Patent Grant
11779677
This disclosure relates generally to centrifugal fan(s)/blower(s) for a heating, ventilation, air conditioning, and refrigeration (HVACR) system. More specifically, the disclosure relates to systems and method for configuring and controlling centrifugal fan(s)/blower(s) with photocatalytic oxidation and/or ultraviolet germicidal irradiation technology to improve the efficiency and efficacy of one-time filtration and/or sterilization of air for an HVACR system.
Centrifugal fans (or blowers) are widely used for circulating air in residential and commercial HVACR systems. Electric motor driven centrifugal fans having volute housing or scroll type fan housing are particularly widely used in HVACR systems wherein the fan housing is mounted in a cabinet which may also contain heat transfer equipment such as a refrigerant fluid heat exchanger or a furnace heat exchanger, etc.
Currently the world is experiencing a global pandemic. Building owners and operators (commercial, industrial, and residential) have different challenges to address the pathogen (bacteria, fungi, protozoa, worms, viruses, and/or infectious proteins such as prions, etc.) spread, such as more complicated building and space design, an increased populous and densities of people, increased movement of people worldwide and the general increasing interconnectedness of people worldwide, and technologies associated with accommodating these complications and increases. Building owners and operators turn to building policies, procedures, and operations, and also use technology to reduce/kill pathogens and to keep air clean. Further solutions in overcoming such challenges could benefit public health and safety.
Building owners and operators (commercial, industrial, and residential) have the ability to control conditioned air movement, temperature, humidity and air cleaning technologies within their building. The issue with today's pandemic is that the science around what are best practices to minimize the amount of infection that may occur within the occupied space is still unknown and being studied. Some studies reveal that there may be specific portions of the populace that have proclivity towards higher infection rates and/or higher susceptibility to illness, for example to illness severity of COVID-19.
This disclosure relates generally to centrifugal fan(s)/blower(s) for an HVACR system. More specifically, the disclosure relates to systems and method for configuring and controlling centrifugal fan(s)/blower(s) with photocatalytic oxidation and/or ultraviolet germicidal irradiation technology to improve the efficiency and efficacy of one-time filtration and/or sterilization of air for an HVACR system. It will be appreciated that the HVACR system can be used for building (e.g., residential and/or commercial) spaces as well as for climate controlled transport unit(s) (e.g., transport refrigeration unit(s), and/or tractor cabin, etc.). In an embodiment, the HVACR system can be a climate control unit (CCU).
Embodiments disclosed herein can be used for example to control conditioned air spaces and lighting to reduce or kill pathogens or microbiologicals, reduce susceptibility of occupants to microbiological infection, reduce impact of illness from microbiologicals, and/or reduce pathogen or microbiologicals spread. Embodiments disclosed herein can provide improved health with the presence of microbiological organisms, particulate matter and other airborne substances that may be detrimental to human (or other animal or plant) health.
A centrifugal fan for an HVACR system is disclosed. The centrifugal fan includes a volute housing having an inner surface and a curved inlet shroud. The volute housing defines an air outlet. The curved inlet shroud defines an air inlet. The air inlet has an inlet airflow cross-sectional area that lies substantially perpendicular to an outlet airflow cross-sectional area of the air outlet. The centrifugal fan also includes an impeller mounted for rotation about a rotational axis within the volute housing. The impeller has a plurality of fan blades. The plurality of fan blades has an outer surface. The centrifugal fan further includes a light source. The inner surface of the volute housing and the outer surface of the plurality of fan blades includes a photocatalyst layer. The light source is configured to emit light on the photocatalyst layer
A method of configuring a centrifugal fan for an HVACR system is disclosed. The centrifugal fan includes a volute housing having an inner surface and a curved inlet shroud. The volute housing defines an air outlet. The curved inlet shroud defines an air inlet. The air inlet has an inlet airflow cross-sectional area that lies substantially perpendicular to an outlet airflow cross-sectional area of the air outlet. The centrifugal fan also includes an impeller mounted for rotation about a rotational axis within the volute housing. The impeller has a plurality of fan blades. The plurality of fan blades has an outer surface. The centrifugal fan further includes a light source. The method includes coating or sintering a photocatalyst layer on the inner surface of the volute housing and the outer surface of the plurality of fan blades. The method also includes emitting light, by the light source, on the photocatalyst layer.
References are made to the accompanying drawings that form a part of this disclosure and which illustrate the embodiments in which systems and methods described in this specification can be practiced.
Like reference numbers represent like parts throughout.
