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CN-117823940-B - Device for improving dynamic adjustment amplitude of wall temperature split ring of rotary air preheater and control method

CN117823940BCN 117823940 BCN117823940 BCN 117823940BCN-117823940-B

Abstract

The invention discloses a device and a control method for lifting dynamic adjustment amplitude of a temperature separation ring of a wall of a rotary air preheater, wherein the end face of a cold end of a rotor of the air preheater is divided into N rings, N separation ring air inlet pipes corresponding to the N rings are arranged at the cold end of at least one cold medium separation bin, each separation ring air inlet pipe is provided with a separation ring cold air guiding pipe and a separation ring guiding pipe adjusting door, the number of the separation ring cold air guiding pipes and the separation ring guiding pipe adjusting doors is N, the separation ring cold air guiding pipes, the separation ring guiding pipe adjusting doors and the wind inlet pipes are in one-to-one correspondence, the separation ring guiding pipe adjusting doors are arranged on the corresponding separation ring cold air guiding pipes, and the upstream ends of the separation ring cold air guiding pipes are led into the corresponding separation ring air inlet pipes from the downstream ends of the corresponding separation ring guiding pipe adjusting doors and the downstream ends of the separation ring cold air guiding pipes are led into smoke separation bin outlets. The invention not only can ensure the temperature rising range of the split ring, but also can better ensure the anti-blocking effect, and simultaneously reduces or avoids the influence of high smoke discharging temperature of a certain ring on downstream dust removing equipment and the like.

Inventors

  • SHEN XIANNIAN
  • SHI WEIWEI
  • WEI HONGQI

Assignees

  • 浙江兴核智拓科技有限公司

Dates

Publication Date
20260505
Application Date
20231206

Claims (7)

  1. 1. The device for improving dynamic regulation amplitude of a temperature separation ring of a wall of a rotary air preheater is characterized by further comprising a separation ring cold air guide pipe (3) and a separation ring cold air guide pipe regulating door (4), wherein the number of the separation ring cold air guide pipe (3) and the separation ring cold air guide pipe regulating door (4) is N, the separation ring cold air guide pipes (3), the separation ring cold air guide pipe regulating doors (4) and the separation ring air guide pipes (1) are in one-to-one correspondence, the separation ring air guide pipes (1) are respectively communicated below the respective rings, the separation ring air guide pipes (1) are provided with the separation ring regulating doors (2), the cold air quantity of each separation ring air guide pipe (1) is independently controlled through the corresponding separation ring regulating door (2), and the number of the separation ring cold air guide pipe (3) and the separation ring cold air guide pipe regulating door (4) is one by one, and the other ends of the separation ring cold air guide pipes (3) are respectively connected to the downstream of the corresponding separation ring air guide pipes (1), and the other ends of the separation ring air guide pipes (3) are respectively connected to the downstream ends of the separation ring air guide pipes (1) and the downstream ends of the separation ring air guide pipes; an annular cold air uniformly distributing device (6) is arranged at the end part of the downstream end of the ring-division cold air dredging pipe (3); The annular cold air uniformly-distributing device (6) comprises at least one arc-shaped pipe, all the arc-shaped pipes are communicated with the end part of the downstream end of the annular cold air-distributing guide pipe, and air outlet holes with downward openings are distributed on the arc-shaped pipes; The split-ring air inlet pipe (1) comprises a sector section, a transition section and a rectangular section which are sequentially connected from top to bottom, the split-ring adjusting door (2) is arranged on the rectangular section, the upper end face of the split-ring air inlet pipe (1) is a sector air outlet, the lower end face of the split-ring air inlet pipe is a rectangular air inlet, and two arc edges of the sector air outlet are opposite to two arc edges of the corresponding ring from top to bottom.
  2. 2. The device for lifting the dynamic range of the wall temperature split ring of the rotary air preheater according to claim 1 is characterized in that each split ring cold air dredging pipe (3) is provided with a split ring cold air dredging temperature measuring point (5).
  3. 3. Device for dynamically adjusting the amplitude of the wall temperature split ring of a lifting rotary air preheater according to claim 1 or 2, characterized in that the downstream end and the upstream end of the split ring cold air evacuation pipe (3) are located in the same ring.
  4. 4. A control method for lifting dynamic regulation amplitude of a wall temperature sub-loop of a rotary air preheater is characterized by comprising the steps of gradually closing the opening of a sub-loop regulating door (2) on a certain sub-loop air inlet pipe (1) and keeping the corresponding sub-loop regulating door (4) completely closed, wherein the closing speed of the sub-loop regulating door (2) is based on the condition that the temperature rise amplitude of a corresponding ring exhaust gas or a heat storage element is not more than 2 ℃ per minute, gradually opening the opening of the sub-loop regulating door (4) when the fact that the overtemperature operation is detected to exist in a downstream device of the air preheater or the corresponding ring heat storage element still needs to be further after the sub-loop regulating door (2) is completely closed in the closing process of the sub-loop regulating door (2), and gradually opening the sub-loop regulating door (4) according to the condition that the temperature rise amplitude of the corresponding ring exhaust gas or the heat storage element is not more than 2 ℃ per minute when the corresponding ring exhaust gas temperature or the corresponding ring heat storage element is completely closed, and gradually opening the corresponding ring heat storage element is not more than 2 ℃ per step after the corresponding ring exhaust gas temperature of the sub-loop regulating door (4) is completed, and the temperature of the corresponding ring exhaust gas is gradually opened after the corresponding ring exhaust gas is completely closed, and the temperature of the corresponding ring heat storage element is gradually opened according to the temperature is not more than 2 per step.
  5. 5. The method of claim 4, wherein the opening degree of the corresponding sub-loop dredging pipe adjusting door is kept unchanged if the temperature of the dredging cold air measured by the sub-loop dredging cold air temperature measuring point (5) rises during the gradual opening of the sub-loop dredging pipe adjusting door.
  6. 6. The method for controlling the dynamic adjustment amplitude of the wall temperature split ring of the lifting rotary air preheater according to claim 4 or 5 is characterized in that cold air in the split ring air inlet pipe (1) is led to a flue gas split bin outlet which is positioned in the same ring with the split ring air inlet pipe (1) through a split ring cold air guiding pipe (3).
  7. 7. The method for controlling the dynamic adjustment amplitude of the wall temperature split ring of the lifting rotary air preheater according to claim 6, wherein the distributed cold air is fully mixed with the local high-temperature flue gas of the corresponding ring by the annular cold air uniformly distributing device (6) at the end part of the downstream end of the split ring cold air distributing pipe (3).

