Refrigerant Expansion Valve Produced with Silicon Processing Technology
Original Publication Date: 2002-Aug-26
Included in the Prior Art Database: 2005-Jun-09
National Institute of Standards and Technology
David Yashar: INVENTOR [+2]
A vapor compression system includes a refrigerant flow restrictor located between the condenser and the evaporator. The function of the restrictor is to establish a pressure (and temperature) difference between the condenser and evaporator so that the transfer of heat from the low-temperature to high-temperature reservoir may occur. It is beneficial for the system's coefficient of performance (COP) that the refrigerant restrictor offers variable flow restriction. This allows the system to adjust in response to a changing refrigerant mass flow rate pumped by the compressor due to changing temperatures of the heat sink and source. Such variable-restriction restrictors (thermostatic or electronic expansion valves (TYVs or EEVs)) have been used for years in rather large-capacity vapor compression systems; however, this type of device has never been cost effective in smaller systems.