According to the Nordic National Waste Management Policy decree, all domestic waste must be pre-treated to be incinerated to form a solid recovery fuel, which they consider to be the separation of metals, the reduction of ash residue from incineration systems, the reduction of fouling, the use of higher parameters to effectively avoid corrosion problems, lower emission standards and improved energy conversion rates.From the technical design level, the typical project practice case level, the Nordic countries to the waste management policy and the industry standard management level and so on several aspects to comb.
一, technical design aspects
In the Nordic countries, solid waste is not only urban living garbage, but also includes agricultural and forestry biomass, industrial waste, so solid waste to be well disposed of, the fuel preparation system and waste incineration boiler is the core equipment of municipal solid waste treatment, so they carried out in-depth research and innovation, the preparation and design process of fuel and the design of the boiler are summarized as follows:
1, fuel preparation (taking BMH company as an example)
(1) pretreatment process composition
Mixed solid domestic waste-----pre-treatment (using screening process)-----sieve into the SRF line-----sieve (organic ingredients)-----into the organic component of the biological drying system (after the dry garbage into the SRF production line or production of biogas, fertilizer, compost can be). Dry garbage or other waste such as commercial waste, industrial waste, such as----sieve and after drying the garbage-----SRF production line, the specific process is: stepping feeder----Garbage crusher--conveyor belt--magnetic separator--non-magnetic metal eddy Current sorting machine--Wind separator—SRF The fuel conveyor belt-----into the finished product library). (2) Process characteristics: Garbage One-time crushing to the size of the ≤80mm, conducive to the separation of metals; wind selection is broken and after the metal sorting after the waste of heavy light materials, the garbage in the construction of waste, glass and other materials to separate; After multi-channel sorting, the final generation of homogeneous SRF fuel storage
, the selected metal and other recyclable materials can be used for recycling, the separation of non-recyclable inert materials for landfill treatment.
(3) Expected environmental benefits and economic benefits
3.1 Clean fuel, low CO2, Nox, CO emissions, homogeneous fuel, to promote the full combustion of fuel, to minimize the production of dioxins, slag volume and fly ash can be significantly reduced, the realization of homogeneous fuel incineration can completely improve the status of poor slag discharge, environmental protection facilities can be controlled emissions.The annual running time of boilers can be greatly improved, which can promote the improvement of equipment utilization rate and increase the efficiency of power generation by using the energy in rubbish.
3.2 The power consumption rate of the plant decreased obviously, the boiler efficiency can be greatly improved, the stability of flue gas quantity can promote the selection and optimization of flue gas system, reduce the investment of flue gas treatment system; enables highly automated operations and reduces operations and maintenance personnel.
(4) Technical process of SRF production line
The core of SRF production line lies in the application of the powerful crusher, supplemented with other sorting facilities for technology integration; In the exchange, after 2012 years, the European countries to locate the peat fossil fuel, the production of biomass waste and derived fuel is an important subject of their research, they have followed the following principles in the design phase:
4.1 If the Tyrannosaurus rex treatment Line 9905 For example, the one step, crushing to a particle size less than 80mm of fuel.
4.2 Boiler design More than 8,000 hours, two processing lines can meet the requirements, the general design of three lines, each line running an annual operation of 6,000 hours, theoretical design can be up to 8,800 hours; design, choose to leave a margin of 30%.
4.3 Make users easy to use, the use of seamless cutting technology, to achieve the required particle size, daily maintenance only through the hydraulic system button to adjust the gap of the blade.
(for example, type 9905 has 5 units set 5 buttons)
4.4 Design to take into account the characteristics of garbage, such as water, organic and inorganic substances.
4.5 The selection effect must be broken after crushing, using a strong magnetic separator, eddy current sorting machine.
4.6 with unique garbage storage equipment---silo, which is more secure than the warehouse, with explosion-proof doors on the top, regular monitoring of the temperature in the warehouse; In the action of gravity, the material is first out, mixed evenly; sampling can be more precise.
2, boiler design (take Foster Wheeler company as an example)
Foster Wheeler is a well-known Finnish boiler equipment design, one of the manufacturers, specializing in oil, gas and nuclear power plant engineering design and development, the world has more than 10,000 employees, 9 billion U.S. dollars of assets, especially in the boiler research and development and flue gas treatment in-depth research, currently in the world has 460 cases into operation.In clean energy, the core research and development of circulating fluidized bed and bubbling fluidized bed.
