Papers by Keyword: Thermal Performance Analysis

Abstract: This paper introduces the design of a solar heating system integrated latent heat store heat exchanger. Aiming at studying the system solar fraction, mathematical models are established for describing solar collector, latent heat store heat exchanger, users’ heating thermal load, and the system in whole. Studies are carried out based on these models. The results show that there are some key influencing factors on solar fraction, including solar irradiance, collector area, collector inclination angle, the difference value between collector inlet fluid temperature and ambient air temperature. Among these, collector inclination angle is the most significant one. If the values between collector inlet fluid temperature and ambient air temperature have big difference, it’ll cause adverse effects. As long as the operation requirements are met, lower collector inlet fluid temperature and suitable ambient air temperature are reasonable conditions for application. The research results provide guide for the system application in engineering.

Abstract: Motorized spindle is high speed machining unit combined with hidden motor and machine tools axis, which has advantages of high speed, stepless transmission, zero transmission chain, and is applied in machine center widely. Key technologies are combined together in motorized spindle designing, such as high speed motor, bearing, manufacturing and assemblage. It is strict in assembling to guarantee rotating precision and dynamic balance and is different from common machine tools designing due to characters of high speed and hidden motor. Hydrostatic bearings have advantages of high carrying capacity, lower friction, and better holding precision, the heat problem is extrusive, but the future of hydrostatic motorized spindle is considerable. Modal and thermal performance analyses are necessary for motorized spindle designing. With modal analysis, inherent frequencies are confirmed, which could be of help to avoid sympathetic vibration in machining. It provides evidence for designing cooling system of thermal performance analysis.