CN111853769A - A kind of heat conduction oil cooling type low NOx pulverized coal burner cooling system and cooling method - Google Patents

Abstract

The invention discloses a cooling system and a cooling method for a heat-conducting oil-cooled low-NOx pulverized coal burner, wherein the cooling system includes a burner and a cooling circulation device, and the burner is connected to the thermal user equipment through the cooling circulation device, so that the The rear end of the burner is provided with a furnace, and the cooling circulation device includes an oil return branch pipe, an oil outlet branch pipe, an oil outlet main pipe, a parallel oil pipe and a spiral coil pipe. , the oil outlet main pipe, the thermal user equipment, the oil return main pipe and the oil return branch pipe are connected, and the oil return branch pipe is connected with the heat conduction oil inlet of the spiral coil pipe. The invention can improve the energy efficiency of the organic heat carrier boiler and reduce the pollutant discharge of the flue gas. The spiral coil is used as the basic component of the burner cooling component, the boiler's own circulating heat-conducting oil is used to cool the burner, and the oil temperature is controlled by the heat-conducting oil flow. , to avoid the occurrence of over-temperature coking of the heat transfer oil and ensure the safe operation of the burner.

Description

A kind of heat conduction oil cooling type low NOx pulverized coal burner cooling system and cooling method

technical field

The invention relates to the technical field of heat-conducting oil pulverized coal industrial boilers, in particular to a cooling system and a cooling method for a heat-conducting oil-cooled low-NOx pulverized coal burner

Background technique

The organic heat carrier boiler is a new type of thermal energy equipment that uses heat transfer oil as the circulating medium for heat supply. The heat transfer oil is used as the heat carrier, and the heat carrier is circulated through the heat oil pump to transfer the heat to the heat-using equipment. It has high temperature and low pressure. At the same time, the equipment does not require water treatment equipment and has no heat loss such as running, running, dripping, and leaking from steam boilers. Therefore, it is increasingly used in heating equipment in food, chemical, and anti-woven industries.

At present, most coal-fired organic heat carrier boilers are mainly based on tube-frame chain furnaces. The furnace is composed of furnace tubes and headers. The convection heating surface is composed of serpentine tubes. The traditional coal-fired organic heat carrier boilers have low energy utilization efficiency, and it is difficult to meet the pollutant emission standards. With the gradual implementation of the "Boiler Air Pollutant Emission Standard" GB 13271-2014 nationwide, coal-fired industrial boilers, which play a major role in the industrial field, are in a difficult situation, and achieving clean emissions has become an urgent problem that the boiler industry needs to solve.

High-efficiency and low- _NOx liquid slag-discharging pulverized coal burner, as a new type of combustion equipment for boilers, seizes the key to improving pulverized coal combustion conditions and separates the "furnace" and "pot", so that high-temperature and high-intensity combustion can be achieved. Combustion is stable under the condition of lean oxygen, liquid slag is trapped in the combustion chamber, and the generation of NOx can be suppressed at the same time, and the thermal efficiency of the boiler can reach more than 91%. The boiler does not undergo denitration treatment, and the _NOx emission value is lower than 150mg/m ³ , which can fully meet the emission limit value in key areas stipulated in the standard GB 13271-2014.

The liquid slag pulverized coal burner, as the combustion equipment of the boiler, mainly completes the ignition and combustion of the pulverized coal. Due to the high-intensity combustion of the liquid slagging burner, the temperature in the combustion chamber is as high as 1500°C or more, and the working environment of the lining structure in the combustion chamber is harsh. The slag in direct contact with it is eroded, and there is a large temperature fluctuation during the furnace start-up and shutdown process. In order to realize the long-lasting and stable operation of the furnace lining, the development experience of traditional cyclone furnaces and coal gasifiers is used for reference, and "slag-resistant slag" is adopted to alleviate the erosion problem. At high temperature, a solid slag layer can be formed on its surface to improve the corrosion resistance of the furnace lining.

For the cooling system of the existing liquid slag discharge burner, a water-cooling method is generally used, such as a jacket-type water-cooling method. The circulating cooling water, the cooling water absorbs a part of the heat, which accelerates the heat dissipation of the burner, and the cooling water and the metal cylinder wall continue to exchange heat to generate a large amount of cooling hot water. The heat taken away by the hot water accounts for about 10% of the effective heat input of the pulverized coal. The rational use of this part of the water and heat has a great impact on the operation of the burner, which is directly related to the economic benefits of the boiler operation. For steam boilers and hot water boilers, the burner cooling water can be directly used by the system itself; but for organic heat carrier boilers, heat transfer oil is used as heat transfer carrier, and the boiler uses heat transfer oil circulation to complete energy absorption and application. The boiler itself has no soda water process. If there is no hot water demand in the production process of the enterprise, a large amount of cooling hot water energy cannot be effectively utilized, and the use of water cooling to cool the burner will cause a great waste of heat energy.