(1) Database construction (selection and analysis of fuel technical parameters): The most important aspect of boiler design is the need for in-depth analysis of the fuel, so foster Wheeler company to the customer needs of the boiler to provide comprehensive analysis of the fuel to form a large database, currently has stored more than 8,000 samples of data.
(2) Furnace selection and cycle rate: basically adopt medium and low ratio of incineration boiler; depending on the characteristics of the fuel to decide whether to use a circulating bed or a bubbling bed; if the fuel has a higher calorific value and sufficient fuel, a large circulating fluidized bed is considered, such as low calorific values of the fuel and various sundries (such as sludge, peat, Other biomass, etc.), consider the use of medium and small bubble beds.
Bubble bed has a good compactness, cost-effective high-quality features.
(3) Ash design: Tail flue gas heating surface using mechanical impact vibration device, vibration transmission beam using water-cooled mode, suitable for hanging heating surface, mechanical ash using program control mode, so that the entire heating surface components can be good process cleaning, maintain a good flue gas and pipeline medium heat transfer process.
(4) Structural design: The use of unique cloth wind and slag, sand and return materials, such as the maximum to achieve continuous feeding, slag smooth; The core is the use of external heat exchanger, to prevent flue gas on the heating surface of the chlorine corrosion; a plurality of Garbage inlet, to achieve uniform feeding, double flue design, reduce flue gas flow and flue gas temperature.
(5) The best choice of material and the flexibility of component assembly; the manufacturer makes an in-depth study and analysis of various problems that may exist in the use process according to the characteristics of the fuel, and makes the optimal selection for the material of the heating surface in different parts and different temperature environments. In the area of particularly prone problems, the modular design The components can be replaced in the shortest time, such as the whole group of superheater replacement only 1 days, the design service life of 6--8 years of use, materials used TB347, TB34102 and so on (Japanese Sumitomo); The application history of 35 years, such as the excitation of the dust, has been quite mature; The feeding system is designed with metering system,Screw conveyors, sub-valves, etc., more than 10 years of engineering application practice.
(6) Disposal of sludge by fluidized bed. Other waste blending is also easy to achieve, such as sludge and other fuel blending can be designed in any proportion; dry sludge and wet sludge (h20=60% or above) can be dried to water 30-40% after steam drying to moisture, and then the mixture is incinerated. No need to add any chemicals to dry sludge, small incineration generally has a thermal tar oven drying sludge.
Summary: Whether with foster Wheeler company or Outotec company, they all agree that according to the Nordic National Waste Management Policy decree, all domestic waste must be pre-treated to enter the incineration, to form a solid recovery of fuel, they believe that the separation of metals, reduce incineration system ash, reduce fouling, and can use higher parameters to effectively avoid corrosion problems, achieve lower emission standards and improve energy conversion rates.
二, typical engineering practice cases
The Nordic countries have high forest coverage, especially in Finland, where the coverage rate is more than 70%, so most incineration plants are not called waste incineration plants, but biomass power plants or energy use plants, because municipal solid waste in a incineration plant only accounted for a certain proportion of the required combustion, as well as other agroforestry or agroforestry substances to be blended But in the eastern Swedish city of Vasteras, a 1.5-hour drive from Stockholm, the capital of Vastmanland province, a veritable waste incineration plant in the estuary of Malar L. and SWAT.For example, we describe the Västerås Mylar energy plant as follows:
1. Factory Introduction
Mylar Energy plant is the largest power plant in the Nordic region, the implementation of regional heating business, started construction in 1954, 1#--3# boiler was completed in 1969 and put into production, 4# boiler production in 1973, the AA boiler in 2000 put into production; 6# boiler is to expand the boiler, 2002 put into use, Boilers that specialize in the incineration of urban recycled fuel, on a separate boiler, burn fuel (SRF) to 480,000 tonnes per year (60 tons per hour), and are imported from other European Union countries because only 11.12 million tonnes are produced annually.In the EU, the cost of landfill in the UK is € 100 per tonne, while the sale to the energy plant is € 40; project investment is € 300 million.
