scholarly journals The Effect of Water Impact on the Refrigerant Pipeline between Compressor and Condensor on COP and Efficiency of Cooling Machine

Author(s):  
Wibowo Kusbandono ◽  

The purpose of this research is (a) to design and assemble a steam compression cycle cooling machine using the main components on the market (b) to obtain the characteristics of the cooling engine, which includes the Coefficient of Performance (COP) and the efficiency of the cooling engine. The research was conducted experimentally in the laboratory. The refrigeration machine works by using a steam compression cycle, with the main components: a compressor, an evaporator, a capillary tube and a condenser. The compressor power is 1/6 PK, while the other main components are adjusted to the size of the compressor power. The refrigerant used is R134a. Variations of the research were carried out on the condition of the refrigerant pipe located between the compressor and condenser: (a) without being submerged in water (b) submerged in 0.50 liters of water and (c) submerged in 0.75 liters of water. The results of the study provide information that the water immersion in the refrigerant pipe which is located between the compressor and condenser affects the COP value and the efficiency of the refrigeration machine. Consecutively (1) without being submerged in water, the COP value is 2.45 and the efficiency is 0.64 (2) submerged in liter of water, the COP value is 2.41 and the efficiency is 0.62 (3) submerged in liter of water, the value COP is 2.34 and efficiency is 0.60.

2021 ◽  
Vol 1 (1) ◽  
pp. 23
Author(s):  
M.Pramuda Nugraha Sirodz ◽  
Lucyana Balqis

Abstrak Buncis merupakan salah satu produk pertanian di Indonesia yang diekspor ke luar negeri. Setelah dipanen, buncis disimpan untuk diproses sebelum diekspor ke konsumen. Kesegaran buncis umumnya hanya bertahan selama 1 minggu, oleh karena itu diperlukan alat khusus untuk mempertahankan kesegaran buncis sebelum diekspor ke konsumen. Untuk mempertahankan kesegaran buncis, temperatur udara 4°C-7°C dengan kelembaban 90%-95% perlu dipertahankan. Dengan menggunakan cold strorage, kondisi ruang penyimpanan dapat diatur sedemikian rupa agar memenuhi kriteria tersebut. Pada penelitian ini dirancang sebuah cold storage dengan kapasitas 10 ton untuk tanaman buncis. Cooling Load Temperatur Difference (CLTD) pada perancangan ini diatur bulan dan waktunya yang disesuaikan dengan posisi dari cold storage. Beban pendinginan total untuk 10 ton buncis adalah sebesar 46,73 kW. Cold storage hasil rancangan menggunakan siklus kompresi uap dengan fluida refrigeran R134a tanpa menggunakan humidifier. Untuk mempertahankan kondisi udara pada cold storage agar sesuai dengan kebutuhan, kompressor AC dengan kapasitas 12,7 kW digunakan pada siklus kompresi uap. Performa dari siklus kompresi uap dengan kondisi operasi tersebut ditentukan oleh Coefficient of Performance (COP). Semakin besar nilai COP, maka sistem  semakin efisien. Coefficient of Performance (COP) dari siklus tersebut adalah sebesar 3,84. Kata kunci: Buncis, CLTD, Refrigeran, COP, Siklus kompresi uap Abstract                                                                                                                                                                                                            Snap beans are one of Indonesian acgricultural product exported to overseas. After harvested, snap beans were stored before exported to consumers. The freshness of the snap beans only lasted for one week, therefor special equipment were required to maintain the snap beans freshness. To maintain the freshness, snap beans must be storage in a room with 4-7°C air temperature and 90-95% humidity. In this research, cold storage was designed for 10 tons of snap beans. Cooling Load Temperature Difference method was used to determine the load of the cold storage based on the position of the building. The total cooling load for 10 tons of snap beans were 46,73 kW. The cold storage was using vapor compression cycle with  refrigerant 134a without humidifier . The cycle requires compressor power of 12,7 kW to maintain the condition in the cold storage room. The performance of the cycle was determined from the Coefficient of Performance (COP). The higher value of the COP, the system will be more efficient. The COP of the vapor compression cycle  was 3,84.   Key words: Snap Beans, Export, Refrigerant, Storage, Humidity.


