CONTROLLER AND METHOD FOR MANAGING ECONOMIZER OUTPUTS

Abstract

There are disclosed controllers and methods for managing economizer outputs. The economizer controller comprises an input component, a processor, and an output component. The input component receives incoming control signals from an input device, in which each incoming control signal is associated with a corresponding compressor. The processor generates an altered association of some of the incoming control signals to a different compressor based on a predetermined criteria. The output component sends output control signals based on the altered association to a control circuit associated with the compressors.

Description

FIELD OF THE INVENTION

[0001] This application relates to the field of environmental control systems and, more particularly, to system operation of fresh air intake components of HVAC units.

BACKGROUND

[0002] An environmental control system of a building manages heating, ventilation, and air conditioning (HVAC) components to manage environmental conditions within the building. The system may include an economizer may allow fresh air external to the building to circulate through the HVAC components and cool the environmental conditions of the building in an efficient manner. Referring to FIG. 1, there is shown a prior art air-side economizer 100 published by the U.S. Department of Energy as a representative Energy Star product. The HVAC components of the conventional economizer 100 include heating and/or cooling coils 102, 104 that modify, if necessary, the temperature of return air 106 to generate supply air 108 for the building. The economizer includes an outside air damper 110 controlled by an outside motorized actuator 112 via an outside linkage 114 to manage the amount of outside air 116 entering the system and a return air damper 118 controlled by a return motorized actuator 120 via a return linkage 122 to manage the amount of return air 106 continuing through the system. A logic controller 124 of the economizer controls the outside and return motorized actuators 112, 120 based on an outside temperature sensor 126 to manage the mixed air 128, i.e., mixture of outside air and return air, circulated through the system.

[0003] Although economizers have the potential to save substantial energy for maintenance of buildings, many existing economizers fail to provide significant cost savings. At least part of the problem may be attributed to the current design of rooftop units having multi-stage cooling capacity. For instance, an economizer may operate one compressor based on a cooling stage 1 signal received from the thermostat, another compressor based on a cooling stage 2 signal received from the thermostat, and so on. For conventional rooftop units, cooling stage 1 is the primary cooling capacity that runs at both full load and partial load. The other cooling stages are more secondary and subsequent, thus provide cooling capacity to meet higher or peak demand such that they run less often. Over time, the run time imbalance among the multiple stages becomes more significant so the compressors wear out unevenly, i.e., the primary compressor wears out sooner than the other compressors. Also, when a primary compressor wears out, the entire rooftop unit is typically replaced (instead of just the worn compressor) so the overall unit lifetime is unacceptable and the repair/replacement cost remains high.

SUMMARY

[0004] In accordance with one embodiment of the disclosure, there is provided a rotational approach of economizer outputs for building management systems.

[0005] One aspect is a controller for managing of economizer outputs comprising an input component, a processor, and an output component. The input component is configured to receive incoming control signals from an input device, in which each incoming control signal is associated with a corresponding compressor. The processor is configured to generate an altered association of some of the incoming control signals to a different compressor based on a predetermined criteria. The output component is configured to send output control signals based on the altered association to a control circuit associated with the compressors.

[0006] Another aspect is a method of a controller for managing economizer outputs. Incoming control signals are received from an input device, in which each incoming control signal is associated with a corresponding compressor. An altered association of some or all of the incoming control signals to a different compressor are generated based on a predetermined criteria. Output control signals are sent based on the altered association to a control circuit associated with the compressors.

[0007] Yet another aspect is a non-transitory computer readable medium including executable instructions which, when executed, causes at least one processor to manage rotation of economizer outputs. Incoming control signals are received, in which each incoming control signal is associated with a corresponding compressor. An altered association of some or all of the incoming control signals to a different compressor is generated based on a predetermined criteria. Output control signals are sent based on the altered association.

[0008] The above described features and advantages, as well as others, will become more readily apparent to those of ordinary skill in the art by reference to the following detailed description and accompanying drawings. While it would be desirable to provide one or more of these or other advantageous features, the teachings disclosed herein extend to those embodiments which fall within the scope of the appended claims, regardless of whether they accomplish one or more of the above-mentioned advantages.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] For a more complete understanding of the present disclosure, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, wherein like numbers designate like objects.

