Patent Application
20250207834
Not applicable.
This disclosure generally relates to climate control systems. More particularly, this disclosure relates to systems and methods for adjusting a minimum compressor speed of a climate control system.
A climate control system, such as a heating, ventilation, and air conditioning (HVAC) system, may circulate a refrigerant between a pair of heat exchangers (referred to as an “evaporator” and a “condenser”) to exchange heat between an indoor space and ambient environment. The refrigerant may be pressurized using a compressor that may include one or more lubricated bearings. During operation, the bearings may be exposed to the flow of refrigerant so that some of the lubricating oil may be swept or flowed out of the compressor and circulated with the refrigerant.
Some embodiments disclosed herein are directed to a climate control system. In some embodiments, the climate control system includes an evaporator, a condenser, and one or more refrigerant lines that partially define a fluid circuit for a refrigerant between the evaporator and the condenser. In addition, the climate control system includes a variable speed compressor lubricated by oil, the compressor being coupled to the fluid circuit so that the oil is exposed to the refrigerant. Further, the climate control system includes a controller operatively coupled to the compressor and including control circuitry. The control circuitry is configured to receive a diameter of at least one of the one or more refrigerant lines, and adjust a minimum operating speed of the compressor based at least in part on the diameter to provide a minimum flow velocity for the refrigerant to return oil to the compressor through the fluid circuit during operation of the climate control system.
Some embodiments disclosed herein are directed to a method of controlling an operating speed of a compressor of a climate control system. In some embodiments, the method includes (a) receiving a diameter of a refrigerant line of the climate control system with a control circuitry. In addition, the method includes (b) selecting, via the control circuitry, a compressor speed map for the compressor based at least in part on a type of refrigerant of the climate control system and the diameter of the refrigerant line, the compressor speed map defining a minimum operating speed of the compressor to return oil to the compressor via the refrigerant line. Further, the method includes (c) preventing operation of the compressor below the minimum operating speed via the control circuitry.
Some embodiments disclosed herein a directed to a climate control system that includes a first unit including a first heat exchanger. In addition, the climate control system includes a second unit including a second heat exchanger and a variable speed or variable capacity compressor. Further, the climate control system includes a refrigerant line coupled between the first unit and the second unit. Further, the climate control system includes control circuitry communicatively coupled to the compressor. The climate control system is configured to receive a diameter of the refrigerant line, and select a compressor speed map for the compressor based at least in part on a type of refrigerant of the climate control system and the diameter of the refrigerant line, the compressor speed map defining a minimum operating speed of the compressor.
Embodiments described herein comprise a combination of features and characteristics intended to address various shortcomings associated with certain prior devices, systems, and methods. The foregoing has outlined rather broadly the features and technical characteristics of the disclosed embodiments in order that the detailed description that follows may be better understood. The various characteristics and features described above, as well as others, will be readily apparent to those having ordinary skill in the art upon reading the following detailed description, and by referring to the accompanying drawings. It should be appreciated that this disclosure may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes as the disclosed embodiments. It should also be realized that such equivalent constructions do not depart from the spirit and scope of the principles disclosed herein.
For a detailed description of various embodiments, reference will now be made to the accompanying drawings in which:
As previously described, the flow of a refrigerant within a climate control system may also circulate lubricating oil for a refrigerant compressor during operations. Accordingly, a climate control system may be configured to maintain a minimum flow velocity of the refrigerant so as to ensure an adequate return flow of oil to the compressor and thereby maintain adequate lubrication therein during operations. For example, in the case of climate control systems that utilize a multi or variable speed compressor, the minimum operating speed of the compressor may be carefully selected by the manufacturer to ensure a sufficient minimum flow velocity through the system for the refrigerant to return oil to the compressor during operations.
As a further complication, different refrigerant types may have different fluid properties (e.g., viscosity, density, specific gravity, etc.) that affect a flow velocity thereof within a particular refrigerant line. Thus, the manufacturer of a climate control system may pre-select an appropriately sized refrigerant line in conjunction with a minimum compressor speed so as to provide a sufficient flow velocity as previously described.
However, many jurisdictions have recently begun to phase out the use of some refrigerants which have been a staple in climate control systems for decades. For example, common hydrofluorocarbon-based refrigerants, such as R-410A, are now being phased out in favor of hydro-olefin-based refrigerants, such as R-454B, due to their reduced environmental impact.
As a result, in the coming years, a great number of existing climate control systems will be updated or retrofitted to accept these newer refrigerant type(s). As noted above, these alternative refrigerant types have materially different flow properties so that commingling components pre-selected for different refrigerant types, such as refrigerant lines for a first refrigerant and a compressor for a second refrigerant, may create issues for the system. However, replacement of the refrigerant lines connecting the evaporator section and condenser section in an existing climate control system may be undesirable for the consumer given that such a replacement is not cost efficient and/or is aesthetically undesirable. For instance, given that occluding the new refrigerant lines via the same walls or floors as the original refrigerant lines of the climate control system is often not possible or practical during a retrofit of the climate control system. Accordingly, a compressor speed (e.g., a minimum compressor speed) may be adjusted to provide adequate flow velocity of the new refrigerant within the refrigerant lines, particularly in the refrigerant lines or tubing connecting the evaporator and condenser sections, to return a sufficient amount of oil to the compressor via the original refrigerant lines.
