Energies (Jun 2016)

Slide Valves for Single-Screw Expanders Working Under Varied Operating Conditions

  • Yuting Wu,
  • Ruiping Zhi,
  • Biao Lei,
  • Wei Wang,
  • Jingfu Wang,
  • Guoqiang Li,
  • Huan Wang,
  • Chongfang Ma

DOI
https://doi.org/10.3390/en9070478
Journal volume & issue
Vol. 9, no. 7
p. 478

Abstract

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This paper fully describes the working principle of slide valves in single-screw expanders (SSEs). A geometric analysis of suction and volume ratio slide valves is presented to determine the relations between volume ratio, suction closure volume, discharge opening volume and slide valves displacement. An organic Rankine cycle (ORC) thermodynamic model with SSE integrated with slide valves is developed to analyze the power output of SSE and the net power output of ORC system and variation law of slide valves displacement. Analysis of a typical ORC system under changing operating conditions shows that the power output of the expander and the net output power of the ORC system with slide valves are much better than those without slide valves. When the condensing temperature is 40 °C and the waste availability is 80 kW, the increase in output power and net output power are approximately 3.4 kW and 5 kW, respectively. The presented geometric analysis of slide valves and the thermodynamic model integrated with slide valves can be used to provide a theoretical and technical basis for designing the slide valves of SSEs and the control strategies of slide valves under varied operating conditions.

Keywords