Patent Application
20250180031
The disclosed technology relates generally to axial fans for heating, ventilation, and air conditioning (HVAC) systems and, more particularly, to axial fans used in air handling units.
Air handlers (e.g., air handling units, fan coil units, etc.), are commonly used in heating, ventilation, and air conditioning (HVAC) systems to regulate and circulate air throughout a building or ventilated space. As illustrated in
Air handling units generally include blowers 108, rather than axial fans, because blowers 108 are capable of producing a high-pressure airflow while outputting comparatively little noise. Unfortunately, due to their design, blowers 108 typically require a large amount of space as compared to axial fans and are generally less efficient at moving air than axial fans. Because of their design, Blowers 108 must consume a greater amount of energy than axial fans to move air through the HVAC system. The use of axial fans in HVAC systems, however, has been limited due to the comparatively high noise output of typical axial fans as compared to blowers 108 and because axial fans typically supply lower-pressure airflow than blowers 108, which can inhibit their usefulness in existing HVAC applications. Furthermore, blowers have typically been less expensive to implement in an air handling unit than axial fans. Consequently, axial fan designs are typically not utilized in existing residential air handling units.
What is needed, therefore, are axial fan designs that can be used in an air handling unit of an HVAC system while using minimal energy (e.g., as compared to existing systems), meeting sound and vibration requirements, and operating at required airflow and external static pressure limits when installed. These and other requirements are addressed by the technology disclosed herein.
The disclosed technology relates generally to an axial fan assembly for an air handling unit. The axial fan assembly can include an axial fan that is configured to direct air through the axial fan assembly, an inlet ring that is disposed in a flow path upstream of the axial fan and configured to direct air toward the axial fan, a stator that is disposed in the flow path downstream of the axial fan and configured to straighten a flow of the air, an outlet ring that is disposed in the flow path downstream of the axial fan and configured to direct air out of the axial fan assembly, and a fan deck that is configured to attach to the air handling unit and support at least the axial fan.
The disclosed technology can also include an air handling unit for a heating, ventilation, and air conditioning (HVAC) system. The air handling unit can include an enclosure having an inlet and an outlet, a heat exchanger coil housed within the enclosure and configured to (i) receive a refrigerant circulated through the heat exchanger coil and (ii) facilitate heat exchange between the refrigerant and air directed across the heat exchanger coil, and the axial fan assembly just described. The axial fan assembly can be housed within the enclosure and configured to direct the air across the heat exchanger coil.
The axial fan can be non-shrouded and include an electrical motor configured to rotate the axial fan at greater than 1750 revolutions per minute. The axial fan can be configured to operate at a static efficiency of greater than 65%.
The inlet ring can have an inlet having a first diameter and an outlet having a second diameter and the first diameter can be greater than the second diameter.
The axial fan assembly can further include a casing disposed around at least a portion of the inlet ring and/or a casing flange configured to support the axial fan and the stator. The inlet ring can extend from an inlet of the axial fan assembly to the casing flange and be attached to the casing flange.
The axial fan can be attached to the stator and configured to support the axial fan.
The outlet ring can have an inlet having a first diameter and an outlet having a second diameter and the first diameter can be less than the second diameter.
The axial fan, the inlet ring, the stator, the outlet ring, and the fan deck can be connected to form the axial fan assembly.
Further features and advantages of the disclosed technology will become apparent throughout this disclosure.
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate various aspects of the presently disclosed subject matter and serve to explain the principles of the presently disclosed subject matter. The drawings are not intended to limit the scope of the presently disclosed subject matter in any manner.
The disclosed technology includes axial fan assemblies used in air handling or fan coil units. In particular, the disclosed technology includes various examples of axial fan assemblies capable of circulating air through an HVAC system while consuming less energy than is typically consumed by traditional blowers. The disclosed technology includes various designs of axial fans that combine various features to help reduce the overall energy consumed by the axial fan and to help reduce the noise generated by the axial fan. Furthermore, the disclosed technology includes various axial fan assemblies that can be deployed in various sizes of air handling units. Additional features and advantages of the disclosed technology will become apparent throughout this disclosure.
