Flue gas treatment device and method for improving the flue gas treatment device

Abstract

The goal is to improve the processing capacity of the flue gas treatment system. [Solution] The system comprises an exhaust gas passage through which exhaust gas flows, a desulfurization device provided in the exhaust gas passage to remove sulfur oxides contained in the exhaust gas, and a blower provided in the exhaust gas passage to blow the exhaust gas. The blower has a first blower and a second blower having a smaller capacity than the first blower, and the first blower and the second blower are arranged in parallel in the exhaust gas passage.

Description

Technical Field

[0001] The present disclosure relates to a flue gas treatment device.

Background Art

[0002] A flue gas treatment device provided in a thermal power generation facility or the like includes a heat recovery device, an electrostatic precipitator, a desulfurization device, a reheating device, and the like. The flue gas discharged from the boiler is removed of the dust contained therein by the electrostatic precipitator, and the sulfurous acid gas contained therein is removed by the desulfurization device. At this time, the heat recovery device recovers heat from the flue gas. The reheating device reheats the desulfurized flue gas by the heat recovered by the heat recovery device to suppress the discharge of white smoke.

[0003] In the flue gas treatment device, a desulfurization blower (BUF / boost up fan) for blowing the flue gas from the boiler to the desulfurization device is disposed in the flue gas passage. The desulfurization blower is disposed, for example, on the downstream side of the desulfurization device in the flue gas passage, and attracts the flue gas from the boiler and sends it into the desulfurization device. As a conventional flue gas treatment device, for example, there is one described in Patent Document 1 below.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The desulfurization blower installed in the flue gas treatment system is a large variable-blade / variable-displacement type blower. The flow rate of exhaust gas from the boiler fluctuates depending on the boiler's operating conditions. For example, the flow rate of exhaust gas increases or decreases depending on the properties and moisture content of the fuel used in the boiler (e.g., coal). Therefore, the desulfurization blower adjusts the opening of its blades according to the flow rate of exhaust gas. However, the flow rate of exhaust gas also increases due to the aging deterioration of the thermal power generation equipment, including the flue gas treatment system. For example, due to the aging deterioration of the boiler, the amount of fuel used to obtain a predetermined generator output increases, resulting in an increase in the amount of exhaust gas. In the flue gas treatment system, holes may form in the flue, allowing air to flow in from the outside into the exhaust gas passage, increasing the flow rate of exhaust gas. In addition, solid components contained in the exhaust gas adhere and accumulate inside the flue gas treatment system, increasing the pressure loss (resistance) in the exhaust gas passage. Therefore, even when the desulfurization blower is operated at maximum output, it may not be possible to secure the rated load. In this case, it is conceivable to increase the maximum output by modifying the desulfurization blower. However, because the desulfurization blower is large and has a complex structure, modification costs will increase, and the modification period will be longer, resulting in a prolonged downtime for the desulfurization equipment.

[0006] This disclosure aims to solve the aforementioned problems and provide a flue gas treatment device that improves processing capacity. [Means for solving the problem]

[0007] To achieve the above objectives, the flue gas treatment apparatus of the present disclosure comprises an exhaust gas passage through which exhaust gas flows, a desulfurization apparatus provided in the exhaust gas passage for removing sulfur oxides contained in the exhaust gas, and a blower provided in the exhaust gas passage for blowing the exhaust gas, wherein the blower comprises a first blower and a second blower having a capacity smaller than that of the first blower, and the first blower and the second blower are arranged in parallel in the exhaust gas passage. [Effects of the Invention]

[0008] The flue gas treatment apparatus of this disclosure can improve treatment capacity. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a schematic diagram showing the flue gas treatment apparatus of this embodiment. [Figure 2] Figure 2 is a schematic diagram showing the blower device of this embodiment. [Figure 3] Figure 3 is a graph illustrating the performance of the blower device in this embodiment. [Figure 4] Figure 4 is a schematic diagram showing the control system of the blower device in this embodiment. [Figure 5] Figure 5 is a schematic diagram showing a first modified example of the control system of the blower device of this embodiment. [Figure 6] Figure 6 is a schematic diagram showing a second modified example of the control system of the blower device of this embodiment. [Figure 7] Figure 7 is a schematic diagram showing a third modified example of the control system of the blower device according to this embodiment. [Modes for carrying out the invention]

[0010] Preferred embodiments of the present disclosure will be described in detail below with reference to the drawings. However, these embodiments do not limit the present disclosure, and where there are multiple embodiments, they may be combinations of these embodiments. Furthermore, the components in the embodiments include those readily conceivable by those skilled in the art, those that are substantially identical, and those that are equivalent.

