In this paper, a detailed simulation model of a solar-powered triple-effect LiBr–H2O absorption chiller is developed to supply both cooling and heating demand of a large-scale building, aiming to reduce the fossil fuel consumption and greenhouse gas emissions in building sector. TRNSYS 17 is used to simulate the performance of the system over a typical year. A combined energetic-economic-environmental analysis is conducted to determine the system annual primary energy consumption and the total cost, which are considered as two conflicting objectives. A multi-objective optimization of the system is performed using a genetic algorithm to minimize these objectives simultaneously. The optimization results show that the final optimal design of the proposed plant has a solar fraction of 72% and leads to an annual primary energy saving of 0.69 GWh and annual CO2 emissions reduction of ~166 tonnes, as compared to a conventional HVAC system. The economics of this design, however, is not appealing without public funding, which is often the case for many renewable energy systems. The results show that a good funding policy is required in order for these technologies to achieve satisfactory payback periods within the lifetime of the plant.
A rapid review on green-rated office buildings, and their operational energy use, found that the conclusions of six studies ranged from the certified buildings performing worse, similarly or much better than the non-certified buildings in terms of energy usage intensity. Two...Read more
Pilots are powerful for two reasons: 1. They are a great way to bring together groups of people to demonstrate how effective collective action can be in helping to change the status quo. More voices, more influence. Pilots, backed by evidence and research, can highlight and expose the challenges and blockages, particularly in government, far more effectively than any individual can (despite many individuals trying!). They also provide perfect opportunities for identifying solutions. And, 2. pilots provide the numbers and the evidence that decision-makers need, in order to believe and make change.Read more
Industry misconceptions around high cost and poor market interest in energy efficient homes continue to obstruct the mass adoption of low carbon housing. Josh’s House demonstrates that low carbon housing is accessible and cost effective. The Star Performers series showcases how...Read more
The feasibility of solar-powered multi-effect LiBr-H2O absorption chillers is investigated under different climate conditions, and three configurations of solar absorption chillers are proposed with respect to the type of the chiller. In the first configuration, a single-effect absorption chiller is coupled with evacuated tube collectors (ETCs), while parabolic trough collectors (PTCs) are utilized to run double- and triple-effect LiBr-H2O chillers in the second and third configurations, respectively. A simulation model for each configuration is developed in TRNSYS 17 environment.
Solar heating and cooling (SHC) systems are currently under rapid development and deployment due to their potential to reduce fossil fuel use and to alleviate greenhouse gas emissions in the building sector – a sector which is responsible for ∼40% of the world energy use. The available technologies on the market for thermally driven cooling systems are absorption and adsorption chillers, solid and liquid desiccant cooling systems, and ejector refrigeration cycles.
Solar heating and cooling (SHC) systems are currently under rapid development and deployment due to their potential to reduce the use of fossil fuel resources and to alleviate greenhouse gas emissions in the building sector – a sector which is responsible for ~40% of the world energy use. Absorption chiller technology (traditionally powered by natural gas in large buildings), can easily be retrofitted to run on solar energy. However, numerous non-intuitive design choices must be analyzed to achieve the best techno-economic performance of these systems.
Solar-assisted cooling technology has enormous potential for air-conditioning applications since both solar energy supply and cooling energy demand are well correlated. Unfortunately, market uptake of solar cooling technologies has been slow due to the high capital cost and limited design/operational experience. In the present work, different designs and operational modes for solar heating and cooling (SHC) absorption chiller systems are investigated and compared in order to identify the preferred design strategies for these systems.