Condensate atomizer for heat pump water heater

Abstract

A heat pump water heating system and method provide heated water to a residence or facility. The heat pump water heating system includes a tank for storing water, an evaporator configured for use in heating the water, where the evaporator produces condensate during operation, a reservoir for collecting the condensate, an atomizer configured to atomize the condensate collected in the reservoir, and a fan configured to eject the atomized condensate from the heat pump water heating system.

Description

BACKGROUND

[0001] The present disclosure relates to water heaters, and more particularly to water heaters for use in a home or business. Even more particularly, this disclosure relates to water heaters that, through normal operation, produce condensate that must be removed from the water heater system.SUMMARY

[0002] A water heater system and method according to the present disclosure provides advantageous solutions to these and other known problems in the art.

[0003] In some aspects, which may be combinable with any other aspect, the techniques described herein relate to a heat pump water heating system including: a tank for storing water, an evaporator configured for use in heating the water, the evaporator configured to produce condensate during operation, a reservoir for collecting the condensate, an atomizer configured to atomize the condensate collected in the reservoir, and a fan configured to eject the atomized condensate from the heat pump water heating system.

[0004] In some aspects, which may be combinable with any other aspect, the techniques described herein relate to a heat pump water heating system, wherein the fan is further configured to direct a flow of air through the evaporator, the flow of air serving as a source of heat for heating the water.

[0005] In some aspects, which may be combinable with any other aspect, the techniques described herein relate to a heat pump water heating system including a blower that draws air through the evaporator and a condensate tray, the condensate tray including: a seat, and the reservoir, wherein the blower is attached to the evaporator and the evaporator is seated within the seat, and wherein the atomizer is fluidly connected to the reservoir to atomize the condensate collected within the reservoir.

[0006] In some aspects, which may be combinable with any other aspect, the techniques described herein relate to a heat pump water heating system, wherein the blower includes an air inlet and an air outlet, wherein the air inlet is located adjacent the evaporator, wherein the condensate tray is configured such that the condensate produced by the evaporator bypasses the air inlet and is drawn into the reservoir, and wherein the fan draws the atomized condensate through a duct adjacent the blower and directs the atomized condensate to the air outlet.

[0007] In some aspects, which may be combinable with any other aspect, the techniques described herein relate to a heat pump water heating system, wherein the fan is configured to continue to operate after the blower is shut off.

[0008] In some aspects, which may be combinable with any other aspect, the techniques described herein relate to a heat pump water heating system, wherein the evaporator is a component of a refrigerant circuit configured to heat the water within the tank, wherein the heat pump water heating system includes a housing that encloses components of the refrigerant circuit, and wherein the housing includes an air inlet and an air outlet.

[0009] In some aspects, which may be combinable with any other aspect, the techniques described herein relate to a heat pump water heating system, wherein the air outlet includes the fan for ejecting air including the atomized condensate from the heat pump water heating system.

[0010] In some aspects, which may be combinable with any other aspect, the techniques described herein relate to a heat pump water heating system, wherein air drawn into the air inlet is passed over the evaporator, directed through a main passage, and is discharged through the air outlet, and wherein the atomized condensate is ducted into the main passage and is directed to flow through the air outlet with the air.

[0011] In some aspects, which may be combinable with any other aspect, the techniques described herein relate to a heat pump water heating system including: a housing arranged adjacent to the tank, the evaporator being arranged within the housing, and an atomizer assembly including the reservoir, the atomizer, and the fan, the atomizer assembly being arranged external to the housing.

[0012] In some aspects, which may be combinable with any other aspect, the techniques described herein relate to a heat pump water heating system, wherein the atomizer assembly includes an interior wall that matches a contour of the housing.

[0013] In some aspects, which may be combinable with any other aspect, the techniques described herein relate to a heat pump water heating system, wherein the fan directs air substantially vertically with respect to gravity, around a flow guide, and into the reservoir to pass the atomized condensate out of the atomizer assembly.

[0014] In some aspects, which may be combinable with any other aspect, the techniques described herein relate to a heat pump water heating system, wherein the atomizer assembly includes an electronics housing, a condensate collection tray, and a top cover, and wherein the electronics housing is fixed below the condensate collection tray and houses the fan and the atomizer therein.

[0015] In some aspects, which may be combinable with any other aspect, the techniques described herein relate to a heat pump water heating system, wherein the condensate collection tray and the top cover define the reservoir, and the top cover includes therein a vent for passing the atomized condensate out of the atomizer assembly.

[0016] In some aspects, which may be combinable with any other aspect, the techniques described herein relate to a heat pump water heating system, wherein the fan directs air substantially vertically with respect to gravity through a chimney within the condensate collection tray before being directed around the flow guide and into the reservoir.

[0017] In some aspects, which may be combinable with any other aspect, the techniques described herein relate to a method of discharging condensate from a heat pump water heating system, the heat pump water heating system including: a tank for storing water, an evaporator configured for use in heating the water, the evaporator configured to produce condensate during operation thereof, a reservoir for collecting the condensate, an atomizer configured to atomize the condensate collected in the reservoir, and a fan configured to eject the atomized condensate from the heat pump water heating system, wherein the method includes: operating the heat pump water heating system to produce the condensate, collecting the condensate within the reservoir, atomizing the condensate with the atomizer, and operating the fan to discharge the atomized condensate from the heat pump water heating system.

[0018] In some aspects, which may be combinable with any other aspect, the techniques described herein relate to a method, wherein the evaporator is part of a heat pump system configured to heat the water within the tank, and wherein the fan and the atomizer are configured to operate after an operating cycle of the heat pump system ends such that the condensate is removed from the reservoir after the heat pump system is no longer heating the water within the tank.

[0019] In some aspects, which may be combinable with any other aspect, the techniques described herein relate to a method of operating a heat pump system including: receiving a flow of air from an environment of the heat pump system, the flow of air having a dewpoint temperature; directing the flow of air through an evaporator of the heat pump system; directing a flow of refrigerant through the evaporator, the flow of refrigerant having a temperature that is below the dewpoint temperature; transferring thermal energy from the flow of air to the flow of refrigerant within the evaporator; condensing water vapor from the flow of air within the evaporator to form liquid condensate; directing the flow of air back into the environment of the heat pump system after directing the flow of air through the evaporator; collecting the liquid condensate; atomizing the liquid condensate to form a mist of liquid-state water droplets; and directing the liquid-state water droplets into the environment of the heat pump system.

[0020] In some aspects, which may be combinable with any other aspect, the techniques described herein relate to a method including combining the liquid-state water droplets and the flow of air prior to directing the liquid-state water droplets and the flow of air into the environment of the heat pump system.

[0021] In some aspects, which may be combinable with any other aspect, the techniques described herein relate to a method, wherein the evaporator is located within a housing and wherein: receiving the flow of air from the environment includes directing the flow of air into the housing; and directing the flow of back into the environment includes directing the flow of air out of the housing.

[0022] In some aspects, which may be combinable with any other aspect, the techniques described herein relate to a method including directing the liquid condensate out of the housing prior to atomizing the liquid condensate.

[0023] Other aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings.BRIEF DESCRIPTION OF THE DRAWINGS

[0024] FIG. 1 is a schematic view of a heat pump water heating system.

[0025] FIG. 2 is a schematic view of the heat pump water heating system shown in FIG. 1 having a housing removed.

[0026] FIG. 3 is an assembly view of a blower assembly, a condensate tray, and a heat exchanger of the heat pump water heating system shown in FIG. 1

[0027] FIG. 4 is a schematic view of the condensate tray shown in FIG. 3.

