Liquefied hydrocarbon gases are used in heating units, water heaters and are a mixture containing propane and butane. The composition is transported and stored in liquid form in storages or cylinders, and before use, the fuel is evaporated and fed to the boiler burner. The energy efficiency of the building determines the consumption of liquefied gas for heating a house of 100 m2 and consumption costs.
Description of LPG
Gas belongs to the substances of the alkane group; it is found in the form of components in natural analogues. Propane without impurities is odorless, but additives with a strong aroma are added to the technical mixture. There is little toxicity, but an effect on the nervous system is noted.
Liquefied petroleum gas (LPG) differs from its natural analogue in that it is a product of high-temperature processing of petroleum fractions and chemical processes. Natural methane is extracted from the earth's interior. Both types are used for heating private buildings, but differ in chemical properties, characteristics and method of transportation.
LPG is characterized by high calorific value, but its cost is higher than that of natural gas. Methane is supplied to the consumer only through a centralized pipeline.
Propane use
Chemical and physical properties of propane:
- molecular weight - 44.097 kg / kmol, molecular volume - 21.997 m3 / kmol;
- liquefied gas consumption per 1 kW of heat is 0.16 dm3 (liter);
- gas density at 0 ° C - 2.0037 kg / m3, at + 20 ° - 1.87 kg / m3;
- density in the liquid phase - 528 kg / m3;
- the volume of air required for combustion of 1 cubic meter is 23.8 m3.
Despite the higher cost, liquefied gas fuel is more convenient to use. It turns into a liquid state and can be stored this way. To save natural methane, it is required to compress it under a pressure of 200-250 atm, and transportation in a liquefied form is possible only at cryogenic temperatures (below 120 K).
Centralized gas pipeline
The main line is constructed of steel pipes with a diameter of up to 1.42 m and is designed for pressure up to 10 MPa. The pipelines pass about 55-60 billion cubic meters of gas per year. Highways are laid underground or on the surface. Comprehensive service includes compressor stations, cleaning and drying stations, gas distribution points.
Gas holders
For continuous supply of LPG, underground and aboveground gas tanks are used, which are installed in a multi-storey sector or on the territory of a private residential area. From the tank, fuel is supplied to apartments and houses, and is used to heat the room.
Gas tanks have a control system and record the filling of the sump. The sensor detects the gas level and sends a signal to the service when the fuel level in the tank drops to 30%. The operator sends a tanker truck to fill the tank.
At the bottom of the gasholder, liquid is constantly accumulating, which has not turned into a gaseous state, the tank needs cleaning. The storages are convenient to use as they provide a continuous supply of fuel.
Cylinders
Gas cylinder parameters:
- unit length 28 - 95 cm;
- diameter - 20 - 30 cm;
- wall thickness - 3 - 4 mm;
- weight - 4 - 22 kg.
Using statistics, you can calculate how much gas is needed to heat 80 square meters of dwelling. At low temperatures, heating of such an area requires 2 forty-liter cylinders when using antifreeze in the heating system. This is 25 - 30% higher than the cost of gas for centralized supplies. It is allowed to combine 15 cylinders in a closed metal cabinet.
Factors Affecting Calculations of LPG Consumption
Most of the heat escapes from the room through the walls. Heat flows are characterized by a complex trajectory of movement and leave the dwelling through the ceiling, floor and windows. The building envelope must be insulated against energy losses, otherwise the gas consumption will be high.
Fuel consumption depends on factors:
- the climate of the area - to calculate the flow, the lowest temperature values are taken;
- heated area, layout, number of storeys of the building, height of ceilings;
- the degree of insulation of the roof, walls, floor;
- building material (concrete, wood, brick);
- type of filling of window openings;
- the presence of organized ventilation of rooms;
- boiler power.
The geometry of the house affects heat loss. A complex perimeter with many wall ridges and a combination roofing increase the risk of cooling. The power of the boiler does not affect the heat loss, but the correct selection of the parameter is required for efficient fuel consumption.
Formula for calculation
Theory and practice show that for heating 1 m2 and heating the liquid in the water supply system, 169.95 kW of heat is needed per year. For the calculation, the calorific value of LPG is used - 12.88% and the boiler efficiency - 98%.
Gas consumption for heating a house of 100 m2 is made according to the formula ((169.95 * 0.1288) / 0.98) x Swhere S means the area of the house. To calculate the cost of heating, the flow rate reading is multiplied by the gas price per kg.
What matters is the calorific value of the fuel, which shows how much heat is produced when a unit of fuel is burned. For LPG, this indicator is always higher than for natural gas, firewood, coal.
Ways to reduce fuel consumption
The energy efficiency of the home needs to be increased in order to reduce the gas consumption for heating the home. With these methods, fuel can be saved up to 5-15%. For the winter period, the dwelling is made as airtight as possible so that the internal energy does not go outside.
Blockage and insulation of the house leads to the need to install an organized ventilation system. The use of a recuperator is recommended. This device is an efficient heat exchanger that reduces heat loss while supplying fresh air to the rooms.
Where have you seen an efficiency of 98% at a gas boiler? Modern floor-standing and wall-mounted boilers have a maximum efficiency of 92%. And that's in theory. In practice, the efficiency will be even lower than 88-90%.
Gennady, any condensing boiler has an efficiency higher than 100%. Do not rush to immediately scratch out my eyes with the law of conservation of energy. Be careful not to sound funny. Study the topic first, then there will be less hasty judgments.
With an efficiency higher than 100%…. This is the Nobel Prize at least and the Perpetual Motion Machine to boot!
it depends on what winter
I installed, maintain and repair dozens of condensation units of different brands up to 90 kilowatts, I tune by instruments, I beat tambourines, I speak, a shaman, but I never achieved 100% :))
calorific value of LPG - 12.88%. It seems that the formula should be multiplied by 0.1288, and not divided by 12.88, as the author wrote :)
In this case, you are ridiculous! It was necessary to teach physics and arithmetic at school, then you would not be so funny)))
I have an Ariston boiler, and so the efficiency of 103% is indicated in the passport, I did not believe it and called the manufacturer, the manufacturer confirmed, I do not know what to think about this.
For non-specialists - the efficiency is more than 100% reality. The catch is how you calculate it. There are two calorific values of gas (any fuel in principle) - the lowest (this is without taking into account the latent heat of condensation of water vapor) and the highest (with this in mind). So, the real efficiency, taking into account the gross calorific value, of the condenser will also be less than 100%, and the usual boiler has a very sad figure. So, as that Jewish accountant from the anecdote said, it is important what we do - we sell or buy.
Marketers rule. For information - the condenser works only up to 55 degrees in supply, that is, only warm floors, no one will go for the gigantic dimensions of the radiators, hence the exit from the condensation mode and goodbye efficiency more than 100%, hello 90%. (this is a pebble in the garden of an adjuster-repairman with a statement that the boilers have not reached 100%).
Yes, the average fuel consumption for the heating season is done in a completely different way. And for an accurate calculation, a normal accurate heat engineering calculation for heat loss at home is required, only in this case it is possible to answer this question with sufficient accuracy. All methods are there.
I do not understand the whole topic, but OGV-22 eats 35 liters of liquefied gas in 3 days, at -25 gold heating, a friend has this, I personally use a gas inverter at the dacha, 35 liters is enough for 10 days at full power 3 burners and this is only for primary heating, then the mode of maintaining a comfortable temperature of 22-24 *, 60 sq.m is heated in 5-6 hours.
My gas consumption at this temperature outside the window is 171 rubles per day, I heat 700m2