5 research outputs found
A Continuous Commissioning Analysis and its Application to a New Installed Solar Driven DEC System Coupled with Heat Pump
No full textAbstractThe aim of this paper is to define and implement a continuous commissioning methodology that can be effectively applied to a solar driven desiccant and evaporative cooling (DEC) system. The objective is to assess the energy performance of the system's components and identify possible operation faults. The methodology consists in the breakdown and analysis of the DEC into sub-systems; for each of them a simplified dynamic mathematical model based on experimental data has been developed. A possible fault is detected when the difference between the theoretical and measured performances is higher than the accuracy of the methodology. The proposed methodology has been successfully implemented for a hybrid solar DEC system comprising a non-conventional DEC air-handling unit, a solar thermal system and an electrical heat pump.The results of the methodology's application to the first experimental data of summer 2014lead to the following conclusions: the solar sub-system operated as expected whereas the heat pump and the desiccant rotor did not. In particular, the electrical heat pump has a higher cooling capacity than the one predicted at partial load but with a similar COP value, this deviation is mainly due to the assumed partial load performance coefficient. The desiccant rotor presents a much lower performance than the one expected. However, the rotor inefficiency is difficult to highlight due to the high measurement uncertainties on the air side
Technical, financial and urban potentials for solar district heating in Italy
No full textAIRU, the Italian association of district heating, and the Department of Energy of Politecnico di Milano have tried to evaluate the economic, technical, and urban potential of solar district heating in Italy as an efficient and flexible system to spread the use of solar thermal energy in urban areas. This potential has been estimated with the analysis of five case studies of solar thermal integration in district heating networks in the north of Italy: three with a centralized solar plant in existing district heating, one with distributed solar in an existing network, and finally one of a new solar district heating network. These studies, realized in the framework of Solar District Heating Plus project, aim at verifying the technical and economic feasibility of this integration. Besides the more common economic and technical study, a critical analysis looking at the urban aspects of this technology is proposed in order to analyze local potentialities and barriers for this technology. Centralized solar thermal integration has had positive results, while distributed solar rooftop-plants integration turns out to be not economically sustainable. A need for heat planning and heat mapping in urban design emerges as needed to promote and simplify the spread of large-scale renewable-energy plants
Field testing of a novel hybrid solar assisted desiccant evaporative cooling system coupled with a vapour compression heat pump
No full textThe aim of this paper is to report on a two-year operational experience with a solar driven desiccant and evaporative cooling (SDEC) system coupled with a vapour compression heat pump. The main objectives are to analyse the benefits and drawbacks of this innovative hybrid SDEC system, to compare the monitoring results against the expected theoretical ones, and to assess the system's performance with respect to a reference air handling unit. The comparison focuses on the summer key operation modes using Primary Energy Ratio (PER) as indicator of the entire system performance. The results of the detailed analysis lead to the following conclusions: the specific design of the hybrid SDEC leads to high air quality, simpler control process and low electricity consumption for partial load conditions. The monitoring results show a summer mode PER 20% lower than expected due to underperformance of the desiccant wheel. Nevertheless, this innovative system is still very efficient as its PER is twice as high as the one of the considered reference system. Lastly, suggestions for optimization of the existing system through the fine-tuning of the control strategy of its main components are presented. (C) 2017 Elsevier Ltd. All rights reserved
SHC Task 48 B2 – Three GOOD Practice Examples of Solar Heat Driven Desiccant Evaporative Cooling Systems
No full textAbstractWithin the activity B2 of IEA SHC Task48, an exhaustive report on GOOD Practice examples of existing solar heat driven desiccant cooling (SDEC) systems was written. Three SDEC systems from Austria, Australia and Italy are well documented from the design phase to the operational phase. The authors of the GOOD Practice SDEC systems belong to research entities and the selected SDEC projects were scientifically accompanied by these partners from the very beginning on. The energy performance of all three SDEC systems in operation is indicated by monthly energy fluxes and key performance indicator as a result from measurement data of a scientific monitoring campaign. The GOOD Practice SDEC report on each system closes with findings and lessons learned in order to guide next projects by answering; What quality and support measures lead to a successful SDEC system implementation with high energy performance figures, high quality of indoor comfort and high user friendliness for facility manager? The SHC Task48 B2 report is published on the official SHC Task48 website
Monitoring and energy performance assessment of an advanced DEC HVAC system in Morocco
No full textThis work addresses the energy performance of a solar Desiccant and Evaporative Cooling (DEC) system working with the freescoo technology. Freescoo is an innovative solar air conditioning concept for ventilation, cooling, dehumidification and heating of buildings in residential and tertiary sectors. The monitoring of the system started in November 2016 and will continue until the end of 2017. Energy performances are evaluated according to the monitoring procedure for solar cooling systems developed by the Task 38 and 48 of the International Energy Agency experts. The analysis based on monitoring data shows that, for typical operating conditions in cooling mode, the electricity saving in comparison to conventional HVAC systems can be over 70%