[0028] FIG. 5 is a section view of the blower assembly, condensate tray, and heat exchanger shown in FIG. 3.

[0029] FIG. 6 is a section view of the heat pump water heating system shown in FIG. 1.

[0030] FIG. 7 is a side profile view of the heat pump water heating system shown in FIG. 1.

[0031] FIG. 8 is a schematic view of an atomizer assembly shown in FIG. 7.

[0032] FIG. 9 is a section view of the atomizer assembly shown in FIG. 8.

[0033] FIG. 10 is a schematic view of an atomizer assembly for use with the heat pump water heating system of FIG. 1.

[0034] FIG. 11 is an assembly view of the atomizer assembly shown in FIG. 10.

[0035] FIG. 12 is a section view of the atomizer assembly shown in FIG. 10.

[0036] FIG. 13 is top-down view of the atomizer assembly shown in FIG. 10.DETAILED DESCRIPTION

[0037] Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways.

[0038] Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The modifier “about” used in connection with a quantity is inclusive of the stated value and has the meaning dictated by the context (for example, it includes at least the degree of error associated with the measurement of the particular quantity). The modifier “about” should also be considered as disclosing the range defined by the absolute values of the two endpoints. For example, the expression “from about 2 to about 4” also discloses the range “from 2 to 4”. The term “about” may refer to plus or minus 10% of the indicated number. For example, “about 10%” may indicate a range of 9% to 11%, and “about 1%” may mean from 0.9-1.1. Other meanings of “about” may be apparent from the context, such as rounding off, so, for example “about 1” may also mean from 0.5 to 1.4.

[0039] FIG. 1 illustrates a heat pump water heating system (i.e., a heat pump water heater) 50. In the heat pump water heating system 50, thermal energy is extracted from the environment and is used to heat water by way of a refrigerant cycle. Refrigerant at a low temperature and pressure, and in an at least partially liquid phase, is placed into a heat exchange relationship with air from the environment that is at a higher temperature, in order to heat the refrigerant and convert it to a superheated vapor state. The superheated vapor refrigerant is subsequently compressed to a higher pressure and temperature state, so that the thermal energy can be transferred at a desirable temperature into the water to be heated.

[0040] In most cases, the air from which the thermal energy is to be extracted will have water vapor content. Since the thermal energy is extracted from the air by passing the air over and / or through heat exchange surfaces that are cooled by the low temperature refrigerant (e.g., a heat exchanger 85 such as an evaporator), condensation of such water vapor will occur when those heat exchange surfaces are at a temperature that is lower than the dewpoint temperature of the air. This condensed water, or condensate, must be disposed of to prevent an undesirable build-up of condensate within the heat pump water heating system 50. Preferably, the condensate is directed to a nearby drain by gravity. In some cases, it may be necessary for the condensate to be pumped to a remotely located drain when there is not a drain suitably located for gravity discharge. Such a condensate pumping system can, however, be expensive and complicated, and in some circumstances unfeasible due to the lack of a suitably located drain.

[0041] These and other problems in the art are addressed by the heat pump water heating system 50 disclosed herein. The heat pump water heating system 50 includes an integrated heat pump system 52 and a tank 60 where water is heated and stored. The heat pump system 52 is at least partially located in a housing 55 located atop the tank 60. The housing 55 can form at least a portion of a housing 57 of the entire heat pump water heating system 50. The housing 55 encloses the heat pump system 52. A blower assembly 90 (see FIGS. 3 and 4) or a fan 170 (see FIG. 6) is used to draw air from the ambient environment 230 surrounding the heat pump water heating system 50 and into the housing 55 through an air inlet 65 located on a top surface of the housing 55 (the left-hand port as seen in FIG. 1). That air is then directed through the evaporator heat exchanger 85 through which low pressure and temperature refrigerant is flowing, and thermal energy is transferred from the higher temperature air to the refrigerant, thereby heating and vaporizing the refrigerant while simultaneously cooling the air. The cooled air is then directed back into the environment 230 by the fan 170 or the blower assembly 90 through an air outlet 70 located on the top surface of the housing 55 (the right-hand port as shown in FIG. 1). The fan 170 therefore directs a flow of the air through the evaporator heat exchanger 85, where the flow of air serves as a source of heat for heating water within the evaporator heat exchanger 85. In some cases, ductwork or tubing may be attached to the air inlet 65 or the air outlet 70 or both, so that the air is sourced from and / or directed to an environment 230 that is not immediately adjacent the heat pump water heating system 50, but the operation remains unchanged. In some cases, one or both of the air inlet 65 and air outlet 70 can be located on alternative portions of the housing 55, such as on the cylindrical side.

[0042] Referring now to the embodiment shown in FIGS. 2-5, the housing 55 is removed so that the components underneath are visible. The heat pump water heating system 50 includes a water inlet 75 for receiving unheated water and a water outlet 80 for passing heated water to the residence or facility where heated water is desired. Components of the heat pump system (i.e., a refrigerant circuit) 52 such as a compressor 100 and tubing 105 that delivers refrigerant to or from a condenser (surrounding the tank 60, but not visible herein) are visible in FIG. 2.

[0043] The blower assembly 90 in this example includes a centrifugal blower, with a radial air inlet 140 and a tangential air outlet (i.e., an exhaust) 150, and is mounted to the exit face of the evaporator heat exchanger 85 so that the blower assembly 90 operates to draw air through the evaporator heat exchanger 85, as shown via the arrows in FIG. 5. In other words, the air inlet 140 is located adjacent the evaporator heat exchanger 85 to draw air therethrough.

[0044] The evaporator heat exchanger 85 and blower assembly 90 are assembled to a condensate tray 95, which is configured so that water vapor that condenses out of the air as it contacts the relatively cooler surfaces of the evaporator heat exchanger 85 drops down into a reservoir 115 of the condensate tray 95 and is collected there. More specifically, the evaporator heat exchanger 85 is positioned within a seat 110 of the condensate tray 95. An atomizer 125 is assembled to the condensate tray 95 in fluid communication with condensate in the reservoir 115 at a relatively low (with respect to a direction of gravity 225) location of the condensate tray 95, so that the collected condensate is directed by gravity towards the atomizer 125.

[0045] The atomizer 125 is an ultrasonic frequency transducer that is electronically connected to a driver circuit board, or that has an integrated driver circuit board. The driver circuit board can be in electrical communication with a controller 175 of the heat pump water heating system 50 (for example, the main controller 175 on the housing 55, 57 cylindrical sidewall, as shown in FIGS. 1 and 7) in order to receive low-voltage electrical power and, optionally, to send and / or receive control signals. As one non-limiting example, such an ultrasonic transducer with integrated driver circuit board is available from Audiowell Sensor technology (Wan Chai, Hong Kong) as model UM0108-005 Smart Atomizer.

[0046] The atomizer 125 includes a piezoelement that is configured to vibrate at a high (ultrasonic) frequency (for example, in the range of 1-5 MHz, e.g. 1.7 MHz). This high-frequency vibration results in cavitation which creates wave crests or columns in the film of condensate water over the piezoelement, and results in water microdroplets (droplets with diameters of, for example, 1-50 micrometers) breaking free from the water film, forming a fine mist of water droplets. The mist of water droplets can be re-introduced into the cooled air downstream of the evaporator heat exchanger 85 and can thereby be discharged from the housing 55 through the outlet 70.

