This paper deals with the dynamic modeling of a typical single-zone building. It describes the development of a dynamic model for thermal transient analysis and its application to a simplified test case considering solar irradiation and internal radiation. The dynamic behavior of the indoor air temperature has been investigated by means of a lumped approach using a state-space representation developed in MATLAB/Simulink. A set of daily temperature profiles, which are representative of the Mediterranean climatic condition, on a few different winter days, has been used as boundary conditions for the dynamic simulations. In addition, the model has been validated using two different sets of experimental data available in the literature, both statically and dynamically. Finally, a layer of insulation with a phase change material (PCM) is applied to the single zone building to quantify its effect on the building’s behavior. The results showed that the rate and amount of energy consumption in the building with PCM are moderately lower than the building without PCM. In addition, the variation of inlet air temperature, solar effects, and energy consumption have been evaluated for a case study example, as well as comfort in transient simulation to achieve a complete evaluation of the test building investigated. A satisfactory agreement was obtained between the experimental and the simulation results and shows that the model can be used for a wide range of materials, dimensions, thermal resistances, and boundary conditions.
Within the framework of the European Combined Efficient Large Scale Integrated Urban Systems (CELSIUS) project, the Genoa demonstrator involves the insertion of a turbo expander (TE) to substitute the standard throttling process in a natural gas expansion station. In this way, the currently wasted mechanical energy will be recovered, while an internal combustion combined heat and power (CHP) unit will be used to meet the heating requirements of the gas before the expansion and to serve a small district heating network (DHN). Both TE and CHP are capable of delivering electric power (EP) up to 1 MW. In order to match the EP production vs demand is highly desirable to use the EP extra capacity for local EP final users, such as a nearby public school and a gas refueling station (RS). For limiting the school’s consumption of fossil fuel, it is possible to use the EP surplus generated by the demonstrator to feed a heat pump in parallel to the heating conventional system. With regard to the RS, the compressors are currently driven by electric motors, with a high-energy consumption. The integrated system gives the possibility of exploiting the surplus of electricity production and of recovering heat, which would be otherwise wasted, from the intercooling of compressed gas, thus powering the DHN through a preheating system. The result expected from this strategy is a relevant energy and emissions saving due to an integrated use of the electricity generated by the Genoese demonstrator for feeding the nearby school and RS.