Layered structure device of heat transfer element of deep-load peak-shaving boiler preheater

Abstract

The invention discloses a layered structure device of a heat transfer element of a deep-load peak-shaving boiler preheater. The device comprises a power station boiler air pre-heater, the power station boiler air pre-heater is provided with an air pre-heater heat transfer element, the air pre-heater heat transfer element is provided with a hot end layer, a cold fault layer is arranged below the hot end layer, and no middle layer exists between the hot end layer and the cold fault layer. The layered structure is used for the heat transfer element of the preheater of the deep-load peak-shaving boiler.

Description

TECHNICAL FIELD

[0001] The application relates to a layered structure device of a deep-load peak-shifting boiler preheater heat transfer element. BACKGROUND

[0002] The installed capacity and power generation proportion of new energy will also be greatly improved, and coal-fired power generating units will become peak-shifting units of new energy in the future, so it is of great significance to improve the deep peak-shifting flexibility of the existing coal-fired power generating units.

[0003] The main function of the air preheater of a power station boiler is to recover the heat of flue gas discharged from a steam-water heat absorption section of the boiler, heat combustion air, and reduce the exhaust gas temperature. The air preheater is a gas-gas heat exchanger, and its main functions are: strengthening combustion, strengthening heat transfer, improving the efficiency of the boiler, and facilitating fuel delivery. However, when the internal structure has defects, the above-mentioned functions cannot be realized. SUMMARY

[0004] The application aims to provide a layered structure device of a deep-load peak-shifting boiler preheater heat transfer element, which has a greatly improved covering ABS area capacity of the cold end element of the reformed preheater.

[0005] The above-mentioned purpose is realized by the following technical scheme.

[0006] A layered structure device of a deep-load peak-shifting boiler preheater heat transfer element comprises the following components: a power station boiler air preheater, wherein the power station boiler air preheater is provided with an air preheater heat transfer element, the air preheater heat transfer element has a hot end layer, the hot end layer is provided below with a cold break layer, and there is no intermediate layer between the hot end layer and the cold break layer.

[0007] The height of the cold break layer of the layered structure device of the deep-load peak-shifting boiler preheater heat transfer element is 1300mm-1400mm.

[0008] When the height of the cold break layer of the layered structure device of the deep-load peak-shifting boiler preheater heat transfer element is 1400mm, the maximum continuous evaporation capacity BMCR flue gas side wall temperature of the boiler is 196.52-218.87, 181.59-205.22, 165.90-190.80, 149.42-175.64, and 132.1-159.71.

[0009] The height of the cold fault layer is 1400mm, the maximum continuous evaporation capacity of the boiler BMCR flue gas side wall temperature is 196.52-218.97, 196.6, 200.73, 202.89, 205.08, 207.32, 209.59, 211.89, 214.22, 216.58, 218.97; 181.59-205.22 is 181.59, 183.88, 186.2, 188.52, 190.86, 193.22, 195.59, 197.97, 200.38, 202.79, 205.22; 165.90-190.80 is 165.90, 168.39, 170.87, 173.36, 175.84, 178.32, 180.81, 183.30, 185.79, 188.29, 190.80; 149.42-175.64 is 149.42, 152.08, 154.73, 157.37, 159.99, 162.62, 165.23, 167.84, 170.44, 173.04, 175.64; 132.1-159.71 is 132.1, 134.93, 137.74, 140.53, 143.31, 146.07, 148.82, 151.56, 154.29, 157, 159.71.

[0010] The height of the cold fault layer is 1400mm, the maximum continuous evaporation capacity of the boiler BMCR flue gas side wall temperature is 196.52-218.97, 196.6, 200.73, 202.89, 205.08, 207.32, 209.59, 211.89, 214.22, 216.58, 218.97; 181.59-205.22 is 181.59, 183.88, 186.2, 188.52, 190.86, 193.22, 195.59, 197.97, 200.38, 202.79, 205.22; 165.90-190.80 is 165.90, 168.39, 170.87, 173.36, 175.84, 178.32, 180.81, 183.30, 185.79, 188.29, 190.80; 149.42-175.64 is 149.42, 152.08, 154.73, 157.37, 159.99, 162.62, 165.23, 167.84, 170.44, 173.04, 175.64; 132.1-159.71 is 132.1, 134.93, 137.74, 140.53, 143.31, 146.07, 148.82, 151.56, 154.29, 157, 159.71.