[0047] Referring now to FIG. 5, a rotating wheel 92 driven by a motor 130 of the blower assembly 90 acts to pull the air through the evaporator heat exchanger 85, and as the air passes over the refrigerant-cooled surface of the evaporator heat exchanger 85, the air is cooled and water is condensed from the air. The condensate is collected in the reservoir 115 of the condensate tray 95 and is routed to the atomizer 125, located at a lower portion of the reservoir 115, by gravity. The condensate bypasses the blower assembly 90. The rotating wheel 92 pressurizes the cooled air and directs it upward towards through a main blower channel 145 and through a blower exhaust 150. As a film of water forms over the atomizer 125, the transducer is actuated to convert the water into microdroplets. A fan 120 pulls a flow of air over the atomizer, entraining the microdroplets therein, and directs the air and entrained microdroplets through a duct 135 and into the main blower channel 145, to flow from the blower assembly 90 in the main exhaust stream out of the blower exhaust 150.

[0048] In some cases, the rate at which condensate is collected in the reservoir 115 when the heat pump system 52 is operating may exceed the rate at which the atomizer 125 can remove condensate from the reservoir 115. The volume of condensate within the reservoir 115 will then increase as the heat pump system 52 is operating. It may therefore be necessary, or desirable, for the atomizer 125 to continue operating for some time after a heat pump system 52 operating cycle ends (i.e., when water within the tank 60 is not actively being heated and / or after the motor 130 of the blower assembly 90 is shut off). In some cases, the atomizer 125 can continue to operate until such time as it detects an absence of water within the reservoir 115. In other cases, the atomizer 125 can continue to operate for a fixed period of time after the heat pump system 52 operating cycle ends. The controller 175 can be configured to supply power to the fan 120 (or the fans 170, 200 shown in FIGS. 6 and 9, respectively) for the period of time that the atomizer 125 is operating, in order to remove the microdroplets from within the housing 55.

[0049] As such, a method for operating a heat pump water heating system 50 can include operating the heat pump system 52 (e.g., including a refrigerant circuit 54) to produce condensate, collecting the condensate within the reservoir 115, atomizing the condensate via the atomizer 125, and operating the fan 120 to discharge the atomized condensate from the heat pump water heating system 50. Further, in some examples the fan 120 and the atomizer 125 are operated after the heat pump system 52 operating cycle ends such that condensate is removed from the reservoir 115 after the heat pump system 52 is no longer heating the water within the tank 60.

[0050] As another example, a method for operating the heat pump system 52 includes receiving a flow of air from an environment 230 of the heat pump system 52, where the flow of air has a dewpoint temperature. The flow of air is then directed through the evaporator heat exchanger 85 (i.e., an evaporator) while simultaneously directing a flow of refrigerant through the evaporator heat exchanger 85. The flow of refrigerant is not specifically illustrated herein, but is present within the evaporator heat exchanger 85. The flow of refrigerant has a temperature that is below the dewpoint temperature. Thermal energy from the flow of air is transferred into the refrigerant within the evaporator heat exchanger 85, which in turn condenses water vapor within the flow of air within the evaporator heat exchanger 85 to produce liquid condensate. After passing through the evaporator heat exchanger 85, the flow of air is passed back into the environment 230 of the heat pump system 52. The liquid condensate is collected and atomized to form liquid-state water droplets. The liquid state water droplets are directed into the environment 230 of the heat pump system 52. In some examples, such as that shown in FIGS. 5 and 6, the liquid-state water droplets are added into the flow of air prior to the flow of air and water droplets being directed into the environment 230.

[0051] In some examples, the method for operating the heat pump system 52 includes receiving the flow of air from the environment 230 and directing the flow of air into the housing 55 where the evaporator heat exchanger 85 is located. The method can further include directing the flow of back into the environment 230 by directing the flow of air out of the housing 55. In other examples, such as those shown in FIGS. 7-13, the liquid condensate is directed out of the housing 55 via the drain line 185 prior to being atomized.

[0052] Referring now to the embodiment shown in FIG. 6, a single fan 170 is used to both pull the air through the evaporator heat exchanger 85 and eject the entrained microdroplets from within the housing 55. In this embodiment, the fan 170 is arranged adjacent the air outlet 70, rather than using the blower assembly 90 shown in the previous example. The air exiting the evaporator heat exchanger 85 is received into a main passage 160 via a collecting scoop 162, and a portion of that air is directed to flow under the collecting scoop 162 and over the atomizer 125 in order entrain the microdroplets before returning to the main passage 160. Condensate from the evaporator heat exchanger 85 is likewise directed (via gravity) under the collecting scoop 162 and into a reservoir 155. The atomizer 125 is located within the reservoir 155 to atomize condensate collected therein. Once the microdroplets are returned to the main passage 160 via a duct 165, the combined air and condensate microdroplets is then directed out of the housing 55 through the air outlet 70 by way of the fan 170. Thus, in this embodiment, the condensate is reintroduced into the air stream between the evaporator heat exchanger 85 and the fan 170. In this embodiment, when the atomizer 125 continues to operate after a heat pump cycle ends, the heat pump controller 175 can continue to operate the fan 170 in order to remove the microdroplets. In some cases, the controller 175 can be configured to operate the fan 170 at a slower speed during such operation than the speed at which the fan 170 operates during the heat pump cycle.

[0053] Referring now to the embodiment shown in FIGS. 7-9, instead of the atomizer 125 and reservoir 115 being located within the housing 55, an atomizer assembly 180 is arranged outside of the housing 55 volume. In this example, the atomizer assembly 180 includes a reservoir 220 that is optionally mechanically fastened to an exterior surface of the heat pump water heating system 50 on the housing 57. A condensate drain line 185 at one end is coupled to the condensate tray 95 within the housing 55, and to a drain line inlet 190 of the reservoir 220 at a second end, the second end being arranged with respect to the direction of gravity 225 lower than first end so that condensate will flow by gravity from the condensate tray 95 to the reservoir 220.

[0054] The atomizer assembly 180 includes a housing 215 having the reservoir 220, the atomizer 125, and the fan 200 therein. The fan 200 includes an inlet 202 where air is drawn into the fan 200, which directs the air, as shown by the arrows in FIG. 9, upwards (i.e., vertically) with respect to the direction of gravity 225 through a duct 205 and around a flow guide 210. The flow guide 210 directs the air down into the reservoir 220 near the atomizer 125 such that condensate droplets created by the atomizer 125 are entrained with the air in the reservoir 220. The air entrained with the condensation droplets is then ejected from an exhaust 195 (and thus, the heat pump water heating system 50) via the force of additional air being pushed into the reservoir 220 at the flow guide 210. FIG. 9 includes arrows denoting the above-explained flow path of the air through the atomizer assembly 180.

[0055] A wiring harness or cable (not shown) can be provided with the atomizer 125, and can be connected to a port of the water heater controller 175 in order to provide power to the atomizer 125 and the fan 200 within the atomizer assembly 180, as well as to provide for communication of control signals between the water heater controller 175 and the atomizer 125 and the fan 200 in order to control the operation thereof.

[0056] The embodiment shown in FIGS. 7-9 allows for the atomizer 125 to be an optional add-on component to the heat pump water heating system 50. When the heat pump water heating system 50 is to be installed in a location where a drain is readily available for gravity draining of the condensate, then the condensate drain line 185 can be routed from the condensate tray 95 connection point to that drain. If such a drain is not readily available, then the atomizer assembly 180 can be added to the heat pump water heating system 50 to achieve the required condensate removal.