To complicate matters further, an over increase in the compressor speed to ensure adequate oil return flow may negatively affect the operating efficiency of the climate control system. Specifically, excessive compressor speeds may increase the rate of temperature change in the indoor space so that the climate control system may cycle on and off more often, which reduces the climate control system's operating efficiency. Moreover, the increased number of cycles may also reduce the ability of the climate control system to reduce a humidity in the indoor space and may cause the temperature of the indoor space to oscillate at a higher frequency so that occupant comfort within the indoor space may suffer.
Accordingly, embodiments disclosed herein include systems and methods for automatically selecting or adjusting a minimum compressor speed of a climate control system based on a refrigerant line size (e.g., diameter, length, etc.) so as to balance the competing needs of adequate oil return flow and operating efficiency. In some embodiments, a climate control system may include a controller that is configured to select a suitable compressor speed map based at least in part on the refrigerant line size and the refrigerant type used, so that the installer may ensure that the replaced or retrofitted climate control system components may operate at an acceptable level of efficiency without causing damage to the compressor. Thus, through use of the embodiments disclosed herein, customers may retrofit or update an existing climate control system to accept an alternative (and potentially more environmentally friendly) refrigerant without also replacing the original refrigerant lines.
Referring now to
Generally speaking, the climate control system 10 (
The climate control system 10 generally includes an evaporator 26, a compressor 30, a condenser 22, and a modulating valve 24. A plurality of refrigerant lines 42, 44, 46, 48 are coupled to and interconnect the evaporator 26, compressor 30, condenser 22, and modulating valve 24 to thereby define a refrigerant fluid circuit 40 (or more simply “fluid circuit”) within the climate control system 10. In particular, a first refrigerant line 42 may be coupled to and extend between the evaporator 26 and the compressor, a second refrigerant line 44 may be coupled to and extend between the condenser 22 and the modulating valve 24, a third refrigerant line 46 may be coupled to and extend between the modulating valve 24 and the evaporator 26, and a fourth refrigerant line 48 may be coupled to and extend between the compressor 30 and the condenser 22.
In some embodiments, the evaporator 26, modulating valve 24 and interconnecting refrigerant line 46 may be embodied as an at least partially integrated first unit 23. In addition, in some embodiments, the compressor 30, condenser 22, and interconnecting refrigerant line 48 may be embodied as an at least partially integrated second unit 25.
In some embodiments, the first unit 23 may be positioned in any suitable space that may or may not be the same (or connected to) the indoor space 12. For instance, the first unit 23 may be positioned in an attic, storage room, basement, building, enclosure, that is proximate to, connected to, or at least partially integrated (or inside of) the indoor space 12. Likewise, the second unit 25 may be positioned in the ambient environment 14, which (as previously described) may be outdoors. Thus, the first unit 23 may be referred to herein as an “indoor unit” and the second unit 25 may be referred to herein as an “outdoor unit.” However, these example positions of units 23 and 25, respectively, is not intended to limit a particular location of either of the units 23, 25 in various embodiments.
The refrigerant lines 42, 44 that extend between the first unit 23 and the second unit 25 may be configured as elongate tubing that may be constructed from a metallic material, such as copper, aluminum, etc. The refrigerant lines 42, 44 may be commonly referred to as the “line set” 45 of the climate control system 10. In many residential applications (e.g., such as in the case of a single-family home), the first unit 23 may be positioned in an attic, basement, or storeroom that is attached or part of the indoor space 12, the second unit 25 may be placed outside of the indoor space 12, and the line set 45 comprising the refrigerant lines 42, 44 may extend through walls or other barriers to connect the first unit 23 and second unit 25.
During operation, a refrigerant (or other heat transfer fluid) is circulated along the fluid circuit 40 between the units 23, 25 to exchange heat between the indoor space 12 and the ambient environment 14. Specifically, the compressor 30 may compress the refrigerant and output the compressed refrigerant to the condenser 22 via the refrigerant line 48. The condenser 22 is a heat exchanger that is configured to facilitate heat transfer between the refrigerant and the ambient environment 14. Because the climate control system 10 is configured as an air conditioner for cooling the indoor space 12, the condenser 22 shown in
Because the refrigerant line 42 carries vaporized (or substantially vaporized) refrigerant during the above-described operations, it may be referred to herein as a “vapor line,” of the fluid circuit 40. In addition, because the refrigerant line 44 carries liquid (or substantially liquid) refrigerant during the above-described operations, it may be referred to herein as a “liquid line,” of the fluid circuit 40.
In some embodiments, the compressor 30 may be operated at a plurality of different speeds so as to change a cooling (or heating) capacity of the climate control system 10 during operations. For instance, the compressor 30 may be a multi-speed compressor 30 that includes a defined number of different operating speeds (e.g., such as a two-stage compressor, three-stage compressor, etc.). In some embodiments, the compressor 30 may be a variable-speed compressor that may be adjusted to a great number of speeds that are between a predefined minimum and maximum speed during operations. Adjusting the speed of the compressor 30 (e.g., via the controller 50 as described in more detail herein) may affect the rate of heating or cooling in the indoor space 12 via the airflow 16. In some embodiments, the speed of the compressor 30 may be actively adjusted during operations based in part on an outdoor ambient temperature as measured by a temperature sensor 56 that is positioned in the ambient environment 14 and communicatively coupled to the controller 50. In some embodiments, the speed of the compressor 30 may be adjusted based on another factor or parameter (e.g., the saturated suction temperature (SST) of the refrigerant).
