Dust remover inlet smoke parameter leveling system based on combination of smoke cooler and air heater

Abstract

The invention discloses a dust remover inlet smoke parameter leveling system based on combination of a smoke cooler and an air heater. An air pre-heater outlet flue is divided into two or more dust remover inlet branch flues in the width direction; a smoke cooler, a first smoke temperature measuring point and a first smoke flow measuring point are at least installed in the branch flue at the inlet of the dust remover with the highest temperature at the same time, and the first smoke temperature measuring point is arranged at the downstream of the smoke cooler; flue gas resistance balance adjusting doors, second flue gas temperature measuring points and second flue gas flow measuring points are arranged in the other dust remover inlet branch flues at the same time; each dust remover inlet branch flue is connected to the dust remover inlet; and based on the feedback values of the first flue gas flow measuring point and the second flue gas flow measuring point and the feedback values of the first flue gas temperature measuring point and the second flue gas temperature measuring point, the opening degree of each flue gas resistance balance door and the liquid water flow in the flue cooler are adjusted, so that the flow and the temperature in each dust remover inlet branch flue are basically consistent. The method is simple and practical.

Description

Technical Field

[0001] The invention relates to a dust collector inlet flue gas parameter leveling system based on a combination of a flue gas cooler and a heater, and belongs to the technical field of waste heat utilization of boilers in coal-fired power plants. Background Art

[0002] In the context of carbon neutrality, coal-fired power will undergo a transformation from a primary energy source to a foundational energy source to a regulating energy source. Across China, most coal-fired units have undergone flue gas cooler retrofits. Frequent deep peak load regulation has exposed a number of common problems: dust accumulation, wear, leakage, and corrosion. For example, at one large power generation group, approximately 80% of its units underwent flue gas cooler retrofits, and 87.4% of these units experienced faulty low-temperature economizers (Note: Failure refers to significant corrosion, wear, or dust accumulation in the units).

[0003] Large coal-fired power plants are generally equipped with rotary air preheaters. A flue gas cooler is installed in the flue between the air preheater and the dust collector, covering the entire flue cross-section. The heat absorbed by the flue gas cooler is sent to the air heater on the air side of the air preheater or the heat recovery system on the steam turbine side, resulting in a high overall cost. However, due to the rotating heat exchange characteristics of the air preheater rotor heat storage element, the flue gas temperature distribution in the air preheater outlet flue is uneven. The air preheater outlet flue is generally rectangular, and the flue gas temperature on both sides differs by about 30°C along the width. This characteristic causes uneven heat exchange in the flue gas coolers evenly distributed in the flue gas. Locally low flue gas temperatures not only have low heat exchange rates but are also prone to low-temperature corrosion. Local corrosion and leakage cause local blockages, which in turn increase the flue gas flow rate in non-blocked areas and exacerbate the corresponding wear problem. Ultimately, traditional flue gas coolers are inefficient and have poor operational reliability. Especially during the low-load operation stage of coal-fired units, the flue gas temperature at the air preheater outlet is relatively low and the heat exchange capacity of the flue gas cooler is relatively small. If there is still a blockage problem at this time, the resistance will be significantly larger, which may eventually produce negative benefits.

[0004] In addition, the above problems also cause a large degree of unevenness in the flue gas flow and flue gas temperature at the dust collector inlet, which in turn causes a decrease in the efficiency of the dust collector; if a bag dust collector is used, it may also easily cause problems such as shortened bag life. Summary of the Invention

[0005] In order to reduce the cost of coal-fired unit smoke coolers, improve their operating efficiency and reliability, and enhance the uniformity of smoke flow and temperature at the dust collector inlet, the present invention provides a dust collector inlet smoke parameter leveling system based on a combination of a smoke cooler and a heater.

