Cold air heater device for coal-fired boiler of direct-fired pulverizing system

Abstract

The utility model discloses a cold air heater device for a coal-fired boiler of a direct-fired pulverizing system, which comprises a cold air heater, one end of the cold air heater is connected with a heating steam pipeline through a branch pipeline, the front part of the heating steam pipeline is connected with plant low-pressure steam, and the other end of the heating steam pipeline is connected with a water collecting device through a water conveying pipeline. The water collecting device is connected with the sewage discharging mechanism, the branch pipeline is provided with a steam adjusting mechanism, and the water collecting device is connected with the exhaust mechanism. According to the utility model, the leakage of heating steam can be prevented, the pressure difference between steam supply and drainage is increased, the drainage is smooth, a water collecting device of an air heater can be washed, and the water quality can be improved; the cold end temperature of the air pre-heater is lower than the acid dew point value due to the too low inlet air temperature, and then low-temperature corrosion is caused.

Description

Technical Field

[0001] The utility model relates to the technical field of coal-fired boiler equipment, in particular to a cold air heater device for a coal-fired boiler of a direct-blowing pulverizing system. Background Art

[0002] In winter, during the several startup and operation processes of the unit grid connection and load shedding tests, the problem of low-temperature corrosion occurred due to the low inlet air temperature causing the air preheater cold end temperature to be lower than the acid dew point. In order to prevent low-temperature corrosion of the air preheater cold end, the existing technology uses hot air recirculation or the installation of a heater to ensure that the air preheater cold end temperature is higher than the acid dew point.

[0003] The existing scheme uses auxiliary steam as a steam source to heat the cold air through the heater. A main valve is set on the heating steam pipe at the heater inlet. The heater drains through the drain adjustment method, that is, when the fan outlet temperature is high, the drain adjustment door is closed to adjust it, and the water is collected to a drain main pipe for drainage. This method uses the drain adjustment method when the temperature is too low in winter. The heater will accumulate water due to poor drainage. The water in the heater flows back to a drain main pipe. There is a crowding phenomenon during operation, which causes poor drainage of individual heaters. Utility Model Content

[0004] The utility model is to overcome the shortcomings of the above-mentioned prior art and provide a cold air heater device for a coal-fired boiler in a direct-blowing pulverizing system. The utility model is provided with a water collecting device to prevent leakage of heating steam, and by setting an exhaust mechanism for the water collecting device of the heater, the steam supply and drainage pressure difference is increased to make drainage unobstructed. The sewage discharge mechanism plays the role of flushing the water collecting device of the heater and improving the water quality, solving the problem that when the primary and secondary fans of the coal-fired boiler in the direct-blowing pulverizing system are running in winter, the inlet air temperature is too low, causing the cold end temperature of the air preheater to be lower than the acid dew point value, thereby causing low-temperature corrosion, avoiding the occurrence of the heater freezing phenomenon, reducing equipment maintenance costs, saving water consumption in power plants, reducing pipeline losses, saving operating costs, and making comprehensive use of heat to improve the comprehensive economic benefits of the pipeline system.

[0005] The technical solution adopted by the utility model to solve its technical problems is:

[0006] A cold air heater device for a coal-fired boiler in a direct-blowing pulverizing system comprises a cold air heater, one end of the cold air heater is connected to a heating steam pipeline through a branch pipeline, the front part of the heating steam pipeline is connected to the low-pressure steam in the plant area, and one end is connected to a water collecting device through a water supply pipeline, the water collecting device is connected to a sewage discharge mechanism, a steam regulating mechanism is provided on the branch pipeline, and the water collecting device is connected to an exhaust mechanism.

[0007] The steam regulating mechanism includes a steam regulating valve and a maintenance manual stop valve. The branch pipe includes a branch pipe one, one end of which is connected to the heating steam pipe and the other end is connected to the cold air heater. The steam regulating valve is connected to the branch pipe one, and a maintenance manual stop valve is respectively provided on the branch pipe one on both sides of the steam regulating valve.

[0008] The branch pipeline includes a second branch pipeline, the second branch pipeline is connected in parallel with the first branch pipeline, and another maintenance manual stop valve is arranged on the second branch pipeline.

[0009] A steam trap is arranged on the water delivery pipeline.

[0010] The exhaust mechanism comprises an exhaust pipe, on which an exhaust valve is arranged.

[0011] The sewage discharge mechanism comprises a sewage discharge pipe, on which a slag pit sewage discharge valve is arranged.

