Flue gas de-whitening device and control method thereof

Abstract

The application provides a flue gas white smoke removal device and a control method thereof, which comprises a heat recovery section, the heat recovery section is connected with a mixing section through a condensation section, the condensation section is arranged vertically, the heat recovery section is located at one side of the lower part of the condensation section, and the mixing section is located at the top of the condensation section; an ambient fresh air inlet is arranged at the other side of the lower part of the condensation section, and an ambient fresh air inlet device is arranged in the ambient fresh air inlet. The flue gas white smoke removal device and the control method thereof are reasonable in structure, convenient and reliable to use, the energy consumption is reduced by simple water circulation and introduction of ambient fresh air, PID control is used to start and stop and adjust the air volume of the fresh air, waste heat is further recovered, the device can be directly installed and connected with a chimney, the modification of the existing system is small, the land occupation is small, the investment is small, the installation is simple, and maintenance is not required.

Description

Technical Field

[0001] The present invention relates to the technical field of machining accessories, and in particular to a flue gas decolorization device and a control method thereof. Background Art

[0002] Flue gas dewhitening is to eliminate the white flue gas emitted by industry (that is, the white flue gas commonly seen). One reason is that the dust content in the flue gas is high and the emission standards are not met; the other reason is that the ambient temperature is lower than the dew point corresponding to the exhaust temperature, causing the moisture in the flue gas to condense and form white smoke.

[0003] The first purpose of flue gas dewhitening is to more thoroughly remove harmful components in the flue gas, including reducing the emissions of nitrogen oxides, sulfides, various smoke particles, aerosols, and ultrafine crystalline salt particles; the second is to reduce the visual appearance of white smoke.

[0004] After the implementation of national environmental protection policies, the desulfurization and denitrification of flue gas is mostly removed by reheating, so that the flue gas temperature is greater than 75-80 ° C and converted to an unsaturated state. This method can effectively achieve flue gas desulfurization, but this method has obvious defects. The high-power reheating of boiler linkage and large amounts of exhaust gas causes waste of electricity and increased operating costs. For small boilers, the exhaust gas temperature is greater than 120 ° C, and there is especially waste of heat source. The reheating process is continuous and the energy consumption is high.

[0005] Therefore, the existing technology needs to be developed. Summary of the Invention

[0006] In view of the above-mentioned shortcomings of the prior art, an object of the present invention is to provide a flue gas desulfurization device and a control method thereof, so as to solve the problems existing in the prior art.

[0007] To achieve the above-mentioned and other related objectives, the present invention provides a flue gas desulfurization device, comprising: a heat recovery section, the heat recovery section being connected to a mixing section via a condensing section, wherein the condensing section is arranged vertically, the heat recovery section being located on one side of a lower portion of the condensing section, and the mixing section being located on top of the condensing section; an ambient fresh air inlet being provided on the other side of the lower portion of the condensing section, and an ambient fresh air intake device being provided in the ambient fresh air inlet;

[0008] The heat recovery section is provided with a steam-water fin-tube heat exchanger, the gas path side of the steam-water fin-tube heat exchanger is respectively provided with a first flue gas inlet and a first flue gas outlet, and the water side of the steam-water fin-tube heat exchanger is respectively provided with a circulating domestic hot water inlet and outlet, wherein the first flue gas inlet is connected to the chimney;

[0009] The inner cavity of the steam-water fin-tube heat exchanger is provided with a finned tube bundle, the tubes in the finned tube bundle connected to the domestic hot water inlet and outlet are water heat exchange channels, and the inner cavity in which the finned tube bundle is connected to the first flue gas inlet and first flue gas outlet of the steam-water fin-tube heat exchanger is the first flue gas heat exchange channel;

[0010] A steam-steam plate heat exchanger is provided in the condensing section, a second flue gas inlet is provided at the lower left end of the steam-steam plate heat exchanger, an ambient fresh air inlet is provided at the lower right end of the steam-steam plate heat exchanger, a second flue gas heat exchange channel and an ambient fresh air heat exchange channel are provided in the cavity of the steam-steam plate heat exchanger, and a second flue gas outlet and an ambient fresh air outlet are provided at the top of the steam-steam plate heat exchanger;

[0011] A smoke exhaust terminal mixing device is provided in the mixing section, and the smoke exhaust terminal mixing device is provided with an inlet and an outlet. The inlet of the smoke exhaust terminal mixing device is connected to the second smoke outlet of the steam-steam plate heat exchanger and the ambient fresh air outlet. A steam guide groove is provided in the cavity of the smoke exhaust terminal mixing device; the outlet of the smoke exhaust terminal mixing device is provided with a bird-proof net.

