Dynamic Modelling by Bond Graph Approach of Convective Drying Phenomena

Drying operations play an important role in food industries. They are often the last operation of the process of manufacturing a product, with a strong influence on the final quality. The processes are numerous and depend on the type and amount of product to be dried and water to be evaporated, the desired final quality, or the desired functionality for the dried product. In this chapter, we present a modeling study of heat transfer during drying a moist agricultural product placed in a hot air flow in a tunnel dryer with partial solar heating. The bond graph approach has been used for system modeling, and it is an object-oriented graphical approach based on an energetic description between subsystems. Some drying tests have been carried out on tomatoes and the experimental results are compared with the theoretical results for the validation of the developed model

Simulation of fluid catalytic cracker

Fluid catalytic cracking unit (FCCU) performs the most vital role in modern refinery process because it is used for producing more economic refinery products. Crude oil contains hydrocarbons ranging from light gases, LPG and gasoline to residues of high boiling point range. Feed to the FCC unit is the residual product from the distillation column; fluid catalytic cracking (FCC) units convert a portion of the heavy material into lighter products, mainly gasoline, olefins, coke and LPG. Simulation of the fractional distillation was being done to find out the feed composition which is the inlet to the riser reactor. The FCC unit was later simulated to get the final yield of gasoline and other valuable product like LPG and the yield obtained by simulation is acceptable in plant scale. Later different values of flow rate, feed temperature, riser time and temperature of the reactor were varied to get the simulated data and from that graphs were plotted to study the behavior of the reactor and from there optimum conditions for the reactor is concluded. Comparison of single and dual riser is done and optimum condition. Additional unit like fractionator is used in the further simulation which hardly affects the riser reactor behavior. Also the effect of process parameters is studied in the case of dual riser reactor.as per the regenerator CFD simulation is done using ANSYS FLUENT 13.0 to show the temperature profile in the regenerator and the reaction product CO2. From the CFD analysis the catalyst bed condition and the heat supplying regenerator’s profile are described. At various concentration of oxygen enrichment temperature profile is observed and the rise of temperature is noted with high oxygen enrichment. Also rise in flow rate of air to the regenerator affect the combustion on the regenerator and hence the rise in temperature

Plantwide simulation and monitoring of offshore oil and gas production facility

Monitoring is one of the major concerns in offshore oil and gas production platform since the access to the offshore facilities is difficult. Also, it is quite challenging to extract oil and gas safely in such a harsh environment, and any abnormalities may lead to a catastrophic event. The process data, including all possible faulty scenarios, is required to build an appropriate monitoring system. Since the plant wide process data is not available in the literature, a dynamic model and simulation of an offshore oil and gas production platform is developed by using Aspen HYSYS. Modeling and simulations are handy tools for designing and predicting the accurate behavior of a production plant. The model was built based on the gas processing plant at the North Sea platform reported in Voldsund et al. (2013). Several common faults from different fault categories were simulated in the dynamic system, and their impacts on the overall hydrocarbon production were analyzed. The simulated data are then used to build a monitoring system for each of the faulty states. A new monitoring method has been proposed by combining Principal Component Analysis (PCA) and Dynamic PCA (DPCA) with Artificial Neural Network (ANN). The application of ANN to process systems is quite difficult as it involves a very large number of input neurons to model the system. Training of such large scale network is time-consuming and provides poor accuracy with a high error rate. In PCA-ANN and DPCA-ANN monitoring system, PCA and DPCA are used to reduce the dimension of the training data set and extract the main features of measured variables. Subsequently ANN uses this lower-dimensional score vectors to build a training model and classify the abnormalities. It is found that the proposed approach reduces the time to train ANN and successfully diagnose, detects and classifies the faults with a high accuracy rate

STUDY OF COCONUT OIL AS OIL BASED FLUID IN DRILLING OPERATION

Drilling fluid is a critical component in the drilling process, where it provides the gel to efficiently lift cuttings, maintain stable wellbore and produce sufficient hydrostatic pressure that could prevent the influx of formation fluids into the wellbore. Even-though Oil-based drilling fluids are widely used in drilling operation because it enable to provide good wellbore stability, good lubrication that leads to faster Rate of penetration, temperature stability and low formation damage but it have been proven that the disposal of oil-contaminated drill cutting causes environmental hazard especially Diesel as base oil. Vegetable oil in this project – Coconut oil is renewable, highly biodegradable could be suitable candidate of a highly biodegradable oil-based mud to achieve the sustainable development. Thus, six mud samples were formulated with six different composition of based fluids which are Saraline, 100%, 80%, 70%, 60%, 50% Coconut oil based mud samples. This paper presents the laboratory study such as viscosity, yield point, gel strength, filtration and electric stability had been undertaken to determine whether the Coconut oil were an acceptable alternative to diesel in order to overcome environmental problem

Marshall Space Flight Center Research and Technology Report 2019

Today, our calling to explore is greater than ever before, and here at Marshall Space Flight Centerwe make human deep space exploration possible. A key goal for Artemis is demonstrating and perfecting capabilities on the Moon for technologies needed for humans to get to Mars. This years report features 10 of the Agencys 16 Technology Areas, and I am proud of Marshalls role in creating solutions for so many of these daunting technical challenges. Many of these projects will lead to sustainable in-space architecture for human space exploration that will allow us to travel to the Moon, on to Mars, and beyond. Others are developing new scientific instruments capable of providing an unprecedented glimpse into our universe. NASA has led the charge in space exploration for more than six decades, and through the Artemis program we will help build on our work in low Earth orbit and pave the way to the Moon and Mars. At Marshall, we leverage the skills and interest of the international community to conduct scientific research, develop and demonstrate technology, and train international crews to operate further from Earth for longer periods of time than ever before first at the lunar surface, then on to our next giant leap, human exploration of Mars. While each project in this report seeks to advance new technology and challenge conventions, it is important to recognize the diversity of activities and people supporting our mission. This report not only showcases the Centers capabilities and our partnerships, it also highlights the progress our people have achieved in the past year. These scientists, researchers and innovators are why Marshall and NASA will continue to be a leader in innovation, exploration, and discovery for years to come

