The embodiments described herein relate to air conditioning systems.
Electrical energy drives a myriad of devices and equipment in commercial, industrial, residential applications, and data centers. For example, electrical energy drives lights, motors, household appliances, medical equipment, computers, air conditioning systems, electric vehicle charging stations, data centers processing and cooling needs, and many other electrical devices. In most areas, power utilities generate and distribute electricity through an AC power grid. Shortages and/or increased costs associated with the use of fossil fuels, intermittency of renewable resources, power demand and supply variabilities, and increased demand of energy, among others factors, significantly impact the continuous availability and cost of electricity to consumers and businesses. In general, shortages and/or increased costs often occur during times of peak demand. Peak demand may occur based on time of day, such as in the morning or in the evening. On a more random basis, peak demand (or a demand greater than an available supply) may occur as a result of a natural disaster, or during extensive times of e.g., cloudiness, if the power from the grid comes from solar energy, or wind variability, if the power from the grid comes from wind turbines. For example, a hurricane or earthquake may damage the power grid and/or electric generators of the power utilities, thereby resulting in substantial loss of electric power to commercial, industrial, and residential applications. Repairs to these damaged lines and generators may take hours, days, or weeks. Various sites also may lose power from the power grid for other reasons, including maintenance. During these times of lost power, the sites may be unable to continue operations. Moreover, increasing numbers of data centers significantly add to the demand of energy from the grid.
Often, electrical energy from the power grid is more expensive during times of peak demand. For example, a power utility may employ low cost electrical generators during periods of minimum demand, while further employing high cost electrical generators during periods of peak demand. Unfortunately, the existing infrastructure does not adequately address these different costs associated with peak and minimum demands. As a result, commercial, industrial, data centers and residential applications typically draw power from the power grid during times of peak demand, despite the higher costs associated with its generation.
Some energy consumers, such as commercial, industrial, data centers, and residential users may be driven by factors other than cost, such as a desire to support sustainable energy options as further described below.
According to an embodiment, an air conditioning system includes a vapor compression cycle having a plurality of components including a compressor, an expansion device, and at least one heat exchanger. A heat transfer fluid is configured to circulate within the vapor compression cycle. An energy storage device is selectively operable to supply power to one of the plurality of components. The energy storage device is thermally coupled to the vapor compression cycle.
In addition to one or more of the features described herein, or as an alternative, further embodiments may include that the energy storage device is arranged directly within a flow path of the heat transfer fluid.
In addition to one or more of the features described herein, or as an alternative, further embodiments may include that the energy storage device includes a housing having at least one flow channel formed therein for receiving the heat transfer fluid.
In addition to one or more of the features described herein, or as an alternative, further embodiments may include that the energy storage device is indirectly thermally coupled to the vapor compression cycle.
In addition to one or more of the features described herein, or as an alternative, further embodiments may include that the at least one heat exchanger of the vapor compression cycle includes a first heat exchanger, a second heat exchanger, and an energy storage heat exchanger. The energy storage device is thermally coupled to the energy storage heat exchanger via a coolant loop.
In addition to one or more of the features described herein, or as an alternative, further embodiments may include that the energy storage heat exchanger is a thermal storage device including a phase change material.
In addition to one or more of the features described herein, or as an alternative, further embodiments may include a coolant expansion device disposed downstream from one of the first heat exchanger and the second heat exchanger and upstream from the energy storage heat exchanger relative to a flow of the heat transfer fluid.
In addition to one or more of the features described herein, or as an alternative, further embodiments may include a bypass conduit arranged in parallel with the coolant expansion device. The bypass conduit includes a valve operable to control the flow of the heat transfer fluid through the bypass conduit.
In addition to one or more of the features described herein, or as an alternative, further embodiments may include that the plurality of components of the vapor compression cycle are arranged within an indoor unit and an outdoor unit and the energy storage heat exchanger is arranged within the indoor unit.
In addition to one or more of the features described herein, or as an alternative, further embodiments may include that the plurality of components of the vapor compression cycle are arranged within an indoor unit and an outdoor unit and the energy storage heat exchanger is arranged within the outdoor unit.
In addition to one or more of the features described herein, or as an alternative, further embodiments may include a sensor for monitoring a temperature of the energy storage device, a pump arranged within the coolant loop, and a controller operably coupled to the sensor and to the pump. The controller is operable to initiate the pump in response to the temperature of the energy storage device.
According to an embodiment a method of operating an air conditioning system includes determining that a temperature of an energy storage device operable to supply power to the air conditioning system is beyond a threshold and managing the temperature of the energy storage device via a heat transfer fluid of the air conditioning system.
In addition to one or more of the features described herein, or as an alternative, further embodiments may include that managing the temperature of the energy storage device via the heat transfer fluid of the air conditioning system includes providing a flow of the heat transfer fluid directly to the energy storage device.
In addition to one or more of the features described herein, or as an alternative, further embodiments may include that managing the temperature of the energy storage device via the heat transfer fluid of the air conditioning system includes cooling the energy storage device when the temperature of the energy storage device exceeds the threshold.
