A high temperature economizer for the tail flue of a thermal power generator set
By setting up light pipe economizers and H-type high-temperature economizers in the tail flue of the thermal generator set, and connecting them through the sealing structure of the middle partition wall, the problems of insufficient space and high transformation costs are solved, and smoke temperature drop and water supply are achieved The temperature equality improves heat transfer efficiency.
Patent Information
- Application Number
- CN201911392573.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2019-12-30
- Publication Date
- 2024-12-13
- Estimated Expiration
- 2039-12-30
AI Technical Summary
Due to space limitations in the tail flue of the thermal generator set, the high-temperature economizer has problems such as insufficient space and high transformation costs. The flue gas temperature drop and water supply temperature rise are affected by the adjustment of the flue gas baffle opening, resulting in the heat exchange of economizer. Uneven.
The light pipe economizer and H-type high-temperature economizer are installed in the front shaft flue, and a sealing plate and casing are installed through the middle partition wall to connect the first and second H-type high-temperature economizers to form a series structure to ensure the smoke The balance between temperature drop and water supply temperature avoids the installation of economizer coupling box and reduces the cost of transformation.
It realizes effective guarantee of smoke temperature drop and water supply temperature, maintains the relative balance of heat exchange of economizer, reduces the transformation cost, avoids the impact of flue gas baffle opening adjustment on economizer, and improves heat transfer efficiency.
Smart Images
Figure CN111043587B_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a high-temperature economizer for a tail flue of a thermal power generating set. Background Art
[0002] The tail flue of the thermal power generator set is divided into a front shaft and a rear shaft flue. The front shaft and the rear shaft flue are separated by a partition wall. The front and rear flues are not connected to each other to adjust the damper. The front shaft and the rear shaft flue are respectively arranged with a low-temperature reheater and a low-temperature superheater. The high-temperature economizer is arranged in the front shaft or the rear shaft flue. The flue gas is diverted by adjusting the opening of the flue gas damper to achieve the purpose of adjusting the steam temperature. In recent years, due to the high limit of the inlet flue gas temperature of the denitrification catalyst and the energy-saving requirements, the high-temperature economizer has been improved by increasing the heat exchange area and improving the heat exchange efficiency. A common method is to add a light tube bundle of a light tube economizer in the front shaft or the rear shaft flue. , adding or replacing fin tube bundles, etc., such changes are simple and low-cost, but the thermal power generating units need to adjust the load according to the load requirements of the power grid, the combustion conditions change frequently, and the flue gas dampers of the superheater and reheater are often adjusted according to the changes in steam temperature. If an economizer is to be added below the low-temperature superheater, due to space limitations, there is a problem of insufficient space if the transformation effect is to be guaranteed. If a tube screen is added below one side of the low-temperature reheater and connected through pipelines, due to the setting of the middle partition wall, it is bound to be necessary to add an economizer header below the low-temperature reheater, the load will increase significantly, the transformation cost is high, and there is a safety risk of different expansion of the two sets of economizers. Summary of the invention
[0003] The present invention solves the deficiencies of existing conditions and provides a high-temperature economizer for the tail flue of a thermal power generator set with low transformation cost, effective guarantee of both smoke temperature drop and feed water temperature, and overcomes the influence of smoke temperature drop and feed water temperature rise on the adjustment of the smoke damper opening, so that the heat exchange of the economizer remains relatively balanced.
[0004] A high-temperature economizer for the tail flue of a thermal power generating unit comprises a bare tube economizer, an H-type economizer and an H-type economizer arranged in a front vertical shaft flue, wherein the front vertical shaft flue is provided with a bare tube economizer below a low-temperature superheater, and an intermediate partition wall is provided between the front vertical shaft flue and the rear vertical shaft flue, and a first H-type high-temperature economizer and a second H-type high-temperature economizer connected in series are respectively provided below the bare tube economizer and the low-temperature reheater, the first H-type high-temperature economizer is connected in series with the bare tube economizer, and the tube screens of the first H-type high-temperature economizer and the second H-type high-temperature economizer are connected to each other through the intermediate partition wall.
[0005] Furthermore, the middle partition wall is provided with an opening at the position where the tube panel passes through, and the tube panel is provided with a sleeve on the outside of the position corresponding to the opening, one end of the sleeve is seal-welded to the tube panel, and sealing plates are provided on the openings on both sides of the middle partition wall to seal the openings, and the sealing plates are seal-welded to the sleeve.
