The district heating set up with a cogeneration system, concurs to attain energetic, economic and ambient benefits. It also provides to citizens a new service. The project strategy is based on the idea of supplying a portion of the necessary thermal power through a combustion alternative engine in cogeneration modality. It's also interesting to modulate the load with auxiliary boilers fed by natural gas. This solution allows to save primary energy, create a centralization of the energy production, which contributes to the problem of polluting emissions, through the decentralization of the sources. The first step to assess the technical-economic feasibility of a district heating system, based on a cogeneration plant, is to underline and to characterize the energetic request of the basin of user.
The objective of the present work is to develop a model that yields an esteem of the hourly thermal load for every days of the heating season of a complex user, represented by a single neighbourhood.
To do this, the present work proposes a new method of simulation of the daily and hourly thermal load trend, known only the value of the power installed in the thermal plant for every user, the seasonal hours of the burner operation and the timetable of the heating service distribution, more than the external mean daily temperature trend.
The results obtained using this model, have been verified with the data of seasonal consumptions, confirming the validity of the proposed methodology.The above allows to determine, with more precision, the thermal request peak to satisfy, taking in consideration the contemporaneity of the loads, also of different typology, and to carry out a better sizing of the generation plant.
At this moment the situation in terms of energy and energetic resource, results critical. The stock of the fossil fuel decreases gradually and the increase of the international energy request has produced a search of objectives, ratified in the Kyoto protocol, such as the rational use of energy, the improvement of the process's efficiency, the passage towards fuel with a minor contained of carbon. But, the principal objective is to reduce the atmospheric emissions which cause the greenhouse effect.
The present work proposes to develop a model of the thermal daily and hourly load of a complex user such as a neighbourhood during the heating season. This to value the thermal power peak necessary to correctly size the generation plant supplying heat to the district heating system [1], [2], [3], [4], [5], [6], [7] and [8]. The model gives the seasonal amount of the thermal energy necessary to the buildings of the basin of user, to guarantee to the users, in function of the trend of the external mean seasonal temperature, the comfort requested.
Knowing the total request, pointing out the better configuration of the operation, it's possible to give a realistic evaluation of the fuel consumption necessary, the corresponding level of the emission in the environment, the electrical energy production and the energetic saving attainable.
The strategy chosen is foreseen to guarantee, with a combustion alternative engine in cogeneration modality, a thermal power satisfying the thermal request characterizing the user for all of the heating season, supplying the remaining power, when necessary, through traditional boilers.
In particular the study relates to the buildings, of an area comprising some neighbourhoods in Perugia, a city in central Italy, in order to arrange a district heating system combined with a cogeneration plant. This to increase the saving of primary energy obtainable, to realize the centralization of the energy generation and the delocalization of the polluting production, controlling at the same time the emissions using suitable control systems.
The present work has been proposed to analyze the benefits in terms of energetic and environmental saving, through the realization of the district heating, combined to a cogeneration unit fed by natural gas.
The objective was to create a model that allows to determine the hourly trend of the daily thermal load of all of the users, for every day of the heating season.
To this aim this work proposes a new simulation model of the hourly and daily trend of the thermal load, knowing only few parameters for each user, like the power installed in the thermal plant, the seasonal operation hours and the timetable of the heating service distribution, as well as the external temperature trend.
Such a model allows to evaluate with precision the peak of the thermal request that must be satisfied, considering the contemporaneity of the loads and their different typology, and a more correct sizing of the generation plant. The results obtained illustrate that the maximum thermal power requested is smaller than the one nowadays installed.
The benefits, both in environmental and energetic terms, are satisfactory and render favourable the realization of the plant.
