Liquid fuel for boilers. Liquid fuel boiler: design, pros and cons of application Fuel for heating boilers

Liquid fuel boilers make it possible to make home heating completely autonomous from the central gas pipeline. They are used for both space heating and water heating. There are many models, so before buying, you need to understand the features of their installation and operation.

Heat your home with oil fired boilers

Advantages and disadvantages of equipment

Liquid fuel heating boilers make the house completely autonomous in the heating and hot water supply scheme. They have their pros and cons that you should be aware of. The main benefits include the following:

• ease of installation;
• ease of operation and maintenance;
• automatic fuel supply;
• no need to obtain a special permit for installation;
• high power and efficiency;
• the ability to use for heating both residential and industrial premises;
• boilers are fully automated.

In this video, we will consider liquid fuel boilers:

If necessary, the type of fuel can be changed, for this you need to replace the nozzle. The devices are highly efficient. The main disadvantages are the following:

• noise during work;
• the need to create a separate room for the boiler and fuel storage;
• availability of uninterrupted power supply;
• the need to install a chimney.

The cost of liquid fuel is quite high. Despite all the shortcomings, such boilers are in demand.

Principle of operation and device

Liquid-fuel devices work on the same principle as gas ones. The main difference lies in the use of a nozzle (fan burner). The boiler has the following structural elements:

• common body;
• burner;
• Control block;
• the combustion chamber;
• chimney;
• heat exchanger.

The package also includes a pump, which is responsible for supplying fuel to a special tank. To improve efficiency, some manufacturers complete the device with heat exchange plates and chimney pipes.

The control unit is fully automatic. The body is completely thermally insulated. This increases the efficiency of the device, and also minimizes heat loss. Outside, the boiler is pasted over with a special film that remains cold even when the unit is heated, so there is no risk of getting burned.

Varieties of boilers

All models can be divided into several groups depending on the principle of operation and the fuel used. There are two principles of fuel combustion:

1. Evaporation of liquid fuel occurs from the surface of the bowl. The fuel itself burns slowly, so the volume of evaporation is quite large. Most often, this principle of operation is found in home-made devices.
2. A flare burner is used. Fuel, as in the first method, passes through pyrolysis. However, the mixture is prepared, evaporated and burned directly in the flame of the torch.

Boilers with a flare burner are more versatile. Most often they are used for heating country houses. They can work for:

• fuel oil;
• diesel;
• reduced gas;
• working off.

Devices that have pre-evaporation cannot burn diesel and gas. Units for heating can also be divided into factory and home-made. The former are safer and more effective.

Device Selection Criteria

Domestic liquid fuel boilers are manufactured by both European and domestic companies. During the selection, you should pay attention to the main characteristics of the device. It is necessary to take into account:

• power;
• price;
• functionality;
• availability of additional functions.

The optimal power of the device must be calculated by a specialist. The functionality of the units is manifested in the fact that single-circuit models are aimed only at heating. Double-circuit can not only heat, but also connect to the hot water supply.

Liquid fuel prices vary. German-made models are the most expensive, most of them belong to the premium class. The average price category is represented by devices from Korea. They have multi-level protection and are fully automated. The most affordable are the models of domestic production.

An important factor when choosing a heater is the manufacturer's brand itself. The most popular are the products of the following manufacturers:

• Gecko;
• 5Energy;
• Viessmann;
• De Dietrich;
• Navien;
• Kiturami.

The choice of a particular device depends directly on the budget and desire of the owner. Domestic models are in no way inferior to European ones. They are not whimsical to raw materials and are equipped with automatic control.

Types of liquid fuel

The list of types of liquid fuel is quite extensive. The choice of a particular type depends on the model of the boiler. Most commonly used:

• fuel oil;
• diesel fuel;
• kerosene;
• used oil.

Fuel oil and diesel fuel are fairly light fuels. They are easy to transport and store. Due to the low viscosity of the fuel, it burns as efficiently as possible. The minimum amount of ash and sulfur in the composition ensures the safety of equipment and minimizes emissions to the environment.

When choosing fuel for an oil-fired heating boiler, attention should be paid to the viscosity and the amount of sulfur in the composition. The price of a low sulfur product is higher, but its use has advantages:

• economical consumption;
• low costs for maintenance and repair of equipment;
• minimum amount of harmful emissions into the atmosphere.

