Patent Application
20160109160
The present subject matter relates generally to packaged terminal air conditioner units.
Certain heat pump systems include a sealed system for chilling and/or heating air with refrigerant. The sealed systems generally include a throttling device for restricting a flow of refrigerant between an outdoor heat exchanger or coil and an indoor heat exchanger or coil of the sealed system. Various throttling devices are available, including capillary tubes, J-T valves, electronic expansion valves, etc. Within the throttling device, at least a portion of the refrigerant within the flow of refrigerant may vaporize.
Packaged terminal air conditioner units generally include a casing and a sealed system. Due to space constraints within the casing, selection of sealed system components for packaged terminal air conditioner units can be limited. For example, relatively small heat exchangers are generally used in packaged terminal air conditioner units due to space constraints within the casing. Utilizing small heat exchangers can result in a large pressure drop across the low pressure side heat exchanger and thereby negatively affect an efficiency of the packaged terminal air conditioner unit. To reduce such pressure drops, certain small heat exchangers include large diameter tubes and/or split refrigerant flow into multiple parallel tubes. However, such small heat exchangers reduce refrigerant velocity through the small heat exchangers and the refrigerant side heat transfer coefficient.
Accordingly, a packaged terminal air conditioner unit with features for reducing a pressure drop of refrigerant across a heat exchanger of the packaged terminal air conditioner unit would be useful. In particular, a packaged terminal air conditioner unit with features for reducing a pressure drop of refrigerant across a heat exchanger of the packaged terminal air conditioner unit without significantly reducing the refrigerant side heat transfer coefficient would be useful.
The present subject matter provides a packaged terminal air conditioner unit. The packaged terminal air conditioner unit includes a phase separator positioned within a casing of the packaged terminal air conditioner unit. The phase separator is coupled to a supply conduit that extends between an exterior coil and an interior coil of the packaged terminal air conditioner unit. The phase separator is configured for separating liquid refrigerant within the supply conduit from vapor refrigerant within the supply conduit. Additional aspects and advantages of the invention will be set forth in part in the following description, or may be apparent from the description, or may be learned through practice of the invention.
In a first exemplary embodiment, a packaged terminal air conditioner unit is provided. The packaged terminal air conditioner unit includes a casing. A compressor is positioned within the casing. The compressor is operable to increase a pressure of a refrigerant. An interior coil is also positioned within the casing. An exterior coil is positioned within the casing opposite the interior coil. A reversing valve is positioned within the casing. The reversing valve is in fluid communication with the compressor in order to receive compressed refrigerant from the compressor. The reversing valve is configured for selectively directing the compressed refrigerant from the compressor to either the interior coil or the exterior coil. A supply conduit is also positioned within the casing. The supply conduit fluidly connects the interior coil and the exterior coil in order to direct refrigerant between the interior coil and the exterior coil. A phase separator is positioned within the casing. The phase separator is coupled to the supply conduit adjacent the interior coil. The phase separator is configured for separating liquid refrigerant within the supply conduit from vapor refrigerant within the supply conduit. The supply conduit directs the liquid refrigerant from the phase separator to the interior coil.
In a second exemplary embodiment, a packaged terminal air conditioner unit is provided. The packaged terminal air conditioner unit includes a casing that extends between an exterior side portion and an interior side portion. A compressor is positioned within the casing. The compressor operable to compress a refrigerant. An interior coil is positioned within the casing at the interior side portion of the casing. An exterior coil is positioned within the casing at the exterior side portion of the casing. A reversing valve is in fluid communication with the compressor in order to receive compressed refrigerant from the compressor. The reversing valve is configured for selectively directing the compressed refrigerant from the compressor to either the interior coil or the exterior coil. A supply conduit extends between the interior coil and the exterior coil. A phase separator is coupled to the supply conduit. The phase separator is configured for separating liquid refrigerant within the supply conduit from vapor refrigerant within the supply conduit. The supply conduit is configured for directing the liquid refrigerant from the phase separator to the interior coil.
In a third exemplary embodiment, a packaged terminal air conditioner unit is provided. The packaged terminal air conditioner unit includes a casing. A compressor is positioned within the casing. The compressor is operable to increase a pressure of a refrigerant. An interior coil is also positioned within the casing. An exterior coil is positioned within the casing opposite the interior coil. A reversing valve is positioned within the casing. The reversing valve is in fluid communication with the compressor in order to receive compressed refrigerant from the compressor. The reversing valve is configured for selectively directing the compressed refrigerant from the compressor to either the interior coil or the exterior coil. A supply conduit is also positioned within the casing. The supply conduit fluidly connects the interior coil and the exterior coil in order to direct refrigerant between the interior coil and the exterior coil. A phase separator is positioned within the casing. The phase separator is coupled to the supply conduit adjacent the exterior coil. The phase separator is configured for separating liquid refrigerant within the supply conduit from vapor refrigerant within the supply conduit. The supply conduit directs the liquid refrigerant from the phase separator to the exterior coil.
