Thermodynamic model and exploration of micro multi-stage compressor inflation system

doi:10.11949/0438-1157.20241418

Abstract

Abstract:

The micro multi-stage compressor charging system has small size, light mass, and high output pressure, and can be widely used in various scenarios. Previous studies have predominantly focused on numerical models of single-stage compressors or single gas bottles. In this work, based on multidisciplinary theories including thermodynamics, fluid mechanics, heat transfer, material mechanics, and compressor principles, a novel thermodynamic model of the multi-stage reciprocating compressor filling system is proposed. This model integrates the components of "cylinders-inter-stage flow channels-gas storage bottle" and is capable of predicting and analyzing the full dynamic working process of the compressor as well as the system charging time. The established model can simulate the transient pressurization and charging process of the multi-stage compressor charging system, as well as the dynamic working characteristics of the cylinder, valve, flow channel, and gas storage bottle. The analysis focuses on several factors that may affect the filling time of the system. The results show that in-cylinder heat transfer and intercooling have a small impact on filling time but affect compressor efficiency. The inlet parameters of the compressor also impact filling time, with inlet pressure having the greatest effect. Leakage significantly affect both filling time and compressor efficiency.

Key words: compressor, multi-stage compression, filling process, thermodynamics, numerical simulation

摘要：

微型多级压缩机充气系统的体积小、质量轻、输出压力高，可广泛应用于各种场景。以往的研究多集中于单级压缩机或单气瓶的数值模型，本研究基于热力学、流体力学、传热学、材料力学及压缩机原理等多学科理论，构建了涵盖“气缸-级间流道-储气瓶”的多级往复式压缩机充气系统热力学模型。该模型可用于预测和分析压缩机的全动态工作过程以及系统充瓶时间。模拟了多级压缩机充气系统的瞬态加压加注过程，模型能够准确反映气缸、气阀、流道和储气瓶的动态工作特性。深入分析了影响系统充气时间的关键因素，结果表明，缸内换热和中间冷却对充瓶时间的影响较小，但对压缩机效率有显著影响；压缩机进气参数对充瓶时间有明显影响，其中进气压力的影响较为显著；泄漏对充瓶时间和压缩机效率均有显著影响。

关键词: 压缩机, 多级压缩, 充气过程, 热力学, 数值模拟

CLC Number:

TB 652

Yu GONG, Shengli WANG, Jinju SUN, Kuo HAI, Wen HUANG. Thermodynamic model and exploration of micro multi-stage compressor inflation system[J]. CIESC Journal, 2025, 76(7): 3626-3638.

龚宇, 王胜利, 孙金菊, 海阔, 黄文. 微型多级压缩机充气系统的热力学模型及规律探究[J]. 化工学报, 2025, 76(7): 3626-3638.

Figures/Tables 16

Fig.1 Simplified diagram of micro inclined disc multi-stage compressor inflation system

Table 1 Design parameters of multi-stage compressor

级数	缸径/mm	活塞行程/mm	吸气阀喉部直径/mm	排气阀喉部直径/mm	压力范围/MPa
1级	50	15	7	6.5	0.07~0.90
2级	20	15	6	5.5	0.6~5.5
3级	7.5	15	4	3	5.0~40.0

Fig.2 Process for solving thermodynamic model of multi-stage compressor inflation system

Fig.3 Experimental testing system

Fig.4 The pressure changes of each part during the inflation process

Fig.5 The pressure change of the third stage cylinder during the last few cycles of the 300 ml gas cylinder inflation process

Fig.6 (a) Pressure, intake valve displacement, and (b) pressure difference between passage 2-3 and the third stage cylinder during the intake process of the third stage cylinder

Fig.7 (a) Pressure and displacement of exhaust valve, and (b) pressure difference between the third stage cylinder and the gas cylinder during the exhaust process of the third stage cylinder

Fig.8 The influence of intake pressure on filling time

Fig.9 The gas temperature inside the cylinder under different intake pressures after inflation

Fig.10 The influence of intake temperature on filling time

Table 2 Results without inter stage cooling

转速/(r/min)	充瓶时间/s	流道1-2温度/K	流道2-3温度/K	储气瓶温度/K
600	545.415	511.628	618.321	713.149
900	364.613	513.807	621.865	727.377
1200	278.759	515.120	625.840	737.866
1500	224.446	517.563	626.892	745.643

Fig.11 The influence of channel wall temperature on filling time

Fig.12 Gas temperature inside the gas cylinder after inflation at different wall temperatures

Fig.13 The influence of clearance between cylinder and piston ring on filling time

Fig.14 Leakage rate of the third stage cylinder at (a) 1500 r/min and (b) 6000 r/min

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