Patent Application
20150226466
Not Applicable.
Not Applicable.
Not Applicable.
This invention pertains to an energy recovery apparatus for use in a refrigeration system.
One aspect of the present invention is an energy recovery apparatus for use in a refrigeration system. The refrigeration system comprises an evaporator, a compressor, and a condenser. The refrigeration system is configured to circulate refrigerant along a flow path such that the refrigerant flows from the evaporator to the compressor, and from the compressor to the condenser, and from the condenser to the evaporator. The energy recovery apparatus is adapted and configured to be in the flow path operatively between the condenser and the evaporator. The energy recovery apparatus comprises a first nozzle, a second nozzle, a turbine, a discharge port, and a housing. The first nozzle comprises a first conduit region defining a first passageway. The first passageway is adapted to constitute a portion of the flow path when the refrigeration system is operated in a first mode. The first passageway has a discharge end. The first nozzle is adapted and configured such that refrigerant is expanded as it passes through the first nozzle and is discharged from the discharge end of the first passageway in a liquid-vapor state with a liquid component and a vapor component. The second nozzle comprises a second conduit region defining a second passageway. The second passageway is adapted to constitute a portion of the flow path when the refrigeration system is operated in a second mode. The second passageway has a discharge end. The second nozzle is adapted and configured such that refrigerant is expanded as it passes through the second nozzle and is discharged from the discharge end of the second passageway in a liquid-vapor state with a liquid component and a vapor component. The turbine is positioned and configured to be driven by refrigerant discharged from the discharge end of the first passageway and by refrigerant discharged from the discharge end of the second passageway. The discharge port is adapted to permit refrigerant to flow out of the energy recovery apparatus. The discharge port of the energy recovery apparatus is downstream of the turbine. The turbine is within the housing.
Another aspect of the present invention is a refrigeration system comprising an evaporator, a multi-speed compressor operable in at least a first speed and a second speed different from the first speed, a condenser, and the energy recovery apparatus. The refrigeration system is configured to circulate refrigerant along a flow path such that the refrigerant flows from the evaporator to the compressor, and from the compressor to the condenser, and from the condenser to the energy recovery apparatus, and from the energy recovery apparatus to the evaporator. The refrigeration system is configured and adapted such that the first passageway is in the flow path when the compressor is operated at the first speed. The refrigeration system is configured and adapted such that the second passageway is in the flow path when the compressor is operated at the second speed but not when the compressor is operated at the first speed.
Another aspect of the present invention is a heat pump system adapted to be operated in a heating mode and in a cooling mode. The heat pump system comprises a first heat exchanger, a second heat exchanger, a compressor, and an energy recovery apparatus. The heat pump system is configured to circulate refrigerant along a first flow path when the heat pump system is operated in one of the heating or cooling modes and configured to circulate refrigerant along a second flow path when the heat pump system is operated in the other of the heating or cooling modes. The heat pump system is configured such that refrigerant flowing along the first flow path flows from the first heat exchanger to the compressor, and from the compressor to the second heat exchanger, and from the second heat exchanger to the energy recovery apparatus, and from the energy recovery apparatus to the first heat exchanger. The heat pump system is configured such that refrigerant flowing along the second flow path flows from the second heat exchanger to the compressor, and from the compressor to the first heat exchanger, and from the first heat exchanger to the energy recovery apparatus, and from the energy recovery apparatus to the second heat exchanger. The heat pump system is configured and adapted such that refrigerant flows through the first passageway of the energy recovery apparatus when the heat pump system is operated in the mode which causes refrigerant to flow along the first flow path. The heat pump system is configured and adapted such that refrigerant flows through the second passageway of the energy recovery apparatus when the heat pump system is operated in the mode which causes refrigerant to flow along the second flow path but not when the heat pump system is operated in the mode which causes refrigerant to flow along the first flow path.
