Development of a virtual EXV flow sensor for applications with two-phase flow inlet conditions

作者：Bach Christian K^*; Groll Eckhard A; Braun James E; Horton W Travis

来源：International Journal of Refrigeration, 2014, 45: 243-250.

DOI：10.1016/j.ijrefrig.2014.05.014

• Virtual flow sensor
• EXV
• Hybrid control
• Two-phase flow expansion
• Evaporator

In conventional vapor compression systems, electronic expansion valves (EXVs) are used for refrigerant flow control. In addition, the EXV control signal can be used along with a model and measurements of boundary conditions to provide a virtual sensor for refrigerant mass flow rate as outlined by Kim and Braun (2012). For typical single-phase inlet conditions, models for characterizing the relationship between the inlet and outlet conditions, the opening, and the mass flow rate have been extensively studied, e.g. by Park et al. (2007), and semi-empirical as well as empirical correlations have been developed. However, two-phase inlet conditions can exist at low refrigerant charge, or for certain applications such as when balancing valves are used in a hybrid control scheme as proposed by Kim et al. (2008). This paper presents a continuous correlation that can be used for both two-phase and subcooled valve inlet conditions.

• 出版日期2014-9