April 20, 2018

In the previous material, we described in detail the process of creating wood pellets. It is natural that the next step in this chain should be the equipment for which these products are manufactured - biofuel boiler plants. Our partners - specialists from the Kovrov Boilers company - shared their experience and talked about the choice of such equipment, taking into account current offers on the market.

Power and number of boilers

The starting point when choosing any boiler house is to determine the power and its distribution among the boilers. At first glance, nothing complicated: calculate from the table, estimate your volume of heated premises and/or add the volume of drying chambers with a coefficient and get the result. However, there are several very important nuances in this matter.
When choosing equipment, you should pay attention to the minimum power of an automated solid fuel boiler. As a rule, it ranges from 30% (for modern models) up to 70% (for the oldest boilers). Therefore, if the adjustment range is small, the consumer may find himself in an unpleasant situation: when it gets warmer outside, it will no longer be possible to reduce the heat supply. In this regard, it makes sense to split the power into two boilers: in this option it will be easier to work during the demi-season periods with a 100% reserve in case of a complete shutdown. In this way, it will be possible to insure against future breakdowns and equipment downtime - especially in winter. True, this solution also has disadvantages. Two boilers are often more expensive and take up more space. In addition, it is more expensive to maintain two machines than one, because you have to work with twice as many big amount engines, sensors and other components that will require the necessary service. Therefore, the choice is always up to the consumer.

Boiler types

The second thing you should pay attention to is the type of design of the boiler itself. The age-old question: water tube or fire tube/smoke tube? The fundamental difference between the two heat transfer schemes lies in the design of the heat exchange part, where the biomass combustion products transfer their energy to the coolant (water, for example). The fire-tube-smoke version is, in fact, a barrel of water; it is pierced with pipes, inside of which a hot flow of gases from combustion moves. The water-tube design is the opposite version: water flows inside the tube, and heat heats it from the outside.
It would seem, what's the difference? Actually, it's big. As a result of burning wood, soot particles remain in the flue gases, which, if the draft is not adjusted correctly, can stick to the walls of these pipes. There is no way to protect yourself from this. These deposits require mechanical cleaning with a brush (non-contact solutions are possible). Cleaning a round pipe inside in a fire-tube/smoke boiler or the same round pipe, moreover, wound into completely indirect screens, outside in a water-tube boiler are two different things. The “don’t clean it at all” option should be discarded immediately, since in this case, after six months, or even earlier, heat transfer will decrease by an average of 60-70% and the boiler power will drop at least several times.
Another big disadvantage of water tube boilers is the limitation of the minimum flow rate of the coolant inside the tube through which the water flows. If it is not provided with a powerful pump or the power supply suddenly stops (the pump breaks, the impeller wears out, the filter gets clogged, etc.), then the water tube boiler will immediately leak. To heat a barrel of water containing several “cubes” (in a fire tube boiler), and locally a tube containing only a few hundred grams of water, to the critical destruction temperature, you will need different time This means different response times for staff.
Next, you need to understand that the water pipe system is less metal intensive, which means it is much cheaper to produce. Even if you compare the dry mass of boilers, the difference will be significantly different. The production of water tube boilers is cheaper than fire tube boilers. But at the same time, you will have to spend a lot of money on pumps for water tubes. They should be more productive along the flow.

Flue gas cleaning

A nuance that should be addressed is the cleaning of flue gases. The same ones that were discussed above, and in which, in any case, soot is present to one degree or another. Some boiler manufacturers offer equipment without a cleaning cyclone and a smoke exhauster. But this is a road to nowhere. You won’t be able to save money here, and the boiler’s operation will ultimately be incorrect, and the situation may end in a fire. You can often hear: “I am not interested in emissions and black smoke from the chimney!”, “Who will come to me here? I can’t be seen, and I’m on the outskirts!” or “I work in the village!” No, it won't work that way. Agree, when the snow around the boiler room turns black, this is the first bell to prick up your ears. If the owner is not concerned about nature, then he should definitely be concerned about the danger of losing production during a fire. After all, one such black particle that fell on the snow in winter can fly back in the summer, still unburned.

