HK1176395B - Receiver with flow metering device - Google Patents

Description

Receiver with flow metering device

Technical Field

The present invention relates generally to refrigerant receivers, and more particularly to refrigerant receivers including flow metering devices integrally formed therewith.

Background

Refrigerant vapor compression systems are well known in the art and are commonly used to condition air to be supplied to climate controlled comfort zones of dwellings, office buildings, hospitals, schools, hotels and other facilities. Refrigerant vapor compression systems are also commonly used to refrigerate air supplied to display cases, point of sale, freezer cabinets, cold rooms or other perishable/frozen product storage areas of commercial establishments. Refrigerant vapor compression systems are also commonly used in transport refrigeration systems to refrigerate the air in a temperature controlled cargo space supplied to trucks, trailers, containers, or similar devices used to transport perishable/frozen products by truck, rail, ship, intermodal transportation, or the like.

Such refrigerant vapor compression systems include a compression device, a condenser heat exchanger, an evaporator expansion device (e.g., an electronic expansion valve or a thermal expansion valve), and an evaporator heat exchanger disposed in series refrigerant flow relationship in a refrigerant flow circuit in accordance with a refrigeration cycle. Many refrigerant vapor compression systems also include a receiver interposed in the refrigerant circuit, typically downstream with respect to refrigerant flow of the condenser and upstream with respect to refrigerant flow of the evaporator expansion device. The receiver functions to collect liquid refrigerant passing from the condenser heat exchanger and to store excess refrigerant. Conventional receivers typically include an inlet port through which refrigerant enters the receiver and a single outlet through which liquid refrigerant may exit the receiver. A discharge valve (e.g., a check valve) is typically mounted to the single receiver outlet to control the flow of refrigerant discharged from the receiver back into the refrigerant circuit upstream of the evaporator expansion valve. In addition, many refrigerant vapor compression systems include a refrigerant filter-drier interposed in the refrigerant flow circuit downstream with respect to refrigerant flow of the receiver and upstream with respect to refrigerant flow of the evaporator expansion valve. The filter-dryer functions to remove foreign substances and moisture from the refrigerant flowing therethrough. U.S. patent No.7,571,622 incorporates an in-line collector/filter-dryer unit disposed between two heat exchangers of a reversible refrigeration system.

In some refrigeration cycles, the refrigerant vapor compression system further includes a liquid injection line establishing refrigerant flow communication between the receiver and the suction side of the compression device. When a liquid injection line is present, a portion of the liquid refrigerant discharged from the single outlet of the receiver via the discharge valve passes through the liquid injection line to reenter the refrigerant flow circuit downstream with respect to refrigerant flow of the evaporator heat exchanger and upstream with respect to refrigerant flow of the suction inlet of the compression device, thereby bypassing the evaporator heat exchanger. A flow metering valve is disposed on the liquid injection line such that the controller can selectively meter the flow of liquid refrigerant through the liquid injection line for compressor capacity control and/or compressor discharge temperature control. Conventionally, the flow metering valve is an electronic expansion valve having a selectively variable flow area or a solenoid valve having a relatively small fixed area metering orifice, which is a fixed area orifice having a port diameter of less than two millimeters.

Disclosure of Invention

A receiver is provided for collecting refrigerant flowing through the refrigerant flow circuit. The housing defines an enclosed volume establishing a refrigerant collection reservoir and has an inlet, a first outlet, and a second outlet. A refrigerant metering device is disposed in the enclosed volume and is operatively associated with the second outlet to control a flow of refrigerant discharged through the second outlet. In one embodiment, the refrigerant metering device is a capillary tube metering device. In one embodiment, the capillary tube metering device includes a capillary tube forming a multi-turn coil defining an inner wall of the housing.

In one embodiment, the housing of the receptacle comprises a cylindrical shell having a first end cap closure and a second end cap closure collectively defining the enclosed volume. In one embodiment, the inlet port opens into the enclosed volume through the first end cap closure of the housing and the second outlet port opens through the outer shell at a location remote from the first end cap closure.

The receiver may also include a filter/dryer disposed within the enclosed volume at a location downstream of the inlet and upstream of both the first outlet and the second outlet. A refrigerant flow control valve may be mounted to the housing external to the enclosed volume and operatively associated with the first outlet. In one embodiment, the refrigerant flow control valve comprises a check valve.

