Radiator

Sectional cast-iron heating radiators are designed for central heating systems of residential, public and industrial buildings with a large number of floors. They differ in significant thermal power per unit length of the device and, accordingly, in compactness. Cast iron radiators are also less susceptible to poor quality coolant and corrosion resistance .

Cast iron radiators are strong and quite durable. Their large mass , on the one hand, provides them with high heat capacity and, accordingly, thermal inertia, allowing them to smooth out sharp changes in temperature in the room; however, it is also a drawback, creating difficulties in installation or maintenance. Also disadvantages include the tendency of intersectional gaskets to degrade; with prolonged use (over 40 years), the destruction of radiator nipples is possible . Cast iron radiators require periodic painting; in addition, the walls of the internal channels are rough and porous, which eventually leads to the formation of plaque and a decrease in heat transfer. The working pressure of the cast-iron section is not more than 6-10 atm.

Aluminum radiators are today considered the most effective due to the high thermal conductivity of aluminum and increased due to the protrusions and ribs of the surface area of ​​the radiator. Almost all modern radiators, designed for operation in central heating systems, have a working pressure of more than 12 atm, pressure testing - more than 18 atm.

The advantages of aluminum radiators include lightness, small size, high working pressure, maximum heat transfer , a large cross-sectional area of ​​the collector tubes.

A significant drawback of aluminum radiators is the corrosion of aluminum in the aquatic environment, which is especially accelerated by the contact of two dissimilar metals or the presence of stray currents in the heating network .

Aluminum is an active metal, and if the oxide film covering its surface is broken, then upon contact with water it decomposes with the release of hydrogen . If the heater is tightly closed, increasing gas pressure can cause the radiator to rupture. This phenomenon is fought by applying a polymer coating to water-contacting surfaces, which also improves anti-corrosion properties, allowing the use of coolants with a pH level of 5 to 10; reduces hydrodynamic resistance, prevents blockages and sticking. If the radiator does not have an internal polymer coating, it is forbidden to block the taps on the supply pipes .

Aluminum radiators are most often divided into three main types: cast with integral sections, extruded with a mechanically connected set of sections and combined, combining the qualities of both of these types. For work in high ^{[ which one? ]} operating pressure, bimetallic radiators made of aluminum and steel are used.

One-piece aluminum radiators

These radiators are structurally composed of profiles made by extrusion and interconnected by welding . The aluminum used in them does not require any additives, and therefore retains its plasticity ; accordingly, external impacts and internal water hammer do not cause chipping of ribs and cracking of such radiators. The absence of intersection gaskets in such radiators gives them strength and reliability, and in the presence of an internal polymer coating their durability can exceed the durability of cast-iron radiators . However, since their design is non-separable, they cannot be extended during operation.

Sectional Aluminum Radiators

Such radiators are structurally composed of sections made by injection molding , which are interconnected using threaded connecting elements ( nipples ); the intersection joint is sealed with gaskets made of paronite , high temperature silicone or other materials. Sectioning provides an opportunity to build up a radiator during operation or replace a damaged section, however, the presence of intersectional connections adversely affects reliability; in addition, the inner surface of the sections is more rough.

Steel panel radiators

Such a radiator is a rectangular panel consisting of two steel sheets welded together with stamped recesses, during welding forming channels for the circulation of the coolant. Sometimes, to increase heat transfer, U-shaped steel ribs are welded to the back of the panel. Several of these panels can be combined into a package and closed with decorative strips on top and sides.

Panels of various heights and widths are available, which allows you to create a device of any thermal power. Panel radiators are shallow and lightweight; accordingly, their thermal inertia is negligible. The area of ​​the heated surface of the panels is very large and stimulates the intense movement of heated air - the proportion of heat flow transmitted by convection reaches 75% , which allows these devices to be classified as convectors.

For the manufacture of panels low carbon steel with increased corrosion resistance is used. The steel surface is degreased, phosphated, coated with powder enamel and heat treated.

In cases where the heating system has direct communication with the atmosphere (for example, through an open expansion tank ), these radiators are prone to corrosion and can only last for a few years.

The disadvantages of panel steel radiators include a small working pressure for which they are designed, sensitivity to hydraulic shocks, and the insecurity of the inner surface from the corrosive effects of water. These properties limit their scope to autonomous heating systems with good water treatment. In addition, the rear surfaces of the devices are difficult to remove dust.

In most cases, panel radiators are designed for operating pressure from 6 to 8.7 atm, pressure testing - up to 13 atm and a maximum coolant temperature of 110 ° C . They are recommended to be used in individual and low-rise construction, and in the presence of an individual heating point - in buildings of any number of storeys.

Steel Sectional Radiators

Outwardly, these radiators resemble cast-iron, but their sections are connected to each other not by threaded nipples, but by spot welding. They are more durable and durable and are designed for operating pressures from 10 to 16 atm. . However, due to the features of the production technology, the cost of these radiators is quite high, which leads to their relatively low popularity.

Steel Tubular Radiators

Tubular steel radiators are a welded tubular construction and are the most expensive. They are produced based on a working pressure of 10-15 atm. . Welded joints minimize the likelihood of leaks, but the disadvantage of these radiators is the small thickness of the steel (1 mm or less).

Bimetal Radiators

Bimetal radiators differ from aluminum in the presence of steel internal elements. The design of these radiators is such that the margin of safety exceeds all possible pressures in the system many times (destructive pressure is 100 atm), the contact of the coolant with aluminum is reduced to almost zero. The only drawback can be considered only the highest cost among radiators.

The oil cooler consists of a sealed enclosure filled with mineral oil , in which an electric heater is located. Heat from the latter is transferred to the oil, then to the body, the temperature of which does not exceed 60-70 ° C, and from it to the surrounding air . The use of oil as a coolant eliminates the possibility of rust. In heating systems where water is used for heat transfer and corrosion of metal parts is possible after the end of the heating season, moisture is removed by blowing with dry compressed air.

The principle of steam heating is the basis of the energy-efficient operation of a heat-sink radiator. The high efficiency of steam heating is a well-known fact, namely steam heating has been used for more than 100 years. In the manufacture of an energy-efficient heat-sink radiator, it was possible to preserve all the advantages of steam heating, while eliminating its disadvantages. The heat-sink radiator is a metal hermetic design, the principle of which is based on the use of the energy of the phase transition of steam - liquid, steam spreads at a high speed throughout the volume of the radiator, condenses on the inner surface, transmitting its energy, thereby quickly and evenly heating the entire radiator.

According to the first and most probable version , the name “battery” came from the fact that the steam heating radiator has from several pieces to several tens of radiator sections and was named by analogy with a galvanic battery. The word radiation is used for energy exchange processes associated with a long distance. And not with the direct interaction of atoms. In the case of long-range energy exchange, energy transfer occurs through the participation of energy carriers in the form of “thermal photons”.

The use of different names

In the literature of the XX and XXI centuries, it is practically impossible to find the official name “radiator” , but the word “battery” is common, the same applies to all electronic and print media.

• In the song by Vladimir Vysotsky, “About the Vacha River and Fellow Traveler Valya,” the lyrical hero reports that he sleeps on the stairs, “where the heat is from the batteries.”

• Convector .

• Which is better - bimetallic radiators or cast iron - a comparison of technical specifications