Basic principles of operation of district heating
District heating is a centralized system that distributes hot water for heating and for domestic and sanitary, connected to the buildings of the city. And 'best when the thermal energy is recovered from the fluids at the end of cycle thermal power plant, preferably fueled by methane (gas turbine combined cycle) or biomass or fuels derived from them (eg biogas), in these cases we speak of cogeneration electricity and thermal energy, are solutions with high energy efficiency, in the worst cases limited by the dispersion of heat in sections of the network too long or for bad network isolation of heat transmission.
New TG combined cycle power plants (natural gas) today are justifiable only if connected to district heating networks.
The district heating that is not downstream of the production of electricity is justifiable only in plants that use geothermal fluids can not be used for the production of electricity also.
A district heating service may also include air conditioning in summer, in this case we speak of trigeneration systems (electricity + calories + refrigeration).
District heating networks by central TGCC for cogeneration
District heating leads directly to the homes heat for space heating and domestic hot water without the need of having boilers, burners, fuel tanks and flues.
Reggio Emilia is a city that is leading in district heating systems, which includes the service of air conditioning in summer, this network is currently being realized a combined cycle power plant combined with the network of district heating and cooling, the maximum efficiency achievable with the technologies, standards, technologies that may have been adopted for many years.
By completing the survey you will receive from Parma AM Services a cost estimate hypothetical use of district heating customized according to the characteristics of the house or condo you selected.
In Brescia, the district heating service has benefited from 65% of homes.
Currently the municipalities served by district heating from combined heat and power gas are less than 30, among them:
Bologna, Turin, Vicenza, Imola, Castelbolognese, Cremona, Rimini, Cesena, Sesto San Giovanni, Lodi, Voghera.
Map of the district heating network of trigeneration in Reggio Emilia
Cogeneration is otherwise possible with renewable fuels such as biogas or biomass generally
An example of a central biomass cogeneration is to Tirano in Valtellina, it is a plant in the top 5 in Europe, characterized by a high efficiency (80%) thanks to the simultaneous production of electricity and heat, entirely from renewable sources. www.teleriscaldamento.valtline.it / pull / welcome.htm
Warehouse collection of biomass cogeneration and district heating in Tirano
District heating networks with geothermal reservoirs
District heating without CHP is justifiable if obtained from primary sources not otherwise recoverable, such as geothermal energy with low temperatures for the production of electricity also
District heating is one of the most interesting ways to directly use geothermal fluids at low temperature (80-100 ° C).
Is to use the geothermal fluid to heat directly through the heat exchanger, the water circulating in the heating elements (radiators, convectors or underfloor heating) of the heating of homes.
The premises required for a geothermal district heating plant are contained in volumes and can be camouflaged in urban areas, because they are not involved in the fuel system and the fluid used does not have temperatures that could create dangerous pressures.
A system of this kind is to Ferrara where you are using a geothermal well situated at 2000 meters deep, develops a power of 12 MW of thermal energy with which they are heated approximately 500,000 m3 of housing connected to the network.
Another example is the network built in Tuscany in the towns of Castelnuovo Val di Cecina, Monterotondo and Pomarance, which, overall, provides heat to more than 3000 users (for a total of over 915,000 cubic meters heated), with an overall annual savings of more than 5200 tons petroleum.
----------------------------------------
Translated via software
----------------------------------------
Source:
Italian version of ReteIngegneri.it