烟气型吸收式制冷机的变工况特性研究

Off-Design Performance of an Exhaust-Fired Absorption Refrigerator

基于分布式冷热电联产系统变工况运行的实际需要,建立了烟气型双效溴化锂吸收式制冷机的变工况模型。制冷机变工况模拟计算时,保持浓溶液流量及换热系数(高压发生器除外)不变,得到了烟气进口温度、烟气流量及冷却水进口温度变化时的制冷机各重要性能参数曲线,发现当烟气流量低于50%时,COP下降较快,冷却水进口温度降低时有利于制冷机运行,但是要注意防止浓溶液结晶。制冷机额定工况模拟计算时,与已有文献进行对比,验证模型的可靠性。

This paper proposed a mathematical model to simulate the off-design performance of an exhaust-fired double-effect absorption refrigerator in a CCHP （Combined cooling, heating and power） system. Effects of exhaust gas inlet temperature and flow rate , cooling water inlet temperature on the performance of absorption refrigerator have been investigated, with the assumptions of constant value of strong solution flow rate and heat transfer coefficients. When the exhaust gas flow ratio is below 50%, COP drops quickly. The decrease of cooling water inlet temperature can improve the performance of absorption refrigerator, with the prevention of solution crystallization. The model has been compared with a published model to validate.