[0011] The height of the cold fault is 1400mm, and the wall temperature of the flue gas side is 190.38-201.7 under the condition of 50% THA, wherein 190.38, 191.41, 192.47, 193.56, 194.66, 195.79, 196.94, 198.1, 199.29, 200.49, 201.7, 178.5-190.55 is 178.5, 179.66, 180.83, 182.01, 183.2, 184.4, 185.61, 186.83, 188.06, 189.3, 190.55, 165.84-178.67 is 165.84, 167.11, 168.38, 169.66, 170.94, 172.22, 173.51, 174.79, 176.08, 177.37, 178.67, 152.36-166.03 is 152.36, 153.74, 155.12, 156.49, 157.86, 159.22, 160.59, 161.95, 163.31, 164.67, 166.03, and 138.02-152.59 is 138.02, 139.5, 140.98, 142.45, 142.91, 145.37, 146.82, 148.27, 149.71, 151.15, 152.59.

[0012] Beneficial effects:

[0013] 1. The heat exchange element is replaced from three sections to two sections, and the height of the cold end enamel heat exchange element is increased to 1300mm-1400mm, effectively covering the ammonium bisulfate dew area, improving the corrosion resistance and anti-clogging ability of the heat exchange element

[0014] 2. The heat exchange element of the air preheater is replaced to reduce the risk of clogging and corrosion of the deep peak shaving air preheater, and to enhance the safety and stability of the unit. By increasing the proportion of the cold end corrosion-resistant heat exchange element, the corrosion resistance and anti-clogging ability are improved, effectively alleviating the problem of large amount of ammonium bisulfate dew under low load. And with the replacement of the heat exchange element from three sections to two sections and the appropriate increase of the height of the cold end enamel heat exchange element, the corrosion resistance and anti-clogging effect of the air preheater is effectively improved from two aspects.

[0015] 3. The layered structure of the present application has been modified in many power plants at home and abroad, and the effect is remarkable, with good popularization value, and can make a contribution to the environmental protection of China's power station boilers.

[0016] 4. This invention calculates data based on actual conditions and combines it with theoretical teaching to help students better understand the combination of theory and practice and the specific problems solved in practice. Attached image description:

[0017] Appendix Figure 1 This is a cross-sectional view of the air preheater for the power plant boiler of this product.

[0018] Appendix Figure 2 This is a schematic diagram of the modification of this product.

[0019] Appendix Figure 3 This is a diagram showing the flue gas sidewall temperature distribution under 50% THA conditions after the third phase of optimization and modification of this product.

[0020] Appendix Figure 4 This is a diagram showing the flue gas sidewall temperature distribution under BMCR conditions after the third phase of optimization and modification of this product.

[0021] Appendix Figure 5 This is the original diagram of the flue gas sidewall temperature distribution under 50% THA conditions.

[0022] Appendix Figure 6 This is the original diagram of the flue gas sidewall temperature distribution under BMCR operating conditions. Detailed implementation method:

[0023] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0024] Example 1:

[0025] A layered structure device for heat transfer elements of a deep-load peak-shaving boiler preheater, comprising: a power plant boiler air preheater 1, wherein the power plant boiler air preheater is provided with an air preheater heat transfer element 2, wherein the air preheater heat transfer element has a hot end layer 3, wherein a cold break layer 4 is provided below the hot end layer, and there is no intermediate layer between the hot end layer and the cold break layer.

[0026] Example 2:

[0027] The layered structure device for the heat transfer element of the preheater of a deep load peak-shaving boiler described in Example 1 has a cold break height of 1300mm-1400mm.

[0028] Example 3:

[0029] The layered structure device of the heat transfer element of the preheater of the deep load peak shaving boiler according to the embodiment 2, when the height of the cold break is 1400mm, the boiler maximum continuous evaporation capacity BMCR flue gas side wall temperature is 196.52-218.87, 181.59-205.22, 165.90-190.80, 149.42-175.64, 132.1-159.71.

[0030] The layered structure device of the heat transfer element of the preheater of the deep load peak shaving boiler according to the embodiment 2, when the height of the cold break is 1400mm, the boiler maximum continuous evaporation capacity BMCR flue gas side wall temperature is 196.52-218.87, 181.59-205.22, 165.90-190.80, 149.42-175.64, 132.1-159.71.

[0031] Embodiment 4:

[0032] The layered structure device of the heat transfer element of the preheater of the deep load peak shaving boiler according to the embodiment 3, when the height of the cold break is 1400mm, the boiler maximum continuous evaporation capacity BMCR flue gas side wall temperature is 196.52-218.97, 181.59-205.22, 165.90-190.80, 149.42-175.64, 132.1-159.71.