[0011] [Smoke exhaust treatment system] Figure 1 is a schematic diagram showing the flue gas treatment apparatus of this embodiment.

[0012] As shown in Figure 1, the flue gas treatment device 100 removes harmful substances such as soot and sulfur oxides (SOx) contained in the flue gas (flue) G discharged from the boiler 111 in various power plants and factories as it is released from the chimney 112.

[0013] The flue gas treatment device 100 includes a heat recovery device 101, an electrostatic precipitator 102, a blower (induced draft fan) 103, a desulfurization device 104, a reheating device 105, and a blower (desulfurization fan) 106. The flue gas treatment device 100 has a first treatment system that sends the exhaust gas G discharged from the boiler 111 to the chimney 112 through the heat recovery device 101, the electrostatic precipitator 102, and the blower 103, and a second treatment system that sends the exhaust gas G discharged from the boiler 111 to the chimney 112 through the heat recovery device 101, the electrostatic precipitator 102, the blower 103, the desulfurization device 104, the reheating device 105, and the blower (desulfurization fan) 106.

[0014] In the first treatment system, when the blower 103 is driven, the exhaust gas G discharged from the boiler 111 is sent to the chimney 112 through the heat recovery unit 101 and the electrostatic precipitator 102. In the second treatment system, when the blowers 103 and 106 are driven, the exhaust gas G discharged from the boiler 111 is sent to the chimney 112 through the heat recovery unit 101, the electrostatic precipitator 102, the desulfurization unit 104, and the reheating unit 105. Note that the arrangement of each device is not limited to the arrangement described above. For example, the order from the exhaust gas upstream side may be the blower (desulfurization blower) 106, the desulfurization unit 104, and the reheating unit 105, or the order may be the desulfurization unit 104, the blower (desulfurization blower) 106, and the reheating unit 105.

[0015] The boiler 111 is provided with two exhaust gas passages 121a and 121b. However, it may also be provided with one exhaust gas passage. Exhaust gas passage 121a is provided with a heat recovery device 101a, an electrostatic precipitator 102a, and a blower 103a, while exhaust gas passage 121b is provided with a heat recovery device 101b, an electrostatic precipitator 102b, and a blower 103b. The two exhaust gas passages 121a and 121b merge downstream into exhaust gas passage 121c. Exhaust gas passage 121c branches into two exhaust gas passages 121d and 121e. Exhaust gas passage 121d constitutes part of the first treatment system, is provided with an on / off valve 122 in the middle, and is connected downstream to the chimney 112.

[0016] The exhaust gas passage 121e constitutes the second treatment system, and a desulfurization device 104 and a reheating device 105 are provided. The downstream side of the exhaust gas passage 121e branches into two exhaust gas passages 121f and 121g. A blower device 106a is provided in the exhaust gas passage 121f, and a blower device 106b is provided in the exhaust gas passage 121g. The downstream sides of the two exhaust gas passages 121f and 121g merge into an exhaust gas passage 121h. Then, the exhaust gas passage 121d that constitutes a part of the first treatment system and the exhaust gas passage 121h that constitutes a part of the second treatment system merge into an exhaust gas passage 121i on the downstream side. The exhaust gas passage 121i is connected to the chimney 112.

[0017] The heat recovery device 101(101a, 101b) recovers heat from the exhaust gas G (about 140 °C) by exchanging heat between the exhaust gas G discharged from the boiler 111 and a heat medium (such as water). The exhaust gas G (about 90 °C) from which heat has been recovered by the heat recovery device 101 is introduced into the electrostatic precipitator 102(102a, 102b). The electrostatic precipitator 102 removes dust from the exhaust gas G.

[0018] The exhaust gas G from which dust has been removed by the electrostatic precipitator 102 is partially or entirely introduced into the desulfurization device 104. The desulfurization device 104 absorbs and removes sulfur oxides in the exhaust gas G with limestone (CaCO3) and generates gypsum (CaSO4·2H2O) as a by-product. The desulfurization device 104 has a mist eliminator 123. The mist eliminator 123 removes mist from the exhaust gas G after desulfurization.

