Geothermal
Geothermal energy embodies a very simple concept: use of the existing energy in the ground, without having to produce any more. In particular, having analysed the context in which the production plants of L’Italiana Aromi are located, the water from a water table just a few dozen metres away from the factory has been retrieved. The water has a temperature which is always constant and it can be used to provide the company with both hot and cold water. By means of a split unit with heat pump, which heats or cools the water, all the industrial processes of L’Italiana Aromi are supplied, in addition to the air-conditioning and heating of the rooms and bathrooms. To best meet the needs of the company, the split unit has been specifically designed to produce thermal energy in the form of hot water at a temperature of 50/55°C and, at the same time, refrigeration energy in the form of refrigerated water at a temperature of 4/7°C. At the end of the process, the water from the water table is fed back into the water table through a return well at a temperature ranging from ±3/4°C than the temperature of the incoming water. In addition to a significant reduction in energy costs, the plant allows a significant improvement from an environmental point of view, given the avoided emissions of greenhouse gases (Table 1).
Table 1 – Geothermal
Production of thermal energy (water at a temperature of 50°C)
Production of refrigeration energy (water at a temperature of 7°C)
Only production of refrigerated water:
- absorbed electric power 146 Kw
- refrigeration power yield 627 kW
Only production of hot water:
- absorbed electric power 201 kW
- refrigeration power yield 639 kW
Simultaneous production, hot and refrigerated water:
- absorbed electric power 206 kW
- refrigeration power yield 487 kW
- thermal power yield 693 kW
Cogeneration
L’Italiana Aromi’s cogenerative system, for the combined production of electric energy and integrated heat, is made up of an endothermal engine fuelled with methane gas coming from the town mains system in Carate Brianza. The engine which makes use of both the exhaust fumes and the cooling heat of the engine block, guarantees the production of electric energy which is passed into the network (Table 2).
Table 2 – Cogeneration
Electric power 240 kW
Useful thermal power 366 kW
Primary thermal power (from methane gas) 669 kW
Methane gas consumption 69,76 Nm3/h
Electric efficiency 35,8 %
Thermal efficiency 54,7 %
Overall efficiency 90,5 %
The thermal power of 366 kW can therefore be guided to the following circuits, listed in order of precedence:
- refrigerated water circuit (absorber)
- district heating water circuit
- hot water circuit tanks