Although various aspects of the disclosed technology are explained in detail herein, it is to be understood that other aspects of the disclosed technology are contemplated. Accordingly, it is not intended that the disclosed technology is limited in its scope to the details of construction and arrangement of components expressly set forth in the following description or illustrated in the drawings. The disclosed technology can be implemented and practiced or carried out in various ways. In particular, the presently disclosed subject matter is described in the context of being an axial fan of an air handling unit of an HVAC system. The present disclosure, however, is not so limited, and can be applicable in other contexts such as fan coil units, refrigerant systems, industrial heating and cooling systems, packaged HVAC systems, etc. Accordingly, when the present disclosure is described in the context of an axial fan for an air handler of an HVAC system, it will be understood that other implementations can take the place of those referred to.
It should also be noted that, as used in the specification and the appended claims, the singular forms “a,” “an,” and “the” include plural references unless the context clearly dictates otherwise. References to a composition containing “a” constituent is intended to include other constituents in addition to the one named.
Also, in describing the disclosed technology, terminology will be resorted to for the sake of clarity. It is intended that each term contemplates its broadest meaning as understood by those skilled in the art and includes all technical equivalents which operate in a similar manner to accomplish a similar purpose.
Ranges may be expressed herein as from “about” or “approximately” or “substantially” one particular value and/or to “about” or “approximately” or “substantially” another particular value. When such a range is expressed, the disclosed technology can include from the one particular value and/or to the other particular value. Further, ranges described as being between a first value and a second value are inclusive of the first and second values. Likewise, ranges described as being from a first value and to a second value are inclusive of the first and second values.
It is also to be understood that the mention of one or more method steps does not preclude the presence of additional method steps or intervening method steps between those steps expressly identified. Moreover, although the term “step” can be used herein to connote different aspects of methods employed, the term should not be interpreted as implying any particular order among or between various steps herein disclosed unless and except when the order of individual steps is explicitly required. Further, the disclosed technology does not necessarily require all steps included in the methods and processes described herein. That is, the disclosed technology includes methods that omit one or more steps expressly discussed with respect to the methods described herein.
Herein, the use of terms such as “having,” “has,” “including,” or “includes” are open-ended and are intended to have the same meaning as terms such as “comprising” or “comprises” and not preclude the presence of other structure, material, or acts. Similarly, though the use of terms such as “can” or “may” are intended to be open-ended and to reflect that structure, material, or acts are not necessary, the failure to use such terms is not intended to reflect that structure, material, or acts are essential. To the extent that structure, material, or acts are presently considered to be essential, they are identified as such.
The components described hereinafter as making up various elements of the disclosed technology are intended to be illustrative and not restrictive. Many suitable components that would perform the same or similar functions as the components described herein are intended to be embraced within the scope of the disclosed technology. Such other components not described herein can include, but are not limited to, similar components that are developed after development of the presently disclosed subject matter.
Referring now to the drawings, in which like numerals represent like elements, the present disclosure is herein described.
One of skill in the art will appreciate that the axial fan 222 can be any type of axial fan that is configured to move air from the first port 204, across the heat exchanger coil 210, and out the second port 206. For example, the axial fan 222 can be a propeller axial fan, a tube axial fan, a vane axial fan, or backward curved axial fan, or any other suitable type of axial fan for the application. In other words, the axial fan 222 can be configured to move air or other fluids in an axial direction, parallel to a shaft about which blades of the axial fan 222 rotate. Furthermore, the axial fan 222 can be a shrouded fan (i.e., the axial fan 222 can include a shroud disposed around an outer edge of the fan blades) or the axial fan 222 can be a non-shrouded fan.
The heat exchanger coil 210 can be configured to exchange heat with the refrigerant circulated through the heat exchanger coil 210 and air passed over the heat exchanger coil 210. The heat exchanger coil 210 can be any type of heat exchanger that can facilitate heat exchange between refrigerant and air and/or water and air. The heat exchanger coil 210, for example, can be an A-coil, an N-coil, a Z-coil, a V-Coil, a slab coil, a cased coil, an uncased coil, a microchannel coil, or any other suitable type of heat exchanger for the application. Furthermore, the heat exchanger coil 210 can be made of any suitable material for the application. For example, the heat exchanger coil 210 can be made of aluminum, copper, titanium, stainless steel, cupronickel, carbon steel, composite materials, or other suitable materials.
The heat exchanger coil 210 can be in fluid communication with an outdoor coil 212 that can be configured to facilitate heat exchange between a refrigerant that is circulated through the outdoor coil 212 and air that is passed over the outdoor coil 212. Although described as being an outdoor coil 212, one of skill in the art will appreciate that the outdoor coil 212 can be located in any suitable location to facilitate heat transfer between the refrigerant and air or another fluid. For example, the outdoor coil 212 can be located outside of a building, inside of a building (e.g., an attic, a garage, etc.), under the ground (e.g., a ground source heat pump), or in any other suitable location for the application. Furthermore, although described herein as exchanging heat between the refrigerant and air, the outdoor coil 212 can be configured to exchange heat between the refrigerant and any suitable fluid (e.g., water, glycol, etc.).
