CAJ | 학술논문

为避免磁力泵温升过高导致永磁体退磁及隔离套损坏，该文对磁力泵冷却循环回路的设计方法进行了探讨，采用ANSYS-APDL软件计算出了隔离套的涡流发热，根据热平衡确定冷却循环流量并设计了冷却循环回路。基于SIMPLEC算法和标准 k-ε湍流模型，通过求解三维N-S方程及能量方程，对冷却循环回路内部流场及温度场进行了数值分析。从数值模拟可以看出，冷却循环回路内部流动为圆周运动和直线运动合成的螺旋运动。对比内循环、外循环2种方式表明，内循环方式隔离套底部温升最高、压力较低；外循环方式温度场分布较均匀，最高温升小于10 K，满足设计要求。在冷却循环流量相同的情况下，轴孔孔径在设计尺寸一定范围内波动对外循环方式的冷却效果影响不大，轴孔分别为3、4、5 mm，其最高温升分别为9.2、9.3、9.4 K并且分布基本相同。通过分析不同转速下冷却循环回路的流场、温度场，发现当内磁转子不转动时，流场最高温度达到了386 K，而随着转速的增加最高温度逐步降低，表明增加泵的转速能够促进不同流体层间的热量交换，改善冷却循环回路的冷却效果。该研究可为磁力泵冷却循环回路的设计提供参考。
위피면자력빙온승과고도치영자체퇴자급격리투손배，해문대자력빙냉각순배회로적설계방법진행료탐토，채용ANSYS-APDL연건계산출료격리투적와류발열，근거열평형학정냉각순배류량병설계료냉각순배회로。기우SIMPLEC산법화표준 k-ε단류모형，통과구해삼유N-S방정급능량방정，대냉각순배회로내부류장급온도장진행료수치분석。종수치모의가이간출，냉각순배회로내부류동위원주운동화직선운동합성적라선운동。대비내순배、외순배2충방식표명，내순배방식격리투저부온승최고、압력교저；외순배방식온도장분포교균균，최고온승소우10 K，만족설계요구。재냉각순배류량상동적정황하，축공공경재설계척촌일정범위내파동대외순배방식적냉각효과영향불대，축공분별위3、4、5 mm，기최고온승분별위9.2、9.3、9.4 K병차분포기본상동。통과분석불동전속하냉각순배회로적류장、온도장，발현당내자전자불전동시，류장최고온도체도료386 K，이수착전속적증가최고온도축보강저，표명증가빙적전속능구촉진불동류체층간적열량교환，개선냉각순배회로적냉각효과。해연구가위자력빙냉각순배회로적설계제공삼고。
In order to avoid excessive temperature rise which leads to permanent magnet demagnetization and damage of containment shell, the design of cooling circuit of magnetic pumps was discussed. Theory analysis showed that the cooling circuit had a great influence on magnetic pumps’ efficiency and reliability. Analysis and calculation showed that the main heat source of magnetic pumps was the eddy current heat of containment shell. ANSYS-APDL was adopted to calculate the eddy current heat, which simplified the distribution of the magnetic field to two-dimensional. The total heat was obtained through the eddy current heat multiplied by an amplification coefficient k. The cooling flow rate was calculated according to the heat balance and the cooling circuit was designed. The flow field model of the cooling circuit was established by Pro/e software, the structured grid was adopted to mesh the model and the near wall boundary layer was refined to ensure the grid quality. The SIMPLEC algorithm and the k-εturbulence model were adopted to solve the N-S equations and energy equation by CFX code. The flow velocity, pressure and temperature distribution were obtained by CFX software post. As could be seen from the numerical simulation, the internal flow of the cooling circuit was spiral motion combining circular motion and linear motion. Through the comparison between internal and external cooling circulations with the same main geometric parameters, it showed that the temperature rise was the highest, and the pressure was low in the internal circulation located in the bottom of containment shell, which maybe caused cavitation. On the other hand, the temperature distribution was uniform and the pressure gradually reduced from shaft hole to external pipeline (the pressure of containment shell bottom was higher) in external cooling circulation, which met the design requirements. Based on the same cooling flow rate, the influence of the shaft bore diameter in external cooling circulation was analyzed. It showed that the spiral movement velocity of cooling circuit was mainly decided by the circular velocity, the axial velocity had a little effect on the system, and a certain level of fluctuations of shaft bore diameter designed had little influence on the cooling result when the cooling flow rate was fixed. Without considering the friction changes at different rotational speeds, the influence of rotational speed was also discussed in external cooling circulation. It showed that the rotational speed powerfully affected the heat transfer. The highest temperature reached 386 K when the internal magnetic rotor didn’t rotate, which was far exceeding the safety range, but the highest temperature was basically stabilized at a reasonable range with the internal magnetic rotating. The wall heat transfer coefficient increased significantly with the increase of rotational speed. So the increase of pump’s rotational speed can promote heat exchange between the different fluid layers and improve the cooling effect. The research is helpful for the design of cooling circuit in magnetic pumps.