Smoke temperature regulation and control system

Abstract

The utility model discloses a smoke temperature regulation and control system. The smoke temperature regulation and control system comprises a boiler, an economizer, an air preheater, an air module, a smoke module and a water supply module, the air module comprises an air main path and an air bypass, the air main path is communicated with a boiler inlet through the air preheater, and the air bypass is directly communicated with the boiler inlet; the flue gas module comprises a flue gas main path and a flue gas bypass, the flue gas main path is communicated with an economizer outlet through an air preheater, and the flue gas bypass is directly communicated with the economizer outlet; the water supply module comprises a water supply main path and a water supply bypass, and the water supply main path and the water supply bypass are connected in parallel and both communicate with the boiler and the economizer. The heat exchange conditions of the economizer and the air preheater are adjusted through the water supply bypass system, the air bypass system and the flue gas bypass system, so that the temperature of the metal wall surface of the heat exchange surface is controlled, the corrosion resistance of the heat exchanger is enhanced, the service life of the heat exchange surface is prolonged, the project investment is saved, and the applicability of the unit is enhanced.

Description

Technical Field

[0001] The utility model relates to the technical field of power generation, in particular to a smoke temperature control system. Background Art

[0002] Coal chemical companies generate large amounts of combustible tail gas (lignite gas) during the coking and gasification processes. Its primary components are H₂ (20%-30%), CH₄ (5%-10%), CO (10%-20%), CO₂ (5%-15%), N₂ (35%-45%), along with small amounts of unsaturated hydrocarbons, O₂, and impurities such as tar, hydrogen sulfide, and NH₃. The calorific value of lignite gas is 7,000-8,000 kJ / Nm³. Most companies process this lignite gas using high-tower flare combustion, which releases the flue gas directly into the atmosphere. This treatment method wastes the thermal energy of the lignite gas and directly releases harmful media (such as SO₂ and NOx) produced by combustion, posing a threat to the atmospheric environment. Some coal chemical companies recycle the lignite gas generated during coking, primarily through direct combustion for power generation.

[0003] However, due to incomplete purification of semi-coke gas during the coking process, it contains numerous impurities, including sulfur compounds that generate acidic gases such as SO2 upon combustion. Semi-coke gas contains high levels of H2 and CH4, and the flue gas after combustion contains high levels of H2O. When exposed to a high concentration of H2O, these acidic gases tend to condense on the heat exchanger surfaces when exposed to cold air, causing low-temperature corrosion of the heat exchanger surfaces. Currently, common methods for preventing low-temperature corrosion of the boiler's rear heating surfaces include installing hot air recirculation or heaters to increase the cold air temperature; selecting materials such as stainless steel or enamel to improve the corrosion resistance of the low-temperature heating surfaces; or raising the exhaust gas temperature to keep it away from the flue gas acid dew point. Using heaters or hot air recirculation requires additional steam or increased fan output, resulting in reduced efficiency. Using stainless steel or enamel increases equipment investment costs, and enamel pipes are prone to detachment during installation and transportation, impacting corrosion protection. Raising the exhaust gas temperature also reduces unit efficiency.

[0004] In summary, the existing semi-coal gas boiler has the technical problem that the tail heating surface is prone to low-temperature corrosion, resulting in reduced efficiency or increased costs. Utility Model Content

[0005] The purpose of this application is to overcome the above technical deficiencies and propose a flue gas temperature control system to solve the technical problem in the prior art that the tail heating surface of the semi-coal gas boiler is prone to low-temperature corrosion, resulting in reduced efficiency or increased costs.

[0006] In order to achieve the above technical objectives, this application adopts the following technical solutions:

[0007] This application provides a flue gas temperature control system, including a boiler, an economizer, an air preheater, an air module, a flue gas module, and a water supply module:

[0008] a boiler having an inlet and an outlet;

[0009] an economizer, the economizer being in communication with the boiler outlet;

[0010] an air preheater, the air preheater being in communication with the economizer and the boiler inlet respectively;

[0011] an air module, the air module comprising a main air path and an air bypass, the main air path being connected to the boiler inlet via the air preheater, and the air bypass being directly connected to the boiler inlet;

[0012] a flue gas module, the flue gas module comprising a main flue gas path and a flue gas bypass, the main flue gas path being connected to the economizer outlet via the air preheater, and the flue gas bypass being directly connected to the economizer outlet; and

[0013] A water supply module, the water supply module includes a water supply main line and a water supply bypass, the water supply main line and the water supply bypass are connected in parallel to each other and are both connected to the boiler and the economizer.

