scholarly journals Performance Scrutiny of Domestic Refrigerator Using a Stepped Mini Orifice as A Capillary Tube Extension with Sio2 Nano Lubricant And R-290 Refrigerant

2021 ◽  
Author(s):  
Bairi Levi Rakshith

A stepped short tube orifice has been proposed as a replacement for the expansion mechanism in a residential refrigerator that runs on R-290. The present work is primarily concerned with the impacts of stepped short tube orifices on system characteristics such as net refrigeration effect, compressor effort, pull down time, and coefficient of performance. A stepped short tube orifice is made up of two short tube orifices linked serially and having varying sizes. It is used as an extension to the capillary tube in the refrigeration system. A stepped short tube orifice is built and fitted to a home refrigerator in this experiment. The experiments must be done on a home refrigerator equipped with a stepped short tube orifice, R-290 refrigerant, and a 0.5% weight SiO2 nanoparticle. Following the completion of all trials, the effects of the stepwise short tube orifice on a residential refrigerator were studied using comparison charts. The results indicate that the performance of the home refrigerator with stepped short tube orifice and SiO2 nano particle inclusion was much better than the domestic refrigerator without stepped short tube orifice.

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.


Author(s):  
Made Ery Arsana ◽  
I Gusti Bagus Wijaya Kusuma ◽  
Made Sucipta ◽  
I Nyoman Suamir

This study was aimed to investigate performance of a split type air conditioning (SAC) system applying exergy destruction method. A numerical model was established based on exergy destruction analysis of a Condenser Outlet Split-Split Air Conditioning (COS-SAC) system integrated with dual-temperature evaporator and incorporated capillary tube and ejector as expansion devices. An experimental test system was also established to experimentally validate the model. Two type of refrigerants R-290 and R-22 were involved in the evaluations. The Coefficient of Performance (COP) of the ejector COS-SAC system, exergy destruction, and exergy efficiency were determined and compared with those in the SAC system utilizing capillary tube. The results showed there was a significant improvement in the overall exergy efficiency of the COS-SAC systems. The COP of the COS-SAC system was also found to be better than the COP of the SAC system.


2019 ◽  
Vol 3 (1) ◽  
pp. 186-192
Author(s):  
Yudi Wibawa

This paper aims to study for accurate sheet trim shower position for paper making process. An accurate position is required in an automation system. A mathematical model of DC motor is used to obtain a transfer function between shaft position and applied voltage. PID controller with Ziegler-Nichols and Hang-tuning rule and Fuzzy logic controller for controlling position accuracy are required. The result reference explains it that the FLC is better than other methods and performance characteristics also improve the control of DC motor.


2005 ◽  
Vol 51 (12) ◽  
pp. 325-329 ◽  
Author(s):  
X. Wang ◽  
X. Bai ◽  
J. Qiu ◽  
B. Wang

The performance of a pond–constructed wetland system in the treatment of municipal wastewater in Kiaochow city was studied; and comparison with oxidation ponds system was conducted. In the post-constructed wetland, the removal of COD, TN and TP is 24%, 58.5% and 24.8% respectively. The treated effluent from the constructed wetland can meet the Chinese National Agricultural and Irrigation Standard. The comparison between pond–constructed wetland system and oxidation pond system shows that total nitrogen removal in a constructed wetland is better than that in an oxidation pond and the TP removal is inferior. A possible reason is the low dissolved oxygen concentration in the wetland. Constructed wetlands can restrain the growth of algae effectively, and can produce obvious ecological and economical benefits.


2021 ◽  
Vol 13 (10) ◽  
pp. 5659
Author(s):  
Farhood Sarrafzadeh Javadi ◽  
Rahman Saidur

Refrigeration systems have experienced massive technological changes in the past 50 years. Nanotechnology can lead to a promising technological leap in the refrigeration industry. Nano-refrigerant still remains unknown because of the complexity of the phase change process of the mixture including refrigerant, lubricant, and nanoparticle. In this study, the stability of Al2O3 nanofluid and the performance of a nano-refrigerant-based domestic refrigerator have been experimentally investigated, with the focus on the thermodynamic and energy approaches. It was found that by increasing the nanoparticle concentration, the stability of nano-lubricant was decreased and evaporator temperature gradient was increased. The average of the temperature gradient increment in the evaporator was 20.2% in case of using 0.1%-Al2O3. The results showed that the energy consumption of the refrigerator reduced around 2.69% when 0.1%-Al2O3 nanoparticle was added to the system.


2014 ◽  
Vol 960-961 ◽  
pp. 643-647
Author(s):  
Yan Sheng Xu

A stepped capillary tube consisting of two serially connected capillary tubes with different diameters is invented to replace the conventional expansion device. The mass flow rate of refrigerant R410A in stepped capillary tubes with different size were tested. The model of stepped capillary tube is proposed, and its numerical algorithm for tube length and mass flow rate is developed. The experimental results show that the performance comparing between stepped capillary tube system and capillary tube assembly system, the cooling capacity is reduced by 0.3%, the energy efficiency ratio (EER) is equal to each other, the heating capacity is increased by 0.3%, the coefficient of performance (COP) is decreased by 0.3%. That is to say, the performance index of the two kinds of throttle mechanism is almost identical. It indicates that the stepped capillary tube can replace the capillary tube assembly in the R410A heat pump type air conditioner absolutely. The model is validated with experimental data, and the results show that the model can be used for sizing and rating stepped capillary tube.


