Heating, ventilation, and air conditioning combustion suppression system

A heating ventilation and air conditioning (HVAC) combustion suppression system. The HVAC combustion suppression system includes a sensor that detects and emits a signal indicative of a refrigerant released from an HVAC system into an enclosed space. The system also includes a suppression component that blocks or reduces combustion of the refrigerant in the enclosed space, and a controller that receives the signal from the sensor. The controller in response to the signal activates the suppression component to suppress combustion of the refrigerant in the enclosed space.

BACKGROUND

The disclosure relates generally to HVAC systems.

Heating, ventilation, and air conditioning (HVAC) systems cool enclosed spaces by exchanging energy between a refrigerant and air. HVAC systems do this by circulating a refrigerant between two heat exchangers commonly referred to as an evaporator coil and a condenser coil. As refrigerant passes through the evaporator coil and the condenser coil, the refrigerant either absorbs or discharges thermal energy. More specifically, as air passes over the evaporator coil, the air cools as it loses energy to the refrigerant passing through the evaporator coil. In contrast, the condenser enables the refrigerant to discharge heat into the atmosphere. Inasmuch as refrigerant leaks compromise system performance or result in increased costs, it is accordingly desirable to provide detection and response systems and methods for the HVAC system to reliably detect and respond to any refrigerant leaks of the HVAC system.

SUMMARY

The present disclosure relates to a heating ventilation and air conditioning (HVAC) combustion suppression system. The HVAC combustion suppression system includes a sensor that detects a refrigerant released from an HVAC system into an enclosed space and emits a signal indicative of the refrigerant. The system also includes a suppression component that blocks or reduces combustion of the refrigerant in the enclosed space, and a controller that receives the signal from the sensor. The controller in response to the signal actuates the suppression component to suppress combustion of the refrigerant in the enclosed space.

The present disclosure also relates to a heating ventilation and air conditioning (HVAC) combustion suppression system. The HVAC combustion suppression system includes a sensor that detects and emits a signal indicative of a combustion event in an enclosed space. The system also includes a suppression component that extinguishes the combustion event, and a controller that receives the signal from the sensor. The controller in response to the signal activates the suppression component to extinguish the combustion event in the enclosed space.

The present disclosure also relates to a heating ventilation and air conditioning (HVAC) safety system that includes a sensor that detects and emits a signal indicative of a refrigerant and/or combustion in an enclosed space. The HVAC safety system also includes an electronic device and a controller that receives the signal from the sensor and transmits a warning message to the electronic device.

DETAILED DESCRIPTION

Embodiments of the present disclosure include an HVAC combustion suppression system that blocks and/or reduces combustion of a refrigerant as well as extinguishes combustion events. The HVAC combustion suppression system may include one or more sensors that detect the presence of a refrigerant and communicate this information to a controller. The controller may then compare the signal indicative of a concentration level of a refrigerant to a threshold level. If the concentration level of the refrigerant is above the threshold level, the controller may activate one or more suppression components to block and/or reduce combustion of the refrigerant. The controller may also receive feedback from one or more sensors capable of sensing combustion. In response, the controller may activate one or more suppression components to reduce the size of and/or extinguish the combustion event. By blocking and/or reducing combustion of a refrigerant as well as extinguishing a combustion event, the HVAC combustion suppression system may increase the safety of an HVAC system using a refrigerant.

FIG. 5is a schematic view of an embodiment of a split HVAC system120that uses a desired refrigerant. The refrigerant being classified as numerically equal to or greater than the refrigerants A2L or B2L according to the ISO 817 refrigerant classification scheme. For example, the refrigerant may be an A2L, B2L, A2, B2, A3, or B3 refrigerant accordingly to the ISO 817 refrigerant classification scheme. Because the HVAC system120uses a refrigerant to cool an enclosed space122, the HVAC system120includes an HVAC combustion suppression system124capable of blocking and/or reduces combustion of the refrigerant as well as reducing and/or extinguishing a combustion event. Examples of an enclosed space122include a home, apartment, office building.

The HVAC system120may be a split system with refrigerant conduits54that couple the indoor unit56to the outdoor unit58. The refrigerant conduits54transfer the refrigerant between the indoor unit56and the outdoor unit58, primarily transferring liquid refrigerant in one direction and vaporized refrigerant in an opposite direction.

A heat exchanger60in the outdoor unit58serves as a condenser for re-condensing vaporized refrigerant flowing from the indoor unit56to the outdoor unit58via one of the refrigerant conduits54, while a heat exchanger62of the indoor unit56functions as an evaporator. During operation, the liquid refrigerant in the heat exchanger62absorbs energy causing it to evaporate. After passing through the heat exchanger62, the evaporated refrigerant is redirected to the outdoor unit58where a fan64draws air over the heat exchanger60enabling the vaporized refrigerant to condense by rejecting heat to the atmosphere. The heat transfer cycle then begins again as the liquid refrigerant is pumped with the compressor65back to the heat exchanger62where it again absorbs energy from air blown by the blower66. The cooled air is then carried through one or more air ducts68to various areas of the enclosed space122.

