REFRIGERANT RECOVERY DEVICE AND METHOD OF OPERATION

Abstract

A refrigerant recovery device comprising a pump; a heat rejecting heat exchanger disposed in fluid communication with the pump; a refrigerant storage container disposed in fluid communication with the heat rejecting heat exchanger and the pump; a fluid interface disposed in fluid communication with the pump and configured for fluidly connecting the refrigerant recovery device to a refrigerant containing device; and a plurality of valves disposed in fluid communication with at least one of the pump, the heat rejecting heat exchanger, the refrigerant storage container, or the fluid interface and configurable to establish a first fluid pathway fluidly connecting the refrigerant containing device to the refrigerant storage container, and a second fluid pathway fluidly connecting the heat rejecting heat exchanger to the refrigerant storage container.

Description

CROSS REFERENCE TO A RELATED APPLICATION

The application claims the benefit of U.S. Provisional Application No. 63/269,490 filed Mar. 17, 2022, the contents of which are hereby incorporated in their entirety.

BACKGROUND

Exemplary embodiments pertain to the art of recovering refrigerant from refrigerant containing devices. More particularly, the present disclosure relates to configurations and operations of a refrigerant recovery device.

Refrigerant containing devices can include air conditioners, heat pumps, condensers, dehumidifiers, refrigerators, freezers, and other vapor compression driven machines. These devices can include one or more closed refrigerant circuits. Evacuation of the refrigerant from the one or more circuits can be necessary to prevent environmental release when part replacement (or refrigerant replacement) is desired. Accordingly, there remains a need in the art for devices capable of evacuating refrigerant from refrigerant containing devices at least to support the maintenance and decommissioning activities associated with these devices.

BRIEF DESCRIPTION

Disclosed is a refrigerant recovery device comprising a pump; a heat rejecting heat exchanger disposed in fluid communication with the pump; a refrigerant storage container disposed in fluid communication with the heat rejecting heat exchanger and the pump; a fluid interface disposed in fluid communication with the pump and configured for fluidly connecting the refrigerant recovery device to a refrigerant containing device; and a plurality of valves disposed in fluid communication with at least one of the pump, the heat rejecting heat exchanger, the refrigerant storage container, or the fluid interface and configurable to establish a first fluid pathway fluidly connecting the refrigerant containing device to the refrigerant storage container, and a second fluid pathway fluidly connecting the heat rejecting heat exchanger to the refrigerant storage container.

In accordance with additional or alternative embodiments, wherein the first fluid pathway extends from the refrigerant containing device, through the fluid interface, the pump and the heat rejecting heat exchanger, and into the refrigerant storage container, and the second fluid pathway extends from the heat rejecting heat exchanger through the pump and into the refrigerant storage container.

In accordance with additional or alternative embodiments, wherein the second fluid pathway is dead ended upstream of the heat rejecting heat exchanger.

In accordance with additional or alternative embodiments, wherein the first fluid pathway is configured such that during operation the pump pressurizes the heat rejecting heat exchanger as it pushes a refrigerant flow therethrough and the second fluid pathway is configured such that the pump depressurizes the heat rejecting heat exchanger as it draws the refrigerant flow into the refrigerant storage container.

In accordance with additional or alternative embodiments, further comprising a second pump, and wherein the second pump is disposed in the second fluid pathway disposed in fluid communication with, and interposed between, the heat rejecting heat exchanger and the refrigerant storage container.

In accordance with additional or alternative embodiments, further comprising an oil separator disposed in the first fluid pathway in fluid communication with, and interposed between, the pump and the heat rejecting heat exchanger.

In accordance with additional or alternative embodiments, further comprising an oil separator disposed in the first fluid pathway.

In accordance with additional or alternative embodiments, further comprising a pressure relief device disposed in fluid communication with the heat rejecting heat exchanger.

In accordance with additional or alternative embodiments, wherein the refrigerant containing device contains a refrigerant to be recovered comprising a refrigerant having a 100-year global warming potential relative to a carbon dioxide reference gas of less than or equal to 2000.

In accordance with additional or alternative embodiments, wherein the heat rejecting heat exchanger comprises a heat conducting coil disposed in thermal communication with a consumable heat sink.

In accordance with additional or alternative embodiments, further comprising a controller in operable communication with the pump and the plurality of valves and configured to change an operating state of one or more valves of the plurality of valves to establish one of the first fluid pathway and the second fluid pathway based on one or more feedback conditions.

In accordance with additional or alternative embodiments, wherein the one or more feedback conditions comprise at least one of a pressure of the refrigerant containing device, a pressure of the heat rejecting heat exchanger, a pressure of the refrigerant storage container, a pressure of the oil separator, a temperature of the refrigerant containing device, a temperature of the heat rejecting heat exchanger, a temperature of the refrigerant storage container, a temperature of the oil separator, or an elapsed time.

In accordance with additional or alternative embodiments, wherein the establishment of the first fluid pathway is mutually exclusive with the establishment of the second fluid pathway.

In accordance with additional or alternative embodiments, further comprising a movable structure configured to hold one or more of the fluid interface, the pump, the heat rejecting heat exchanger, the refrigerant storage container, or the plurality of valves.