[0014] In some embodiments of the present application, the air preheater includes an air duct and a flue gas duct, the air duct and the flue gas duct are isolated from each other, the air duct is connected in series with the main air path and in parallel with the air bypass, and the flue gas duct is connected in series with the main flue gas path and in parallel with the flue gas bypass.

[0015] In some embodiments of the present application, the air module further includes an air supply unit and a combustion unit, the air supply unit is connected to the main air inlet, and the combustion unit is connected to the main air outlet.

[0016] In some embodiments of the present application, the air module further includes an air bypass valve, which is connected to the air bypass.

[0017] In some embodiments of the present application, the flue gas module further includes an air induction unit, and the air induction unit is connected to the main flue gas outlet.

[0018] In some embodiments of the present application, the flue gas module further includes a flue gas bypass valve, which is connected to the flue gas bypass.

[0019] In some embodiments of the present application, a plurality of temperature measuring points are further included, and the plurality of temperature measuring points are respectively arranged at the inlet and outlet of the air duct and the inlet and outlet of the flue gas duct in the air preheater.

[0020] In some embodiments of the present application, the water supply module further includes a water supply unit, the water supply unit is connected to the main water supply inlet, and the main water supply outlet is respectively connected to the steam drum of the boiler and the economizer outlet.

[0021] In some embodiments of the present application, the water supply module further includes a main water supply regulating valve group and a bypass water supply regulating valve group, the main water supply regulating valve group is connected to the main water supply line, and the bypass water supply regulating valve group is connected to the bypass water supply line.

[0022] In some embodiments of the present application, the water supply module further includes a bypass valve, and the bypass valve is located between the main water supply outlet and the bypass water supply outlet.

[0023] Compared with the prior art, the technical solution provided by the present application brings the following beneficial technical effects: the embodiment of the present application uses a feed water bypass to divert the feed water flow in the economizer, thereby controlling the flue gas temperature at the economizer outlet, further controlling the flue gas temperature at the air preheater outlet, thereby controlling the metal wall temperature of the heat exchange surface of the air preheater, and enhancing the corrosion resistance of the heat exchanger; the embodiment of the present application uses an air bypass system to divert the amount of air flowing through the air preheater, thereby controlling the heat exchange conditions of the air preheater, and further controlling the flue gas temperature at the air preheater outlet. Improved the corrosion resistance of the air preheater; The embodiment of the present application uses a flue gas bypass system to divert the flue gas flow passing through the air preheater, thereby controlling the heat exchange conditions of the air preheater, further controlling the flue gas temperature at the air preheater outlet, and improving the corrosion resistance of the air preheater; The embodiment of the present application uses a water bypass system, an air bypass system, and a flue gas bypass system to adjust the heat exchange conditions of the economizer and the air preheater under low load conditions of the unit, thereby controlling the metal wall temperature of the heat exchange surface, enhancing the corrosion resistance of the heat exchanger, and improving the life of the heat exchange surface. The embodiment of the present application controls the metal wall temperature of the heat exchange surface through the water bypass system, the air bypass system, and the flue gas bypass system, which can reduce the material grade of the heat exchange surface and save engineering investment; At the same time, the setting of the above system increases the adjustment performance of the unit under different load conditions and enhances the applicability of the unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in this application, the following briefly introduces the drawings required for use in the embodiments:

[0025] Figure 1 It is a structural diagram of a smoke temperature control system provided in an embodiment of the present application.

