Martin Belusko

Can the Excess Heat Factor Indicate Heatwave-Related Morbidity? A Case Study in Adelaide, South Australia

Although heatwave-related excess mortality and morbidity have been widely studied, results are not comparable spatially and often longitudinally because of different heatwave definitions applied. The excess heat factor (EHF) quantifies heatwave intensity relative to the local climate, enabling cross-regional comparisons. Previous studies have shown a strong relationship between EHFs and daily mortality during severe heatwaves. An extensive study about the relationship between EHFs and daily morbidity compared to the currently applied heatwave thresholds in Adelaide has not yet been undertaken. This paper analyzes the association of EHFs with daily morbidity between 2008 and 2014 in the Adelaide metropolitan region, South Australia, and probes three different approaches to calculate the EHF. The EHF is found to differentiate days with heatwave-related excess morbidity significantly better than other widely used weather parameters, resulting in fewer days per year with heatwave alerts than using previously proposed methods. The volume of excess morbidity can be predicted by the EHF more reliably with a model proposed for the SA Ambulance Service to support their heatwave preparation plan.

Design for Upgradability Algorithm: Configuring Durable Products for Competitive Reutilization

Product upgrade, achieved through the improvement of the functionality of reused or remanufactured products, is often accepted as an effective way to attain a competitive reutilization. Design for upgradability (DFU) is a tool that primarily focuses on enhancing a product’s functional as well as physical fitness for ease of upgrade. This paper presents the development of a novel approach and its implementation algorithm for a systematic design of product upgradability. The framework of this approach consists of two major phases––modeling and optimization. Fuzzy logic is used as a tool to facilitate the modeling of a product’s upgradability based on its technical characteristics and the reutilization mode. In the optimization phase, a new DFU optimization program is developed by using genetic algorithm techniques. The objective of a product’s DFU optimization is defined so as to configure/redesign a product for the maximal level of upgradability with minimal associated costs and violations of engineering, economic, and environmental constraints. A case study on a solar heating system is presented to demonstrate the application of the proposed DFU algorithm and its effectiveness in generating optimal configurations for the system, which are reflected as significant improvements in the system’s upgradability, cost efficiency, and overall functionality.

Drivers and barriers to heat stress resilience

Heatwaves are the most dangerous natural hazard to health in Australia. The frequency and intensity of heatwaves will increase due to climate change and urban heat island effects in cities, aggravating the negative impacts of heatwaves. Two approaches exist to develop population heat stress resilience. Firstly, the most vulnerable social groups can be identified and public health services can prepare for the increased morbidity. Secondly, the population level of adaptation and the heat stress resistance of the built environment can be increased. The evaluation of these measures and their efficiencies has been fragmented across research disciplines. This study explored the relationships between the elements of heat stress resilience and their potential demographic and housing drivers and barriers. The responses of a representative online survey (N=393) about heat stress resilience at home and work from Adelaide, South Australia were analysed. The empirical findings demonstrate that heat stress resistant buildings increased adaptation capacity and decreased the number of health problems. Air-conditioning increased dependence upon it, limited passive adaptation and only people living in homes with whole-house air-conditioning had less health problems during heatwaves. Tenants and respondents with pre-existing health conditions were the most vulnerable, particularly as those with health conditions were not aware of their vulnerability. The introduction of an Energy Performance Certificate is proposed and discussed as an effective incentive to increase the heat stress resistance of and the general knowledge about the built environment.

9 – Using solid-liquid phase change materials (PCMs) in thermal energy storage systems

This chapter presents the principles of solid-liquid phase change materials (PCMs). The classifications of PCMs are discussed along with their advantages and disadvantages. PCMs can have problems in regards to incongruent melting, phase separation, subcooling and low thermal conductivity. Literature in relation to overcoming these issues has been reviewed and is summarised. Methods to measure the thermophysical properties of PCMs are presented. A list of key PCMs is given along with a comparison of their physical and technical properties. The future trend of PCM development is being conducted in conjunction with the application.

