Flue gas direct combustion heating device

Abstract

The utility model belongs to the technical field of flue gas denitration treatment, and particularly relates to a flue gas direct combustion heating device. Comprising an inner cylinder and an outer cylinder, the inner cylinder is sleeved with the outer cylinder, the top of the outer cylinder is fixed to the outer side of the inner cylinder, a smoke inlet is formed in the upper end of the outer cylinder, a gap allowing smoke to enter the inner cylinder is formed between the bottom of the outer cylinder and the bottom of the inner cylinder, and a combustor used for heating the smoke at the bottom of the inner cylinder is fixedly arranged at the bottom of the outer cylinder. A flue gas outlet communicated with the SCR denitration reactor is formed in the top of the inner cylinder, and an ammonia spraying and mixing device for uniformly mixing ammonia gas to flue gas is further arranged at the flue gas outlet. According to the device, flue gas is heated in a direct combustion mode, the indirect heating mode of a traditional heat exchanger is avoided, the heat transfer efficiency is improved, energy waste is reduced, and the operation cost is reduced; the device adopts the design of the inner cylinder and the outer cylinder, the structure is compact, the integration degree is high, and a plurality of components in a traditional system are reduced, so that the complexity of the system is reduced, and the installation and maintenance processes are simplified; according to the device, a direct combustion heating mode is adopted, so that the stability and the high efficiency of denitration are ensured, and a good denitration effect can be kept even when working conditions change. The device not only solves the problems of low heat efficiency, complex and inconvenient system maintenance, slow response speed and the like in a traditional system, but also improves the overall performance of the system through optimization design, greatly reduces the size of the device, and has remarkable technical advantages and application prospects.

Description

Technical Field

[0001] The utility model belongs to the technical field of flue gas denitrification treatment, and particularly relates to a flue gas direct-combustion heating device. Background Art

[0002] With the increasingly stringent environmental regulations, nitrogen oxides (NO x ) control has become an important issue. Selective catalytic reduction (SCR) technology is a highly efficient denitrification method that is currently widely used. By evenly spraying ammonia (NH3) into the flue gas, under the action of the catalyst, ammonia reacts with nitrogen oxides in the flue gas to produce harmless nitrogen (N2) and water (H2O), thereby achieving NO x effective removal.

[0003] In traditional SCR denitrification systems, flue gas typically requires preheating to reach the catalyst's optimal operating temperature. However, this preheating process has several drawbacks: 1) Low thermal efficiency: Traditional flue gas heating often relies on indirect heating, such as using a heat exchanger. This method has low heat transfer efficiency and results in energy waste; 2) System complexity: Traditional systems typically include multiple components, such as heat exchangers and piping, increasing system complexity and maintenance costs; 3) Slow response: Traditional systems struggle to quickly adjust to changes in flue gas flow or composition, resulting in reduced denitrification efficiency.

[0004] Therefore, a new type of flue gas direct-fired heating device is urgently needed to solve the problems of low thermal efficiency, complex and inconvenient maintenance, and slow response speed of existing devices.

[0005] In view of this, the present utility model is proposed. Utility Model Content

[0006] The purpose of the utility model is to overcome the shortcomings of the above-mentioned prior art and provide a flue gas direct-fired heating device.

[0007] To achieve the above objectives, the present invention provides the following technical solutions:

[0008] A flue gas direct-fired heating device comprises an inner cylinder, an outer cylinder which is sleeved outside the inner cylinder and the top of which is fixed to the outside of the inner cylinder, a flue gas inlet is provided at the upper end of the outer cylinder, a gap is provided between the bottom of the outer cylinder and the bottom of the inner cylinder so that the flue gas can enter the inner cylinder, a burner for heating the flue gas at the bottom of the inner cylinder is fixed at the bottom of the outer cylinder, a flue gas outlet connected to the SCR denitrification reactor is provided at the top of the inner cylinder, and an ammonia spray mixing device for uniformly mixing the flue gas with ammonia is also provided at the flue gas outlet.