[0012] The beneficial effects of the utility model are:

[0013] The utility model sets a steam regulating valve at the steam inlet of each air duct heating device. When the fan outlet temperature is high, the temperature control purpose is achieved by closing the steam regulating valve. The heating steam amount can be controlled according to the wind temperature to save energy. At the same time, low-temperature corrosion of the air preheater and freezing of the heater can be effectively avoided, equipment maintenance costs can be reduced, water consumption of the power plant can be saved, pipeline losses can be reduced, operating costs can be saved, heat can be comprehensively utilized, and the comprehensive economic benefits of the pipeline system can be improved.

[0014] In addition, when the regulating door fails, close the two manual stop valves on branch pipe one and open the manual stop valve on branch pipe two without affecting the operation of the heater.

[0015] 2. Set the exhaust valve of the heater water collecting device to exhaust the atmosphere. When the equipment is running, open the exhaust valve of the heater water collecting device to increase the pressure difference between steam supply and drain to make the drain unobstructed.

[0016] 3. By setting a water collection device, when the water level of condensed water reaches the set height, the drain valve will automatically open to drain and prevent the heating steam from leaking. When the water level is low, the drain valve will automatically close to prevent the heating steam from leaking.

[0017] Set the heater water collecting device to exhaust the atmosphere. During operation, open the exhaust valve of the heater water collecting device to increase the pressure difference between steam supply and drain to make the drain unobstructed.

[0018] 4. By setting the heater water collecting device to discharge sewage to the slag pit, when the heater water collecting device is not flushed or the water quality is unqualified, open the heater water collecting device and discharge it through the slag pit sewage valve, which plays the role of flushing the heater water collecting device and improving the water quality. In addition, the heater drainage condition can also be checked at any time. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0020] Figure 1 It is a schematic diagram of the structure of an embodiment of the utility model;

[0021] In the figure, there are heating steam pipeline 1, drain pipe 2, heater 3, water collecting device 4, drain trap 5, steam regulating valve 6, exhaust pipe 7, sewage pipe 8, maintenance manual stop valve 9, exhaust valve 10, slag pit sewage valve 11. DETAILED DESCRIPTION

[0022] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments.

[0023] like Figure 1 As shown, a cold air heater device for a coal-fired boiler in a direct-blowing pulverizing system includes a cold air heater 3, one end of the cold air heater 3 is connected to a heating steam pipe 1 through a branch pipe, the front of the heating steam pipe 1 is connected to the low-pressure steam in the plant area, and one end is connected to a water collecting device 4 through a water supply pipe 2, the water collecting device 4 is connected to a sewage discharge mechanism, a steam regulating mechanism is provided on the branch pipe, and the water collecting device 4 is connected to an exhaust mechanism.

[0024] The steam regulating mechanism includes a steam regulating valve 6 and a maintenance manual stop valve 9. The branch pipeline includes a branch pipeline 1, one end of which is connected to the heating steam pipeline 1 and the other end is connected to the cold air heater 3. The steam regulating valve 6 is connected to the branch pipeline 1, and a maintenance manual stop valve 9 is respectively provided on the branch pipeline 1 on both sides of the steam regulating valve 6.

[0025] The branch pipeline includes a second branch pipeline, the second branch pipeline is connected in parallel with the first branch pipeline, and another manual stop valve 9 is arranged on the second branch pipeline.

[0026] A steam trap 5 is provided on the water delivery pipeline.

[0027] The exhaust mechanism comprises an exhaust pipe 7 , on which an exhaust valve 10 is provided.

[0028] The sewage discharge mechanism comprises a sewage discharge pipe 8 on which a slag pit sewage discharge valve 11 is provided.

[0029] The utility model sets a steam regulating valve 6 at the steam inlet of each air duct heating device. When the fan outlet temperature is high, the temperature control purpose is achieved by closing the steam regulating valve 6. The heating steam amount can be controlled according to the wind temperature, energy can be saved, and the occurrence of low-temperature corrosion can be effectively avoided. When the regulating valve 6 fails, the two manual stop valves 9 on the branch pipe 1 are closed, and the manual stop valve 9 on the branch pipe 2 is opened, without affecting the operation of the heater 3.

[0030] In addition, by setting the exhaust valve 10 of the heater water collecting device to exhaust the atmosphere, when the equipment is running, the exhaust valve 10 of the heater water collecting device is opened to increase the pressure difference between steam supply and drainage, so that drainage is unobstructed.

[0031] By setting the heater water collecting device to discharge sewage to the slag pit, when the heater water collecting device is not flushed or the water quality is unqualified, the heater water collecting device is opened to discharge through the slag pit sewage valve 11, which plays the role of flushing the heater water collecting device and improving the water quality. In addition, the heater drainage condition can also be checked at any time.