The heat exchanger coil 210 can be configured to function as an evaporator or a condenser depending on the particular application. As a non-limiting example, the heat exchanger coil 210 can be part of an air conditioning system and can be configured to perform a cooling function. Alternatively or in addition, the heat exchanger coil 210 can be part of a heat pump system and can be configured to perform both a cooling and a heating function. For example, if the temperature of the air within the ventilated space is greater than a predetermined high temperature, the heat exchanger coil 210 can be configured to function as an evaporator to absorb heat from the air passed across the heat exchanger coil 210, thereby providing cooled air to the ventilated space. On the other hand, if the temperature of the air within the ventilated space is less than a predetermined low temperature, the heat exchanger coil 210 can be configured to function as a condenser and provide heat to the air passed across the heat exchanger coil 210, thereby providing heated air to the ventilated space. The predetermined high temperature can be the same temperature as, or a greater temperature than, the predetermined low temperature.
As described previously, the axial fan assembly 220 can include a stator 224. The stator 224 can be positioned in an airflow path downstream of the axial fan 222 and can be configured to enable straightening of the air downstream of the axial fan 222. For example, the stator 224 can comprise a plurality of vanes that are sized and positioned to direct the air moved by the axial fan 222 such that the flow of the air becomes straighter in a direction generally parallel with a longitudinal axis of the axial fan 220 from a first side of the stator 224 to a second side of the stator 224. Because the axial fan 222 directs the air through the stator 224, the air flow path can be straightened prior to delivery of the air to the various components of the air handling unit 200 and the HVAC system. As will be described in greater detail herein, the stator 224 can be incorporated into the axial fan assembly 220. Alternatively, the stator 224 can be mounted separate from the axial fan 222. For example, the stator 224 can be mounted within the enclosure 202 such that the stator 224 is in an airflow path downstream of the axial fan 222.
The axial fan assembly 220 can be mounted within an air handling unit 200 by attaching to the enclosure 202 via the fan deck 337. The fan deck 337 can be sized to fit within the enclosure 202 such that the fan deck 337 helps prevent air from passing around the fan deck 337 and causes the air to pass through the inlet ring 332. In other words, the fan deck 337 can be shaped to substantially obstruct the airflow path through the air handling unit 200 except for the airflow pathway formed through the inlet ring 332, the stator 224, and the outlet ring 330. The fan deck 337 can be secured to the enclosure 202 via fasteners, brackets, clamps, rails, or other suitable mounting systems. The fan deck 337 can be attached to the casing flange 336, which can support the stator 224 and/or the axial fan 222 and the motor assembly 326. In this way, the motor assembly 326 (which is attached to the fan shaft 328 and the axial fan 222) can be supported by the casing flange 336. Alternatively, the motor assembly 326 can be supported by the stator 224 directly with the stator 224 being supported by the casing flange 336. In other words, the stator 224 can be attached to the casing flange 336 and the motor assembly 326 can be attached to the stator 224. Alternatively, the motor assembly 326 and the stator 224 can each be attached to the casing flange 336.
The motor assembly 326 can be any suitable type of electrical motor for the particular application. For instance, in any of the examples described herein, the motor assembly 326 can include a bushed motor or a brushless motor and can be powered by direct current (DC) or alternating current (AC) power sources. Furthermore, the capacity of the motor assembly 326 can be any capacity suitable for the application. For example, the motor assembly 326 can include a ¼ horsepower motor, a ⅓ horsepower motor, a ½ horsepower motor, a ¾ horsepower motor, a 1 horsepower motor, a 2 horsepower motor, a 5 horsepower motor, a 10 horsepower motor, etc. Furthermore, the motor assembly 326 can be configured to cause the axial fan 222 to rotate at a suitable speed for the application. For example, the motor assembly 326 can be configured to cause the axial fan 222 to rotate at 1000 revolutions per minute (RPM), 1,250 RPM, 1,500 RPM, 1,750 RPM, 2,000 RPM, 3,000 RPM, 5,000 RPM, 7,500 RPM, 10,000 RPM, etc.