[0006] In order to solve the above technical problems, the technical solutions adopted by the present invention are as follows: The dust collector inlet flue gas parameter leveling system based on the combination of the flue gas cooler and the heater branches the air preheater outlet flue into two or more dust collector inlet branch flues along the width direction; A smoke cooler, a first smoke temperature measuring point, and a first smoke flow measuring point are installed simultaneously in at least the branch flue at the inlet of the dust collector with the highest temperature. The first smoke temperature measuring point in the branch flue at the inlet of the same dust collector is set downstream of the smoke cooler. The flue gas resistance balance regulating door, the second flue gas temperature measuring point and the second flue gas flow measuring point are installed in the branch flue gas ducts at the inlet of the other dust collectors; The branch flues at the inlet of each dust collector are connected to the inlet of the dust collector; Based on the feedback values ​​of the first flue gas flow measurement point and the second flue gas flow measurement point, and the feedback values ​​of the first flue gas temperature measurement point and the second flue gas temperature measurement point, the opening of each flue gas resistance balance door and the liquid water flow in the flue gas cooler are adjusted so that the flow deviation in the branch flue at the inlet of each dust collector is less than 10% of the average flow, and the flue gas temperature deviation in the branch flue at the inlet of each dust collector is less than 5°C.

[0007] The direction from upstream to downstream of this application is consistent with the direction of smoke flow.

[0008] The smoke cooler is cooled by water, and the water after absorbing heat can be used to heat the cold air of the air preheater, thereby realizing the recycling of heat.

[0009] The "other branch flues at the dust collector inlet" mentioned above refer to those branch flues at the dust collector inlet that are not equipped with a flue gas cooler. Specifically, in this application, at least one branch flue gas duct at the dust collector inlet with the highest temperature is equipped with a flue gas cooler, a first flue gas temperature measuring point, and a first flue gas flow measuring point; while the remaining branch flues at the dust collector inlet are equipped with a flue gas resistance balancing damper, a second flue gas temperature measuring point, and a second flue gas flow measuring point.

[0010] The above-mentioned dust collector inlet flue gas parameter leveling system based on the combination of a flue gas cooler and a heater branches the air preheater outlet flue along the width direction, and simultaneously installs a flue gas cooler, a first flue gas temperature measuring point and a first flue gas flow measuring point in at least the dust collector inlet branch flue with the highest temperature, and simultaneously installs a flue gas resistance balance adjustment door, a second flue gas temperature measuring point and a second flue gas flow measuring point in the remaining dust collector inlet branch flues. By adjusting the opening of each flue gas resistance balance door and the liquid water flow in the flue gas cooler, balanced control of the flue gas flow and temperature of the dust collector inlet is achieved, while avoiding the local corrosion problem of the flue gas cooler caused by low local flue temperature and the series of problems such as low efficiency and poor operation reliability of the overall flue gas cooler caused by local corrosion. The system is simple and practical.

[0011] In order to solve the problem of blocking, the above system also includes an air preheater bypass flue, and also includes an air preheater bypass flue, the air preheater bypass flue inlet is connected to the air preheater inlet flue; the air preheater bypass flue outlet is connected to the dust collector inlet branch flue installed with a flue gas cooler, and the interface (the connection between the air preheater bypass flue outlet and the dust collector inlet branch flue) is located upstream of the flue gas cooler on the dust collector inlet branch flue, or the air preheater bypass flue outlet is connected to the high-temperature side of the air preheater outlet flue (in the width direction of the air preheater outlet flue, the temperature on one side is higher and the temperature on the other side is lower, and the side with higher temperature is defined as the high-temperature side); a flue gas bypass regulating door is provided on the air preheater bypass flue.

[0012] In order to meet the needs of general production and facilitate modification and control, as one of the preferred implementation schemes, the air preheater outlet flue is branched along the width direction into two dust collector inlet branch flues, namely a relatively high temperature flue and a relatively low temperature flue. That is, the dust collector inlet branch flue with a higher temperature is defined as a relatively high temperature flue, and the dust collector inlet branch flue with a lower temperature is defined as a relatively low temperature flue. A flue gas cooler, a first flue gas temperature measuring point, and a first flue gas flow measuring point are installed simultaneously in the relatively high temperature flue, with the first flue gas temperature measuring point being located downstream of the flue gas cooler; Install a flue gas resistance balance regulating door, a second flue gas temperature measuring point and a second flue gas flow measuring point in the low temperature flue at the same time; Based on the feedback values ​​of the first and second flue gas flow measurement points, the opening of each flue gas resistance balance door is adjusted so that the flow deviation in the branch flue of each dust collector inlet is less than 10% of the average flow; Based on the feedback values ​​of the first flue gas temperature measuring point and the second flue gas temperature measuring point, the liquid water flow in the flue gas cooler is adjusted to make the flue gas temperature deviation in the branch flue of each dust collector inlet less than 5°C.

