TWM668196U - Boiler system for reducing combustion flue gas emissions - Google Patents

Abstract

The present disclosure provides a boiler system boiler system that reduces combustion flue gas emissions. The system comprises a boiler body, an oil supply tank, a water supply tank, a flue gas monitoring device, boiler thermometer, and an injection device. The boiler body burns fluid fuel to heat water and generate water vapor. The flue gas monitoring device and boiler thermometer monitors the concentration and combustion temperature of at least one combustion flue gas in the boiler body. The injection device is configured to inject a combustion improving agent into the boiler body, to reduce the concentration of combustion flue gas generated during combustion and to solve the conventional problem of high concentration of nitrogen oxides in combustion flue gas.

Description

Boiler systems to reduce combustion flue gas emissions

This work is related to the field of boiler structure technology for generating steam through combustion, especially a boiler system for reducing combustion flue gas emissions.

The boiler mainly converts the chemical energy in the fuel into thermal energy steadily and continuously through the process of burning fuel, and then uses this thermal energy to heat water or heat medium to serve as a heat source for drying or heating, or a power source.

However, although the use of boilers brings convenience to factory operations, it is also accompanied by environmental problems. For example, during the combustion of fuel, the boilers emit waste gases such as sulfur oxides (SOx), nitrogen oxides (NOx), carbon monoxide (CO) and carbon dioxide (CO ₂ ), which cause serious environmental pollution, increase the greenhouse effect and lead to global warming, and the fine suspended particles (PM2.5) produced after combustion deteriorate the air quality and endanger human health. The earliest method was to add a bag to the exhaust outlet to absorb the suspended particles emitted after combustion as much as possible. However, under the requirements of environmental protection, the emission requirements of nitrogen oxides are becoming more and more stringent, and this method of using bags to absorb exhaust gas cannot reduce the concentration of nitrogen oxides.

Furthermore, the types of fuel oil currently used in industrial combustion boilers include: heavy oil, diesel, low-sulfur fuel oil, etc. The changes in the composition of the fuel oil will affect the combustion efficiency of the boiler and the composition and content of harmful substances in the combustion flue gas. Therefore, the boiler burning the above fuel oil will cause a large amount of combustion flue gas including nitrogen oxides to be discharged, causing air pollution and increasing the content of nitrogen oxide gas (NOx) in the air. In order to reduce the exhaust pollution caused by the use of fossil fuels in combustion equipment, how to control the concentration ratio of boiler combustion flue gas and avoid the disadvantage of excessively high concentration of nitrogen oxides in combustion flue gas is an important problem that needs to be solved urgently.

Furthermore, in the prior art, the removal of nitrogen oxides from combustion flue gas requires the use of additional exhaust gas treatment equipment or scrubbing equipment, which will produce a large amount of waste liquid, which will not only increase the cost of wastewater treatment, but also cause a large amount of water resources to be wasted.

On the other hand, the basic structure of the boiler in the prior art includes a furnace body and a combustion chamber inside, in which fuel can be placed for combustion, and the hot water or water vapor generated after heating can be provided for various purposes. In the existing boiler system, the technology of recycling the water vapor generated by the combustion of the boiler itself and applying it to reduce the concentration of combustion flue gas has not yet been developed.

Therefore, it is imperative to develop a boiler system that complies with environmental regulations and can control the concentration of boiler combustion flue gas.

In view of this, this invention provides a boiler system that can reduce combustion flue gas emissions. By introducing a combustion improver into the boiler body, the flue gas generated by boiler combustion is reduced, that is, the NOx concentration is reduced, and the generation of carbon monoxide (CO) can be avoided simultaneously.