[0057] The example shown in FIGS. 10-13 is another example of an external atomizer assembly 180, which includes features that are combinable with the other atomizer assemblies 180 described herein. The atomizer assembly 180 illustrated in FIG. 10 is optionally mechanically fastened to an exterior surface of the heat pump water heating system 50 on the housing 57. However, this example of the atomizer assembly 180 includes a curved interior wall 235. The curved interior wall 235 has a contour that matches, or closely resembles, the external contour of the housing 57, which is generally cylindrically shaped, allowing the curved interior wall 235 to be mounted flush to the housing 57. The drain line 185 is connected to the drain line inlet 190, and condensate from the heat pump system 52 flows into the atomizer assembly 180 via the drain line inlet 190. Similar to the other examples described herein, the water is atomized and ejected through a vent 240 in a vent cap 245 located on top of the atomizer assembly 180.

[0058] Referring now to FIG. 11, the atomizer assembly includes a top cover 250, a condensate collection tray 255, and an electronics housing 260. These components are stacked one on top of the other – the top cover 250 is positioned on the condensate collection tray 255, which is positioned on the electronics housing 260. Apertures 265 are included around the outside of each of the top cover 250, the condensate collection tray 255, and the electronics housing 260, and are aligned such that fasteners can extend through the apertures to fix the top cover 250 to the condensate collection tray 255 and fix the condensate collection tray 255 to the electronics housing 260. In other examples, the top cover 250, the condensate collection tray 255, and the electronics housing 260 may be otherwise fixed to one another or formed from a single monolithic unit. The condensate collection tray includes the drain line inlet 190, which is in fluid communication with a reservoir 270 defined by the condensate collection tray 255 and the top cover 250. Condensate enters the reservoir 270 via the drain line inlet 190. The electronics housing 260 positioned below the reservoir 270 includes the atomizer 125, which is in fluid communication with the reservoir 270 such that the atomizer 125 can atomize the condensate within the reservoir 270. As can be seen in FIG. 12, the atomizer 125 is positioned at the lowest point in the reservoir 270, so that the condensate will naturally travel (via gravity 225) into contact with the atomizer 125.

[0059] Referring now collectively to FIGS. 11-13, the structure and process of expelling the atomized condensate from the reservoir 270 will be explained. The electronics housing 260 includes the fan or blower 200, which has a fan outlet 280. The electronics housing 260 may include other electronic components as well, for example, power and / or controller assemblies for the atomizer 125 and fan 200, and may be used to house and route wiring for these and other components. The condensate collection tray includes a chimney 275 that extends up through the reservoir 270. The fan 200 sucks air into the electronics housing 260 via an air inlet 285, which is positioned in a sidewall of the electronics housing 260. This air passes through the fan 200 and out of the fan outlet 280, which is fluidly connected to the chimney 275. The fan 200 therefore passes the air through the chimney 275 and into the reservoir 270. The top cover 250 in this example includes a flow guide 295 that turns air from the generally vertical direction while travelling through the chimney, to direct air into the reservoir 270. The reservoir 270 is sealed by the top cover 250 except for the vent 240 within the vent cap 245. Thus, air passing from the chimney 275 is circulated throughout the reservoir 270 to entrain droplets of condensate created by the atomizer 125, and then the air with the entrained droplets passes out of the reservoir 270 via the vent 240. In other examples, the vent 240 may be located at another location on the top cover 250, and may not be part of the vent cap 245. Arrows in FIG. 12 generally depict the flow of air into the air inlet 285, through the atomizer assembly 180, and out of the vent 240.

[0060] By converting the condensate into entrained liquid microdroplets, rather than into water vapor, the condensate can be removed from the heat pump water heating system 50 with substantially less energy than would be required to vaporize the water. By way of example, the Audiowell UM0108-005 transducer (i.e., an example atomizer 125) has a rated mist volume production of 210 mL / h with a power consumption of 18.15W, which is equal to an energy consumption of 311 J / mL (Joules of energy per milliliter of water removed). In contrast, the latent heat of vaporization alone of water is 2260 J / mL, more than seven times greater. In addition, the condensate would need to be heated to the boiling point at a sensible heat capacity of 4.186 J / mL / °C, requiring an additional 380-400 J / mL or approximately 1.25x the amount of energy required by the atomizer 125.

[0061] After the condensate has been introduced into the ambient air as a fine mist, the water droplets will re-evaporate into water vapor by absorbing heat from the air surrounding the microdroplets. This can occur rapidly, due to the high surface area to volume ratio of the microdroplets. The net effect over time, then, is that the heat pump water heating system 50 can operate by removing only sensible heat from the ambient environment 230.

[0062] Although the invention has been described in detail with reference to certain preferred embodiments, variations and modifications exist within the scope and spirit of one or more independent aspects of the invention as described.

Examples

Embodiment Construction

[0037]Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways.

[0038]Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The modifier “about” used in connection with a quantity is inclusive of the stated value and has the meaning dictated by the context (for example, it includes at least the degree of error associated with the measurement of the particular quantity). The modifier “about” should also be considered as disclosing the range defined by the absolute values of the two endpoints. For example, the expression “from about 2 to about 4” also discl...

BACKGROUND

[0001] The present disclosure relates to water heaters, and more particularly to water heaters for use in a home or business. Even more particularly, this disclosure relates to water heaters that, through normal operation, produce condensate that must be removed from the water heater system.SUMMARY

[0002] A water heater system and method according to the present disclosure provides advantageous solutions to these and other known problems in the art.

[0003] In some aspects, which may be combinable with any other aspect, the techniques described herein relate to a heat pump water heating system including: a tank for storing water, an evaporator configured for use in heating the water, the evaporator configured to produce condensate during operation, a reservoir for collecting the condensate, an atomizer configured to atomize the condensate collected in the reservoir, and a fan configured to eject the atomized condensate from the heat pump water heating system.

[0004] In some aspects, which may be combinable with any other aspect, the techniques described herein relate to a heat pump water heating system, wherein the fan is further configured to direct a flow of air through the evaporator, the flow of air serving as a source of heat for heating the water.

[0005] In some aspects, which may be combinable with any other aspect, the techniques described herein relate to a heat pump water heating system including a blower that draws air through the evaporator and a condensate tray, the condensate tray including: a seat, and the reservoir, wherein the blower is attached to the evaporator and the evaporator is seated within the seat, and wherein the atomizer is fluidly connected to the reservoir to atomize the condensate collected within the reservoir.

[0006] In some aspects, which may be combinable with any other aspect, the techniques described herein relate to a heat pump water heating system, wherein the blower includes an air inlet and an air outlet, wherein the air inlet is located adjacent the evaporator, wherein the condensate tray is configured such that the condensate produced by the evaporator bypasses the air inlet and is drawn into the reservoir, and wherein the fan draws the atomized condensate through a duct adjacent the blower and directs the atomized condensate to the air outlet.

[0007] In some aspects, which may be combinable with any other aspect, the techniques described herein relate to a heat pump water heating system, wherein the fan is configured to continue to operate after the blower is shut off.

[0008] In some aspects, which may be combinable with any other aspect, the techniques described herein relate to a heat pump water heating system, wherein the evaporator is a component of a refrigerant circuit configured to heat the water within the tank, wherein the heat pump water heating system includes a housing that encloses components of the refrigerant circuit, and wherein the housing includes an air inlet and an air outlet.

