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For a long time, in every house located in the Russian expanses, the heating stove was the most important place. Thanks to the stove, the house was warm in winter. In addition, food was prepared on them, and some structures with a bed even made it possible to sleep. In many rural huts, the stoves are still preserved. Over time, they have undergone significant changes and now owners use solid fuel, electricity or gas boilers to provide heating.
Gas heating is deservedly considered the most optimal solution to the heat supply problem, but, unfortunately, the mains are not laid in all populated areas. Electric heating of a home is an expensive option, and an unstable power supply can lead to equipment shutdown or breakdown. Therefore, property owners, especially in rural areas, prefer to install solid fuel heat generators.
Classification of solid fuel boilers
Depending on the material of manufacture, a solid fuel heating boiler can be:- cast iron;
- steel.
The operation of all models of devices operating on solid fuel depends on the presence of water in the heating structure. If the amount of coolant in the system reaches a critical level, overheating and deformation of individual elements is possible. Steel units are more resistant to temperature fluctuations, and cast iron products are more resistant to corrosive processes.
The following information will be useful for consumers: the required volume of fuel for loading is calculated based on certain standards. For one kilowatt, steel boilers require 1.6 - 2.6 liters, and for cast iron appliances 1.1 -1.4 liters.
Thus, cast iron and steel heat generators differ not only in weight and material of manufacture, but also in other characteristics, including structural differences. So the cooling coil in steel solid fuel boilers is located inside them. When the coolant heats up to a critical temperature, you can open the thermostatic tap slightly, after which cold water will begin to flow and thereby lower the temperature.
In cast iron boilers, such as in the photo, similar elements are located on the supply. You can lower the temperature in them only by partially draining the hot water and adding cold coolant. When producing a cast iron product, its sections are assembled into a single device using steel pins. As for the steel unit, its parts are connected by welding. The strength of the seams depends on its quality.
Loading firewood, coal, pellets into solid fuel heating boilers is done manually by opening/closing the loading hatch door. Since its internal part comes into contact with fire and gets very hot, a person can get a serious burn if they come into contact with it. To prevent this from happening, cast iron units have a door with a special protective layer. For steel appliances, the door is equipped with a water-cooling circuit along the contour.
To clean a cast iron boiler from ash and ash, you will need a poker. Steel heat generators are equipped with rotating grate bars, mechanically controlled - as a result, to clean the stove you do not need to open the door to the firebox.
The design of solid fuel boilers varies. These devices are:- single-circuit;
- double-circuit.
classical (traditional) and gas generator (pyrolysis). The latest devices consist of two chambers located one above the other, which are separated by nozzles.
Solid fuel is placed in the upper part, but it does not burn immediately. Thanks to the pyrolysis process, the wood is initially dried and at the same time the air is slightly heated. As a result, efficient heat exchange is ensured. Pyrolysis boilers are equipped with a ventilation device, which not only facilitates quick combustion, but also minimizes harmful emissions into the atmosphere.
If such a bunker is filled completely, the next loading will only be required after a few days. The warranty period for these devices is about 10 years. But if the operating conditions are observed, the boiler can last a much longer period.
Safety of the heating system
The main point when a solid fuel heating boiler is installed is to prevent overheating of the heating supply structure. Since the heat generator cools down very slowly, it is necessary to avoid situations where the temperature reaches the maximum limit. This is especially true for metal-plastic and plastic elements. When the temperature exceeds 100 degrees, they can melt and the heating equipment may become unusable.
You also need to be extremely careful when draining hot water (to prevent overheating) into the sewer system if it is equipped with plastic pipes that can become deformed.
The need to install a chimney
Effective operation of a solid fuel boiler is impossible without the correct choice of installation location for the chimney, which must withstand high temperatures without problems and not be subject to corrosion. It cannot be less than 4 meters in height, and 18 centimeters in diameter.Installation of the boiler and smoke exhaust system should only be carried out by professionals. But the customer of installation services does not bother to study the relevant information in order to assess the quality of the work. After installation is completed, the boiler ash pan must be regularly cleaned of accumulated ash and slag, which reduce the efficiency of the equipment.