Further disclosed is a method of removing a refrigerant from a refrigerant containing device comprising pumping the refrigerant along a first fluid pathway from the refrigerant containing device through a heat rejecting heat exchanger and into a refrigerant storage container until an initial pull-down threshold condition is satisfied; cooling the refrigerant as it passes through the heat rejecting heat exchanger; and pumping the refrigerant along a second fluid pathway from the heat rejecting heat exchanger to the refrigerant storage container until a final pull-down threshold condition is satisfied.

In accordance with additional or alternative embodiments, wherein the initial pull-down threshold condition comprises reaching one or more of a predetermined pressure condition within the refrigerant containing device, a predetermined temperature condition within the refrigerant containing device, a predetermined pressure condition within the heat rejecting heat exchanger, a predetermined temperature condition within the heat rejecting heat exchanger, a predetermined pressure condition within the refrigerant storage container, a predetermined temperature condition within the refrigerant storage container, or a predetermined initial pull-down time duration.

In accordance with additional or alternative embodiments, wherein the final pull-down threshold condition comprises reaching one or more of a predetermined pressure condition within the heat rejecting heat exchanger, a predetermined temperature condition within the heat rejecting heat exchanger, a predetermined pressure condition within the refrigerant storage container, a predetermined temperature condition within the refrigerant storage container, or a predetermined second pull-down time duration.

In accordance with additional or alternative embodiments, further comprising at least partially obstructing the second fluid pathway while refrigerant is pumped along the first fluid pathway; and at least partially obstructing the first fluid pathway while refrigerant is pumped along the second fluid pathway.

In accordance with additional or alternative embodiments, further comprising pressurizing the heat rejecting heat exchanger when the refrigerant is pumped along the first fluid pathway and depressurizing the heat rejecting heat exchanger when the refrigerant is pumped along the second fluid pathway.

In accordance with additional or alternative embodiments, further comprising providing a refrigerant removal device comprising a pump, the heat rejecting heat exchanger and the refrigerant storage container disposed in configurable fluid communication, wherein the refrigerant removal device is configurable between at least a first configuration establishing the first fluid pathway and a second configuration establishing the second fluid pathway; configuring the refrigerant removal device in the first configuration; fluidly connecting the refrigerant containing device to the refrigerant removal device; pumping the refrigerant with the pump along the first fluid pathway while at least partially obstructing the second fluid pathway, cooling the refrigerant in the heat rejecting heat exchanger before it enters the refrigerant storage container; receiving the refrigerant in the refrigerant storage container; and pumping the refrigerant with the pump along the second fluid pathway while at least partially obstructing the first fluid pathway.

Technical effects of embodiments of the present disclosure include establishing an improved refrigerant evacuation device and operational methods for removing refrigerant from refrigerant containing devices. The improved device and evacuation methods disclosed herein are capable of achieving very high refrigerant recovery from refrigerant containing devices, e.g., removal of up to 99.0 weight % of refrigerant from a refrigerant containing device. Such removal extent is considered sufficient to inert the device when it has previously contained a flammable refrigerant.

The foregoing features and elements may be combined in various combinations without exclusivity, unless expressly indicated otherwise. These features and elements as well as the operation thereof will become more apparent in light of the following description and the accompanying drawings. It should be understood, however, that the following description and drawings are intended to be illustrative and explanatory in nature and non-limiting.

BRIEF DESCRIPTION OF THE DRAWINGS

The following descriptions should not be considered limiting in any way. With reference to the accompanying drawings, like elements are numbered alike:

FIG. 1 is a schematic illustration of an exemplary refrigerant recovery device having bi-directional valves during initial pull-down in accordance with one or more embodiments of the disclosure.

FIG. 2 is a schematic illustration of an exemplary refrigerant recovery device having bi-directional valves during final pull-down in accordance with one or more embodiments of the disclosure.

FIG. 3 is a schematic illustration of an exemplary refrigerant recovery device having three-way valves during initial pull-down in accordance with one or more embodiments of the disclosure.

FIG. 4 is a schematic illustration of an exemplary refrigerant recovery device having three-way valves during final pull-down in accordance with one or more embodiments of the disclosure.

FIG. 5 is a schematic illustration of an exemplary refrigerant recovery device having two pumps during initial pull-down in accordance with one or more embodiments of the disclosure.

FIG. 6 is a schematic illustration of an exemplary refrigerant recovery device having two pumps during final pull-down in accordance with one or more embodiments of the disclosure.

FIG. 7 is a schematic illustration of an exemplary refrigerant recovery method in accordance with one or more embodiments of the disclosure.

DETAILED DESCRIPTION

A detailed description of one or more embodiments of the disclosed apparatus and method are presented herein by way of exemplification and not limitation with reference to the Figures.