The following definitions are applicable throughout this disclosure. As defined herein, the term “photocatalyst” may refer to a material which absorbs light to bring the material to a higher energy level and provides such energy to a reacting substance to make a chemical reaction occur. It will be appreciated that in catalyzed photolysis, light is absorbed by an adsorbed substrate. In photo-generated catalysis, the photocatalytic activity depends on the ability of the catalyst to create electron-hole pairs, which generate free radicals (e.g. hydroxyl radicals: OH) able to undergo secondary reactions. It will also be appreciated that the practical application was made possible by the discovery of e.g., water electrolysis by means of e.g., titanium dioxide (TiO2). It will be appreciated that photons have a certain energy. When irradiated on certain substances (such as semiconductors including TiO2), the electrons of the atoms will jump from the valence band to the conduction band after absorbing certain energy. There will be a positively charged hole, that is, photo-generated electrons and photo-generated holes. Positively charged holes combine with water molecules in the air to produce hydroxyl radicals that have the ability to oxidize and decompose, while negative electrons combine with oxygen in the air to form active oxygen. Because such electrons and holes have strong reducing and oxidizing properties, respectively, so they can make the substances on the semiconductor undergo an oxidation-reduction reaction (e.g., to reduce/kill pathogens), thereby converting light energy into chemical energy. These substances are called photocatalysts.
As defined herein, the term “ultraviolet” or “UV” may refer to a form of electromagnetic radiation with a wavelength ranges from at or about 10 nm to at or about 400 nm. As defined herein, the term “UVA” may refer to UV with a wavelength ranges from at or about 315 nm to at or about 400 nm, the term “UVB” may refer to UV with a wavelength ranges from at or about 280 nm to at or about 315 nm, and the term “UVC” may refer to UV with a wavelength ranges from at or about 100 nm to at or about 280 nm.
Particular embodiments of the present disclosure are described herein with reference to the accompanying drawings; however, it is to be understood that the disclosed embodiments are merely examples of the disclosure, which may be embodied in various forms. Well-known functions or constructions are not described in detail to avoid obscuring the present disclosure in unnecessary detail. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present disclosure in virtually any appropriately detailed structure. In this description, as well as in the drawings, like-referenced numbers represent elements that may perform the same, similar, or equivalent functions.
Additionally, the present disclosure may be described herein in terms of functional block components, code listings, optional selections, page displays, and various processing steps. It should be appreciated that such functional blocks may be realized by any number of hardware and/or software components configured to perform the specified functions. For example, the present disclosure may employ various integrated circuit components, e.g., memory elements, processing elements, logic elements, look-up tables, and the like, which may carry out a variety of functions under the control of one or more microprocessors or other control devices.
The scope of the disclosure should be determined by the appended claims and their legal equivalents, rather than by the examples given herein. For example, the steps recited in any method claims may be executed in any order and are not limited to the order presented in the claims. Moreover, no element is essential to the practice of the disclosure unless specifically described herein as “critical” or “essential.”
The refrigerant circuit 100 can generally be applied in a variety of systems used to control an environmental condition (e.g., temperature, humidity, air quality, or the like) in a space (generally referred to as a conditioned space). Examples of such systems include, but are not limited to, HVACR systems, transport refrigeration systems, or the like. In an embodiment, a HVACR system can be a rooftop unit or a heat pump air-conditioning unit.
The compressor 120, condenser 140, expansion device 160, and evaporator 180 are fluidly connected. In an embodiment, the refrigerant circuit 100 can be configured to be a cooling system (e.g., an air conditioning system) capable of operating in a cooling mode. In an embodiment, the refrigerant circuit 100 can be configured to be a heat pump system that can operate in both a cooling mode and a heating/defrost mode. A centrifugal fan (not shown, described later) can be provided to a heat exchanger such as the condenser 140 and/or the evaporator 180.
It will be appreciated that the centrifugal fans are disclosed in e.g., the U.S. Pat. Nos. 7,591,633; 7,186,080; 7,108,478; 5,570,996; 5,558,499; 3,627,440; 3,307,776; 3,217,976; 2,981,461; 2,951,630; 2,798,658; 2,727,680; 3,221,983; and 1,862,523, the entire disclosure of which are hereby incorporated by reference herein.
The refrigerant circuit 100 can operate according to generally known principles. The refrigerant circuit 100 can be configured to heat and/or cool a liquid process fluid (e.g., a heat transfer fluid or medium (e.g., a liquid such as, but not limited to, water or the like)), in which case the refrigerant circuit 100 may be generally representative of a liquid chiller system. The refrigerant circuit 100 can alternatively be configured to heat and/or cool a gaseous process fluid (e.g., a heat transfer medium or fluid (e.g., a gas such as, but not limited to, air or the like)), in which case the refrigerant circuit 100 may be generally representative of an air conditioner and/or heat pump.
