the opening of the smoke cooler bypass valve group 121, the condensate flow flowing through the smoke cooler 13 is adjusted, so that the temperature of the smoke flowing into the low-temperature electric dust remover 14 is controlled, and the stable operation and the dust removal effect of the low-temperature electric dust remover 14 are ensured.

The reheater bypass line is connected in parallel to the reheater 110, and in detail, an inlet of the reheater bypass line is connected to a pipe section of the condensed water line 113 located between the reheater 110 and the flue gas cooler 13, and an outlet of the reheater bypass line is connected to a pipe section of the condensed water line 113 located between the reheater 110 and the heater 112. The flow of condensate through the reheater 110 is adjusted by adjusting the opening of the reheater bypass valve set 122 to accommodate different ambient temperatures and operating conditions.

The bypass line is connected in parallel with the heater 112, and in detail, the inlet of the bypass line is connected to the section of the condensed water line 113 located between the heater 112 and the reheater 110, and the outlet of the bypass line is connected to the section of the condensed water line 113 located downstream of the heater 112. The flow of condensate flowing through the air heater 112 is adjusted by adjusting the opening of the bypass valve set 123 of the air heater, so as to adapt to different environmental temperatures and operating conditions.

By providing the bypass line and the bypass valve set, the amounts of condensed water flowing through the flue gas cooler 13, the reheater 110 and the heater 112 can be individually adjusted, which facilitates independent control.

With continued reference to fig. 1.

The inlet of the condensed water pipeline 113 of the flue gas treatment system 1 is communicated with the condensed water low-pressure heating system 2 of the steam turbine to introduce the condensed water from the condensed water low-pressure heating system 2. The low-pressure condensed water heating system 2 comprises a main pipeline 21 and a low-pressure heater 22 which is sequentially connected in series on the main pipeline 21, wherein an electric door 23 is arranged on the main pipeline 21. In detail, the inlet of the condensation water line 113 of the flue gas treatment system 1 communicates with the main line 21.

In a specific embodiment, the condensate pipe 113 is provided with a circulation pump group 126 and a circulation valve group 125, and the amount of condensate flowing into the condensate pipe 113 is adjusted by adjusting the opening of the circulation valve group 125. In practical implementation, if the pump head of the condensate low-pressure heating system 2 can meet the requirement of introducing the condensate in the condensate pipe 113, the circulating pump unit 126 may not be provided. In actual practice, if the provided circulation pump group 126 is an inverter pump, the amount of condensate flowing into the condensate line 113 can be adjusted by adjusting the operating frequency of the circulation pump group 126 without providing the circulation valve group 125.

In a specific embodiment, the inlet of the condensate line 113 is connected to a first location of the main line 21 via a first inlet branch 114 and to a second location of the main line 21 via a second inlet branch 115. The first location is upstream of the second location to introduce relatively lower temperature condensate through the first inlet branch 114 and relatively higher temperature condensate through the second inlet branch 115. A first valve group 118 is provided in the first inlet branch 114, and a second valve group 119 is provided in the second inlet branch 115. By means of the arrangement, the mixing ratio of the condensate water with a lower temperature and the condensate water with a higher temperature can be changed by adjusting the opening degrees of the first valve group 118 and the second valve group 119, so that the temperature of the condensate water entering the smoke cooler 13 can be changed to adapt to different environmental temperatures and operating conditions.

In a specific embodiment, the first position is located upstream of the most upstream low-pressure heater 22 of the low-pressure condensate heating system 2, and the second position is located between the two low-pressure heaters 22 of the low-pressure condensate heating system 2.

In a specific scheme, an electric door bypass pipeline is arranged in parallel with the electric door 23, and an electric door bypass valve group 124 is arranged on the electric door bypass pipeline. During the application, can make electrically operated gate 23 normal close, make electrically operated gate bypass valves 124 normally open, make the condensate water flow through electrically operated gate bypass pipeline, like this, do benefit to and reduce the condensate water and get into the resistance of condensate water pipeline 113 from condensate water low pressure heating system 2 to can reduce lift and the power requirement, the saving system construction cost to circulating pump group 126. Further, the amount of the condensate flowing into the condensate pipe 113 can be further reduced by reducing the opening degree of the electric gate bypass valve group 124.

With continued reference to fig. 1.

The outlet of the condensed water line 113 of the flue gas treatment system 1 is connected to a third position of the main line 21 via a first outflow branch 116, and the condensed water flowing out of the fan heater 112 is returned to the condensed water low-pressure heating system 2 of the steam turbine. The third position is located downstream of the second position. Compared with a heat recovery system for returning the condensed water to the steam turbine in the background art, the length of the condensed water pipeline 113 can be effectively shortened, and the system construction cost is reduced; on the other hand, when the condensed water returns to the condensed water low-pressure heating system 2, the previously absorbed flue gas waste heat is not consumed, so that the condensed water is heated by further utilizing the flue gas waste heat, and therefore, the operation energy consumption of the low-pressure heater 22 can be reduced, and the system operation cost is further reduced.

In a specific scheme, an outlet of the condensed water pipeline 113 of the flue gas treatment system 1 is further communicated with an inlet position of the condensed water pipeline 113 through a second outflow branch 117, and a third valve bank 120 is disposed on the second outflow branch 117. With this arrangement, when the inlet condensate temperature of the flue gas cooler 13 cannot be achieved by adjusting only the first valve set 118 and the second valve set 119, the inlet condensate temperature of the flue gas cooler 13 can be further adjusted by increasing the opening of the third valve set 120 to return part of the condensate from the air heater 112 to the flue gas cooler 13.

The flue gas treatment system 1 according to the present invention has been described in detail above. The principles and embodiments of the present invention are explained herein using specific examples, which are presented only to assist in understanding the method and its core concepts. It should be noted that, for those skilled in the art, it is possible to make various improvements and modifications to the present invention without departing from the principle of the present invention, and those improvements and modifications also fall within the scope of the claims of the present invention.