STUDY OF THE SAN GIUSEPPE EMPOLI’S HOSPITAL COGENERATION PLANT REVAMPING

In the current framework of global energy transition and environmental regulations, improving energy efficiency and reducing carbon footprints have become the main objectives for facilities. Among these, hospitals represent a critical category, in fact they require an uninterrupted, highly reliable, and simultaneous supply of electricity, thermal energy and cooling energy. The objective of this thesis is to evaluate the best alternative for the revamping of the cogeneration plant at the Empoli Hospital, with the aim of updating its White Certificates. The project has started with the analysis of thermal energy, electrical energy and cooling energy demands, categorized by days of the week and season. Based on these data, two alternatives were selected for evaluation: Configuration A, which is characterized by a smokes or water recovery system to add hot water, a hybrid absorber (smokes + hot water) to produce chilled water and an evaporative tower to serve the absorber; Configuration B carachterized by a smokes recovery system integrated with double economizer to produce vapor, heat moisture and post heat hot water. Furthermore, an assessment was conducted on whether or not to install fuel cells. Despite considering the advantages of this emerging technology, the initial investment was found to be too high, leading to the decision to exclude them. The main objective of the requalification project is to install two new engines with a power that ranges between 1050 kWe and 1200 kWe in addition to: • two saturated steam boilers 8 bar with economizer • a steam absorber in common to the two engines • a hot water absorber in common with the two engines Evaluating the calculations, the solutions A and B are considered equivalent under an energetic point of view, but configuration A has been excluded for a main purpose: each absorber is joint to its motor, as in the current project, meaning that when engine 1 is shut down, also absorber 1 is stopped although would be cooling demand and hot input to make it functioning. Configuration B lets to decouple heat production from its using. The plant is also equipped with a DENOX SCR system and an OXYDATION CATALIST with relative control and regulation system for each engine and a cooling system consisting of two circuits for each machine: • cooling circuit water/engine oil/intercooler • cooling circuit intercooler 1° stage The project involves a heat recovery solution also aimed at producing chilled water, consisting of: • 2 saturated steam boilers (8 bar) with economizer • 1 steam absorption chiller shared between the two engine systems • 1 hot water absorption chiller shared between the two engine systems In conclusion for the revamping of the plant under consideration the choice is a trigeneration system based on two natural gas internal combustion engines of 1200 kWe each.