The compressor 30 may be any suitable compressor type of system, including, for instance, a centrifugal compressor, or positive displacement compressor (reciprocating compressor, scroll compressor, screw compressor, etc.). The compressor 30 may be driven by a driver 31, such as an electric motor (which may include or be coupled to a variable frequency drive), hydraulic motor, pneumatic motor, etc. The compressor 30 may include one or more bearings 32 and/or other mechanical components (e.g., shaft(s), bushing(s), piston(s), cross-head(s), etc.) that may be lubricated with oil 36 (or other suitable lubricant) during operations. In some embodiments, oil 36 may be supplied to the one or more bearings 32 (or other mechanical components as previously described) from a suitable reservoir 38 via a pump 34 (which may comprise a positive displacement pump, centrifugal pump, screw pump, etc.). The pump 34 and/or reservoir 38 may be included or integrated into the housing or casing of the compressor 30 in some embodiments. However, in some embodiments, the reservoir 38 and pump 34 may be omitted and the oil 36 may be initially injected or supplied to the bearings 32 or other mechanical components of the compressor 30 during manufacturing, installation, and/or servicing thereof.
During operations of the climate control system 10, the oil 36 may be at least partially exposed to the flow of refrigerant through the compressor 30. As a result, oil 36 may be swept or flowed out of the compressor 30 and into the fluid circuit 40. Thus, in order to ensure adequate lubrication within the compressor 30 (such as for the bearings 32 and/or other mechanical components), a threshold flow velocity of refrigerant should be maintained in the fluid circuit 40 to return oil 36 to the compressor 30. Failure to return a sufficient amount of oil 36 back to the compressor 30 via the fluid circuit 40 may lead to lack of lubrication and therefore failure of one or more mechanical components of the compressor 30 (e.g., bearings 32, or other components as previously described). Accordingly, during operations, controller 50 may (among other things) adjust the speed of the compressor 30 during operation (via modulation of the driver 31) to ensure a minimum flow velocity of the refrigerant along the fluid circuit 40 to carry or flow a threshold (or minimum) flow of oil 36 back to the compressor 30.
As previously described, existing climate control systems may be retrofitted or updated to allow for use of newer, more environmentally friendly refrigerants. For instance, one or both of the units 23, 25 of climate control system 10 may be retrofitted, updated, and/or replaced to facilitate the use of an alternative refrigerant therein, which may have one or more different fluid properties (e.g., density, viscosity, specific gravity, etc.) from the original refrigerant of climate control system 10 as previously described. However, the different fluid properties of the new refrigerant may benefit from the use of a different sized (e.g., such as a different diameter) line set 45 to provide adequate oil return at the default or pre-set minimum speed of the compressor 30. Because the replacement of the original line set 45 is undesirable as previously described, the operating speed envelope of the compressor 30 may be adjusted to ensure adequate oil return with the new refrigerant via the original line set 45.
Accordingly, the controller 50 may be configured to adjust a minimum speed of the compressor 30 to ensure an adequate flow velocity through the original refrigerant lines 42, 44 to return oil 36 to the compressor 30 during operations. The controller 50 may comprise one or more of a thermostat, a system controller (for the climate control system 10), a controller of the first unit 23 (e.g., such as an “indoor controller”), a controller of the second unit 25 (e.g., such as an “outdoor controller”). Thus, the controller 50 may be at least partially co-located with one or more components of the climate control system 10 (e.g., units 23, 25, compressor 30, evaporator 26, condenser 22, etc.). In some embodiments, the controller 50 may be at least partially embodied in one or more computing devices (e.g., a desktop computer, laptop computer, tablet computer, smartphone, server, or some combination thereof) that are separate (and potentially remotely positioned from) the climate control system 10 and that are communicatively coupled to the climate control system (or a component or controller thereof) via a wired connection, wireless connection, or some combination thereof. In addition, the controller 50 may include one or more control circuitries 52 (which is illustrated as a single control circuitry 52 in
In some embodiments, the controller 50 may comprise a control circuitry 52 that may allow or prompt an installer to input or otherwise provide a diameter (such as an inner diameter, outer diameter, nominal diameter, etc.) of the existing refrigerant lines 42, 44. In some embodiments, the inner diameter of the refrigerant line(s) 42, 44 may be the parameter that affects the flow velocity of the refrigerant during operations. However, the inner diameter of the refrigerant line(s) 42, 44 may be characterized via another, related value, such as an outer diameter, nominal diameter, gauge/type/size number, etc. Thus, in some embodiments, a user may input an outer diameter (or other indicia or value) of one or both of the existing refrigerant lines 42, 44 to the control circuitry 52, and the control circuitry 52 may then determine an associated inner diameter of the refrigerant line(s) 42, 44 based on the received outer diameter (or other indicia or value).
