Coal-fired flue gas waste heat recycling device

Abstract

A coal-fired flue gas waste heat recycling device comprises a heat exchanger shell, an inner container, a flow guide cover, a bypass flue, a control valve and an auxiliary pipeline. According to the utility model, by opening the flue gas inlet bypass valve and the flue gas outlet bypass valve and closing the flue gas inlet positive valve and the flue gas outlet positive valve, flue gas circulates from the bypass flue on the outer side, and the inner container of the heat exchanger can be overhauled or troubleshot without shutdown; the flue gas waste heat recycling device has the advantages of being compact in structure, easy to operate, convenient to overhaul and maintain, good in flue gas waste heat recycling efficiency and the like.

Description

Technical Field

[0001] The utility model relates to the technical field of boiler auxiliary equipment, in particular to a device for recycling waste heat of coal-fired flue gas. Background Art

[0002] The flue gas generated after boiler combustion generally has a relatively high waste heat temperature, and a large part of the heat energy is discharged into the atmosphere, resulting in a waste of heat energy. At the same time, during the operation of the boiler, the outlet flue gas temperature of the electrostatic precipitator, especially the bag-type dust collector or the electric bag-type dust collector, is usually 120°C or higher. If it directly enters the desulfurization tower, a large amount of desulfurization water will evaporate, and the heat will also be discharged into the atmosphere with the flue gas, resulting in water and heat energy loss. Therefore, there is a relatively large space for heat recovery and reuse at this location, which can realize heat recovery from the flue gas temperature difference of 120°C to 60°C, thereby achieving the goals of energy saving, water saving, comprehensive utilization of waste heat, and emission reduction.

[0003] In the boiler waste heat recovery device of patent number 99222731.3, although the waste heat of the flue gas is utilized, since the flue gas contains ash and other solid particles, it may cause ash blockage and corrosion outside the tube after a long period of use, affecting the normal operation of the system. Summary of the invention

[0004] The purpose of the utility model is to provide a device for recycling waste heat from coal-fired flue gas, which adopts a heat exchange process to heat the medium to be heated when the flue gas passes through the device, so that the heated medium can be recycled to achieve the effect that can be obtained without additional heating, and the heat exchanger can be repaired, descaled or troubleshooted without stopping work.

[0005] To achieve the above-mentioned purpose, the technical solution of the utility model is a coal-fired flue gas waste heat recycling device, which includes: a heat exchanger shell, an inner tank, a flow guide cover, a bypass flue, a control valve and an auxiliary pipeline, wherein: an inner tank is arranged in the heat exchanger shell, and the pipelines of the inner tank are arranged in an array, the heated medium flows in the pipelines of the inner tank, and the flue gas flows outside the pipeline, a flow guide cover is arranged on the upper part of the inner tank, and a bypass flue is arranged on one side outside the inner tank ， There are two sets of control valves, one of which controls the flue gas inlet and outlet and flow distribution, and the other controls the heated medium inlet and outlet and flow distribution. The control valves include: a flue gas inlet positive valve, a flue gas inlet side valve, a flue gas outlet positive valve, a flue gas outlet side valve, a first medium distribution valve and a second medium distribution valve; one of the auxiliary pipelines is a flue gas inlet and outlet pipeline, and the other is a heated medium inlet and outlet pipeline. The auxiliary pipelines include: a flue gas inlet, a flue gas outlet, a medium inlet and a medium outlet. The flue gas inlet is connected to the dust collector, and the flue gas outlet is connected to the desulfurization tower.

[0006] The heat exchanger shell is a double-layer shell with thermal insulation material arranged inside.

[0007] The heated medium is air or water.

[0008] A partition is arranged in the middle of the inner container.

[0009] The smoke inlet positive valve, the smoke inlet side valve, the smoke outlet positive valve, the smoke outlet side valve, the first medium distribution valve and the second medium distribution valve can be controlled by an electrical control system to achieve automatic control.

[0010] Compared with the prior art, the beneficial effects of the utility model are as follows:

[0011] 1. The utility model opens the flue gas inlet side valve and the flue gas outlet side valve, closes the flue gas inlet positive valve and the flue gas outlet positive valve, and the flue gas flows from the outer bypass flue, so that the inner tank of the heat exchanger can be inspected, descaled or troubleshooted without stopping the work;

[0012] 2. The utility model has the characteristics of compact structure, simple operation, and good efficiency in recycling waste heat from flue gas.

[0013] The utility model is further described in detail below with reference to the accompanying drawings: BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is the main view schematic diagram of the utility model;

[0015] Figure 2 for Figure 1 AA view;

[0016] Figure 3 This is a schematic diagram of the application of the utility model in the system.

