An improved operation strategy of combined cooling heating and power system following electrical load

• Propose an improved operation strategy of CCHP system.
• Battery and PGU are combined to improve efficiency at variable load.
• Energy saving potential of this strategy is influenced by load fluctuation.
• The maximum PESR of this strategy compared to base strategy is 4.2%.

The operation strategy of CCHP (combined cooling heating and power) system is a vital factor governing its overall performance. This paper proposed an improved operation strategy of CCHP system FEL (following electrical load) to minimize primary energy consumption. In this strategy, the generated electricity of PGU (power generation unit) is optimized to improve the average generation efficiency at the lower electrical load of building. Battery is cooperated with PGU to finish a charge and discharge cycle in 24 hours so as to limit the size of battery. Different operation logics of the proposed operation strategy are presented with the combination of PGU and battery. The energetic performance analysis demonstrates the feasibility of the improved operation strategy. The energy saving potential influenced by fluctuation characteristic of electrical load is discussed to find out the impact relationship of PGU average generation factor, charge factor and supplementary electricity factor on primary energy saving ratio. The comparison results between four types of building indicated that the proposed strategy can achieve more energy saving in the building where the electrical demand has dramatic fluctuation during a day, whereas it is not suitable to the buildings with stable electrical load.