Danfoss A/s

Bjarke Skovgard Dam

Georg Fosel

Louis Sullivan

Carsten Molhede Thomsen

Hans Kurt Petersen

Jens Pawlik

An expansion valve () for a vapour compression system, the valve () comprising a first valve part () having an outlet orifice () and a piston () movable inside the outlet orifice () in response to a differential pressure across the expansion valve (), controlling a fluid flow through the first valve part (). A cross-sectional flow area of the outlet orifice () between a circumference at an inner surface of the outlet orifice () and a circumference at an outer surface of the piston () varies as a function of the position of the piston () relative to the outlet orifice (). A first cross-sectional flow area is defined at a first differential pressure, and a second cross-sectional flow area is defined at a second differential pressure, where the first cross-sectional flow area is smaller than the second cross-sectional flow area, and the first differential pressure is lower than the second differential pressure.

Expansion valve with a variable orifice area

An expansion valve () for a vapour compression system, the valve comprising a first valve part () having an outlet orifice () and a piston () movable inside the outlet orifice () in response to a differential pressure across the expansion valve (), controlling a fluid flow through the first valve part (), via a forward fluid passage through the first valve part (). The piston () has different cylindrical shapes stepwise along a longitudinal extension of the piston (), the piston () defining a first cross-sectional area along a first longitudinal extension and a second-cross sectional area along a second longitudinal extension, the first cross-sectional area being smaller than the second-cross sectional area. The first longitudinal extension is in the outlet orifice () at a first differential pressure and the second longitudinal extension is in the outlet orifice () at a second differential pressure, the first differential pressure being lower than the second differential pressure.

Expansion valve with a two-step variable orifice area

An expansion valve () for a vapor compression system, the valve () comprising a first valve part () having an outlet orifice () and a piston () movable inside the outlet orifice () in response to a differential pressure across the expansion valve (), controlling a fluid flow through the valve (). The piston () comprises a stop element () at an outlet end () of the piston () and mechanical forcing means () to force the piston () towards a position in which the stop element () is brought into abutment with a valve seat () of the first valve part (). A differential pressure below a predefined threshold value causes the stop element () of the piston () to abut the valve seat () of the first valve part (), preventing fluid flow through the first valve part (), via the forward fluid passage.

Expansion valve comprising a stop element

A flow control valve () for a refrigeration system is disclosed. The valve () comprises a valve port () having a substantially cylindrical inner circumference arranged to receive a protruding portion of a valve member (). The valve member () comprises a protruding portion having a substantially cylindrical outer circumference corresponding to the inner circumference of the valve port (), said protruding portion also having at least one fluted part (), said at least one fluted part () defining fluid passage along the at least one fluted part () when the valve member () is in the open position. The valve member () is provided with at least one first fluid passage () extending through the valve member () between a second valve chamber () and a pressure balancing chamber (), and at least one second fluid passage () establishing a fluid connection between a first valve chamber () and the first fluid passage (). The second fluid passage () has an opening arranged on the substantially cylindrical part of the protruding portion of the valve member (). The invention allows the pressure of the balancing chamber () to be adjusted independently of the primary flow through the valve (), via the fluted parts(s) ().

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Almind, Denmark

Bjarke Skovgard Dam