In some embodiments, the indoor unit56may include the furnace system70. The furnace system70may include a burner assembly and heat exchanger, among other components. In some embodiments, the furnace system70combusts a fuel, such as natural gas, to generate heat. The combustion products may pass through tubes or piping in a heat exchanger, separate from heat exchanger62, such that air directed by the blower66passing over the tubes or pipes absorbs heat from the combustion products. The heated air may then be routed from the furnace system70to the ductwork68for heating the enclosed space122. In some embodiments, the furnace70may not combust a fuel, but may instead use electrical energy to heat air blown by the blower66.

The HVAC system120includes an HVAC combustion suppression system124that blocks, reduces, and/or extinguishes combustion events. The HVAC combustion suppression system124includes one or more sensors126capable of sensing the presence of the refrigerant and/or a burning refrigerant and transmitting a signal(s) indicative of the condition to a controller128. The sensors126may be positioned in various locations on the indoor unit56and/or in the enclosed space122. For example, the HVAC combustion suppression system124may include sensors126in air ducts68, in one or more rooms of the enclosed space122, as well as sensors in the indoor unit56. The sensors126within the indoor unit56may be upstream as well as downstream from the heat exchanger62. As illustrated, the indoor unit56includes a sensor126in a blower compartment130, a furnace compartment132, and in a heat exchanger compartment134. The types of sensors126used to detect concentrations of the refrigerant may include electrochemical, catalytic bead, photoionization, infrared point, infrared imaging, semiconductor, ultrasonic, holographic.

The controller128may include a processor136and a memory138used in processing one or more signals from one or more sensors126. For example, the processor136may be a microprocessor that executes software to control the HVAC combustion suppression system124. The processor136may include multiple microprocessors, one or more “general-purpose” microprocessors, one or more special-purpose microprocessors, and/or one or more application specific integrated circuits (ASICS), or some combination thereof. For example, the processor136may include one or more reduced instruction set (RISC) processors.

The memory138may include a volatile memory, such as random access memory (RAM), and/or a nonvolatile memory, such as read-only memory (ROM). The memory138may store a variety of information and may be used for various purposes. For example, the memory138may store processor executable instructions, such as firmware or software, for the processor136to execute. The memory may include ROM, flash memory, a hard drive, or any other suitable optical, magnetic, or solid-state storage medium, or a combination thereof. The memory may store data, instructions and any other suitable data.

In operation, one or more sensors126send signals indicative of the refrigerant concentration to a controller128. The controller128receives and interprets the signals, and then compares the detected concentration of refrigerant to a threshold concentration. The controller128compares the detected concentration of refrigerant to the threshold concentration to determine whether the detected concentration of refrigerant is capable of combustion. If the concentration is incapable of combustion, the controller128may continue to monitoring feedback from the sensors126. However, if the concentration is capable of combustion, the controller128may activate one or more suppression components140to reduce and/or block combustion of the refrigerant from an energy source.

The suppression components140may be placed at one or more locations in the HVAC system102and/or enclosed space122. For example, the suppression components140may couple to the indoor unit58, be placed within one or more compartments of the indoor unit58, be placed within one or more air ducts68. By including multiple suppression components, the HVAC combustion suppression system124enables a focused/tailored response to detection of a combustion event and/or detection of a refrigerant concentration above a threshold level.

In some embodiments, the suppression component140may be a pump142that pumps an inert gas, such as nitrogen, from an inert gas supply144, such as a tank, into the HVAC system120. The inert gas acts as a combustion suppressant by reducing the percentage of oxygen available for combustion in vicinity of the refrigerant. In addition to reducing the oxygen concentration, the inert gas may also facilitate dispersion of the refrigerant to a concentration level that is incapable of combusting. In some embodiments, one or more of the sensors126may detect the concentration of oxygen in the air enabling the controller128to lower the oxygen concentration with the inert gas to a level that blocks and/or reduces combustion of the refrigerant while simultaneously maintaining the oxygen at a level suitable for humans.

The pump142may pump the inert gas upstream and/or downstream from the heat exchanger62, and/or into the heat exchanger compartment134. For example, the pump142may pump the inert gas into the HVAC system120upstream from the blower66enabling the blower66to suck/draw the inert gas into the indoor unit56. The blower66may then blow the inert gas through the indoor unit56to suppress combustion of the refrigerant within the indoor unit56or downstream of the indoor unit56. In some embodiments, the pump142may pump the inert gas upstream of the heat exchanger62. For example, the pump142may pump the inert gas into the air ducts68and/or into the rooms fed by the air ducts68.

In some embodiments, the pump142may pump a dry chemical from a dry chemical supply144into the HVAC system120. Like the inert gas, the dry chemical blocks combustion of the refrigerant by inhibiting the combustion reaction. The pump142may pump the dry chemical upstream and/or downstream from the heat exchanger compartment134, and/or into the heat exchanger compartment134. For example, the pump142may pump the dry chemical into the HVAC system120upstream from the blower66enabling the blower66to suck/draw the dry chemical into the indoor unit56. The blower66may then blow the inert gas through the indoor unit56to suppress combustion of the refrigerant within the indoor unit56or downstream of the indoor unit56.

