Flue gas desulfurization system with recycling of desulfurizer

Abstract

The present application relates to the field of air pollution prevention and control in advanced environmental protection industry, and particularly relates to a flue gas desulfurization system with recycling of desulfurizer. The flue gas desulfurization system comprises: a desulfurization device, comprising: a rough desulfurization device and a fine desulfurization device; a flue gas shunting pipeline, an inlet of which is connected to a total flue gas inlet, a first outlet of which is connected to a flue gas inlet of the rough desulfurization device through a rough desulfurization branch pipeline, and a second outlet of which is connected to a flue gas inlet of the fine desulfurization device through a fine desulfurization branch pipeline; a first new desulfurizer injection port, which is arranged in the fine desulfurization branch pipeline and / or the fine desulfurization device, and which sprays the primary use of new desulfurizer into the flue gas; and a recycled desulfurizer injection port, which is arranged in the rough desulfurization branch pipeline and / or the rough desulfurization device, and which sprays the at least once used recycled desulfurizer into the flue gas. In the present application, the sulfur capacity of the recycled desulfurizer is used to achieve the rough desulfurization of the flue gas in the rough desulfurization device, and the maximum utilization of resources is achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of air pollution prevention and control in the advanced environmental protection industry, and particularly relates to a flue gas desulfurization system with recycling of desulfurizing agent. BACKGROUND

[0002] With increasingly stringent environmental protection requirements, wet desulfurization is gradually replaced by dry desulfurization due to the need for supporting white elimination, desulfurization wastewater zero discharge facilities, and chimney anticorrosion reconstruction, which leads to a complex wet desulfurization system and high investment. The powder dry desulfurization technology (including calcium-based powder desulfurization ACA and sodium-based powder desulfurization SDS) is widely applied in coking, boiler, steel and other industries due to its remarkable desulfurization effect, simple process flow, small running resistance, small device investment, small land occupation, no wastewater and strong load fluctuation resistance.

[0003] The typical calcium-based powder dry desulfurization process flow is as follows: the desulfurizing agent from the new agent bin is conveyed by gas to the inlet flue of the dust collector. After the desulfurizing agent is fully mixed with the treated flue gas, it enters the bag dust collector. The desulfurizing agent is filtered by the bag when the flue gas passes through the bag, and the desulfurizing agent uniformly falls on the surface of the bag to form a desulfurizing agent bed layer of a certain thickness on the bag. When the flue gas passes through the bag bed layer, the desulfurizing agent reacts with SO2 in the flue gas to achieve the purpose of removing SO2 in the flue gas. The waste desulfurizing agent is periodically blown off by the pulse valve into the dust collector hopper, and the waste desulfurizing agent is conveyed by gas to the waste agent bin. The purified flue gas is pressurized by the induced draft fan and discharged through the original chimney.

[0004] At present, the waste agent of the powder dry desulfurization device (including calcium-based and sodium-based) is mostly directly discarded. Due to insufficient utilization of the desulfurizing agent, the consumption of the desulfurizing agent is increased, the calcium-sulfur ratio (sodium-sulfur ratio) is increased, and the device operation cost is increased. SUMMARY

[0005] I. Technical problems to be solved

[0006] The present application expects to at least partially solve one of the above technical problems.

[0007] II. Technical solutions

[0008] The present application provides a flue gas desulfurization system with recycling of desulfurizing agent. The flue gas desulfurization system of the present application comprises:

[0009] The desulfurization device comprises a coarse desulfurization device and a fine desulfurization device, wherein the flue gas outlet of the coarse desulfurization device is communicated to the flue gas inlet of the fine desulfurization device, and the flue gas outlet of the fine desulfurization device is connected to the flue gas total outlet.

[0010] The flue gas diversion pipeline has its inlet connected to the main flue gas inlet, its first outlet connected to the flue gas inlet of the coarse desulfurization unit via a coarse desulfurization branch pipeline, and its second outlet connected to the flue gas inlet of the fine desulfurization unit via a fine desulfurization branch pipeline.

[0011] The first new agent injection port is set in the fine desulfurization branch pipeline and / or fine desulfurization unit, which injects the new desulfurization agent used for the first time into the flue gas flowing through it.

[0012] A circulating agent injection port is installed in the coarse desulfurization branch pipeline and / or coarse desulfurization unit, which injects at least one used circulating desulfurizing agent into the flue gas flowing through it.

[0013] In some embodiments of the present invention, the device further includes: a new agent silo storing new desulfurizing agent for initial use; a circulating agent silo, the upstream side of which is connected to the discharge port of the fine desulfurization unit and is not connected to the discharge port of the coarse desulfurization unit; a first new agent feeder, the upstream side of which is connected to the new agent silo and the downstream side of which is connected to the first new agent injection port; a circulating agent feeder, the upstream side of which is connected to the downstream side of the circulating agent silo and the downstream side of which is connected to the circulating agent injection port; a sensor group including a coarse desulfurization flue gas concentration sensor and a fine desulfurization flue gas concentration sensor, respectively disposed at the flue gas outlets of the coarse desulfurization unit and the fine desulfurization unit; and a control device, the control signal output terminal of which is connected to the first new agent feeder and the circulating agent feeder.

[0014] In some embodiments of the present invention, the first new agent feeder and the circulating agent feeder are electronically controlled variable frequency feeders; the flue gas concentrations sensed by the coarse desulfurization flue gas concentration sensor and the fine desulfurization flue gas concentration sensor are C1 and C2, respectively; the control device internally stores: the upper limit C11 and the lower limit C12 of the coarse desulfurization target concentration; the upper limit C21 and the lower limit C22 of the fine desulfurization target concentration; the control device executes the following control logic:

[0015] The control logic for the first new agent feeder is as follows: If C1≥C11 and the first new agent feeder has not reached the maximum feeding frequency, then the first new agent feeder is controlled to increase the feeding frequency by a preset step size; if C1≤C12 and the first new agent feeder has not reached the minimum feeding frequency, then the first new agent feeder is controlled to decrease the feeding frequency by a preset step size.

[0016] The control logic for the circulating agent feeder is as follows: If C2 ≥ C21 and the circulating agent feeder has not reached the maximum feeding frequency, the circulating agent feeder is controlled to increase the feeding frequency by a preset step size; if C2 ≤ C22 and the circulating agent feeder has not reached the minimum feeding frequency, the circulating agent feeder is controlled to decrease the feeding frequency by a preset step size.

[0017] In some embodiments of the present application, further comprising: a flue gas regulating valve assembly, comprising: a flue gas regulating valve arranged at at least one of: the flue gas shunt pipeline, the coarse desulfurization branch pipeline, the fine desulfurization branch pipeline, which regulates the proportion of flue gas entering the coarse desulfurization device and the fine desulfurization device from the total flue gas inlet; the flue gas regulating valve assembly comprises: a coarse desulfurization flue gas branch valve arranged on the coarse desulfurization branch pipeline; a fine desulfurization flue gas branch valve arranged on the fine desulfurization branch pipeline; both are electrically controlled valves; a control device, the control signal output end of which is connected to: the coarse desulfurization flue gas branch valve, the fine desulfurization flue gas branch valve; the control device executes the following control logic:

[0018] Flue gas regulating valve assembly control logic: the initial state is that the fine desulfurization flue gas branch valve has the smallest opening degree and the coarse desulfurization flue gas branch valve has the largest opening degree;

[0019] In the first new agent feeder control logic: if C1≥C11 and the first new agent feeder has reached the maximum feeding frequency, the flue gas regulating valve assembly control logic is called, and the fine desulfurization flue gas branch valve is reduced in valve opening degree according to a preset step size; if C1≤C12 and the first new agent feeder has reached the minimum feeding frequency, the flue gas regulating valve assembly control logic is called, and the fine desulfurization flue gas branch valve is increased in valve opening degree according to a preset step size;

[0020] In the circulating agent feeder control logic: if C2≥C21 and the circulating agent feeder has reached the maximum feeding frequency, the flue gas regulating valve assembly control logic is called, and the coarse desulfurization flue gas branch valve is reduced in valve opening degree according to a preset step size; if C2≤C22 and the circulating agent feeder has reached the minimum feeding frequency, the flue gas regulating valve assembly control logic is called, and the coarse desulfurization flue gas branch valve is increased in valve opening degree.

