scholarly journals Analisis Unjuk Kerja Prototype Trainer Lemari Pendingin dengan Variasi Beban Pendinginan

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Andi Arifudin ◽  
I Gede Wiratmaja ◽  
I Nyoman Pasek Nugraha

This study aimed to find the effect of variations in cooling load on the performance of the prototype trainer refrigerator, which in this refrigerator prototype had never been tested performance. In this study, the experimental method was used. The values sought in this study were the rate of room cooling and the Coefficient of Performance (COP). In this study, the variation of the cooling load used started from temperatures of 300C, 350C, 400C 450C, with 15 repetitions, and the temperature performance used was 1000C. The study results showed that the highest room cooling rate occurred at 300C cooling load variation, namely 0.00265, and the smallest room cooling rate occurred at 450C cooling load variation, namely 0.00174. The highest Coefficient of Performance (COP) results occurred at a cooling load variation of 450C, namely 34.09, and the lowest Coefficient of Performance (COP) occurred at a cooling load variation of 300C, namely 29.60. From these results, it can be concluded that the cooling rate of the room was inversely proportional to the increase in cooling load because the more significant the cooling load, the longer the time obtained, resulting in a small room cooling rate. And for the results of the Coefficient of Performance (COP), it was directly proportional to the increase in the cooling load because the more significant the cooling load given, the higher the temperature at T1 and T2, resulting in a significant Coefficient of Performance (COP).

2019 ◽  
Vol 7 (1) ◽  
pp. 12-22
Author(s):  
Ratu Mutia Fajarani ◽  
Yopi Handoyo ◽  
Raden Hengki Rahmanto

Cooling is the best preservation method than others because the food that has been cooled will remain fresh and will not experience a change in taste, color and aroma, besides all the activities that cause decay will stop so that the cooled food will last longer. (Hartanto, 1984). With the proper cooling engine planning, it can help with spatial adjustments, adjustments to loading, estimation of the power to be used, and budget plans. That is what is commonly called the cooling load calculation. Calculation of cooling load needs to be carried out before planning. This is necessary because the magnitude of the pending load is very influential on the selection of the cooling engine so that the freezing point for preserving food can be accurate. Pendiginan burden is influenced by external and internal factors. With the experimental method, it is obtained the results of the external cooling load as the external cooling load is 11.6 kW, the inner cooling load is 138.8 kW and the performance work coefficient (COP) is 2.


2012 ◽  
Vol 614-615 ◽  
pp. 64-68
Author(s):  
Tuo Wang ◽  
Feng Wu ◽  
Jin Hua Fei ◽  
Ming Fang Liu

Thermo-acoustic refrigerator is a new type of engine, which is based on the thermo-acoustic effect. A new model which expresses as an ellipse in pressure-volume diagram is established to investigate the thermodynamic performance of an actual thermo-acoustic refrigeration micro-cycle. The demarcation points of endothermic processes and exothermic processes in the actual micro-cycle are found. The analytic expressions of the dimensionless cooling load and the coefficient of performance (COP) are deduced. The relationship between the dimensionless cooling load and the COP are investigated by numerical examples. The results show that the dimensionless cooling load is a monotonically increasing function of the COP and the pressure amplitude.


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.


Author(s):  
A. YUNUS NASUTION ◽  
ADITYA PRATAMA

The initial problems of fishermen still use their semi-modern catches and still use ice cubes as a cooling medium, due to the lack of innovation in the development of the cooling media caught by fishermen. The implementation of solar panel energy is the beginning for the development of refrigerator power consumption caught by fishermen. The goal is to calculate the cooling load on the refrigerator, calculate the Coefficient of performance (COP) at the refrigerator and the loading factors at the refrigerator, where the average ambient temperature is 34 ℃ and the temperature to be achieved is 0℃, the fisherman results used in the study this is a shrimp with a capacity of 20 kg and the cooling time is 4 hours. Where the total cooling load value is 244.29 Watt, multiplied by 10% safety factor, so the overall cooling load is 268.72 Watts, refrigerant mass flow rate is 0.0012 Kg / s, the evaporator capacity is 261 Watt, compressor power is 15.6 Watt, The coefficient of performance (COP) value was 16.73 while for the refrigerant capacity was 0.074 Tons of refrigerant, the loading factors in the study were used to run a refrigerator with 80 Watt power for 4 hours, so that the total refrigerator load was 320 Wh (Watt hour) , to produce 320 Wh power is used 2 solar panel modules with a capacity of 50 Wp (Watt Peak), and uses a solar change controller (SCC) with a capacity of 10 A. The output power of the solar panel is influenced by the intensity of the sun's light emitted, from the test obtained an average value the average output of solar panels is 90.6 watts, while the total power generated in 11 test points is 536 watts, the type used is polycrystalline, solar panels battery and inverter capacity must be greater than the refrigerator power consumption, in this study used a 12V 35 Ah battery capacity and 500 Watt Inverter