[0009] Specifically, an air intake device is provided inside the inner tube and near the smoke inlet, which allows smoke to directly enter the inner tube. The air intake device includes a plurality of air intake holes provided on the wall of the inner tube, and a temperature-controlled opening and closing device fixed on the inner wall of the inner tube and controlling the opening and closing of the air intake holes according to the smoke temperature of the inner tube.

[0010] Specifically, the temperature-controlled opening and closing device also includes a blocking rod for support and a sliding bracket for facilitating the sliding of the blocking rod. The two ends of the sliding bracket are respectively fixed on two fixed brackets, and a sliding hole is provided in the middle to facilitate the sliding of the blocking rod and to match the shape of the blocking rod.

[0011] Specifically, the burner includes a fire tube with one end fixed to the bottom of the outer tube and the other end extending into the bottom of the inner tube. One end of the fire tube is also provided with a first interface for accessing natural gas and a second interface for accessing compressed air.

[0012] Specifically, the first interface is further provided with a gas valve for controlling the amount of natural gas, and the second interface is provided with an air compression pump.

[0013] Specifically, the ammonia injection mixing device includes an annular porous plate fixed at the flue gas outlet and used to evenly inject ammonia into the inner cylinder. An annular outer cylinder for forming an ammonia accommodating chamber is also fixed outside the annular porous plate, and an ammonia inlet is opened on the annular outer cylinder.

[0014] Compared with the prior art, the technical solution provided by the utility model has the following beneficial effects:

[0015] This device heats the flue gas by direct combustion, avoiding the indirect heating method of the traditional heat exchanger and improving the heat transfer efficiency. This method reduces energy waste and lowers operating costs. The device adopts an inner and outer tube design with a compact structure and high integration, reducing multiple components in the traditional system, thereby reducing the complexity of the system and simplifying the installation and maintenance process. Since this device adopts a direct combustion heating method, it can quickly adjust the heating power to cope with changes in the flue gas flow or composition. This rapid response capability ensures the stability and efficiency of denitrification and maintains a good denitrification effect even when the working conditions change. The flue gas direct combustion heating device provided by the utility model not only solves the problems of low thermal efficiency, complex and inconvenient system maintenance, and slow response speed existing in the traditional system, but also improves the overall performance of the system through optimized design and greatly reduces the size of the device. It has significant technical advantages and application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings are incorporated into and constitute a part of this specification and, together with the description, are used to explain the principles of the present invention.

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0018] Figure 1 It is a three-dimensional structural schematic diagram of the utility model;

[0019] Figure 2 This is the main view of the utility model;

[0020] Figure 3 for Figure 2 AA section view.

[0021] Among them: 1 is the inner cylinder; 11 is the flue gas outlet; 12 is the air intake device; 13 is the air inlet; 2 is the outer cylinder; 21 is the flue gas inlet; 3 is the burner; 31 is the fire cylinder; 32 is the first interface; 33 is the second interface; 34 is the air valve; 35 is the air compression pump; 4 is the ammonia injection mixing device; 41 is the annular porous plate; 42 is the annular outer cylinder; 43 is the ammonia gas inlet. DETAILED DESCRIPTION

[0022] Exemplary embodiments will now be described in detail, with examples shown in the accompanying drawings. The embodiments described in the following exemplary embodiments are not intended to represent all embodiments consistent with the present invention. Instead, they are merely examples consistent with certain aspects of the present invention as detailed in the appended claims.

[0023] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below with reference to the accompanying drawings and embodiments.

[0024] Example 1

[0025] See also Figure 1-3 As shown, this embodiment provides a flue gas direct-combustion heating device, comprising an inner cylinder 1, an outer cylinder 2 which is sleeved outside the inner cylinder 1 and whose top is fixed to the outside of the inner cylinder 1, a flue gas inlet 21 is provided at the upper end of the outer cylinder 2, and a gap is provided between the bottom of the outer cylinder 2 and the bottom of the inner cylinder 1 so that the flue gas can enter the inner cylinder 1, a burner 3 for heating the flue gas at the bottom of the inner cylinder 1 is fixed at the bottom of the outer cylinder 2, a flue gas outlet 11 connected to the SCR denitrification reactor is provided at the top of the inner cylinder 1, and an ammonia spray mixing device 4 for uniformly mixing ammonia with the flue gas is also provided at the flue gas outlet 11.

