Patent Grant
10876773
Various commercial applications may require conditioning a medium, such as fluid in an environment. For example, occupants of a building may have a preferred air temperature range for their environment. Thus, controlling air temperature in the building or a portion of the building may provide a comfortable environment for the occupants. Moreover, controlling the medium temperature in an environment may be necessary or preferable for sustaining life and/or preventing damage to property. For instance, a preferred temperature range may be required for vitality of fish and other living organisms. Similarly, maintaining a particular temperature range in an environment may sustain and promote growth of plants. In addition, maintaining a temperature range in an environment may avoid damaging equipment (e.g., avoid freezing of fluid in lines, overheating, etc.) and other property.
Therefore, manufacturers and users of medium conditioning systems continue to seek systems with improved useful life, operating efficiency, low noise, and/or other advantages.
Embodiments disclosed herein relate to devices, systems, and methods for cooling and/or heating a medium as well as cooling and/or heating an environment containing the medium. More specifically, at least one embodiment includes a heat pump that may heat and/or cool a medium and, in some instances, may transfer heat from one location to another location. For example, the heat pump may remove heat from a first location (e.g., interior of a building) to a second location (e.g., exterior of the building), thereby reducing the temperature of the medium at the first location. Alternatively or additionally, the heat pump may heat the medium at the first location.
At least one embodiment includes a heat pump. For example, the heat pump includes a compressor configured to compress a refrigerant and a hot-side heat exchanger operably connected to the compressor. The hot-side heat exchanger is configured to receive the compressed refrigerant from the compressor. The heat pump also includes a cold-side heat exchanger operably connected to the expansion valve and configured to receive the refrigerant therefrom. Additionally, one or more of the hot-side heat exchanger or the cold-side heat exchanger is rotatable.
Embodiments also include a method of operating a heat pump. The method includes compressing a refrigerant and distributing the compressed refrigerant into a hot-side heat exchanger. The method further includes rotating the hot-side heat exchanger together with at least some of the compressed refrigerant, thereby condensing the compressed refrigerant to a liquid-phase.
In an embodiment, a heat pump can be formed that includes a hot-side heat exchanger and a cold-side heat exchanger, wherein the hot-side heat exchanger and the cold-side heat exchanger are concentrically located relative to each other about a common axis of rotation. In another exemplary embodiment, a heat pump can be formed that includes a hot-side heat exchanger and a cold-side heat exchanger that are co-axial but displaced from one another.
In another embodiment, a compressor utilized to compress and circulate a refrigerant through a heat pump is presented. A portion of the compressor assembly is configured to move (e.g., orbitally) relative to a remainder of the compressor assembly. In an embodiment, the compressor assembly comprises a scroll compressor, wherein a relative movement between a non-orbital scroll and an orbital scroll can be achieved by orbitally rotating the orbital scroll at a speed that is different to a speed of rotation of the heat pump, and, accordingly, the non-orbital scroll. In an embodiment, the orbital scroll can operate as a compressor stator. In one or more embodiments, independent control of compressor speed can be performed by utilizing a magnetic coupling to rotate the orbital scroll without breaching a hermetic seal of the compressor assembly, operating the orbital scroll as a rotor of a brushless secondary motor, etc.
In a further embodiment, pressure reduction between the hot-side heat exchanger and the cold-side heat exchanger can be controlled by measuring a pressure (e.g., hydrostatic pressure) at an edge channel of the cold-side heat exchanger. Based upon the measured pressure, a respective size of one or more orifices located between the hot-side heat exchanger and the cold-side heat exchanger can be adjusted, with a corresponding adjustment of pressure in either the hot-side heat exchanger or the cold-side heat exchanger or both. The measured pressure can be translated into a signal that affects an actuator that changes the orifice size. Adjustment of the one or more orifices, in response to a change in the measured pressure, enables pressure control and reduction between a first pressure in the hot-side heat exchanger and a second pressure in the cold-side heat exchanger.
Owing to compressor load increasing with a lower evaporator temperature (for a given condenser temperature), it is advantageous to operate an evaporator at as high an operating temperature as possible, given that the heating/cooling/dehumidification demands placed upon the heat pump by an atmosphere of operation are able to be met. Likewise, it is advantageous to operate a condenser at as low an operating temperature as possible, given that the heating/cooling/dehumidification demands placed upon the heat pump are able to be met. In an embodiment, to enable high temperature operation of the evaporator, a staged set of evaporators can be utilized (e.g., arranged in series), wherein, for a configuration comprising a two-stage evaporator process, a first part of a heat load is first transferred from an air flow (e.g., medium) to a first evaporator (e.g., a refrigerant located therein), and upon exiting the first evaporator, the same air flow enters a second evaporator, where the remainder of the heat load is transferred from the medium to the refrigerant located at the second evaporator. With such a configuration, the first evaporator can operate at a higher evaporator temperature since the temperature decrease of the air flow across the first evaporator is only a fraction of that associated with the total heat load. The remainder of the heat load is transferred to the second evaporator, causing the air temperature to decrease further, hence, the second evaporator can operate at a lower evaporator temperature than the first evaporator.
Features from any of the disclosed embodiments may be used in combination with one another, without limitation. In addition, other features and advantages of the present disclosure will become apparent to those of ordinary skill in the art through consideration of the following detailed description and the accompanying drawings.
The drawings illustrate several embodiments, wherein identical reference numerals refer to identical or similar elements or features in different views or embodiments shown in the drawings.
Embodiments disclosed herein relate to devices, systems, and methods for cooling and/or heating a medium as well as cooling and/or heating an environment containing the medium. More specifically, at least one embodiment includes a heat pump that may heat and/or cool a medium and, in some instances, may transfer heat from one location to another location. For example, the heat pump may remove heat from a first location (e.g., interior of a building) to a second location (e.g., exterior of the building), thereby reducing the temperature of the medium at the first location. Alternatively or additionally, the heat pump may heat the medium at the first location.
In some embodiments, the heat pump may include a hot-side and a cold-side and two respective hot-side and cold-side heat exchangers, which may allow a medium to pass therethrough during operation of the heat pump. Hence, in some instances, a cold-side medium passing through the cold-side heat exchanger may be cooled and hot-side medium passing through the hot-side heat exchanger may be heated. Generally, the heat pump may operate substantially continuously and may, for example, substantially continuously cool or heat medium inside a chamber (e.g., a building) to a suitable or desired temperature.
In an embodiment, cold-side and/or hot-side heat exchangers may be rotatable. For instance, the cold-side and/or hot-side heat exchangers may include one or more rotatable blades, which may have a refrigerant therein (e.g., the blades of the heat exchanger may be hollow and/or may include one or more channels for the refrigerant to flow therein, as described below). Accordingly, the cold-side and/or hot-side medium may exchange heat with blades as the coldside and the hot-side media pass across or otherwise in contact with the blades. Under some operating conditions, rotation of the cold-side and/or hot-side heat exchangers and corresponding blades thereof may reduce the boundary layer at surfaces of the blades of the hot-side and/or cold-side heat exchangers, which may reduce thermal resistance (as compared with an unreduced boundary layer). Reduction of thermal resistance of the blades may be facilitated by including blades with high aspect ratio.
Furthermore, rotation of the cold-side and/or hot-side heat exchangers may reduce fouling and/or clogging thereof, which may facilitate extended operation at an intended or suitable heat-exchange efficiency (as compared with stationary blades of a heat exchanger). Also, in some instances, rotation of the cold-side heat exchanger also may decrease or eliminate reduction in heat transfer between the blades of the cold-side heat exchanger and the cold-side medium that may otherwise result from condensate settling on the blades of the cold-side heat exchanger and/or freezing or frosting of the blades from the condensate. For example, rotation of the blades of the cold-side heat exchanger may expel or otherwise discharge the condensate therefrom. In other words, the centrifugal force due to the rotation, may prevent dust, condensate and other debris from attaching to the heat transfer surfaces of the heat exchangers.
Moreover, under some operating conditions, rotating the cold-side and/or hot-side heat exchanger directly produces relative motion between such heat exchanger (e.g., blades of the heat exchanger) and the surrounding media, which may produce an increase in relative velocity therebetween (as compared with forcing media through a stationary heat exchanger by a blower). In other words, to produce the relative speed between the media forced by the blower and the heat exchanger equal to the speed of the rotating heat exchanger, the blower would require a higher rotational speed than the rotating heat exchanger.