Description

Device for improving dynamic adjustment amplitude of wall temperature split ring of rotary air preheater and control method Technical Field The invention relates to a device and a control method for lifting dynamic adjustment amplitude of a wall temperature split ring of a rotary air preheater, and belongs to the technical field of blockage control of rotary air preheaters of coal-fired power plants. Background The rotary air preheater applied in the field of coal-fired power generation is generally in a three-bin or four-bin structure and comprises an air bin (comprising a primary air bin and a secondary air bin) and a flue gas bin, and the rotary air preheater utilizes the heat of high-temperature flue gas to heat air, so that energy recycling is realized. However, after the temperature of the flue gas is reduced, SO 3 in the flue gas reacts with NH 3 escaping from the denitration at the upstream to generate ammonium bisulfate (NH 4HSO4), which is in a liquid state within the range of 146-207 ℃, and adheres to the surface of the heat storage element together with the coal-fired fly ash to cause the ash blocking problem of the air preheater, and when the temperature is further reduced, SO 3 and water vapor in the flue gas generate liquid sulfuric acid (H 2SO4) to form low-temperature corrosion, SO that the blocking and corrosion problems of the heat storage element of the air preheater are further aggravated. Chinese patent 202122061569.7 discloses a rotary air preheater anti-blocking system based on temperature rising is patrolled by a ring separating wheel, the air preheater rotor is divided into a plurality of concentric rings, the cold air quantity of each concentric ring can be independently regulated through a ring separating regulating door, when the cold air quantity of one ring is reduced, the smoke exhaust temperature of the corresponding ring smoke side is increased, the wall temperature of the ring heat storage element is increased, namely, the dynamic regulation operation of the wall temperature of the air preheater is carried out, the acid liquor which is blocked by ash is formed by ring separating and time sharing gasification, and the accumulated ash is periodically loosened. In actual use, as the dynamic and static sealing gap exists and zero leakage is difficult to achieve under the closed state of the split ring regulating door, once the installation process is not up to standard, a small amount of cold air still flows through the heat storage element of the corresponding ring when the corresponding split ring regulating door is completely closed, and the upper limit value of the split ring temperature rise of the air preheater rotor can not reach more than 207 ℃, thereby affecting the gasification rate of ammonium bisulfate and the blocking treatment effect of the air preheater. In addition, in the dynamic adjustment process of the temperature separation ring of the wall of the air preheater, the smoke discharge temperature of a certain ring at the smoke separation outlet of the air preheater is high, and the smoke discharge with lower temperature of other rings cannot be fully mixed, so that adverse effects on equipment such as downstream dust removal and the like can be caused, and the problem is particularly remarkable when a cloth bag dust remover is directly arranged at the smoke side downstream of the air preheater. The target value of the air preheater ring separation heating is more than 200 ℃, namely, the flue gas with the local temperature exceeding 200 ℃ exists at the outlet of the air preheater flue gas separation bin, the highest allowable temperature of the bag-type dust collector is generally not more than 170 ℃, and if the temperature exceeds the allowable temperature, the dust collection bag is ablated, and the dust collection efficiency is greatly affected. Disclosure of Invention The invention provides a device for improving the wall temperature split ring dynamic adjustment amplitude of a rotary air preheater and a control method thereof, in order to widen the wall temperature split ring adjustment amplitude of the rotary air preheater in the prior art and solve the problem of local overtemperature in the wall temperature split ring adjustment process. In order to solve the technical problems, the technical scheme adopted by the invention is as follows: The utility model provides a promote device of rotary air preheater wall temperature branch ring dynamic adjustment range, air preheater rotor cold junction terminal surface divide into the N ring, N is greater than or equal to 2, the cold junction setting of at least one cold medium branch storehouse is with N branch ring air-supply line that the N ring corresponds, each branch ring air-supply line matches respectively and communicates in the below of each ring, all be equipped with branch ring regulating gate on the branch ring air-supply line, the cold wind volume of every branch ring air-supply line passes through