In some embodiments, the suppression component140may be a valve146that releases a compressed inert gas from an inert gas supply144, such as a tank. The inert gas may be released upstream from the heat exchanger compartment134, downstream from the heat exchanger compartment134, and/or into the heat exchanger compartment134. For example, the valve146may release the inert gas into the HVAC system120upstream from the blower66enabling the blower66to suck/draw the inert gas into the indoor unit56. The blower66may then blow the inert gas through the indoor unit56to suppress combustion of the refrigerant within the indoor unit56or downstream of the indoor unit56.

In some embodiments, the valve146may release a dry chemical from a dry chemical supply144for use in suppressing combustion of the refrigerant. For example, when the valve146opens the blower66may draw the dry chemical from the dry chemical supply144and blow it through the HVAC system120to suppress combustion of the refrigerant.

In some embodiments, the suppression component140is the blower66. The blower66may act as a suppression component140by reversing the direction in which it blows in order to suck the refrigerant out of the HVAC system120and discharging it into the atmosphere. In other words, the blower66may draw the refrigerant out of the HVAC system120in order to reduce the concentration of the refrigerant to a level where it can no longer ignite.

As explained above, the HVAC combustion suppression system124may also use sensors126that detects burning refrigerant, and in response sends a signal to the controller128. In some embodiments, the sensor126may be a chemical sensor capable of detecting the combustion products of the refrigerant and/or combustion products produced by a combustion event. In some embodiments, the sensor126may be a sensor capable of detecting energy emissions such as an optical sensor, infrared sensor. It should also be understood that the HVAC combustion suppression system124may use a combination of sensors to detect a combustion event. For example, the HVAC combustion suppression system124may use multiple sensors126to verify the existence of a combustion event, cross-reference, before engaging one or more suppression components140that disperse a dry chemical, an inert gas.

The controller128may communicate through wireless and/or wired networks with one or more electronic devices152. That is, the controller128may provide updates and/or receive input from a user through electronic devices152. The electronic devices152may be a cell phone, laptop, smart thermostat, tablet, watch. For example, the controller128may provide a warning to a user that refrigerant has leaked into the enclosed space122or that a combustion event has been detected. The warning may be provided in a variety ways including as a written message on a display of an electronic device152, an audio message, a warning sound, flashing lights, or combinations thereof.

The controller128may also request feedback from the user through electronic device152. For example, the controller128may request confirmation before deploying the dry chemical, the inert gas, or a combination thereof. The requested feedback may also include confirming shutoff of the compressor65and/or the blower66to reduce spreading the refrigerant or introducing more refrigerant into the enclosed space122.

FIG. 6is a schematic view of an embodiment of an HVAC combustion suppression system124. As explained above, the HVAC combustion suppression system124controls one or more suppression components140to reduce/block combustion of a refrigerant and/or extinguish a combustion event. As illustrated, the enclosed space122may include one or more rooms170. Instead of injecting inert gas and/or dry chemicals into each room170, air duct68, and/or compartment of the indoor unit58, the controller128may be programmed to inject the inert gas and/or dry chemicals into a subset/portion of the enclosed space122depending on the detected location of the refrigerant and/or combustion event. For example, one of the rooms170may have a concentration of refrigerant capable of combustion or an actual combustion event. Accordingly, the controller128may only activate the suppression component140closest to the problem area.

FIG. 7illustrates a flow chart190of a method for controlling an HVAC combustion suppression system124. The method begins as the controller128receives signals from one or more sensors126, as indicated by step192. The signals from the sensors126are indicative of a concentration of refrigerant in an enclosed space122and/or a detection of a combustion event. The controller128receives the one or more signals from the sensors126to determine/detect the concentration of the refrigerant and/or combustion, as indicated by step194. The controller128then determines if the concentration of the refrigerant is greater than a threshold, such as a concentration capable of combusting, and/or if there is a combustion event, as indicated by step196. If the answer is yes to either question, the controller128may activate one or more suppression components140to inhibit combustion of the refrigerant and/or extinguish a combustion event, as indicated by step198. The controller128may then transmit a warning to the electronic device152and/or request feedback from a user through the electronic device152, as indicated by step200. As explained above, in some embodiments the requested feedback from the controller128may include confirmation to activate one or more suppression components. The requested feedback may also include a request for the user to designate which suppression components140to activate.

If the concentration is less than the threshold and no combustion is detected, the controller128may still transmit a warning to an electronic device152advising a user that there is a leak of refrigerant in the enclosed space122, as indicated by step202. In some embodiments, the controller128may request feedback from the user regarding activation of one or more suppression components140. The controller128receives the feedback from the electronic device152as a signal indicating a command to activate one or more suppression components140, as indicated by step204. In response to the signal, the controller128may activate one or more suppression components140to block and/or reduce combustion of the refrigerant, as indicated by step206.