2. Core equipment Provider
Waste preparation equipment (Finnish BMH Company), boilers (Finnish Valmet company), Turbo generators (Germany siemens), flue gas treatment systems (France Alston), flue gas emissions are fully in line with EU standards.
3. Process Flow Municipal solid waste by transport vehicles or shipping to the pier-----car transfer to the garbage native library-----Automatic Crane-----Crusher-----Magnetic Separator (Iron metal)-----Eddy current Sorting machine (aluminum,Copper and other metals)-----Wind Sorting machine (can be automatically adjusted)------Inert material separation------light material into the waste product library-----by automatic grasping the crane into the front of the furnace feeding device------by the furnace before the garbage conveyor into the boiler incineration.
Incinerator needs 150 tons of sand as a bed to start the boiler, the boiler cold start the fuel used is oil, when the bed temperature reached 550 ℃ when the wood chip biomass fuel, when the bed temperature reached 850 ℃ input garbage (SRF), start oil and biomass outage. After a series of energy conversion, the heat generated by the boiler generates 50MW of electricity, 7.5MPA, 480 ℃ of Steam, 150MW of regional heating; flue gas purification system disposed flue gas using lime humidification activation spray, activated carbon injection and water, after the dust bag dust collector after the flue gas washing tower,
Then using flue gas condensation technology to reduce the smoke temperature of 135 ℃ to 35 ℃, to achieve 30MW of regional heating, total 180MW is the regional heating (no power generation), summer 74 ℃, Winter 120 ℃, pressure 1.6Mpa, for the surrounding residents to use.
4. Operation Management
(1) Sampling management; Factory area and domestic waste incineration plant similar to set up automatic metering system, at the same time in the pound area has sampling room and laboratory, into the factory of the vehicle sampling sampling, and marking, testing, recording, storage.
(2) Yellow, blue zoning to divide; Blue Area description is safe and no odor, dust, not harmful to the human body, and the marked yellow area is a certain harm to the human body area, need to enter the area for work protection, access to clean areas before flushing, replacement of protective equipment.
(3) Other: First, logo signage, the whole plant logo, signs very standardized and neat, and construction engineering cable, pipe laying, external insulation installation and other mutually reinforcing; followed by the whole plant every device has a listing and two-dimensional scanning code, access to the computer program can know all relevant information equipment, equipment for the point of inspection laid the foundation. Again, the factory automation level is very high, the whole factory work on duty personnel for 12 people, responsible for 6 boiler operation (pretreatment Workshop did unattended).
(4) Operation General Information:
4.1 Revenue Source: Electricity price electricity 0.1 euros/kw.
H; steam and heating; prices vary according to the user, the company, the family is different and pay the difference; purchased garbage subsidy, import 480,000 tons per year (40 euros a ton)
4.2 Slag and fly ash, the total production is 10%, the proportion of 5:5; slag is used for paving, building materials or landfill coverage; Fly ash is also a dangerous waste, and in Sweden there is no such landfill, shipped to Norway, generally cured after landfill (abandoned limestone mine).
4.3 Annual set up 2 weeks of maintenance, maintenance staff generally for the main outsourcing, business assistance; 2014 profit reached 5.5 million euros.
4.4 Analysis and judgment of the stability of fuel sources: a database analysis of the amount of solid waste produced in Europe, such as Sweden's population of 9 million, 34 plants, 24 factories in England, to save transportation costs, from the original train to shipping.
5. Sweden's principle of the emergence and disposal of municipal solid waste
(1) To call upon the people to comprehensively classify the rubbish, reduce the amount from the source,
(2) make the sorting and reuse through the modernized mechanical device of each link,
(3) The selected material can be recycled, and
(4) make the recycled energy fuel as energy or other forms of use.
(5) Terminal processing.
Summary: The SRF as the main fuel incineration or gasification of the project positioning Energy plant, high standards of construction, the use of the world's most advanced equipment and industry, coupled with lean production management system, to create an intelligent factory and efficient energy utilization plant, to run continuous stability, clean emissions, energy conversion rate to achieve the best environmental protection power plant
As a model for the Nordic countries and the European Union as a whole
三, solid waste policy and industry norm system construction
The Finnish National Technology Center (VTT) is an important base for scientific and technological innovation in the country, comprising 18 domestic top enterprises and 11 state-level universities and research institutes, which aims at joint research on natural resources, environment, basic application studies, pilot research, clean and sustainable development,is a non-profit organization composed of 1/3 joint investments by the government, EU agencies and enterprises.
