Mixed fuel fire-tube boiler with electric heating function

Abstract

The invention discloses a mixed fuel fire-tube boiler with an electric heating function and relates to the technical field of boilers for ships. The problems that in combustion of an ammonia boiler, needed ignition energy is large, the combustible range is narrow, the laminar flow combustion speed is low, combustion is unstable due to natural nitrogen, and nitrogen oxide emission is high are solved. A feed water heating cabin is arranged in the fire-tube boiler, so that the exhaust gas temperature can be greatly reduced, and the exhaust gas loss is reduced; in addition, the device can burn two fuels of No.0 diesel oil and ammonia gas together, clean energy ammonia gas fuel which is easy to store and low in price can be fully utilized, stable combustion of the ammonia fuel is guaranteed, and the calorific value of the fuel is properly increased. Further, the heat exchange efficiency is improved to 90%-95%; the fire-tube boiler with the structure is small in size, so that a large amount of marine space is saved; when the ship arrives at the shore, the requirement for water or steam on the ship is met through the electric heater, and water flows into the evaporation cabin to further generate steam after being preliminarily heated by the electric heater in the water heating cabin. The invention is suitable for the technical field of marine boilers.

Description

Technical Field

[0001] This invention relates to the field of marine boiler technology, and more specifically to a mixed-fuel fire-tube boiler with electric heating. Background Technology

[0002] Currently, space is limited on ships, and marine boiler designs strive to minimize size. Fire-tube boilers, due to their simple structure and ease of maintenance, are used as auxiliary boilers in vessels. The demand for green and clean fuel marine boilers is increasingly strong across various types of ships. Ammonia fuel is easy to store and inexpensive. Ammonia is one of the most common, readily available, and inexpensive green and clean compounds. Ammonia can be liquefied under normal pressure (approximately 8-10 atmospheres) or at low temperatures (-33.4℃), significantly reducing its volume and facilitating transportation and storage. Liquid ammonia is chemically relatively stable and does not easily spontaneously combust or decompose. Based on these characteristics, ammonia fuel is well-suited for use as fuel for marine auxiliary boilers.

[0003] However, ammonia combustion has problems such as requiring a large ignition energy, having a narrow combustible range, slow laminar combustion speed, and unstable combustion and high nitrogen oxide emissions caused by natural nitrogen content. Summary of the Invention

[0004] This invention addresses the problems of high ignition energy requirements, narrow combustible range, slow laminar combustion speed, combustion instability and high nitrogen oxide emissions caused by natural nitrogen content in ammonia boilers. It aims to improve the stability of ammonia combustion, ensure high-efficiency energy output, increase boiler efficiency, and reduce pollutant emissions by proposing an electrically heated mixed-fuel fire-tube boiler.

[0005] The present invention provides a mixed fuel fire tube boiler with electric heating, which comprises a mixed fuel burner 1, a furnace 2, an evaporation chamber 4, an electric heater 5, a water level gauge 6, a feedwater heating chamber 8, a flue gas collection area 9, a first baffle 12, a second baffle 15, a threaded flue assembly 16, and a shell 19.

[0006] The inner cavity of the shell 19 is provided with a furnace 2 at the bottom. The lower part of the outer surface of the shell 19 is provided with a mixed fuel burner 1. The output end of the mixed fuel burner 1 is connected to the furnace 2. The shell 19 is provided with a first partition 12 and a second partition 15 from top to bottom. The first partition 12 and the second partition 15 divide the interior of the shell 19 into a flue gas collection area 9, a feedwater heating chamber 8 and an evaporation chamber 4. The evaporation chamber 4 is provided with a water level gauge 6 and an electric heater 5 from top to bottom. The dial of the water level gauge 6 is fixed on the outer surface of the shell 19. A steam outlet 7 is provided on one side of the outer surface of the shell 19. The steam outlet 7 is corresponding to the evaporation chamber 4 inside the shell 19. The top of the shell 19 is provided with a flue gas outlet 11. The flue gas outlet 11 is corresponding to the flue gas collection area 9 inside the shell 19. The shell 19 is provided with a threaded smoke pipe assembly 16. The threaded smoke pipe assembly 16 passes through and is fixed inside the feedwater heating chamber 8 and the evaporation chamber 4.