[0019] The exhaust gas G (about 50°C) desulfurized by the desulfurization device 104 is introduced into the reheating device 105 of the gas-gas heater. In the process of circulating the heat medium between the reheating device 105 and the heat recovery device 101, the exhaust gas G is reheated by the heat recovered by the heat recovery device 101. The heat recovery device 101 and the reheating device 105 are connected by a first heat medium circulation line L11 and a second heat medium circulation line L12. The first heat medium circulation line L11 is provided with a circulation pump 131. By driving the circulation pump 131, the heat medium of the reheating device 105 is returned to the heat recovery device 101 through the first heat medium circulation line L11. The second heat medium circulation line L12 is provided with a heater 132. The circulation pump 131 supplies the heat medium of the heat recovery device 101 to the reheating device 105 through the second heat medium circulation line L12. In this process, the heat medium is heated by operating the heater 132 as necessary.

[0020] The temperature of the exhaust gas G decreases due to desulfurization treatment in the desulfurization device 104, and if it remains at a low temperature, it is difficult to diffuse and may become white smoke. The reheating device 105 reheats the exhaust gas G for the purpose of diffusion and white smoke reduction to raise the temperature (about 90°C) and discharges it into the atmosphere from the chimney 112. Note that the temperature of the exhaust gas G described above is an example and is not limited.

[0021] [Configuration of the Blower Device] In the present embodiment, the blower device will be described as being applied to the blower device 106 described above. That is, the blower device will be described as being applied to the blower device 106a arranged in the exhaust gas passage 121f or the blower device 106b arranged in the exhaust gas passage 121g. In this case, the blower device is not limited to having two blower devices 106a and 106b respectively arranged in a plurality of parallel exhaust gas passages 121f and 121g, and may have one blower device arranged in one exhaust gas passage. Further, the flue gas treatment device 100 is not limited to the above-described configuration. That is, the flue gas treatment device 100 only needs to be provided with a desulfurization device and a blower device in at least the exhaust gas passage.

[0022] Figure 2 is a schematic diagram showing the blower device of the present embodiment.

[0023] As shown in Figure 2, the flue gas treatment device 100 comprises an exhaust gas passage 121f (121g), a desulfurization device 104, and a blower 106a (106b).

[0024] The exhaust gas passage 121f carries the exhaust gas G that has been treated by the desulfurization unit 104. The exhaust gas passage 121f has one first exhaust gas passage 11 and a plurality (three in this embodiment) second exhaust gas passages 12, 13, and 14. That is, the exhaust gas passage 121f branches into four: one first exhaust gas passage 11 and three second exhaust gas passages 12, 13, and 14, and the four exhaust gas passages 11, 12, 13, and 14 merge downstream in the flow direction of the exhaust gas G. However, the number of second exhaust gas passages 12, 13, and 14 is not limited to three, and may be one or more.

[0025] The desulfurization unit 104 is installed in the exhaust gas passage 121f. The desulfurization unit 104 removes sulfur oxides contained in the exhaust gas G. The desulfurization unit 104 is the same as the one described above, so its explanation is omitted.

[0026] The blower 106a is installed in the exhaust gas passage 121f. The blower 106a blows the exhaust gas G in the exhaust gas passage 121f. The blower 106a is installed downstream of the desulfurization unit 104 in the exhaust gas passage 121f in the direction of the flow of exhaust gas G. However, the blower 106a may be installed upstream of the desulfurization unit 104 in the direction of the flow of exhaust gas G in the exhaust gas passage 121f.

[0027] The blower 106a has one first blower 21 and a plurality (three in this embodiment) of second blowers 22, 23, 24. The one first blower 21 and the four second blowers 22, 23, 24 are arranged in parallel in the exhaust gas passages 121a and 121b. That is, the first blower 21 is located in the first exhaust gas passage 11. The second blower 22 is located in the second exhaust gas passage 12. The second blower 23 is located in the second exhaust gas passage 13. The second blower 24 is located in the second exhaust gas passage 14.

[0028] The first blower 21 is a large variable displacement blower. The first blower 21 has, for example, a motor with a rated output of 2000 kW. The first blower 21 is a variable displacement type in which the opening of the rotor blades can be changed. The second blowers 22, 23, and 24 are blowers with a smaller capacity than the first blower 21. The second blowers 22, 23, and 24 are small fixed displacement blowers. The second blowers 22, 23, and 24 have, for example, a motor with a rated output of 150 kW. The second blowers 22, 23, and 24 are fixed displacement types in which the opening of the rotor blades is fixed.