[0013] To reduce or avoid blockage, when using a two-branch structure, the system also includes an air preheater bypass duct, with the air preheater bypass duct inlet connected to the air preheater inlet duct; the air preheater bypass duct outlet connected to the relatively high-temperature flue, and the interface (the connection between the air preheater bypass duct outlet and the relatively high-temperature flue) located upstream of the flue gas cooler, or the air preheater bypass duct outlet connected to the high-temperature side of the air preheater outlet flue, and a flue gas bypass regulating door installed on the air preheater bypass duct. When the flue gas bypass regulating door is open, although it is not conducive to energy conservation, it can significantly increase the wall temperature of the flue gas cooler, which is beneficial for preventing blockage of the flue gas cooler, and the secondary air temperature of the air preheater is also increased, which is beneficial for preventing blockage of the air preheater.

[0014] The side with higher temperature in the width direction of the air preheater outlet flue is defined as the high-temperature side. For ease of control, the branching position of the high-temperature flue and the low-temperature flue is located at 1 / 3 to 2 / 3 of the width of the air preheater outlet flue from the high-temperature side. More preferably, the branching position of the high-temperature flue and the low-temperature flue is located at 1 / 2 of the width of the air preheater outlet flue from the high-temperature side.

[0015] The dust collector inlet flue gas parameter leveling system based on the combination of a flue gas cooler and a heater in this application is applicable to various air preheaters, and is more preferably applicable to a rotary three-compartment air preheater (air preheater).

[0016] In order to realize the recycling of energy, a heater is installed in the air duct of the cold secondary air inlet of the air preheater; the liquid water is driven by a circulating pump to absorb heat from the smoke cooler and then release heat in the heater, forming a cycle.

[0017] To improve measurement accuracy and stability, within the same dust collector inlet branch flue, the first flue gas flow measurement point is located downstream of the flue gas cooler. The first flue gas temperature measurement point and the first flue gas flow measurement point are each at least 20 cm apart from the flue gas cooler. Furthermore, preferably, the flue gas cooler, the first flue gas temperature measurement point, and the first flue gas flow measurement point are installed sequentially from upstream to downstream.

[0018] To improve measurement accuracy and stability and minimize the impact of the balancing valve on flow and temperature measurements, the second flue gas temperature and flow measurement points are installed upstream of the balancing valve in the branch flue duct at the inlet of the same dust collector. The interval between the second flue gas temperature and flow measurement points and the balancing valve is no less than 100 cm. Furthermore, preferably, the second flue gas temperature measurement point, the second flue gas flow measurement point, and the balancing valve are installed in order from upstream to downstream.

[0019] In order to adapt to the low-load operation of coal-fired units (referring to operation below rated load, under low-load conditions, the flue gas volume is small and the overall flue gas temperature is low, which easily causes dust accumulation in the flue or flue gas cooler), the above-mentioned flue gas resistance balance regulating door can be completely closed during the low-load operation stage of the coal-fired unit, allowing all the flue gas to pass through the flue gas cooler, thereby increasing the flue gas flow rate and alleviating the dust accumulation problem in the flue or flue gas cooler.

[0020] Any technology not specifically described in the present invention is referred to the prior art.

[0021] The present invention is based on a dust collector inlet flue gas parameter leveling system combined with a flue gas cooler and a heater, which avoids or effectively alleviates the local corrosion problem of the flue gas cooler caused by low local flue gas temperature and a series of problems such as low utilization efficiency and poor operation reliability of the overall flue gas cooler caused by local corrosion, thereby improving the economic benefits of the flue gas cooler operation; at the same time, it realizes balanced control of the flue gas flow rate and flue gas temperature at the dust collector inlet, avoids or effectively alleviates the decrease in dust removal efficiency caused by uneven flue gas flow rate and flue gas temperature at the dust collector inlet, thereby improving the dust removal efficiency and extending the service life of the dust collector; it is simple, practical and easy to promote. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic diagram of the structure of the dust collector inlet flue gas parameter leveling system based on the combination of a flue gas cooler and a heater. Figure 1 .

[0023] Figure 2 yes Figure 1 AA view.

[0024] Figure 3 This is a schematic diagram of the structure of the dust collector inlet flue gas parameter leveling system based on the combination of a flue gas cooler and a heater. Figure 2 .