Investigation of Conducting Pins in Sphere Filled with Phase Change Material for Enhancing Heat Transfer in Thermal Energy Storage

The utilisation of phase change material (PCM) for thermal energy storage (TES) can significantly enhance the energy savings achievable with renewable thermal systems. Sphere based packed bed systems have been used as TES for many years. However, due to the thermal resistance within these systems, the heat transfer is limited and not all the PCM can be used effectively. This study focuses on heat transfer enhancement options for single PCM sphere in a TES system. An experimental investigation has been conducted using water as the PCM. The thermal performance of plain plastic sphere containing PCM has been compared to plastic sphere encapsulated with conducting pins. The heat transfer rate of the sphere with conducting pins was more than 34% that of the sphere without pins.

Integrating Solar Heating and PV Cooling into the Building Envelope

Photovoltaic/thermal (PVT) systems generate electrical and thermal energy. In summer, the usage of the collected heat is limited to domestic hot water heating. By contrast in winter, more useful heat collection is favorable, however, the PVT collectors require less cooling; therefore, the improved electrical output is limited. In this paper a new one-dimensional steady-state building integrated solar collector model is presented and examined, incorporating PVT and thermal (PVTT) collectors connected in series. In summer, the PVT collector is air-cooled, and the collected heat is discarded to the surroundings while the thermal collector heats the water for domestic use. In winter, both the PVT and thermal collectors are water-cooled generating domestic hot water. The efficiencies of the new collector are compared to that of a PVT collector, with both collectors having the same total area and characteristics. Both collectors are able to meet the summer thermal load and to provide useful thermal energy in winter. The PVTT collector reduces the collector thermal stresses and provides slight additional electrical power output.

Experimental Investigation of PCM Spheres in Thermal Energy Storage System

This paper presents the experimental result of a small scale packed bed of random spheres with encapsulated PCM being charged and discharged. A vapor compression refrigerator and heated room with fan heater were used to supply constant heat transfer fluid at a minimum temperature of -28°C for charging and 16°C for discharging. Even though the temperature differences were not fixed in the experiments, the performance of the thermal energy storage is depicted in the form of effectiveness values. Different results were obtained for charging and discharging the thermal storage unit. The differences are expected to come from natural convection and super cooling. The super cooling during the charging process was as high as 6°C.

Mathematical Modeling on Thermal Energy Storage Systems

Mathematical representations of the encapsulated phase change material (PCM) within thermal energy storage (TES) models are investigated. Applying the Effectiveness - Number of Transfer Unit (ɛ-NTU) method, the performances of these TES are presented in terms of the effectiveness considering the impact of different variable parameters. The mathematical formulations summarized can be used for future research work with the suggestion to maximize the heat transfer within the storage. Thus the optimisation on the configuration of the encapsulation can be done through a parametric analysis.

Direct Contact Phase Change Material Thermal Energy Storage

Abstract This chapter presents information relevant to the design and application of direct contact molten salt based phase change material (PCM) thermal storage for high temperatures. Given the limited research, many of the concepts and processes are examined at low temperatures. The focus of this concept is with gas-based heat transfer fluid, although conceptually, a liquid-based system is also presented. The experience associated with a classical direct contact arrangement at low temperature led to the development of a system which was tested at high temperature. It was demonstrated that mechanical design requirements and pumping losses are the most critical factors in developing direct contact PCM thermal storage systems. Experimental results are presented for testing conducted with water and sodium nitrate as PCMs.

Dynamic Concept at University of South Australia

Abstract This chapter discusses a new heat transfer enhancement concept known as dynamic melting. This concept makes use of recirculation of the melted phase change material during the melting process to enhance heat transfer. This technique was first investigated for low-temperature applications using water. The experimental work was conducted on a tube-in-tank thermal energy storage system with two melt paths for the recirculation. It was found that this technique produced better effectiveness and shorter phase change duration. The average effectiveness was increased by between 58% and 82%. The time taken for the melting process was also found to be much shorter during dynamic melting. It can therefore be concluded that this technique can effectively enhance the heat transfer of the melting process of a tube-in-tank thermal storage system, Numerical works on dynamic melting were also conducted and presented in this chapter. Experimental investigation on the dynamic concept on high temperature applications were investigated and results were analysed. It was found that the improvement in effectiveness for the high temperature application is significantly lower than the low temperature application.