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Studi Reduksi Beban Termal ke Dalam Ruangan Secara Konveksi dengan Sistem Underground Thermal Storage Sebagai Altenatif untuk Mendinginkan Ruangan Rumah Hunian
No full textSpace cooling is required all year around in the tropics area especially Indonesia. To provide the space cooling requirement, the electricity cost and environment impact are important aspect that it must be considered. The household in the tropical area is real conditions require a cooling device and greatest potential to use alternative cooling. In fact, solar radiation over the roof surface can be thrown to the environmental by convection mechanism in order to the room can be remaining in comfortable condition.The experimental investigation was performed to two model of household. That is household without and using evaporator, respectively. Also in this reasearch, evaporator was placed in two location, over and or under surface of the roof. Water from underground thermal storage is used as a working fluid to pick up amount of heat over the roof and then rejected on thermal storage environment. The mesurement of experimental data was conducted start from 08.00 WIB to 17.00 WIB. Roof temperature will fluctuation with raise of time start from the morning to evening. The maximum temperature difference between household without and with evaporator are ± 12 0C with water mass flow rate 0.0125 kg/s and ± 8 0C with water mass flow rate 0.0187 kg/s for evaporator over and under the surface of the roof respectively.This research result have still uncomfortable condition for household. However, this research can be used as an initial step to build up a cooling system with low cost of electrical power and environmental friendly. Moreover, thermal reduction on the wall and the window to increase in the performance of this method are necessary. Then, the impromevent of roof geometry has to performed to keep the maximum interface area of heat transfer. Keywords: convection mechanism, space cooling, househol
KEMAMPUAN BENTONIT PELET TEKAN TERAKTIVASI FISIK SEBAGAI PENGGANTI ZEOLIT DALAM MENGHEMAT KONSUMSI BAHAN BAKAR MOTOR DIESEL 4-LANGKAH
Get PDFPropinsi Lampung merupakan salah satu produsen zeolit terbaik dan terbesar di Indonesia. Herry Wardono telah membuktikan kemampuan zeolit Lampung dalam meningkatkan prestasi motor bakar. Disamping zeolit, potensi bahan tambang bentonit juga tersedia melimpah di Propinsi Lampung. Bentonit memiliki bentuk senyawa yang tidak jauh berbeda dengan zeolit, dan kesamaan sifat dengan zeolit yaitu dapat mengadsorbsi uap air dan nitrogen. Bentonit pellet tekan teraktivasi fisik diletakkan pada saringan udara motor diesel 4-langkah. Konsentrasi bentonit dalam bentonit pelet diaktivasi fisik adalah 70, 75, dan 80%, dan berat bentonit divariasi sebesar 25, 50, dan 100 gram. Hasil pengujian menunjukkan bahwa terjadi penurunan (penghematan) konsumsi bahan bakar spesifik engkol. Persentase penghematan konsumsi bahan bakar tertinggi terjadi pada konsentrasi 70 % yaitu sebesar 8,1331 % pada putaran mesin 3500 rpm dengan berat 25 gram dan diameter 15 mm, dan pada konsentrasi 80 % sebesar 9,4275 % pada putaran mesin 3000 rpm dengan berat 100 gram dan diameter 10 mm. Namun, secara rata-rata persentase penghematan konsumsi bahan bakar tertinggi terjadi pada konsentrasi 70 %, yaitu sebesar 3,6031%.Kata Kunci: bentonit pelet tekan, adsorpsi nitrogen, prestasi mesin diesel
KARAKTERISTIK ALAT PENGERING PADI SKALA LAB DENGAN MENGGUNAKAN BAHAN BAKAR SEKAM PADI
Get PDFThe drying process is a stage that is quiteimportant to determine the quality of rice is good, especially the rainy season, so the use ofpaddy dryers (oven) is a must. For the heatsource used fuel waste rice husk obtained fromthe rest of the rice mill. Well as efforts toovercome the energy crisis and environmental sustainability. The purpose of this study is to determine the amount of heat that occurs ineach rack, knowing the rate of decline dryingand knowing the water content of rice and the long drying time. Testing rice dryers done by connecting the oven with a stove burner burningrice husk as a place with a pipe to drain the hotair. In the rice dryer (oven) there is a rack / container of rice be nested six and intersecteach containing 2 kg of rice. Hot airenters from below to above the rack 1 to 6 and then to the outer shelf. From the test results is known that the decrease in average water content of 8.875 %, moisture content of grain /rice after drying that is 16.125 %, the drying rate of 0.2695 % / min, the amount of heat received by rice 173.703 J/ kg. The amount of rice husks are used in a single drying 1 kg with a time of 60 minutes and the rice is dried as much as 12 kgKeywords: drying, oven, rice, hus
Pengaruh Rasio Panjang dan Diameter Pipa Suplai terhadap Unjuk Kerja Model Pompa Tanpa Motor (Hydraulic Ram Pump)
Get PDFA hydraulic ram pump is environmentally friendly devices using the energy from a stream of water falling from a low head as the driving power to pump part of the water to a head much higher than the supply head for agricultural or domestic use. In the use of this pump, one of factors that influence the performance is ratio of drive pipe length to diameter (L/D). This paper presents the experimental study of effect of ratio of drive pipe length to diameter on hydraulic ram pump designing model. This hydraulic ram pump designing model is tested on various ratio of drive pipe length to diameter, namely 158, 165, 176, and 202. The results of the testing of the model hydraulic ram pump shows that the operation of this pump should use the ratio of drive pipe length to diameter (L/D) of 176. Using supply head of 1 m and volume of air chamber of 5702,754 cm3, water can be pumped with the volume flow rate of 3 lit/min to the height of 8,5 m, and the efficiency of this pump is 78,7 %. The data of the testing results also show that using the volume of air chamber of 4562,203 cm3, and supply head of 1 m, this model of hydraulic ram pump can lift water of 2,727 lit/min to the height of 9,5 m with the maximum efficiency of 87,96 %.
