Flue gas baffle and flue gas recirculation combined temperature adjusting device and system for subcritical gas-fired boiler
By using a combined temperature regulation device of flue gas baffle and flue gas recirculation in a subcritical gas boiler, the problem of insufficient temperature regulation effect in low load and fuel calorific value fluctuation is solved, and under high load conditions, it is also solved. Reducing the power consumption rate of the factory achieves effective control of steam temperature and guaranteeing economic benefits.
Patent Information
- Application Number
- CN202421354371.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-13
- Publication Date
- 2025-02-25
- Estimated Expiration
- 2034-06-13
AI Technical Summary
In the prior art, the temperature adjustment effect of the flue gas baffle is not obvious in the boiler's low load and fuel calorific value fluctuation conditions; in the boiler's high load or fuel calorific value stable, the flue gas recirculation increases the plant's electricity consumption rate, which affects the Economic benefits.
The temperature regulation device of the combined flue gas baffle and flue gas recirculation is adopted. The flue gas baffle device is set on the flue gas flue, and the baffle device and a recirculation fan are set on the recirculation inlet and outlet flue to regulate the flue gas. The flow rate and recirculated flue gas volume achieve effective control of steam temperature.
Under all working conditions, the steam temperature can be effectively controlled, the boiler temperature regulation performance can be improved, economic benefits can be ensured, and the flexibility of multiple gas fuels can be adapted to reduce the impact of fuel calorific value and pressure fluctuations on steam temperature.
Smart Images
Figure CN222527683U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of boiler equipment, in particular to a temperature regulating device and a regulating system combined with a smoke damper and a smoke recirculation for a subcritical gas boiler. Background Art
[0002] Steam temperature is an important parameter that needs to be monitored at all times during the safe operation of the boiler. Due to the low calorific value and frequent fluctuations of the fuel calorific value of subcritical gas boilers, it is a huge challenge to adjust the boiler steam temperature. Therefore, the boiler must have more flexible steam adjustment methods to ensure that the steam temperature reaches the rated temperature. At present, there are two common temperature adjustment methods for domestic subcritical gas boilers: flue gas damper temperature adjustment and flue gas recirculation temperature adjustment.
[0003] Flue gas damper temperature control means that the boiler sets the heating surfaces of the superheater and reheater in the double flue at the rear, and sets two temperature control dampers at the outlet of the double flue. By adjusting the opening of the temperature control dampers, the distribution ratio of the flue gas volume in the double flue is changed, and the heat exchange of the heating surface in each flue is adjusted, thereby adjusting the steam temperature. This adjustment method has a simple structure and is easy to operate, but when the boiler is under low load and the calorific value of the fuel is greatly increased, the flue gas volume is reduced, the flue gas flow rate is greatly reduced, the flue gas heat exchange capacity is reduced, and the temperature control effect is not obvious.
[0004] Flue gas recirculation temperature control refers to setting a smoke outlet at the outlet of the economizer in the tail flue, and using the recirculation fan to draw part of the flue gas back to the bottom of the furnace and circulate it into the boiler furnace. A large amount of low-temperature flue gas enters the furnace, which can reduce the radiation heat exchange in the furnace and increase the flue gas volume for heat exchange on the heating surface. The amount of recirculated flue gas is controlled by adjusting the frequency of the recirculation fan. As the amount of recirculated flue gas increases, the heat exchange effect of the heated surface is enhanced, which is conducive to achieving the rated steam temperature of the reheated steam. This adjustment method has a large adjustment range and is sensitive to response. It can evenly distribute the heat load of the furnace. It can achieve a good adjustment effect at both high and low loads, and can reduce the generation of NOx. However, when the boiler is under high load or the fuel calorific value is stable, the recirculation fan will increase the plant power consumption rate and affect the economic benefits. Utility Model Content
[0005] Therefore, the technical problem to be solved by the utility model is to overcome the problem in the prior art that the temperature control effect of the flue gas damper device is not obvious under the working conditions of low boiler load and fluctuating fuel calorific value, and the flue gas recirculation increases the plant power consumption rate and affects the economic benefits under the working conditions of high boiler load or stable fuel calorific value, thereby providing a temperature control device and regulation system combined with a flue gas damper and flue gas recirculation for a subcritical gas boiler.
