scholarly journals Improving Energy Efficiency in the Supermarket by Retrofitting Low E Glass Doors for Open Refrigerated

Author(s):  
Piyanut Saengsikhiao ◽  
Juntakan Taweekun ◽  
Kittinan Maliwan ◽  
Somchai Sae-ung ◽  
Thanansak Theppaya

This research presents the improving energy efficiency by retrofitting doors for open refrigerated in central Thailand supermarkets that open in the daytime (06.00 am - 6:00 pm) and close in night-time (00.00 am – 6:00 am). The Materials and Methods were open refrigerated 15 cabinet and retrofitting doors for open refrigerated that 41 frames, 82 doors in medium temperature refrigeration system and measure power consumption kW, kWh by power meter data logger for analysis and summarize. The power consumption saving average per 7 days for retrofitting doors was 576 kWh/day, 39.67% that daytime 418 kWh/day, 41.93%, and night-time 116 kWh/day, 33.24%. Besides, the energy of day time more than night time because 1) The time of opening store is longer than closing store 2) In the night time, the refrigerated will close by plastic curtain 3) The request cooling load of day time is longer than day time 4) The sale area/ambient temperature of night time more than day time but the humidity was contrasted. Before retrofitting doors, the maximum and minimum of power consumption was 83.25 kw/hour and 44.73 kw/hour, respectively. Also, the power consumption swing at 38.52 kw/hour, 46.72%, and the maximum and minimum of power consumption after retrofitting doors was 33.15 kw/hour and 30.19 kw/hour, respectively. The power consumption swing at 2.96 kw/hour, 8.93%. In addition, the power consumption swing will after be retrofitting doors will less than before retrofitting doors by 1) The average cooling load will be the same as bolt conditions 2) The request cooling load of doors refrigerated will less than by product load, the swing of sale area temperature and humidity, customer behavior that effect power condition will have the low running operation. This research's investment was 21,694 €, while the payback period of this research was 14 months. Besides, within 1.1 years, that energy saving was 16,020 kWh/Month or 1,542 €/Month, 16,020 kWh/month or 192,220 kWh/Year or 18,503 €/Year.

Author(s):  
Piyanut Saengsikhiao ◽  
Juntakan Taweekun

This research will be presenting energy efficiency improvement options by retrofitting doors for open refrigeration systems in Central Thailand supermarkets that open during the daytime (06:00 am – 06:00 pm), and are closed during the night-time (00:00 am – 6:00 am). The materials and methods used consisted of 15 open refrigeration cabinets with 82 retrofitted doors supported by 41 frames, with the temperature set at medium. The power consumption was indicated in kW, kWh through a power meter data logger for analysis and summarization. The investment required was €21,694 /store, while the payback period of this research was determined to be at 14 months. The cost of energy savings was found to be within a period of 1.1 years, at the rate of 192,220 kWh/year or €18,503 annually. The retrofitted doors is expected to reduce the cooling load and over-burdening of the compressor. The research found that the most viable solution was to use a digital semi-hermetic compressor that can operate in unload and full load status, that was being controlled by the evaporator temperature (TEV) which was set at -10 degree, the condenser temperature (TCD) set at 38 degrees, and the superheat temperature (TSH) at 10 degrees. In the unload status, the power consumption of the digital semi hermetic compressor will decrease by 50%, which has a significant impact for energy savings and is important for night-time when low cooling load is required whereby the compressor’s multiple start–stop cycles are not required. The investment for a digital semi-hermetic compressor was determined to be €7,800/store, and is able to yield energy savings of up to 26,890 kWh/year, or €2,589 annually, with a payback period of 2.9 years.


2016 ◽  
Vol 20 (3) ◽  
pp. 949-952
Author(s):  
Hui-Fan Zheng ◽  
Shu-Qing Guo ◽  
Yin-Long Chen ◽  
Cong-Min Wang

A model was established for solar ejector-compression refrigeration system. The influence of generator temperature, middle-temperature, and evaporator temperature on the performance of the refrigerant system was analyzed. An optimal generator temperature is found for maximal energy efficiency ratio and minimal power consumption.


