1. How are energy saving requirements changing the sector?
These days, energy saving is no longer the prerogative of a few companies; rather, it is a bona fide obligation, which is enshrined by the European Community through the climate-energy package. This is a Directive that was issued in 2005, with the triple objective of reducing greenhouse gas emissions by 20% and increasing energy saving and the use of renewable energy sources by 20%, all within the year 2020. In this respect, manufacturing companies in the sector of compressed air are also getting involved in research and development of solutions aimed at pursuing these efficiency parameters. Energy improvement passes through a number of actions, which, as regards the technological aspects, involve the electric motor, the compressor, and the distribution lines of the compressed air. Considering the operational aspects, on the other hand, the regulation of the quantity of compressed air produced (which must balance the demand coming from the utilities) and the monitoring of line losses would appear to be the two most important issues.
2. When did you begin collaborating with Mattei and what were your goals? What, in your opinion, are the advantages that can be achieved with the rotary vane technology developed by the company?
My collaboration with Mattei began in 2002, in the wake of a degree of visibility that the Department of Mechanical Engineering, Energy and Management of the University of L’Aquila (DIMEG) had accrued through having participated in a European SAVE Project, which was created to evaluate the potential for energy saving in the sector of compressed air, and to examine the broader economic issues. In this project, DIMEG carried out an operation of considerable importance, defining the indices of energy consumption and CO2 emission associated with the production of compressed air. At that stage, we accordingly found an Italian company, which was already well informed as regards the energy saving sector, and together with the company, we began an absolutely innovative procedure of model making and experimentation.
In the sectors of compressed air for light and heavy industrial use, and recently, also in other sectors associated with haulage, rotary displacement compressor technology is without a doubt the most widespread, compared to other types of machines (dynamic compressors, reciprocating compressors). This is due to a number of reasons connected with compression ratios (normally comprised between 7.5 and 10 bar), and to the mass flow rates (or volumetric flow rates) required by the applications.
Among rotary displacement machines, in some power bands, those with vanes have advantages associated with energy absorption, with greatly reduced vibration and noise, and with the adoption of technologies that allow the machines to operate at a more efficient partial load. This aspect is particularly important in that the various utilities require variable air flows (depending on the use of the compressed air) and sometimes the demand is reduced drastically: switching the machines on and off produces inefficiency and transient operation which is very wasteful from an energy perspective. Vane compressors require decidedly less time to reach a thermal steady state, their rotating masses are smaller, they do not suffer from thermal expansion of the rotor during operation, and they do not necessitate particularly heavy and critical shaft supports (bearings). Thanks to all these aspects, the maintenance of these machines is greatly reduced, and is essentially limited to replacing the lubricating oil at very infrequent intervals.
During recent years, the Department of Mechanical Engineering, Energy and Management of the University of L’Aquila has carried out in-depth research, creating a software simulator that represents the operation of a vane compressor with a high degree of precision. In this way, it is possible to predict the functioning of the compressor without constructing expensive prototypes, limiting this phase to the final part only. From these simulations and measurements, a further potential 7-9 % of energy savings can be observed, which, given the high cost of energy, is an extremely interesting target in industrial applications.
3. What, in your opinion, are the new fields of application where vane compressor technology could be beneficial?
The advantages of vane compressors lie in the simplicity of the machines, the high level of reliability, and the possibility of notably reducing the dimensions, if the speed of rotation is increased. The absence of vibrations is another unquestionable plus. Hence, they would appear to be particularly suitable for all applications in the sector of light and heavy haulage, by road or by rail. The aforementioned characteristics are also significant in those high-end sectors where space and comforts are priority items, such as in the shipbuilding industry.
During these years of collaboration with Mattei, we have also investigated the possibility of introducing vane compressor technology into the automobile sector as an element for controlling flow. Vane compressors, in fact, supply a flow from the machines that is linearly dependent on the speed of rotation. The results have been very promising and research is continuing with the collaboration of a major company operating in the field of internal combustion engines.
4. What advice do you feel you should give to companies regarding the implementation of energy saving activities?
As was previously mentioned, these days energy saving is more of a necessity than a technological option. At a national level, subjects have been identified (the distributors of electricity and gas) which must attain specific energy saving values, in all the sectors relating to final uses (thermal and electrical energy). The unit that is commonly referred to for quantifying the efficiency of energy saving is the tonne of oil equivalent (TOE), which reports, in fossil fuel units (tonnes of oil saved), the various energy saving or optimization actions.
When a company implements a policy of reducing energy consumption, it achieves energy savings which, quantified in TOE saved, may be acquired by those entities that are obliged to achieve fixed quotas of energy savings, but which have not been able to do so in their facilities. The energy saving is hence transformed into “energy efficiency certificates (white certificates)”, which can be sold by the company, thus yielding a profit. The considerable savings of electricity associated with the adoption of high-efficiency compressors, in addition to a reduction in expenditure on electricity, end up ensuring an extra income relating to the sale of the white certificates.
Professor Roberto Cipollone – Graduated in Electrical Engineering (specializing in Automatic Control Systems) in 1980. In 1983, Roberto Cipollone transferred to Brussels and joined the Von Karman Institute for Fluid Dynamics, one of the world’s most prestigious learning centres for experimental and computational fluid dynamics.
In 1989 he won the public competition for the position of Researcher, in 1991 the contest for Associate Professor in the teaching post of Dynamics and control of fluid machines, and in 1993 he became Full Professor, instituting the Full Professorship in Interaction between machines and the environment. In 1994 he took over as President of the Environment Committee of the University and of the Council of the Degree Course in Environmental and Territorial Engineering: in the first sphere, he was responsible for a University project on the restoration of the water catchment area of the Aterno-Pescara river; in the second, he contributed towards the establishment of the Degree Course in Environmental and Territorial Engineering for the Industrial Systems segment.
At present, he holds the role of Director of the Academic Board of the Research Doctorate in Mechanical Engineering, Energy and Management of the University of L’Aquila. He is also the President of the University Consortium of Marsica, a member of the Board of Directors of the Fucino Energia Consortium, and he plays a managerial role in the establishment of the energy innovation campus of the Abruzzo Region. Within the sphere of his doctoral activities, Roberto Cipollone has contributed towards the foundation of a school of Energy and Environmental Planning of the Territory, which involves the participation of several PhD students.
WHO IS MATTEI
Ing. Enea Mattei SpA designs, manufactures and sells rotary vane compressors on a worldwide scale. This exclusive and distinctive technology has made it one of the authorities in the market segment of compressed air. Every year the company makes 6,500 rotary vane compressors, exporting more than 50% of its production.
Mattei is based in Vimodrone, in the province of Milan, and has two plants in Vimodrone and Verdello-Zingonia (Bergamo). It has subsidiaries in France, Germany, Great Britain and the USA, representative offices in Russia, Spain and Singapore and numerous commercial partners in the rest of the world. In addition, to meet the growing demands of the South-East Asian market, since 2007 a Mattei production and assistance site has been operative in China.
Founded in 1919, Mattei is still a family-owned company today.
