Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings.
The condenser assembly 10 includes an inlet line or inlet header 15, an outlet line or outlet header 20, and a plurality of condenser modules 25. The inlet header 15 is coupled to the plurality of condenser modules 25 to receive refrigerant from the one or more compressors and to distribute the compressed, gaseous refrigerant to the plurality of condenser modules 25. In the illustrated embodiment, an inlet 26 is disposed adjacent an end of the condenser assembly 10. Refrigerant from the one or more compressors is delivered to the inlet header 15 through the inlet 26 at the end of the condenser assembly 10 in the direction of arrow 27. In other embodiments, the inlet 26 may be disposed in other locations, such as adjacent a middle of the condenser assembly 10 where the refrigerant from the compressors may be delivered to the inlet header 15 at a location between an approximately equal number of condenser modules 25.
The outlet header 20 is coupled to the plurality of condenser modules 25 adjacent a bottom of the condenser assembly 10 to receive the cooled, liquid refrigerant from the plurality of condenser modules 25 and to send the refrigerant to the one or more evaporators. In some embodiments, the outlet header 20 may include space to store liquid refrigerant condensed by the condenser assembly 10 to eliminate a separate, dedicated receiver tank in the refrigeration system.
An outlet 28 is disposed adjacent an end of the condenser assembly 10. Refrigerant from the condenser modules 25 is delivered from the outlet header 20 through the outlet 28 to the one or more evaporators from the end of the condenser assembly 10 in the direction of arrow 29. In other embodiments, the outlet 28 may be disposed in other locations, such as adjacent a middle of the condenser assembly 10 where the refrigerant from the condenser modules 25 may be delivered from the outlet header 20 at a location between an approximately equal number of condenser modules 25.
The plurality of condenser modules 25 are supported by a frame 30. The frame 30 provides support to the plurality of condenser modules 25 to adequately support the condenser assembly 10 on a surface (not shown). The frame 30 may be a freestanding structure as shown in
As shown in
Each condenser coil 35 includes a first inlet port 60, a second inlet port 65, an outlet port 70, an inlet manifold 75, a receiver manifold 80, and an outlet manifold 85. The first inlet port 60 is coupled to the condenser coil 35 adjacent an upper end of the inlet manifold 75 to receive a portion of the refrigerant from the inlet header 15 through the inlet distributor 45. The second inlet port 65 is coupled to the condenser coil 35 below the first inlet port 60 adjacent a lower portion of the inlet manifold 75 to also receive refrigerant from the inlet distributor 45. The outlet port 70 is coupled to the condenser coil 35 at a lower end of the outlet manifold 85 to discharge the refrigerant from the condenser coil 35 into the outlet header 20.
The inlet manifold 75, the receiver manifold 80, and the outlet manifold 85 are fluidly connected by a plurality of microchannels 90 (see
The air moving device 40 is attached to an upper portion of the condenser module 25 to draw ambient air over the condenser coil 35. The illustrated embodiment in
The inlet distributor 45 attaches to the condenser module 25 downstream of the inlet header 15 and upstream of the first and second inlet ports 60, 65 to distribute refrigerant from the inlet header 15 to the first and second inlet ports 60, 65. On condenser modules 25 that include the inlet valve 50, the inlet valve 50 is in fluid communication with the first and second inlet ports 60, 65 and attached to the condenser module 25 adjacent the inlet distributor 45. The inlet valve 50 includes an open position and a closed position to regulate flow of refrigerant into the respective condenser module 25. In the illustrated embodiment, the inlet valve 50 is a solenoid valve, although other valves having open and closed positions are also considered.
The outlet valve 55 is disposed on the condenser module 25 adjacent the outlet port 70 to regulate flow of refrigerant between the condenser coil 35 and the outlet header 20. The outlet valve 55 is a check valve that allows refrigerant to flow from the condenser coil 35 to the outlet header 20 and inhibits flow of refrigerant from the outlet header 20 to the condenser coil 35.
The condenser assembly 10 further includes a sensor 120 and a controller 125.
The controller 125 is coupled to the inlet valve 50 to vary the inlet valve 50 between the open and closed positions to control flow of refrigerant into the condenser coil 35 in response to the condenser inlet pressure. In some embodiments, the controller 125, or portions thereof, may be in electrical communication with the outlet valve 55, as well as other components of the refrigeration system (e.g., compressors, evaporators, thermal expansion valves, etc.). In other embodiments, the controller 125 can base control on other parameters, such as the temperature of the refrigerant in the refrigeration system and the temperature of the air surrounding or interacting with the condenser coils, the evaporator coils, or other refrigeration components. Still other embodiments may include a controller that controls the valve 50 based on a pressure of the refrigeration system other than the condenser inlet pressure, such as a compressor outlet pressure or a compressor inlet pressure.
