Novel low-temperature coal economizer for realizing deliming by utilizing front electric heating
By using a front electric heating tube in a low-temperature economizer to heat the flue gas and combine it with a sponge structure, the ABS adhesion blockage problem is solved, and the dust accumulation is cleaned and the stable operation of the system is achieved.
Patent Information
- Application Number
- CN202421732606.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-22
- Publication Date
- 2025-07-22
- Estimated Expiration
- 2034-07-22
AI Technical Summary
The ABS in existing low-temperature economizers is prone to sticking and causing blockage, affecting the safety of the boiler operation and difficult to effectively remove.
The flue gas is heated to the ABS sublimation/vaporization temperature using a front electric heating tube, combined with the sponge plate, sponge cylinder and barbed structure to promote ABS volatility and clean up dust accumulation.
It effectively reduces the probability of blockage of low-temperature economizers and improves the safety and efficiency of boiler operation.
Smart Images
Figure CN223137857U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of environmental protection and energy conservation, in particular to a novel low-temperature economizer for ash removal by using pre-positioned electric heating. Background Technique
[0002] A low-temperature economizer is a device that can effectively save coal and improve the boiler efficiency in the low-temperature section. It is mainly applied to the medium-low temperature section at the outlet of the air preheater of large boilers such as power plants and thermal power plants. By recovering the waste heat of the flue gas to heat the boiler feed water, the heat efficiency of the flue gas discharge can be effectively reduced. The low-temperature economizer is usually installed in the tail flue at the outlet of the boiler air preheater. It can not only improve the electric dust removal efficiency and meet the low-emission requirements, but also reduce the power consumption, reduce the specifications of downstream equipment, and at the same time remove most of the acidic gases.
[0003] Most of the existing low-temperature economizers in coal-fired power plants use finned tubes. Since the heating medium water directly enters the heat exchange tubes, when the heat exchange tubes are worn, the heating medium water will directly leak into the flue, resulting in serious ash accumulation, affecting the normal operation of the boiler flue gas and air system, and even causing the boiler system to shut down, with poor operation safety.
[0004] During the SCR denitrification process, there is ammonia escape, which reacts with the incompletely burned product SO3 to generate ammonium bisulfate (ABS). The melting point of ABS is 147°C and the boiling point is 350°C. It exists in the flue gas in solid and liquid forms, and at the same time has strong viscosity and adsorption, and is extremely easy to adhere in the low-temperature economizer. The ammonium bisulfate generated during the denitrification process adheres to the surface of the heat exchange plate, and the fly ash in the flue gas is adsorbed and aggregated, resulting in the blockage of the economizer.
[0005] Therefore, the utility model provides a novel low-temperature economizer for ash removal by using pre-positioned electric heating. Content of the Utility Model
[0006] The purpose of the utility model is to solve the defect that ABS is extremely easy to adhere in the low-temperature economizer and difficult to remove in the prior art, and to provide a novel low-temperature economizer for ash removal by using pre-positioned electric heating.
[0007] To achieve the above purpose, the utility model adopts the following technical scheme: A novel low-temperature economizer for ash removal by using pre-positioned electric heating, including an inlet header, an inlet pipe connected to the inlet header and installed on the sealed box body, an outlet header, an outlet pipe connected to the outlet header and installed on the sealed box body, a plurality of pipes located inside the top steam-water heat exchanger and communicating with the inlet header and the outlet header, a plurality of plate heat exchange fins arranged at equal intervals inside the wide-channel heat exchanger, a bottom heating medium water tank located below the plate heat exchange fins and a water collecting tank located above, a downcomer connecting the bottom heating medium water tank and the water collecting tank, and a plurality of pre-positioned electric heating tubes.
[0008] Preferably, a sponge board is arranged on the outer surface of the water collecting tank.
[0009] Preferably, a sponge cylinder is sleeved on the outer surface of the downcomer.
