Multi-stage circulating fluidized bed combustion equipment

Abstract

The utility model provides multi-stage circulating fluidized bed combustion equipment. The multi-stage circulating fluidized bed combustion equipment comprises a primary fan, a secondary fan, a secondary air stage distribution pipe, a first-stage constant feeder, a second-stage constant feeder, a first-stage return feeder, a second-stage return feeder, a main combustion chamber, an auxiliary combustion chamber, a burnout chamber and a cyclone separator, wherein the main combustion chamber, the auxiliary combustion chamber, the burnout chamber and the cyclone separator are communicated in sequence; the first-stage constant feeder and the second-stage constant feeder are sequentially arranged at the front part of the main combustion chamber from bottom to top; the first-stage constant feeder and the second-stage constant feeder are both communicated with the main combustion chamber; the primary return feeder is arranged below the auxiliary combustion chamber and the after-combustion chamber; the main combustion chamber, the auxiliary combustion chamber and the burnout chamber are all communicated with the first-stage return feeder, and the second-stage return feeder is communicated with the cyclone separator and the main combustion chamber. A heat flow meter sensor is arranged on a water cooling wall of the main combustion chamber; an anti-blocking pitot tube is arranged on a pipeline between the cyclone separator and the main combustion chamber; the multi-stage circulating fluidized bed combustion equipment is reliable in structure, and combustion efficiency can be improved and original generation of NOx can be reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to circulating fluidized bed combustion technology field, concretely relates to a kind of multi-stage circulating fluidized bed combustion equipment. BACKGROUND

[0002] Circulating fluidized bed boiler is the high-efficiency clean combustion technology developed in recent years, due to flexible operation, convenient maintenance, can be used with inferior coal, solid waste, biomass and other fuels in industrial boiler field increasingly favored. Some new circulating fluidized bed boilers and corresponding control method are constantly proposed.

[0003] A kind of new low-emission circulating fluidized bed boiler of fuel and desulfurizer double-stage supply in prior art, break through single air staging combustion traditional thought, through air, fuel double-stage combustion and staged desulfurization, make fuel combustion sufficient while pollutant low emission. There is also a multi-flow horizontal circulating fluidized bed boiler, boiler is provided with bed pressure pressure transmitter, main combustion chamber differential pressure transmitter, auxiliary combustion chamber differential pressure transmitter and burn-out chamber differential pressure transmitter.

[0004] However, the above two circulating fluidized bed boilers are difficult to realize online monitoring of the heat flow distribution of water-cooled wall, cannot realize online monitoring of the pressure difference of material circulation amount loop, the monitoring measures for heat flow distribution in furnace and material circulation adjustment are limited, and the potential for further reducing NOx original generation is still large. UTILITY MODEL CONTENTS

[0005] In view of at least one problem in the prior art, the utility model provides a kind of multi-stage circulating fluidized bed combustion equipment, the multi-stage circulating fluidized bed combustion equipment structure is reliable, can be convenient for subsequent improvement combustion efficiency and reduce NOx original generation.

[0006] To solve the above technical problems, the utility model provides the following technical solutions:

[0007] The application provides a kind of multi-stage circulating fluidized bed combustion equipment, including: primary air blower, secondary air blower, secondary air staging distribution pipe, primary quantitative feeder, secondary quantitative feeder, primary return feeder, secondary return feeder, main combustion chamber, auxiliary combustion chamber, burn-out chamber and cyclone separator are sequentially communicated and arranged;

[0008] The primary quantitative feeder and secondary quantitative feeder are sequentially arranged from below to above in the front of the main combustion chamber;The primary quantitative feeder and the secondary quantitative feeder are respectively communicated with the main combustion chamber;

[0009] The primary return feeder is located below the secondary combustion chamber and the burnout chamber, and the secondary return feeder is located below the cyclone separator; the main combustion chamber, the secondary combustion chamber, and the burnout chamber are all connected to the primary return feeder, and the secondary return feeder is connected to the cyclone separator and the main combustion chamber respectively;

[0010] The bottom of the main combustion chamber is connected to the primary air fan; the secondary air grading and distribution pipe is arranged in the main combustion chamber and connected to the secondary air fan; a heat flow meter sensor is arranged on the water-cooled wall of the main combustion chamber; and an anti-clogging Pitot tube is installed on the pipe between the cyclone separator and the main combustion chamber.