Author(s):  
I Nyoman Suamir ◽  
I Made Rasta ◽  
Adi Winarta ◽  
I Wayan Adi Subagia ◽  
Made Ery Arsana

Recent research shows great interest in increasing energy efficiency of a refrigeration system and finding appropriate configurations to optimize its performance. One of the main component in the refrigeration system is compressor. Therefore, the compressor plays an important role in a refrigeration system for energy performance optimization. The study is aimed to experimentally investigate temperature and energy performance of a scroll compressor applied for medium temperature refrigeration systems. Tests were conducted in a water cooled medium temperature refrigeration system. Temperature performance evaluation of the compressor referred to the IEEE Standard 112, while energy efficiency of the compressor was calculated from the energy performance of the refrigeration system. The results clearly show that evaporating temperature together with degree of superheat at suction line of the compressor can significantly affect temperature performance of the scroll compressor. Results of the study have also shown significant improvement on the compressor energy efficiency accounted for 10.4% when the evaporating temperature increases from -8.3 °C to -2.4 °C.


2021 ◽  
Vol 53 (5) ◽  
pp. 453-475
Author(s):  
C Ticleanu

Typical home lighting practice is mainly centred on visual aspects to enable safe movement between spaces, flexibility in multiuse spaces, a sense of aesthetics and energy efficiency. Whilst lighting impacts on the health of residents have not received similar consideration, this area is gaining increasing interest. This is even more important and actual in the context of the recent pandemic where people have been working or studying from home. A combination of bright daytime light and night-time darkness is essential for circadian entrainment and maintenance of a regular daily sleep–wake cycle, whereas exposure to light at night can negatively impact circadian rhythms and sleep patterns and ultimately lead to potential health problems. Additionally, lighting also has the potential to affect health through associated effects such as flicker, glare, optical hazards or electromagnetic fields. This article discusses the main areas of concern related to home lighting and outlines general recommendations to limit detrimental effects and contribute to good health.


Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4089
Author(s):  
Kaiqiang Zhang ◽  
Dongyang Ou ◽  
Congfeng Jiang ◽  
Yeliang Qiu ◽  
Longchuan Yan

In terms of power and energy consumption, DRAMs play a key role in a modern server system as well as processors. Although power-aware scheduling is based on the proportion of energy between DRAM and other components, when running memory-intensive applications, the energy consumption of the whole server system will be significantly affected by the non-energy proportion of DRAM. Furthermore, modern servers usually use NUMA architecture to replace the original SMP architecture to increase its memory bandwidth. It is of great significance to study the energy efficiency of these two different memory architectures. Therefore, in order to explore the power consumption characteristics of servers under memory-intensive workload, this paper evaluates the power consumption and performance of memory-intensive applications in different generations of real rack servers. Through analysis, we find that: (1) Workload intensity and concurrent execution threads affects server power consumption, but a fully utilized memory system may not necessarily bring good energy efficiency indicators. (2) Even if the memory system is not fully utilized, the memory capacity of each processor core has a significant impact on application performance and server power consumption. (3) When running memory-intensive applications, memory utilization is not always a good indicator of server power consumption. (4) The reasonable use of the NUMA architecture will improve the memory energy efficiency significantly. The experimental results show that reasonable use of NUMA architecture can improve memory efficiency by 16% compared with SMP architecture, while unreasonable use of NUMA architecture reduces memory efficiency by 13%. The findings we present in this paper provide useful insights and guidance for system designers and data center operators to help them in energy-efficiency-aware job scheduling and energy conservation.


Author(s):  
Behzad Omidi Kashani

The present research is about increasing the energy efficiency ratio (EER) in current direct evaporative coolers (DEC) in Iran. Increasing the cooling load and reducing the electrical energy consumption simultaneously (increasing the energy efficiency ratio (EER)) in DEC are the main goals of manufacturers and consumers of this device. When the circulation water pump runs continuously (static state), the circulation water rate is about 1.89 to 2.90 times of the amounts recommended in the reasonable standards. In order to adjust the circulation water rate to the recommended amount by standards, the present study has utilized repetitive cyclic scheduling programs to reduce the circulation rate to the optimal amount, (by turning the circulation pump on and off by dynamic pattern operation). In other words, the circulation pump stays on only for a certain period of a working cycle, and then the pump stays off for the rest of it. The cooling load and EER were measured based on ASHRAE 133 (2015). The results indicated that the cooling load in the dynamic state increased by 5.03 and 6.18 percent compared to the static state at low and high fan speeds, respectively. Moreover, in comparison with the static state, the amount of electrical energy consumed (kW-hr) in the dynamic state decreased by 8.8 and 4.2 percent at low and high fan speeds, respectively. Finally, the coefficient of performance (COP or EER) of the DEC in the dynamic state is increased by 15.16 and 10.78 in comparison with the static state at low and high fan speeds, respectively.


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