Modern heating system is a demonstrationabsolutely new approach to its regulation. To date, this is not a preliminary adjustment before starting the system with the relief of the subsequent hydraulic mode of operation. Modern heating in a private house in the process of work has a constantly changing thermal regime. What requires the equipment is not only to track changes in the heating of the room, but also to respond to them correctly.
There are some points, compliance with which will ensure a high-quality and efficient operation of the heating system:
To calculate the heating in a private house,It is required to know the necessary amount of heat. For this purpose, the heat losses of the entire house are calculated in the warm and cold season. This includes heat loss through window, doorways, enclosing structures, etc. This is a rather laborious calculation. It is generally accepted that on average the heat source should produce 10 kW per 100 m2 heated area.
Под отопительной системой понимают взаимосвязь between the set of devices: pipelines, pumps, shut-off and control equipment, control and automation equipment for the transfer of heat from the source directly into the room.
Before making a hydraulic calculationheating systems, it is necessary to choose the right boiler (heat source). There are the following types of boilers: electric, gas, solid fuel, combined and others. The choice in most cases depends on the fuel prevailing in the area of residence.
Due to problems with power connection and a rather high price for electricity, this equipment has not found its wide distribution.
Чтобы установить такой котел, ранее требовалось special separate room (boiler room). At present, this applies only to equipment with an open combustion chamber. A similar option is most common in places with gasification.
With relative availability of fuel, thisequipment is not very popular. There are some inconveniences when using it. During the day, it is necessary to produce several times a furnace. In addition, the heat transfer regime has a cyclic character. The use of these boilers is facilitated (reducing the number of furnaces) by using a thermal cylinder or a fuel with a high combustion temperature, due to which the burning time is increased due to the controlled air supply. This can also be done by means of water heat accumulators, to which central heating is connected.
There are also generally accepted values of power density, which depend on the climatic zone:
Before proceeding to such a responsible event as the hydraulic calculation of heating systems, it is necessary to determine the power of the heat source using the following formula:
ATcat = S × Wud/ten.
For convenience of calculation we take the average value of Wud for 1 kW, so we get that 10 kW must fall on 100 m2 heated area. As a result, the installation scheme of the heating system will depend on the area of the house.
In other cases, forced circulation of the coolant using circulation pumps is used.
This is the classic version of the heating system,which has proven itself well for a long time of operation. Hydraulic calculation of the two-pipe heating system will be discussed below. Why is she called that? The fact is that the foundation of the engineering idea was the installation of several pipelines across the floors of the building. A heater was connected to one hot water riser on all floors, and cooled water from the heater was fed to the pipeline laid next to it.
В результате еще не успевший остыть теплоноситель from the first device entered the device, which was located on the floor below, and the circulating fluid had the same temperature as in the first one. Thus, the temperature of the coolant in the first and last pipelines was identical - this means that the heat transfer was the same.
Central heating in a private house with a two-pipe system has the following advantages:
Performing a complex hydraulic calculation of heating systems, first of all it is necessary to make a number of preliminary measures:
The settlement section is the one that has a constant flow rate and the same cross section.
In the calculated segment, the heat load is equal to the heat flux, which must pass on the supply pipe, and on the back has already transferred the circulating fluid that passed through this section.
Coolant flow Gand-f, kg / h is calculated by the following formula:
Dand-f = 0.86 × Qand-f/ (t2-t0), where
Dand-f - is the amount of heat in the calculated segment i-j;
t2-t0 - these are calculated temperatures of hot and cold liquids, respectively.
To reduce the cost of overcomingresistances during the movement of the circulating fluid, the diameters of the pipelines must be located within the minimum coolant velocity, which is required to remove air bubbles that contribute to the appearance of air traffic jams. To reduce them, the diameter of the pipelines is reduced to a minimum value that does not lead to hydraulic noise in the fittings and pipes of the system.
All production pipelinesdivided into polymer and metal. The first are more durable, the second - mechanically more durable. Which pipes to use in the heating system depends on its individual characteristics.
Given the amount of work that needs to be done at the design stage, you can use specialized software.
Используя исходные данные, программа выполняет automatic selection of pipelines of the required diameter; it pre-sets the regulating and balancing valves, thermostatic valves and automatic regulators in the heating system. Also, the program can independently assess what size heaters will be required.