[0026] Reference numerals:

[0027] 1. Boiler, 2. Steam drum, 3. Economizer, 4. Air preheater, 5. Air supply unit, 6. Induced draft unit, 7. Water supply main line regulating valve group, 8. Water supply bypass line regulating valve group, 9. Bypass valve, 10. Flue gas bypass valve, 11. Air bypass valve, 12. Air main line, 13. Combustion unit, 14. Air bypass, 15. Flue gas main line, 16. Flue gas bypass, 17. Water supply main line, 18. Water supply bypass, 19. Temperature measuring point, 20. Water supply unit. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solutions and advantages of this application more clearly understood, the present application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0029] Those skilled in the art will understand that in this specification, the wording "including" is an open-ended expression, which means that the described features exist but does not exclude other features. The directional words "up", "down", "left", "right", etc. are exemplary directions based on the drawings. Features defined as "first" and "second" implicitly include one or more of the features. Singular expressions can also be used in the plural. "Multiple" means two or more. The terms "installed", "connected", and "connected" can be fixed connections, detachable connections, or integrated connections; they can be directly connected, or indirectly connected through an intermediate medium, or they can be internal connections between two elements. In addition, "connected" can include wireless connections.

[0030] The purpose of this application is to overcome the above technical deficiencies and propose a flue gas temperature control system to solve the technical problem in the prior art that the tail heating surface of the semi-coal gas boiler is prone to low-temperature corrosion, resulting in reduced efficiency or increased costs.

[0031] In order to achieve the above technical objectives, this application adopts the following technical solutions:

[0032] This application provides a smoke temperature control system, such as Figure 1 As shown, Figure 1 It is a structural diagram of a smoke temperature control system provided in an embodiment of the present application.

[0033] A flue gas temperature control system includes a boiler 1, an economizer 3, an air preheater 4, an air module, a flue gas module, and a water supply module:

[0034] A boiler 1 having an inlet and an outlet;

[0035] an economizer 3, the economizer 3 being connected to the outlet of the boiler 1;

[0036] An air preheater 4, the air preheater 4 being connected to the economizer 3 and the inlet of the boiler 1 respectively;

[0037] An air module, the air module comprising a main air path 12 and an air bypass 14, the main air path 12 being connected to the inlet of the boiler 1 through the air preheater 4, and the air bypass 14 being directly connected to the inlet of the boiler 1;

[0038] A flue gas module, comprising a flue gas main path 15 and a flue gas bypass 16, wherein the flue gas main path 15 is connected to the outlet of the economizer 3 through the air preheater 4, and the flue gas bypass 16 is directly connected to the outlet of the economizer 3; and

[0039] The water supply module includes a water supply main line regulating valve group 7 and a water supply bypass 18 . The water supply main line regulating valve group 7 and the water supply bypass 18 are connected in parallel to each other and are both connected to the boiler 1 and the economizer 3 .

[0040] The present application uses the water bypass 18 system, the air bypass 14 system and the flue gas bypass 16 system to adjust the heat exchange conditions of the economizer 3 and the air preheater 4 under low load conditions of the unit, thereby controlling the metal wall temperature of the heat exchange surface, enhancing the corrosion resistance of the heat exchanger, and improving the life of the heat exchange surface.

[0041] The present application controls the metal wall temperature of the heat exchange surface through the water bypass 18 system, the air bypass 14 system and the flue gas bypass 16 system, which can reduce the material grade of the heat exchange surface and save engineering investment; at the same time, the setting of the above system increases the adjustment performance of the unit under different load conditions and enhances the applicability of the unit.

[0042] In some embodiments of the present application, the air preheater 4 includes an air duct and a flue gas duct, the air duct and the flue gas duct are isolated from each other, the air duct is connected in series with the main air path 12 and in parallel with the air bypass 14, and the flue gas duct is connected in series with the main flue gas path 15 and in parallel with the flue gas bypass 16.

[0043] In some embodiments of the present application, the air module further includes an air supply unit 5 and a combustion unit 13 , wherein the air supply unit 5 is connected to the inlet of the main air path 12 , and the combustion unit 13 is connected to the outlet of the main air path 12 .

[0044] In some embodiments of the present application, the air module further includes an air bypass valve 11 , and the air bypass valve 11 is connected to the air bypass 14 .