Based on the inputted diameter, for example the inner diameter, control circuitry 52 may then select one or more compressor speed maps 54 (or arrays) for the compressor 30 that may provide a minimum operational speed (or multiple minimum operational speeds) for the compressor 30 that will ensure an adequate flow velocity of the refrigerant through the refrigerant lines 42, 44 to thereby return oil 36 to the compressor 30 during operations while minimizing the negative impact to the operational efficiency and performance of the climate control system 10. The selected compressor speed map(s) 54 may be selected from a plurality of compressor speed maps 54 that are stored on a memory that is included with or communicatively coupled to the controller 50.
Once the compressor speed map(s) are selected, the control circuitry 52 (or another control circuitry of controller 50) may then adjust the operational speed of the compressor 30 during operation within the selected compressor speed map(s) to maintain the speed of the compressor 30 at or above the adjusted minimum compressor speed(s). For instance, in some embodiments, the controller 50 (or control circuitry 52) may determine the outdoor ambient temperature of the ambient environment via the sensor 56 (or another parameter such as the SST as previously described), and then may select a compressor speed from the selected compressor speed map 54 based at least in part on the outdoor ambient temperature (or other parameter) and the demand.
Thus, the controller 50 (particularly the control circuitry 52 of controller 50) may allow an installer to automatically adjust an operating speed envelope of a compressor 30 on-location so as to allow for the use of the existing refrigerant lines 42, 44 in a climate control system 10 that is retrofitted or updated to operate with a new and different refrigerant.
The process 100 may be carried out, at least partially, by one or more apparatuses, components, circuits, and/or the like according to some embodiments disclosed herein. In some embodiments, the process 100 may be performed at least partially by the control circuitry 52 of the controller 50. In some embodiments, the process 100 may be performed by two or more control circuits (or control circuitries) that are, at least in part, communicatively coupled together, such as within or otherwise a part of the controller 50. In some embodiments, the process 100 or instructions for performing the process 100 may be stored in one or more memories included with or accessible by the controller 50, e.g., as a controller algorithm, executable program code, or the like. For instance, the process 100 (or machine-readable instructions therefor) may be stored as computer-readable program code 508 on the memory 504 of the example control circuitry 52 shown in
As shown in
For embodiments in which the refrigerant type is received or confirmed by a user via blocks 102, 104, the control circuitry 52 may prompt a user to input the refrigerant type via a suitable output device (e.g., output device(s) 512 shown in
In addition, in some embodiments, the process 100 may include receiving (and also prompting a user for) a length of the line set 45. For instance, in addition to the inner diameter, the length of the line set 45 may affect the oil retention quantity characteristics of a given refrigerant in that a longer line set 45 may increase a pressure drop of the refrigerant as it flows therethrough. Thus, in some embodiments, the control circuitry 52 may receive a length of the line set 45 (such as a length of either of the lines 42, 44 or the combined length of both lines 42, 44, etc.), and may thereby adjust a minimum compressor speed based (at least in part) on the line set length 45 (e.g., in addition to or in lieu of the diameter).
Next, process 100 includes determining whether the refrigerant line diameter has been received at decision block 106. The refrigerant line diameter may refer to the diameter (such as the inner diameter or outer diameter as previously described) of an existing line set (e.g., lines 42, 44 in
If, on the other hand, the determination at block 106 is “no,” so that the refrigerant line diameter has not already been input or received, the process 100 may proceed to decision block 108 to determine if the user has already been prompted to input the refrigerant line diameter. If, the determination at block 108 is “yes,” then the process 100 may proceed to apply a default line diameter at block 112. If, on the other hand, the determination at block 108 is “no,” and the user has not been prompted to input the line diameter, the process 100 may proceed to block 110 and thereby prompt the user to input the refrigerant line diameter. As previously described for the refrigerant type at block 104, the control circuitry 52 may prompt the user to input the refrigerant line diameter at block 110 via a suitable output device (e.g., an electronic display) and may receive the input refrigerant line diameter via one or more suitable user input devices. In addition, the control circuitry 52 may allow a user to select an appropriate refrigerant line diameter from a plurality of potential diameters (e.g., such as via a drop-down box or other menu type). Once the user has been prompted to input the refrigerant line diameter at block 110, the process 100 may recycle to decision block 106 to determine if the refrigerant line diameter has been received as previously described.
In some embodiments, the line diameter may be input by a user (and thus received by the control circuitry 52) as an inner diameter of one or both of the refrigerant lines 42, 44, or another value indicative thereof. For instance, in some embodiments, the line diameter may be input as a nominal line size, type number, gauge number, or any other number, name, or character that is indicative of or correlated to an inner diameter thereof. Thus, no particular limitation is intended for the particular format of the inputted line diameter for some embodiments disclosed herein.
In some embodiments, the blocks 106, 108, 110 may be repeated a number of times so that the control circuitry 52 prompts the user to input the refrigerant line diameter more than once. In some embodiments, the process 100 may not proceed forward unless and until the user inputs the refrigerant line diameter.
The default line diameter (or “default diameter”) applied at block 112 may comprise a maximum possible line diameter for the refrigerant line(s) 42, 44. For instance, without being limited to this or any other theory, a larger diameter for a refrigerant line may correspond with a lower flow velocity for the refrigerant at a given compressor speed. As a result, if a largest possible diameter is presumed for a refrigerant line 42, 44, then a minimum compressor speed may be increased to ensure a sufficient refrigerant flow velocity as previous described. Thus, in the absence of an inputted line diameter via blocks 106, 108, the control circuitry 52 may assume (via block 112) a maximum default diameter so as to provide a higher overall compressor speed and thereby ensure adequate return flow of oil to the compressor 30 during operations.
