Study on Conceptual Design of a Solar Ejector Refrigeration System

2020 ◽  
Vol 28 (01) ◽  
pp. 2030001 ◽  
Author(s):  
Md. Khairul Bashar Shovon ◽  
Raman Senthil Kumar ◽  
Tae Ho Kim ◽  
Heuy Dong Kim
Keyword(s):  
Working Conditions ◽  
Renewable Energy Sources ◽  
Area Ratio ◽  
Coefficient Of Performance ◽  
Energy Sources ◽  
Refrigeration System ◽  
Critical Mode ◽  
Evaporator Temperature ◽  
Critical System ◽  
Wide Range

The refrigeration system based on the conventional compression cycle consumes an enormous amount of high-grade energy. Using fossil fuels as the energy sources results in the addition of CO2 into the atmosphere and consequently stimulating higher greenhouse effect. The ejector refrigeration systems powered by renewable energy sources would be an effective alternative without increasing global CO2 footprint. In this study, the performance characteristics of a solar ejector refrigeration system working with R718 are analytically calculated by using a one-dimensional flow model. At the critical mode, the solar ejector-refrigeration system is analyzed at various working conditions such as condenser temperature, evaporator temperature, generator temperature, and ejector area ratio. The critical system performance is analyzed to meet any designated working conditions with a wide range of condenser temperatures. It is found that during the critical mode of operation, higher area ratio, higher evaporator temperature and lower generator temperature enhance the performance of the system. The minimum evaporator temperature, and the maximum generator temperature designed to acquire the required coefficient of performance value are also calculated.

Experimental Investigation of Ejector-Assisted Vapor Compression System

2019 ◽  
Vol 27 (03) ◽  
pp. 1950029
Author(s):  
Vikas Kumar ◽  
Gulshan Sachdeva
Keyword(s):  
Capillary Tube ◽  
Area Ratio ◽  
Coefficient Of Performance ◽  
Vapor Compression ◽  
Evaporator Temperature ◽  
Compression System ◽  
Wide Range ◽  
Expansion Valve ◽  
Maximum Improvement ◽  
Vapor Compression System

The performance of an ejector as an expansion device rather than the conventional expansion valve or capillary tube in a vapor compression system is experimentally analyzed. Experiments have been conducted using 28 ejectors of different dimensions at the same condenser and evaporator temperatures, and it has been observed that for utmost performance, an optimum area ratio of the ejector is required. One of the ejector geometry has been experimented further for a wide range of condenser and evaporator temperatures. The coefficient of performance is found to be enhanced by at least 10% in comparison to the conventional vapor compression system for the considered range of condenser and evaporator temperatures and the maximum improvement in COP obtained is 12.83% at 14.3∘C evaporator temperature and 32.4∘C condenser temperature with 17.9211 ejector area ratio. The refrigerant R134a has been used as the working substance.

Experimental Investigation of a Miniature Ejector Using Water as Working Fluid

2020 ◽  
Vol 12 (6) ◽  
Author(s):  
Jingming Dong ◽  
Qiuyu Hu ◽  
Yuxin Xia ◽  
He Song ◽  
Hongbin Ma ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
High Temperature ◽  
Working Conditions ◽  
Thermal Energy ◽  
Nozzle Exit ◽  
Cooling System ◽  
Area Ratio ◽  
Coefficient Of Performance ◽  
Working Fluid ◽  
Condensing Pressure

Abstract This paper presents an experimental investigation of a miniature ejector using water as the working fluid. The investigated ejector cooling system can utilize the thermal energy to be removed to power the cooling system and maintain the temperature of an electronic component below ambient temperature. The effects of working conditions, nozzle exit position (NXP), and area ratio on the coefficient of performance (COP) of ejector performance were investigated. Experimental results show that the miniature ejector can function well when the temperature in the high-temperature evaporator (HTE) ranges from 55 °C to 70 °C and can achieve a COP (coefficient of performance) of 0.66. With an increase of the NXP, the COP decreases, while the critical condensing pressure first increases and then decreases. As the area ratio of the miniature ejector increases, the COP increases, and the critical condensing pressure decreases.