2001 ◽  
Author(s):  
Ali Heydari ◽  
Kathy Russell

Abstract A small refrigeration system for cooling of computer system components is evaluated. A thermodynamic model describing the performance of the cycle along with a computer simulation program is developed to evaluate its performance. The refrigeration system makes use of a miniature reciprocating vapor compression compressor. Due to space limitations in some high performance computer servers, a miniature refrigeration system composed of a compressor, capillary tube, a compact condenser, and a cold-plate evaporator heat exchanger are used. Mathematical multi-zone formulation for modeling thermal-hydraulic performance of heat exchanger for the condenser and evaporator are presented. The throttling device is a capillary tube and there is presented a mathematical formulation for predicting refrigerant mass flow rate through the throttling device. A physically based efficiency formulation for simulating the performance of the miniature compressor is used. An efficient iterative numerical scheme with allowance for utilization of various refrigerants is developed to solve the governing system of equations. Using the simulation program, the effects of parameters such as the choice of working refrigerant, evaporating and condensing temperatures on system components and overall efficiency of system are studied. In addition, a RAS (reliability, availability and serviceability) discussion of the proposed CPU-cooling refrigeration solution is presented. The results of analysis show that the new technology not only overcomes many shortcomings of the traditional fan-cooled systems, but also has the capacity of increasing the cooling system’s coefficient of performance.


1988 ◽  
Vol 1 (1) ◽  
pp. 19-34 ◽  
Author(s):  
Raymond A. Belliotti

Rhetoric in praise of “our adversary system” flows freely in the prose of many legal insiders. But unexamined rhetoric, like self-praise, is of itself of little recommendation.I will here (I) state and explain the four defining characteristics of our adversary system: (A) formal proceedings, (B) partisan presentation, (C) a neutral, passive fact finder, and (D) principles of professional responsibility. I will then (II) state, explain, and analyze critically the most common justifications advanced in defense of our adversary system: (A) the truth rationale, (B) the rights rationale, (C) the autonomy rationale, (D) the lawyer as friend rationale, (E) the ritualistic function rationale, (F) the dispute rationale, and (G) the pragmatic rationale. I conclude (III) that to date no convincing justification has been advanced which argues persuasively that our adversary system has independent value or that it serves important societal objectives better than other existing or possible legal systems.


Nano Hybrids ◽  
2015 ◽  
Vol 9 ◽  
pp. 33-43 ◽  
Author(s):  
A. Manoj Babu ◽  
S. Nallusamy ◽  
K. Rajan

This paper investigates the reliability and performance of a refrigeration system using nanolubricant with 1, 1, 1, 2-Tetrafluoroethane (HFC-134a) refrigerant. Mineral Oil (MO) is mixed with nanoparticles such as Titanium Dioxide (TiO2) and Aluminium Oxide (Al2O3). These mixtures were used as the lubricant instead of Polyolester (POE) oil in the HFC-134a refrigeration system as HFC-134a does not compatible with raw mineral oil. An investigation was done on compatibility of mineral oil and nanoparticles mixture at 0.1 and 0.2 grams / litre with HFC-134a refrigerant. To carry out this investigation, an experimental setup was designed and fabricated in the lab. The refrigeration system performance with the nanolubricant was investigated by using energy consumption test. The results indicate that HFC-134a and mineral oil with above mentioned nanoparticles works normally and safely in the refrigeration system. The refrigeration system performance was better than the HFC-134a and POE oil system. Thus nanolubricant (Mixture of Mineral Oil (MO) and nanoParticles) can be used in refrigeration system to considerably reduce energy consumption and better Coefficient of Performance (COP).


2013 ◽  
Vol 15 (2) ◽  
pp. 90
Author(s):  
Retno Indahwati ◽  
Ign Budi Hendrarto ◽  
Munifatul Izzati

The aim of this research to analyze the difference of apple farm quality the influence of  intensification of agriculture system with environmentally-friendly of agriculture system. A descriptive field research was conducted in June until August 2012. The soil samples were taken in each location by using disturb sample method. The Arthropods sample were taken every five days for five time by using pitfall trap method with five transek in each location.The research applied a  qualitative and quantitative-descriptive. The farm quality were comparison soil quality analyze and  compositions of ground Arthropods. The composition of ground Arthropods were analyzed using Important Value Index and the diversities were analyzed by using Shannon Wiener Index. The result showed that farm quality with environmentally-friendly of agriculture system was better than intensification of agriculture system. The ground Arthropods collected at 150 pitfall trap in environmentally-friendly of agriculture system were 15.079 individual while those in intensification of agriculture system were 9.461 individual. Based on Important Value Index (40,83-64,31), Collembolla ordo Entomobryidae family dominated in each location. Based on Shannon Wiener Index that diversity of ground Arthropods in intensification of agriculture system (H’= 1,58-2,04) was greater than environmentally-friendly of agriculture system (H’= 1,56- 1,99), but both of them at medium criteria.   Keywords : farm quality, agriculture system, Arthropods composition


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