CAJ | 학술논문

针对跨临界二氧化碳半封闭式往复式活塞压缩机建立了一个通用数学模型，既包括热力学模块，也包括机械模块。热力学模块主要描述气缸内部的气体压缩过程。机械模块包括运动学模型和曲轴连杆机构模型，考虑了轴承上的功耗损失。采用一台压缩机样机对模型进行了不同运行工况下的实验验证，结果显示压缩机流量和耗功的最大误差分别不超过5％和8％。通过仿真分析了变结构和变工况条件下的压缩机性能，结果表明：在不同的运行工况下，存在最佳缸径行程比；容积效率和等熵效率都随着转速的增加而下降；吸排气阀门内径存在最佳值；对于容积效率的影响，吸气阀间隙比排气阀间隙更大，活塞与汽缸间隙比活塞环与汽缸间隙更大。
침대과림계이양화탄반봉폐식왕복식활새압축궤건립료일개통용수학모형，기포괄열역학모괴，야포괄궤계모괴。열역학모괴주요묘술기항내부적기체압축과정。궤계모괴포괄운동학모형화곡축련간궤구모형，고필료축승상적공모손실。채용일태압축궤양궤대모형진행료불동운행공황하적실험험증，결과현시압축궤류량화모공적최대오차분별불초과5％화8％。통과방진분석료변결구화변공황조건하적압축궤성능，결과표명：재불동적운행공황하，존재최가항경행정비；용적효솔화등적효솔도수착전속적증가이하강；흡배기벌문내경존재최가치；대우용적효솔적영향，흡기벌간극비배기벌간극경대，활새여기항간극비활새배여기항간극경대。
A comprehensive physics-based model for a semi-hermetic CO2 reciprocating compressor is presented. The model is composed of two major sub modules, the thermal module and the mechanical module. The thermal module is used to simulate the vapor compression process inside the cylinder, while the mechanical module is to simulate the frictional loss happened in the bearing connected to the cylin-der. Extensive experimental validation of the compressor model were carried out for a CO2 prototype compressor under different operating conditions. The maximum deviations of mass flow rate and power consumption are within 3% and 8%, respectively. Furthermore, para-metric study was conducted to investigate the compressor performance as a function of the stroke-to-bore ratio and the gap between cylinder and piston under different operating conditions. The results indicated that there is an optimal stroke-to-bore ratio under different operating conditions. Both volumetric efficiency and isentropic efficiency fall with the increasing compressor speed. There are optimal diameters for suction and discharge valves. On the volumetric efficiency, the gap between suction valve and valve seat has heavier impact than the gap between discharge valve and valve seat, while the gap between piston and cylinder has greater impact than the gap between cylinder and cylinder ring. The analysis would help further improvement on the compressor design.