Environment Friendly Mixed Refrigerant to Replace R-134a in a VCR System with Exergy Analysis

2014 ◽  
Vol 984-985 ◽  
pp. 1174-1179
Author(s):  
N. Austin ◽  
P.M. Diaz ◽  
D.S. Manoj Abraham ◽  
N. Kanthavelkumaran
Keyword(s):  
Global Warming ◽  
Global Warming Potential ◽  
Ozone Depletion ◽  
Exergy Analysis ◽  
Coefficient Of Performance ◽  
Refrigeration System ◽  
Evaporator Temperature ◽  
Environment Friendly ◽  
A Charge ◽  
Vapour Compression

Study on environment friendly mixed refrigerant to replace R134a in vapour compression refrigeration (VCR) System. The mixed refrigerants investigated are propane (R290), butane (R600), isobutene (R600a) and R134a. Even though the ozone depletion potentials of R134a relative to CFC-11 are very low; the global warming potentials are extremely high and also expensive. For this reason, the production and use of R134a will be terminated in the near future. Hydrocarbons are free from ozone depletion potential and have negligible global warming potential. The results showed that, mixed refrigerant with charge of 80 g satisfy the required freezer air temperature when R134a with a charge of 110 g is used as refrigerant. The actual COP of refrigerator using mixed refrigerant was almost nearer that of the system using R134a as refrigerant. The coefficient of performance of the vapour compression refrigeration system using mixed refrigerant MR-3 [R134a/R290/ R600a/ R600 (20/35/40/5)] is having very close value with R134a and the Global warming potential of MR-3 is negligible when compared with R134a. Hence the mixed refrigerant MR-3 is chosen as an environmental friendly alternate refrigerant to R134a. The exergy analysis of the vapour compression refrigeration system using R134a and all the above mixtures are investigated. The effect of evaporator temperature on exergy efficiency and exergy destruction ratio of the system are experimentally studied. The exergy defect in the compressor, condenser, expansion device and evaporator are also obtained. Key words: R134a, Mixed refrigerant, Chlorofluorocarbons, Propane, Butane, Isobutene, REFPROP, COP, ODP, GWP, Exergy, VCR System.

Ecological houses of Southern Kazakhstan using renewable energy sources

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ardasher Namazbay Yussupov ◽  
Akmaral Ardasherovna Yussupova
Keyword(s):  
Renewable Energy ◽  
Rural Areas ◽  
Building Materials ◽  
Residential Buildings ◽  
Renewable Energy Sources ◽  
Local Population ◽  
Climatic Conditions ◽  
Energy Sources ◽  
Content Type ◽  
Wide Range