In operation, the compressor 120 compresses a working fluid (e.g., a heat transfer fluid (e.g., refrigerant or the like)) from a relatively lower pressure gas to a relatively higher-pressure gas. The relatively higher-pressure gas is also at a relatively higher temperature, which is discharged from the compressor 120 and flows through the condenser 140. In accordance with generally known principles, the working fluid flows through the condenser 140 and rejects heat to the process fluid (e.g., water, air, etc.), thereby cooling the working fluid. The cooled working fluid, which is now in a liquid form, flows to the expansion device 160. The expansion device 160 reduces the pressure of the working fluid. As a result, a portion of the working fluid is converted to a gaseous form. The working fluid, which is now in a mixed liquid and gaseous form flows to the evaporator 180. The working fluid flows through the evaporator 180 and absorbs heat from the process fluid (e.g., a heat transfer medium (e.g., water, air, etc.)), heating the working fluid, and converting it to a gaseous form. The gaseous working fluid then returns to the compressor 120. The above-described process continues while the heat transfer circuit is operating, for example, in a cooling mode (e.g., while the compressor 120 is enabled).
The transport climate control system 10 includes a climate control unit (CCU) 20 that provides environmental control (e.g. temperature, humidity, air quality, etc.) within a climate controlled space 25 of the transport unit 15. The CCU 20 is disposed on a front wall 30 of the transport unit 15. In other embodiments, it will be appreciated that the CCU 20 can be disposed, for example, on a rooftop or another wall of the transport unit 15. The CCU 20 includes a climate control circuit (see e.g.,
The transport climate control system 10 also includes a programmable climate controller 35 and one or more sensors (not shown) that are configured to measure one or more parameters of the transport climate control system 10 (e.g., an ambient temperature outside of the transport unit 15, an ambient humidity outside of the transport unit 15, a compressor suction pressure, a compressor discharge pressure, a supply air temperature of air supplied by the CCU 20 into the climate controlled space 25, a return air temperature of air returned from the climate controlled space 25 back to the CCU 20, a humidity within the climate controlled space 25, etc.) and communicate climate control data to the climate controller 35. It will be appreciated that a supply fan or blower (e.g., a centrifugal fan or blower, not shown, see 600 of
The climate controller 35 is configured to control operation of the transport climate control system 10 including components of the climate control circuit. The climate controller 35 may include a single integrated control unit 40 or may include a distributed network of climate controller elements 40, 45. The number of distributed control elements in a given network can depend upon the particular application of the principles described herein. The measured parameters obtained by the one or more climate control sensors can be used by the climate controller 35 to control operation of the climate control system 10.
The climate controlled transport unit 20 includes an independent sensor 50. In the illustrated embodiment, the independent sensor 50 is represented as a single sensor. It will be appreciated that in other embodiments, the climate controlled transport unit 20 can include a plurality of independent sensors 50. In some embodiments, the independent sensor 50 is a dedicated regulatory sensor that can provide independent verification of climate control parameters (e.g., temperature, humidity, atmosphere, etc.) within the climate controlled space 25. The independent sensor 50 is not used by the climate controller 35 to control operation of the transport climate control system 10. The independent sensor 50 is in electronic communication with a power source (not shown) of the CCU 20. In an embodiment, the independent sensor 50 is in electronic communication with the climate controller 35. It will be appreciated that the electronic communication between the independent sensor 50 and the climate controller 35 can enable network communication of the sensed verification values or parameters (e.g., temperature data of cargo stored in the climate controlled space 300) measured by the independent sensor 50. The electronic communication between the climate controller 35 and the independent sensor 50 does not enable the sensed verification values or parameters to be utilized in a control of the CCU 20.
The upper compartment 314 can be configured to contain a plurality of components of the CCTU 311 including, for example, a compressor, an engine, a battery, an air filter and/or a muffler. The condenser compartment 315 can contain a condenser 317. A plurality of fans 340 are installed at a bottom portion 319 of the condenser compartment 315. Each of the fans 340 has an inlet that is generally located inside the condenser compartment 315 and an outlet that is generally located outside of the condenser compartment 315. A guard 318 of the condenser compartment 315 has apertures to allow air to get inside the condenser compartment 315. In some embodiments, the engine is a diesel engine. The condenser 317 is positioned in a front part of the condenser compartment 315 behind the guard 318. The condenser compartment 315 also includes the fan 347 that is installed at the bottom portion 319.
