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Abstrak :
ABSTRAK
Skripsi ini membahas mengenai uji eksperiment mesin refrigerasi tanpa menggunakan refrigerant Dimana refrigerant diganti menggunakan LiBR (Lithium Bromida). Fluida kerja campuran seperti LiBr+H2O merupakan zat pendingin yang ramah lingkungan dan sangat hemat energi. Kedua jenis refrigeran tersebut digunakan. pada mesin refrigerasi siklus absorpsi, baik untuk kebutuhan kenyamanan ruangan maupun kebutuhan proses industry. Riset yang dilakukan bertujuan untuk mengetahui unjuk kerja sebuah mesin refrigerasi siklus absorpsi, berpendingin udara yang menggunakan campuran larutan dan LiBr+H2O+additive sebagai fluida kerja. Manfaat dari hasil riset ini dapat digunakan sebagai salah satu upaya alternative untuk mendukung program penghematan energi pada sector residensial dan komersial yang telah ditetapkan pemerintah. Selain itu hasil riset ini secara langsung dapat membantu pemerintah dalam implementasi program pembatasan penggunaan refrigeran yang berpotensi menimbulkan pemanasan global dan penipisan lapisan ozon.

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ABSTRACT
This thesis discusses the experimental working of refrigeration machine without using refrigerant Where the refrigerant is replaced using LiBR (Lithium Bromide). Working fluid mixtures such as LiBr + H2O is an environmentally friendly refrigerant and highly energy efficient. Both types of refrigerants used in absorption cycle refrigeration machines, either for the comfort of the room as well as the needs of the industry. Research conducted aimed to determine the performance of an absorption cycle refrigeration machine, air-cooled using a mixture of solution and LiBr + H2O + additive as a working fluid. The benefits of this research can be used as part of efforts to support alternative programs for energy conservation in residential and commercial sectors that have been set by the government. In addition, the results of this research directly to assist the government in implementing programs that have the potential restrictions on the use of refrigerant causing global warming and ozone depletion.

Abstrak :
The limited of ozon depleting substance (ODS) such as CFC and HCFC refrigrants has encourage researchers to find a new alternative refrigrant......

Abstrak :
Sistem Pendingin Ultra Low semakin berkembang untuk tujuan pengobatan dan medis. Sel hidup atau organ tubuh memerlukan suhu yang sangat rendah dalam penyimpanannya, untuk itu perlu adanya mesin pendingin ultra low, mesin pendingin ini kemudian dikenal dengan Sistem refrigerasi Autocascade. Dalam perkembangannya Sistem refrigerasi Autocascade menggunakan refrigeran yang dapat merusak ozon atau menyebabkan pemanasan global yang segera dilarang pemakaiannya. Oleh karena itu, ditelitilah refrigeran yang lebih ramah lingkungan seperti refrigeran hidrokarbon. Sistem refrigerasi Autocascade memiliki karakteristik yang tergantung pada refrigeran yang digunakan, maka dari itu dilakukan penelitian terhadap pemilihan refrigeran hidrokarbon baik untuk high system (fase liquid) maupun low system (fase gas). Penelitian ini menginvestigasi sistem refrigerasi autocascade dengan menggunakan tiga campuran refrigeran dengan memvariasikan refrigeran untuk low system (fase gas). Refrigeran yang digunakan adalah Propane dan Butan sebagai refrigeran fase liquid dan Metan dan Etan sebagai refrigeran fase gas. Penelitian ini menunjukkan bahwa pada komposisi yang hampir sama, pemilihan metan sebagai refrigeran fase gas pada sistem menghasilkan sistem yang lebih stabil walaupun temperaturnya hanya sampai -26,8°C. ......Ultra Low Refrigeration System growing for medicinal purposes and medical research. Living cells or organs of the body requires very low temperatures in storage, to the need for ultra low engine coolant, engine coolant is then known as Autocascade refrigeration system. In the development of refrigeration systems using refrigerant Autocascade that can damage the ozone or global warming are immediately banned its use. Therefore, scientist are invented more environmentally friendly refrigerants such as hydrocarbon refrigerants. Autocascade refrigeration system has characteristics that depend on the refrigerant used, and therefore conducted a study of selection for hydrocarbon refrigerant on high system (liquid phase) and low system (gas phase). This study investigates autocascade refrigeration system using refrigerant mixtures of three refrigerants by varying the low system (gas phase) refrigerant. Refrigerants used are Propanee and Butane as a refrigerant liquid phase and the Methane and Ethane as a refrigerant gas phase. This study shows that at nearly the same composition, the selection of methane as a gas phase refrigerant in the system produces a more stable system, although the temperature only up to -26,8°C.

