Esteban Codina Macià

Bio: Esteban Codina Macià is an academic researcher. The author has contributed to research in topics: Pneumatic circuit & Plastic bottle. The author has an hindex of 1, co-authored 1 publications receiving 3 citations.

Air recovery assessment on high-pressure pneumatic systems

Abstract: A computational simulation and experimental work of the fluid flow through the pneumatic circuit used in a stretch blow moulding machine is presented in this paper. The computer code is built around a zero-dimensional thermodynamic model for the air blowing and recycling containers together with a non-linear time-variant deterministic model for the pneumatic three stations single acting valve manifold, which, in turn, is linked to a quasi-one-dimensional unsteady flow model for the interconnecting pipes. The flow through the pipes accounts for viscous friction, heat transfer, cross-sectional area variation, and entropy variation. Two different solving methods are applied: the method of characteristics and the Harten-Lax-Van Leer (HLL) Riemann first-order scheme. The numerical model allows prediction of the air blowing process and, more significantly, permits determination of the recycling rate at each operating cycle. A simplified experimental set-up of the industrial process was designed, and the pressure and temperature were adequately monitored. Predictions of the blowing process for various configurations proved to be in good agreement with the measured results. In addition, a novel design of a valve manifold intended for the polyethylene terephthalate (PET) plastic bottle manufacturing industry is also presented.

Energy efficiency of high pressure pneumatic systems

Abstract: The energy efficiency assessment of high-pressure pneumatic circuits is the aim of this dissertation. From a historical perspective the past and cur- rent activities with regards to the energy saving conservation in pneumatic technology were examined, and it could be concluded that high pressure pneumatic circuits have been repeatedly used for years in several industrial applications but to date no studies on that specific field are known. After a systematic review of studies concerning energy saving in pneumatic applications, a complete dynamic model for a high-pressure air blowing machine, employed in the production of plastic bottles, was developed. A synthetic version of the real pneumatic system was considered and consisted of a valve manifold, two tanks, one that simulated the mould cavity where the plastic preform is commonly blown and the other, was intended to recycle air. The one-dimensional models were derived for the pneumatic valve, pipes and vessels. The dynamic modelling of the valve took into account the flow non-linearities through the various geometrical restrictions as well as the pressure and temperature evolution at the inner chambers. Because of the existence of flow discontinuities in the pipes, different solving methods were applied, taking as starting point the Method of Characteristics and continued delving into finite volume methods such as Riemann-solver-based schemes. On the experimental phase a single blowing station unit was designed and built up. The pressure and temperature characteristics at different positions of the pneumatic circuit were measured in detail. In addition, the fluid flow through the valve manifold could be characterised by the sonic conductance and critical pressure ratio, which were determined by the isothermal discharge method. Effort was also expended to study the behaviour of the pressure waves generated along the tubes. The pressure wave propagation was computationally charted, with the intention of assessing how this parameter affected the recycling process. The examination of the experimental results proved the efficiency of the re- cycling process and demonstrated to be in close agreement with the mathematical model. The parameters governing the maximum amount of air to be recycled at each working cycle were identified, and the influence of the pipe geometry was discussed. Finally the author provides recommendations for future research and makes suggestions regarding the valve design to enhance the efficiency of the system.

Validation of A 0D/1D Computational Code for the Design of Several Kind of Internal Combustion Engines

Abstract: A code for computational simulation of internal combustion engines is presented. One-dimensional gas dynamics equations are used for model the flow through pipes and manifolds, and the remaining components in the engine (cylinders, valves, etc.) are modeled by using thermodynamic or 0D models. The numerical code developed is able to simulate spark-ignition and compressionignition, two-stroke and four-stroke, multicylinder and multi-valve engines, naturally aspirated or turbo-charged, and different geometries of the combustion chamber. The code was implemented in the scripting language Python, which is a dynamic object-oriented programming language that offers strong support for integration with other languages and tools. The numerical methods used in the discretization of the equations and implementation details are presented. Several test cases are included in order to show the performance of the code.

Review of Compressed Air Receiver Tanks for Improved Energy Efficiency of Various Pneumatic Systems

Abstract: This review examines compressed air receiver tanks (CARTs) for the improved energy efficiency of various pneumatic systems such as compressed air systems (CAS), compressed air energy storage systems (CAESs), pneumatic propulsion systems (PPSs), pneumatic drive systems (PDSs), pneumatic servo drives (PSDs), pneumatic brake systems (PBSs), and compressed air vehicles (CAVs). The basic formulas and energy efficiency indicators used in a CART calculation and selection are included. New scientific research by the authors on measurements based on tank methods, numerical solutions in the process of charging and discharging, the valve-to-tank-to-valve system and pneumatic propulsion system was presented. The numerical model of the valve-tank-valve system takes into account CART polytropic charging and discharging processes, the mass flow balance equation, and the sound (choked) and subsonic mass flow rate in the inlet and outlet valves. Future research directions to improve the energy efficiency of a CART charging and discharge are highlighted. The effective density of energy storage in CART was compared to that of other renewable energy sources and other fuels. Economic and environmental issues were also considered by adopting various energy performance indicators. The discussion also focused on the design concept and computational model of the hybrid tricycle bike (HTB) pneumatic propulsion system.

Measurement of Pneumatic Valve Flow Parameters on the Test Bench with Interchangeable Venturi Tubes and Their Practical Use

Abstract: A test bench with interchangeable venturi tubes was built to automatically measure the flow parameters of pneumatic valves of a wide range of sizes. This measuring stand contained components recommended by the ISO 6358 standard, an individually configured flow meter circuit, and HMI measurement and control panels. The flow meter circuit, individually configured with interchangeable venturi tubes, bypass loops, and Setaram thermal microflow meter, was calibrated using Molbloc/Molbox equipment. The tuning curve and theoretical flow rate characteristics of the tested valve were fitted to the flow rate measurement data. The best fit value of the critical pressure ratio was obtained using the numerical method of least squares minimization. The pneumatic valve with measured flow parameters was compared with data from the catalogue on the discharge characteristics of the compressed air tank. A practical solution for high-pressure tank discharge time using two valves connected in series to the hybrid tricycle bike (HTB) pneumatic propulsion system is presented. This article presents a solution to the practical problem of measuring the flow parameters of industrial pneumatic valves with a wide range of nominal diameters on a test bench with replaceable venturi tubes.