[0009] In some aspects, which may be combinable with any other aspect, the techniques described herein relate to a heat pump water heating system, wherein the air outlet includes the fan for ejecting air including the atomized condensate from the heat pump water heating system.

[0010] In some aspects, which may be combinable with any other aspect, the techniques described herein relate to a heat pump water heating system, wherein air drawn into the air inlet is passed over the evaporator, directed through a main passage, and is discharged through the air outlet, and wherein the atomized condensate is ducted into the main passage and is directed to flow through the air outlet with the air.

[0011] In some aspects, which may be combinable with any other aspect, the techniques described herein relate to a heat pump water heating system including: a housing arranged adjacent to the tank, the evaporator being arranged within the housing, and an atomizer assembly including the reservoir, the atomizer, and the fan, the atomizer assembly being arranged external to the housing.

[0012] In some aspects, which may be combinable with any other aspect, the techniques described herein relate to a heat pump water heating system, wherein the atomizer assembly includes an interior wall that matches a contour of the housing.

[0013] In some aspects, which may be combinable with any other aspect, the techniques described herein relate to a heat pump water heating system, wherein the fan directs air substantially vertically with respect to gravity, around a flow guide, and into the reservoir to pass the atomized condensate out of the atomizer assembly.

[0014] In some aspects, which may be combinable with any other aspect, the techniques described herein relate to a heat pump water heating system, wherein the atomizer assembly includes an electronics housing, a condensate collection tray, and a top cover, and wherein the electronics housing is fixed below the condensate collection tray and houses the fan and the atomizer therein.

[0015] In some aspects, which may be combinable with any other aspect, the techniques described herein relate to a heat pump water heating system, wherein the condensate collection tray and the top cover define the reservoir, and the top cover includes therein a vent for passing the atomized condensate out of the atomizer assembly.

[0016] In some aspects, which may be combinable with any other aspect, the techniques described herein relate to a heat pump water heating system, wherein the fan directs air substantially vertically with respect to gravity through a chimney within the condensate collection tray before being directed around the flow guide and into the reservoir.

[0017] In some aspects, which may be combinable with any other aspect, the techniques described herein relate to a method of discharging condensate from a heat pump water heating system, the heat pump water heating system including: a tank for storing water, an evaporator configured for use in heating the water, the evaporator configured to produce condensate during operation thereof, a reservoir for collecting the condensate, an atomizer configured to atomize the condensate collected in the reservoir, and a fan configured to eject the atomized condensate from the heat pump water heating system, wherein the method includes: operating the heat pump water heating system to produce the condensate, collecting the condensate within the reservoir, atomizing the condensate with the atomizer, and operating the fan to discharge the atomized condensate from the heat pump water heating system.

[0018] In some aspects, which may be combinable with any other aspect, the techniques described herein relate to a method, wherein the evaporator is part of a heat pump system configured to heat the water within the tank, and wherein the fan and the atomizer are configured to operate after an operating cycle of the heat pump system ends such that the condensate is removed from the reservoir after the heat pump system is no longer heating the water within the tank.

[0019] In some aspects, which may be combinable with any other aspect, the techniques described herein relate to a method of operating a heat pump system including: receiving a flow of air from an environment of the heat pump system, the flow of air having a dewpoint temperature; directing the flow of air through an evaporator of the heat pump system; directing a flow of refrigerant through the evaporator, the flow of refrigerant having a temperature that is below the dewpoint temperature; transferring thermal energy from the flow of air to the flow of refrigerant within the evaporator; condensing water vapor from the flow of air within the evaporator to form liquid condensate; directing the flow of air back into the environment of the heat pump system after directing the flow of air through the evaporator; collecting the liquid condensate; atomizing the liquid condensate to form a mist of liquid-state water droplets; and directing the liquid-state water droplets into the environment of the heat pump system.

[0020] In some aspects, which may be combinable with any other aspect, the techniques described herein relate to a method including combining the liquid-state water droplets and the flow of air prior to directing the liquid-state water droplets and the flow of air into the environment of the heat pump system.

[0021] In some aspects, which may be combinable with any other aspect, the techniques described herein relate to a method, wherein the evaporator is located within a housing and wherein: receiving the flow of air from the environment includes directing the flow of air into the housing; and directing the flow of back into the environment includes directing the flow of air out of the housing.

[0022] In some aspects, which may be combinable with any other aspect, the techniques described herein relate to a method including directing the liquid condensate out of the housing prior to atomizing the liquid condensate.

[0023] Other aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings.BRIEF DESCRIPTION OF THE DRAWINGS

[0024] FIG. 1 is a schematic view of a heat pump water heating system.

[0025] FIG. 2 is a schematic view of the heat pump water heating system shown in FIG. 1 having a housing removed.

[0026] FIG. 3 is an assembly view of a blower assembly, a condensate tray, and a heat exchanger of the heat pump water heating system shown in FIG. 1

[0027] FIG. 4 is a schematic view of the condensate tray shown in FIG. 3.

[0028] FIG. 5 is a section view of the blower assembly, condensate tray, and heat exchanger shown in FIG. 3.

[0029] FIG. 6 is a section view of the heat pump water heating system shown in FIG. 1.

[0030] FIG. 7 is a side profile view of the heat pump water heating system shown in FIG. 1.

[0031] FIG. 8 is a schematic view of an atomizer assembly shown in FIG. 7.

[0032] FIG. 9 is a section view of the atomizer assembly shown in FIG. 8.

[0033] FIG. 10 is a schematic view of an atomizer assembly for use with the heat pump water heating system of FIG. 1.

[0034] FIG. 11 is an assembly view of the atomizer assembly shown in FIG. 10.

[0035] FIG. 12 is a section view of the atomizer assembly shown in FIG. 10.

[0036] FIG. 13 is top-down view of the atomizer assembly shown in FIG. 10.DETAILED DESCRIPTION

[0037] Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways.

[0038] Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The modifier “about” used in connection with a quantity is inclusive of the stated value and has the meaning dictated by the context (for example, it includes at least the degree of error associated with the measurement of the particular quantity). The modifier “about” should also be considered as disclosing the range defined by the absolute values of the two endpoints. For example, the expression “from about 2 to about 4” also discloses the range “from 2 to 4”. The term “about” may refer to plus or minus 10% of the indicated number. For example, “about 10%” may indicate a range of 9% to 11%, and “about 1%” may mean from 0.9-1.1. Other meanings of “about” may be apparent from the context, such as rounding off, so, for example “about 1” may also mean from 0.5 to 1.4.

[0039] FIG. 1 illustrates a heat pump water heating system (i.e., a heat pump water heater) 50. In the heat pump water heating system 50, thermal energy is extracted from the environment and is used to heat water by way of a refrigerant cycle. Refrigerant at a low temperature and pressure, and in an at least partially liquid phase, is placed into a heat exchange relationship with air from the environment that is at a higher temperature, in order to heat the refrigerant and convert it to a superheated vapor state. The superheated vapor refrigerant is subsequently compressed to a higher pressure and temperature state, so that the thermal energy can be transferred at a desirable temperature into the water to be heated.

[0040] In most cases, the air from which the thermal energy is to be extracted will have water vapor content. Since the thermal energy is extracted from the air by passing the air over and / or through heat exchange surfaces that are cooled by the low temperature refrigerant (e.g., a heat exchanger 85 such as an evaporator), condensation of such water vapor will occur when those heat exchange surfaces are at a temperature that is lower than the dewpoint temperature of the air. This condensed water, or condensate, must be disposed of to prevent an undesirable build-up of condensate within the heat pump water heating system 50. Preferably, the condensate is directed to a nearby drain by gravity. In some cases, it may be necessary for the condensate to be pumped to a remotely located drain when there is not a drain suitably located for gravity discharge. Such a condensate pumping system can, however, be expensive and complicated, and in some circumstances unfeasible due to the lack of a suitably located drain.

