Infrastructure Engineering - Research Publications

Permanent URI for this collection

Search Results

Now showing 1 - 10 of 58
  • Item
    Thumbnail Image
    Sizing behind-the-meter solar PV for pumped water distribution systems: A comparison of methods
    Zhao, Q ; Wu, W ; Yao, J ; Simpson, AR ; Willis, A ; Aye, L (Elsevier BV, 2024-01-01)
    Water distribution systems (WDSs) are vital urban infrastructure systems. To meet increasing pumping energy demands and minimise environmental impacts, behind-the-meter (BTM) solar photovoltaic (PV) systems have been considered by water utilities. However, there currently is not a systematic approach to size BTM solar PV for WDSs, considering the life cycle performance of the integrated systems. This study evaluates three methods to size BTM solar PV in pumped WDSs: 1) the heuristic method developed from current industry practice; 2) the minimum total life cycle cost (TLCC) method based on the system minimum TLCC; and 3) the minimum payback method to minimise the time needed to pay off the solar capital investment. The performance of the integrated water-solar system has been assessed against economic, energy and emissions performance metrics using two case studies. The results indicate that the heuristic method leads to the largest solar PV size, potentially oversizing the system. The minimum payback method leads to the smallest solar PV system, potentially under-sizing the system. The minimum TLCC method leads to more balanced system performance, but the solar PV size determined using this method is sensitive to the discount rate used. The insights into the performance of the system sized using the three methods provide decision-makers guidance to select appropriate solar PV systems for WDSs.
  • Item
    Thumbnail Image
    High water use plants influence green roof substrate temperatures and their insulative benefits
    Pianella, A ; Zhang, Z ; Farrell, C ; Aye, L ; Chen, Z ; Williams, NSG (Elsevier BV, 2023-12-01)
    Green roofs are amongst the solutions employed to deliver sustainable buildings in cities. Their vegetation and substrate layers can reduce the heat transfer through the roof, thus potentially reducing energy used for building cooling and heating. However, little research has investigated the insulative properties of drought-tolerant plants which also have high water use. These plants have been found to improve runoff retention by removing larger volumes of water from the substrate through higher transpiration rates than succulents. This planting strategy may also enhance green roof cooling performance due to their greater evapotranspiration rates. In this study, the thermal performance of three drought-tolerant species with high water use — Lomandra longifolia, Dianella admixta, and Stypandra glauca — was evaluated and compared with a commonly used succulent species (Sedum pachyphyllum) and a bare unplanted module. L. longifolia had the best insulative performance during the entire investigated period, reducing green roof substrate surface temperature up to 1.86 °C compared to succulent S. pachyphyllum. In summer, the mixture reduced heat gain to a greater extent than monoculture plantings of all species except L. longifolia. Summer measurements also suggest that plants with high leaf area index (LAI) and higher albedo should be selected to reduce surface temperatures. High evapotranspiration rates of high water use L. longifolia led to greatest reduction of bottom surface temperatures during a heatwave when decreasing its water content from 18.5% to 2.9%. Results obtained using an analytical hierarchical partitioning technique indicated air temperature had the most significant impact on temperatures at both the surface of the planting substrate and the bottom of each green roof unit, accounting for 48% to 58% of the variation.
  • Item
    Thumbnail Image
    The carbon footprint of treating patients with septic shock in the intensive care unit
    McGain, F ; Burnham, J ; LAU, R ; Aye, L ; Kollef, MH ; McAlister, S (College of Intensive Care Medicine of Australia and New Zealand, 2018-12-01)
    OBJECTIVE: To use life cycle assessment to determine the environmental footprint of the care of patients with septic shock in the intensive care unit (ICU). DESIGN, SETTING AND PARTICIPANTS: Prospective, observational life cycle assessment examining the use of energy for heating, ventilation and air conditioning; lighting; machines; and all consumables and waste associated with treating ten patients with septic shock in the ICU at BarnesJewish Hospital, St. Louis, MO, United States (US-ICU) and ten patients at Footscray Hospital, Melbourne, Vic, Australia (Aus-ICU). MAIN OUTCOME MEASURES: Environmental footprint, particularly greenhouse gas emissions. RESULTS: Energy use per patient averaged 272 kWh/day for the US-ICU and 143 kWh/day for the Aus-ICU. The average daily amount of single-use materials per patient was 3.4 kg (range, 1.0-6.3 kg) for the US-ICU and 3.4 kg (range, 1.2-8.7 kg) for the Aus-ICU. The average daily particularly greenhouse gas emissions arising from treating patients in the US-ICU was 178 kg carbon dioxide equivalent (CO2-e) emissions (range, 165-228 kg CO2-e), while for the Aus-ICU the carbon footprint was 88 kg CO2-e (range, 77-107 kg CO2-e). Energy accounted for 155 kg CO2-e in the US-ICU (87%) and 67 kg CO2-e in the Aus-ICU (76%). The daily treatment of one patient with septic shock in the US-ICU was equivalent to the total daily carbon footprint of 3.5 Americans' CO2-e emissions, and for the Aus-ICU, it was equivalent to the emissions of 1.5 Australians. CONCLUSION: The carbon footprints of the ICUs were dominated by the energy use for heating, ventilation and air conditioning; consumables were relatively less important, with limited effect of intensity of patient care. There is large opportunity for reducing the ICUs' carbon footprint by improving the energy efficiency of buildings and increasing the use of renewable energy sources.
