Nozzle tip for a solid fuel burner

Abstract

A nozzle tip for a pulverized solid fuel duct nozzle of a pulverized solid fuel fired furnace is provided. The nozzle tip includes an inner nozzle portion and an outer nozzle portion that houses the inner nozzle portion therein. The outer nozzle portion has a lower support surface configured to support a lower surface of the inner nozzle portion. The outer nozzle portion also includes a plurality of ribs that define a plurality of flow passages for air passage therebetween. In addition to defining the air flow passages, the ribs also provide support support for the lower support surface. The outer nozzle portion is formed of stainless steel.

Description

Background Technology Technical Field

[0002] Embodiments of the present invention generally relate to combustion systems for use with pulverized solid fuel burners, and more specifically to adjustable nozzle tips for such combustion systems.

[0003] Discussion of the field

[0004] Systems for conveying pulverized solid fuel (e.g., coal) to a steam generator typically include multiple nozzle assemblies through which pulverized coal is delivered by air into the combustion chamber of the steam generator. The nozzle assemblies are typically housed within bellows, which may be located near a corner of the steam generator. Each nozzle assembly includes a nozzle tip that protrudes into the combustion chamber. Each nozzle tip delivers a single stream or jet of pulverized coal and air into the combustion chamber. After exiting the nozzle tip, the individual pulverized coal / air jet disperses within the combustion chamber.

[0005] Typically, nozzle tips are arranged to be angled upwards and downwards to adjust the flame position within the combustion chamber. The flame produced at each pulverized solid fuel nozzle is stabilized through global heat and mass transfer processes. Thus, a single rotating flame encapsulation (e.g., a "fireball") centrally located in the furnace provides a gradual but thorough and uniform pulverized solid fuel-air mixture throughout the furnace.

[0006] Although existing solid fuel pulverizing nozzle tips operate for their intended purpose, further improvements to such nozzle tips have proven necessary, particularly in terms of increased durability and service life. Specifically, existing nozzle tips are ceramic castings, which can be damaged by the extremely high temperatures within the combustion chamber and / or by the impact of falling molten slag.

[0007] Given the above, there is a need for a pulverized coal nozzle tip that is more durable and has a longer service life than existing nozzle tips. Summary of the Invention

[0008] In one embodiment, a nozzle tip for a pulverized solid fuel conduit nozzle for a pulverized solid fuel combustion furnace is provided. The nozzle tip includes an inner nozzle portion and an outer nozzle portion therein receiving the inner nozzle portion. The outer nozzle portion has a lower support surface configured to support a lower surface of the inner nozzle portion. The outer nozzle portion also includes a plurality of ribs defining a plurality of flow channels for air passage. In addition to defining the airflow channels, the ribs also provide support for the lower support surface. The outer nozzle portion is formed of stainless steel. Attached Figure Description

[0009] The invention will be better understood by referring to the following description of non-limiting embodiments, in which:

[0010] Figure 1 It is a graphical representation of a vertical cross-section of a pulverized solid fuel combustion furnace embodying a combustion system, wherein a solid fuel nozzle tip structure according to the present invention can be utilized;

[0011] Figure 2 It is an embodiment of the present invention for use with Figure 1 An exploded perspective view of the tip of a solid fuel nozzle used in a pulverized solid fuel combustion furnace.

[0012] Figure 3 yes Figure 2 A front perspective view of the nozzle tip.

[0013] Figure 4 yes Figure 2 Rear perspective view of the nozzle tip.

[0014] Figure 5 yes Figure 2 A frontal view of the nozzle tip.

[0015] Figure 6 yes Figure 2 The rear front view of the nozzle tip. Detailed Implementation

[0016] Exemplary embodiments of the invention will now be described in detail, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numerals used throughout the drawings refer to the same or similar parts. While embodiments of the invention relate to nozzle tips for solid fuel combustion furnaces, embodiments of the invention can also be used to control the rate of fuel in any state (i.e., solid, liquid, or gas).

