The presently disclosed embodiments generally relate to heating, ventilation, air conditioning, and refrigeration (HVAC/R) systems, and more particularly, to a system and method of diluting a leaked refrigerant in an HVAC/R system.
Refrigeration systems, as used in HVAC/R applications, utilize a closed loop refrigerant circuit to condition air inside an interior space. Over the years, the HVAC industry has been using refrigerants with ozone depleting chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs); however, the use of ozone depleting refrigerants is currently being phased out of the industry.
New refrigerants have been developed to comply with environmental regulations relating to global warming potential (GWP). In order to comply with the proposed GWP regulations, hydrofluorocarbon (HFC) and hydrocarbon refrigerants with various levels of flammability are being developed and are being considered for use in HVAC/R systems.
As with any system, there is a potential for flammable refrigerants used in HVAC/R applications to leak and migrate to undesirable areas in the vicinity of the HVAC/R system. When the flammable refrigerants, in the presence of air or another oxidizer, are exposed to an ignition source, the potential for a combustion event exists if the mixture is above the lower flammability limit (LFL) and below the upper flammability limit (UFL). There is therefore a need for an HVAC/R system which mitigates the possibility of igniting a leaked refrigerant.
In one aspect, an HVAC/R system is provided. The HVAC/R system includes a mitigation damper disposed within a return air conduit, wherein the return air conduit includes an opening adjacent to the mitigation damper. The mitigation damper includes a first portion operably coupled to a rotating component. In an embodiment, the first portion is positioned to cover the opening when the mitigation damper is in a closed position. In another embodiment, the mitigation damper further includes a second portion operably coupled to the rotating component. In this embodiment, the second portion is positioned to cover the opening from the exterior of the return air conduit when the mitigation damper is in a closed position, and the first portion is located within the interior of the return conduit. In an embodiment, the first and second portions of the mitigation damper are the same. In another embodiment, the first and second portions of the mitigation damper are the different. In one embodiment, the rotating component is selected from a group consisting of a motorized and non-motorized hinge.
The system further includes at least one HVAC component operably coupled to the return air conduit, the at least one HVAC component being configured to allow a refrigerant to flow therethrough. In one embodiment, the refrigerant may be a flammable refrigerant. In one embodiment, the flammable refrigerant includes difluoromethane (R32), and in another embodiment the flammable refrigerant includes 2,3,3,3-tetrafluoro-1-propene (R1234yf). In an embodiment, the at least one HVAC component may be a combination of an evaporator coil and a furnace. In another embodiment, the at least one HVAC component may be a refrigeration unit.
In one aspect, a method of diluting a leaked refrigerant in the HVAC/R system with the mitigation damper is provided. The method includes the step of determining whether a refrigerant leak has been detected. If a refrigerant leak is not detected, the HVAC/R system continues normal operation.
The method further includes the step of operating the mitigation damper from a closed position to an open position if a refrigerant leak is detected. In an embodiment, the step further includes operating the blower motor if a refrigerant leak is detected.
The embodiments and other features, advantages and disclosures contained herein, and the manner of attaining them, will become apparent and the present disclosure will be better understood by reference to the following description of various exemplary embodiments of the present disclosure taken in conjunction with the accompanying drawings, wherein:
For the purposes of promoting an understanding of the principles of the present disclosure, reference will now be made to the embodiments illustrated in the drawings, and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of this disclosure is thereby intended.
The system 10 further includes at least one HVAC component 22 operably coupled to the return air conduit 14, the at least one HVAC component 22 being configured to allow a refrigerant to flow therethrough. In one embodiment, the refrigerant may be a flammable refrigerant, such that the refrigerant has the ability to ignite and/or propagate a flame in the presence of air. The flammability of a refrigerant is evaluated at specific ambient conditions, including, but not limited to initial temperature, humidity, and pressure relevant to conditions of operation. In one embodiment, the flammable refrigerant includes difluoromethane (R32), and in another embodiment the flammable refrigerant includes 2,3,3,3-tetrafluoro-1-propene (R1234yf). It will be appreciated that other flammable refrigerants may be used within the HVAC/R system 10.
In the illustrated, non-limiting embodiment, the at least one HVAC component 22 is a fan coil containing an evaporator coil 24, a controller 25, and a blower motor 26 in electrical communication with the controller 25. A sensor 27 is in electrical communication with the mitigation damper 12 and the controller 25, and is configured to detect a refrigerant leak in the system 10. It will be appreciated that the sensor may be located internal or external to the at least one HVAC component 22.
In normal operation to condition an interior space, a compressor (not shown) of the HVAC/R system 10 is fluidically coupled to the evaporator coil 24. Compressed refrigerant is configured to enter the evaporator coil 24 via a refrigerant supply line 28 and is configured to exit the evaporator coil 24 via a refrigerant return line 30. As the refrigerant flows through the evaporator coil 24, the blower motor 26 operates to circulate the conditioned air 32 through a supply conduit 34 to an interior space (not shown). Return air 36 from the interior space enters the at least one HVAC component 22 via the return conduit 14. In an embodiment, the at least one HVAC component 22 may be a combination of an evaporator coil and a furnace. In another embodiment, the at least one HVAC component 22 may be a refrigeration unit.