As illustrated in
As will be appreciated, the axial fan 222 can be configured to direct air through the axial fan 222 and then through the stator 224 as illustrated by the arrows indicating airflow direction in
The axial fan 222 can be a shrouded fan, or the axial fan 222 can be a non-shrouded fan, depending on the application. If the axial fan 222 is a shrouded fan, the shroud can be configured to help form the airflow path through the axial fan assembly 220. For example, although not shown, the axial fan 222 can have a shroud formed at an outer edge of the fan blades that can form an airflow path through the axial fan 222. Furthermore, if the axial fan 222 is a shrouded fan, the inlet ring 332 can extend between an inlet end of the axial fan assembly 220 to a location proximate the shroud of the axial fan 222. As will be appreciated, a small gap can be present between the shroud of the axial fan 222 and the inlet ring 332 and the casing flange 336 such that the shroud of the axial fan 222 does not contact the inlet ring 332 or the casing flange 336.
As shown in
The outlet ring 330 can be sized and shaped to help improve the efficiency of the outflow of air by enabling smooth expansion of the air as it exits the axial fan assembly 220. Similar to the inlet ring 332, the outlet ring 330 can be sized such that an outer edge of the outlet ring 330 is disposed proximate the enclosure 202 when the axial fan assembly 220 is mounted in the enclosure 202. Furthermore, the outlet ring 330 can have a first diameter (or inlet area) at an inlet of the outlet ring 330 that is smaller than a second diameter (or outlet area) at an outlet of the outlet ring 330 and the outlet ring 330 can diverge from the inlet to the outlet of the outlet ring 330. Similar to the inlet ring 332, although described as a ring, the outlet ring 330) can include at least a portion of the outlet ring 330 that does not have a circular shape. For example, the outlet ring 330 can have a substantially rectangular shape proximate an outlet side of the outlet ring 330 and converge from a circular inlet of the outlet ring 330 toward a rectangular outlet of the outlet ring 330. In this way, the outlet ring 330 can be configured to substantially direct air from the circular axial fan 222 through a rectangular enclosure 202.
As illustrated in
As will be appreciated by one of skill in the art, the performance of the axial fan 222 is dependent on the design of the axial fan 222 and design of the HVAC system in which the axial fan 222 will be deployed. For example, HVAC systems having longer ducts, smaller ducts, or otherwise more obstruction in the airflow path of the axial fan 222 will result in a higher static pressure on the axial fan 222. Therefore, the axial fan 222 must be capable of circulating air through the HVAC system given the expected static pressure. Furthermore, as shown in
The axial fan 222 of the present disclosure can be designed to efficiently operate in a given HVAC system at a performance level that is greater than those exhibited by blowers 120. For example, while blowers 120 typically have a static efficiency range of 45-55%, the axial fan 222 of the present disclosure can have a static efficiency of greater than 65%. For instance, the axial fan 222 can have a peak static efficiency of approximately 70%. In other examples, the axial fan 222 can have a static efficiency of greater than 70%. Furthermore, the axial fan 222 can be designed to prevent stall up to a total external static pressure of approximately 1.5 inches WC. In some examples, the axial fan can be designed to operate with a static efficiency of greater than 70% when a static pressure exhibited by the heat exchanger coil is approximately 0.3 inches WC and the external static pressure is approximately 0.3 inches WC.
As will be appreciated, as the speed of the axial fan 222 increases, the volume of the sound output by the axial fan 222 will also generally increase. Because air handling units 200 are often installed in residential homes or inside occupied buildings, the sound output by the axial fan should remain at a level that does not negatively affect the occupants of the building. Therefore, in light of the particular characteristics of the axial fan 222 and the system shown in
While the present disclosure has been described in connection with a plurality of exemplary aspects, as illustrated in the various figures and discussed above, it is understood that other similar aspects can be used, or modifications and additions can be made to the described subject matter for performing the same function of the present disclosure without deviating therefrom. In this disclosure, methods and compositions were described according to aspects of the presently disclosed subject matter. But other equivalent methods or compositions to these described aspects are also contemplated by the teachings herein. Therefore, the present disclosure should not be limited to any single aspect, but rather construed in breadth and scope in accordance with the appended claims.
This application is an international application of, and claims priority to and the benefit of, U.S. Application No. 63/322,269, filed Mar. 22, 2022, the entirety of which is hereby incorporated by reference.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2023/013423 | 2/20/2023 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 63322269 | Mar 2022 | US |
