scholarly journals EFEK VARIASI BEBAN PENDINGINAN TERHADAP COEFFICIENT OF PERFORMANCE (COP) MESIN PENDINGIN PADA BOX COOLER ALAT DISTILASI

2021 ◽  
Vol 8 (2) ◽  
pp. 110
Author(s):  
Ahmad Akromul Huda ◽  
Karyanik Karyanik ◽  
Earlyna Sinthia Dewi
Keyword(s):  
Capillary Tube ◽  
Engine Performance ◽  
Study Data ◽  
Office Building ◽  
Coefficient Of Performance ◽  
Cooling Load ◽  
Refrigeration System ◽  
Pressure Data ◽  
Load Variations ◽  
Temperature And Pressure

Refrigerator has been widely used by the community and can be found in almost every shop, office building and household. The application of refrigeration machines can also be developed in many other equipment and machines, one of which is in the distillation apparatus. Distillation is a method of separating two substances. A distillation machine using a cooling machine in the condenser will be very helpful, especially for distillation. This study aims to determine the effect of cooling on the performance of the cooling machine. Cooling engine performance coefficient of achievement (COP). Load variations are carried out by adjusting the boiler temperature using a thermostat. In this study, data on the temperature and pressure of the refrigerant flowing in the refrigeration system were taken at four points, namely before entering the compressor, before entering the capillary tube and before entering the evaporator . In this study also used four variations of the cooling load given to the box cooler of 110 °C, 125 °C, 140 °C, and 155 °C. Then the temperature and pressure data is processed to get the COP value every time from all variations of the cooling load. The results showed that the increaseing in the cooling load, the smaller the COP value of the cooling machine. In its effect on the length of time the COP value of each variation of the cooling load increases. The highest COP value in this study was obtained at a cooling load temperature of 110 ºC of 10.69 and the lowest was obtained at a temperature of 155 ºC of 9.38.

Miniature Vapor Compression Refrigeration Systems for Active Cooling of High Performance Computers

2001 ◽  
Author(s):  
Ali Heydari ◽  
Kathy Russell
Keyword(s):  
Heat Exchanger ◽  
High Performance ◽  
Capillary Tube ◽  
New Technology ◽  
Mathematical Formulation ◽  
Coefficient Of Performance ◽  
Simulation Program ◽  
Vapor Compression ◽  
Refrigeration System ◽  
System Components

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.

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 Exergy and Exergoeconomic Analysis of a Cogeneration Hybrid Solar Organic Rankine Cycle with Ejector

Entropy ◽  
2020 ◽  
Vol 22 (6) ◽  
pp. 702
Author(s):  
Bourhan Tashtoush ◽  
Tatiana Morosuk ◽  
Jigar Chudasama
Keyword(s):  
Electrical Power ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Combined Cycle ◽  
Coefficient Of Performance ◽  
Working Fluid ◽  
Refrigeration Cycle ◽  
Refrigeration System ◽  
Entrainment Ratio ◽  
Temperature And Pressure

Solar energy is utilized in a combined ejector refrigeration system with an organic Rankine cycle (ORC) to produce a cooling effect and generate electrical power. This study aims at increasing the utilized share of the collected solar thermal energy by inserting an ORC into the system. As the ejector refrigeration cycle reaches its maximum coefficient of performance (COP), the ORC starts working and generating electrical power. This electricity is used to run the circulating pumps and the control system, which makes the system autonomous. For the ejector refrigeration system, R134a refrigerant is selected as the working fluid for its performance characteristics and environmentally friendly nature. The COP of 0.53 was obtained for the ejector refrigeration cycle. The combined cycle of the solar ejector refrigeration and ORC is modeled in EBSILON Professional. Different parameters like generator temperature and pressure, condenser temperature and pressure, and entrainment ratio are studied, and the effect of these parameters on the cycle COP is investigated. Exergy, economic, and exergoeconomic analyses of the hybrid system are carried out to identify the thermodynamic and cost inefficiencies present in various components of the system.