You can't skimp on fuel. Otherwise, you will have to constantly change the nozzles, the fuel filter and clean the tanks from precipitation.

Operation features

In order for liquid fuel heating boilers to work efficiently and properly, it is necessary to adhere to the basic operating recommendations. You need to constantly monitor the amount of fuel in the boiler.

The equipment is regularly inspected and maintained. It is recommended to carry out cleaning and detailed inspection for damage at least 2 times a year. The first inspection is carried out before the start of the heating season, and the second immediately after its end.

An important nuance is the use of only high-quality fuel and the installation of a special filter to clean it. Periodically, it is necessary to check the integrity of the containers in which liquid fuel is stored.

Boilers for liquid fuel of long burning, with proper operation, can serve for a long period. It is important to carry out technical inspection and troubleshooting on time. Only in this case, the operation of the device will be not only effective, but also safe.

Modern liquid fuel heating boilers, despite their technical excellence and the ability to efficiently heat buildings in the absence of a connection to a centralized natural gas supply, are rarely found in our homes. At the same time, in the countries of Western Europe, which have a more developed infrastructure and are sensitive to the problems of saving, the percentage of such equipment in the total mass of heat generators is higher. We propose to figure out together what is good and what is bad for a liquid fuel heating boiler (ZHTKO) and in which case its installation in domestic conditions justifies itself.

What types of liquid fuels do liquid fuel heat generators work on?

Household (industrial, this does not apply) ZHTSW are capable of operating on the following types of fuel:

• Diesel fuel is the highest quality, but also the most expensive type of liquid fuel. Operating costs when using it are comparable, and under some conditions even higher than when heating with electricity and liquefied gas.
• Fuel oil or petroleum heating oil is a product of the distillation of petroleum, similar to diesel fuel, but obtained from heavier fractions. Its calorific value is 15-20% lower, but the price is almost two times less. Fuel oil needs more thorough filtration than diesel fuel.
• Biofuels - vegetable combustible oils, as a rule, are used in a mixture with diesel fuel or petroleum oil. The characteristics of vegetable oils are similar to petroleum oils, the cost is slightly lower.
• "Working out" - used technical lubricating oil drained from mechanisms. For auto enterprises, service stations, agricultural equipment bases, this is a godsend, because fuel costs nothing. Private traders rarely manage to find a cheap and permanent source of used oil.

Heat exchangers for oil boilers

Heat exchanger - a device in which fuel is burned and the coolant is heated. In modern boilers, it has a developed finning, which allows you to take the maximum amount of heat during the combustion process. There were also condensing liquid wastewater treatment plants with an additional heat exchanger section, which makes it possible to utilize the secondary heat of the exhaust gases. The circulation of the coolant is organized according to the principle of "water jacket".

Heat exchangers can be made of cast iron or steel. Cast iron roads are heavy, afraid of thermal and mechanical shocks, but with careful handling they are very durable, they last at least half a century.

Even the steel heat exchangers of liquid fuel boilers are very heavy, not to mention the cast iron ones, therefore ZhTKO are produced only in a floor version.

There are also combined heat exchangers made of cast iron and steel.

Fan burners and their control

• The oil burner has an integrated pump and fan. The first one sucks fuel from the tank, injects it under pressure and sprays it into the heat exchanger, the second one forcibly supplies air in the metered amount necessary for combustion. The presence of a fan at the same time increases the efficiency of smoke removal. A liquid fuel burner is a complex and expensive device that is sensitive to fuel quality. Installation of pre-filters and their timely replacement for its cleaning is mandatory. Simple and cheap burners can only operate at maximum mode, more advanced ones have 2-3 power levels. This contributes to lower fuel consumption and longer equipment life.

Most burners operate on relatively light fuels: diesel, petroleum oil, biofuels. But there are also burners with fuel preheating for thicker and less flammable used technical oil, as well as universal burners that can effectively burn all types. Burners for "working off" and universal ones are significantly more expensive than usual ones.

Universal burner capable of operating on waste oil.

• The control automation of modern ZhKW coordinates the operation of the burner with the heating system as a whole, allows achieving economical fuel consumption and optimal thermal conditions, which are in no way inferior in terms of comfort to gas and electric heating. In the presence of high-quality fuel, the equipment operates completely autonomously, many heat generators can be built into the “smart home” system and controlled remotely.