These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.
A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures.
Reference now will be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents.
As may be seen in
Casing 110 defines a mechanical compartment 116. Sealed system 120 is disposed or positioned within mechanical compartment 116 of casing 110. A front panel 118 and a rear grill or screen 119 are mounted to casing 110 and hinder or limit access to mechanical compartment 116 of casing 110. Front panel 118 is mounted to casing 110 at interior side portion 112 of casing 110, and rear screen 119 is mounted to casing 110 at exterior side portion 114 of casing 110. Front panel 118 and rear screen 119 each define a plurality of holes that permit air to flow through front panel 118 and rear screen 119, with the holes sized for preventing foreign objects from passing through front panel 118 and rear screen 119 into mechanical compartment 116 of casing 110.
Packaged terminal air conditioner unit 100 also includes a drain pan or bottom tray 138 and an inner wall 140 positioned within mechanical compartment 116 of casing 110. Sealed system 120 is positioned on bottom tray 138. Thus, liquid runoff from sealed system 120 may flow into and collect within bottom tray 138. Inner wall 140 may be mounted to bottom tray 138 and extend upwardly from bottom tray 138 to a top wall of casing 110. Inner wall 140 limits or prevents air flow between interior side portion 112 of casing 110 and exterior side portion 114 of casing 110 within mechanical compartment 116 of casing 110. Thus, inner wall 140 may divide mechanical compartment 116 of casing 110.
Packaged terminal air conditioner unit 100 further includes a controller 146 with user inputs, such as buttons, switches and/or dials. Controller 146 regulates operation of packaged terminal air conditioner unit 100. Thus, controller 146 is in operative communication with various components of packaged terminal air conditioner unit 100, such as components of sealed system 120 and/or a temperature sensor, such as a thermistor or thermocouple, for measuring the temperature of the interior atmosphere. In particular, controller 146 may selectively activate sealed system 120 in order to chill or heat air within sealed system 120, e.g., in response to temperature measurements from the temperature sensor.
Controller 146 includes memory and one or more processing devices such as microprocessors, CPUs or the like, such as general or special purpose microprocessors operable to execute programming instructions or micro-control code associated with operation of packaged terminal air conditioner unit 100. The memory can represent random access memory such as DRAM, or read only memory such as ROM or FLASH. The processor executes programming instructions stored in the memory. The memory can be a separate component from the processor or can be included onboard within the processor. Alternatively, controller 146 may be constructed without using a microprocessor, e.g., using a combination of discrete analog and/or digital logic circuitry (such as switches, amplifiers, integrators, comparators, flip-flops, AND gates, and the like) to perform control functionality instead of relying upon software.
As may be seen in
During operation of sealed system 120 in the cooling mode, refrigerant flows from interior coil 124 flows through compressor 122. For example, refrigerant may exit interior coil 124 as a fluid in the form of a superheated vapor and/or high quality vapor mixture. Upon exiting interior coil 124, the refrigerant may enter compressor 122. Compressor 122 is operable to compress the refrigerant. Accordingly, the pressure and temperature of the refrigerant may be increased in compressor 122 such that the refrigerant becomes a more superheated vapor.
Exterior coil 126 is disposed downstream of compressor 122 in the cooling mode and acts as a condenser. Thus, exterior coil 126 is operable to reject heat into the exterior atmosphere at exterior side portion 114 of casing 110 when sealed system 120 is operating in the cooling mode. For example, the superheated vapor from compressor 122 may enter exterior coil 126 via a first distribution conduit 134 that extends between and fluidly connects reversing valve 132 and exterior coil 126. Within exterior coil 126, the refrigerant from compressor 122 transfers energy to the exterior atmosphere and condenses into a saturated liquid and/or liquid vapor mixture. An exterior air handler or fan 150 is positioned adjacent exterior coil 126 may facilitate or urge a flow of air from the exterior atmosphere across exterior coil 126 in order to facilitate heat transfer.
Sealed system 120 also includes a supply conduit 128 disposed between interior coil 124 and exterior coil 126, e.g., such that supply conduit 128 extends between and fluidly couples interior coil 124 and exterior coil 126. Refrigerant, which may be in the form of high liquid quality/saturated liquid vapor mixture, may exit exterior coil 126 and travel through supply conduit 128 before flowing through interior coil 124. The refrigerant may then be flowed through interior coil 124.
