Effective U-shaped economizer double-recirculation system
By introducing a dual recirculation system and a one-way check valve into the U-shaped economizer, the steam retention and pipe explosion problems caused by the single-circulation design are solved, and the smooth flow of circulating water and the stability and safety of the system are achieved.
Patent Information
- Application Number
- CN202421919802.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-09
- Publication Date
- 2025-05-30
- Estimated Expiration
- 2034-08-09
AI Technical Summary
The single cycle design of the existing U-shaped economizer is likely to cause steam retention, which in turn causes circulation stagnation and pipe bursting.
The U-shaped economizer dual recirculation system is adopted. By setting up a second connecting pipe connecting the steam drum and the U-shaped connecting pipe and the third connecting pipe connecting the U-shaped economizer and the steam drum, a one-way check valve is installed in these connecting pipes to ensure that the circulating water flows from bottom to top and avoid steam retention.
The water circulation in the economizer is smooth, and the steam is retained is avoided, ensuring that the economizer will not explode due to stagnation of circulation, improving the stability and safety of the system.
Smart Images
Figure CN222925486U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to a boiler economizer, specifically an effective U-shaped economizer double recirculation system. Background Art
[0002] With the economic development and the promotion of garbage classification collection, the calorific value of domestic waste has increased rapidly, and the urban waste incineration treatment is also developing towards large-scale and centralized. The three-pass heating surface of the vertical boiler is prone to ash accumulation, which affects the operation cycle of the boiler. Therefore, large waste incineration boilers basically adopt horizontal boilers. The economizer of the early horizontal boiler was a horizontal small header structure. Due to the manufacturing process and uneven operation expansion of this header structure, it was very easy to burst pipes, and the problem of water conveyance could not be solved by making it into a serpentine tube structure; at the same time, due to structural reasons, the economizer could not be made into a recirculation system. Therefore, the evaporator and superheater were made into a horizontal structure, and the economizer was made into a vertical structure, which solved the problem of ash accumulation in the evaporator and superheater; however, the number of vertical economizer tube boxes was large, occupying a large space in the flue gas flow direction. The height of the horizontal boiler was generally lower than that of the vertical boiler, and the height of the horizontal flue was also relatively high. Therefore, the height of a single flue could basically not accommodate the economizer, and the economizer needed to be arranged in a U-shape in two flues. The water flow direction of the U-shaped economizer is to enter from the inlet header at the upper part of one flue, make a 180° turn at the lower part of this flue and then enter the lower part of the other flue, and then be output from the outlet header at the upper part of this flue. However, the water circulation is a single circulation mode, that is, the recirculated water output from the steam drum enters from the inlet header, is output from the outlet header and then flows back to the steam drum; in this way, steam is easily retained at the inlet header, and even the water circulation stagnates, causing the economizer to burst pipes. Content of the Utility Model
[0003] The purpose of the utility model is to overcome the deficiencies of the above background art and provide an effective U-shaped economizer double recirculation system to ensure that the U-shaped economizer will not burst due to circulation stagnation.
[0004] In order to achieve the above purpose, the utility model adopts the following technical solutions:
[0005] An effective U-shaped economizer double recirculation system includes a steam drum, a vertically arranged U-shaped economizer, a first connecting pipe connecting the steam drum and the economizer outlet header in the U-shaped economizer, a third connecting pipe connecting the steam drum and the economizer inlet header in the U-shaped economizer, and a water supply pipe connecting the economizer inlet header. A U-shaped connecting pipe is arranged at the bottom end of the U-shaped economizer; its characteristic lies in that: the U-shaped economizer double recirculation system is also provided with a second connecting pipe connecting the steam drum and the U-shaped connecting pipe to input recirculated water to the economizer, and enabling the recirculated water to be conveyed to the steam drum through the third connecting pipe.
[0006] The second connecting pipe is provided with a one-way check valve, so that the second connecting pipe is only conducted in the direction towards the U-shaped connecting pipe.
[0007] The third connecting pipe is provided with a one-way check valve, so that the third connecting pipe is only conductive in the direction of the steam drum.
[0008] Each feed water pipe is provided with a one-way check valve, so that the feed water pipe is only conductive in the direction of the inlet header of the U-shaped economizer.