FIGS. 1-6 are schematic illustrations of a refrigerant recovery device 100 including a pump 40, a heat rejecting heat exchanger 60, and a refrigerant storage container 80 disposed in fluid communication with one another. The refrigerant recovery device 100 can include a fluid interface 22 for connecting the refrigerant recovery device 100 to a refrigerant containing device 20. The refrigerant recovery device 100 can include a plurality of valves disposed in fluid communication with at least one of the pump 40, the heat rejecting heat exchanger 60, the refrigerant storage container 80, or the fluid interface 22 for directing a refrigerant from the refrigerant containing device 20 to the refrigerant storage device 80. The plurality of valves can be configurable to establish a first fluid pathway 11 (shown with a thicker line in FIGS. 1, 3, and 5) fluidly connecting the refrigerant containing device 20 to the refrigerant storage device 80 and a second fluid pathway 12 (shown with a thicker line in FIGS. 2, 4, and 6) fluidly connecting the heat rejecting heat exchanger 60 to the refrigerant storage device 80. In the figures, for illustrative purposes, grayed out reference block indicates a closed valve, and a ungrayed reference block indicates an open valve. Further, in FIGS. 3-4, a closed valve pathway is indicated by a solid black triangle and an open valve pathway is indicated by a white triangle.

The first fluid pathway 11 can originate at the refrigerant containing device 20 and terminate at the refrigerant storage device 80. For example, the fluid interface 22 can fluidly connect the refrigerant containing device 20 to the refrigerant recovery device 100 and the plurality of valves can be configured to establish the first fluid pathway 11 from the refrigerant containing device 20 to the refrigerant storage device 80. Where the first fluid pathway 11 extends from the refrigerant containing device 20, through the fluid interface 22, the pump 40, and the heat rejecting heat exchanger 60, and into the refrigerant storage container 80. Further, as in FIG. 1, the plurality of valves can be configured in a first position where interface valve 61, heat exchanger hot side inlet valve 62, and heat exchanger hot side outlet valve 63 are set in an open position and heat exchanger bypass valve 64 and recycle valve 65 are set in a closed position. In this configuration, the refrigerant containing device 20 can be dead ended (e.g., sealed except for an outlet) such that the pump 40 can be operated to depressurize the refrigerant containing device 20 by drawing refrigerant from the refrigerant containing device 20 and push it through the hot side of the heat rejecting heat exchanger 60 and into the refrigerant storage container 80. The operation of the pump 40 in this configuration can be referred to as an initial pull-down, where refrigerant from the refrigerant containing device 20 is initially removed until an initial pull-down threshold condition is satisfied.

The initial pull-down threshold condition can include reaching one or more of a predetermined pressure condition anywhere in the first fluid pathway 11, or a predetermined temperature condition anywhere along the first fluid pathway 11. For example, the initial pull-down threshold condition can include reaching a predetermined pressure condition within the refrigerant containing device 20, a predetermined temperature condition within the refrigerant containing device 20, a predetermined pressure condition within the pump 40, a predetermined temperature condition within the pump 40, a predetermined pressure condition within the heat rejecting heat exchanger 60, a predetermined temperature condition within the heat rejecting heat exchanger 60, a predetermined pressure condition within the refrigerant storage container 80, or a predetermined temperature condition within the refrigerant storage container 80, or a predetermined initial pull-down time duration. In an example, the initial pull-down threshold condition can include reaching less than or equal to about 3 pounds per square inch gauge pressure (psi(g)) within the refrigerant containing device 20, such as less than or equal to about 2.5 psi(g), or about 2.0 psi(g), or about 1.5 psi(g), or about 1.0 psi(g), or about 0.5 psi(g) or about 0 psi(g). The initial pull-down threshold condition can include a negative gauge pressure (vacuum condition) but doing so can result in air ingress into the refrigerant containing device 20 if there are any air leak paths.

The second fluid pathway 12 can originate at the heat rejecting heat exchanger 60 and terminate at the refrigerant storage container 80. For example, the plurality of valves can be configured to establish the second fluid pathway 12 from the heat rejecting heat exchanger 60 to the refrigerant storage device 80. Where the second fluid pathway 12 extends from the heat rejecting heat exchanger 60 through the pump 40 and into the refrigerant storage container 80. Further, as in FIG. 2, the plurality of valves can be configured in a second position where interface valve 61, heat exchanger hot side inlet valve 62, and heat exchanger hot side outlet valve 63 are set in a closed position and heat exchanger bypass valve 64 and recycle valve 65 are set in an open position. The second position of the valves can be the opposite of the first position such that establishment of the first fluid pathway 11 can be mutually exclusive with the establishment of the second fluid pathway 12. In this configuration, the heat rejecting heat exchanger 60 can be dead ended (e.g., sealed except for an outlet) such that the pump 40 can be operated to depressurize the heat rejecting heat exchanger 60 by drawing refrigerant from the heat rejecting heat exchanger 60 and push it into the refrigerant storage container 80. In this way, the first fluid pathway 11 can be configured such that during operation the pump 40 pressurizes the heat rejecting heat exchanger 60 as it pushes a refrigerant flow therethrough and the second fluid pathway 12 is configured such that the pump 40 depressurizes the heat rejecting heat exchanger 60 as it draws the refrigerant flow into the refrigerant storage container 80. The operation of the refrigerant removal device 100 in this configuration (e.g., where the plurality of valves are disposed in their second position) can be referred to as a final pull-down, where refrigerant from the heat rejecting heat exchanger 60 is removed by the action of the pump 40 until a final pull-down threshold condition is satisfied.