The fan burner atomizes fuel in the combustion chamber of the heat exchanger under pressure, air is also injected

Types of oil boilers

We have already mentioned the difference in burners by type of fuel, as well as the presence of different power levels. A few words about the form factor of the boilers: the burner can be located inside the heat generator housing or outside. In the second version, it is easily removable and can be replaced with a gas one in a couple of hours. A couple of decades ago, universal gas / liquid fuel heat generators were considered a rational choice. But today, when condensing gas equipment with modulating burners has appeared, and universal boilers, due to the impossibility of changing the design of the heat exchanger, are significantly inferior to them in terms of efficiency, the dual-fuel solution can no longer be called relevant.

Whenever possible, water heating for hot water supply is divided into:

• Single-circuit, have only a circuit for heating the coolant.
• Double-circuit with a flow heater, hot water passes directly through a dedicated section of the water jacket.
• Double-circuit with the built-in boiler.

Note: it will cost more, but the installation of a pair of single-circuit boiler + storage water heater of indirect heating (boiler) per 100-150 liters will give the most comfortable hot water supply.

How much fuel does the ZHKF consume and how expensive is it

Manufacturers are often "embarrassed" to indicate the "appetites" of their heat generators. But we can estimate the approximate fuel consumption for a liquid fuel heating boiler on our own. At the maximum mode, the burner consumes an amount of diesel fuel approximately equal to its power divided by 10. That is, a boiler (burner, to be more precise) of 20 kW "eats" 2 liters of "diesel fuel" per hour of continuous operation or 48 per day. 20 kW - this is quite enough for a house of 200 m2 in the climatic conditions of Central Russia. So, let's assume that for 3 months a year the boiler operates with a load of 75% of the maximum, 3 months - 50% and another 3 - 25%. In total we get 6480 liters for the heating season. Let's add 10% for hot water supply, we get 7,128 liters or 7.1 m3. More fuel oil will be required, 8.550 liters or 8.5 m3. You need to understand that these are very average data, they do not take into account either the level of performance of the boiler itself or the degree of insulation of the house. By effectively insulating the building from the outside, fuel consumption can be reduced by a factor of two, and by switching to a low-temperature mode - by another quarter.

We will not talk about the price of fuel, it is constantly changing and depends on the region. To accurately calculate operating costs, you need to find local wholesale suppliers and find out how much it will cost to load a particular type of fuel into storage, taking into account transportation costs. By the way, unlike diesel fuel, fuel oil is not always available everywhere and can not always be purchased.

On a note: the cost of replacing filters should also be included in operating costs, although this is incomparably less than the fuel itself.

Where and how to store fuel

When choosing a heat generator, consumers do not always take into account the need to build a fuel storage facility, and equipment sellers do not tactfully remind them of this. You can’t get diesel fuel in canisters, and it’s much cheaper to buy in bulk. Wholesale - this means a fuel truck. The smallest is on the chassis of the Gazelle, the capacity of its tank is 1.3 m3. The next one is the GAZ 3309 chassis, it will bring 4.9 m3. Then there are 6.2, 6.5, 6.8 m3 and so on, up to a maximum of 15.8 m3. In the cost of fuel, a considerable share is “pulled” by transportation costs, so it is unprofitable to carry half a tank. Based on this and the seasonal accessibility of heavy vehicles, it is recommended to take the fuel storage capacity within 0.25-1 annual requirement and not less than the tank truck available in the region.

Building and fire regulations allow storing only 50 liters of fuel in the boiler room, so a capacious fuel storage should be arranged outside the house or in an extension isolated from the building with a fire wall with a separate entrance. We do not recommend burying a metal tank (for example, a decommissioned tank) into the ground, as was often done before. The soil freezes, the tank and pipelines need to be thermally insulated, steel corrodes over time, it is impossible to control the tightness of the tank. A new, durable metal tank is very expensive.

Polymer fuel tanks exist for in-ground placement, they are not subject to corrosion, but are not as strong as steel

For a small object, which is a private residential building, it is more rational to build a separate outbuilding or an extension to the house, where it will be possible to maintain a positive temperature. Tanks - standard polymer tanks, more often used for 1000 liters. They are compact, take up little space, have all the necessary technological holes for integration into the system, and are relatively easy to load and clean.

The fuel storage of a private house of 3 m3 in a heated room is convenient and safe.

Note: it should be borne in mind that the fuel storage should have a convenient access for special vehicles.