The CCTU 311 also includes an evaporator compartment 352 that is generally positioned behind the condenser compartment 315. The condenser compartment 315 and the evaporator compartment 352 are separated by a partition 354. As illustrated, both of the condenser compartment 315 and the evaporator compartment 352 are generally positioned in a lower part of the housing 312 of the CCTU 311 in relation to the upper compartment 314.
The CCTU 311 is configured to be attached on a front wall 330 of a transport unit 325. The evaporator compartment 352 is configured to have a transport unit air inlet 361 and a transport unit outlet 362 in communication with an inner space 326 of the transport unit 325. A blower 358 (e.g., a centrifugal fan, see also 600 of
The arrows in
In the evaporator compartment 352, airflow generated by the operation of the blower 358 is generally sucked into the evaporator compartment 352 from the transport unit air inlet 361 and then passes through the evaporator 356. The airflow is then driven out of the transport unit air outlet 362 by the blower 358.
It is to be noted that the condenser 317, the fans 340, the evaporator 356 and the blower 362 are all configured to be positioned close to the bottom portion 319 of the CCTU 311 in relation to the upper compartment 314. By positioning the condenser 317, the fans 340, the evaporator 356 and the blower 358 generally below the upper compartment 314, the upper compartment 314 can have relatively more room to accommodate components of the CCTU 311 without increasing a profile of the CCTU 311. The upper compartment 314 is generally isolated from the airflow generated by the operation of the fans 340 and/or the blower 358.
Generally, the upper compartment 314, which is configured to accommodate components such as the engine and the compressor, can have a raised temperature in operation due to heat generated by the components. Isolating the upper compartment 314 from the evaporator compartment 352 that is configured to accommodate the evaporator 356 can help shield the heat generated by, for example, the engine and/or the compressor, away from the evaporator 356.
The transport climate control system 14 includes a climate control unit (CCU) 13 that is mounted to a front wall 17 of the climate controlled space 16. The CCU 13 can include, among other components, a climate control circuit (see, e.g.,
The transport climate control system 14 also includes a programmable climate controller 19 and one or more climate control sensors (not shown) that are configured to measure one or more parameters of the transport climate control system 14 (e.g., an ambient temperature outside of the truck 11, an ambient humidity outside of the truck 11, a compressor suction pressure, a compressor discharge pressure, a supply air temperature of air supplied by the CCU 13 into the climate controlled space 16, a return air temperature of air returned from the climate controlled space 16 back to the CCU 13, a humidity within the climate controlled space 16, etc.) and communicate climate control data to the climate controller 19. It will be appreciated that a supply fan or blower (e.g., a centrifugal fan or blower, not shown, see 600 of
The climate controller 19 is configured to control operation of the transport climate control system 14 including components of the climate control circuit. The climate controller 19 may include a single integrated control unit 19 or may include a distributed network of climate controller elements 19, 12. The number of distributed control elements in a given network can depend upon the particular application of the principles described herein. The measured parameters obtained by the one or more climate control sensors can be used by the climate controller 19 to control operation of the climate control system 14.
The truck 11 includes an independent sensor 18. In the illustrated embodiment, the independent sensor 18 is represented as a single sensor. It will be appreciated that in other embodiments, the truck 11 includes a plurality of independent sensors 18. In some embodiments, the independent sensor 18 is a dedicated regulatory sensor that can provide independent verification of climate control parameters (e.g., temperature, humidity, atmosphere, etc.) within the climate controlled space 16. The independent sensor 18 is not used by the climate controller 19 to control operation of the transport climate control system 14. The independent sensor 18 is in electronic communication with a power source (not shown) of the CCU 13. In an embodiment, the independent sensor 18 is in electronic communication with the climate controller 19. It will be appreciated that the electronic communication between the independent sensor 18 and the climate controller 19 can enable network communication of the sensed verification values or parameters (e.g., temperature data of cargo stored in the climate controlled space 16) measured by the independent sensor 18. The electronic communication between the climate controller 19 and the independent sensor 18 does not enable the sensed verification values or parameters to be utilized in a control of the CCU 13.
The unit 200 includes an enclosure 260. In one embodiment, the enclosure 260 can be a generally rectangular cabinet having a first end wall defining an air inlet opening 270 (to allow air to flow into an internal space of the enclosure 260) and a second end wall defining an air outlet opening (not shown, to allow air to flow out of the enclosure 260 via an air outlet (that overlaps with the air outlet opening) of the centrifugal fan 250, see e.g., 660 in
The unit 200 also includes a primary filter 210 and a secondary filter 220. In one embodiment, the primary filter 210 and the secondary filter 220 can be one filter. It will be appreciated that the primary filter 210 and/or the secondary filter 220 can be a porous device configured to remove impurities or solid particles from air flow passed through the device.
