Water-cooled full-premix vacuum boiler

Abstract

The utility model relates to a boiler technical field discloses a kind of water-cooled full premix vacuum boilers, including furnace body and the condensing chamber located above furnace body, and the combustion chamber is formed in the hollow inside furnace body shell, and the side of combustion chamber close to air inlet is equipped with vertical fire grate pipe, and fire grate pipe includes the fire grate square pipe of interval setting along furnace body shell width direction, and the gap between adjacent fire grate square pipe forms air inlet channel, and fire grate pipe further includes the fire grate round pipe of setting in fire grate square pipe inboard, and gap is left between fire grate round pipe and fire grate square pipe, and fire grate round pipe is opposite with air inlet channel;By setting fire grate pipe in the side of combustion chamber close to air inlet, the temperature of flame root is reduced using the evaporation heat absorption of hot coal water inside fire grate pipe, and then reduce the thermal power nitrogen oxide compound (i.

Description

Technical Field

[0001] This utility model belongs to the field of boiler technology, specifically relating to a water-cooled fully premixed vacuum boiler. Background Technology

[0002] Currently, the existing vacuum boilers on the market employ either diffusion combustion or surface premixed burners. The boiler consists of upper and lower drums arranged on a base. The lower drum contains the furnace chamber and flue pipes, where flue gas transfers heat. Hot coal and water are heated outside the furnace chamber and flue pipes, evaporating and flowing into the upper condensing chamber. A tubular heat exchanger is installed above the condensing chamber, connected to the front and rear headers. Steam exchanges heat with the heat exchanger tubes, condenses, and then flows into the lower furnace body. This cycle repeats, heating the water within the heat exchanger.

[0003] The aforementioned vacuum boilers still have certain drawbacks in some applications: Firstly, the combustion process needs optimization, as it generates large amounts of thermal NOx, which, if released into the atmosphere, will not only damage the ecosystem but also directly impact human health. Secondly, although these vacuum boilers employ direct diffusion and surface premixing combustion methods, their overall structure is relatively loose, resulting in large boiler dimensions, a large footprint, and high steel consumption. Therefore, a more specialized vacuum boiler is urgently needed to address these shortcomings. Utility Model Content

[0004] In view of this, the purpose of this utility model is to provide a water-cooled fully premixed vacuum boiler to solve the technical problem that a large amount of thermal NOx is generated during the combustion process of vacuum boilers in the prior art.

[0005] To achieve the above objectives, this utility model provides the following technical solution:

[0006] A water-cooled fully premixed vacuum boiler includes a furnace body and a condensing chamber located above the furnace body. The furnace body includes a furnace shell and a lower header located at the bottom of the furnace shell. One end of the furnace shell is narrowed along its length. The interior of the furnace shell is hollow to form a combustion chamber. A vertical burner pipe is provided on the side of the combustion chamber near the air inlet. The upper and lower ends of the burner pipe are respectively connected to the condensing chamber and the lower header. The burner pipe includes burner square tubes spaced apart along the width of the furnace shell. The gap between adjacent burner square tubes forms an air inlet channel. The burner pipe also includes burner round tubes provided inside the burner square tubes. There is a gap between the burner round tubes and the burner square tubes, and the burner round tubes are directly opposite the air inlet channel. An ignition needle is provided inside the burner pipe. Multiple vertical heat exchange tubes are also provided inside the ignition needle. The upper and lower ends of the heat exchange tubes are respectively connected to the condensing chamber and the lower header.

[0007] Furthermore, one end of the furnace shell along its length tapers from all sides toward the center line to form a cone-shaped air inlet. A fully premixed burner is installed on the outside of the air inlet of the furnace shell and is connected to the combustion chamber.

[0008] Furthermore, the condensing chamber includes a condensing chamber shell and a tubular heat exchanger. The tubular heat exchanger includes a front tube box and a rear tube box located on both sides of the condensing chamber shell. Heat transfer tubes are provided inside the condensing chamber shell, and the two ends of the heat transfer tubes are connected to the front tube box and the rear tube box respectively. A baffle parallel to the heat transfer tubes is provided in the middle of the front tube box. The baffle divides the internal space of the front tube box into two independent water inlet space and water outlet space. The top of the water inlet space is provided with a heat exchanger inlet, and the top of the water outlet space is provided with a heat exchanger outlet.

[0009] Furthermore, multiple heat transfer tubes are evenly distributed on the vertical plane;

[0010] Furthermore, an energy-saving device is also provided on one side of the furnace body. The energy-saving device includes an energy-saving device shell. A flue gas inlet is opened at the top of the energy-saving device shell facing the furnace body, and a discharge outlet is opened at the bottom of the energy-saving device shell facing away from the furnace body. A flue gas outlet is opened at the top of the furnace body facing the energy-saving device shell. A pipe connects the flue gas outlet and the flue gas inlet. A preheating tube is provided inside the energy-saving device. The preheating tube is arranged horizontally inside the energy-saving device and is connected to the front and rear headers. A water inlet is provided on the front header and a water outlet is provided on the rear header. The water outlet is connected to the water inlet of the heat exchanger.