During operation of the refrigeration system utilizing the condenser assembly 10 the compressed, gaseous refrigerant is directed into the inlet header 15 and through the condenser modules 25 where the heat transfer between the airflow passing over each condenser coil 35 causes the gaseous refrigerant to at least partially condense. The refrigerant flows from the first and second inlet ports 60, 65 into the inlet manifold 75 and through the portion of the condenser coil 35. The refrigerant collects in the receiver manifold 80 and is distributed through the remaining portion of the condenser coil 35 to further discharge heat from the refrigerant into the atmosphere. The cooled, substantially liquid refrigerant flows through the outlet port 70 into the outlet header 20 from the outlet manifold 85. The first and second fans 100, 105 may be activated by the controller to provide and/or enhance the airflow through the condenser coil 35 and to further enhance refrigerant cooling.
The condenser assembly 10 includes a capacity that is indicative of the ability of the condenser assembly 10 to effectively reject heat from refrigerant in the refrigeration circuit to the atmosphere. The condenser capacity varies based on the overall surface area of the condenser assembly 10 that is available to provide heat transfer between the condenser assembly 10 and the atmosphere, and may be affected by ambient temperatures of a surrounding environment or atmosphere. In high ambient air temperature conditions (i.e., summer operation), the condenser capacity to cool refrigerant is relatively low. The high ambient conditions require a high condenser volume to achieve adequate rejection of heat from refrigerant to the atmosphere. In low ambient air temperature conditions (i.e., winter operation), the condenser capacity is relatively high and must be reduced to maintain the condenser inlet pressure due to an increase in heat transfer effectiveness between the condenser assembly 10 and the relatively cool atmosphere. Reduction in heat transfer surface area by decreasing a volume of the condenser during winter operation maintains an effective and efficient refrigeration system.
Winter operation of the condenser assembly 10 requires less condenser capacity to adequately cool refrigerant due to low ambient temperatures. The low ambient temperatures cause refrigerant pressure at the inlet of the condenser assembly 10 to lower and allow less condenser capacity to adequately cool refrigerant flowing through the assembly 10. Likewise, relatively high ambient temperatures cause refrigerant pressure at the inlet of the condenser assembly to increase and cause a need for a higher condenser capacity.
The condenser capacity is at least partially defined by a condenser volume available to reject heat from refrigerant to the atmosphere. The condenser assembly 10 defines a first condenser volume that is indicative of a first condenser capacity when the all inlet valves are open and the plurality of condenser coils 35 are connected to the refrigeration circuit. The refrigerant flows through all available condenser modules 25 to provide adequate cooling for the refrigerant. When the inlet refrigerant pressure drops below the predetermined level, the controller 125 selectively actuates at least one inlet salve 50 independent of the remaining inlet valves 50 to isolate the corresponding condenser module 25 from the refrigeration circuit and to reduce the condenser capacity a first amount.
The condenser assembly 10 defines a second condenser volume that is indicative of a second condenser capacity that is different from the first condenser volume when at least one condenser module 25 is isolated from the refrigeration circuit. The second condenser volume can be more than fifty percent of the first condenser volume by isolating less than one-half of the available condenser modules 25. Alternatively, the second condenser volume can be less than fifty percent of the first condenser volume by isolating more than one-half of the available condenser modules 25. In the condenser assembly 10 shown in
The controller 125 provides effective refrigeration management for the refrigeration system by regulating the condenser capacity. The controller 125 independently operates and controls each condenser module 25 in the condenser assembly 10 and selectively isolates or connects each condenser module 25 with the refrigeration circuit.
The air moving device 40 generates airflow over the condenser coil 35 to regulate the condenser capacity of the condenser assembly 10. The first and second fans 100, 105 are cycled between “on” and “off” conditions to vary the condenser capacity based on the condenser inlet pressure of the condenser assembly 10. Cycling the first and second fans 100, 105 between “on” and “off” conditions varies the condenser capacity of the condenser assembly 10 by adjusting ambient airflow passing over the condenser coils 35. The first and second fans 100, 105 are cycled “off” in response to a low condenser inlet pressure to reduce the condenser capacity. Similarly, the first and second fans 100, 105 are cycled “on” in response to a high condenser inlet pressure to increase the condenser capacity. At least one of the first and second fans 100, 105 remains “on” when refrigerant flows through the corresponding condenser coil 35 of the condenser module 25 that includes those fans 100, 105. The controller selectively cycles at least one of the first fan 100 and the second fan 105 independent of the other of the first fan 100 and the second fan 105 to vary the condenser capacity. In other embodiments, the controller simultaneously cycles the first and second fans 100, 105 between “on” and “off” conditions to vary the condenser capacity. In still other embodiments, the first and second tans 100, 105 can be cycled or controlled by other methods as described above.