In addition to one or more of the features described herein, or as an alternative, further embodiments may include that managing the temperature of the energy storage device via the heat transfer fluid of the air conditioning system includes transferring heat from a coolant at an energy storage heat exchanger of the air conditioning system. The coolant is fluidly coupled to the energy storage device.
In addition to one or more of the features described herein, or as an alternative, further embodiments may include that the energy storage heat exchanger includes a phase change material. Transferring heat from the coolant at the energy storage heat exchanger of the air conditioning system causes the phase change material to transform from a first phase to a second phase.
In addition to one or more of the features described herein, or as an alternative, further embodiments may include determining that the temperature of the energy storage device is within the threshold and recharging the energy storage heat exchanger to transform the phase change material from the second phase to the first phase.
In addition to one or more of the features described herein, or as an alternative, further embodiments may include that recharging the energy storage heat exchanger includes providing a flow of the heat transfer fluid to the energy storage heat exchanger.
In addition to one or more of the features described herein, or as an alternative, further embodiments may include that managing the temperature of the energy storage device via the heat transfer fluid of the air conditioning system includes heating the energy storage device when the temperature of the energy storage device is below the threshold.
In addition to one or more of the features described herein, or as an alternative, further embodiments may include that managing the temperature of the energy storage device via the heat transfer fluid of the air conditioning system includes transferring heat to a coolant at an energy storage heat exchanger of the air conditioning system. The coolant is fluidly coupled to the energy storage device.
The foregoing features and elements may be combined in various combinations without exclusivity, unless expressly indicated otherwise. These features and elements as well as the operation thereof will become more apparent in light of the following description and the accompanying drawings. It should be understood, however, that the following description and drawings are intended to be illustrative and explanatory in nature and non-limiting.
With current global electrification and decarbonization efforts, there are incentives to use efficient, optimized, all-electric air conditioning systems that provide comfort while being dispatchable (on-off, adjusted or variable) under different pricing conditions, or after receiving a utility signal. By way of example, the utility signal may be received from an electrical AC power grid, and may include an independent system operator (ISO), which may include an independent, federally regulated entity established to coordinate regional transmission in a non-discriminatory manner and ensure the safety and reliability of the electric system, or a regional transmission organization (RTO) which may operate bulk electric power systems across much of a geographic area and are generally independent, membership-based, non-profit organizations that ensure reliability and optimize supply and demand bids for wholesale electric power, or from a virtual power plant, generally considered to include a connected aggregation of distributed energy resource (DER) technologies providing integration of renewables and demand flexibility. Reference to a utility refers to one or more entities involved in the generation, transmission and/or distribution of electrical power.
Embodiments described herein relate to an air conditioning system that includes electrical energy storage systems (e.g., batteries, supercapacitors) to provide a level of dispatchability needed to interconnect with the electrical power grid.
In the example shown in
The system 100 includes a controller 220, a power converter 230 and an energy storage device (ESD) 240.
The first unit 200 may include a heat exchanger (not shown) that will serve as a condenser/gas cooler and/or as an evaporator, as part of a vapor compression refrigeration cycle.
In the FIGURES, the locations of all components in the drawings are examples, and embodiments include modification of the locations of components shown in the drawings. For example, components illustrated as connected to the first unit 200, may be retrofit components added to an existing first unit 200. Although shown as separate boxes, elements may be joined into sub-assemblies and assemblies, anywhere in the system, indoor or outdoor, without departing from embodiments of the disclosure.
The controller 220 may communicate with an air conditioning controller system controller and/or an energy storage device controller. In some embodiments, a single controller may implement all the functions of the controller 220, air conditioning controller and energy storage device controller. The controller 220 communicates with components of the described systems using wired and/or wireless connections, which are not illustrated in the drawings.
The system of
The controller 220 includes a memory 226 that may store a computer program executable by the processor 224, reference data, sensor data, etc. The memory 226 may be implemented using known devices, such as random access memory. The controller 220 includes a communication unit 228 which allows the controller 220 to communicate with other components of the system 100, such as first unit 200, second units 250 and a thermostat 260. The communication unit 228 may be implemented using wired connections (e.g., LAN, ethernet, twisted pair, etc.) and/or wireless connections (e.g., Wi-Fi, near field communications (“NFC”), Bluetooth, etc.).