[0009] The U-shaped economizer includes a front header of the economizer and a rear header of the economizer which are vertically arranged, the economizer outlet header and the first lower header of the economizer arranged at the upper and lower ends of the front header of the economizer, the economizer inlet header and the second lower header of the economizer arranged at the upper and lower ends of the rear header of the economizer, and the U-shaped connecting pipe connecting the first lower header of the economizer and the second lower header of the economizer; a group of economizer tube sheets are arranged in both the front header of the economizer and the rear header of the economizer.
[0010] A first ash hopper is arranged below the first lower header of the economizer, and a second ash hopper is arranged below the second lower header of the economizer.
[0011] The U-shaped economizer is installed in the inner cavity of a U-shaped flue.
[0012] The beneficial effects of the utility model are as follows: Since the circulating water in the entire economizer can flow from bottom to top, the steam generated by heating the economizer tube sheets can smoothly enter the steam drum together with the circulating water, and the situation that the steam stays and hinders the circulating water will no longer occur at the economizer inlet header part, thereby effectively eliminating the accident hidden danger of tube explosion. Brief Description of the Drawings
[0013] The following is further described with reference to the embodiments shown in the drawings.
[0014] Figure 1 It is a schematic structural diagram of an embodiment of the utility model.
[0015] Figure 2 It is a schematic structural diagram of an existing U-shaped economizer.
[0016] Reference numerals in the drawings: steam drum 1, front header of the economizer 2, fifth economizer tube sheet 2-1, sixth economizer tube sheet 2-2, rear header of the economizer 3, first economizer tube sheet 3-1, second economizer tube sheet 3-2, third economizer tube sheet 3-3, fourth economizer tube sheet 3-4, economizer inlet header 4, economizer outlet header 5, first lower header of the economizer 6, second lower header of the economizer 7, one-way check valve 8, U-shaped connecting pipe 9, first ash hopper 10, U-shaped flue 11, second ash hopper 12, first connecting pipe 13, second connecting pipe 14, third connecting pipe 15, feed water pipe 16. Detailed Embodiment
[0017] The U-shaped economizer double recirculation system shown in the accompanying drawings includes a steam drum 1, a vertically arranged U-shaped economizer, a first connecting pipe 13 connecting the steam drum and the U-shaped economizer outlet header 5, a third connecting pipe 15 connecting the steam drum and the U-shaped economizer inlet header 4, and a water supply pipe 16 connecting the U-shaped economizer inlet header, and a U-shaped connecting pipe 9 is provided at the bottom end of the U-shaped economizer; the above structure is similar to the existing U-shaped economizer.
[0018] The improvement of the utility model is that the U-shaped economizer double recirculation system is further provided with a second connecting pipe 14 connecting the steam drum and the U-shaped connecting pipe, which is used to input recirculating water to the economizer, and allows part of the recirculating water to be input to the steam drum through the third connecting pipe;
[0019] Furthermore, the second connecting pipe is provided with a one-way check valve so that the recirculating water passing through the second connecting pipe only flows in the direction of the U-shaped connecting pipe;
[0020] Furthermore, the third connecting pipe is provided with a one-way check valve so that the circulating water passing through the third connecting pipe only flows toward the steam drum.
[0021] Furthermore, the water supply pipes are all provided with one-way check valves 8, so that the water supply pipes are only connected to the direction of the U-shaped economizer inlet header.
[0022] The U-shaped economizer includes a vertically arranged economizer front pipe box (2) and an economizer rear pipe box (3), an economizer outlet header and a first economizer lower header arranged at the upper and lower ends of the economizer front pipe box, an economizer inlet header and a second economizer lower header arranged at the upper and lower ends of the economizer rear pipe box, and the U-shaped connecting pipe connecting the first economizer lower header and the second economizer lower header; a group of economizer segments (including the fifth economizer segment 2-1 and the sixth economizer segment 2-2 connected in sequence) are arranged in the economizer front pipe box, and a group of economizer segments (including the first economizer segment 3-1, the second economizer segment 3-2, the third economizer segment 3-3, and the fourth economizer segment 3-4 connected in sequence) are also arranged in the economizer rear pipe box. A first ash hopper (composed of a steel plate) is disposed below the first lower header of the economizer, and a second ash hopper (composed of a steel plate) is disposed below the second lower header of the economizer. The U-shaped economizer is installed in the inner cavity of the U-shaped flue. Obviously, this is a conventional structure of a U-shaped economizer.