[0033] Embodiment 5:

[0034] The layered structure device of the heat transfer element of the deep load peak shaving boiler preheater according to the embodiment 2, wherein the wall temperature of the flue gas of the cold break layer is 190.38-201.7, 178.5-190.55, 165.84-178.67, 152.36-166.03 and 138.02-152.59 when the height of the cold break layer is 1400mm and the working condition is 50%THA.

[0035] The wall temperature of the flue gas of the cold break layer is 190.38-199.29, 178.5-190.55, 165.84-178.67, 152.36-166.03 and 146.82-148.27 when the height of the cold break layer is 1400mm and the working condition is 50%THA.

[0036] Embodiment 6:

[0037] The layered structure device of the heat transfer element of the deep load peak shaving boiler preheater according to the embodiment 5, wherein the wall temperature of the flue gas of the cold break layer is 190.38-201.7, 178.5-190.55, 165.84-178.67, 152.36-166.03 and 138.02-152.59 when the height of the cold break layer is 1400mm and the working condition is 50%THA.

[0038] Embodiment 7:

[0039] The layered structure device of the heat transfer element of the deep load peak shaving boiler preheater described in the above embodiments first, from the perspective of professional knowledge, this layered structure patent involves the knowledge of multiple disciplines such as thermal energy engineering, materials science, and mechatronics. In teaching work, teachers can introduce these patents as actual cases into the teaching of related courses, helping students better understand the application of theoretical knowledge in actual engineering. Through the analysis and discussion of these patents, students can gain a deep understanding of the design principles, structural optimization, and performance improvement of boiler preheater heat transfer elements, thereby enhancing their professional competence and practical ability.

[0040] Secondly, the innovative thinking and problem-solving ability represented by this layered structure patent is also an important aspect of teaching work. In the teaching process, teachers can guide students to analyze the innovation points and technical advantages of this patent, and encourage them to come up with their own improvement plans or new design ideas. Through such teaching activities, students' innovative thinking ability, problem-solving ability, and critical thinking ability can be cultivated, laying a solid foundation for their future scientific research and engineering practice.

[0041] In addition, teaching work can also combine the actual application of this layered structure patent to carry out practical teaching activities. For example, students can be organized to visit relevant boiler manufacturing enterprises or research institutions to understand the application and effect of this layered structure in actual production. Through on-site investigation and exchange learning, students can more intuitively understand the practical application and market demand of patent technology, providing valuable reference for their future career development.

[0042] BMCR(Boiler maximum continue rate): Boiler maximum continuous evaporation, mainly the maximum output under the conditions of meeting the steam parameters and furnace safety.

[0043] THA condition (turbine heat acceptance) is: the turbine can continuously operate the generator at rated power under the conditions of rated inlet steam parameters, rated back pressure, normal operation of the regenerative system, and 0% make-up water rate. Some also call it rated output condition.

[0044] The main function of the air preheater of a power plant boiler is to recover the heat of flue gas leaving the steam-water absorption section of the boiler, heat the combustion air, and reduce the exhaust gas temperature. It is a gas-gas heat exchanger.

[0045] The air preheater of a power plant boiler can enhance combustion; after the combustion air is heated, it can dry the fuel, accelerate the evaporation of volatile components, benefit the ignition, combustion, and burnout of the fuel, enhance the combustion stability, and improve the combustion efficiency.

[0046] The air preheater of the power station boiler can strengthen the heat transfer; after the combustion air is heated, the furnace temperature is improved, the temperature difference between the flue gas and the water vapor side is increased, thereby the boiler heat transfer is strengthened.

[0047] The air preheater of the power station boiler can improve the boiler efficiency; the boiler exhaust gas temperature is obviously reduced by using the preheater, the boiler efficiency is correspondingly improved, generally, the boiler efficiency is increased by about 1% when the exhaust gas temperature is reduced by 20℃, for the preheater which reduces the exhaust gas temperature by about 250℃, the boiler efficiency is increased by more than 12%, and the fuel saving amount is very considerable.

[0048] The heated hot primary air can heat the fuel during the transportation of the fuel, evaporate the water carried by the fuel, and be beneficial to the preparation and transportation of the pulverized coal.

[0049] The heat transfer element is the core component of the air preheater of the power station boiler, and its weight accounts for about half of the air preheater.

[0050] The focus of the design of the present application is to change the layered structure of the heat transfer element of the air preheater of the power station boiler, and the total height of the heat transfer element of the air preheater is taken as an example for modification.