In some embodiments, communication unit 228 may provide high-speed data communications over existing wiring systems and/or communication with newer equipment having a high-speed bus, while maintaining communications with existing equipment (e.g., having RS-485 communications bus). In some embodiments, an HVAC equipment may include 4 wires used for data communications, Power, Ground, Data+, and Data−. Of these lines, Data+ and Data− are used to carry the low-speed, standard RS-485 data. The power line is used to power the wall control and comes from a second unit 250. This same power line is carried to the first unit 200 although it is generally not used. The ability to take advantage of the power and ground lines of the 4-wire system (referred to as “Power Line Communications” (PLC) technology) allows digital/data signals to be sent over power lines. In some embodiments, PLC technology may allow for data transmission at or near gigabit speed rates using standard 2-conductor wiring. This includes the 2 wires represented by Power and Ground of the HVAC equipment. It should be appreciated that other data transmission speeds may be possible. In some embodiments, the communication unit 228 of the present disclosure may be configured such that, while the PLC high-speed communication is occurring over the Power and Ground line of the 4-wire system, the low-speed RS-485 communication can also be occurring on the Data+ and Data− lines. In some embodiments, the ability to use high speed communications or a combination of high speed and low speed communications enable the controller 220 to utilize machine-learning (ML) based or artificial intelligence (AI) based, algorithms. In some embodiments, the high speed and low speed communications may occur approximately simultaneously (e.g., within milliseconds of one another). This may allow the standard HVAC wire to communicate with both RS-485 controlled equipment as well as HVAC equipment which contains the additional PLC transceivers. This may be advantageous because both new high-speed HVAC equipment and existing RS-485 HVAC equipment can co-exist on existing wiring of the building.
Referring to
The energy storage device 240 is configured to provide, under certain circumstances, at least a portion of the power to operate one or more of components of the air conditioning system, such as the first unit 200, the second unit(s) 250, along with the indoor load(s) 270, and any other loads. The energy storage device 240 may be implemented using apparatus for storing electrical energy including one or more of, for example, a battery, battery modules, battery cells, supercapacitor, etc. The battery 240 may include several cells in either modular form or as a stand-alone, multi-cell array. The battery 240 may be made of a single or multiple packaged self-contained systems, battery modules or individual cells. The battery 240, such as a complete plug and play battery, may include a box, wires, cells, and modules. For example, the battery 240 may include a group of cells configured into a self-contained mechanical and electrical unit. The energy storage device 240 may include other components (e.g., an ESD management system (ESDMS)) that are electrically coupled to the energy storage device 240 and may be adapted to communicate directly or through the ESDMS to controller 220.
The first unit 200 also includes components used as part of the air conditioning system, and includes a compressor 242, one or more drives 244, a fan 246, and other loads 248, and a control unit (not shown). A heat exchanger (not shown) in the first unit 200 may act as evaporator or condenser/gas cooler. These components are described in further detail herein when relevant to embodiments.
In a split system, inside the building 102, one or more second units 250 are positioned to condition one or more zones of the building 102. The second units 250 may be employed using a variety of known second units, including variable air volume (VAV) units, liquid cooled second units, fan coil units, furnaces, air handler(s), etc., which usually include heat exchangers. In other types of systems (e.g., packaged or chillers) the second unit(s) 250 may be located outdoors and include any form of heat exchangers such as cooling towers, etc.
An optional thermostat 260 provides a user interface for the air conditioning system 100, and allows the user to enter operational modes of the air conditioning system 100, enter setpoints for various zones of the system 100, etc. The indoor loads 270 may be supplied electrical power by the first unit 200. The indoor loads 270 include a wide variety of loads, such as appliances, lighting, electric vehicle chargers, etc. A thermostat 260 is not required and other techniques may be used for control of the air conditioning system.
As shown in
The AC power grid 302 is connected to indoor AC loads 308 (such as an air handler, or any fixture in residential, commercial, industrial buildings or data centers). The AC power grid 302 is also provided to an AC/AC converter 310 which supplies conditioned AC power to a compressor drive 244A of the compressor 242 and the fan 246. The AC/AC converter 310 may control the amplitude, frequency, phase, etc. of AC power provided to the compressor drive 244A of the compressor 242 and the fan 246.
The AC power grid 302 may also be connected to one of a unidirectional or a bi-directional AC/DC converter 312 which interfaces the AC power bus 305 with a DC power bus 313. The DC power bus 313 supplies power to the DC loads 248, which may be located in the first unit 200. Under certain conditions, the DC power bus 313 supplies power to the one or more of components of the air conditioning system (e.g., compressor 242 and fan 246) through the bi-directional AC/DC converter 312 and the AC/AC converter 310. This allows the one or more of components of the air conditioning system to operate independent of, or in conjunction with, the AC power grid 302. The bi-directional AC/DC converter 312 also allows power from the DC bus 313 to be directed to the AC power grid 302.
The DC power bus 313 may be powered by the energy storage device 240. In charging mode, the DC power bus 313 is used to charge the energy storage device 240 (charger not shown). The DC power bus 313 may also be powered by one or more auxiliary DC sources 314, such as solar DC power, wind DC power, geothermal DC power, fuel cells, etc. A DC/DC converter 316 may be used to couple the auxiliary DC sources 314 to the DC power bus 313. The DC power bus 313 may provide power to indoor DC loads 318. A DC/DC converter 320 may be used to couple the indoor DC loads 318 to the DC power bus 313. An AC/DC converter 347 may be used to couple the DC power bus 313 to indoor AC loads 308 through a disconnect 348. In some operating modes, the energy storage device 240 is used to power indoor AC loads 308. The AC/AC converter 310, the AC/DC converter 312, the DC/DC converter 320, the DC/DC converter 316 and the AC/DC converter 347 may be implementations of the power converter 230 in
The compressor drive 244A may be implemented in a variety of manners. In one embodiment, the compressor drive 244A is a switch, such as a contactor or relay, that connects the compressor 242 to the output of the AC/AC converter 310. In other embodiments, the compressor drive 244A may be a power converter, such as an AC/AC converter or an AC/DC converter.