[0025] Figure 4 yes Figure 3 AA view.

[0026] In the figure, 1 is the air preheater, 2 is the dust collector, 3 is the relatively high temperature flue, 4 is the relatively low temperature flue, 5 is the cold secondary air duct, 6 is the cold secondary air heater, 7 is the flue gas cooler, 8 is the flue gas resistance balance regulating door, 9 is the first flue gas temperature measuring point, 10 is the second flue gas temperature measuring point, 11 is the first flue gas flow measuring point, 12 is the second flue gas flow measuring point, 13 is the circulating pump, 14 is the air preheater inlet flue, 15 is the air preheater bypass flue, and 16 is the flue gas bypass regulating valve. DETAILED DESCRIPTION

[0027] In order to better understand the present invention, the content of the present invention is further illustrated below in conjunction with the examples, but the content of the present invention is not limited to the following examples. Example 1

[0028] like Figure 1-2 As shown, based on the dust collector inlet flue gas parameter leveling system combined with the flue gas cooler and the air heater, the air preheater outlet flue is branched into two or more dust collector inlet branch flues along the width direction; A smoke cooler, a first smoke temperature measuring point, and a first smoke flow measuring point are installed simultaneously in at least the branch flue at the inlet of the dust collector with the highest temperature. The first smoke temperature measuring point in the branch flue at the inlet of the same dust collector is set downstream of the smoke cooler. The flue gas resistance balance regulating door, the second flue gas temperature measuring point and the second flue gas flow measuring point are installed in the branch flue gas ducts at the inlet of the other dust collectors; The branch flues at the inlet of each dust collector are connected to the inlet of the dust collector; Based on the feedback values ​​of the first flue gas flow measurement point and the second flue gas flow measurement point, and the feedback values ​​of the first flue gas temperature measurement point and the second flue gas temperature measurement point, the opening of each flue gas resistance balance door and the liquid water flow in the flue gas cooler are adjusted so that the flow deviation in the branch flue at the inlet of each dust collector is less than 10% of the average flow, and the flue gas temperature deviation in the branch flue at the inlet of each dust collector is less than 5°C.

[0029] The above-mentioned dust collector inlet flue gas parameter leveling system based on the combination of a flue gas cooler and a heater branches the air preheater outlet flue along the width direction, and simultaneously installs a flue gas cooler, a first flue gas temperature measuring point and a first flue gas flow measuring point in at least the dust collector inlet branch flue with the highest temperature, and simultaneously installs a flue gas resistance balance adjustment door, a second flue gas temperature measuring point and a second flue gas flow measuring point in the remaining dust collector inlet branch flues. By adjusting the opening of each flue gas resistance balance door and the liquid water flow in the flue gas cooler, balanced control of the flue gas flow and temperature of the dust collector inlet is achieved, while avoiding the local corrosion problem of the flue gas cooler caused by low local flue temperature and the series of problems such as low efficiency and poor operation reliability of the overall flue gas cooler caused by local corrosion. The system is simple and practical. Example 2

[0030] The difference from Example 1 is that: Figure 2 As shown, in this example, the air preheater outlet flue is branched along the width direction into two dust collector inlet branch flues, which are a relatively high temperature flue and a relatively low temperature flue respectively; a flue gas cooler, a first flue gas temperature measuring point and a first flue gas flow measuring point are installed simultaneously in the relatively high temperature flue, and the first flue gas temperature measuring point is set downstream of the flue gas cooler; a flue gas resistance balance regulating door, a second flue gas temperature measuring point and a second flue gas flow measuring point are installed simultaneously in the relatively low temperature flue; the opening of each flue gas resistance balance door is adjusted based on the feedback values ​​of the first flue gas flow measuring point and the second flue gas flow measuring point, so that the flow deviation in each dust collector inlet branch flue is less than 10% of the average flow; the liquid water flow in the flue gas cooler is adjusted based on the feedback values ​​of the first flue gas temperature measuring point and the second flue gas temperature measuring point, so that the flue gas temperature deviation in each dust collector inlet branch flue is less than 5°C. Example 3

[0031] Based on Example 2, the following improvements were further made: the side with higher temperature in the width direction of the air preheater outlet flue was defined as the high-temperature side. For ease of control, the branching position of the high-temperature flue and the low-temperature flue was located at 1 / 2 of the width of the air preheater outlet flue from the high-temperature side. Example 4

