THERMAL SCIENCE

International Scientific Journal

Xingyuan Huo

,

Xiaolin Sun

,

Jinfeng Wang

,

Jianguo Zhang

,

Zhigang Zhoud

,

Yu Hu

EXPERIMENTAL PERFORMANCE OF A COMBINED THROTTLING DEVICE WITH STEPPER MOTOR AND NEEDLE VALVE IN AN AMMONIA-WATER ABSORPTION REFRIGERATION SYSTEM

ABSTRACT
Electronic expansion valves (EEVs) for ammonia-water absorption refrigeration systems are expensive and limited in model selection. In this paper, a combined throttling device (CTD) based on a stepper motor and needle valve is proposed to replace the electronic expansion valve (EEV). An experimental platform was established to study its performance. Results show that with PID, fuzzy, and fuzzy PID superheat degree control algorithms, the maximum deviation of the superheat degree is no more than 1°C, and fuzzy PID reduces fluctuation by 14.6% at the superheat degree of 9.5°C compared with PID. At the superheat degree of 9.5°C, the system performs refrigerating capacity of 2.8kW and COP of 0.48. The experimental results validate the practical feasibility and engineering application potential of the proposed CTD for ammonia-water absorption refrigeration systems.
KEYWORDS
ammonia-water absorption refrigeration, combined throttling device, superheat degree, control algorithms, fuzzy PID
PAPER SUBMITTED: 2026-02-03
PAPER REVISED: 2026-03-22
PAPER ACCEPTED: 2026-03-29
PUBLISHED ONLINE: 2026-05-17
DOI REFERENCE: https://doi.org/10.2298/TSCI260203061H
REFERENCES
[1] Kumar, M., Das, R., Experimental Analysis of Absorption Refrigeration System Driven by Waste Heat of Diesel Engine Exhaust, Thermal Science, 23 (2019), 1, pp. 149-157
[2] Srikhirin, P., et al., A Review of Absorption Refrigeration Technologies, Renewable and Sustainable Energy Reviews, 5 (2001), 4, pp. 343-372
[3] Ma, X., et al., Optimization of Zero Superheat Control at the Evaporator Outlet: Application of EXV and Pressure Regulation Valve, Thermal Science and Engineering Progress, 55 (2024), pp. 102919
[4] Ding, X., et al., A novel on-line auto-tuning PI controller for the superheat of evaporator with electronic expansion valve, Proceedings, 2017 Chinese Automation Congress (CAC), Jinan, 2017, pp. 7513-7517
[5] Shi, Y., et al., Thermodynamic Analysis of a Novel GAX Absorption Refrigeration Cycle, International Journal of Hydrogen Energy, 42 (2017), 7, pp. 4540-4547
[6] Zhao, D.D., et al., Theoretical Study on Solar-Driven Air-Cooled LiBr/Water Absorption Refrigeration System, AMR, 608-609 (2012), pp. 3-10
[7] Yari, M., et al., Simulation Study of the Combination of Absorption Refrigeration and Ejector-Expansion Systems, Renewable Energy, 60 (2013), pp. 370-381
[8] Imroz Sohel, M., Dawoud, B., Dynamic Modelling and Simulation of a Gravity-Assisted Solution Pump of a Novel Ammonia-Water Absorption Refrigeration Unit, Applied Thermal Engineering, 26 (2006), 7, pp. 688-699
[9] Elliott, M., et al., Superheat Control: A Hybrid Approach, HVAC&R Research, 15 (2009), 6, pp. 1021-1043
[10] Ibrahim, N., et al., On Dual-Loop Model-Free Adaptive Iterative Learning Control and its Application, Journal of Process Control, 147 (2025), pp. 103376
[11] Estrada, A., et al., Enhancing Vapor Compression Refrigeration Systems Efficiency Via Two-Phase Length and Superheat Evaporator MIMO Control, Processes, 12 (2024), 8, pp
[12] Li, S., et al., Design of Fractional Order PID Controller Using IMOPSOA for Degree of Superheating of Refrigerant at Evaporator Outlet, Proceedings of the Institution of Mechanical Engineers, Part I: Journal of Systems and Control Engineering, 239 (2025), 4, pp. 574-591
[13] Hu, H. T., et al., A Self-Tuning Fuzzy Logic Controller for Superheat of Evaporator by Using Electronic Expansion Valve, Proceedings, 2013 Sixth International Symposium on Computational Intelligence and Design, Hangzhou, 2013, pp. 277-280
[14] Tesfay, M., et al., Adaptive-Model Predictive Control of Electronic Expansion Valves with Adjustable Setpoint for Evaporator Superheat Minimization, Building and Environment, 133 (2018), pp. 151-160
[15] Maia, A.A.T., et al., Superheating Control Using an Adaptive PID Controller, HVAC&R Research, 20 (2014), 4, pp. 424-434
[16] Elliott, M., Rasmussen, B.P., Evaporator Superheat Regulation via Emulation of Semi-Active Flow Control, Proceedings, ASME 2009 Dynamic Systems and Control Conference, Volume 2, Hollywood, California, USA, 2009, pp. 465-472
[17] Hu, Y., et al., Influence of Feed Flow Rate and Feed Concentration on the Ammonia Absorption Refrigeration System, Thermal Science, 29 (2025), 6B, pp. 4587-4598
[18] Sathyabhama, A., Ashok, B., Thermodynamic Simulation of Ammonia-Water Absorption Refrigeration System, Thermal Science, 12 (2008), 3, pp. 45-53
[19] Franco, S.S., et al., Thermal Analysis and Development of PID Control for Electronic Expansion Device of Vapor Compression Refrigeration Systems, Applied Thermal Engineering, 206 (2022), pp. 118130
[20] Wei, H., et al., Research on the Intelligent Control Strategy of Pressurizer Pressure in PWRs Based on a Fuzzy Neural Network PID Controller, Nuclear Engineering and Design, 433 (2025), pp. 113875
[21] Moreno, J.A., Asymptotic Tracking and Disturbance Rejection of Time-Varying Signals with a Discontinuous PID Controller, Journal of Process Control, 87 (2020), pp. 79-90
[22] Zhai, Y., et al., Intelligent PID Controller Based on Deep Reinforcement Learning, Proceedings, 2024 8th International Conference on Robotics, Control and Automation (ICRCA), Shanghai, 2024, pp. 343-348
[23] Dubois, D., Prade, H., What are Fuzzy Rules and How to Use them, Fuzzy Sets and Systems, 84 (1996), 2, pp. 169-185
[24] Zhou, Z., et al., Simulation analysis of steam drum water level system based on fuzzy PID control, Proceedings, 2024 3rd International Conference on Energy and Power Engineering, Control Engineering (EPECE), Chengdu, 2024, pp. 159-163
[25] Abbasi, S.A., Miller, A., MDEWMA Chart: An Efficient and Robust Alternative to Monitor Process Dispersion, Journal of Statistical Computation and Simulation, 83 (2013), 2, pp. 247-268
PDF VERSION [DOWNLOAD]
Experimental performance of a combined throttling device with stepper motor and needle valve in an ammonia-water absorption refrigeration system

© 2026 Society of Thermal Engineers of Serbia. Published by the Vinča Institute of Nuclear Sciences, National Institute of the Republic of Serbia, Belgrade, Serbia. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International licence