In at least one embodiment, the cold-side and hot-side heat exchangers may be rotated together or substantially simultaneously (e.g., at the same speed or at different speeds). For example, a single motor may rotate both the cold-side and the hot-side heat exchangers. Alternatively, a first motor may rotate the cold-side heat exchanger and a second motor may rotate the hot-side heat exchanger. Moreover, in some instances, the blades of the cold-side heat exchanger may advance the cold-side medium therethrough. Similarly, the hot-side heat exchanger may advance the hot-side medium therethrough.
In an embodiment, as described below in more detail, the heat pump may include a compressor, which may compress and/or pressurize a refrigerant in the heat pump. In some configurations, at least a portion of the compressor may rotate together with the hot-side heat exchanger and/or cold-side heat exchanger. Under some operating conditions, the hot-side heat exchanger, the cold-side heat exchanger, and at least a portion of the compressor may rotate together in a manner that facilitates cooling of the cold-side medium and/or heating of the hotside medium.
For example, the compressor may compress the refrigerant, and the compressed refrigerant may flow from the hot side of the heat pump toward and/or into the cold side of the heat pump. For instance, the compressed refrigerant may be cooled and at least partially condensed at the hot-side heat exchanger and may flow from the hot-side heat exchanger to the cold-side heat exchanger. Specifically, in at least some embodiments, the compressed and condensed refrigerant may expand prior to the cold-side heat exchanger, thereby cooling at least a portion of the cold-side heat exchanger. As the cold-side medium passes through the cold-side heat exchanger, heat from the cold-side medium may be transferred to the cold-side heat exchanger and to the refrigerant therein (i.e., the temperature of the cold-side medium may be lowered as the cold-side medium passes through the cold-side heat exchanger).
Conventional heat pumps typically include a section that superheats the vapor prior to entry into the compressor (i.e., temperature above the vaporization temperature of the refrigerant) to assure that liquid refrigerant does not enter the compressor. This superheating may reduce coefficient of performance of the heat pump. Preventing liquid refrigerant from entering the compressor may increase the useful life thereof. In some embodiments, heat exchangers of the heat pumps described herein may separate the liquid-phase and gas-phase refrigerant, thereby minimizing or eliminating the requirement of superheating of the refrigerant vapor, while channeling the gas-phase refrigerant (i.e., vaporized refrigerant) to the compressor. For example, superheating may be reduced by ensuring that only gas-phase refrigerant exits the cold-side heat exchanger.
Additionally, in some instances, separation of the liquid-phase and gas-phase refrigerant may produce a favorable pressure drop and/or increase heat transfer to the refrigerant. For instance, phase separation may prevent the development and rupture of vapor bubbles and ejection of liquid into surrounding flow of gas-phase refrigerant during phase change from liquid to vapor. Hence, in some examples, such phase-separated, stratified flow may decrease pressure drop in the flow and increase local heat transfer between the refrigerant and media surrounding the heat exchanger. In an embodiment, the heat pump may include microstructures or nanostructures inside channels carrying the refrigerant; such structures may facilitate phase separation and further evaporation at channel surface. For example, such structures may spread a film of liquid-phase refrigerant on the inner surface of channel(s) that carry the refrigerant, such that a larger surface of the liquid-phase refrigerant is in contact with the channel and is exposed to heat transfer with surrounding media.
It should be appreciated that various embodiments described herein are not limited to heat pumps utilizing vapor-compression refrigeration cycles. Other embodiments may include vapor absorption cycles and single-phase gas cycles (e.g., reverse Brayton cycle, Stirling cycle, etc.). Furthermore, the mechanisms of heat exchange and fluid flow characteristics in rotation described herein may be used in other thermal systems that require the transfer of heat between two or more thermal reservoirs. Such embodiments may include phase-change cycles (e.g., Rankine cycle), single-phase cycles (e.g., Brayton cycle, Stirling cycle, Ericsson cycle, Carnot cycle) and electron cycles (e.g., thermoelectric cycles for extraction of useful work therefrom). For consistency in description, the following descriptions will focus on heat pump embodiments utilizing vapor-compression cycles.
Generally, the heat pump 100 may include a hot side 101 and a cold side 102. The hot side 101 may be a condenser side, which may include a compressed refrigerant, and the cold side 102 may be an evaporator side, which may include expanded and/or evaporated refrigerant. Furthermore, the refrigerant may be transferred or distributed from the hot side 101 to the cold side 102 (e.g., the refrigerant may expand before and/or during distribution from the hot side 101 to the cold side 102).
In an embodiment, the heat pump 100 may include a hot-side heat exchanger 120 at the hot side 101 and a cold-side heat exchanger 130 at the cold side 102. As such, for example, the heat pump 100 may pass a cold-side medium (e.g., air from the chamber 10 (as shown in
In an embodiment, as shown in
In some embodiments, the refrigerant may be compressed in the hot side 101 of the heat pump 100. For example, a compressor 140 may compress the refrigerant. Also, the compressed refrigerant may be distributed or circulated into the hot-side heat exchanger 120. Moreover, the compressed refrigerant may be cooled and/or may condense in the hot-side heat exchanger 120 by releasing heat to the hot-side medium. The hot-side medium may therefore increase in temperature as it passes through the hot-side heat exchanger.
In one embodiment, as shown in
Moreover, cooled and compressed and/or condensed refrigerant may be distributed to and expanded prior to entering the cold-side heat exchanger 130, thereby resulting in a lower temperature at the cold-side heat exchanger 130 than at the hot-side heat exchanger 120. The expanded refrigerant in the cold-side heat exchanger 130 may evaporate and/or be may be heated through heat gain from the cold-side medium. Consequently, the medium exiting the cold-side heat exchanger 120 may have a lower temperature than the medium entering the cold-side heat exchanger 120. Circulating the air exiting the hot-side heat exchanger 120 back into the chamber 10 as shown in
In some embodiments, the hot-side heat exchanger 120 and/or cold-side heat exchanger 130 may rotate about one or more rotation axes. For instance, the hot-side heat exchanger 120 and cold-side heat exchanger 130 may rotate about a single rotation axis. In an example, the heat pump 100 may include a motor 150 (e.g., an electric AC or DC motor) that may rotate the hot-side heat exchanger 120 and cold-side heat exchanger 130 about the rotation axis during operation of the heat pump 100. In some examples, the motor 150 may be mounted on or otherwise secured to a motor mount (e.g., the motor mount may remain stationary relative to the housing of the motor 150).
It should be appreciated that the heat pump 100 may include any suitable number of motors that may be arranged in any number of suitable configurations to rotate the hot-side heat exchanger 120 and/or cold-side heat exchanger 130. In an embodiment, a drive shaft 151 may connect the motor 150 to the hot-side heat exchanger 120 and/or cold-side heat exchanger 130. For example, the drive shaft 151 may be connected to the motor 150 or may be integrated therewith. Similarly, the drive shaft 151 may be connected to the hot-side heat exchanger 120 and/or cold-side heat exchanger 130 or may be integrated therewith. In any event, the drive shaft 151 may transfer rotation from the motor 150 to the hot-side heat exchanger 120 and/or cold-side heat exchanger 130. In other embodiments, other power transmission methods, such as gears, pulleys, non-direct couplings (e.g. magnetic coupling) or any combination thereof may be utilized to impart rotation.
In at least one embodiment, the hot-side heat exchanger 120 and cold-side heat exchanger 130 may be connected together by a connecting shaft or connecting conduit 103. In some examples, as described below in more detail, the connecting conduit 103 may include one or more channels for the refrigerant to flow from the hot-side heat exchanger 120 toward the cold-side heat exchanger 130. Additionally or alternatively, the connecting conduit 103 may include one or more channels for the refrigerant to flow toward and/or into the compressor 140. As such, for example, the hot-side heat exchanger 120, cold-side heat exchanger 130, compressor 140, expansion valve 240 (
In some embodiments, the heat pump 100 may heat the chamber medium. For example, as shown in
After exiting the hot-side heat exchanger 120, the air may be directed back into the chamber 10. In an embodiment, the ductwork 110 may include hot-side supply outlet 116, and the air flowing out of the hot-side heat exchanger 120 may enter the chamber 10 through the hotside supply outlet 116. Hence, for instance, the air in the chamber 10 may be heated by circulating the air from the chamber 10, through the hot-side heat exchanger 120.