In order to solve the above problems, the present invention provides a boiler system for reducing combustion flue gas emissions, comprising: a boiler body, the boiler body including a combustion chamber, a liquid water layer and a water vapor layer in order from bottom to top, the combustion chamber is arranged at the bottom of the boiler body, the water vapor layer is formed at the top of the boiler body, the liquid water layer is formed between the combustion chamber and the water vapor layer, the combustion chamber is used to burn a liquid fuel to heat liquid water to generate water vapor, wherein the steam pressure in the boiler body is 3 to 5 kg/cm ² ; an oil supply tank, including an oil supply pipeline and an oil nozzle, the oil supply pipeline is arranged between the oil nozzle and the oil supply tank, and is used to supply the liquid fuel to the oil nozzle, and the oil nozzle is arranged in the combustion chamber, and is used to inject the liquid fuel into the combustion chamber; a water supply tank, through a water supply pipeline to supply liquid water to the liquid water layer; a smoke detector, The boiler body comprises a steam nozzle, which is used to monitor the concentration of at least one combustion flue gas in the boiler body; a steam nozzle, which is used to inject a combustion improver into the combustion chamber when the liquid fuel is burned to control the concentration of the combustion flue gas generated during combustion; and at least one main steam supply pipeline, which is connected to the water vapor layer of the boiler body and is used to transmit the water vapor generated during combustion.

In an embodiment of the present invention, the boiler system further includes: a header box connected to the main steam supply pipeline for collecting the water vapor transmitted by the main steam supply pipeline, and the header box is also connected to at least one production steam pipeline for transmitting the water vapor for heating; a blower connected to the combustion chamber and providing air into the combustion chamber of the boiler body through an air supply pipeline and an air supply port, so that the air and the liquid fuel flowing out of the oil nozzle are evenly mixed and burned; a flue gas exhaust pipe is connected to the combustion chamber and is used to discharge the combustion flue gas generated during combustion.

In an embodiment of the present invention, the header box further includes a steam return pipe, and the header box is connected to the steam nozzle through the steam return pipe, and is used to inject the collected water vapor into the combustion chamber through the steam nozzle.

In an embodiment of the present invention, the steam nozzle is disposed at a central position of a combustion flame of the nozzle, so that the steam nozzle injects the water vapor into the combustion chamber and ejects the water vapor from the central position of the combustion flame of the nozzle, so as to completely vaporize the water vapor and increase the contact area between the water vapor and the combustion flame around the nozzle.

In one embodiment of the present invention, the steam nozzle includes a steam regulating valve, which is configured to control the flow rate and/or flow velocity of the combustion improver entering the combustion chamber from the steam nozzle.

In one embodiment of the present invention, the water supply pipeline extends from the water vapor layer at the top of the boiler body to the liquid water layer.

In one embodiment of the present invention, the flue gas detector monitors an initial concentration of a first combustion flue gas in the boiler body, and monitors the generation of a second combustion flue gas in the boiler body after the combustion improver is injected into the combustion chamber.

In an embodiment of the present invention, the first combustion flue gas is nitrogen oxide (NOx) gas, and the second combustion flue gas is carbon monoxide (CO).

In an embodiment of the present invention, the boiler system further includes a boiler thermometer for measuring at least one combustion temperature in the boiler body. The boiler thermometer is configured to measure a first combustion temperature corresponding to the generation of the first combustion flue gas in the boiler body, and is configured to measure a second combustion temperature corresponding to the generation of the second combustion flue gas in the boiler body.

In one embodiment of the present invention, the combustion improver is water vapor.

In an embodiment of the present invention, the liquid fuel is a plant fuel, and the plant fuel is selected from at least one of the group consisting of palm oil, coconut oil, corn oil, rice bran oil, cottonseed oil, olive oil, peanut oil, rapeseed oil, safflower oil, sesame oil, soybean oil, sunflower oil, taro oil, hemp oil, pistacia oil, and pine oil.

The technical effects produced by this creation are as follows:

1) By installing a steam nozzle, the combustion improver is introduced into the boiler body, effectively reducing the concentration of combustion flue gas (especially nitrogen oxides (NOx)) and simultaneously avoiding the generation of carbon monoxide (CO).

2) By placing the steam nozzle at the center of the combustion flame of the nozzle, the combustion improver is ejected from the center of the combustion flame, and the combustion improver is completely vaporized into smaller gas molecules. When nitrogen atoms and oxygen atoms in the combustion flue gas collide effectively to generate nitrogen oxide molecules (such as nitrogen monoxide and nitrogen dioxide), the vaporized combustion improver can block the effective collision between nitrogen atoms and oxygen atoms, thereby reducing the probability of nitrogen oxides being formed due to effective collision between nitrogen atoms and oxygen atoms, thereby reducing the concentration of nitrogen oxides in the emitted flue gas and simultaneously avoiding the generation of carbon monoxide (CO).