The final pull-down threshold condition can include reaching one or more of a predetermined pressure condition anywhere in the second fluid pathway 12, or a predetermined temperature condition anywhere along the second fluid pathway 12. For example, the final pull-down threshold condition can include reaching one or more of a predetermined pressure condition within the heat rejecting heat exchanger 60, a predetermined temperature condition within the heat rejecting heat exchanger 60, a predetermined pressure condition within the pump 40, a predetermined temperature condition within the pump 40, a predetermined pressure condition within the refrigerant storage container 80, a predetermined temperature condition within the refrigerant storage container 80, or a predetermined final pull-down time duration. In an example, the final pull-down threshold condition can include reaching less than or equal to about 3 pounds per square inch gauge pressure (psi(g)) within the heat rejecting heat exchanger 60, such as less than or equal to about 2.5 psi(g), or about 2.0 psi(g), or about 1.5 psi(g), or about 1.0 psi(g), or about 0.5 psi(g) or about 0 psi(g). The final pull-down threshold condition can include a negative gauge pressure (vacuum condition) but doing so can result in air ingress into the heat rejecting heat exchanger 60 if there are any air leak paths.

The first fluid pathway 11 and the second fluid pathway 12 can each include a plurality of conduits disposed between and fluidly connecting one or more of the fluid interface 22, the pump 40, the heat rejecting heat exchanger 60, the refrigerant storage container 80, the refrigerant containing device 20, and the plurality of valves into the pathway. The conduits can be made of any material suitable for conveying refrigerant e.g., including a low global warming potential refrigerants. Such materials can include polymers, such as polypropylene, polyphthalamide, acetal, phenolic, polyvinylidene fluoride, polycarbonate, polyethylene terephthalate, polyetherimide, polyimides, liquid crystal polymer, polyamide, and the like, and metals, such as aluminum, aluminum alloys, copper, copper alloys, iron, iron alloys, lead, lead alloys, tin, tin alloys, zinc, zinc alloys, or combinations thereof.

The fluid interface 22 can be disposed in fluid communication with the pump 40 and can be configured for fluidly connecting the refrigerant recovery device 100 to the refrigerant containing device 20. For example, the fluid interface 22 can include any suitable connector type for fluidly connecting to a refrigerant containing device 20 such as a compression fitting, swage fitting, threaded connector, or the like for fastening to a corresponding fitting of the refrigerant containing device 20.

An interface valve 61 can be fluidly interposed between the pump 40 and the fluid interface 22. The interface valve 61 can be used to allow, or prevent, refrigerant flow from the refrigerant containing device 20 during operation of the pump 40. For example, during the initial pull-down the interface valve 61 can be configured in an open position to allow refrigerant to be evacuated from the refrigerant containing device 20. During the final pull-down the interface valve 61 can be configured in a closed position to prevent refrigerant from flowing into, or out of, the refrigerant containing device 20 or creating a vacuum therein.

The interface valve 61 can serve as a shutoff valve when connecting and disconnecting the refrigerant recovery device 100 to the refrigerant containing device 20. For example, while the fluid interface 22 is connected to the refrigerant containing device 20 the interface valve 61 can be closed to prevent refrigerant from entering the refrigerant removal device 100 prematurely. Similarly, while the fluid interface 22 is disconnected from the refrigerant containing device 20 the interface valve 61 can be closed to prevent refrigerant from escaping the refrigerant recovery device 100.

The plurality of valves can include two-way valves or three-way valves (as shown in FIG. 3-4). When one or more three-way valves are used, one or more of the fluid interface valve 61, the heat exchanger hot side inlet valve 62, the heat exchanger hot side outlet valve 63, the heat exchanger bypass valve 64, and the recycle valve 65 may become optional as the one or more three-way valves may assume their function(s). For example, as in FIGS. 3-4, a first three-way valve 71 and a second three-way valve 72 cooperate to eliminate the fluid interface valve 61, the heat exchanger hot side inlet valve 62, the heat exchanger bypass valve 64, and the recycle valve 65.

When the first three-way valve 71 is used, an optional flow control device 73 can be disposed in the second fluid pathway 12. For example, a flow control device 73, such as an orifice, flow control valve, or the like, can be disposed upstream of the pump 40 inlet, e.g., interposed between the heat exchanger 60 and the pump 40 as in FIGS. 4-5. This optional flow control device 73 can be used to reduce the pressure of fluid flowing from the heat exchanger 60 during the final pull-down and can be set to minimize liquid ingestion into the pump 40. Furthermore, the flow control device 73 can be configured in operable communication with the controller 50 and can be configured to adjust an opening amount of the flow control device 73 in response to a condition measured along the second fluid pathway 12, such as fluid temperature at the inlet to the pump 40, temperature at the flow control device 73, temperature of the heat exchanger 60 outlet, temperature of the heat exchanger 60 inlet, or the like.