Abstrak :
Two things that become world concern are energy crisis and environmental problem, Refrigerator is one of the causes of the problems either direct or indirect. Refrigerator uses electricity source that comes front fossil fuel as indirect cause of energy crisis and environmental' problem which contributes to ozone depletion and global warming by using the refrigerant. Therefore we need a solution that can answer the problems. The solution is photovoltaic refrigerator .system with hydrocarbon refrigerant. This system uses photovoltaic module connected to the inverter. The function of inverter is to convert i2 Volt DC electric voltage from photovoltaic module into 220 Volt A C electric voltage, The refrigerant are hydrocarbon R-600a and HC-134 which charged at 20 bar pressure. The experiment shows that the inverter which suitable for refrigerator is pure sine wave inverter type and the alternative refrigerant is R-600a. Refrigerator with photovoltaic module can be used until 21.5 hours without charging.

Abstrak :
Global warming is a very pertinent issue these days because the effects of extreme climate change are becoming quite apparent. Therefore, the first problem to address is the formation of strict regulations regarding emissions into the air. The main emissions to tackle are CFC and HCFC refrigerants. Conventional cascade refrigeration systems until now have been dependent on refrigerants and it is time to find a substitute that is environmentally friendly. This study builds a prototype cascade refrigeration machine using the environmentally friendly hydrocarbon refrigerants (propane, ethane and CO2). Resulting from this research, the characteristics of the pressure and temperature of each component and the COP value at low temperature circuit of load variations using an electric heater at 90 W, 120 W and 150 W result in a COP value of 0.35, 0.48 and 0.60 respectively.

Abstrak :
ABSTRAK
Kebutuhan energi listrik dari sektor rumah tangga setiap tahunnya terus mengalami peningkatan yang sangat dominan dibandingkan dengan sektor lainnya dan lemari pendingin merupakan salah satu peralatan elektronik yang paling besar mengkonsumsi energi listrik dalam rumah tangga. Oleh karena itu pemerintah dirasa perlu untuk mengambil kebijakan-kebijakan dalam mempertahankan atau meningkatkan kesediaan energinya. Standar dan labeling efisiensi energi untuk peralatan rumah tangga adalah salah satu strategi yang popular dalam melakukan penghematan energi dan menjadi wadah pembelajaran bagi masyarakat atau konsumen agar mampu mengunakan energi dengan bijak. Perilaku konsumen juga dapat mempengaruhui peningkatan konsumsi energi listrik. Sehingga tujuan dari penelitian ini adalah untuk mencari kondisi operasi terbaik dari lemari pendingin rumah tangga agar dapat menjadi rekomendasi kepada pengguna, produsen maupun kepada para pemangku kebijakan energi nasional. Pada penelitian ini dilakukan beberapa studi eksperimental antara lain variasi setting thermostat, variasi massa refrigeran dan variasi massa fraksi nanopartikel terhadap lemari pendingin 2 pintu dengan jenis refrigeran R600a. Kemudian dilakukan analisis terhadap nilai COP dan konsumsi energi listrik serta potensi penghematan energinya. Hasilnya didapat bahwa efek setting thermostat optimum ada pada temperatur internal lemari pendingin sebesar -21 ^oC dengan konsumsi energi listrik 1.22 kWh/hari. Sementara efek variasi massa refrigerant optimum adalah pada massa 43 gram dengan nilai COP 3.22 dan konsumsi energi listrik 1.16 kWh/hari. Sedangkan efek variasi massa fraksi nanopartikel optimum adalah 0.2 wt% dengan konsumsi energi listrik 0.94 kWh/hari dan nilai COP 3.54.