[0010] FIG. 1 is a partial perspective view of a rooftop unit known in the art.

[0011] FIG. 2 is a schematic representation of an economizer controller in an example implementation that is operable to employ techniques described herein.

[0012] FIG. 3 is a planar view with input/output representations of an example embodiment of the economizer controller of FIG. 2.

[0013] FIG. 4 is a block diagram representing an example implementation of the internal components of the economizer controller of FIG. 2.

[0014] FIG. 5 is a flow diagram representing an example operation of the economizer controller of FIG. 2.

[0015] FIG. 6 is an abstract view representing an example operational information about cooling and/or heating components associated with the economizer controller.

DETAILED DESCRIPTION

[0016] Various technologies that pertain to systems and methods that facilitate rotation of economizer controller outputs for heating, ventilation, and air conditioning (HVAC) components will now be described with reference to the drawings, where like reference numerals represent like elements throughout. The drawings discussed below, and the various embodiments used to describe the principles of the present disclosure in this patent document are by way of illustration only and should not be construed in any way to limit the scope of the disclosure. Those skilled in the art will understand that the principles of the present disclosure may be implemented in any suitably arranged apparatus. It is to be understood that functionality that is described as being carried out by certain system elements may be performed by multiple elements. Similarly, for instance, an element may be configured to perform functionality that is described as being carried out by multiple elements. The numerous innovative teachings of the present application will be described with reference to exemplary non-limiting embodiments.

[0017] An economizer controller manages free cooling, mechanical cooling, or both, depending on environmental air conditions. The economizer controller also routes the cooling and/or heating demands, represented by signals from an input device (such as a thermostat), to economizer controller outputs corresponding cooling and/or heating components of the HVAC unit or rooftop unit. Examples of economizer controller outputs include Y1-Out, Y2-Out, Y3-Out, etc. in the case of cooling components (such as compressors for cooling), or in the case of heating components (such as compressors for heating) in heat pump configuration. For some embodiments, the economizer controller may route the cooling and/or heating commands based on a start/stop order stored at the controller and/or determined by a device remote from the controller. Conventional cooling systems have fixed compressor priority for cooling systems in which Y1-Out always corresponds to primary compressor #1, Y2-Out always corresponds to compressor #2, etc., and the staging logic would be always first-in and last-out, which causes the primary compressor with higher priority to wear excessively. In contrast, the economizer controller adjusts the priority of cooling and/or heating components to rotate utilization of these components and maximize their longevity.

[0018] Referring to FIG. 2, there is shown a schematic representation 200 of an economizer controller 210 in an example implementation that is operable to employ techniques described herein. Although other components may be included in the example implementation, the schematic representation 200 has been simplified (omitting certain components) to facilitate general understanding of the economizer controller 210 and its operation. The economizer controller 210 communicates with an input device 220, such as a thermostat, as well as a control component 230 of the HVAC unit or rooftop unit, such as a terminal board. The economizer controller 210 also communicates with other devices of the HVAC unit and/or environmental control system via HVAC control lines 240.

[0019] Among other functions, the economizer controller 210 receives cooling and/or heating signals 250 from the input device 220, prioritizes the incoming signals based on a predetermined criteria 260, and routes the prioritized outgoing signals 270 to the control component 230 of the HVAC unit or rooftop unit. For embodiments where the economizer controller 210 resorts and routes signals for cooling components, such as compressors for cooling, the incoming signals 250 may be designated and Y1, Y2, and the like, and the outgoing signals 270 may be designated similar as Y1, Y2, and the like. For some embodiments, the number of outgoing signals 270 may equal the number of incoming signals. The predetermined criteria may be based on, but not limited to, run time data, cycle count data, availability information, and/or other operational information about cooling and/or heating components of the HVAC unit

[0020] It is to be noted that the process of resorting and rerouting results in one or more incoming signals being assigned to a cooling and/or heating component different from the component that may have been intended by the input device 220. For example, the input device 220 may have provided an incoming signal Y1 to the economizer controller 210 for the purpose of operating a first compressor of the cooling system. However, the economizer controller 210 may prioritize the other incoming signals Y2, Y3, and Y4 higher than incoming signal Y1, such that incoming signal Y2 is designated as outgoing signal Y1 to operate the first compressor, incoming signal Y3 is designated as outgoing signal Y2 to operate a second compressor, and incoming signal Y4 is designated as outgoing signal Y3 to operate a third compressor. As a result, incoming signal Y1 is designated as outgoing signal Y4 to operate a fourth compressor. Thus, by adjusting the priority and usage of the cooling and/or heating components, the economizer controller 210 may rotate utilization of these components and maximize their longevity.

