Energy Procedia最新文献

The Paris Agreement aims to combat climate change by keeping a global temperature rise this century well below 2^oC by the reduction of CO₂ production. Scotland aims to be a world leader in the change and has set ambitious targets to meet this commitment. With nearly 70% of the energy cost in the production of ice cream spent on refrigeration, any improvement in their efficiency will reduce energy costs and CO₂ production. A waste heat recovery system presents a great opportunity to reclaim energy from the onsite refrigeration systems and convert it into useful hot water. A £216,275 project funded by The Engineering and Physical Sciences Research Council and Innovate UK was setup to investigate the use of a waste recovery system within an onsite refrigeration system. The results showed a savings of 5% by the refrigeration plant in total along with an individual saving of 27% by the compressor within the refrigeration system. The WHRS also produced a supply of hot water which could be used onsite within the manufacturing or cleaning processes required onsite.

This paper compares three different natural refrigerants based system configurations in terms of cooling performance, total equivalent warming impact per year and annual power consumption for the proposed refrigeration systems. Two different cooling load levels were selected to represent a typical supermarket and a convenience store applications. The systems selected in this study include the R717/R744 cascade system configuration, a typical R744 booster configuration and a R744 parallel-compressor booster refrigeration system. The weather conditions of London, UK and Larnaca, Cyprus, were used for the modelling of energy consumption and environmental impacts to represent moderate and warm climatic conditions respectively.

The current research presents a comprehensive model of a 100 kWe Trilateral Flash Cycle TFC system composed of sub-modules for the plate heat exchangers and twin-screw expanders to assess and identify the operating parameters that mostly affect the TFC performance at off-design conditions. The modelling approach for heat exchangers and piping is based on 1D CFD while considering the operating maps for pump and expander. The simulation process takes into account variations of the heat source temperature and mass flow rate from the design point. The TFC performance is analysed in terms of efficiency and power output while the expander performance is discussed in terms of volumetric and isentropic efficiencies. A sensitivity analysis is carried out to assess the most suitable parameter for control purposes and system performance optimisation. The results point out a large sensitivity of the inlet quality at the expander due to the revolution speed of the machine but also the off-design behaviour of the heater.

The Circular Economy is an economic and industrial system in which resources are used for as long as possible. This typically involves businesses implementing a range of alternative business models, such as remanufacture. With the manufacture of Refrigerated Display Cabinets (RDCs) being a material and energy intensive process, there is scope for remanufacturing to support a more resource-efficient production of RDCs. Despite the potential, the remanufacture of RDCs in the UK is uncommon. Many Retailers and RDC Manufacturers typically have unfavourable attitudes towards the purchase and production of remanufactured RDCs. However, more favourable attitudes could increase their Behavioural Intentions towards the purchase and production of remanufactured RDCs, which could lead to the adoption of remanufacturing across the industry. This paper gives an overview of interventions that could be implemented to encourage Retailers and RDC Manufacturers to adopt the pro-circular behaviours. The three interventions discussed in this paper are: Financial Incentives, Quality Standards and Process-Supporting tools.

In food processing, insufficient cleaning can result in reduced efficiency, contamination in final product, and energy losses. To optimise widely implemented clean-in-place (CIP) systems, it is critical to understand the influence of the interactions between surfaces, foulant, and chemical agents on the efficiency of the cleaning process. The present work investigates the effect of wall temperature and surface roughness on the surface free energy of stainless steel 316L coupons. Equilibrium contact angles (ECA) of four commonly used liquids, namely ethylene glycol, 1-bromonaphathalene, water, and diiodomethane were measured on the surfaces of interest. Finally, ECAs of liquids were used to quantify surface free energy (SFE) of the solid substrate. Our results show that surface energy is proportional to the roughness and well-prediction of liquids wettability as a function of roughness and temperature. It demonstrates the importance of surface characteristics in determining interfacial energy, and consequently the efficiency of CIP for food engineering.

Nowadays, all industry, including the agri-food sector, faces the urgent need to increase its competitiveness in order to survive in a global market. In this context, it is vital to ensure a strong, renewed and innovative industrial base throughout all stages of the value chain, capable of competing internationally and differentiating itself by the quality of its products and services. Since wealth generation cannot be dissociated from productivity, which in turn is closely related to the trinomial: processes, technologies and quality, it is concluded that the implementation of this strategy requires a commitment to the qualification of organizational management, operational management, project management and processes and productive systems themselves and associated technologies. This paper presents the characterization of the energy consumption and technologies in bakery and pastry sector, one of the most significant in the Portuguese agri-food sector.

In recent times, there has been a rise in interest on the applications of electro-technology based food processing methods. With drying in food industries being an energy intensive process with huge environmental impacts, the objective of this study was to design and develop a purpose-built laboratory system, for experimentally characterising an energy efficient electro-osmosis dewatering system. Electro-osmosis is a unique dewatering technique in which, moisture in food materials are removed by the application of low electric field (5-30 V). Different food materials namely, yogurt, orange pulp and egg whites were tested using electro-osmosis at 15 V and 30 V over 15 min and 30 min, respectively. The energy consumption (kWh), carbon footprint (kgCO₂e) and cost indices (£/kg dried food) were also evaluated and compared with thermal drying.