A refrigerant vapor compression system comprising: a compression device, a condenser heat exchanger, an evaporator expansion device, and an evaporator heat exchanger disposed in a refrigerant flow circuit in series refrigerant flow relationship in a refrigeration cycle; a receiver having a housing defining an enclosed volume establishing a refrigerant collection reservoir, the housing having an inlet, a first outlet, and a second outlet, the first inlet in refrigerant flow communication with the condenser heat exchanger and the first outlet in refrigerant flow communication with the evaporator expansion device; a refrigerant metering device disposed in the enclosed volume of the housing and operatively associated with the second outlet to control a flow of refrigerant discharged through the second outlet; and a refrigerant injection line establishing refrigerant flow communication between the second outlet and the refrigerant circuit at a location upstream with respect to refrigerant flow of the compression device and downstream with respect to refrigerant flow of the evaporator heat exchanger. In one embodiment, the refrigerant metering device is a capillary tube metering device.

The refrigerant vapor compression system may further include a refrigerant flow control valve disposed on the refrigerant injection line. In one embodiment, the flow control valve disposed on the refrigerant injection line comprises a fixed orifice flow control valve that is selectively positionable in an open position or a closed position. In one embodiment, the fixed orifice solenoid valve has a fixed orifice with a flow opening diameter of at least two millimeters.

Drawings

For a further understanding of the invention, reference will be made to the following detailed description, to be read in conjunction with the accompanying drawings, in which:

FIG. 1 is a schematic illustration of an exemplary embodiment of a refrigerant vapor compression system according to the present invention; and

FIG. 2 is a perspective view, partially in section, of an exemplary embodiment of a receiver having a flow metering device integrally formed therein according to the present invention.

Detailed Description

Referring initially to fig. 1 of the drawings, wherein an exemplary embodiment of a refrigerant vapor compression system 100 is depicted, the refrigerant vapor compression system 100 includes a compression device 20, a condenser heat exchanger 30, an evaporator heat exchanger 40 connected in series refrigerant flow communication by refrigerant lines 102, 104 and 106, thereby connecting the aforementioned components in a main refrigerant circuit of a refrigeration cycle. A refrigerant line 102 interconnects a refrigerant discharge outlet of the compression device 20 in refrigerant flow communication with a refrigerant inlet of the condenser heat exchanger 30. A refrigerant line 104 interconnects a refrigerant outlet of the condenser heat exchanger 30 in refrigerant flow communication with a refrigerant inlet of the evaporator heat exchanger 40. A refrigerant line 106 interconnects a refrigerant outlet of the evaporator heat exchanger 40 in refrigerant flow communication with a suction inlet of the compression device 20.

One or more condenser fans 34 associated with the condenser heat exchanger 30 convey a fluid to be heated, typically ambient air, through the condenser heat exchanger 30 into heat exchange relationship with the refrigerant flowing through the condenser heat exchanger 30, thereby cooling the refrigerant. One or more evaporator fans 44 associated with the evaporator heat exchanger 40 pass air drawn from the climate-controlled space 200 through the evaporator heat exchanger 40 to be in heat exchange relationship with the refrigerant flowing through the evaporator heat exchanger 40, whereby the refrigerant is evaporated and may also be superheated, the air cooled and possibly also dehumidified. The conditioned air that has passed through the evaporator heat exchanger 40 is supplied back into the climate controlled space.

An evaporator expansion device 45 (e.g., an electronic expansion valve or a thermostatic expansion valve) operatively associated with the evaporator 40 is disposed in refrigerant line 104 upstream with respect to refrigerant flow of the refrigerant inlet of the evaporator heat exchanger 40. The receiver 50 is disposed on the refrigerant line 104 downstream with respect to refrigerant flow of the condenser heat exchanger 30 and upstream with respect to refrigerant flow of the evaporator expansion device 45. In addition, a liquid refrigerant injection line 108 establishes refrigerant flow communication between the receiver 50 and the suction inlet of the compression device 20.

Referring now also to fig. 2, the receiver 50 has a housing 52 defining an enclosed volume 55, the enclosed volume 55 establishing a refrigerant collection reservoir for collecting refrigerant that has passed through the condenser heat exchanger 30 and storing excess refrigerant. The housing 52 has a refrigerant inlet 54, a first liquid refrigerant outlet 56 and a second liquid refrigerant outlet 58. In the depicted embodiment, the housing 52 of the receiver 50 comprises a cylindrical shell having a first end cap closure 62 and a second end cap closure 64 that collectively define the enclosed volume 55. In the depicted embodiment, the refrigerant inlet 54 opens to the enclosed volume 55 through a first end cap closure 62 of the housing 52. A second liquid refrigerant outlet 58 opens through the shell of the shell 52 at a location remote from the first end cap closure 62. As depicted in fig. 1, a sight glass 53 can be provided in operative association with the receptacle 50 to allow for observation of the liquid level within the enclosed volume 55 of the receptacle 50.