[0021] The control component 230 may also bypass the economizer controller 210 and communicate directly with the input device 220 via control lines 280. For example, for some embodiments, the cooling demand signals Y1, Y2, etc. may be managed by the economizer controller 210 whereas the heating demand signals W1, W2, etc. may be provided to the control component 230 by the input device 220.

[0022] Referring to FIG. 3, there is shown a planar view with input/output representations of an example embodiment 300 of an economizer controller 302. The economizer controller 302 is an example representation of the economizer controller 210 of FIG. 2, and the economizer controller is coupled to an input device, such as a thermostat 304, and a terminal board 306 of the HVAC unit or rooftop unit (represented by FIG. 1). In particular, some ports of the thermostat ports 308 of the thermostat 304 are coupled to input ports 310 of the economizer controller 302, and some ports of the terminal ports 312 of the terminal board 306 (of the HVAC unit or rooftop unit) are coupled to the output ports 314 of the economizer controller. The economizer controller 302 may manage routing of cooling components via connections Y1, Y2, and the like, and heating components via connections W1, W2, and the like. For example, for management of cooling components (such as compressors for cooling) as represented by FIG. 3, thermostat ports 308 for Y1 and Y2 are connected to input ports 310 for Y1I and Y2I, respectively, of the economizer controller 302. Similarly, output ports 314 of the economizer controller are coupled to some ports of the terminal ports 312 of the terminal board 308. For example, as shown in FIG. 3, output ports 314 for Y1O and Y2O are connected to terminal ports 312 for Y1 and Y2, respectively, of the terminal board 306. Although FIG. 3 shows W1 and W2 of the thermostat ports 308 coupled directly to W1 and W2 of the terminal ports 312, W1, W2, and the like of the thermostat ports and the terminal ports may connect to the input and output ports 310, 314 of the economizer controller 302 for other embodiments where heating components are managed. Also, a power source 316, such as a 24 volt transformer, may be connected to the ports 308, 310, 312, 314 of the economizer controller 302, the thermostat 304, and/or the terminal board 306.

[0023] As noted above, the economizer controller 302 manages free cooling, mechanical cooling, or both, depending on environmental air conditions. Thus, the economizer controller 302 may be coupled to other components of the HVAC unit or rooftop unit as well. Examples of the other components includes, but are not limited to, mixed-air temperature and/or discharge-air temperature devices 318, outdoor air temperature negative temperature coefficient devices 320, and damper actuators 322.

[0024] FIG. 4 represents an example economizer controller 400 of an environmental control system. The economizer controller 400 may be any type of controlling device that is capable of managing cooling and/or heating of a designated area and routing cooling and/or heating demands from a thermostat signal to an HVAC unit having multi-stage cooling and/or heating capacity. An example of an economizer controller 400 is, but are not limited to, a direct digital controller (DDC) capable of compressor rotation for cooling components of the HVAC unit. The economizer controller 400 comprises a communication bus 402 for interconnecting the other device components directly or indirectly, one or more processors 406, and one or more memory components 408. Optionally, some embodiments of the economizer controller 400 may also include a communication component 402 for wired or wireless connection to a mobile device and/or a memory-based drive.