[0006] In order to solve the above technical problems, the utility model provides a temperature control device combined with a flue gas damper and flue gas recirculation for a subcritical gas-fired boiler, comprising: a flue gas damper device and a recirculation inlet flue, a recirculation inlet flue damper device, a recirculation fan, a recirculation outlet flue, a recirculation outlet flue damper device, a recirculation furnace bottom device, and a sealed air duct; the flue gas damper device is arranged on the flue gas duct, the recirculation inlet flue is connected to the flue gas duct, the recirculation inlet flue damper device is arranged on the recirculation inlet flue, one end of the recirculation fan is connected to the recirculation inlet flue, the other end of the recirculation fan is connected to the recirculation outlet flue, the recirculation outlet flue damper device is arranged on the recirculation outlet flue, the recirculation outlet flue is connected to the recirculation furnace bottom device, the sealed air is introduced into one end of the sealed air duct, and the other end is connected to the recirculation furnace bottom flue.
[0007] Furthermore, it also includes a smoke damper control device, and the smoke damper control device is connected to the smoke damper device.
[0008] Furthermore, the smoke duct has at least two smoke baffle devices, and at least two of the smoke ducts are located at the same height.
[0009] Furthermore, the recirculation inlet flue damper device is close to one side of the recirculation fan.
[0010] Furthermore, there are at least two recirculation outlet flue baffle devices, and the two recirculation outlet flue baffle devices are arranged on the recirculation outlet flue at intervals.
[0011] Furthermore, a sealed air duct baffle device is provided on the sealed air duct.
[0012] Furthermore, it also includes an expansion joint, which is connected to the sealed air duct and the recirculation outlet flue.
[0013] Furthermore, the recycling furnace bottom device is connected to the furnace.
[0014] Furthermore, the recirculation fan is a variable frequency fan.
[0015] The utility model also provides a temperature control system for a subcritical gas-fired boiler combined with a flue gas baffle and flue gas recirculation, comprising the temperature control device for a subcritical gas-fired boiler combined with a flue gas baffle and flue gas recirculation.
[0016] The technical solution of the utility model has the following advantages:
[0017] 1. The temperature control device combined with a flue gas damper and flue gas recirculation for a subcritical gas-fired boiler provided by the utility model comprises: a flue gas damper device and a recirculation inlet flue, a recirculation inlet flue damper device, a recirculation fan, a recirculation outlet flue, a recirculation outlet flue damper device, a recirculation furnace bottom device, and a sealed air duct; the flue gas damper device is arranged on the flue gas duct, the recirculation inlet flue is connected to the flue gas duct, the recirculation inlet flue damper device is arranged on the recirculation inlet flue, one end of the recirculation fan is connected to the recirculation inlet flue, the other end of the recirculation fan is connected to the recirculation outlet flue, the recirculation outlet flue damper device is arranged on the recirculation outlet flue, the recirculation outlet flue is connected to the recirculation furnace bottom device, the sealed air is introduced into one end of the sealed air duct, and the other end is connected to the recirculation furnace bottom.
[0018] By arranging the smoke damper device on the smoke duct, the smoke damper device can be used to adjust the angle of the smoke duct, thereby controlling the opening of the smoke damper device; at the same time, the recirculation inlet flue damper device is fixedly installed on the recirculation inlet flue to ensure that the smoke of the recirculation fan and the smoke duct are separated. The recirculation fan is arranged at one end of the recirculation inlet flue damper device, and the flow speed of the smoke can be adjusted by adjusting the output power of the recirculation fan. The recirculation outlet flue damper device is fixedly installed on the recirculation outlet flue, the recirculation outlet flue is connected to the recirculation furnace bottom device, and the recirculation furnace bottom device is connected to the furnace, so that the recirculated smoke enters the furnace.
[0019] When the flame and flue gas temperatures in the furnace are extremely high, it is strictly forbidden for the flue gas in the furnace to flow back into the recirculation fan. A sealed air duct should be arranged. When the recirculation fan is not in use and the damper device of the recirculation outlet flue is closed, the opening of the sealed air is controlled and high-pressure air is introduced to ensure that there is no flue gas backflow in the recirculation outlet flue.
[0020] The combined temperature control device of flue gas damper and flue gas recirculation for subcritical gas-fired boiler is suitable for various operating conditions of gas-fired boiler. It can effectively control steam temperature regardless of high load, low load and fluctuation of fuel calorific value, improve boiler temperature control performance and ensure economic benefits. It can also adapt to the flexible combination of various gas fuels, effectively reduce the influence of fuel calorific value and pressure fluctuation on steam temperature; make all superheaters and reheaters of the boiler participate in flue gas regulation, enhance the convection heat transfer and heat absorption of the heating surface, reduce the radiation heat transfer and heat absorption of the furnace, make the flue gas regulation range wider, and have more obvious regulation effect, which can effectively improve the ability of reheat steam temperature to reach the rated value. At the same time, the choice of different temperature control methods does not affect the selection and operation of other equipment supporting the boiler, and effectively improves the regulation ability of subcritical gas-fired boiler reheat steam temperature.