In one embodiment, outer surface(s) (e.g., the entire surface facing the airflow and/or the entire surface opposite to the surface facing the airflow) of the secondary filter 220 (and/or the primary filter 210) can be covered (or coated or sintered) with e.g., a photocatalyst layer (see
The unit 200 further includes a component (e.g., a coil) 230. In one embodiment, the component 230 can be an air conditioning evaporator coil disposed in the flow path of air passing from the air inlet opening 270 to the air outlet opening of the enclosure 260 (which is also the air outlet of the fan 250). It will be appreciated that the component 230 can be different types in that the working fluid can be e.g., refrigerant, water, or the like. For example, when the working fluid is refrigerant, the component 230 can be an evaporator coil for cooling, and/or can be a condenser coil for heating. For example, when the working fluid is water, the component 230 can be tube(s) for chilled water to go through for cooling, and can be tube(s) for hot water to go through for heating.
The unit 200 also includes a humidifier 240 configured to add moisture to the air to prevent dryness that can cause irritation in many parts of the human body or to increase humidity in the air.
Also the unit 200 includes a fan (or blower) 250. In one embodiment, the fan 250 can be a centrifugal fan having electric drive motor (not shown) to drive the fan 250 (e.g., to drive a shaft of the fan 250, see
The light source 320 includes a lamp 322 and a controller 321. In one embodiment, the controller 321 can be a control gear and/or a ballast. The lamp 322 can be the light source described in
The centrifugal fan 600 also includes an impeller 620 mounted for rotation about a rotational axis 695 within the volute housing 610. The impeller 620 has a plurality of fan blades 625. The plurality of fan blades 625 has an outer surface.
The centrifugal fan 600 further includes a light source 640 disposed at a first end of the centrifugal fan 600 opposite to a second end (where the air outlet 660 locates) of the centrifugal fan 600. The centrifugal fan 600 includes a window 630 and a reflector 650 that covers the window 630. The light source 640 is enclosed by the window 630 and the reflector 650. It will be appreciated that the window 630 is part of the volute housing 610 so that the shape of the volute housing 610 is unchanged. The centrifugal fan 600 includes a photocatalyst layer 690 disposed on the inner surface of the volute housing 610 and the outer surface of the impeller 620 including outer surface of the plurality of fan blades 625. It will be appreciated that although a small number of fan blades 625 are shown in
As shown in
The centrifugal fan 1000 includes a volute housing 1010 having an inner surface and a curved inlet shroud 1070. The volute housing 1010 defines an air outlet 1060. The curved inlet shroud 1070 defines an air inlet 1080. The air inlet 1080 has an inlet airflow cross-sectional area that lies substantially perpendicular to an outlet airflow cross-sectional area of the air outlet 1060.
The centrifugal fan 1000 also includes an impeller 1020 mounted for rotation about a rotational axis 1095 within the volute housing 1010. The impeller 1020 has a plurality of fan blades 1025. The plurality of fan blades 1025 has an outer surface. The plurality of fan blades 1025 is typically circumferentially spaced, and generally radially outwardly projecting from e.g., the axis 1095.
The centrifugal fan 1000 further includes a light source 1040 disposed at a first end of the centrifugal fan 1000 opposite to a second end (where the air outlet 1060 locates) of the centrifugal fan 1000. The centrifugal fan 1000 includes a window 1030 to allow light to pass through and a reflector 1050 that covers the window 1030 and reflects the light. The light source 1040 is enclosed by the window 1030 and the reflector 1050 and is configured to emit light. In an embodiment, the window 1030 can be part of the volute housing 1010 so that the shape of the volute housing 1010 is unchanged. The centrifugal fan 1000 includes a photocatalyst layer (not shown, see
In
It will be appreciated that for the light source described herein in all figures, the light source can be of the same type. One light source can include at least one lamp (e.g., at least one mercury lamp or at least one LED lamp). The one light source can also include at least one light-emitting diode light source. The light source can be configured to emit UVA, UVB, UVC, and/or visible light. The light can be emitted e.g., as ultraviolet germicidal irradiation to inactivate or kill the pathogens in the air (e.g., UVC light can kill pathogens in the air directly) or be emitted on the photocatalyst layer to react with the photocatalyst to generate hydroxyl radicals (which can oxidize airborne biological particles and convert volatile organic compound to H2O and CO2 to inactivate or kill the pathogens). For example, UVC (e.g., having at or about 254 nm wavelength) photons can damage RNA/DNA of cells and viruses. UVC photons can also react with photocatalyst to create hydroxyl radicals, hydroxyl radicals can oxidize airborne biological particles and/or convert volatile organic compound to H2O and CO2.