Video about a solid fuel heating boiler:
Solid fuel heating boilers in past times were somewhat primitive and inconvenient, but today everything has changed. Manufacturers offer consumers improved equipment that harmoniously combines high efficiency and ease of operation. Such units are used in areas where there is no gas main and where there are power outages.
Design and principle of operation of the equipment
Devices of this type are structures consisting of several main elements:
- heat exchanger - this unit transfers energy from heated water;
- combustion chamber - it is made of high-alloy steel, high-quality cast iron;
Heating schemes can include the simplest single-circuit devices and powerful units
- thermostat;
- ash pit - combustion products accumulate here;
- grate – firewood, coal, pellets are placed on it;
- cleaning hatch;
- dampers that regulate the operation of the chimney.
The principle of operation of the units is that fuel is burned in a volumetric firebox, water is heated and supplied to the system. Ash and slag fall into a special bunker and are periodically removed manually.
When developing equipment, original technical and ergonomic developments are used
Companies that produce modernized solid fuel heating boilers are trying in every possible way to simplify the operating process. Modern devices are equipped with draft regulators and thermostatic valves. Draft regulators influence the rate of fuel combustion by opening and closing the damper. As for thermostatic valves, they consist of cooling circuits, thermostats and are designed to drain water when overheated.
This is important to know: in pyrolysis boilers, a different principle is used: in one chamber, the firewood smolders with limited access to air flow, and in the second, the resulting gas is burned.
Connection diagram for a solid fuel heating boiler
The duration of uninterrupted operation of the devices depends on how correctly the design and installation were carried out. Solid fuel boilers for water heating are devices that heat the coolant. But do not forget that there are additional elements. The standard connection diagram looks like this:
- unit;
- circulation pump - the driving force that moves water;
- expansion tank - such an element compensates for temperature expansion of water;
- buffer tank is a vertical tank whose main purpose is to accumulate excess heat. A heating system with a solid fuel boiler using a buffer is an excellent option, because the number of loads is reduced, the operating temperature of the equipment is improved, and the consumer is provided with hot water;
- safety group - three devices combined on one console: pressure gauge, Mayevsky valve, safety valve. It is designed to protect the system from airing and overpressure;
The safety group is mounted above the boiler in a vertical position
- emergency circuit - it ensures normal operation of the system in unusual situations.
The heating scheme with a solid fuel boiler can be different, because there are many nuances. For example, if the system is open, the tank is installed in the attic, on the staircase. In other cases, membrane tanks are used, which are durable vessels separated by a partition made of environmentally friendly rubber.
Tying a solid fuel heating boiler solves several important problems. These include maintaining the temperature of the coolant, creating optimal conditions for the operation of equipment, one hundred percent protection against overheating, and removing air. The heating system with a solid fuel boiler is quite complex, so design and installation must be carried out by competent specialists.
How are devices classified?
There is a wide range of equipment on the market, which differ not only in size and appearance, but also in many other indicators. Let's talk about them further.
The method of fuel combustion is a fundamental parameter of priority importance. According to this indicator, devices are divided into:
- Classic - they undergo the usual process of burning wood and coal with the release of beneficial heat.
- Pyrolysis - at high temperatures and in the absence of oxygen, flammable gas is released. Such boilers are equipped with a forcing fan and ensure almost complete combustion of pellets and firewood.
- With natural draft - the combustion process of granules and peat briquettes in such models is controlled by a thermostatic regulator.
- With additional draft - such units are equipped with fans, with the help of which air is supplied to the firebox.
This is important to know: pyrolysis equipment has significant advantages, but it is more expensive. In addition, the devices are more demanding on wood moisture.
Type of fuel - depending on this indicator, boilers can be coal, pellet, or wood. The first uses briquettes, brown and hard coal, anthracite, the second uses cylindrical granules of standard sizes, and the third uses dry firewood. There are also universal solid fuel boilers for water heating.