Automation system

The next point that requires more in-depth attention from the buyer is the automation system. Manufacturers can write “in automatic mode...”, but in reality everything turns out to be different from what the customer imagines. It is always necessary to clarify what exactly is meant by the term “automation system”. What exactly works in automatic mode, and what the operator will have to tighten on the spot.
It is worth explaining that the issue here is the correct organization of biofuel combustion, or more precisely, the correct mixture formation in the combustion device. Let's figure out what it is. For proper combustion it is necessary to observe exact proportion fuel and oxygen to achieve the required coolant temperature, just like in a car engine. If there is too little oxygen, incomplete combustion will occur and black smoke will come out of the chimney (carbon has not been fully oxidized). The danger is that this process may end now outside the boiler room, which will lead to a fire. If there is too much oxygen, harmful gases called NOx will be formed, and environmentalists will not miss this chance to punish the owner of this equipment. So it turns out that every stove maker can build a stove, but not everyone can manage the combustion process.
From the experience of communicating with the owners of boiler plants, we can conclude that many by automation understand the mechanization of fuel supply, and oxygen is regulated by eye. Not everyone knows what a gas analyzer and oxygen control are, and, most importantly, what the consequences of incorrect settings are.
The operation of any equipment, including a biofuel boiler, involves many subtleties, knowledge of which comes with experience working with such systems. Therefore, when choosing such units, it is best to seek the help of specialists.

Currently, the problem of finding energy sources other than traditional ones is becoming more acute. Supplies of traditional energy resources are finite and expensive, so preference is increasingly being given to renewable energy sources. Humanity is already using the potential of water, wind, and the sun, but also one of the renewable sources of fuel are the waste products of humanity itself.

Turbopar specialists have been successfully dealing with the problems of recycling waste from poultry farming, livestock farming and agriculture in general for more than 6 years.

1. Types of biofuels.

Biofuel refers to fuel produced by processing animal or plant by-products (biomass). This includes wood (chips), straw, oil cakes, oilseed husks, and waste products of domestic animals and humans. And this source of energy resources will exist as long as man and our planet exist.
Different types of biofuels have different energy potential and, accordingly, require different approach to extract this potential.

2.Methods of using biofuels(preparation for use in the boiler room for subsequent supply to boilers).

There are various technologies for using biofuel and preparing the final product from it for feeding into the boiler furnace. And the selection of a specific technology for a specific type of biofuel depends on the Customer’s conditions. Previously, we discussed the use of wood chips; in this section we will highlight the issues of recycling other types of biofuel, as well as biowaste.

Depending on the moisture content of the source fuel, its properties and origin, technologies such as direct combustion, gasification, or biogas production are distinguished. So, when the humidity of the initial fuel is more than 50%, as a rule, it is more expedient to use the technology for producing biogas; when the humidity is less than 50%, methods of direct fuel combustion or fuel gasification.
Let's dwell on general description each of the above methods.

Method for producing biogas. The essence of this method is as follows: biofuel (biomass) is loaded into bioreactors, where the fermentation process occurs, during which methane bacteria produce the actual primary biogas. The requirements for this technology are very high; any violation of the technology or temperature
presses can lead to the death of bacteria, and, accordingly, to stopping the bioreactor to clean it.

The disadvantages of this method are both additional costs for increasing the humidity of the initial biofuel (depending on the time of year up to 92-94%) and heating the added water (if the technology is used in regions with cold periods of the year), and a rather long time for preparing the fuel itself - biogas . It should also be taken into account that with this technology the total mass of the feedstock is reduced by 3-5%, i.e. As a method, including waste disposal, this technology is of little use (although the product after fermentation in some cases can be used as a fertilizer). However, at the same time, it is worth noting such undoubted advantages of this technology as:
- high calorie content of the resulting fuel (according to its characteristics, biogas is closest to natural gas),
- use of the obtained biogas for various needs, including the production of biofuel for cars,
- significant savings on the energy production process if the moisture content of the initial fuel is high (from 65%).

