Automatic ash discharging device of low-temperature economizer

Abstract

The application discloses an automatic ash discharging device of a low-temperature economizer, which comprises an automatic baffle, a slag retriever, an ash discharging pipeline, an air injection pipeline and a central controller. The automatic baffle is installed at an ash discharging port of the low-temperature economizer. The automatic baffle is always closed to the ash discharging port of the low-temperature economizer in a natural state and can automatically open the ash discharging port of the low-temperature economizer when the ash accumulation reaches a specified degree. The slag retriever is connected with the low-temperature economizer through the ash discharging pipeline. The air injection pipeline is connected with a compressed air source and the ash discharging pipeline so that the compressed air can be injected into the ash discharging pipeline. The automatic ash discharging device can effectively solve the problem of serious ash accumulation at the bottom of the low-temperature economizer when the boiler is under low load.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of low-temperature economizers, in particular to the technical field of an automatic ash removal device of a low-temperature economizer. BACKGROUND

[0002] The heat generated by burning coal cannot be fully utilized, one of the reasons being that the temperature of the flue gas emitted is high, which is referred to as "exhaust heat". At present, the exhaust temperature of the coal-fired power plant boiler in China is generally 120-150 DEG C, and in some power plants that use high-sulfur coal and lignite, the exhaust temperature is even higher, reaching 160 DEG C. The "exhaust heat" loss is the largest among all the heat losses of the coal-fired power plant boiler, accounting for 5-8% of the total, and accounting for more than 50% of the total heat loss of the boiler. Moreover, the operating exhaust temperature of some thermal power plants is often higher than the design value. Therefore, reducing the exhaust temperature of the power plant boiler has important practical significance for energy saving and emission reduction. In this context, low-temperature economizers have been widely used. The installed low-temperature economizer can recover and reuse the waste heat of the high-temperature flue gas emitted.

[0003] Most of the existing low-temperature economizers are arranged on the horizontal flue between the air preheater outlet and the electric precipitator inlet. According to the "Technical Regulations for the Design of Flue Gas, Air and Pulverized Coal Piping in Thermal Power Plants" and engineering experience, in order to prevent the ash accumulation in this horizontal section of the flue and to prevent the heat exchange tubes of the low-temperature economizer from being severely worn, the flue gas flow rate in this section of the flue is usually designed to be about 9 m / s. However, the operating load of most power plant boilers in China is low, and the flue gas flow rate in the flue is often lower than the design value of 9 m / s, which weakens the ability of the flue gas to carry fly ash, resulting in severe ash accumulation in this horizontal section, which in turn causes the heat exchange tubes of the low-temperature economizer to be severely worn and causes the leakage of the heat medium water, directly affecting the economy and safety of the boiler. So far, there has been no reasonable solution to the problem of severe ash accumulation in the low-load low-temperature economizer system in the industry, which needs to be solved urgently. SUMMARY

[0004] The purpose of the present application is to solve the problems in the prior art, and to provide an automatic ash removal device of a low-temperature economizer, which can effectively solve the problem of severe ash accumulation at the bottom of the low-temperature economizer when the boiler is in low load.

[0005] To achieve the above-mentioned purpose, the present application provides an automatic ash removal device of a low-temperature economizer, which comprises an automatic baffle, a slag extractor, an ash removal pipeline, an air injection pipeline and a central controller. The automatic baffle is installed at the ash removal port of the low-temperature economizer. The automatic baffle is always closed to the ash removal port of the low-temperature economizer in the natural state, but can automatically open the ash removal port of the low-temperature economizer when the accumulated ash reaches a specified degree. The slag extractor is connected to the low-temperature economizer through the ash removal pipeline. The air injection pipeline is connected to a compressed air source and communicates with the ash removal pipeline, so that compressed air can be injected into the ash removal pipeline.

