District Heating: a wide experience in energy networks

Cannon Bono Energia counts on several important references in the district-heating sector: plants have been installed in Italy, France, Switzerland, Kazakhstan, Vietnam, etc. The most popular type of equipment supplied for this challenging application is based on a heater solution named CTH, a multi-tubular water tube design: these heat generators can be installed directly on the district heating networks —where network hot water circulates directly in the CTH tubes —or through heat exchangers, depending on water characteristics.

Having no practical limitation on the pressure design, that can reach values higher than 40 bar, and on hot water inlet temperature, limited only for flue gas temperature consideration, the CTH have been extensively installed in many large Italian district heating applications.

Main advantages offered by CTH design are connected to the package configuration —they are shop assembled up to 40 MW —and to their quick response time to load variation. Furthermore the possibility for shop prefabrication of many parts of the heaters in a modular concept provides for very short delivery and installation times for field erected units (up to 80 MW).

Simplicity of the water treatment, elimination of the thermo physical deaeration, rationalization of the primary and secondary water distribution lines are also important aspects to be taken into consideration.

High efficiency, low emissions, competitive cost

The thermal efficiency up to 95/96 % and ultra low emission levels (100 mg/m3 of NOx levels @ 3% of Oxygen in the flue gases) are absolutely significant in the emission reduction as required by Kyoto Protocol. With a very simple design involving a reduced number of components, the CTH generators have a competitive price for a wide threshold range starting from about 10MW.

For all these reasons this Cannon Bono Energia thermal machine has become a preferred solution for the important district heating plants operated by utility companies in various Italian cities (A2A in Milano, Bergamo, Brescia) and airports (Milano Malpensa and Linate, and Roma Fiumicino). Even the CERN (European Centre for Nuclear Research) large compound of offices and laboratories in Geneva has been provided with Cannon Bono Energia district heating solutions!

Stringent emission levels have always been a “must have” specification from the utility companies, facing tough daily exams from the public opinion and environmentalist groups, always keen in keeping them under a strict scrutiny for emissions and pollution.

The law-permitted limits, valid at the time of starting a new plant, are always drastically cut by the client, in order to be safe with their emissions also in the future, when those limits will be more restrictive.

Cannon Bono Energia always complied with the imposed specifications, combining high thermal efficiency and low emissions.

HRSG, recovering waste heat from power generation to feed the airport thermal conditioning systems

An airport is a complex system of buildings and facilities with costs comparable to, if not higher than those of major sea ports and definitely more difficult to manage. Good temperature-conditioning in lounges, offices and areas devoted to passenger services is key to ease the tension of long waiting hours and to provide a pleasant break for those who are required by their business schedule to spend the day at the airport.

Three major airport terminals in Italy (Milano Linate, Milano Malpensa, Roma Fiumicino) are demonstrating the Cannon Group capability to focus on advanced technological solutions in the district heating. Specifically, the air-conditioning system of Milano Malpensa is driven by a Cannon Bono Energia thermal station with an installed capacity of 46 MWt, roughly equal to the amount of power used by a city district composed of 2,500 medium-sized flats. The company has supplied two gas-turbine recovery boilers to produce superheated water at 150°C that is transferred to a thermal cycle to provide heating/conditioning to all airport facilities.bb

Cannon Bono Energia has also supplied the district heating plant for Roma Fiumicino international airport, which requires an overall capacity of 50 MWt. superheated water at 150°C, with a return temperature of 90°C, is distributed by a network of pressurised systems at 16 bar.

Feedwater system for boilers Cannon Bono Energia
The feed water treatment equipment, composed by a reverse osmosis section and two degassing units.
Discrict heating boilers, internal view Cannon Bono Energia
Distric Heating Boilers, Cannon Bono Energia