Pros and cons

Actually, we have already mentioned all the advantages and disadvantages of liquid fuel boilers, but just in case, we will repeat them:

Pros:

• High degree of automation, the ability to create maximum thermal comfort.
• Full autonomy from other energy sources (in addition to electricity, but the needs for it are small, you can get by with a generator)

Minuses:

• High operating costs.
• The need to have a capacious fuel storage, to prevent freezing of it and pipelines.
• Fan burners are quite noisy, their work is clearly audible through the wall.
• ZHTSW should be located in a separate room with good ventilation, preferably not connected with living quarters - the "aroma" of diesel fuel is indestructible.

A modern oil-fired boiler room is a clean room, you will not see puddles of “solarium” on the floor in it. But the specific smell of fuel still seeps through

So, who will install ZHTS in his house? Firstly, those who do not have and are not expected to lay a gas pipeline in the near future. Secondly, a person is not poor, who prefers to pay more money, but to get comfortable living conditions. Thirdly, the one in whose house there are no electrical capacities sufficient for organizing alternative heating, and he is not satisfied with heating with firewood.

In conclusion, let's say that liquid fuel boilers are a rather complicated technique that requires professional maintenance. Therefore, installation, connection and service work must be carried out by qualified personnel.

Video: underground diesel boiler

Liquid fuel for boilers: quality standards and storage conditions

For liquid fuel boilers, Luch Tepla recommends using two types of combustible materials that maintain optimal combustion, but at the same time do not harm heating devices. These are diesel fuel and fuel oil of light grades. They are easy to store and transport, do not contain a lot of ash and sulfur, and also have a low degree of viscosity, which guarantees ease of combustion.

Quality standards

According to foreign standards, all fuel for boilers is divided into two categories:

1. furnace ( distillate);
2. residual (fuel oil).

The first is produced by catalytic and thermal cracking of petroleum products and coking of residual fuel. About 60 percent of it is used to heat various buildings with autonomous heating systems. In the USA it is also called nozzle, in France - light, in the UK - household. However, calling heating oil diesel is incorrect. The fact is that in terms of severity it exceeds diesel fuel several times (in terms of fractional composition). But both are suitable for heat supply.

Based on GOST 305/82, diesel fuel is divided into:

• A (arctic);
• Z (winter);
• L (summer).

In addition, the sulfur content is taken into account. All this information is displayed in the brand designation. In addition, the pour point and flash point are also important. For example, summer fuel is marked as L / 0.2 / 40, where the first digit is the volume of sulfur, the second is the ignition temperature. And the coding Z / 0.2 / 35 indicates that this is an earthly fuel with a sulfur content of 0.2 percent and a freezing point of minus 35 degrees. The most frost-resistant is the Arctic brand of diesel fuel. It is designated as A / 0.4 / 50. The basic difference between all the indicated brands of fuel for liquid fuel boilers is low viscosity. Even at plus 20 degrees, it reaches from 3 to 6 cSt.

With regard to the presence of sulfur, in recent years, the foreign market prefers boiler fuel with a content of this substance in the range of 0.005 percent by weight. It costs more, but is much better in terms of completeness and cleanliness of combustion. In addition, it is also ideal for condensing boilers, as there is no longer any need to neutralize the condensate. As a result, such diesel fuel endows boiler equipment with such important qualities as:

• harmlessness of emissions into the environment;
• reducing the cost of service maintenance of the heating device and the system as a whole;
• fuel economy.

Storage conditions

Liquid fuel oil is stored under special conditions. This is due to the high degree of combustibility of the material and its unsafety for the environment. Therefore, it is placed in plastic or steel containers. Moreover, the former are preferable to the latter, since metal tanks are subject to corrosion both from the outside and from the inside.

While plastic ones are made from special high-strength polyethylene and can hold from 500 to 5,000 liters of fuel. They are interconnected by a special mount (fixed packages) and form batteries that have a direct supply to the heating boiler. However, the total volume of such storage should be within 25,000 liters, no more.

In addition, there are two types of tanks:

1. single-walled;
2. double-walled.

Tanks made of plastic with one wall are oriented to ground installation. They are located in such a way that in the event of a sudden leak, all fuel is securely contained and does not spread. Therefore, preference is given to rooms with a sealed lower part of the walls and impervious floors. It is also allowed to use special pallets. Their total volume must correspond to the volume of the tanks.