In an embodiment, the refrigerant may be heated in the cold-side heat exchanger 130 by passing a medium therethrough. For instance, under some operating conditions, ambient air in the ambient environment 20 may have a higher temperature than the expanded refrigerant in the cold-side heat exchanger 130. Accordingly, passing ambient air through the cold-side heat exchanger 130 may heat and/or evaporate the expanded refrigerant therein (i.e., the cold-side heat exchanger 130 may transfer heat from the ambient air to the refrigerant). In at least one example, the ambient air may enter the cold-side heat exchanger 130 through a cold-side ambient intake 117 of the connected ductwork 110 and may be directed toward and into the cold-side heat exchanger 130. After passing through the cold-side heat exchanger 130, the air may be directed back out to the ambient environment 20 through the cold-side ambient outlet 118.
Furthermore, in some embodiments, the connected ductwork 110 may include valves, dampers, louvers, similar mechanisms, or combinations thereof that may reconfigure the heat pump 100 from cooling the air in the chamber 10 (e.g.,
Additionally or alternatively, louvers 161, 162 may close the cold-side chamber intake 111 and the cold-side supply-side outlet 112 of the ductwork 110, such that the air from the chamber 10 is prevented from entering the cold-side heat exchanger 130. In an embodiment, however, louver 167 may be open in a manner that allows the ambient air from the ambient environment 20 to flow through the cold-side ambient intake 117 and into the cold-side heat exchanger 130. Furthermore, louver 168 also may be opened in a manner that allows the air exiting the cold-side heat exchanger 130 flow into the ambient environment 20 through the coldside ambient outlet 118.
Conversely, as shown in
In an embodiment, the louvers 165, 166 may be closed, thereby preventing the air in the chamber 10 from entering the hot-side heat exchanger 120. In some instances, however, the louvers 163, 164 may be open to allow the ambient air to enter and pass through the hot-side heat exchanger 120, in a manner described above. In any case, the heat pump 100 may include any suitable number of louvers, such as louvers 161, 162, 163, 164, 165, 166, 167, 168, which may be operated to reconfigure the conditioning of the air (or other media; e.g. air in the chamber 10). Specifically, the heat pump 100 may be configured to heat or to cool the air in the chamber 10 be opening and/or closing suitable louvers (e.g., as described above). Also, some of the louvers may be opened to allow ingress of fresh/ambient air into the chamber or expulsion of chamber air into the ambient surroundings. For example, when louvers 161 and 162 are opened to allow air from the chamber to pass through the cold-side heat exchanger, louver 167 may be opened to allow some of the ambient air to pass through the cold-side heat exchanger and mix with the air being drawn from the chamber.
In an embodiment, the blades 121 and the inner condenser shell 122 may rotate together about the rotation axis 30. The connecting conduit 103 also may include a core shaft 106 (e.g., the core shaft 106 may provide structural connection between the hot-side heat exchanger 120 and the cold-side heat exchanger 130 (
In an embodiment, as shown in
Generally, the pressure generated by the compressor 140 drives or forces the refrigerant along the hot-side heat exchanger 120 and toward the cold side of the heat pump (e.g., toward the cold-side heat exchanger) as indicated by the arrows. Furthermore, as described below in more detail, in some embodiments, the compressed refrigerant may be in the gas phase. As the compressed refrigerant is cooled in the blades 121, at least some of the refrigerant may condense to a liquid phase. Also, in an embodiment, the condensed refrigerant channel 127 may be radially spaced apart from the rotation axis 30 (e.g., by the blades). Moreover, in some instances, the condensed refrigerant channel 127 may be radially spaced apart from the compressed refrigerant channel 124 (i.e., the blades 121 may space the condensed refrigerant channel 127 from the compressed refrigerant channel 124). In any case, under at least some operating conditions, as the hot-side heat exchanger 120 rotates about the rotation axis 30, centrifugal forces may separate the liquid or condensed refrigerant from the refrigerant in the gas phase and may force the condensed refrigerant away from the rotation axis 30 and into the condensed refrigerant channel 127 of the hot-side heat exchanger 120 (as described below in more detail).
Furthermore, the hot-side heat exchanger 120 may include a blade casing 125 and an outer shell 126 (e.g., the outer shell 126 may define the exterior of the hot-side heat exchanger 120). For example, the condensed refrigerant channel 127 may be formed by and between the blade casing 125 and outer shell 126 (e.g., the condensed refrigerant channel 127 may be approximately cylindrical and/or may wrap around the blade casing 125 and may be enclosed by and between the outer shell 126 and the blade casing 125). In at least one embodiment, the blade casing 125 may be approximately cylindrical. Similarly, the outer shell 126 may be approximately cylindrical. For example, the blades 121 may extend between the inner shell 122 and blade casing 125 (e.g., the blade casing 125 may be secured to the core shaft 106 by the blades 121). Hence, for instance, the blades 121, the inner shell 122, and blade casing 125 may rotate together with the connecting conduit 103.
Also, the outer shell 126 may be attached or connected to the blade casing 125. For example, a portion of the outer shell 126 may be folded or turned toward the blade casing 125 and/or a portion of the blade casing 125 may be folded or turned toward the outer shell 126 and may connect together. In any event, in some embodiments, the blade casing 125 may be attached to the outer shell 126. As such, for instance, the outer shell 126 may rotate together with the blades 121 about the rotation axis 30.
In at least one embodiment, connecting conduit 103 may include a core channel 104. The refrigerant in the core channel 104 may flow and/or may be forced into the compressor 140, where the refrigerant may be compressed thereby. More specifically, in an embodiment, the compressor 140 may be in fluid communication with the core channel 104 (as shown in
For example, the channel(s) passing through the blades 121, at one end, may terminate at openings 129a inside the compressed refrigerant channel 124, and at another end, may terminate at openings 129b inside the condensed refrigerant channel 127. Hence, the compressed refrigerant in the compressed refrigerant channel 124 may enter the blades 121 through the openings 129a and may exit the blades 121 (e.g., after cooling therein) through the openings 129b into the condensed refrigerant channel 127.
Furthermore, in an embodiment, the cooled and/or condensed refrigerant may pass from the condensed refrigerant channel 127 into a refrigerant outlet channel 170. For instance, the refrigerant outlet channel 170 may be formed by and between the inner shell 122 and core shaft 106 and may be separated from the compressed refrigerant channel 124 by a divider. Hence, for example, the hot-side heat exchanger 120 may include a cooling portion 180 and an outlet portion 190. Specifically, along the cooling portion 180, the compressed refrigerant may flow out of the compressed refrigerant channel 124 and into the condensed refrigerant channel 127, while along the outlet portion 190, the condensed refrigerant may flow from the condensed refrigerant channel 127 (through the blades 121) into the refrigerant outlet channel 170. Additionally or alternatively, the core channel 104 may be separated from the compressed refrigerant channel 124 by insulation 105, which may prevent or reduce heat transfer between the refrigerant in the core channel 104 and compressed refrigerant in the compressed refrigerant channel 124 (
In some embodiments, from the refrigerant outlet channel 170, the condensed refrigerant may enter a connector channel 200 through one or more ports 171. As described below in more detail, the condensed refrigerant may flow toward the cold-side of the heat pump (e.g., into the evaporator) through the connector channel 200. In other words, the refrigerant may be compressed by the compressor 140 and may enter the compressed refrigerant channel 124 therefrom. Subsequently, the refrigerant may enter the blades 121 from the compressed refrigerant channel 124 and may be cooled and condensed therein as the hot-side heat exchanger 120 rotates and/or as cooling medium passes over the blades 121. After passing through the blades 121, the compressed and condensed refrigerant may enter the condensed refrigerant channel 127 and move along the condensed refrigerant channel 127 toward the cold side of the heat pump, as indicated with the arrows. Furthermore, the condensed refrigerant may flow from the condensed refrigerant channel 127 across the blades 121 (located in the outlet portion 190 of the hot-side heat exchanger 120) and into the refrigerant outlet channel 170, where the condensed refrigerant may be distributed through the orifices 171 into the connector channel 200 (or, in some instances, into multiple connector channels) and toward the cold-side heat exchanger (e.g., evaporator).
Again, the compressed refrigerant may flow from the compressor into the compressed refrigerant channel 124 of the hot-side heat exchanger 120.
