Research Article
The Effect of Cooling Load Variations on Basic Refrigerator Simulation Performance
Nyoman Gede Baliarta,
M. Yusuf*
Issue:
Volume 9, Issue 1, February 2024
Pages:
1-7
Received:
3 January 2024
Accepted:
15 January 2024
Published:
1 February 2024
Abstract: The working principle of the cooling machine is to transfer heat from a place / material with a low temperature to another place / material with a higher temperature. Refrigeration technology is very closely related to modern life, and also the convenience of life. Currently, refrigeration machine innovation is very rapid development, one of which is a basic refrigerator simulation machine. For testing carried out for 1.5 hours with data collection for 5 minutes using variations in lamp loads, so that the data obtained from the test process in the basic refrigerator simulation with two evaporators include: Temperature, pressure, electric current, voltage, Cos φ and the length of the test process, the COP (Coefficient of Performance) and input power needed can be calculated. The resulting temperature in box 1 (freezer) is -5.5°C in the 14th minute and in box 2 (chiller) is 8°C. The relationship between the cooling load and the COP of the system forms a parabolic curve, where the largest COP position is found at a load between 50 watts to 75 watts, and then the COP of the system decreases. The decrease in temperature of evaporator box 2 (chiller) is longer than the temperature of box 1 (freezer), this is because on the exit side of evaporator box 2 (chiller) installed EPR valve (evaporator pressure regulator) where this valve functions to hold the temperature of the evaporator.
Abstract: The working principle of the cooling machine is to transfer heat from a place / material with a low temperature to another place / material with a higher temperature. Refrigeration technology is very closely related to modern life, and also the convenience of life. Currently, refrigeration machine innovation is very rapid development, one of which ...
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Research Article
Risk Analysis of Upper Limb Musculoskeletal Disorders in Industrial Skin Measurement Workers Using the Assessment of Repetitive Task Method
Tri Budiyanto*,
Sef Feriyansa,
M. Yusuf
Issue:
Volume 9, Issue 1, February 2024
Pages:
8-18
Received:
20 January 2024
Accepted:
4 February 2024
Published:
21 February 2024
Abstract: In the leather industry production process in the Piyungan area of Yogyakarta, Indonesia, the operators do a lot of repetitive activities with intensity and frequency of movement for a long time, for 8 hours in a sitting position. Operators measure on average 4700 pieces of leather per day. This leads to fatigue and complaints of musculoskeletal disorders (MSDs). For this reason, research was conducted to measure the level of risk of MSDs and improve them to reduce muscle complaints. This research was conducted experimentally on all skin-cutting operators at companies in the Piyungan area of Yogyakarta. Measurement of the risk level of upper limb musculoskeletal disorders using the Assessment of Repetitive Tasks (ART) method. The data was analyzed based on ART scores obtained, ranging from low, medium, and high risk level scores. The conclusion of the results showed that the risk level of upper limb musculoskeletal disorders in this skin measurement operator included medium and high risk levels on the left and right upper limb operators. Improvements that can be made to reduce the level of risk are improvements to work facilities in the form of chairs, additional short rest periods, and stretching muscles before and after doing work on all skin measurement production operators.
Abstract: In the leather industry production process in the Piyungan area of Yogyakarta, Indonesia, the operators do a lot of repetitive activities with intensity and frequency of movement for a long time, for 8 hours in a sitting position. Operators measure on average 4700 pieces of leather per day. This leads to fatigue and complaints of musculoskeletal di...
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