[0012] In one embodiment of the present invention, the bottom of the heat exchange channel cavity on the gas path side of the steam-water fin-tube heat exchanger and the steam-steam plate heat exchanger are both provided with a condensate drain port.

[0013] In one embodiment of the present invention, the bottom of the heat exchange channel cavity on the gas path side of the steam-water fin-tube heat exchanger and the steam-steam plate heat exchanger are both provided with a condensate drain port.

[0014] In one embodiment of the present invention, water flows in the water heat exchange channel of the steam-water fin-tube heat exchanger. The water pipes are high-efficiency internally threaded pipes, and the tube bundles are covered with high-efficiency corrugated fins, all of which are made of rust-proof and corrosion-resistant materials.

[0015] In one embodiment of the present invention, the exhaust terminal mixing device corresponds to the second flue gas outlet of the steam-steam plate heat exchanger and the ambient fresh air outlet, and spray cleaning components of the third flue gas heat exchange channel and the ambient air heat exchange channel are respectively arranged on both sides, and are provided with air dampers, which can be opened in the working state and closed in other states. The spray cleaning components include a first group of spray heads and a second group of spray heads. The first group of spray heads and the second group of spray heads are both connected to the spray water inlet pipe, and the spray water inlet pipe is directly connected to the high-pressure water pipeline to clean the third flue gas heat exchange channel and the ambient air heat exchange channel.

[0016] In one embodiment of the present invention, the gas guide groove is a spiral guide groove.

[0017] In one embodiment of the present invention, air dampers are respectively provided in the spray cleaning components. The air dampers are opened in the cleaning mode and closed after the cleaning is completed.

[0018] The present invention also provides a control method for a flue gas desulfurization device, comprising the following steps:

[0019] Get the flue gas inlet temperature T4 of the heat recovery section, compare T4 with the set temperature T4S of the flue gas inlet of the heat recovery section, when T4 ≥ T4S, the heat recovery section starts and continues to work, when T4 <T4S时,烟气满足热回收段排出需求,热回收段停止工作,烟气排入冷凝段;

[0020] Get the condensing section flue gas inlet temperature T2, the condensing section flue gas inlet humidity H2, compare T2 with the terminal exhaust set temperature T3S, compare H2 with the terminal exhaust set humidity H3S, when T3S ≤ T2 or H2 ≧ H3S, the condensing section starts and continues to work, when T3S> T2 and H2 <H3S时,烟气满足冷凝段排出需求,冷凝段停止工作,烟气排入混合段。于本发明的一实施例中,所述步骤S2的冷凝段采用PID控制调节。冷凝段上的风机风量由PID控制调节,当冷凝段与空气进行热交换时,会使周围空气变热,而通过PID能够实时调控风机风量,保证风机风量处于较大的范围,吹散热空气,使环境温度升高幅度较小,几乎可以忽略不计,不影响环境。

[0021] As described above, the flue gas desulfurization device and control method of the present invention have the following beneficial effects: In the prior art, unsaturated exhaust flue gas is generated by heating, while in this solution, the gas in the condensation section enters the mixing section and mixes with the gas in the air to generate unsaturated exhaust flue gas in the form of a mixed gas. This eliminates the need for continuous heating of the exhaust flue gas, thereby reducing the energy consumption of the desulfurization device. The device has a reasonable structure, is easy to use, and is reliable. Through simple water circulation and the introduction of ambient fresh air, the start and stop of the device and the adjustment of the fresh air volume are controlled, thereby reducing energy consumption and further recovering waste heat. The device can be directly installed and connected to the chimney, requiring minimal modification to the existing system, requiring a small footprint, requiring low investment, being simple to install, and requiring no maintenance. Therefore, the present invention effectively overcomes the various shortcomings of the prior art and has high industrial value. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 Shown is a schematic diagram of the front view of a flue gas desulfurization device disclosed in an embodiment of the present invention.

[0023] Figure 2 Shown is a schematic left view of a flue gas desulfurization device disclosed in an embodiment of the present invention.

[0024] Figure 3 Shown is a schematic right view of a flue gas desulfurization device disclosed in an embodiment of the present invention.