3) By setting up a header box and a steam return pipe, the water vapor generated by heating liquid water during the boiler combustion process is collected by the header box, and part of the collected water vapor is transmitted to the steam nozzle through the steam return pipe, and then introduced into the combustion chamber of the boiler body through the steam nozzle, forming a water vapor circulation inside the boiler body. In this way, the step of introducing water vapor/combustion improver from the outside can be omitted, and the concentration of combustion flue gas (especially nitrogen oxides (NOx)) can be further reduced.

1: Boiler system

10: Boiler body

11: Combustion chamber

111: Window

12: Liquid water layer

13: Water vapor layer

20: Oil supply tank

21: Oil supply pipeline

22: Grease nozzle

23: Oil supply pump

24: Oil supply regulating valve

30: Water supply tank

31: Water supply pipeline

32: Water supply pump

40: Smoke detector

50: Steam nozzle

51: Steam regulating valve

60: Main steam supply pipeline

61: header box

611: Steam return pipe

612: Steam flow meter

62: Steam pipeline for production

70: Blower

71: Air supply pipe

72: Air outlet

80: Flue gas exhaust pipe

90: Boiler thermometer

200: Burning flames

300: Vaporized combustion improver

Figure 1 is a schematic diagram of a boiler system block for reducing combustion flue gas emissions in an embodiment of the present invention.

Figure 2 is a schematic diagram of the configuration of the oil nozzle and steam nozzle of the boiler system of an embodiment of the present invention.

The technical content and detailed description of this invention are described in conjunction with the diagram as follows: Please refer to Figure 1, which is a block diagram of a boiler system for reducing combustion flue gas emissions according to an embodiment of this invention. The boiler system 1 of this invention includes: a boiler body 10, an oil supply tank 20, a water supply tank 30, a flue gas detector 40, a steam nozzle 50, a main steam supply pipeline 60, a header box 61, a blower 70, and a flue gas exhaust pipe 80.

A combustion chamber 11 is formed inside the boiler body 10, and the combustion chamber 11 is used to burn liquid fuel, wherein the boiler body 10 includes the combustion chamber 11, a liquid water layer 12 and a water vapor layer 13 from bottom to top, the combustion chamber 11 is arranged at the bottom of the boiler body 10, the water vapor layer 13 is formed at the top of the boiler body 10, and the liquid water layer 12 is formed between the combustion chamber 11 and the water vapor layer 13. An igniter (not shown) is arranged beside the combustion chamber 11, and a window 111 (see FIG. 2) is provided for the user to view the combustion state inside the boiler body 10. The heat energy generated by burning the liquid fuel is used to heat the liquid water, and the water vapor generated by the heated and vaporized liquid water is used for drying and heating purposes. During the combustion process, the steam pressure in the boiler body is maintained in the range of 3 to 5 Kg/ ^cm2 . In a preferred embodiment, the steam pressure in the boiler body is maintained at about 5 Kg/ ^cm2 .

The fuel supply tank 20 is connected to the fuel nozzle 22 through the fuel supply pipeline 21. The fuel supply pipeline 21 is arranged between the fuel nozzle 22 and the fuel supply tank 20, and is used to supply the liquid fuel to the fuel nozzle 22. The fuel nozzle 22 is arranged in the combustion chamber 11, and is used to spray the liquid fuel into the combustion chamber 11. A fuel supply pump 23 and a fuel supply regulating valve 24 are respectively arranged in the fuel supply pipeline 21. The fuel supply pump 23 pumps the liquid fuel from the fuel supply tank 20 to the fuel nozzle, and the fuel supply regulating valve 24 is used to control the flow rate of the liquid fuel sprayed to the combustion chamber 11 through the fuel supply pipeline 21.

