Application fields of scroll compressors

Accumulated specialized knowledge on refrigeration engineering and technologies provided a substantial progress in science and technology in the 20th century that introduced many new types of compressor equipment including scroll compressors.

The idea of a spiral is known to mankind more than 3 thousand years. Spirals (from Greek “speira” – turn) are curves twisted around the point on a plane (flat spirals), for example, a Archimedean spiral, a hyperbolic spiral, a logarithmic spiral, or around the axis (a helix), for example, a helical line. But the mankind was able to embody this idea only by the end of 20th century.

Scroll-compressors-Bitzer

All started in 1905, when Leon Crux, a French engineer, developed the scroll compressor design and received the patent for it. However, at that time this technology could not be implemented due to the absence of required production facilities. That is why the design of a working prototype was waited till the second half of the twentieth century because for effective functioning a small constructional gap in mating parts (spirals) should be provided in a scroll compressor. Such accuracy was possible only at precision machining developed during the second half of the 20th century, so the scroll compressor has rather recently appeared at the market of high-technology equipment. The idea of spiral compressors was re-invented by the physicist Niels Young in 1972. He brought the idea to “Arthur D. Little” company (USA), its management saw a high potential of this concept and began the development of possible model in January, 1973. Large manufacturers of petrochemical and refrigeration equipment were very interested in development of a compressor with principally new design, which allowed reaching a sufficient efficiency. During testing of a scroll compressor prototype it was found that it could create a high compression rate and had the largest efficiency of all refrigeration compressors existing in the early 1970s, and also had high performances (reliability, low noise level etc.).

Then at the end of 1973, “Arthur D. Little” company took great efforts for development of acting model of refrigeration scroll compressor for American Corporation “Trane”. A little later many large companies, for example, “Bitzer” (Germany), “Copeland” (USA), “Hitachi” (Japan), “Volkswagen1″ (Germany) began to research and improve the refrigeration scroll compressor design, and to master the whole compressor and its parts production technique. Prototyping of air scroll compressor has not been as rapid. By the end of the 1980s “Hitachi” and “Mitsui Seiki” (Japan) presented the oil lubricated air compressor. However these compressors were just modifications of refrigeration scroll compressors. “Iwata Compressor” (Japan) negotiated a license agreement with “Arthur D. Little” for air scroll compressor development in 1987. As a result, “Iwata Compressor” company was the first to present “dry” (without oil) scroll compressor in January, 1992. Air compressors initial power was 2.2 and 3.7 kW. Main advantages of “dry” scroll compressors by “Iwata Compressor” company in comparison with reciprocating “dry” compressors are the following: endurance, reliability, low noise and vibration level.

At the present time all manufacturers of compressors for refrigeration industry conduct the broad-scale research. Refrigeration scroll compressors have successfully withstood the test of time and actively began to oust other types of compressors (especially reciprocating ones) from the refrigerating equipment market having taken a dominant position on the market of conditioners and heat pumps just in few years. Every year scroll compressors find more application in refrigeration engineering and air conditioning systems. The reason for this is that they are more reliable in operation and contain by 40 % of parts less than reciprocating ones, they create less noise and have longer service life.

Last few years scroll compressors production volume have quickly increased and 20 million compressors had been produced by January, 2000.

Scroll compressors have found an application in all main systems of air conditioning including split and multi-split models, ground-type versions and in chillers, roof-tops (conditioners located under the roof) and heat pumps. A typical use is air conditioning in flats, on board, plants and large buildings, as well as on ATS, in cooling processes and transport. Refrigeration scroll compressors are widely used in condensing units, in “remote cold” systems of supermarkets, in industrial cold and transport systems including containers. Refrigeration capacity limits for scroll compressors are constantly increased and now approach to 200 kW when using a multi-compressor station.

Scroll compressors popularity is very high due to wide application field that can be explained by their reliability and multifunctionality.

Household (comfort) conditioning

Scroll compressors meet the requirements of this air conditioning sector as they have a low noise level, small dimensions and reduced weight in comparison with reciprocating compressors.

Their characteristics being more constant, better meet the requirements of comfort conditioning.

Single-phase electric motors of compressors (used for room conditioning) have no need in start relay and condensers. They are preferable because of their minimum action upon other loop elements.

Commercial conditioning

Scroll compressors refrigeration capacity is enough for meeting the requirements of commercial conditioning.

Also scroll compressors are applied for air conditioning in shops, travel agencies, offices, banks, restaurants, fast foods, bars and in many other objects. Conditioners with scroll compressors are successful technical solution especially for aggregates operating in summer and year-round and in heat pump mode.

Heat pumps

Scroll compressors in heat pumps have the reliability improvement advantages over other compressors types used in heat pumps due to the ability to control the liquid refrigerant supplied into the compressor in emergency cases (without its component elements damage).

Refrigeration units for computer centers and ATS

These branches require actually continuous operation of refrigeration units, often more than 8000 h/year. It is particularly significant to provide the continuous operation for the given conditions at the expense of constant service. At such conditions scroll compressors can have a favourable impact on energy consumption which reduces due to high efficiency.

A low noise level of scroll compressors is another factor that permits to use them in conditioning systems often installed in the compartments to be conditioned.

Autonomous units “roof-top”

The most typical field of their application is plants and food supermarkets where the advantages of high capacity of scroll compressors are especially required, because these sectors are usually characterized by high power consumption of air conditioning systems and refrigeration units.

The reliability is one more important benefit, which scroll compressor contributes to costs saving during supermarket working hours where the equipment operation continuity is a determining factor.

Other application fields

Multifunctionality of scroll compressors extends their application fields in technological processes, for example, in autoclaves for wine refinement, cooling systems of chemical industry molding machines, refrigeration systems, testing chambers, cooling canning of biogenic raw material (meat food, fruit and vegetables etc.), cooling of water-free cleaning equipment (solvents condensation), edible raw material processing etc.

Now many manufacturers of scroll compressors lead the active advertising campaigns. Reciprocating and screw compressors manufacturers lead not less active anti-advertising campaigns. That is why it is necessary to analyze as objective as possible the advantages and disadvantages of scroll compressors.

In particular, the scroll compressors have extensive prospects in restructured objects of distribution cold-store warehouses, cold-store complexes, vegetables and fruit storages. With transfer to market relations, cooling chambers utilization efficiency has considerably decreased. It is because of the freight turnover growth because of freights short-term storage and cooling chambers underutilization. For example, in distribution cold-store warehouses disposing chambers with 400 ton and higher (90 %) capacity, there were previously used nearly 100% of capacities; now, in respect of freight turnover increase and storage life reduction, 25…40 % of capacities are used.

Cost of freight storage services in distribution cold-store warehouses is reduced with increase of refrigerators loading from 25 to 100 % – 2.1…2.5 times, and specific cooling load decreases 4.1…4.4 times.

When restructuring the cooling chambers, the refrigerators loading increases and the cost of freight turnover reduces that ultimately improves a financial condition of enterprises.

For cooling of restructured cooling chambers (the transfer from chambers with 400 ton capacity to chambers with a capacity from 10 to 100 ton) the scroll compressors can be successfully applied with decentralized cooling system that, besides above mentioned advantages, reduces the system cooling capacity, the length and the quantity of pipelines and fittings, and thus provides the reliability and the environmental safety of refrigeration systems.

Поделитесь с друзьями
  • Facebook
  • Twitter
  • LinkedIn
  • Добавить ВКонтакте заметку об этой странице

Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>