[0032] Based on Example 3, the following improvements were made: This example adopted a rotary three-compartment structure. A heater was installed in the air preheater cold secondary air inlet duct. A circulating pump drove liquid water to absorb heat from the flue gas cooler and release heat to the heater, forming a cycle. Example 5

[0033] Based on Example 4, the following improvements were made: To improve measurement accuracy and stability, the flue gas cooler, first flue gas temperature measurement point, and first flue gas flow measurement point in the relatively high temperature flue were installed sequentially from upstream to downstream. The distance between the first flue gas temperature measurement point and the flue gas cooler was 30 cm (based on experiments, it can also be 40 cm, 50 cm, etc.), and the distance between the first flue gas temperature measurement point and the first flue gas flow measurement point was 15 cm (based on experiments, it can also be 5 cm, 20 cm, etc.). The second flue gas temperature measurement point, second flue gas flow measurement point, and balancing valve in the relatively low temperature flue were installed sequentially from upstream to downstream. The distance between the second flue gas temperature measurement point and the balancing valve was 120 cm (based on experiments, it can also be 150 cm, 160 cm, etc.), and the distance between the second flue gas temperature measurement point and the second flue gas flow measurement point was 40 cm (based on experiments, it can also be 30 cm, 60 cm, etc.). Example 6

[0034] On the basis of Example 5, the following improvements were made: Figure 3-4 As shown, the dust collector inlet flue gas parameter leveling system based on a combined flue gas cooler and air heater also includes an air preheater bypass duct, the air preheater bypass duct inlet of which is connected to the air preheater inlet duct; the air preheater bypass duct outlet is connected to the relatively high-temperature flue, and the interface (the connection between the air preheater bypass duct outlet and the relatively high-temperature flue) is located upstream of the flue gas cooler, or the air preheater bypass duct outlet is connected to the high-temperature side of the air preheater outlet flue, and a flue gas bypass regulating valve is installed on the air preheater bypass duct. When the flue gas cooler or air preheater becomes clogged, the flue gas bypass regulating valve is opened. After the clog is resolved or alleviated, the flue gas bypass regulating valve is closed.

[0035] When the coal-fired unit is in the low-load operation stage, the flue gas resistance balance regulating door can be completely closed to allow all the flue gas to pass through the flue gas cooler, thereby increasing the flue gas flow rate and alleviating the ash accumulation problem in the flue or flue gas cooler.

[0036] The above-mentioned examples are based on the dust collector inlet flue gas parameter leveling system combined with the flue gas cooler and the heater, which avoids or effectively alleviates the local corrosion problem of the flue gas cooler caused by the low local flue gas temperature and a series of problems such as low utilization efficiency and poor operation reliability of the overall flue gas cooler caused by the local corrosion, thereby improving the economic benefits of the flue gas cooler operation; at the same time, it realizes the balanced control of the flue gas flow and flue gas temperature at the dust collector inlet, avoids or effectively alleviates the decrease in dust removal efficiency caused by the unevenness of the flue gas flow and flue gas temperature at the dust collector inlet, thereby improving the dust removal efficiency and extending the service life of the dust collector; it is simple, practical and easy to promote.

Claims

1. A dust collector inlet flue gas parameter leveling system based on a combination of a flue gas cooler and a heater, characterized by: The air preheater outlet flue is branched into two or more dust collector inlet branch flues along the width direction; A smoke cooler, a first smoke temperature measuring point, and a first smoke flow measuring point are installed simultaneously in at least the branch flue at the inlet of the dust collector with the highest temperature. The first smoke temperature measuring point in the branch flue at the inlet of the same dust collector is set downstream of the smoke cooler. The flue gas resistance balance regulating door, the second flue gas temperature measuring point and the second flue gas flow measuring point are installed in the branch flue gas ducts at the inlet of the other dust collectors; The branch flues at the inlet of each dust collector are connected to the inlet of the dust collector; Based on the feedback values ​​of the first flue gas flow measurement point and the second flue gas flow measurement point, and the feedback values ​​of the first flue gas temperature measurement point and the second flue gas temperature measurement point, the opening of each flue gas resistance balance door and the liquid water flow in the flue gas cooler are adjusted so that the flow deviation in the branch flue at the inlet of each dust collector is less than 10% of the average flow, and the flue gas temperature deviation in the branch flue at the inlet of each dust collector is less than 5°C.