[0032] The function of the water collecting device 4 is to automatically open the drain valve to drain water when the water level of the condensed water reaches the set height, and prevent the leakage of the heating steam. When the water level is low, the drain valve is automatically closed to prevent the leakage of the heating steam. The heater water collecting device is set to discharge the air 7. During operation, the heater water collecting device discharge valve 10 is opened to increase the pressure difference between the steam supply and the drain to make the drain unobstructed.

[0033] A heater water collecting device 4 is set to discharge sewage 8 to the slag pit. When the heater water collecting device 4 is not flushed or the water quality is unqualified, the heater water collecting device 4 to the slag pit discharge door 11 is opened to flush the heater water collecting device and improve the water quality. In addition, the water drainage condition of the heater 3 can be checked at any time.

[0034] A heater slag pit sewage collection device 4 is set to the slag pit sewage 8. When the heater water collecting device is not flushed or the water quality is unqualified, the heater water collecting device 8 is opened to the slag pit sewage door 11, which plays the role of flushing the heater water collecting device 4 and improving the water quality. In addition, the condition of the heater drain pipe 2 can also be checked at any time.

[0035] The steam trap 5 is an automatic drainer or condensate drainer, through which the condensate, air and carbon dioxide in the steam system are discharged as quickly as possible; at the same time, the steam leakage is automatically prevented to the greatest extent.

[0036] Due to the different heating steam parameters of different projects and the different primary and secondary cold air volumes, it is necessary to select heating steam and drain pipes with different design parameters, and the water collection device exhaust pipe 7 and the slag pit drain valve 11 and other mechanisms are matched accordingly. Compared with the traditional cold air heating device in the prior art, the utility model sets a steam regulating valve 6 and a maintenance manual stop valve 9 on the heating steam pipeline 1. When the fan outlet temperature is high, the steam regulating valve 6 is closed to adjust the temperature, effectively avoiding the occurrence of low-temperature corrosion, and controlling the heating steam volume to achieve reasonable use of energy and avoid waste.

[0037] In short, the utility model can effectively prevent low-temperature corrosion of the air preheater, avoid the freezing of the heater, reduce the maintenance cost of the equipment, save water consumption in the power plant, reduce pipeline losses, save operating costs, comprehensively utilize heat, and improve the comprehensive economic benefits of the pipeline system.

[0038] In the description of the present invention, the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "vertical", "horizontal" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the purpose of describing the present invention rather than requiring the present invention to be constructed or operated in a specific position, and therefore cannot be understood as a limitation on the present invention. The terms "connected" and "connected" in the present invention should be understood in a broad sense, for example, it can be a connection or a detachable connection; it can be a direct connection or an indirect connection through an intermediate component. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific circumstances.

[0039] The above is a preferred embodiment of the present invention, and the description of the specific embodiment is only used to better understand the concept of the present invention. For ordinary technicians in this technical field, several improvements or equivalent substitutions can be made according to the principle of the present invention, and these improvements or equivalent substitutions are also considered to fall within the protection scope of the present invention.

Claims

1. A cold air heater device for a coal-fired boiler in a direct-blowing pulverizing system, comprising a cold air heater, characterized in that: One end of the cold air heater is connected to the heating steam pipe through a branch pipe, the front of the heating steam pipe is connected to the low-pressure steam in the factory area, and one end is connected to the water collecting device through a water supply pipe, the water collecting device is connected to the sewage discharge mechanism, a steam regulating mechanism is provided on the branch pipe, and the water collecting device is connected to the exhaust mechanism.

2. The cold air heater device for a coal-fired boiler in a direct-blowing pulverizing system according to claim 1, characterized in that: The steam regulating mechanism includes a steam regulating valve and a maintenance manual stop valve. The branch pipe includes a branch pipe one, one end of which is connected to the heating steam pipe and the other end is connected to the cold air heater. The steam regulating valve is connected to the branch pipe one, and a maintenance manual stop valve is respectively provided on the branch pipe one on both sides of the steam regulating valve.

3. The cold air heater device for a coal-fired boiler in a direct-blowing pulverizing system according to claim 2, characterized in that: The branch pipeline includes a second branch pipeline, the second branch pipeline is connected in parallel with the first branch pipeline, and another maintenance manual stop valve is arranged on the second branch pipeline.

4. The cold air heater device for a coal-fired boiler in a direct-blowing pulverizing system according to claim 1, characterized in that: A steam trap is arranged on the water delivery pipeline.

5. The cold air heater device for a coal-fired boiler in a direct-blowing pulverizing system according to claim 1, characterized in that: The exhaust mechanism comprises an exhaust pipe, on which an exhaust valve is arranged.

6. The cold air heater device for a coal-fired boiler in a direct-blowing pulverizing system according to claim 1, characterized in that: The sewage discharge mechanism comprises a sewage discharge pipe, on which a slag pit sewage discharge valve is arranged.

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