PurposeThe purpose of this article discusses the design of underground eco-houses using a dome structure of light construction while taking into account the historical experience of the development of the local population. This article considered the traditions of folk architecture and modern sophistication in the creation of energy-efficient eco-houses in foreign countries in the context of architecture and construction of affordable residential homes for the local population.Design/methodology/approachThe research presented in this paper was motivated by the need for developing agro-tourism facilities in hard-to-reach areas of the Silk Road in Southern Kazakhstan causes the construction of eco-houses built using local construction materials. Since ancient times in Southern Kazakhstan and during seasonal migrations in yurts of light construction, people have lived in mud-brick houses deep in the ground. Along with architectural and artistic solutions in building construction, great importance was attached to saving material resources, labour costs and achieving heat stability of residential buildings.FindingsIn the architectural and planning solution of the eco¬-house, progressive directions of construction of agrotechnical structures using renewable energy sources are adopted. Particular importance was given to the choice of the construction site on an elevated area nearby historical monuments and a favourable season for the construction of eco-houses with considering the natural and climatic characteristics of rural areas of Southern Kazakhstan.Research limitations/implicationsThis paper discussed the issues of insulation, ventilation and improving the eco-house microclimate comfort using local building materials. Improving the architectural and artistic expressiveness of the eco-house in terms of the tradition of folk architecture was also explicitly discussed in this paper.Practical implicationsTables with the justification of expediency of construction of economical eco-houses in natural and climatic conditions of Kazakhstan and Central Asia are provided. The results help to improve the energy efficiency of eco-houses in Kazakhstan by using renewable energy sources.Social implicationsSocial benefits are associated with the use of local raw materials. Eco-houses built from traditional building materials can become accessible to a wide range of people and stimulate the development of small businesses. This may be associated with the construction of eco-houses to serve visiting tourists in remote picturesque oases, as well as the manufacture of dome structures, felt products and the preparation of reed panels and so on.Originality/valueThe thermotechnical characteristics of the region's ground energy are given, which can significantly save the cost of heating the eco-house. Solutions for optimal insolation, ventilation of the eco-house are provided, taking into account the natural and climatic conditions of Southern Kazakhstan.

scholarly journals COP enhancement of vapour compression refrigeration system using dedicated mechanical subcooling cycle

2020 ◽  
Vol 39 (3) ◽  
pp. 776-784
Author(s):  
T.S. Mogaji ◽  
A. Awolala ◽  
O.Z. Ayodeji ◽  
P.B. Mogaji ◽  
D.E. Philip
Keyword(s):  
System Performance ◽  
Cooling Capacity ◽  
Coefficient Of Performance ◽  
Condensation Temperature ◽  
Refrigeration System ◽  
Wide Range ◽  
Cascade Refrigeration System ◽  
Cascade Refrigeration ◽  
Vapour Compression ◽  
Better Than

This study focused on development of an improved vapour compression refrigeration system (IVCR system). Dedicated mechanical subcooling cycle is employed in attaining the developed IVCR system. The system is composed of two cycles cascade refrigeration system working with R134a. It consists of a rectangular shape with total storage space of 0.582 m3, made of galvanized mild steel and internally insulated with 0.05 m polystyrene foam. Tests under a wide range operating temperature conditions were carried out on the developed IVCR system. Performance evaluation of the system was characterized in terms of cooling capacity and coefficient of performance (COP). Experimental results showed that the COP of the subcooled system improved better than that of the main system from 18.0% to about 33.5% over an evaporating temperature range of -10 to 30oC. It can be concluded that the use of dedicated sub cooling cycle in VCR system is more efficient and suitable for the betterment of thermal system performance. Keywords: Vapour compression Refrigeration system, Coefficient of performance, dedicated subcooled system, Condensation temperature, Evaporation temperature.

scholarly journals Energy and exergy analysis of vapour compression refrigeration system using selected eco-friendly hydrocarbon refrigerants enhanced with tio2-nanoparticle

2017 ◽  
Vol 6 (4) ◽  
pp. 91 ◽  
Author(s):  
Luke Ajuka ◽  
Moradeyo Odunfa ◽  
Olayinka Ohunakin ◽  
Miracle Oyewola
Keyword(s):  
Power Consumption ◽  
Exergy Analysis ◽  
Capillary Tube ◽  
Coefficient Of Performance ◽  
Refrigeration System ◽  
Exergetic Efficiency ◽  
Evaporator Temperature ◽  
Energy And Exergy ◽  
Nano Lubricant ◽  
Energy And Exergy Analysis