In
In one embodiment, the reflector 1050 has a curved shape. The reflector 1050 can be made of polished aluminum or polished stainless steel or polytetrafluoroethylene to reflect the light emitted from the light source 1040 back into the volute housing 1010 (to e.g., prevent light leaking).
In another embodiment, a set of a light source, a window, and a reflector can be disposed at location A (at the top of the volute housing 1010) and/or location B (at the bottom of the volute housing 1010), respectively. Location A and location B align with the rotational axis 1095 in a vertical direction.
The light source 1040 includes a controller 1041 (e.g., a control gear and/or a ballast) connected to an AC and/or DC power source 1042.
Embodiments disclosed herein do not impact the size and/or length and/or shape of the air handling unit (and/or the centrifugal fan 1000), do not add air-pressure drop (at or about 0 Pa pressure drop), do not add additional resistance to airflow, and provide optimal efficacy and efficiency because all (or almost all) air passing through the air handling unit may pass through the centrifugal fan 1000 (e.g., through the impeller 1020 and the inner space of the volute housing 1010) and thus all (or almost all) air may be treated (e.g., by the photocatalytic oxidation and/or ultraviolet germicidal irradiation solution disclosed herein).
It will be appreciated that virus (such as the COVID-19 virus) typically resides in the droplet nuclei having a size of at or about 0.5 to at or about 5 micrometer (see
The centrifugal fan 1100 includes a shaft 1090 that drives the impeller 1020 to rotate (e.g., by a motor via the shaft 1090). In one embodiment, the shaft 1090 aligns with the rotational axis 1095. The light source(s) 1043, 1044 is/are disposed in an empty space inside the curved inlet shroud 1070 (e.g., at a location on or away from the rotational axis 1095). Brackets (1110, 1120) are provided on the volute housing 1010 to support the light source(s) 1043, 1044. In one embodiment, each of the light source(s) 1043, 1044 can have an H-shape lamp. In an embodiment, the impeller 1020 can have a partition 1021. The light source 1044 extends from a first side 1011 of the volute housing 1010 toward the partition 1021 and an end of the light source 1044 is disposed near the partition 1021 (for better light coverage). The light source 1043 extends from a second side 1012 of the volute housing 1010 toward the partition 1021 and an end of the light source 1043 is disposed near the partition 1021 (for better light coverage). In an embodiment, the partition 1021 separates the chamber (1150 and 1160) of the impeller 1020 into two independent spaces. The partition 1021 may have a disc shape.
Referring back to
Embodiment disclosed herein can provide the light source(s) 1045, 1046 as e.g., rectifier ring(s) for air inlet rectification at the air inlet 1080. Such embodiments do not add resistance to the airflow due to the shape and location of the light source(s) 1045, 1046, and provide optimal aerodynamics. In such embodiments, due to the locations of the light source(s) 1045, 1046, some light from the light source(s) 1045, 1046 may not be emitted directly on the airflow nor on the photocatalyst layer on the inner surface of the volute housing 1010 and the outer surface of the impeller 1020 including outer surface of the plurality of fan blades 1025, and the power efficiency of the light may not be optimal.
In
Embodiments disclosed herein provide a relatively closest distance of light (from the light source 1047) to the upper wall (where the density of pathogens is relatively high) of the volute housing 1010 to direct remove/kill pathogens (i.e., high efficiency of killing pathogens), and provide direct light from the light source 1047 onto most of the photocatalyst layer on the inner surface/walls of the volute housing 1010 and the outer surface of the impeller 1020 including outer surface of the plurality of fan blades 1025. It will be appreciated that such embodiments might not be optimal for aerodynamics, but provide a balanced solution regarding the efficiency of killing pathogens and the aerodynamics.
In
In one embodiment, a primer layer can be added on the surface (1630 or 1640), and 10 nm (particle size) TiO2 alcoholics can be added, along with 5 nm (particle size) TiO2 aqua (e.g., TiO2 powder adding water). It will be appreciated that the smaller the particle size of the TiO2, the better efficacy for air filtering/disinfection.
It will be appreciated that the photocatalyst layer (1610-1620 or 1670) can be coated or sintered (or using other methods as disclosed in U.S. 2020/0016587 and CN110075706A, the entire disclosure of which are hereby incorporated by reference herein) on the surface (1630 or 1640-1660 or 1680 or 1690-1692). It will also be appreciated that sintering process can help to remove unwanted material from e.g., the TiO2 layer (1620, 1670) so that the TiO2 can be exposed to more air or can be exposed more directly to air.