What makes this technology special is the utilization of chicken manure from laying hens, the humidity of which can reach 90% or more. This is primarily due to high content nitrogen in this type of fuel, which, when using this technology, leads to the formation of a large amount of nitrogenous water, which requires expensive disposal solutions.

Gasification method. The method is based on obtaining generator gas. This technology is used with fuel humidity up to 50% (even if manufacturers of such equipment declare the humidity higher, we must take into account that they are not deceiving, they are simply talking about the humidity of the original fuel. A briquette with a maximum humidity of 50% enters the gasifier).
This technology requires briquetting, in contrast to technology based on biogas (with biogas technology, you can limit yourself to a fuel receiving and mixing area, after which the resulting primary mass is loaded into a bioreactor). Thus, in the process, additional electrical costs appear for this unit. It should also be noted that the requirements for the ash content of the initial fuel, which should not exceed 40% (the maximum achievable value in experiments to date is 45% ash content). This requirement is due to the fact that these technologies are based on combustion with a limited air supply. Fuel with high ash content will not burn stable. In addition, significant costs will be required to maintain this process. We also note that the resulting gas has lower quality characteristics in comparison with biogas (so the calorie content and calorific value of the generator gas can be 3-5 times lower than biogas). In addition, if the resulting gas is planned to be supplied to the gas compressor, then an additional system for purifying the gas from combustion products, as well as a cooling chamber, is required. It should also be taken into account that at present this technology is mainly developed at an experimental level, at least in the CIS countries, and there are strong restrictions on the possible amount of biomass processed.

These technologies also have their own unique advantages compared to other methods. One of the main advantages of this technology is that it is applicable to almost any type of fuel. Using this technology, generator or pyrolysis gas can be obtained not only from biomass, but also from solid waste (solid waste), petroleum products (plastics, polyethylene, etc.). This technology is the most stable and controllable. The final product (generator gas) is stable in composition. By investment this option comparable to the direct combustion method. There is a significant recycling of waste, which also provides an undoubted advantage of this technology, as well as the fact that the combustion products of this technology are (when recycling biomass) high-quality fertilizers. Note that the time spent on obtaining the final product in the form of generator gas is significantly lower than with the biogas method (with biogas, the time for obtaining biogas, depending on the type of initial biofuel used, can reach up to 12-14 days), and depends on the power of the briquetter, the time for drying and time for gasification. Finally, we note that when this method There are also no harmful emissions into the atmosphere.
The resulting generator gas is fed into standard gas boilers (steam or hot water), but with burners converted for generator gas.

Direct combustion method. As the name implies, the essence of the method is the direct combustion of biofuels. With this method key value It does not even have boiler equipment, but a fuel preparation method, although there is a connection between fuel preparation and the planned combustion method (chain grate, vortex, fluidized bed, etc.).
This technology requires low fuel moisture (45% and below), just as the previous method is sensitive to the ash content of primary biomass. In addition, depending on the type of fuel, the composition of the equipment itself can change, and radically, as an example, from briquetters to crushers. Also, do not forget that in classic version This technology, when burned, has the problem of flue gas emissions, sometimes with temperatures up to 250 0C, which naturally does not contribute to the environmental situation around the mini-CHP complex. At the same time, the system requires quite expensive filtration systems to reduce emissions of harmful substances into the atmosphere.
This technology is the most mature, although modern world Using this technology, they are trying to utilize more and more types of biofuels. The technology is in demand when converting a boiler house into a mini-CHP to local fuels, which can significantly reduce initial capital investments (you must understand that we are talking about solid fuel boilers).
The question may arise, what method is applicable when the humidity of the initial biomass is 50-65%? And a definite answer will not be given, since this is the boundary value at which everything will be shown by economic calculations and comparison of technologies.