The water supply tank 30 supplies liquid water to the liquid water layer 12 of the boiler body 10 via a water supply pipeline 31. More specifically, the water supply tank 30 includes a water supply pump 32, and the water supply pump 32 pumps the liquid water from the water supply tank 30 through the water supply pipeline 31 to the liquid water layer 12 of the boiler body 10.

The flue gas detector 40 is disposed on the boiler body 10 and optionally includes one or more gas sensors (not shown) for monitoring the concentration of at least one type of combustion flue gas generated in the boiler body 10 when burning liquid fuel.

The steam nozzle 50 is disposed in the combustion chamber 11 of the boiler body 10 and is used to inject/spray a combustion improver into the combustion chamber 11. The combustion improver is used to reduce the flame temperature in the combustion chamber 11, thereby reducing the generation of nitrogen oxides (NOx) during the combustion process. In some embodiments, the steam nozzle 50 is at least one nozzle structure in the group consisting of a gas nozzle, a liquid nozzle or a vaporization nozzle.

At least one main steam supply pipeline 60 is connected to the water vapor layer 13 of the boiler body 10. The water vapor generated by the boiler body 10 in the combustion state is transmitted to the header box 61 through the main steam supply pipeline 60, that is, the main steam supply pipeline 60 is arranged in the water vapor layer 13 of the boiler body 10, and extends to the outside of the boiler body 10 and connected to the header box 61. The header box 61 is connected to the main steam supply pipeline 60 to collect the water vapor transmitted by the main steam supply pipeline 60. The header box 61 is also connected to at least one production steam pipeline 62 for transmitting the water vapor for other heating purposes.

The blower 70 is connected to the boiler body 10, and provides air to enter the combustion chamber 11 of the boiler body 10, and provides air to enter the combustion chamber 11 of the boiler body 10 through an air supply pipe 71 and an air supply port 72. The air supply port 72 is arranged in the combustion chamber 11, so that the air and the liquid fuel flowing out of the oil nozzle 22 are evenly mixed and burned, thereby burning the liquid fuel, and controlling a damper (not shown) of the air supply pipe 71 to adjust the flow rate of air passing through.

The flue gas exhaust pipe 80 is disposed at the top of the boiler body 10 and is connected to the combustion chamber 11 to discharge the combustion flue gas generated during combustion.

Basically, the boiler body 10 includes a combustion chamber 11, a liquid water layer 12 and a water vapor layer 13 from bottom to top. The combustion chamber 11 is arranged at the bottom of the boiler body 10 corresponding to the window 111, and the water supply pipeline 31 extends from the top of the boiler body 10 into the liquid water layer 12 of the boiler body 10.

A boiler thermometer 90 is disposed on the boiler body 10, and optionally includes one or more temperature detectors (not shown), for measuring at least one combustion temperature in the boiler body 10 when burning liquid fuel. In addition, the header box 61 further includes a steam return pipe 611, and the header box 61 is connected to the steam nozzle 50 through the steam return pipe 611, and is used to inject the collected water vapor into the combustion chamber 11 through the steam nozzle 50. The combustion chamber 11, the main steam supply pipeline 60, the header box 61, the steam return pipeline 611 and the steam nozzle 50 of the boiler system 1 form a boiler body water vapor circulation loop. The main steam supply pipeline 60 recovers and concentrates the water vapor generated by combustion to the header box 61. Part of the recovered and concentrated water vapor flows from the header box 61 through the steam return pipeline 611 and is ejected from the steam nozzle 50 into the combustion chamber 11 to control the concentration of the combustion flue gas generated during combustion. In this water vapor circulation loop, it is no longer necessary to provide additional water vapor from the outside. In addition, the steam return pipe 611 also includes a steam flow meter 612, which allows the user to clearly know the flow rate of the combustion improver sprayed to the combustion chamber 11 through the steam nozzle 50.