In order to widen the application range of the high-efficiency and low-NOx liquid slag-discharging pulverized coal burner on the organic heat carrier boiler, the present invention proposes a new idea of using heat-conducting oil to cool the furnace lining. If the jacket type cooling structure is used directly, on the one hand, the jacket type structure has poor pressure bearing capacity, and the strength of the jacket is not enough to meet the application requirements under the forced circulation of the heat transfer oil; on the other hand, for the organic heat carrier boiler, the circulating heat transfer oil flows There is a minimum flow rate limit. Generally, the flow velocity in the radiant section should not be lower than 2m/s, and the flow velocity in the convection section should not be lower than 1.5m/s. The circulating flow of heat transfer oil in the jacket is prone to over-temperature coking. The main reasons are: (1) The inner flow area of the jacket structure is large and it is easy to cause uneven flow rate of the heat transfer oil. When the heat transfer oil flows in the channel, the flow rate is too low in some areas. : (2) Fluid retention in some areas of the jacketed shell structure is easy to occur, and the heat transfer oil in this area is very easy to coke and denature.

SUMMARY OF THE INVENTION

In view of at least one defect in the above-mentioned prior art, the present invention provides a cooling system and a cooling method for a heat-conducting oil-cooled low-NOx pulverized coal burner, so as to solve the problem of energy waste caused by the use of water-cooling method for the burner of an organic heat carrier boiler. , improve the energy efficiency of the boiler, reduce the emission of flue gas pollutants, and since the jacket cooling structure is not suitable for the heat transfer oil cooling method, the spiral coil is used as the basic structure of the heat transfer oil cooling method, so that the heat transfer oil is forced in the spiral coil. It can circulate and reach a turbulent flow state, thereby reducing the thickness of the oil film of the heat transfer oil near the wall surface, avoiding the occurrence of over-temperature coking, and ensuring the safe operation of the organic heat carrier boiler.

To achieve the above object, the present invention adopts the following technical solutions:

A heat-conducting oil-cooled low-NOx pulverized coal burner cooling system, comprising a burner and a cooling circulation device, the burner is connected to thermal user equipment through the cooling circulation device, the rear end of the burner is provided with a furnace, the A cooling circulation device, including an oil return branch pipe, an oil discharge branch pipe, an oil discharge main pipe, a parallel oil pipe and a spiral coil pipe, the spiral coil pipe is connected to the oil discharge branch pipe, the oil discharge main pipe, the thermal user equipment, and the oil return main pipe in turn through the heat transfer oil outlet. It is connected with the oil return branch pipe, the oil return branch pipe is connected with the heat conduction oil inlet of the spiral coil pipe, and the oil return main pipe and the oil outlet main pipe are also respectively connected with the circulation branch from the convection section to the furnace. Equipped with temperature transmitter.

The burner includes a burner and a combustion chamber. The burner is respectively connected to the secondary hot air inlet of the burner and the front end of the combustion chamber through a casing. The casing is provided with a bluff body, an igniter, and a horn. The small round end of the horn body is connected with the primary air/pulverized coal pipe passing through the casing, the large round end of the horn body is connected with the front end of the combustion chamber, and the primary air/pulverized coal pipe passes through The horn body is communicated with the combustion chamber, the outlet of the primary air/pulverized coal pipe is provided with a bluff body, the horn body is also provided with a swirl vane, and the horn body is connected with an igniter passing through the casing.

The combustion chamber includes an outer cylinder, a cooling assembly, a spiral coil, a furnace lining and a hot air inlet of the combustion chamber, the cooling assembly includes a spiral coil, an inner wall, and an outer wall, and the cooling assembly is arranged on the outer cylinder. The interior is arranged coaxially with it, the two ends of the outer cylinder and the outer wall are respectively connected with the front end and the rear end to form an isobaric air chamber, and the heat transfer oil outlet and the heat transfer oil inlet of the two ends of the spiral coil are respectively connected from the outer circle. The cylinder passes out, the isobaric air chamber is connected with the hot air inlet of the combustion chamber, the outer vertices of the two adjacent pipes of the spiral coil are welded and connected by the outer flat steel to form the outer wall surface, and the inner vertices of the two adjacent pipes pass through The inner flat steel is welded and connected to form the inner wall surface. The inner wall surface is provided with a furnace lining. The furnace lining includes slag nails and castables. The slag nails are uniformly welded on the inner wall of the inner flat steel, and the slag nails are poured. material covering, and uniformly distributed grading air ducts are arranged along the axial direction of the combustion chamber and passing through the outer wall surface, the inner wall surface and the furnace lining. A slag falling pipe is arranged in the furnace chamber, a slag tapping machine is arranged below the slag falling pipe, a flue gas convection section is also arranged in the furnace chamber, and the end of the flue gas convection section is connected to a flue gas outlet.

