U.S. patent application number 15/787539 was filed with the patent office on 2018-04-19 for hvac/r system with auxiliary power source and method of operating an hvac/r system.
The applicant listed for this patent is Carrier Corporation. Invention is credited to Larry D. Burns, Richard G. Lord, Paul Papas, Parmesh Verma.
Application Number | 20180106492 15/787539 |
Document ID | / |
Family ID | 61902748 |
Filed Date | 2018-04-19 |
United States Patent
Application |
20180106492 |
Kind Code |
A1 |
Papas; Paul ; et
al. |
April 19, 2018 |
HVAC/R SYSTEM WITH AUXILIARY POWER SOURCE AND METHOD OF OPERATING
AN HVAC/R SYSTEM
Abstract
An HVAC/R system configured to receive power from a main power
source is provided. The HVAC/R system includes an HVAC/R component
configured to contain a refrigerant and allow a refrigerant to flow
therethrough, a detecting mechanism configured to detect a
concentration of the refrigerant outside of the HVAC/R component,
and a blower configured to operate under power from an auxiliary
power source upon detection of the refrigerant above a
predetermined refrigerant level during a main power source
outage.
Inventors: |
Papas; Paul; (West Hartford,
CT) ; Verma; Parmesh; (South Windsor, CT) ;
Lord; Richard G.; (Murfreesboro, TN) ; Burns; Larry
D.; (Avon, IN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Carrier Corporation |
Palm Beach Gardens |
FL |
US |
|
|
Family ID: |
61902748 |
Appl. No.: |
15/787539 |
Filed: |
October 18, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62409795 |
Oct 18, 2016 |
|
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|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F24F 11/38 20180101;
F24F 11/36 20180101; F25B 2500/222 20130101; F24F 11/37 20180101;
F25B 2700/04 20130101; F24F 11/72 20180101; F24F 13/10 20130101;
F25B 2500/23 20130101 |
International
Class: |
F24F 11/37 20060101
F24F011/37; F24F 11/72 20060101 F24F011/72; F24F 11/38 20060101
F24F011/38; F24F 13/10 20060101 F24F013/10 |
Claims
1. An HVAC/R system configured to receive power from a main power
source, the HVAC/R system comprising: an HVAC/R component
configured to contain a refrigerant and allow a refrigerant to flow
therethrough; a detecting mechanism configured to detect a
concentration of the refrigerant within a gas volume outside of the
HVAC/R component; and a blower configured to operate under power
from an auxiliary power source upon detection of the refrigerant
above a predetermined refrigerant level during a main power source
outage, wherein the blower is in fluid communication with the gas
volume.
2. The system of claim 1, wherein the detecting mechanism operates
under power from the auxiliary power source at least during the
main power source outage.
3. The system of claim 1, further comprising a return conduit
operably coupled to the at least one HVAC/R component, the return
conduit including an opening to allow airflow therethrough.
4. The system of claim 3, further comprising a mitigation damper
operably coupled to the return conduit and positioned adjacent to
the opening to selectively allow airflow through the opening upon
detection of the refrigerant by the detecting mechanism.
5. The system of claim 1, further comprising a controller in
electrical communication with the detecting mechanism and the
blower.
6. The system of claim 5, wherein the controller operates under
power from the auxiliary power source at least during the main
power source outage.
7. The system of claim 1, wherein the blower is further configured
to operate for a predetermined time period following detection of
the refrigerant below the predetermined refrigerant level by the
detecting mechanism.
8. The system of claim 1, wherein the predetermined refrigerant
level is a lower flammability limit of the refrigerant.
9. The system of claim 1, wherein the HVAC/R system is disposed in
an outdoor space.
10. The system of claim 1, wherein the HVAC/R system is disposed in
an indoor space.
11. The system of claim 1, wherein the auxiliary power source
includes at least one battery.
12. The system of claim 1, wherein the auxiliary power source
includes a distributed energy source.