It will be further appreciated that TiO2 is of low cost and can work with UV lights (UVA, UVB, and UVC; which have relative short wavelength and high energy, can activate TiO2, and can generate hole-electron pair to create hydroxyl radicals). Also it will be appreciated that UVC can kill pathogens directly (without relying on the photocatalyst layer).
In one embodiment, the photocatalyst layer can include TiO2 or ZnO or any other suitable material to work with UV light lamp(s). In another embodiment, the photocatalyst layer can include doped TiO2 or graphitic carbon nitrides such as g-C3N4 or any other suitable materials to work with visible light from visible light lamp(s) (such as LED, to create hydroxyl radicals). The photocatalyst layer can include many semiconductor materials, CdS, WO3, SnO2, Fe2O3, ZrO2, PbS, SiO2, ZnS, SrTiO3, etc., and/or graphene-based photocatalysts, etc.
It will be appreciated that for maximum disinfection effect, UVC (e.g., in an embodiment, with at or about 254 nm wavelength) light source is preferred, forming a combination of photocatalytic oxidation and ultraviolet germicidal irradiation. UV leakage may be controlled to a level under the national standard (e.g., at or about 5 microwatt /cm2).
It will also be appreciated that UVA light source is safer for a human-being. For example, the exposure limit of UVA (e.g., having at or about 370 nm to at or about 380 nm wavelength) is at or about 10,000 times that of 254 nm UVC's. For example, an 8-hour UVA exposure limit is at or about 6.0 mJ/cm2 with at or about 254 nm wavelength, at or about 3.2*105 mJ/cm2 with at or about 370 nm wavelength, or at or about 5.7*105 mJ/cm2 with at or about 385 nm wavelength. It will further be appreciated that doped TiO2 or g-C3N4 working with visible light source can provide no safety risk to human.
Embodiments disclosed herein can utilize the extensive contact between the airflow and the impeller blades and the inner wall of the volute housing, to improve the efficiency of killing pathogens such as COVID-19.
Self-clean, regeneration, and super hydrophilicity tests have been conducted for the photocatalyst layer. The photocatalyst layer shows super hydrophilicity after e.g., UV light emitted on the photocatalyst layer. With water spay and the movement of the impeller, the photocatalyst layer can be easily cleaned of dirt or can self-clean the dirt on the photocatalyst layer, and the photocatalyst layer can be regenerated with water spray. Without replacing or changing the photocatalyst layer for a long period of time. In a self-cleaning test, TiO2 shows photo-induced super hydrophilicity. For example, for 10 nm TiO2 having contact angle at or about 60°, after UVC light irradiation for at or about 30 minutes, the contact angle is changed to at or about 16°. In a regeneration test, water spray can clean the photocatalyst layer and regenerate TiO2 from deactivation.
It is appreciated that any of aspects 1-19, 20, and 21-23 can be combined with each other.
Aspect 1. A centrifugal fan for a heating, ventilation, air conditioning, and refrigeration (HVACR) system, the centrifugal fan comprising:
a volute housing having an inner surface and a curved inlet shroud, the volute housing defining an air outlet, the curved inlet shroud defining an air inlet, and the air inlet having an inlet airflow cross-sectional area that lies substantially perpendicular to an outlet airflow cross-sectional area of the air outlet;
an impeller mounted for rotation about a rotational axis within the volute housing, the impeller having a plurality of fan blades, and the plurality of fan blades having an outer surface; and
a light source,
wherein the inner surface of the volute housing and the outer surface of the plurality of fan blades includes a photocatalyst layer,
wherein the light source is configured to emit light on the photocatalyst layer.
Aspect 2. The centrifugal fan according to aspect 1, wherein the volute housing is made of plastic, the photocatalyst layer includes a primer layer disposed on the inner surface of the volute housing and the outer surface of the plurality of fan blades, and a titanium dioxide layer disposed on top of the primer layer.
Aspect 3. The centrifugal fan according to aspect 1, wherein the volute housing is made of galvanized steel, the photocatalyst layer includes a primer layer disposed on the inner surface of the volute housing and the outer surface of the plurality of fan blades, and a titanium dioxide layer disposed on top of the primer layer.
Aspect 4. The centrifugal fan according to aspect 1, wherein the volute housing is made of plastic, the photocatalyst layer includes a titanium dioxide layer having titanium dioxide on foamed polyurethane or foamed metal, the titanium dioxide layer is disposed on the inner surface of the volute housing and the outer surface of the plurality of fan blades.
