Natural gas oxygen-enriched heating furnace system

Abstract

The utility model discloses a natural gas oxygen-enriched heating furnace system. It comprises a heating furnace, a natural gas pipeline, an air pipeline, and an oxygen main pipeline. The heating furnace is equipped with a first natural gas burner and a second natural gas burner connected to the natural gas pipeline. The air pipeline is connected to the hot air main pipeline through an air heat exchanger. The hot air main pipeline is connected to the first natural gas burner through a first hot air branch pipe and a first burner hot air branch pipe. The hot air main pipeline is connected to the second natural gas burner through a second hot air branch pipe and a second burner hot air branch pipe; the oxygen main pipeline is connected to the air pipeline, the first hot air branch pipe and the second burner hot air branch pipe through the first oxygen pipeline, the second oxygen pipeline and the third oxygen pipeline respectively. The utility model can operate in the whole furnace oxygen supply and combustion-supporting mode, the zoned oxygen supply and combustion-supporting mode and the burner oxygen supply and combustion-supporting mode, and can be directly switched online to realize the oxygen-enriched combustion function of different concentrations, optimize the configuration of energy media, reduce pollutant emissions, and save energy and reduce emissions.

Description

Technical Field

[0001] The utility model relates to a furnace in the metallurgical industry, in particular to a natural gas oxygen-enriched heating furnace system. Background Art

[0002] The steel rolling heating furnace is an indispensable and important link in the steel rolling process production, and is a key part of energy consumption and carbon emissions. Many steel rolling heating furnaces use natural gas as fuel, and the fuel cost accounts for a very large proportion. At present, heating furnaces at home and abroad generally use air-assisted combustion. In order to achieve the heating temperature of the billet and increase production, the amount of natural gas used is also gradually increasing. In recent years, the unit price of natural gas has gradually increased, resulting in a continuous increase in the fuel cost of the heating furnace. Oxygen-enriched combustion can improve combustion efficiency and reduce pollutant emissions under the same fuel usage conditions. It is a low-carbon, energy-saving combustion technology.

[0003] The Chinese invention application with application number 2022109932504U discloses an oxygen-enriched heating furnace system, which is applicable to heating furnaces fueled by coal gas. How to use oxygen-enriched combustion in natural gas heating furnaces and flexibly meet the use of various production conditions under the conditions of existing heating furnaces has become a technical problem that needs to be solved urgently. Utility Model Content

[0004] The present invention aims to solve the above technical problems, thereby providing a natural gas oxygen-enriched heating furnace system to optimize the energy medium configuration and reduce the production cost.

[0005] The utility model solves the technical problem and adopts the following technical solution:

[0006] A natural gas oxygen-enriched heating furnace system comprises a heating furnace, a natural gas pipeline, an air pipeline, and an oxygen main pipeline. The heating furnace is provided with a first natural gas burner and a second natural gas burner connected to the natural gas pipeline.

[0007] The air pipeline is connected to the hot air main pipeline through the air heat exchanger, the hot air main pipeline is connected to the first natural gas burner through the first hot air branch pipe and the first burner hot air branch pipe, and the hot air main pipeline is connected to the second natural gas burner through the second hot air branch pipe and the second burner hot air branch pipe;

[0008] The main oxygen pipeline is connected to the air pipeline, the first hot air branch pipe and the second burner hot air branch pipe through the first oxygen pipeline, the second oxygen pipeline and the third oxygen pipeline respectively.

[0009] Compared with the prior art, the utility model adopting the above technical solution has the following beneficial effects:

[0010] 1) It can operate in the whole furnace oxygen supply combustion mode, the zone oxygen supply combustion mode and the burner oxygen supply combustion mode. Without changing the equipment, it can be directly switched online to achieve oxygen-enriched combustion functions of different concentrations. Steel mills can use it flexibly according to their own gas and oxygen conditions to achieve the optimization of energy medium configuration;

[0011] 2) Reduce the load of the air supply system, improve combustion efficiency, reduce the generation of nitrogen oxides, reduce pollutant emissions, save energy and reduce emissions, and reduce costs.

[0012] Further, the optimization scheme of the utility model is:

[0013] The heating furnace is divided into a preheating zone, a heating zone and a soaking zone in sequence. The first natural gas burner is placed at the upper part of the heating zone, and the second natural gas burner is placed at the lower part of the soaking zone.

[0014] The nozzle of the first natural gas burner is downward, and the nozzle of the second natural gas burner is upward.

[0015] The main oxygen pipeline is installed with an oxygen main valve, the first oxygen pipeline is installed with a first valve, the second oxygen pipeline is installed with a second valve, and the third oxygen pipeline is installed with a third valve and a fourth valve.