The grading air duct communicates with the isobaric air chamber and the combustion chamber, and the space surrounded by the outer wall surface, the inner wall surface and the spiral coil is filled with thermally conductive fillers.

A heat-conducting oil-cooled low-NOx pulverized coal burner cooling method adopts a heat-conducting oil-cooled low-NOx pulverized coal burner system to achieve high-quality utilization of burner cooling and heat dissipation energy: through the burner cooling circulation device, the use of organic The circulating heat transfer oil of the heat carrier boiler itself is used for burner cooling. The heat transfer oil after heat exchange and heating by the burner cooling device is sent to the heat user equipment together with the furnace oil. step:

S1: The circulating oil pump for boiler operation is started, and the heat transfer oil flows in two paths under the drive of the circulating oil pump. One path passes through the cooling circulation device of the burner to form a cooling circulation branch of the heat transfer oil burner, and the other path passes through the convection section-furnace to form heat transfer oil. Convection section - furnace circulation branch;

S2: The low temperature return oil flowing on the cooling circulation branch of the heat transfer oil burner flows into the spiral coil through the oil return branch under the control of the regulating valve, and the high temperature heat generated by the burner is introduced into the spiral coil through the furnace lining, inner wall surface and heat transfer filler. The tube heats it up, and the low-temperature return oil flows in the high-temperature spiral coil and exchanges heat with it to form a high-temperature output oil;

S3: The high-temperature effluent heated up by the heat exchange branch of the heat transfer oil burner and the high temperature effluent heated by the heat transfer section of the heat transfer oil convection section-furnace circulation branch are sent to the thermal user equipment through the oil outlet manifold, and cooled by production energy consumption Afterwards, it becomes the low temperature return oil and flows into the return oil main pipe, and is recirculated under the drive of the circulating oil pump.

In the step S2, a set temperature value is set by the high temperature oil outlet temperature of the burner, and its value is equal to the set value of the furnace oil outlet temperature and ensures that the value does not exceed the maximum use temperature of the heat transfer oil.

The oil outlet temperature of the burner is realized by controlling the flow rate of the heat transfer oil in the circulation branch of the heat transfer oil burner. According to the measured oil outlet temperature, the set temperature is compared. When the temperature is lower than the set temperature, the flow rate is reduced and the flow rate is the lowest. At this time, the flow rate of the heat transfer oil in the spiral coil should be ≥ 1.5m/s. When the temperature is higher than the set temperature, the flow rate should be increased.

The flow rate of the heat transfer oil in the cooling circulation branch of the heat transfer oil burner in the step S1 is controlled by controlling the opening degree of the regulating valve and the frequency of the pressurized oil pump. When the operating load of the boiler is small, the regulating valve can meet the flow regulation requirements. When the operation load of the boiler is high, the pressure oil pump is started when the full opening of the regulating valve cannot meet the flow requirement.

Beneficial effects of the present invention:

(1) By arranging the spiral coil 205 on the outer layer of the furnace lining 207, when the burner 10 is running, the high temperature heat in the combustion chamber 200 is introduced into the spiral coil 205 through the furnace lining 207, the inner wall surface 203, and the thermally conductive filler 212, and the oil return end The low-temperature heat-conducting oil flows through the helical coil 205 to exchange heat with it, which speeds up the heat dissipation rate of the burner 10 and cools the burner 10 so that the burner 10 will not burn out due to high temperature. The spiral coil 205 is welded and fixed by the inner flat steel 216 and the outer flat steel 217, which has a good pressure bearing capacity and high safety performance. (2) After the heat-conducting oil absorbs heat from the burner 10 and heats up, it is transported to the thermal user equipment 21 together with the oil from the boiler convection section 24-furnace 23. After the heat is consumed and cooled down, it is returned to the burner 10 to continue heat exchange, forming the combustion of heat-conducting oil. The cooling circulation branch of the burner 10 directly uses the organic heat carrier boiler's own circulating heat-conducting oil to cool the burner 10 without complicated processes and equipment. The heat absorbed by the heat-conducting oil cooling is effectively applied to production, improving the The use value and utilization of energy avoid the waste of energy. (3) The combustion chamber 200 is provided with an axially graded air distribution system. When the pulverized coal is burned in the combustion chamber 200, the secondary hot air is sent into the isobaric air chamber 202 through the combustion chamber hot air inlet 215, and then sprayed through the graded air duct 208. into the combustion chamber 200 to participate in the combustion of pulverized coal. The axially graded air distribution makes the pulverized coal combustion atmosphere change from anoxic to oxygen-enriched. In the oxygen-deficient stage, the pulverized coal combustion produces a large number of reducing radicals, forming a strong reducing atmosphere, which is not conducive to the oxidation of N under the strong reducing atmosphere. The formation of NOx is hindered, and NOx will be reduced to N ₂ in the high-temperature reducing atmosphere; in the oxygen-enriched area, the combustion temperature is lowered by excess air, which effectively reduces the generation of thermal NOx; Clean combustion and reduce NOx generation. (4) Since the heat transfer oil is volatile and coked under the condition of high temperature, the coking of the heat transfer oil will form a coking layer on the inner wall of the tube, resulting in an increase in the flow resistance and a decrease in the heat transfer efficiency, which will seriously lead to the explosion of the tube and an accident; in order to avoid heat conduction The oil is coked at high temperature in the spiral coil 205, and the combustion circulation flow of the heat transfer oil is controlled by the regulating valve 13 and the pressurizing pump 14, so that the oil outlet temperature is controlled within the coking temperature, and the flow rate is ≥1.5m/s, Under this flow rate condition, the heat transfer oil is turbulent in the tube, and the boundary layer in the tube is thin at this time, which can effectively avoid the heat transfer oil from coking and enhance heat transfer.