Another aspect of the present invention is an energy recovery apparatus for use in a refrigeration system. The refrigeration system comprises an evaporator, a compressor and a condenser. The refrigeration system is configured to circulate refrigerant along a flow path such that the refrigerant flows from the evaporator to the compressor, and from the compressor to the condenser, and from the condenser to the evaporator. The energy recovery apparatus is adapted and configured to be in the flow path operatively between the condenser and the evaporator. The energy recovery apparatus comprises a nozzle apparatus, a turbine, a discharge port, and a housing. The nozzle apparatus is adapted to be in the flow path and configured to expand refrigerant passing through the nozzle apparatus. The nozzle apparatus is adapted to be operable in first and second modes. The nozzle apparatus has a first discharge cross-sectional area through which refrigerant is discharged in a liquid-vapor state with a liquid component and a vapor component when the nozzle apparatus is operated in the first mode. The nozzle apparatus has a second discharge cross-sectional area through which refrigerant is discharged in a liquid-vapor state with a liquid component and a vapor component when the nozzle apparatus is operated in the second mode. The second discharge cross-sectional area is different from the first discharge cross-sectional area. The turbine is positioned and configured to be driven by refrigerant discharged from the first discharge cross-sectional area when the nozzle apparatus is operated in the first mode. The turbine is positioned and configured to be driven by refrigerant discharged from the second discharge cross-sectional area when the nozzle apparatus is operated in the second mode. The discharge port is adapted to permit refrigerant to flow out of the energy recovery apparatus. The discharge port of the energy recovery apparatus is downstream of the turbine. The turbine is within the housing.
Reference numerals in the written specification and in the drawing figures indicate corresponding items.
An embodiment of a refrigeration system of the present invention is indicated generally by reference numeral 16 in
Referring to
The energy recovery apparatus 24 is similar to the energy recovery apparatus described in co-pending U.S. patent application Ser. No. 13/948,942 filed Jul. 23, 2013 (incorporated herein by reference) except the energy recovery apparatus 24 of the present invention includes two nozzles. In particular, the energy recovery apparatus 24 further includes a first nozzle 46 and a second nozzle 48. The first and second nozzles 46, 48 may be integrally formed with the side wall 36 as a single, unitary, monolithic piece as shown in
The first nozzle 46 comprises a first conduit region 50 defining a first passageway 52. The first nozzle further comprises a first necked-down region 54. The first passageway 52 is downstream of the first necked-down region 54. The first necked down region 54 and the first passageway 52 are adapted to constitute portions of the flow path when the refrigeration system is operated in a first mode. The first passageway 52 has an upstream cross-section, indicated by the dash line 56, a downstream cross-section, indicated by the dash line 58, a first passageway length PL1 extending from the upstream cross-section 56 of the first passageway to the downstream cross-section 58 of the first passageway, and a discharge end 60. The downstream cross-section 58 of the first passageway 52 is closer to the discharge end 60 of the first passageway 52 than to the upstream cross section 56 of the first passageway. The first nozzle 46 is adapted and configured such that refrigerant is expanded as it passes through the first nozzle and is discharged from the discharge end 60 of the first passageway 52 in a liquid-vapor state with a liquid component and a vapor component. The second nozzle 48 comprises a second conduit region defining a second passageway.
The second nozzle 48 comprises a second conduit region 62 defining a second passageway 64. The second nozzle 48 further comprises a second necked-down region 66. The second passageway 64 is downstream of the second necked-down region 66. The second necked-down region 66 and the second passageway 64 are adapted to constitute portions of the flow path when the refrigeration system is operated in a second mode. The second passageway 64 has an upstream cross-section, indicated by the dash line 68, a downstream cross-section, indicated by the dash line 70, a second passageway length PL2 extending from the upstream cross-section 68 of the second passageway 64 to the downstream cross-section 70 of the second passageway, and a discharge end 72. The downstream cross-section 70 of the second passageway 64 is closer to the discharge end 72 of the second passageway than to the upstream cross section 68 of the second passageway. The second nozzle 48 is adapted and configured such that refrigerant is expanded as it passes through the second nozzle and is discharged from the discharge end 72 of the second passageway in a liquid-vapor state with a liquid component and a vapor component. The turbine 28 is positioned and configured to be driven by refrigerant discharged from the discharge end 60 of the first passageway 52 and by refrigerant discharged from the discharge end 72 of the second passageway 64. The discharge port 44 is adapted to permit refrigerant to flow out of the energy recovery apparatus 24. The discharge port 44 of the energy recovery apparatus 24 is downstream of the turbine 28.
