Low load stable combustion boiler

Abstract

The application discloses a low-load stable combustion boiler and belongs to the technical field of power station boilers. The low-load stable combustion boiler comprises a hearth, a heating surface arranged in the interior of the hearth, and a heat radiation curtain arranged between a flame generated by combustion and the heating surface in the hearth. The heat radiation curtain absorbs heat radiated by the flame and returns the absorbed heat to the flame to increase the temperature of the flame. When the boiler is in a low-load state, the heat radiation curtain is arranged between the combustion flame and the heating surface in the hearth, heat radiation of the heat radiation curtain is utilized, the temperature of the combustion flame in the hearth is increased, stable combustion of the boiler is realized, coking of the heating surface is prevented, and stable combustion of the boiler can be realized when coal is deteriorated.

Description

Technical Field

[0001] This application belongs to the field of power plant boiler technology, and in particular relates to a low-load stable combustion boiler. Background Technology

[0002] In the current energy landscape, the installed capacity of new energy sources such as wind power, hydropower, and photovoltaics continues to climb, profoundly changing the power grid structure. However, new energy sources are constrained by natural conditions, exhibiting significant intermittency, volatility, and randomness, making it difficult to guarantee a stable power supply. To maintain power system stability, coal-fired power plants, as supporting peak-shaving and frequency-regulating power sources, need to frequently operate in deep peak-shaving mode. Deep peak-shaving of coal-fired units mainly relies on reducing the amount of coal fed to achieve stable combustion under low loads. In this process, many problems arise. When the boiler load of the unit decreases, the amount of coal fed into the furnace is greatly reduced, the calorific value of the coal decreases, and the furnace temperature drops significantly, leading to delayed ignition of pulverized coal, poor combustion stability, and in severe cases, even boiler flameout, greatly threatening the safe and stable operation of the unit. Utility Model Content

[0003] To address the aforementioned problems in the existing technology, this application provides a low-load stable combustion boiler.

[0004] To achieve the above objectives, one technical solution adopted in this application is to provide a low-load stable combustion boiler, which includes: a furnace; a heating surface arranged inside the furnace; and a heat radiation curtain arranged between the flame generated by combustion and the heating surface inside the furnace. The heat radiation curtain absorbs the heat radiated by the flame and returns the absorbed heat to the flame, thereby increasing the temperature of the flame.

[0005] The beneficial effects of this application are as follows: when the boiler is under low load, by setting a high-temperature resistant heat radiation curtain between the combustion flame and the heating surface in the furnace, the heat radiation curtain radiates heat, thereby increasing the temperature of the combustion flame in the furnace, so as to achieve stable combustion of the boiler, and prevent coking on the heating surface. Stable combustion of the boiler can also be achieved when the coal deteriorates (e.g., when using lean coal). Attached Figure Description

[0006] Figure 1 This is a schematic diagram of a specific embodiment of the low-load stable combustion boiler of this application. Detailed Implementation

[0007] The preferred embodiments of this application will now be described in detail with reference to the accompanying drawings, so that the advantages and features of this application can be more easily understood by those skilled in the art, thereby providing a clearer and more definite definition of the scope of protection of this application.

[0008] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes said element.

[0009] The inventive concept of this application is as follows: the heat generated by the combustion of pulverized coal in the boiler is the input power, and the heat transferred to the heating surface by the flame through radiation is the output power. The physical quantity relating input power and output power is the flame temperature T. When the input power increases, the flame temperature rises, and the output power increases; conversely, when the input power decreases, the flame temperature decreases, and the output power decreases. Therefore, under low load conditions, the flame temperature can be stabilized when the input power decreases by limiting the heat radiated by the flame to the heating surface, thereby achieving stable combustion.

[0010] Figure 1 This is a schematic diagram of a specific embodiment of the low-load stable combustion boiler of this application.

[0011] Figure 1 The low-load stable combustion boiler shown includes: a furnace 101; a heating surface 102 arranged inside the furnace; and a heat radiation curtain 103 arranged between the flame generated by combustion and the heating surface inside the furnace. The heat radiation curtain absorbs the heat radiated by the flame and returns the absorbed heat to the flame, thereby increasing the temperature of the flame.

