THERMAL SCIENCE

International Scientific Journal

Authors of this Paper

External Links

Long Ni

,

Jijin Wang

,

Dehu Qv

,

Qiang Cai

,

Yang Yao

PERFORMANCE IMPROVEMENT OF WATER-COOLED SCREW CHILLER UNDER PART LOAD OPERATION CONDITIONS BY THE PARALLELING THROTTLE MECHANISM

ABSTRACT
Currently, water-cooled screw chiller is widely applied in commercial and industrial buildings, and the energy consumption of water chiller even could cover 70% of air-conditioning energy consumption in the most adverse operating conditions. Moreover, a number of chillers are running at a low rate under part-load state. In order to reduce the energy consumption of water-cooled screw chillers under part-load state, the paper presents the paralleling throttle mechanism. Through experimental study, under part-load state, it can be found that the by-pass tube diameter Ø16 has the most positive effect on the performance of water-cooled screw chiller in four by-pass tube diameters. The oblique access mode is better than the vertical access mode, while the spiral access mode has little influence on the chiller performance. Because of paralleling throttle using, the exergetic loss of the evaporator and chiller is able to be reduced by 3.4%-15.5% and 0-6.7%, respectively. Meanwhile, the coefficient of performance of chiller can be enhanced by 0.2%-1.6%, and discharge temperature can be reduced by 0.4-2.7°C. In addition, the economic and environmental benefits of the advanced water-cooled screw chiller are more evident than the conventional water-cooled screw chiller's.
KEYWORDS
Water-cooled screw chiller, performance improvements, paralleling throttle mechanism, exergetic analysis
PAPER SUBMITTED: 2017-10-11
PAPER REVISED: 2017-11-27
PAPER ACCEPTED: 2017-11-28
PUBLISHED ONLINE: 2018-02-18
DOI REFERENCE: https://doi.org/10.2298/TSCI171011043N
CITATION EXPORT: view in browser or download as text file
THERMAL SCIENCE YEAR 2018, VOLUME 22, ISSUE Supplement 2, PAGES [S585 - S596]
REFERENCES
  1. Lam, J.C., et al., An analysis of electricity end-use in air-conditioned office buildings in Hong Kong. Building and Environment, 38 (2003), pp. 493-498
  2. Fong, K.F., et al., Investigation on variable flow control in existing water-cooled chiller plant of high-rise commercial building in subtropical climate. HVAC&R Research, 20 (2014), pp. 51-60
  3. Allen, J.J., Hamilton, J. F., Steady-state reciprocating water chiller models. Ashrae Transactions, 89 (1983), pp. 398-407
  4. Goto, Y., Yoshida, H., Development of optimal operation of thermal storage tank and the validation by simulation. IBPSA Building Simulation, 23 (1999), 6, pp. 345-356
  5. Liu, J.H., et al., A new model of screw compressor for refrigeration system simulation. International Journal of Refrigeration, 35 (2012), pp. 861-870
  6. Fu, L., et al., Steady-state simulation of screw liquid chillers. Applied Thermal Engineering, 22 (2002), pp. 1731-1748
  7. Zhao, L.X., et al., Steady-state hybrid modeling of economized screw water chillers using polynomial neural network compressor model. International Journal of Refrigeration, 33 (2010), pp. 729-738
  8. Lee, T.S., et al., Evaluation of the suitability of empirically-based models for predicting energy performance of centrifugal water chillers with variable chilled water flow. Applied Energy, 93 (2012), pp. 583-595
  9. Lee, D.Y., et al., Experimental investigation on the drop-in performance of R407C as a substitute for R22 in a screw chiller with shell-and-tube heat exchangers. International Journal of Refrigeration, 25 (2002), pp. 575-585
  10. Yu, F.W., Chan, K. T., Experimental determination of the energy efficiency of an air-cooled chiller under part load conditions. Energy, 30 (2005), pp. 1747-1758
  11. Yu, F.W., Chan, K. T., Environmental performance and economic analysis of all-variable speed chiller systems with load-based speed control. Applied Thermal Engineering, 29 (2009), pp. 1721-1729
  12. Yu, F.W., Chan, K. T., Improved energy management of chiller systems by multivariate and data envelopment analyses. Applied Energy, 92 (2012), pp. 168-174
  13. Seo, B.M., Lee, K. H., Detailed analysis on part load ratio caracteristics and cooling energy saving of chiller staging in an office building. Energy and Building, 119 (2016), pp. 309-322
  14. Gang, W., et al., Robust optimal design of building cooling systems considering cooling load uncertainty and equipment reliability. Applied Energy, 159 (2015), pp. 265-275
  15. Chua, K., et al., Achieving better energy-efficient air conditioning a review of technologies and strategies. Applied Energy, 104 (2013), pp. 87-104
  16. Wang, F.J., et al., Energy conservation for chiller plants by implementation of variable speed driven approach in an industrial building. Energy Procedia, 61 (2014), pp. 2537-2540
  17. Zhang, X.S., et al., A novel energy-saving method for air-cooled chiller plant by parallel connection. Applied Thermal Engineering, 26 (2006), pp. 2012-2019
  18. Mei, K., et al., Influence of variable-volume on performance of cooling coil. Journal of Chemical Industry and Engineering, 59 (2008), pp. 109-113
  19. Jiang, Y., et al., Principle of heat thermal-hygro environment building process, China Architecture & Building Press, Beijing, CHN, 2016
PDF VERSION [DOWNLOAD]
Performance improvement of water-cooled screw chiller under part load operation conditions by the paralleling throttle mechanism

© 2024 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