An Experimental Investigation of Steam Ejector Refrigeration Systems

2011 ◽  
Author(s):  
J. M. Dong ◽  
D. A. Pounds ◽  
P. Cheng ◽  
H. B. Ma ◽  
X. X. Pan
Keyword(s):  
Cooling Capacity ◽  
Back Pressure ◽  
Coefficient Of Performance ◽  
Refrigeration System ◽  
Operation Temperature ◽  
Steam Ejector ◽  
Mixing Chamber ◽  
Flow Mechanisms ◽  
Ejector System ◽  
Temperature And Pressure

A steam ejector refrigeration system with a movable primary nozzle was developed in order to determine the nozzle exit position (NXP) effect on the coefficient of performance (COP). Experimental results show that an optimum NXP exists for the ejector system investigated herein. In addition, the effects of the operation temperature, diffuser size, nozzle throat diameter, and structure of mixing chamber on the COP and cooling capacity were conducted experimentally. It was found that the critical condenser pressure and COP can be increased by increasing the low-temperature-evaporator (LTE) temperature and pressure. Although an increase of the high-temperature-evaporator (HTE) can increase the critical condenser pressure, the system COP did not increase as the HTE temperature increased. While the diffuser size significantly affected the critical back pressure, it had almost no effect on the system COP. A finned mixing chamber was tested at NXP = 0mm and NXP = 36mm. Compared with the regular mixing chamber, the finned mixing chamber can increase the critical back pressure. The results provide a better understanding of heat transfer and fluid flow mechanisms occurring in a steam ejector refrigeration system.

EXPERIMENTAL INVESTIGATION OF A REFRIGERATION SYSTEM WORKING UNDER TRANSIENT CONDITIONS

2014 ◽  
Vol 22 (03) ◽  
pp. 1450013 ◽  
Author(s):  
J. K. DABAS ◽  
SUDHIR KUMAR ◽  
A. K. DODEJA ◽  
K. S. KASANA
Keyword(s):  
Capillary Tube ◽  
Coefficient Of Performance ◽  
Tube Length ◽  
Design Parameters ◽  
Transient Operation ◽  
Refrigeration System ◽  
Transient Conditions ◽  
Cooling Period ◽  
Optimum Selection ◽  
The Impact

The impact of transient conditions along with varied capillary tube length and charge quantity over the performance of a simple refrigeration system under all time transient operations has been investigated in a specially designed experimental setup. A maximum drop of 75% in the coefficient of performance (COP) of the system was recorded by the end of the transient cooling period. The continuous deterioration in performance from start to end of the transient cooling job can be well minimized by the optimum selection of capillary tube length and charge quantity. This paper refers some of the existing methods to determine the appropriate length of the coiled capillary tube and charge quantity for a newly designed refrigeration machine working under steady state conditions and compares the experimental results of transient operation with these. Optimum charge quantity for transient operation in the present study is 3.5% to 5% less than that calculated by the existing analytical and numerical methods. The optimum length of coiled capillary tube for transient operation as found in this experimental study matches approximately with the length predicted by the existing dimensionless correlation on the basis of design parameters as estimated towards the end of the transient cooling period.

Retrofitting R-22 Split Type Air Conditioning with Hydrocarbon (HCR-22) Refrigerant

2013 ◽  
Vol 388 ◽  
pp. 91-95 ◽  
Author(s):  
Henry Nasution ◽  
Abdul Latiff Zulkarnain ◽  
Azhar Abdul Aziz ◽  
Mohd Rozi Mohd Perang
Keyword(s):  
Energy Consumption ◽  
Air Conditioning ◽  
Room Temperature ◽  
Internal Heat ◽  
Electrical Energy ◽  
Coefficient Of Performance ◽  
Cooling Load ◽  
Refrigeration System ◽  
Electrical Energy Consumption ◽  
The One

An experimental study to evaluate the energy consumption of a split type air conditioning is presented. The compressor works with the fluids R-22 and HCR-22 and has been tested varying the internal heat load 0, 500, 700 and 1000 W. The measurements taken during the one hour experimental periods at 10-minutes interval times for temperature setpoint of 20oC. The performance data considered where the evaporator cooling load, the condenser heat rejection, the electrical energy consumption, the refrigeration system temperatures, and the room temperature. And hence the Coefficient of Performance (COP) could be determined. The final results of this study show an overall better energy consumption of the HFC-22 compared with the R-22.