[0026] Specifically, the burner 3 includes a fire tube 31 with one end fixed to the bottom of the outer tube 2 and the other end extending into the bottom of the inner tube 1. One end of the fire tube 31 is also provided with a first interface 32 for accessing natural gas and a second interface 33 for accessing compressed air.

[0027] Specifically, the first interface 32 is further provided with a gas valve 34 for controlling the amount of natural gas, and the second interface 33 is provided with an air compression pump 35 .

[0028] Specifically, the ammonia injection mixing device 4 includes an annular porous plate 41 fixed at the flue gas outlet 11 and used to uniformly inject ammonia into the inner tube 1. An annular outer tube 42 for forming an ammonia accommodating chamber is fixed outside the annular porous plate 41, and an ammonia inlet 43 is opened on the annular outer tube 42.

[0029] Preferably, in this device, the flue gas flow rate at the flue gas inlet 21, the flame combustion temperature of the burner, and the ammonia flow rate are all uniformly adjusted by the control system, so that the flue gas temperature flowing to the SCR denitrification device is 230°C and the mixed ammonia is uniform, so as to improve the denitrification efficiency.

[0030] This embodiment also provides a method for using the flue gas direct-fired heating device, which is as follows:

[0031] Cold flue gas (temperature of 80-160°C) enters the outer tube 2 from the flue gas inlet 11, and then enters the bottom of the inner tube 1 from the bottom of the outer tube 2. At the same time, natural gas and compressed air are mixed and burned in the fire tube 31, generating high-temperature flue gas greater than 750°C at the bottom of the inner tube 1. After the cold flue gas mixes with the high-temperature flue gas at the bottom of the inner tube 1, the temperature reaches the flue gas suitable for the SCR denitrification reaction temperature (230°C). The flue gas then mixes evenly with the ammonia sprayed by the ammonia spray mixing device 4 before passing through the flue gas outlet 11, and then passes through the flue gas outlet 11 to the SCR denitrification device for subsequent denitrification process. See Figure 3 shown.

[0032] The above description is merely a specific embodiment of the present invention, which enables those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention.

[0033] It should be understood that the present invention is not limited to the above description and that various modifications and changes can be made without departing from the scope of the present invention. The scope of the present invention is limited only by the appended claims.

Claims

1. A flue gas direct combustion heating device, characterized in that: The invention comprises an inner cylinder (1), an outer cylinder (2) which is sleeved outside the inner cylinder (1) and whose top is fixed on the outer side of the inner cylinder (1), a flue gas inlet (21) is provided at the upper end of the outer cylinder (2), a gap is provided between the bottom of the outer cylinder (2) and the bottom of the inner cylinder (1) so that the flue gas can enter the inner cylinder (1), a burner (3) is fixed at the bottom of the outer cylinder (2) for heating the flue gas at the bottom of the inner cylinder (1), a flue gas outlet (11) which is connected to the SCR denitration reactor is provided at the top of the inner cylinder (1), and an ammonia spray mixing device (4) is also provided at the flue gas outlet (11) for uniformly mixing the flue gas with ammonia.

2. The flue gas direct combustion heating device according to claim 1, characterized in that: The burner (3) comprises a fire tube (31) with one end fixed to the bottom of the outer tube (2) and the other end extending into the bottom of the inner tube (1); one end of the fire tube (31) is also provided with a first interface (32) for receiving natural gas and a second interface (33) for receiving compressed air.

3. The flue gas direct combustion heating device according to claim 2, characterized in that: The first interface (32) is further provided with a gas valve (34) for controlling the amount of natural gas, and the second interface (33) is provided with an air compression pump (35).

4. The flue gas direct combustion heating device according to claim 1, characterized in that: The ammonia spray mixing device (4) comprises an annular porous plate (41) fixed at the flue gas outlet (11) and used for uniformly spraying ammonia into the inner cylinder (1); an annular outer cylinder (42) for forming an ammonia accommodating chamber is fixed outside the annular porous plate (41); an ammonia inlet (43) is opened on the annular outer cylinder (42).

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