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ABSTRACT
The electrical energy needs of the household sector continue to experience a very significant increase compared to other sectors and refrigerators are one of the largest electronic devices that consume electricity in the household. Therefore, the government is deemed necessary to take policies in maintaining or increasing its energy availability. Energy efficiency standards and labeling for household appliances is one of the popular strategies in saving energy and becoming a learning forum for the community or consumers to be able to use energy wisely. Consumer behavior can also influence the increase in electricity consumption. The purpose of this study is to find the best operating conditions of household refrigerators so that they can become recommendations to users, producers and national energy policy makers. In this study several experimental studies were carried out including variations in thermostat settings, variations in mass of refrigerants and variations in mass of nanoparticle fractions against 2-door refrigerators with R600a refrigerants. Then an analysis of the value of COP is carried out and the consumption of electrical energy and energy saving potential. The result is that the effect of the optimum thermostat setting is on the refrigerator's internal temperature of -21 ^oC with an electrical energy consumption of 1.22 kWh / day. While the effect of variations in optimum mass of refrigerant is at a mass of 43 grams with a value of COP 3.22 and electricity consumption of 1.16 kWh / day. While the effect of the optimum mass variation of nanoparticle fraction is 0.2 wt% with electrical energy consumption of 0.94 kWh / day and COP value 3.54.

Abstrak :
Modern technology for refrigerators and coolers is based on the chemical gas Chlorofluorocarbon (CFC) compression method that is indicative of a high consumption of electricity. The CFC is also understood as a reason for global warming. One of the solutions to this issue is magnetic refrigeration technology, which is environmentally friendly because it does not use any hazardous chemicals or ozone depleting/greenhouse gases. Magnetic refrigeration technology is based on the magnetocaloric effect of magnetic refrigerant materials. Exploring the magnetocaloric effect of magnetic refrigerant materials is important because these contain many of the physical properties needed for magnetic refrigeration technology. Herein, the present work reports on the magnetocaloric effect of La0.7Ca0.3Mn1?xSnxO3 (x = 0.0, x = 0.02 and x = 0.04) compound samples produced with the solid state reaction technique. Curie temperature TC obtained for the La0.7Ca0.3Mn1?xSnxO3 (x = 0.0, x = 0.02 and x = 0.04) are 260 K, 176 K and 170 K with -?SM max of 4.32 J×kg-1×K-1, 1.61 J×kg-1×K-1 and 1.24 J×kg-1×K-1 and a refrigerant capacity of 48 J/kg, 41.43 J/kg and 28.53 J/kg for x = 0.0, x = 0.02 and x = 0.04, respectively. A small addition of Sn-doped resulted in a significant decrease of more than 80 K on the Curie temperature scale compared to that of La0.7Ca0.3MnO3. The large gap in the decreasing magnetic temperature phase transition might be useful as an option of metal/transition metal doped for tuning the Curie temperature of magnetic refrigerant materials.

Abstrak :
Dalam penelitian ini membahas tentang studi refrigeran campuran R-290/134a (70/30 % berat) sebagai pengganti R-22, di mana di dalamnya rnenerangkan atas alasan pemilihan campuran refrigeran dan koinposisinya dengan analisa sifat-sifat termodinamikanya yang dibantu program REFPROP 6.01. Penelitian dilanjutkan dengan membandingkan unjuk kerja refrigeran yang telah ditetapkan campurannya dengan R-22 dan R-290 dalam sistem pendingin. Parameter pengujian yang dilakukan adalah dengan menyamakan efek pendinginan yang diperoleh melalui pengaturan banyak pengisian refrigeran dengan kondisi sisi sekunder yang sama. Kemudian pengujian dilakukan dengan melakukan perubahan temperatur udara inlet evaporator pada sisi sekunder dengan kondisi pendinginan di kondensor tetap. Hasil yang diperoleh menunjukkan bahwa.Refrigeran campuran R-290/134a (70/30) menunjukkan unjuk kerja yang lebih baik dibandingkan dengan R-22, dan sedikit lebih buruk dibandingkan dengan R-290. Sebagai refrigerant baru, refrigeran campuran ini dapat dijadikan sebagai salah satu pilihan diantara banyak refrigeran pengganti yang ditawarkan saat ini, karena refrigeran campuran ini dapat langsung dipakai pada sistem R-22 yang sudah ada dan memiliki harga indeks GWP yang jauh lebih rendah dari R-22.