It should be noted that, please refer to FIG. 2, which is a schematic diagram of the configuration of the oil nozzle and the steam nozzle of the boiler system of an embodiment of the present invention. In the embodiment of FIG. 2, the steam nozzle 50 is arranged at a central position of the combustion flame 200 of the oil nozzle 22, that is, the steam nozzle 50 is arranged at the central position of the range of the combustion flame 200. The above arrangement enables the steam nozzle 50 to inject the combustion improver into the combustion chamber 11 so that the combustion improver can be ejected from the central position of the combustion flame 200, so as to completely vaporize the combustion improver and increase the contact area between the vaporized combustion improver 300 and the combustion flame 200. The higher the degree of vaporization (smaller molecules) of the combustion improver, the more small molecules can be generated to block the combination of nitrogen atoms and oxygen atoms in the combustion flue gas, reducing the probability of nitrogen oxides being generated due to effective collisions between nitrogen atoms and oxygen atoms. This will prevent the concentration of nitrogen oxides (NOx) in the combustion flue gas from rising, thereby controlling the concentration of the combustion flue gas generated during combustion of the liquid fuel and achieving the effect of stabilizing the combustion process.

In some embodiments, the combustion improver is water vapor, and the liquid fuel is a plant fuel, which is at least one selected from the group consisting of palm oil, coconut oil, corn oil, rice bran oil, cottonseed oil, olive oil, peanut oil, rapeseed oil, safflower oil, sesame oil, soybean oil, sunflower oil, tamarisk oil, hemp oil, pistacia oil, and pine oil. In a preferred embodiment, the plant fuel is vegetable oil. The advantages of using vegetable oil as the fuel for burning in the boiler system 1 are: 1) Vegetable oil has a high calorific value (Heating Value). The calorific value is the heat generated when a unit amount of fuel is completely burned. The calorific value of vegetable oil is about 9400Kcal/Kg or more. The calorific value generated by burning vegetable oil is higher than that generated by burning coal, and the carbon dioxide emissions generated by burning vegetable oil are much lower than those generated by burning coal; 2) There will be no concerns about the generation of sulfide and heavy metal particles after burning vegetable oil. The suspended particles generated after burning vegetable oil are less, and the nitrogen oxide and carbon emissions are relatively low.

It should be noted that the steam nozzle 50 includes a steam regulating valve 51 for controlling the flow rate and/or flow velocity of the combustion improver entering the combustion chamber 11 from the steam nozzle 50. The steam nozzle 50 can adjust the flow rate and/or flow velocity of the combustion improver added to the combustion chamber 11 according to combustion conditions such as the concentration of at least one combustion flue gas generated in the boiler body 10 and/or at least one combustion temperature in the boiler body 10. For example, the flue gas detector 40 monitors an initial concentration of a first combustion flue gas in the boiler body 10, and monitors the generation of a second combustion flue gas in the boiler body 10 after the combustion improver is injected into the combustion chamber 11; or for example, the boiler thermometer 90 is used to measure a first combustion temperature corresponding to the generation of the first combustion flue gas in the boiler body 10, and is used to measure a second combustion temperature corresponding to the generation of the second combustion flue gas in the boiler body 10. Here, the first combustion flue gas is nitrogen oxide (NOx) gas, and the second combustion flue gas is carbon monoxide (CO). More specifically, after the combustion improver is added into the combustion chamber 11, the concentration of the first combustion flue gas in the boiler body 10 is monitored until a second combustion flue gas is generated in the boiler body 10, the temperature in the boiler body 10 is measured to be a second combustion temperature, and the rate of adding the combustion improver is reduced to a critical rate to avoid generating the second combustion flue gas. The critical rate is to provide the combustion improver at a rate greater than or equal to 20 kg/hour and less than 40 kg/hour. Therefore, the relationship among the amount of combustion improver added, the combustion temperature in the boiler body 10 and the concentration of combustion flue gas is monitored, so that the combustion improver can indeed gradually reduce the flue gas generated by the combustion in the boiler body 10, and the concentration of NOx emitted can be reduced, and the amount of water vapor added to the boiler body 10 is controlled, that is, when the second combustion flue gas (carbon monoxide (CO)) is generated in the boiler body 10, the amount of water vapor introduced into the boiler body 10 is reduced, and the generation of carbon monoxide (CO) is simultaneously avoided. Therefore, by controlling the amount of water vapor added to the boiler body 10 and monitoring the corresponding temperature in the boiler body 10 corresponding to different amounts of water vapor, an ideal combustion state can be achieved in the boiler body 10 to minimize the emission of nitrogen oxides (NOx) without the generation of carbon monoxide (CO).

