Heating - in
effect is the creation of artificial comfort for the occupants.
Heating is one of the construction and technological
installations building that meets the following requirements:
Aesthetic -
should blend in with the interior design space and not take up much space;
Assembly - have a
quick access to all components for assembly and disassembly;
Construction -
installation of elements of the heating system in conjunction with the architectural
- planning and design placement of buildings, without breaking the strength of
load-bearing structures at the time of installation and repair of heating
system;
Economic - as
much as possible to reduce the material consumption for heating in the
investigation and reduce costs;
Operational - to
present characteristics such as simplicity and ease of use, quiet and security;
Sanitary -
hygienic - the indoor temperature to be at a comfortable level, are required by
SNIP, without deteriorating air quality in the room.
Heating systems distinguish between local and centralized.
Local heating - a heating one or several buildings, centralized - it is
intended for residential and industrial area.
Central heating systems are divided into two main types of
heat sources: district heating plants (WT) and combined heat and power (CHP).
The composition of the heat supply system includes the
following types of elements: thermal network (piping from the boiler room to
the building), the heat source (boiler or boiler unit) inputs and local heating
systems heat.
In central heating systems use heat source combined heat and
power (CHP), which simultaneously produce and electricity and heat, or boilers,
which are called district heating stations.
In district heating systems are used mostly either water or
steam or air as the coolant. Of - for the type of heat carrier heating systems
are water, steam and air heating systems.
Heat carrier heating systems should have the following
qualities:
• Large heat impact;
• Mobility - in consequence of that loss in the pipelines
will be minor.
From the heat transfer performance depends initial and
operating costs of the heating system.
The parameters that tend coolant:
Water - it has high density (1000 kg / m3) and excellent
heat capacity [4.187 kJ / (kg * K)], which is characteristic of a large heat
output at low volumes. It is also possible temperature changes over a wide
range. In order to reduce the cost of water speed in heating systems is
limited 1.5 m / sec.
The steam which is used in heating systems, has a small
density (0.6 - 1.6 kg / m3), but in this density a large amount of heat. Heat
is the result of condensate generation in boiler units. Movement steam in
the steam has a speed of 40 - 80 m / s, as a result there is a significant
release of heat over long distances, but the economic costs are minor.
The air density is small (1.2 - 1 kg / m3), the heat
capacity [1 kJ / (kg * K)], in consequence of that return for the right amount
of heat will require a significant amount of air. From the point of view
of the economy it is not advisable to use air heating.
Consider the pros and cons of such heating systems, such as
water, steam and air system.
Water heating systems are reliable and suitable from an
environmental point of view. Such heating systems are most commonly used
in civil and industrial buildings, more online GazSintez .
Positive aspects of the water heating system:
·
Easy to maintain;
·
Silent operation of the system;
·
Ability to maintain a constant temperature
heaters on the surface;
·
Temperature control in view of outside air.
·
Negative sides:
·
The limited height of the heating system;
·
Freezing of water in the heating duct which is
located between the heating units and the consumer.
Unlike water, steam heating systems have several
disadvantages in operation and hygienic point of view. Therefore, these
systems are often used for industrial buildings and in buildings where people
are not a long time.
·
Positive aspects of the steam heating system:
·
Large heat heaters;
·
From the point of view of the economy is not
high cost of pipes and heaters;
·
Low Probability freezing, unlike a water heating
system;
·
Moving the steam over large distances without
any - any mechanical assistance.
The negative side of this heating system:
Great temperature heaters on the surface, resulting in burns
and the dust produced unsanitary conditions in the room;
There is no possibility of temperature control, it is a
constant, and as a result, to maintain the desired temperature based on the
outdoor air heating system has to turn on and off;
Large losses in the thermal circuit between the boiler and
the consumer;
possible deformation of the system - due to thermal stress;
Not long service life of the - due to corrosion of pipes.
But air heating systems meet the sanitary - hygienic norms,
but - for a number of shortcomings have been applied in combination with
ventilation. Applied as in public buildings and industrial.
·
Positive aspects of air heating systems:
·
These systems are compatible with good
ventilation;
·
Has the ability to control;
·
Large heat quickly warms the room up to a
comfortable environment;
·
The advantage is that the heating devices are
absent.
·
The negative side of this heating system:
·
Requires a large cross-section of the duct;
·
Significant heat loss in ducts.
These are the main characteristics that define the scope of
the heating systems of one kind or another.
