Lai Shiyao
'Abstract' In recent years, along with the rapid development of the domestic economy, China's resources and energy have been in short supply, and the environment has been damaged and polluted to varying degrees. These problems have seriously restricted China's economic development and transformation. And upgrade. For biomass energy, it is a relatively clean energy source, and it has little pollution to the environment during the combustion process. Therefore, it is necessary to develop and apply biomass pellet fuel combustion equipment at this stage. Discussion. This paper combines the development and application of energy-saving and environment-friendly biomass pellet boiler system to explore equipment development, energy saving, environmental protection characteristics and application status.
1 Introduction
In general, biomass pellet fuels have a diameter of less than 25 mm and are cylindrical in shape. In the process of forming and strengthening fuel, the density of particles will increase significantly. Compressed biomass pellet fuel Density, strength and combustion performance will be significantly improved, so the combustion effect is higher than that of general agricultural materials. The biomass fuel in the biomass pellet fuel combustion equipment silo is added to the basin depression through the closed air feeding device, and then ignited. The igniting, and the subsequent addition of biomass fuel under the action of high temperature and swirling air supply, showing a semi-vaporized state, boiling combustion above the basin-shaped depression, can make it fully burned. Minimize pollution while achieving the highest thermal efficiency Emissions
2 Significance of the development of biomass pellet fuel combustion equipment
China is a country with a large population and a country with rapid economic development. In the 21st century, it faces the dual pressures of economic growth and environmental protection. In recent years, China’s annual fuel consumption has reached 1.215 billion tons, of which more than 80% is used for boilers. Direct combustion of thermal equipment, sulfur dioxide emitted by coal-fired boilers is between 14 and 17 million tons. At present, the average annual concentration of sulfur dioxide in 62.3% of cities in China exceeds the national secondary standard. Acid rain has caused serious harm in many cities. Seriously. Making full use of various biomass energy sources, vigorously developing circular economy, and reducing pollution caused by the surrounding environment are one of the main measures to promote the sustainable development of China's economy. It is also of great significance to the development and cultivation of China's emerging industries.
Through the use of biomass boilers, not only can the utilization efficiency of crop straws in rural areas be improved, but also the protection of the environment is of great significance.
3Biomass pellet fuel combustion equipment
3.1 Research on design of biomass pellet steam furnace
The system uses a biomass pellet steam furnace, the main components of which are the furnace body, the feeding device and the air supply device. The furnace body is provided with a grate, the grate is provided with an igniter, and the furnace outlet is provided. It is connected with the steam boiler. There is a basin-shaped depression at the center of the grate, an igniter is arranged in the basin-shaped depression, and a concave grate structure is adopted. The boiling combustion method can make the combustion efficiency reach 92% or more. There are also rollers under the furnace body to facilitate the movement and flexible docking with the steam boiler. The feeding device includes a silo, a first-stage auger, a second auger and a variable frequency motor, and the inlet end of the first-stage auger and the silo The material inlets are connected, the outlet end of the first-stage auger is connected with the feeding end of the second auger, and the discharge end of the second auger is connected to the upper side of the grate, the first-stage auger, the second auger Both are connected with variable frequency motors to provide power for feeding.
3.2 Research on the design of biomass pellet burner
The biomass pellet burner of the system, in particular, relates to a biomass burning furnace used in combination with a boiler, a furnace body, a feeding device and a blowing device. The furnace body has a grate in the furnace, and a basin is arranged in the center of the grate. The sag is provided with an igniter in the basin-shaped depression, and the fire body is connected to the existing boiler on one side of the furnace body, and the biomass pellet fuel in the silo is added to the basin-shaped depression through the idle air feeding device. Then it is ignited by the igniter, and the subsequently added biomass pellet fuel exhibits a semi-gasification state under the action of high temperature and swirling air supply, boiling combustion above the basin-shaped depression, which can make it burn fully, and obtain the highest thermal efficiency. At the same time, the emission of pollutants is minimized: the flame generated in the biomass burning furnace is directly sent to the boiler through the fire outlet provided on one side of the furnace for secondary combustion to provide heat to the boiler through the use of a recessed grate structure and The swirling air supply structure can achieve a combustion efficiency of 92~95% or more: There are also several rollers under the furnace body, which makes it easy to move and dock or separate from the boiler.
3.3 Design of biomass pellet hot blast stove installation
The technical research of the biomass pellet hot blast stove of the system mainly includes the furnace body, the feeding device and the warm air device are respectively: the furnace body is provided with a grate in the furnace, and the center of the grate is provided with a basin-shaped depression, in the basin-shaped depression An igniter is arranged, and the grate portion is also connected with a supply duct; the feeding device comprises a silo, a screw feeder, a frequency conversion motor and a feeding tube, and an inlet end of the screw feeder is connected with a discharge port of the silo, the screw feeder The outlet end of the feed pipe is connected to one end of the feed pipe, and the other end of the feed pipe is obliquely connected downward to the top of the basin-shaped recess. The variable frequency motor is mechanically connected with the screw feeder to convey the material in the screw feeder to the outlet end. Then the material falls into the basin-shaped depression by gravity: The speed of the fan and the motor equipment is adjusted by the frequency converter to save electricity. The heater unit includes adjacent and unconnected flue gas passages and heat exchange channels, flue gas. The passage is arranged below or inside the heat exchange passage, one end of which is connected with the furnace, and the other end is connected downward to connect the exhaust fan and then communicates to the outside through the flue, and one end of the heat exchange passage is an indoor air inlet. One end is a heating outlet, and a convection fan is arranged in the heat exchange passage to allow air to enter from the indoor air inlet. After absorbing the heat in the flue gas passage in the heat exchange passage, it is discharged through the heating outlet to provide warm air to the room. Heat.
