Performance analysis of high-gravity heat pump distillation heat integrated system based on ethanol compression

doi:10.11949/j.issn.0438-1157.20180512

Abstract

Abstract:

Combining with the high-gravity distillation column, single screw compressor and new heat pump technology, and then the concept of high-gravity heat pump distillation was proposed. Firstly, high-gravity heat pump distillation heat integrated system was designed and built, which treatment capacity was about 300 kg·h^-1. Ethanol-water solution was taken as the actual research object. The single screw compressor was used to directly compress ethanol vapor. Afterwards, based on the full reflux experiments under the different rotational frequency of high-gravity distillation column, and different feed positions and reflux ratios experiments under the industrial condition, the changes of the affected parameters, energy-saving characteristics and economic benefits of the system were analyzed synthetically. Present results clearly show that the performance of the system is optimal when the frequency of high-gravity distillation column (f_HG) is operated at 40 Hz. By moving down the feed position or increasing reflux ratio, mass fraction of the vapor at the top of the column (y_D) can be improved. If only y_D is considered, feed location 03 (F_L03) is the best. In comparison with the low concentration of ethanol-water solution, it has a great advantage in treating the high concentration. In addition, energy-saving and economic benefits of the system are obvious, which can provide theoretical guidance for the high-gravity heat pump distillation in the selection, design and application of the ethanol distillation process.

Key words: ethanol, high-gravity, heat pump, distillation, heat integration

摘要：

将超重力精馏塔、单螺杆压缩机与新型热泵工艺技术创新性地相结合，提出超重力热泵精馏的概念。设计并搭建一套处理量为300 kg·h^-1的超重力热泵精馏热集成系统。以乙醇-水溶液为研究对象，使用单螺杆压缩机直接压缩乙醇蒸气。通过对超重力精馏塔不同转动频率的全回流实验和工业条件下系统的不同进料位置、不同回流比实验的研究，综合分析系统各影响参数的变化情况、节能特性和经济效益。结果表明，f_HG在40 Hz下运转时系统性能最佳；进料位置下移或增加回流比，都可提高y_D；如果仅从y_D值大小考虑，F_L03位置最佳；相比于低浓度乙醇-水溶液，处理高浓度优势更大；系统节能及经济效益显著，可为超重力热泵精馏在乙醇精馏的工艺流程选择、设计和应用方面提供理论指导。

关键词: 乙醇, 超重力, 热泵, 精馏, 热集成

CLC Number:

TQ051.4

LIU Jun, ZHANG Yu, MAO Xiang, ZHANG Zhentao, YANG Luwei. Performance analysis of high-gravity heat pump distillation heat integrated system based on ethanol compression[J]. CIESC Journal, 2018, 69(10): 4342-4352.

刘军, 张钰, 毛祥, 张振涛, 杨鲁伟. 基于乙醇压缩的超重力热泵精馏热集成系统性能分析[J]. 化工学报, 2018, 69(10): 4342-4352.

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