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The present Thesis describes the differences between the refrigerant R-22 and the replacement candidates R-290 and the zeotropic refrigerant R-290/R-134a (70/30 % weight). The study of the composition of blends was performed to determine the mass fraction of each component in the mixtures that are most promising on the basis of work pressure. Starting from the thermodynamic point of view, different methods of comparison will be applied : a) The theoretical comparison using thermo dynamical calculation leading to results as if the different fluids worked each in physically optimized system for the fluid in the ideal cycle of the refrigeration system. b) The experimental comparison in concerning the external behavior based on equal secondary fluid temperatures taking in the evaporator and condenser also into account the heat exchange in the evaporator, and The result show that the zeotropic refrigerant mixtures were used as working fluids shown to increase the coefficient of performance (COP) by 7% compared R-22, but the propane (R-290) performs up to 16% better than the refrigerant mixtures. The conclusion of this study is the refrigerant mixtures R-290/134a (70/30 % weight) can be used at all air conditioning system, because approximately they work at the same pressure.

Abstrak :
ABSTRAK
Dalam beberapa tahun terakhir, pembahasan mengenai kebutuhan akan energi yang terus meningkat yang disertai dengan dampak penggunaan energi terhadap lingkungan, terutama energi fosil meliputi perubahan iklim, penipisan lapisan ozon dan pemanasan global menjadi topik yang hangat diperbincangkan. Upaya untuk menjaga ketersediaan energi dalam batas aman serta mengurangi permasalahan lingkungan akibat penggunaan energi disebut sebagai tantangan yang harus dihadapi menuju masa depan yang berkelanjutan. Hingga saat ini sistem refrigerasi dan heat pump yang ramah lingkungan dinilai dapat menjadi salah satu teknologi yang menjanjikan untuk dikembangkan agar dapat mengatasi kedua persoalan tersebut. Pada penelitian ini dilakukan suatu kajian dan pemodelan serta studi eksperimental sistem refrigerasi dan heat pump dengan menggunakan refrigeran yang ramah lingkungan dan menggunakan solar kolektor sebagai energi input. Refrigeran yang digunakan pada penelitian ini adalah R1224yd. Pemodelan dilakukan dengan menggunakan software Matlab 2017b dan REFPROP versi 10. Kemudian dilakukan analisis terhadap nilai energi, exergy, ekonomi dan dampak sistem terhadap lingkungan. Selanjutnya dilakukan optimisasi dengan menggunakan multi objective genetic algorithm untuk memperoleh kondisi optimum dari sistem yang dimodelkan.

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ABSTRACT
In recent years, energy issues related to the use of fossil energy sources and renewable energy, as well as their impact on the environment which includes climate change, ozone layer depletion and global warming become hot topics to be discussed. Maintaining energy availability within the safe limits and reducing the contribution of energy use to environmental problems is a big challenge that must be faced towards a sustainable future. The use of environmentally friendly refrigeration technology could be an option in order to solve the energy and environmental problem. In this research, a modeling and an experimental study of refrigeration system are proposed. Modeling conducted by using Matlab 2017b and REFPROP version 10 software. Refrigerant used in this study is an environmentally friendly refrigerant R1224yd and solar collector as the energy input. Then analyses of energy, exergy, economic and the environmental impact are conducted. Further, optimization procedure is conducted by using multi objective genetic algorithm to obtain optimum condition from the modeled system.

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