[0016] The inlet end of the first hot air branch pipe is equipped with a first hot air branch pipe valve, the outlet end of the second oxygen pipeline is located at the rear side of the first hot air branch pipe valve, and the inlet end of the second hot air branch pipe is equipped with a second hot air branch pipe valve.

[0017] The inlet end of the first burner hot air branch pipe is equipped with a first burner valve, the inlet end of the second burner hot air branch pipe is equipped with a second burner valve, and the outlet end of the third oxygen pipeline is located at the rear side of the second burner valve.

[0018] The first oxygen pipeline, the second oxygen pipeline and the third oxygen pipeline have different diameters.

[0019] The heating furnace system is provided with a whole-furnace oxygen supply combustion-supporting mode, a zoned oxygen supply combustion-supporting mode and a burner oxygen supply combustion-supporting mode. The oxygen concentration of the whole-furnace oxygen supply mode is ≤30%, the oxygen-enriched concentration of the zoned oxygen supply combustion-supporting mode is 30%-50%, and the oxygen-enriched concentration of the burner oxygen supply combustion-supporting mode is 100%. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A schematic diagram of an embodiment of the utility model;

[0021] In the figure: air pipeline 1; oxygen main pipeline 2; oxygen main valve 2-1; first oxygen pipeline 3; first valve 3-1; second oxygen pipeline 4; second valve 4-1; third oxygen pipeline 5; third valve 5-1; fourth valve 5-2; first natural gas burner 6; second natural gas burner 7; heating furnace 8; natural gas main pipeline 9; natural gas branch pipe 10; air heat exchanger 11; hot air main pipeline 12; first hot air branch pipe valve 13; first hot air branch pipe 14; first burner valve 15; first burner hot air branch pipe 16; second hot air branch pipe valve 13-1; second hot air branch pipe 14-1; second burner valve 15-1; second burner hot air branch pipe 16-1. DETAILED DESCRIPTION

[0022] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments.

[0023] In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0024] See also Figure 1 The present embodiment provides a natural gas oxygen-enriched heating furnace system, which is mainly composed of an air pipeline 1, an oxygen main pipeline 2, a first oxygen pipeline 3, a second oxygen pipeline 4, a third oxygen pipeline 5, a first natural gas burner 6, a second natural gas burner 7, a heating furnace 8 and a natural gas main pipeline 9. The body of the heating furnace 8 is divided into a preheating zone, a heating zone and a uniform heating zone in sequence. The first natural gas burner 6 is installed at the upper part of the heating zone, and the nozzle of the first natural gas burner 6 is downward. The second natural gas burner 7 is installed at the lower part of the uniform heating zone, and the nozzle of the second natural gas burner 7 is upward. The natural gas interfaces of the first natural gas burner 6 and the second natural gas burner 7 are connected to the natural gas main pipeline 9 through the natural gas branch pipe 10 respectively.

[0025] The outlet of the air pipeline 1 is connected to the inlet of the air heat exchanger 11, the outlet of the air heat exchanger 11 is connected to the middle of the hot air main pipeline 12, the hot air main pipeline 12 is arranged vertically, the upper end of the hot air main pipeline 12 is connected to the inlet of the first hot air branch pipe 14, the inlet end of the first hot air branch pipe 14 is equipped with a first hot air branch pipe valve 13, the outlet of the first hot air branch pipe 14 is connected to the inlet of the first burner hot air branch pipe 16, the inlet end of the first burner hot air branch pipe 16 is equipped with a first burner valve 15, and the outlet of the first burner hot air branch pipe 16 is connected to the oxygen supply port of the first natural gas burner 6.

[0026] The lower end of the hot air main line 12 is connected to the inlet of the second hot air branch pipe 14-1, and the inlet end of the second hot air branch pipe 14-1 is equipped with a second hot air branch pipe valve 13-1. The outlet of the second hot air branch pipe 14-1 is connected to the inlet of the second burner hot air branch pipe 16-1, and the inlet end of the second burner hot air branch pipe 16-1 is equipped with a second burner valve 15-1. The outlet of the second burner hot air branch pipe 16-1 is connected to the oxygen supply port of the second natural gas burner 7.

[0027] The oxygen main pipeline 2 is connected to the inlet of the first oxygen pipeline 3, the second oxygen pipeline 4 and the third oxygen pipeline 5 respectively through the oxygen main valve 2-1. The diameters of the first oxygen pipeline 3, the second oxygen pipeline 4 and the third oxygen pipeline 5 are different, so as to achieve different oxygen flow rates. The first oxygen pipeline 3 is equipped with a first valve 3-1, and the outlet of the first oxygen pipeline 3 is connected to the outlet of the air pipeline 1. The second oxygen pipeline 4 is equipped with a second valve 4-1, and the outlet of the second oxygen pipeline 4 is connected to the first hot air branch pipe 14, and the outlet of the second oxygen pipeline 4 is located at the rear side of the outlet of the first hot air branch pipe valve 13. The third oxygen pipeline 5 is equipped with a third valve 5-1 and a fourth valve 5-2, and the outlet of the third oxygen pipeline 5 is connected to the second burner hot air branch pipe 16-1, and the outlet of the third oxygen pipeline 5 is located at the rear side of the outlet of the second burner valve 15-1.