  • Item
    Thumbnail Image
    Comparison of waste photovoltaic panel processing alternatives in Australia
    Suyanto, ER ; Sofi, M ; Lumantarna, E ; Aye, L (Elsevier BV, 2023-09-15)
    This work aims to compare end-of-life (EoL) alternative processing scenarios of waste photovoltaic panel in Australia. Landfill, generic waste electrical and electronic equipment recycling (European business-as-usual (EU BAU)), full-recovery EoL photovoltaic (FRELP), and Modified FRELP are the alternative processing scenarios considered for the next five years. Environmental analysis by a simplified life cycle assessment is performed using Material, Energy, Chemical, and Other (MECO) matrix. This semi-quantitative comparison eliminates reliance on LCA software and environmental expertise for preliminary screening. Financial analysis is also performed by using a life cycle costing (LCC) approach. Overall, comparative findings are consistent with full-quantitative LCA and LCC despite magnitude differences. Simplified analysis merely reflects process complexity and resource consumption. A full financial insight can only be acquired when non-resource-derived costs are incorporated. Considering the increasing trend of waste levies and landfill ban extending into the future, landfill is no longer the cheapest option in Australia. Consequently, mass-based waste recovery for landfill diversion facilitates cost savings. Recovering 8% more waste with FRELP compared to modified FRELP has the potential to save $19 more per tonne of processed PV waste. EU BAU is the most eco-efficient interim solution, while waste volume is still low. Modified FRELP saves 321 kg CO2-e emission by avoiding traditional incineration. The focus on reclaiming solar-grade silicon rather than silver has the potential to attract $154 more revenue per tonne compared to FRELP.
  • Item
    Thumbnail Image
    Efficient HVAC system identification using Koopman operator and machine learning for thermal comfort optimisation
    Wahba, N ; Rismanchi, B ; Pu, Y ; Aye, L (Elsevier BV, 2023-08-15)
    The aim of this article is to improve the efficiency of heating, ventilation, and air conditioning (HVAC) systems by using a linear control approach. Conventional HVAC systems use a wall thermostat and a simplified ON/OFF controller to condition the thermal environment, but this approach is not always efficient in meeting indoor heat loads. To address this issue, we propose using the Koopman operator combined with Machine Learning, a linear embedding method, to model the nonlinear behaviour of thermal comfort indices. Specifically, we use the Predictive Mean Vote (PMV) index, which has been a superior indicator of occupants’ thermal sensation. We apply Computational Fluid Dynamics to create high-dimensional training, testing, and validation datasets, and a deep autoencoder network framework to map the original nonlinear coordinates of the PMV index into a latent space where the system is behaving linearly. Our results show that the Koopman autoencoder can reproduce and predict data from the latent space, enabling offline system identification for the zone thermal conditions and this has the potential to improve HVAC feedback control systems.