Description of drawings

Fig. 1 is the overall structure schematic diagram of the present invention;

Fig. 2 is the internal structure schematic diagram of the burner of the present invention;

FIG. 3 is an enlarged view of part A of FIG. 2;

Fig. 4 is the structure schematic diagram of the spiral coil of the present invention;

FIG. 5 is a left side view of FIG. 4 .

In the picture: 10 burners, 11 liquid slag, 12 oil return branch pipes, 13 regulating valves, 14 booster pumps, 15 check valves, 16 parallel oil pipes, 17 temperature transmitters, 18 oil outlet branch pipes, 19 oil circulation pumps, 20 Oil return main pipe, 21 hot user equipment, 22 oil outlet main pipe, 23 furnace chamber, 24 convection section, 25 flue gas outlet, 26, slag drop pipe, 27 slag tapping machine, 28 secondary hot air duct, 100 burner, 101 primary Air/pulverized coal pipe, 102 bluff body, 103 igniter, 104 horn, 105 swirl blade, 106 shell, 107 burner secondary hot air inlet, 200 combustion chamber, 201 outer cylinder, 202 equal pressure air chamber, 203 inner wall surface, 204 outer wall surface, 205 spiral coil, 206 rear end surface, 207 furnace lining, 208 graded air duct, 209 front end surface, 210 slag nail, 211 castable, 212 thermal conductive filler, 213 thermal conduction oil inlet, 214 thermal conduction oil outlet , 215 combustion chamber hot air inlet, 216 inner flat steel, 217 outer flat steel.

Detailed ways

The present invention will be described below in detail and clearly with reference to the accompanying drawings. It should be understood that the accompanying drawings are provided only for better understanding of the present invention, and should not be construed as limiting the present invention.

As shown in Figures 1-5, a heat transfer oil-cooled low NOx pulverized coal burner cooling system includes a burner 10 and a cooling circulation device, the burner 10 is connected to the thermal user equipment 21 through the cooling circulation device, and the The rear end of the burner 10 is provided with a furnace chamber 23, and the cooling circulation device includes an oil return branch pipe 12, an oil outlet branch pipe 18, an oil outlet main pipe 22, a parallel oil pipe 16 and a spiral coil 205. The spiral coil 205 is heated by heat. The oil outlet 214 is sequentially connected with the oil outlet branch pipe 18 , the oil outlet main pipe 22 , the thermal user equipment 21 , the oil return main pipe 20 and the oil return branch pipe 12 . The oil return branch pipe 12 is connected with the heat transfer oil inlet 213 of the spiral coil 205 , The oil return main pipe 20 and the oil outlet main pipe 22 are also respectively connected with the circulation branch from the convection section 24 to the furnace chamber 23 , and the oil outlet branch pipe 18 is provided with a temperature transmitter 17 .

The burner 10 includes a burner 100 and a combustion chamber 200. The burner 100 is connected to the secondary hot air inlet 107 of the burner and the front end face 209 of the combustion chamber 200 through the casing 106, respectively. A bluff body 102, an igniter 103, a horn body 104 and a swirl vane 105 are provided. The small round end of the horn body 104 is connected with the primary air/pulverized coal pipe 101 passing through the casing 106. The large round end of the horn body 104 Connected to the front end of the combustion chamber 200, the primary air/pulverized coal pipe 101 is communicated with the combustion chamber 200 through a horn body 104, a bluff body 102 is provided at the outlet of the primary air/pulverized coal pipe 101, and the horn The body 104 is also provided with a swirl vane 105 , and the horn body 104 is connected with an igniter 103 passing through the casing 106 .