[0006] As a preferred, the automatic baffle comprises an electric valve and an electric soot sensing mechanism, the electric valve can be opened and closed to the soot outlet of the low-temperature economizer, the electric soot sensing mechanism is a weight sensor and / or a height sensor, the weight sensor and the height sensor can respectively sense the weight and the height of the soot above the electric valve to determine whether the soot is accumulated to a specified degree, and the automatic baffle is electrically connected with the central controller.

[0007] As a preferred, the automatic baffle comprises a baffle body and a physical soot limiting mechanism, one end of the baffle body is hinged to the soot outlet of the low-temperature economizer, the physical soot limiting mechanism is a combination of one or more of a spring, a weight and a magnet, the spring, the weight and the magnet can respectively force the baffle body to close the soot outlet of the low-temperature economizer through elastic force, self-gravity and magnetic force, and when the soot above the baffle body is accumulated to a specified degree, the baffle body can resist the physical soot limiting mechanism and open the soot outlet of the low-temperature economizer.

[0008] As a preferred, the ash hopper is further provided, the ash hopper is covered outside the automatic baffle, and two ends of the soot outlet pipeline are respectively connected with the ash hopper and the slag extractor.

[0009] Further, the water sensing sensor is installed in the ash hopper, and the water sensing sensor is electrically connected with the central controller.

[0010] Further, the water supplement pipeline is further provided, the water supplement pipeline is connected with the water source and the ash hopper to inject water into the ash hopper.

[0011] As a preferred, the air lock is further provided, the air lock is installed above the soot outlet pipeline and is synchronously opened and closed with the automatic baffle through interlocking.

[0012] Further, the air lock is located above the connection between the air injection pipeline and the soot outlet pipeline.

[0013] Further, the shaft seal is additionally installed in the air lock.

[0014] As a preferred, the soot outlet pipeline is sequentially provided with a plurality of air injection openings along the length direction, one end of the air injection pipeline is connected with the compressed air source, and the other end is connected with each air injection opening through a plurality of branch connecting pipes.

[0015] The beneficial effects of the present application are as follows:

[0016] The application adds an automatic baffle in a closed state normally at the ash outlet of the low-temperature economizer, so that the flue gas flow field inside the low-temperature economizer is not affected, and when the accumulated ash reaches a specified degree, the automatic baffle is automatically opened, and at the same time, compressed air is injected into the ash discharge pipeline through the air injection pipeline, to assist the discharge of the accumulated ash, effectively solving the problem of serious ash accumulation at the bottom of the low-temperature economizer of the boiler under low load; by adding a hopper outside the automatic baffle between the low-temperature economizer and the ash discharge pipeline, the accumulated ash and leaked heat medium water are collected, and at the same time, in cooperation with the water sensing sensor, the harm caused by the flow of heat medium water to the dust collector is effectively avoided, ensuring the safe and reliable operation of the system; by sequentially arranging a plurality of air injection openings along the length direction of the ash discharge pipeline, the stability of the ash discharge device is effectively improved; by adding a water supply pipeline, the accumulated ash in the hopper can be washed.

[0017] The features and advantages of the present application will be described in detail with reference to the embodiments combined with the drawings.

BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is a front view of an automatic ash discharge device of a low-temperature economizer.

[0019] In the figure: 1-low-temperature economizer, 2-automatic baffle, 3-hopper, 4-air lock, 5-slag extractor, 6-ash discharge pipeline, 7-air injection pipeline, 8-water supply pipeline.

DETAILED DESCRIPTION

[0020] Example one:

[0021] Referring to Figure 1 , the automatic ash discharge device of a low-temperature economizer comprises an automatic baffle 2, a slag extractor 5, an ash discharge pipeline 6, an air injection pipeline 7, and a central controller, the automatic baffle 2 is installed at the ash outlet of the low-temperature economizer 1, the automatic baffle 2 always closes the ash outlet of the low-temperature economizer 1 in a natural state and can automatically open the ash outlet of the low-temperature economizer 1 when the accumulated ash reaches a specified degree, the slag extractor 5 is connected with the low-temperature economizer 1 through the ash discharge pipeline 6, the air injection pipeline 7 is connected with the compressed air source and the ash discharge pipeline 6 in communication, so that compressed air can be injected into the ash discharge pipeline 6. Since the automatic baffle 2 is only opened when the accumulated ash reaches a specified degree, it is in a closed state normally, and does not change the internal flow field of the low-temperature economizer 1.