With respect to the climate control system 10 shown in
The default refrigerant line diameter applied at block 112 may be an assumed refrigerant line diameter that will result in a relatively higher minimum compressor speed so that a return oil flow to the compressor 30 may be assured. Thus, the default line diameter may be a largest possible line diameter that may selected or input to ensure adequate return oil flow for the compressor 30. However, the higher compressor speed associated with the default line diameter applied at block 112 may negatively impact an operational efficiency and/or performance of the climate control system 10 as previously described. Thus, the default line diameter applied at block 112 may prioritize adequate lubrication to the compressor 30 over operational efficiency of the climate control system 10 in an effort to avoid a failure of the compressor 30.
Once the refrigerant line diameter has been designated (either an input line diameter via blocks 106, 108, 110 or the default line diameter via block 112), the process 100 may proceed to query the operating mode of the climate control system 10 at block 114. For instance, as previously described, the climate control system 10 may be operated in a cooling mode to cool the indoor space 12 or may be operated in a heating mode (e.g., as a heat pump) to the heat the indoor space 12 during operations. The speed control of the compressor 30 may be different depending on whether the climate control system 10 is operated in the cooling mode or the heating mode. Still other operating modes of the climate control system 10 are contemplated in addition to the cooling mode and heating mode (e.g., a defrost mode). Thus, prior to selecting a particular compressor speed map for the compressor 30, the process 100 may first determine the operating mode of the climate control system 10 via block 114. In some embodiments, the operating mode of the climate control system 10 may be determined by querying another component, controller (or control circuitry) of the climate control system. For instance, in some embodiments, the operating mode may be set by the user (or another user) at a thermostat or other device (including a user input device as previously described), and may be communicated to the control circuitry 52.
Following block 114, the process 100 may proceed to select a compressor speed map based on the refrigerant line diameter, refrigerant type, and operating mode at block 116. The compressor speed map selected at block 114 may define a minimum operating speed for the compressor that is configured to return oil to the compressor 30 via the fluid circuit 40 while also facilitating more efficient operation of the climate control system 10. Specifically, the selected compressor speed map may include or define a plurality of compressor speeds (including a plurality of discrete compressor speeds or a continuous range of compressor speeds), and the lowest or smallest of these defined compressor speeds may further define a minimum operating speed for the compressor while operating within the selected compressor speed map. The compressor speed map may be selected at block 114 from a plurality of compressor speed maps that are stored on a memory that is included with or accessible by the controller 50. The plurality of compressor speed maps may be empirically derived using a number of different variables such as the refrigerant type, the refrigerant line diameter, and the operating mode of the climate control system 10. Thus, the plurality of compressor speed maps may be catalogued, sorted, and filtered by one or more of these variables to provide a best fit compressor speed map for the particular configuration of the updated climate control system 10 during operations.
While the compressor speed map 350 is illustrated as a chart including lines 352, 354, it should be appreciated that control circuitry 52 may receive and/or store the compressor speed map 350 in any suitable form. For instance, the control circuitry 52 may receive and/or store the compressor speed map 350 as an array of plot points, one or more mathematical expressions that define the lines 352, 354, a matrix, etc.
The speed of the compressor 30 may be measured or characterized in a number of different ways, the choice of which may be based on the type or design of the compressor 30 itself. For instance, the speed of the compressor may be represented in the compressor speed map 350 as a rotational speed of a primary shaft (e.g., in revolutions-per-minute (RPM), revolutions-per-second (RPS)) of the compressor 30 and/or the driver 31. In addition, in embodiments in which the compressor 30 is a positive displacement style compressor, the speed of the compressor 30 may be represented as a number of strokes or cycles of a piston or plunger per unit time. In some embodiments, the speed of the compressor 30 may be represented in the compressor speed map as a percentage of a maximum speed of the compressor 30 (e.g., such as a maximum allowable speed based on one or more design and/or safety criteria). In some embodiments, the control circuitry 52 may select an input voltage or current to the driver 31 of the compressor 30, and the selected voltage or current may be associated with a particular operating speed of the driver 31 and/or compressor 30.
Referring again to
In some embodiments, block 116 may comprise selecting a plurality of compressor speed maps that are each associated with the selected refrigerant type and the refrigerant line diameter, but that are each associated with a different operating mode for the climate control system 10. Thus, following the selection of the plurality of compressor speed maps and cessation of the process 100, the controller 50 (or one or more control circuitries thereof) may control the speed of the compressor 30 by further selecting the one of the selected plurality of compressor speed maps that corresponds to the current operating mode of the climate control system 10, and then adjusting the speed using the one of the selected plurality of compressor speed maps to ensure adequate return flow of oil to the compressor 30 during operations.
Referring now to
As shown in
Referring still to
Method 200 may also include maintaining the operating speed of the compressor at or greater than the minimum operating speed at block 206 so as to ensure that oil is returned to the compressor 30 to lubricate one or more components thereof during operations. For instance, the control circuitry 52 may ensure that the compressor is operated at or above the minimum operating speed by adjusting the speed of the compressor during operation of the climate control system 10 via the selected compressor speed map, and turning off the compressor when demand for heating and cooling falls below the capacity of the system associated with the minimum compressor speed dictated by the selected compressor speed map.