[0041] These and other problems in the art are addressed by the heat pump water heating system 50 disclosed herein. The heat pump water heating system 50 includes an integrated heat pump system 52 and a tank 60 where water is heated and stored. The heat pump system 52 is at least partially located in a housing 55 located atop the tank 60. The housing 55 can form at least a portion of a housing 57 of the entire heat pump water heating system 50. The housing 55 encloses the heat pump system 52. A blower assembly 90 (see FIGS. 3 and 4) or a fan 170 (see FIG. 6) is used to draw air from the ambient environment 230 surrounding the heat pump water heating system 50 and into the housing 55 through an air inlet 65 located on a top surface of the housing 55 (the left-hand port as seen in FIG. 1). That air is then directed through the evaporator heat exchanger 85 through which low pressure and temperature refrigerant is flowing, and thermal energy is transferred from the higher temperature air to the refrigerant, thereby heating and vaporizing the refrigerant while simultaneously cooling the air. The cooled air is then directed back into the environment 230 by the fan 170 or the blower assembly 90 through an air outlet 70 located on the top surface of the housing 55 (the right-hand port as shown in FIG. 1). The fan 170 therefore directs a flow of the air through the evaporator heat exchanger 85, where the flow of air serves as a source of heat for heating water within the evaporator heat exchanger 85. In some cases, ductwork or tubing may be attached to the air inlet 65 or the air outlet 70 or both, so that the air is sourced from and / or directed to an environment 230 that is not immediately adjacent the heat pump water heating system 50, but the operation remains unchanged. In some cases, one or both of the air inlet 65 and air outlet 70 can be located on alternative portions of the housing 55, such as on the cylindrical side.

[0042] Referring now to the embodiment shown in FIGS. 2-5, the housing 55 is removed so that the components underneath are visible. The heat pump water heating system 50 includes a water inlet 75 for receiving unheated water and a water outlet 80 for passing heated water to the residence or facility where heated water is desired. Components of the heat pump system (i.e., a refrigerant circuit) 52 such as a compressor 100 and tubing 105 that delivers refrigerant to or from a condenser (surrounding the tank 60, but not visible herein) are visible in FIG. 2.

[0043] The blower assembly 90 in this example includes a centrifugal blower, with a radial air inlet 140 and a tangential air outlet (i.e., an exhaust) 150, and is mounted to the exit face of the evaporator heat exchanger 85 so that the blower assembly 90 operates to draw air through the evaporator heat exchanger 85, as shown via the arrows in FIG. 5. In other words, the air inlet 140 is located adjacent the evaporator heat exchanger 85 to draw air therethrough.

[0044] The evaporator heat exchanger 85 and blower assembly 90 are assembled to a condensate tray 95, which is configured so that water vapor that condenses out of the air as it contacts the relatively cooler surfaces of the evaporator heat exchanger 85 drops down into a reservoir 115 of the condensate tray 95 and is collected there. More specifically, the evaporator heat exchanger 85 is positioned within a seat 110 of the condensate tray 95. An atomizer 125 is assembled to the condensate tray 95 in fluid communication with condensate in the reservoir 115 at a relatively low (with respect to a direction of gravity 225) location of the condensate tray 95, so that the collected condensate is directed by gravity towards the atomizer 125.

[0045] The atomizer 125 is an ultrasonic frequency transducer that is electronically connected to a driver circuit board, or that has an integrated driver circuit board. The driver circuit board can be in electrical communication with a controller 175 of the heat pump water heating system 50 (for example, the main controller 175 on the housing 55, 57 cylindrical sidewall, as shown in FIGS. 1 and 7) in order to receive low-voltage electrical power and, optionally, to send and / or receive control signals. As one non-limiting example, such an ultrasonic transducer with integrated driver circuit board is available from Audiowell Sensor technology (Wan Chai, Hong Kong) as model UM0108-005 Smart Atomizer.

[0046] The atomizer 125 includes a piezoelement that is configured to vibrate at a high (ultrasonic) frequency (for example, in the range of 1-5 MHz, e.g. 1.7 MHz). This high-frequency vibration results in cavitation which creates wave crests or columns in the film of condensate water over the piezoelement, and results in water microdroplets (droplets with diameters of, for example, 1-50 micrometers) breaking free from the water film, forming a fine mist of water droplets. The mist of water droplets can be re-introduced into the cooled air downstream of the evaporator heat exchanger 85 and can thereby be discharged from the housing 55 through the outlet 70.

[0047] Referring now to FIG. 5, a rotating wheel 92 driven by a motor 130 of the blower assembly 90 acts to pull the air through the evaporator heat exchanger 85, and as the air passes over the refrigerant-cooled surface of the evaporator heat exchanger 85, the air is cooled and water is condensed from the air. The condensate is collected in the reservoir 115 of the condensate tray 95 and is routed to the atomizer 125, located at a lower portion of the reservoir 115, by gravity. The condensate bypasses the blower assembly 90. The rotating wheel 92 pressurizes the cooled air and directs it upward towards through a main blower channel 145 and through a blower exhaust 150. As a film of water forms over the atomizer 125, the transducer is actuated to convert the water into microdroplets. A fan 120 pulls a flow of air over the atomizer, entraining the microdroplets therein, and directs the air and entrained microdroplets through a duct 135 and into the main blower channel 145, to flow from the blower assembly 90 in the main exhaust stream out of the blower exhaust 150.

[0048] In some cases, the rate at which condensate is collected in the reservoir 115 when the heat pump system 52 is operating may exceed the rate at which the atomizer 125 can remove condensate from the reservoir 115. The volume of condensate within the reservoir 115 will then increase as the heat pump system 52 is operating. It may therefore be necessary, or desirable, for the atomizer 125 to continue operating for some time after a heat pump system 52 operating cycle ends (i.e., when water within the tank 60 is not actively being heated and / or after the motor 130 of the blower assembly 90 is shut off). In some cases, the atomizer 125 can continue to operate until such time as it detects an absence of water within the reservoir 115. In other cases, the atomizer 125 can continue to operate for a fixed period of time after the heat pump system 52 operating cycle ends. The controller 175 can be configured to supply power to the fan 120 (or the fans 170, 200 shown in FIGS. 6 and 9, respectively) for the period of time that the atomizer 125 is operating, in order to remove the microdroplets from within the housing 55.

[0049] As such, a method for operating a heat pump water heating system 50 can include operating the heat pump system 52 (e.g., including a refrigerant circuit 54) to produce condensate, collecting the condensate within the reservoir 115, atomizing the condensate via the atomizer 125, and operating the fan 120 to discharge the atomized condensate from the heat pump water heating system 50. Further, in some examples the fan 120 and the atomizer 125 are operated after the heat pump system 52 operating cycle ends such that condensate is removed from the reservoir 115 after the heat pump system 52 is no longer heating the water within the tank 60.

