Commercial refrigeration - An overview of current status

[EN] Commercial Refrigeration comprises food freezing and conservation in retail stores and supermarkets, so, it is one of the most relevant energy consumption sectors, and its relevance is increasing. This paper reviews the most recent developments in commercial refrigeration available in literature and presents a good amount of results provided these systems, covering some advantages and disadvantages in systems and working fluids. Latest researches are focused on energy savings to reduce CO2 indirect emissions due to the burning of fossil fuels. They are focused on system modifications (as dedicated subcooling or the implementation of ejectors), trigeneration technologies (electrical, heating and cooling demand) and better evaporation conditions control. Motivated by latest GWP regulations that are intended to reduce high GWP HFC emissions; R404A and R507 are going to phase out. Besides hydrocarbons and HFO, CO2 appears as one of the most promising HFC replacements because its low contribution to global warming and high efficiencies when used in transcritical and low-stage of cascade systems.The authors thankfully acknowledge "Ministerio de Educacion, Cultura y Deporte" for supporting this work through "Becas y Contratos de Formacion de Profesorado Universitario del Programa Nacional de Formacion de Recursos Humanos de Investigacion del ejercicio 2012".Mota Babiloni, A.; Navarro Esbri, J.; Barragán Cervera, Á.; Moles, F.; Peris, B.; Verdú Martín, GJ. (2015). Commercial refrigeration - An overview of current status. International Journal of Refrigeration. 57:186-196. doi:10.1016/j.ijrefrig.2015.04.013S1861965

Kamu Binalarında Düşük Karbon Salınımlı Enerji Yönetim Modeli ve Örnek Uygulama

Integrated structures are integrated buildings, most of which are in public administration, which consume more than one source of energy. Despite the different energy demands, these structures are operated by domestic energy conversion systems with a central management structure. It is seen that there are excessive losses with high irreversibility in most fossil fuel source consuming heat needs. in these structures, steam production technologies and energy inefficiency are often above the need. in this study, firstly, energy efficiency potential is examined by reference to demand analysis in a campus. in the study, together with concentrated solar technologies, a framework was proposed to manage the energy demand of the system. in this context, the optimal system requirements were evaluated and a consumption saving analysis was examined. in addition to the thermoeconomic analysis in the model, the environmental savings of the model were investigated. At the end of the study, information was given about the application procedures and needs were discussed.Bütünleşik yapılar, çoğunluğu kamunun yönetiminde olan, birden çok enerji kaynağı tüketen bütünleşmiş binalardır. Bu yapılar farklı enerji taleplerine karşın merkezi bir yönetim yapısına sahip, konvansiyonel enerji dönüşüm sistemleriyle işletilir. Çoğu fosil yakıt kaynağı tüketen ısı ihtiyaçlarında yüksek tersinmezliklerden dolayı aşırı kayıpların olduğu görülür. Çoğunlukla ihtiyacın üstünde, buhar üretim teknolojileri ile enerji verimsizliğinin yoğun olduğu yapılardır. Bu çalışma öncelikle bir yerleşke içinde talep analizi referans alınarak enerji verimlilik potansiyeli irdelenmiştir. Çalışmada, konsantre güneş teknolojileriyle birlikte, sistemin enerji talebini yönetecek bir çerçeve önerilmiştir. Bu kapsamda optimal sistem ihtiyaçları değerlendirilerek bir tüketim tasarruf analizleri incelenmiştir. Çalışmada model alınan yerleşkede termoekonomik analizler ile birlikte, modelin sağlayacağı çevresel tasarruflar da incelenmiştir. Çalışmanın sonunda uygulama prosedürlerine ilişkin bilgi verilmiş ve ihtiyaçlar irdelenmiştir

Economic and Environmental Optimization of an Airport Terminal Building’s Wall and Roof Insulation

HVAC systems use the largest share of energy consumption in airport terminal buildings. Thus, the efficiency of the HVAC system and the performance of the building envelope have great importance in reducing the energy used for heating and cooling purposes. In this study, the application of thermal insulation on the walls and roof of the Hasan Polatkan Airport terminal building was investigated from energy, environment and cost aspects. This study determined the optimum insulation thickness and assessed its effects on environmental performance based on energy flows. Environmental payback periods were calculated depending on the optimum insulation thickness. The life cycle assessment (LCA) method was used to assess whether the decrease in energy consumption after applying the insulation balanced the environmental effects during the period between the production and application of the thermal insulation material. The global warming potential (GWP) based on IPCC100, and the effects on human health (HH), the ecosystem and natural resources were evaluated according to the ReCiPe method. LCA results were obtained by processing data taken from ecoinvent 3 database present in the Sima Pro 8.3.0.0 software. Applying thermal insulation on the walls and roof of the terminal building was found to decrease heat loss by 48% and 56%, respectively. In addition, the analyses showed that the environmental payback periods for the thermal insulation were shorter than the economic payback periods

Concept mapping sustainable energy management for a holistic approach to energy strategies

One of the important reasons for global warming and climate change is regarded as the improper management of fossil energy consumption. There may be various models or approaches to energy management (EM). However, strategic EM and its applications are still away from achieving their goals. In this regard, the main objectives of the present study are to design, develop and propose a knowledge framework primarily based on an EM concept map for a holistic EM. Aligned with the research purposes, a qualitative four-phase study was conducted, and the research question was formulated as: 'What would be the components and concepts required for the holistic EM?' The study also integrated systematic literature review (SLR) and focus group discussion (FGD) techniques. Initially, a list of the key EM concepts was formed and a preliminary concept map was constructed. Then, the final version of the concept map was achieved through several iterative revisions and FGDs. This concept map may be seen as a complementary and contributory tool for strategy development and decision-making processes in the EM knowledge domain. It is hoped that the study may extend the previous knowledge both by the tools it has utilised and approaches it has adopted for the holistic EM