The first necked-down region 54 has a downstream end 54a and the second necked-down region 66 has a downstream end 66a. The downstream end 54a of the first necked-down region 54 has a cross-sectional area less than a cross-sectional area of the intake opening of the first nozzle 46. The downstream end 66a of the second necked-down region 66 has a cross-sectional area less than a cross-sectional area of the intake opening of the second nozzle 48. Preferably, each necked-down region 54, 66 gradually decreases in cross-sectional area toward its downstream end 54a, 66a, respectively. Alternatively, each necked-down region may abruptly decrease in cross-sectional area without departing from the scope of the present invention.
Preferably, the first and second passageways 52, 64 are each in the form of a cylindrical bore, but can be of other shapes without departing from the scope of this invention. In the present embodiment, the downstream cross-section 58 of the first passageway 52 is adjacent the discharge (downstream) end 60 of the first passageway 52, and the downstream cross-section 70 of the second passageway 64 is adjacent the discharge (downstream) end 72 of the second passageway 64.
The downstream cross-section 58 of the first passageway 52 has a first effective diameter defined as (4A1/π)1/2, where A1 is the cross-sectional area of the first passageway 52 at the downstream cross-section 58 of the first passageway. The downstream cross-section 70 of the second passageway 64 has a second effective diameter defined as (4A2/π)1/2, where A2 is the cross-sectional area of the second passageway 64 at the downstream cross-section 70 of the second passageway 64. As used herein, the cross-sectional area is the planar area generally perpendicular to the intended direction of flow at the given point in the first or second passageway, e.g., at the downstream cross-section 58 or 70 of the first or second passageway. The cross section of each of the first and second passageways 52, 64 at any point along the passageway length PL1, PL2 is preferably circular, but it is to be understood that other cross-sectional shapes may be employed without departing from this invention. Preferably, the cross-sectional area of the first passageway 52 at the downstream cross-section 58 of the first passageway is not greater than the cross-sectional area of the first passageway at any point along the first passageway length PL1, and the cross-sectional area of the second passageway 64 at the downstream cross-section 70 of the second passageway is not greater than the cross-sectional area of the second passageway at any point along the second passageway length PL2. In the present embodiment, the first passageway 52 has a generally constant cross-sectional area along the first passageway length PL1, and the second passageway 64 has a generally constant cross-sectional area along the second passageway length PL2. The cross-sectional area of the first passageway 52 may be different from the cross-sectional area of the second passageway 64 or may be the same as the cross-sectional area of the second passageway. If the cross-sectional area of the first passageway 52 is the same as the cross-sectional area of the second passageway 64, it is contemplated that the refrigerant will flow through only one of the first and second passageways when the refrigeration system is operated in the first mode, and will simultaneously flow through both the first and second passageways when the refrigeration system is operated in the second mode. Even if the cross-sectional areas of the first and second passageways 52, 64 are the same and the discharge cross-sectional areas are the same, the effective discharge cross-sectional areas will be different for the two modes of operation because in one mode of operation refrigerant will be discharged from only one passageway and in the other mode of operation refrigerant will simultaneously be discharged from both passageways.
Preferably, the passageway length PL1 of the first passageway 52 is at least five times the first effective diameter, and more preferably at least seven and one-half times the first effective diameter, and more preferably at least ten times the first effective diameter, and even more preferably at least twelve and one-half times the first effective diameter. The passageway length PL2 of the second passageway 64 is preferably at least five times the second effective diameter, and more preferably at least seven and one-half times the second effective diameter, and more preferably at least ten times the second effective diameter, and even more preferably at least twelve and one-half times the second effective diameter.
The first nozzle 46 is preferably adapted and configured such that the liquid component of the refrigerant discharged from the discharge end 60 of the first passageway 52 has a velocity that is at least 60% that of the velocity of the vapor component of the refrigerant discharged from the discharge end 60 of the first passageway and more preferably has a velocity that is at least 70% of the velocity of the vapor component of the refrigerant discharged from the discharge end of the first passageway. Likewise, the second nozzle 48 is preferably adapted and configured such that the liquid component of the refrigerant discharged from the discharge end 72 of the second passageway 64 has a velocity that is at least 60% that of the velocity of the vapor component of the refrigerant discharged from the discharge end 72 of the second passageway and more preferably has a velocity that is at least 70% of the velocity of the vapor component of the refrigerant discharged from the discharge end 72 of the second passageway. If the refrigerant is expanded too rapidly in the nozzle (e.g., if the passageway is insufficiently long), then the velocity of the liquid component will be insufficient to impart the desired force on the turbine blades 50.