[0022] The automatic baffle 2 comprises an electric valve and an electric accumulated ash sensing mechanism, the electric valve can electrically open and close the ash outlet of the low-temperature economizer 1, the electric accumulated ash sensing mechanism is a weight sensor and / or a height sensor, the weight sensor and the height sensor can respectively sense the weight and height of the accumulated ash above the electric valve to determine whether the accumulated ash reaches a specified degree, and the automatic baffle 2 is electrically connected with the central controller.

[0023] Further comprising an ash hopper 3, which is covered outside the automatic baffle 2, and the two ends of the ash discharge pipeline 6 are connected with the ash hopper 3 and the slag extractor 5 respectively.

[0024] The water sensing sensor is installed in the ash hopper 3 and is electrically connected with the central controller. The ash hopper 3 can assist the guiding and conveying of the accumulated ash on one hand, and can collect the heat medium water leaked from the heat exchange pipe of the low-temperature economizer 1 due to abrasion on the other hand. The water sensing sensor can detect whether the heat medium water exists in the ash hopper 3, so as to cooperate with the central controller to issue an alarm and prompt the staff to handle as soon as possible, effectively avoiding the harm caused by the flow of heat medium water to the dust remover, and ensuring the safe and reliable operation of the system.

[0025] Further comprising a water supplement pipeline 8, which is connected with a water source and communicates with the ash hopper 3, so as to inject water into the ash hopper 3. The added water supplement pipeline 8 can inject water into the ash hopper 3, flush the accumulated ash in the ash hopper 3, and make the flushing water and the accumulated ash flow to the slag extractor 5 along the ash discharge pipeline 6.

[0026] Further comprising an air lock 4, which is installed on the ash discharge pipeline 6 and is synchronously opened and closed with the automatic baffle 2 through interlocking. The added air lock 4 can effectively prevent the backflow of fly ash.

[0027] The air lock 4 is located above the connection between the air injection pipeline 7 and the ash discharge pipeline 6.

[0028] The air lock 4 is additionally provided with a shaft seal. The added shaft seal can further enhance the sealing performance.

[0029] The ash discharge pipeline 6 is sequentially provided with a plurality of air injection openings along the length direction, and one end of the air injection pipeline 7 is connected with a compressed air source, and the other end is connected with each air injection opening through a plurality of branch connecting pipes. Since a plurality of air injection openings are additionally provided on the ash discharge pipeline 6, a plurality of air supplement points are formed, which can further ensure the ash discharge capacity of the device.

[0030] The working process of the present application is as follows:

[0031] When the flue gas passes through the low-temperature economizer 1, the fly ash can fall onto the automatic baffle 2. When the accumulated ash accumulates to a specified degree, the automatic baffle 2 can be automatically opened, and at the same time the air lock 4 is started synchronously, so that the accumulated ash is sequentially conveyed into the slag extractor 5 along the ash hopper 3 and the ash discharge pipeline 6. At the same time, compressed air can be injected into the ash discharge pipeline 6 through the air injection pipeline 7, so as to provide power for ash discharge. In addition, the water supplement pipeline 8 can also inject water into the ash hopper 3 to flush the ash hopper.