TURBOPAR specialists perform:

1. Analysis of existing fuel.

2. Selecting the most efficient fuel combustion.

3. Recycling effect.
What are the benefits of using biofuels?
Of course, the most important effect of using this fuel is significant savings in money.
But it is also important that, unlike classical types of energy resources (such as coal, gas, fuel oil), biofuels are renewable. We will not run out of this type of fuel. Sooner or later, humanity will be forced to obtain energy using renewable fuel sources.

It should be noted that biofuel is often waste, the disposal of which is quite expensive, and what to hide, this waste is harmful to the environment. Thus, when using biofuel, in addition to saving on electrical and thermal energy due to its own generation, there are significant savings on waste disposal, including agricultural waste, savings on areas previously allocated for storing waste before sending it for disposal, and maintaining the environment ( saving at least on environmental fines).

So, let’s summarize and highlight the advantages of using biofuel:
1. Biofuels are renewable.
2. The cost of biofuel is significantly lower than the cost of classical fuel.
3. Based on point 2, the cost of received thermal and electrical energy is significantly lower.
4. Various wastes can be considered as fuel sources, such as straw, oilseed husks, sugar processing waste (bagasse, tops), manure/litter and many other wastes of animal and plant origin.
5. The end product of biofuel boiler houses and mini-CHPs is not only thermal and electrical energy. Very often, the waste from boiler houses and mini-CHPs using biofuel can be used in the future (fertilizers, by-products in the form of chemical compounds, construction industry, etc.).
6. Improving the environmental situation.
7. Savings, and very often significant ones, on waste disposal, such as manure/litter, oilseed husks, etc.

Description of the biofuel boiler room.

This section provides a description of several boiler houses, taking into account the method of preparing the final fuel.

Biogas boiler room.

As noted above, the basis is the preparation of biogas and its subsequent use.
The enlarged composition of the equipment of such a boiler house: fuel receiving area, biofuel mixing equipment, bioreactors, fuel supply system to bioreactors, biogas purification systems (if required). Further, depending on the purpose of the boiler room, you can install a classic gas boiler (hot water or steam). If necessary, production electrical energy in addition to thermal, it is possible to install either a gas compressor or gas turbine, or a steam turbine. A waste heat boiler is installed after the gas turbine.
Such a boiler house can be installed, including near treatment facilities, for the disposal of sludge accumulations.

Boiler room using generator gas.

The enlarged composition of such a boiler house: a site for receiving the initial fuel, mixing equipment, drying equipment, briquetters, a gas generator unit. The resulting generator gas is then sent either to a gas boiler (hot water or steam) with burners adapted for this gas, or to a gas compressor (in the case of a gas compressor, a generator gas purification system is required). Implemented on this moment in the CIS countries there are projects only based on the production of pyrolysis during the processing of wood chips.

Boiler room using direct combustion.

The composition of a given boiler room may vary depending on the type of biofuel planned for combustion.
So, for example, when recycling oilseed husks, the enlarged equipment may consist of: a biofuel receiving platform, fuel conveyors, fuel dispenser bunkers and the boilers themselves (hot water or steam). If it is necessary to mix several types of husks or add other types of plant waste to the husks, mixing, drying and briquetting equipment is installed.
The following is an example of the work of Turbosteam, the development of a pre-design study for the utilization of chicken manure in Ukraine in 2010.

How to choose the disposal of chicken manure. Brief description of the project.