[0029] The first blower 21 is a conventional blower. The blower 106a of this embodiment is the first blower 21 with the addition of second blowers 22, 23, and 24. The blower 106a controls the first blower 21 according to the flow rate of exhaust gas G flowing through the exhaust gas passage 121f, for example, and adjusts the opening of the rotor blades. The blower 106a also controls the operation and stopping of the second blowers 22, 23, and 24 according to the flow rate of exhaust gas G flowing through the exhaust gas passage 121f, for example.

[0030] [Effects and Effects of Air Blower Devices] Figure 3 is a graph illustrating the performance of the blower device in this embodiment.

[0031] The solid line in Figure 3 is a performance curve showing the airflow and air pressure in the blower 121 when the opening of the rotor blades of the first blower 21 is between 80% and 100%. Here, a conventional blower consists only of the first blower 21. The blower 106a of the embodiment consists of the first blower 21 and second blowers 22, 23, and 24.

[0032] The blade opening angle indicates that the greater the value, the greater the capacity to expel exhaust gas G. As shown in Figure 3, compared to the performance curve of a conventional blower that drives only the first blower 21, the operating point of the blower 106a in this embodiment, which drives both the first blower 21 and the second blowers 22, 23, and 24, shows a decrease in the airflow of the first blower 21 at the same air pressure. This improvement in the operating point corresponds to a decrease in the blade opening angle of the first blower 21, and allows for a margin in the exhaust gas G expelling capacity of the first blower 21. Therefore, the first blower 21 and the second blowers 22, 23, and 24 of the blower 106a in this embodiment can handle an increase in exhaust gas G.

[0033] [Control system for the blower] Figure 4 is a schematic diagram showing the control system of the blower device in this embodiment.

[0034] As shown in Figure 4, the flue gas treatment device 100 comprises an exhaust gas passage 121f (121g), a desulfurization device 104 (see Figure 1), a blower 106a (106b), and a control device 31.

[0035] The blower 106a comprises one first blower 21 and a plurality (three in this embodiment) of second blowers 22, 23, and 24. The first blower 21 is located in the first exhaust gas passage 11, and the second blowers 22, 23, and 24 are located in the second exhaust gas passages 12, 13, and 14, respectively. The first blower 21 is a large variable-displacement blower. The second blowers 22, 23, and 24 are small fixed-displacement blowers with a capacity smaller than that of the first blower 21.

[0036] The control device 31 is connected to the first blower 21 and the second blowers 22, 23, and 24. The control device 31 can control the stopping of the operation of the first blower 21 and can also control the opening of the rotor blades. In addition, the control device 31 can control the stopping of the operation of the second blowers 22, 23, and 24.

[0037] The control device 31 can control the second blowers 22, 23, and 24 according to the operating state of the first blower 21. For example, the control device 31 controls the driving and stopping of the second blowers 22, 23, and 24 according to the blade opening of the first blower 21.

[0038] Specifically, the control device 31 controls the number of drives in the multiple second blowers 22, 23, and 24 according to the operating state (moving blade opening) of the first blower 21. For example, the control device 31 increases the number of drives in the multiple second blowers 22, 23, and 24 as the moving blade opening of the first blower 21 increases, thereby increasing the total flow rate of exhaust gas G that can be blown by the entire blower 106a (106b), lowering the moving blade opening of the first blower 21, and providing a margin in the capacity of the first blower 21 to send out exhaust gas G, so that the first blower 21 and the second blowers 22, 23, and 24 of the blower 106a (106b) can cope with the increase in exhaust gas G.

[0039] Furthermore, the control device 31 controls the rotational speeds of the multiple second blowers 22, 23, and 24 according to the operating state (moving blade opening) of the first blower 21. For example, the control device 31 increases the rotational speeds of the multiple second blowers 22, 23, and 24 in accordance with the increase in the moving blade opening of the first blower 21, thereby increasing the total flow rate of exhaust gas G that can be blown by the entire blower 106a (106b), lowering the moving blade opening of the first blower 21, and providing a margin in the capacity of the first blower 21 to send out exhaust gas G, so that the first blower 21 and the second blowers 22, 23, and 24 of the blower 106a (106b) can cope with the increase in exhaust gas G.

