What are the specific energy-saving ways of boiler energy-saving transformation? How much energy-saving rate can it achieve?
Now there is an advanced energy-saving technology: nano-micron high radiation coating technology. Nano-micron high emissivity coating technology is to coat a layer of material with nano-micron particle size and high emissivity on the surface of heat transfer object, so that the surface of the object has stronger ability to absorb and radiate heat and improve the heat transfer efficiency of the object.
Nano-micron high radiation coating technology can change the physical properties, morphology, chemical composition, microstructure and stress state of refractory surface by coating a small amount of high radiation materials on the surface, and obtain excellent heat transfer performance and mechanical properties, so it has good economy and technology.
Energy saving principle
There are three ways of heat transfer: convection, radiation and conduction.
Generally speaking, when the furnace temperature is above 900 degrees Celsius, the heat transfer is dominated by radiation, and the radiation heat transfer is 15 times that of convection heat transfer, accounting for more than 80%.
The emissivity of refractories is generally 0.6 ~ 0.8 at room temperature, and it will be greatly reduced with the increase of furnace temperature, only 0.4 ~ 0.5 at high temperature, while the emissivity of high emissivity coatings can always be above 0.9.
According to Kirchhoff's law, the absorption rate and emissivity of materials are equal. When the emissivity of the surface of an object increases, its heat absorption capacity also increases accordingly.
Energy-saving transformation technology of industrial boilers-Energy-saving efficiency Take 10 ton boiler for example, the minimum designed coal consumption per steam ton per hour is 150 kg.
10 ton boiler's coal consumption per hour is:150kg×10 =1500kg =1.5 ton.
The coal consumption for 24 hours a day and night is: 1.5 tons× 24 = 36 tons.
According to the coal saving rate 10%: 36 tons×10% = 3.6 tons (one day and night), the production furnace runs for 300 days a year, and the other 60 days are downtime, saving 3.6×300 = 1080 tons a year. Take Liaoning, Jilin, Heilongjiang and other northeastern regions as examples. Coal price per ton of 600 yuan, coal saving 1.08 ton ×600 yuan/ton = 648,000 yuan. A heating period of the heater is calculated as 150 days: 50×3.6 tons =540 tons, and 540 tons× 600 yuan/ton = 324,000 yuan.
Energy-saving transformation technology of industrial boiler
-( 1) Increase the economizer of oil-fired boiler; The molecular structure of hydrocarbon treated by economizer changes, the number of fine molecules increases, the intermolecular distance increases and the viscosity of fuel decreases. In this way, the degree of atomization and refinement of fuel oil before combustion is greatly improved, and the fuel oil is fully combusted when it is injected into the combustion chamber under the condition of low oxygen, so the blast volume of combustion equipment can be reduced by 15% to 20%, the heat carried away in the flue is avoided, and the flue temperature is reduced by 5℃ to 10. After the fuel of combustion equipment is treated by economizer, the fuel can be saved by 4.87% ~ 6. 10% due to the improvement of combustion efficiency, and the flame is bright and dazzling, the black smoke disappears, and the furnace is clear and transparent. Completely eliminate the coking phenomenon of combustion nozzle and prevent coking again. The phenomenon of slag accumulation on the furnace wall caused by incomplete combustion of fuel is eliminated, and the effect of environmental protection and energy saving is achieved. Greatly reduce the air pollution caused by the exhaust gas discharged from combustion equipment, and the harmful components such as carbon monoxide (CO), nitrogen oxides (nitrogen oxides) and hydrocarbons (HC) in the exhaust gas are greatly reduced, and the harmful exhaust gas discharged is reduced by more than 50%. At the same time, the dust content in the waste gas can be reduced by 30%-40%. Installation position: it is installed between the oil pump and the combustion chamber or nozzle, and the ambient temperature does not exceed 360℃.
Energy-saving transformation technology of industrial boiler
-② Installation of economizer of condensing gas boiler;
Flue gas condenser The flue gas discharged from the gas-fired boiler of flue gas condenser contains as much as 18% of water vapor, which contains a lot of unused latent heat, resulting in high flue gas temperature and large sensible heat loss. Natural gas still emits pollutants such as nitrogen oxides and a small amount of sulfur dioxide after combustion. Reducing fuel consumption is the best way to reduce costs. The economizer of condensing gas-fired boiler can be directly installed in the flue of existing boiler, which can recover the energy in high-temperature flue gas and reduce fuel consumption, and the economic benefit is very obvious. At the same time, the condensation of water vapor absorbs pollutants such as nitrogen oxides and sulfur dioxide in flue gas, which reduces pollutant emissions and has important environmental protection significance.
Energy-saving transformation technology of industrial boiler
—— ③ adopting condensing waste heat recovery boiler technology; In traditional boilers, the flue gas temperature is generally 160 ~ 250℃, and the water vapor in the flue gas is still overheated, so it is impossible to condense into liquid water and release the latent heat of vaporization. As we all know, the thermal efficiency of boiler is calculated according to the low calorific value of fuel, and the heat loss of latent heat of vaporization in the high calorific value of fuel is not considered. So the thermal efficiency of traditional boilers can only reach 87% ~ 9 1%. The condensing waste heat recovery boiler reduces the temperature of flue gas to 50 ~ 70℃, fully recovers the sensible heat in flue gas and the latent heat of condensation of water vapor, and improves the thermal efficiency; Condensed water can also be recovered.