4 energy saving and environmental protection characteristics
In order to respond to the national goal of “energy saving and consumption reduction” and achieve the goal of effective energy utilization, the project team will strengthen the awareness of energy saving and consumption reduction, pay attention to energy conservation from the consciousness, and ensure the effective implementation of energy conservation work. Key production equipment and testing equipment require low energy consumption, high reliability and high degree of automation; office equipment is also preferred to use high-quality energy-saving equipment. Strengthen energy-saving management and education work, water, electricity, gas, etc. to install flowmeters, easy to understand energy in a timely manner Consumption: It is necessary to regularly inspect and maintain related equipment to ensure normal operation of the equipment and reduce energy waste.
The main environmental protection contents of the project include sewage in the normal production process, waste gas treatment, production machinery noise control, waste disposal, etc.
1 This project adopts purchased copper plate. When the spare parts are machined and assembled, there will be cooling circulating water in the production process, all of which will be recycled, no production waste water is discharged; the sewage is mainly from the domestic sewage of the employees, and the collection is unified. After the treatment pool, it enters the urban sewage treatment station for treatment through the municipal pipe network.
2 In the assembly process, the welding waste gas and a small amount of painted exhaust gas are generated during the assembly process. The main pollutant of the welding exhaust gas is soot, and the concentration and amount are small. The ventilation is added by adding an exhaust fan to ensure the production environment. Painted exhaust gas, in the closed operation process, semi-automatic spraying, will produce a small amount of paint mist, the company uses environmentally friendly paint and the use of water curtain to treat paint mist, to ensure that the exhaust gas emission concentration and discharge rate can meet the secondary standard requirements .
3 After the completion of the project, the noise mainly comes from the production equipment. The shock absorbers must be installed on the bottom of the power equipment such as the air compressor, and the sound insulation of the motor room should be done inside. The noise source of other equipment in this project is small, after shock absorption. Noise reduction, after wall isolation, can meet the standard limit requirements.
4 In the production process after the completion of the project, the solid waste generated mainly includes the production of solid waste and domestic garbage. The production of solid waste is mainly waste iron scraps, scraps, and various packaging materials produced in the machining production, all of which can be integrated. Utilization. After the garbage is collected in a unified manner, it is regularly disposed of by the sanitation department, which has little impact on the environment.
5 combustion equipment application
5.1 for anecdotes, heating work
At this stage, biomass pellet fuel equipment for households in some countries in Europe and America has become more popular. At the same time, more than 200 million farmers in China have used the fuel-saving stoves, and the thermal efficiency of these combustion equipment can reach 25%. Compared with traditional stove facilities, the use of coal-saving stoves is safer, more convenient, and more sanitary. At the same time, there are many R&D institutions in China that have achieved good results in the development of biomass pellet heating equipment. For example, the Wanfa Furnace Center in Beijing has developed a warm-hearted fireplace and a plumbing stove, a cooking stove and other equipment that use straw-based pellet fuel.
5.2 for biomass power generation work
As early as the 1970s, some countries have started graduate material power generation technology. In general, biomass power generation technology can be divided into three types, namely, biomass direct combustion power generation and biomass and coal mixed combustion power generation. Also includes biomass gasification power generation. At this stage, this technology has received the attention of China.
5.3 Heating, drying applications
For the application of biomass pellet fuel, it is widely used in industrial large-scale heating and drying. At present, industrial combustion technology can be divided into fixed-bed combustion and fluidized bed combustion and suspension combustion. Countries such as the United Kingdom, France and Italy have used large boilers for centralized treatment of straw, and the treated straw will be used for heating and drying.
6 Conclusion
At this stage, along with the drastic reduction of China's energy quantity, the state pays more attention to the development and application of biomass pellet fuel combustion equipment. Therefore, it is necessary for R&D personnel to improve the quality of research and development. Improve the performance level of combustion equipment and improve China's biomass. Fuel utilization efficiency.
references
'1' Ma Longlong. Research and Development of Biomass Energy Utilization Technology 'J'. Chemical Industry, 2007(8): 9-14.
'2' Liu Shengyong. Chen Kaiwei. Zhang Bailiang, Research and Development Status of Biomass Fuel and Combustion Equipment at Home and Abroad 'J'. Renewable Energy, 2008(4): 14-15.
'3' Yue Feng. Lei Tingzhou. Qian Weifang, Development and Utilization of Cattle Material Energy Conversion Technology in China 'J'. Energy Research and Utilization, 2000(2): 3-6.