2020 ◽  
Vol 28 (04) ◽  
pp. 2050031
Author(s):  
Ali K. Shaker Al-Sayyab

In this study, the performance of a window-type air-conditioning unit with an alternative, ozone-friendly refrigerant was enhanced by incorporating a nozzle instead of a capillary tube as an expansion device. An experimental evaluation was adopted on a 1.5 RT window-type air-conditioning unit with a controlled environmental zone. According to operating conditions, an ANSYS-Fluent program was used to predict an appropriate nozzle size for a lower pressure ratio. The refrigeration cycle model was simulated using the Engineering Equation Solver (EES).27 The results showed that using a nozzle of 30[Formula: see text]mm length and inner and outer diameters of 9 and 2[Formula: see text]mm, respectively instead of the capillary tube with R404A reduces compressor power consumption by 7.7% and increases the coefficient of performance (COP) by 7.4%.


2021 ◽  
Vol 7 (6) ◽  
pp. 469
Author(s):  
Atsushi Kurahashi

The sweet drink amazake is a fermented food made from Aspergillus oryzae and related koji molds in Japan. There are two types of drinks called amazake, one made from koji (koji amazake) and the other made from sake lees, a by-product of sake (sakekasu amazake). The sweetness of koji amazake is from glucose, derived from starch broken down by A. oryzae amylase. The other, sakekasu amazake, depends on added sugar. The main components are glucose and sucrose, but they also contain more than 300 other ingredients. Koji amazake contains oligosaccharides and ergothioneine, and sakekasu amazake has a resistant protein and α-ethyl glucoside, which are characteristic ingredients of each amazake. However, there are also common ingredients such as glycosylceramide. Functionality is known to include anti-fatigue, bowel movement, skin barrier, and other effects on human health. In particular, the bowel movement-improving effects have been well studied for both amazakes. These functions result from ingesting approximately 100 mL per day, but human clinical trials have clarified that this amount has no effect on blood glucose levels and weight gain. In the future, the identification of substances associated with each function is required.


Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1261
Author(s):  
Catarina S. P. Borges ◽  
Alireza Akhavan-Safar ◽  
Eduardo A. S. Marques ◽  
Ricardo J. C. Carbas ◽  
Christoph Ueffing ◽  
...  

Short fiber reinforced polymers are widely used in the construction of electronic housings, where they are often exposed to harsh environmental conditions. The main purpose of this work is the in-depth study and characterization of the water uptake behavior of PBT-GF30 (polybutylene terephthalate with 30% of short glass fiber)as well as its consequent effect on the mechanical properties of the material. Further analysis was conducted to determine at which temperature range PBT-GF30 starts experiencing chemical changes. The influence of testing procedures and conditions on the evaluation of these effects was analyzed, also drawing comparisons with previous studies. The water absorption behavior was studied through gravimetric tests at 35, 70, and 130 °C. Fiber-free PBT was also studied at 35 °C for comparison purposes. The effect of water and temperature on the mechanical properties was analyzed through bulk tensile tests. The material was tested for the three temperatures in the as-supplied state (without drying or aging). Afterwards, PBT-GF30 was tested at room temperature following water immersion at the three temperatures. Chemical changes in the material were also analyzed through Fourier-transform infrared spectroscopy (FTIR). It was concluded that the water diffusion behavior is Fickian and that PBT absorbs more water than PBT-GF30 but at a slightly higher rate. However, temperature was found to have a more significant influence on the rate of water diffusion of PBT-GF30 than fiber content did. Temperature has a significant influence on the mechanical properties of the material. Humidity contributes to a slight drop in stiffness and strength, not showing a clear dependence on water uptake. This decrease in mechanical properties occurs due to the relaxation of the polymeric chain promoted by water ingress. Between 80 and 85 °C, after water immersion, the FTIR profile of the material changes, which suggests chemical changes in the PBT. The water absorption was simulated through heat transfer analogy with good results. From the developed numerical simulation, the minimum plate size to maintain the water ingress unidirectional was 30 mm, which was validated experimentally.