An optional DC/DC converter 241 may provide power conversion between the energy storage device 240 and the DC power bus 313. The DC/DC converter 241 may be a bi-directional converter used to step up or step down a DC voltage so that the energy storage device 240 can power the DC power bus 313 and the DC power bus 313 can charge the energy storage device 240. The DC/DC converter 241 may be part of the energy storage device 240 or may be a separate component from the energy storage device 240.
The electrical architecture of
The fan 246 is provided power from a fan drive 244B. The fan drive 244B may be a switch, such as a contactor or relay, that connects the fan 246 to the AC power bus 305. In other embodiments, the fan drive 244B may be a power converter, such as an AC/AC converter or an AC/DC converter. The fan drive 244B may be controlled by the controller 220.
The electrical architecture of
In
The compressor drive 244A may be a switch, such as a contactor or relay, that connects the compressor 242 to the DC power bus 313. In other embodiments, the compressor drive 244A may be a power converter, such as a DC/AC converter or a DC/DC converter. The compressor drive 244A may be controlled by the controller 220.
The electrical architecture of
The electrical architecture of
Not all components of the first unit 200 are shown for ease of illustration and explanation. The power converter 230 may be used in conjunction with the embodiments described above, or other embodiments. For example, one or more auxiliary DC sources 314 may be connected to the energy storage device 240 (via a DC bus) to supplement power from the energy storage device 240. As shown in
Both the AC/DC converter 370 and the DC/AC converter 372 operate under the control of the controller 220. Between the AC/DC converter 370 and the DC/AC converter 372 is a DC link 371 that is connected to the energy storage device 240, optionally through the DC/DC converter 241. Under this arrangement, energy storage device 240 may be charged by the power converter 230. Alternatively, the energy storage device 240 may provide DC power to the DC link 371 to power the DC/AC converter 372 and the compressor 242. This allows the first unit 200 to operate independent of, or in conjunction with, the AC power grid 302. The AC/DC converter 370 may be bi-directional to allow the energy storage device 240 to provide power to, and be charged from, the AC power grid 302.
The controller 220, the power converter 230, the energy storage device 240, DC\DC converters 320 and 316, and AC\DC converter 347, and the DC/DC converter 241 may be retrofit to an existing first unit 200. This allows the energy storage device 240 to be added to existing air conditioning systems to enable the first unit 200 to operate independent of the AC power grid 302 or operate under power from both the AC power grid 302 and the energy storage device 240. It allows also for auxiliary power sources to be added in a modular way.
The electrical architecture of
Not all components of the first unit 200 are shown for ease of illustration and explanation. The power converter 230 may be used in conjunction with the embodiments described above, or other embodiments. For example, one or more auxiliary DC sources 314 may be connected to the energy storage device 240 (via a DC bus) to supplement power from the energy storage device 240.
In
The controller 220, the power converter 230, the energy storage device 240 may be retrofit to an existing first unit 200. This allows the energy storage device 240 to be added to existing air conditioning systems to enable the first unit 200 to operate independent of the AC power grid 302 or operate under power from both the AC power grid 302 and the energy storage device 240.
The electrical architecture of
The controller 220, the power converter 230, the energy storage device 240 and the DC/DC converter 241 may be retrofit to an existing first unit 200. This allows the energy storage device 240 to be added to existing air conditioning systems to enable the first unit 200 to operate independent of the AC power grid 302 or operate under power from both the AC power grid 302 and the energy storage device 240.
Not all components of the first unit 200 are shown for ease of illustration and explanation. The power converter 230 may be used in conjunction with the embodiments described above, or other embodiments. For example, one or more auxiliary DC sources 314 may be connected to the energy storage device 240 (via a DC bus) to supplement power from the energy storage device 240.
The electrical architecture of
Not all components of the first unit 200 are shown for ease of illustration and explanation. The power converter 230 may be used in conjunction with the embodiments described above, or other embodiments. For example, one or more auxiliary DC sources 314 may be connected to the energy storage device 240 (via a DC bus) to supplement power from the energy storage device 240.
The controller 220, the power converter 230 and the energy storage device 240 may be retrofit to an existing first unit 200. This allows the energy storage device 240 to be added to existing air conditioning systems to enable the first unit 200 to operate independent of the AC power grid 302 or operate under power from both the AC power grid and the energy storage device 240.
The electrical architecture of
As shown in
The multilevel inverter 382 synthesizes a sinusoidal current waveform to run and control the compressor 242. This is done traditionally by a two-level inverter. Integration with the energy storage device 240 allows for a natural progression to higher order inverters. Three and five level inverters require independent power supplies to set the voltage levels. In the embodiment of
The voltage levels used in the multilevel inverter 382 do not need to be supplied by separate battery modules. The voltage levels used to create the sinusoidal output waveform can be created using one battery module, with the battery voltage being split, for example, by capacitors.