[0007] Furthermore, on the other side of the outer surface of the shell 19, a water supply heating outlet 13 and a water supply heating inlet 14 are provided from top to bottom, and the water supply heating outlet 13 and the water supply heating inlet 14 are both provided corresponding to the water supply heating chamber 8 inside the shell 19.

[0008] Furthermore, an evaporation chamber inlet 17 is provided on the lower part of the other side of the outer surface of the shell 19, and the evaporation chamber inlet 17 is correspondingly provided with the evaporation chamber 4 inside the shell 19.

[0009] Furthermore, an inspection port 10 is provided on the upper part of the outer surface of the housing 19, and the inspection port 10 is correspondingly provided with the flue gas collection area 9 inside the housing 19.

[0010] Furthermore, a maintenance manhole 3 is provided on the outer surface of the shell 19 at the lower part of the evaporation chamber 4;

[0011] Furthermore, the inner top plate of the inner shell 18 of the furnace 2 is used to absorb the radiant heat of the flame combustion and transfer the heat to the interior of the evaporation chamber 4;

[0012] Furthermore, the threaded smoke tube assembly 16 includes heat exchange tubes 20 and support tubes 21; multiple heat exchange tubes 20 are evenly arranged between the first partition 12 inside the shell 19 and the upper surface of the furnace 2, and the multiple heat exchange tubes 20 are arranged in a semi-circular shape, with a support tube 21 between every two heat exchange tubes 20.

[0013] Furthermore, the outer diameter of both the support tube 21 and the heat exchange tube 20 is 38mm;

[0014] Furthermore, the wall thickness of the support tube 21 is 6.5 mm;

[0015] Furthermore, the wall thickness of the heat exchange tube 20 is 5mm;

[0016] Furthermore, this invention uses both No. 0 diesel and ammonia as fuel for co-combustion. Under the design conditions, the calorific value ratio of ammonia to diesel is 4:1, and the mass ratio is 9.6:1. The fuel ratio can also be adjusted according to specific needs. During ship navigation, boiler feedwater enters the feedwater heating chamber 8 through the feedwater heating inlet 14. After heating, the water flows out from the feedwater heating outlet 13 and enters the evaporation chamber inlet 17 through the connecting pipeline. In the evaporation chamber 4, the water is heated into saturated steam and enters the steam pipeline through the steam outlet 7, thereby supplying steam to the steam supply equipment. Through dual-fuel combustion, the flue gas generated by combustion enters the threaded flue assembly 16. The flue gas transfers heat to the water and steam in the evaporation chamber and also transfers some heat to the water in the feedwater heating chamber. After heat transfer, the flue gas passes through the first partition 12 and enters the flue gas collection area 9, and finally exits the boiler through the flue gas outlet 11 and enters the exhaust channel.

[0017] When the ship docks, the water and steam needs on board are met by electric heaters. The water is initially heated by the electric heaters in the water heating chamber and then further generates steam in the evaporation chamber 4. In order to facilitate boiler maintenance, the present invention is provided with a maintenance manhole 3 and a maintenance port 10. In order to observe the water level in time during boiler operation, a water level gauge 6 is provided.

[0018] Compared with the prior art, the present invention has the following advantages:

[0019] This invention overcomes the shortcomings of existing technologies. The fire-tube boiler of this invention has an internal feedwater heating chamber, which can significantly reduce flue gas temperature and minimize flue gas losses. Furthermore, this device can co-burn both No. 0 diesel and ammonia, making full use of easily stored and inexpensive clean energy ammonia fuel. This ensures stable combustion of ammonia fuel while appropriately increasing the fuel's calorific value, thereby improving heat exchange efficiency to 90%-95%. Moreover, this fire-tube boiler has a smaller volume, saving considerable space on ships. Attached Figure Description

[0020] Figure 1 This is a front sectional view of a mixed-fuel fire-tube boiler with electric heating according to the present invention.