[0040] In this case, the control device 31 adjusts the blade opening of the first blower 21 as the operating state so that, for example, the pressure of the exhaust gas G downstream of the blower 106a in the exhaust gas passage 121f in the direction of the flow of exhaust gas G reaches a predetermined pressure. Therefore, the blade opening of the first blower 21 is a command value for the first blower 21.

[0041] [First modified example of the control system for a blower] Figure 5 is a schematic diagram showing a first modified example of the control system of the blower device of this embodiment.

[0042] As shown in Figure 5, the flue gas treatment device 100 includes an exhaust gas passage 121f (121g), a desulfurization device 104 (see Figure 1), a blower 106a (106b), a control device 31, and a pressure sensor 32.

[0043] The control device 31 can control the second blowers 22, 23, and 24 according to the operating state of the first blower 21. For example, the control device 31 controls the driving and stopping of the second blowers 22, 23, and 24 according to the pressure of the exhaust gas G in the exhaust gas passage 121f. The pressure sensor 32 is located downstream of the blower 106a (106b) in the exhaust gas passage 121f in the direction of the flow of the exhaust gas G and detects the pressure of the exhaust gas G. Alternatively, the pressure sensor 32 may be located upstream of the blower 106a in the direction of the flow of the exhaust gas G in the exhaust gas passage 121f and detect the pressure of the exhaust gas G.

[0044] Specifically, the control device 31 controls the number of driven units in the multiple second blowers 22, 23, and 24 according to the operating state (pressure of exhaust gas G) of the first blower 21. For example, the control device 31 increases the number of driven units in the multiple second blowers 22, 23, and 24 as the pressure of exhaust gas G decreases, thereby increasing the total flow rate of exhaust gas G that can be blown by the entire blower 106a (106b), lowering the blade opening of the first blower 21, and providing a margin in the capacity of the first blower 21 to send out exhaust gas G, so that the first blower 21 and the second blowers 22, 23, and 24 of the blower 106a (106b) can cope with an increase in exhaust gas G.

[0045] Furthermore, the control device 31 controls the rotational speed of the multiple second blowers 22, 23, and 24 according to the operating state of the first blower 21 (pressure of exhaust gas G). For example, the control device 31 increases the rotational speed of the multiple second blowers 22, 23, and 24 as the pressure of exhaust gas G decreases, thereby increasing the total flow rate of exhaust gas G that can be blown by the entire blower 106a (106b), lowering the rotor blade opening in the first blower 21, and providing a margin in the capacity of the first blower 21 to blow out exhaust gas G, so that the first blower 21 and the second blowers 22, 23, and 24 of the blower 106a (106b) can cope with an increase in exhaust gas G.

[0046] [Second modified example of the control system for the blower] Figure 6 is a schematic diagram showing a second modified example of the control system of the blower device of this embodiment.

[0047] As shown in Figure 1, the exhaust gas passage 121c is provided in parallel with the exhaust gas passage 121d, which constitutes part of the first treatment system, and the exhaust gas passage 121e, which constitutes part of the second treatment system. The exhaust gas passage 121d, which constitutes part of the first treatment system, is provided with an on-off valve 122, and the exhaust gas passage 121e, which constitutes part of the second treatment system, is provided with a desulfurization device 104. That is, when the exhaust gas G is not to be desulfurized, the on-off valve 122 is opened and the exhaust gas G flows into the exhaust gas passage 121d. On the other hand, when the exhaust gas G is to be desulfurized, the on-off valve 122 is closed and the exhaust gas G flows into the exhaust gas passage 121e.

[0048] As shown in Figure 6, the flue gas treatment device 100 includes an exhaust gas passage 121f (121g), a desulfurization device 104 (see Figure 1), a blower 106a (106b), a control device 31, and a differential pressure sensor 33.

[0049] The control device 31 can control the second blowers 22, 23, and 24 according to the operating state of the first blower 21. When the on-off valve 122 is closed, the control device 31 controls the driving and stopping of the second blowers 22, 23, and 24 according to the differential pressure between the exhaust gas G pressure in the exhaust gas passage 121d and the exhaust gas G pressure in the exhaust gas passage 121e. The differential pressure sensor 33 detects the differential pressure (P2 / P1) between the exhaust gas G pressure P1 at the downstream end of the exhaust gas passage 121d (downstream of the on-off valve 122) and the exhaust gas G pressure P2 at the downstream end of the exhaust gas passage 121e (downstream of the reheating device 105).