[0025] The one or more processors 406 may execute code and process data received at other components of the economizer controller 400, such as information received at the communication component 404 or stored at the memory component 408. The code associated with the economizer controller 400 and stored by the memory component 408 may include, but is not limited to, operating systems, applications, modules, drivers, and the like. An operating system includes executable code that controls basic functions of the economizer controller 400, such as interactions among the various components of the economizer controller, communication with external devices via the communication component 404, and storage and retrieval of code and data to and from the memory component 408. Each application includes executable code to provide specific functionality for the processor 406 and/or remaining components of the economizer controller 400. An example of an application executable by the processor 406 includes, but is not limited to, a resorting logic 410 based on run time data, cycle count data, availability information, and/or other operational information about cooling and/or heating components of the HVAC unit. Data is information that may be referenced and/or manipulated by an operating system or application for performing functions of the economizer controller 400. Examples of data associated with the economizer controller 400 and stored by the memory component 408 may include, but are not limited to, the operational information about cooling and/or heating components of the HVAC unit 412 utilized by the resorting logic, an initial matrix of incoming thermostat signals 414, and a new matrix of cooling and/or heating demand 416 by routing the incoming thermostat signals.

[0026] The economizer controller 400 may further comprise one or more input components 418 and one or more output components 420. A user interface 422 of the economizer controller 400 may include portions of the input and output components 418, 420 and be used to interact with a user of the economizer controller. For example, the user interface 422 may include a combination of hardware and software to provide a user with a desired user experience. The input and output components 418 and 420 may include ports for receiving incoming signals from a thermostat or sending outgoing signals to a cooling and/or heating component of an HVAC unit. Examples of the ports of the input components 418 for receiving incoming signals include, but are not limited to, a Y or Y1 input port 424, aY2 input port 426, a Y3 input port 428, and/or a Y4 input port 430. Examples of ports of the output components 420 for sending outgoing signals include, but are not limited to, a Y or Y1 output port 432, a Y2 output port 434, a Y3 output port 436, and/or a Y4 output port 438.

[0027] It is to be understood that FIG. 4 is provided for illustrative purposes only to represent examples of the internal components of the economizer controller 400 and is not intended to be a complete diagram of the various components that may be utilized by the device. Therefore, the economizer controller 400 may include various other components not shown in FIG. 4, may include a combination of two or more components, or a division of a particular component into two or more separate components, and still be within the scope of the present invention.

[0028] Referring to FIG. 5, there is shown a flow diagram representing an example operation (500) of the economizer controller. In particular, there is presented a method of an economizer controller 210 for managing economizer controller outputs in the form of output signals (270). The economizer controller 210 receives multiple incoming control signals, in the form of input signals 250 (for example, Y1 In, Y2 In, Y3 In, and Y4 In), from an input device 220 (502). An example of the input device is, but is not limited to, a thermostat of an HVAC unit or environmental control system. Each incoming control signal of the multiple incoming control signals is associated with a corresponding compressor of the multiple compressors. The compressor may be a compressor for cooling, a compressor for heating, or a combination cooling-compressor for heating.

[0029] The economizer controller 210 may execute one or more preliminary actions before remapping the received input signals to rerouted output signals. For some embodiments, the economizer controller 210 may determining whether outside environmental air is suitable for free cooling (504). The economizer controller 210 may assign free cooling to be a primary stage of cooling, in which free cool outside air intake may be modulated with damper and fan speed (506), in response to determining that outside environmental air is suitable for free cooling. Free cool may be a "virtual compressor" that uses outside air intake to cool a space or area. On the other hand, the economizer controller 210 may simply allow the cooling demand to transpass in response to determining that the outside environmental air is not suitable for free cooling (508). For some embodiments, the economizer controller 210 may determine whether a cooling lockout is due to a detected low outside environmental temperature (510). The economizer controller 210 may inactivate mechanical cooling (512) in response to determining that the cooling lockout is due to the low outside environmental temperature. On the other hand, the economizer controller 210 may just calculate the mechanical cooling demand (514) in response to determining that the cooling lockout is not due to the low outside environmental temperature.

[0030] The economizer controller 210 determines whether to remap the received input signals to rerouted output signals (516). The rotation process may be executed on a predetermined periodic basis, based on a determine time schedule, or in response to a user action (such as, a signal from a user interface).