13. The system of claim 1, wherein the auxiliary power source
includes a renewable energy source.
14. The system of claim 1, wherein the detecting mechanism is a
sensor.
15. The system of claim 1, wherein the detecting mechanism is a
system control algorithm.
16. The system of claim 1, further comprising an enclosure which at
least partially surrounds the gas volume and the HVAC/R
component.
17. A method of operating an HVAC/R system configured to receive
power from a main power source, the method comprising: circulating
a refrigerant through an HVAC/R component; detecting a
concentration of the refrigerant outside of the HVAC/R component;
and powering a blower with an auxiliary power source during a main
power source outage if the concentration of refrigerant detected is
above a predetermined refrigerant level.
18. The method of claim 16, further comprising opening a mitigation
damper if the concentration of refrigerant detected is above the
predetermined refrigerant level.
19. The method of claim 17, wherein the mitigation damper is
operably coupled to a return conduit.
20. The method of claim 16, further comprising powering a detecting
mechanism configured to detect a concentration of the refrigerant
outside of the HVAC/R component with the auxiliary power source
during the main power source outage.
21. The method of claims 16, further comprising: controlling the
blower with a controller electrically connected to a detecting
mechanism; and powering the controller with the auxiliary power
source during the main power source outage.
22. The method of claim 16, further comprising operating the blower
for a predetermined time period following detection of a
concentration of the refrigerant above the predetermined
refrigerant level.
23. The method of claim 16, wherein the auxiliary power source
includes at least one battery.
24. The method of claim 16, wherein the auxiliary power source
includes a distributed energy source.
Description
TECHNICAL FIELD OF THE DISCLOSED EMBODIMENTS
[0001] The present application is an international patent
application, which claims priority to U.S. patent application Ser.
No. 62/409,795, filed Oct. 18, 2016, which is herein incorporated
in its entirety.
TECHNICAL FIELD OF THE DISCLOSED EMBODIMENTS
[0002] 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 operating
an HVAC/R system with an auxiliary power source.
BACKGROUND OF THE DISCLOSED EMBODIMENTS
[0003] 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.
[0004] 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.
SUMMARY OF THE DISCLOSED EMBODIMENTS
[0005] In accordance with an embodiment of the present disclosure,
an HVAC/R system configured to receive power from a main power
source is provided. The HVAC/R system includes an HVAC/R component
configured to contain a refrigerant and allow a refrigerant to flow
therethrough, a detecting mechanism configured to detect a
concentration of the refrigerant within a gas volume outside of the
HVAC/R component, and a blower configured to operate under power
from an auxiliary power source upon detection of the refrigerant
above a predetermined refrigerant level during a main power source
outage, wherein the blower is in fluid communication with the gas
volume.
[0006] The detecting mechanism may operate under power from the
auxiliary power source at least during the main power source
outage. The system may further include a return conduit operably
coupled to the at least one HVAC/R component, the return conduit
including an opening to allow airflow therethrough. The system may
further include a mitigation damper operably coupled to the return
conduit and positioned adjacent to the opening to selectively allow
airflow through the opening upon detection of the refrigerant by
the detecting mechanism. The system may further include a
controller in electrical communication with the detecting mechanism
and the blower. The controller may operate under power from the
auxiliary power source at least during the main power source
outage. The blower may be further configured to operate for a
predetermined time period following detection of the refrigerant
below the predetermined refrigerant level by the detecting
mechanism. The predetermined refrigerant level may be a lower
flammability limit of the refrigerant. The HVAC/R system may be
disposed in an outdoor space. The HVAC/R system may be disposed in
an indoor space. The auxiliary power source may include at least
one battery. The auxiliary power source may include a distributed
energy source. The auxiliary power source may include a renewable
energy source. The detecting mechanism may be a sensor. The
detecting mechanism may be a system control algorithm. The system
may further include an enclosure which at least partially surrounds
the gas volume and the HVAC/R component.