[0050] Specifically, when the on-off valve 122 is closed, the control device 31 controls the number of driven units in the multiple second blowers 22, 23, and 24 according to the operating state (differential pressure of exhaust gas G) of the first blower 21. For example, the control device 31 increases the number of driven units in the multiple second blowers 22, 23, and 24 as the differential pressure of exhaust gas G decreases, thereby increasing the total flow rate of exhaust gas G that can be blown by the entire blower 106a (106b), lowering the rotor blade opening of the first blower 21, and providing a margin in the capacity of the first blower 21 to blow out exhaust gas G, so that the first blower 21 and the second blowers 22, 23, and 24 of the blower 106a (106b) can cope with an increase in exhaust gas G.

[0051] Furthermore, when the on-off valve 122 is closed, the control device 31 controls the rotational speed of the multiple second blowers 22, 23, and 24 according to the operating state of the first blower 21 (differential pressure of the exhaust gas G) and the pressure of the exhaust gas G. For example, the control device 31 increases the rotational speed of the multiple second blowers 22, 23, and 24 as the differential pressure of the exhaust gas G decreases, thereby increasing the total flow rate of exhaust gas G that can be blown by the entire blower 106a (106b), lowering the rotor blade opening in the first blower 21, and giving the first blower 21 more capacity to blow out the exhaust gas G, so that the first blower 21 and the second blowers 22, 23, and 24 of the blower 106a (106b) can cope with an increase in exhaust gas G.

[0052] [Third modified example of the control system for a blower] Figure 7 is a schematic diagram showing a third modified example of the control system of the blower device according to this embodiment.

[0053] As shown in Figure 7, the blower 106a has one first blower 21 and three second blowers 22, 23, and 24. The first blower 21 is located in the first exhaust gas passage 11, and the second blowers 22, 23, and 24 are located in the second exhaust gas passages 12, 13, and 14, respectively. In the second exhaust gas passage 12, an on-off valve 41 is located downstream of the second blower 22, and a flow control valve 51 is located upstream. In the second exhaust gas passage 13, an on-off valve 42 is located downstream of the second blower 23, and a flow control valve 52 is located upstream. In the second exhaust gas passage 14, an on-off valve 43 is located downstream of the second blower 24, and a flow control valve 53 is located upstream.

[0054] The on-off valves 41, 42, and 43 are switchable valves that allow the second exhaust gas passages 12, 13, and 14 to be either open or closed. The flow rate control valves 51, 52, and 53 are valves that allow the flow rate of exhaust gas G flowing through the second exhaust gas passages 12, 13, and 14 to be adjusted by adjusting the degree of opening. The control device 31 is connected to the on-off valves 41, 42, and 43 and the flow rate control valves 51, 52, and 53. The control device 31 can open and close the on-off valves 41, 42, and 43 and can control the degree of opening of the flow rate control valves 51, 52, and 53.

[0055] The control device 31 can control the on / off valves 41, 42, 43 and the flow control valves 51, 52, 53 according to the operating state of the first blower 21. The control device 31 controls the driving and stopping of the second blowers 22, 23, 24 according to the blade opening of the first blower 21, the pressure of the exhaust gas G in the exhaust gas passage 121f, the differential pressure of the exhaust gas G, etc.

[0056] Specifically, the control device 31 controls the opening of the on-off valves 41, 42, 43 and the flow control valves 51, 52, 53 to the open side in response to an increase in the rotor blade opening of the first blower 21, a decrease in the pressure of the exhaust gas G in the exhaust gas passage 121f, and a decrease in the differential pressure of the exhaust gas G. This increases the total flow rate of exhaust gas G that can be blown by the entire blower 106a (106b), lowers the rotor blade opening of the first blower 21, and provides a margin in the capacity of the first blower 21 to blow out the exhaust gas G. As a result, the first blower 21 and the second blowers 22, 23, 24 of the blower 106a (106b) can respond to an increase in exhaust gas G.