[0006] Furthermore, comb-type anti-wear clips and anti-wear dummy tubes are installed on the top row of tube panels of the first and second H-type high-temperature economizers.
[0007] Furthermore, anti-wear tiles are installed at the bend of the connecting pipe between the first H-type high-temperature economizer and the light tube economizer.
[0008] Furthermore, anti-wear covers are installed at the elbows at both ends of the tube panels of the first and second H-type high-temperature economizers.
[0009] The above structure is adopted, which changes the traditional arrangement of the original economizer only arranged on one side of the front and rear vertical shaft flues, and adds H-type high-temperature economizers in the front and rear vertical shaft flues. The H-type high-temperature economizer is arranged in series with the original light tube economizer. Under the condition of adjusting the dampers of the low-temperature superheater and the low-temperature reheater, a certain amount of flue gas in the front and rear vertical shaft flues passes through the H-type high-temperature economizer, so that the flue gas temperature drop and the feed water temperature can be effectively guaranteed, thereby overcoming the flue gas temperature drop and the feed water temperature rise affected by the flue gas damper opening adjustment. The overall effect makes the economizer heat exchange rate remain relatively balanced in each load section, and since the device is directly modified on the basis of the original economizer structure, the modification cost is low. A sealing plate is set at the position of the middle partition wall, the tube screen passes through the sealing plate, and a casing is welded on the tube screen. The casing and the sealing plate are sealed and welded to solve the weld cracking caused by stress changes between the middle partition wall and the economizer wall pipe, prevent wind from penetrating the chamber, and solve the safety hazard of the tube screen passing through the wall. There is no need to set an economizer header, which greatly saves the modification cost.
[0010] In summary, the present invention has low transformation cost, and both the flue gas temperature drop and the feed water temperature can be effectively guaranteed, thus overcoming the influence of the flue gas temperature drop and the feed water temperature rise on the flue gas damper opening adjustment, thereby maintaining a relatively balanced heat exchange of the economizer. BRIEF DESCRIPTION OF THE DRAWINGS
[0011] Figure 1 It is a structural schematic diagram of the present invention.
[0012] Figure 2 It is a schematic diagram of the structure of the tube panel passing through the middle partition wall of the present invention.
[0013] The figure is marked as: 1. front vertical shaft flue; 2. rear vertical shaft flue; 3. middle partition wall; 4. low-temperature superheater; 5. low-temperature reheater; 61. first H-type high-temperature economizer; 62. second H-type high-temperature economizer; 7. sealing plate; 8. casing; 9. tube screen. Specific implementation methods
[0014] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. In order to more clearly illustrate the technical solutions in the embodiments of this patent or the prior art, the accompanying drawings required for use in the embodiments or the description of the prior art are briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative labor.
[0015] like Figure 1 , 2 As shown, a high-temperature economizer for the tail flue of a thermal power generator unit comprises a light tube economizer, a first H-type high-temperature economizer 61 and a second H-type high-temperature economizer 62 arranged in a front vertical shaft flue 1, wherein the front vertical shaft flue 1 is provided with a light tube economizer below a low-temperature superheater 4, an intermediate partition wall 3 is provided between the front vertical shaft flue 1 and the rear vertical shaft flue 2, and the first H-type high-temperature economizer 61 and the second H-type high-temperature economizer 62 are respectively provided below the light tube economizer and the low-temperature reheater 5, which are interconnected. The tube panels 9 of the first H-type high-temperature economizer 61 and the second H-type high-temperature economizer 62 are interconnected through the middle partition wall 3. The middle partition wall 3 is provided with an opening at the position where the tube panel 9 passes through. The tube panel 9 is provided with a sleeve 8 on the outer side of the position corresponding to the opening. One end of the sleeve 8 is sealed and welded to the tube panel 9. Sealing plates 7 are provided on the openings on both sides of the middle partition wall 3 to seal the openings. The sealing plates 7 are sealed and welded to the sleeve 8, thereby ensuring that the sleeve and the sealing plate are tightly sealed and smoke-free.
[0016] The high-efficiency high-temperature economizer in this application refers to an economizer that adds an H-type fin economizer on the basis of the original light tube economizer, thereby increasing the heat transfer efficiency, reducing the smoke temperature, and increasing the feed water temperature.
