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Abstract To improve the efficiency, a 13 kW used vehicle permanent magnet synchronous motor was remanufactured, whose stator core was replaced by a combination of amorphous alloy laminations and silicon steel laminations. But the speed regulation ability with field weakening of the remanufactured motor limits its development towards high speed direction. Taking the remanufactured motor as the object, based on the theory of speed regulation with field weakening, the maximum speed range was improved by increasing direct‐axis inductance, and the structural optimization parameters affecting the direct‐axis inductance were analysed. The two‐dimensional inductance superposition method was proposed to calculate the direct‐axis and quadrature‐axis inductance of the remanufactured motor, and its accuracy and feasibility were verified by finite element simulation. The segmented structure of the V‐type permanent magnet was used, and the motor structure was optimised from three aspects: the width and position of magnetic bridge and the magnetic pole implantation depth. The orthogonal experiments were designed to determine the best parameter combination. The results show that the direct‐axis inductance of the optimised remanufactured motor is increased by 16.33%, and the performance of speed regulation with field weakening is improved significantly.

Since the electric vehicle battery (EVB) is wildly recycled in industry, the disassembly procedures of variable EVBs is so important that can influence the efficiency and environmental impacts in remanufacturing. To improve disassembly efficiency in EVB remanufacturing, a disassembly sequence planning method based on frame-subgroup structure is proposed in this paper. Firstly, the improved disassembly relation hybrid graph and disassembly relation matrix are proposed to identify the disassembly precedence relationship and connection relationship between the components in EVB. Secondly, the frame - subgroup structure is given, and the method for solving disassembly sequence planning with frame-subgroup structure and genetic algorithm is introduced. In this method, to simplify the series of processes such as encoding, decoding, crossover and mutation, the solution space composed of all disassembly sequences is transformed into the positive integer sequence for the disassembly efficiency in battery remanufacturing. Finally, the case study of EVB disassembly sequence planning is presented to validate the feasibility of this proposed method. Comparing with other traditional methods, the advantage and application of this proposed method are introduced.

The present study analyzed the recovery mechanism of the thermosetting phenolic resin waste, optimizing the recovery process parameters, based on the mechanochemical recovery method. The physical and chemical structure of the ultrapulverized phenolic resin powder was characterized by the low-field NMR (nuclear magnetic resonance), IR (infrared spectroscopy), and SEM (scanning electron microscopy). The recovery process parameters were designed by using the response surface analysis method, and the multiple quadratic regression model was established and the multiobjective process parameter was optimized. The results show that the body network structure of the material is destroyed during the crushing process. The intensity of the internal cross-linking signal is reduced and tends to be stable at about 60%, when the particle size exceeds 120 mesh. The cross-linking bonds methylene (-CH2-) in the main chain of the molecular chain and the C-O bond in the methylol group on the branch are broken. The tensile strength of the recycled sheet made of the phenolic resin powder is 8.27 MPa, and the bending strength is 17.76 Mpa through the mechanical properties test. The influences on the change rate of the cross-linking signal intensity and the yield of the recycled powder are in the following order: rotation speed, feed size, time, and feed volume. The best recovery parameters are as follows: rotation speed of 2820 r/min, time of 80 min, feed particle diameter of 0.43 mm, and feed volume of 60 g.

Ultra-high pressure water jet is proposed for recycling of vulcanized waste rubber, and cavitation desulfurization in the recycling process is analyzed. The chemical effects of mechanical shearing, pyrolysis, free radical oxidation, and supercritical oxidation produced by bubble collapse are considered the main causes of desulfurization. Scanning electron microscopy, Fourier transform infrared spectrometry, differential scanning calorimetry, nuclear magnetic resonance test, and X-ray photoelectron spectroscopy are used to determine the performance of rubber powder. Gel fraction of rubber powder is measured to analyze the effect of jet pressure on desulfurization. Results indicate that the vulcanized rubber could achieve partial desulfurization. The glass transition temperature of the rubber powder slightly increases after crushing. With the increase of jet pressure, the gel fraction of rubber powder initially decreases and then increases, as well as achieves a minimum value at the jet pressure of nearly 220 MPa, which is ideal for desulfurization. [ABSTRACT FROM AUTHOR]