[0025] Figure 4Shown is a schematic diagram of the working process of a control method for a flue gas decolorization device disclosed in an embodiment of the present invention.

[0026] Figure 5 Shown is a schematic diagram of the workflow of a control method for a flue gas desulfurization device disclosed in an embodiment of the present invention.

[0027] Component number description

[0028] 1. First flue gas inlet

[0029] 2 Steam-water fin-tube heat exchanger

[0030] 3 Domestic hot water inlet and outlet

[0031] 4 First flue gas outlet

[0032] 5 Second flue gas inlet

[0033] 6. Fresh air inlet

[0034] 7 Steam-steam plate heat exchanger

[0035] 8 Smoke exhaust terminal mixing device

[0036] 9 Second flue gas outlet

[0037] 10 Condensate drain

[0038] 11 Spray water inlet pipe

[0039] 12. First group of sprinkler heads

[0040] 13 Second set of sprinkler heads

[0041] 14. Environmental fresh air intake device DETAILED DESCRIPTION

[0042] The following describes the implementation of the present invention through specific embodiments. People skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

[0043] See also Figures 1 to 3. It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention. Therefore, they have no substantive technical significance. Any modification of the structure, change in the proportional relationship or adjustment of the size should still fall within the scope of the technical content disclosed by the present invention without affecting the efficacy and purpose that can be achieved by the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" quoted in this specification are only for the convenience of description, and are not used to limit the scope of the implementation of the present invention. Changes or adjustments in their relative relationships should also be regarded as the scope of the implementation of the present invention without substantially changing the technical content.

[0044] See also Figures 1 to 3 , the present invention provides a flue gas dewhitening device, including a heat recovery section, which is connected to a mixing section through a condensing section, wherein the condensing section is arranged vertically, the heat recovery section is located on one side of the lower part of the condensing section, and the mixing section is located on the top of the condensing section; an ambient fresh air inlet 6 is provided on the other side of the lower part of the condensing section, and an ambient fresh air intake device 14 is provided in the ambient fresh air inlet 6; by adopting this technical solution: the ambient fresh air intake device adopts multiple groups of axial flow fans, introduces fresh air through the axial flow fans, selects the number of running fans according to the air volume demand, or adjusts the fan speed by frequency conversion, a steam-water fin-tube heat exchanger 2 is provided in the heat recovery section, a first flue gas inlet 1 and a first flue gas outlet 4 are respectively provided on the gas path side of the steam-water fin-tube heat exchanger 2, and a circulating domestic hot water inlet and outlet 3 are respectively provided on the water side of the steam-water fin-tube heat exchanger 2, wherein the first flue gas inlet 1 is connected to the chimney;

[0045] The inner cavity of the steam-water fin-tube heat exchanger 2 is provided with a fin tube bundle, and the tubes connecting the fin tube bundle with the domestic hot water inlet and outlet 3 are water heat exchange channels, and the inner cavity connecting the fin tube bundle with the first flue gas inlet 1 and the first flue gas outlet 4 of the steam-water fin-tube heat exchanger 2 is a first flue gas heat exchange channel;

[0046] The condensing section is provided with a steam-steam plate heat exchanger 7, a second flue gas inlet 5 is provided at the lower left end of the steam-steam plate heat exchanger 7, an ambient fresh air inlet 6 is provided at the lower right end of the steam-steam plate heat exchanger 7, a second flue gas heat exchange channel and an ambient fresh air heat exchange channel are provided in the cavity of the steam-steam plate heat exchanger 7, and a second flue gas outlet 9 and an ambient fresh air outlet are provided at the top of the steam-steam plate heat exchanger 7. By adopting this technical solution: the plates of the second flue gas heat exchange channel are evenly arranged, the flow velocity is low, the flow channel cross-section is large, and the flow resistance is minimized, which does not affect the operation of the boiler;

[0047] The mixing section is provided with a smoke exhaust terminal mixing device 8, which is provided with an inlet and an outlet. The inlet of the smoke exhaust terminal mixing device 8 is connected to the second smoke outlet 9 of the steam-steam plate heat exchanger 7 and the ambient fresh air outlet. A steam guide groove is provided in the cavity of the smoke exhaust terminal mixing device 8; the outlet of the smoke exhaust terminal mixing device 8 is provided with a bird-proof net, which does not affect the air outlet and ensures good air outlet.