The combustion chamber 200 includes an outer cylinder 201, a cooling assembly, a spiral coil 205, a furnace lining 207 and a combustion chamber hot air inlet 215. The cooling assembly includes a spiral coil 205, an inner wall 203, and an outer wall 204. The cooling The components are arranged inside the outer cylinder and coaxial with it. The outer cylinder 201 and the two ends of the outer wall surface 204 are respectively connected with the front end surface 209 and the rear end surface 206 to form an isobaric air chamber 202. The heat transfer oil outlet 214 and the heat transfer oil inlet 213 at both ends of the 205 pass through the outer cylinder 201 respectively, the isobaric air chamber 202 is connected with the combustion chamber hot air inlet 214, and the outer vertices of the two adjacent pipes of the spiral coil 205 pass through. The outer flat steel 217 is welded and connected to form the outer wall surface 204, and the inner vertices of the adjacent two pipes are welded and connected by the inner flat steel 216 to form the inner wall surface 203. The inner wall surface 203 is provided with a furnace lining 207. The furnace lining 207, including slag nails 210 and castables 211, the slag nails 210 are uniformly welded on the inner wall of the inner flat steel 216, the slag nails 210 are covered by the castables 211, along the axial direction of the combustion chamber 200 and through the The outer wall surface 204 , the inner wall surface 203 and the furnace lining 207 are provided with evenly distributed grading air ducts 208 .

The oil return branch pipe 12 is provided with a regulating valve 13 and a check valve 15, the oil return branch pipe 12 is also provided with a pressurizing pump 14 through the parallel oil pipe 16, and the oil return main pipe 20 is provided with a circulating oil pump 19.

The furnace chamber 23 is provided with a slag dropping pipe 26, and a slag tapping machine 27 is arranged below the slag dropping pipe 26. The furnace chamber 23 is also provided with a flue gas convection section 24, and the end of the flue gas convection section 24 is connected to the flue gas outlet. 25.

The grading air duct 208 communicates with the isobaric air chamber 202 and the combustion chamber 200 , and the space surrounded by the outer wall surface 204 , the inner wall surface 203 and the spiral coil 205 is filled with thermally conductive filler 212 .

A heat-conducting oil-cooled low-NOx pulverized coal burner cooling method, characterized in that a heat-conducting oil-cooled low-NOx pulverized coal burner system is used to achieve high-quality utilization of burner cooling and heat dissipation energy: through the burner cooling cycle The device uses the circulating heat-conducting oil of the organic heat carrier boiler itself for burner cooling. The heat-conducting oil after heat exchange and heating through the burner cooling device is sent to the thermal user equipment together with the furnace oil. cycle, including the following steps:

S1: The circulating oil pump for boiler operation is started, and the heat transfer oil flows in two paths under the drive of the circulating oil pump. One path passes through the cooling circulation device of the burner to form a cooling circulation branch of the heat transfer oil burner, and the other path passes through the convection section-furnace to form heat transfer oil. Convection section - furnace circulation branch;

S2: The low temperature return oil flowing on the cooling circulation branch of the heat transfer oil burner flows into the spiral coil through the oil return branch under the control of the regulating valve, and the high temperature heat generated by the burner is introduced into the spiral coil through the furnace lining, inner wall surface and heat transfer filler. The tube heats it up, and the low-temperature return oil flows in the high-temperature spiral coil and exchanges heat with it to form a high-temperature output oil;

S3: The high-temperature effluent heated up by the heat exchange branch of the heat transfer oil burner and the high temperature effluent heated by the heat transfer section of the heat transfer oil convection section-furnace circulation branch are sent to the thermal user equipment through the oil outlet manifold, and cooled by production energy consumption Afterwards, it becomes the low temperature return oil and flows into the return oil main pipe, and is recirculated under the drive of the circulating oil pump.

In the step S2, a set temperature value is set by the high temperature oil outlet temperature of the burner, and its value is equal to the set value of the furnace oil outlet temperature and ensures that the value does not exceed the maximum use temperature of the heat transfer oil.

The oil outlet temperature of the burner is realized by controlling the flow rate of the heat transfer oil in the circulation branch of the heat transfer oil burner. According to the measured oil outlet temperature, the set temperature is compared. When the temperature is lower than the set temperature, the flow rate is reduced and the flow rate is the lowest. At this time, the flow rate of the heat transfer oil in the spiral coil should be ≥ 1.5m/s. When the temperature is higher than the set temperature, the flow rate should be increased.

