Modeling and Control of Distillation Column in a Petroleum Process

This paper introduces a calculation procedure for modeling and control simulation of a condensate distillation column based on the energy balance (-) structure. In this control, the reflux rate and the boilup rate are used as the inputs to control the outputs of the purity of the distillate overhead and the impurity of the bottom products. The modeling simulation is important for process dynamic analysis and the plant initial design. In this paper, the modeling and simulation are accomplished over three phases: the basic nonlinear model of the plant, the full-order linearised model, and the reduced-order linear model. The reduced-order linear model is then used as the reference model for a model-reference adaptive control (MRAC) system to verify the applicable ability of a conventional adaptive controller for a distillation column dealing with the disturbance and the model-plant mismatch as the influence of the plant feed disturbances

Numerical modeling on drilling fluid and cutter design effect on drilling bit cutter thermal wear and breakdown

The unconventional reservoir geological complexity will reduce the drilling bit performance. The drill bit poor performance was the reduction in rate of penetration (ROP) due to bit balling and worn cutter and downhole vibrations that led to polycrystalline diamond compact (PDC) cutter to break prematurely. These poor performances were caused by drilling the transitional formations (interbedded formations) that could create huge imbalance of forces, causing downhole vibration which led to PDC cutter breakage and thermal wear. These consequently caused worn cutter which lowered the ROP. This low performance required necessary improvements in drill bit cutter design. This research investigates thermal–mechanical wear of three specific PDC cutters: standard chamfered, ax, and stinger on the application of heat flux and cooling effect by different drilling fluids by using FEM. Based on simulation results, the best combination to be used was chamfered cutter geometry with OBM or stinger cutter geometry with SBM. Modeling studies require experimental validation of the results

Development and investigation of an inexpensive low frequency vibration platform for enhancing the performance of electrical discharge machining process

Difficulty in debris removal and the transport of fresh dielectric into discharge gap hinders the process performance of electrical discharge machining (EDM) process. Therefore, in this work, an economical low frequency vibration platform was developed to improve the performance of EDM through vibration assistance. The developed vibratory platform functions on an eccentric weight principle and generates a low frequency vibration in the range of 0–100 Hz. The performance of EDM was evaluated in terms of the average surface roughness (Ra), material removal rate (MRR), and tool wear rate (TWR) whilst varying the input machining parameters viz. the pulse-on-time (Ton), peak current (Ip), vibration frequency (VF), and tool rotational speed (TRS). The peak current was found to be the most significant parameter and contributed by 78.16%, 65.86%, and 59.52% to the Ra, MRR, and TWR, respectively. The low frequency work piece vibration contributed to an enhanced surface finish owing to an improved flushing at the discharge gap and debris removal. However, VF range below 100 Hz was not found to be suitable for the satisfactory improvement of the MRR and reduction of the TWR in an electrical discharge drilling operation at selected machining conditions

Design Of Linear Polarization Antenna For Wireless Mimo Application

This paper presents the design of the linear polarized antenna for wireless MIMO communication system.It is impossible to fulfill the demand of the wireless communication system due to limitations in channel capacity on single input single output (SISO) systems. Multiple input multiple output (MIMO) system has become a famous research field for the next generation wireless communication system in order to overcome this problem. Since polarization diversity is effective to avoid the fading loss caused by multipath effects, therefore, polarization diversity becomes one of the most important techniques that can be used to enhance MIMO system performances.It can be utilized to improve the communications channel capacity and utilize the frequency spectrum with frequency reuse technique.Therefore,the development of linear polarized antenna is significant in order to improve the wireless MIMO system performance based on polarization diversity technique.Polarization diversity can be utilized to double the frequency spectrum to realize frequency reuse and improve the communications capacity.This project is to design an antenna that can provide linear polarization to reduce the signal losses

The effect of mould temperature on properties of flexible PU foam

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Integrating analysis and design improvement in a reverse engineering framework

Includes bibliographical references (pages [66]-68)The problems in reverse engineering a clone from an existing part involve the risk of duplicating inherent deficiencies that might exist in the original design. Currently, all existing reverse engineering systems (RES) focus on the acquisition of geometric data and the generation of numerical control (NC) programs to manufacture the clone part. The RES fails to provide critical performance information on parts for remanufacture. The purpose of this research was to develop an improved method for implementing reverse engineering by integrating engineering analysis within the reverse engineering framework. Rules and procedures for conducting engineering analysis and design modification are formulated. Initially the existing part is digitized and the CAD model generated. The CAD model is then transformed into a FEA model by generating nodes and meshes, loading and boundary conditions. Based on the stress distribution and deflection output from the analysis, iterations of design modification and analysis are conducted until a superior design is achieved. Together, these allow critical part performance information to be predicted. Costly and time consuming destructive or nondestructive testing on the part is eliminated. The results of this study will make the task of reverse engineering an existing part and producing an improved part greatly simplified and structured. A significant benefit provided by the new RES is the total cost savings due to more efficient manufacturing and prototype testing of the clone part, thus improving productivity.M.S. (Master of Science

Thermal Conductivity Augmentation of Epoxy Injection Moulds for Cooling Time Reduction

Polymer injection moulds are generally manufactured with tool steels which give reliable functioning of moulds with long service life. Manufacturing of injection moulds in steel is a lengthy process due to the strength and hardness. If the injection mould is required quickly for a short prototype or production run, one of the good choices is to use Aluminum filled epoxy material, which can give a mould in a very short time using Rapid Tooling (RT) techniques, as compared to a machined tool. Aluminum-filled epoxy tools work best for relatively simple shapes. The benefits of fabricating injection moulds with epoxy resins includes time saving, ability to set at room temperature and ease of machining. But a major drawback of epoxy material is that the cooling time for epoxy injection moulds are still relatively long due to the poor thermal conductivity of epoxy. This paper reports investigation of an innovative idea for enhancing the thermal conductivity for epoxy moulds. The basic concept behind the idea was to embed high thermal conductive metal insert within the mould between the cavity and the cooling channel. This technique will increase the effective thermal conductivity of the epoxy mould, leading to reduction in cooling time for the injection moulded polymer part. By substituting part of the epoxy with low-cost aluminum, a cost advantage is also to be derived, besides increased mould strength. Experimental analysis done in the current study also verified that mould with embedded metal insert has considerable shorter cooling time.Published versio

Enhanced polymer rapid tooling for metal injection moulding process

Presently, mold material for metal injection molding (MIM) process is metal and are made through machining. However, machining could be time consuming, costly and skill intensive process to accurately process the mold. Moreover, for the demands when MIM part requirements are in low volume and features are customized, the machined mold is rendered useless once the part demands have been met. 3D printing could be a quick process to make molds from polymers for the customized and low volume MIM cycles. While this 3D printed mold may not be sustainable for mass production, yet they could potentially be viable for small MIM cycles like prototype manufacturing. The present study investigates the performance of polymer molds made form fused deposition modeling (FDM) process for their potential use as direct Rapid Tooling (RT) in MIM process. It was concluded that 3D printed polymer molds could be successfully applied in MIM process for prototype manufacturing and low volume demands of end-use parts.Published versio