2016 ◽  
Vol 819 ◽  
pp. 202-206
Author(s):  
Reza Maziar ◽  
Kasni Sumeru ◽  
M.Y. Senawi ◽  
Farid Nasir Ani

In this study, two experiments were performed, one with the conventional compression refrigeration cycle (CRC) and the other with an ejector refrigeration cycle (ERC). The CRC system for automotive air conditioning was designed, fabricated and experiments were conducted. The system was then retrofitted with an ejector as the expansion device and experiments were repeated for the ERC system. Calculations of the entrainment ratio, compressor compression ratio and coefficient of performance (COP) were made for each cycle. The calculations showed that ERC has some advantages over the CRC. In this study, an average improvement of 5% in COP has been obtained for the ERC compared with the CRC.


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.


Ethnography ◽  
2017 ◽  
Vol 18 (4) ◽  
pp. 471-492 ◽  
Author(s):  
Bowen Paulle

This article examines GRIP, a rehabilitation program currently spreading through California’s state prison system. While most ‘violent offenders’ come to GRIP hoping to increase chances of parole, this yearlong program with four main components – stopping violence, mindfulness, emotional intelligence, understanding victim impact – is meant to create conditions in which inmates can ‘do the work’ leading to genuine transformation. A central claim is that due in part to the trauma-treatment model GRIP follows, inmates end up ‘stumbling on the gold’ and going through changes (involving recovery of an ‘authentic self ’ rooted in childhood) that helps enable skillful responses even to ‘moments of imminent danger’. Understandably, researchers of such programs may seek theoretical inspiration from the ‘dominant’ version of Foucault. Yet this paper sets out to change the conversation about prisons and rehabilitation in part by demonstrating the utility of the ‘other’ Foucault’s pragmatic recovery of body-based self-disciplining practices and regimes.


2021 ◽  
Vol 4 ◽  
pp. 133-139
Author(s):  
Rikhard Ufie ◽  
Cendy S. Tupamahu ◽  
Sefnath J. E. Sarwuna ◽  
Jufraet Frans

Refrigerant R-22 is a substance that destroys the ozone layer, so that in the field of air conditioning it has begun to be replaced, among others with refrigerants R-32 and R-410a, and also R-290. Through this research, we want to know how much Coefficient of Performance (COP) and Refrigeration Capacity (Qe) can be produced for the four types of refrigerants. The study was carried out theoretically for the working conditions of the vapor compression cycle with an evaporation temperature (Tevap) of 0, -5, and -10oC, a further heated refrigerant temperature (ΔTSH) of 5 oC, a condensation temperature (Tkond) of 45 oC and a low-cold refrigerant temperature. (ΔTSC) 10 oC and compression power of 1 PK . The results of the study show that the Coefficient of Performance (COP) in the use of R-22 and R-290 is higher than the use of R-32 and R-410a, which are 4,920 respectively; 4,891; 4.690 and 4.409 when working at an evaporation temperature of 0 oC; 4.260; 4,234; 4.060 and 3.812 when working at an evaporation temperature of -5 oC; and amounted to 3,730; 3,685; 3,550 and 3,324 if working at an evaporation temperature of -10 oC. Based on the size of the COP, if this installation works with a compression power of 1 PK, then the cooling capacity of the R-22 and R-290 is higher than the R-32 and R-410a, which are 3,617 respectively. kW; 3,597 kW; 3,449 kW and 3,243 kW. If working at an evaporation temperature of 0 oC; 3.133 kW; 3.114 kW; 2,986 kW and 2,804 kW if working at an evaporation temperature of -5 oC; and 2,741 kW; 2,710 kW; 2,611 kW and 2,445 kW if working at an evaporation temperature of -10oC.


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


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