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吸收式制冷机在工业余热回收利用中有非常广泛的应用前景,能有效改善因工业生产造成的热污染。从热力学定律和火积效率定义出发,介绍了吸收式制冷机的工作原理,并在质量和能量守恒定律基础上设计了吸收制冷机各部件的数学模型。在建立的热力学方程中,有5个假定:1)系统在稳态和热平衡条件下运行;2)各部件的热损和压降可以忽略不计;3)离开发生器和吸收器的溶液是饱和的;4)发生器出口蒸汽是纯工质,且离开发生器的稀溶液是平衡的;5)节流阀前后是等熵过程。研究了各个系统参数随火积效率(G*)的变化趋势。结果表明,当发生温度不变时,蒸发温度、制冷量、放气范围和系统COP随火积效率的增加而增加,而系统循环比、泵功和系统火用效率随之下降;如果火积效率一定,蒸发温度、制冷量、放气范围和系统COP随发生温度的增加而增加,系统循环比、泵功和系统火用效率则随之下降。因此,在吸收制冷机中,可以通过改变火积效率G*来改善系统性能。
Absorption chiller in the industrial waste heat recovery has a very wide range of applications, can effectively improve the thermal pollution caused by industrial production. Based on the definition of thermodynamics law and fire efficiency efficiency, the operating principle of absorption chiller is introduced. Based on the conservation of mass and energy, a mathematical model of each component of chiller is designed. There are five assumptions in the established thermodynamic equations: 1) The system is operating at steady-state and thermal equilibrium conditions; 2) The heat losses and pressure drops across components are negligible; 3) The solution leaving the generator and absorber is saturated ; 4) generator outlet steam is pure working fluid, and leave the generator dilute solution is balanced; 5) before and after the throttle is the isentropic process. The trend of various system parameters with the fire accumulation efficiency (G *) was studied. The results show that the evaporation temperature, cooling capacity, deflation range and system COP increase with the increase of fire accumulation efficiency when the temperature is constant, while the system circulation ratio, pump power and system exergy efficiency decrease. If the product of ignition The efficiency is certain. The evaporation temperature, cooling capacity, deflation range and system COP increase with the increase of temperature. The system circulation ratio, pump work and system exergy efficiency decrease accordingly. Therefore, in the absorption chiller, the system performance can be improved by changing the ignition efficiency G *.