[0021] In some embodiments of the present application, further comprising: a second new agent injection port arranged on the coarse desulfurization branch pipeline and / or the coarse desulfurization device, which sprays the first used new desulfurization agent into the flue gas; a second new agent feeder, the upstream side of which is connected to the new agent bin, and the downstream side of which is connected to the second new agent injection port; wherein the second new agent feeder is an electrically controlled variable frequency feeder; the control signal output end of the control device is connected to: the control end of the second new agent feeder; the control device executes the following control logic: second new agent feeder control logic:

[0022] In normal operation, the second new agent feeder is not enabled;

[0023] When C1≥C11 and C2≥C21 and both the first new agent feeder and the circulating agent feeder reach the maximum frequency, the automatic interlock switch is triggered: ① the second new agent feeder is automatically started; ② at the same time, the coarse desulfurization flue gas branch valve opening degree is increased according to a preset step size; ③ at the same time, the fine desulfurization flue gas branch valve opening degree is reduced according to a preset step size;

[0024] When C1≤C12 and C2≤C21, the automatic interlock switch is triggered to close the second new sorbent feeder.

[0025] In some embodiments of the present application, the control device executes the following control logic: after executing the adjustment of the first new sorbent feeder, the circulation sorbent feeder, the second new sorbent feeder, and the flue gas conditioning valve assembly, a preset time is stabilized, and the first new sorbent feeder control logic, the circulation sorbent feeder control logic, the flue gas conditioning valve assembly control logic, and the second new sorbent feeder control logic are re-executed.

[0026] In some embodiments of the present application, the sensor group includes a coarse desulfurization flue gas flow sensor and a fine desulfurization flue gas flow sensor, which are respectively arranged in the coarse desulfurization branch pipeline and the fine desulfurization branch pipeline, and are used to feed back the flue gas flow passing through the coarse desulfurization flue gas branch valve and the fine desulfurization flue gas branch valve.

[0027] In some embodiments of the present application, further comprising: a bin pump, the upstream side of which is connected to the discharge port of the coarse desulfurization device; a waste sorbent bin, the upstream side of which is connected to the downstream side of the bin pump and is isolated from the circulation sorbent bin; wherein the bin pump transports the waste desulfurization agent discharged from the discharge port to the waste sorbent bin.

[0028] In some embodiments of the present application, the first new sorbent injection port is arranged in the fine desulfurization branch pipeline.

[0029] In some embodiments of the present application, the circulation sorbent injection port and the second new sorbent injection port are arranged in the coarse desulfurization branch pipeline.

[0030] In some embodiments of the present application, a first plug valve is arranged between the upstream side of the first new sorbent feeder and the new sorbent bin.

[0031] In some embodiments of the present application, a second plug valve is arranged between the upstream side of the second new sorbent feeder and the new sorbent bin.

[0032] In some embodiments of the present application, a third plug valve is arranged between the discharge port of the coarse desulfurization device and the upstream side of the bin pump.

[0033] In some embodiments of the present application, a fourth plug valve is arranged between the discharge port of the fine desulfurization device and the circulation sorbent bin.

[0034] In some embodiments of the present application, a fifth plug valve is arranged between the circulation sorbent bin and the circulation sorbent feeder.

[0035] In some embodiments of the present application, further comprising: a first new sorbent pneumatic conveying device, which conveys the new desulfurization agent supplied by the first new sorbent feeder to the first new sorbent injection port by pneumatic conveying.

[0036] In some embodiments of the present application, further comprising: a second new agent pneumatic conveying device for conveying the new desulfurizing agent supplied by the second new agent feeder to the second new agent injection port by pneumatic conveying.

[0037] In some embodiments of the present application, further comprising: a circulating agent pneumatic conveying device for conveying the circulating desulfurizing agent supplied by the circulating agent feeder to the circulating agent injection port by pneumatic conveying.

[0038] In some embodiments of the present application, the desulfurization device, the coarse desulfurization device and the fine desulfurization device are arranged side by side.

[0039] In some embodiments of the present application, the coarse desulfurization device comprises: M coarse desulfurization chambers, M≥1; a coarse desulfurization flue gas transfer structure arranged on the side away from the fine desulfurization device, comprising: a flue gas inlet chamber and a flue gas outlet chamber; wherein the upstream side of the flue gas inlet chamber is connected to the flue gas inlet of the coarse desulfurization device, and the downstream side is connected to the coarse desulfurization chamber; the upstream side of the flue gas outlet chamber is connected to the coarse desulfurization chamber.

[0040] In some embodiments of the present application, the fine desulfurization device comprises: N fine desulfurization chambers, N≥1; a fine desulfurization flue gas transfer structure arranged on the side away from the coarse desulfurization device, comprising: a flue gas inlet chamber and a flue gas outlet chamber; wherein the downstream side of the flue gas inlet chamber is connected to the fine desulfurization chamber; the upstream side of the flue gas outlet chamber is connected to the fine desulfurization chamber, and the downstream side is connected to the flue gas outlet of the flue gas fine desulfurization device.

[0041] In some embodiments of the present application, further comprising: a conveying pipeline arranged on the back side of the coarse desulfurization device and the fine desulfurization device or a separate pipeline, the upstream side of which is connected to the downstream side of the flue gas outlet chamber of the coarse desulfurization flue gas transfer structure, and the downstream side of which is connected to the upstream side of the flue gas inlet chamber of the fine desulfurization flue gas transfer structure.

[0042] In some embodiments of the present application, M≥2, and the M coarse desulfurization chambers are arranged in parallel.

[0043] In some embodiments of the present application, N≥2, and the N fine desulfurization chambers are arranged in parallel.

[0044] In some embodiments of the present application, the coarse desulfurization flue gas transfer structure and the fine desulfurization flue gas transfer structure each comprise: a structure body in a hollow box shape; a flue gas partition plate arranged obliquely in the structure body, dividing the internal space of the hollow box shape into two parts: a flue gas inlet chamber and a flue gas outlet chamber.

[0045] In some embodiments of the present application, the coarse desulfurization chambers and the fine desulfurization chambers each comprise: a desulfurization cloth bag arranged inside; an ash bucket arranged at the lower part; for the coarse desulfurization device, the downstream side of the flue gas inlet chamber is connected to the ash bucket of the M coarse desulfurization chambers; the upstream side of the flue gas outlet chamber is connected to the upper part of the M coarse desulfurization chambers; for the fine desulfurization device, the downstream side of the flue gas inlet chamber is connected to the ash bucket of the N fine desulfurization chambers; the upstream side of the flue gas outlet chamber is connected to the upper space of the N fine desulfurization chambers.

[0046] In some embodiments of the present application, the total flue gas outlet is connected to the high chimney through the induced draft fan.

[0047] III. Beneficial effects

[0048] From the above technical solution, the present application has at least one of the following beneficial effects compared with the prior art:

[0049] 1. The desulfurizing agent after the use of the fine desulfurization device still has a certain sulfur capacity. In the present application, the sulfur capacity of the recycled desulfurizing agent after use is utilized in the coarse desulfurization device to achieve coarse desulfurization of flue gas, thereby achieving maximum utilization of resources. For example, when the utilization rate of the desulfurizing agent is 80%, the utilization rate of the desulfurizing agent is greatly improved from 80% to 96%, the utilization rate of the desulfurizing agent is increased by 20%, and the utilization rate is almost the same as that of the conventional high-rate recycling process. However, in terms of equipment cost or equipment modification cost, it is greatly improved.