Referring to FIGS. 5-6, the refrigerant recovery device 100 can include an optional second pump 42. The second pump 42 can replace one or more of the plurality of valves to achieve the same overall function of the refrigerant recovery device 100. For example, the second pump 42 can be disposed in the second fluid pathway 12 in fluid communication with, and interposed between, the heat rejecting heat exchanger 60 and the refrigerant storage container 80. The second pump 42 can be fluidly disconnected from the first fluid pathway 11 while refrigerant is pumped along the first fluid pathway 11 during the initial pump down as in FIG. 5 and can be fluidly connected to the heat rejecting heat exchanger 60 (e.g., via inlet valve 67 and/or outlet valve 69) to establish the second fluid pathway 12 during the final pull-down. For example, inlet valve 67 and outlet valve 69 could be replaced with sealable access ports (e.g., quick disconnect fittings) such that the second pump 42 can be fluidly disconnected during the initial pump down and fluidly reconnected during the final pump down. When the second pump 42 is used, an optional flow control device 73 can be disposed in the second fluid pathway 12. For example, a flow control device 73, such as an orifice, flow control valve, or the like, can be disposed upstream of the second pump 42 inlet, e.g., interposed between the heat exchanger 60 and the second pump 42 as in FIGS. 5-6. This optional flow control device 73 can be used to reduce the pressure of fluid flowing from the heat exchanger 60 during the final pull-down and can be set to minimize liquid ingestion into the second pump 42. Furthermore, the flow control device 73 can be configured in operable communication with the controller 50 and can be configured to adjust an opening amount of the flow control device 73 in response to a condition measured along the second fluid pathway 12, such as fluid temperature at the inlet to the second pump 42, fluid temperature at the flow control device 73, fluid temperature of the heat exchanger 60 outlet, fluid temperature of the heat exchanger 60 inlet, or the like.

During the final pull-down the heat exchanger hot side inlet valve 62, or equivalent three-way valve (e.g., first three-way valve 71), can be closed. In this case, the downstream heat rejecting heat exchanger 60 is said to be dead ended because there is only a fluid outlet connected thereto. When refrigerant is sucked from the heat rejecting heat exchanger 60 in this condition (e.g., with pump 40 or second pump 42), the pressure inside the heat rejecting heat exchanger 60 decreases toward a vacuum condition.

Optionally, the refrigerant recovery device 100 can include an oil separator 90. The optional oil separator 90 can be disposed anywhere in the first fluid pathway 11 or the second fluid pathway 12. For example, the oil separator 90 can be disposed upstream of the heat rejecting heat exchanger 60 to reduce the presence of oil in the heat rejecting heat exchanger 60. Furthermore, the optional oil separator 90 can be interposed between the pump 40 and the heat rejecting heat exchanger 60, such as between the heat exchanger hot side inlet valve 62 and the heat rejecting heat exchanger 60.

Optionally, the refrigerant recovery device 100 can include a pressure relief valve 91 for relieving pressure within the refrigerant recovery device 100 in the event that pressure builds beyond a safe level. The optional pressure relief valve 91 can be disposed anywhere in the first fluid pathway 11 or the second fluid pathway 12 and can be configured to release pressure from either pathway. For example, the optional pressure relief valve can be disposed in fluid communication with the heat rejecting heat exchanger 60, such as downstream of the heat rejecting heat exchanger 60. The pressure relief device 91 can be configured to release pressure at a predetermined high-pressure value to avoid over-pressurizing other components of the refrigerant recovery device 100 (e.g., valve, fluid conduits, the heat rejecting heat exchanger 60, the refrigerant storage container 80, or the like). In an example, the pressure relief valve 91 can be set to relieve pressure it is exposed to a pressure differential of about 30 psi(g) or more.

The refrigerant containing device 20 can include any device having a refrigerant circuit such as including air conditioning systems, heat pump systems, refrigeration systems, or the like. The refrigerant recovery device 100 can be configured for operation with a refrigerant containing device 20 containing any type of refrigerant. For example, the refrigerant of the refrigerant containing device 20 can include a low global warming potential refrigerant, such as a refrigerant having a 100-year global warming potential relative to a carbon dioxide reference gas of less than or equal to 3000, or less than or equal to 2000, or less than or equal to 1000, or equal to or less than 500. Some none-limiting examples of refrigerants that can be recovered using the disclosed refrigerant recovery device 100 include R32, R410A, R454B, R466A, R454C, DR4, DR930, and the like.

When flammable refrigerants are recovered with the refrigerant recovery device 100 the components of the device, including the pump 40 (and optional pump 42) and motor(s) associated therewith, can be selected to meet National Electric Code (NEC) Class I Division II standards. These standards define a Class I location as a location containing flammable gases or vapors sufficient to pose risk of explosion or ignition. While the designation of Division II indicates that the flammable gases or vapors are only present during abnormal conditions, e.g., failure conditions. Accordingly, the refrigerant recovery device 100 can include non-arcing and non-sparking brushless DC motors suitable for operation in environments designated as Class I and Division II by the NEC.

