Implementation of impedance sensors for detection and determination of void fraction at the entrance of an expansion valve of the refrigeration cycle

• Grant number: 05/01456-1
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: January 01, 2006
• End date: December 31, 2007
• Field of knowledge: Engineering - Mechanical Engineering
• Principal Investigator: José Roberto Simões Moreira
• Grantee: Marcelo da Silva Rocha
• Host Institution: Escola Politécnica (EP). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

In this work it will be developed an impedance sensor, and it will be implanted at the entrance of an expansion valve (electronic and/or thermostatic) of a cooling system for sensing and, possibly, determining the void fraction present at the entrance of that device, with the objective of producing an electrical signal which will be available for system controling purposes to avoid mal operation conditions of the cycle. For that it will be mounted a test rig facility containing a basic cooling cycle with all necessary instruments, i.e., sensors of pressure, temperature and flow, and a flow visualization section. The behavior of the expansion valve will be analyzed by standard measuring and viewing techniques. The results will be analyzed for the verification of a possible request for intellectual rights.