Biomass boilers are becoming more and more popular due to the fact that they provide low heating costs and their work is environmentally friendly. These types of heat sources are characterized by solutions that guarantee safety and comfort of use of the heating installation.
Biomass boilers purchased and assembled must meet the requirements resulting from the provisions of: Directive 2009/125 / EC of October 21, 2009, in particular in the Commission Regulation (EU) 2015/1189 of 28 April 2015 on the implementation of the Directive of the European Parliament and Council 2009/125 / EC with regard to ecodesign requirements for solid fuel boilers.
Biomass boilers guarantee cheap heating of the house and a positive impact on the natural environment as well as a clean boiler room. Burning biomass, we get a lot of heat, which is why it is an attractive fuel for central heating. The most popular biomass comes from plants, the production of which is quite simple and cheap. Another advantage is that during combustion, compounds that are burdensome to the environment are not released as when burning fossil fuels, because the carbon monoxide produced in this process is absorbed by the cultivated plants and does not increase in the atmosphere. The most commonly used biomass is Pelle in the form of sawdust granules, chips, chips or straw. One-time loading does not last long.
Biomass, due to the form of occurrence in nature, is divided into:
· Solid – wood waste, briquettes, pellets, straw, sewage sludge, wood chips.
· Liquid – ethanol, methanol and other fractions of vegetable oils,
· Gas – biogas (mud gas).
A large variety of products collectively referred to as biomass enforces the use of a division depending on the type of application.
To obtain heat, the most common are:
· Low quality technological and waste wood,
· Animal droppings,
· Sewage sludge,
· Straw, oil cake and other agricultural production waste
· Seaweed cultivated specifically for energy purposes,
· Organic waste, eg beet pulp, corn stalks, grass, alfalfa,
· Vegetable oils and animal fats,
Pellets are biomass pressed under very high pressure. Due to the relatively small volume, so much energy is obtained. The small size of pellet granules makes it easy to dispense using boilers with a feeder, which makes them convenient to use.
For convenience, however, you need to pay a good quality pellet boiler with a feeder is a considerable expense. The costs for heating a house with a pellet are comparable to the costs incurred for the operation of a natural gas boiler. The use of pellets makes sense, above all, if you use a biomass boiler that allows them to be automatically loaded. However, these devices are constructed with the intention of burning ecogroszty coal in them, and the pellets are treated as substitute fuel. To obtain the lowest possible operating costs, it is better to buy a special biomass boiler for pellet burning. Devices of this type are more resistant to chlorine compounds found in biomass. They have control rooms optimized for the combustion of just such fuel, thanks to which they achieve higher efficiency and fuel consumption is lower. They are usually equipped with lambda probes controlling the oxygen level in the flue gas, thanks to which the temperature in the room or outside controls the operation of the air inflow fan, fuel feeder and circulation pumps.
Types of boilers
Boilers with upper combustion
Boilers with lower combustion
Boilers gassing wood
The most important advantages of biomass boilers are:
low fuel purchase costs
lower emission of SO2, NOx and CO and neutral CO2 balance
they use advanced control devices that supervise not only the fuel feeding process but also combustion
taking into account the set temperature and water flow, the controller adjusts the intensity of the combustion process in terms of the amount of fuel and air supplied
providing control of the fuel supply system to the combustion location.
Comfort of the boiler is provided by the fuel tank
Modern controllers perform functions related to switching on / off the boiler, lighting up, and combustion efficiency adjustment. The burner and heat exchanger are also supervised. It is possible to control not only the internal functions of the boiler, but also the operation of external devices, including the coordination of additional heat sources. The controller supervises the measurement of the fuel temperature and, if necessary, the system is activated to prevent the flame from returning to the fuel tank.
In modern pellet boilers, burners are used, which in combination with other devices automatically adjust the work to the current heat demand. Another technical solution are burners with variable geometry, the burner operating temperature is monitored by means of a controller. Thanks to the ignition of fuel with regard to specific phases, the risk of explosions was removed and the cleaning of the boiler is performed during its operation. If the supply voltage fails, the boiler will operate on the basis of previous settings after its return.
Wood gasification boilers use a wood burning process in two stages. First, in the batch chamber incomplete burning of wood occurs with limited air access. As a result, gases are generated that burn in the secondary chamber. The boiler requires proper temperature to be maintained for proper operation. Therefore, the water circulating after installation can not be too low to avoid cooling the chamber and stop the gasification process. And maintaining the temperature of the working medium at 70-80 ° C throughout the heating season would cause overheating of the rooms and the necessity of cyclical boiler operation. As a result, wood gasification boiler usually works with heat buffer and mixing valve. This solution ensures that the temperature of the medium circulating in the furnace is adequately high and that the heating circuits receive the right temperature. The heat buffer with a capacity of 10 liters / m2 of the house’s surface is able to accumulate heat, providing heating of the house at least a few hours after the boiler is extinguished.