scholarly journals Simulation and Analysis of Biogas operated Double Effect GAX Absorption Refrigeration System

2011 ◽  
pp. 14-19
Author(s):  
G. Subba Rao ◽  
Vemuri Lakshminarayana
Keyword(s):  
High Temperature ◽  
Thermodynamic Simulation ◽  
Double Effect ◽  
Coefficient Of Performance ◽  
Absorption Refrigeration ◽  
Refrigeration System ◽  
Basic Parameters ◽  
Temperature And Pressure ◽  
Absorption Refrigeration System ◽  
Effect Generator

A thermodynamic simulation of a double effect generator heat exchanger absorption refrigeration cycle using biogas as source of energy has been carried out. The binary mixture considered in the present investigation was NH3 – H2O (Ammonia - Water). This simulation was performed in order to investigate the effect of the temperature and pressure of the high temperature generator and the pressure of evaporator have over the Coefficient of Performance (COP) for a constant condenser and absorber temperatures. The basic parameters at various state points of the cycle was computed using standard correlations. The solution circulation rates and volume of biogas required for operation of the cycle are analysed for the variations in operating parameters at the high temperature generator and evaporator.

scholarly journals Performance of Commercially Open Refrigerated Showcases with and without Ice Storage—A Case Study

Processes ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 683
Author(s):  
Kai-Shing Yang ◽  
Yun-Sheng Chao ◽  
Chia-Hsing Hsieh ◽  
Min-Lun Chai ◽  
Chi-Chuan Wang
Keyword(s):  
Peak Power ◽  
Storage System ◽  
Coefficient Of Performance ◽  
Working Fluid ◽  
Ice Storage ◽  
Air Cooling ◽  
Refrigeration System ◽  
Temperature And Pressure ◽  
Immersion Type

This study examines the applicability of the ice storage systems in the small commercial refrigerated showcases through experimental analysis. R-404A is used as the working fluid and various influence of parameter settings and improvements, are discussed in details. In the ice storage system, the condenser is changed from air-cooling (refrigeration mode) to an immersion type that is placed in an ice storage tank, the corresponding condensing temperature and pressure are reduced appreciably. This increased the efficiency and can effectively reduce the peak power consumption. The reduction of the condensing temperature and pressure increased the coefficient of performance (COP) from 3.6 (refrigeration mode) to 6.35 (melting mode), effectively enhancing the refrigeration efficiency. The results indicated that the ice storage system could effectively increase the coefficient of performance from 3.6 to 6.35 during ice melting when compared to the conventional refrigeration system. It also can shift approximately 35% of the power during peak hours and lower the energy cost by USD$ 17.13 per month.

An Experimental Investigation of Steam Ejector Refrigeration Systems

2012 ◽  
Vol 4 (3) ◽  
Author(s):  
Jingming Dong ◽  
D. A. Pounds ◽  
P. Cheng ◽  
H. B. Ma
Keyword(s):  
Operating Temperature ◽  
Back Pressure ◽  
Coefficient Of Performance ◽  
Refrigeration System ◽  
Nozzle Throat ◽  
Steam Ejector ◽  
Mixing Chamber ◽  
Ejector System ◽  
Throat Diameter ◽  
Temperature And Pressure

A steam ejector refrigeration system with a movable primary nozzle was developed in order to determine the nozzle exit position (NXP) effect on the coefficient of performance (COP). Experimental results show that there exists an optimum NXP for the ejector system investigated herein. The effects of the operating temperature, diffuser size, nozzle throat diameter, and mixing chamber configuration on the COP and critical back pressure were investigated experimentally. It is found that the critical back pressure and COP can be increased by increasing the low temperature evaporator (LTE) temperature and pressure. Although an increase of the high temperature evaporator (HTE) temperature can increase the critical condenser pressure, the system COP does not increase as the HTE temperature increases. The diffuser size significantly affects the critical back pressure but had almost no effect on the system COP. A finned mixing chamber was tested at NXP = 0 mm and NXP = 36 mm. Compared with the regular mixing chamber, the finned mixing chamber can increase the critical back pressure.

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