[0012] In this specific embodiment, when the boiler is under low load, a high-temperature resistant heat radiation curtain is installed between the combustion flame and the heating surface in the furnace. The heat radiation curtain radiates heat, thereby increasing the temperature of the combustion flame in the furnace to achieve stable combustion of the boiler. It can also prevent coking on the heating surface and achieve stable combustion of the boiler even when the coal deteriorates (e.g., when using lean coal).

[0013] In one specific embodiment of this application, the low-load stable combustion boiler of this application includes: furnace 101.

[0014] In one specific embodiment of this application, the low-load stable combustion boiler of this application includes: a heating surface 102, which is arranged inside the furnace.

[0015] In this specific embodiment, the heating surface of the furnace inner wall is mainly a water-cooled wall, which is arranged inside the furnace.

[0016] In one specific embodiment of this application, the low-load stable combustion boiler of this application includes: a thermal radiation curtain 103, which is arranged in the furnace between the flame generated by combustion and the heating surface. The thermal radiation curtain absorbs the heat radiated by the flame and returns the absorbed heat to the flame, thereby increasing the temperature of the flame.

[0017] In this specific embodiment, by setting a heat radiation curtain between the flame generated by combustion in the furnace and the heating surface, the heat radiated by the flame first passes through the heat radiation curtain, raising the temperature of the heat radiation curtain. The heat absorbed by the heat radiation curtain is not only radiated to the heating surface, but also radiated back to the flame, thereby raising the temperature of the flame. This achieves stable combustion under low load conditions of the boiler and prevents coking on the heating surface.

[0018] In one specific embodiment of this application, the heat radiation curtain is arranged parallel to or perpendicular to the heated surface.

[0019] In this specific embodiment, depending on actual needs, the heat radiation curtain can be arranged parallel to the heated surface or perpendicular to the heated surface. By adjusting the transmission path and distribution of heat radiation, the functional requirements of the heated surface can be matched.

[0020] In one specific embodiment of this application, the distance between the thermal radiation curtain and the heated surface is greater than a preset distance threshold.

[0021] In this specific embodiment, the heat radiation curtain and the heated surface cannot be touching and need to maintain a certain distance, that is, the distance between the two must be greater than a preset distance threshold. For example, the preset distance threshold can be 100mm, then the distance between the heat radiation curtain and the heated surface can be greater than 100mm.

[0022] In one specific embodiment of this application, the thermal radiation curtain is made of high-temperature carbon fiber fabric.

[0023] In this specific embodiment, the high-temperature carbon fiber fabric has excellent high temperature resistance and thermal stability. The heat radiation curtain made of the high-temperature carbon fiber fabric can withstand high temperatures without deformation, making it suitable for long-term use in boilers.

[0024] In one specific embodiment of this application, the thermal radiation curtain is composed of multiple thin sheets of tungsten alloy or nickel-based alloy with coated surfaces connected in series.

[0025] In this specific embodiment, the heat radiation curtain can also be made of multiple thin sheets made of tungsten alloy or nickel-based alloy using a surface coating technique, which are then strung together. Both tungsten alloy and nickel-based alloy are high-temperature resistant materials, suitable for long-term use inside boilers.

[0026] In one specific embodiment of this application, the heat radiation curtain is composed of multiple sheet-like high-temperature resistant ceramic blocks connected in series.

[0027] In this specific embodiment, the heat radiation curtain can also be made of multiple small pieces of high-temperature resistant ceramic connected in series.

[0028] In one specific example of this application, the thermal radiant curtain utilizes a pivot and a dedicated track to support its unfolding and rolling.

[0029] In this specific embodiment, with the help of a rotating shaft and a dedicated track, the radiant curtain can be unfolded or rolled up, making it convenient to unfold or roll up the radiant curtain according to the actual operating conditions of the boiler.