The heat rejecting heat exchanger 60 can include any suitable heat transfer device for removing heat from a refrigerant stream. For example, the heat rejecting heat exchanger 60 can include a plate or tube style heat exchanger having a high surface area section that can be disposed in thermal communication with a coolant. The coolant can include a fluid coolant that is moved through the heat rejecting heat exchanger 60 (e.g., glycol, air, or the like) or can include a consumable heat sink material, such as ice, an ice and water mixture, dry ice, or the like, that is placed in thermal communication with the heat rejecting heat exchanger 60. For example, the heat rejecting heat exchanger 60 can include a coil of metal conduit (e.g., copper coil) disposed within an insulated housing (e.g., a cooler) suitable for holding a consumable heat sink material. The heat sink material can be placed inside the housing in thermal communication with the coil of metal conduit. In this way, the heat rejecting heat exchanger 60 can be kept at a relatively constant temperature (e.g., the solid-liquid transition temperature of the solid coolant such as ice, the sublimation temperature of solid carbon dioxide, or the like) during the operation of the refrigerant recovery device 100.

The use of a consumable heat sink material in the heat rejecting heat exchanger 60 can allow service persons to use readily available materials (e.g., bagged ice) to execute refrigerant recovery in the field. Furthermore, use of the consumable heat sink material can eliminate the need for noisy condenser fans and/or plumbing coolant supply/return lines to the heat rejecting heat exchanger 60, thereby improving the portability, performance, and convenience of the refrigerant recovery device 100 making it suitable for field service personnel.

Accordingly, the refrigerant recovery device 100 can be configured into a movable device for use in servicing refrigerant containing equipment in the field. For example, the refrigerant recovery device 100 can include a movable structure (e.g., frame, housing, and the like) for supporting components of the refrigerant recovery device 100. In this way, the movable frame can be configured to hold one or more of the fluid interface 22, the pump 40, the heat rejecting heat exchanger 60, the refrigerant storage container 80, one or more valves of the plurality of valves (e.g., 61, 62, 63, 64, 65, 67, 69, 71, or 72), one or more conduits of the plurality of conduits, an optional controller 50, the optional oil separator 90, or the optional pressure relief valve 91. The movable structure can include a plurality of wheels for transporting the refrigerant recovery device 100 to and from a work area to perform refrigerant recovery operations. For example, the refrigerant recovery device 100 can include a movable structure frame for securing components of the refrigerant recovery device 100. The movable structure can be disposed in operable communication with a plurality of wheels for moving the refrigerant recovery device 100, such as wheeled cart holding components, or the likes. Further the refrigerant recovery device 100 can include a housing to enclose the components of the refrigerant recovery device 100 such as to protect them from damage during storage, set up, or operation.

Referring to FIG. 7, methods 200 of operating the refrigerant recovery device 100 can include an initial pull-down 210, a final pull-down 240, and a transition therebetween 220. These methods of operating the refrigerant recovery device 100 can be performed manually or automatically with the optional controller 50. For example, when configured for manual operation the plurality of valves can include hand valves (e.g., quarter turn ball valves, of the like), the pump can include a manual start switch, and manually readable pressure and/or temperature gauges can be applied at points along the first fluid pathway 11 and/or second fluid pathway 12 (e.g., at the refrigerant containing device 20, the heat rejecting heat exchanger 60, the refrigerant storage container 80, and the like) to feedback conditions to the operator.

The initial pull-down 210 can include fluidly connecting the refrigerant removal device 100 to the refrigerant containing device 20, such as by connecting the fluid interface 22 to an outlet port of the refrigerant containing device 20. In addition, the initial pull-down can include positioning the plurality of valves in the first position to establish the first fluid pathway 11 originating at the refrigerant containing device 20 and terminating at the refrigerant storage container 80. Once the plurality of valves are positioned and the refrigerant containing device 20 is fluidly connected to the refrigerant storage container 80 the initial pull-down can begin. The initial pull-down can include pumping the refrigerant along the first fluid pathway 11 from the refrigerant containing device 20 through the heat rejecting heat exchanger 60 and into the refrigerant storage container 80 until the initial pull-down threshold condition is satisfied. During this initial pull-down pumping, the refrigerant can be pushed through the heat rejecting heat exchanger 60 by the pump 40 thereby pressuring the heat rejecting heat exchanger 60 and cooling the refrigerant as it passes therethrough. Furthermore, the positioning of the plurality of valve in the first position can include at least partially obstructing the second fluid pathway 12 while refrigerant is pumped along the first fluid pathway 11.

The methods 200 of the refrigerant recovery device 100 can include a transition 220 between the initial pull-down 210 and the final pull-down 240. This transition 220 can include satisfying any one or more of the previously mentioned initial pull-down threshold conditions, including holding for a pre-determined time duration before transitioning operational mode to the final pull-down 240.

The cooling operation during pull-down can reduce the refrigerant pressure and can aide in evacuating the refrigerant containing device 20 by keeping the refrigerant in the storage container 80 relatively cold and at a corresponding low pressure. For example, in reclaiming refrigerant from the refrigerant containing device 20 having 20 pounds (lbs.) of refrigerant, the initial pull-down described herein can remove all but about 0.2 lbs. of refrigerant for a removal efficiency of about 99.0%. However, the initial pull-down will leave refrigerant in the refrigerant removal device 100, e.g., within the heat rejecting heat exchanger 60. Following the initial pull-down, the final pull-down 240 can be performed to evacuate the heat rejecting heat exchanger 60 to near completion.