In an embodiment, the coupling 210 may include an inlet channel 220 that may be in fluid communication with the core channel 104. Hence, the expanded and/or evaporated refrigerant may flow from the core channel 104, through the inlet channel 220, and into the compressor. Additionally or alternatively, the coupling 210 may include an outflow channel 230 that may be in fluid communication with the compressed refrigerant channel 124, such that the compressed refrigerant exiting the compressor may enter the compressed refrigerant channel 124 through the outflow channel 230 and may subsequently flow into the hot-side heat exchanger. In any case, the coupling 210 may facilitate suitable circulation of the refrigerant into and out of the compressor.
As described above, the condensed refrigerant may flow from the hot-side heat exchanger toward the cold-side heat exchanger across the connector channel therebetween. Furthermore, as shown in
In some embodiments, as shown in
Moreover, as described below in more detail, the liquid-phase of the refrigerant may separate from the gas-phase refrigerant in the cold-side heat exchanger 130 (e.g., in the blades 131 and/or in the upper inner channel 132). For example, the gas-phase refrigerant may be forced to flow into a lower inner channel 133 and may flow therein (as indicated within the arrows). In an embodiment, the upper inner channel 132 and the lower inner channel 133 may be separated by a perforated wall 134, which may include one or more openings that may allow the gas-phase refrigerant to pass from the upper inner channel 132 into the lower inner channel 133. Furthermore, the gas-phase refrigerant may flow from the lower inner channel 133 into the core channel 104, as shown in
Generally, as illustrated in
For instance, the core shaft 106 and inner shell 135 may define a single channel that may be separated or divided into the upper inner channel 132 and lower inner channel 133 by perforated wall 134. In any event, the cold-side heat exchanger 130 may include the upper inner channel 132 and lower inner channel 133 that may facilitate separation and/or separate flow of gas-phase and liquid-phase refrigerant in the cold-side heat exchanger 130. Moreover, in an embodiment, as mentioned above, the connecting conduit 103 may span between and/or connect together the hot-side heat exchanger 120 (
The cold-side heat exchanger 130 also may include outer channel 136 that may extend along the cold-side heat exchanger 130. More specifically, in an embodiment, the liquid-phase refrigerant may be forced into the outer channel 136 from the blades 131. The outer channel 136 may be formed by and between an outer shell 137 and blade casing 138 of the cold-side heat exchanger 130 (e.g., in a similar manner, such that the condensed refrigerant channel 127 may be formed by and between the outer shell 125 and blade casing 126 of the hot-side heat exchanger 120 (
In at least one embodiment, the liquid-phase refrigerant may flow from the upper inner channel 132 through the blades 131 and into the outer channel 136 (i.e., the blades 131 may provide fluid communication between the outer channel 136 and the upper inner channel 132). The blades 131 may have openings such as 139a at a first end thereof (i.e., at the end attached to the inner shell 135), such that the blades 131 are in fluid communication with the upper inner channel 132 through the openings 139a. The blades 131 also may have a second opening 139b at a second, opposite end thereof (i.e., at the second end, the blades 131 may attach to the blade casing 138, such that the openings 139b are in fluid communication with the outer channel 136). In any case, the blades 131 may provide fluid communication between the upper inner channel 132 and outer channel 136 in a manner that facilitates flow of the liquid-phase refrigerant from the upper inner channel 132 into the outer channel 136. Moreover, the blades 131 may facilitate flow of the gas-phase refrigerant from the blades 131 and/or from the outer channel 136 into upper inner channel 132 (and, subsequently, into the lower inner channel 133).
In an embodiment, the evaporated or gas-phase refrigerant may exit the lower inner channel 133 into the core channel 104. For instance, at an end of the cold-side heat exchanger 130 and/or of the lower inner channel 133, which may be opposite to the expansion valve 240, the lower inner channel 133 may connect with the core channel 104 (e.g., through one or more channels that may be in fluid communication with the core channel 104). Hence, after entering the cold-side heat exchanger 130 through the expansion valve 240 and evaporating in the coldside heat exchanger 130 (e.g., in the blades 131 and/or in the outer channel 136 of the cold-side heat exchanger 130), the gas-phase refrigerant may enter the core channel 104 and may flow toward the compressor (as indicated with the arrows). More specifically, for example as described above, the gas-phase refrigerant may flow into the compressor 140 (
In one or more embodiments, as the cold-side heat exchanger 130 rotates and/or as the cold side medium passes about and/or across the blades 131 of the cold-side heat exchanger 130, heat from the cold-side medium may be transferred to the blades 131 and to the liquid-phase refrigerant therein, thereby heating the liquid-phase refrigerant and cooling the cold-side medium. In some embodiments, the heat transferred from the cold-side medium may evaporate at least a portion of the liquid-phase refrigerant in the channels within the blades 131. Moreover, as described in further detail below, the gas-phase refrigerant may separate from the liquid-phase refrigerant, such that the gas-phase refrigerant flows toward the rotation axis 30 (e.g., into the lower inner channel 133) and the liquid-phase refrigerant flows away from the rotation axis 30 (e.g., from the upper inner channel 132 toward and/or into the outer channel 136).
Generally, as mentioned above, in one or more embodiments, the hot-side and coldside heat exchangers may rotate together. In some instances, the hot-side and cold-side heat exchangers may be approximately coaxial (i.e., may rotate about the same rotation axis) and may be longitudinally spaced from each other (e.g., as shown in
More specifically, as shown in
In some embodiments, the hot-side heat exchanger 120a and cold-side heat exchanger 130a may rotate together as a single unit. For instance, the heat pump 100a can include a motor 150a operatively connected to the hot-side heat exchanger 120a and/or cold-side heat exchanger 130a (e.g., a drive shaft 151a can connect the motor 150a to the hot-side heat exchanger 120a, which may be connected to the cold-side heat exchanger 130a, wherein a first end of the drive shaft 151a connects to the motor 150a, and a second end of the drive shaft 151a connects to the hot-side heat exchanger 120a and/or cold-side heat exchanger 130a).
Furthermore, the media may be directed to flow into the hot-side heat exchanger 120a and cold-side heat exchanger 130a to respectively heat and cool such media and/or to respectively cool and heat the refrigerant in the hot-side heat exchanger 120a and cold-side heat exchanger 130a. More specifically, in an embodiment, the heat pump 100a may include and/or may be connected to ductwork 110a, which may distribute the medium into the hot-side heat exchanger 120a and cold-side heat exchanger 130a. For example, to cool air inside a chamber (e.g., a building, room, compartment, etc.), the ductwork 110a may direct air from the chamber into the cold-side heat exchanger 130a and back into the chamber after the air passes through the cold-side heat exchanger 130a. Conversely, for instance, to heat air in the chamber, the connected ductwork 110a may direct air into the hot-side heat exchanger 120a and back into the chamber after the air exits the hot-side heat exchanger 120a. The arrows shown in
As shown in
Also, in at least one embodiment, the hot-side heat exchanger 120a may include blades 121a that may be attached to and/or between the inner shell 122a and a blade casing 125a (e.g., the blades 121a may secure the blade casing 125a to the inner shell 122a of the hot-side heat exchanger 120a). Moreover, the compressed refrigerant (e.g., gas-phase compressed refrigerant) may enter the compressed refrigerant channel 124a from the core channel 104a and may further flow or may be forced into the blades 121a (e.g., the blades 121a may be similar to one or more of the blades described herein and may include one or more channels therein). For example, the core channel 104a may include multiple perforations or openings providing fluid communication between the core channel 104a and the compressed refrigerant channel 124a (i.e., the refrigerant may flow through the openings in the core channel 104a into the compressed refrigerant channel 124a).
In some embodiments, the refrigerant may flow or may be forced into a condensed refrigerant channel 127a, which may be formed by and between the blade casing 125a and an insulation layer 205 that may be positioned between the hot-side heat exchanger 120a and coldside heat exchanger 130a. The blades 121a may extend between the inner shell 122a and the blade casing 125a and may be secured thereto. Also, the channel(s) of the blades 121a may be in fluid communication with the compressed refrigerant channel 124a and condensed refrigerant channel 127a.