[0011] In one embodiment, the side walls of the main combustion chamber, the auxiliary combustion chamber, and the burnout chamber, the intermediate partition wall between the main combustion chamber and the auxiliary combustion chamber, and the intermediate partition wall between the auxiliary combustion chamber and the burnout chamber are all provided with water-cooled walls.

[0012] In one embodiment, the water-cooled wall includes: a plurality of water-cooled wall tubes, with fins disposed between adjacent water-cooled wall tubes;

[0013] The heat flow meter sensor includes: a fin-end thermocouple, a vertex thermocouple, and a dielectric-side thermocouple;

[0014] The fin-end thermocouple is fixed on the fin, the vertex thermocouple is installed on the vertex of the backfire side of the water-cooled wall tube, and the medium-side thermocouple is fixed at one end of the water-cooled wall tube.

[0015] In one embodiment, the multi-stage circulating fluidized bed combustion device further includes: a boiler drum arranged above the main combustion chamber;

[0016] The water-cooled wall is connected to the boiler drum, and the boiler drum is connected to the heating surfaces located in the main combustion chamber, auxiliary combustion chamber, and burnout chamber.

[0017] In one embodiment, the bottom of the main combustion chamber is connected to the primary air fan via a primary air duct, and the primary air duct is equipped with a primary air flow meter.

[0018] In one embodiment, the secondary air distribution pipe is connected to the secondary air fan via a secondary air duct, and the secondary air duct is equipped with a secondary air flow meter.

[0019] In one embodiment, a steam pressure gauge is arranged on the boiler drum, and a steam flow meter is arranged on the outlet pipe of the heating surface.

[0020] In one embodiment, an oxygen analyzer is arranged in the burnout chamber.

[0021] In one embodiment, the main combustion chamber, auxiliary combustion chamber, burnout chamber, cyclone separator, primary return feeder, secondary return feeder, and corresponding pipelines are equipped with body measuring instruments.

[0022] In one embodiment, the pipe includes: a vertical pipe and an inclined pipe;

[0023] One end of the vertical pipe is connected to the cyclone separator, and the other end is connected to the secondary return feeder; one end of the inclined pipe is connected to the secondary return feeder, and the other end is connected to the main combustion chamber.

[0024] The anti-clogging Pitot tube is installed on the vertical pipe.

[0025] As can be seen from the above technical solution, this utility model provides a multi-stage circulating fluidized bed combustion device, including: a primary air fan, a secondary air fan, a secondary air grading and distribution pipe, a primary quantitative feeder, a secondary quantitative feeder, a primary return feeder, a secondary return feeder, a main combustion chamber, a secondary combustion chamber, a burnout chamber, and a cyclone separator arranged sequentially; the primary quantitative feeder and the secondary quantitative feeder are arranged sequentially from bottom to top at the front of the main combustion chamber; the primary quantitative feeder and the secondary quantitative feeder are respectively connected to the main combustion chamber; the primary return feeder is located below the secondary combustion chamber and the burnout chamber, and the secondary return feeder... The return feeder is located below the cyclone separator; the main combustion chamber, auxiliary combustion chamber, and burnout chamber are all connected to the first-stage return feeder, and the second-stage return feeder is connected to both the cyclone separator and the main combustion chamber; the bottom of the main combustion chamber is connected to the primary air fan; the secondary air staged distribution pipe is arranged inside the main combustion chamber and connected to the secondary air fan; a heat flow meter sensor is arranged on the water-cooled wall of the main combustion chamber; an anti-clogging Pitot tube is installed on the pipe between the cyclone separator and the main combustion chamber; the multi-stage circulating fluidized bed combustion equipment has a reliable structure, which facilitates subsequent improvement of combustion efficiency and reduction of initial NOx formation.