[0050] 2. Considering that the effective components of the desulfurizing agent after secondary or multiple utilization are low, increasing the recycling rate will greatly increase the overall energy consumption of the system, which is not worth the cost. Through experiments, the applicant found that when the utilization rate of the primary desulfurizing agent is higher than 75%, secondary waste agent recycling is not recommended. Based on this, in the present application, the discharge port of the fine desulfurization device is connected to the circulating agent bin, and the desulfurizing agent entering the circulating agent bin is transported to the coarse desulfurization device by the circulating agent feeder for recycling; and the discharge port of the coarse desulfurization device using the recycled desulfurizing agent is transported to the waste agent bin by the bin pump.

[0051] 3. In the present application, only the primary waste agent is recycled, and the design capacity of the desulfurizer changes little, and the increase in device investment and power consumption is negligible. Therefore, the process investment cost of the present application changes little compared with the non-recycling process; compared with the conventional high-rate recycling process, the investment cost is greatly reduced. However, the flue gas desulfurization system using the present application has a considerable amount of desulfurizing agent saved, and the calcium-sulfur ratio (sodium-sulfur ratio) is greatly improved, and the device operating cost is greatly reduced. Therefore, in terms of desulfurization efficiency, investment cost, operating cost, etc., the present application is obviously superior to the non-recycling process and the ordinary recycling process, and has high popularization value.

[0052] 4. In the present application, the flue gas is divided by the flue gas volume regulating valve and the flue gas shunt pipeline, the circulating desulfurizer reacts with the high concentration SO2 flue gas, which can improve the utilization rate of the circulating desulfurizer; the new desulfurizer reacts with the low concentration SO2 flue gas, which can effectively save the amount of new desulfurizer, can make the remaining utilization rate of the circulating desulfurizer higher (or prolong the use time of the desulfurizer in the fine desulfurization device), and can improve the total utilization rate of the desulfurizer and reduce the total amount of the desulfurizer. In addition, only part of the flue gas enters the coarse desulfurization device, the flue gas flow rate in the coarse desulfurization device is lower, and the flue gas has a longer residence time in the coarse desulfurization device, so that the circulating desulfurizer can be more fully utilized, and the total utilization rate of the desulfurizer is higher, that is, the remaining utilization value of the waste desulfurizer is lower.

[0053] 5. In the present application, by adjusting the opening of the flue gas volume regulating valve, the amount of flue gas treated by the two devices, i.e. the coarse desulfurization device and the fine desulfurization device, can be controlled.

[0054] 6. Under the premise of ensuring that the export meets the standard, the discharge frequency of the three feeders can be adjusted according to the amount of new desulfurizer and circulating desulfurizer, for example, if the production of circulating desulfurizer (i.e. the amount of fly ash discharged by the fine desulfurization system) is greater than the amount used, the amount of feed of the first new desulfurizer feeder is reduced, and the frequency of blowing ash of the fine desulfurization device is also reduced, so that the residence time of the new desulfurizer in the fine desulfurization system is longer, i.e. the reaction time is extended, the utilization rate of the new desulfurizer is increased, the residual sulfur capacity of the circulating desulfurizer is reduced, and the amount of circulating desulfurizer used will naturally increase. In the present application, the amount of flue gas entering the coarse desulfurization device and the fine desulfurization device is controlled by the flue gas shunt pipeline, and the amount of new desulfurizer and circulating desulfurizer is controlled by the first new desulfurizer feeder, the second new desulfurizer feeder and the circulating desulfurizer feeder, so that the amount of new desulfurizer is saved to the maximum, and the circulating desulfurizer can be fully utilized. BRIEF DESCRIPTION OF DRAWINGS

[0055] Figure 1 It is a schematic diagram of the flue gas desulfurization system for the desulfurizer recycling of the embodiment of the present application.

[0056] Figure 2A and Figure 2B It is a perspective view of the desulfurization device in the flue gas desulfurization system of the embodiment of the present application, observed from the front side and the rear side, respectively.

[0057] Figure 3 It is Figure 1 a top view of the flue gas dust removal equipment shown in the figure.

[0058] Figure 4 , Figure 5 , Figure 6 It is Figure 3 a sectional view of the flue gas dust removal equipment shown in the figure, observed along the A direction, the B direction and the C direction, respectively. DETAILED DESCRIPTION

[0059] The application designs a circulating return material process for efficient recycling of desulfurizer, and designs a flue gas desulfurization device for recycling of desulfurizer.

[0060] To make the objectives, technical solutions and advantages of the present application clearer, further detailed description will be made to the present application with reference to the specific embodiments and the accompanying drawings.

[0061] Figure 1 A schematic diagram of the flue gas desulfurization device for recycling of desulfurizer in the embodiment of the present application. As shown in the figure, the flue gas desulfurization system for recycling of desulfurizer in the embodiment of the present application is characterized in that it comprises:

[0062] The desulfurization device comprises a coarse desulfurization device 100 and a fine desulfurization device 200, wherein the flue gas outlet of the coarse desulfurization device is connected to the flue gas inlet of the fine desulfurization device;

[0063] The flue gas shunting pipeline 300 has an inlet connected to the flue gas total inlet, a first outlet connected to the flue gas inlet of the coarse desulfurization device through the coarse desulfurization branch pipeline 310, and a second outlet connected to the flue gas inlet of the fine desulfurization device through the fine desulfurization branch pipeline 320;

[0064] The bin group comprises a new agent bin 511, a recycled agent bin 512 and a waste agent bin 513;

[0065] The injection port group comprises a first new agent injection port 411, a recycled agent injection port 412 and a second new agent injection port 413;

[0066] The feeder group comprises a first new agent feeder 611, a recycled agent feeder 612 and a second new agent feeder 613;

[0067] The flue gas adjusting valve assembly adjusts the proportion of flue gas entering the coarse desulfurization device and the fine desulfurization device from the flue gas total inlet.

[0068] For the injection port group, the first new agent injection port 411 is arranged at the fine desulfurization branch pipeline 320 and / or the fine desulfurization device 200, and sprays the newly used new desulfurizer into the flue gas. The recycled agent injection port 412 is arranged at the coarse desulfurization branch pipeline 310 and / or the coarse desulfurization device 100, and sprays the recycled desulfurizer used at least once into the flue gas. The second new agent injection port 413 is arranged at the coarse desulfurization branch pipeline and / or the coarse desulfurization device, and sprays the newly used new desulfurizer into the flue gas;

[0069] For the group of bins, the new agent bin 511, which stores the initial use of new desulfurizer. Circulating agent bin 512, its upstream side is connected to the discharge port of the fine desulfurization device, and is not communicated with the discharge port of the coarse desulfurization device. Waste agent bin 513, its upstream side is connected to the discharge port of the coarse desulfurization device, and is not communicated with the discharge port of the fine desulfurization device.

[0070] For the group of feeders, the first new agent feeder 611, its upstream side is connected to the new agent bin, and its downstream side is connected to the first new agent injection port. Circulating agent feeder 612, its upstream side is connected to the downstream side of the circulating agent bin, and its downstream side is connected to the circulating agent injection port. The second new agent feeder 613, its upstream side is connected to the new agent bin, and its downstream side is connected to the second new agent injection port.

[0071] The flue gas regulating valve assembly comprises: a flue gas volume regulating valve arranged in at least one of the coarse desulfurization branch pipeline, the fine desulfurization branch pipeline and the flue gas shunt pipeline, which regulates the proportion of flue gas entering the coarse desulfurization device and the fine desulfurization device from the flue gas total inlet.

