16 research outputs found
COMPARISON OF THE DRYER AIR INLET POSITION ON THE SPRAY DRYER WITH A DOUBLE CONDENSER TO PRODUCE A ROTATING FLOW THROUGHOUT THE DRYING CHAMBER: CFD ANALYSIS
Simulation of the drying air and the spray of liquid in the spray dryer chamber with Discrete Phase Material (DPM) and Discrete Random Walk (DRW) was presented in this study using CFD methods to analyze the drying liquid. The main problem in spray drying is the adhesion of the material to the drying chamber walls, which causes uneven drying material. This adhesion can slow down the drying process and reduce productivity. The design of the drying air inlet into the drying chamber becomes essential to research. Variations in the position of the drying air inlet into the drying chamber are carried out in the 3D spray dryer room to see the mechanism of the centrifugal velocity of the drying airflow, which can improve uniform mixing with flow resistance due to friction with small walls and the drying air velocity. This phenomenon is impossible to observe in experiments. A geometric model consisting of 1,054,000 hexa-mesh elements at the area around the nozzle, the top spot of the chamber and the remaining area covered with a tetrahedral mesh, was determined to predict velocity, temperature, and fluid flow behavior. The first position, the dryer air inlet, is at an angle from the diameter of the spray drying chamber. The second position is in the middle of the diameter of the drying chamber. The position of the first inlet produces a more even temperature contour with a more tangential velocity due to the small frictional resistance with the walls. At the same time, the second position is not recommended because the flow leads to one side of the wall and creates sticking and even material buildup. A double-heated condenser can dry air at moderate temperatures, and it is a very effective drying product— positioning the dryer air inlet into the drying chamber, achieving the economical production of high-quality products
Performance Evaluation of Ammonia Refrigeration Systems in a Texturizing Plant
This study evaluates the performance of an ammonia refrigeration system used as a cooling medium in a texturizing plant. The analysis was conducted over a 10-day period, focusing on key performance indicators such as compressor work, condenser exhaust heat, refrigeration effect, mass flow rate, Coefficient of Performance (COP), and overall system efficiency. The data revealed that the system performed optimally on Day 5, achieving a peak efficiency of 91%, with compressor work at 304.1 kJ/kg and condenser exhaust heat at 1414.6 kJ/kg. In contrast, the lowest efficiency was recorded on Day 3, at 77%. The refrigeration effect reached its highest value of 491.3 kJ/kg on Day 3, highlighting efficient heat absorption despite lower overall system efficiency. On Day 4, the mass flow rate was 0.001049929 kg/s, with an actual COP of 1.39, while the ideal COP peaked on Day 10 at 1.69, reflecting the system’s theoretical maximum efficiency under optimal conditions. The study emphasizes the critical role of the condenser in the system’s performance. Optimizing the condenser’s operation by controlling temperature, pressure, and flow rates, alongside regular maintenance, significantly impacts system efficiency. The findings suggest that careful monitoring of operational parameters, including compressor work and refrigerant flow, can enhance the overall efficiency and reliability of ammonia refrigeration systems in industrial settings. This research provides practical insights into improving the cooling performance, reducing energy consumption, and ensuring consistent production quality in texturizing plants
Design and Analysis of a Vertical Axis Ocean Current Turbine Tunnel Using SolidWorks Computational Fluid Dynamics
The development of renewable energy in the marine power generation sector presents a promising approach to producing electrical energy in a sustainable and environmentally friendly manner. Indonesia, with its vast oceanic territory, holds significant potential for harnessing marine energy. However, the relatively slow speed of ocean currents in the region, typically ranging from 0.1 m/s to 1.5 m/s, poses a challenge to the efficiency of marine power generation. To overcome this limitation, this research focuses on the design and analysis of a vertical-axis ocean current turbine tunnel aimed at increasing the speed of ocean currents, thereby enhancing the overall efficiency of energy production. The study combines a thorough literature review with experimental research methods, utilizing SolidWorks Computational Fluid Dynamics (CFD) software to simulate the tunnel's impact on ocean current velocity. The simulations reveal that the tunnel construction significantly boosts current speeds, increasing them from 1.0 m/s to 1.7 m/s, and from 