As wood drying kiln system has the nonlinear characteristics of a large lag, multivariable, large inertia and strong coupling. It is difficult to establish an accurate mathematical model of the wood drying kiln system by using traditional mathematical Modeling method. The data of wood drying kiln is drawn by CFD-Fluent, and the translate function of the control system is obtained by Matlab system identification. The simulation results show that the method has good accuracy, and can meet the control requirements of the system.
A comparison focusing on the properties and the system performances in working fluids selection for both subcritical and supercritical ORC is proposed. 16 candidates including wet, isentropic and dry fluids are considered. Thermal efficiency, exergy efficiency, Specific net power output and UA value are set as the system performance indicators. Under the premise of working fluids safety and comprehensive consideration of all aspects of system performances, R152a by supercritical ORC is determined by integrated comparison.
The choice of evaluating indicator has a most important influence on the performance analysis and optimization of Organic Rankine-cycle (ORC) system. In this paper, the net output power of unit mass of exhaust gas (), the cycle exergy efficiency (), the total waste heat emissions () and the product of exchanger's area and total heat transfer coefficient () are selected as the four key indicators which can reflect the characteristics of ORC system. And then, a comprehensive evaluating indicator of ORC system performance () is obtained according to the theory of multi-objective optimization. Further, a comprehensive evaluation method of ORC system performance based on the multi-objective optimization is put forward in this paper. After that, this method is used to optimize the evaporation temperature which is considered as a key parameter of ORC system performance. According to researches, the results gained by using a single-objective optimization method with only one performance parameter as the indicator, cannot often take a global view of the ORC system performance and sometimes may lead to a deviation. Researches also show that increases firstly and then decreases with the increment of the evaporation temperature, and there exists a value of evaporation temperature to maximize . Through analysis and researches, it can be found that the comprehensive evaluation method of ORC system performance based on the multi-objective optimization provided in this paper gives a synthetic consideration to the requirements from high-efficiency, economy, thermodynamic perfection and environment protection. Moreover, by using this method, the ORC power generation system may be more likely to achieve the best comprehensive performance.
As the composition, working principle and failure data recorded in the process of actual operation, in the nonretractable valve controlled anti-rolling fin system are in-depth analyzed.FTA method is used to set up the fault tree model, and the model is analyzed to determine the failure modes and the main reasons of the fin system.In allusion to the shortage of fault tree analysis method that path searching is not clear enough in actual fault search, the optimum search strategy based on the multi-objective decision in fault diagnosis of fin system is put forward, the path of locating failure cause is realized to be simple, steps of fault diagnosis are optimized, so that the efficiency of diagnosis is improved further.
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