[0030] In one specific embodiment of this application, when the boiler is under low load and the flame temperature needs to be increased, the heat radiation curtain is unfolded; when the boiler is under high load and the flame temperature does not need to be increased, the heat radiation curtain is rolled up.

[0031] In this specific embodiment, when the boiler is under low load, the flame temperature decreases. At this time, the radiant heat curtain can be lowered and expanded to radiate heat to the flame, thereby raising the flame temperature. When the boiler is under high load, the flame temperature is high, and it is not necessary to radiate heat to the flame through the radiant heat curtain. In this case, the radiant heat curtain can be rolled up. When the radiant heat curtain is not needed for a long period of time (e.g., one month), it can also be moved outside the boiler.

[0032] In one specific embodiment of this application, the thermal radiation curtain includes one or more layers, wherein when the thermal radiation curtain includes multiple layers, the layers are arranged at predetermined intervals.

[0033] In this specific embodiment, when the flame temperature inside the furnace is not very low, a layer of heat radiation curtain can be set between the flame and the heated surface to increase the flame temperature accordingly; when the flame temperature inside the furnace is low, multiple layers of heat radiation curtain can be set, with each layer of heat radiation curtain arranged at a predetermined interval, for example, the distance between two adjacent layers of heat radiation curtain can be 3cm-5cm, so that the flame temperature can be increased significantly through layer-by-layer radiation.

[0034] In the low-load stable combustion boiler of this application, when the boiler is under low load, a high-temperature resistant heat radiation curtain is set between the combustion flame and the heating surface in the furnace. The heat radiation curtain radiates heat, thereby increasing the temperature of the combustion flame in the furnace to achieve stable combustion of the boiler. It can also prevent coking on the heating surface and achieve stable combustion of the boiler even when the coal deteriorates (e.g., when using lean coal).

[0035] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely exemplary; multiple components or devices may be combined or integrated into another system, or some features may be omitted or removed. Furthermore, the interconnections disclosed or discussed may be via connectors, which may be electrical, mechanical, or other forms.

[0036] The components or devices may or may not be physically separate; that is, they may be arranged in a specific location or in other locations within the device or system. Some or all of the components or devices can be selected to achieve the technical objectives of this specific embodiment, depending on actual needs.

[0037] The above description is merely an embodiment of this application and does not limit the patent scope of this application. Any equivalent structural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A low-load stable combustion boiler, characterized in that, include: Furnace; Heating surfaces are arranged inside the furnace chamber; A heat radiation curtain is arranged inside the furnace between the flame generated by combustion and the heated surface. The heat radiation curtain absorbs the heat radiated by the flame and returns the absorbed heat to the flame, thereby increasing the temperature of the flame.

2. The low-load stable combustion boiler according to claim 1, characterized in that, The heat radiation curtain is arranged parallel to or perpendicular to the heated surface.

3. The low-load stable combustion boiler according to claim 1, characterized in that, The heat radiation curtain is made of high-temperature carbon fiber fabric.

4. The low-load stable combustion boiler according to claim 1, characterized in that, The heat radiation curtain is made of multiple thin sheets of tungsten alloy or nickel-based alloy with coated surfaces strung together.

5. The low-load stable combustion boiler according to claim 1, characterized in that, The heat radiation curtain is composed of multiple sheet-like high-temperature resistant ceramic blocks connected in series.

6. The low-load stable combustion boiler according to claim 1, characterized in that, The heat radiation curtain is supported by a rotating shaft and a dedicated track for unfolding and rolling up.

7. The low-load stable combustion boiler according to claim 1, characterized in that, The heat radiation curtain may include one or more layers, wherein when the heat radiation curtain includes multiple layers, the layers are arranged at predetermined intervals.

8. The low-load stable combustion boiler according to claim 1, characterized in that, The distance between the heat radiation curtain and the heated surface is greater than a preset distance threshold.

9. The low-load stable combustion boiler according to claim 6, characterized in that, When the boiler is under low load and the temperature of the flame needs to be increased, the heat radiation curtain is deployed. When the boiler is under high load and there is no need to increase the temperature of the flame, the heat radiation curtain is rolled up.

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