Referring the
The electrical architecture of
In the above embodiments, one or more auxiliary DC sources 314 may be used to provide DC power. The one or more auxiliary DC sources 314, may include sources such as solar DC power, wind DC power, geothermal DC power, fuel cells, etc.
One or both of the controller 220 and the thermostat 260 may be in communication with a remote system 410 over a network 406. The network 406 may be a long range network and may be implemented by a variety of communication protocols. The network 406 may be implemented via one or more networks, such as, but are not limited to, one or more of WiMax, a Local Area Network (LAN), Wireless Local Area Network (WLAN), a Personal area network (PAN), a Campus area network (CAN), a Metropolitan area network (MAN), a Wide area network (WAN), a Wireless wide area network (WWAN), or any broadband network, and further enabled with technologies such as, by way of example, Global System for Mobile Communications (GSM), Personal Communications Service (PCS), Bluetooth, Wi-Fi, Matter, Fixed Wireless Data, 2G, 2.5G, 3G (e.g., WCDMA/UMTS based 3G networks), 4G, IMT-Advanced, pre-4G, LTE Advanced, 5G, 6G, mobile WiMax, WiMax 2, WirelessMAN-Advanced networks, enhanced data rates for GSM evolution (EDGE), General packet radio service (GPRS), enhanced GPRS, iBurst, UMTS, HSPDA, HSUPA, HSPA, HSPA+, UMTS-TDD, 1×RTT, EV-DO, messaging protocols such as, TCP/IP, SMS, MMS, extensible messaging and presence protocol (XMPP), real time messaging protocol (RTMP), instant messaging and presence protocol (IMPP), instant messaging, USSD, IRC, or any other wireless data networks, broadband networks, or messaging protocols.
The remote system 410 may be embodied as any type of processor-based computation or computer device capable of performing the functions described herein, including, without limitation, a computer, a server, a workstation, a desktop computer, a laptop computer, a notebook computer, a tablet computer, a mobile computing device, a wearable computing device, a network appliance, a web appliance, a distributed computing system (e.g., cloud computing), a processor-based system, and/or a consumer electronic device. The remote system 410 provides information that is used by the controller 220 and/or thermostat 260 to implement an energy management routine that controls how power is consumed by the one or more components of the air conditioning system and the loads 270. The information provided by the remote system 410 may include utility pricing, indicating the cost of electricity on the AC power grid 302 and weather information, which may be used to predict future utility pricing and usage of the one or more components of the air conditioning system. The utility pricing and weather may be pushed to, or pulled by, the remote system 410 using known networking techniques. The utility pricing and/or weather may be determined in real time or be forecasts of future conditions.
In the above-described embodiments, the controller 220 communicates with components of the described systems using wired and/or wireless connections, which are not illustrated in the drawings. Depending on the power sources used in an operation mode (e.g., one or more of AC grid power, energy storage device power, auxiliary power sources, etc.) the controller 220 sends command signals to the various system components, (for example, AC/AC converter 310, AC/DC converter 312, AC/DC converter 347, DC/DC converter 320, DC/DC converter 316, DC/DC converter 241, AC/DC converter 370, DC/AC converter 372, AC/DC converter 380 and/or multilevel inverter 382, AC disconnect 304, etc.) to route power to one or more components of the air conditioning system, such as the first unit 200, the second unit(s) 250, along with the indoor load(s) 270, and any other loads.
If a request for a reduction in energy usage is present, flow proceeds to 602 where a user (e.g., a customer of the utility) can approve or deny the request to reduce energy usage. The approve or deny determination may be pre-established by the user and pre-programmed into the controller 220 and/or the thermostat 260. For example, the user may wish to always reduce energy consumption, regardless of the terms. The user may wish to never reduce energy consumption, regardless of the terms. The user may wish to reduce energy consumption only if the utility offers an incentive. The approve or deny determination at 602 may also be in real time, where the user enters an approval or denial of reduced energy consumption through the thermostat 260 or through a mobile device.
If the user approves reduced energy usage at 602, flow proceeds to 604 where one or more components of the air conditioning system (if needed), and/or other loads, are powered, at least in part, by the energy storage device 240. This may entail opening the AC disconnect 304 (e.g., power from the AC power grid 302 is zero) and powering one or more components of the air conditioning system and/or other loads, using only the energy storage device 240. Operating one or more components of the air conditioning system and/or other loads may also include using both the AC power grid 302 and the energy storage device 240, in conjunction, to power the one or more components of the air conditioning system and/or other loads. The controller 220 can limit the amount of power drawn from the AC power grid 302 by controlling the various power converters 230 in the system (e.g., AC/AC converter 310, AC/DC converter 312, AC/DC converter 347, DC/DC converter 320, DC/DC converter 316, DC/DC converter 241, AC/DC converter 370, DC/AC converter 372, AC/DC converter 380 and/or multilevel inverter 382) to reduce the amount of AC power drawn from the AC power grid 302. The energy storage device 240 and the AC power grid 302 are used in conjunction to power one or more components of the air conditioning system and/or one or more loads.