The final pull-down 240 can include positioning the plurality of valves in the second position to establish the second fluid pathway 12 originating at the heat rejecting heat exchanger 60 and terminating at the refrigerant storage container 80. Once the plurality of valves are positioned, the final pull-down 240 can begin. The final pull-down 240 can include pumping the refrigerant along the second fluid pathway 12 from the heat rejecting heat exchanger 60 to the refrigerant storage container 80 until the final pull-down threshold condition is satisfied. During this final pull-down pumping, the refrigerant can be drawn from the heat rejecting heat exchanger 60 thereby depressurizing the heat rejecting heat exchanger 60 as it is evacuated. Furthermore, the positioning of the plurality of valve in the second position can include at least partially obstructing the first fluid pathway 11 while refrigerant is pumped along the second fluid pathway 12. The refrigerant can continue to cool during this pumping while it is in thermal communication with the heat rejecting heat exchanger 60. The cooling operation reduces the refrigerant pressure and can aide in evacuating the heat rejecting heat exchanger 60 by keeping the refrigerant in the storage container 80 relatively cold and at a corresponding low pressure.

The method can include fluidly disconnecting the refrigerant removal device 100 from the refrigerant containing device 20, such as by disconnecting the fluid interface 22 from the outlet port of the refrigerant containing device 20. Once the initial pull-down is complete and the plurality of valves are set in their second position, the refrigerant removal device 100 can be disconnected from the refrigerant containing device 20 without affecting the refrigerant recovery.

Optionally, the refrigerant recovery device 100 can include a controller 50 for controlling the operation of the device during use. The controller 50 can be implemented using a field programmable gate array (FPGA), central processing unit (CPU), application specific integrated circuits (ASIC), or the like. As indicated by the dashed lines in the Figures, the controller 50 can be configured in operable communication with the pump 40, one or more valves of the plurality of valves, the second pump 42 (when included), one or more temperature sensors disposed along the first fluid pathway 11 (e.g., measuring the temperature within the refrigerant containing device 20, the pump 40, the heat rejecting heat exchanger 60, the storage container 80, at the fluid interface 22, or the like), one or more pressure sensors disposed along the first fluid pathway 11 (e.g., measuring the pressure within the refrigerant containing device 20, the pump 40, the heat rejecting heat exchanger 60, the storage container 80, at the fluid interface 22, or the like), one or more temperature sensors disposed along the second fluid pathway 12 (e.g., measuring the temperature within the pump 40, the heat rejecting heat exchanger 60, the storage container 80, or the like), one or more pressure sensors disposed along the second fluid pathway 12 (e.g., measuring the pressure within the pump 40, the heat rejecting heat exchanger 60, the storage container 80, or the like). For simplicity in illustration, pressure and temperature sensors are not shown in the corresponding drawings.

The controller 50 can be configured to perform one or more refrigerant recovery methods of the refrigerant recovery device 100. For example, the controller 50 can be disposed in operable communication with the pump 40 and the plurality of valves and configured to change an operating state of one or more valves of the plurality of valves to establish one of the first fluid pathway 11 and the second fluid pathway 12 based on one or more feedback conditions from the refrigerant recovery device 100. These feedback conditions can include any of the previously mentioned initial pull-down threshold conditions or final pull-down threshold conditions and can be used (e.g., by an operator or by the controller 50) to change the operating mode of the refrigerant recovery device 100 (e.g., from an initial pull-down to a final pull-down, or from a final pull-down to an off mode).

The term “about” is intended to include the degree of error associated with measurement of the particular quantity based upon the equipment available at the time of filing the application.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present disclosure. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, element components, and/or groups thereof.

While the present disclosure has been described with reference to an exemplary embodiment or embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the present disclosure. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the present disclosure without departing from the essential scope thereof. Therefore, it is intended that the present disclosure not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this present disclosure, but that the present disclosure will include all embodiments falling within the scope of the claims.

Claims

1. A refrigerant recovery device comprising:

a pump;

a heat rejecting heat exchanger disposed in fluid communication with the pump;

a refrigerant storage container disposed in fluid communication with the heat rejecting heat exchanger and the pump;

a fluid interface disposed in fluid communication with the pump and configured for fluidly connecting the refrigerant recovery device to a refrigerant containing device; and

a plurality of valves disposed in fluid communication with at least one of the pump, the heat rejecting heat exchanger, the refrigerant storage container, or the fluid interface and configurable to establish a first fluid pathway fluidly connecting the refrigerant containing device to the refrigerant storage container, and a second fluid pathway fluidly connecting the heat rejecting heat exchanger to the refrigerant storage container.

2. The refrigerant recovery device of claim 1, wherein the first fluid pathway extends from the refrigerant containing device, through the fluid interface, the pump and the heat rejecting heat exchanger, and into the refrigerant storage container, and the second fluid pathway extends from the heat rejecting heat exchanger through the pump and into the refrigerant storage container.