Energy-saving transformation technology of industrial boiler
-④ Heat pipe waste heat recovery technology is adopted at the tail of the boiler; Waste heat is the unused energy in energy utilization equipment under certain economic and technical conditions, that is, redundant and abandoned energy. Including seven kinds of waste heat: waste heat of high-temperature exhaust gas, waste heat of cooling medium, waste steam and waste water, waste heat of high-temperature products and slag, waste heat of chemical reaction, waste heat of combustible exhaust gas and waste, and residual pressure of high-pressure fluid. According to the survey, the total amount of waste heat resources in various industries accounts for about 17%~67% of the total fuel consumption, and the recoverable waste heat resources account for about 60% of the total amount of waste heat resources.
Superconducting heat pipe is the main heat conduction element of heat pipe waste heat recovery device, which is essentially different from ordinary heat exchanger. The heat exchange efficiency of the heat pipe waste heat recovery device can reach more than 98%, which is beyond the reach of any ordinary heat exchanger. The waste heat recovery device of heat pipe is small, which is only 1/3 of that of ordinary heat exchanger. Its working principle is as shown in the figure: the flue gas channel is on the left, the clean air (water or other media) channel is on the right, and there is a partition in the middle that does not interfere with each other. High-temperature flue gas is discharged from the left channel. When discharged, the high-temperature flue gas washes the heat pipe. When the flue gas temperature >: the heat pipe is activated at 30℃, it will automatically conduct heat to the right. At this time, the left side of the heat pipe absorbs heat, the temperature of high-temperature flue gas drops after flowing through the heat pipe, and the heat is absorbed by the heat pipe and conducted to the right side. Under the action of the blower, clean air (water or other medium) at room temperature flows in the opposite direction along the right channel to scour the heat pipe. At this time, the right side of the heat pipe releases heat to heat clean air (water or other media), and the temperature of the air rises after flowing through the heat pipe. A waste heat recovery device consisting of multiple heat pipes is installed in the flue of the boiler to absorb the heat in the flue gas and conduct it to the other end at high speed, so as to reduce the temperature of the flue gas to the dew point and reduce the heat loss. The heated clean air can dry the material or supplement it to the boiler for recycling. Improve the thermal efficiency of boilers and industrial kilns, reduce fuel consumption and achieve the purpose of energy saving.
In the design and manufacture of industrial oil-fired, gas-fired and coal-fired boilers, in order to prevent the corrosion and ash blockage of the heating surface at the tail of the boiler, the standard exhaust smoke temperature is generally not lower than 180℃, and the highest can reach 250℃. High temperature flue gas emission not only wastes a lot of heat energy, but also pollutes the environment.
The heat pipe waste heat recoverer can recover the heat of flue gas, and the recovered heat can be used to heat water as boiler make-up water and domestic water, or heat air as boiler combustion air or dry materials as required. Save fuel costs, reduce production costs, reduce tail gas emissions, and kill two birds with one stone by saving energy and protecting the environment. The transformation investment can be recovered within 3- 10 months, and the economic benefit is remarkable.
Energy-saving transformation technology of industrial boiler
-⑤ Adopt anti-scaling and descaling technology; By using boiler scale remover and electronic scale inhibitor, the water vapor circulation system is optimized, the boiler discharge is reasonably controlled, the scale is reduced, and the boiler thermal efficiency is improved.
Energy-saving transformation technology of industrial boiler
—— ⑥ adopting fuel additive technology; Adding additives to fuel can optimize fuel, reduce smoke and dust and improve thermal efficiency.
Energy-saving transformation technology of industrial boiler
-⑦ adopting new fuels; The purpose of reducing fuel cost is achieved by using new environmentally friendly fuel oil.
Energy-saving transformation technology of industrial boiler
-⑧ Adopt oxygen-enriched combustion technology; The oxygen content in the air is ≤2 1%. The combustion of industrial boilers is also carried out under such air. Practice shows that when the oxygen content of coal gas burned by the boiler reaches more than 25%, the energy saving is as high as 20%; Boiler startup heating time shortened 1/2-2/3. Oxygen enrichment is to collect oxygen in the air by physical methods, so that the oxygen content in the collected gas is 25%-30%. Oxygen-enriched combustion is a new energy-saving and environmental protection technology. In recent ten years, with the continuous improvement of environmental protection requirements and the need of energy saving, oxygen-enriched combustion, as a new combustion technology, has flourished around the world. At present, some developed countries in the west require all newly-built industrial furnaces and boilers to burn with oxygen-enriched air instead of ordinary air.
Energy-saving transformation technology of industrial boiler
-pet-name ruby using swirl combustion boiler technology; As we all know, the traditional boiler has two shortcomings. One is that smoke and dust are emitted during combustion, which becomes an important pollution source; Second, the coal cinder is not fully burned and the energy waste is extremely serious. Compared with traditional industrial boilers, the new technology of pure smokeless energy-saving swirl combustion boiler has absolute advantages. It saves 30%~35% coal compared with hand-fired boiler and 25% coal compared with chain automatic boiler. Because the pure smokeless energy-saving technology adopts PID frequency conversion and ABM energy-saving system, it saves electricity by 40% compared with the traditional boiler, and the volatile can be burned and utilized by more than 90%, while the volatile burn-out rate of the traditional boiler is only about 78%, and 22% of the flue gas is discharged into the atmosphere. The pure smokeless and energy-saving swirl combustion technology makes the ash burnout rate reach 97%, while the traditional boiler ash burnout rate is only about 80%. It is for these reasons. The pure smokeless energy-saving combustion technology can increase the furnace temperature from the original 1200℃ to about 1500℃, improve the combustion efficiency, save fuel and meet the needs of customers.
Energy-saving transformation technology of industrial boiler
-attending the replacement technology of air source heat pump hot water unit; Replace the existing oil (gas) hot water boiler with air source heat pump hot water unit; Can save 30% to 50% of energy consumption.