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R744 integrated systems can meet oscillating heating and cooling demands efficiently and become a game changer in countries such as India. The present work aims to develop and present R744 system designs and disseminate the knowledge under the framework of the INDEE+ project in India, with the focus on three vital sectors: supermarkets, hotels, and seafood industries. Ejector-supported R744 systems are observed to be an ideal solution to increase the R744 system efficiency at high ambient temperature operations as in tropical regions. The strategy is also to evaluate the system operations to deal with an individually proposed R744 system performances to fulfil the thermal load handling demand on both heating and cooling side. Furthermore, students, vendors and end-users are planned to train by utilizing the upcoming demonstration sites with R744 technology. Support is being provided to communicate and finalize the R744 system design specification for the various system configurations. Each development aspect will be evaluated critically to make the proposed R744 technology demo units a success and to become flagship developments supporting India to transfer towards clean cooling and heating technologies. Advanced R744 solution for supermarkets, hotel chillers and maritime applications in India

An experimental campaign investigated the dependency of air temperature on the CO2 concentration accuracy for commercial low-cost NDIR CO2 sensors from the manufacturers Netatmo and IC-Meter. The test was conducted under different temperatures and CO2 concentrations based on steady state conditions. Highly accurate instruments were employed to obtain reference temperatures and CO2 concentrations. The IC-Meter modules were vaguely influenced by temperature, resulting in no significant difference compared to the reference concentration values. However, the Netatmo station modules were found to be positively temperature dependent.

The aim of this study is to set up a simplified and validated numerical platform to describe several technologies concerning the energy performance improvements of glazed and opaque building envelopes. The study included the validation of DIGITHON, a detailed simulation software and the development of a simplified transient numerical model in respect of glazed buildings. DIGITHON, was validated against experimental data, and then a parametric study was carried out through it to evaluate the air pre-heat efficiency of implementing the façade as an energy recovery unit. The simplified model was dedicated to the thermal engineering designers dealing with projects preliminary phases .The simplified model was validated against experimental data. Later an extensive comparison between the detailed software DIGITHON and the simplified model was carried out for different climatic conditions to evaluate the influence of considering indoor zones thermal inertia. Although the simplified model estimates thermal loads higher than DIGITHON, nevertheless this can be considered a beneficial design safety aspect as long as it is implemented in the preliminary design phases. Later an innovative locating of photovoltaic modules at building glazed facades was investigated through the commercial software TRNSYS. The methodology of modelling double skin-glazed façades combined with different strategies of ventilation applying TRNflow software was thoroughly clarified. The results show a reduction in thermal heating loads compared to conventional location of PV on external building surfaces. On the other hand the cooling loads are increased, hence to improve the performance of the system in summer hot season, the technology of phase changing material (PCM) was tackled in the research as a latent thermal storage system. A numerical investigation of the effect of PCM in building sector, solely and combined with PV modules to improve its thermal performance, has been carried out. Two numerical models (equivalent capacitance and enthalpy linearization methods) describing the PCM thermal and optical performance have been developed and validated. Results show that thermal loads reductions of a system implementing PV/PCM modules reach 30% in summer season. Afterwards, the research through experimental campaign and numerical heat transfer modelling optimised the selection and location of two technologies within a residential roof attic: the technologies considered were PCM modules and reflective surfaces; five transient numerical models have been developed and validated. The results clarify the influence of the proper selection for melting-solidification PCM range suiting each application in order to reach optimum specific heat capacity values which could improve the overall thermal balance of the inner zone. Finally, computational fluid dynamics CFD models have been applied to different case studies to describe the thermal performance of vertical glazed envelopes.

Oppgaven undersøker numerisk ytelsen til en CO2 varmepumpe kjøleenhet integrert med en ejektor for å dekke behovet for kjøling og varmtvann (DHW) til et hotell i India. Systemet er komplett med fem lagdelte lagringstanker for termisk energi i serien og et kjøletårn. Basert på varme- og kjølebehov, bestemmer det avanserte kontrollsystemet systemets driftsmodus; enten samtidig oppvarming og kjøling, kun kjøling eller kun oppvarming. I tillegg veksler den mellom å implementere kjøletårnet som kjøleribbe eller kilde for systemet. Simulerings- og kontrollsystemet gjøres i Modelica med implementering av TIL- og MBL-bibliotekene. Det simulerte systemet har en gjennomsnittlig COP på 6 for varmebelastninger på 50kW med samtidige kjølebelastninger på 35kW. The thesis investigates numerically the performance of a CO2 heat pump chiller unit integrated with an ejector to provide for the cooling and Domestic Hot Water (DHW) demands of a hotel in India. The system is complete with five in-series stratified heating thermal energy storage tanks and a cooling tower. Based on heating and cooling demands, the advanced control system decides the system operating mode; either simultaneous heating and cooling, cooling only, or heating only. In addition, it switches between implementing the cooling tower as a heat sink or source for the system. The simulation and control system are done in Modelica with implementation of the TIL and MBL libraries. The simulated system has an average COP of 6 for heating loads of 50kW with simultaneous cooling loads of 35kW.