[0011] The beneficial effects of this utility model are as follows:

[0012] (1) Compared with the prior art, by setting the fire tube on the side of the combustion chamber near the air inlet, on the one hand, the evaporation of hot coal and water inside the fire tube absorbs heat to reduce the temperature of the flame root, thereby reducing the thermal nitrogen oxides (i.e. thermal NOx) generated due to high temperature, and fundamentally reducing the emission of pollutants; on the other hand, the spaced air inlet channels and the fire tubes set opposite to the air inlet channels can effectively achieve uniform dispersion of the flame, thereby avoiding the generation of local high temperature in the flame, which can not only further suppress the generation of thermal nitrogen oxides, but also effectively improve the uniformity of flame distribution and ensure that the heat exchange tube is heated evenly.

[0013] (2) During the heating process of the heat transfer tube, the steam releases heat and undergoes a phase change after contacting the heat exchange surface of the heat transfer tube, and condenses into liquid water, i.e. condensate. The condensate falls back into the heat exchange tube under its own gravity, completing the hot and cold cycle of the hot coal water. Therefore, there is no need to add hot coal water, which not only effectively saves water resources, but also reduces the pretreatment cost of hot coal water. In addition, it can also ensure the cleanliness and stability of the hot coal water.

[0014] (3) By setting up an energy-saving device, not only can the temperature of high-temperature flue gas emissions be significantly reduced to protect the atmospheric environment, but the water in the tubular heat exchanger can also be preheated, thereby improving the heat exchange efficiency during the heat exchange process and effectively saving resources. Attached Figure Description

[0015] To make the objectives, technical solutions, and beneficial effects of this utility model clearer, the following drawings are provided for illustration:

[0016] Figure 1 This is an overall sectional view of the water-cooled fully premixed vacuum boiler in Embodiment 1 of this utility model;

[0017] Figure 2 This is a schematic diagram of the burner tube in Embodiment 1 of this utility model, used to show the shape of the square burner tube and the round burner tube and the positional relationship between them;

[0018] Figure 3 This is a cross-sectional view of the tubular heat exchanger in Embodiment 1 of this utility model;

[0019] Figure 4 This is a cross-sectional view of the front tube box in Embodiment 1 of this utility model.

[0020] The following labels are shown in the attached diagram:

[0021] Furnace body 1, furnace shell 101, fully premixed burner 102, burner tube 103, burner square tube 104, burner round tube 105, ignition needle 106, heat exchange tube 107, lower header 108, flue gas outlet 109, condenser chamber 2, condenser chamber shell 201, tubular heat exchanger 202, heat transfer tube 203, front tube box 204, rear tube box 205, heat exchanger inlet 206, heat exchanger outlet 207, baffle 208, economizer 3, economizer shell 301, flue gas inlet 302, preheating tube 303, exhaust port 304. Detailed Implementation

[0022] Example 1, specifically as follows Figures 1-4 As shown.

[0023] A water-cooled fully premixed vacuum boiler includes a furnace body 1 and a condensing chamber 2 located above the furnace body 1.

[0024] like Figure 1 As shown, the furnace body 1 includes a rectangular furnace shell 101 and a lower header 108 located at the bottom of the furnace shell 101, which is used to store hot coal and water. The interior of the furnace shell 101 is hollow to form a combustion chamber. One end of the furnace shell 101 in the length direction narrows from all sides towards the center line to form a conical air inlet. A fully premixed burner 102 is arranged on the outside of the air inlet of the furnace shell 101 and is connected to the combustion chamber.

[0025] A vertical burner pipe 103 is provided on the side of the combustion chamber near the air inlet. The upper and lower ends of the burner pipe 103 are connected to the condensing chamber 2 and the lower header 108, respectively. Under the action of a water pump (not shown in the figure) or other pressurizing equipment, the hot coal water in the lower header 108 enters the burner pipe 103 and maintains the water level at the top of the burner pipe 103; Figure 2 As shown, the burner pipe 103 includes burner square pipes 104 spaced apart along the width direction of the furnace shell 101. The gap between adjacent burner square pipes 104 forms an air intake channel. The combustible mixture after being mixed by the fully premixed burner 102 enters the combustion chamber through the air intake channel. The burner pipe 103 also includes burner round pipes 105 disposed inside the burner square pipes 104 (on the side opposite to the air intake). There is a gap between the burner round pipes 105 and the burner square pipes 104. The burner round pipes 105 are also spaced apart along the width direction of the combustion chamber, and the burner round pipes 105 are directly opposite the air intake channel.

