Small micro-superheated steam through-flow type gas condensing boiler

Abstract

The invention discloses a small micro-superheated steam through-flow type gas condensation boiler, belongs to the technical field of boilers, and solves the problems that the current small gas boiler is developed towards the high-efficiency, low-emission and compact direction, and particularly pays attention to waste heat recovery and steam quality control. Comprising an annular water chamber allowing water to enter, a combustion chamber arranged above the annular water chamber and an ultra-low nitrogen surface fiber combustor located above the combustion chamber and communicated with the combustion chamber, and an annular steam chamber is arranged above the combustion chamber. The ultra-low nitrogen surface fiber burner works to burn gas and raise the temperature, and the composite fin straight water pipe converts water in the water pipe into wet steam through efficient heat exchange of the spiral fins and enters the annular steam chamber. External water is injected into the annular water chamber through the finned tube group of the flue gas condenser and the connecting tube, and then enters the steam chamber through the straight tube. Wet steam in the steam chamber enters the superheater through an inlet pipe to form micro superheated steam. Combustion smoke is condensed and discharged after being filtered by a filter screen and subjected to heat exchange, and dryness of the combustion chamber is guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of boilers, and particularly relates to a small-scale micro-superheated steam once-through gas condensing boiler. Background Art

[0002] A gas boiler is a heating device that uses gases such as natural gas as fuel. It burns natural gas and transfers heat to water or steam using high-temperature flames and flue gas, and can produce hot water or steam for industrial production, civil heating, etc. It has a high thermal efficiency, up to 90% or even higher, and can meet different scales of heat energy requirements. At the same time, the gas boiler has good environmental protection performance, low nitrogen oxide emissions, meets the current requirements of energy conservation and emission reduction, and has a flexible installation method, relatively low requirements for the site, and is convenient for operation and maintenance.

[0003] However, currently small-scale gas boilers are developing towards high efficiency, low emissions, and compactness, with particular emphasis on waste heat recovery and steam quality control.

[0004] Therefore, a small-scale micro-superheated steam once-through gas condensing boiler is proposed to solve or alleviate the above problems. Summary of the Invention

[0005] The purpose of the invention is to solve the deficiencies existing in the prior art, and a small-scale micro-superheated steam once-through gas condensing boiler is proposed.

[0006] To achieve the above purpose, the invention adopts the following technical solutions: A small-scale micro-superheated steam once-through gas condensing boiler, including an annular water chamber that can be provided with water inlet, a combustion chamber arranged above it, and an ultra-low nitrogen surface fiber burner located above the combustion chamber and communicating with the combustion chamber. An annular steam chamber is arranged above the combustion chamber. A composite fin straight water pipe passing through the combustion chamber is connected between the annular water chamber and the annular steam chamber. An overheater bare tube group is arranged in the combustion chamber. The lower end of the overheater bare tube group is connected to the annular steam chamber through a wet steam inlet pipe, and the upper end of the overheater bare tube group is connected to an overheated steam pipe that penetrates through the combustion chamber and can be opened and closed.

[0007] Preferably, a steam valve is connected to the overheated steam pipe to achieve opening and closing.

[0008] Preferably, a temperature sensor is connected to the overheated steam pipe.

[0009] Preferably, a filter screen is arranged in the combustion chamber at the connection between the combustion chamber and the ultra-low nitrogen surface fiber burner, and the filter screen is cylindrical.

[0010] Preferably, the combustion chamber is connected to a bottom annular smoke collecting chamber located below the annular water chamber, and the bottom annular smoke collecting chamber is connected to a smoke condensation water discharge port that can be opened and closed.

[0011] Preferably, a finned tube group of a flue gas condenser is arranged in the combustion chamber above the connection between the combustion chamber and the bottom annular smoke collecting chamber. The lower end of the finned tube group of the flue gas condenser is communicated with a pipe penetrating through the combustion chamber to the outside, and a water supply check valve is communicated with this pipe. The upper end of the finned tube group of the flue gas condenser is communicated with a connecting pipe that penetrates through the combustion chamber to the outside and then penetrates through the bottom annular smoke collecting chamber until it reaches the annular water chamber.