[0017] Embodiment: This application arranges an H-type high-temperature economizer in a space of about 1.3 meters at an elevation of 32.994 meters and 31.582 meters below the original light tube economizer and low-temperature reheater. The H-type high-temperature economizer includes two types of double-fin tubes and single-fin tubes. The base tube specification of the H-type high-temperature economizer is Φ51×6.5mm, and the material is 20G, which is the same as the original economizer heating surface tube specification and material; the fins of the H-type high-temperature economizer have two specifications, 38×180mm and 38×40mm, both with a thickness of 2mm, a pitch between fins of 25mm, and a material of pickled carbon steel.
[0018] The transverse pitch of the H-type high-temperature economizer is 152.4mm, and the number of transverse rows is 78; the number of longitudinal rows is 10 in the front shaft flue and 8 in the rear shaft flue; the H-type high-temperature economizer tube screen is divided into two parts, the part in the front shaft flue is the first H-type high-temperature economizer, and the part in the rear shaft flue is the second H-type high-temperature economizer. The design flue gas velocity of the H-type high-temperature economizer is 8.77m / s, and the design working fluid flow rate is 1.36m / s.
[0019] In this embodiment, the H-type high-temperature economizer adopts the following anti-wear methods: first, comb-type anti-wear clips and anti-wear dummy tubes are installed on the top row of the H-type high-temperature economizer tube screen; second, anti-wear tiles are installed at the bends of the connecting pipes between the H-type high-temperature economizer and the light tube economizer; third, large anti-wear covers are installed at the elbows at both ends of the H-type high-temperature economizer tube screen.
[0020] After the equipment was put into operation, the feed water temperature of the equipment increased by 11.8℃, the flue gas temperature at the denitrification inlet decreased by 33.25℃, and the exhaust gas temperature decreased by 15.3℃ under the test conditions, which were better than the expected targets of feed water temperature increase of 4℃, denitrification inlet temperature decrease of 20℃, and exhaust gas temperature decrease of 8℃. At the same time, the overheated gas and flue gas dampers were freely adjusted, and the performance indicators remained stable, which was significantly optimized compared with the operation indicators after the single-side flue economizer transformation.
[0021] In addition, it should be noted that this patent is not limited to the above-mentioned embodiments. As long as the specific size or shape of its parts is not specified, the parts can be of any size or shape that is compatible with its structure, and regardless of any changes in its material composition, any structural design provided by the present invention is a variation of the present invention and should be considered to be within the scope of protection of the present invention.
Claims
1. A high-temperature economizer for the tail flue of a thermal power generating unit, characterized in that: The invention comprises a bare tube economizer, a first H-type high temperature economizer (61) and a second H-type high temperature economizer (62) arranged in a front vertical shaft flue (1), wherein the bare tube economizer is arranged below the low temperature superheater (4) in the front vertical shaft flue (1), and an intermediate partition wall (3) is arranged between the front vertical shaft flue (1) and the rear vertical shaft flue (2), and a first H-type high temperature economizer (61) and a second H-type high temperature economizer (62) connected in series are respectively arranged below the bare tube economizer and the low temperature reheater (5), and the first H-type high temperature economizer (61) is connected in series with the bare tube economizer, and the tube screens (9) of the first H-type high temperature economizer (61) and the second H-type high temperature economizer (62) are connected to each other through the intermediate partition wall (3).
2. The high-temperature economizer for the tail flue of a thermal power generator set according to claim 1, characterized in that: The middle partition wall (3) is provided with an opening at a position where the tube panel (9) passes through; the tube panel (9) is sleeved with a sleeve (8) at an outer side of a position corresponding to the opening; one end of the sleeve (8) is sealed and welded to the tube panel (9); sealing plates (7) are provided on the openings on both sides of the middle partition wall (3) to seal the openings; the sealing plates (7) are sealed and welded to the sleeve (8).
3. The high temperature economizer for the tail flue of a thermal power generating unit according to claim 2, characterized in that: Comb-shaped anti-wear clips and anti-wear dummy tubes are installed on a row of tube panels (9) at the top of the first and second H-type high-temperature economizers.
4. The high-temperature economizer for the tail flue of a thermal power generating unit according to claim 2, characterized in that: Anti-wear tiles are installed at the elbow of the connecting pipe between the first H-type high-temperature economizer (61) and the light tube economizer.
5. The high temperature economizer for the tail flue of a thermal power generating unit according to claim 2, characterized in that: Anti-wear covers are installed at the elbows at both ends of the tube panels (9) of the first and second H-type high-temperature economizers.