[0026] An ignition needle 106 is provided on the inner side of the burner pipe 103 (the side opposite to the air inlet). The ignition needle 106 ignites the combustible mixture to form a high-temperature flame. Multiple vertical heat exchange tubes 107 are also provided on the inner side of the ignition needle 106. The heat exchange tubes 107 are arranged in a matrix in the horizontal direction, with gaps between adjacent heat exchange tubes 107. The upper and lower ends of the heat exchange tubes 107 are connected to the condensing chamber 2 and the lower header 108, respectively. Similarly, under the action of a water pump (not shown in the figure) or other pressurizing equipment, hot coal water in the lower header 108 enters the heat exchange tubes 107, maintaining the water level at the top of the heat exchange tubes 107. It is worth noting that the two ends of the burner pipe 103 and the heat exchange tubes 107 are welded and fixed to the furnace shell 101.

[0027] In use, firstly, the fuel and air are mixed evenly in proportion by the fully premixed burner 102 to form a combustible mixture. The combustible mixture enters the combustion chamber through the air inlet. Then, the combustible mixture passes through the air inlet channel to the ignition needle 106. Finally, the ignition needle 106 ignites it to form a high-temperature flame. The high-temperature flame heats the heat exchange tube 107. The hot coal water in the heat exchange tube 107 evaporates to form steam and enters the condensing chamber 2 above. Similarly, the hot coal water in the burner tube 103 also evaporates to form steam and enters the condensing chamber 2 above.

[0028] By installing a burner pipe 103 on the side of the combustion chamber near the air inlet, on the one hand, the evaporation of hot coal and water inside the burner pipe 103 absorbs heat to reduce the temperature at the root of the flame, thereby reducing the thermal nitrogen oxides (i.e., thermal NOx) generated due to high temperature, fundamentally reducing pollutant emissions; on the other hand, the spaced air inlet channels and the burner pipe 105 arranged opposite to the air inlet channels can effectively achieve uniform dispersion of the flame, thereby avoiding the generation of local high temperature in the flame, which can not only further suppress the generation of thermal nitrogen oxides, but also effectively improve the uniformity of flame distribution and ensure that the heat exchange tube 107 is heated uniformly.

[0029] like Figure 3 , Figure 4 As shown, the condensing chamber 2 includes a condensing chamber shell 201 and a tubular heat exchanger 202. The condensing chamber shell 201 is fixed to the furnace shell 101 by bolts. The tubular heat exchanger 202 includes a front tube box 204 and a rear tube box 205 located on both sides of the length of the condensing chamber shell 201. In this embodiment, the front tube box 204 is located on one side of the fully premixed burner 102. The front tube box 204 and the rear tube box 205 are both fixed to the condensing chamber shell 201 by bolts.

[0030] A heat transfer tube 203 extending horizontally is installed inside the condenser shell 201. The two ends of the heat transfer tube 203 are connected to the front tube box 204 and the rear tube box 205, respectively. Multiple heat transfer tubes 203 are evenly distributed in a vertical plane. In this embodiment, the heat transfer tubes 203 are either bare tubes or finned tubes. It should be further noted that a baffle 208 parallel to the heat transfer tubes 203 is provided in the middle of the front tube box 204. The baffle 208 is welded and fixed to the front tube box 204. The baffle divides the internal space of the front tube box 204 into two independent water inlet spaces and water outlet spaces. A heat exchanger inlet 206 is provided at the top of the water inlet space, and a heat exchanger outlet 207 is provided at the top of the water outlet space.

[0031] In operation, the steam generated by the evaporation of hot coal and water through the burner tubes 103 and heat exchange tubes 107 enters the condenser chamber 2. First, the water to be heated flows into the water inlet space through the heat exchanger inlet 206, then flows into the rear tube box 205 through the heat transfer tubes 203 connected to the water inlet space, achieving primary heating. Subsequently, the water after primary heating flows into the water outlet space through the heat transfer tubes 203 connected to the water outlet space, achieving secondary heating. Primary heating and secondary heating constitute one cycle. The water to be heated can undergo one cycle or multiple cycles. That is, the water after one cycle can be discharged from the heat exchanger outlet 207 or transferred back to the heat exchanger inlet 206 for the next cycle.

[0032] During the heating process of heat transfer tube 203, steam releases heat and undergoes a phase change after contacting the heat exchange surface of heat transfer tube 203, condensing into liquid water, i.e. condensate. The condensate falls back into heat exchange tube 107 under its own gravity, completing the hot and cold cycle of hot coal water. Therefore, there is no need to add extra hot coal water, which not only effectively saves water resources, but also reduces the pretreatment cost of hot coal water. In addition, it can also ensure the cleanliness and stability of hot coal water.