[0007] In accordance with an embodiment of the present disclosure,
a method of operating an HVAC/R system configured to receive power
from a main power source is provided. The method includes
circulating a refrigerant through an HVAC/R component, detecting a
concentration of the refrigerant outside of the HVAC/R component,
and powering a blower with an auxiliary power source during a main
power source outage if the concentration of refrigerant detected is
above a predetermined refrigerant level.
[0008] The method may further include opening a mitigation damper
if the concentration of refrigerant detected is above the
predetermined refrigerant level. The mitigation damper may be
operably coupled to a return conduit. The method may further
include powering a detecting mechanism configured to detect a
concentration of the refrigerant outside of the HVAC/R component
with the auxiliary power source during the main power source
outage. The method may further include controlling the blower with
a controller electrically connected to a detecting mechanism, and
powering the controller with the auxiliary power source during the
main power source outage. The method may further include operating
the blower for a predetermined time period following detection of a
concentration of the refrigerant above the predetermined
refrigerant level. The auxiliary power source may include at least
one battery. The auxiliary power source may include a distributed
energy source.
BRIEF DESCRIPTION OF DRAWINGS
[0009] 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:
[0010] FIG. 1 is a schematic diagram of a HVAC/R system in
accordance with one embodiment of the present disclosure;
[0011] FIG. 2 is a schematic diagram of a HVAC/R system in
accordance with one embodiment of the present disclosure;
[0012] FIG. 3 is a schematic flow diagram of a method of operating
an HVAC/R system;
[0013] FIG. 4 is a schematic diagram of a HVAC/R system in
accordance with one embodiment of the present disclosure; and
[0014] FIG. 5 is a schematic diagram of a HVAC/R system in
accordance with one embodiment of the present disclosure.
DETAILED DESCRIPTION OF THE DISCLOSED EMBODIMENTS
[0015] 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.
[0016] 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), the propagation
of a deflagration is possible resulting in the production of toxic
combustion products such as HF and a harmful pressure rise. There
is therefore a need for an HVAC/R system which mitigates the
possibility of igniting a leaked refrigerant. However, during power
outages, mitigation systems and methods may not receive energy
supply for mitigation operation. Therefore, there further exists a
need for an HVAC/R system and method capable of a mitigation
operation during a main power outage.
[0017] FIG. 1 illustrates a schematic diagram of an embodiment of a
heating, ventilation, air conditioning, and refrigeration (HVAC/R)
system 10 in an embodiment of the present disclosure, indicated
generally at 10. The system 10 is configured to receive power
during its operation from a main power source (not shown). The main
power source may be an electrical grid in accordance with one
embodiment. The system 10 includes a blower 26 in electrical
communication with a controller 25. The blower 26 of one embodiment
includes a fan designed to operate under relatively low power, such
as a fan configured or rated for operation between 100 watts and
1000 watts in one non-limiting example. The system 10 further
includes a detecting mechanism, such as a sensor 42 in electrical
communication with the controller 25, in one non-limiting
embodiment. In one or more additional embodiments, the detecting
mechanism includes a system control algorithm. In such embodiments,
detection is accomplished through system controls that monitor one
or more values, such as pressure(s) and superheat and subcooling
signatures, to name a few non-limiting examples, of the system 10.
In the illustrated embodiment, the sensor 42 and/or the controller
25 are also in communication with a mitigation damper 12 in one
embodiment, as explained further below. The sensor 42 is configured
to detect refrigerant. The sensor 42 and/or the controller 25 may
determine if the refrigerant level sensed by the sensor 42 is above
a predetermined refrigerant level. In an embodiment, a refrigerant
level above a predetermined refrigerant level indicates a
refrigerant leak in the system 10. The predetermined refrigerant
level is the lower flammability limit (LFL) of the refrigerant in
an embodiment. In non-limiting examples, the LFL of difluoromethane
(R32) refrigerant is as high as 14.4%, and the LFL of hydrocarbons,
such as propane R290, is about 2% percent volume to air
concentration. In one embodiment, the predetermined refrigerant
level is between 3% and 10% percent volume refrigerant to air
concentration. In another embodiment, the predetermined refrigerant
level is between 5% and 8% percent volume refrigerant to air
concentration. In an embodiment, the predetermined refrigerant
level is between 1% and 3% percent volume refrigerant to air
concentration. In additional embodiments, the predetermined
refrigerant level is below 3% or above 10% percent volume
refrigerant to air concentration.