The material of the heat exchanger is an equally important indicator on which a lot depends. On this basis there is the following classification:
- steel units are unpretentious equipment that does not fail when exposed to high temperatures. Thanks to the introduction of modern design solutions, the devices have good efficiency and last for 20-25 years;
Steel solid fuel boilers "Viessmann Vitoligno 100-S" operate on wood logs and have an electronic control system
- cast iron solid fuel heating boilers - they are reliable, durable and resistant to corrosion. But there is one drawback: heat exchangers made of cast iron can be destroyed by sudden temperature changes.
What are the advantages of modern solid fuel boilers?
For homes that do not have gas, solid fuel boilers are ideal. This statement can be argued by the fact that the equipment has many advantages:
- profitability – the cost of fuel (peat briquettes, granulated waste from the woodworking industry) is acceptable. Therefore, a comfortable temperature is maintained in the house throughout the entire season, and the budget does not suffer much;
Solid fuel boilers are an ideal solution because they can operate on coal, straw, wood - an ideal solution because they can operate on coal, straw, wood
- high efficiency – heat is provided to rooms of any size;
- safety - this point is carefully thought out, because the devices are equipped with monitoring systems;
- long service life - this figure is 20-30 years and is directly related to correct installation and regular maintenance;
- autonomy - heating a country house with a solid fuel boiler does not depend on third-party factors: the presence of a gas pipeline, electrical networks;
- ease of placement - to set up a functional system, you need to install a heating unit, connect pipes, an expansion tank, and radiators to it;
- ease of use - modern solid fuel long-burning heating boilers are fully automated, so human participation is reduced to a minimum. Naturally, one should not forget about periodically cleaning the ash pan from waste products, since this process is carried out manually.
What to look for when choosing a heating boiler
Purchasing heating equipment involves a number of tasks that need to be resolved in advance. Therefore, before making a purchase, you need to understand the following points:
- Power is the primary parameter by which units are selected. The power of a solid fuel heating boiler is calculated using a simple formula: the area of the house is divided by 10. Why is this so? Because 1 kW of power is required for high-quality heating of ten square meters of housing.
- Heat exchanger type.
- Dependence on external factors - solid fuel electric heating boilers with a forced-air fan do not function without electrical energy. If the circulation is natural, this problem does not exist.
- Duration of work from one load.
Polish solid fuel boilers "PEREKO" are equipped with a pressurization fan, which increases the time of continuous fuel combustion
Heating a wooden house with a solid fuel boiler is the right solution if the home is cut off from the benefits of civilization. But you need to understand that correct operation of the system is possible when the design and installation of all units and components is carried out by specialists. Competent specialists know the intricacies of their work and guarantee uninterrupted operation of the equipment for many years.
Video: heating a house with a solid fuel boiler
Figure 3.
Volatile installations
The principle of operation and design of the Wattek PYROTEK pyrolysis boiler.
The unit operates in automatic mode, for which each PYROTEK model has a control panel that allows for modernization by adding other control and control circuits to the circuit. Using the panel, the user can make adjustments to the settings of the central heating and hot water circulation pumps, as well as the exhaust fan based on the data obtained on the temperature of the boiler coolant. The temperature of the water in the system can be controlled using a boiler thermostat. The control panel also has a minimum temperature thermostat, which deactivates the fan if the coolant temperature drops to 50 °C. For convenience, you can also connect a room temperature sensor to the panel, which will affect the functionality of the pyrolysis boiler.
Advantages:
- Various functional modes (summer, DHW priority, with weekly program settings).
- Making sustainable adjustments that are effective over a long period of time (up to 1 week).
- The clear interaction of all functionality with room temperature ensures the specified comfort of the environment.
Flaws:
- relatively high costs for purchasing equipment,
- The dimensions of the working chamber limit the loading volume.
Figure 4.
Non-volatile pyrolysis plants
As an example for consideration, let’s take the pyrolysis non-volatile boiler “Burzhuy-K”.