[0033] An energy-saving device 3 is also installed on one side of the furnace body 1, such as Figure 1 As shown, the energy-saving device 3 includes an energy-saving device housing 301. A flue gas inlet 302 is located at the top of the energy-saving device housing 301 on the side facing the furnace body 1, and a discharge outlet 304 is located at the bottom of the energy-saving device housing 301 on the side away from the furnace body 1. A flue gas outlet 109 is located at the top of the furnace body 1 on the side facing the energy-saving device housing 301. A pipe connects the flue gas outlet 109 and the flue gas inlet 302, thereby connecting the furnace body 1 and the energy-saving device 3. A preheating pipe 303 is installed inside the energy-saving device 3. The preheating pipe 303 is horizontally arranged inside the energy-saving device 3 and connected to the front and rear headers. The front header (not shown in the figure) has a water inlet, and the rear header (not shown in the figure) has a water outlet. The water outlet is connected to the heat exchanger inlet 206.

[0034] High-temperature flue gas enters the energy-saving device 3 through the flue gas outlet 109 and the flue gas inlet 302, heating the preheating tube 303 inside the energy-saving device 3. The heated water is discharged from the water outlet and enters the water inlet space through the heat exchanger inlet 206, thereby effectively improving the heat exchange efficiency of the heat transfer tube 203. After the high-temperature flue gas releases heat and cools down, its temperature decreases and it is discharged from the exhaust port 304.

[0035] By setting up the energy saver 3, not only can the temperature of high-temperature flue gas emissions be significantly reduced, protecting the atmospheric environment, but the water in the tubular heat exchanger 202 can also be preheated, thereby improving the heat exchange efficiency during the heat exchange process and effectively saving resources.

[0036] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit it. Although the utility model has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made to it in form and detail without departing from the scope defined by the claims of this utility model.

Claims

1. A water-cooled fully premixed vacuum boiler, characterized in that, The furnace includes a furnace body and a condensing chamber located above the furnace body. The furnace body includes a furnace shell and a lower header located at the bottom of the furnace shell. One end of the furnace shell is narrowed along its length. The interior of the furnace shell is hollow to form a combustion chamber. A vertical burner pipe is provided on the side of the combustion chamber near the air inlet. The upper and lower ends of the burner pipe are connected to the condensing chamber and the lower header, respectively. The burner pipe includes burner square tubes spaced apart along the width of the furnace body. The gap between adjacent burner square tubes forms an air inlet channel. The burner pipe also includes burner round tubes located inside the burner square tubes. There is a gap between the burner round tubes and the burner square tubes, and the burner round tubes are directly opposite the air inlet channel. An ignition needle is provided inside the burner pipe. Multiple vertical heat exchange tubes are also provided inside the ignition needle. The upper and lower ends of the heat exchange tubes are connected to the condensing chamber and the lower header, respectively.

2. The water-cooled fully premixed vacuum boiler according to claim 1, characterized in that, One end of the furnace shell along its length tapers from all sides toward the center line to form a cone-shaped air inlet. A fully premixed burner is installed on the outside of the air inlet of the furnace shell and is connected to the combustion chamber.

3. The water-cooled fully premixed vacuum boiler according to claim 1 or 2, characterized in that, The condensing chamber includes a condensing chamber shell and a tubular heat exchanger. The tubular heat exchanger includes a front tube box and a rear tube box located on both sides of the condensing chamber shell. Heat transfer tubes are installed inside the condensing chamber shell, and the two ends of the heat transfer tubes are connected to the front tube box and the rear tube box respectively. A baffle parallel to the heat transfer tubes is provided in the middle of the front tube box. The baffle divides the internal space of the front tube box into two independent water inlet space and water outlet space. The top of the water inlet space is provided with a heat exchanger inlet, and the top of the water outlet space is provided with a heat exchanger outlet.

4. The water-cooled fully premixed vacuum boiler according to claim 3, characterized in that, Multiple heat transfer tubes are evenly distributed on a vertical plane.

5. The water-cooled fully premixed vacuum boiler according to claim 3, characterized in that, An economizer is also provided on one side of the furnace body. The economizer includes an economizer shell. The top of the economizer shell facing the furnace body has a flue gas inlet, and the bottom of the economizer shell facing away from the furnace body has a discharge outlet. The top of the furnace body facing the economizer shell has a flue gas outlet. A pipe connects the flue gas outlet and the flue gas inlet. A preheating tube is provided inside the economizer. The preheating tube is arranged horizontally inside the economizer and is connected to the front and rear headers. The front header has a water inlet, and the rear header has a water outlet. The water outlet is connected to the water inlet of the heat exchanger.

Images