Refrigeration – Reversible – i.e. – heat pump – With flow control or compressor details
Reexamination Certificate
1999-11-19
2001-03-13
McDermott, Corrine (Department: 3744)
Refrigeration
Reversible, i.e., heat pump
With flow control or compressor details
C062S324100, C062S511000
Reexamination Certificate
active
06199399
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention is directed to a bi-directional refrigerant expansion and metering valve for use in a minisplit air conditioner, a heat pump system, or an air conditioning system. The bi-directional refrigerant expansion and metering valve is an alternative to metering valves, to capillary tube and to other expansion valve concepts.
Present heat pump systems either require two metering valves with differing diameters and differing short tube length to diameter ratios in order to properly operate, or fail to fully utilize bi-directional valves. The use of two metering valves is subsequently discussed with regard to
FIGS. 1A and 1B
. Most bi-directional metering valves are complex spring loaded or shuttle arrangements such as are shown in U.S. Pat. Nos. 5,029,454 to Eisberg, 5,052,192 to Drucker, and 5,038,579 to Drucker. The spring or shuttle changes position to compensate for changes in flow direction. However, these patents fail to recognize that controlling the geometry of both ends can control the flow rate entering those respective ends. The bi-directional valve of U.S. Pat. No. 5,345,780 recognizes the advantages of controlling the approach to one end of a short tube restrictor but fails to appreciate the advantages of controlling both approaches.
It would be advantageous to minimize the number and type of refrigerant expansion and metering components.
SUMMARY OF THE INVENTION
It is an object, feature and advantage of the present invention to solve the problems of prior art metering valves.
It is a further object, feature and advantage of the present invention to eliminate previous metering valves in favor of a bi-directional system that has a reduced cost and a reduced number of components.
It is an object, feature and advantage of the present invention to provide proper metering for a given short tube length to diameter ratio.
It is a further object, feature and advantage of the present invention to have a metering arrangement with no moving parts and only a single short tube restrictor device.
It is a further object, feature and advantage of the present invention to provide a bi-directional refrigerant metering and expansion valve which includes a short tube restrictor and which controls the approaches to each end of the restrictor.
It is a further object, feature and advantage of the present invention to differentiate the approaches so as to cause differing flow rates through the short tube restrictor depending upon the direction of access.
The present invention provides a bi-directional refrigerant metering and expansion valve. The bi-directional valve comprises a body; a short tube portion in the body, a heating inlet portion and a cooling inlet portion. The short tube portion includes a tubular portion having a short tube length, a short tube diameter, and a pre-selected short tube length to short tube diameter ratio and includes first and second ends interconnected by the tubular portion. The heating inlet portion is connected to the first end of the short tube portion, and includes a heating inlet chamfer having a first length and a first angle of a first magnitude. The cooling inlet portion is connected to the second end of the short tube portion, and includes a cooling inlet chamfer having a second length and a cooling inlet angle of a second magnitude. The second length is greater than the first length.
The present invention also provides a method of metering refrigerant flow in expansion in a heat pump system. The method comprises the steps of: chamfering a first end of a bi-directional metering and expansion device to a first set of requirements to produce a first chamfer angle; chamfering a second end of the metering device to a second set of requirements to produce a second chamfer angle less than the first chamfer angle; operating in a heating mode wherein refrigerant flows into the first end and out the second end; and operating a cooling mode wherein refrigerant flows into the second end and out the first end.
REFERENCES:
patent: 4311020 (1982-01-01), Tobin et al.
patent: 4445343 (1984-05-01), McCarty
patent: 4653291 (1987-03-01), Moeller et al.
patent: 4793150 (1988-12-01), Wattley et al.
patent: 5029454 (1991-07-01), Eisberg
patent: 5031416 (1991-07-01), Drucker et al.
patent: 5038579 (1991-08-01), Drucker
patent: 5052192 (1991-10-01), Drucker
patent: 5085058 (1992-02-01), Aaron et al.
patent: 5186021 (1993-02-01), Keller
patent: 5345780 (1994-09-01), Aaron et al.
patent: 5689972 (1997-11-01), Schuster et al.
patent: 5806326 (1998-09-01), Watanabe et al.
patent: 5808209 (1998-09-01), Zielinska et al.
patent: 5813244 (1998-09-01), Palmer
patent: 5966960 (1999-10-01), Cummings et al.
patent: 6006544 (1999-12-01), Watanabe et al.
American Standard Inc.
Beres William J.
Ferguson Peter D.
McDermott Corrine
Norman Marc
LandOfFree
Bi-directional refrigerant expansion and metering valve does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Bi-directional refrigerant expansion and metering valve, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Bi-directional refrigerant expansion and metering valve will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2492595