Tanks made of plastic with two walls do not have such requirements. They are simply equipped with diesel fuel leak control devices, which are mounted between the outer and inner shells. Double-walled tanks are designed for underground placement and storage of fuel in very large volumes - over 1,000 liters per tank.

With all this, the tanks must comply with a number of characteristics and be:

• durable, but at the same time easily adaptable to specific conditions (unobstructed pass through any doorways);
• resistant to temperature, chemical, mechanical, ultraviolet and other influences;
• equipped with various strapping elements.

When placed in a domestic environment, boiler fuel tanks cannot be located near air ducts, chimneys, chimneys, or above furnace appliances. Also, they cannot be mounted in places of passage and aisle, on attics and roofs of offices, hospitals, individual housing construction, on stairwells (with the exception of combined housing of 2 apartments). The best option is specially equipped cabinets, non-residential premises, boiler rooms, outbuildings, closed warehouses.

Efficient and economical liquid fuel heating boilers make it possible to achieve complete autonomy from a centralized gas pipeline. Reflecting on the installation of the unit, it is necessary to understand its device, the principle of operation and the features of operation.

The choice of a boiler should be based on a comparative assessment of the characteristics and functionality of different models. An important factor is the reputation of the manufacturer.

In this material, we will talk about the varieties of liquid fuel models of heating boilers, their advantages and disadvantages, and also consider several popular devices from well-known brands.

Liquid fuel boilers, despite the ability to efficiently heat a building and technical excellence, are not as common as gas or solid fuel heat generators.

Equipment that runs on diesel fuel or mining is very popular in Western Europe.

Among the significant advantages of a liquid fuel heating boiler are:

1. High work efficiency. The efficiency of most models reaches 95%. Fuel is consumed practically without loss.
2. Great power. The performance of the units allows you to heat both compact living quarters and spacious production workshops.
3. High level of work automation. The boiler operates for a long time without human intervention.
4. Autonomy from energy sources. Except for electricity. If necessary, you can get by with a generator.
5. Possibility of transition to gas fuel.

There are additional advantages of such equipment. The installation of the boiler does not require approval and obtaining permission. In addition, the absence of a gas pipeline greatly facilitates installation work.

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When supplied from outside, the air is supplied through or through a separate channel. To improve efficiency, the smoke channels are equipped with steel plates - the exhaust gases form turbulent flows that reduce their speed. Traction is maintained.

Instrument control unit

Automation is designed to maintain the set temperature. Auxiliary functions reduce the cost of boiler operation. From a technical point of view, weather-dependent units are considered the most advanced, which change the heating temperature of the coolant based on the readings of external sensors.

Boiler housing

All elements of the system are enclosed in a durable heat-insulating case. This "shell" reduces heat loss and increases the efficiency of the boiler.

Outside, the case is pasted over with a layer of heat-insulating film, which remains cold when heated and protects the operator from burns.

How is the space heated?

The whole process of generating heat in a liquid fuel boiler and transferring heat energy to heating radiators can be divided into several stages.

Stage 1. Diesel fuel or other fuel is poured into the storage. The fuel pump supplies liquid to the burner - pressure is created in the pipeline. At the same time, the fuel pump, using sensors, determines the quality of the fuel and the percentage of its thickening.

Stage 2. Diesel fuel enters the preparation chamber. Here the fuel is mixed with air, the mixture is heated and diluted.

Stage 3. The fuel-air composition is supplied to the nozzle. Under the action of the fan, the mixture is sprayed and the fuel mist is ignited in the combustion chamber.

Stage 4. The chamber walls are heating up. Due to this, the heat exchanger is heated and. The latter enters and circulates in the heating system.

Stage 5. When combustible substances are burned, gases are formed that are discharged through the chimney. Rushing outward, the smoke passes through a series of heat exchange plates and also gives off its heat.

When fuel is burned, soot is formed. To maintain the efficiency of the boiler at the proper level, the walls of the combustion chamber must be periodically cleaned

Varieties of liquid fuel models

All oil-fired boilers can be classified according to the following criteria: scope, functionality, type of adjustment, material of manufacture, type of fuel used and method of installation.

By scope

The main indicator that determines whether a boiler plant belongs to one of the types is power. Household models are produced with power from 6 to 230 kW. This is enough to heat small houses with an area of ​​​​50 square meters. m and large country cottages of 2200 sq. m.