[0023] Working principle: During normal operation, the boiler feed water enters the economizer inlet header 4 through the feed water pipe 16 in sequence, then passes through a group of economizer tube sheets (flowing through the fourth economizer tube sheet 3-4, the third economizer tube sheet 3-3, the second economizer tube sheet 3-2, and the first economizer tube sheet 3-1 in sequence), the second lower header 7 of the economizer, and then enters the U-shaped connecting pipe 9, the first lower header 6 of the economizer, another group of economizer tube sheets (flowing through the sixth economizer tube sheet 2-2 and the fifth economizer tube sheet 2-1 in sequence), the economizer outlet header 5, and the first connecting pipe 13 to enter the steam drum 1. During recirculation, the water comes out of the steam drum, is transported to the U-shaped connecting pipe through the third connecting pipe 14, and then is divided into two parts of water flow. One part enters the second lower header of the economizer, a group of economizer tube sheets (flowing through the first economizer tube sheet 3-1, the second economizer tube sheet 3-2, the third economizer tube sheet 3-3, and the fourth economizer tube sheet 3-4 in sequence), the economizer inlet header, and the second connecting pipe 15 to return to the steam drum. The other part passes through the first lower header 6 of the economizer, another group of economizer tube sheets (flowing through the sixth economizer tube sheet 2-2 and the fifth economizer tube sheet 2-1 in sequence), the economizer outlet header 5, and the first connecting pipe to flow back to the steam drum. Since the water flows from bottom to top, it can ensure that when the economizer tube sheets are heated, the water flows from bottom to top, and a natural circulation can be formed in the whole economizer. Steam cannot stay in the economizer inlet header, which can ensure that the economizer will not burst due to stagnant water circulation.
Claims
1. An effective U-shaped economizer double recirculation system, comprising a steam drum (1), a vertically arranged U-shaped economizer, a first connecting pipe (13) connecting the steam drum with an economizer outlet header (5) in the U-shaped economizer, a third connecting pipe (15) connecting the steam drum with an economizer inlet header (4) in the U-shaped economizer, and a water supply pipe (16) connecting the economizer inlet header, wherein a U-shaped connecting pipe (9) is arranged at the bottom end of the U-shaped economizer; and characterized in that: The U-shaped economizer double recirculation system is also provided with a second connecting pipe (14) connecting the steam drum and the U-shaped connecting pipe, so as to input recirculating water to the economizer, and the recirculating water is input to the steam drum through the third connecting pipe.
2. The effective U-type economizer dual recirculation system according to claim 1, characterized in that: The second connecting pipe is provided with a one-way check valve (8), so that the second connecting pipe is only connected to the U-shaped connecting pipe; The third connecting pipe is provided with a one-way check valve so that the third connecting pipe is only connected to the steam drum; The water supply pipes are all equipped with one-way check valves, so that the water supply pipes are only connected to the U-shaped economizer inlet header.
3. The effective U-type economizer dual recirculation system according to claim 2, characterized in that: The U-shaped economizer comprises a vertically arranged economizer front pipe box (2) and an economizer rear pipe box (3), the economizer outlet header and the economizer first lower header (6) arranged at the upper and lower ends of the economizer front pipe box, the economizer inlet header and the economizer second lower header (7) arranged at the upper and lower ends of the economizer rear pipe box, and the U-shaped connecting pipe connecting the economizer first lower header and the economizer second lower header; a group of economizer tube segments are arranged in the economizer front pipe box and the economizer rear pipe box.
4. The effective U-type economizer dual recirculation system according to claim 3, characterized in that: A first ash hopper (10) is arranged below the first lower header of the economizer, and a second ash hopper (12) is arranged below the second lower header of the economizer.
5. The effective U-type economizer dual recirculation system according to claim 4, characterized in that: The U-shaped economizer is installed in the inner cavity of the U-shaped flue (11).