[0072] In the flue gas desulfurization device of the embodiment, after the flue gas enters from the flue gas total inlet, it is divided into two streams, one stream of flue gas enters the coarse desulfurization device first, and then merges with another stream of flue gas to enter the fine desulfurization device for fine desulfurization, and the flue gas after fine desulfurization is discharged from the high chimney through the induced draft fan. In the desulfurization process, the flue gas with high SO2 concentration in the coarse desulfurization device is subjected to coarse desulfurization by using the primary circulating desulfurizer with high desulfurization value, and the flue gas with greatly reduced SO2 concentration in the fine desulfurization device is subjected to fine desulfurization by using new desulfurizer. This design greatly saves the amount of new desulfurizer, and also makes the utilization rate of the primary desulfurizer higher.

[0073] Regarding the flue gas desulfurization device of the embodiment, the following aspects need to be particularly explained.

[0074] I. Recycling of desulfurizer

[0075] The desulfurizer after use of the fine desulfurization device still has a certain sulfur capacity. In the embodiment, the sulfur capacity of the used circulating desulfurizer is utilized in the coarse desulfurization device to achieve coarse desulfurization of flue gas, thereby achieving maximum utilization of resources. For example, when the utilization rate of desulfurizer is 80%, the utilization rate of desulfurizer is greatly improved from 80% to 96%, the utilization rate of desulfurizer is increased by 20%, and the utilization rate is almost the same as that of the conventional high rate recycling process. However, in terms of equipment cost or equipment modification cost, it is greatly improved.

[0076] II. Improvement cost and operation cost of equipment

[0077] In this embodiment, only one waste agent cycle is performed, the design capacity of the desulfurizer remains largely unchanged, and the increase in equipment investment and power consumption is negligible. Therefore, the process investment cost in this embodiment is not significantly different from that of the non-cycle process; compared with the conventional high-rate cycle process, the investment cost is significantly reduced.

[0078] However, the flue gas desulfurization system of this embodiment achieves considerable savings in desulfurizing agent, a significantly increased calcium-to-sulfur ratio (sodium-to-sulfur ratio), and a substantial reduction in operating costs. Therefore, considering desulfurization efficiency, investment costs, and operating costs, this embodiment is significantly superior to both non-circulating and conventional circulating processes, and has high potential for widespread application.

[0079] III. Effective Separation of Circulating Desulfurizing Agent and Waste Agent

[0080] Considering the low effective content of desulfurizing agent after secondary or multiple uses, increasing the circulation rate would significantly increase the overall energy consumption of the system, making it counterproductive. Through experiments, the applicant found that when the utilization rate of primary desulfurization waste agent exceeds 75%, secondary waste agent recycling is not recommended. Therefore, in this embodiment, the discharge port of the fine desulfurization unit is connected to the circulating agent silo. The desulfurizing agent entering the circulating agent silo is transported to the coarse desulfurization unit for recycling by the circulating agent feeder. Meanwhile, the discharge port of the coarse desulfurization unit, after utilizing the recycled desulfurizing agent from the first cycle, is transported to the waste agent silo 513 via the silo pump 614.

[0081] Specifically, in this embodiment:

[0082] 1. After use, the new agent can be used as a circulating desulfurizing agent.

[0083] Fresh desulfurizing agent from the new agent silo is pneumatically conveyed to the inlet flue gas duct of the fine desulfurization unit. The pre-purified flue gas merges with another stream of unpurified flue gas and enters the fine desulfurization unit. The remaining SO2 in the flue gas reacts chemically with the high-efficiency new desulfurizing agent in the flue and on the bag filter bed. By controlling the amount of new desulfurizing agent added, the SO2 concentration at the unit outlet can be precisely controlled. The purified flue gas is pressurized by an induced draft fan and then discharged high into the atmosphere through the chimney. The circulating desulfurizing agent discharged from the bottom of the fine desulfurization unit is collected in a circulating agent silo.

[0084] 2. The circulating desulfurizing agent is discharged as waste after use.

[0085] The circulating desulfurizing agent from the circulating agent silo is pneumatically conveyed to the inlet flue of the coarse desulfurization unit. The circulating desulfurizing agent reacts chemically with SO2 in the flue gas on the flue and bag filter bed, removing some of the SO2 and achieving preliminary purification. The recycled desulfurizing agent is discharged from the discharge port at the bottom of the coarse desulfurization unit and pneumatically conveyed by the silo pump 614 to the waste agent silo 513, from which it is periodically removed from the unit.

[0086] In summary, the desulfurizer used by the fine desulfurization device and the coarse desulfurization device is effectively separated, the content of the desulfurization effective component in the circulating desulfurizer is stable, and the circulating desulfurizer has a high utilization value.

[0087] IV. The flue gas diversion improves the utilization efficiency of the circulating desulfurizer

[0088] In the embodiment, the flue gas is diverted through the flue gas flow adjusting valve and the flue gas diversion pipeline, the circulating desulfurizer is reacted with the high-concentration SO2 flue gas, and the utilization rate of the circulating desulfurizer can be improved; the new desulfurizer is reacted with the low-concentration SO2 flue gas, the amount of the new desulfurizer can be effectively saved, the residual utilization rate of the circulating desulfurizer is higher (or the use time of the desulfurizer of the fine desulfurization device is prolonged), the total utilization rate of the desulfurizer is improved, and the total amount of the desulfurizer is reduced. In addition, only part of the flue gas enters the coarse desulfurization device, the flue gas flow rate of the coarse desulfurization device is lower, the flue gas has a longer residence time in the coarse desulfurization device, the circulating desulfurizer can be more fully utilized, the total utilization rate of the desulfurizer is higher, and the residual utilization value of the waste desulfurizer is lower.

[0089] V. Control of the first new desulfurizer feeder, the second new desulfurizer feeder and the circulating desulfurizer feeder

[0090] In the application, the opening degree of the flue gas flow adjusting valve is adjusted, and the flue gas flow rates of the coarse desulfurization device and the fine desulfurization device can be controlled; under the premise that the outlet meets the standard, the discharge frequency of the three feeders can be adjusted according to the use amount of the new desulfurizer and the circulating desulfurizer, for example, when the production amount (i.e., the ash discharge amount of the fine desulfurization system) of the circulating desulfurizer is greater than the use amount, the feeding amount of the first new desulfurizer feeder is reduced, and the ash blowing frequency of the fine desulfurization device is reduced, so that the residence time of the new desulfurizer of the fine desulfurization system in the system is prolonged, the reaction time is prolonged, the utilization rate of the new desulfurizer is increased, the residual sulfur capacity of the circulating desulfurizer is reduced, and the use amount of the circulating desulfurizer is naturally increased.

[0091] In the application, the flue gas flow rates of the coarse desulfurization device and the fine desulfurization device are controlled through the flue gas diversion pipeline, and the feeding amounts of the new desulfurizer and the circulating desulfurizer are controlled by combining the first new desulfurizer feeder, the second new desulfurizer feeder and the circulating desulfurizer feeder, so that the amount of the new desulfurizer is saved to the maximum extent, and the circulating desulfurizer can be fully utilized.

[0092] VI. Backup of the second new desulfurizer injection port

[0093] The coarse desulfurization device uses the waste desulfurizer for coarse desulfurization, and the second new desulfurizer injection port is used as backup to prevent the SO2 concentration in the flue gas of some devices from being too high, and a small amount of new desulfurizer and circulating desulfurizer can be mixed to meet the special requirement of ultra-clean emission.

[0094] Unlike the coarse desulfurization device, the fine desulfurization device only uses the new desulfurizer for fine desulfurization, and only the new desulfurizer injection port is provided.

[0095] Seven, the position of the injection port

[0096] In this embodiment, the first new agent injection port is arranged in the fine desulfurization branch pipeline; the circulating agent injection port and the second new agent injection port are arranged in the coarse desulfurization branch pipeline.

[0097] Through the above position setting of the injection port, the first aspect utilizes the flue gas flow to realize the transportation of the desulfurizing agent; the second aspect realizes the preliminary mixing reaction of the flue gas and the desulfurizing agent in the transportation process.