[0048] The bottom of the heat exchange channel cavity on the gas path side of the steam-water fin-tube heat exchanger 2 and the steam-steam plate heat exchanger 7 are both provided with a condensation drain port 10;

[0049] The exhaust terminal mixing device 8 corresponds to the second flue gas outlet 9 of the steam-steam plate heat exchanger 7 and the spray cleaning components of the third flue gas heat exchange channel and the ambient air heat exchange channel on both sides of the ambient fresh air outlet, and is provided with a damper that can be opened in the working state and closed in other states;

[0050] The water heat exchange channel of the steam-water fin-tube heat exchanger 2 is water-transmitted. The water pipes are high-efficiency internally threaded pipes. The tube bundles are covered with high-efficiency corrugated fins, all made of rust-proof and corrosion-resistant materials. By adopting this technical solution, efficient recovery and utilization of flue gas waste heat is achieved.

[0051] like Figure 2 、 Figure 3 As shown, the spray cleaning assembly includes a first group of spray heads 12 and a second group of spray heads 13. The first group of spray heads 12 and the second group of spray heads 13 are both connected to a spray water inlet pipe 11. The spray water inlet pipe 11 is directly connected to a high-pressure water pipeline to clean the third flue gas heat exchange channel and the ambient air heat exchange channel. By adopting this technical solution, blockage of the flow channel is avoided and heat exchange efficiency is guaranteed.

[0052] The steam guide groove adopts a spiral guide groove; by adopting this technical solution: the saturated flue gas that is condensed and cooled is fully mixed with the ambient air by adopting the spiral guide groove;

[0053] Air dampers are provided in the spray cleaning components, which are opened in the cleaning mode and closed after the cleaning is completed. By adopting this technical solution, the air dampers can block and protect the spray cleaning components without affecting the mixing of smoke and air.

[0054] A method for controlling a flue gas desulfurization device comprises the following steps:

[0055] Get the flue gas inlet temperature T4 of the heat recovery section, compare T4 with the set temperature T4S of the flue gas inlet of the heat recovery section, when T4 ≥ T4S, the heat recovery section starts and continues to work, when T4 <T4S时,烟气满足热回收段排出需求,热回收段停止工作,烟气排入冷凝段;

[0056] Get the condensing section flue gas inlet temperature T2, the condensing section flue gas inlet humidity H2, compare T2 with the terminal exhaust set temperature T3S, compare H2 with the terminal exhaust set humidity H3S, when T3S ≤ T2 or H2 ≧ H3S, the condensing section starts and continues to work, when T3S> T2 and H2 <H3S时,烟气满足冷凝段排出需求,冷凝段停止工作,烟气排入混合段。

[0057] Specifically, the condensation stage in step S2 utilizes PID control. PID control is used to adjust the air intake volume to achieve control of the exhaust outlet temperature and humidity. While PID control technology is currently available, the present invention eliminates the conventional practice of continuous high-temperature heating to remove white smoke. Instead, the present invention detects the humidity and temperature of the ambient air at the end and activates the device through PID control, achieving energy savings and environmental protection. In summary, the prior art generates unsaturated exhaust gas through heating. In contrast, the present solution allows the gas from the condensation stage to enter the mixing stage and mix with the air in the air, generating unsaturated exhaust gas as a mixed gas. This eliminates the need for continuous heating of the exhaust gas, thereby reducing the energy consumption of the de-whitening device. The present solution features a rational structure, ease of use, and reliability. Through a simple water circulation system and the introduction of fresh air from the environment, the start and stop control and adjustment of the fresh air volume are achieved, reducing energy consumption and further recovering waste heat. The device can be directly installed and connected to the chimney, requiring minimal modification to existing systems, requiring minimal floor space, requiring minimal investment, and is simple to install and maintenance-free. Therefore, the present invention effectively overcomes the various shortcomings of the prior art and possesses high industrial value.

[0058] Therefore, the present invention effectively overcomes various shortcomings of the prior art and has high industrial utilization value.

[0059] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical principles disclosed herein are intended to be covered by the claims of the present invention.

