Energy conservation in the refrigeration system through improvement of Coefficient of Performance and power consumption reduction using Nanofluids

Author(s):  
Nagarajan Jeyakumar ◽  
C. Uthranarayan ◽  
Bose Narayanasamy
2017 ◽  
Vol 6 (4) ◽  
pp. 91 ◽  
Author(s):  
Luke Ajuka ◽  
Moradeyo Odunfa ◽  
Olayinka Ohunakin ◽  
Miracle Oyewola

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.


2016 ◽  
Vol 78 (10-2) ◽  
Author(s):  
Ahmad Zulkhairie Amran ◽  
Zulkarnain Abdul Latiff ◽  
Henry Nasution ◽  
Mohd Rozi Mohd Perang ◽  
Hishammudin Mohd Jamil ◽  
...  

To evaluate an air-conditioning system performance on board is quite cumbersome and tedious process due to the limitation of space in the engine compartment. This paper presents the process of designing and the result from the automotive refrigeration system simulation that have been integrated into the test rig. To perform the test on automotive refrigeration simulator the location for the temperature measurement selected and thermocouples were installed. The locations of the temperature probes are at the inlet and outlet of compressor, condenser outlet and the inlet of the evaporator. The gas pressure was measured at low and high pressure sides located at evaporator outlet and receiver-drier respectively. The test results were analyzed using the properties table of the refrigerant used. The coefficient of performance (COP), cooling load of the system and compressor power consumption were determined. The variable parameters used are the evaporator blower speed and the air velocity passes through the condenser. The experimental results obtained show that increasing the blower speed will reduce the COP of the refrigeration system. The maximum COP of the system is 4.3 at the lowest evaporator blower speed. The power consumption will be reduced when the air flow velocity through the condenser is increased from 0, 40, 50, 60, 70 km/h respectively.


Energies ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1887
Author(s):  
Whei-Min Lin ◽  
Chung-Yuen Yang ◽  
Ming-Tang Tsai ◽  
Hong-Jey Gow

This paper proposes a control strategy for the energy saving of refrigerating chambers. Combining binary coding and proteome reorganization, the binary proteome algorithm (BPA) is proposed to solve this problem. The refrigeration system model is firstly established based on the performance data of compressors and temperature measurements of each refrigerating chamber. The objective function is an averaged coefficient of performance (COP), which considers the switching loss of the compressors, power consumption of the compressors, and refrigerating capacity of the chambers. The control strategy is defined as an optimization problem with constraints to avoid the ineffective operation of a refrigeration system for improving the COP. BPA is adopted to solve the control strategy for optimizing energy saving. The effectiveness and efficiency of the BPA are demonstrated using a real system, and the results are compared with the original control strategy. Results show that the average power consumption drops from 115.92 kW to 108.82 kW, and the average COP value rises from 1.92 to 2.03. The proposed control strategy is feasible, robust, and more effective in energy-saving problems. Other than energy saving, the proposed control strategy also has the benefits of reducing the evaporator frost formation, which allows the products to avoid chill damage.


Author(s):  
Anupam Mishra

Abstract: This review paper is a study on various methods of performance improvement in domestic refrigeration systems, based on the vapor compression refrigeration VCRS cycle. Here air-cooled, water-cooled, fog cooled, evaporatively cooled condensers and nano-fluid lubricant /coolant methods their working and efficiency are reviewed, compared, analyzed and presented. The paper inspects the work done by different researchers for the maximization of heat loss from condenser & compressor and bringing about necessary modifications to reduce the overall power consumption of domestic refrigerators by improving Coefficient of Performance (COP). Numerous works have been done on improving the heat dissipation capacity of condenser but using nano-fluid in lubricant base as refrigerant and in the compressor shell as coolant is a new technology. Nano-fluid increase heat transfer due the high conductivity nano particles. It has been observed that water cooled condensers and compressors with nano-lubricants/coolants give the best performance improvements but they suit better for big or large refrigeration systems like centralized air conditioning systems or cold storage warehousing, whereas air cooled and evaporative condensers are optimal for small scale or low power appliances like domestic refrigerators, water coolers or split air conditioners to reduce overall power consumption by increasing the COP. Keywords: Refrigeration system, COP improvement, Condenser, Water mist, Evaporative cooling, Nano-fluid coolant, VCRS cycle.


2009 ◽  
Vol E92-C (3) ◽  
pp. 352-355
Author(s):  
Ki-Sang JUNG ◽  
Kang-Jik KIM ◽  
Young-Eun KIM ◽  
Jin-Gyun CHUNG ◽  
Ki-Hyun PYUN ◽  
...  

2013 ◽  
Vol 329 ◽  
pp. 36-39 ◽  
Author(s):  
Qiu Hong Wang

In this paper, according to the requirements on energy conservation and emissions reduction, the theoretical foundation for the essence, objective and elements of energy accounting is introduced around energy conservation and consumption reduction, and also energy accounting is elaborated from expenditure expensing and capitalization, recording and accounting, and information disclosure.


Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 1079 ◽  
Author(s):  
Martin Belusko ◽  
Raymond Liddle ◽  
Alemu Alemu ◽  
Edward Halawa ◽  
Frank Bruno

Dew point cooling (DPC) is a novel indirect evaporative cooling concept capable of delivering air temperatures approaching the dew point. Coupling this technology with CO2 refrigeration is well suited to minimising transcritical operation when the coefficient of performance (COP) is dramatically reduced in hot climates. A substantial experimental program was conducted to characterise this combination by testing a 20 kW CO2 refrigeration system subject to ambient temperatures above 40 °C. It was demonstrated that DPC operation not only avoided transcritical operation during such weather conditions, but also increased the COP by up to 140% compared to the conventional system. The combination of these technologies was successfully mathematically modelled, from which the optimum condenser inlet air temperature was identified for each condenser temperature. Using this optimum condition, it was possible to maximise the COP for a range of conditions applicable to the psychometric chart. An annual case study for Adelaide, Australia was conducted which demonstrated that optimally coupling DPC with CO2 refrigeration can reduce the annual energy consumption and peak demand by 16% and 47%, respectively, compared to a conventional CO2 booster system. Furthermore, the number of hours of transcritical operation was reduced from 3278 to 27.


Author(s):  
B Sairamakrishna ◽  
◽  
T Gopala Rao ◽  
N Rama Krishna ◽  
◽  
...  

This experimental investigation exemplifies the design and testing of diffuser at compressor inlet and nozzle at condenser outlet in vapour compression refrigeration system with the help of R134a refrigerant. The diffuser with divergence angle of 12°,14° and the nozzle with convergent angle 12°,14° are designed for same inlet and outlet diameters. Initially diffusers are tested at compressor inlet diffuser is used with inlet diameter equal to exit tube diameter of evaporator and outlet tube diameter is equal to suction tube diameter of the compressor. Diffuser helps to increases the pressure of the refrigerant before entering the compressor it will be helps to reduces the compression work and achieve higher performance of the vapour compression refrigeration system. Then nozzles are testing at condenser outlet, whereas nozzle inlet diameter equal to discharging tube diameter of condenser and outlet diameter equal to inlet diameter of expansion valve. Additional pressure drop in the nozzle helped to achieve higher performance of the vapour compression refrigeration system. The system is analyzes using the first and second laws of thermodynamics, to determine the refrigerating effect, the compressor work input, coefficient of performance (COP).


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