Aspect 5. The centrifugal fan according to aspect 1, wherein the volute housing is made of galvanized steel, the photocatalyst layer includes a titanium dioxide layer having titanium dioxide on foamed polyurethane or foamed metal, the titanium dioxide layer is disposed on the inner surface of the volute housing and the outer surface of the plurality of fan blades.
Aspect 6. The centrifugal fan according to any one of aspects 1-5, wherein the photocatalyst layer is coated or sintered on the inner surface of the volute housing and the outer surface of the plurality of fan blades.
Aspect 7. The centrifugal fan according to any one of aspects 1-6, wherein the light source is configured to emit UVA light.
Aspect 8. The centrifugal fan according to any one of aspects 1-6, wherein the light source is configured to emit UVC light.
Aspect 9. The centrifugal fan according to any one of aspects 1-7, wherein the light source is a mercury lamp.
Aspect 10. The centrifugal fan according to any one of aspects 1-6, wherein the light source is a light-emitting diode light source.
Aspect 11. The centrifugal fan according to any one of aspects 1-10, wherein the volute housing includes a window that allows the light to pass through into an inner space of the volute housing, the centrifugal fan includes a reflector covering the window, the reflector is configured to reflect the light, and the light source is enclosed by the window and the reflector.
Aspect 12. The centrifugal fan according to aspect 11, wherein the window is made of silica glass, the reflector is made of polished aluminum or polished stainless steel or polytetrafluoroethylene,
wherein the light source, the window, and the reflector extend from a first side of the volute housing to a second side of the volute housing.
Aspect 13. The centrifugal fan according to any one of aspects 1-10, wherein the light source is disposed inside a chamber of the centrifugal fan.
Aspect 14. The centrifugal fan according to aspect 13, wherein the light source includes a first light source and a second light source, the impeller includes a partition, the first light source extends from a first side of the volute housing toward the partition, and the second light source extends from a second side of the volute housing toward the partition.
Aspect 15. The centrifugal fan according to any one of aspects 1-10, wherein the light source has a ring-shape and is disposed at a side of the volute housing.
Aspect 16. The centrifugal fan according to any one of aspects 1-10, wherein the light source includes a first light source and a second light source, the first light source has a ring-shape and is disposed at a first side of the volute housing, the second light source has a ring-shape and is disposed at a second side of the volute housing.
Aspect 17. The centrifugal fan according to any one of aspects 1-10, wherein the light source is inserted in the volute housing in a direction toward the air outlet of the volute housing.
Aspect 18. The centrifugal fan according to any one of aspects 1-10, wherein the light source is disposed inside the volute housing near the air outlet, the light source extends from a first side of the volute housing to a second side of the volute housing.
Aspect 19. The centrifugal fan according to aspect 18, wherein the volute housing includes a reflector configured to reflect the light, the light source is disposed on the reflector.
Aspect 20. A method of configuring a centrifugal fan for a heating, ventilation, air conditioning, and refrigeration (HVACR) system, the centrifugal fan including a volute housing having an inner surface and a curved inlet shroud, the volute housing defining an air outlet, the curved inlet shroud defining an air inlet, and the air inlet having an inlet airflow cross-sectional area that lies substantially perpendicular to an outlet airflow cross-sectional area of the air outlet; an impeller mounted for rotation about a rotational axis within the volute housing, the impeller having a plurality of fan blades, and the plurality of fan blades having an outer surface; and a light source,
the method comprising:
coating or sintering a photocatalyst layer on the inner surface of the volute housing and the outer surface of the plurality of fan blades, and
emitting light, by the light source, on the photocatalyst layer.
Aspect 21. A heating, ventilation, air conditioning, and refrigeration (HVACR) system, the system comprising:
a compressor, a condenser, an expansion device, and an evaporator fluidly connected; and
a centrifugal fan for the condenser or the evaporator, the centrifugal fan comprising:
The terminology used in this specification is intended to describe particular embodiments and is not intended to be limiting. The terms “a,” “an,” and “the” include the plural forms as well, unless clearly indicated otherwise. The terms “comprises” and/or “comprising,” when used in this specification, specify the presence of the 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, elements, and/or components.
With regard to the preceding description, it is to be understood that changes may be made in detail, especially in matters of the construction materials employed and the shape, size, and arrangement of parts without departing from the scope of the present disclosure. This specification and the embodiments described are exemplary only, with the true scope and spirit of the disclosure being indicated by the claims that follow.
| Number | Date | Country | Kind |
|---|---|---|---|
| 202011033778.4 | Sep 2020 | CN | national |
| 202022157496.7 | Sep 2020 | CN | national |
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