The performance indicator determines the fuel consumption in a liquid fuel heating boiler - it takes about 1 kg of diesel fuel per hour to produce 10 kW of heat. Household units are designed for the maximum allowable operating pressure - 4-6 bar.

The power of industrial liquid fuel boilers ranges from 500 to 12000 kW. Heavy-duty models work to heat buildings with an area of ​​​​more than 15 thousand square meters. m. Management of industrial heating units is fully automated.

Industrial boiler equipment is divided into hot water and steam boilers. The former heat water under pressure, while the latter generate superheated or saturated steam.

High-power heat generators are used in block-modular boiler houses - autonomous stations for the generation of steam and heat. Steam generators are in demand in the food, furniture industry, wood processing, oil production and feed production

By functionality

Single-circuit boilers are designed exclusively for space heating. They are connected to radiators, and the coolant circulates through a closed heating system. Such a unit does not heat water for domestic consumption - this must be taken care of separately by installing a boiler.

Double-circuit models are more functional. Boilers provide heating of the house and supply of warm water to different points of water intake (shower, washbasin, etc.). The design of the equipment provides for an additional heat exchanger to provide hot water.

On the modern market, there are a lot of offers of various equipment for heating private houses and cottages, using various types of energy carriers to generate heat, from main gas and electricity to firewood and sawdust. But what to do and how to heat your home if natural gas is not connected to it, a small limit on electricity is set, and various types of biofuels are not available for various reasons? In this situation, there is only one alternative - heating boilers for liquid fuel (diesel fuel).

Varieties of boilers for diesel fuel

So, due to the inability to use other common energy sources, you decided to arrange liquid fuel heating in your home. It's time to choose a heating boiler, and here you should figure out what types of these products exist and choose the most suitable option. Manufacturers offer liquid fuel heating boilers of the following types:

• diesel boilers;
• universal units, they provide for the possibility of switching from diesel to natural gas;
• diesel condensing boilers;
• installations that burn all types of waste oils.

If in the foreseeable future there is no change in the situation with energy carriers, then your option is to heat a private house with a heating boiler of the first type, which burns only diesel fuel.

For reference. Most of these plants can also operate on liquid biological fuel, which is obtained from industrial crops (biodiesel). This option can be very useful if such an energy source is available to you.

Some homeowners who are looking for a heating boiler believe that they can burn their car waste in a diesel boiler. This is the wrong approach, and here are the reasons why:

1. Not every burner device works on contaminated oils.
2. The calorific value of liquid fuel is much higher than that of used oils. Accordingly, the areas of heat exchange surfaces are calculated for liquid fuel; during combustion, the efficiency will be much lower.
3. Mining during combustion releases significantly more soot deposited in the entire smoke path. This can be a big problem when maintaining and cleaning fire tubes.

By their design, liquid fuel boilers are very similar to heat generators running on natural gas. Accordingly, many manufacturers offer universal hot water installations with alternate use of liquid and gaseous fuels. The transition from one type of fuel to another is carried out by replacing the burner. True, a universal boiler that runs on liquid fuel and main gas will cost you a little more.

If the area of ​​the heated room or building is less than 200 m2, and in the near future you expect to be connected to the gas pipeline, then you should not rush to purchase a universal heater.

The fact is that the cost of a boiler block and two burners may be higher than two separate full-fledged units. Therefore, at first you can put the boiler on diesel fuel, and after connecting to the main line, buy and install a gas heat generator. You can find out more by watching the video:

Domestic condensing boilers for diesel fuel are the most economical and efficient representatives of this family of heat sources. Manufacturers declare the efficiency of their condensing units at 97%, which is the highest among all other heaters. As usual, their cost is quite high and not every owner can afford to include such a high-tech product in the heating system.

It is very good if you have access to such a secondary resource as used car oil in sufficient quantities. Then, specifically for this purpose, there is a waste oil boiler, the product is manufactured and offered on the market by many manufacturers. Also, similar boilers for heating have been well mastered by various craftsmen who make home-made heaters.

Device and principle of operation

As mentioned above, liquid fuel heating boilers are structurally similar to two-way and three-way gas boilers. By virtue of their design, the products are produced in the floor version.

For reference. In boiler plants with a fire-tube heat exchanger, the combustion products can change direction several times, making several passes through the flame tubes and intensely transferring heat to the water jacket. According to the number of moves, the heat exchanger is assigned a characteristic - three-way or two-way.