The customer was given the following task: a large poultry farm needed to dispose of up to 200 tons of litter per day, generating thermal and electrical energy. The mini-CHP operates 24 hours a day and all year round.
There are no similar projects in the CIS countries. The bottleneck in this project is the processing of the initial biomass (litter manure), since its moisture content varies depending on the time of year. The type of fuel itself obtained from this biomass has an average calorific value and contains many harmful substances. Various options for preparing fuel for subsequent supply to the boiler were considered - from direct supply to the furnace to the pulverized combustion method (conversion of the original fuel into fine dust, which has higher combustion properties, with the subsequent supply of this pulverized fuel to special furnaces in boilers). As a result, the following version was tentatively adopted:
- a primary fuel storage facility is installed with a fuel reserve for 7 days of continuous operation of the thermal power plant,
- after this, mixing equipment with other types of biofuel is installed,
- drying equipment,
- grinding to the required particle sizes
- and supply to dosing bunkers in front of the boilers.
Next, the feed is carried out from the dosing hoppers directly into the steam boilers.
After the boilers, one or two steam turbines condensing type with adjustable steam output. Steam from the extractions is sent for the own needs of the boiler house (to the fuel drying area) and the poultry complex.
Electrical energy is used for the poultry plant's own needs. The remainder of unused electrical energy is transferred to the national electrical network.
Also, this mini-CHP, in addition to electrical and thermal energy, will produce high-quality fertilizer (ash is a product of biomass combustion) as a by-product, which will be used either for its own needs or sold on the fertilizer market (a fertilizer packaging area is provided).
Methods for recycling flue gases from mini-CHPs and detailed description equipment systems. Let’s just say that when implementing the project, the enterprise will generate about 144 MW of electrical energy per day and the same amount of heat. The payback period for this project, taking into account all investments, will be three years. The architectural part of the project is being carried out Disposal of chicken manure.

steam boilers, hot water boilers, design treatment facilities

Automated biofuel boiler houses

A biofuel boiler house is designed to produce thermal energy by burning biofuel and transferring it to the consumer through a heated coolant for the purpose of heating residential and industrial buildings, as well as technological premises with a coolant temperature of 95–115 o C. The boiler house complex represents a logical system of interrelations for the provision and delivery of biofuel to the building of the boiler house itself, storage and supply of biofuel, its combustion and production of thermal energy.

Biofuel boiler room, basic composition of equipment:

To ensure manufacturability, reduce the volume of installation work, increase the level of maintainability and ease of maintenance, the boiler room equipment is grouped into modules:

Biofuel boiler room, main modules:

1 - receiving and unloading module for receiving biofuel from dump trucks and unloading onto a reloading conveyor; 2 - storage and unloading module for accumulating the required volume of fuel, providing uninterrupted operation boiler room with rated power for 4-5 days, and dosed unloading of biofuel onto conveyors that supply fuel to the boiler furnace; 3 - hot water boilers operating on biofuel and providing the production of thermal energy in the form of water heated to 95-105 o C; 4 - monitoring and automated control system, providing ongoing monitoring and regulation of boiler room parameters: vacuum in the combustion chamber of the boiler; proper quality of fuel combustion; heating capacity of boilers.

Biofuel boiler room. Functional diagram.

The main equipment of the boiler room (mechanized fuel warehouse, fuel supply means - scraper and screw conveyors, biofuel hot water boilers) is located in a prefabricated, non-insulated hangar-type building. Additional boiler room equipment (pumping and distribution stations, monitoring and automatic control equipment, water treatment system, membrane and expansion tanks, shut-off and control valves and other heating components and assemblies) are located in separate heated rooms in the operator and engine rooms.

Renewables are used as biofuels energetic resources, such as peat (lumpy and milled), sawmill waste (bark, chips, sawdust). The fuel fraction is limited to dimensions of 50x50x5 mm. Fuel is prepared by fractionation using rotary crushers or hammer crushers.

The biofuel boiler is capable of using wood waste with high relative humidity without pre-drying. Fuel moisture content can reach 55%.

Boiler room piping.

Recommendations for the design of boiler and fuel storage buildings

Biofuel boiler houses are divided into:

Heating - to provide heat to heating, ventilation and hot water supply systems;
heating and industrial - to provide heat for heating, ventilation, hot water supply and process heat supply systems;
production - for process heat supply.

Biofuel boiler housesaccording to placement they are divided into:

Freestanding;
attached to buildings for other purposes;
built into buildings for other purposes;
roof (only for gas and liquid fuel boiler houses).

