Bidirectional meterd flow control device

• US 5,706,670 A
• Filed: 11/25/1996
• Issued: 01/13/1998
• Est. Priority Date: 11/25/1996
• Status: Expired due to Term

• Current Assignee: Carrier Corporation (Carrier Global Corporation)
• Original Assignee: Carrier Corporation (Carrier Global Corporation)
• Inventors: Voorhis, Roger J.
• Primary Examiner(s): Sollecito, John M.
• Application Number:
  US08/758,130
• Time in Patent Office: 414 Days
• Field of Search: 62/324.1, 62/324.6, 137/493, 137/493.8, 137/493.9, 137/513.5
• US Class Current: 62/324.6
• CPC Class Codes: F25B 41/38 specially adapted for reversible cycles, e.g. bidirectional expansion restrictors
• CPC Class Codes: Y10T 137/7779 Axes of ports parallel

Abstract

A device for controlling or metering fluid flow in either direction through a conduit. The device comprises an elongated body having two end walls forming an internal chamber therebetween. Disposed within the chamber is a free piston having an axial passageway extending therethrough. One end wall of the device has a metering orifice and one or more bypass openings. The other end wall also has a metering orifice and one or more bypass openings. Fluid flow through the device urges piston against the end wall in the direction of fluid flow. In this position, the piston blocks the bypass opening(s) in the end wall in the direction of fluid flow. Fluid flowing into the device can pass through the bypassing the opening(s) of the opposite end wall. Fluid flowing out of the device must pass through the metering orifice in the end wall in the direction of the fluid flow. Upon a flow reversal, the piston is urged against the opposite end wall. In this position, fluid will flow through the metering orifice in the end wall of the fluid direction and through the bypass opening(s) in the opposite end wall. The device is adapted for use in a reversible vapor compression air conditioning system. In this application, the sizes of the two orifices are different so that one can provide proper metering for cooling mode operation and the other can provide proper metering for heating mode operation.

Claims

1. A device for controlling the flow of a fluid in a conduit in a first and second direction comprising:

an elongated body having a first end wall and a second end wall defining an internal chamber therebetween;

the first end wall having a metering orifice axially extending therein and in communication with the internal chamber and further having a bypass opening axially extending therein and in communication with the internal chamber;

the second end wall having a metering orifice axially extending therein, in communication with the internal chamber and in axial alignment with the metering orifice of the first end wall and further having a bypass opening axially extending radially outward from the metering orifice and in communication with the internal chamber;

a foreshortened piston disposed in the internal chamber and being slidably movable axially in response to fluid flow, the piston having a first end face parallel to the first end wall and a second end face parallel to the second end wall, and further having a passageway extending therethrough and in axial alignment with the metering orifice of each end wall;

whereby the piston closes off the bypass opening and establishes communication through the metering orifice in the direction of the fluid flow.

2. The device as set forth in claim 1 wherein the metering orifice disposed in the first end wall is of a different size than metering orifice disposed in the second end wall.

3. The device as set forth in claim 1 wherein the first and second end walls as disposed within the conduit.

4. A reversible vapor compression air conditioning system having a compressor, a first heat exchanger and a second heat exchanger being selectively connected to the compressor, switching means for selectively connecting the inlet and discharge side of the compressor between the exchanger and a refrigerant supply line for delivering refrigerant from one exchanger to the other, comprising:

a flow control device mounted in the supply line between each exchanger having an elongated body having a first end wall and a second end wall defining an internal chamber therebetween;

the first end wall having a metering orifice axially extending therein and in communication with the internal chamber and further having a bypass opening axially extending therein and in communication with the internal chamber;

the second end wall having a metering orifice axially extending therein, in communication with the internal chamber and in axial alignment with the metering orifice of the first end wall and further having a bypass opening axially extending radially outward from the metering orifice and in communication with the internal chamber;

a foreshortened piston disposed in the internal chamber and being slidably movable axially in response to fluid flow, the piston having a first end face parallel to the first end wall and a second end face parallel to the second end wall, and further having a passageway extending therethrough and in axial alignment with the metering orifice of each end wall;

whereby the piston closes off the bypass opening and establishes communication through the metering orifice in the direction of the fluid flow and permits the fluid to flow into the supply line.

5. A reversible vapor compression air conditioning system as set forth in claim 4 wherein the supply line comprises the elongated body.