The experimental study investigated the energy and exergy performance of a domestic refrigerator using eco-friendly hydrocarbon refrigerants R600a and LPG (R290/R600a: 50%/50%) at 0, 0.05, 0.15 and 0.3wt % concentrations of 15nm particle size of TiO2 nano-lubricant, and R134a. The effects of evaporator temperature on power consumption, coefficients of performance, exergetic efficiency and efficiency defects in the compressor, condenser, capillary tube and evaporator of the system were examined. The results showed that LPG + TiO2 (0.15wt %) and R600a + TiO2 (0. 15wt %) had the best of performances with an average of 27.6% and 14.3% higher coefficient of Performance, 34.6% and 35.15% lower power consumption, 13.8% and 17.53% higher exergetic efficiency, a total exergetic defect of 45.8% and 64.7% lower compared to R134a. The exergetic defects in the evaporator, compressor, condenser, and capillary tube were 38.27% and 35.5%, 49.19% and 55.56%, 29.7% and 33.7%, 39.1% and 73.8% lower in the system when compared to R134a respectively. Generally, the refrigerants with nano-lubricant mixture gave better results with an appreciable reduction in the exergy defect in the compressor than the pure refrigerants, and LPG + TiO2 (0. 15wt %) gave the best result in the refrigeration system based on energy and exergy analysis.

scholarly journals Sustainable Design of a Nearly Zero Energy Building Facilitated by a Smart Microgrid

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Gandhi Habash ◽  
Daniel Chapotchkine ◽  
Peter Fisher ◽  
Alec Rancourt ◽  
Riadh Habash ◽  
...  
Keyword(s):  
Renewable Energy ◽  
Integrated Control ◽  
Renewable Energy Sources ◽  
Energy Sources ◽  
Zero Energy ◽  
Complex Concept ◽  
Reduction Techniques ◽  
Wide Range ◽  
Yearly Average ◽  
Occupant Comfort

One of the emerging milestones in building construction is the development of nearly zero energy buildings (NZEBs). This complex concept is defined as buildings that on a yearly average consume as much energy as they generate using renewable energy sources. Realization of NZEBs requires a wide range of technologies, systems, and solutions with varying degrees of complexity and sophistication, depending upon the location and surrounding environmental conditions. This paper will address the role of the above technologies and solutions and discusses the challenges being faced. The objective is to maximize energy efficiency, optimize occupant comfort, and reduce dependency on both the grid and the municipal potable water supply by implementing sustainable strategies in designing a research and sports facility. Creative solutions by the architectural and engineering team capitalize on the design of a unique glazing system; energy efficient technologies; water use reduction techniques; and a combined cooling, heating, and power (CCHP) microgrid (MG) with integrated control aspects and renewable energy sources.

scholarly journals Evaluation of the solar conditions for the acquisitions of energy from renewable sources on the base of Sosnowiec city (Poland)

2014 ◽  
Vol 3 (1) ◽  
pp. 83-90
Author(s):  
Sonia Sarapata
Keyword(s):  
Renewable Energy ◽  
Solar Radiation ◽  
Energy Security ◽  
Renewable Energy Sources ◽  
Energy Sources ◽  
Security Risk ◽  
Annual Average ◽  
Radiation Data ◽  
Wide Range ◽  
Annual Total

Abstract The country’s energy security risk, as well as a desire to protect the environment from the pollution and degradation which are the results of conventional fuels acquisition - these was a motivation for intensive researches on the use of renewable energy sources in eco - innovative installations. Solar radiation is one of the self - renewable energy sources which can be used both as a source of electricity and heat. The area of research is Sosnowiec city located in the south of Poland in the eastern part of Silesia voivodeship. The solar radiation data covering the years 2003 to 2013 was used. The intra - annual variability of daily averaged solar radiation hesitated in a wide range from 0.6 kWh/m2 (December) to 5.2 kWh/m2 (June). Day duration varies on average from 10 hours in January, November and December to 17 hours in May, June and July. Day occupies 56% of the 8767 hours in year. On average the largest amount of energy reached the analyzed area in July: 157 kWh/m2 (15% of the annual average), while the smallest in December: 18 kWh/m2 (less than 2% of the annual average). The 75% of the average annual total of energy falls on the period from 1st March to 31th August (spring - summer). The range of the annual solar radiation was determined by the minimum of 980 kWh/m2 and the maximum of 1094 kWh/m2. In Sosnowiec the average annual irradiation total on the horizontal surface amounts to 1052 kWh/m2 (2003 - 2013)

scholarly journals Fuzzy logic control of hybrid systems including renewable energy in microgrids