[0045] In this embodiment, the air inlet of the air module is connected to the air supply unit 5 , and the air outlet is connected to the combustion unit 13 .

[0046] Optionally, the inlet of the air bypass 14 is connected to the main air path 12 on the inlet side of the air preheater 4, and the outlet of the air bypass 14 is connected to the main air path 12 on the outlet side of the air preheater 4. An air bypass valve 11 is provided at the inlet of the air bypass 14. The air bypass valve 11 has an adjustment function, and the bypass air flow rate can be set according to demand. The final exhaust gas temperature is determined by setting a temperature measuring point 19 at the main flue gas path 15 at the outlet of the air preheater 4. By adjusting the air bypass valve 11, the air flow rate entering the air preheater 4 for heat exchange is controlled, thereby controlling the exhaust gas temperature at the outlet of the air preheater 4. In order to take into account both the unit efficiency and the life of the heat exchange surface, the exhaust gas temperature at the outlet of the air preheater 4 is controlled to be 10°C to 15°C above the acid dew point temperature.

[0047] Alternatively, the air bypass 14 system can be a single-path bypass or a multi-path bypass, each of which is provided with a bypass regulating valve. This embodiment adopts the function of adjusting the flue gas temperature at the outlet of the air preheater 4 by adjusting the amount of air entering the air preheater 4 and changing the heat exchange characteristics of the air preheater 4.

[0048] Optionally, the ratio of the air flow of the air bypass 14 to the air flow of the main air path 12 is 10% to 30%, and the adjustment range can also be adjusted according to actual conditions.

[0049] Optionally, the air bypass 14 can adjust the flue gas temperature at the outlet of the air preheater 4 when the unit is running at normal load, and can also be switched to the air main path 12 when the unit is under low load to enhance the corrosion protection of the air preheater 4.

[0050] In some embodiments of the present application, the flue gas module further includes an air induction unit 6 , and the air induction unit 6 is connected to the outlet of the flue gas main path 15 .

[0051] In some embodiments of the present application, the flue gas module further includes a flue gas bypass valve 10 , and the flue gas bypass valve 10 is connected to the flue gas bypass 16 .

[0052] In this embodiment, the flue gas inlet of the flue gas module is connected to the economizer 3 unit, and the flue gas outlet is connected to the induced draft fan inlet.

[0053] Optionally, the inlet of the flue gas bypass 16 is connected to the main flue gas path 15 on the inlet side of the air preheater 4, and the outlet of the flue gas bypass 16 is connected to the main flue gas path 15 on the outlet side of the air preheater 4. A flue gas bypass valve 10 is provided at the inlet of the flue gas bypass 16. The flue gas bypass valve 10 has an adjustment function, and the bypass flue gas flow rate can be set according to demand. The final exhaust gas temperature is determined by setting a temperature measuring point 19 at the main flue gas path 15 at the outlet of the air preheater 4. By adjusting the flue gas bypass valve 10, the flue gas flow entering the air preheater 4 for heat exchange is controlled, thereby controlling the exhaust gas temperature at the outlet of the air preheater 4. In order to take into account both the unit efficiency and the life of the heat exchange surface, the exhaust gas temperature at the outlet of the air preheater 4 is controlled to be 10°C to 15°C above the acid dew point temperature.

[0054] Alternatively, the flue gas bypass 16 system can be a single-path bypass or a multi-path bypass, each of which is provided with a bypass regulating valve. This embodiment adopts the function of adjusting the flue gas temperature at the outlet of the air preheater 4 by adjusting the flue gas volume entering the air preheater 4 and changing the heat exchange characteristics of the air preheater 4.

[0055] Alternatively, the recommended adjustment ratio range of the flue gas bypass 16 system is 10% to 30%, and the adjustment range can also be adjusted according to actual conditions.

[0056] Optionally, the flue gas bypass 16 can adjust the flue gas temperature at the outlet of the air preheater 4 when the unit is running at normal load, and can also be switched to the flue gas main path 15 when the unit is under low load to enhance the corrosion protection of the air preheater 4.

