Bi-flow expansion device

• US 5,085,058 A
• Filed: 07/18/1990
• Issued: 02/04/1992
• Est. Priority Date: 07/18/1990
• Status: Expired due to Fees

• Current Assignee: United States Secretary of Commerce
• Original Assignee: THE GOVERNMENT OF THE UNITED STATES OF AMERICA, AS REPRESENTED BY THE SECRETARY OF COMMERCE
• Inventors: Aaron, David A., Domanski, Piotr A.
• Primary Examiner(s): Makay, Albert J.
• Assistant Examiner(s): SOLLECITO, JOHN M
• Application Number:
  US07/553,831
• Time in Patent Office: 566 Days
• Field of Search: 62/324.6, 62/324.1, 62/528, 62/222, 62/511, 138/44
• US Class Current: 62/324.6
• CPC Class Codes: F25B 2500/01 Geometry problems, e.g. for reducing size
• CPC Class Codes: F25B 41/38 specially adapted for reversible cycles, e.g. bidirectional expansion restrictors
• CPC Class Codes: F25B 41/385 Dispositions with two or more expansion means arranged in parallel on a refrigerant line leading to the same evaporator
• CPC Class Codes: Y10T 137/7847 With leak passage

Abstract

A bi-flow expansion device for a heat pump or other apparatus where fluid avel is reversed with different required flow rates in each direction. The device comprises a tubular member mounted in a refrigerant line and having non-symmetrical entrance-exits at the ends of the tubular member for changing the mass flow rate of refrigerant through the expansion device when the direction of refrigerant flow is changed.

Claims

1. A bi-flow expansion device for refrigerant in a heat pump having a cooling mode in which refrigerant flows through said expansion device in a first direction, and a heating mode in which refrigerant flows through said device in a second direction, said expansion device comprising a tubular member having a first refrigerant entrance-exit means at a first end, said first entrance-exit means facing the direction from which refrigerant flows when said heat pump is in the cooling mode, a second refrigerant entrance-exit means at a second end, said second entrance-exit means facing the direction from which refrigerant flows when said heat pump is in the heating mode, at least one passage for refrigerant extending between said first and second entrance-exit means, and means for changing the rate of flow of refrigerant through said expansion device upon a change in direction of flow of refrigerant between said first and second entrance-exit means, said means for changing the rate of flow of refrigerant comprising a less obstructive opening to refrigerant flow at said first entrance-exit means than at said second entrance-exit means.

2. A bi-flow expansion device according to claim 1 wherein said entrance-exit means at the first end of said tubular member has a decreasing cross-sectional area in the direction toward said second end, and said second end comprises a sharp-edged entrance-exit.

3. A bi-flow expansion device according to claim 2 wherein said entrance-exit means at said first end is cone-shaped.

4. A bi-flow expansion device according to claim 2, wherein said entrance-exit means at said first end is in the form of a surface of revolution defined by rotating a curved line about an axis.

5. A bi-flow expansion device according to claim 1 wherein said entrance-exit means at the first end of said tubular member has a decreasing cross-sectional area in the direction toward said second end, and said second end comprises a re-entrant entrance-exit.

6. A bi-flow expansion device according to claim 5 wherein said entrance-exit means at said first end is cone-shaped.