[0098] Those skilled in the art should understand that the above setting position of the injection port is only an example, and the present application is not limited thereto. Those skilled in the art can also set the position of the injection port according to the actual scene needs, and the same can also achieve the present application, and is also within the protection scope of the present application.

[0099] Eight, plug valve

[0100] In this embodiment, a first plug valve is arranged between the upstream side of the first new agent feeder and the new agent bin; a second plug valve is arranged between the upstream side of the second new agent feeder and the new agent bin; a third plug valve is arranged between the discharge port of the coarse desulfurization device and the upstream side of the bin pump; a fourth plug valve is arranged between the discharge port of the fine desulfurization device and the circulating agent bin; and a fifth plug valve is arranged between the circulating agent bin and the circulating agent feeder. In this embodiment, through the plurality of plug valves, reliable control of the system operation is realized.

[0101] Those skilled in the art should understand that the above plug valve setting is only an example, and those skilled in the art can also set the position of the plug valve according to the actual scene needs, increase other plug valves or remove certain plug valves, and the same can also achieve the present application, and is also within the protection scope of the present application.

[0102] Nine, specific setting mode of flue gas regulating valve assembly

[0103] In this embodiment, the flue gas regulating valve assembly includes two flue gas volume regulating valves, i.e., a coarse desulfurization flue gas branch valve 711 arranged on the coarse desulfurization branch pipeline and a fine desulfurization flue gas branch valve 712 arranged on the fine desulfurization branch pipeline.

[0104] In this embodiment, through the two branch valves, the distribution and accurate regulation of the inlet flue gas between the coarse desulfurization device and the fine desulfurization device are realized, which is conducive to adjusting the distribution of the flue gas according to the change of the sulfur content in the outlet flue gas, and realizing more sufficient utilization of the circulating desulfurizing agent. These will be described in detail later, and will not be described here.

[0105] Those skilled in the art should understand that although two branch valves are provided in the present embodiment, the present application is not limited thereto. In other embodiments of the present application, only one valve can be provided, and the distribution of flue gas can also be achieved, which is also within the protection scope of the present application.

[0106] X. Pneumatic conveying

[0107] For powder desulfurizer, pneumatic conveying is the most effective, simple and low-cost conveying method. In the present embodiment, it also includes:

[0108] The first new agent pneumatic conveying device 611a conveys the new desulfurizer supplied by the first new agent feeder to the first new agent injection port by pneumatic conveying;

[0109] The second new agent pneumatic conveying device 613a conveys the new desulfurizer supplied by the second new agent feeder to the second new agent injection port by pneumatic conveying;

[0110] The circulating agent pneumatic conveying device 612a conveys the circulating desulfurizer supplied by the circulating agent feeder to the circulating agent injection port by pneumatic conveying.

[0111] Those skilled in the art should understand that a gas source is provided at the front end of each pneumatic conveying device. Specifically, a first Roots blower and a second Roots blower are respectively provided at the gas source side of the first and second new agent pneumatic conveying devices, and a low-pressure nitrogen source is provided at the gas source side of the waste agent pneumatic conveying device.

[0112] Those skilled in the art should understand that the above pneumatic conveying is only an example. In other embodiments of the present application, other conveying methods can also be used, which can also achieve the present application and are also within the protection scope of the present application.

[0113] XI. Desulfurization device

[0114] Regarding the desulfurization device in the present embodiment, its structure is similar to the flue gas dust removal and desulfurization equipment disclosed in CN116850711A filed by the applicant on October 10, 2023, the difference is that the dust removal system in CN116850711A is used as the rough desulfurization device in the present embodiment, and the desulfurization system is used as the fine desulfurization device in the present embodiment. The following describes the parts related to the present embodiment.

[0115] Figure 2A and Figure 2B are respectively the front and rear perspective views of the desulfurization device in the flue gas desulfurization system of the present embodiment. Figure 3 is Figure 1 is the top view of the flue gas dust removal equipment. Figure 4 , Figure 5 , Figure 6 are respectivelyFigure 3 Figure 3 is a sectional view of the flue gas dedusting device along the A, B, and C directions.

[0116] As shown in the figure, in this embodiment, the coarse desulfurization device 100 includes M coarse desulfurization chambers 110 and a coarse desulfurization flue gas transfer structure 120, M≥1. The fine desulfurization device 200 includes N fine desulfurization chambers 210 and a fine desulfurization flue gas transfer structure 220, N≥1. The desulfurization device further includes a conveying pipeline 150 arranged at the rear side of the coarse desulfurization device and the fine desulfurization device or a separate pipeline, connected between the flue gas outlet of the coarse desulfurization device and the flue gas inlet of the fine desulfurization device.

[0117] 1. Specific arrangement of flue gas transfer structure

[0118] The coarse desulfurization flue gas transfer structure 120 is arranged on the side away from the fine desulfurization device, and includes a structure body 121 in a hollow box shape, and a flue gas partition plate 122 arranged obliquely in the structure body, dividing the internal space of the hollow box shape into two parts: a flue gas inlet chamber 122A and a flue gas outlet chamber 122B.

[0119] In the coarse desulfurization flue gas transfer structure 120, the upstream side of the flue gas inlet chamber 122A is connected to the flue gas inlet of the coarse desulfurization device, and the downstream side is connected to the coarse desulfurization chamber; the upstream side of the flue gas outlet chamber 122B is connected to the coarse desulfurization chamber, and the downstream side is connected to the conveying pipeline.

[0120] The fine desulfurization flue gas transfer structure 220 is arranged on the side away from the coarse desulfurization device, and includes a structure body 221 in a hollow box shape, and a flue gas partition plate 222 arranged obliquely in the structure body, dividing the internal space of the hollow box shape into two parts: a flue gas inlet chamber 222A and a flue gas outlet chamber 222B.

[0121] In the fine desulfurization flue gas transfer structure 220, the upstream side of the flue gas inlet chamber 222A is connected to the conveying pipeline, and the downstream side is connected to the fine desulfurization chamber; the upstream side of the flue gas outlet chamber 222B is connected to the fine desulfurization chamber, and the downstream side is connected to the flue gas outlet of the fine desulfurization device.

[0122] 2. Specific arrangement of desulfurization chamber

[0123] The coarse desulfurization chamber 110 and the fine desulfurization chamber 210 each include a desulfurization cloth bag arranged inside, and a hopper arranged at the lower part. For the coarse desulfurization device, the downstream side of the flue gas inlet chamber is connected to the hoppers of the M coarse desulfurization chambers, and the upstream side of the flue gas outlet chamber is connected to the upper parts of the M coarse desulfurization chambers. For the fine desulfurization device, the downstream side of the flue gas inlet chamber is connected to the hoppers of the N fine desulfurization chambers, and the upstream side of the flue gas outlet chamber is connected to the upper spaces of the N fine desulfurization chambers.

[0124] In this embodiment, M≥2, M coarse desulfurization chambers are arranged in parallel; N≥2, N fine desulfurization chambers are arranged in parallel, but the present application is not limited thereto. In other embodiments of the present application, the specific data of the desulfurization chambers in the coarse and fine desulfurization devices can be arranged as needed, and the specific structure of the desulfurization chambers can also achieve the present application and is also within the scope of protection of the present application.

[0125] 3. Specific arrangement of the conveying pipeline

[0126] In this embodiment, the coarse desulfurization device 100 and the fine desulfurization device 200 are arranged side by side, and the conveying pipeline 150 is arranged at the rear side of the coarse desulfurization device and the fine desulfurization device, the upstream side of which is connected to the downstream side of the flue gas outlet chamber of the coarse desulfurization flue gas transfer structure, and the downstream side of which is connected to the upstream side of the flue gas inlet chamber of the fine desulfurization flue gas transfer structure.