Computer Simulation Studies for the Production of 7-Tetradecene by Reactive Distillation

The production of 7-tetradecene was examined. Properties for this compound were estimated using group contribution methods and compared to experimental data. Process simulation was used as a tool to identify competitive processing strategies. For reactive distillation, three different models were compared to determine the model complexity needed to describe the process: Model A, with the assumption of physical and chemical equilibrium; Model B, with kinetics described by a second order reaction and physical equilibrium; and Model C, a non-equilibrium stage model that accounts for mass transfer. A conceptual design was obtained with Model B and was checked with Model C, which described the process more accurately but was more difficult to converge. Since, Model A was easier to converge, it was used to predict process conversions at different pressures. Predictions favor working at 1 bar, due to the lower heat duty and the minimum stages required

Aktiveeritud süsinike mikrostruktuuri ja poorsuse mõju elektrilise kaksikkihi kondensaatorite omadustele

Väitekirja elektrooniline versioon ei sisalda publikatsiooneKuna elektrijaamu (tuule-, päikese-, hüdro-, tuumaenergia jne) mugavalt kaasas kanda ei saa, on ikka vaja uuemaid ja paremaid energiasalvestusseadmeid, mida saab tasku panna. Energiat saab salvestada näiteks superkondensaatorisse. Energiasalvestusseadmeid iseloomustab nende energia ja võimsus. Mida rohkem energiat saab seadmesse, näiteks elektriauto akusse, salvestada, seda kaugemale saab see auto sõita enne, kui aku tühjaks saab. Kui sama aku on ka suure võimsusega, siis suudab see aku energiat kiiremini välja anda ehk auto kiirendus on suurem. Superkondensaatorid on väga hea võimsusega energiasalvestusseadmed (hind võimuse ühiku kohta 4500 EUR (kWh)−1). Seega kasutatakse superkondensaatoreid põhiliselt rakendustes, kus on oluline energiat salvestada/kätte saada väga kiiresti. Näiteks nutitelefoni kaamera välk saab oma energia superkondensaatorilt. Üks tähtsamaid superkondensaatori koostisosi on elektroodid. Tavaliselt tehakse elektroodid poorsest süsinikust, mis on olemuselt sarnane aktiivsöega, mida kasutatakse näiteks söetablettides. Poorseid süsinikke iseloomustab eripind ehk suur pindala väikese massi kohta. Selles töös sünteesiti mitmeid huvitava ehitusega suure eripinnaga süsinikmaterjale, kasutades lähteainetena glükoosi, sahharoosi ja turvast. Sünteesitud süsinikmaterjalidest tehti edasi superkondensaatori elektroodid ja neid kasutati superkondensaatori katserakus. Nähti, et mõned sünteesitud materjalid koosnesid 1 μm (umbes 100 korda väiksem kui juuksekarva läbimõõt) kerakujulistest osakestest. Nende väikeste sfääride sees on keeruline poorne võrgustik, mille eripind oli suurusjärgus 2000 m2 g−1 ja kuhu pääsevad ligi ioonid ja molekulid. Uurimuse käigus selgus, et igasuguse suurusega poorid pole võrdselt head selleks, et saada suure võimsusega superkondensaatorit. Selgus, et suure võimsusega superkondensaatorite valmistamiseks on äärmiselt vajalikud poorid, mille läbimõõt on ligi 1 nm või laiem (läbimõõt, mis on sarnane DNA molekuli läbimõõdule).Since the conventional power plants (wind, solar, hydro, nuclear, etc) currently do not fit in the pocket there is still an ever-increasing problem of needing newer and better energy storage devices. A part of the solution seems to come in the form of a device called supercapacitor. At first approximation, any energy storage system can be described by two main key parameters: energy and power. An electric car with a high energy battery system means it can drive further without needing to refill. If the same system had high power, then the car's acceleration from would be fast. That said, at equal basis, supercapacitors are considered to be cheap for obtaining high power values (4500 EUR (kWh)−1). Thus supercapacitors are used in applications that require high power intakes and outputs. For example, a smartphone camera uses supercapacitors for the flash. One of the most influential supercapacitor components is electrodes. Most commonly the electrodes are made of carbon materials that are in nature similar to the carbon materials used in charcoal tablet and carbon materials in water filters. They all function because of a high active surface area. In the current study, several promising high surface area carbon materials were synthesised using glucose, saccharose and peat as precursors. Resulting materials were meticulously evaluated in a supercapacitor test cell and interpreted using modern structural analysis methods. Obtained results revealed that some synthesised materials consisted of 1 m (about 100 times smaller than the diameter of a human hair) spherical particles. Inside of these extremely small particles lays a complex porous network where a lot of additional surfaces is located (>2000 m2 g−1). These pores are accessible to small particles like ions and molecules that can find a home at pores. However, not all pores are equally good. Data indicated that the best pores for making high power supercapacitors were approximately 1 nm in diameter or wider (close to the diameter of a DNA molecule).https://www.ester.ee/record=b536185