[0017] Now refer to the attached diagram, and more specifically to it. Figure 1 The accompanying drawing depicts a pulverized solid fuel combustion furnace, typically indicated by reference numeral 10. Due to the nature of the construction and operation modes of pulverized solid fuel combustion furnaces known to those skilled in the art, it is deemed unnecessary to elaborate upon them herein. Figure 1 A detailed description of the pulverized solid fuel combustion furnace 10 shown is provided. Instead, for the purpose of gaining an understanding of the pulverized solid fuel combustion furnace 10 in the combustion system, the solid fuel nozzle tip constructed according to the invention is suitable for use, and it is considered sufficient that only a description of the nature of the components of the pulverized solid fuel combustion furnace 10 and the components of the combustion system is presented herein, wherein the pulverized solid fuel combustion furnace 10 is suitably provided and mates with the solid fuel nozzle tip.

[0018] Further reference Figure 1The pulverized solid fuel combustion furnace 10 includes a burner region 14. It is within the burner region 14 of the pulverized solid fuel combustion furnace 10 that the combustion of pulverized solid fuel and air is initiated in a manner known to those skilled in the art. The hot gas generated by the combustion of the pulverized solid fuel and air rises upward within the pulverized solid fuel combustion furnace 10. During its upward movement within the pulverized solid fuel combustion furnace 10, the hot gas provides heat to a fluid passing through tubes (not shown), which are conventionally arranged along all four walls of the pulverized solid fuel combustion furnace 10. The hot gas then exits the pulverized solid fuel combustion furnace 10 through a horizontal passage 16, which in turn leads to a rear gas passage 18. Both the horizontal passage 16 and the rear gas passage 18 typically contain additional heat exchanger surfaces (not shown) for generating and superheating steam in a manner known to those skilled in the art. Steam is then typically fed to a turbine (not shown), which forms a component of a turbine / generator assembly (not shown), so that the steam provides power to drive the turbine (not shown), and thereby also provides a generator (not shown), which is cooperatively associated with the turbine in a known manner, so that electricity is thus generated by the generator (not shown).

[0019] For the purposes described herein, reference is made again to the aforementioned background techniques. Figure 1 The description of the construction properties and operating modes of the pulverized solid fuel combustion furnace 10 is provided as appropriate. (See reference...) Figure 1 The observed main combustion system includes a casing in the form of a main air box 20, which is provided with multiple air compartments (not shown). Air supplied from a suitable source (not shown) is injected through these air compartments into the burner region 14 of the pulverized solid fuel combustion furnace 10. Additionally, the air box 20 is provided with multiple fuel compartments (not shown), through which solid fuel is injected into the burner region 14. The solid fuel injected through the aforementioned multiple fuel compartments (not shown) is supplied to these multiple fuel compartments (not shown) via a pulverized solid fuel supply device, which is typically composed of… Figure 1 Reference numeral 22 is used in the accompanying drawings. For this purpose, the pulverized solid fuel supply device 22 includes a pulverizer, which is typically made of… Figure 1Reference numeral 24 in the figures indicates a plurality of pulverized solid fuel conduits 26. Pulverized solid fuel is conveyed from a pulverizer 24 via pulverized solid fuel conduits 26 which are fluidly connected to the pulverizer and also fluidly connected to the aforementioned plurality of fuel chambers (not shown). Although not shown for clarity in the figures, the pulverizer 24 is operatively connected to a fan (not shown), which in turn is fluidly connected to the aforementioned plurality of air chambers (not shown), such that air is supplied from the fan (not shown) not only to the aforementioned plurality of air chambers (not shown) but also to the pulverizer 24, thereby conveying the pulverized solid fuel supplied from the pulverizer 24 to the aforementioned plurality of fuel chambers (not shown) in an airflow through the pulverized solid fuel conduits 26 in a manner known in the art.