[0021] Figure 2 This is a side sectional view of a mixed-fuel fire-tube boiler with electric heating according to the present invention. Detailed Implementation

[0022] Specific implementation method one: Combining Figure 1 and Figure 2This embodiment describes a mixed-fuel fire-tube boiler with electric heating, which comprises a mixed-fuel burner 1, a furnace 2, an evaporation chamber 4, an electric heater 5, a water level gauge 6, a feedwater heating chamber 8, a flue gas collection area 9, a first baffle 12, a second baffle 15, a threaded flue assembly 16, and a shell 19.

[0023] The inner cavity of the shell 19 is provided with a furnace 2 at the bottom. The lower part of the outer surface of the shell 19 is provided with a mixed fuel burner 1. The output end of the mixed fuel burner 1 is connected to the furnace 2. The shell 19 is provided with a first partition 12 and a second partition 15 from top to bottom. The first partition 12 and the second partition 15 divide the interior of the shell 19 into a flue gas collection area 9, a feedwater heating chamber 8 and an evaporation chamber 4. The evaporation chamber 4 is provided with a water level gauge 6 and an electric heater 5 from top to bottom. The dial of the water level gauge 6 is fixed on the outer surface of the shell 19. A steam outlet 7 is provided on one side of the outer surface of the shell 19. The steam outlet 7 is corresponding to the evaporation chamber 4 inside the shell 19. The top of the shell 19 is provided with a flue gas outlet 11. The flue gas outlet 11 is corresponding to the flue gas collection area 9 inside the shell 19. The shell 19 is provided with a threaded smoke pipe assembly 16. The threaded smoke pipe assembly 16 passes through and is fixed inside the feedwater heating chamber 8 and the evaporation chamber 4.

[0024] In this specific embodiment, the present invention uses two fuels, No. 0 diesel and ammonia, for co-combustion. Under the design conditions, the calorific value ratio of ammonia to diesel is 4:1, and the mass ratio is 9.6:1. The fuel ratio can also be adjusted according to specific needs. During ship navigation, boiler feedwater enters the feedwater heating chamber 8 through the feedwater heating inlet 14. After heating, the water flows out from the feedwater heating outlet 13 and enters the evaporation chamber inlet 17 through the connecting pipeline. In the evaporation chamber 4, the water is heated into saturated steam and enters the steam pipeline through the steam outlet 7, thereby supplying steam to the steam supply equipment. Through dual-fuel combustion, the flue gas generated by combustion enters the threaded flue assembly 16. The flue gas transfers heat to the water and steam in the evaporation chamber and also transfers some heat to the water in the feedwater heating chamber. After heat transfer, the flue gas passes through the first partition 12 and enters the flue gas collection area 9, and finally exits the boiler through the flue gas outlet 11 and enters the exhaust channel.

[0025] When the ship docks, the water and steam needs on board are met by electric heaters. The water is initially heated by the electric heaters in the water heating chamber and then further generates steam in the evaporation chamber 4. In order to facilitate boiler maintenance, the present invention is provided with a maintenance manhole 3 and a maintenance port 10. In order to observe the water level in time during boiler operation, a water level gauge 6 is provided.

[0026] Specific Implementation Method Two: Combining Figure 1 and Figure 2This embodiment further defines the fire-tube boiler described in Specific Embodiment 1. In this embodiment, a mixed-fuel fire-tube boiler with electric heating is provided with a feedwater heating outlet 13 and a feedwater heating inlet 14 on the other side of the outer surface of the shell 19 from top to bottom. Both the feedwater heating outlet 13 and the feedwater heating inlet 14 are corresponding to the feedwater heating chamber 8 inside the shell 19.