[0012] Preferably, an electric control safety valve is communicated with the top of the annular steam chamber. A pressure sensor and a pressure switch are installed on the annular steam chamber. The probe of the pressure sensor extends into the annular steam chamber, and the pressure sensor is coupled with the pressure switch. The pressure switch is coupled with the electric control safety valve.

[0013] Preferably, the number of the composite finned straight water pipes is several, and several composite finned straight water pipes are arranged in an annular array with the central axis of the annular water chamber as the center.

[0014] Preferably, the composite finned straight water pipe includes a straight pipe in a circular tube shape and a spiral fin fixedly connected to the outer circle of the branch pipe and arranged along its length direction.

[0015] The invention has the following beneficial effects: When the present invention provides fuel combustion, the ultra-low nitrogen surface fiber burner works to make the gas in the combustion chamber burn to generate heat and the temperature rises. The composite finned straight water pipe improves the heat exchange efficiency through the spiral fins, and the water in the straight pipe quickly turns into wet steam and enters the annular steam chamber. At the same time, the outside water source continuously injects water, and the conventional water enters the annular water chamber through the finned tube group of the flue gas condenser and the connecting pipe, and then enters the steam chamber through the straight pipe. After the wet steam increases in the steam chamber, it enters the superheater smooth tube group through the wet steam inlet pipe and is heated into slightly superheated steam to ensure the steam quality and temperature. The flue gas after combustion is filtered by the filter screen, exchanges heat with the superheater smooth tube group and the finned tube group of the flue gas condenser to realize waste heat recovery. The flue gas is condensed and then discharged into the smoke collecting chamber, and is discharged after heat exchange with the connecting pipe to keep the combustion chamber dry. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the invention, the following will briefly introduce the drawings required to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the invention, and therefore should not be regarded as a limitation of the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0017] Figure 1 is a structural schematic diagram of the invention; Figure 2 is a partial cross-sectional view of the composite finned straight water pipe in the invention; Figure 3 Cross-sectional view of the composite fin straight water pipe in the invention.

[0018] 1. Ultra-low nitrogen surface fiber burner; 2. Combustion chamber; 3. Filter screen; 4. Superheater bare tube group; 5. Superheated steam pipe; 6. Temperature sensor; 7. Steam valve; 8. Bottom annular smoke collecting chamber; 9. Flue gas condensate discharge port; 10. Annular water chamber; 11. Flue gas condenser fin tube group; 12. Feed water check valve; 13. Connecting pipe; 14. Composite fin straight water pipe; 141. Straight pipe; 142. Spiral fin; 15. Annular steam chamber; 16. Electric control safety valve; 17. Pressure sensor; 18. Pressure switch; 19. Wet steam inlet pipe. Detailed implementation mode

[0019] To make the objectives, technical solutions and advantages of the embodiments of the invention clearer, the technical solutions in the embodiments of the invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the invention. Obviously, the described embodiments are some but not all of the embodiments of the invention. Usually, the components of the embodiments of the invention described and illustrated in the accompanying drawings here can be arranged and designed in various different configurations.

[0020] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the invention without creative efforts fall within the scope of protection of the invention.

[0021] It should be noted that: similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0022] In the description of the invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of the invention is usually placed during use, or the orientation or positional relationship commonly understood by those skilled in the art. It is only for the convenience of describing the invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention.

[0023] In addition, the terms "first", "second", "third", etc. are only used for descriptive distinction and cannot be understood as indicating or implying relative importance.

[0024] In the description of the invention, it should also be noted that unless otherwise clearly specified and defined, the terms "set", "installed", "connected", and "linked" 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 invention can be understood according to specific circumstances.

[0025] A small and slightly superheated steam once-through gas condensing boiler, as Figure 1 shown, includes an annular water chamber 10 that can be set to admit water, a combustion chamber 2 arranged above it, and an ultra-low nitrogen surface fiber burner 1 located above the combustion chamber 2 and communicating with the combustion chamber 2. An annular steam chamber 15 is arranged above the combustion chamber 2. A composite fin straight water pipe 14 passing through the combustion chamber 2 is connected between the annular water chamber 10 and the annular steam chamber 15. A superheater bare tube group 4 is arranged in the combustion chamber 2. The lower end of the superheater bare tube group 4 is connected to the annular steam chamber 15 through a wet steam inlet pipe 19. The upper end of the superheater bare tube group 4 is connected to a superheated steam pipe 5 that penetrates through the combustion chamber 2 and can be opened and closed. A steam valve 7 is connected to the superheated steam pipe 5 to achieve opening and closing, and a temperature sensor 6 is connected to the superheated steam pipe 5.