1.5 m/s to 2.6 m/s. This increase in velocity directly translates to higher kinetic energy available for conversion into electrical power by the turbine. Moreover, the study shows that the tunnel construction contributes to a more uniform flow of ocean currents, as evidenced by the Reynolds numbers obtained—100.250 at a current speed of 1.0 m/s and 150.375 at 1.5 m/s. These values, being below 2000, indicate laminar flow conditions within the tunnel, which are beneficial for optimizing turbine performance by reducing turbulence and ensuring a stable energy output. The findings underscore the effectiveness of the tunnel design in improving the efficiency of vertical-axis ocean current turbines, making it a viable solution for enhancing renewable energy production in regions with low ocean current speeds
Performance Evaluation of a Condenser at a Combined Cycle Power Plant Using the LMTD Method
This study evaluates the performance of the condenser at the Cilegon Combined Cycle Power Plant (CCPP) using the Logarithmic Mean Temperature Difference (LMTD) method to measure the heat transfer rate. Routine maintenance carried out on the condenser in the form of cleaning the condenser water box and condenser tube from garbage and crust on the condenser tube wall. Currently, condenser maintenance follows a routine schedule that is tied to steam turbine maintenance, without taking actual condenser performance into account. This can lead to inefficiencies and unnecessary downtime. The goal of this research is to assess the heat transfer rate of the condenser before and after maintenance to judge its effectiveness. Data on temperature changes were gathered in June 2023, before maintenance, and again in July 2023, after an overhaul. The analysis shows that the heat transfer rate increased from 51,362,294.48 kcal/h to 127,246,219.7 kcal/h, while the LMTD value rose from 0.76°C to 1.86°C. Based on these results, the study suggests a new approach to maintenance that focuses on performance. Specifically, maintenance should be done when the heat transfer rate drops below 110,000,000 kcal/h. This approach will help ensure the condenser works at its best, improve the plant's overall efficiency, and prevent the need for unnecessary maintenance. By aligning maintenance with performance data, the plant can boost output while lowering costs and downtime
PENGARUH VARIASI DIAMETER TUBE PIPA EVAPORATOR DENGAN CIRCULAR FINS TERHADAP PRESSURE DROPS ALIRAN REFRIGERANT PADA SISTEM REFRIGERASI
Kebutuhan akan mesin pendingin udara di Indonesia sangat tinggi karena iklim tropis yang menyebabkan Indonesia memiliki dua musim, yaitu musin kemarau dan musin penghujan. Namun pada beberapa tahun ini, musim kemarau atau secara awam dikatakan musim panas, terasa lebih panjang dibanding musim hujan. Sistem refrigerasi dipilih untuk kebutuhan pendingin udara di Indonesia khususnya dan asia pada umumnya. Sistem refrigrasi terdiri dari evaporator, condenser, kompresser dan katup ekspansi. Efek pendinginan terjadi di evaporator, dimana cairan refrigerant berubah menjadi uap atau yang disebut dengan proses evaporasi. Pada penelitian ini, evaporator dirancang menggunakan beberapa diameter tube pipa evaporator, yaitu : 0,005435 m, 0,007036 m, 0,008103 m, 0,008407 m, 0,009398 m, 0,010338 m, 0,011278 m, 0,00125 m, 0,012954 m dan 0,014224 m. Perancangan evaporator untuk biaya perancangan yang optimum dipilih pada rancangan dengan Din 0,009398 m dan Dout 0,0127 dengan panjang tube 5,08 m karena ukuran dan panjang tube yang tidak terlalu besar dan panjang
Combination of Electric Air Heater and Refrigeration System to Reduce Energy Consumption: A Simulation of Thermodynamic System
This study is about the analysis of thermodynamic
system of a refrigeration system with two condensers coupled in series to the
electric air heater system. The condenser produces waste heat reaches 90oC and
the heat is accumulated into a space heater up to 140oC. That means: the heater works only up to 50oC, so
the temperature of the air is high and dry, but has a very low RCES (Ratio of
Specific Energy Consumption) in dew point 20oC, which is indicate that the system is very
significant
ANALISA PERBANDINGAN MECHANICAL DAN ELECTRICAL PROPERTIES TERHADAP PENAMBAHAN JUMLAH KANDUNGAN OKSIGEN PADA BATANG TEMBAGA DIAMETER 8MM
Kandungan oksigen sangatlah berpengaruh terhadap mekanikal dan electrical properties pada batang tembaga. Pengujian terhadap 4 (tiga) sample yang mempunyai kandungan oksigen yang berbeda memberikan hasil beberapa sifat  mekanikal dan  elektrikal yang berbeda, di antaranya sample  1  dengan  kandungan oksigen  169.2  ppm  mempunyai tensile  strength   22.26  kg/mm2, regangan (elongation) 43.40%, modulus young 51.22kg/mm2, electrical conductivity 102.6%IACS, resistivity at 20°C 1.6796 µΩ.cm, sample 2 dengan kandungan oksigen 317.16 ppm mempunyai tensile strength 22.70 kg/mm2, regangan (elongation) 41.80%, modulus young 54.49 kg/mm2, electrical conductivity 101.80%IACS, resistivity at 20°C 1.6935 µΩ.cm, sample 3 dengan kandungan oksigen 387.18 ppm mempunyai tensile strength 23.42 kg/mm2, regangan (elongation) 40.50%, modulus young 57.81 kg/mm2, electrical conductivity 101.60%IACS, resistivity at 20°C 1.6954 µΩ.cm, sample 4 dengan kandungan oksigen 465.66 ppm mempunyai tensile strength 23.98 kg/mm2, regangan (elongation) 38.13%, modulus young 62.90 kg/mm2, electrical conductivity 101.13%IACS, resistivity at 20°C 1.7047 µΩ.cm