[0020] Further regarding the nature of the combustion system, two or more discrete positions for separating superburned air are incorporated at each corner of the pulverized solid fuel combustion furnace 10, located between the top of the main air box 20 and the furnace outlet plane 28. For this purpose, the combustion system of the pulverized solid fuel combustion furnace 10 is suitably configured to include two or more discrete positions for separating superburned air, i.e. Figure 1 The lower part of the separated superburning air, usually indicated by reference numeral 30 in the attached figure, is... Figure 1 The high position of the separated superburned air is generally indicated by reference numeral 32 in the accompanying drawings. The low position 30 of the separated superburned air is suitably supported by any conventional form of support device (not shown) suitable for this purpose within the burner region 14 of the pulverized solid fuel combustion furnace 10, so as to be suitably spaced from the top of the bellows 20 and thus substantially aligned with the longitudinal axis of the main bellows 20. Similarly, the high position 32 of the separated superburned air is suitably supported by any conventional form of support device (not shown) suitable for this purpose within the burner region 14 of the pulverized solid fuel combustion furnace 10, so as to be suitably spaced from the low position 30 of the separated superburned air and thus substantially aligned with the longitudinal axis of the main bellows 20. The low position 30 and the high position 32 of the separated superburned air are suitably located between the top of the main bellows 20 and the furnace outlet plane 28, such that the gas generated by the combustion of pulverized solid fuel travels from the top of the main bellows 20 to the top of the high position 32 of the separated superburned air over a predetermined amount of time.

[0021] Although Figure 1Not shown, but each having a solid fuel nozzle tip, the pulverized solid fuel nozzles are suitably supported in each of a plurality of fuel compartments (not shown), which have been referenced above. The nozzles and their nozzle tips are mounted to direct pulverized solid fuel (e.g., solid fuels such as coal and biomass or coal) and air into the burner region 14 of the furnace. As shown below, according to an embodiment of the invention, the nozzle tips of one or more nozzles are configured to allow adjustment of the vertical and / or horizontal angle of the nozzle tips, as well as adjustment of the cross-sectional area of ​​the nozzle tip outlet.

[0022] Now for reference Figures 2 to 6 This illustration shows a nozzle tip 100 for a solid fuel nozzle in a solid fuel burner / furnace (e.g., furnace 10) according to one embodiment of the invention. It is conceivable that the nozzle tip of the invention disclosed herein can be used in any bellows configuration, with or without a separate overburning air port. As shown, the nozzle tip 100 includes an inner nozzle portion 110 and an outer nozzle portion 112, the inner nozzle portion 110 being mounted within the outer nozzle portion. In one embodiment, the inner nozzle portion 110 is an integral casting, for example, formed of ceramic. The inner portion may be formed of cast ceramic, which may be composed of ceramics including silicon nitride, silicon carbide silicide, mullite-bonded silicon carbide alumina composites, alumina-zirconia composites, and alumina composites with optimized fibers. As shown, the inner nozzle portion 110 is generally rectangular in shape and tapers such that the cross-sectional area of ​​the rear end of the inner nozzle portion 110 is larger than the cross-sectional area of ​​the front end or outlet end of the inner nozzle portion 110. In one embodiment, as... Figures 2 to 6 As shown, the inner nozzle portion 110 may have a separator 120 that divides the internal space into two channels 114, 116 stacked on top of each other.

[0023] Perhaps Figure 2 As best shown, the outer nozzle portion 112 is generally rectangular in shape and has an open internal space 118 that roughly corresponds in size and shape to the outer surface / shape of the inner nozzle portion 110. For example, if the inner nozzle portion 110 is tapered, the internal space 118 can also be tapered. Furthermore... Figure 2 As shown, the outer nozzle portion 112 includes upper and lower support surfaces 122 and 124, respectively, and a plurality of vertically oriented ribs 126 extending between the outer housing of the outer nozzle portion 112 and the upper and lower support surfaces 122 and 124. These ribs 126 define a plurality of flow channels 128 extending from the rear end to the front end of the outer nozzle portion 112. In one embodiment, the support surfaces 122 and 124 are substantially planar.

[0024] As described above, the inner nozzle portion 110 is accommodated within the outer nozzle portion 112 such that the upper and lower outer surfaces of the inner nozzle portion 110 are tightly received and supported thereon by the upper and lower support surfaces 122, 124 of the outer nozzle portion 112. In this respect, the outer nozzle portion 112 serves as a shield to protect and support the inner nozzle portion 110. In one embodiment, the outer nozzle portion 112 is formed of a material capable of withstanding the harsh environment within the combustion chamber (e.g., high operating temperatures and impacts from falling molten slag), with the nozzle tip 100 positioned within the combustion chamber. For example, in one embodiment, the outer nozzle portion may be formed of stainless steel.

