Why and how is the heat transfer calculation

What to consider when carrying out calculations.

steel tube heat transfer calculation is performed to determine the amount of heat released from the surface of the tubes.This calculation requires only two cases:

• definition of heating system parameters to obtain the desired temperature;
• calculation of heat for the subsequent selection of insulating materials

Heat transfer pipe is calculated as follows:

Q = K * F * Δt,

where

Q - heat, kcal / h;

K coefficient of thermal conductivity, kcal / (m * h * 0C)

F - square pipes, m;

Δt - temperature difference, which is calculated as follows:

Δt = 0,5 x (ts + t î) - TV,

where: ts - water inlet temperature, 0C

t î - water temperatureexit, 0C

TV - temperature environment, 0C

required values ​​for determining the temperature difference are taken according to the tables SNIP:

• ts = 80 0C
• to = 70 0C
• ti = 20 0C

thermal conductivityIt depends on such data:

• pipe material;
• its diameter;
• number of construction details;

Calculate the area of ​​the pipe is also easy:

F = P * d * l,

where: P = 3,14

d - diameter of the pipe

l - the length of the pipe

give an example.

How much heat can radiate steel tube length of 1 m and a diameter of 30 mm?

Since this theoretical calculation, we take the value of Δt = 55 0C.

Next:

F = 3,14 * 0,03 * 1 = 0.09 sq.m

coefficient of thermal conductivity of the steel pipe is approximately R = 11.5.

Q = 11,5 * 0,09 * 55 = 56.9 kcal / h

Since almost everything is much more difficult, then, for a more precise calculation is necessary to see a specialist.

be taken into account and secondary indicators, affecting the heat:

external shape of the pipe;

• its area and diameter;
• presence or absence of the paint;
• physical properties used heaters;
• air temperature in the house (or outside);
• motion coolant velocity.

Increase heat.

To effectively increase the index of radiant heat, there are many ways:

• installation convector;
• paint tubes with black paint;
• setting register;
• extra battery section.

convector is a curved pipe with metal plates.Produce can be your own or buy in the store a more modern equivalent.

Application of matte black paint for painting the surface of the coolant also provides a good result.Aesthetically it does not look very attractive, but when it comes to comfort, we have to choose.

Another inexpensive and very popular design is the case.This is somewhat interconnected pipes with broad brewed slices.They also include heated towel rails, radiators, trunk lines, and even ordinary steel pipe, fixed around the perimeter of the room.

Reducing heat.

To save energy, become actual reduction of heat transfer tubes in those areas of communication that are not used for other purposes, for example when moving from one building to another or in an unheated room.

For this there are many options for using insulating materials.Manufacturers are enough to choose from a wide range of products, ranging from cheap fiberglass to more expensive types of polystyrene foam.Can be purchased tube with built in it insulation elements.

To summarize, we conclude that the use of such calculations help save considerably and avoid the many technical hurdles in designing water and heating systems.