Papers by Keyword: Energy Flow

Abstract: The calculation of the structural intensity allows for a better understanding of the NVH behavior of complex structures as it shows vibratory energy flows between an excitation and radiating areas. However, the information gathered is underlying aleatory and epistemic uncertainties and needs to be dealt with carefully. In this paper two aspects are discussed: Firstly how the structural intensity calculation helps to reduce uncertainty in NVH design and secondly what currently existing uncertainties need to be considered and how they can be further reduced. This does not only include an improvement of the current calculation process itself but also an extension towards an integrated, holistic calculation of vibratory energetic quantities for structure-borne and air-borne sound.

Abstract: The battery ability of recovering electricity plays a significant role in improving the regenerative braking performance. In this paper, a control for recovery of braking energy in Electric Vehicles (EVs) with electro hydraulic brake (EHB) is proposed, which makes the recovery transfer to the electric hydraulic pump of EHB directly, rather than being stored statically in the battery. An energy flow strategy was designed for the maximum braking energy recovery based on this control. The simulation results show higher energy recovery rate in comparison to the general recycling control.

Abstract: This publication is focused on thermal balance of the experimental pyrolysis system furnace. Especially, a relationship between a kind of input material for thermal processing and pyrolysis furnace efficiency has been researched here. Mass intake of materials was 60 kg per an hour and the process temperature of 600 °C was set in the reactor. Presented findings relate to three kinds of materials that have been tested - brown coal, rubber and polyethylene. The main aim of this research is to answer the following question: "In which case does the furnace have the highest efficiency" Inter alia, the article contains a description of the individual input and output energy flows within the system that is thermal input in heating gas, profitably utilised heat, heat losses in waste burnt gases, heat losses by convection and radiation from the unit surface and coherent information. The best efficiency of the system is shown under thermic processing of the rubber.

Abstract: Based on the analysis the theoretical of regenerative braking and energy flow of the pure electric vehicle, the main influence factors of braking energy recovery were obtained. Ignoring the energy loss and the efficiency of system components as well as the response delay of the hydraulic braking system, two different regenerative braking control strategies were established without regard to the braking force distribution restrictions of the relevant brake laws. The simulation model was built on MATLAB/Simulink platform to analysis the effect of control strategies, vehicle mass and driving cycle for pure electric vehicle braking energy recovery. It was guidance for the development of pure electric vehicle braking energy recovery control strategy.

Abstract: This manuscript developed two methodologies of mapping energy flows of coal utilization in the form of Sankey diagrams: one was energy allocation diagram without illustrating any energy losses and the other was energy efficiency diagram illustrating main energy losses. Based on the methodologies, energy flow diagrams of China's coal utilization in the year 2005 and 2010 were presented. The two diagrams divided coal utilization into four stages from raw coal supply, by coal products supply and coal conversion, to energy end-use. Comparing with previous studies, some technical details were further introduced into the mapping, including coal preparation and the distribution of end-use energy such as electricity, heat and coke etc. Based on the results, the main characteristics of coal utilization in China and its main changes from 2005 to 2010 were discussed.

Abstract: In this paper, a method for the localisation and quantification of impacts on orthotropic plates, based on the measurement of the resulting vibrational energy flow, or structural intensity, is presented. The outputs of a compact array of bonded piezo-electric sensors are digitally filtered and combined to yield a local estimate of the instantaneous vibrational energy flow. In the case of transient vibration due to an impact, two or more such estimates can be used to localise the point of impact. The use of energy flow vectors for localisation requires a priori knowledge of the material properties, but may provide more direct access to position information than conventional techniques. Furthermore, the magnitude of the measured energy flow, when combined with knowledge of the impact location, can provide a quantitative measure of impact severity. The approach is based on Kirchhoff orthotropic plate theory, and is thus applicable to low frequencies, and utilises instantaneous estimates of the local wave field to allow the estimation of the various forces, moments and velocities that are required to calculate the vibrational energy flow. The theoretical background and principles of implementation of the approach are outlined, and the effects of sensor array design on systematic errors and sensitivity to measurement noise are discussed. Numerical simulations are used to assess the effectiveness of the technique and to determine its sensitivity to noise and other errors. These simulations suggest that the obtained energy flow estimates can be used for impact localisation.

Abstract: The article presents the analysis of thermal flows into reactor walls within the semi-operational pyrolytic system. There were hydrodynamic and thermodynamic similarity theories and heat transfer by radiation laws used for the solution of this issue. The entry data for the heat transfer analysis were gained by conducted experiments. The correctness of the resulting values has been verified by measurements. The required reactor parameters, for the required heat intake, have been derived from the analytical results at the end of this article.

Abstract: Basing on the analysis, the functions of the V2G system, such as peak shaving, frequency adjusting, UPS and disturbance stabilizing, are discussed in this paper. And the key technologies of V2G are put forward according to the ongoing research and demonstration. The main research route and methods are established, which includes the nonlinear multivariable decoupling method of power battery pack, the integrated process control method of EV energy and driving system, the statistical characteristics of EV large-scale demonstration and the control theory and method.

Abstract: This publication presents a novel piezoelectric shunt damping circuit. It consists of a negative capacitance in parallel to a synchronized switch damping on inductor (SSDI) branch. This combination utilizes the increased piezoelectric coupling due to the negative capacitance together with the adaptive ability of the SSDI technique. This novel circuit is theoretically modelled using non-dimensional parameters, and optimum network parameters and the corresponding maximum damping is obtained. The increase in damping performance due to the negative capacitance is clearly highlighted. Theoretically, the energy dissipation can be increased unlimited when tuning the system at the stability boundary, given the system would still be excited to vibrations. However, due to imperfections and practical realization using operational amplifiers the increase is limited.

Abstract: Based on the summarization of the concept of Vehicle-to-Grid and its recent development in the world, two topologies of V2G are put forward accounting for the different power supply modes. According to the analysis of the nowadays EV driving and energy system, a new topology of EV energy control system, which is suitable for application under V2G mode, is put forward, and its working principle is developed. The characteristics of this system are efficient, low cost and high integration. 1. Introduction