[0050] As another example, a method for operating the heat pump system 52 includes receiving a flow of air from an environment 230 of the heat pump system 52, where the flow of air has a dewpoint temperature. The flow of air is then directed through the evaporator heat exchanger 85 (i.e., an evaporator) while simultaneously directing a flow of refrigerant through the evaporator heat exchanger 85. The flow of refrigerant is not specifically illustrated herein, but is present within the evaporator heat exchanger 85. The flow of refrigerant has a temperature that is below the dewpoint temperature. Thermal energy from the flow of air is transferred into the refrigerant within the evaporator heat exchanger 85, which in turn condenses water vapor within the flow of air within the evaporator heat exchanger 85 to produce liquid condensate. After passing through the evaporator heat exchanger 85, the flow of air is passed back into the environment 230 of the heat pump system 52. The liquid condensate is collected and atomized to form liquid-state water droplets. The liquid state water droplets are directed into the environment 230 of the heat pump system 52. In some examples, such as that shown in FIGS. 5 and 6, the liquid-state water droplets are added into the flow of air prior to the flow of air and water droplets being directed into the environment 230.

[0051] In some examples, the method for operating the heat pump system 52 includes receiving the flow of air from the environment 230 and directing the flow of air into the housing 55 where the evaporator heat exchanger 85 is located. The method can further include directing the flow of back into the environment 230 by directing the flow of air out of the housing 55. In other examples, such as those shown in FIGS. 7-13, the liquid condensate is directed out of the housing 55 via the drain line 185 prior to being atomized.

[0052] Referring now to the embodiment shown in FIG. 6, a single fan 170 is used to both pull the air through the evaporator heat exchanger 85 and eject the entrained microdroplets from within the housing 55. In this embodiment, the fan 170 is arranged adjacent the air outlet 70, rather than using the blower assembly 90 shown in the previous example. The air exiting the evaporator heat exchanger 85 is received into a main passage 160 via a collecting scoop 162, and a portion of that air is directed to flow under the collecting scoop 162 and over the atomizer 125 in order entrain the microdroplets before returning to the main passage 160. Condensate from the evaporator heat exchanger 85 is likewise directed (via gravity) under the collecting scoop 162 and into a reservoir 155. The atomizer 125 is located within the reservoir 155 to atomize condensate collected therein. Once the microdroplets are returned to the main passage 160 via a duct 165, the combined air and condensate microdroplets is then directed out of the housing 55 through the air outlet 70 by way of the fan 170. Thus, in this embodiment, the condensate is reintroduced into the air stream between the evaporator heat exchanger 85 and the fan 170. In this embodiment, when the atomizer 125 continues to operate after a heat pump cycle ends, the heat pump controller 175 can continue to operate the fan 170 in order to remove the microdroplets. In some cases, the controller 175 can be configured to operate the fan 170 at a slower speed during such operation than the speed at which the fan 170 operates during the heat pump cycle.

[0053] Referring now to the embodiment shown in FIGS. 7-9, instead of the atomizer 125 and reservoir 115 being located within the housing 55, an atomizer assembly 180 is arranged outside of the housing 55 volume. In this example, the atomizer assembly 180 includes a reservoir 220 that is optionally mechanically fastened to an exterior surface of the heat pump water heating system 50 on the housing 57. A condensate drain line 185 at one end is coupled to the condensate tray 95 within the housing 55, and to a drain line inlet 190 of the reservoir 220 at a second end, the second end being arranged with respect to the direction of gravity 225 lower than first end so that condensate will flow by gravity from the condensate tray 95 to the reservoir 220.

[0054] The atomizer assembly 180 includes a housing 215 having the reservoir 220, the atomizer 125, and the fan 200 therein. The fan 200 includes an inlet 202 where air is drawn into the fan 200, which directs the air, as shown by the arrows in FIG. 9, upwards (i.e., vertically) with respect to the direction of gravity 225 through a duct 205 and around a flow guide 210. The flow guide 210 directs the air down into the reservoir 220 near the atomizer 125 such that condensate droplets created by the atomizer 125 are entrained with the air in the reservoir 220. The air entrained with the condensation droplets is then ejected from an exhaust 195 (and thus, the heat pump water heating system 50) via the force of additional air being pushed into the reservoir 220 at the flow guide 210. FIG. 9 includes arrows denoting the above-explained flow path of the air through the atomizer assembly 180.

[0055] A wiring harness or cable (not shown) can be provided with the atomizer 125, and can be connected to a port of the water heater controller 175 in order to provide power to the atomizer 125 and the fan 200 within the atomizer assembly 180, as well as to provide for communication of control signals between the water heater controller 175 and the atomizer 125 and the fan 200 in order to control the operation thereof.

[0056] The embodiment shown in FIGS. 7-9 allows for the atomizer 125 to be an optional add-on component to the heat pump water heating system 50. When the heat pump water heating system 50 is to be installed in a location where a drain is readily available for gravity draining of the condensate, then the condensate drain line 185 can be routed from the condensate tray 95 connection point to that drain. If such a drain is not readily available, then the atomizer assembly 180 can be added to the heat pump water heating system 50 to achieve the required condensate removal.

[0057] The example shown in FIGS. 10-13 is another example of an external atomizer assembly 180, which includes features that are combinable with the other atomizer assemblies 180 described herein. The atomizer assembly 180 illustrated in FIG. 10 is optionally mechanically fastened to an exterior surface of the heat pump water heating system 50 on the housing 57. However, this example of the atomizer assembly 180 includes a curved interior wall 235. The curved interior wall 235 has a contour that matches, or closely resembles, the external contour of the housing 57, which is generally cylindrically shaped, allowing the curved interior wall 235 to be mounted flush to the housing 57. The drain line 185 is connected to the drain line inlet 190, and condensate from the heat pump system 52 flows into the atomizer assembly 180 via the drain line inlet 190. Similar to the other examples described herein, the water is atomized and ejected through a vent 240 in a vent cap 245 located on top of the atomizer assembly 180.

[0058] Referring now to FIG. 11, the atomizer assembly includes a top cover 250, a condensate collection tray 255, and an electronics housing 260. These components are stacked one on top of the other – the top cover 250 is positioned on the condensate collection tray 255, which is positioned on the electronics housing 260. Apertures 265 are included around the outside of each of the top cover 250, the condensate collection tray 255, and the electronics housing 260, and are aligned such that fasteners can extend through the apertures to fix the top cover 250 to the condensate collection tray 255 and fix the condensate collection tray 255 to the electronics housing 260. In other examples, the top cover 250, the condensate collection tray 255, and the electronics housing 260 may be otherwise fixed to one another or formed from a single monolithic unit. The condensate collection tray includes the drain line inlet 190, which is in fluid communication with a reservoir 270 defined by the condensate collection tray 255 and the top cover 250. Condensate enters the reservoir 270 via the drain line inlet 190. The electronics housing 260 positioned below the reservoir 270 includes the atomizer 125, which is in fluid communication with the reservoir 270 such that the atomizer 125 can atomize the condensate within the reservoir 270. As can be seen in FIG. 12, the atomizer 125 is positioned at the lowest point in the reservoir 270, so that the condensate will naturally travel (via gravity 225) into contact with the atomizer 125.

