摘要 |
An electronic variable orifice tube suitable for use as an expansion valve in a refrigeration system providing two flow rates in response to electronic control signals comprises a bodytube, a restrictor mounted within the bodytube and defining a first flowpath. A plunger is translatably positioned within the bodytube in proximity to the restrictor and defines a second and a third flowpath. A valve actuator is functionally coupled to the plunger to translate the plunger within the bodytube to transition between the two flow rates. A high flowpath is formed through the bodytube by the first, second, and third flowpaths, and a low flowpath is formed through the bodytube by the first and the second flowpaths to the exclusion of the third flowpath. A solenoid may be used as the valve actuator and a spring may be employed to return the plunger to its quiescent state when the solenoid is not energized. |