For industrial buildings industrial enterprises It is allowed to design attached, built-in boiler rooms. For boiler houses attached to buildings for the specified purpose, the total productivity of the installed boilers, the unit productivity of each boiler and the coolant parameters are not standardized. In this case, boiler rooms must be located near the walls, where the horizontal distance from the boiler room wall to the nearest opening must be at least 2 m. The vertical distance from the boiler room ceiling to the zero point is at least 8 m. It is not allowed to design attached boiler rooms directly adjacent to residential buildings with sides of entrance entrances and sections of walls with window openings, where the horizontal distance from the external wall of the boiler room to the nearest residential window is less than 4 meters, and the vertical distance from the boiler room ceiling to the nearest window is less than 8 meters. General thermal power an individual boiler room should not be a multiple of the heat requirements of the building or structure for which it is intended to supply heat.

The process flow diagram and equipment layout of a biofuel boiler house must ensure:
optimal mechanization and automation of technological processes, safe and convenient maintenance of equipment;
installation of equipment in turns; shortest length of communications; optimal conditions for mechanization of repair work;
the possibility of entry into the boiler room of outdoor vehicles (forklifts, electric vehicles) for transporting equipment units and pipelines during both repair and installation work.

Land plots for the construction of biofuel boiler houses are selected in accordance with the heat supply scheme, planning and development projects for cities, towns and rural areas settlements, master plans of enterprises, master plans of groups of enterprises with common facilities (industrial hubs).
The dimensions of land plots for biofuel boiler houses located in residential areas should be taken in accordance with building codes and regulations for the planning and development of cities, towns and rural settlements. When designing a master plan for a boiler house, it is necessary to provide for the possibility of placing enlarged assembly sites, warehouses, as well as temporary structures necessary for the period of construction and installation work.
The fencing of boiler rooms should be designed in accordance with the Guidelines for the design of fencing of sites and areas of enterprises, buildings and structures.
When designing buildings and structures of boiler houses, one should be guided by building codes and rules for the design of industrial buildings, administrative and domestic buildings, and structures of industrial enterprises.
The span dimensions of boiler house buildings and structures should be taken as multiples of 6 m. The column spacing should be 6 m. With special justification, the column spacing may be 12 m. Boiler house buildings must be designed with spans in the same direction. Layout solutions with spans different directions are allowed in conditions of a cramped construction site when designing the reconstruction of boiler houses. Space-planning and design solutions of buildings and structures of boiler houses may allow for the possibility of their expansion. To ensure the possibility of large-block installation of equipment in the walls and ceilings of boiler house buildings, installation openings must be provided in accordance with the recommendations of installation organizations. Such openings, as a rule, should be provided in the end wall on the expansion side of the boiler room.

Built-in biofuel boiler rooms must be separated from adjacent rooms by type 2 fire walls or type 1 fire partitions and type 3 fire ceilings. Attached boiler rooms must be separated from the main building by a type 2 fire wall. In this case, the wall of the building to which the boiler room is attached must have a fire resistance limit of at least 0.75 hours, and the ceiling of the boiler room must be made of non-combustible materials. Exits from built-in and attached boiler rooms should be provided directly to the outside. Window sashes above this level should be designed with single glazing. The area and placement of window openings in external walls should be determined based on natural light conditions, as well as taking into account the requirements for aeration to ensure required area opening openings. The area of ​​window openings should be minimal. The coefficient of natural illumination with side lighting in buildings and structures of boiler houses should be taken equal to 0.5, except for the turbine room, rooms with automation panels and repair shops, for which this coefficient is taken equal to 1.5.

Biofuel boilers of the KTU series with a power from 300 to 1000 kW can be installed without a special foundation or on reinforced monolithic concrete slabs with a thickness of at least 200 mm. Biofuel boilers of the KTU series with a power from 1500 to 2500 kW are installed on a special foundation, the design of which is sent by the manufacturer.

Also "TEPLORESURS" produces

Increased demand for heating equipment designed for burning brown coal, wood, peat, as well as waste that produces thermal energy, is associated with a constant increase in tariffs for electricity and gas. Briquettes and pellets are made from the remains of agricultural and wood processing enterprises.