[0021] 2. The temperature control device combined with a flue gas damper and flue gas recirculation for a subcritical gas-fired boiler provided by the utility model further includes a flue gas damper control device, which is connected to the flue gas damper device. That is, the angle of the flue gas damper device can be controlled by the flue gas damper control device, thereby controlling the opening of the flue gas damper device.
[0022] 3. The combined temperature control device of the flue gas damper and flue gas recirculation for a subcritical gas-fired boiler provided by the utility model further comprises an expansion joint, which is connected to the sealed air duct and the recirculation outlet flue. The setting of the expansion joint realizes the connection between the sealed air duct and the recirculation outlet flue and ensures the sealing of the connection.
[0023] The utility model summary is provided to introduce a selection of concepts in a simplified form, which will be further described in the following detailed description. The utility model summary is not intended to identify key features or essential features of the present disclosure, nor is it intended to limit the scope of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0025] Figure 1 The utility model is a schematic structural diagram of a temperature regulating device combined with a flue gas baffle and flue gas recirculation for a subcritical gas boiler.
[0026] Description of reference numerals:
[0027] 1. Smoke damper device; 2. Smoke damper control device; 3. Recirculation inlet flue; 4. Recirculation inlet flue damper device; 5. Recirculation fan; 6. Recirculation outlet flue; 7. Recirculation outlet flue damper device; 8. Sealed air duct damper device; 9. Sealed air duct; 10. Recirculation furnace bottom device; 11. Expansion joint; 12. Smoke duct; 13. Furnace. DETAILED DESCRIPTION
[0028] In the following, only some exemplary embodiments are briefly described. As those skilled in the art will appreciate, the described embodiments may be modified in various ways without departing from the spirit or scope of the present disclosure. Therefore, the drawings and descriptions are considered to be exemplary and non-restrictive in nature.
[0029] In the description of the present disclosure, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the present disclosure and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present disclosure. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present disclosure, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.
[0030] In the description of the present disclosure, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or can communicate with each other; it can be directly connected, or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present disclosure can be understood according to specific circumstances.
[0031] In the present disclosure, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply means that the first feature is lower in level than the second feature.
[0032] The disclosure below provides many different embodiments or examples to realize different structures of the present disclosure. In order to simplify the disclosure of the present disclosure, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present disclosure. In addition, the present disclosure can repeat reference numbers and / or reference letters in different examples, and this repetition is for the purpose of simplicity and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the present disclosure provides various specific examples of processes and materials, but those of ordinary skill in the art can be aware of the application of other processes and / or the use of other materials.
[0033] The preferred embodiments of the present disclosure are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present disclosure, and are not used to limit the present disclosure.
[0034] See also Figure 1 As shown, the utility model provides a temperature control device combined with a flue gas damper and flue gas recirculation for a subcritical gas-fired boiler, comprising: a flue gas damper device 1 and a recirculation inlet flue 3, a recirculation inlet flue damper device 4, a recirculation fan 5, a recirculation outlet flue 6, a recirculation outlet flue damper device 7, a recirculation furnace bottom device 10, and a sealed air duct 9; the flue gas damper device 1 is arranged on the flue gas duct 12, the recirculation inlet flue 3 is connected to the flue gas duct 12, the recirculation inlet flue damper device 4 is arranged on the recirculation inlet flue 3, one end of the recirculation fan 5 is connected to the recirculation inlet flue 3, the other end of the recirculation fan 5 is connected to the recirculation outlet flue 6, the recirculation outlet flue damper device 7 is arranged on the recirculation outlet flue 6, the recirculation outlet flue 6 is connected to the recirculation furnace bottom device 10, and the sealed air duct 9 has sealing air introduced into one end, and the other end is connected to the recirculation furnace bottom flue.