The method 100 further includes step 104 of operating the mitigation damper 12 from a closed position to an open position if a refrigerant leak is detected. In an embodiment, step 104 further includes operating the blower motor 26 if a refrigerant leak is detected. For example, once the sensor 27 has detected a refrigerant leak, an electrical signal is transmitted to the mitigation damper 12 to be placed in an open position such that first portion 16 rotates to block the return air 36 within the return conduit 14 and exposes the opening 15 within the return conduit 14 (see
It will be appreciated that upon detection of a refrigerant leak, the mitigation damper 12 operates to block the return air 36 and expose an opening 15 within the return conduit 14 to increase the volume of air 17 through the at least one HVAC component 22 to dilute the leaked refrigerant as part of a mitigation strategy to prevent ignition of the refrigerant.
While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only certain embodiments have been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected.
The present application is related to, and claims the priority benefit of, U.S. Provisional Patent Application Ser. No. 62/173,058 filed Jun. 9, 2015, the contents of which are hereby incorporated in their entirety into the present disclosure.
Number | Name | Date | Kind |
---|---|---|---|
1938833 | Irons, Sr. | Dec 1933 | A |
2184473 | Scanlan | Dec 1939 | A |
2212356 | Shure | Aug 1940 | A |
2970768 | Curran | Feb 1961 | A |
3421576 | Roane | Jan 1969 | A |
3859818 | Goettl | Jan 1975 | A |
3946575 | Barr | Mar 1976 | A |
3949808 | Gilles | Apr 1976 | A |
3982583 | Shavit | Sep 1976 | A |
4018266 | Kay | Apr 1977 | A |
4099553 | Burnham | Jul 1978 | A |
4136732 | Demaray | Jan 1979 | A |
4407185 | Haines | Oct 1983 | A |
4437608 | Smith | Mar 1984 | A |
4718244 | Kobayashi | Jan 1988 | A |
4887438 | Meckler | Dec 1989 | A |
5267451 | Cleveland | Dec 1993 | A |
5346127 | Creighton | Sep 1994 | A |
5479787 | Carter | Jan 1996 | A |
5579993 | Ahmed | Dec 1996 | A |
5590830 | Kettler | Jan 1997 | A |
5597354 | Janu | Jan 1997 | A |
5918475 | Sakakibara | Jul 1999 | A |
6071189 | Blalock | Jun 2000 | A |
6415617 | Seem | Jul 2002 | B1 |
6427454 | West | Aug 2002 | B1 |
6514138 | Estepp | Feb 2003 | B2 |
6579993 | Hilden | Jun 2003 | B2 |
6604688 | Ganesh | Aug 2003 | B2 |
6629886 | Estepp | Oct 2003 | B1 |
6698219 | Sekhar | Mar 2004 | B2 |
6719625 | Federspiel | Apr 2004 | B2 |
6722154 | Tan | Apr 2004 | B1 |
6749125 | Carson et al. | Jun 2004 | B1 |
7017827 | Shah | Mar 2006 | B2 |
7341201 | Stanimirovic | Mar 2008 | B2 |
10001289 | Mowris | Jun 2018 | B2 |
10514176 | Weinert | Dec 2019 | B2 |
10533764 | Yamada | Jan 2020 | B2 |
10935454 | Kester | Mar 2021 | B2 |
20050103029 | Kawahara | May 2005 | A1 |
20120052791 | Kurelowech | Mar 2012 | A1 |
20120071082 | Karamanos | Mar 2012 | A1 |
20140033752 | Gunjima et al. | Feb 2014 | A1 |
20150323225 | Matsumoto | Nov 2015 | A1 |
20160363358 | Papas | Dec 2016 | A1 |
20160370029 | Kurelowech | Dec 2016 | A1 |
20180106492 | Papas | Apr 2018 | A1 |
20190170383 | Weinert | Jun 2019 | A1 |
20190170604 | Kester | Jun 2019 | A1 |
20190242602 | Yamada | Aug 2019 | A1 |
20200141601 | Weinert | May 2020 | A1 |
Number | Date | Country |
---|---|---|
H08178397 | Jul 1996 | JP |
2755003 | May 1998 | JP |
H10281569 | Oct 1998 | JP |
H10300294 | Nov 1998 | JP |
2001134827 | May 2001 | JP |
2002115939 | Apr 2002 | JP |
3291407 | Jun 2002 | JP |
2011127847 | Jun 2011 | JP |
20090097587 | Sep 2009 | KR |
Number | Date | Country | |
---|---|---|---|
20160363358 A1 | Dec 2016 | US |
Number | Date | Country | |
---|---|---|---|
62173058 | Jun 2015 | US |