[0057] In some embodiments of the present application, a plurality of temperature measuring points 19 are further included, and the plurality of temperature measuring points 19 are respectively arranged at the air duct inlet and outlet and the flue gas duct inlet and outlet in the air preheater 4 .

[0058] In this embodiment, the flue gas main path 15 and the air main path 12 are provided with temperature measuring points 19, and the temperature measuring points 19 are respectively arranged at the air side inlet air main path 12 of the air preheater 4, the air side outlet air main path 12 of the air preheater 4, the flue gas main path 15 of the flue gas side inlet of the air preheater 4, and the flue gas main path 15 of the flue gas side outlet of the air preheater 4.

[0059] Optionally, the flue gas side temperature measuring point 19 of the air preheater 4 is interlocked with the flue gas bypass 16 regulating valve to control the opening of the flue gas bypass 16 regulating valve so that the flue gas side outlet temperature of the air preheater 4 is above the flue gas acid dew point temperature.

[0060] Optionally, the flue gas side temperature measuring point 19 of the air preheater 4 is interlocked with the air bypass 14 regulating valve to control the opening of the air bypass 14 regulating valve so that the flue gas side outlet temperature of the air preheater 4 is above the flue gas acid dew point temperature.

[0061] Optionally, the flue gas side temperature measuring point 19 of the air preheater 4 is interlocked with the water supply bypass 18 regulating valve to control the opening of the water supply bypass 18 regulating valve so that the flue gas side outlet temperature of the air preheater 4 is above the flue gas acid dew point temperature.

[0062] In some embodiments of the present application, the water supply module also includes a water supply unit 20, which is connected to the inlet of the water supply main circuit regulating valve group 7, and the outlet of the water supply main circuit regulating valve group 7 is respectively connected to the steam drum 2 of the boiler 1 and the outlet of the economizer 3.

[0063] In some embodiments of the present application, the water supply module also includes a water supply main line regulating valve group 7 and a water supply bypass regulating valve group 8, the water supply main line regulating valve group 7 is connected to the water supply main line regulating valve group 7, and the water supply bypass regulating valve group 8 is connected to the water supply bypass 18.

[0064] In some embodiments of the present application, the water supply module further includes a bypass valve 9 , which is located between the outlet of the water supply main line regulating valve group 7 and the outlet of the water supply bypass 18 .

[0065] In this embodiment, the inlet of the water supply module is connected to the water supply unit 20 , and the outlet of the water supply module is connected to the drum 2 unit of the boiler 1 .

[0066] Optionally, the feedwater bypass inlet 18 is connected to the main feedwater regulating valve group 7 at the feedwater pump outlet, and the feedwater bypass outlet 18 is connected to the main feedwater regulating valve group 7 at the outlet of the economizer 3. The feedwater bypass regulating valve group 8 has a regulating function, and the bypass feedwater flow rate can be set according to demand. The final exhaust gas temperature is determined by setting a temperature measuring point 19 on the main flue gas path 15. By adjusting the feedwater bypass regulating valve 18, the feedwater flow rate entering the economizer 3 for heat exchange is controlled, thereby controlling the exhaust gas temperature at the economizer 3 outlet, and further controlling the exhaust gas temperature at the air preheater 4 outlet.

[0067] Alternatively, the water supply bypass system 18 may be a single-path bypass or a multi-path bypass, each of which is provided with a regulating valve group. This embodiment adopts the function of adjusting the flue gas temperature at the outlet of the air preheater 4 by adjusting the water supply entering the economizer 3 and changing the heat exchange characteristics of the economizer 3.

[0068] Alternatively, the water flow rate of the water supply main line regulating valve group 7 unit accounts for 50% to 100% of the total flow rate, and the regulation range can also be adjusted according to actual conditions.

[0069] Alternatively, the water supply flow rate of the water supply bypass unit 18 accounts for 10% to 50% of the flow rate of the water supply main circuit regulating valve group 7, and the regulation range can also be adjusted according to actual conditions.