[0028] This embodiment is provided with three combustion modes, namely, the whole furnace oxygen supply combustion supporting mode, the zoned oxygen supply combustion supporting mode and the burner oxygen supply combustion supporting mode. The oxygen concentration of the whole furnace oxygen supply mode is ≤30%, the oxygen-enriched concentration of the zoned oxygen supply combustion supporting mode is 30%-50%, and the oxygen-enriched concentration of the burner oxygen supply combustion supporting mode is 100%.

[0029] Full-furnace oxygen supply combustion-supporting mode: When the heating furnace 8 is operated in the full-furnace oxygen supply combustion-supporting mode, the oxygen main valve 2-1 on the oxygen main pipeline 2 is opened, and the second valve 4-1 on the second oxygen pipeline 4 and the third valve 5-1 on the third oxygen pipeline 5 are both closed. Oxygen is connected to the air pipeline 1 through the first oxygen pipeline 3 and the first valve 3-1. This mode operates with an oxygen enrichment concentration below 30%. After cold air is mixed with oxygen, it is introduced into the hot air main duct 12 through the air heat exchanger 11. The oxygen-enriched hot air enters the first natural gas burner 6 through the hot air main pipe 12, the first hot air branch pipe valve 13, the first hot air branch pipe 14, the first burner valve 15 and the first burner hot air branch pipe 16; and enters the second natural gas burner 7 through the hot air main pipe 12, the second hot air branch pipe valve 13-1, the second hot air branch pipe 14-1, the second burner valve 15-1 and the second burner hot air branch pipe 16-1. The first burner valve 15 and the second burner valve 15-1 are in an open state, and the first hot air branch pipe valve 13 and the second hot air branch pipe valve 13-1 play a role in adjusting the air volume.

[0030] Partitioned oxygen supply combustion-supporting mode: When the heating furnace 8 operates in the partitioned oxygen supply combustion-supporting mode, the oxygen enrichment concentration is between 30% and 50%. The oxygen main valve 2-1 on the oxygen main pipeline 2 is opened, and the first valve 3-1 on the first oxygen pipeline 3 and the third valve 5-1 on the third oxygen pipeline 5 are both closed. The cold air in the air pipeline 1 is introduced into the hot air main pipeline 12 through the air heat exchanger 11. The oxygen in the second oxygen pipeline 4 enters the first natural gas burner 6 through the first hot air branch pipe 14, the first burner valve 15 and the first burner hot air branch pipe 16 in one way; and enters the second natural gas burner 7 through the first hot air branch pipe 14, the first hot air branch pipe valve 13, the hot air main pipeline 12, the second hot air branch pipe valve 13-1, the second hot air branch pipe 14-1, the second burner valve 15-1 and the second burner hot air branch pipe 16-1 in the other way. The first hot air branch pipe valve 13 and the second hot air branch pipe valve 13-1 play the role of adjusting the air volume, and the first burner valve 15 and the second burner valve 15-1 are in an open state.

[0031] Burner oxygen supply combustion-supporting mode: When the heating furnace 8 is operated in the burner oxygen supply combustion-supporting mode, the oxygen enrichment concentration is 100%. The oxygen main valve 2-1 on the oxygen main pipeline 2 is opened, and the first valve 3-1 on the first oxygen pipeline 3 and the second valve 4-1 on the second oxygen pipeline 4 are both closed. The air pipeline 1 stops supplying cold air, the second hot air branch valve 13-1 is in a closed state, the second burner valve 15-1 is in a closed state, and the oxygen in the third oxygen pipeline 5 is connected to the second burner hot air branch 16-1 through the third valve 5-1 and the fourth valve 5-2, and finally enters the first natural gas burner 6.

[0032] When the heating furnace 8 switches between different oxygen supply and combustion-supporting modes, oxygen needs to be supplied through different pipelines, and the relevant valves in the deactivation mode are closed. Burner oxygen supply and combustion-supporting means that the natural gas burner only supplies natural gas and oxygen for combustion. Oxygen concentration refers to the oxygen concentration after the air and oxygen supplied to the natural gas burner for oxygen supply and combustion are evenly mixed.