[0026] It should be understood that the above general description and the following detailed description are merely exemplary and do not limit this application. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a schematic diagram of the structure of the multi-stage circulating fluidized bed combustion device in the embodiments of this application.

[0029] Figure 2 This is a comparative schematic diagram of the elevation and top view of the heat flow meter sensor in the embodiments of this application.

[0030] Symbol explanation:

[0031] 1. Multi-stage circulating fluidized bed combustion equipment; 101. Primary air fan; 102. Primary air flow meter; 103. Primary air duct; 104. Secondary air fan; 105. Secondary air flow meter; 106. Secondary air duct; 107. Secondary air grading and distribution pipe; 108. Primary quantitative feeder; 109. Secondary quantitative feeder; 110. Main combustion chamber; 1101. Water-cooled wall; 1102. Duct; 111. Secondary combustion chamber; 112. Boiler drum; 113. 114. Steam pressure gauge; 115. Heating surface; 116. Steam flow meter; 117. Combustion chamber; 118. Oxygen analyzer; 119. Cyclone separator; 120. Primary return feeder; 121. Secondary return feeder; 122. Body measuring instrument; 123. Bed temperature measuring point; 6. Heat flow meter sensor; 601. Fin-end thermocouple; 602. Vertex thermocouple; 603. Water-cooled wall tube; 604. Fin; 605. Medium-side thermocouple; 7. Anti-clogging Pitot tube. Detailed Implementation

[0032] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0033] Specific embodiments of the present invention are disclosed in detail with reference to the following description and accompanying drawings, indicating how the principles of the present invention can be employed. It should be understood that the embodiments of the present invention are not limited in scope. Within the spirit and scope of the appended claims, the embodiments of the present invention include many changes, modifications, and equivalents.

[0034] Features described and / or illustrated for one embodiment may be used in the same or similar manner in one or more other embodiments, combined with features in other embodiments, or substituted for features in other embodiments.

[0035] It should be emphasized that the term "including / comprises" as used herein refers to the presence of a feature, whole, step, or component, but does not exclude the presence or addition of one or more other features, wholes, steps, or components.

[0036] This utility model provides an example of a multi-stage circulating fluidized bed combustion device. It features a reliable structure and the ability to monitor the heat flow rate of the water-cooled walls and the return flow rate online, facilitating subsequent improvements in combustion efficiency and reductions in initial NOx formation. (See also...) Figure 1 The multi-stage circulating fluidized bed combustion device 1 includes:

[0037] A primary air fan 101, a secondary air fan 104, a secondary air grading and distribution pipe 107, a primary quantitative feeder 108, a secondary quantitative feeder 109, a primary return feeder 119, a secondary return feeder 120, a main combustion chamber 110, a secondary combustion chamber 111, a burnout chamber 116, and a cyclone separator 118 are arranged in sequence and connected together. The primary quantitative feeder 108 and the secondary quantitative feeder 109 are arranged from bottom to top at the front of the main combustion chamber 110. The primary quantitative feeder 108 and the secondary quantitative feeder 109 are respectively connected to the main combustion chamber 110. The primary return feeder 119 is located in the secondary combustion chamber 111 and the burnout chamber 120. Below 16, the secondary return feeder 120 is located below the cyclone separator 118; the main combustion chamber 110, the auxiliary combustion chamber 111, and the burnout chamber 116 are all connected to the primary return feeder 119, and the secondary return feeder 120 is connected to the cyclone separator 118 and the main combustion chamber 110 respectively; the bottom of the main combustion chamber 110 is connected to the primary air fan 101; the secondary air grading distribution pipe 107 is arranged in the main combustion chamber 110 and is connected to the secondary air fan 104; a heat flow meter sensor 6 is arranged on the water-cooled wall of the main combustion chamber 110; an anti-clogging Pitot tube 7 is installed on the pipe between the cyclone separator and the main combustion chamber.