[0026] A filter screen 3 is arranged in the combustion chamber 2 at the connection between the combustion chamber 2 and the ultra-low nitrogen surface fiber burner 1. The filter screen 3 is cylindrical. The combustion chamber 2 is connected to a bottom annular smoke collecting chamber 8 located below the annular water chamber 10. The bottom annular smoke collecting chamber 8 is connected to a smoke condensate discharge port 9 that can be opened and closed.

[0027] A flue gas condenser fin tube group 11 is arranged in the combustion chamber 2 above the connection between the combustion chamber 2 and the bottom annular smoke collecting chamber 8. The lower end of the flue gas condenser fin tube group 11 is connected to a pipe that penetrates through the combustion chamber 2 to the outside, and a feed water check valve 12 is connected to this pipe. The upper end of the flue gas condenser fin tube group 11 is connected to a connecting pipe 13 that penetrates through the combustion chamber 2 to the outside and then penetrates through the bottom annular smoke collecting chamber 8 until it reaches the annular water chamber 10. The number of the composite fin straight water pipes 14 is several, and several composite fin straight water pipes 14 are arranged in a circular array with the central axis of the annular water chamber 10 as the center, as Figure 2 and Figure 3 shown. The composite fin straight water pipe 14 includes a straight pipe 141 in the shape of a circular tube and a spiral fin 142 fixedly connected to the outer circle of the branch pipe and arranged along its length direction.

[0028] The top of the annular steam chamber 15 is connected to an electronically controlled safety valve 16. A pressure sensor 17 and a pressure switch 18 are installed on the annular steam chamber 15. The probe of the pressure sensor 17 extends into the annular steam chamber 15, and the pressure sensor 17 is coupled to the pressure switch 18, and the pressure switch 18 is coupled to the electronically controlled safety valve 16.

[0029] During the actual application of the invention, the ultra-low nitrogen surface fiber burner 1 works and burns, causing the gas in the combustion chamber 2 to burn, thereby generating a large amount of heat. The temperature in the combustion chamber 2 rises rapidly, enabling the composite fin straight pipe 14 to improve the heat exchange efficiency through the spiral fins 142, allowing the water in the straight pipe 141 to quickly turn into wet steam and enter the annular steam chamber 15. During this process, external water continuously injects into the pipe where the water supply check valve 12 is located, enabling the conventional water to pass through the flue gas condenser fin tube group 11 and then enter the annular water chamber 10 through the connecting pipe 13. The water in the annular water chamber 10 enters the annular steam chamber 15 through the straight pipe 141. As the amount of subsequent steam gradually increases, the wet steam that has just transformed and is in the annular steam chamber 15 can enter the superheater bare tube group 4 through the wet steam inlet pipe 19. When this part of the wet steam enters the superheater bare tube group 4, since the superheater bare tube group 4 is located in the combustion chamber 2, it can come into contact with the high-temperature environment, further heating the wet steam in the superheater bare tube group 4, turning the wet steam passing through the superheater bare tube group 4 into slightly superheated steam. This can ensure the control of the steam quality leaving, and at the same time, the temperature sensor 6 can detect the temperature of the steam leaving the superheated steam pipe 5, and finally leave through the steam valve 7 to complete the supply of steam. Also, if the pressure in the annular steam chamber 15 is too high, the electronically controlled safety valve 16 can be opened for appropriate pressure relief to avoid damage and leakage due to excessive pressure. In addition, the flue gas after combustion in the combustion chamber 2 can be filtered by a certain amount by the filter screen 3 first, and then the flue gas exchanges heat with the superheater bare tube group 4 and the flue gas condenser fin tube group 11 in sequence. Especially after contacting the flue gas condenser fin tube group 11, the flue gas can be significantly cooled, and at the same time, the external water in the flue gas condenser fin tube group 11 is preheated, thus achieving a good effect of waste heat recovery. The flue gas after waste heat recovery can be condensed to form flue gas condensate, which enters the bottom annular smoke collecting chamber 8 along with the remaining flue gas. The flue gas in the bottom annular smoke collecting chamber 8 can exchange heat with the connecting pipe 13 for further condensation, so as to be finally discharged through the flue gas condensate discharge port 9, preventing a large accumulation of flue gas and flue gas condensate in the combustion chamber 2 and ensuring that the combustion chamber 2 has good dryness for combustion.

