US 8,136,364 B2 · Refrigerant system with expansion device bypass

Abstract

A refrigerant system is provided with an expansion device that may be a thermostatic expansion device or an electronic expansion device. A bypass line selectively allows a portion of refrigerant to bypass the expansion device and to flow through a fixed restriction expansion device such as an orifice positioned in parallel configuration with the main expansion device. A valve selectively enables or blocks refrigerant flow through this bypass line depending on the volume of refrigerant required to circulate through the refrigerant system as defined by environmental conditions and a mode of operation. The valve can be a simple shutoff valve or a three-way valve selectively allowing or blocking refrigerant flow through a particular refrigerant line or lines. In one embodiment, the expansion device is the main expansion device for the refrigerant system. In the other embodiment, the expansion device is a vapor injection expansion device for expanding refrigerant for performing an economizer function. The present invention allows the use of a smaller expansion device, which can be more precisely controlled, while still allowing the accommodation of higher refrigerant mass flow when necessary.

Claims19

Dependent claims

A refrigerant system comprising:

a compressor, said compressor compressing refrigerant and delivering it downstream to a first heat exchanger, refrigerant passing from said first heat exchanger through a first expansion device positioned downstream of the first heat exchanger, through a second heat exchanger positioned downstream of said first expansion device, and from said second heat exchanger back to said compressor;
and
a bypass line for selectively bypassing at least a portion of refrigerant around said first expansion device, said bypass line including an auxiliary expansion device to provide expansion of the refrigerant flowing through said bypass line, and an isolation member on said bypass line for selectively blocking flow of refrigerant to the auxiliary expansion device on said bypass line, said isolation member allowing selective flow of refrigerant through said bypass line from a point upstream of said first expansion device, and then back into a refrigerant flow line upstream of the connection to said second heat exchanger such that said bypass line and said first expansion device both deliver refrigerant to said second heat exchanger.

Dependencies are inferred from the claim text.

Refrigerant system with expansion device bypass

Life of this patent

Refrigerant system with expansion device bypass

Life of this patent

Abstract

Claims19