The flow rate of the heat transfer oil in the cooling circulation branch of the heat transfer oil burner in the step S1 is controlled by controlling the opening degree of the regulating valve and the frequency of the pressurized oil pump. When the operating load of the boiler is small, the regulating valve can meet the flow regulation requirements. When the operation load of the boiler is high, the pressure oil pump is started when the full opening of the regulating valve cannot meet the flow requirement.

working principle:

The invention realizes the cooling and heat dissipation of the burner 10 and the high-quality utilization of energy: the organic heat carrier boiler itself is used to circulate heat-conducting oil for cooling the burner 10, so that the boiler heat-conducting oil circulation system is divided into two paths for circulation, one for the boiler itself. The circulation branch from the convection section 24 to the furnace hearth 23, one is the cooling circulation branch of the burner 10, and the heat transfer oil passes through the cooling circulation system of the burner 10 and the circulation branch from the convection section 24 to the furnace hearth 23. User equipment 21, after the heat is processed and utilized, the heat is recirculated to the two-branch heating cycle.

The oil outlet branch pipe 18 is provided with a temperature transmitter 17 for measuring the oil outlet temperature of the burner 10. The temperature of the heat transfer oil outlet 214 should be guaranteed not to exceed its coking temperature, and its set temperature is equal to that of the furnace chamber 23. Oil set temperature.

The control of the outlet oil temperature of the burner 10 is realized by controlling the flow rate of the heat transfer oil in the circulation branch of the heat transfer oil burner 10 . Compare the set temperature according to the measured oil outlet temperature. When the temperature is lower than the set temperature, reduce the flow rate. When the flow rate is the lowest, the flow rate of the heat transfer oil in the spiral coil 205 should be ≥1.5m/s. Increase traffic.

The heat transfer oil flow of the circulation branch of the burner 10 is controlled by controlling the opening of the regulating valve 13 and the frequency of the booster pump 14. When the boiler operating load is small, the regulating valve 13 can meet the flow regulation requirements. , the pressurizing pump 14 is not started; when the boiler operation load is high, the pressurizing pump 14 is started when the full opening of the regulating valve 13 cannot meet the flow requirement.

The burner 10 is a liquid slag discharge burner 10, and the outer layer of the furnace lining 208 of the combustion chamber 200 is provided with a spiral coil 205, and the spiral coil 205 is connected to the boiler heat transfer oil circulation system through an oil pipe; The burner 10 is cooled by the low temperature return oil of the heat transfer oil circulation system, which can not only meet the cooling requirements of the burner 10, but also directly use the heat transfer oil after heat exchange and temperature rise for industrial production, making it equivalent to the heating surface of the boiler.

The present invention uses the heat-conducting oil circulation system of the organic heat carrier boiler itself to cool the burner 10, the equipment process is simple, the energy dissipated by the burner 10 is fully absorbed and utilized, the energy utilization rate is effectively improved, and the energy of the cooling burner 10 is directly used for In production, the energy utilization value is improved. The burner 10 adopts high-temperature and low-oxygen cyclone combustion, and air is distributed in stages, which can effectively reduce pollution emissions, and has significant significance for boiler energy saving and emission reduction.

The specific implementation process of the present invention: the pulverized coal airflow is sent into the burner 100 through the primary air/pulverized coal pipe 101 and then divided by the bluff body 102, and the secondary hot air passes from the air preheater through the secondary hot air duct 28, The secondary hot air inlet 107 of the burner 100 and the combustion chamber hot air inlet 215 of the combustion chamber 200 are introduced into the burner 100 and the isobaric air chamber 202, and the secondary hot air entering the burner 100 is formed by the swirl blades 105. The cyclone is mixed with the split pulverized coal airflow, and then ignited by the igniter 103 and then enters the combustion chamber 200 with the secondary cyclone. The secondary hot air is injected into the combustion chamber 200 from the grading air duct 208 to combust with the pulverized coal, so that the pulverized coal combustion environment changes from anoxic to an oxygen-rich environment, realizes the classified combustion of pulverized coal and air, and effectively reduces the generation of nitrogen oxides. emission. Since the combustion air distribution is set in the burner 10, most of the pulverized coal combustion process is completed in the burner 10, and the high temperature generated by the high-intensity combustion of the pulverized coal in the burner 10 for a short time causes the ash to melt into the liquid slag 11, The liquid slag 11 covers the inner wall of the furnace lining 207 under the action of the cyclone, and falls into the slag extractor 27 through the slag drop pipe 26 along with the high-temperature flue gas flow toward the outlet of the burner 10. The furnace lining 207 transfers heat by exchanging heat with the high-temperature liquid slag 11. to the helical coil 205. In order to ensure that the spiral coil 205 has good mechanical properties and is uniformly heated, the spiral coil 205 is welded together through the inner flat steel 216 and the outer flat steel 217, and the gap is filled with thermal conductive fillers 212. The high-temperature flue gas generated by the combustion of the burner 10 enters the furnace 23 from the burner 10 , and then flows through the convection section 24 and then flows out from the flue gas outlet 25 . The heat transfer oil is driven by the circulating oil pump 19, and the heat exchange cycle is carried out in two ways, one is the cooling circulation branch of the burner 10, the other is the circulation branch of the convection section 24-furnace 23, and the heat conduction in the cooling circulation branch of the burner 10. The oil mainly absorbs the heat of the high-temperature liquid slag 11, and the heat-conducting oil in the circulation branch of the convection section 24-furnace 23 mainly absorbs the heat of the high-temperature flue gas. In the equipment 21, the low-temperature oil returned after production energy consumption is returned to the two-branch heating cycle. In order to prevent the heat transfer oil from being coked at high temperature in the spiral coil 205, the flow rate of the heat transfer oil passing through the spiral coil 205 is controlled by the regulating valve 13 and the pressurizing pump 14, so that the oil outlet temperature is lower than the coking temperature and the flow rate of the heat transfer oil is guaranteed. Greater than 1.5m/s.