The first liquid refrigerant outlet 56 opens through the shell of the shell 52 at a location intermediate the refrigerant inlet 52 and the second liquid refrigerant outlet 58. A refrigerant flow control valve 60 (depicted as a check valve in fig. 2) can be mounted to the housing outside the enclosed volume to be operatively associated with the first outlet 56. The valve 60 has an outlet 66 therein, the outlet 66 being in flow communication with the first outlet 56. The inlet 54 of the receiver 50 is in refrigerant flow communication with the upstream branch of refrigerant line 104, and the outlet 66, and therefore the first outlet 56, of the valve 60 is in refrigerant flow communication with the downstream branch of refrigerant line 104.

The receiver 50 may be mounted in a horizontal orientation (e.g., as in the embodiment depicted in fig. 2) or in a vertical orientation. In the horizontal or vertical direction, the first and second liquid refrigerant outlets 56, 58 are in refrigerant flow communication with a region of the enclosed volume 55 that is below a typical liquid level within the enclosed volume 55 of the receiver 50 under normal operating conditions.

A refrigerant flow metering device 70 is disposed within the enclosed volume 55 and is operatively associated with the second liquid refrigerant outlet 58 to control the flow of refrigerant discharged through the second liquid refrigerant outlet 58. The refrigerant flow metering device 70 opens to a region of the enclosed volume 55 that is below a typical liquid level within the enclosed volume 55 of the receiver 50 under normal operating conditions to ensure that liquid refrigerant enters the refrigerant flow metering device 70. In the exemplary embodiment of the receiver 50 shown in fig. 2, the refrigerant flow metering device 70 includes a capillary tube metering device 72, depicted as a capillary tube forming a multi-turn coil defining the inner surface of the shell of the housing 52. The capillary tube 72 is sized in diameter and length in a conventional manner to provide the desired flow metering characteristics. The capillary tube metering device 72 has an inlet 75, which inlet 75 opens into a region of the enclosed volume 55 that is below a typical liquid level within the enclosed volume 55 of the receiver 50 under normal operating conditions to ensure that liquid refrigerant enters the capillary tube metering device 72.

A refrigerant liquid injection line 108 establishes refrigerant flow communication between the second refrigerant outlet 58 and the suction inlet of the compression device 20. In the depicted embodiment, the refrigerant liquid injection line 108 taps back into the refrigerant flow circuit from a location on refrigerant line 106 downstream with respect to refrigerant flow of the evaporator heat exchanger 40 and upstream with respect to refrigerant flow of the suction inlet of the compression device 20. Further, a flow control valve 85 is interposed in the refrigerant liquid injection line 108. Since the flow of refrigerant through refrigerant line 108 is metered by metering device 70, flow control valve 85 may simply be a two-position on/off flow control valve, such as a two-position solenoid valve, that is selectively positionable in an open position wherein refrigerant flows through refrigerant line 108 and a closed position wherein refrigerant flow through refrigerant line 108 is blocked. In a typical prior art refrigerant vapor compression system, in which a refrigerant liquid injection line connects the receiver with the suction inlet of the compression device, the flow metering valve is, for example, an electronic expansion valve with a variable flow area metering orifice or an electromagnetic metering valve with a small fixed area metering orifice, which is an orifice less than two millimeters in diameter. Since the solenoid flow control valve 85 does not perform a metering function, the solenoid flow control valve 85 may have a relatively large fixed orifice, i.e., a fixed area orifice having a diameter of at least two millimeters.

The refrigerant vapor compression system includes a controller 110 for controlling operation of the refrigerant vapor compression system 100 as is conventional practice. The controller may include a microprocessor and its associated memory, and an input/output interface with an associated analog-to-digital converter. As in conventional practice, the controller 110 may communicate with and/or operate various devices in the refrigerant vapor compression system 100, including but not limited to: a drive motor (not shown) operatively associated with the compressor 20; a condenser fan 34 associated with the condenser heat exchanger 30; and an evaporator fan 44 associated with the evaporator heat exchanger 40; and various system valves such as an evaporator expansion device 45 in the case of an electronic expansion valve. The controller 110 may also communicate with and receive input from various pressure sensors (not shown), such as pressure transducers, and temperature sensors (not shown), such as thermistors, thermocouples, thermostats, and the like, such as compressor discharge pressure transducers, compressor suction pressure transducers, evaporator pressure transducers, compressor discharge temperature sensors, evaporator outlet refrigerant temperature sensors, box air temperature sensors, humidity sensors, ambient air sensors, and other such sensors as desired.

In operation, the controller 110 also controls whether refrigerant liquid is passed through the refrigerant liquid injection line 108 by selectively positioning the electromagnetic flow control valve 85 in an open position or selectively positioning the electromagnetic flow control valve 85 in a closed position. However, the metering function (i.e. the determination of the flow rate of the refrigerant flow through the refrigerant liquid injection line 108) is performed solely by the flow metering device 70, which flow metering device 70 is disposed within the closed volume 55 of the receiver 50 and is operatively associated with the second outlet 58 opening to the inlet of the refrigerant liquid injection line 108.