[0027] Specific implementation method three: Combining Figure 1 and Figure 2 This embodiment is a further limitation of the fire-tube boiler described in Specific Embodiment Two. In this embodiment, a mixed-fuel fire-tube boiler with electric heating is provided with an evaporation chamber inlet 17 on the lower part of the other side of the outer surface of the shell 19. The evaporation chamber inlet 17 is correspondingly arranged with the evaporation chamber 4 inside the shell 19.

[0028] Specific implementation method four: Combination Figure 1 and Figure 2 This embodiment further defines the fire-tube boiler described in Specific Embodiment 3. In this embodiment, a mixed-fuel fire-tube boiler with electric heating is provided with an inspection port 10 on the upper part of the outer surface of the shell 19, and the inspection port 10 is correspondingly arranged with the flue gas collection area 9 inside the shell 19.

[0029] Specific Implementation Method Five: Combining Figure 1 and Figure 2 This embodiment further defines the fire-tube boiler described in Specific Embodiment 4. In this embodiment, a mixed-fuel fire-tube boiler with electric heating is provided with a maintenance manhole 3 on the outer surface of the shell 19 corresponding to the lower part of the evaporation chamber 4.

[0030] Specific Implementation Method Six: Combination Figure 1 and Figure 2 This embodiment further defines the fire-tube boiler described in Specific Embodiment 1. In this embodiment, a mixed-fuel fire-tube boiler with electric heating is described, wherein the inner top plate of the inner shell 18 of the furnace 2 is used to absorb the radiant heat of the flame combustion and transfer the heat to the interior of the evaporation chamber 4.

[0031] Specific implementation method seven: Combination Figure 1 and Figure 2This embodiment further defines the fire-tube boiler described in Specific Embodiment 1. The fire-tube boiler with electric heating and mixed fuel described in this embodiment includes a threaded smoke tube assembly 16 comprising heat exchange tubes 20 and a support tube 21. Multiple heat exchange tubes 20 are evenly arranged between the first partition 12 inside the shell 19 and the upper surface of the furnace 2, and the multiple heat exchange tubes 20 are arranged in a semi-circular shape. A support tube 21 is provided between every two heat exchange tubes 20.

[0032] Specific implementation method eight: Combination Figure 1 and Figure 2 This embodiment further defines the fire-tube boiler described in Specific Embodiment Seven. In this embodiment, the outer diameter of both the support tube 21 and the heat exchange tube 20 in the electrically heated mixed-fuel fire-tube boiler is 38 mm.

[0033] Specific Implementation Method Nine: Combining Figure 1 and Figure 2 This embodiment further defines the fire-tube boiler described in Specific Embodiment Eight. In this embodiment, the wall thickness of the support tube 21 in the electrically heated mixed-fuel fire-tube boiler is 6.5 mm.

[0034] Specific Implementation Method Ten: Combining Figure 1 and Figure 2 This embodiment further defines the fire-tube boiler described in Specific Embodiment Eight. In this embodiment, the heat exchange tube 20 of the electrically heated mixed-fuel fire-tube boiler has a wall thickness of 5 mm.

[0035] Working principle

[0036] This invention uses both No. 0 diesel and ammonia as fuel. Under the design conditions, the calorific value ratio of ammonia to diesel is 4:1, and the mass ratio is 9.6:1. The fuel ratio can also be adjusted according to specific needs. During ship navigation, boiler feedwater enters the feedwater heating chamber 8 through the feedwater heating inlet 14. After heating, the water flows out from the feedwater heating outlet 13 and enters the evaporation chamber inlet 17 through connecting pipes. In the evaporation chamber 4, the water is heated into saturated steam and enters the steam pipeline through the steam outlet 7, thereby supplying steam to the steam supply equipment. Through dual-fuel combustion, the flue gas generated by combustion enters the threaded flue assembly 16. The flue gas transfers heat to the water and steam in the evaporation chamber and also transfers some heat to the water in the feedwater heating chamber. After heat transfer, the flue gas passes through the first partition 12 and enters the flue gas collection area 9, and finally exits the boiler through the flue gas outlet 11 and enters the exhaust channel.