Referring now to
Method 250 initially includes selecting a plurality of compressor speed maps based on a refrigerant type of a climate control system at block 252. For instance, block 252 may include selecting a plurality of compressor speed maps from a catalogue or other database of compressor speed maps that correspond with a refrigerant type that is to be used with the climate control system 10. As previously described, the compressor speed maps may be stored on a memory that is included with or accessible by the controller 50, may be empirically derived, and may be catalogued and sorted by one or more variables such as, for instance, refrigerant type, refrigerant line diameter, operating mode for the climate control system 10, etc.
In some embodiments, the compressor 30 of the climate control system 10 may be pre-associated with a particular refrigerant type and therefore the plurality of compressor speed maps associated with the pre-selected refrigerant type. As a result, in some embodiments, block 252 may be omitted from method 250.
In addition, method 250 includes receiving a diameter of a refrigerant line for the climate control system at block 254. Receipt of the refrigerant line diameter at block 254 may be the same or substantially the same as previously described for block 202 of method 200. Thus, at block 254, the control circuitry 52 may prompt (e.g., via an output device) or otherwise allow a user to input the diameter (or a value, character, name, or designation indicative thereof) of the refrigerant lines (e.g., lines 42, 44) via one or more suitable user input devices as previously described.
Method 250 also includes determining the operating mode of the climate control system at block 256. For instance, as previously described, the climate control system 10 may be operated in the cooling mode to cool the indoor space 12 or the heating mode to heat the indoor space 12, and the compressor speed map may be different depending on the choice of these two operating modes. Thus, the control circuitry 52 may determine what operating mode the climate control system 10 is placed or configured in at block 256.
Further, method 250 includes selecting one of the plurality of compressor speed maps based on the diameter and the operating mode at block 258. Specifically, as previously described, the compressor speed maps 54 may be catalogued by refrigerant line diameter and operating mode (among other variables). So, at block 258, the control circuitry 52 may select the compressor speed map 54 that is associated with the refrigerant line size and the operating mode of the climate control system from blocks 154, 156, respectively.
Finally, method 250 includes preventing operation of the compressor below a minimum speed defined in the selected one of the plurality of compressor speed maps at block 260. Specifically, the compressor speed map may have a minimum speed defined therein, and the minimum speed may be configured to provide a threshold flow velocity within the refrigerant lines 42, 44 to return oil to the compressor 30 during operations as previously described. Thus, by adjusting the speed of the compressor 30 within the selected one of the plurality of compressor speed maps, the controller 50 (and particularly the control circuitry 52) can ensure the compressor speed is at or above the minimum speed defined in the selected one of the plurality of compressor speed maps to therefore provide adequate lubrication to the compressor 30 during operation of the climate control system 10.
Referring now to
Initially, method 300 may include replacing one or more components of a climate control system that was initially configured to circulate a first refrigerant at block 302. For instance, retrofitting or updating climate control system 10 may include removing or replacing one or more components of the first unit 23 and/or the second unit 25 (e.g., such as evaporator 26, modulating valve 24, condenser 22, compressor 30, etc.).
However, in order to save costs and maintain the aesthetic appearance of the original climate control system, one or more of the original refrigerant lines, such as the refrigerant lines 42, 44 defining the line set of the climate control system 10, may not be removed or replaced along with the one or more components at block 302. Thus, the method 300 includes maintaining one or more of the original refrigerant lines of the climate control system at block 304.
In addition, method 300 includes charging a second refrigerant into the climate control system at block 306. The second refrigerant may be different from the first refrigerant that was originally included in the climate control system. In addition, the second refrigerant may have one or more fluid properties (e.g., density, viscosity, specific gravity, etc.) that are different from the corresponding fluid properties of the first refrigerant. These differences in first and second refrigerants may cause a standard operating speed (particularly a standard minimum operating speed) of the compressor 30 to be incompatible with the original refrigerant lines that were maintained from the initial configuration of the climate control system 10. As a result, operation of the compressor 30 (which may have been replaced or otherwise updated per block 302) at the standard operating speeds thereof may not return an adequate flow of oil to the compressor 30 during operations to maintain an acceptable level of lubrication therein. Accordingly, blocks 308, 310, 312 of method 300 may be performed to update and adjust the minimum speed of the compressor to ensure sufficient lubrication for the compressor while utilizing the original refrigerant lines (e.g., refrigerant lines 42, 44) of the climate control system.
Specifically, method 300 includes providing a diameter of the one or more original refrigerant lines to control circuitry at block 308. As previously described, the diameter of the original refrigerant lines that are maintained from the original configuration of the climate control system 10 may be input to control circuitry 52 of controller 50 via a suitable user input device as previously described.
In addition, method 300 includes selecting, with the control circuitry, a minimum speed of the compressor based at least in part on the diameter of the original refrigerant lines and the second refrigerant at block 310, and then adjusting the operating speed of the compressor to be equal to or greater than the minimum operating speed at block 312. For instance, as previously described, the control circuitry 52 may select one or more compressor speed maps from a plurality of compressor speed maps that are stored on a memory that is included with or accessible by the controller 50. The plurality of compressor speed maps may be empirically determined based on a number of variables such as, for instance, refrigerant line diameter, refrigerant type, operating mode of the climate control system, etc. Thus, at block 310, the selected compressor speed map may be selected so as to correspond to the diameter of the original refrigerant line, the second refrigerant type, and the current operating mode of the climate control system.