[0070] Optionally, a bypass valve 9 is provided at the outlet of the water supply bypass regulating valve group 18 and the outlet of the water supply main regulating valve group 7 regulating valve. When the bypass valve 9 is opened and the water supply main regulating valve group 7 regulating valve group is closed at the same time, the water supply bypass regulating valve group 8 can be switched to the upper water supply main regulating valve group 7 valve group. After the switch, the water supply flow rate of the water supply main regulating valve group 7 unit accounts for 10% to 50% of the total flow rate, and the regulation range can also be adjusted according to actual conditions.

[0071] Optionally, a bypass valve 9 is provided at the outlet of the water supply bypass regulating valve group 18 and the outlet of the water supply main regulating valve group 7 regulating valve. When the bypass valve 9 is opened and the water supply bypass regulating valve group 18 is closed at the same time, the water supply main regulating valve group 7 regulating valve group can be switched to the water supply bypass valve group 18. The water supply flow of the switched water supply bypass 18 unit accounts for 50% to 100% of the flow of the water supply main regulating valve group 7. The regulation range can also be adjusted according to actual conditions.

[0072] The process of adjusting the flue gas temperature by the flue gas temperature control system of the semi-coal gas boiler 1 of the embodiment is as follows:

[0073] The flue gas from the combustion of semi-coal gas in boiler 1 is discharged into the flue gas module after combustion. It then enters the economizer 3 and air preheater 4 in sequence through the main flue gas line 15, and finally enters the flue gas module after exhaust through the induced draft unit 6. The feed water from boiler 1 is fed into the water inlet of economizer 3 through the feed water unit 20 after heat recovery at various stages. After heat exchange in economizer 3, it is delivered to the steam drum 2 of boiler 1 through the main feed water line regulating valve group 7.

[0074] By adjusting the feed water flow through the feed water bypass regulating valve group 8, the feed water amount flowing through the economizer 3 can be reduced, thereby increasing the temperature of the flue gas main path 15 at the economizer 3 outlet. According to the adjustment range of 10% to 50%, the temperature of the flue gas main path 15 changes between 0 and 60°C.

[0075] By adjusting the air flow through the air bypass valve 11, the amount of air passing through the air preheater 4 can be reduced, thereby increasing the temperature of the flue gas main path 15 at the outlet of the air preheater 4. According to the adjustment range of 10% to 30%, the temperature of the flue gas main path 15 changes between 0 and 50°C.

[0076] By adjusting the flue gas flow through the flue gas bypass valve, the amount of flue gas passing through the air preheater 4 can be reduced, thereby increasing the temperature of the flue gas main path 15 at the outlet of the air preheater 4. According to the adjustment range of 10% to 30%, the temperature of the flue gas main path 15 changes between 0 and 45°C.

[0077] At the same time, under the condition that the water supply heat recovery system is cut off, when the temperature of the water supply main line regulating valve group 7 is reduced, the flue gas temperature can be adjusted by the above means to ensure that the temperature of the flue gas main line 15 at the outlet of the air preheater 4 is higher than the flue gas acid dew point, thereby protecting the heating surface from corrosion.

[0078] Furthermore, under winter conditions, when the temperature of the main air path 12 at the inlet of the air preheater 4 is low, the flue gas temperature can be adjusted by the above means to ensure that the temperature of the main flue gas path 15 at the outlet of the air preheater 4 is higher than the flue gas acid dew point, thereby protecting the heating surface from corrosion.

[0079] Finally, under low load conditions, when the temperature of the main flue gas path 15 at the inlet of the air preheater 4 is low, the flue gas temperature can be adjusted by the above means to ensure that the temperature of the main flue gas path 15 at the outlet of the air preheater 4 is higher than the flue gas acid dew point, thereby protecting the heating surface from corrosion.