Not all organizations and owners of private houses can afford to install gas in the current conditions. This is due to large material costs. In addition, it will take a lot of time to obtain permission, prepare the project, and directly connect the system.

Consumers are looking for alternative options, exploring the possibility of heating residential and industrial spaces with affordable materials. It could be coal, the advantages of using which are obvious: it burns for a long time and produces a large amount of heat. But it is worth paying attention to biofuels.

Types of available biofuels

Anyone can prepare material for the winter that will be used to heat the premises:

• non-business logs from logging and wood processing enterprises;
• various wood waste: branches, twigs, tops, stripped bark after machine processing of trunks, blanks that were considered defective, boards with defects, remains of carpentry work, slabs;
• fragments of trunks that were not used, parts of fallen trees. As well as roots, stumps, shoots and shrubs that need to be pruned and cut down. For example, near power lines, communications, pipelines, along highways;
• dried plants in whole or in part: sunflower stems, reeds, potato tops, straw;
• peat briquettes;
• pellets made from compressed wood and plant waste.

Different heating materials differ in energy efficiency. To determine which of them will generate more heat, you should study their composition.

Let's compare productivity

Any materials that relate to biofuels include:

• water;
• resin;
• flammable substance.

The percentage of components determines its properties and ability to release a certain amount of heat. This is how the materials differ from each other. Moisture content may vary depending on storage and processing methods. The percentage of moisture may be too high if the biofuel is difficult to dry. This will affect the flammable properties of the material.

The humidity of tree trunks after felling can be 60%. To dry it, it is kept for two or even three months in the open air. If the weather is sunny, without precipitation, and even with a slight wind, then the logging humidity will be 40–45%. Artificial drying in production areas or warehouses allows achieving a moisture content of 15–20%. If we compare peat with other types of biofuels (wood, plant residues), we can note an increased content of ash and sulfur compounds, which emit an unpleasant odor when burned.

Liquid fuel boilers

If we compare equipment running on diesel fuel and solid biofuel, we can note that the range of both options is quite wide. Finding suppliers of units of any kind is not a problem for an interested buyer. In addition, both Russian and foreign manufacturers are represented on the market. Boilers can be purchased at any power and thus heated large areas. If the performance of one boiler is not enough, you can arrange a boiler room from several simultaneously operating units.

Users raise questions about the storage system and automated fuel supply. This has long ceased to be a problem. Transfer schemes from silos have been developed that conserve both diesel and biofuel in boilers that burn continuously. The process is mechanized and automated and does not require frequent monitoring or constant presence of an operator. The cost of a system for supplying solid biofuels is more expensive than for boiler houses using gas or liquid fuel. It is easy to determine whether it will be profitable to install it.

Operating costs

Comparing the energy efficiency of two boiler houses of the same power, equal to 2 MW, one of which will be heated by diesel, and the second - solid fuel, you need to calculate the cost of fuel:

1. The diesel boiler consumes 180 l/hour, so the consumption per season will be 450,000 liters. Taking into account the cost of diesel fuel, expenses will amount to 13.5 million rubles. The boiler also consumes electricity to operate the burner. Cost for 6 months of the heating period at a price of 5 rubles. per kW/h - 100,000 rub. Total amount: RUB 13,600,000.
2. If you use wood chips as fuel, then with a consumption of about 4 m 3 / hour per season, the costs will be 3,850,000 rubles.
3. Pellets and briquettes will cost more. Consumption - 430 kg per hour at a price of 6 rubles. per kg, heating will cost 6,450,000 rubles. per season. You need to add the cost of electricity consumed by the burner. Its power is 15 kW, so you will have to pay another 375,000 rubles.

You can calculate how much you need to pay for gas for a given power consumption. The gas consumption of the boiler is 240 m 3 /hour. Let's take the average fuel tariff - 5 rubles / m 3. Then the total cost of heating for a period of 6 months will be 300,000 rubles.

Draw your own conclusions.