Supply conduit 128 may generally expand the refrigerant, lowering the pressure and temperature thereof. Thus, supply conduit 128 may function as a throttling device for sealed system 120. Supply conduit 128 may include various components for throttling refrigerant flow through supply conduit 128. For example, in the exemplary embodiment shown in
Interior coil 124 is disposed downstream of supply conduit 128 in the cooling mode and acts as an evaporator. Thus, interior coil 124 is operable to heat refrigerant within interior coil 124 with energy from the interior atmosphere at interior side portion 112 of casing 110 when sealed system 120 is operating in the cooling mode. For example, the liquid refrigerant from supply conduit 128 may enter interior coil 124 via a second distribution conduit 136 that extends between and fluidly connects interior coil 124 and reversing valve 132. Within interior coil 124, the refrigerant from supply conduit 128 receives energy from the interior atmosphere and vaporizes into superheated vapor and/or high quality vapor mixture. An interior air handler or fan 148 is positioned adjacent interior coil 124 may facilitate or urge a flow of air from the interior atmosphere across interior coil 124 in order to facilitate heat transfer.
During operation of sealed system 120 in the heating mode, reversing valve 132 reverses the direction of refrigerant flow through sealed system 120. Thus, in the heating mode, interior coil 124 is disposed downstream of compressor 122 and acts as a condenser, e.g., such that interior coil 124 is operable to reject heat into the interior atmosphere at interior side portion 112 of casing 110. In addition, exterior coil 126 is disposed downstream of supply conduit 128 in the heating mode and acts as an evaporator, e.g., such that exterior coil 126 is operable to heat refrigerant within exterior coil 126 with energy from the exterior atmosphere at exterior side portion 114 of casing 110.
As discussed above, when the refrigerant enters supply conduit 128, refrigerant is mostly liquid and is typically subcooled below the saturation temperature. As the refrigerant flows through supply conduit 128, the refrigerant pressure decreases and refrigerant vapor bubbles form. As may be seen in
As may be seen in
Sealed system 120 includes a bypass conduit 162 for directing vapor phase refrigerant from phase separator 160 around interior coil 124. As may be seen in
To facilitate reintroduction of the vapor phase refrigerant from phase separator 160 into second distribution conduit 136, sealed system 120 may include an injector or ejector 166, e.g., configured for combining streams of refrigerant via the Venturi effect. Ejector 166 is positioned at a junction between bypass conduit 162 and second distribution conduit 136. Ejector 166 receives the vapor phase refrigerant from bypass conduit 162 and directs or urges the vapor phase refrigerant into second distribution conduit 136 and refrigerant flowing through second distribution conduit 136.
Ejector 166 may generate a resistance to refrigerant flow upstream from ejector 166 within bypass conduit 162. The resistance of ejector 166 may allow for or provide a balance in the pressure drops across bypass conduit 162 and across interior coil 124, e.g., such that the pressure drops across such components are equal or about (e.g., within ten percent of each other) equal. To provide such balance in pressure drops, bypass conduit 162 may have a smaller diameter than tubing within interior coil 124 and have a suitable length, as will be understood by those skilled in the art.
It should be understood that phase separator 160 may be any suitable type of phase separator. For example, phase separator 160 may be constructed in the same or similar manner to the phase separator described in U.S. patent application Ser. No. 14/088,558 of Brent Alden Junge and/or the phase separator described in U.S. patent application Ser. No. 14/258,397 of Brent Alden Junge et al., both of which are incorporated by reference herein for all purposes. Within a casing of phase separator 160, liquid phase refrigerant may collect or pool at a bottom portion of phase separator 160 and vapor phase refrigerant may collect or pool at a top portion of phase separator 160, e.g., due to density differences between the liquid and vapor phase refrigerants.
By directing vapor phase refrigerant around interior coil 124, a performance and/or efficiency of packaged terminal air conditioner unit 100 may be improved or increased. For example, at an entrance of the interior coil, refrigerant may be approximately twenty to thirty percent vapor by mass in previous packaged terminal air conditioner units. By volume however, the refrigerant is mostly vapor at the entrance of the interior coil because the vapor specific volume is many times larger than that of the liquid refrigerant. By providing phase separator 160 and separating liquid refrigerant from vapor refrigerant as described above, the velocity of refrigerant entering interior coil 124 may be greatly decreased. Such reduction in refrigerant velocity at the inlet of interior coil 124 may reduce a pressure drop across interior coil 124 without a significant reduction in cooling, e.g., because the quantity of liquid refrigerant is unchanged. In particular, phase separator 160 may reduce the pressure drop across interior coil 124 by more than fifty percent while only causing a small reduction in heat transfer. In such a manner, the efficiency of packaged terminal air conditioner unit 100 may be increased by five percent by providing phase separator 160 within sealed system 120 of packaged terminal air conditioner unit 100.
It should be under that the exemplary embodiments of sealed system 120 provided in
This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.