[0038] Specifically, the multi-stage circulating fluidized bed combustion device can be a circulating fluidized bed boiler; it can be positioned with the fuel and flue gas flow directions as front and back, with the main combustion chamber in front and the combustion chamber behind. In this embodiment, the bottom of the main combustion chamber 110 can be connected to the primary air fan 101 via a primary air duct 103, and the primary air duct is equipped with a primary air flow meter 102; the secondary air grading distribution pipe 107 is connected to the secondary air fan 104 via a secondary air duct 106, and the secondary air duct 106 is equipped with a secondary air flow meter 105. A bed temperature measuring point 122 can also be provided in the main combustion chamber. The primary air fan 101 and the secondary air fan 104 can supply the air required for fuel combustion to the main combustion chamber 110 in stages. The air supplied by the primary air fan ensures the normal fluidization of the circulating fluidized bed and provides sufficient air to maintain the combustion of fixed carbon in the fuel, while the air supplied by the secondary air fan mainly ensures the continued combustion of volatiles and unburned carbon in the fuel. By grading the fuel, the oxygen atmosphere in the furnace is suppressed, thereby inhibiting the formation of thermal nitrogen oxides. By supplying fuel to the main combustion chamber 110 in stages through a primary metering feeder 108 and a secondary metering feeder 109, staged combustion of the fuel within the main combustion chamber 110 can be maintained. A portion of the nitrogen oxides produced by the combustion of the fuel supplied by the primary metering feeder 108 is reduced by the fuel supplied by the secondary metering feeder 109, thereby further reducing the initial formation of nitrogen oxides and increasing the temperature of the main combustion chamber. The pipeline between the cyclone separator and the main combustion chamber can serve as a material circulation loop.

[0039] In this embodiment, a steam pressure gauge 113 may be arranged on the boiler drum 112, and a steam flow meter 115 may be arranged on the outlet pipe of the heating surface 114.

[0040] In this embodiment, an oxygen analyzer 117 can be arranged in the combustion chamber 116, and physical measuring instruments 121 are arranged in the main combustion chamber 110, auxiliary combustion chamber 111, combustion chamber 116, cyclone separator 118, primary return feeder 119, secondary return feeder 120, and corresponding pipelines. The physical measuring instruments may include: a thermometer T, a flow meter F, a pressure gauge P, and a differential pressure measuring instrument DP.

[0041] In this embodiment, the pipeline may include a vertical pipeline and an inclined pipeline; one end of the vertical pipeline is connected to the cyclone separator, and the other end is connected to the secondary return feeder; one end of the inclined pipeline is connected to the secondary return feeder, and the other end is connected to the main combustion chamber; the anti-clogging Pitot tube 7 is arranged on the vertical pipeline, and the reliability of the anti-clogging Pitot tube 7 arrangement can be improved by setting the vertical pipeline. Setting the anti-clogging Pitot tube 7 can realize the differential pressure of the gas-solid two-phase flow material in the vertical pipeline.

[0042] Conventional circulating fluidized bed boilers typically have only one main combustion chamber. As described above, this embodiment expands the combustion chamber to include a main combustion chamber, a secondary combustion chamber, and a burnout chamber. Within the main combustion chamber, not only is there staged combustion of air formed by primary and secondary air, but the fuel is also supplied in stages, resulting in staged combustion of the fuel. The lower part of the secondary combustion chamber and the lower part of the cyclone separator have primary and secondary return feeders, respectively, to return the circulating ash back to the main combustion chamber, thus forming staged return feed. This triple staged combustion—air staged, fuel staged, and circulating ash staged—constitutes a multi-stage circulating combustion system, which facilitates improved combustion efficiency and reduced initial NOx formation.

[0043] To improve the operating efficiency of the multi-stage circulating fluidized bed combustion equipment, in one embodiment, water-cooled walls 1101 are arranged on the side walls of the main combustion chamber 110, the auxiliary combustion chamber 111, the burnout chamber 116, the intermediate partition wall between the main combustion chamber 110 and the auxiliary combustion chamber 111, and the intermediate partition wall between the auxiliary combustion chamber 111 and the burnout chamber 116. The water-cooled walls are connected to the boiler drum 112 arranged above the main combustion chamber 110, and the boiler drum 112 is connected to the heating surface 114 arranged in the main combustion chamber 110, the auxiliary combustion chamber 111, and the burnout chamber 111.