[0127] It should be noted that only the structure of the desulfurization device closely related to the present application is described in detail above, and more detailed content can be referred to the related description of CN116850711A, which will not be described here.

[0128] 4. Flue gas treatment process

[0129] Inlet flue gas S O is divided into two streams at the flue gas distribution pipeline 300 and flows into the coarse desulfurization branch pipeline 310 and the fine desulfurization branch pipeline 320, respectively. In the coarse desulfurization branch pipeline 310, the circulating desulfurizer DSc is sprayed to form a mixture of inlet flue gas and circulating desulfurizer: S O + DS C In the fine desulfurization branch pipeline, the fresh desulfurizer DS F is sprayed to form a mixture of inlet flue gas and fresh desulfurizer: So+ DS F . The mixture of inlet flue gas and circulating desulfurizer enters the coarse desulfurization device for coarse desulfurization to form the flue gas after coarse desulfurization: S CD ; and the flue gas after coarse desulfurization together with the mixture of inlet flue gas and fresh desulfurizer enters the fine desulfurization device for fine desulfurization to form the flue gas after fine desulfurization S FD .

[0130] Twelfth, intelligent control of the flue gas desulfurization system

[0131] In this embodiment, the first new agent feeder, the second new agent feeder, and the circulating agent feeder are electrically controlled variable frequency feeders. The flue gas regulating valve assembly includes a coarse desulfurization flue gas branch valve arranged on the coarse desulfurization branch pipeline and a fine desulfurization flue gas branch valve arranged on the fine desulfurization branch pipeline. Both of them are electrically controlled valves.

[0132] In the embodiment, the sensor group is further included. The sensor group includes: a coarse desulfurization flue gas concentration sensor 811 and a fine desulfurization flue gas concentration sensor 812, which are arranged in the coarse desulfurization device and the high-altitude chimney respectively, and the flue gas concentrations sensed by the two are C1 and C2 respectively; the signal output ends of the two are connected to the sensing signal input end of the control device respectively. The coarse desulfurization flue gas flow sensor 811a and the fine desulfurization flue gas flow sensor 812a are arranged in the coarse desulfurization branch pipeline and the fine desulfurization branch pipeline respectively, and the flue gas flows sensed by the two are F1 and F2 respectively, which are used to feed back the flue gas flow passing through the coarse desulfurization flue gas branch valve 711 and the fine desulfurization flue gas branch valve 712, that is, the flue gas flow entering the coarse desulfurization device and the fine desulfurization device.

[0133] In the embodiment, the control device 900 is further included, the sensing signal input end of which is connected to the signal output end of the coarse and fine desulfurization flue gas concentration sensor; the control device has the following pre-stored in the internal: the upper limit C11 and the lower limit C12 of the coarse desulfurization target concentration; the upper limit C21 and the lower limit C22 of the fine desulfurization target concentration; the control signal output end of which is connected to the coarse desulfurization flue gas branch valve and the fine desulfurization flue gas branch valve in the flue gas regulating valve assembly, the first new agent feeder, the second new agent feeder and the circulating agent feeder. The control device executes the following control logic: the first new agent feeder control logic, the second new agent feeder control logic and the flue gas regulating valve assembly control logic. The following are described in detail respectively.

[0134] 1. The first new agent feeder control logic:

[0135] If C1≥C11 and the first new agent feeder has not reached the maximum feeding frequency, the first new agent feeder is controlled to increase the feeding frequency by a preset step;

[0136] If C1≥C11 and the first new agent feeder has reached the maximum feeding frequency, the flue gas regulating valve assembly control logic is called, and the fine desulfurization flue gas branch valve is controlled to decrease the valve opening by a preset step;

[0137] If C1≤C12 and the first new agent feeder has not reached the minimum feeding frequency, the first new agent feeder is controlled to decrease the feeding frequency by a preset step;

[0138] If C1≤C12 and the first new agent feeder has reached the minimum feeding frequency, the flue gas regulating valve assembly control logic is called, and the fine desulfurization flue gas branch valve is controlled to increase the valve opening by a preset step.

[0139] Specifically, the difference between the SO2 concentration measured at the outlet of the coarse desulfurization device and the target SO2 concentration range is used to automatically adjust the feeding frequency of the coarse desulfurization device feeder. For example, if the SO2 concentration value measured by the outlet analyzer of the coarse desulfurization device is higher than the upper limit C11 of the target value, the feeding frequency of the coarse desulfurization device feeder is increased by 2 Hz, and stabilized for 10 minutes. If the concentration is still greater than the upper limit C11 of the target value, the feeder frequency is increased by 2 Hz again, and stabilized for 10 minutes, until the SO2 concentration reaches the target range, and the feeder frequency is no longer adjusted. Conversely, if the measured SO2 concentration is less than the lower limit C12 of the target value, the feeder frequency is gradually reduced, and the control mode is similar to the above, which will not be described here.

[0140] 2. Circulating agent feeder control logic

[0141] If C2≥C21 and the circulating agent feeder has not reached the maximum feeding frequency, control the circulating agent feeder to increase the feeding frequency by a preset step size;

[0142] If C2≥C21 and the circulating agent feeder has reached the maximum feeding frequency, call the flue gas regulating valve assembly control logic, and adjust the coarse desulfurization flue gas branch valve opening to decrease the valve opening by a preset step size;

[0143] If C2≤C22 and the circulating agent feeder has not reached the minimum feeding frequency, control the circulating agent feeder to decrease the feeding frequency by a preset step size;

[0144] If C2≤C22 and the circulating agent feeder has reached the minimum feeding frequency, call the flue gas regulating valve assembly control logic, and adjust the coarse desulfurization flue gas branch valve opening to increase the valve opening.

[0145] 3. Second new agent feeder control logic

[0146] During normal operation, the second new agent feeder is not enabled;

[0147] When C1≥C11 and C2≥C21 and both the first new agent feeder and the circulating agent feeder have reached the maximum power frequency, trigger the automatic interlock switch: ① the second new agent feeder is automatically started; ② at the same time, the coarse desulfurization flue gas branch valve opening is increased by a preset step size; ③ at the same time, the fine desulfurization flue gas branch valve opening is decreased by a preset step size;

[0148] When C1≤C12 and C2≤C21, trigger the automatic interlock switch to close the second new agent feeder.

[0149] Specifically, according to the difference between the SO2 concentration value monitored in real time by the chimney analyzer and the target SO2 concentration, the feeding frequency and regulating valve opening of the coarse desulfurization and fine desulfurization device feeders are automatically adjusted, which can realize automatic feeding of the desulfurizing agent of the coarse desulfurization and fine desulfurization devices, and realize that the SO2 concentration at the outlet of the flue gas desulfurization system meets the design requirements.

[0150] 4. Flue gas regulating valve assembly control logic

[0151] The initial state of the flue gas regulating valve assembly is that the fine desulfurization flue gas branch valve is at the minimum opening degree and the coarse desulfurization flue gas branch valve is at the maximum opening degree. Then, the opening degree is adjusted according to the specific conditions of each feeder.

[0152] Specifically, the coarse desulfurization branch pipeline and the fine desulfurization branch pipeline are each provided with an electric regulating valve, and an operator can adjust the opening degree of the flue gas regulating branch valve at the inlet of the coarse desulfurization device and the fine desulfurization device at any time in the control room, and adjust the flue gas amount entering the two desulfurization devices respectively. After the interlocking control is put into operation, the device can be automatically controlled.

[0153] Through the adjustment of the flue gas amount, in combination with the interlocking automatic control of the frequency of the two feeders and the SO2 concentration of the analyzer, on the basis of ensuring that the SO2 at the outlet of the device meets the standard, the regulating valve of the coarse desulfurization device is at the maximum opening degree, the frequency of the feeder system is at a relatively high frequency, at this time, the valve of the fine desulfurization device must be at a relatively small opening degree, and the frequency of the feeder is also at a relatively low frequency, so that the utilization rate of the desulfurizing agent is the highest and the economy is maximized. Further, through the adjustment of the third feeder, the exceptional case of the SO2 concentration in the flue gas of some devices being too high is prevented, and the reliable operation of the flue gas desulfurization system is realized.

