Bidirectional flow control device

• US 5,813,244 A
• Filed: 08/18/1997
• Issued: 09/29/1998
• Est. Priority Date: 11/25/1996
• Status: Expired due to Fees

• Current Assignee: Carrier Corporation (Carrier Global Corporation)
• Original Assignee: Carrier Corporation (Carrier Global Corporation)
• Inventors: Palmer, John M.
• Primary Examiner(s): Sollecito, John M.
• Application Number:
  US08/912,729
• Time in Patent Office: 407 Days
• Field of Search: 62/324.6, 62/504, 62/511, 62/525, 138/44, 138/45
• US Class Current: 62/324.6
• CPC Class Codes: F25B 41/38 specially adapted for reversible cycles, e.g. bidirectional expansion restrictors

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. One end wall of the device has a first metering orifice. The other end wall has one or more bypass openings. Disposed within the chamber is a free piston having a rod portion extending therefrom and disposed within the first metering orifice. The free piston and rod portion has a second metering orifice axially extending therethrough and in axial alignment with the first metering orifice. Fluid flow through the device urges piston against the end wall in the direction of fluid flow. In one position, fluid flowing into the device passes through the bypassing the opening(s) of the opposite end wall. Fluid flowing out of the device passes through the second metering orifice in the piston. Upon a flow reversal, the piston is urged against the opposite end wall. In this position, fluid flows through the metering orifice in the end wall then flows in serial fashion through the metering orifice in the piston. The device is adapted for use in a reversible vapor compression air conditioning system. In this application, the metering orifice in the end wall is sized to provide proper metering for heating mode operation. The metering orifice in the piston, in combination with the metering orifice in the end wall, is sized to provide proper metering for cooling mode operation.

Claims

1. A device for controlling the flow of a fluid in a conduit both 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 at least one bypass opening axially extending therethrough and in communication with the internal chamber;

the second end wall having a first metering orifice axially extending therethrough;

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;

a rod portion extending from the second end face slidably disposed within the first metering orifice;

the piston and rod portion further having a second metering orifice extending therethrough and in axial alignment with the first metering orifice;

whereby the piston meters flow-through the second metering orifice in a first fluid flow direction and meters flow serially through the first orifice and thence the second orifice in a second fluid flow direction and permits the fluid to flow into the conduit.

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

3. 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 at least one bypass opening axially extending therethrough and in communication with the internal chamber;

the second end wall having a first metering orifice axially extending therethrough;

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;

a rod portion extending from the second end face slidably disposed within the first metering orifice;

the piston and rod portion further having a second metering orifice extending therethrough and in axial alignment with the first metering orifice;

whereby the piston meters flow through the second metering orifice in a first fluid flow direction and meters flow serially through the first orifice and thence second orifice in a second fluid flow direction and permits the fluid to flow into the supply line.

4. A reversible vapor compression air conditioning system as set forth in claim 3 wherein the supply line comprises the elongated body.