Claims

1. A flue gas desulfurization device, comprising: a heat recovery section, characterized in that The heat recovery section is connected to the mixing section via the condensing section, wherein the condensing section is arranged vertically, the heat recovery section is located on one side of the lower portion of the condensing section, and the mixing section is located on the top of the condensing section; an ambient fresh air inlet (6) is provided on the other side of the lower portion of the condensing section, and an ambient fresh air inlet device (14) is provided in the ambient fresh air inlet (6); The heat recovery section is provided with a steam-water fin-tube heat exchanger (2), the gas path side of the steam-water fin-tube heat exchanger (2) is provided with a first flue gas inlet (1) and a first flue gas outlet (4), and the water side of the steam-water fin-tube heat exchanger (2) is provided with a circulating domestic hot water inlet and outlet (3), wherein the first flue gas inlet (1) is connected to the chimney; The inner cavity of the steam-water fin-tube heat exchanger (2) is provided with a finned tube bundle, the inner cavity of the tubes connected to the domestic hot water inlet and outlet (3) of the finned tube bundle is a water heat exchange channel, and the inner cavity of the finned tube bundle connected to the first flue gas inlet (1) and the first flue gas outlet (4) of the steam-water fin-tube heat exchanger (2) is a first flue gas heat exchange channel; A steam-steam plate heat exchanger (7) is provided in the condensing section, a second flue gas inlet (5) is provided at the lower left end of the steam-steam plate heat exchanger (7), an ambient fresh air inlet (6) is provided at the lower right end of the steam-steam plate heat exchanger (7), a second flue gas heat exchange channel and an ambient fresh air heat exchange channel are provided in the cavity of the steam-steam plate heat exchanger (7), and a second flue gas outlet (9) and an ambient fresh air outlet are provided at the top of the steam-steam plate heat exchanger (7); A smoke exhaust terminal mixing device (8) is provided in the mixing section. The smoke exhaust terminal mixing device (8) is provided with an inlet and an outlet. The inlet of the smoke exhaust terminal mixing device (8) is connected to the second smoke outlet (9) of the steam-steam plate heat exchanger (7) and the ambient fresh air outlet. A steam guide groove is provided in the cavity of the smoke exhaust terminal mixing device (8); and a bird-proof net is provided at the outlet of the smoke exhaust terminal mixing device (8). The bottom of the heat exchange channel cavity on the gas path side of the steam-water finned tube heat exchanger (2) and the steam-steam plate heat exchanger (7) are both provided with a condensation drain port (10); The water heat exchange channel of the steam-water finned tube heat exchanger (2) is provided with water, the water pipes are high-efficiency internally threaded pipes, and the tube bundles are covered with high-efficiency corrugated fins, all of which are made of rust-proof and corrosion-resistant materials.

2. The flue gas desulfurization device according to claim 1, characterized in that The exhaust terminal mixing device (8) corresponds to the second flue gas outlet (9) of the steam-steam plate heat exchanger (7), and the spray cleaning components of the third flue gas heat exchange channel and the ambient air heat exchange channel are respectively arranged on both sides of the ambient fresh air outlet, and are provided with air dampers, which can be opened in the working state and closed in other states. The spray cleaning components include a first group of spray heads (12) and a second group of spray heads (13). The first group of spray heads (12) and the second group of spray heads (13) are both connected to the spray water inlet pipe (11), and the spray water inlet pipe (11) is directly connected to the high-pressure water pipeline to clean the third flue gas heat exchange channel and the ambient air heat exchange channel.

3. The flue gas desulfurization device according to claim 1, characterized in that : The steam guide groove adopts a spiral guide groove.

4. The flue gas desulfurization device according to claim 2, characterized in that : The spray cleaning components are each equipped with an air damper, which opens in the cleaning mode and closes after the cleaning is completed.

5. A control method for a flue gas decolorization device, characterized in that: For controlling the flue gas de - whitening device in any one of claims 1 to 4, the method includes the following steps: Obtain the flue gas inlet temperature T4 of the heat recovery section, compare T4 with the set temperature T4S of the flue gas inlet in the heat recovery section. When T4≥T4S, the heat recovery section starts and continues to operate. When T4<T4S, the flue gas meets the discharge requirement of the heat recovery section, the heat recovery section stops operating, and the flue gas is discharged into the condensation section; Obtain the flue gas inlet temperature T2 and the flue gas inlet humidity H2 of the condensation section, compare T2 with the set temperature T3S of the end flue gas discharge, and compare H2 with the set humidity H3S of the end flue gas discharge. When T3S≤T2 or H2≧H3S, the condensation section starts and continues to operate. When T3S>T2 and H2<H3S, the flue gas meets the discharge requirement of the condensation section, the condensation section stops operating, and the flue gas is discharged into the mixing section.

6. The control method of the flue gas desulfurization device according to claim 5, characterized in that : The condensation section in step S2 adopts PID control regulation.

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