Operating the one or more components of the air conditioning system using the energy storage device 240 may also include limiting the amount of power used from the AC power grid 302 to a power limit (e.g., 1 kW during 2 hours). The controller 220 can limit the amount of power drawn from the AC power grid 302 by controlling the various power converters 230 in the system (e.g., AC/AC converter 310, AC/DC converter 312, AC/DC converter 347, DC/DC converter 320, DC/DC converter 316, DC/DC converter 241, AC/DC converter 370, DC/AC converter 372, AC/DC converter 380 and/or multilevel inverter 382) to reduce the amount of AC power drawn from the AC power grid 302. At 604, other loads may be powered by the energy storage device 240, including indoor load(s) 270, which may include indoor DC load(s) 318 and/or indoor AC load(s) 308. The process returns to 600.
At some point, the energy storage device 240 will lack sufficient charge such that the one or more components of the air conditioning system will need to be powered exclusively by the AC power grid 302. The controller 220 can detect when a status, such as state of charge (SOC), state of health (SoH), voltage, temperature, etc., of the energy storage device 240 is not within acceptable limits to power the one or more components of the air conditioning system or other loads. If the status of the energy storage device 240 is not within acceptable limits, the one or more components of the air conditioning system and/or other loads need to be powered by the AC power grid 302. This results in discontinuing discharging the energy storage 240 and/or initiating charging the energy storage device 240.
If the utility, or some other source, has not requested to reduce the energy usage at 600, flow proceeds to 606 where the controller 220 determines if the system 100 should use power from the energy storage device 240. One example of a situation where the system 100 should use power from the energy storage device 240 occurs when the utility power is at least one of at a peak price, approaching a grid capacity or at the grid capacity. This determination may be made in real time or may be made previously using forecasting and communicated to the air conditioning system from the utility. Peak price does not necessarily require that the price for electricity be at a maximum, but is generally known in the art as a period of higher than average energy costs. Whether the utility is at a peak price may be determined by utility pricing obtained from the remote system 410 or current or future weather information obtained from the remote system 410. This information may also be locally stored at controller 220. If the utility is at least one of at a peak price, approaching a grid capacity or at the grid capacity, flow proceeds to 604 where the one or more components of the air conditioning system and loads 270, including indoor AC loads 308 and/or other loads are powered by the energy storage device 240 alone or in conjunction with the AC power grid 302. The controller 220 can limit the amount of power drawn from the AC power grid 302 by controlling the various power converters 230 in the system, as noted above. The utility power at a peak price and grid capacity are not the only factors that may be relied on in determining that the system should use power from the energy storage device 240.
With respect to grid capacity, information regarding the grid capacity and current grid load can be obtained from a remote system, such as the source of the utility pricing. If the AC power grid 302 is at grid capacity or approaching grid capacity (e.g., within a threshold range of grid capacity and, optionally, increasing), then it may be prudent to use power from the energy storage device 240 to avoid a power disruption.
Another example of a situation where the system should use power from the energy storage device 240 occurs when a user requests reduced energy usage. The user may use the thermostat 260 to place the system 100 in reduced energy usage mode (e.g., eco-friendly mode) which causes the system to use power from the energy storage device 240 to power one or more components of the air conditioning system.
In another example, the system may use power from the energy storage device 240 based on machine learning (ML) and/or artificial intelligence (AI) control algorithms implemented by controller 220 based on data from block 602 (e.g., User agree), or based on data from block 600 (e.g., Request reduced energy usage).
If at 606, the system should not use power from the energy storage device 240, flow proceeds to 608 where the energy storage device 240 is charged using the AC power grid 302. At 610, the controller 220 determines if the battery status is within acceptable limits, including state of charge (SOC), state of health (SoH), temperature, voltage, or status beyond safety and/or operational limits. If yes, flow returns to 600. At 610, the controller 220 can detect parameters of the energy storage device 240, to confirm that parameters such as state of health of the battery, operating range, temperature range, voltages, capacity, etc., are within the valid limits.
It should be noted that the energy storage device 240 may be charged even if the utility power is at a peak price. This may include failure modes, test modes, etc. Thus, charging the energy storage device 240 is not limited to off-peak utility power price times.
If at 610, the energy storage device has a status that is not within acceptable limits, flow proceeds to 612 where the energy storage device 240 may be charged if the SoC is low or may be disconnected completely if the energy storage device 240 is not operating per safety and/or operational limits.
While
One or more operations of the process of
In other embodiments, the controller 220 and/or the thermostat 260 executes a system enhancement routine to improve performance of the entire air conditioning system, based on optimization (including model predictive controls) or machine learning techniques, considering carbon impact, energy performance, energy cost, lifecycle cost, lifetime impact on equipment, reliability. The system enhancement routine may operate with or without use of information regarding weather, occupancy, historical usage, customer preferences, equipment performance maps (HVAC, battery), potential for energy outages etc. Machine learning techniques on customer preferences, usage, elasticity of decisions regarding temperature, cost, environmental issues, etc. could be used to improve controls logic, and optimization. Other control strategies such as pre-cooling and preheating, that have an advantage on cost, performance, efficiency, environment, comfort, reliability, may be implemented by the controller 220 and/or the thermostat 260.