1999 ◽  
Author(s):  
R. Tang ◽  
M. A. Rosen

Abstract The thermodynamic effects are demonstrated of integrating steam turbine-based cogeneration systems with absorption chillers. A wide range of realistic extraction steam pressures and coefficient of performance (COP) values of absorption chillers are considered. A simple model of a steam turbine-based cogeneration plant is used for the evaluation of the integrated system. The integrated systems are evaluated based on the ratio of fuel consumption between a base case (one-stage absorption chiller with a COP value of 0.6) and several alternative cases (multi-stage absorption chillers with COP values ranging from 0.6 to 1.5). Two categories of scenarios are considered: (i) cases where the cooling load is fixed; and (ii) cases where the cooling load is fixed and the electrical output for the integrated system is set equal to that for the base case.


Author(s):  
Doan V. K. Khanh ◽  
Pandian Vasant ◽  
Irraivan Elamvazuthi ◽  
Vo N. Dieu

In this chapter, the technical issues of two-stage TEC were discussed. After that, a new method of optimizing the dimension of TECs using differential evolution to maximize the cooling rate and coefficient of performance was proposed. A input current to hot side and cold side of and the number ratio between the hot stage and cold stage are searched the optima solutions. Thermal resistance is taken into consideration. The results of optimization obtained by using differential evolution were validated by comparing with those obtained by using genetic algorithm and show better performance in terms of stability, computational efficiency, robustness. This work revealed that differential evolution more stable than genetic algorithm and the Pareto front obtained from multi-objective optimization balances the important role between cooling rate and coefficient of performance.


2020 ◽  
Vol 142 (6) ◽  
Author(s):  
Muhammad Zubair ◽  
Sajid Ghuffar ◽  
Muhammad Shoaib ◽  
Ahmed Bilal Awan ◽  
Abdul Rauf Bhatti

Abstract Photovoltaic (PV) estimation in an urban environment requires detection of rooftop area, design of PV system based on optimization on PV placement distance and the study of additional benefit of lower cooling load of building by shading provided by PV panels. The study is aimed at policymakers to introduce renewable energy policy toward net-zero energy buildings in urban areas. In this research, the capital city of Pakistan, Islamabad, is analyzed for rooftop PV capabilities using deep learning algorithms. The area of the rooftop is calculated by extracting buildings in high-resolution satellite imagery using a deep learning algorithm. The site location is analyzed for available solar energy resources. The distance between the rooftop-PV array is optimized based on self-shading losses, coefficient of performance, energy yield, net-zero energy analysis, and reduction of cooling load of the building provided by PV arrays as shading devices. The 40-km2 area of Islamabad considered in this research can generate 1038 GWh of solar energy annually from its 4.3-km2 rooftop area by installed capacity of 447 MW PV panels rows placed at 0.75 m apart. The electricity generated by Islamabad can curtail residential load from the national grid and form a near net-zero energy zone while the electrical energy from the grid can be provided to the industries to enhance the economy and reduce unemployment in Pakistan.


2011 ◽  
Vol 19 (01) ◽  
pp. 57-68 ◽  
Author(s):  
MIGUEL PADILLA

Commercial multiple evaporators variable refrigerant flow (VRF) HVAC systems present many advantages such as being energy saving and the capability of adjusting refrigerant mass flow rate according to the change of high rises occurrence. This paper deals with an experimental control volume exergy analysis in a VRF air conditioning system. The experimental results show that the brunt of the total exergy destroyed in the whole system occurs in the outdoor unit, where the exergy destroyed in the condenser is more important. The values of coefficient of performance (COP) obtained for the tests increase as the system reaches operational conditions imposed in every indoor unit zone. The VRF system analyzed is highly sensitive to the action of the constant speed compressor. The use of an inverter compressor improves the system performance by adjusting the power consumption according to the cooling load in the evaporators.


2021 ◽  
Vol 7 (1) ◽  
pp. 8
Author(s):  
Khairul Mustofa ◽  
Yohanes Primadiyono

COP on a cooling machine is used to reveal the performance of a cooling engine. To increase the COP value in the system, it can be done by changing the dimensions of the filter-drier and capillary pipes used. Therefore, this study was conducted to determine the effect of changing the dimensions of the filter-drier and capillary pipe on the COP and the consumption of electrical power produced by the 2-door refrigerator unit. The method used was an experimental method, namely by varying the filter drier and capillary tube dimensions of the 2-door refrigerator. Variations of filter driers used were filter driers with sizes 7 cm and 9 cm. While the capillary pipes used were 0.31 inches in diameter and 0.51 inches in diameter with a length of 200 cm and 250 cm respectively. The results obtained from this study indicate that the greatest COP value is obtained when using a 7 cm filter-drier and a capillary pipe with a diameter of 0.31 inches with a length of 200 cm, which is 2.80. The COP value also continues to decline as the size of the filter-drier and capillary pipes used increases.


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