Capillary tube mat

A capillary tube is a flat composite thin tubes ( capillaries) with a manifold and a collector pipe. Main applications are chilled ceilings and underfloor heating.

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Technology

Idea

The construction of the capillary tube has created by nature networks of fine veins under the skin ( surface ) of living creatures provide a model organism not only nutrients, but also serve for thermal regulation of the body. The function of heat regulation has given the inspiration to move into the surrounding surfaces of spaces close to the surface capillary tube to let this flow through with warm or cool water and to control the temperature in this way the rooms. Similarly, since the veins under the skin of the body always many capillary tubes are traversed in parallel, the heat exchange with the environment is very intense and energetic at the same time effectively. A room that is heated using capillary as surface heat exchanger, required for heating or cooling supply temperatures, which must be chosen only a few degrees from the desired room temperature. At the same time, the large number of parallel capillary tubes is the driving energy for maintaining the flow compared to " one-pipe systems," which are laid as a meander ( typical installation of underfloor heating pipes ), comparatively low. The short distance of the capillary tubes to the surface of the space, the system is very responsive. The temperature of the heating or cooling medium is delivered very smoothly and quickly through the large number of capillary tubes to the environment. These two properties - excellent heat transfer and low pressure drop - are advantageous in terms of energy savings. In a further version of the terms of the art, the capillary tube is a surface heat exchanger and can be used to transfer heat between two media.

Features

The capillary tube has a typical capillary tubes with an outer diameter of less than 5 mm. Thus, the design is very flexible and thus underlines the property " mat ". The individual capillary tubes are arranged in register with a mutual distance of 10 to a maximum of 50 mm. Capillary tube mats are usually made ​​of plastic. Common is the production of polypropylene, which is often used in construction for piping and in the ventilation and air conditioning technology. This material and the small dimensions justify the flexibility of the register and thereby the property of the mat. The use of plastic in the manufacture of capillary tube, instead of copper or steel as in other cooling ceiling ducts, affects greatly reducing cost. Since the capillaries have very thin walls, the lower thermal conductivity of the plastic over metal but is not detrimental to the heat transfer from. Polypropylene is very resistant to many chemicals (DIN 8078) and is therefore very durable. Polypropylene is very easy to recycle. Polypropylene is oxygen- permeable. This property requires that the capillary tube mats are always operated in corrosion-resistant piping systems. This guarantees the safe functioning of equipment and adequate protection against corrosion (corrosion and corrosion protection). The preparation of the capillary tube is in standard methods of plastics processing by extrusion, thermal plastic welding and injection molding.

History

The invention of the capillary tube goes back to the year 1981, when the Berlin Dipl. -Ing. Donald autumn has filed his first patent ( DE 31 24 048, filing date 06/15/1981, " braid piping for hot water radiant heating of floors or walls " ) for this technique. It followed from his long career in the service of Kapillarrohrmattentechnik a variety of complementary inventions / patents, whereby the manufacturing process and the applications of capillary tube mats were constantly evolving. In the early years of the capillary tube were brought under the brand " KaRo " in the market. On the occasion of the International Building Exhibition 1984 in Berlin, won the design by the architects von Gerkan, Marg and Partners for an energy efficient house. Here capillary tube mats were used in a complex system in a 1,200 m² residential building for the first time. Extensive scientific work of Prof. Dr. Mathias Fraaß (since 1991) and later by Prof. Dr. Bernd luck (since 1994) laid the necessary foundations for the theory in the applications of capillary tube. Today capillary tube mats are installed worldwide. The annual production is estimated at more than 400,000 m² (2010).

Meaning and application

Capillary tube mats are mainly used in cooling ceilings. Each design of a cooling blanket can be activated by capillary tube. In addition to the cooling plaster ceilings with capillary tube, which require less than 15 mm plaster layer, the capillary tube are placed in metal coffered ceilings and suspended plasterboard ceilings. The transmitted cooling capacities are with the different designs each at a temperature difference of 10 K between the mean fluid temperature and the room temperature between 65 and 90 W / m². Free in the room hanging capillary achieve cooling capacities of more than 100 W / m².

Plaster ceiling with cooling capillary

Also in the thermal component activation BTA capillary tube can be used. Unlike conventional concrete core BKT are the thermal activation device, the capillary tubes about 5 mm just below the ceiling surface. This arrangement ensures a fast response and a high transmission power up to 90 W / m² (at 10 K temperature difference above) and also uses the concrete mass as thermal storage. With very thin capillary -building heating surfaces can be built as a floor heating or wall heating. A layer thickness of less than 15 mm is possible. Capillary tube can also be used as a compact collectors for use of geothermal heat in heat pump systems. The withdrawal area can be reduced through the use of the capillary tube. In the processing and manufacturing industry capillary tube mats are already used for temperature control, among others, acid baths.

Great projects

  • Olympic Village Vancouver, Canada
  • Twin Towers Vienna, Austria
  • UNIQA Tower Vienna, Austria
  • Alliance Treptow Berlin, Germany
  • Hôpital de Lagny, Marne la Vallee, France
  • Jin Mao Palace, Beijing, China

Determination of performance

Since the capillary tube mats are versatile, also different methods for determining the performance require. So is the case for cooling ceilings DIN EN 14240 ( measurement in a test area). For many applications of capillary tube but there are no test standards, such as for geothermal collectors, cooling ducts, storage with PCM shares etc. For this purpose, simulation methods have become very important. This is economical optimum can also be used in the development of components, as can be sometimes greatly shortened by previous trend calculations relating to the expected benefits of the development effort. Many simulation models are downloadable for free. For more general studies are also available free of charge.

Capillary (disambiguation)
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