The coolant is directed to the unit through the return line pipe (8), where, receiving heat energy from the boiler water jacket (12, 13, 14), the supply line pipe (5) is sent to the heating system through the pipe. The fuel should be placed in the combustion chamber (19), into which the combustion procedure is carried out in the absence of oxygen. The volume of air in the chamber is regulated by the primary air supply door (3), the operating mode of which can be found in more detail in the “Firehouse Rules” section. In automated models, its operation is controlled by a temperature control sensor. During the combustion process, pyrolysis gas is produced, which is sent to the exhaust gas afterburning chamber (17), where it is mixed through afterburner injectors with calibrated holes with secondary air, preheated (11). Thus, a thermochemical reaction occurs in which fuel gases burn, releasing thermal energy. Residual carbon monoxide is disposed of through the pipe (6) and the chimney into the atmosphere.
This complexity, which lies in the very design of the boiler and the fuel combustion process, contributes to a significant increase in combustion time per fuel load.
Advantages:
- the consumption of fuel resources is reduced by 4 times; on average, heating 100 m2 will require up to 17 kg of firewood per day;
- time and effort are saved for the user, who only needs to add fuel no more than once every 12 hours for wood and every 15 hours for coal;
- the non-volatility of the boiler eliminates the cost of electricity and protects equipment from power failures;
- The pyrolysis heat generator has relatively small dimensions, which allows it to be installed anywhere;
- The boiler consumes almost all combustible materials as fuel energy resources.
Flaws:
- Inability to make adjustments to the parameters of the set home temperature.
Today, an autonomous heating system in a house is not something surprising and unique, but a completely normal state of affairs. Year after year, heating systems are improved and become better and better. Today, the culmination of progress is precisely solid fuel heating systems.
For your convenience, the article is divided into chapters:
What is important to know when installing a heating system
What do you need to know when installing a heating system? Most often, boiler users do not know what exactly they need and therefore it is very easy to succumb to the “wise” advice of neighbors, acquaintances and relatives about what and how to do. Nevertheless, the heating system is a complex and important mechanism that contains circuits for coolant, and much, much more. Therefore, it is necessary to have at least basic knowledge so as not to reproach yourself later for the money saved and an inoperative or unreliable heating system.
- To begin with, even if your house is almost finished or you just want to change the boiler, think and analyze Is your home properly insulated? After all, if the house is poorly insulated, no heating system will help you. And it doesn’t matter whether the heating system is gas or solid fuel. So task number one: a well-insulated house.
- Find a good specialist. Ideally, this should be an authorized company. Yes, they will take more money, but they will give a guarantee for their work. Of course, maybe you will be lucky and come across a folk craftsman, but is it worth the risk? By the way, a businessman’s connections with all sorts of companies, such as gas companies or others, are not at all an indicator of quality. Discuss whether it is a single-circuit system or a double-circuit system.
- remember, that A heating system is not just elements assembled in a certain order, but a complex engineering network. In which all diameters, pressure levels and much more must be clearly thought out.
Types of heating systems based on fuel
Depending on the type of fuel, heating systems are divided into the following types:
- Liquid fuel heating systems(fuel oil, alcohol) - A very expensive pleasure today. But maximum autonomy. In addition, if, for example, a diesel generator is used in parallel, then electricity can also be generated. Although again - very expensive. Fuel oil is more practical, but is not used in private homes, although it serves well as a type of fuel for heating entire areas or cities.
- Gas heating systems. A common sight today. Gas boilers are quite reliable and unpretentious. Of course, the main disadvantage is the need for gas supply through a central supply.
- Since our site is dedicated to solid fuel boilers, we will talk separately about heating systems using solid fuel. What needs to be taken into account in this case is the different efficiency of boilers depending on the type of fuel. For example, briquettes can also be burned in wood boilers, but the efficiency will change significantly. on solid fuel and correlate this calculation with the fuel that you are going to use, because in some cases it happens that it is cheaper to heat with the same gas, if, of course, the gas is supplied to the house. Also be prepared for the fact that a solid fuel heating device will cost you more than any other system. But at the same time savings on fuel will range from 15 to 50% depending on the type of consumption, type of fuel and degree of insulation of the house.