[0080] Compared with the prior art, the technical solution provided by the present application brings the following beneficial technical effects: the embodiment of the present application adopts the feed water bypass 18 to divert the feed water flow in the economizer 3, thereby controlling the flue gas temperature at the outlet of the economizer 3, further controlling the flue gas temperature at the outlet of the air preheater 4, thereby controlling the metal wall temperature of the heat exchange surface of the air preheater 4, and enhancing the corrosion resistance of the heat exchanger; the embodiment of the present application adopts the air bypass 14 system to divert the amount of air flowing through the air preheater 4, thereby controlling the heat exchange conditions of the air preheater 4, further controlling the flue gas temperature at the outlet of the air preheater 4, and improving Improve the corrosion resistance of the air preheater 4; the embodiment of the present application adopts the flue gas bypass 16 system to divert the flue gas flow passing through the air preheater 4, thereby controlling the heat exchange conditions of the air preheater 4, further controlling the flue gas temperature at the outlet of the air preheater 4, and improving the corrosion resistance of the air preheater 4; the embodiment of the present application can adjust the heat exchange conditions of the economizer 3 and the air preheater 4 under low load conditions of the unit through the water bypass 18 system, the air bypass 14 system and the flue gas bypass 16 system, thereby controlling the metal wall temperature of the heat exchange surface, enhancing the corrosion resistance of the heat exchanger, and improving the life of the heat exchange surface. The embodiment of the present application controls the metal wall temperature of the heat exchange surface through the water bypass 18 system, the air bypass 14 system and the flue gas bypass 16 system, which can reduce the material grade of the heat exchange surface and save engineering investment; at the same time, the setting of the above system increases the adjustment performance of the unit under different load conditions and enhances the applicability of the unit.

[0081] Those skilled in the art will understand that the various operations, methods, steps, measures, and schemes in the processes discussed in this application may be alternated, changed, rearranged, decomposed, combined, or deleted.

[0082] The specific implementation methods of the present application described above do not limit the scope of protection of the present application. Any other corresponding changes and modifications made based on the technical concept of the present application should be included in the scope of protection of the claims of the present application.

Claims

1. A smoke temperature control system, characterized in that: include: a boiler having an inlet and an outlet; an economizer, the economizer being in communication with the boiler outlet; an air preheater, the air preheater being in communication with the economizer and the boiler inlet respectively; an air module, the air module comprising a main air path and an air bypass, the main air path being connected to the boiler inlet via the air preheater, and the air bypass being directly connected to the boiler inlet; A flue gas module, comprising a main flue gas path and a flue gas bypass, wherein the main flue gas path is connected to the economizer outlet via the air preheater, and the flue gas bypass is directly connected to the economizer outlet; as well as A water supply module, the water supply module includes a water supply main line and a water supply bypass, the water supply main line and the water supply bypass are connected in parallel to each other and are both connected to the boiler and the economizer.

2. The smoke temperature control system according to claim 1, characterized in that: The air preheater includes an air duct and a flue gas duct, the air duct and the flue gas duct are isolated from each other, the air duct is connected in series with the main air path and in parallel with the air bypass, and the flue gas duct is connected in series with the main flue gas path and in parallel with the flue gas bypass.

3. The smoke temperature control system according to claim 2, characterized in that: The air module further includes an air supply unit and a combustion unit. The air supply unit is communicated with the main air path inlet, and the combustion unit is communicated with the main air path outlet.

4. The smoke temperature control system according to claim 3, characterized in that: The air module further includes an air bypass valve connected to the air bypass.

5. The smoke temperature control system according to claim 2, characterized in that: The smoke module further includes an air induction unit, which is communicated with the main smoke outlet.

6. The smoke temperature control system according to claim 5, characterized in that: The flue gas module further includes a flue gas bypass valve, which is connected to the flue gas bypass.

7. The smoke temperature control system according to claim 2, characterized in that: It also includes a plurality of temperature measuring points, which are respectively arranged at the air duct inlet and outlet and the flue gas duct inlet and outlet in the air preheater.

8. The smoke temperature control system according to claim 1, characterized in that: The water supply module further includes a water supply unit, which is communicated with the main water supply inlet.

9. The smoke temperature control system according to claim 7, characterized in that: The water supply module further includes a main water supply regulating valve group and a bypass water supply regulating valve group. The main water supply regulating valve group is connected to the main water supply line, and the bypass water supply regulating valve group is connected to the bypass water supply line.

10. The smoke temperature control system according to claim 7, characterized in that: The water supply module further includes a bypass valve, which is located between the main water supply outlet and the bypass water supply outlet.

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