[0057] Furthermore, the control device 31 controls the number of open valves 41, 42, 43 and flow control valves 51, 52, 53 to increase in response to an increase in the rotor blade opening of the first blower 21, a decrease in the pressure of the exhaust gas G in the exhaust gas passage 121a, and a decrease in the differential pressure of the exhaust gas G. This increases the total flow rate of exhaust gas G that can be blown by the entire blower 106a (106b), lowers the rotor blade opening of the first blower 21, and provides a margin in the capacity of the first blower 21 to blow out the exhaust gas G. As a result, the first blower 21 and the second blowers 22, 23, 24 of the blower 106a (106b) can respond to an increase in exhaust gas G. Additionally, the valves 41, 42, 43 may be located upstream of the second blowers 22, 23, 24 in the second exhaust gas passages 12, 13, 14.

[0058] [Effects of this embodiment] The flue gas treatment device according to the first embodiment comprises exhaust gas passages 121f, 121g through which exhaust gas G flows, a desulfurization device 104 provided in the exhaust gas passages 121f, 121g to remove sulfur oxides contained in the exhaust gas G, and blowers 106a, 106b provided in the exhaust gas passages 121f, 121g to blow the exhaust gas G, wherein the blowers 106a, 106b have a first blower 21 and second blowers 22, 23, 24 having a smaller capacity than the first blower 21, and the first blower 21 and the second blowers 22, 23, 24 are arranged in parallel in the exhaust gas passages 121f, 121g.

[0059] According to the first embodiment of the flue gas treatment device, by arranging second blowers 22, 23, and 24, which have a smaller capacity than the first blower 21, in parallel with the exhaust gas passages 121f and 121g, the capacity can be changed without modifying the first blower 21, thereby improving the treatment capacity.

[0060] The flue gas treatment device according to the second embodiment is the same as the flue gas treatment device according to the first embodiment, further comprising a plurality of second blowers 22, 23, and 24 arranged in parallel in the exhaust gas passages 121f and 121g. This allows the capacity to be changed in stages by individually operating or stopping the second blowers 22, 23, and 24.

[0061] The third embodiment of the flue gas treatment device is a flue gas treatment device according to the first or second embodiment, further comprising a first blower 21 which is a variable-blade / variable-capacity blower and second blowers 22, 23, and 24 which are fixed-blade blowers. This allows for adjustment of the opening of the blades in the first blower 21 in response to fluctuations in the flow rate of the exhaust gas G, as well as individual operation or deactivation of the second blowers 22, 23, and 24.

[0062] The fourth embodiment of the flue gas treatment device is a flue gas treatment device according to any one of the first to third embodiments, and further includes a control device 31 connected to a first blower 21 and second blowers 22, 23, 24, the control device 31 controls the second blowers 22, 23, 24 according to the operating state of the first blower 21. By controlling not only the first blower 21 but also the second blowers 22, 23, 24, it is possible to respond appropriately to fluctuations in the flow rate of the exhaust gas G.

[0063] The exhaust gas treatment device according to the fifth embodiment is an exhaust gas treatment device according to the fourth embodiment, wherein the control device 31 further controls the driving and stopping of the second blowers 22, 23, and 24 according to the rotor blade opening of the first blower 21. This makes it possible to appropriately drive and stop the second blowers 22, 23, and 24 according to the operating state of the first blower 21.

[0064] The flue gas treatment device according to the sixth embodiment is the flue gas treatment device according to the fifth embodiment, further comprising a control device 31 that controls the second blowers 22, 23, and 24 according to the pressure of the exhaust gas G in the exhaust gas passages 121a and 121b. This makes it possible to maintain the pressure of the exhaust gas G in the exhaust gas passages 121a and 121b at an appropriate value, thereby stabilizing the desulfurization treatment.

[0065] The flue gas treatment device according to the seventh embodiment is a flue gas treatment device according to the fifth or sixth embodiment, further comprising a plurality of second blowers 22, 23, and 24 arranged in parallel in the exhaust gas passages 121a and 121b, and the control device 31 controls the number of driven units in the plurality of second blowers 22, 23, and 24 according to the operating state of the first blower 21. This simplifies control in response to fluctuations in the flow rate of exhaust gas G.

[0066] The flue gas treatment device according to the eighth embodiment is a flue gas treatment device according to any one of the fifth to seventh embodiments, and further, the control device 31 controls the rotational speed of the second blowers 22, 23, and 24 according to the operating state of the first blower 21. This enables precise adjustment control in response to fluctuations in the flow rate of the exhaust gas G.