[0033] Since the amount of natural gas, amount of oxygen and proportion required for combustion are different under different combustion modes, the utility model adopts a first oxygen pipeline, a second oxygen pipeline and a third oxygen pipeline of different capacity / flow / flux to flexibly switch the functions of the three combustion modes under different combustion modes. In the full-furnace oxygen supply and combustion-supporting mode, the amount of air required in the combustion process is less than the amount of air required for conventional combustion. At this time, according to the calculated oxygen concentration, the supply of cold air needs to be lowered. In the zoned oxygen supply and combustion-supporting mode, the amount of air required in a single zone is less than the amount of air required for conventional combustion, so the amount of air in the zone needs to be lowered, and the air amount is controlled by the hot air branch pipe regulating valve; in the burner oxygen supply and combustion-supporting mode, a state of pure oxygen combustion can be achieved, and since no air needs to be introduced, the valve of the hot air branch pipe can be in a closed state.

[0034] The utility model designs the distribution connection of air pipelines and oxygen pipelines, and respectively sets equipment such as cut-off valves, so that the heating furnace can operate in three modes: full furnace oxygen supply and combustion mode, zoned oxygen supply and combustion mode, and burner oxygen supply and combustion mode. The utility model can directly switch online without changing the equipment to achieve the function of oxygen-enriched combustion of different concentrations. The steel plant can use it flexibly according to its own production conditions and oxygen conditions to optimize the configuration of energy media. It is a flexible, efficient, and low-carbon heating system and process.

[0035] The above shows and describes the basic principle and main features of the utility model and the advantages of the utility model. The technicians in this industry should understand that the utility model is not limited by the above embodiments, and the above embodiments and descriptions are only for explaining the principle of the utility model. Without departing from the spirit and scope of the utility model, the utility model will have various changes and improvements, and these changes and improvements fall within the scope of the utility model to be protected.

Claims

1. A natural gas oxygen-enriched heating furnace system, comprising a heating furnace, a natural gas pipeline, an air pipeline, and an oxygen main pipeline, wherein the heating furnace is provided with a first natural gas burner and a second natural gas burner connected to the natural gas pipeline, characterized in that: The air pipeline is connected to the hot air main pipeline through the air heat exchanger, the hot air main pipeline is connected to the first natural gas burner through the first hot air branch pipe and the first burner hot air branch pipe, and the hot air main pipeline is connected to the second natural gas burner through the second hot air branch pipe and the second burner hot air branch pipe; The main oxygen pipeline is connected to the air pipeline, the first hot air branch pipe and the second burner hot air branch pipe through the first oxygen pipeline, the second oxygen pipeline and the third oxygen pipeline respectively.

2. The natural gas oxygen-enriched heating furnace system according to claim 1 is characterized in that: The heating furnace is divided into a preheating zone, a heating zone and a soaking zone in sequence. The first natural gas burner is placed at the upper part of the heating zone, and the second natural gas burner is placed at the lower part of the soaking zone.

3. The natural gas oxygen-enriched heating furnace system according to claim 1 is characterized in that: The nozzle of the first natural gas burner is downward, and the nozzle of the second natural gas burner is upward.

4. The natural gas oxygen-enriched heating furnace system according to claim 1 is characterized in that: The main oxygen pipeline is installed with an oxygen main valve, the first oxygen pipeline is installed with a first valve, the second oxygen pipeline is installed with a second valve, and the third oxygen pipeline is installed with a third valve and a fourth valve.

5. The natural gas oxygen-enriched heating furnace system according to claim 1 is characterized in that: The inlet end of the first hot air branch pipe is equipped with a first hot air branch pipe valve, the outlet end of the second oxygen pipeline is located at the rear side of the first hot air branch pipe valve, and the inlet end of the second hot air branch pipe is equipped with a second hot air branch pipe valve.

6. The natural gas oxygen-enriched heating furnace system according to claim 1 is characterized in that: The inlet end of the first burner hot air branch pipe is equipped with a first burner valve, the inlet end of the second burner hot air branch pipe is equipped with a second burner valve, and the outlet end of the third oxygen pipeline is located at the rear side of the second burner valve.

7. The natural gas oxygen-enriched heating furnace system according to claim 1 is characterized in that: The first oxygen pipeline, the second oxygen pipeline and the third oxygen pipeline have different diameters.

8. The natural gas oxygen-enriched heating furnace system according to claim 1 is characterized in that: The heating furnace system is provided with a whole-furnace oxygen supply combustion-supporting mode, a zoned oxygen supply combustion-supporting mode and a burner oxygen supply combustion-supporting mode. The oxygen concentration of the whole-furnace oxygen supply mode is ≤30%, the oxygen-enriched concentration of the zoned oxygen supply combustion-supporting mode is 30%-50%, and the oxygen-enriched concentration of the burner oxygen supply combustion-supporting mode is 100%.

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