Capital construction costs

Gasification of the facility will cost at least 5 million rubles - this is official data, which includes the cost of project development and connection. In reality, everything looks different. Unforeseen expenses have to be paid; the amount spent usually doubles by the time the work is completed. We can give an example when the estimated amount for a gasification project for a facility (technical data: boiler house with a load of 1.5 MW) in the Moscow region amounted to 82 million rubles. The owner refused to sell.

The cost of equipment for gas and diesel boiler houses is approximately the same. But please note that a fuel storage bunker is required. Its price is approximately 1 million rubles.

Solid fuel units, burners and bunkers will cost much more than the two previous options. However, the cost of biofuel will quickly cover all costs. Therefore, at the moment it is most profitable to equip a boiler room operating on this material. It should be noted that the combustion of biofuel is the most environmentally friendly, it pollutes less environment. There will be no coal dust or foreign odors in the room, which are usually present when using diesel fuel.

Wood waste boiler thermal performance

5.5 MW (4.7 Gcal/h),

intended for burning wood waste (bark, sawdust, wood chips)
with absolute humidity up to 110% .

This is a completely Russian solution and only uses domestic equipment. If you have a standard boiler room running on fuel oil, diesel fuel or gas, with boilers DKVR, KE, DE, etc. and you decide to build a new biofuel boiler house, then do not rush to take the step, because the service life of the boilers themselves is very significant, and during normal operation, the operation of the boiler can be extended by 10-15 years.

There are two modernization options: build a completely new boiler house, or convert an existing boiler house to use biofuel with the installation of a biofuel pre-furnace. Wood processing waste can be used as fuel: wood chips, sawdust, chipped veneer, slab, pulpwood, firewood, bark, etc. The use of biofuel can significantly reduce the cost of coolant production and significantly improve the environmental situation, because wood waste is considered an environmentally friendly type of fuel.

The main element of the boiler plant being modernized is the furnace with a loading device and a raw material dosing system. This firebox was developed on the basis of the TGU FT thermal heat generating unit, popular in Russia, and is available in modifications with capacities from 1.0 to 9.0 MW.

When ordering a biofuel boiler kit, the customer receives the following kit:

v boiler block (with fittings and GUV, complete with economizer, ash collector and smoke exhauster),

v pre-furnace heat generator (complete with blower fans, loading auger, supply hopper and auger feeder),

v auxiliary equipment for general boiler purposes,

v hydraulically driven fuel storage (for daily fuel supply) with a feed bunker loading conveyor,

v water treatment system (complete with circulation and make-up pumps, pipelines, fittings, heat exchangers),

v instrumentation and electrical equipment for general boiler purposes,

v boiler power supply and automation system based on a control controller with a computer point for collecting and processing information.

Brief description of the technology:

The combustion of wood waste is carried out in the pre-furnace heat generator of the boiler. A retort-type firebox is a cylindrical metal structure lined from the inside and equipped with an “air jacket”, installed directly under the combustion chamber of the boiler. To accommodate the pre-furnace heat generator, the boiler block is installed on its own supports at a height of at least 3 m above the zero mark.

Wet wood fuel is fed by a loading auger into the lower part of the pre-firebox (retort) under the burning layer from a supply hopper with a “living bottom”, which is part of a feeder installed under the hopper. Air is forced by two separate fans through the “air jacket” of the pre-furnace under the fuel layer and into the space above the layer, which ensures uniform heating of the layer and complete combustion of solid particles and combustible gases in the chamber volume.

Fuel is supplied to the supply bunker by a scraper conveyor from a stocker-type mechanized warehouse (with a moving floor on pushers with hydraulic cylinders), located under a canopy.

The power supply, automatic regulation and control system is developed on the basis of a microprocessor (control controller) and provides electricity to the auger drives, motors and actuators of the fans and smoke exhauster, regulation of the fuel and air supply according to the temperature in the boiler and regulation of the vacuum in the furnace. The system includes all the necessary electrical protection, blocking and instrumentation.

Extinguishing sparks and cleaning flue gases is carried out in an ash collector installed in front of the smoke exhauster. To clean the heating surfaces of boilers, a shock wave generator (SWG) is used.