[0051] Example 8:

[0052] The layered structure device of the heat transfer element of the preheater of the deep load peak shaving boiler described in the above examples, the heat transfer element of the current air preheater of the power station boiler is generally arranged in three or four layers, when the boiler can work at full load, this arrangement is very good. However, under the current international economic form, domestic and foreign power station boilers will be deeply peaking for a long time and high frequency. However, deep peaking has a great influence on the operation of the air preheater of the boiler power station, which is specifically manifested in: heat transfer element blockage problem, cold end heat transfer element low temperature corrosion. Heat transfer element blockage and corrosion will reduce the heat transfer efficiency of the air preheater, reduce the operation economy of the boiler, and at the same time bring safety hazards to the operation of the boiler power station, which may cause the phenomenon of jamming, fire, etc. According to the design boundary conditions such as the weather conditions, the designed coal quality, and the flue gas and air parameters of a domestic power plant, the layered structure of the heat transfer element is changed from three layers to two layers, and by changing the height of the layered heat transfer element, the above problems are solved.

[0053] According to the design coal type and boiler design condition data of a 1000MW unit, the generation temperature of the preheater liquid ammonium bisulfate (design sulfur content 0.84%) is about 194℃, when the preheater operates at BMCR condition and medium-high load condition, the height of the cold end heat transfer element can meet the ABS area coverage requirement, and can operate stably for a long time, and the preheater wall temperature distribution is as follows Figure 3 、 Figure 4 .

Claims

1. A layered structure device for the heat transfer element of a preheater in a high-load peak-shaving boiler, comprising: An air preheater for a power plant boiler is characterized in that: the air preheater for the power plant boiler is provided with an air preheater heat transfer element, the air preheater heat transfer element has a hot end layer, a cold break layer is provided below the hot end layer, and there is no intermediate layer between the hot end layer and the cold break layer.

2. The layered structure device for heat transfer elements of a deep-load peak-shaving boiler preheater according to claim 1, characterized in that: The height of the cold fracture is 1300mm-1400mm.

3. The layered structure device for heat transfer elements of a deep-load peak-shaving boiler preheater according to claim 2, characterized in that: When the height of the cold fracture is 1400mm, the maximum continuous evaporation rate (BMCR) flue gas sidewall temperature of the boiler is 196.52-218.87, 181.59-205.22, 165.90-190.80, 149.42-175.64, and 132.1-159.

71.

4. The layered structure device for heat transfer elements of a deep-load peak-shaving boiler preheater according to claim 2, characterized in that: When the height of the cold fracture layer is 1400mm, the maximum continuous evaporation rate (BMCR) flue gas sidewall temperature of the boiler is as follows: 196.52-218.97: 196.6, 200.73, 202.89, 205.08, 207.32, 209.59, 211.89, 214.22, 216.58, 218.97; 181.59-205.22: 181.59, 183.88, 186.2, 188.52, 190.86, 193.22, 195.59, 197.97, 200.38, 202.79, 205.22; 165.90-190.80: 165.90, 168.39, ... 170.87, 173.36, 175.84, 178.32, 180.81, 183.30, 185.79, 188.29, 190.80; the range 149.42-175.64 is 149.42, 152.08, 154.73, 157.37, 159.99, 162.62, 165.23, 167.84, 170.44, 173.04, 175.64; the range 132.1-159.71 is 132.1, 134.93, 137.74, 140.53, 143.31, 146.07, 148.82, 151.56, 154.29, 157, 159.

71.

5. The layered structure device for heat transfer elements of a deep-load peak-shaving boiler preheater according to claim 2, characterized in that: When the height of the cold fracture is 1400mm, the flue gas sidewall temperature under 50% THA conditions is 190.38-201.7, 178.5-190.55, 165.84-178.67, 152.36-166.03, and 138.02-152.

59.

6. The layered structure device for heat transfer elements of a deep-load peak-shaving boiler preheater according to claim 5, characterized in that: When the height of the cold fracture is 1400mm, the flue gas sidewall temperature under 50% THA conditions is as follows: 190.38-201.7: 190.38, 191.41, 192.47, 193.56, 194.66, 195.79, 196.94, 198.1, 199.29, 200.49, 201.7; 178.5-190.55: 178.5, 179.66, 180.83, 182.01, 183.2, 184.4, 185.61, 186.83, 188.06, 189.3, 190.55; 165.84-178.67: 165.84, 167.11, 168. 0.38, 169.66, 170.94, 172.22, 173.51, 174.79, 176.08, 177.37, 178.67, the range 152.36-166.03 is 152.36, 153.74, 155.12, 156.49, 157.86, 159.22, 160.59, 161.95, 163.31, 164.67, 166.03, and the range 138.02-152.59 is 138.02, 139.5, 140.98, 142.45, 142.91, 145.37, 146.82, 148.27, 149.71, 151.15, 152.59.

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