Air preheater with adjustable exhaust gas temperature

Abstract

The utility model relates to the technical field of air preheaters, and discloses a smoke exhaust temperature adjustable air preheater which comprises a preheater body, one end of the preheater body is provided with a smoke inlet, the other end of the preheater body is provided with a smoke outlet, one side of the preheater body is provided with a preheating air blower, and the other side of the preheater body is provided with a smoke outlet. The output end of the preheating air blower communicates with the preheater body, an air mixing and preheating assembly is installed on the other side of the preheater, a hot air conveying assembly is arranged on one side of the air mixing and preheating assembly, and the preheating air blower controls the air volume in a frequency conversion control mode. The air volume can be reduced in a frequency conversion control mode, heat of absorbed smoke is reduced, condensed water is prevented from being generated in the smoke, normal operation of a rear cloth bag is protected, and the problems that in the prior art, the smoke exhaust temperature is too low, water is attached to a cloth bag dust remover, the bag blockage phenomenon is caused, and normal operation of a boiler is affected are solved.

Description

Technical Field

[0001] This utility model relates to the field of air preheater technology, and in particular to an air preheater with adjustable flue gas temperature. Background Technology

[0002] An air preheater is a low-temperature energy-saving device at the tail end of a boiler. Its purpose is to recover heat from the flue gas into the boiler's feed air, which then returns to the boiler for combustion, thereby reducing the exhaust gas temperature and improving the boiler's thermal energy utilization efficiency.

[0003] However, for boilers burning biomass fuel, the moisture content of the fuel is unstable. Some biomass combustion has a moisture content as high as 50%. If the flue gas temperature is too low at this time, condensate will form in the flue gas. The condensate will affect the operation of the downstream bag filter. In particular, if the flue gas carries water, the water will stick in the bag filter and cause bag blockage, affecting the normal operation of the boiler. Utility Model Content

[0004] The purpose of this invention is to solve the problems existing in the prior art by proposing an adjustable flue gas temperature air preheater.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] An adjustable exhaust temperature air preheater includes a preheater body, one end of which has a flue gas inlet and the other end has a flue gas outlet. A preheating blower is installed on one side of the preheater body, and the output end of the preheating blower is connected to the inner cavity of the preheater body. An air mixing preheating component is installed on the other side of the preheater body, and a hot air conveying component is provided on one side of the air mixing preheating component. The air volume of the preheating blower is controlled by frequency conversion control.

[0007] Preferably, the air mixing preheating assembly includes a mixing chamber connected to the preheater body and an air inlet opened on one side of the mixing chamber.

[0008] Preferably, a regulating valve is installed on one side of the air inlet.

[0009] Preferably, the hot air delivery assembly includes two air outlet pipes connected to the mixing chamber and two fans mounted on the air outlet pipes.

[0010] Preferably, a dust discharge outlet is provided at the bottom of the flue gas inlet, and a conveying pipe is connected to the other end of the dust discharge outlet, and a spiral conveying assembly is installed inside the conveying pipe.

[0011] Compared with the prior art, the beneficial effects of this utility model are:

[0012] This invention, through its specially designed flue gas inlet, connects to the boiler's exhaust port, allowing the flue gas generated by the boiler to enter the preheater body. A preheating blower then transfers the heat from the flue gas to the air-mixing preheating component, preheating the air. The hot air is then transported to the boiler's combustion chamber via a hot air conveying component, promoting more complete and efficient fuel combustion. Compared to existing technologies, this device, with its preheating blower, can reduce the airflow through frequency conversion control if the fuel has a high moisture content. This reduces the heat absorbed from the flue gas, preventing condensation and protecting the downstream filter bags. It also solves the problem in existing technologies where low exhaust temperatures cause water to stick to the filter bags, leading to bag blockage and affecting boiler operation. Attached Figure Description

[0013] Figure 1 This is a plan view of an adjustable exhaust temperature air preheater proposed in this utility model;

[0014] Figure 2 This is a schematic diagram of an embodiment 2 of the adjustable exhaust temperature air preheater proposed in this utility model.

[0015] In the diagram: 1. Preheater body; 2. Flue gas inlet; 3. Flue gas outlet; 4. Preheating blower; 5. Mixing chamber; 6. Air inlet; 7. Regulating valve; 8. Air outlet pipe; 9. Fan; 10. Dust outlet; 11. Conveying pipe; 12. Screw conveyor assembly. Detailed Implementation

[0016] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0017] Example 1

[0018] Reference Figure 1 An adjustable exhaust temperature air preheater includes a preheater body 1, with a flue gas inlet 2 at one end and a flue gas outlet 3 at the other end. A preheating blower 4 is installed on one side of the preheater body 1, and the output end of the preheating blower 4 is connected to the inner cavity of the preheater body 1. An air mixing preheating component is installed on the other side of the preheater body, and a hot air conveying component is provided on one side of the air mixing preheating component. The air volume of the preheating blower 4 is controlled by frequency conversion control.

[0019] The preheater body 1 is equipped with a heat exchange component, which includes heat dissipation fins disposed in the inner cavity of the preheater body 1. Waste flue gas enters the preheater body 1 through the flue gas inlet 2. The preheating blower 4 blows the waste flue gas into contact with the heat contact surface of the heat dissipation fins, so that the heat dissipation fins absorb the heat of the flue gas and transfer it to the mixing chamber 5, where it mixes with the air in the mixing chamber 5, increasing the temperature of the air. The air that has absorbed the heat is then transported to the combustion chamber through the hot air conveying component. This heat exchange component is existing technology and will not be described in detail here.