[0017] In the figure, 1. medium inlet, 2. first medium distribution valve, 3. medium switch valve, 4. partition, 5. medium outlet; 6. second medium distribution valve, 7. flue gas inlet positive valve, 8. flue gas inlet, 9. flue gas inlet side valve, 10. guide cover, 11. medium flow channel, 12. flue gas flow channel, 13. flue gas outlet side valve, 14. flue gas outlet, 15. flue gas outlet positive valve, 16. bypass flue, 21. boiler, 22. dust collector, 23. desulfurization tower, 24. chimney. DETAILED DESCRIPTION

[0018] The utility model discloses a device for recycling waste heat of coal-fired flue gas, which comprises: a heat exchanger shell, an inner tank, a flow guide hood 10, a bypass flue 16, a control valve and an auxiliary pipeline, wherein: an inner tank is arranged in the heat exchanger shell, the pipelines of the inner tank are arranged in an array, the heated medium flows in the pipelines of the inner tank, and the flue gas flows outside the pipeline, the flow guide hood 10 is arranged on the upper part of the inner tank, and the bypass flue 16 is arranged on one side outside the inner tank ，There are two sets of control valves, one of which controls the flue gas inlet and outlet and flow distribution, and the other controls the heated medium inlet and outlet and flow distribution. The control valves include: a flue gas inlet positive valve 7, a flue gas inlet side valve 9, a flue gas outlet positive valve 15, a flue gas outlet side valve 13, a first medium distribution valve 2 and a second medium distribution valve 6; one of the auxiliary pipelines is a flue gas inlet and outlet pipeline, and the other is a heated medium inlet and outlet pipeline. The auxiliary pipelines include: a flue gas inlet 8, a flue gas outlet 14, a medium inlet 1 and a medium outlet 5. The flue gas inlet 8 is connected to the dust collector 22, and the flue gas outlet 14 is connected to the desulfurization tower.

[0019] The heat exchanger shell is a double-layer shell with thermal insulation material arranged inside.

[0020] The heated medium is air or water.

[0021] A partition 4 is arranged in the middle of the inner container.

[0022] The smoke inlet positive valve 7, the smoke inlet side valve 9, the smoke outlet positive valve 15, the smoke outlet side valve 13, the first medium distribution valve 2 and the second medium distribution valve 6 can be controlled by an electrical control system to achieve automatic control.

[0023] In the figure, the first medium distribution valve 2 and the second medium distribution valve 6 adjust the inlet and outlet flow of the heated medium. The medium switch valve 3 cooperates with the first medium distribution valve and the second medium distribution valve to determine whether the heated medium needs to be heated and whether the flow needs to be increased, and opens and closes the corresponding valves as needed; when the heated medium does not need to be heated, the flue gas inlet bypass valve 9 and the flue gas outlet bypass valve 13 are opened, and the flue gas passes through the outer bypass flue 16; when the heated medium needs to be heated, the flue gas inlet bypass valve 9 and the flue gas outlet bypass valve 13 are closed, and the flue gas inlet positive valve 7 and the flue gas outlet positive valve 15 are opened; when the temperature of the heated medium needs to be adjusted, the opening and closing angles of each valve need to be adjusted to adjust the flow; when the flue gas flows from the bypass flue 16, the heated medium is not heated, and the inner tank of the heat exchanger can be inspected, descaled or troubleshooted.

[0024] The above description is only a preferred specific implementation manner of the present utility model, but the protection scope of the present utility model is not limited thereto. Any technician familiar with the technical field within the technical scope disclosed by the present utility model can make equivalent substitutions or changes based on the technical scheme and utility model concept of the present utility model, which should be covered by the protection scope of the present utility model.

Claims

1. A device for recycling waste heat from coal-fired flue gas, the device comprising: A heat exchanger shell, an inner tank, a flow guide cover (10), a bypass flue (16), a control valve and auxiliary pipelines, characterized in that: the inner tank is arranged in the heat exchanger shell, the pipelines of the inner tank are arranged in an array, the heated medium flows in the pipelines of the inner tank, and the smoke flows outside the pipelines, the flow guide cover (10) is arranged on the upper part of the inner tank, and the bypass flue (16) is arranged on one side outside the inner tank ， The control valves are in two sets, one set controls the flue gas inlet and outlet and flow distribution, and the other set controls the heated medium inlet and outlet and flow distribution. The control valves include: a flue gas inlet positive valve (7), a flue gas inlet side valve (9), a flue gas outlet positive valve (15), a flue gas outlet side valve (13), a first medium distribution valve (2) and a second medium distribution valve (6); one of the auxiliary pipelines is a flue gas inlet and outlet pipeline, and the other is a heated medium inlet and outlet pipeline. The auxiliary pipelines include: a flue gas inlet (8), a flue gas outlet (14), a medium inlet (1) and a medium outlet (5). The flue gas inlet (8) is connected to a dust collector (22), and the flue gas outlet (14) is connected to a desulfurization tower.

2. The device for recycling waste heat from coal-fired flue gas according to claim 1, characterized in that: The heat exchanger shell is a double-layer shell with thermal insulation material arranged inside.

3. The device for recycling waste heat from coal-fired flue gas according to claim 1, characterized in that: The heated medium is air or water.

4. The device for recycling waste heat from coal-fired flue gas according to claim 1, characterized in that: A partition (4) is arranged in the middle of the inner container.

5. The device for recycling waste heat from coal-fired flue gas according to claim 1, characterized in that: The smoke inlet positive valve (7), the smoke inlet side valve (9), the smoke outlet positive valve (15), the smoke outlet side valve (13), the first medium distribution valve (2) and the second medium distribution valve (6) can be controlled by an electrical control system to achieve automatic control.

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