As is also previously described above, the selected compressor speed map may define a plurality of operational speeds of the compressor based on one or more other variables (e.g., outdoor ambient temperature, SST, etc.). Thus, a minimum speed of the selected compressor speed map may define a minimum speed of the compressor during operation with the climate control system. However, because the compressor speed map is selected to correspond with one or more of the parameters of the updated climate control system, namely the original refrigerant line diameter and the second refrigerant type, the minimum speed of the compressor defined by the compressor speed map may be sufficient to return a threshold flow of oil to the compressor during operations so as to ensure adequate lubrication thereof.
Indoor unit 402 generally comprises an indoor air handling unit comprising an indoor heat exchanger 408, an indoor fan 410, an indoor metering device 412, and an indoor controller 424. The indoor heat exchanger 408 may generally be configured to promote heat exchange between a refrigerant fluid carried within internal tubing of the indoor heat exchanger 408 and an airflow that may contact the indoor heat exchanger 408 but that is segregated from the refrigerant fluid. Indoor unit 402 may at least partially include, or be coupled to, a duct system 432 including one or more of an air return duct, a supply duct, a register, a vent, a damper, an air filter, or the like for providing airflow.
The indoor metering device 412 may generally comprise an electronically-controlled motor-driven electronic expansion valve (EEV). In some examples, however, the indoor metering device 412 may comprise a thermostatic expansion valve, a capillary tube assembly, and/or any other suitable metering device.
Outdoor unit 404 generally comprises an outdoor heat exchanger 414, a compressor 416, an outdoor fan 418, an outdoor metering device 420, a switch over valve 422, and an outdoor controller 426. The compressor 416 may be any type of compressor, including a compressor the same or similar to compressors discussed above. The outdoor heat exchanger 414 may generally be configured to promote heat transfer between a refrigerant fluid carried within internal passages of the outdoor heat exchanger 414 and an airflow that contacts the outdoor heat exchanger 414 but is segregated from the refrigerant fluid.
The outdoor metering device 420 may generally comprise a thermostatic expansion valve. In some examples, however, the outdoor metering device 420 may comprise an electronically-controlled motor driven EEV similar to indoor metering device 412, a capillary tube assembly, and/or any other suitable metering device.
In some examples, the switch over valve 422 may generally comprise a four-way reversing valve. The switch over valve 422 may also comprise an electrical solenoid, relay, and/or other device configured to selectively move a component of the switch over valve 422 between operational positions to alter the flow path of refrigerant fluid through the switch over valve 422 and consequently the climate control system 400. Additionally, the switch over valve 422 may also be selectively controlled by the system controller 406, an outdoor controller 426, and/or the indoor controller 424.
The system controller 406 may generally be configured to selectively communicate with the indoor controller 424 of the indoor unit 402, the outdoor controller 426 of the outdoor unit 404, and/or other components of the climate control system 400. In some examples, the system controller 406 may be configured to control operation of the indoor unit 402, and/or the outdoor unit 404. In some examples, the system controller 406 may be configured to monitor and/or communicate with a plurality of temperature and pressure sensors associated with components of the indoor unit 402, the outdoor unit 404, and/or the outdoor ambient environment.
Additionally, in some examples, the system controller 406 may comprise a temperature sensor and/or may further be configured to control heating and/or cooling of conditioned spaces or zones associated with the climate control system 400. In some examples, the system controller 406 may be configured as a thermostat for controlling the supply of conditioned air to zones associated with the climate control system 400, and in some examples, the thermostat includes a temperature sensor.
The system controller 406 may also generally comprise an input/output (I/O) unit (e.g., a graphical user interface, a touchscreen interface, or the like) for displaying information and for receiving user inputs. The system controller 406 may display information related to the operation of the climate control system 400 and may receive user inputs related to operation of the climate control system 400. However, the system controller 406 may further be operable to display information and receive user inputs tangentially related and/or unrelated to operation of the climate control system 400. In some examples, the system controller 406 may not comprise a display and may derive all information from inputs that come from remote sensors and remote configuration tools.
In some examples, the system controller 406 may be configured for selective bidirectional communication over a communication bus 428, which may utilize any type of communication network. For example, the communication may be via wired or wireless data links directly or across one or more networks, such as a control network. Examples of suitable communication protocols for the control network include CAN, TCP/IP, BACnet, LonTalk, Modbus, ZigBee, Zwave, Wi-Fi, SIMPLE, Bluetooth, and the like.
The indoor controller 424 may be carried by the indoor unit 402 and may generally be configured to receive information inputs, transmit information outputs, and/or otherwise communicate with the system controller 406, the outdoor controller 426, and/or any other device 430 via the communication bus 428 and/or any other suitable medium of communication. In some examples, the device 430 may be a sensor (e.g., temperature sensor 56 shown in
The outdoor controller 426 may be carried by the outdoor unit 404 and may be configured to receive information inputs from the system controller 406, which may be a thermostat. In some examples, the outdoor controller 426 may be configured to receive information related to an ambient temperature associated with the outdoor unit 404, information related to a temperature of the outdoor heat exchanger 414, and/or information related to refrigerant temperatures and/or pressures of refrigerant entering, exiting, and/or within the outdoor heat exchanger 414 and/or the compressor 416.