[0044] Specifically, the furnace walls that do not contact each other in the main combustion chamber, auxiliary combustion chamber, and burnout chamber can be used as side walls, and the furnace walls that contact each other in the main combustion chamber and auxiliary combustion chamber, and between the auxiliary combustion chamber and burnout chamber, can be used as intermediate partition walls.

[0045] like Figure 2As shown, in one embodiment, the water-cooled wall includes: a plurality of water-cooled wall tubes 603, with fins 604 disposed between adjacent water-cooled wall tubes; the heat flux sensor includes: a fin-end thermocouple 601, a vertex thermocouple 602, and a medium-side thermocouple 605; the fin-end thermocouple 601 is fixed on the fins, the vertex thermocouple 602 is installed on the vertex of the backfire side of the water-cooled wall tube 603, and the medium-side thermocouple 605 is fixed to one end of the water-cooled wall tube 603.

[0046] Specifically, the fin-end thermocouple 601 can be fixed in the middle of the outer wall of the fin between two adjacent water-cooled wall tubes 603. The vertex thermocouple 602 can be installed on the vertex of the backfire side wall of the water-cooled wall tube 603. The medium-side thermocouple 605 can be inserted into the water-cooled wall tube 603. The heat flux sensor can collect the temperature of the fins, the vertex of the backfire side of the water-cooled wall tube, and the inside of the water-cooled wall tube.

[0047] Based on the above, this application also provides an application example of a multi-stage circulating fluidized bed combustion device, including:

[0048] The combustion chamber of the multi-stage circulating fluidized bed combustion device 1 is formed by sequentially arranging a main combustion chamber 110, a secondary combustion chamber 111, a burnout chamber 116, a cyclone separator 118, a primary return feeder 119, and a secondary return feeder 120. A primary air duct 103 is connected to the bottom of the main combustion chamber 110, and the primary air duct 103 is connected to a primary air fan 101 via a primary air flow meter 102. A secondary air grading and distribution pipe 107 is arranged in the middle of the main combustion chamber 110, and the secondary air grading and distribution pipe 107 is connected to a secondary air fan 104 via a secondary air duct 106 and a secondary air flow meter 105. A primary quantitative feeder 108 and a secondary quantitative feeder 120 are arranged sequentially from bottom to top at the front of the main combustion chamber 110. The feeder 109; water-cooled walls 1101 are arranged on the side walls and intermediate partition walls of the main combustion chamber 110, auxiliary combustion chamber 111 and burnout chamber 116. The water-cooled walls are connected to the boiler drum 112 arranged above the main combustion chamber 110 via conduits 1102. A steam pressure gauge 113 is arranged on the boiler drum 112. The boiler drum 112 is connected to the heating surface 114. A steam flow meter 115 is arranged on the outlet pipe of the heating surface 114. An oxygen analyzer 117 is arranged in the burnout chamber 116. Body measuring instruments 121 are arranged on the main combustion chamber 110, auxiliary combustion chamber 111, burnout chamber 116, cyclone separator 118, primary return feeder 119, secondary return feeder 120 and corresponding pipelines.

[0049] Furthermore, a heat flow meter sensor 6 is arranged on the water-cooled wall of the main combustion chamber 110. The heat flow meter sensor consists of a fin-end thermocouple 601, a tube wall apex thermocouple 602, and a medium-side thermocouple 605. The fin-end thermocouple 601 is fixed in the middle of the fin 604 between two adjacent water-cooled wall tubes 603, and the apex thermocouple is installed on the apex of the backfire side of the water-cooled wall tube 603.

[0050] Furthermore, an anti-clogging Pitot tube 7 is arranged on the vertical pipe connecting the cyclone separator 118 and the secondary return feeder 120.

[0051] This utility model uses specific embodiments to illustrate the principle and implementation of the utility model. The above description of the embodiments is only for the purpose of helping to understand the method and core idea of ​​the utility model. At the same time, for those skilled in the art, there will be changes in the specific implementation and application scope based on the idea of ​​the utility model. Therefore, the content of this specification should not be construed as a limitation of the utility model.