The above is only a detailed description of the embodiments of the present invention. It should be pointed out that for those skilled in the art, without departing from the technical principles of the present invention, several improvements and modifications can also be made. These improvements and modifications should also be regarded as the protection scope of the present invention.

Claims (10)

1. A heat-conducting oil cooling type low-NOx pulverized coal burner cooling system, characterized in that: comprising a burner (10) and a cooling circulation device, the burner (10) passing through the cooling circulation device and thermal user equipment (21) connection, the rear end of the burner (10) is provided with a furnace chamber (23), and the cooling circulation device includes an oil return branch pipe (12), an oil outlet branch pipe (18), an oil outlet main pipe (22), and a parallel oil pipe ( 16) and the helical coil pipe (205), the helical coil pipe (205) is connected to the oil outlet branch pipe (18), the oil outlet main pipe (22), the thermal user equipment (21), and the oil return pipe in sequence through the heat transfer oil outlet (214). The main pipe (20) is connected with the oil return branch pipe (12), the oil return branch pipe (12) is connected with the heat transfer oil inlet (213) of the spiral coil pipe (205), the oil return main pipe (20) and the oil outlet main pipe (22) is also connected to the circulation branch from the convection section (24) to the furnace (23) respectively, and the oil outlet branch pipe (18) is provided with a temperature transmitter (17). 2. A heat-conducting oil-cooled low-NOx pulverized coal burner cooling system according to claim 1, characterized in that: the burner (10) comprises a burner (100) and a combustion chamber (200), The burner (100) is respectively connected with the burner secondary hot air inlet (107) and the front end face (209) of the combustion chamber (200) through a casing (106), and a bluff body (106) is provided in the casing (106). 102), an igniter (103), a horn body (104) and a swirl vane (105), the small round end of the horn body (104) is connected with a primary air/pulverized coal pipe (101) passing through the casing (106) ), the large round end of the horn body (104) is connected to the front end of the combustion chamber (200), the primary air/pulverized coal pipe (101) is communicated with the combustion chamber (200) through the horn body (104), the A bluff body (102) is provided at the outlet of the primary air/pulverized coal pipe (101), a swirl blade (105) is further provided on the horn body (104), and the horn body (104) is connected with a swirl blade (104) passing through the casing. igniter (103) of (106). 3. A heat-conducting oil-cooled low-NOx pulverized coal burner cooling system according to claim 2, characterized in that: the combustion chamber (200) comprises an outer cylinder (201), a cooling assembly, a spiral coil ( 205), the furnace lining (207) and the hot air inlet (215) of the combustion chamber, the cooling component includes a spiral coil (205), an inner wall surface (203), and an outer wall surface (204), and the cooling component is arranged on the outer circle The inside of the cylinder is arranged coaxially with it, and the two ends of the outer cylinder (201) and the outer wall surface (204) are respectively connected with the front end surface (209) and the rear end surface (206) to form an isobaric air chamber (202). The heat-conducting oil outlet (214) and the heat-conducting oil inlet (213) at both ends of the spiral coil (205) respectively protrude from the outer cylinder (201), and the isobaric air chamber (202) is connected with the combustion chamber hot air inlet (214) , the outer vertices of the two adjacent pipes of the spiral coil (205) are welded and connected by the outer flat steel (217) to form the outer wall surface (204), and the inner vertices of the two adjacent pipes are welded by the inner flat steel (216) connected to form the inner wall surface (203), the inner wall surface (203) is provided with a furnace lining (207), and the furnace lining (207) includes a slag nail (210) and a castable (211), the slag nail (210) uniformly welded on the inner wall of the inner flat steel (216), the slag nail (210) is covered by the castable (211), along the axial direction of the combustion chamber (200) and passing through the outer wall surface (204) , the inner wall surface (203) and the furnace lining (207) are provided with evenly distributed grading air ducts (208). 4. A heat-conducting oil-cooled low-NOx pulverized coal burner cooling system according to claim 1, characterized in that: the oil return branch pipe (12) is provided with a regulating valve (13) and a check valve (15) The oil return branch pipe (12) is also provided with a pressurizing pump (14) through the parallel oil pipe (16), and the oil return main pipe (20) is provided with a circulating oil pump (19). 