Preferably, the first nozzle 46 is adapted and configured to discharge the liquid component of the refrigerant from the discharge end 60 of the first passageway 52 at a velocity of at least about 190 feet per second (58 m/s) and more preferably at a velocity of at least about 220 feet/second (67 m/s). Preferably the second nozzle 48 is adapted and configured to discharge the liquid component of the refrigerant from the discharge end 72 of the second passageway 64 at a velocity of at least about 190 feet per second (58 m/s) and more preferably at a velocity of at least about 220 feet/second (67 m/s). Also, the passageways should not be made excessively long such that the pressure of the refrigerant is too low to match the pressure requirements of the evaporator.
Preferably, each of the nozzles 46, 48 is shaped and configured such that refrigerant entering the nozzle at X % liquid and (100-X) % vapor, by mass, is expanded as it passes through the nozzle and is discharged from the discharge end of the corresponding passageway in a liquid-vapor state with a liquid component that is at most at (X-5) % and a vapor component that is at least (105-X) %, by mass. One of ordinary skill in the art will appreciate that “X”, as used herein, is typically the number 100, but could be a number somewhat less than 100.
Referring again to the embodiment of
The energy recovery apparatus of the present invention may be sold or distributed as part of a complete refrigerant system or as a separate unit to be added to a refrigerant system (e.g., to replace an expansion valve of an existing refrigeration system). In connection with the sale or distribution of the energy recovery apparatus, a user (e.g., a purchaser of the energy recovery apparatus) is instructed that the purpose of the energy recovery apparatus is to expand refrigerant in a refrigerant system. The user is induced to have the energy recovery apparatus placed in fluid communication with a fluid line of a refrigeration system, and to have the energy recovery apparatus placed in fluid communication with a condenser and evaporator of a refrigeration system.
Referring to
Another embodiment of a refrigeration system of the present invention is shown schematically in
The heat pump system 216 preferably also includes first and second reversing valves 226, 228 each being movable between a first configuration and a second configuration. The first and second reversing valves 226, 228 are in the first configurations when the heat pump system 216 is operated in the mode which causes refrigerant to flow along the first flow path and are in the second configurations when the heat pump system is operated in the mode which causes refrigerant to flow along the second flow path. The heat pump system is adapted and configured such that refrigerant flows from the compressor 220 to the second heat exchanger 222 via the first reversing valve 226 and from second heat exchanger 222 to the energy recovery apparatus 24 via the second reversing valve 228 when the heat pump system is operated in the mode which causes refrigerant to flow along the first flow path. Refrigerant flows from the compressor 220 to the first heat exchanger 218 via the first reversing valve 226 and from the first heat exchanger 218 to the energy recovery apparatus 24 via the second reversing valve 228 when the heat pump system is operated in the mode which causes refrigerant to flow along the second flow path.
Another embodiment of an energy recovery apparatus of the present invention is indicated generally by reference number 324 in
As various modifications could be made in the constructions and methods herein described and illustrated without departing from the scope of the invention, it is intended that all matter contained in the foregoing description or shown in the accompanying drawings shall be interpreted as illustrative rather than limiting. Thus, the breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims appended hereto and their equivalents.
It should also be understood that when introducing elements of the present invention in the claims or in the above description of exemplary embodiments of the invention, the terms “comprising,” “including,” and “having” are intended to be open-ended and mean that there may be additional elements other than the listed elements. Additionally, the term “portion” should be construed as meaning some or all of the item or element that it qualifies. Moreover, use of identifiers such as first, second, and third should not be construed in a manner imposing any relative position or time sequence between limitations. Still further, the order in which the steps of any method claim that follows are presented should not be construed in a manner limiting the order in which such steps must be performed.