We know in the Finnish National Technology Center (VTT) that they believe that bio-economy is an important part of the circular economy, their responsibility is value chain innovation, help enterprises to profit, leading the preparation of national standards, industry norms and even participate in the EU standards and norms system, so in the simulation, industry updates, A great deal of work has been done to increase value added.
VTT's experts briefed us on the EU standards for solid waste management, definition and analysis of SRF, fuel and flue gas detection, and the application of the CFB combustion SRF, as follows:
European waste legislation based on the principle of waste management
(1) EU waste framework directive: 2008/98/EC Defining Basic Principles
1.1 Waste disposal shall not endanger human health or the environment
1.2 choice of treatment method must be priority
1.3 waste processor Responsibility
1.4 polluter pays system
(2) Enforcement of national legislation requiring the provision of waste utilization
2.1 May 2012, released the latest Finnish waste disposal law
2.2 reduce landfill disposal, improve source classification, recovery.
2.3 Recycling target: Garbage 70% (2020), MSW 50% (2016); the paper, metal, Plastic, glass 50% (2016)
2.4 of domestic waste is forbidden to landfill organic waste, and the landfill of MSW will be disposed of in practice.
2.5 Landfill Tax 2011 for 40 euros per ton, 2015 € 55 per ton.
(3) Decree clarifying the responsibilities of all parties in the solid waste management process
3.1 Government agencies are responsible for the garbage (urban waste) generated by household waste and public services.
3.2 Enterprises responsible for their own production of garbage (30-40% of total MSW)
3.3 The processor is responsible for the following types of waste collection and recycling, such as waste tires, recycled paper, scrap cars, electronic and electrical equipment, packaging waste, batteries and so on.
3.4 Main Collection System: Specify the collection point of the feature items, local collection points (e.g. near supermarkets, etc.).
2, standards (related to the SRF system)
Solid recovered fuel: a solid fuel that survives from non-hazardous waste species for energy recovery and reuse in incineration plants or combustion facilities, which must meet the grading and specification requirements set in the EN15359 standard.
The term SRF is only used in conditions that meet the standard EN15359 settings; SRF is not equivalent to RDF (garbage derived fuel refuse derived fuel)
(2) SRF standardization process
In the 1890s, several implementation guidelines for the recovery of fuel were carried out, and in 2002, CEN (M/325) was authorized to standardize the SRF, establish technical specifications (TS), and convert technical specifications to European standards (EN); March 13, 2002, establishment of the CEN/TS 343 Working Group The Finnish Standardization Association set up a working group, comprising 27 mandatory terms of work, assigned to 5 working groups, the publication of technical reports starting in 2004, the completion and publication of technical reports in 2010, 2011 and 2012, the publication of technical specifications for the European version; February 2012, m/325 Implement authorization.
(3) standardization and objectives of SRF
(4) Benefit analysis
Solid recovery fuel: standardized high-quality fuel, high calorific value and biomass content, reduce carbon emissions, meet environmental requirements, provide efficient waste management solutions to help meet the target of reducing landfill, reduce dependence on limited and imported fossil fuels.
Standardization: Strengthening understanding-----SRF is fuel, providing tools----quality consistency and quantification attributes, improving the business environment, example of garbage management.
(5) Objectives of the EN15359 standard
The European Standard (EN) is committed to facilitating the efficient trading of SRF, enhancing the acceptability of the fuel market to SRF, increasing the credibility of this standard, which will facilitate a good understanding between the buyers and sellers, facilitate the purchase, cross-border transactions, use and management, and communicate with the equipment manufacturers; licensing.
(6) SRF grading system
EN15359 is the core standard of SRF standardization, which is based on three main parameters:
6.1 Economic parameters: low calorific value of fuel
6.2 Technical Data: chlorine content in waste
6.3 Environmental parameters: Mercury content in waste
The selected parameters will be described in a straightforward and straightforward manner, showing the SRF quality and values in the negotiations to stakeholders.