In an embodiment, at least some of the gas-phase refrigerant may condense in the blades 121a of the hot-side heat exchanger 120a and compressed, liquid-phase refrigerant may enter the condensed refrigerant channel 127a (e.g., as described above in connection with the heat pump 100 (
Additionally or alternatively, the compressed, liquid-phase refrigerant may expand into the cold-side heat exchanger 130a. For example, the compressed, liquid-phase refrigerant may pass through one or more expansion valves throttle valves, or orifices located between the hot-side heat exchanger 120a and the cold-side heat exchanger 130a and may enter an inner channel 132a of the cold-side heat exchanger 130a. The inner channel 132a may be formed by and between the insulation layer 205 and an inner shell 135a of the cold-side heat exchanger 130a. In some embodiments, the liquid-phase refrigerant may enter blades 131a of the cold-side heat exchanger 130a (i.e., the blades 131a of the cold-side heat exchanger 130a may be in fluid communication with the inner channel 132a, such that the liquid-phase, expanded refrigerant may enter one or more channels of the blades 131a, as described above).
As mentioned above, after expansion, the temperature of the liquid-phase refrigerant drops. As medium passes through the cold-side heat exchanger 130a and/or about the blades 131a, the heat from the medium may be transferred to the refrigerant. Hence, in some instances, at least some of the refrigerant may be heated sufficiently to evaporate or form gas-phase refrigerant that may be centrifugally separated from the liquid-phase refrigerant as the cold-side heat exchanger 130a rotates about rotation axis 30a″, in a manner described above. More specifically, the gas-phase refrigerant may flow and/or may be forced back into the inner channel 132a and toward the compressor 140a. For instance, the gas-phase refrigerant may be forced toward a return section 139a of the cold-side heat exchanger 130a and may flow across the blades 131a located in the return section 139a and into the compressor 140a.
In some embodiments, the cold-side heat exchanger 130a also may include an outer channel 136a that may be formed or defined by and between an outer shell 137a and blade casing 138a. For example, the expanded, liquid-phase refrigerant may be forced into the outer channel 136a under centrifugal forces as the cold-side heat exchanger 130a rotates about the rotation axis 30a″. In some examples, at least some of the expanded, liquid-phase refrigerant in the outer channel 136a may be evaporated in the same manner as in the blades 131a. In any event, the evaporated, gas-phase refrigerant in the cold-side heat exchanger 130a may flow and/or maybe forced into the compressor 140a, as indicated with the arrows in the return section 139a.
In some embodiments, as mentioned above, the blades 121a and/or the blades 131a of the heat pump 100a may comprise an impeller-like or propeller-like configuration, such that the blades 121a and/or the blades 131a may force media (e.g., air) through the respective hot-side heat exchanger 120a and cold-side heat exchanger 130a. Additionally or alternatively, the heat pump 100a may include one or more fans, blowers, blades configured to advance medium through the hot-side heat exchanger 120a and/or cold-side heat exchanger 130, or combinations thereof. For example, the heat pump 100a may include propeller blades 270a secured to the hotside heat exchanger 120a and/or cold-side heat exchanger 130a and/or the connecting conduit 103a and configured to advance medium therethrough (e.g., the propeller blades 270a may be rotatably or fixedly secured to the hot-side heat exchanger 120a and/or to the cold-side heat exchanger 130a (e.g., the propeller blades 270a may rotate independently of the hot-side heat exchanger 120a and/or cold-side heat exchanger 130a or together therewith). It should also be appreciated that the hot-side heat exchanger 120 and cold-side heat exchanger 130 (
In any event, the heat pump that includes hot-side and/or cold-side heat exchangers with multiple blades (e.g., similar in operation to the blade 260′) may operate continuously to heat and/or cool media on respective hot and cold sides thereof. Generally, however, the refrigeration cycle of the heat pump may vary from one embodiment to the next.
Starting at point A, for example, the refrigerant may be in the gas phase (e.g., the gas-phase refrigerant may be located in the core channel 104 (
After sufficient or suitable cooling in the hot-side heat exchanger to change the phase of the gas-phase refrigerant to liquid, the liquid-phase refrigerant may exit the hot-side heat exchanger, such as at point D. In at least one embodiment, the temperature of the liquid-phase refrigerant (point D) may be lower than the condensation temperature (point C) thereof. In some embodiments, the liquid-phase, compressed refrigerant may expand before or after entering the cold-side heat exchanger (e.g., the liquid-phase refrigerant may pass through an expansion valve 240 (
In addition, as mentioned above, the expanded refrigerant liquid-gas mixture (point E), or, as shown in the embodiment in
The gas-phase refrigerant at point F may flow toward the point A of the cycle (e.g., the gas-phase refrigerant may enter the core channel 104). In some embodiments, the gas-phase refrigerant from point F to point A may be heated or superheated (e.g., inside the core channel 104 (
Moreover, as described above, the gas-phase refrigerant may be separated by centrifugal acceleration from the liquid-phase refrigerant inside the evaporator (e.g., in the blades 131 of the cold-side heat exchanger 130 (
In at least one embodiment, the refrigerant in the cold-side heat exchanger may completely evaporate before entering the conduit connected to the compressor. For example, as shown in
While each of the blades of the compressor and/or evaporator may have a single channel therein, this disclosure is not so limited. For example,
In an embodiment, the multiple channels 261 may be enclosed in and/or defined by one or more outer walls 262, 263 of the blade 260. For example, the outer walls 262, 263 may generally define the outer shape of the blade 260. Generally, the outer shape of the blade 260 may vary from one embodiment to the next. In some embodiments, the outer walls 262, 263 may define or form a wide side 264 and a narrow side or edge 265 of the blade 260. Furthermore, the wide side 264 may have an arcuate shape (e.g., the wide side 264 may be a radius connecting substantially planar portions of the outer walls 262, 263.
The channels 261 may extend between first and second ends 266, 267 of the blade 260. In particular, refrigerant may enter and exit the channels 261 of the blade 260 at the first and/or second ends 266, 267. In addition, in one or more embodiments, the channels 261 are substantially linear. Hence, the refrigerant may flow along an approximately shortest path between the first and second ends 266, 267 of the blade 260.
In some embodiments, the channels 261 may be sufficiently small, such as to prevent stratification or separation of the liquid-phase refrigerant from the gas-phase refrigerant. For example, the direction of flow of the refrigerant may be determined by the pressure produced by the compressor. Hence, in some instances, the flow of the liquid-phase refrigerant and the gas-phase refrigerant may be in the same direction.
Also, as shown in
Generally, the fins 268a may be attached to and/or incorporated with the blades 260a. Furthermore, as noted above, the fins 268a may be in thermal communication with the blade 260, such that heat may be exchanged between the blades 260a and fins 268a and the medium passing through the hot-side and/or cold-side heat exchanger and about the blades 260a and fins 268a. Likewise, heat may be exchanged between the refrigerant in the hot-side and/or cold-side heat exchanger and the blades 260a and fins 268a. Hence, in some examples, increasing surface area of the hot-side and/or cold-side heat exchanger, which is encountered by the medium passing over such surface area, may increase heat transfer between the medium and refrigerant in the corresponding hot-side and/or cold-side heat exchanger.
In some embodiments, the blades 260a may be interconnected with one another by the fins 268a. As such, for instance, the fins 268a may increase the structural rigidity of the blades 260a, as well as the entire heat exchanger assembly. Furthermore, with increased structural rigidity, thickness of the blades 260a may be reduced, thereby facilitating increasing the number of the blades 260a in the hot-side and/or cold-side heat exchanger and surface area provided thereby for heat transfer between medium and refrigerant.
Moreover, according to at least one embodiment, the fins 268a may be approximately perpendicular to the blades 260a (e.g., perpendicular to one or more of the outer walls of the blades 260a). For instance, at least some of the fins 268a may be aligned approximately along and/or parallel to the rotation axis 30a′ (
In an embodiment, the fins 268b may interconnect the blades 260b and blades 260b′. For example, the fins 268b may extend between the blades 260b and blades 260b′ at approximately 45 degree angle. It should be appreciated however, that the fins 268b may extend between the blades 260b and blades 260b′ at any suitable angle. In any event, the fins 268b may increase the overall surface area available for heat transfer between the medium passing through the hot-side and/or cold-side heat exchanger, which includes the blades 260b, blades 260b′ and fins 268b, and the refrigerant (e.g., as such a hot-side and/or cold-side heat exchanger rotates about rotation axis 30b).
Also, while in some embodiments one or more of the channels in the blades may be approximately linear, this disclosure is not so limited.