[0010] Preferably, a plurality of first barbs are uniformly and fixedly connected to the outer side of the water collecting tank, and the first barbs are obliquely and fixedly installed on the outer side of the water collecting tank.
[0011] Preferably, a plurality of second barbs are uniformly and fixedly connected to the side wall of the downcomer, and the second barbs are obliquely and fixedly connected to the outer side of the downcomer.
[0012] Preferably, an elastic ring is sleeved on the outer side of the sponge cylinder, and the elastic ring is of a closed ring structure.
[0013] In summary:
[0014] In the present utility model, the function of the preposed electric heating tube is to heat the flue gas temperature to the sublimation / vaporization temperature of ABS when there is a blockage, so as to realize the cleaning of the ash accumulation. By setting the above structure, the volatilization of ABS is effectively promoted, the probability of system blockage and ash accumulation is reduced, and the service performance of the low-temperature economizer is improved to a certain extent. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Figure 1 is a three-dimensional structure schematic diagram of the present utility model;
[0016] Figure 2 is in the present utility model Figure 1 enlarged view of part A;
[0017] Figure 3 is in the present utility model Figure 2 enlarged view of part B.
[0018] Legend: 1, water inlet pipe; 2, water inlet header; 3, water outlet pipe; 4, water outlet header; 5, top steam-water heat exchanger; 6, water collecting tank; 7, plate heat exchange fin; 8, downcomer; 9, bottom heat medium water tank; 10, preposed electric heating tube; 11, sponge board; 12, sponge cylinder; 13, first barb; 14, second barb; 15, elastic ring. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0019] Referring to Figures 1-3 as shown, the present utility model provides a technical solution: a novel low-temperature economizer for deashing by using preposed electric heating, including a water inlet header 2, a water inlet pipe 1 connected to the water inlet header 2 and installed on a sealed box body, a water outlet header 4, and a water outlet pipe 3 connected to the water outlet header 4 and installed on the sealed box body.
[0020] Next, the overall specific settings and functions will be specifically described.
[0021] In this implementation scheme: several pipes located inside the top steam-water heat exchanger 5 and communicating with the water inlet header 2 and the water outlet header 4, several plate heat exchange fins 7 arranged at equal intervals inside the wide-channel heat exchanger, the bottom heat medium water tank 9 located below the plate heat exchange fins 7 and the water collection tank 6 located above, the downcomer 8 connecting the bottom heat medium water tank 9 and the water collection tank 6, and several preheating electric heating pipes 10.
[0022] Specifically, a sponge plate 11 is arranged on the outer surface of the water collection tank 6, a sponge cylinder 12 is sleeved on the outer surface of the downcomer 8, several first barbs 13 are uniformly and fixedly connected to the outside of the water collection tank 6, the first barbs 13 are obliquely and fixedly installed on the outside of the water collection tank 6, several second barbs 14 are uniformly and fixedly connected to the side wall of the downcomer 8, the second barbs 14 are obliquely and fixedly connected to the outside of the downcomer 8, and an elastic ring 15 is sleeved on the outside of the sponge cylinder 12, and the elastic ring 15 is a closed ring structure.
