Energy Management System for Cogenerating Units

A Combined Heat and Power (CHP) node is a generating power unit where electrical and thermal power are co-generated. The presence of loads requiring at the same time electric and thermal power, allows to use for heating purposes at least part of the heat dissipated in the thermodynamic cycle. The optimal management of a CHP node must cope with several time evolving data, for instance electric and thermal loads, costs for purchasing and/or selling power to the external electrical network etc. In this paper a linear mathematical model of a CHP node is described and used to define the optimal scheduling of the generating unit. A Combined Heat and Power (CHP) node is a generating power unit where electrical and thermal power are generated together. The presence of loads requiring at the same time electric and thermal power allows to use for heating purposes at least part of the heat dissipated in the thermodynamic cycle. In this way the integrated power source has an energy efficiency higher than that of two separated units: one for electric and one for thermal power. Obviously, the operational planning of the integrated unit must fulfil in time both electric and thermal requirements of the loads which often have different scheduling and can, when it is economically convenient, buy or sell electrical power to the external power network. Examples of this application can be presently found in district heating and in industrial processes, but there are indications that this scheme could be extended to micro-generating units trying thus to increase the efficiency of the energy management system. The management of this energy production unit is not an easy task when energy prices are time varying on a daily or weekly basis, thus requiring an optimal management of production scheduling.