Heating system with solid fuel boiler
How comfortable is the heating system to use? In addition to the fact that heating systems are not inferior in comfort of use to conventional, more popular systems, they are also much more economical. In a solid fuel heating system, the following elements are used:
- Boiler - heat generator
- - this element takes care of the uniform combustion of fuel, for its most efficient combustion. The storage tank has a very important function: even after fuel combustion, it releases accumulated heat into the system, which generally stabilizes the operation of the entire system. Depending on the type, it may contain a tank to meet the needs for large volumes of water, for example for taking a bath. Also, depending on the configuration, the tank may have an additional heating element - ten. During peak loads, it supports the system by helping to heat the water. There are also small electric boilers that are installed directly on the flow pipe, with the same purpose - to support the main boiler during peak loads and prevent the water from quickly cooling after the fuel burns out. After all, maintaining the temperature requires less energy than for initial heating.
- Thermostatic mixer— controls stable temperature by mixing hot (already heated) and cold water.
Today, modern solid fuel boilers are often used to heat a private home, despite the fact that they are inferior in ease of use to their electric and gas competitors. This popularity of this equipment is primarily due to rising prices for traditional energy resources (especially electricity), as well as the lack of centralized gas supply in some regions. We should also not forget that waste from an agricultural or woodworking enterprise is often used as fuel for solid fuel boilers, which makes heating a private home absolutely free.
Types of fuel for solid fuel boilers
The list of fuel types suitable for use in a solid fuel boiler is quite wide; it includes almost everything that is not a gas or liquid and can burn. In most cases, the heat sources are:
- coal;
- peat;
- wood briquettes;
- pellets;
- waste in the form of wood shavings and sawdust;
- husks and husks of oilseeds and grain crops;
- straw.
Each type of fuel has its own requirements for the material and design of the firebox, the air supply system and some other components of the boiler. Of course, the fuel will burn even if all these parameters do not meet, but the efficiency of the boiler in this case will be significantly lower than the maximum possible. Therefore, before choosing a suitable solid fuel boiler model, you should decide exactly what type of fuel you will use in it.
The disadvantage of household solid fuel boilers is that this equipment is not capable of operating without user participation. Even in models with automatic fuel supply, it is necessary to constantly add fuel to the storage hopper, and the owner also needs to periodically remove ash.
Features of the design of solid fuel boilers
In their simplest form, household solid fuel boilers are devices consisting of a housing, a combustion chamber located inside it and a chimney. Such boilers provide so-called air heating, that is, simply put, they heat the air around them in the same way as a traditional Russian stove does. These models have the lowest cost, but it is impossible to use these types of modern boilers for a private house with several rooms. They are suitable for small buildings consisting of one or two rooms.
To heat the coolant of a water heating system, you should use a solid fuel boiler with a heat exchanger. The heat exchanger is blown by the hot gases generated during fuel combustion, due to which the water circulating through it is heated. Heat exchangers are made of steel or cast iron.
Cast iron heat exchangers are considered the most preferable: they are more durable than steel, are not subject to corrosion and have better performance. However, they also have some disadvantages: cast iron is much less ductile than steel, so it tolerates temperature changes less well; The cast iron heat exchanger weighs significantly more than the steel one, which complicates the transportation and installation of the boiler. The main “minus” of steel heat exchangers is the fear of corrosion.
In modern models of household solid fuel boilers, this problem is solved by adding special additives to the steel composition that increase anti-corrosion resistance. Another disadvantage is that a steel heat exchanger, unlike a cast iron one, is a welded structure:
- firstly, welds are the weak point of the product;
- secondly, this method of manufacturing a heat exchanger significantly complicates its repair.
However, steel heat exchangers offer a very useful feature, which is the use of a cooling coil. When the temperature of the coolant rises above the permissible limits, the thermostatic valve will open, allowing cold water to flow into the container. Boilers with cast iron heat exchangers cannot use this method to lower the temperature of the coolant; the system must be refilled with cool water.