The controller 125 also operates the inlet valve 50 to regulate the condenser capacity. The controller 125 manages the refrigeration system by varying the inlet valve 50 between the open and closed positions to isolate the condenser module 25 from the refrigeration circuit. Isolation of the condenser module 25 closes off the condenser coil 35 from refrigerant flowing through the refrigeration circuit. Each inlet valve 50 is operated by the controller 125 independent of the remaining plurality of inlet valves 50 to isolate the corresponding condenser module 25 from the remaining plurality of condenser modules 25. In the illustrated embodiment, the controller is configured to selectively isolate the condenser modules 25 that include the inlet valves 50 without shutting down the condenser assembly 10. Refrigerant continues to flow through the condenser module 25 that is nearest the inlet 26 (i.e., the condenser module 25 without the inlet valve 50), due to the lack of the inlet valve 50 on that condenser module 25. The condenser module 25 without the inlet valve 50 cannot be isolated until the condenser assembly 10 is completely shutdown. In embodiments that include the inlet valve 50 on each condenser module 25, the controller 125 can move the inlet valve 50 on the condenser module 25 that is nearest the inlet 26 to isolate the condenser assembly 10 so that maintenance can be performed on the condenser assembly 10.
If the pressure of the refrigerant at the inlet to the condenser assembly 10 is below a predetermined level, the controller 125 first cycles “off” at least one of the first and second fans 100, 105 of one of the condenser modules 25 to decrease the condenser capacity. The controller 125 cycles “off” the remaining fans 100, 105 as needed to vary the condenser capacity and to maintain adequate refrigerant pressure at the inlet to the condenser assembly 10.
The controller 125 simultaneously cycles “off” any of the first and second fans 100, 105 that are “on” when the corresponding inlet valve 50 is moved to the closed position. There is no need for the first and second fans 100, 105 to operate when the inlet valve 50 is closed because no refrigerant flows through the condenser coil 35 of the respective isolated condenser module 25. In the illustrated embodiment, the controller 125 moves the inlet valve 50 of the condenser module 25 farthest from the inlet of the condenser assembly 10 to the closed position to further decrease the condenser capacity by reducing the condenser volume in response to the condenser inlet pressure below the predetermined level. The controller 125 continues to reduce condenser capacity by closing each of the remaining inlet valves 50 as needed to isolate the remaining condenser modules 25.
In embodiments that include the inlet 26 and/or outlet 28 of the condenser assembly 10 adjacent the middle of the condenser assembly 10, the sequence of shutdown of the condenser modules 25 begins with the condenser module 25 that is farthest from the condenser module 25 that is the last to be shutdown or isolated prior to shutdown of the condenser assembly 10. In the illustrated embodiment, the condenser module 25 that is the last to be deactivated corresponds to the condenser module 25 that is without the inlet valve 50 adjacent the end of the condenser assembly 10. The sequence of isolation moves from the condenser modules 25 located farthest from the condenser module 25 without the inlet valve 50 toward the condenser module 25 without the inlet valve 50, such that the condenser modules 25 that are closest to the condenser module 25 without the inlet valve 50 are the last to be isolated. In other words, the condenser module 25 that is closest to the inlet 26 and/or outlet 28 of the condenser assembly 10 is the last to be deactivated.
The refrigeration management provided by the controller 125 allows precise control of the condenser volume to maintain an adequate condenser inlet pressure. The sequence of isolation of the condenser modules 25 generally begins with the condenser module 25 farthest from the inlet to the condenser assembly 10. The controller 125 isolates the next-farthest condenser module 25 each time the condenser volume must be reduced. When the condenser volume must increase to compensate for an increased condenser inlet pressure, the sequence is reversed. Specifically, the controller 125 opens the inlet valve 50 of the previously-isolated condenser module 25 that is closest to the inlet of the condenser assembly 10. As the condenser inlet pressure increases and there is a need for more condenser volume, the controller 125 opens the inlet valve 50 of the condenser module 25 that is the next-closest to the inlet of the condenser assembly 10. The process continues until there is adequate condenser volume to reject heat from refrigerant to the surrounding environment.
The amount of refrigerant in the refrigeration circuit remains constant during summer and winter operation and reduces the need for large receivers to store refrigerant. Isolation of the condenser module 25 from the refrigeration circuit by the controller 125 limits flow of refrigerant through a portion of the condenser assembly 10. After isolation of the condenser module 25, the outlet valve 55 allows refrigerant within the condenser coil 35 to drain into the outlet header 20. The outlet valve 55 inhibits flow of refrigerant from the outlet header 20 into the condenser coil 35 and isolates the coil 35 from the refrigeration circuit. Draining the refrigerant from the isolated condenser coil 35 maintains the condenser inlet pressure at the predetermined level without the need for a receiver to store excess refrigerant.
When the sensor 120 indicates an increase in the inlet refrigerant pressure above the predetermined level, the controller 125 actuates the inlet valve 50 of at least one condenser module 25 to allow refrigerant to flow into the corresponding condenser coil 35. The controller 125 connects each isolated condenser module 25 one at a time to the refrigeration circuit. If the condenser capacity remains inadequate to cool the refrigerant and to maintain the inlet pressure at about the predetermined level, one or both of the first and second fans 100, 105 may be activated to draw ambient air over the condenser coil 35 of the respective condenser module 25 to improve the condenser capacity. The controller 125 connects enough of the condenser modules 25 to the refrigeration circuit to maintain the inlet condenser pressure at about the predetermined level.
Thus, the invention provides, among other things, an electronic control to regulate condenser capacity and refrigerant charge of a condenser assembly. Various features and advantages of the invention are set forth in the following claims.