2020 ◽  
Vol 10 (6) ◽  
pp. 5559
Author(s):  
Omar Feddaoui ◽  
Riad Toufouti ◽  
Labed Jamel ◽  
Salima Meziane
Keyword(s):  
Fuzzy Logic ◽  
Renewable Energy ◽  
Power System ◽  
Hybrid Systems ◽  
Fuzzy Logic Control ◽  
Renewable Energy Sources ◽  
Storage System ◽  
Energy Sources ◽  
Logic Control ◽  
Wide Range

With a growing demand for more energy from subscribers, a traditional electric grid is unable to meet new challenges, in the remote areas remains the extension of the conventional electric network very hard to do make prohibitively expensive. Therefore, a new advanced generation of traditional electrical is inevitable and indispensable to move toward an efficient, economical, green, clean and self-correcting power system. The most well-known term used to define this next generation power system is Micro Grid (MG) based on renewable energy sources (RES). Since, the energy produced by RES are not constant at all times, a wide range of energy control techniques must be involved to provide a reliable power to consumers. To solve this problem in this paper we present a Fuzzy Logic Control of isolated Hybrid Systems (HRES) Including Renewable Energy in Micro-Grids to maintain a stability in voltage and frequency output especially in the standalone application. The considered HRES combine a wind turbine (WT) and photovoltaic (PV) panels as primary energy sources and an energy storage system (ESS) based on battery as a backup solution. Simulation results obtained from MATLAB/Simulink environment demonstrate the effectiveness of the proposed algorithm in decreasing the electricity bill of customer.

The features of Slovenia ecological policy

2021 ◽  
pp. 264 (317)-272 (324)
Author(s):  
Yuriy Konstantinovich Knyazev
Keyword(s):  
European Union ◽  
Renewable Energy ◽  
Environmental Policy ◽  
Raw Materials ◽  
Renewable Energy Sources ◽  
Energy Sources ◽  
Total Production ◽  
The European Union ◽  
Wide Range ◽  
The Government

In Slovenia, there is an urgent problem of limiting the harmful effects of economic activities that deteriorate the living conditions of people, animals and fl ora. The state is taking measures to encourage residents to stay in their home towns and take care of their arrangement and development, the preservation of natural resources and a comfortable environment for people. Numerous public organizations of civil society play an important role in this. This article outlines the features of the modern environmental policy of Slovenia, carried out within the framework of the general line of the European Union, aimed at the phasing out of carbon fuels and the transition to renewable energy sources. The article analyzes Slovenian official documents, setting out the country's environmental strategy, progress in the implementation of plans for energy and climate measures until 2030, the current state of the energy sector and its compliance with the planned tasks. The author's assessment of the efficiency of the environmental policy carried out in Slovenia and its possible results is presented. It is stated that although the indicators of improving the environmental situation are gradually increasing, the emission of harmful gases is decreasing, and the efficiency of the use of energy and raw materials is improving, Slovenia still lags behind the European average in most of these indicators. Meanwhile, it has a relatively high share of renewable energy sources in its total production. This is achieved through budget subsidies for the energy produced from renewable energy sources so that its price does not exceed the market level. Significant monetary resources are spent to apply a wide range of incentive measures. Therefore, the government is forced to seek opportunities to further increase the funding for environmental activities, in particular through European Union funds, including assistance to fight the coronavirus pandemic. English version of the article on pp. 317-324 at URL: https://panor.ru/articles/features-of-the-environmental-policy-in-slovenia/66114.html

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