Refrigerant leak mitigation for multi-circuit refrigerant systems

Abstract

The present disclosure relates to a multi-circuit heating, ventilation, and air conditioning (“HVAC”) system for use with a first refrigerant in a first refrigerant circuit and a second refrigerant in a second refrigerant circuit. The second refrigerant circuit is fluidically isolated from the first refrigerant circuit. Additionally, a first sensor is operable to detect a leak of at least one of the first and second refrigerants or is operable to measure temperature or pressure from the first refrigerant circuit or the second refrigerant. The multi-circuit HVAC system further including a controller programmed to receive the measurement from the sensor to identify the circuit or circuits that are leaking, to turn off operation of the leaking circuit or circuits, and if only one circuit is leaking, operate only the other of the circuits.

What is claimed is: 
     
         1 . A multi-circuit heating, ventilation, and air conditioning (“HVAC”) system for use with a first refrigerant and a second refrigerant, the multi-circuit HVAC system comprising:
 a first refrigerant circuit for the first refrigerant comprising a first compressor, a first outdoor heat exchanger, a first expansion valve, and a first set of tubes of an indoor heat exchanger; 
 a second refrigerant circuit for the second refrigerant and comprising a second compressor, a second outdoor heat exchanger, a second expansion valve, and a second set of tubes of the indoor heat exchanger, wherein the first set of tubes are fluidically isolated from the second set of tubes to fluidically isolate the first refrigerant circuit from the second refrigerant circuit; 
 at least one of a first sensor operable to detect a leak of refrigerant from both the first refrigerant circuit and the second refrigerant circuit or second sensors operable to measure at least one of temperature or pressure along the first refrigerant circuit and the second refrigerant circuit; and 
 a controller in communication with the first sensor or second sensors and with a database including a stored set of operational values, wherein the controller is programmed to:
 receive measurements from at least one of the first sensor or the second sensors; 
 compare the received measurements with a predefined range of the stored set of operational values; 
 identify the refrigerant circuit or circuits that are leaking based on the received measurements being outside of the predefined range; and 
 turn off operation of the leaking circuit or circuits, and if only one circuit is leaking, operate the other of the circuits. 
 
 
     
     
         2 . The multi-circuit HVAC system of  claim 1 , wherein the operation that the controller is turning off is an operation of the corresponding compressor of the leaking circuit or circuits, while allowing the corresponding compressor of the non-leaking circuit or circuits to remain operational or set to a partial-load mode. 
     
     
         3 . The multi-circuit HVAC system of  claim 2 , further comprising a blower operable to move an air flow through at least one of the first indoor heat exchanger or the second indoor heat exchanger, wherein the controller is further programed to operate the blower while the corresponding compressor is turned off. 
     
     
         4 . The multi-circuit HVAC system of  claim 1 , further comprising the first sensor, wherein the first sensor is a leak detector positioned to detect a leak from either of the first and second indoor heat exchangers, wherein upon detecting the leak, the leak detector is configured to trigger the controller to compare the received measurements with the stored set of operational values to confirm the leak. 
     
     
         5 . The multi-circuit HVAC system of  claim 1 , further comprising the second sensors, wherein the second sensors are temperature or pressure sensors on the first outdoor heat exchanger, the second outdoor heat exchanger, or refrigerant lines within the refrigerant circuit or circuits, and wherein the controller is further programmed to identify the leaking circuit based on measurements of the second sensors. 
     
     
         6 . The multi-circuit HVAC system of  claim 5 , wherein if both the first refrigerant circuit and the second refrigerant circuit are operating in a cooling mode or a heating mode, the controller is programmed to compare measured temperature or pressure from the second sensors of the first refrigerant circuit to the second refrigerant circuit, and the controller is programmed identify the refrigerant circuit or circuits that are leaking based on which measured temperature or pressure of the refrigerant circuit is lower. 
     
     
         7 . The multi-circuit HVAC system of  claim 6 , wherein the controller is programmed to determine a leak location along the leaking circuit based on which of the second sensors measure the lower temperature or pressure. 
     