[0030] The above are only the preferred embodiments of the invention and are not intended to limit the invention. For those skilled in the art, the invention can have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the invention shall be included within the protection scope of the invention.

Claims

1. A small-sized slightly superheated steam once-through gas condensing boiler, characterized in that, It includes an annular water chamber (10) with a water inlet setting, a combustion chamber (2) arranged above it, and an ultra-low nitrogen surface fiber burner (1) located above the combustion chamber (2) and communicating with the combustion chamber (2). An annular steam chamber (15) is arranged above the combustion chamber (2). A composite fin straight water pipe (14) passing through the combustion chamber (2) is connected between the annular water chamber (10) and the annular steam chamber (15). A superheater bare tube group (4) is arranged in the combustion chamber (2). The lower end of the superheater bare tube group (4) is connected to the annular steam chamber (15) through a wet steam inlet pipe (19). The upper end of the superheater bare tube group (4) is connected to a superheated steam pipe (5) that penetrates the combustion chamber (2) and can be opened and closed.

2. A small and slightly overheated steam once-through gas condensing boiler according to claim 1, characterized in that, A steam valve (7) is connected to the superheated steam pipe (5) to achieve opening and closing.

3. A small-scale micro overheated steam once-through gas condensing boiler according to claim 1, characterized in that, A temperature sensor (6) is connected to the superheated steam pipe (5).

4. A small-scale micro overheated steam once-through gas condensing boiler according to claim 1, characterized in that, A filter screen (3) is arranged in the combustion chamber (2) at the connection between the combustion chamber (2) and the ultra-low nitrogen surface fiber burner (1), and the filter screen (3) is in a cylindrical shape.

5. A small-scale micro overheated steam once-through gas condensing boiler according to claim 1, characterized in that, The combustion chamber (2) is connected to a bottom annular smoke collecting chamber (8) located below the annular water chamber (10), and the bottom annular smoke collecting chamber (8) is connected to a flue gas condensate discharge port (9) that can be opened and closed.

6. A small and slightly superheated steam once-through gas condensing boiler according to claim 5, characterized in that, A flue gas condenser fin tube group (11) is arranged in the combustion chamber (2) above the connection between the combustion chamber (2) and the bottom annular smoke collecting chamber (8). The lower end of the flue gas condenser fin tube group (11) is connected to a pipe that penetrates the combustion chamber (2) to the outside, and a feed water check valve (12) is connected to this pipe. The upper end of the flue gas condenser fin tube group (11) is connected to a connecting pipe (13) that penetrates the combustion chamber (2) to the outside and then penetrates the bottom annular smoke collecting chamber (8) until it reaches the annular water chamber (10).

7. A small and slightly superheated steam once-through gas condensing boiler according to claim 1, characterized in that, An electric control safety valve (16) is connected to the top of the annular steam chamber (15). A pressure sensor (17) and a pressure switch (18) are installed on the annular steam chamber (15). The probe of the pressure sensor (17) extends into the annular steam chamber (15), and the pressure sensor (17) is coupled to the pressure switch (18), and the pressure switch (18) is coupled to the electric control safety valve (16).

8. A small and slightly overheated steam once-through gas condensing boiler according to claim 6, characterized in that, The number of the composite fin straight water pipes (14) is several, and several composite fin straight water pipes (14) are arranged in a circular array with the central axis of the annular water chamber (10) as the center.

9. A small and slightly superheated steam once-through gas condensing boiler according to claim 8, characterized in that, The composite fin straight water pipe (14) includes a straight pipe (141) in a circular tube shape and a spiral fin (142) fixedly connected to the outer circle of the branch pipe and arranged along its length direction.

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