[0032] Example two:

[0033] The automatic baffle 2 comprises a baffle body and a physical ash accumulation limiting mechanism, one end of the baffle body is hinged at the ash outlet of the low-temperature economizer 1, the physical ash accumulation limiting mechanism is a combination of one or more of spring, weight and magnet, the spring, weight and magnet can respectively force the baffle body to close the ash outlet of the low-temperature economizer 1 through elastic force, self-gravity and magnetic force, when the ash accumulated above the baffle body accumulates to a specified degree, the baffle body can resist the physical ash accumulation limiting mechanism and open the ash outlet of the low-temperature economizer 1.

[0034] Other same as example one.

[0035] The above examples are descriptions of the present application, not limitations of the present application, any simple transformation of the present application also belongs to the protection scope of the present application.

Claims

1. An automatic ash removal device for a low-temperature economizer, characterized in that: The application relates to an automatic ash damper (2), a slag scoop (5), an ash discharge pipeline (6), an air injection pipeline (7) and a central controller, wherein the automatic ash damper (2) is installed at an ash discharge port of a low-temperature economizer (1), the automatic ash damper (2) is always closed to the ash discharge port of the low-temperature economizer (1) in a natural state and can automatically open the ash discharge port of the low-temperature economizer (1) when the accumulated ash reaches a specified degree, the slag scoop (5) is connected with the low-temperature economizer (1) through the ash discharge pipeline (6), and the air injection pipeline (7) is connected with the ash discharge pipeline (6) and connected with a compressed air source so as to inject compressed air into the ash discharge pipeline (6). The application further comprises an ash bucket (3), the ash discharge pipeline (6) is connected with the ash bucket (3) and the slag scoop (5) respectively, the ash bucket (3) is covered outside the automatic ash damper (2), and a water sensing sensor is installed in the ash bucket (3) and electrically connected with the central controller. The ash discharge pipeline (6) is provided with a plurality of air injection ports along the length direction, one end of the air injection pipeline (7) is connected with the compressed air source, and the other end is connected with the air injection ports through a plurality of branch pipes.

2. The automatic ash discharging device of a low-temperature economizer according to claim 1, characterized in that: The automatic ash damper (2) comprises an electric valve and an electric accumulated ash sensing mechanism, the electric valve can electrically open and close the ash discharge port of the low-temperature economizer (1), the electric accumulated ash sensing mechanism is a weight sensor and / or a height sensor, the weight sensor and the height sensor can respectively sense the weight and the height of the accumulated ash above the electric valve so as to judge whether the accumulated ash reaches a specified degree, and the automatic ash damper (2) is electrically connected with the central controller.

3. The automatic ash discharging device of a low-temperature economizer according to claim 1, characterized in that: The automatic ash damper (2) comprises a plate body and a physical accumulated ash limiting mechanism, one end of the plate body is hinged to the ash discharge port of the low-temperature economizer (1), the physical accumulated ash limiting mechanism is a combination of one or more of a spring, a weight and a magnet, the spring, the weight and the magnet can respectively force the plate body to close the ash discharge port of the low-temperature economizer (1) through elastic force, self-gravity and magnetic force, and when the accumulated ash above the plate body reaches a specified degree, the accumulated ash can resist the physical accumulated ash limiting mechanism and open the ash discharge port of the low-temperature economizer (1).

4. The automatic ash discharging device of a low-temperature economizer according to claim 1, characterized in that: The application further comprises a water supplement pipeline (8), the water supplement pipeline (8) is connected with a water source and connected with the ash bucket (3) so as to inject water into the ash bucket (3).

5. The automatic ash discharging device of a low-temperature economizer according to claim 1, characterized in that: The application further comprises an air lock (4), the air lock (4) is installed on the ash discharge pipeline (6) and is synchronously opened and closed with the automatic ash damper (2) through interlocking.

6. A low-temperature economizer automatic ash discharging device according to claim 5, characterized in that: The air lock (4) is located on the connection between the air injection pipeline (7) and the ash discharge pipeline (6).

7. The automatic ash discharging device of a low-temperature economizer according to claim 5, characterized in that: The air lock (4) is additionally provided with a shaft seal.

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