[0023] Working principle: The waste heat flue gas at the outlet of the air preheater passes through the wide-flow channel heat exchange plate, transferring the waste heat to the plate heat exchange fins 7. After heat exchange in the wide-channel heat exchanger, the heat medium water turns into a steam-water mixture and rises until it becomes steam and enters the top steam-water heat exchanger 5; after heat exchange with the top steam-water heat exchanger 5, the steam condenses, and the steam turns into condensate droplets, which flow back to the water collection tank 6 through the inclined plate at the lower part of the top header; the heat medium water in the water collection tank 6 utilizes the density difference and flows back to the bottom heat medium water tank 9 under the action of gravity through the downcomer 8; the water in the bottom heat medium water tank 9 utilizes the density difference between the downcomer 8 and the heat plate, and at the same time, under the combined action of the upward force of the steam bubbles on the heat plate and the partial capillary condensed liquid film force, it enters the plate heat exchange fins 7 for heating. Thus, the heat medium water forms a self-contained cycle. After passing through the top heat exchanger, the boiler condensate is heated and directly returns to the condensate outlet pipe. Since the boiler condensate pipe does not contact the flue gas and only exchanges heat with the top steam, there is no risk of leakage, and zero leakage of the boiler condensate can be achieved. The electric heating tube is turned on to heat the flue gas. After the flue gas is heated, it contacts and transfers heat with the ABS adsorbed on the surface of the heat exchange fins. When it reaches a certain temperature, the ABS exits the economizer in a gaseous or liquid form with the flue gas, thereby realizing the cleaning of the ABS. By setting the sponge plate 11, the heat preservation effect during the use of the water collection tank 6 is facilitated, and further, the condensation efficiency of the water liquid inside the water collection tank 6 is improved. The setting of the first barb 13 improves the stability of the sponge plate 11 fixed on the outside of the water collection tank 6 for use. Similarly, the setting of the sponge cylinder 12 facilitates the heat preservation work during the flow of the water liquid inside the downcomer 8, avoiding the influence of external factors on the water liquid. By setting the second barb 14, the stability of the sponge sleeve sleeved on the outside of the downcomer 8 for use is improved. By setting the elastic ring 15 with a closed structure, the stability of the sponge cylinder 12 shrunk on the surface of the downcomer 8 for use is improved, and further, the performance of the sponge cylinder 12 is improved. The function of the pre-positioned electric heating tube 10 is to heat the flue gas temperature to the sublimation / vaporization temperature of the ABS when it is blocked, realizing the cleaning of the ash accumulation. By setting the above structure, the volatilization of the ABS is effectively promoted, the probability of system blockage and ash accumulation is reduced, and to a certain extent, the performance of the low-temperature economizer is improved.
[0024] In the description of the present invention, it should be noted that unless otherwise clearly defined and limited, the terms "installation", "connection", and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood through specific situations.
Claims
1. A novel low-temperature economizer that uses preheating to achieve ash removal, characterized in that: It includes an inlet header (2), an inlet pipe (1) connected to the inlet header (2) and installed on a sealed housing, an outlet header (4), an outlet pipe (3) connected to the outlet header (4) and installed on the sealed housing, a number of pipes located inside the top steam-water heat exchanger (5) and communicating with the inlet header (2) and the outlet header (4), a number of plate heat exchange fins (7) arranged at equal intervals inside the wide-channel heat exchanger, a bottom heat medium water tank (9) below the plate heat exchange fins (7) and a water collecting trough (6) above, a downcomer (8) connecting the bottom heat medium water tank (9) and the water collecting trough (6), and a number of preheating electric heating tubes (10).
2. The novel low-temperature economizer for ash removal by means of pre-positioned electric heating according to claim 1, wherein: A sponge board (11) is arranged on the outer surface of the water collecting trough (6).
3. A novel low-temperature economizer for ash removal using pre-positioned electric heating according to claim 1, characterized in that: A sponge cylinder (12) is sleeved on the outer surface of the downcomer (8).
4. A novel low-temperature economizer for ash removal using pre-positioned electric heating according to claim 1, characterized in that: A number of first barbs (13) are uniformly and fixedly connected to the outer side of the water collecting trough (6), and the first barbs (13) are obliquely and fixedly installed on the outer side of the water collecting trough (6).
5. A novel low-temperature economizer for ash removal using preheating by electricity according to claim 1, characterized in that: A number of second barbs (14) are uniformly and fixedly connected to the side wall of the downcomer (8), and the second barbs (14) are obliquely and fixedly connected to the outer side of the downcomer (8).
6. The novel low-temperature economizer for ash removal using pre-positioned electric heating according to claim 3, wherein: An elastic ring (15) is sleeved on the outer side of the sponge cylinder (12), and the elastic ring (15) is a closed ring structure.