[0035] By arranging the smoke damper device 1 on the smoke flue 12, the smoke damper device 1 can be used to adjust the angle of the smoke flue 12, thereby controlling the opening of the smoke damper device 1; at the same time, the recirculation inlet flue damper device 4 is fixedly installed on the recirculation inlet flue 3 to ensure that the smoke of the recirculation fan 5 and the smoke flue 12 are separated, and the recirculation fan 5 is arranged at one end of the recirculation inlet flue damper device 4, and the flow speed of the smoke can be adjusted by adjusting the output power of the recirculation fan 5. The recirculation outlet flue damper device 7 is fixedly installed on the recirculation outlet flue 6, and the recirculation outlet flue 6 is connected to the recirculation furnace bottom device 10, and the recirculation furnace bottom device 10 is connected to the furnace 13, so that the recirculation smoke enters the furnace 13.
[0036] When the flame and flue gas temperatures in the furnace 13 are extremely high, it is strictly forbidden for the flue gas in the furnace 13 to flow back into the recirculation fan 5. A sealed air duct 9 is arranged. When the recirculation fan 5 is not in use and the damper device of the recirculation outlet flue 6 is closed, the opening of the sealed air is controlled and high-pressure air is introduced to ensure that there is no flue gas backflow in the recirculation outlet flue 6.
[0037] The combined temperature control device of flue gas damper and flue gas recirculation for subcritical gas-fired boiler is suitable for various operating conditions of gas-fired boiler. It can effectively control the steam temperature regardless of high load, low load and fuel calorific value fluctuation, improve the boiler temperature control performance and ensure economic benefits. It can also adapt to the flexible combination of various gas fuels, effectively reduce the influence of fuel calorific value and pressure fluctuation on steam temperature; make all superheaters and reheaters of the boiler participate in flue gas regulation, enhance the convection heat transfer and heat absorption of the heating surface, reduce the radiation heat transfer and heat absorption of the furnace 13, make the flue gas regulation range wider, and have more obvious regulation effect, which can effectively improve the ability of reheat steam temperature to reach the rated value. At the same time, the choice of different temperature control methods does not affect the selection and operation of other equipment supporting the boiler, and effectively improves the regulation ability of subcritical gas-fired boiler reheat steam temperature.
[0038] Wherein, the recirculation fan 5 is a variable frequency fan, that is, the output power of the recirculation fan 5 can be adjusted by a frequency converter.
[0039] In some optional embodiments, a smoke damper control device 2 is further included, and the smoke damper control device 2 is connected to the smoke damper device 1. That is, the smoke damper control device 2 can control the angle of the smoke damper device 1, thereby controlling the opening degree of the smoke damper device 1.
[0040] In some optional embodiments, the smoke duct 12 has at least two smoke baffle devices 1, and the smoke baffle devices 1 on at least two of the smoke ducts 12 are located at the same height.
[0041] Two smoke ducts 12 are arranged in parallel, and the smoke damper devices 1 of different smoke ducts 12 are arranged at the same height. The smoke damper control device 2 of each smoke duct 12 can synchronously adjust the angles of all smoke damper devices 1 in the same smoke duct, thereby controlling the opening.
[0042] In this embodiment, the recirculation inlet flue damper device 4 is close to one side of the recirculation fan 5 .
[0043] In some optional embodiments, the recirculation outlet flue baffle device 7 has at least two, and the two recirculation outlet flue baffle devices 7 are arranged at intervals on the recirculation outlet flue 6. That is, by the arrangement of the two recirculation outlet flue baffle devices 7, the sealing of the recirculation outlet flue 6 is ensured.
[0044] The recirculation outlet flue baffle device 7 is a zero-leakage flue baffle. At the same time, high-pressure cold air is injected as sealing air for the baffle to ensure zero leakage.
[0045] At the same time, a sealed air duct baffle device 8 is also provided on the sealed air duct 9. The sealed air duct baffle device 8 controls the opening of the sealed air duct to introduce high-pressure air to ensure that the recirculation outlet flue 6 does not have a flue gas backflow.
[0046] The combined temperature regulating device of the flue gas damper and flue gas recirculation for the subcritical gas-fired boiler further comprises an expansion joint 11, which is connected to the sealed air duct 9 and the recirculation outlet flue 6. The arrangement of the expansion joint 11 realizes the connection between the sealed air duct 9 and the recirculation outlet flue 6 and ensures the sealing of the connection.
[0047] The working principle of the combined flue gas damper and flue gas recirculation temperature control device for subcritical gas boilers is as follows:
[0048] When the fuel is stable as a low calorific value gas and the boiler is running under high load conditions, the amount of flue gas generated by combustion is large, the flue gas filling degree flowing through the heating surface of the boiler is good, and the fluctuation of the boiler steam parameters is small. Only the flue gas damper device 1 is put into use, and the amount of flue gas flowing through the heating surface in each tail flue gas duct 12 is changed, so that the steam temperature can be well regulated. It is convenient to operate and maintain.