Moreover, in some embodiments, maintaining the refrigerant in the blades 260c for a longer period of time (e.g., as compared with blades including linear channel(s)) may result in greater heat transfer between the refrigerant and the medium passing through the hot-side and/or cold-side heat exchanger that includes at least one of the blades 260c. For example, more refrigerant may be condensed between the first and second ends 266c, 267c and/or the temperature of the condensed or liquid-phase refrigerant exiting the blades 260c may be lower (as compared with blades including linear channel(s)). Alternatively, the condensation temperature may be lower for the same heat transfer load to the hot medium. Similarly, more refrigerant may be evaporated between the first and second ends 266c, 267c of the blades 260c and/or the temperature of the evaporated or gas-phase refrigerant exiting the blades 260c may be higher (as compared with blades including linear channels). Alternatively, the evaporator temperature may be higher for the same heat transfer load to the cool medium. In other words, heat transfer to the refrigerant may be improved in the cold-side heat exchanger including the blades 260c (or similar blades with nonlinear channels) and heat transfer from the refrigerant may be improved in the hot-side heat exchanger including the blades 260c (or similar blades with nonlinear channels).
Generally, the compressor 140a may be located at any suitable location or end of the core channel 104a. Hence, the refrigerant may have any number of suitable circulation paths and patterns through the heat pump 100a. Moreover, a system may include multiple heat pumps.
Under some operating conditions, as the medium (cold-side or hot-side) passes through corresponding heat exchangers, the medium may develop angular velocity. For example, depending on the length of the heat exchanger, speed of rotation, type of medium, etc., the medium may have the same or similar angular velocity as the rotating heat exchanger. As such, the relative velocity between the blades of the heat exchange and the medium may be reduced, thereby decreasing heat transfer therebetween.
In at least one embodiment, the heat exchange system 400 may include a stator 410 that may remove some or all of the angular movement (swirl) from the medium passing therethrough. For example, the stator 410 may be located between the first and second heat pumps 100a, 100a′ (e.g., the stator 410 may be located downstream from the first heat pump 100a and before the second heat pump 100a′). In an embodiment, the stator 410 may include one or more blades 411 that may be oriented in a manner that may remove angular velocity from the medium as the medium passes through the stator 410, before entering the second heat pump 100a′. In other embodiments, a stator may be placed within a single heat pump to reduce the angular velocity of the medium.
For instance, the blades 411 of the stator 410 may have a twist in a direction opposite to the direction of rotation of the first heat pump 100a, such that the medium exiting the first pump 100a and having an angular velocity in the direction of rotation of the heat pump 100a may straighten out its flow after passing through the stator 400. Moreover, in some embodiments, the stator 400 may be substantially stationary relative to a stationary component (e.g., base) of the first and/or second heat pumps 100a, 100a′. In other embodiments, successive rows of blades may use a different number of blades and/or a different pitch angle. For example, if successive rows of blades have substantially different exit-flow swirl distributions, then to some extent the swirl problem (or minimum relative motion between the air and the nth blade) may be mitigated.
Generally, media may enter and exit the hot-side heat exchanger 120a and cold-side heat exchanger 130a (as well as hot-side heat exchanger 120 and cold-side heat exchanger 130 (
As shown in
As shown in
As mentioned above, in some instances, the blades may include and/or may be interconnected by one or more fins.
In at least one embodiment, as shown in
In some embodiments, as shown in
In at least one embodiment, the channel 124d′ may route the refrigerant in multiple cycles or undulations through the blade 121d′, such that the refrigerant is forced to change directions more than two times. Additionally or alternatively, as shown in
In an embodiment, the channel 124d″ may include multiple undulations, such that the refrigerant may flow in two or more directions in at least some of the blades 121d″. Also, in some examples, multiple blades 121d″ also may be connected together and/or attached to a common base 125d″. It should be appreciated that any of the channel configurations described herein may be included in any of the blades described herein.
As shown in
(1) stagnation of a liquid phase refrigerant in a certain region of a channel (e.g., similar to the stagnation of liquid in a drain trap due to gravity) or
(2) counter-current flow where the vapor flows radially inward while the liquid flows radially outwards, which may inhibit the proper operation of an evaporator 130 with the aforementioned channels (e.g., channel 124 or 261) with discrete inlet and outlets (e.g.,
Alternatively, if the interior features of the hollow fin/blade are appropriately designed to operate with the counter-current flow pattern (i.e. large Bond number), centrifugal and Coriolis forces can segregate and stratify the liquid and vapor flow, potentially leading to heat transfer enhancement and pressure drop reduction in the evaporating flow. An embodiment that enables counter-current flow is a radial channel in the hollow fin/blade that contains both two-phase entry and vapor exit ports at radially inward positions. Evaporation can occur as the liquid is drawn radially outwards, and the evaporated vapor flows radially inward to exit the evaporator. A series of such channels may be made in a single hollow fin/blade, connected by manifolds for the entry and exit flows.
In another embodiment, shown in
As can be ascertained, the shelves are for configured to “catch” liquid that enters the hollow fin 1305 by way of the inlet port 1307, where liquid flows in the manner depicted in
A process for forming liquid pools 1324 can comprise the following: liquid at a radial inward location (e.g., liquid at the inlet port 1307) will be drawn by centrifugal force to flow in the radial outward direction towards the shelves 1310-1318. The liquid will first arrive at the shelf 1318, and after sufficiently filling the first shelf 1318, the overflowing liquid will flow into the shelf 1316. The process of filling the shelves will continue in a radial outward direction by overflowing or through specially designed channel(s) connecting the shelves (e.g., any of 1310-1318), wherein the connecting channels are not shown. Heat transfer to the surface of the hollow fin 1305 can result in vaporization at any of the individual pools 1324. The vapor will flow from the pools to a common open space (e.g., connected to outlet 1309) that manifolds the flow as it moves in the radial inward direction towards the compressor (e.g., compressor 140), e.g., via the outlet port 1309.
In any event, the refrigerant may enter the channels of the blades in the hot-side heat exchanger after being compressed by a compressor, and, after exiting the channels of the blades of the cold-side heat exchanger, may be channeled back to the compressor. Generally, the heat pump may include any suitable compressor, which may vary from one embodiment to the next. Typical compressors compress fluids through the relative movement of the compressor components (e.g., relative movement in the piston/cylinder, scroll/scroll, screw(s)/housing, rotor/housing combinations for reciprocating, scroll, screw and rotary motion (rotary vane, rolling piston, Wankel rotary) compressors, respectively), where the relative movement is driven by a shaft (straight shaft, crankshaft or eccentric shaft depending on the motion required). In an embodiment, the refrigerant may be compressed by maintaining a difference in angular velocity between the compressor shaft and the remainder of the compressor. For example, the heat pump may include a scroll compressor.
In an embodiment, a portion of the compressor may be attached or connected to a support or a stand supporting the heat pump and/or one or more portions thereof.
Furthermore, the compressor 140a may include a rotatable housing 147a, which may rotate together with one or more heat exchangers of the heat pump. For example, the rotatable housing may be connected to the cold-side and/or hot-side heat exchangers of the heat pump. Hence, the rotatable housing 147a may rotate together with the at least one heat exchanger of the heat pump relative to the support 146a. In some instances, the rotatable housing 147a may rotate together with a non-orbital scroll 141a, in a manner that the non-orbital scroll 141a moves relative to the orbital scroll 142a. In some examples, the refrigerant may be fully contained within the rotatable housing 147a and may rotate together therewith.
In an embodiment, the rotatable housing 147a may be coupled or rotatably connected to the mount 143a. For example, one or more bearings (e.g., tapered roller bearings, radial bearings, thrust bearings, etc.) may rotatably support the rotatable housing 147a inside the mount 143a. As mentioned above, the mount 143a may be supported by at least one support 146a.
In an embodiment, the orbital scroll 142a may be actuated by an eccentric shaft 144a. The eccentric shaft 144a may be rotatably connected to the rotatable housing 147a. For instance, the compressor 140a may include one or more bearings that may rotatably secure the eccentric shaft 144a and the orbital scroll 142a to the rotatable housing 147a. As such, the rotatable housing 147a may rotate relative to the eccentric shaft 144a and the orbital scroll 142a.
As described above, in some embodiments, the orbital scroll 142a may maintain an orbital motion relative to at least a portion of the compressor 140a. In an embodiment, this orbital motion may be generated by maintaining the eccentric shaft 144a stationary relative to the mount 143a, while the non-orbital scroll 141a is connected to and rotates with the rotating portions of the heat pump (e.g., the rotating hot-side and/or cold-side heat exchangers). Hence, relative orbital movement of the non-orbital scroll 141a and orbital scroll 142a may compress the refrigerant inside the compressor 140a and produce refrigerant flow as indicated with the arrows. In other embodiments, the orbital motion of the orbital scroll 142a may be generated by rotating the eccentric shaft 144a at a different speed than the non-orbital scroll 141a to compress the refrigerant. In such embodiment, the mount 143a may rotate with the eccentric shaft 144a, and may not be connected to the support 146a.