     
         8 . A method of operating a multi-circuit heating, ventilation, and air conditioning (“HVAC”) system for use with a first refrigerant in a first refrigerant circuit and a second refrigerant in a second refrigerant circuit fluidically isolated from the first refrigerant circuit to condition an environment of a space, the method comprising:
 receiving measurements from at least one of a first sensor or second sensors within the first refrigerant circuit and the second refrigerant circuit at a controller in communication with a database including a stored set of operational values; 
 comparing the received measurements with a predefined range of the stored set of operational values; 
 identifying the refrigerant circuit or circuits experiencing a leak of refrigerant based on the compared received measurements being outside of the predefined range; 
 turning off operation of the leaking circuit or circuits using the controller; and 
 if only one circuit is leaking, operating the other of the circuits using the controller. 
 
     
     
         9 . The method of  claim 8 , wherein the turning off the operation of the leaking circuit or circuits using the controller further comprises turning off an operation of a corresponding compressor of the leaking circuit or circuits, while allowing a corresponding compressor of the non-leaking circuit or circuits remains operational or set to a partial-load mode. 
     
     
         10 . The method of  claim 9 , further comprising operating a blower to move an air flow through at least one of a first indoor heat exchanger or a second indoor heat exchanger when the corresponding compressor is turned off. 
     
     
         11 . The method of  claim 8 , wherein the first refrigerant circuit comprises a first indoor heat exchanger and the second refrigerant circuit comprises a second indoor heat exchanger, the method further comprising:
 detecting a leak of refrigerant from either of the first and second indoor heat exchangers using the first sensor comprising a leak detector; and   triggering, with the leak detector, a comparison of the received measurements with a predefined range of the stored set of operational values to confirm the leak.   
     
     
         12 . The method of  claim 8 , further comprising determining, with the controller, a leak location along the leaking circuit based on a position of the first sensor or second sensors. 
     
     
         13 . The method of  claim 8 , wherein the received measurements comprises a temperature or pressure of the first refrigerant circuit and a temperature or pressure of the second refrigerant circuit. 
     
     
         14 . The multi-circuit HVAC system of  claim 13 , further comprising comparing the temperature or pressure of the first refrigerant circuit with the temperature or pressure of the second refrigerant circuit; and determining a leak location along the leaking circuit based on which of the received measurements is at a lower temperature or pressure. 
     
     
         15 . A controller for a multi-circuit heating, ventilation, and air-conditioning (“HVAC”) system for use with a first refrigerant circuit and a second refrigerant circuit, wherein the multi-circuit HVAC system comprises at least one of a leak detector operable to detect a leak of refrigerant from both the first refrigerant circuit and the second refrigerant circuit or sensors operable to measure at least one of temperature or pressure along the first refrigerant circuit and the second refrigerant circuit, wherein the controller in communication with a database including a stored set of operational values is programmed to:
 receive measurements from at least one of the leak detector or the sensors; 
 compare the received measurements with a predefined range of the stored set of operational values; 
 identify the refrigerant circuit or circuits that are leaking based on the compared received measurements being outside of the predefined range; and 
 turn off operation of the leaking circuit or circuits, and if only one circuit is leaking, operate the other of the circuits. 
 
     
     
         16 . The controller of  claim 15 , wherein the controller is further programmed to turn off the operation of a compressor of the leaking circuit or circuits, while allowing a corresponding compressor of the non-leaking circuit or circuits remains operational or set to a partial-load mode. 
     
     
         17 . The controller of  claim 16 , wherein the controller is further programmed to operate a blower to move an air flow through at least one of a first indoor heat exchanger or a second indoor heat exchanger when the compressor is turned off. 
     
     
         18 . The controller of  claim 15 , wherein the first refrigerant circuit comprises a first indoor heat exchanger and the second refrigerant circuit comprises a second indoor heat exchanger and wherein the leak detector is positioned such that the leak detector is operable to detect the leak from either of the first and second indoor heat exchangers, and the leak detector is operable to trigger the controller to compare the received measurements with a predefined range of the stored set of operational values. 
     
     
         19 . The controller of  claim 15 , wherein the multi-circuit HVAC system comprises the leak detector and the sensors and wherein the controller is further programmed to determine a leak location along the leaking circuit based on a position of the leak detector and the sensors. 
     
     
         20 . The controller of  claim 15 , wherein the multi-circuit HVAC system comprises the sensors to measure a temperature or pressure of the first refrigerant circuit and a temperature or pressure of the second refrigerant circuit, the controller is further programmed to compare the temperature or pressure of the first refrigerant circuit with the temperature or pressure of the second refrigerant circuit, and the controller is further programmed to determine a leak location along the leaking circuit based on which of the received measurements is at a lower temperature or pressure.