As described above, embodiments can be in the form of processor-implemented processes and devices for practicing those processes, such as a controller 240 and/or the thermostat 260. Embodiments can also be in the form of computer program code containing instructions embodied in tangible media, such as network cloud storage, SD cards, flash drives, floppy diskettes, CD ROMs, hard drives, or any other computer-readable storage medium, wherein, when the computer program code is loaded into and executed by a computer, the computer becomes a device for practicing the embodiments. Embodiments can also be in the form of computer program code, for example, whether stored in a storage medium, loaded into and/or executed by a computer, or transmitted over some transmission medium, loaded into and/or executed by a computer, or transmitted over some transmission medium, such as over electrical wiring or cabling, through fiber optics, or via electromagnetic radiation, wherein, when the computer program code is loaded into an executed by a computer, the computer becomes a device for practicing the embodiments. When implemented on a general-purpose microprocessor, the computer program code segments configure the microprocessor to create specific logic circuits.
With reference now to
With continued reference to
In other embodiments, as shown in
An energy storage device 1100 as illustrated in
As shown, the coolant heat exchanger 1102 may be arranged within the interior of the indoor unit 1020 or outdoor unit 1000 whether or not the energy storage device 1100 is also arranged within the interior of the indoor unit 1020 or outdoor unit 1000. In the illustrated, non-limiting embodiments illustrated in
A configuration of the coolant heat exchanger 1102 may be the same or, may be different than a configuration of the heat exchanger 1002, 1024 configured to receive the flow of heat transfer fluid, as shown in the FIGS. For example, in the illustrated, non-limiting embodiment of
In some embodiments, the coolant heat exchanger 1102 is arranged downstream from the heat exchanger 1002, 1024 relative to a flow of air. With reference to the outdoor unit 1000 illustrated in
Similarly, with reference to
With reference now to
With reference now to
In the outdoor unit 1000 illustrated in
With reference now to
Alternatively, or in addition to the previously described systems for thermally managing the energy storage device 1100, the energy storage device 1100 may be cooled by the flow of heat transfer fluid circulating within the air conditioning system. In some embodiments, the energy storage device 1100 is directly cooled by the flow of heat transfer fluid circulating within the air conditioning system. In such embodiments, one or more flow channels 1120 configured to receive the heat transfer fluid may extend through the housing of the energy storage device 1100.
In other embodiments, the energy storage device may be indirectly cooled via the flow of heat transfer fluid within the air conditioning system. With reference to
At least one compressor 1210 may be located within the indoor portion 1202 or the outdoor portion 1204 of the heat pump 1200. The one or more compressors 1210 may be any suitable single or multistage compressor, including, but not limited to a screw compressor, reciprocating compressor, centrifugal compressor, scroll compressor, rotary compressor, or axial-flow compressor. The compressor(s) 1210 may be driven by an electrically powered motor, or another suitable energy source.
A first heat exchanger 1212 is arranged within the first or indoor portion 1202 and is directly or indirectly fluidly coupled to the one or more compressors 1210. The first heat exchanger 1212 may be any suitable type of heat exchanger configured to transfer heat between a refrigerant and air or another medium. For example, the first heat exchanger 1212 may include one or more coils of thermally conductive material, such as copper, aluminum, alloys thereof, or combinations thereof. In other embodiments, the first heat exchanger 1212 may be a shell-and tube heat exchanger, a printed circuit heat exchanger, a plate-fin heat exchanger, microchannel heat exchange or any combination thereof. In the illustrated, non-limiting embodiment, the air or other medium is moved (drawn or blown) over the first heat exchanger 1212 via a first movement mechanism 1214, such as a fan for example.
The heat pump 1200 includes at least one expansion device. In the illustrated, non-limiting embodiment, a plurality of expansion devices are included. For example, an indoor expansion device 1216 is positioned within the indoor portion 1202 and an outdoor expansion device 1218 may be positioned within the outdoor portion 1204. In such embodiments, a heat transfer fluid is only configured to flow through one of the expansion devices in each direction of flow through the circuit. However, embodiments having only a single expansion device are also within the scope of the disclosure. The first heat exchanger 1212 is fluidly coupled to the indoor expansion device 1216.
A second heat exchanger 1220 is arranged within the second or outdoor portion 1204 of the heat pump 1200 and is fluidly coupled to the outdoor expansion device 1218. Similar to the first heat exchanger 1212, the second heat exchanger 1220 may be any suitable type of heat exchanger configured to transfer heat between a refrigerant and air or another medium. In the illustrated, non-limiting embodiment, the second heat exchanger 1220 is disposed about the outer extent of the outdoor portion 1204. However, embodiments where the second heat exchanger 1220 is arranged at another location, such as within or proximal to the outdoor portion 1204 are also contemplated herein.