[0154] It needs to be particularly pointed out that the automatic control of each feeder and the flue gas regulating valve assembly according to the sensing information of the sensor is only a preferred implementation manner of the present application. In some embodiments of the present application, each feeder and the flue gas regulating valve assembly can still be controlled in a manual or semi-automatic manner, although the degree of intelligence is slightly lower and the operation is relatively cumbersome, but the present application can still be realized, and it is also within the protection scope of the present application.

[0155] Thirteen, relationship between each part

[0156] The above is a detailed description of the overall embodiment of the present application. However, those skilled in the art should understand that each innovation point in the present application can be independently executed and solve the related technical problems, for example:

[0157] 1. By setting up a new agent bin, a circulating agent bin, a first new agent injection port, a circulating agent injection port, etc., even without a flue gas amount regulating valve, the effective separation of the circulating desulfurizing agent and the waste agent can also be realized, and the efficiency of improving the calcium-sulfur ratio (sodium-sulfur ratio) can also be achieved.

[0158] 2. By setting up a flue gas regulating valve assembly, the proportion of the flue gas distributed to the coarse desulfurization device and the fine desulfurization device can be adjusted, in this case, even without other components, part of the functions of the present application can also be realized, and it is also within the protection scope of the present application.

[0159] Thus far, the various embodiments of the present application have been described. Based on the above description, those skilled in the art should have a clear understanding of the present application.

[0160] The ordinal numbers, such as "first", "second", "third", "main", "secondary", and Arabic numbers, letters, etc., used in the description and claims are used to modify the corresponding elements (or steps) and are intended to distinguish the elements (or steps) from each other, but do not mean that the elements (or steps) have any ordinal number, nor represent the order of the elements (or steps).

[0161] It should also be noted that the directional phrases mentioned in the embodiments, such as "center", "lateral", "longitudinal", "top", "bottom", "upper", "lower", "front", "back", "left", "right", "inner", "outer", etc., indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not mean that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be understood as limiting the present application. Furthermore, throughout the drawings, the same elements are represented by the same or similar reference numerals. Furthermore, the shapes and sizes of the components in the drawings do not reflect the true size and proportion, but only illustrate the content of the embodiments of the present application.

[0162] In the description of the present application, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected", "connected" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be directly connected, or indirectly connected through an intermediate medium, or it can be connected inside two elements. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0163] Those skilled in the art should understand that in the claims and description of the present application, the word "comprising" does not exclude the presence of elements (or steps) not listed in the claims. The word "a" or "an" before an element (or step) does not exclude the presence of multiple such elements (or steps).

[0164] For certain implementations, if they are not the key content of the present application and are well known to those skilled in the art, they are not described in detail in the drawings or text of the specification due to the limitation of the length, and can be understood by referring to the relevant prior art.

[0165] Furthermore, the purpose of providing the above embodiments is only to satisfy the legal requirements of the present application, and the present application can be implemented in many different forms, and should not be interpreted as being limited to the embodiments set forth herein.

[0166] Similarly, it is to be understood that the brans of the application which has been often grouped in a single embodiment, figure or description thereof in the above description of illustrative embodiments of the application, have sometimes been grouped together in a single embodiment, figure, or description thereof in the above description of illustrative embodiments of the application, for the purpose of brevity in the foregoing detailed description of the application. However, no inference should be drawn that the brans of the application has required more features than the claims attached hereto actually describe. To the contrary, as will be appreciated by those skilled in the art upon reading this disclosure, each of the individual brans of the application, in one embodiment, is based upon fewer than all of the brans of the other embodiments. In addition, brans of one embodiment can be combined with brans of another embodiment or other embodiments to create further embodiments, which can be claimed or used as a basis for further claims. Thus, the claims following, directly or indirectly, from the detailed description of specific embodiments, are demonstrative but not limiting, and that every combination of brans described is contemplated, even if not explicitly stated in the claims. As such, the brans of the application are to be understood not necessarily limited to the specific embodiments illustrated, but only by the brans of the claims, and equivalents thereof. Accordingly, the claims are what define the brans of the application, and are intended to embrace all changes and modifications that come within the spirit and scope of the claims.

[0167] The specific embodiments described above are illustrative of specific ways to make and use the application. Numerous other embodiments will become readily apparent to those skilled in the art from the foregoing detailed description, and it is intended that the scope of the application disclosed herein include all such alternatives, modifications and variations.

Claims

1. A flue gas desulfurization system that recycles desulfurizing agent, characterized in that, include: The desulfurization device includes a coarse desulfurization device and a fine desulfurization device, wherein the flue gas outlet of the coarse desulfurization device is connected to the flue gas inlet of the fine desulfurization device; and the flue gas outlet of the fine desulfurization device is connected to the total flue gas outlet. The flue gas diversion pipeline has its inlet connected to the main flue gas inlet, its first outlet connected to the flue gas inlet of the coarse desulfurization unit via a coarse desulfurization branch pipeline, and its second outlet connected to the flue gas inlet of the fine desulfurization unit via a fine desulfurization branch pipeline. The first new agent injection port is set in the fine desulfurization branch pipeline and / or the fine desulfurization device, which injects the new desulfurization agent used for the first time into the flue gas flowing through it. A circulating agent injection port is provided in the coarse desulfurization branch pipeline and / or the coarse desulfurization device, which injects at least one used circulating desulfurizing agent into the flue gas flowing through it. The new agent silo stores the new desulfurizing agent for the first time; The circulating agent silo is connected upstream to the discharge port of the fine desulfurization unit, but is not connected to the discharge port of the coarse desulfurization unit; The first new agent feeder is connected to the new agent silo on its upstream side and to the first new agent injection port on its downstream side. A circulating agent feeder, the upstream side of which is connected to the downstream side of the circulating agent silo, and the downstream side of which is connected to the circulating agent injection port; The sensor group includes a coarse desulfurization flue gas concentration sensor and a fine desulfurization flue gas concentration sensor, which are respectively installed at the flue gas outlets of the coarse desulfurization unit and the fine desulfurization unit; The control device, whose control signal output terminal is connected to: the first new agent feeder and the circulating agent feeder; The first new agent feeder and the circulating agent feeder are electronically controlled variable frequency feeders; the flue gas concentrations sensed by the coarse desulfurization flue gas concentration sensor and the fine desulfurization flue gas concentration sensor are C1 and C2, respectively; the control device internally stores: upper limit C11 and lower limit C12 of the coarse desulfurization target concentration; upper limit C21 and lower limit C22 of the fine desulfurization target concentration; the control device executes the following control logic: The control logic for the first new agent feeder is as follows: If C1≥C11 and the first new agent feeder has not reached the maximum feeding frequency, then the first new agent feeder is controlled to increase the feeding frequency by a preset step size; if C1≤C12 and the first new agent feeder has not reached the minimum feeding frequency, then the first new agent feeder is controlled to decrease the feeding frequency by a preset step size. The control logic for the circulating agent feeder is as follows: If C2 ≥ C21 and the circulating agent feeder has not reached the maximum feeding frequency, the circulating agent feeder is controlled to increase the feeding frequency by a preset step size; if C2 ≤ C22 and the circulating agent feeder has not reached the minimum feeding frequency, the circulating agent feeder is controlled to decrease the feeding frequency by a preset step size.