[0031] In response to determining that the received input signals are to be remapped to the rerouted output signals (516), the rotation mode is initiated by the economizer controller 210 (518) in which the input signals 250 are collected and prepared for analysis. For some embodiments, a setpoint for the rotation mode determines whether and/or when to execute a sorting logic to alter or otherwise change a priority order of some or all of the compressors. The sorting logic determines the priority (lead-lag) order based on run time, or cycling times at real time or at the time when a sorting command is initiated. Accordingly, an altered association of at least some of the multiple incoming control signals to a different compressor of the multiple compressors is generated based on a predetermined criteria (520). The predetermined criteria may include a run time count, a cycle count, or a combination of the run time and cycle counts for the multiple compressors.

[0032] In response to executing the sorting logic (520) in which the cooling and/or heating demand from the thermostat is remapped to the cooling and/or heating command to the HVAC unit or rooftop unit, the economizer controller 210 operates the compressors based on the updated compressor priority (522). For example, the original priority order [Y1-Out, Y2-Out, Y3-Out, Y4-Out] may be adjusted to a different one with the least run compressor in the first priority, the second least run compressor in the second priority, etc., or with the least cycled compressor in the first priority, the second least cycled compressor in the second priority, etc. For some embodiments, the least run/cycled compressor may be the first to run thus have the most chance to run, thus balancing the run times among the multiple compressors over time.

[0033] In response to determining that the received input signals are not to be remapped to the rerouted output signals (516), the economizer controller 210 may execute, or schedule to execute, a predefined rotation plan (regardless of the sorting algorithm) with predefined rules and/or predetermined compressor priority. For example, the prior lead compressor may be one of the present lag compressor, and one of the prior lag compressors may be the present lead compressor.

[0034] In response to operating the compressors, whether based on the updated compressor priority (522) or not (524), the economizer controller 210 sends output control signals based on the altered association to a control circuit associated with the compressors (526). An example of the control circuit is, but is not limited to, a terminal board of the HVAC unit or rooftop unit. Thereafter, the economizer controller 210 may terminate the example operation (500) or update one or more run time counters or cycle counters (530) and continue execute the sorting logic (520).

[0035] Referring to FIG. 6, there is shown an abstract view representing an example operational information 600 about cooling and/or heating components associated with the economizer controller 210. The example operational information 600 indicates that the first compressor has a status Cmpr.CC1 of "Off" (602), a cycle count Cmpr.CC1Cnt.Cnt of "93" (604), and a run time count Cmpr.CC1-Elapsed/ActiveHour of "21 h" (606). Other properties of the first compressor indicated by the example operational information 600 include nominal horsepower (608), kilowatt-hour count (610), and cycle count reset (612). Similarly, the example operational information 600 indicates that the second compressor has a status Cmpr.CC2 of "Off" (614), a cycle count Cmpr.CC2Cnt.Cnt of "15" (616), and a run time count Cmpr.CC1-Elapsed/ActiveHour of "2 h" (618), and other properties of the second compressor indicated by the example operational information 600 include nominal horsepower (620), kilowatt-hour count (622), and cycle count reset (624). Accordingly, for the first and second compressors represented by the example operational information 600, the cycle count of the first compressor is higher than the cycle count of the second compressor, so the priority of the first compressor may be raised and the priority of the second compressor may be reduced. Similarly, the run time count of the first compressor is higher than the run time count of the second compressor, so the priority of the first compressor may be raised and the priority of the second compressor may be reduced. Based on this example, the first and second compressors may be rotated in order balance their usage and increase the longevity of the associated HVAC unit or rooftop unit.

[0036] Those skilled in the art will recognize that, for simplicity and clarity, the full structure and operation of all data processing systems suitable for use with the present disclosure are not being depicted or described herein. Also, none of the various features or processes described herein should be considered essential to any or all embodiments, except as described herein. Various features may be omitted or duplicated in various embodiments. Various processes described may be omitted, repeated, performed sequentially, concurrently, or in a different order. Various features and processes described herein can be combined in still other embodiments as may be described in the claims.

[0037] It is important to note that while the disclosure includes a description in the context of a fully functional system, those skilled in the art will appreciate that at least portions of the mechanism of the present disclosure are capable of being distributed in the form of instructions contained within a machine-usable, computer-usable, or computer-readable medium in any of a variety of forms, and that the present disclosure applies equally regardless of the particular type of instruction or signal bearing medium or storage medium utilized to actually carry out the distribution. Examples of machine usable/readable or computer usable/readable mediums include: nonvolatile, hard-coded type mediums such as read only memories (ROMs) or erasable, electrically programmable read only memories (EEPROMs), and user-recordable type mediums such as floppy disks, hard disk drives and compact disk read only memories (CD-ROMs) or digital versatile disks (DVDs).