In an embodiment, the eccentric shaft 144a connected to the orbital scroll 142a may be connected to the mount 143a by magnetic pairs 145a (e.g., a pair of magnets in attraction with each other, which may have respective N and S poles facing each other). More specifically, for instance, first magnetic portions may be attached to the mount 143a and second magnetic portions may be attached to a section of the eccentric shaft 144a. The first and second magnetic portions may exhibit magnetic attraction/repulsion to one another, such that the second magnetic portions and the eccentric shaft 144a remain substantially stationary relative to the mount 143a (i.e. the eccentric shaft 144a and the mount 143a have the same rotation speed). In such embodiment, use of magnetic coupling enables hermetic sealing of the compressor, by avoiding the use of shaft seals, which are needed when the compressor shaft is directly connected to a motor, mount 143a, support 146a or other stationary fixture. It should be appreciated that, in some embodiments, the orbital scroll 142a may exhibit some angular movement (e.g. orbital movement) or rotation during operation of the compressor 140a. In any event, however, the non-orbital scroll 141a may have movement relative to the orbital scroll 142a during operation of the compressor 140a, thereby compressing the refrigerant therein.
In one or more of the embodiments described above, however, a difference in a rotational speed in the compressor, between that of the eccentric shaft and the non-orbital scroll, (hereafter “compressor speed”) will be directly influenced by and equal to the rotational speed of the evaporator (e.g., cold-side heat exchanger 130) and the condenser (e.g., hot-side heat exchanger 120), e.g., as attached to the non-orbital scroll 141a. Such a direct dependence between compressor speed and the rotational speed of the evaporator/condenser may not be desired, and rather, a compressor speed that is independent of the rotational speed of the evaporator 130/condenser 120 may be desired.
In one or more embodiments, it is possible to rotate the compressor stator at a speed different than that of the remainder of the compressor 140a and the heat pump 100, where such independent control of compressor speed can be accomplished in various ways. Examples of achieving independent control include:
(a) a magnetic coupling (e.g., utilizing the magnets 145a) can be used to rotate the compressor stator without breaching the hermetic seal of compressor assembly 140a, and this coupling can be: (1) connected to the stationary frame (e.g., of which support 146a forms a part) by a clutch mechanism, which can be switched off and on, in a manner analogous to a belt-driven automotive air conditioning (A/C) compressor, to vary the average compressor speed and therefore pressure ratio and/or refrigerant flow rate through the scroll compressor, wherein motion of the magnets 145a is transferred to the shaft 114a and the orbital scroll 142a via the spokes of the shaft 144a; (2) a first magnet in the pair of magnets 145a attached to the heat pump mount 143a can be driven by a motor (hereafter “secondary motor”) separate from a motor (e.g., the motor 150, hereafter “primary motor”) that drives the rotation of the remainder of the heat pump 100; or (3) driven by the primary motor (e.g., the motor 150) but at a different speed by the use of a mechanical transmission (e.g. based on a set of gears or pulleys), e.g., applied to the heat pump mount 143a. In this embodiment, component 1410 indicates a secondary motor being utilized.
(b) alternatively, a rotating magnetic field can be established with a motor stator, and the eccentric shaft 144a can be designed to be a rotor of a brushless secondary motor, where the motor stator is located outside of the compressor housing (e.g., outside of the rotatable housing 147a and integrated into the heat pump mount 143a) so that the hermetic seal is not breached. In this embodiment, component 1410 indicates a brushless secondary motor being utilized. The rotating magnetic field generated by the motor stator drives the rotor of the brushless secondary motor 1410, wherein material selection of the compressor housing enables application of an electrical and/or magnetic field through the compressor housing. Examples of brushless secondary motor 1410 include a brushless direct current (DC) motor, an induction motor, a synchronous alternating current (AC) motor, a switched reluctance motor, etc.
In some embodiments, at least a portion of the housing 147a may comprise a low-electrical-conductivity material (e.g., carbon fiber, fiberglass, plastic, etc.). Also, in an embodiment, one or more “black-iron” elements may be used for flux guiding and to minimize reluctance of the magnetic circuit. In some instances, the N and S pairs that comprise the magnetic pair 145a may be alternating, such that each S pole magnet includes an adjacent N pole magnet facing in the same direction. In a further embodiment, a hermetic barrier between rotor and stator of a drive motor may be used to impart relative rotational motion without loss of hermeticity. For example, a non-rotating stator assembly may be used to generate a rotating magnetic field adapted to impart rotation to a rotor structure (e.g., a permanent magnet rotor or squirrel cage induction rotor) that is rigidly attached to one or more structures to which torque is to be transmitted to the eccentric (compressor) shaft.
Alternatively, hermeticity may be maintained in the compressor 140g, as shown in
It should be also appreciated that the compressor may have any suitable configuration (e.g. the compressor can be of various topologies—rotary vane, reciprocating piston, rotary piston, centrifugal, trochoid etc.). For example, a conventional compressor may be used in the heat pump that includes rotatable hot-side and/or cold-side heat exchangers. In an embodiment, a conventional compressor may include an electric motor coupled in a manner that permits rotation of the electric motor and the compressor relative to a stationary power supply. In other words, the compressor may be powered by a motor that may be independent of the motor rotating the hot-side and/or cold-side heat exchangers. Furthermore, in some embodiments, the heat pump and the compressor may form a sealed system that may have fewer or none of the mechanical or movable seals, which may be otherwise present in a conventional heat pump, thereby minimizing or eliminating leakage paths. Additionally, the aforementioned methods of using a magnetic coupling to produce relative motion between compressor components without breaching a hermeticity (i.e. use of a shaft seal) can be applied to other, non-scroll-type mechanical compressors that also compress refrigerant by relative motion between compressor components.
The compressor assembly 140 can be lubricated by oil that is mixed with the refrigerant; however, a condition can arise where lubricant can flow out from the compressor 140. In an embodiment, to mitigate the outflow of lubricant, as shown in
As mentioned above, in some embodiments, the heat pump may include one or more heat exchangers that may be stationary.
Furthermore, the cooling fluid may be cooled in the secondary heat exchanger 290h (e.g., by passing ambient air through the secondary heat exchanger 290h and exchanging heat between the cooling fluid and ambient air, thereby reducing the temperature of the cooling fluid). In some embodiments, the secondary heat exchanger 290h may be a cooling tower. Also, in at least one embodiment, the hot-side heat exchanger 120h may be a tubular member or a conduit in thermal communication with the cooling fluid, such that the refrigerant passing through the hot-side heat exchanger 120h may condense therein. In any event, the condensed refrigerant may exit the hot-side heat exchanger 120h and, after expanding (e.g., after passing through an expansion valve 240h) may enter the cold-side heat exchanger 130h. Similarly, the cold-side heat exchanger may be in thermal communication with a stationary heat exchanger.
In some embodiments, the condenser, or the hot-side heat exchanger, of the heat pump may remain stationary. For example, as illustrated in
Turning to
The orifice size of the pressure reduction device can be dynamically adjusted depending on such conditions as temperature of the air flowing through the evaporator, heat load, compressor speed, etc., such that the volume of liquid in the evaporator 130 remains at a level optimal for evaporation heat transfer. System 1800 comprises a valve 1810, which can be located between the condenser 120 and the evaporator 130. Further, the valve 1810 is connected via a tube 1820 (e.g., a capillary tube) to the outer channel 136 of the evaporator 130 (e.g., the outer rim/manifold, the outer channel 136). As shown, based upon the hydrostatic pressure existent at the evaporator outer channel 136, a diaphragm 1830 is caused to be displaced, causing the valve stem/needle 1840 to move with respect to an orifice 1850 (
A controller 1880, or other device, can be incorporated into the feedback control system 1800, wherein the controller 1880 is configured to generate a signal 1890; the magnitude of the signal 1890 is proportional to the magnitude of hydrostatic pressure of the liquid-phase refrigerant at the outer rim/manifold 136. As further described herein, the signal 1890 can be received at an actuator that can control operation of a pressure reduction device based upon the magnitude of the signal. The controller 1880 can operate by any suitable method, e.g., sensing displacement of the diaphragm 1830, position of the valve stem/needle 1840, etc.