[0059] Referring now collectively to FIGS. 11-13, the structure and process of expelling the atomized condensate from the reservoir 270 will be explained. The electronics housing 260 includes the fan or blower 200, which has a fan outlet 280. The electronics housing 260 may include other electronic components as well, for example, power and / or controller assemblies for the atomizer 125 and fan 200, and may be used to house and route wiring for these and other components. The condensate collection tray includes a chimney 275 that extends up through the reservoir 270. The fan 200 sucks air into the electronics housing 260 via an air inlet 285, which is positioned in a sidewall of the electronics housing 260. This air passes through the fan 200 and out of the fan outlet 280, which is fluidly connected to the chimney 275. The fan 200 therefore passes the air through the chimney 275 and into the reservoir 270. The top cover 250 in this example includes a flow guide 295 that turns air from the generally vertical direction while travelling through the chimney, to direct air into the reservoir 270. The reservoir 270 is sealed by the top cover 250 except for the vent 240 within the vent cap 245. Thus, air passing from the chimney 275 is circulated throughout the reservoir 270 to entrain droplets of condensate created by the atomizer 125, and then the air with the entrained droplets passes out of the reservoir 270 via the vent 240. In other examples, the vent 240 may be located at another location on the top cover 250, and may not be part of the vent cap 245. Arrows in FIG. 12 generally depict the flow of air into the air inlet 285, through the atomizer assembly 180, and out of the vent 240.

[0060] By converting the condensate into entrained liquid microdroplets, rather than into water vapor, the condensate can be removed from the heat pump water heating system 50 with substantially less energy than would be required to vaporize the water. By way of example, the Audiowell UM0108-005 transducer (i.e., an example atomizer 125) has a rated mist volume production of 210 mL / h with a power consumption of 18.15W, which is equal to an energy consumption of 311 J / mL (Joules of energy per milliliter of water removed). In contrast, the latent heat of vaporization alone of water is 2260 J / mL, more than seven times greater. In addition, the condensate would need to be heated to the boiling point at a sensible heat capacity of 4.186 J / mL / °C, requiring an additional 380-400 J / mL or approximately 1.25x the amount of energy required by the atomizer 125.

[0061] After the condensate has been introduced into the ambient air as a fine mist, the water droplets will re-evaporate into water vapor by absorbing heat from the air surrounding the microdroplets. This can occur rapidly, due to the high surface area to volume ratio of the microdroplets. The net effect over time, then, is that the heat pump water heating system 50 can operate by removing only sensible heat from the ambient environment 230.

[0062] Although the invention has been described in detail with reference to certain preferred embodiments, variations and modifications exist within the scope and spirit of one or more independent aspects of the invention as described.

Examples

Embodiment Construction

[0037]Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways.

[0038]Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The modifier “about” used in connection with a quantity is inclusive of the stated value and has the meaning dictated by the context (for example, it includes at least the degree of error associated with the measurement of the particular quantity). The modifier “about” should also be considered as disclosing the range defined by the absolute values of the two endpoints. For example, the expression “from about 2 to about 4” also discl...

Claims

1. A heat pump water heating system comprising:a tank for storing water,an evaporator configured for use in heating the water, the evaporator configured to produce condensate during operation,a reservoir for collecting the condensate,an atomizer configured to atomize the condensate collected in the reservoir, anda fan configured to eject the atomized condensate from the heat pump water heating system.

2. The heat pump water heating system of claim 1, wherein the fan is further configured to direct a flow of air through the evaporator, the flow of air serving as a source of heat for heating the water.

3. The heat pump water heating system of claim 1, further comprising a blower that draws air through the evaporator and a condensate tray, the condensate tray including:a seat, andthe reservoir,wherein the blower is attached to the evaporator and the evaporator is seated within the seat, andwherein the atomizer is fluidly connected to the reservoir to atomize the condensate collected within the reservoir.

4. The heat pump water heating system of claim 3, wherein the blower includes an air inlet and an air outlet,wherein the air inlet is located adjacent the evaporator,wherein the condensate tray is configured such that the condensate produced by the evaporator bypasses the air inlet and is drawn into the reservoir, andwherein the fan draws the atomized condensate through a duct adjacent the blower and directs the atomized condensate to the air outlet.

5. The heat pump water heating system of claim 4, wherein the fan is configured to continue to operate after the blower is shut off.

6. The heat pump water heating system of claim 1, wherein the evaporator is a component of a refrigerant circuit configured to heat the water within the tank,wherein the heat pump water heating system includes a housing that encloses components of the refrigerant circuit, andwherein the housing includes an air inlet and an air outlet.

7. The heat pump water heating system of claim 6, wherein the air outlet includes the fan for ejecting air including the atomized condensate from the heat pump water heating system.

8. The heat pump water heating system of claim 7, wherein air drawn into the air inlet is passed over the evaporator, directed through a main passage, and is discharged through the air outlet, andwherein the atomized condensate is ducted into the main passage and is directed to flow through the air outlet with the air.

9. The heat pump water heating system of claim 1, further comprising:a housing arranged adjacent to the tank, the evaporator being arranged within the housing, andan atomizer assembly including the reservoir, the atomizer, and the fan, the atomizer assembly being arranged external to the housing.

10. The heat pump water heating system of claim 9, wherein the atomizer assembly includes an interior wall that matches a contour of the housing.

11. The heat pump water heating system of claim 9, wherein the fan directs air substantially vertically with respect to gravity, around a flow guide, and into the reservoir to pass the atomized condensate out of the atomizer assembly.

12. The heat pump water heating system of claim 11, wherein the atomizer assembly includes an electronics housing, a condensate collection tray, and a top cover, andwherein the electronics housing is fixed below the condensate collection tray and houses the fan and the atomizer therein.

13. The heat pump water heating system of claim 12, wherein the condensate collection tray and the top cover define the reservoir, and the top cover includes therein a vent for passing the atomized condensate out of the atomizer assembly.

14. The heat pump water heating system of claim 13, wherein the fan directs air substantially vertically with respect to gravity through a chimney within the condensate collection tray before being directed around the flow guide and into the reservoir.

15. A method of discharging condensate from a heat pump water heating system, the heat pump water heating system comprising:a tank for storing water,an evaporator configured for use in heating the water, the evaporator configured to produce condensate during operation thereof,a reservoir for collecting the condensate,an atomizer configured to atomize the condensate collected in the reservoir, anda fan configured to eject the atomized condensate from the heat pump water heating system,wherein the method comprises:operating the heat pump water heating system to produce the condensate,collecting the condensate within the reservoir,atomizing the condensate with the atomizer, andoperating the fan to discharge the atomized condensate from the heat pump water heating system.

16. The method of claim 15, wherein the evaporator is part of a heat pump system configured to heat the water within the tank, and wherein the fan and the atomizer are configured to operate after an operating cycle of the heat pump system ends such that the condensate is removed from the reservoir after the heat pump system is no longer heating the water within the tank.

17. A method of operating a heat pump system, comprising:receiving a flow of air from an environment of the heat pump system, the flow of air having a dewpoint temperature;directing the flow of air through an evaporator of the heat pump system;directing a flow of refrigerant through the evaporator, the flow of refrigerant having a temperature that is below the dewpoint temperature;transferring thermal energy from the flow of air to the flow of refrigerant within the evaporator;condensing water vapor from the flow of air within the evaporator to form liquid condensate;directing the flow of air back into the environment of the heat pump system after directing the flow of air through the evaporator;collecting the liquid condensate;atomizing the liquid condensate to form a mist of liquid-state water droplets; anddirecting the liquid-state water droplets into the environment of the heat pump system.

18. The method of claim 17, further comprising combining the liquid-state water droplets and the flow of air prior to directing the liquid-state water droplets and the flow of air into the environment of the heat pump system.

19. The method of claim 17, wherein the evaporator is located within a housing and wherein:receiving the flow of air from the environment comprises directing the flow of air into the housing; anddirecting the flow of back into the environment comprises directing the flow of air out of the housing.

20. The method of claim 19, further comprising directing the liquid condensate out of the housing prior to atomizing the liquid condensate.

Images