2. The dust collector inlet flue gas parameter leveling system based on the combination of a flue gas cooler and a heater according to claim 1 is characterized by: It also includes an air preheater bypass flue, the air preheater bypass flue inlet of which is connected to the air preheater inlet flue; The air preheater bypass flue outlet is connected to the dust collector inlet branch flue equipped with a flue gas cooler, and the interface is located upstream of the flue gas cooler on the dust collector inlet branch flue, or the air preheater bypass flue outlet is connected to the high-temperature side of the air preheater outlet flue; a flue gas bypass regulating door is provided on the air preheater bypass flue.

3. The dust collector inlet flue gas parameter leveling system based on the combination of a flue gas cooler and a heater according to claim 1 or 2, characterized in that: The air preheater outlet flue is branched into two dust collector inlet branch flues along the width direction, namely a relatively high temperature flue and a relatively low temperature flue; A flue gas cooler, a first flue gas temperature measuring point, and a first flue gas flow measuring point are installed simultaneously in the relatively high temperature flue, with the first flue gas temperature measuring point being located downstream of the flue gas cooler; Install a flue gas resistance balance regulating door, a second flue gas temperature measuring point and a second flue gas flow measuring point in the low temperature flue at the same time; Based on the feedback values ​​of the first and second flue gas flow measurement points, the opening of each flue gas resistance balance door is adjusted so that the flow deviation in the branch flue at the inlet of each dust collector is less than 10% of the average flow; Based on the feedback values ​​of the first flue gas temperature measuring point and the second flue gas temperature measuring point, the liquid water flow in the flue gas cooler is adjusted to make the flue gas temperature deviation in the branch flue of each dust collector inlet less than 5°C.

4. The dust collector inlet flue gas parameter leveling system based on the combination of a flue gas cooler and a heater according to claim 3 is characterized by: The side with higher temperature in the width direction of the air preheater outlet flue is defined as the high temperature side, and the branching position of the high temperature flue and the low temperature flue is located at 1 / 3 to 2 / 3 of the width of the air preheater outlet flue from the high temperature side.

5. The dust collector inlet flue gas parameter leveling system based on the combination of a flue gas cooler and a heater according to claim 4 is characterized in that: The branching position of the relatively high temperature flue and the relatively low temperature flue is located at 1 / 2 of the width of the flue at the air preheater outlet starting from the high temperature side.

6. The dust collector inlet flue gas parameter leveling system based on the combination of a flue gas cooler and a heater according to any one of claims 1 to 5, characterized in that: The air preheater is a rotary three-compartment structure.

7. The dust collector inlet flue gas parameter leveling system based on the combination of a flue gas cooler and a heater according to claim 6 is characterized by: A heater is installed in the air duct of the cold secondary air inlet of the air preheater; a circulation pump drives liquid water to absorb heat from the smoke cooler and then release heat to the heater, forming a cycle.

8. The dust collector inlet flue gas parameter leveling system based on the combination of a flue gas cooler and a heater according to any one of claims 1 to 5, characterized in that: In the branch flue of the same dust collector inlet, the first flue gas flow measuring point is set downstream of the flue gas cooler, and the intervals between the first flue gas temperature measuring point and the first flue gas flow measuring point and the flue gas cooler are not less than 20 cm.

9. The dust collector inlet flue gas parameter leveling system based on the combination of a flue gas cooler and a heater according to any one of claims 1 to 5, characterized in that: In the branch flue of the same dust collector inlet, the second flue gas temperature measuring point and the second flue gas flow measuring point are both installed upstream of the balancing adjustment door in the branch flue of the dust collector inlet; the intervals between the second flue gas temperature measuring point and the second flue gas flow measuring point and the balancing adjustment door are not less than 100cm.

10. The dust collector inlet flue gas parameter leveling system based on the combination of a flue gas cooler and a heater according to any one of claims 1 to 5, characterized in that: During the low-load operation phase of the coal-fired unit, the flue gas resistance balance regulating valve is completely closed to allow all the flue gas to pass through the flue gas cooler, thereby increasing the flue gas flow rate and alleviating the problem of ash accumulation in the flue or flue gas cooler.

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