The similarity lies in the design of the heat exchanger from the flame tubes enclosed in a water jacket. In the very center there is a chamber for burning fuel, only for a diesel unit it has a cylindrical shape. This is due to the design features of the burner device using liquid fuel. The main elements and details are shown in the figure.

installation of a Viessmann oil-fired boiler

A - outer heat-insulating shell; B - heat exchange surfaces of flame tubes; C - combustion chamber; D - electronic control unit; E - burner mouth swarming.

In the products of leading foreign manufacturers, the firebox is made of heat-resistant stainless steel, budget domestic heat generators can also be made of ordinary thick metal. The material of the heat exchanger is cast iron or steel; basalt fiber or dense polyurethane foam is used for thermal insulation. A burner that runs on liquid fuel and is of particular interest, its design with a breakdown of the elements is shown below.

Diesel burner drawing

A - air control throttle; D - block of the ignition system with a flame control sensor; E - fuel line; F - fan motor; G - pump; K, H - supply and return pipelines for fuel; I – electromagnetic valve; L - fault signal reset button; M - automatic heating control; N - console; O - ignition cable; P - electrodes of the ignition system; R - cylindrical working part; S - mixing device; T - nozzle; U - rod with fuel heater; V - air intake device; W - burner body; X - air channel; Y - fan impeller.

The working part is made in the form of a cylinder with many holes through which the flame passes. When the combustion of fuel occurs, the flame of the burner heats the cylindrical walls of the furnace, as shown in the photo.

Diesel burner operation

A special container is intended for fuel, it can be free-standing or suspended from the wall, a supply line is laid from it to the burner. Some burners have a return fuel line to relieve pressure, then the installation of the boiler and its connection are provided by two pipes - supply and return, going into the fuel tank. Ignition is performed automatically at the command of the control unit.

Brief description of the work process

The combustion of diesel fuel has its own characteristics, as well as the principle of operation of a heating boiler for liquid fuel. To begin with, the fuel needs to be heated to a certain temperature, usually 50 ºС. For this purpose, the burner is equipped with a heating element. When the fuel pump has created pressure in the line, the control unit turns on the heater and ensures that the temperature of the diesel fuel in the tubes remains 50 ºС.

After warming up, the controller turns on the fan and, using the solenoid valve, opens the fuel supply to the nozzle. The latter sprays it, and the fan supplies air, at the same moment a spark jumps on the ignition electrodes and the air-fuel mixture ignites. Further, the burner switches to the normal mode of operation of the diesel boiler. The intensity of combustion is controlled by an air supply throttle connected to the fuel pump. When the heating system warms up or the fuel tank is empty, the controller turns off the burner and, if necessary, restarts it.

Many homeowners are interested in the question, how much does a diesel fuel boiler consume fuel in operating mode? The answer depends on many factors, such as climatic conditions, the degree of insulation of the building, the quality of diesel fuel, and so on.

Based on various practical observations, it can be said that for heating a house with an area of ​​150 m2 in the coldest time and operating the burner at full power, the mass fuel consumption of a diesel boiler will be about 2.5 kg / h. In the average mode, this figure can decrease by 20-30%.

Advantages and disadvantages

The main advantage of a diesel fuel boiler is that its use is possible in the absence of all energy carriers. The exception is electricity, it is still needed a little, approximately up to 100 W / h. Other advantages of oil fired boilers are:

1. High efficiency index, the efficiency of the units lies in the range of 90-97%.
2. The absence of inertia during shutdown, which will protect the coolant from overheating.
3. A high level of automation (in foreign units), thanks to which it is possible to organize weather-dependent regulation of home heating.
4. Possibility of switching to natural gas by replacing the burner.
5. Small overall dimensions allow to put a heater in the small room.

As usual, in any business is not without flaws. In this case, the main disadvantage is the high cost. Expensive equipment, fuel and maintenance. The latter should be carried out quite rarely, the manufacturers say, but in fact, our diesel fuel is not of good quality, and therefore there is a prospect of often messing with the burner. This also includes the cleaning of smoke pipes from soot, which inevitably occurs during the combustion of low-quality diesel.

Conclusion

Liquid fuel boilers for heating a private house, as a rule, are purchased for two reasons: often this is a forced and temporary step, made due to the lack of other energy sources. The second case is when there is access to cheap fuel, because its cost is the main obstacle to the popularity of this family of boilers.