It should be noted that the purpose of maintaining the steam pressure in the boiler body 10 at about 3Kg/ ^cm2 to 5Kg/ ^cm2 is that when the steam pressure in the boiler body 10 is lower than 3Kg/cm ² , the content of liquid water in the water vapor is high, that is, the water molecules in the water vapor may not be completely vaporized and present a semi-atomized droplet state, or a semi-liquefied and semi-vaporized droplet state. From the above description, it can be seen that the higher the degree of vaporization of the water vapor molecules, the larger the contact area with the combustion flue gas. When the nitrogen atoms and oxygen atoms in the combustion flue gas produce effective collisions to generate nitrogen oxide molecules (such as nitric oxide and nitrogen dioxide), the water molecules in the steam state (small molecule state) will block the combination of nitrogen atoms and oxygen atoms in the combustion flue gas. The vaporized water vapor can block the effective collision between nitrogen atoms and oxygen atoms, thereby reducing the probability of nitrogen oxides being generated due to effective collisions between nitrogen atoms and oxygen atoms. Therefore, the steam pressure in the boiler body 10 is maintained at about 3Kg/ ^cm2 to 5Kg/cm ² , which helps to make the degree of gasification of water molecules in water vapor higher, thereby enhancing the ability to block the combination of nitrogen atoms and oxygen atoms in combustion flue gas to form nitrogen oxides.

In summary, the technical effects produced by this creation are as follows:

1) By installing a steam nozzle, the combustion improver is introduced into the boiler body when the boiler system is burning, effectively reducing the concentration of combustion flue gas (especially nitrogen oxides (NOx)). The principle is that the combustion improver is water vapor, which can reduce the flame temperature in the combustion chamber, thereby reducing the generation of nitrogen oxides (NOx) during the combustion process.

2) By arranging the steam nozzle at the center of the combustion flame of the nozzle, the combustion improver is ejected from the center of the combustion flame, and the combustion improver is completely vaporized into smaller gas molecules, that is, completely vaporized water vapor is obtained. When nitrogen atoms and oxygen atoms in the combustion flue gas effectively collide to generate nitrogen oxide molecules (such as nitric oxide and nitrogen dioxide), the vaporized water vapor can block the effective collision between nitrogen atoms and oxygen atoms, that is, the vaporized water vapor molecules block the ability of nitrogen atoms and oxygen atoms in the combustion flue gas to combine to generate nitrogen oxides, thereby reducing the concentration of nitrogen oxides in the emitted flue gas and simultaneously avoiding the generation of carbon monoxide (CO). And nitrogen oxides can be removed with low-cost equipment and a simple method, without relying on additional exhaust gas treatment equipment or scrubbing equipment.

3) By arranging the combustion chamber, the main steam supply pipeline, the header box, the steam return pipeline and the steam nozzle 50 into a boiler body water vapor circulation loop, the water vapor generated by heating the liquid water during the combustion process is recovered and concentrated, and part of the water vapor recovered and concentrated in the header box is injected into the boiler body through the steam nozzle to form the boiler body water vapor circulation loop. In this way, the step of introducing water vapor/combustion improver from the outside can be omitted, and the concentration of combustion flue gas (especially nitrogen oxide (NOx) gas) can be further reduced.

In summary, although the present invention has been disclosed as above with the preferred embodiment, it is not intended to limit the present invention. People with ordinary knowledge in the technical field to which the present invention belongs can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the scope defined in the attached patent application.