The receiver 50 may also include a filter/dryer 80 disposed within the enclosed volume 55 at a location downstream of the inlet 54 and upstream of both the first outlet 56 and the second outlet 58. So positioned, all of the refrigerant entering the enclosed volume 55 of the receiver 50 passes through the filter/dryer 80, whereby foreign matter, such as dirt and moisture, is removed from the refrigerant. The filter/dryer 80 may include a desiccant.

The terminology used herein is for the purpose of description and not of limitation. Specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for teaching one skilled in the art to variously employ the present invention. While the present invention has been particularly shown and described with reference to the exemplary embodiments shown in the drawings, it will be understood by those skilled in the art that various changes may be made without departing from the spirit and scope of the invention. It will also be recognized by those of skill in the art that equivalents may be substituted for elements described with reference to the exemplary embodiments disclosed herein without departing from the scope of the invention.

Therefore, it is intended that the disclosure not be limited to the particular embodiments disclosed, but that the disclosure will include all embodiments falling within the scope of the appended claims.

Claims (14)

1. A receiver for collecting refrigerant flowing through a refrigerant flow circuit, comprising:

a housing defining an enclosed volume establishing a refrigerant collection reservoir, the housing having an inlet, a first liquid refrigerant outlet, and a second liquid refrigerant outlet; and

a refrigerant metering device disposed in the enclosed volume and operatively associated with the second liquid refrigerant outlet to control a flow of refrigerant discharged through the second liquid refrigerant outlet,

the second liquid refrigerant outlet is in fluid communication with a refrigerant injection line establishing refrigerant flow communication with the refrigerant flow circuit at a location upstream with respect to refrigerant flow of the compression device and downstream with respect to refrigerant flow of the evaporator heat exchanger.

2. The receiver of claim 1, further comprising a filter/dryer disposed within the enclosed volume at a location downstream of the inlet and upstream of both the first liquid refrigerant outlet and the second liquid refrigerant outlet.

3. The receiver of claim 1, wherein the refrigerant metering device comprises a capillary tube metering device.

4. A receiver according to claim 3 wherein the capillary tube metering device comprises a capillary tube forming a multi-turn coil defining an inner wall of the housing.

5. The receiver of claim 1, further comprising a refrigerant flow control valve mounted to the housing outside the enclosed volume and in operative association with the first liquid refrigerant outlet.

6. The receiver of claim 5, wherein the refrigerant flow control valve comprises a check valve.

7. The receptacle of claim 1, wherein the housing comprises a cylindrical shell having a first end cap closure and a second end cap closure that collectively define the enclosed volume.

8. The receiver of claim 7, wherein the inlet port opens into the enclosed volume through the first end cap closure of the housing and the second liquid refrigerant outlet port opens through the shell at a location remote from the first end cap closure.

9. A refrigerant vapor compression system comprising:

a compression device, a condenser heat exchanger, an evaporator expansion device, and an evaporator heat exchanger arranged in a refrigerant flow circuit in series refrigerant flow relationship in a refrigeration cycle;

a receiver having a housing defining an enclosed volume establishing a refrigerant collection reservoir, the housing having an inlet in refrigerant flow communication with the condenser heat exchanger, a first liquid refrigerant outlet in refrigerant flow communication with the evaporator expansion device, and a second liquid refrigerant outlet;

a refrigerant metering device disposed within the enclosed volume of the housing and operatively associated with the second liquid refrigerant outlet to control a flow of refrigerant discharged therethrough; and

a refrigerant injection line establishing refrigerant flow communication between the second liquid refrigerant outlet and the refrigerant flow circuit at a location upstream with respect to refrigerant flow of the compression device and downstream with respect to refrigerant flow of the evaporator heat exchanger.

10. The refrigerant vapor compression system as recited in claim 9 further comprising a refrigerant flow control valve disposed on the refrigerant injection line.

11. A refrigerant vapor compression system as recited in claim 10 wherein said flow control valve disposed on said refrigerant injection line comprises a fixed orifice solenoid valve.

12. A refrigerant vapor compression system as recited in claim 11 wherein said fixed orifice solenoid valve has a fixed orifice with a flow opening diameter of at least two millimeters.

13. A refrigerant vapor compression system as recited in claim 9 further comprising a refrigerant flow control valve mounted to said shell outside said enclosed volume and operatively associated with said first liquid refrigerant outlet.

14. A refrigerant vapor compression system as recited in claim 13 wherein said refrigerant flow control valve comprises a check valve.