Transient Simulation of a Solar Cooling System for an Agro-Industrial Application

The advantage of a solar cooling system is the simultaneity of strong sunlight and cooling demand in the summer season. In fact, when the demand of electricity reaches extreme peaks for the excessive use of air conditioners, solar energy is available. In this study, simulation based on a performance analysis of a solar cooling system is carried out by means of TRNSYS for an agro-industrial application. The configuration is fully modelled in TRNSYS and dynamic simulations are run for the entire year. First, the analysis determines the peak energy demand for a low-temperature room for an agro-industrial application located in the Naples area. The room is 11 m long, 9.50 m wide and 3.20 m high and a set-point temperature is assigned equal to 10°C. Two different types of collector (ETC and PTC) with a double effect (H2O-BrLi) chiller (150 kW) are considered. The analysis is carried out considering the optimal solar field area, collector slope and hot storage tank. A supplementary conventional boiler of 50 kW and a cold storage tank with volume 5 m3 are also present. The terminal part of the system is constituted by fan coils. Various performance factors such as solar fraction, collector efficiency and primary energy savings are evaluated to optimize the key system design variables which include collector tilt, storage volume, type and size of the solar collector. Besides, a financial analysis is carried out.