Perkiraan Kebutuhan Energi dalam Operasional Under Ground Terminal untuk Smart Eco Airport
Penanganan penumpang di bandar udara selain dilakukan di terminal penumpang juga dilakukan pada sisi udara, terutama pada remote area dimana proses penanganan penumpang terdapat unnecessary movement yang berisiko terjadinya insiden seperti kebakaran bus atau tabrakan bus, ketidak-efisienan penggunaan waktu dan biaya operasional, kesalahan penjemputan dan ketidak tepatan pelayanan. Seiring dengan kemajuan teknologi infrastruktur kebandarudaraan dimungkinkan untuk pengembangan under ground terminal berupa terminal dan akses bawah tanah dari terminal ke pesawat atau sebaliknya. Pengembangan teknologi mekanikal memerlukan konsumsi energi sebagai penunjang peralatan mekanikal tersebut berupa escalator atau travelator yang melalui trowongan. Akses bawah tanah ini juga dapat dimanfaatkan untuk smart baggage handling system, peralatan lain yang memerlukan energi yang terbesar adalah sistem pendingin. Total kebutuhan daya untuk sistem pendingin pada Terminal 3 saja saat ini adalah 12511.4 kW atau sekitar 12.5 MW. Dengan melakukan pendekatan kedalaman tanah yang berfungsi sebagai media pendingin dengan luasan terminal yang dianggap sama maka hasil simulasi perhitungan menunujukkan penurunan daya sebesar 37% sehingga total daya untuk pendinginan menjadi 7882.4 kW atau energi dapat ditekan sebesar 4629 kW. simulasi total daya pada under ground terminal dari semua peralatan mekanikal dan peralatan pendingin sebesar 14144,4 k
PENGARUH VARIASI DIAMETER TUBE PIPA EVAPORATOR DENGAN CIRCULAR FINS TERHADAP PRESSURE DROPS ALIRAN REFRIGERANT PADA SISTEM REFRIGERASI
Kebutuhan akan mesin pendingin udara di Indonesia sangat tinggi karena iklim tropis yang menyebabkan Indonesia memiliki dua musim, yaitu musin kemarau dan musin penghujan. Namun pada beberapa tahun ini, musim kemarau atau secara awam dikatakan musim panas, terasa lebih panjang dibanding musim hujan. Sistem refrigerasi dipilih untuk kebutuhan pendingin udara di Indonesia khususnya dan asia pada umumnya. Sistem refrigrasi terdiri dari evaporator, condenser, kompresser dan katup ekspansi. Efek pendinginan terjadi di evaporator, dimana cairan refrigerant berubah menjadi uap atau yang disebut dengan proses evaporasi. Pada penelitian ini, evaporator dirancang menggunakan beberapa diameter tube pipa evaporator, yaitu : 0,005435 m, 0,007036 m, 0,008103 m, 0,008407 m, 0,009398 m, 0,010338 m, 0,011278 m, 0,00125 m, 0,012954 m dan 0,014224 m. Perancangan evaporator untuk biaya perancangan yang optimum dipilih pada rancangan dengan Din 0,009398 m dan Dout 0,0127 dengan panjang tube 5,08 m karena ukuran dan panjang tube yang tidak terlalu besar dan panjang
CONDENSOR DESIGN ANALYSIS WITH KAYS AND LONDON SURFACE DIMENSIONS
The use of condensers in air conditioning units is more common in large-capacity units than in ones with a smaller capacity. Air conditioning provides comfort and freshness to an air-conditioned room. It should be noted that each room has a different heat load, which affects the specifications of the condenser used. The accuracy with which appropriate condenser specifications are determined affects the performance of the air conditioner. Thus, considering how important condenser needs are, it is necessary to design condensers with optimal performance, which adhere to proven standards. To achieve this, the design of a condenser should be based on the results of the smallest condenser dimensions of three types of surfaces, as they are intended for a limited place. This condenser design uses the standard dimensions of the Kays and London charts. Data is collected by measuring the results of temperature and enthalpy of a refrigerant at desuperheating and condensation, inlet air temperature, outlet air temperature, refrigerant mass flow rate, and air mass flow rate. The results of the compact condenser design are based on existing data, which is obtained from the smallest design results. The result uses the type of Surface CF-8.72(c) with a heat transfer area of 0.259 m2, a total tube length of 9.5 m, crossing tube length 0.594 m and a pressure drop of 3778 Pascal (Pa) on the side of a tube. This design fulfills the stipulated requirements, as the pressure drop is less than the specified maximum limit in most units