3. The refrigerant recovery device of claim 1, wherein the second fluid pathway is dead ended upstream of the heat rejecting heat exchanger.

4. The refrigerant recovery device of claim 1, wherein the first fluid pathway is configured such that during operation the pump pressurizes the heat rejecting heat exchanger as it pushes a refrigerant flow therethrough and the second fluid pathway is configured such that the pump depressurizes the heat rejecting heat exchanger as it draws the refrigerant flow into the refrigerant storage container.

5. The refrigerant recovery device of claim 1, further comprising a second pump, and wherein the second pump is disposed in the second fluid pathway disposed in fluid communication with, and interposed between, the heat rejecting heat exchanger and the refrigerant storage container.

6. The refrigerant recovery device of claim 1, further comprising an oil separator disposed in the first fluid pathway in fluid communication with, and interposed between, the pump and the heat rejecting heat exchanger.

7. The refrigerant recovery device of claim 1, further comprising an oil separator disposed in the first fluid pathway.

8. The refrigerant recovery device of claim 1, further comprising a pressure relief device disposed in fluid communication with the heat rejecting heat exchanger.

9. The refrigerant recovery device of claim 1, wherein the refrigerant containing device contains a refrigerant to be recovered comprising a refrigerant having a 100-year global warming potential relative to a carbon dioxide reference gas of less than or equal to 2000.

10. The refrigerant recovery device of claim 1, wherein the heat rejecting heat exchanger comprises a heat conducting coil disposed in thermal communication with a consumable heat sink.

11. The refrigerant recovery device of claim 1, further comprising a controller in operable communication with the pump and the plurality of valves and configured to change an operating state of one or more valves of the plurality of valves to establish one of the first fluid pathway and the second fluid pathway based on one or more feedback conditions.

12. The refrigerant recovery device of claim 11, wherein the one or more feedback conditions comprise at least one of a pressure of the refrigerant containing device, a pressure of the heat rejecting heat exchanger, a pressure of the refrigerant storage container, a pressure of the oil separator, a temperature of the refrigerant containing device, a temperature of the heat rejecting heat exchanger, a temperature of the refrigerant storage container, a temperature of the oil separator, or an elapsed time.

13. The refrigerant recovery device of claim 1, wherein the establishment of the first fluid pathway is mutually exclusive with the establishment of the second fluid pathway.

14. The refrigerant recovery device of claim 1, further comprising a movable structure configured to hold one or more of the fluid interface, the pump, the heat rejecting heat exchanger, the refrigerant storage container, or the plurality of valves.

15. A method of removing a refrigerant from a refrigerant containing device comprising:

pumping the refrigerant along a first fluid pathway from the refrigerant containing device through a heat rejecting heat exchanger and into a refrigerant storage container until an initial pull-down threshold condition is satisfied;

cooling the refrigerant as it passes through the heat rejecting heat exchanger; and

pumping the refrigerant along a second fluid pathway from the heat rejecting heat exchanger to the refrigerant storage container until a final pull-down threshold condition is satisfied.

16. The method of claim 15, wherein the initial pull-down threshold condition comprises reaching one or more of a predetermined pressure condition within the refrigerant containing device, a predetermined temperature condition within the refrigerant containing device, a predetermined pressure condition within the heat rejecting heat exchanger, a predetermined temperature condition within the heat rejecting heat exchanger, a predetermined pressure condition within the refrigerant storage container, a predetermined temperature condition within the refrigerant storage container, or a predetermined initial pull-down time duration.

17. The method of claim 15, wherein the final pull-down threshold condition comprises reaching one or more of a predetermined pressure condition within the heat rejecting heat exchanger, a predetermined temperature condition within the heat rejecting heat exchanger, a predetermined pressure condition within the refrigerant storage container, a predetermined temperature condition within the refrigerant storage container, or a predetermined second pull-down time duration.

18. The method of claim 15, further comprising at least partially obstructing the second fluid pathway while refrigerant is pumped along the first fluid pathway; and at least partially obstructing the first fluid pathway while refrigerant is pumped along the second fluid pathway.

19. The method of claim 15, further comprising pressurizing the heat rejecting heat exchanger when the refrigerant is pumped along the first fluid pathway and depressurizing the heat rejecting heat exchanger when the refrigerant is pumped along the second fluid pathway.

20. The method of claim 15, further comprising:

providing a refrigerant removal device comprising a pump, the heat rejecting heat exchanger and the refrigerant storage container disposed in configurable fluid communication, wherein the refrigerant removal device is configurable between at least a first configuration establishing the first fluid pathway and a second configuration establishing the second fluid pathway;

configuring the refrigerant removal device in the first configuration;

fluidly connecting the refrigerant containing device to the refrigerant removal device;

pumping the refrigerant with the pump along the first fluid pathway while at least partially obstructing the second fluid pathway,

cooling the refrigerant in the heat rejecting heat exchanger before it enters the refrigerant storage container;

receiving the refrigerant in the refrigerant storage container; and

pumping the refrigerant with the pump along the second fluid pathway while at least partially obstructing the first fluid pathway.