[0037] When the ship docks, the water and steam needs on board are met by electric heaters. The water is initially heated by the electric heaters in the water heating chamber and then further generates steam in the evaporation chamber 4. In order to facilitate boiler maintenance, the present invention is provided with a maintenance manhole 3 and a maintenance port 10. In order to observe the water level in time during boiler operation, a water level gauge 6 is provided.

Claims

1. A mixed-fuel fire-tube boiler with electric heating, characterized in that: It includes a mixed fuel burner (1), furnace (2), evaporation chamber (4), electric heater (5), water level gauge (6), water supply heating chamber (8), flue gas collection area (9), first partition (12), second partition (15), threaded flue assembly (16), and shell (19). The inner cavity of the shell (19) is provided with a furnace (2), and the lower part of the outer surface of the shell (19) is provided with a mixed fuel burner (1). The output end of the mixed fuel burner (1) is connected to the furnace (2). The shell (19) is provided with a first partition (12) and a second partition (15) from top to bottom. The first partition (12) and the second partition (15) divide the interior of the shell (19) into a flue gas collection area (9), a water heating chamber (8) and an evaporation chamber (4) from top to bottom. The evaporation chamber (4) is provided with a water level gauge (6) and an electric heater (6) from top to bottom. Heater (5), and the dial of water level gauge (6) is fixed on the outer surface of housing (19). Steam outlet (7) is provided on one side of the outer surface of housing (19), and steam outlet (7) is corresponding to evaporation chamber (4) inside housing (19). Flue gas outlet (11) is provided at the top of housing (19), and flue gas outlet (11) is corresponding to flue gas collection area (9) inside housing (19). Threaded flue pipe assembly (16) is provided inside housing (19), and threaded flue pipe assembly (16) is fixed through and fixed inside water supply heating chamber (8) and evaporation chamber (4).

2. A mixed-fuel fire-tube boiler with electric heating according to claim 1, characterized in that: On the other side of the outer surface of the shell (19), a water supply heating outlet (13) and a water supply heating inlet (14) are arranged from top to bottom, and the water supply heating outlet (13) and the water supply heating inlet (14) are both arranged corresponding to the water supply heating chamber (8) inside the shell (19).

3. A mixed-fuel fire-tube boiler with electric heating according to claim 2, characterized in that: The lower part of the other side of the outer surface of the shell (19) is provided with an evaporation chamber inlet (17), which is corresponding to the evaporation chamber (4) inside the shell (19).

4. A mixed-fuel fire-tube boiler with electric heating according to claim 3, characterized in that: The outer surface of the housing (19) is provided with an inspection port (10), and the inspection port (10) is correspondingly provided with the flue gas collection area (9) inside the housing (19).

5. A mixed-fuel fire-tube boiler with electric heating according to claim 4, characterized in that: The outer surface of the shell (19) is provided with a maintenance manhole (3) at the lower part of the evaporation chamber (4).

6. A mixed-fuel fire-tube boiler with electric heating according to claim 1, characterized in that: The inner top plate of the inner shell (18) of the furnace (2) is used to absorb the radiant heat of the flame combustion and transfer the heat to the interior of the evaporation chamber (4).

7. A mixed-fuel fire-tube boiler with electric heating according to claim 1, characterized in that: The threaded smoke tube assembly (16) includes heat exchange tubes (20) and support tubes (21); multiple heat exchange tubes (20) are evenly arranged between the first partition (12) inside the shell (19) and the upper surface of the furnace (2), and the multiple heat exchange tubes (20) are arranged in a semi-circular shape, with a support tube (21) between every two heat exchange tubes (20).

8. A mixed-fuel fire-tube boiler with electric heating according to claim 7, characterized in that: The outer diameter of both the support tube (21) and the heat exchange tube (20) is 38 mm.

9. A mixed-fuel fire-tube boiler with electric heating according to claim 8, characterized in that: The wall thickness of the support tube (21) is 6.5 mm.

10. A mixed-fuel fire-tube boiler with electric heating according to claim 8, characterized in that: The heat exchange tube (20) has a wall thickness of 5 mm.

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