Claims

1. A multi-stage circulating fluidized bed combustion apparatus, characterized by, It comprises: primary air fan, secondary air fan, secondary air grading distribution pipe, primary quantitative feeder, secondary quantitative feeder, primary return feeder, secondary return feeder, main combustion chamber, auxiliary combustion chamber, burn-out chamber and cyclone separator arranged in sequence; The primary quantitative feeder and the secondary quantitative feeder are arranged in sequence from bottom to top in the front of the main combustion chamber; The primary quantitative feeder and the secondary quantitative feeder are respectively communicated with the main combustion chamber; The primary return feeder is arranged below the auxiliary combustion chamber and the burn-out chamber, and the secondary return feeder is arranged below the cyclone separator; the main combustion chamber, the auxiliary combustion chamber and the burn-out chamber are communicated with the primary return feeder, and the secondary return feeder is respectively communicated with the cyclone separator and the main combustion chamber; The bottom of the main combustion chamber is communicated with the primary air fan; the secondary air grading distribution pipe is arranged in the main combustion chamber and is communicated with the secondary air fan; the water-cooled wall of the main combustion chamber is provided with a hot stream meter sensor; a pitot tube for preventing blocking is arranged on the pipeline between the cyclone separator and the main combustion chamber.

2. The multi-stage circulating fluidized bed combustion equipment according to claim 1, wherein: The side walls of the main combustion chamber, the auxiliary combustion chamber and the burn-out chamber, the intermediate partition wall between the main combustion chamber and the auxiliary combustion chamber and the intermediate partition wall between the auxiliary combustion chamber and the burn-out chamber are all provided with water-cooled walls.

3. The multi-stage circulating fluidized bed combustion apparatus according to claim 1, characterized by, The water-cooled wall comprises: a plurality of water-cooled wall pipes, and fins are arranged between adjacent water-cooled wall pipes; The hot stream meter sensor comprises: a fin-end thermocouple, a vertex thermocouple and a medium-side thermocouple; The fin-end thermocouple is fixed on the fin, the vertex thermocouple is installed on the vertex of the backfire side of the water-cooled wall pipe, and the medium-side thermocouple is fixed on one end of the water-cooled wall pipe.

4. The multi-stage circulating fluidized bed combustion apparatus according to claim 2, characterized by It further comprises: A drum arranged on the upper part of the main combustion chamber; The water-cooled wall is connected with the drum, and the drum is connected with the heated surface arranged in the main combustion chamber, the auxiliary combustion chamber and the burn-out chamber.

5. The multi-stage circulating fluidized bed combustion equipment according to claim 1, wherein: The bottom of the main combustion chamber is communicated with the primary air fan via a primary air pipe, and the primary air pipe is provided with a primary air flow meter.

6. The multi-stage circulating fluidized bed combustion equipment according to claim 1, wherein: The secondary air grading distribution pipe is communicated with the secondary air fan via a secondary air pipe, and the secondary air pipe is provided with a secondary air flow meter.

7. The multi-stage circulating fluidized bed combustion equipment according to claim 4, wherein: A steam pressure gauge is arranged on the drum, and a steam flow meter is arranged on the outlet pipeline of the heated surface.

8. The multi-stage circulating fluidized bed combustion equipment according to claim 1, wherein: An oxygen analyzer is arranged in the burn-out chamber.

9. The multi-stage circulating fluidized bed combustion equipment according to claim 1, wherein: Body measuring instruments are arranged on the main combustion chamber, the auxiliary combustion chamber, the burn-out chamber, the cyclone separator, the primary return feeder, the secondary return feeder and the corresponding pipelines.

10. The multi-stage circulating fluidized bed combustion apparatus according to claim 1, wherein, The pipeline comprises: a vertical pipeline and an inclined pipeline; The vertical pipeline is communicated with the cyclone separator at one end and communicated with the secondary return feeder at the other end; the inclined pipeline is communicated with the secondary return feeder at one end and communicated with the main combustion chamber at the other end. The anti-blocking pitot tube is arranged on the vertical pipeline.

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