The Qualification of Electricity Production in High Efficiency Cogeneration for the Access to the Support Scheme through Green Certificates

The promotion of high efficiency cogeneration is a priority of the European Union, given the potential benefits of cogeneration relating to primary energy savings, avoiding network losses and reducing emissions of greenhouse gases. The paper presents the manner of determining the amount of electricity generated in high efficiency cogeneration for access to the support scheme through green certificates. The support scheme for the promotion of cogeneration is based on useful heat demand and primary energy savings compared with separate production of electricity and heat. We examine a cogeneration heat and power plant with ORC technology and biomass fuel, which have the technical characteristics in the nominal conditions of 1.3 MWe (electrical power) and 5.4 MWth (thermal power). We also propose an algorithm for determining the useful heat, who takes into account the operational requirements of the analysed CHP unit

Modeling Shapes for Pattern Recognition: A Simple Low-Cost Spline-based Approach

We present a simple procedure for modeling shapes and trajectories of points using cubic polynomial splines. The procedure may prove useful for researchers working in the field of pattern recognition that are in the search of a simple functional representation for shapes and which are not particularly interested in diving into the hightheoretical aspects of more complex representations. The use of splines brings in a few advantages with regards to data dimensionality, speed and accuracy of processing, with minimal effort required for the implementation part. We describe several algorithms for data reduction, spline creation and query for which we provide pseudo code procedures in order to demonstrate the ease of implementation. We equally provide measurements on the approximation error and rate of data reduction

Use of dual numbers in kinematical analysis of spatial mechanisms. Part I: principle of the method

Abstract The general methodology of solving a problem of kinematical analysis of a spatial mechanism is presented. The method is based on the system proposed by Hartenberg and Denavit, concerning the notations of the coordinate frames attached to the elements of the mechanism and on the closure matrix equation of a kinematical chain. Carrying out the closure equation for the case of spherical mechanisms and then applying the transfer principle of Kotelnikov, the equations which allow for finding the unknown parameters of the kinematical chain are obtained. Starting from the typical form of closure equation based on homogenous operators Hartenberg-Denavit, the closure matrix equation is obtained in dual format. By identifying two special matrices it is shown that the coefficient of the dual part from the closure equation is in fact a sum in which each term is attained from the real part of the closure equation by performing simple operations involving the special matrices, that reduce the calculus volume.</jats:p

Kinematics analysis of the swash plate mechanism

Abstract The swash plate mechanism is one of the most exploited mechanisms from technical applications due to its constrictive simplicity. The kinematical analysis supposes establishing the motion of the plunger as function of the motion of the plate and of the constructive characteristics of the mechanism. The work presents the kinematical analysis of the mechanism performed by two methods. In the first way, the mechanism is replaced by a mechanism with lower pairs to which the Hartenberg-Denavit procedure is applied. In the second way, the definition conditions of the pair of first class, plunger-plate, are used. The results are obviously identical for the two methods but for the second approach, the labour required for the analysis is significantly reduced. The main outcome of the paper refers to the scheme of kinematical solving of a mechanism. The type of pairs should be a criterion and for the higher pairs, the use of direct condition of the structural definition is recommended.</jats:p

The study of the motion of a gyroscope without rotational symmetry

Abstract In rigid dynamics theory the gyroscope has a special role, as one of the bodies with the most complex motion, having three degrees of freedom. As consequence of the complexity of the motion is the fact that only for three situations, the equations of motion can be analytically integrated. For all the three situations, it is assumed that the principal moments of inertia (PMI) with respect to the principal axes that are normal to the rotation axes, are equal, condition fulfilled by the shape of body of revolution of the gyroscope. The paper analyses the case when the two principal moments of inertia are unequal. The equations of motion are numerically integrated for different values of the ratio between the two PMI. The effect of the disparity between the two PMI upon the motion of the gyroscope is proved by comparison with the motion of the axisymmetric gyroscope, both obtained by numerical integration.</jats:p