[0020] In operation, this device connects the flue gas inlet 2 to the boiler exhaust port, allowing the flue gas generated by the boiler to enter the preheater body 1. The heat from the flue gas is then transferred to the air mixing preheating component by the preheating blower 4 to preheat the air. The hot air is then transported to the boiler combustion chamber by the hot air conveying component, which helps the fuel to burn more completely and efficiently. Compared with the prior art, this device, through the preheating blower 4, can reduce the air volume by frequency conversion control if the fuel has a high moisture content. This reduces the heat absorbed by the flue gas, prevents condensation in the flue gas, and protects the downstream filter bags for normal operation. It also solves the problem in the prior art where the exhaust temperature is too low, causing water to stick in the filter bags and causing bag blockage, which affects the normal operation of the boiler.

[0021] In this invention, a frequency converter is connected to the motor of the preheating blower 4 via a cable. The frequency converter controls the speed at which the motor drives the fan blades to rotate, thereby controlling the air volume of the preheating blower 4.

[0022] Furthermore, the air mixing preheating assembly includes a mixing chamber 5 connected to the preheater body 1 and an air inlet 6 opened on one side of the mixing chamber 5. Through the mixing chamber 5, the preheating blower 4 can transport the heat of the flue gas into the mixing chamber 5. Through the air inlet 6, the external air is mixed with the heat to preheat the air. Then, the preheated air is discharged into the combustion chamber through the hot air conveying assembly to increase the combustion effect of the fuel.

[0023] Furthermore, a regulating valve 7 is installed on one side of the air inlet 6. The air intake of the air inlet 6 can be adjusted by the regulating valve 7. If the amount of air used by the boiler is insufficient, the regulating valve 7 will be opened to supply ambient temperature air and prevent it from affecting the combustion of fuel in the combustion chamber.

[0024] Furthermore, the hot air delivery assembly includes two outlet pipes 8 connected to the mixing chamber 5 and two fans 9 installed on the outlet pipes 8. Through the outlet pipes 8 and the fans 9, preheated air can be delivered to the combustion chamber of the boiler through the outlet pipes 8 to increase the combustion effect of the fuel. Through the two outlet pipes 8, the preheated air can be distributed to the combustion chamber to reduce the problems of local overheating and incomplete combustion.

[0025] Example 2

[0026] The difference between this embodiment and Embodiment 1 is that:

[0027] In this embodiment, a dust discharge outlet 10 is provided at the bottom of the flue gas inlet 2. The other end of the dust discharge outlet 10 is connected to a conveying pipe 11. A spiral conveying assembly 12 is installed inside the conveying pipe 11. Through the dust discharge outlet 10, dust discharged with the flue gas is allowed to fall due to gravity, entering the conveying pipe 11 through the dust discharge outlet 10. The spiral conveying assembly 12 then discharges the dust from the conveying pipe 11 (e.g., ...). Figure 2 (As shown).

[0028] The spiral conveying assembly 12 includes a rotary motor installed in the conveying pipe 11, a rotary shaft installed at the drive end of the rotary motor, and spiral blades installed on the outer periphery of the rotary shaft. The drive end of the rotary motor is connected to the rotary shaft through a coupling. The rotary motor drives the rotary shaft to rotate, which in turn drives the spiral blades on the outer periphery of the rotary shaft to rotate, thus discharging the dust that falls into the conveying pipe 11 through the spiral blades.

[0029] The flue gas inlet 2 is connected to the economizer via a connecting pipe. The top of the economizer is connected to the boiler via a pipe. The bottom of the connecting pipe between the economizer and the flue gas inlet is also provided with a dust outlet 10, which is also connected to the conveying pipe 11.

[0030] Economizers are typically installed at the tail end of the boiler or in the flue. Their main function is to use the heat from the boiler's exhaust gas to preheat the feedwater entering the boiler, thereby improving the boiler's thermal efficiency and reducing fuel consumption.

[0031] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. An adjustable exhaust temperature air preheater, comprising a preheater body (1), one end of which has a flue gas inlet (2), and the other end of which has a flue gas outlet (3), a preheating blower (4) installed on one side of the preheater body (1), the output end of which is connected to the inner cavity of the preheater body (1), an air mixing preheating assembly installed on the other side of the preheater body, and a hot air conveying assembly provided on one side of the air mixing preheating assembly, characterized in that: The preheating blower (4) controls the air volume in a variable frequency control mode.

2. An air preheater with adjustable flue gas temperature according to claim 1, characterized in that: The air mixing preheating assembly comprises a mixing chamber (5) communicated with the preheater body (1) and an air inlet (6) formed on one side of the mixing chamber (5).

3. An air preheater with adjustable flue gas temperature according to claim 2, characterized in that: An adjusting valve (7) is mounted on one side of the air inlet (6).

4. The air preheater of claim 2, wherein: The hot air conveying assembly comprises two air outlet pipes (8) communicated with the mixing chamber (5) and two fans (9) mounted on the air outlet pipes (8).

5. The air preheater of claim 1, wherein: A dust discharge port (10) is formed at the bottom of the flue gas inlet (2), another end of the dust discharge port (10) is communicated with a conveying pipe (11), and a spiral conveying assembly (12) is mounted in the conveying pipe (11).

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