[0049] When the fuel blending ratio changes significantly, or the gas fuel pressure fluctuates, or the boiler is operating at a low load, the amount of flue gas generated by the combustion is greatly reduced, especially at a low load, where the flue gas volume is only 50% or even less of that at a high load. It is difficult to achieve reasonable regulation of the steam temperature by adjusting the flue gas volume on the heating surface in the tail flue 12 through a single flue gas damper device 1.
[0050] In conjunction with the recirculation inlet flue damper device 4, the recirculation fan 5, the recirculation outlet flue damper device 7, and the recirculation furnace bottom device 10, the amount of flue gas flowing through the heating surfaces of the furnace 13, the recirculation inlet flue 3, and the recirculation outlet flue 6 is increased. This can not only make it more effective for each flue gas damper device 1 to regulate the steam temperature, but also allow more heating surfaces of the boiler to participate in temperature regulation, and the range of temperature regulation is wider.
[0051] The utility model also provides a temperature control system for a subcritical gas-fired boiler combined with a flue gas baffle and flue gas recirculation, comprising the temperature control device for a subcritical gas-fired boiler combined with a flue gas baffle and flue gas recirculation.
[0052] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention of the utility model.
Claims
1. A flue gas damper and flue gas recirculation combined temperature control device for a subcritical gas boiler, characterized in that: include: A flue gas damper device (1), a recirculation inlet flue (3), a recirculation inlet flue damper device (4), a recirculation fan (5), a recirculation outlet flue (6), a recirculation outlet flue damper device (7), a recirculation furnace bottom device (10), and a sealed air duct (9); A flue gas damper device (1) is arranged on a flue gas duct (12); a recirculation inlet flue (3) is connected to the flue gas duct (12); a recirculation inlet flue damper device (4) is arranged on the recirculation inlet flue (3); one end of a recirculation fan (5) is connected to the recirculation inlet flue (3); the other end of the recirculation fan (5) is connected to the recirculation outlet flue (6); a recirculation outlet flue damper device (7) is arranged on the recirculation outlet flue (6); the recirculation outlet flue (6) is connected to a recirculation furnace bottom device (10); and a sealing air is introduced into one end of a sealing air duct (9); the other end of the sealing air duct is connected to the recirculation furnace bottom flue.
2. The combined temperature control device of flue gas damper and flue gas recirculation for subcritical gas boiler according to claim 1, characterized in that: It also comprises a smoke damper control device (2), and the smoke damper control device (2) is connected to the smoke damper device (1).
3. The combined temperature control device of flue gas damper and flue gas recirculation for subcritical gas boiler according to claim 2, characterized in that: The smoke duct (12) has at least two smoke damper devices (1), and the smoke damper devices (1) on at least two smoke ducts (12) are located at the same height.
4. The combined temperature control device of flue gas damper and flue gas recirculation for a subcritical gas boiler according to any one of claims 1 to 3, characterized in that: The recirculation inlet flue damper device (4) is close to one side of the recirculation fan (5).
5. The combined temperature control device of flue gas damper and flue gas recirculation for subcritical gas boiler according to claim 4, characterized in that: There are at least two recirculation outlet flue baffle devices (7), and the two recirculation outlet flue baffle devices (7) are arranged on the recirculation outlet flue (6) at intervals.
6. The combined temperature control device of flue gas damper and flue gas recirculation for subcritical gas boiler according to claim 5, characterized in that: A sealed air duct baffle device (8) is provided on the sealed air duct (9).
7. The combined temperature control device of flue gas damper and flue gas recirculation for subcritical gas boiler according to claim 6, characterized in that: It also comprises an expansion joint (11), which is connected to the sealed air duct (9) and the recirculation outlet flue (6).
8. The combined temperature control device of flue gas damper and flue gas recirculation for subcritical gas boiler according to claim 1, characterized in that: The recirculation furnace bottom device (10) is in communication with the furnace (13).
9. The combined temperature control device of flue gas damper and flue gas recirculation for subcritical gas boiler according to claim 1, characterized in that: The recirculation fan (5) is a variable frequency fan.
10. A combined flue gas damper and flue gas recirculation temperature control system for a subcritical gas boiler, characterized in that: The invention comprises a temperature regulating device combined with a flue gas damper and flue gas recirculation for a subcritical gas boiler as described in any one of claims 1 to 9.