Methods and systems for controlling working fluid in hvacr systems

Abstract

Methods and systems for controlling working fluid flow in a heating, ventilation, air conditioning and refrigeration (HVACR) unit for an HVACR system are disclosed. The unit includes a compressor having a motor and a drive. The unit also includes a condenser fluidly connected to the compressor. A subcooler is located downstream of the condenser. The unit further includes an evaporator fluidly connected to the condenser. Also the unit includes a controller. The unit also includes a bypass assembly connected to the condenser. The bypass assembly includes a bypass flow control device and a bypass fluid line controlled by the bypass flow control device. When a heat recovery demand is detected by the controller, the controller is configured to open the bypass flow control device to allow a first portion of working fluid to bypass the condenser or the subcooler.

1 - 17 . (canceled) 
     
     
         18 . A heating, ventilation, air conditioning and refrigeration (HVACR) unit for an HVACR system, the HVACR unit comprising:
 a compressor;   a condenser unit having a condenser and a subcooler, the condenser being fluidly connected to the compressor, the subcooler being located downstream of the condenser;   an evaporator fluidly connected to the subcooler;   a heat recovery heat exchanger, the heat recovery heat exchanger and the condenser being arranged in parallel for heat recovery; and   a receiver disposed downstream of the heat recovery heat exchanger and the condenser;   wherein the condenser is a split condenser having at least two slabs of coil,   at least one flow control device is disposed between the compressor and the condenser, the at least one flow control device being disposed upstream of the at least two slabs of coil,   the at least one flow control device is configured to isolate or activate one or more slabs of the at least two slabs of coil.   
     
     
         19 . The HVACR unit of  claim 18 , wherein the heat recovery heat exchanger is a heat recovery condenser. 
     
     
         20 . The HVACR unit of  claim 18 , wherein the condenser is an air cooled condenser. 
     
     
         21 . The HVACR unit of  claim 18 , wherein the flow control device is a valve, a solenoid valve, or a stepping motor valve. 
     
     
         22 . The HVACR unit of  claim 18 , wherein an outlet of the receiver is in fluid communication with an inlet of the subcooler. 
     
     
         23 . The HVACR unit of  claim 18 , further comprising a second flow control device disposed upstream of the receiver and downstream of an outlet of the heat recovery heat exchanger,
 the second flow control device is configured to regulate a working fluid flow from the heat recovery heat exchanger to the receiver.   
     
     
         24 . The HVACR unit of  claim 18 , further comprising a third flow control device disposed upstream of an inlet of receiver and downstream of the condenser. 
     
     
         25 . The HVACR unit of  claim 24 , wherein the at least two slabs of coil have at least two outlets including a first outlet and a second outlet. 
     
     
         26 . The HVACR unit of  claim 25 , further comprising a first valve and a second valve, the first valve being disposed between the first outlet and the third flow control device, the second valve being disposed between the second outlet and the third flow control device. 
     
     
         27 . The HVACR unit of  claim 26 , wherein the first outlet and the second outlet are in fluid communication with an inlet of the receiver. 
     
     
         28 . The HVACR unit of  claim 27 , wherein the first valve is a check valve, the second valve is a check valve, and the first valve and the second valve are configured to prevent a working fluid from flowing back into the condenser. 
     
     
         29 . The HVACR unit of  claim 28 , wherein the third flow control device is a ball valve, an electronic flow pressure regulating valve, or an automatic electronic expansion valve. 
     
     
         30 . The HVACR unit of  claim 18 , further comprising a filter and an expander disposed between the subcooler and the evaporator. 
     
     
         31 . The HVACR unit of  claim 18 , wherein the condenser unit includes a second condenser. 
     
     
         32 . The HVACR unit of  claim 31 , wherein the at least one flow control device is configured to isolate or activate at least one of the condenser and the second condenser. 
     
     
         33 . The HVACR unit of  claim 32 , wherein the at least one of the condenser and the second condenser are isolated when the at least one flow control device is closed. 
     
     
         34 . The HVACR unit of  claim 18 , wherein the compressor is a single compressor. 
     
     
         35 . The HVACR unit of  claim 18 , wherein the compressor includes at least two compressors sharing a suction line and a discharge line.