6.4 Mandatory instructions also stipulate other ancillary regulations, such as source, particle form, particle size, net calorific value, ash content, water content, chlorine content, heavy metals, etc., each project has a guiding guideline,
3, the National Technical center of CRF in CFB incinerator combustion research
(1) High integration of production, study and research
With the efficient use of SRF fuel for clean use, Finland has two major research bases, located in the middle and south, in the middle of the study of fluidized bed combustion technology, and in the south responsible for gasification technology; the fluidized bed platform is comprised of more than 100 technical experts; they are ready for the technology to realize:
3.1 The difference between the various processes mainly depends on the temperature grade and the gas environment.
3.2 Process integration, industry close cooperation and excellent and powerful experimental capability.
(2) Emission standards strictly enforced 2000/76/EC
(3) Capacity building of emission measurement, and cooperation with relevant international agencies.
(4) In-depth study of fluidized-bed combustion waste, such as combustion, emissions, fly ash, lime, coking, corrosion, ash, combustion imbalance, combined with engineering practice, a variety of environmental simulation simulation test.
Summary: In accordance with EU and Finnish laws, untreated municipal domestic waste cannot be filled, "who generates, who is responsible for" the principle of taxation; the definition of SRF is fuel, not garbage, the basis of quantitative attributes, the solid recovery of fuel, the improvement of the commercial environment to provide demonstrations, the formulation of fuel specifications, set the grade, and the application of industrialization In addition, our waste management company in Lahti also learned that the landfill is not recyclable waste, the current landfill has been closed many, waste management companies also with a number of partners to carry out recycling work, these venues as students study in one of the practice, and the introduction of the next 5-10
Waste management program to achieve a high level.
Through the study of Nordic countries, personal understanding of the management and rational disposal of municipal waste is a huge system engineering, needs the government, enterprises and scientific research institutes coordination and support, while the strong innovative ability of high-quality equipment manufacturers is to support the recycling of waste, energy clean transformation of one of the key, summarized as follows:
1. Management policy and industry standard level
(1) Call on the government departments to break the single line management mode, to achieve cross-border cooperation, such as the agricultural sector, the forestry sector, urban sanitation sector and other relevant competent institutions of the powerful combination of people in the production, living process, as well as agriculture and forestry, biomass and other waste produced by the unified and coordinated management.
(2) According to the different kinds of waste, learn from the experience of foreign countries, formulate and promulgate the SRF standards in line with Chinese characteristics, comprehensively promote the use of resources, promote the construction of a conservation-minded, environmentally friendly society.
(3) In the investment, construction, operation mode, in addition to bot, BOO, BT and other models, whether or not to consider the practice of promoting the PPP model.
(4) The regulation of waste management, to be bound by law, to improve the rate of charge of waste producers, and improve the reasonable disposal of the processor profit space.For example, in the UK: All incineration plants need to be pre-treated for incineration or gasification to generate electricity; The Netherlands, as an emerging country, is also maximizing waste disposal after incineration.
(5) Actively encourage the national source classification, resource recovery, renewable resources can not be wasted, into the cycle system.
2, scientific research institutions and waste treatment providers (operating enterprises) level
(1) In a good environment driven by the national policy level, universities, research institutes and running enterprises, equipment manufacturers work closely together, the production, learning, research and powerful combination is very necessary, because engineering practice needs the support of science and technology.
(2) Multi-team composition research institutions must have the spirit of innovation, the establishment of a strong information database and a variety of test equipment, for the follow-up engineering practice to provide scientific design and operational basis.
(3) Vigorously develop distributed energy, cogeneration projects, industrial waste, agricultural waste, biomass, municipal solid waste and other collaborative treatment is a good urban and urban waste solutions; Individual fuel designs can also be designed for multiple fuels.
(4) Investors should focus on the world's most advanced technology and equipment, in order to achieve efficient energy use and conversion rate and high-quality parameters (high temperature and pressure), so to achieve high parameters, high standards, energy efficiency, it must be efficient preparation and incineration system, clean emission of flue gas purification system, efficient steam turbine power system, etc.Requires full integration of equipment.
(5) Learn from foreign equipment and production technology, especially material selection and processing technology, the development of state-owned equipment technology, the establishment of engineering equipment demonstration base, so equipment manufacturers also need to improve in metallurgical manufacturing, mechanical design and processing, in order to better serve the environment industry.