[0067] The flue gas treatment device according to the ninth embodiment is a flue gas treatment device according to any one of the fifth to eighth embodiments, further comprising on-off valves (flow control valves) 41, 42, 43 on the upstream or downstream side of the second blowers 22, 23, 24 in the exhaust gas passages 121a, 121b, and the control device 31 controls the opening degree of the on-off valves 41, 42, 43 according to the operating state of the first blower 21. This enables precise adjustment control in response to fluctuations in the flow rate of the exhaust gas G.

[0068] The flue gas treatment device according to the tenth embodiment is a flue gas treatment device according to any one of the fifth to eighth embodiments, further comprising on-off valves 41, 42, and 43 downstream of the second blowers 22, 23, and 24 in the exhaust gas passages 121a and 121b, and the control device 31 controls the opening and closing of the on-off valves 41, 42, and 43 according to the operating state of the first blower 21. This simplifies the control in response to fluctuations in the flow rate of the exhaust gas G. [Explanation of Symbols]

[0069] 11. First exhaust gas passage 12, 13, 14 Second exhaust gas passage 21. First blower 22, 23, 24 Second blower 31 Control device 41, 42, 43 Shut-off valves 51, 52, 53 Flow control valve 100 Flue gas treatment equipment 101 Heat Recovery System 102 Electrostatic precipitator 103 Blower 104 Desulfurization equipment 105 Reheating device 106, 106a, 106b Blower 111 Boiler 112 Chimney 121a, 121b, 121c, 121d, 121e, 121f, 121g, 121h, 121i Exhaust gas passage 122 Shut-off valve 123 Mist Eliminator 131 Circulation pump 132 Heater G exhaust gas

Claims

1. The exhaust gas passage through which exhaust gas flows, A desulfurization device provided in the exhaust gas passage for removing sulfur oxides contained in the exhaust gas, A blower provided in the exhaust gas passage for blowing the exhaust gas, Equipped with, The blower comprises a first blower and a second blower having a capacity smaller than that of the first blower, and the first blower and the second blower are arranged in parallel in the exhaust gas passage. The system includes a control device connected to the first blower and the second blower, and the control device controls the second blower according to the operating state of the first blower. The first blower is a variable-blade / variable-capacity blower, and the second blower is a fixed-blade blower. The control device is capable of adjusting the opening degree of the rotor blades in the first blower and can operate or stop the second blower. Flue gas treatment device.

2. The second blower is arranged in parallel with the exhaust gas passage in multiple locations. The flue gas treatment apparatus according to claim 1.

3. The control device responds to the blade opening in the first blower. The driving and stopping of the second blower is controlled by The flue gas treatment apparatus according to claim 1.

4. The control device controls the second blower according to the pressure of the exhaust gas in the exhaust gas passage. The flue gas treatment apparatus according to claim 1.

5. Multiple second blowers are arranged in parallel in the exhaust gas passage, and the control device controls the number of driven units in the multiple second blowers according to the operating state of the first blower. The flue gas treatment apparatus according to claim 1.

6. The control device controls the rotation speed of the second blower according to the operating state of the first blower. The flue gas treatment apparatus according to claim 1.

7. A flow control valve is provided on the upstream or downstream side of the second blower in the exhaust gas passage, and the control device controls the opening degree of the flow control valve according to the operating state of the first blower. The flue gas treatment apparatus according to claim 1.

8. An on-off valve is provided downstream of the second blower in the exhaust gas passage, and the control device controls the opening and closing of the on-off valve according to the operating state of the first blower. The flue gas treatment apparatus according to claim 1.

9. The exhaust gas passage includes a first treatment system that sends exhaust gas G discharged from the boiler to the chimney through a third blower and an on-off valve, and a second treatment system that sends exhaust gas G discharged from the boiler to the chimney through a third blower and a desulfurization unit. The flue gas treatment apparatus according to claim 1.

10. An exhaust gas passage through which exhaust gas flows, A desulfurization device provided in the exhaust gas passage for removing sulfur oxides contained in the exhaust gas, A blower having a first blower installed in the exhaust gas passage for blowing the exhaust gas, In a flue gas treatment apparatus equipped with, As the aforementioned blowing device, a second blowing device having a smaller capacity than the first blowing device is added, and the first blowing device and the second blowing device are arranged in parallel in the exhaust gas passage. Methods for improving flue gas treatment equipment.

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