浓缩蔗糖汁的高效节能热泵并流多效蒸发系统

Heat Pump Concurrent Multi-Effect Evaporation System of High-Efficiency Saving Energy for Concentrating Sugar Cane Juice

摘要:

为了大幅降低蔗糖厂蒸发工艺的能耗,首次将蒸汽喷射式热泵技术、冷凝水闪蒸和引出额外蒸汽预热糖汁等3种节能措施,同时运用于糖汁浓缩并流多效蒸发系统中,并建立了用矩阵方程描述的该系统的数学模型。模型具有很强的通用性,可实现上述节能措施的自由组合和热泵在任意效抽汽的功能,还可推广用于食品工业其它热敏性溶液的蒸发浓缩;模型存在最佳的热泵喷射系数和抽汽位置,同时采用上述3种节能措施且在最佳条件下可以高效节能。用迭代法结合矩阵法求解浓缩糖汁的热泵并流四效蒸发系统的模型,结果表明,同时采用上述3种节能措施,并在满足约束条件的前提下,将糖汁预热至90 ℃,热泵的喷射系数为0.5,抽汽位置在第2效时节省的生蒸汽消耗量高达41%左右。

Abstract:

In order to greatly reduce the energy consumption of evaporation process in sugar plant,three kinds of energy-saving measures which include steam jet heat pump technology,extra vapor elicitation to preheat the sugar cane juice and condensate water flash are applied together in concurrent multi-effect evaporation system to concentrate sugar cane juice for the first time,meanwhile,the mathematical model of the system which is described as the form of matrix equation was established. The developed model has strong versatility,it not only can be simplified as a concurrent multi-effect evaporation model with different combinations of energy-saving measures,but also can achieve the function of extracting stream at any effect,and it can be generalized to the concentrate of other heat-sensitive solution by evaporating in food industry. There is an optimal injection coefficient and pumping position of the steam jet heat pump,and the mathematical model is high efficiency and energy saving when above three energy conservation measures are used simultaneously and the model is under optimal conditions. Iteration method combining with matrix method is used to solve the model of concentrated sugar cane juice 4 effects concurrent evaporation system with heat pump. The simulation results show that the evaporation system developed is high efficiency and energy saving when above three energy conservation measures are used simultaneously and it is under the premise of satisfying the constraints,the steam consumption can save up to about 41% when the injection coefficient is 0.5 and pumping position are set to the second effect and the temperature of sugar cane juice is preheated to 90 ℃.