[0018] It will be appreciated that the detecting mechanism, such as
the sensor 42, may be located internal and/or external to the
system 10 and/or the one or more HVAC/R component 22. In an
embodiment, the detecting mechanism, such as the sensor 42, detects
a concentration of the refrigerant outside of the HVAC/R
component(s) 22. In an embodiment, the detecting mechanism is
configured to detect a concentration of the refrigerant within a
gas volume outside of the HVAC/R component. Further, the blower 26
is in fluid communication with the gas volume in an embodiment.
[0019] As explained in further detail below, the blower 26, the
controller 25, the sensor 42, and/or the damper 12 are electrically
coupled to an auxiliary power source 40. The auxiliary power source
40 of an embodiment is different than and/or separate from the main
power source (not shown). The auxiliary power source 40 is not
electrically coupled to the main power source in one embodiment. In
one or more additional embodiments, the auxiliary power source 40
includes one or more batteries, one or more distributed power
sources, and/or one or more alternative and/or renewable energy
sources, including such non-limiting examples as a solar energy
source, a wind energy source, a water or wave energy source, and a
thermoelectric energy source.
[0020] In one embodiment, the HVAC/R system 10 includes the
mitigation damper 12 disposed within a return air conduit 14,
wherein the return air conduit 14 includes an opening 15 adjacent
to the mitigation damper 12. The mitigation damper 12 includes a
first portion 16 operably coupled to a rotating component 20. In an
embodiment, the first portion 16 is positioned to cover the opening
15 when the mitigation damper 12 is in a closed position. In
another embodiment, as shown in FIG. 2, the mitigation damper 12
further includes a second portion 18 operably coupled to the
rotating component 20. In this embodiment, the second portion 18 is
located within the interior of the return conduit 14, and the first
portion 16 is positioned to cover the opening 15 from the exterior
of the return air conduit 14 when the mitigation damper 12 is in a
closed position. In the embodiment of FIG. 1, the first and second
portions 16, 18 of the mitigation damper 12 are the same. For
example, the first and second portions, 16, 18 may be formed as a
unitary piece from the same materials, have the same shape,
thickness, etc. In the embodiment FIG. 2, the first and second
portions 16, 18 of the mitigation damper 12 are different. The
mitigation damper 12 is configured to rotate between a closed and
an open position if a refrigerant leak is detected. In one
embodiment, the rotating component 20 is selected from a group
consisting of a motorized and non-motorized hinge. It will be
appreciated that an example of a non-motorized hinge includes a
spring loaded latching mechanism operable to rotate the mitigation
damper 12 upon receiving an electrical signal. It will further be
appreciated that the interior portion 16 and exterior portion 18
may be formed in any shape, and composed of any material suitable
for blocking airflow, such as metal, plastic, wood, etc. to name a
few non-limiting examples.
[0021] The system 10 further includes at least one HVAC/R component
22 operably coupled to the return air conduit 14, the at least one
HVAC/R 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/R component 22 further includes a fan coil
containing an evaporator coil 24 in electrical communication with
the controller 25.
[0022] 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 26 operates to circulate the
conditioned air 32 through a supply conduit 34 to an interior
space. Return air 36 from the interior space enters the at least
one HVAC/R component 22 via the return conduit 14. In an
embodiment, the at least one HVAC/R component 22 may be a
combination of an evaporator coil and a furnace. In another
embodiment, the at least one HVAC/R component 22 may be a
refrigeration unit.