1: Boiler system

10: Boiler body

11: Combustion chamber

12: Liquid water layer

13: Water vapor layer

20: Oil supply tank

21: Oil supply pipeline

22: Grease nozzle

23: Oil supply pump

24: Oil supply regulating valve

30: Water supply tank

31: Water supply pipeline

32: Water supply pump

40: Smoke detector

50: Steam nozzle

51: Steam regulating valve

60: Main steam supply pipeline

61: Manifold box

611: Steam return pipe

612: Steam flow meter

62: Steam pipeline for production

70: Blower

71: Air supply pipe

72: Air outlet

80: Flue gas exhaust pipe

90: Boiler thermometer

Claims (10)

A boiler system for reducing combustion flue gas emissions comprises: a boiler body, a combustion chamber is formed inside the boiler body, the boiler body comprises the combustion chamber, a liquid water layer and a water vapor layer in order from bottom to top, the combustion chamber is used to burn a liquid fuel to heat the liquid water to generate water vapor, wherein the steam pressure in the boiler body is in the range of 3 to 5 Kg/ ^cm2 ; an oil supply tank, comprising an oil supply pipeline and an oil nozzle, the oil supply pipeline is arranged between the oil nozzle and the oil supply tank, and is used to supply the liquid fuel to the oil nozzle, and the oil nozzle is arranged in the combustion chamber, and is used to spray the liquid fuel into the combustion chamber; a water supply tank, which supplies liquid water to the liquid water layer of the boiler body through a water supply pipeline; a flue gas detector, which is configured to monitor the concentration of at least one combustion flue gas in the boiler body; a steam nozzle, which is configured to inject a combustion improver into the combustion chamber when the liquid fuel is burned to control the concentration of the combustion flue gas generated during combustion; and at least one main steam supply pipeline, which is connected to the water vapor layer of the boiler body and is configured to transmit the water vapor generated during combustion. A boiler system for reducing combustion flue gas emissions as described in claim 1, wherein the boiler system further comprises: A header box connected to the main steam supply pipeline for collecting water vapor transmitted by the main steam supply pipeline, and the header box is also connected to at least one production steam pipeline for transmitting the water vapor for heating; A blower connected to the combustion chamber and providing air through an air supply pipeline and an air supply port into the combustion chamber of the boiler body, so that the air and the liquid fuel flowing out of the oil nozzle are evenly mixed and burned; A flue gas exhaust pipe connected to the combustion chamber for exhausting the combustion flue gas generated during combustion. A boiler system for reducing combustion flue gas emissions as described in claim 2, wherein the header box further includes a steam return pipe, and the header box is connected to the steam nozzle through the steam return pipe for injecting the collected water vapor into the combustion chamber through the steam nozzle. A boiler system for reducing combustion flue gas emissions as described in claim 3, wherein the steam nozzle is arranged at a central position of a combustion flame of the oil nozzle, so that the steam nozzle injects the water vapor into the combustion chamber and makes the water vapor spray out from the central position of the combustion flame of the oil nozzle to completely vaporize the water vapor and increase the contact area between the water vapor and the combustion flame around the oil nozzle. A boiler system for reducing combustion flue gas emissions as described in claim 3, wherein the steam nozzle includes a steam regulating valve configured to control the flow rate and/or flow rate of water vapor entering the combustion chamber from the steam nozzle. A boiler system for reducing combustion flue gas emissions as described in claim 1, wherein the flue gas detector monitors an initial concentration of a first combustion flue gas in the boiler body and monitors the generation of a second combustion flue gas in the boiler body after the combustion improver is injected into the combustion chamber. A boiler system for reducing combustion flue gas emissions as described in claim 6, wherein the first combustion flue gas is nitrogen oxide (NOx) gas and the second combustion flue gas is carbon monoxide (CO). A boiler system for reducing combustion flue gas emissions as described in claim 6, wherein the boiler system further includes a boiler thermometer for measuring at least one combustion temperature in the boiler body, the boiler thermometer being configured to measure a first combustion temperature corresponding to the generation of the first combustion flue gas in the boiler body, and being configured to measure a second combustion temperature corresponding to the generation of the second combustion flue gas in the boiler body. A boiler system for reducing combustion flue gas emissions as described in claim 1, wherein the combustion improving agent is water vapor. A boiler system for reducing combustion flue gas emissions as described in claim 1, wherein the liquid fuel is a plant-based fuel, and the plant-based fuel is selected from at least one of the group consisting of palm oil, coconut oil, corn oil, rice bran oil, cottonseed oil, olive oil, peanut oil, rapeseed oil, safflower oil, sesame oil, soybean oil, sunflower oil, tamarisk oil, hemp oil, pistacia oil, and pine oil.