  • Item
    No Preview Available
    Fire safety performance of 3D GFRP nanocomposite as a cladding material
    Soufeiani, L ; Nguyen, KTQ ; White, N ; Foliente, G ; Wang, H ; Aye, L (ELSEVIER SCI LTD, 2022-10)
    Vertical fire spread along highly flammable claddings is a major safety issue for buildings. In this project, a potential new type of cladding material, 3D Glass Fibre Reinforced Polymer (3D GFRP) with improved thermal stability, and fire performance is developed. 3D GFRP nanocomposite samples were fabricated with different percentages of Sepiolite (Sep), Sepiolite-phosphate (SepP), Ammonium Polyphosphate (APP) flame retardant, and 3D glass fabrics. Synthesis of SepP, dispersion analysis of nanoparticles, and manufacturing process have been studied. The characterisation of materials was conducted using Scanning Electron Microscopy, Helium Ion Microscopy, Transmission Electron Microscopy, Thermogravimetric Analysis (TGA), and X-ray Diffraction Analysis. The thermal stability and fire behaviour of the 3D GFRP nanocomposite was studied via TGA and cone calorimeter test. TGA results showed that the optimum amount of additives that improved the thermal stability is 15% flame retardants. Results of cone calorimeter tests showed that different percentages of APP, Sep, and SepP decreased the peak of the heat release rate between 4% and 42%. Also, the effects of APP flame retardant in improving thermal and fire reaction properties were more than Sep and SepP. The test results of 3D GFRP nanocomposite also showed a prospective cladding that can benefit the construction industry in near future.
  • Item
    No Preview Available
    The life aquatic
    McNiven, B ; Aye, L ; Holzer, D (AIRAH, 2023-05-01)
    Students and academics from the University of Melbourne joined forces with industry consultants and local government representatives to explore achieving net zero carbon design for those most energy-intensive buildings: aquatic centres. The university’s Brendon McNiven, Dominik Holzer and Lu Aye, F.AIRAH, elaborate.
  • Item
    Thumbnail Image
    Thermal and energy performance evaluation of a full-scale test cabin equipped with PCM embedded radiant chilled ceiling
    Mousavi, S ; Rismanchi, B ; Brey, S ; Aye, L (Elsevier BV, 2023-06-01)
    The escalating global demand for space cooling has led to the emergence of new cooling technologies, including the phase change material embedded radiant chilled ceiling (PCM-RCC) system. This technology improves energy efficiency and indoor environmental quality, while also offering demand-side flexibility. The present study experimentally evaluates the thermal efficiency and energy performance of a PCM-RCC system in a full-scale test cabin equipped with PCM panels. Here, the transient thermal behaviour of PCM ceiling panels besides the cooling energy delivered during charging-discharging cycles are examined. The indoor thermal comfort and peak electricity demand reduction enabled by the present PCM-RCC are also discussed. The results reveal that chilled water circulation for 4–5 h overnight was sufficient to fully recharge the PCM panels. Over 80% of the occupancy time was classified as “Class B″ thermal comfort according to ISO 7730. The system's daily electricity usage was mostly concentrated during off-peak hours, accounting for ∼70% of the total usage. While the controlling schedule used in this study responded to the transient thermal behaviour of the indoor space and PCM ceiling panels, a more dynamic, predictive schedule is necessary to improve the system's overall efficiency and further enhance indoor thermal comfort in response to the changing environmental conditions.
  • Item
    No Preview Available
    Emergency
    McNiven, B ; Aye, L ; Holzer, D (Australian Institute of Refrigeration, Air Conditioning and Heating (AIRAH), 2022-10-31)
    As part of the i-Hub project, masters-level architectural and engineering students from the University of Melbourne, industry consultants, university academics, and Ambulance Victoria staff embraced the challenge of designing net zero emergency response stations. The university’s Brendon McNiven; Lu Aye, F.AIRAH; and Dominik Holzer discuss.
  • Item
    No Preview Available
    Upcycling opportunities and potential markets for aluminium composite panels with polyethylene core (ACP-PE) cladding materials in Australia: A review
    Pilipenets, O ; Gunawardena, T ; Hui, FKP ; Nguyen, K ; Mendis, P ; Aye, L (ELSEVIER SCI LTD, 2022-11-28)
    Many buildings worldwide have high fire-risk materials as part of their cladding. As governments in Australia strive to make buildings safer, it is expected that a large volume of end-of-life dangerous cladding will be replaced with safer materials. This high volume of hazardous materials might be upcycled into value-added products. This article presents a systematic market analysis and literature review in identifying current and potential uses for the raw materials used in hazardous ACP-PE cladding. The most promising areas were identified to be non-food-contact packaging (US$228 M p.a.), non-pressure pipes (US$30 M p.a.), footwear (US$5.29 M p.a.) and 3D printer filament (US$2.73 M p.a.)