[0038] Although an example embodiment of the present disclosure has been described in detail, those skilled in the art will understand that various changes, substitutions, variations, and improvements disclosed herein may be made without departing from the spirit and scope of the disclosure in its broadest form.

Claims

1. A controller for managing of economizer outputs comprising: an input component configured to receive a plurality of incoming control signals from an input device, each incoming control signal of the plurality of incoming control signals being associated with a corresponding compressor of a plurality of compressors; a processor configured to generate an altered association of at least some of the plurality of incoming control signals to a different compressor of the plurality of compressors based on a predetermined criteria; and an output component configured to send a plurality of output control signals based on the altered association to a control circuit associated with the plurality of compressors.

2. The controller as described in claim 1, wherein the input device is a thermostat and the control circuit is a terminal board of an HVAC unit or rooftop unit.

3. The controller as described in claim 1, wherein the compressor is at least one of a compressor for cooling and a compressor for heating.

4. The controller as described in claim 1, wherein the predetermined criteria includes at least one of a run time count or a cycle count for the plurality of compressors.

5. The controller as described in claim 1, wherein the processor updates at least one of run time counter or cycle counter in response to the output component sending the plurality of output control signals.

6. The controller as described in claim 1, wherein the economizer controller assigns free cooling to a primary stage of cooling in response to determining that outside environmental air is suitable for free cooling.

7. The controller as described in claim 1, wherein the economizer controller inactivates mechanical cooling in response to determining that a cooling lockout is due to low outside environmental temperature.

8. A method of a controller for managing economizer outputs, the method comprising: receiving a plurality of incoming control signals from an input device, each incoming control signal of the plurality of incoming control signals being associated with a corresponding compressor of a plurality of compressors; generating an altered association of at least some of the plurality of incoming control signals to a different compressor of the plurality of compressors based on a predetermined criteria; and sending a plurality of output control signals based on the altered association to a control circuit associated with the plurality of compressors.

9. The method as described in claim 8, wherein the input device is a thermostat and the control circuit is a terminal board of an HVAC unit or rooftop unit.

10. The method as described in claim 8, wherein the compressor is at least one of a compressor for cooling and a compressor for heating.

11. The method as described in claim 8, wherein the predetermined criteria includes at least one of a run time count or a cycle count for the plurality of compressors.

12. The method as described in claim 8, further comprising updating at least one of run time counter or cycle counter.

13. The method as described in claim 8, further comprising: assigning free cooling to a primary stage of cooling in response to determining that outside environmental air is suitable for free cooling.

14. The method as described in claim 8, further comprising: inactivating mechanical cooling in response to determining that a cooling lockout is due to low outside environmental temperature.

15. A non-transitory computer readable medium including executable instructions which, when executed, causes at least one processor to manage rotation of economizer outputs by: receiving a plurality of incoming control signals, each incoming control signal of the plurality of incoming control signals being associated with a corresponding compressor of a plurality of compressors; generating an altered association of at least some of the plurality of incoming control signals to a different compressor of the plurality of compressors based on a predetermined criteria; and sending a plurality of output control signals based on the altered association.

16. The non-transitory computer readable medium as described in claim 15, wherein the input device is a thermostat and the control circuit is a terminal board of an HVAC unit or rooftop unit.

17. The non-transitory computer readable medium as described in claim 15, wherein the compressor is at least one of a compressor for cooling and a compressor for heating.

18. The non-transitory computer readable medium as described in claim 15, further comprising updating at least one of run time counter or cycle counter, wherein the predetermined criteria includes at least one of a run time count or a cycle count for the plurality of compressors.

19. The non-transitory computer readable medium as described in claim 15, further comprising: assigning free cooling to a primary stage of cooling in response to determining that outside environmental air is suitable for free cooling.

20. The non-transitory computer readable medium as described in claim 15, further comprising: inactivating mechanical cooling in response to determining that a cooling lockout is due to low outside environmental temperature.