Analisis Prestasi Lampu Petromax Berbahan Bakar LPG
No full textIn order to decrease subsidy cost of kerosene consumption, Indonesian government right now proposes to convert kerosene to LPG. Consequently, the price of kerosene is expensive in society. LPG can be alternatively used as fuel for the petromax lamp. The use of LPG for the petromax lamp fuel is strongly recommended for sidewalk food sellers as source of light at night if the electricity source is not available. Therefore, it is important to investigate some advantages of the use of LPG as replacing of kerosene for the petromax lamp. The performance of the petromax lamp using LPG as fuel had been carried out with parameters: rate of fuel consumption and light intensity, representing to the need of energy consumption. In the view of economic, the performance of the petromax lamp using LPG was also compared with the performance of petromax lamp using kerosene. The results show that the use of LPG is more clearly efficiency than those of use of kerosene. The fuel energy needed by the petromax lamp to generate lighting is around 224.87MJ/h for kerosene and 213.24 MJ/h for LPG. The energy consumption of LPG is decreased by a factor of 1.05. Economically, the comparison of the price between kerosene and LPG is very significant. The price of kerosene consumption per hour was approximate Rp.941.00, whereas the price of LPG consumption per hour was approximate Rp. 368.00. This shows that if the petromax lamp is operated using LPG for 6 h, the seller foods can save around of Rp 3,438.00. Keywords: petromax lamp, kerosene, LPG, energy consumption
Review Dan Analisa Karakteristik Dan Penyebab Kerusakan Sudu Turbin Gas
No full textThe present study concerns the review and the analysis of malfunctions characteristic and the reasons of moving blade damage. Such malfunctions are breakage of moving blade in excessive temperature conditions, increasing vibration, little cyclic weariness from frequent heat exchange at start-up and shut-down, and erosive deterioration and highly temperature corrosion. The type of damage can be divided on static, fatigue, thermal fatigue, corrosion and erosive.Keywords: gas turbine, moving blade, pressure, temperature, defect
Reduksi Bising Motor Diesel Menggunakan Partial Enclosure
No full textNoise is one of the environmental problems that we must concern on it, not just it can produce healthy problems, but it can reduce working productivity too. This research is aimed to reduce noise produced by diesel engine in the laboratory of motor combustion engine.The experiment was conducted by using partial enclosure to enclose side by side of the engine. The enclosure was made by plywood 1.2 cm and filled by coconut husk. The data was taken by started giving 1000 rpm first to the engine, then with 500 rpm gradually until 3500 rpm. The probe used in this research Integrating Sound Level Meter - Type 2239 A.The result shown that by using partial enclosure noise was reduce about 15,52 % to the origin and the distribution of the noise high on air intake channel and discharge channel of the engine. Keywords: noise reduction, partial enclosure, sound level meter
Pengaruh Sudut Kontak Statis terhadap Penyebaran Droplet di Atas Permukaan Padat yang Dipanaskan pada Bilangan Weber Menengah
No full textThe influence of static contact angle on the spreading of droplet on a heated solid surface has been studied experimentally. Static contact angle was important parameter which influenced the impact behavior and heat transfer during the interaction of droplet and solid surface. Droplet substance was destilated water with initial diameter of 2.5 mm and solid surface material was stainless steel. Impact energy was expressed in Weber number, they were 52.1 and 57.7. Solid surface temperature was varied from 60−285°C to cover the heat transfer regimes, they were single-phase liquid, nucleate boiling, transition boiling, and film boiling. Static contact angle were 0°, 35.04°, and 85.72°. As result, it was known that static contact angle has influence on spread characteristic after droplet impacting solid surface. Spreading factor increases due to the decrease of static contact angle. Evaporation time decreases due to the decrease of static contact angle.Keywords: droplet, impact, spreading, static contact angl
Analisis Limit Momen Pipa Elbow dengan Beban In-Plane Bending
No full textPipe bends or elbows are of important component in a piping system. In addition to its function for changing the direction of piping due to layout restriction, an elbow can accommodate expansion because it is more flexible than an equivalent straight pipe with the same material and dimension. However, and elbow can not be analyzed using the engineer theory of bending, because its cross-section become oval under bending. This paper reports a result of finite element study of bending behavior of a pipe elbow and its influence on limit moment. Limit moment was obtained using nonlinear analysis and Newton-Raphson algorithm was employed. Material behavior of pipe was treated as large strain, elastic-perfectly-plastic. The results show that a pipe elbow under in-plane opening bending is stiffer than those under in-plane closing bending, indicated by their limit load – 4.83 times yield stress for in-plane opening bending and 1.34 times the yield stress for in-plane closing bending. Keywords: pipe elbow, limit moment, nonlinear analysis, in-plane bendin
Effect of Cutting Parameter Variation on Drilling of AISI 1045: Experimental and Simulation
No full textThis work is focused on the study of the effect of spindle speed and feed rate on the tool temperature distribution in the drilling of AISI-1045 steel. The e data were collected under different cutting conditions. The maximum tool temperature is predicted during the drilling using finite element simulation techniques. The predicted temperature was compared to the measured temperature. The result shows the finite element simulation is reasonable. Analyses show that the range of temperature from 157 °C to 288 °C. The difference between measured temperature and simulated temperature are in the range of 17-38%. The s increased in accordance with the increasing of cutting speed and feed. Keywords: drilling, spindle speed, feed, tool edge, maximum temperatur