In an embodiment, where the rotational speed of the evaporator/condenser assembly 100 is changed, the change in centrifugal acceleration and the corresponding change in the hydrostatic liquid pressure in the outer rim/manifold 136 (for a given constant liquid level) may be taken into account in the feedback system 1800. In an embodiment, to account for the change in the hydrostatic liquid pressure, a calibrated mass 1815 (which is similarly affected by the change in centrifugal acceleration) can be attached to the valve diaphragm 1830 to compensate for the change in liquid pressure acting on the valve diaphragm 1830. One or more of valve assemblies 1800 can be utilized throughout the system 100, and can be further utilized in the concentric heat pump 100a comprising a hot-side heat exchanger 120a and a cold-side heat exchanger 130a concentrically located relative to each other about a rotation axis 30a″, as illustrated in
In an embodiment shown in
A plurality of capillary channels 1960 can be formed in the channel structure 1940, wherein one or more of the channels 1960 can be positioned to be aligned with the orifices (e.g., co-aligned orifices 1970 and 1980). The channel structure 1940 can be a thermally insulating structure that separates the evaporator 130 and the condenser 120. The channel structure 1940 can have a pipe-like structure, and can be formed from a material(s) having a low thermal conductivity, e.g., a closed cell foam, a polymer, etc. Alternatively, the individual pores of an open-cell foam or other permeable material may be used as the structure channels 1960 to supply the required pressure reduction between the evaporator-side 130 and the condenser-side 120.
In an embodiment, the channel structure 1940 can be formed from a compressible material, where
However,
In another embodiment, where the channel structure 1940 cannot be compressed, the degree of pressure reduction between the evaporator 130 and the condenser 120 can also be adjusted by changing a size of an orifice.
In a further embodiment, where the channel structure 1940 cannot be compressed, the degree of pressure reduction between the evaporator 130 and the condenser 120 may be adjusted by altering the length of the capillary flow path only which a refrigerant 2125 is conveyed, as shown in
The concepts of pressure reduction and/or control presented in
In response to receiving a signal 1890 indicating that the channel effective channel orifice size should be decreased (e.g., a large volume of fluid 2120 is present in the evaporator outer channel 136), the actuator 1955 can adjust the position of the channel structure 2010 and the hole 2020 by sliding the channel structure 2010 such that the position of the hole 2020 is no longer co-aligned with the holes 1970 and 1980, and rather, a center of the hole 2020 is offset with regard to respective centers of the holes 1970 and 1980. The offset position of the hole 2020 with regard to the holes 1920 and 1930, results in a reduction in the relative size of the hole 2020 (per openings 1990 vs. 1995, 2040 vs. 2060, etc.), or an increase in a flow path length which includes the hole 2020 (e.g., the flow path 2130, 2120, and 2140 of
In an embodiment, due to the roughly uniform pressure in the evaporator (e.g., components comprising the cold side 102 of
It is to be noted that a serially staged configuration analogous to that described above may be employed for the condenser 120 (e.g., components comprising the hot side 101 of
To enable staging of two or more evaporators, two or more pressure reduction devices can be utilized to throttle a heat exchanger system to a number of low pressures equal to the number of evaporator stages. Considering a situation in which the pressure reduction (throttling) occurs from a single high pressure source (e.g., from a single condenser), this can be performed in two ways:
1) As shown in
2) In contrast to the serial throttling presented in configuration 2400, throttling can occur in parallel, as shown in
Upon exiting the evaporators, the separated refrigerant flows can be compressed to higher pressures(s), via a plurality of methods:
1) The individual mass flows can have dedicated compressors, which may connect to a common high pressure manifold.
2) The individual mass flows, at different pressures, can also be throttled further to match the lowest pressure evaporator, after which the mass flows can be compressed as a single flow.
3) The individual mass flows, at different pressures, can be introduced to a staged compression system at different stages.
4) The individual mass flows, at different pressures, may be brought to a single, intermediate pressure using an ejector pump (
Alternative embodiments may use multiple condensers, at different temperatures and pressures. Similar to the compression methods described above, compression to the different pressures may be accomplished by using separate compressors for each condenser, or by using a multi-stage compressor with multiple pressure outlets connected to the individual condensers. Likewise, the individual refrigerant flows form the condensers may be combined into a single flow by using an ejector or by throttling the higher pressure flows to match the pressure of the lowest pressure flow. It should be noted that an embodiment may have both multiple evaporators and multiple condensers, where pressurization and throttling of the refrigerant flows can take place in any combination of the methods described above.
Further, a mechanism of returning oil to the compressor 140 can be implemented in the evaporator 130. In an embodiment that allows for liquid refrigerant collection at the outer rim/manifold (e.g., the outer channel 136) of the evaporator, this rim/manifold is analogous to an accumulator in conventional vapor compression cycles, with the difference of liquid accumulation occurring due to centrifugal acceleration (e.g., from rotation of the heat pump 100) rather than a gravitational acceleration.
Other embodiments of the present invention may use different thermal sinks for the heat transfer, such as liquids or a combination of liquid and gas (e.g. air). Referring to
The various embodiments presented herein can be fabricated using traditional sheet metal working methods, extrusions, and joining techniques such as brazing, soldering and welding. In addition to this, a unique fabrication scheme is proposed, as described below.
As shown in
As shown in
In the proposed fabrication process, the individual clam shell pairs of the condenser 120 or the evaporator 130 may be butt welded together, and then the resulting closed-shell assemblies may be butt welded together to build-up each axial assembly/stack. It is possible to stack together the cold forged parts comprising the condenser (evaporator) assembly, and perform a welding operation in series in a single concerted process. The simultaneous creation of multiple welds in series or parallel is a commonly exploited feature of resistance projection welding. In the case of parallel welds, the positive temperature coefficient of resistivity facilitates even current sharing between adjacent welds. In the case of series welds, conservation of current ensures that the current flowing through successive sets of welds (or successive sets of parallel welds) is identical. During the welding process, an aspect of process control is the application of controlled displacement to affect compression of the weld regions (rather than simply applying axial compressive force to the part under the assumption that all weld regions will compress uniformly). It is to be further noted that weld formation does not entail complete melting of the parent material. Rather, elevated temperature is used to drastically reduce the yield strength and increase the diffusivity of the parent material, such that a pressure welded joint can be affected. In additional embodiments, the components to be welded may be coated (e.g. electroplated) with a material that facilitates weld joint formation.
The proposed fabrication/assembly process may potentially eliminate the difficulties associated with controlled atmosphere and salt bath brazing of a large number of individual parts, and associated requirements for complex fixturing. The high temperature pressure welding process may also be advantageous from the standpoint of preserving rotational balance, because no filler material is added, and no parent material is consumed. If necessary, minor adjustments to rotational balancing (static and dynamic) can be implemented as a simple subtractive machining process at the conclusion of the fabrication process.
As depicted schematically in the embodiment shown in
Referring again to
While various aspects and embodiments have been disclosed herein, other aspects and embodiments are contemplated. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting.
This application is a divisional application of, and discloses subject matter that is related to subject matter disclosed in, parent application U.S. patent application Ser. No. 14/857,652, filed Sep. 17, 2015 and entitled “HEATING AND COOLING DEVICES, SYSTEMS AND RELATED METHOD” which claims priority to U.S. Provisional Patent Application No. 62/052,396, filed on Sep. 18, 2014, and entitled “System, Method and Apparatus for Heat Exchange”. U.S. patent application Ser. No. 14/857,652 is additionally a continuation in part of U.S. patent application Ser. No. 14/487,540, filed on Sep. 16, 2014, and entitled “Heating and Cooling Devices, Systems and Related Method”, which claims priority to U.S. Provisional Patent Application No. 61/881,853, filed on Sep. 24, 2013, and entitled “System, Method and Apparatus for Heat Exchange.” The entireties of each of these applications are incorporated herein by reference.
This invention was developed under contract DE-AC04-94AL85000 between Sandia Corporation and the U.S. Department of Energy. The U.S. Government has certain rights in this invention.
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| Number | Date | Country | |
|---|---|---|---|
| Parent | 14857652 | Sep 2015 | US |
| Child | 16546465 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 14487540 | Sep 2014 | US |
| Child | 14857652 | US |