In some embodiments, the climate control system 400 may also include the control circuitry (e.g., the control circuitry 52 previously described) for adjusting a minimum operating speed of the compressor 416 based on the diameter of one of more refrigerant fluid lines forming the refrigerant fluid circuit 434 as previously described herein. In some embodiments, the control circuitry may be at least partially included in one or more of the system controller 406, the indoor controller 424, or the outdoor controller 426.
The processor 502 may be configured to access and/or execute computer programs such as computer-readable program code 506, which may be stored onboard the processor or otherwise stored in the memory 604. In some examples, the processor 502 may be embodied as, or otherwise include, one or more ASICs, FPGAs or the like. Thus, although the processor 502 may be capable of executing a computer program to perform one or more functions, the processor 502 of various examples may be capable of performing one or more functions without the aid of a computer program.
The memory 504 is generally any piece of computer hardware capable of storing information such as, for example, data, computer-readable program code 506 or other computer programs, and/or other suitable information either on a temporary basis and/or a permanent basis. The memory 504 may include volatile memory such as random access memory (RAM), and/or non-volatile memory such as a hard drive, flash memory or the like. In various instances, the memory may be referred to as a computer-readable storage medium, which is a non-transitory device capable of storing information. In some examples, then, the computer-readable storage medium is non-transitory and has computer-readable program code stored therein that, in response to execution by the processor 502, causes the control circuitry 52 to perform various operations as described herein, some of which may in turn cause the climate control system to perform various operations.
In addition to the memory 504, the processor 502 may also be connected to one or more peripherals such as a network adapter 506, one or more input/output (I/O) devices (e.g., input device(s) 510, output device(s) 512) or the like. The network adapter 506 is a hardware component configured to connect the control circuitry 500 to a computer network to enable the control circuitry to transmit and/or receive information via the computer network. The I/O devices may include one or more input devices capable of receiving data or instructions for the control circuitry, and/or one or more output devices capable of providing an output from the control circuitry. Examples of suitable input devices include a keyboard, keypad or the like, and examples of suitable output devices include a display device such as a one or more light-emitting diodes (LEDs), a LED display, a liquid crystal display (LCD), or the like.
As explained above and reiterated below, the present disclosure includes, without limitation, the following example implementations.
Embodiments disclosed herein include systems and methods for automatically selecting or adjusting a minimum compressor speed of a climate control system based on a refrigerant line size (e.g., diameter) so as to balance the competing needs of adequate oil return flow and operating efficiency. As previously described, in some embodiments, a climate control system may include a controller that is configured to select a suitable compressor speed map based at least in part on the diameter of the refrigerant line and the refrigerant type used, so that the installer may ensure that the replaced or retrofitted climate control system may operate at an acceptable level of efficiency without causing damage to the compressor. Thus, through use of the embodiments disclosed herein, consumers may retrofit or update an existing climate control system to accept an alternative (and potentially more environmentally friendly) refrigerant without also replacing the original refrigerant lines.
The preceding discussion is directed to various exemplary embodiments. However, one of ordinary skill in the art will understand that the examples disclosed herein have broad application, and that the discussion of any embodiment is meant only to be exemplary of that embodiment, and not intended to suggest that the scope of the disclosure, including the claims, is limited to that embodiment.
The drawing figures are not necessarily to scale. Certain features and components herein may be shown exaggerated in scale or in somewhat schematic form and some details of conventional elements may not be shown in interest of clarity and conciseness.
In the discussion herein and in the claims, the terms “including” and “comprising” are used in an open-ended fashion, and thus should be interpreted to mean “including, but not limited to . . . ” Also, the term “couple” or “couples” is intended to mean either an indirect or direct connection. Thus, if a first device couples to a second device, that connection may be through a direct connection of the two devices, or through an indirect connection that is established via other devices, components, nodes, and connections. In addition, as used herein, the terms “axial” and “axially” generally mean along or parallel to a given axis (e.g., central axis of a body or a port), while the terms “radial” and “radially” generally mean perpendicular to the given axis. For instance, an axial distance refers to a distance measured along or parallel to the axis, and a radial distance means a distance measured perpendicular to the axis. Further, when used herein (including in the claims), the words “about,” “generally,” “substantially,” “approximately,” and the like, when used in reference to a stated value mean within a range of plus or minus 10% of the stated value.
While exemplary embodiments have been shown and described, modifications thereof can be made by one skilled in the art without departing from the scope or teachings herein. The embodiments described herein are exemplary only and are not limiting. Many variations and modifications of the systems, apparatus, and processes described herein are possible and are within the scope of the disclosure. Accordingly, the scope of protection is not limited to the embodiments described herein, but is only limited by the claims that follow, the scope of which shall include all equivalents of the subject matter of the claims. Unless expressly stated otherwise, the steps in a method claim may be performed in any order. The recitation of identifiers such as (a), (b), (c) or (1), (2), (3) before steps in a method claim are not intended to and do not specify a particular order to the steps, but rather are used to simplify subsequent reference to such steps.