5. A heat-conducting oil-cooled low-NOx pulverized coal burner cooling system according to claim 1, characterized in that: the furnace chamber (23) is provided with a slag drop pipe (26), and the slag drop pipe (26) A slag extractor (27) is arranged below the furnace (23), and a flue gas convection section (24) is also arranged in the furnace chamber (23), and the end of the flue gas convection section (24) is connected to the flue gas outlet (25). 6. A heat-conducting oil-cooled low-NOx pulverized coal burner cooling system according to claim 3, characterized in that: the grading air duct (208) communicates with the isobaric air chamber (202) and the combustion chamber (200). ), and the space enclosed by the outer wall surface (204), the inner wall surface (203) and the spiral coil tube (205) is filled with a thermally conductive filler (212). 7. A method for cooling a heat-conducting oil-cooled low-NOx pulverized coal burner, characterized in that, adopting a heat-conducting oil-cooled low-NOx pulverized coal burner system described in any one of claims 1-6 to achieve burner cooling And high-quality utilization of heat dissipation energy: through the burner cooling circulation device, the circulating heat transfer oil of the organic heat carrier boiler itself is used for burner cooling, and the heat transfer oil after heat exchange and heating through the burner cooling device is sent together with the furnace oil. To the hot user equipment, after the production energy consumption and cooling down, the recirculation is recirculated, including the following steps: S1: The circulating oil pump for boiler operation is started, and the heat transfer oil flows in two paths under the drive of the circulating oil pump. One path passes through the cooling circulation device of the burner to form a cooling circulation branch of the heat transfer oil burner, and the other path passes through the convection section-furnace to form heat transfer oil. Convection section - furnace circulation branch; S2: The low temperature return oil flowing on the cooling circulation branch of the heat transfer oil burner flows into the spiral coil through the oil return branch under the control of the regulating valve, and the high temperature heat generated by the burner is introduced into the spiral coil through the furnace lining, inner wall surface and heat transfer filler. The tube heats it up, and the low-temperature return oil flows in the high-temperature spiral coil and exchanges heat with it to form a high-temperature output oil; S3: The high-temperature effluent heated up by the heat exchange branch of the heat transfer oil burner and the high temperature effluent heated by the heat transfer section of the heat transfer oil convection section-furnace circulation branch are sent to the thermal user equipment through the oil outlet manifold, and cooled by production energy consumption Afterwards, it becomes the low temperature return oil and flows into the return oil main pipe, and is recirculated under the drive of the circulating oil pump. 8. The oil-cooling method for an oil-cooled low-NOx pulverized coal burner according to claim 7, wherein in the step S2, a set temperature value is provided by the high-temperature oil outlet temperature of the burner, which The value is equal to the set value of the furnace oil outlet temperature and ensure that the value does not exceed the maximum operating temperature of the heat transfer oil. 9 . The oil-cooling method for an oil-cooled low-NOx pulverized coal burner according to claim 8 , wherein the oil outlet temperature of the burner is obtained by controlling the flow rate of the heat-conducting oil in the circulating branch of the heat-conducting oil burner. 10 . To achieve this, compare the set temperature according to the measured oil outlet temperature. When the temperature is lower than the set temperature, reduce the flow rate. When the flow rate is the lowest, the flow rate of the heat transfer oil in the spiral coil should be ≥1.5m/s, which is higher than the set temperature. When the temperature is high, increase the flow rate. 10. The oil-cooling method for an oil-cooled low-NOx pulverized coal burner according to claim 7, wherein the flow rate of the heat-conducting oil in the cooling circuit branch of the heat-conducting oil burner in the step S1 is adjusted by controlling It is controlled by the valve opening and the frequency of the pressurized oil pump. When the operating load of the boiler is small, when the regulating valve can meet the flow regulation requirements, the pressurized oil pump does not start. When the operating load of the boiler is high, the regulating valve When the full opening cannot meet the flow requirement, the pressurized oil pump is started.

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