2. The flue gas desulfurization system according to claim 1, characterized in that, It also includes: flue gas regulating valve assembly, including: a flue gas flow regulating valve disposed in at least one of the following locations: flue gas diversion pipeline, coarse desulfurization branch pipeline, fine desulfurization branch pipeline, which regulates the proportion of flue gas entering from the total flue gas inlet into the coarse desulfurization unit and the fine desulfurization unit; The flue gas regulating valve assembly includes: a coarse desulfurization flue gas branch valve, installed on the coarse desulfurization branch pipeline; and a fine desulfurization flue gas branch valve, installed on the fine desulfurization branch pipeline; both are electrically controlled valves. The control device has its control signal output terminal connected to: the coarse desulfurization flue gas branch valve and the fine desulfurization flue gas branch valve; The control device executes the following control logic: The control logic of the flue gas regulating valve assembly is as follows: its initial state is that the fine desulfurization flue gas branch valve is at its minimum opening and the coarse desulfurization flue gas branch valve is at its maximum opening. In the control logic of the first new agent feeder: if C1≥C11 and the first new agent feeder has reached the maximum feeding frequency, the control logic of the flue gas regulating valve component is invoked, and the opening of the fine desulfurization flue gas branch valve is reduced according to the preset step size; if C1≤C12 and the first new agent feeder has reached the minimum feeding frequency, the control logic of the flue gas regulating valve component is invoked, and the opening of the fine desulfurization flue gas branch valve is increased according to the preset step size. In the control logic of the circulating agent feeder: if C2≥C21 and the circulating agent feeder has reached the maximum feeding frequency, the control logic of the flue gas regulating valve component is invoked, and the opening of the coarse desulfurization flue gas branch valve is reduced according to the preset step size; if C2≤C22 and the circulating agent feeder has reached the minimum feeding frequency, the control logic of the flue gas regulating valve component is invoked, and the opening of the coarse desulfurization flue gas branch valve is increased.

3. The flue gas desulfurization system according to claim 2, characterized in that, Also includes: The second new agent injection port is set in the coarse desulfurization branch pipeline and / or the coarse desulfurization device, which injects the new desulfurizing agent used for the first time into the flue gas flowing through it. The second new agent feeder is connected to the new agent silo on its upstream side and to the second new agent spray nozzle on its downstream side. The second new agent feeder is an electronically controlled frequency converter feeder; the control signal output terminal of the control device is connected to the control terminal of the second new agent feeder. The control device executes the following control logic: Second fresh agent feeder control logic: During normal operation, the second fresh agent feeder is not activated; When C1≥C11 and C2≥C21, and both the first new agent feeder and the circulating agent feeder reach their maximum frequency, the automatic interlock switch is triggered: ① The second new agent feeder starts automatically; ② At the same time, the opening of the coarse desulfurization flue gas branch valve is increased according to the preset step size; ③ At the same time, the opening of the fine desulfurization flue gas branch valve is decreased according to the preset step size. When C1≤C12 and C2≤C21, the automatic interlock switch is triggered, shutting down the second new agent feeder.

4. The flue gas desulfurization system according to claim 3, characterized in that, The control device executes the following control logic: after adjusting the first new agent feeder, the circulating feeder, the second new agent feeder, and the flue gas regulating valve assembly, it stabilizes for a preset time and then re-executes the control logic of the first new agent feeder, the circulating feeder, the flue gas regulating valve assembly, and the second new agent feeder. And / or, the sensor group includes: a coarse desulfurization flue gas flow sensor and a fine desulfurization flue gas flow sensor, respectively installed in the coarse desulfurization branch pipeline and the fine desulfurization branch pipeline, both used to provide feedback on the flue gas flow rate passing through the coarse desulfurization flue gas branch valve and the fine desulfurization flue gas branch valve.

5. The flue gas desulfurization system according to claim 1, characterized in that, It also includes: a silo pump, the upstream side of which is connected to the discharge port of the coarse desulfurization unit; and a waste agent silo, the upstream side of which is connected to the downstream side of the silo pump and isolated from the circulating agent silo; wherein, the silo pump transports the waste desulfurization agent discharged from the discharge port to the waste agent silo. And / or, the first new agent injection port is located in the fine desulfurization branch pipeline; And / or, the circulating agent injection port and the second new agent injection port are located in the coarse desulfurization branch pipeline.

6. The flue gas desulfurization system according to claim 5, characterized in that, A first gate valve is provided between the upstream side of the first new agent feeder and the new agent silo; And / or, a second gate valve is provided between the upstream side of the second new agent feeder and the new agent hopper; And / or, a third gate valve is provided between the discharge port of the coarse desulfurization unit and the upstream side of the silo pump; And / or, a fourth gate valve is provided between the discharge port of the fine desulfurization unit and the circulating agent silo; And / or, a fifth gate valve is provided between the circulating agent silo and the circulating agent feeder; And / or, it also includes: a first new agent pneumatic conveying device, which conveys the new desulfurizing agent supplied by the first new agent feeder to the first new agent injection port by pneumatic conveying; And / or, also includes: a second new agent pneumatic conveying device, which conveys the new desulfurizing agent supplied by the second new agent feeder to the second new agent injection port by pneumatic conveying; And / or, also includes: a circulating agent pneumatic conveying device, which conveys the circulating desulfurizing agent supplied by the circulating agent feeder to the circulating agent injection port by pneumatic conveying.

7. The flue gas desulfurization system according to any one of claims 1 to 6, characterized in that, In the desulfurization unit, the coarse desulfurization unit and the fine desulfurization unit are arranged side by side and integrated. The crude desulfurization unit includes: There are M coarse desulfurization chambers, where M ≥ 1; The coarse desulfurization flue gas transfer structure is located on the side away from the fine desulfurization unit and includes: a flue gas inlet chamber and a flue gas outlet chamber; wherein, the upstream side of the flue gas inlet chamber is connected to the flue gas inlet of the coarse desulfurization unit, and the downstream side is connected to the coarse desulfurization chamber; the upstream side of the flue gas outlet chamber is connected to the coarse desulfurization chamber. Fine desulfurization unit, including: There are N desulfurization chambers, where N≥1; The flue gas transfer structure for fine desulfurization is located on the side away from the coarse desulfurization unit and includes: a flue gas inlet chamber and a flue gas outlet chamber; wherein, the downstream side of the flue gas inlet chamber is connected to the fine desulfurization chamber; the upstream side of the flue gas outlet chamber is connected to the fine desulfurization chamber, and the downstream side is connected to the flue gas outlet of the flue gas fine desulfurization unit. It also includes: a conveying pipeline, which is located behind the coarse desulfurization unit and the fine desulfurization unit or is a separate pipeline, with its upstream side connected to the downstream side of the flue gas outlet chamber of the coarse desulfurization flue gas transfer structure, and its downstream side connected to the upstream side of the flue gas inlet chamber of the fine desulfurization flue gas transfer structure.

8. The flue gas desulfurization system according to claim 7, characterized in that, M≥2, M coarse desulfurization chambers are set up in parallel; And / or, N≥2, N desulfurization chambers are set up in parallel; And / or, both the coarse desulfurization flue gas transfer structure and the fine desulfurization flue gas transfer structure include: a structural body, which is a hollow box-shaped structure; and a flue gas baffle, which is obliquely arranged in the structural body to divide the internal space of the hollow box-shaped structure into two parts: a flue gas inlet chamber and a flue gas outlet chamber. And / or, both the coarse desulfurization chamber and the fine desulfurization chamber include: internally installed desulfurization filter bags; and ash hoppers installed at the bottom; for the coarse desulfurization device, the downstream side of the flue gas inlet chamber is connected to the ash hoppers of M coarse desulfurization chambers; and the upstream side of the flue gas outlet chamber is connected to the upper part of the M coarse desulfurization chambers; for the fine desulfurization device, the downstream side of the flue gas inlet chamber is connected to the ash hoppers of N fine desulfurization chambers; and the upstream side of the flue gas outlet chamber is connected to the upper space of the N fine desulfurization chambers. And / or, the total flue gas outlet is connected to a high-altitude chimney via an induced draft fan.

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