The second heat exchanger 1220 may have any suitable configuration. For example, the second heat exchanger 1220 may include one or more coils of thermally conductive material, such as copper, aluminum, alloys thereof, or combinations thereof. In other embodiments, the second heat exchanger 1220 may be a shell-and tube heat exchanger, a printed circuit heat exchanger, a plate-fin heat exchanger, microchannel heat exchange or any combination thereof. In the illustrated, non-limiting embodiment, the outdoor portion 1204 includes a second movement mechanism 1222, such as a fan assembly for example, to move air or another medium over the second heat exchanger 1220.
The heat pump 20 additionally includes a reversing valve 1224 configured to redirect the flow of refrigerant R therein. In the illustrated embodiment, the reversing valve 1224 is arranged within the outdoor portion 1204 and includes a fluidly separate first flow path and second flow path. In a first state, as shown in
During normal operation of the heat pump 1200, the heat pump is operable in a “heating” mode (
During normal operation of the heat pump 1200, frost can accumulate on the second heat exchanger 1220. To eliminate, or at least mitigate, this frost, the heat pump 1200 may transition to a defrost mode, such as by switching the reversing valve 1224 to the second state. With the reversing valve 1224 in the second state, shown in
In the illustrated, non-limiting embodiment, an energy storage heat exchanger 1230 is fluidly coupled to the fluid flow path of the heat transfer fluid R at a location downstream from the heat exchanger 1212 or 1220 functioning as the condenser and upstream from a corresponding expansion device 1216, 1218. The energy storage heat exchanger 1230 may be configured as a heat sink to remove heat from the coolant C circulating within the coolant loop. In the illustrated, non-limiting embodiment, the energy storage heat exchanger 1230 is a thermal storage device filled with any suitable phase change material, such as ice or wax for example.
During cooling of the energy storage device 1100, the air conditioning system 1200 may not be running. The heated coolant C flows across, around, and/or through the thermal storage device 1230 causing heat from the coolant C to transfer to the phase change material within the thermal storage device. This heat transfer not only cools the coolant C, but also may cause at least a portion of the phase change material within the thermal storage device 1230 to transform from a first state, such as a solid for example, to a second state, such as a liquid for example. However, embodiments where the first state is a liquid and the second state is a gas are also contemplated herein. The size of the thermal storage device 1230, and in some embodiments the phase change material stored therein, may be selected to sufficiently cool the coolant C circulating through the coolant loop based on the amount of heat generated by and/or to be removed from the energy storage device 1100. Once the energy storage device 1100 is cooled to a desired temperature, the thermal storage device 1230 can be “recharged” by removing the heat therefrom. This heat removal is performed by directing a portion of the flow of the cold heat transfer fluid R output from the heat exchanger 1212, 1220 operating as the condenser to the thermal storage device 1230. In an embodiment, a coolant expansion device 1232 is arranged directly upstream from the thermal storage device 1230 relative to a flow of the heat transfer fluid R. In embodiments where the thermal storage device 1230 is filled with a phase change material, recharging the thermal storage device 1230 via a flow of cold heat transfer fluid causes the phase change material to transform from the second phase back to the first phase. The hot heat transfer fluid R output from the thermal storage device 1230 may be returned directly to an inlet of the compressor 1210. Once the thermal storage device 1230 is recharged, the flow of heat transfer fluid R provided to the thermal storage device 1230 may be stopped.
In some embodiments, the energy storage heat exchanger 1230 may be used to transfer heat to the coolant C circulating within the coolant loop, such as to warm the energy storage device 1100 when the ambient temperature surrounding the energy storage device 1100 or the outdoor unit 1204 is cold. In such embodiments, the heat transfer fluid R is configured to bypass the coolant expansion device 1232 and is provided directly to the energy storage heat exchanger 1230. For example, as shown in
A management system including a controller C is operable to monitor a temperature of the energy storage device 1100. The controller C may be any of the controller 220, the HVAC controller, or an energy storage device controller as previously described herein. The management system may include one or more sensors S operable to monitor a temperature of each of the battery cells of the energy storage device 1100. When the sensed temperature exceeds a heated temperature threshold or is below a cold temperature threshold, the controller C of the management system will energize the pump 1104 causing the coolant C within the coolant loop to circulate. Once the temperature of the energy storage device 1100 has fallen below the threshold or reached a predetermined temperature, operation of the pump 1104 may cease.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present disclosure. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, element components, and/or groups thereof.
Those of skill in the art will appreciate that various example embodiments are shown and described herein, each having certain features in the particular embodiments, but the present disclosure is not thus limited. Rather, the present disclosure can be modified to incorporate any number of variations, alterations, substitutions, combinations, sub-combinations, or equivalent arrangements not heretofore described, but which are commensurate with the scope of the present disclosure. Additionally, while various embodiments of the present disclosure have been described, it is to be understood that aspects of the present disclosure may include only some of the described embodiments. Accordingly, the present disclosure is not to be seen as limited by the foregoing description but is only limited by the scope of the appended claims.
This application claims the benefit of U.S. Application No. 63/513,021, filed Jul. 11, 2023, the contents of which are incorporated by reference herein in its entirety.
Number | Date | Country | |
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63513021 | Jul 2023 | US |