[0023] FIG. 3 illustrates a method 100 of operating an HVAC/R
system 10 configured to receive power from the main power source.
The method 100 includes circulating, at step 102, a refrigerant
through the HVAC/R component 22. The method 100 further includes
sensing, at step 104, a refrigerant level by the sensor 42. The
method 100 further includes the sensor 42 and/or the controller 25
determining, at step 106, whether the refrigerant level is above
the predetermined refrigerant level. If the refrigerant level is
not above the predetermined refrigerant level, the system 10
continues normal operation at step 103. If the refrigerant level is
above the predetermined refrigerant level, the controller 26
determines, at step 108, if the system 10 is currently experiencing
a main power source outage. If the system 10 is not currently
experiencing a main power source outage, the system 10 continues
normal operation at step 103. If the system 10 is currently
experiencing a main power source outage, the system 10 operates, at
step 110, the blower 26 under power from the auxiliary power source
40. In an embodiment, the system 10 operates the blower 26 under
power from the auxiliary power source 40 until the sensor 42 either
no longer detects refrigerant or senses refrigerant at a
refrigerant level below the predetermined refrigerant level. In an
embodiment, the system 10 operates the blower 26 under power from
the auxiliary power source 40 for a predetermined time period
following the sensor 42 either not detecting refrigerant or sensing
refrigerant at a refrigerant level below the predetermined
refrigerant level. The predetermined time period is between one
minute and one hour in one embodiment, between 10 and 45 minutes in
another embodiment, and between 20 and 40 minutes in another
embodiment. In additional embodiments, the predetermined time
period is less than one minute or greater than one hour.
[0024] In an additional embodiment, the method 100 further includes
operating the mitigation damper 12 from a closed position to an
open position if the refrigerant level is above the predetermined
refrigerant level, and such operation may be performed under power
from the auxiliary power source 40. Further, the sensing of step
104 and any function of the controller 25 may be performed under
power from the auxiliary power source 40, such as by the sensor 42
and/or the controller 25 being powered by the auxiliary power
source 40.
[0025] The system 10 may be positioned in an indoors space or at an
outdoor location. During a refrigerant leak from the system 10, the
refrigerant may collect near or around the base of the system 10
inside or outside of the system 10 due to the refrigerant being
heavier than the surrounding air. Such collection or concentration
may cause a flammability hazard. The sensor 42 of one or more
embodiments will be located at or near the base or lowest point of
the system 10. With the system 10 and/or method 100 of the present
disclosure, the operation of the blower 26 functions to dilute,
disperse, or otherwise disrupt the collected refrigerant, such as
refrigerant leaking from the system 10, to reduce the concentration
of refrigerant in the air of an indoor or outdoor space in which
the system 10 is located, thereby reducing the refrigerant level to
a level below the lower flammability limit and reducing the
likelihood of ignition.
[0026] Further, the opening 15 in the return conduit 14 operates to
create a vacuum effect whereby the air atmosphere 17 surrounding
the HVAC/R system is pulled into the opening 15 in the room in
which HVAC/R system 10 is located by increasing the speed and
volume of air 17 entering therein. The air 17 entrainment in the
vicinity, in effect, pulls additional air into the at least one
HVAC/R component 22 and the room in which the HVAC/R system 10 is
located, thereby, diluting the leaked refrigerant to reduce the
likelihood of ignition. It will be appreciated that, upon a main
power source outage, the mitigation or dilution operations
described above may not be available. It will be further
appreciated that the auxiliary power source 40, control logic of
the controller 25 and/or sensor 42 upon sensing of a refrigerant
level above a predetermined refrigerant level, and the powering of
the blower 26, the controller 25, the sensor 42, and/or the damper
12 provide a mitigation system and operation to reduce the
likelihood of refrigerant ignition in the event of a main power
source outage.
[0027] 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.
* * * * *