[0025] like Figures 2 to 6 As shown, the inner nozzle portion 110 and the outer nozzle portion 112 are fixedly connected to each other via mounting pins 130. This connection mechanism allows for a certain degree of different thermal expansion between the inner nozzle portion 110 and the outer nozzle portion 112. A central pin 132 of the nozzle tip 100 allows the nozzle tip to be mounted to a coal nozzle (not shown). Upper and lower pins are used to connect the nozzle tip 100 to the tilting arm of the nozzle assembly via mounting holes 134, 136, and allow the nozzle tip 100 to tilt or angle during operation, as known in the art.

[0026] As described above, the upper support surface 122 and lower support surface 124 of the outer nozzle portion 112 provide large surface areas for supporting the upper and lower surfaces of the inner nozzle portion 110. This is in contrast to existing devices, where support for the cast ceramic nozzle tip is provided only at discrete points. In fact, the flat surface contact between the cast ceramic bulk 110 and the stainless steel housing 112 is the opposite of point contact, which has been a feature of the prior art to date. These support surfaces 122, 124 are supported by reinforcing ribs 126, which, in addition to providing support for the inner nozzle portion 110 when it is received within the internal space 118, also define flow channels therebetween for the passage of air (e.g., secondary air surrounding the pulverized coal flow).

[0027] As described above, the stainless steel outer nozzle portion 112 is far more robust than ceramic, thus preventing damage from falling molten slag. Additionally, air cooling through the outer nozzle portion 112 (i.e., through channel 128) minimizes potential warping. Therefore, this particular combination provides a level of durability and useful service life / lifespan not seen to date in the art.

[0028] As used herein, elements or steps listed in the singular and beginning with the words "an" or "a" should be understood to not exclude multiple said elements or steps unless such exclusion is explicitly stated. Furthermore, references to "an embodiment" of the invention are not intended to be construed as excluding the existence of other embodiments that also include the listed features. Moreover, unless explicitly stated to the contrary, embodiments that "comprise," "contain," or "have" one or more elements having a particular attribute may include other such elements that do not have that attribute.

[0029] This written description uses examples to disclose several embodiments of the invention, including the best mode, and also enables those skilled in the art to practice embodiments of the invention, including making and using any device or system and performing any combined methods. The patentable scope of the invention is defined by the claims and may include other examples that would occur to those skilled in the art. Such other examples are contemplated within the scope of the claims if they have structural elements that are not different from the literal language of the claims, or if they include equivalent structural elements that are not substantially different from the literal language of the claims.

Claims

1. A nozzle tip for a solid fuel pulverizing pipeline nozzle in a solid fuel pulverizing furnace, the nozzle tip comprising: Internal nozzle section; and The outer nozzle portion has a housing, a lower support surface within the housing, and a plurality of ribs extending between the housing and the lower support surface; The lower support surface is configured to support the housing of the inner nozzle portion when the inner nozzle portion is received within the outer nozzle portion; and The lower support surface is flat and configured to contact and support the corresponding lower surface of the inner nozzle portion in the direction of the extension of the plurality of ribs.

2. The nozzle tip according to claim 1, wherein: The plurality of ribs define a plurality of flow channels for air passage therebetween; The ribs provide support to the lower support surface of the outer nozzle portion.

3. The nozzle tip according to claim 1, wherein: The outer nozzle portion includes an upper support surface within the housing and a plurality of ribs extending between the housing and the upper support surface.

4. The nozzle tip according to claim 1, wherein: The inner nozzle portion is ceramic; and The outer nozzle portion is made of stainless steel.

5. The nozzle tip according to claim 1, wherein: The inner nozzle portion is fixedly connected to the outer nozzle portion.

6. The nozzle tip according to claim 1, wherein: The outer nozzle portion has a tapered shape that moves from the rear end to the front end.

7. The nozzle tip according to claim 1, wherein: The outer nozzle portion has multiple mounting points for pivotally connecting the nozzle tip to the tilting arm of the pulverized solid fuel pipeline nozzle.

Images