Double-circuit boilers
More “advanced” models of solid fuel boilers can be used not only for heating private houses , but also for heating water in a hot water supply system. Such boilers are called double-circuit boilers. Anyone who wants to buy such a device should take into account one circumstance: immediately at the moment of using a hot water tap, the boiler completely switches to heating the DHW circuit, and the heating is turned off.
This happens as follows: as a result of switching the valves, the coolant heated by the boiler is redirected to the heat exchanger of the DHW circuit, so it temporarily does not enter the heating system. Therefore, such a connection scheme for a solid fuel boiler is justified only if hot water is consumed occasionally and in small volumes. If you need a lot of water, the water supply system is supplemented with a storage tank (boiler), which provides the following advantages:
- allows you to increase the consumption of hot water;
- makes it possible to use hot water longer without turning off the heating;
- smoothes the operating mode of the boiler, reducing the frequency of its switching from the heating circuit to the DHW.
In inexpensive models of solid fuel boilers, fuel is loaded manually, while in more advanced versions this process is partially automated. Such boilers are equipped with a hopper from which fuel is supplied to the firebox by a screw or piston feeder. Of course, such a system is unlikely to be able to supply firewood instead of the user, but with bulk fuels - fine coal (with a size of 5 to 25 mm), pellets, etc. – will cope “excellently”. The volume of one filling of the bunker is usually enough for several days.
Pellet boilers
One of the most high-calorie and easy-to-use types of fuel are pellets, which are also called biogranules. They are mainly made from wood chips, but peat, sunflower seed husks, etc. can also be used. To obtain granules, the raw materials are crushed and then pressed under pressure reaching 300 atm. Therefore, pellets occupy a much smaller volume than a portion of chips in their pure form, having the same mass. Using pellet boilers for home heating is very convenient: one load into the bunker is enough for a whole week, and the fuel burns almost completely, so you can remove ash about once a month. This equipment differs from other types of solid fuel boilers, first of all, by the presence of a special burner called a pellet burner.
Basic setup of a pellet boiler consists of the following steps:
- precise adjustment of the turn-on and wait time of the screw feeder when supplying fuel;
- selection of the optimal fan speed for air supply;
- adjustment of operating modes of circulation pumps in heating and hot water circuits;
- setting temperature conditions.
The maximum and minimum consumption of a pellet boiler is determined by several factors:
- boiler efficiency;
- fuel calorie content;
- thermal resistance of the building envelope;
- outside air temperature;
- the number of consumers connected to the boiler in addition to the heating system (warm floor system, hot water supply).
Pyrolysis boilers
If a domestic heating boiler in a private house is supposed to be heated with coal or wood fuel, it is better to give preference to a pyrolysis or, what is the same thing, a gas generator model. Such equipment is also called long-burning boilers. Pyrolysis is the process of formation of flammable gas during the smoldering of coal or wood fuel without access to oxygen. It takes place in a special boiler chamber and is accompanied by the release of a significant amount of heat. Wood gas, consisting mostly of ethylene and propylene, is fed through a ceramic nozzle into the second chamber, where air is pumped and where it is burned. Solid fuel pyrolysis boilers for the home are very beneficial because they have increased efficiency, and besides, cleaning them requires much less effort, because there is not much ash left after pyrolysis.
Rules for choosing a solid fuel boiler
Before choosing long-burning solid fuel boilers, you should calculate their power. On average, the specific energy consumption for heating a house with an area of 100 - 150 square meters. m is 120 – 130 W/sq. m, for a house with an area of 400 - 500 sq. m – from 80 to 85 W/sq. m.
It is also worth paying attention to various improvements that can significantly facilitate the operation of the equipment. For example, heating a country house with a solid fuel boiler can be controlled by commands from a mobile phone if the boiler is equipped with a GSM module with a SIM card installed in it.
As a conclusion, we recommend watching an interesting video with a review of the operation of a cast iron solid fuel boiler.