A method includes receiving, by a processing device and from a variable frequency drive coupled to one or more compressors, operation information of the one or more compressors. The method also includes comparing the operation information of the one or more compressors to an operation threshold and determining that the operation information satisfies the operation threshold. The method also includes changing, based on the determination that the operation information of the one or more compressors satisfies the operation threshold, an operation parameter of a component of the refrigeration system. Changing the operation parameter increases at least one of: (i) a velocity of a working fluid in a piping assembly fluidly coupled to the one or more compressors, or (ii) a flow rate of an oil in the piping assembly flowing into the one or more compressors.

A method of operating a transport refrigeration system having a plurality of inverters configured to power a refrigeration unit includes placing a first inverter of the plurality of inverters in an active state; monitoring a load on the first inverter; comparing the load on the first inverter to an upper threshold; placing a second inverter of the plurality of inverters in an active state upon the load on the first inverter being greater than the upper threshold.

There is disclosed a method of controlling an air-cargo transport refrigeration unit to regulate a compressor speed and a condenser fan speed. There is also disclosed a method of controlling an air-cargo transport refrigeration unit based on determining an in-flight condition of the refrigeration unit.

Disclosed are climate systems and methods for control the climate systems. A climate system includes a refrigerant circuit, a first compressor, a second compressor, a first refrigerant-to-air heat exchanger, a second refrigerant-to-air heat exchanger, and a controller communicatively coupled to the first and second compressors. Respective outlets of the first and second compressors are fluidically coupled to the first refrigerant-to-air heat exchanger, the first refrigerant-to-air heat exchanger is fluidically coupled to the second refrigerant-to-air heat exchanger, and the second refrigerant-to-air heat exchanger is fluidically coupled with respective inlets of the first and second compressors. The fluidic connection between the second refrigerant-to-air heat exchanger and the first and second compressors includes a vertical split that is configured to mitigate or reduce the amount of compressor oil that migrates to dormant components.

A method of detecting electrical failure in a refrigeration system is provided. The method includes determining whether a present superheat of the refrigeration system is between a maximum superheat and a minimum superheat for the refrigeration system, the maximum superheat and the minimum superheat defining a normal operating range. The method also includes detecting an electrical property of an expansion valve assembly of the refrigeration system responsive to the superheat being outside the normal operating range. The method further includes determining whether the expansion valve assembly as experienced an electrical failure based on at least the electrical property. A signal indicating that the expansion valve has experienced an electrical failure is generated based on a determination that the expansion valve assembly has experienced the electrical failure.

Disclosed herein are air conditioning systems including a refrigerant line configured to transport a refrigerant; a compressor in fluid communication with the suction line; and a controller in communication with a sensor configured to measure a characteristic of the refrigerant line. The compressor can be configured to move the refrigerant through the refrigerant line, and the refrigerant can have a first temperature at the outlet of the compressor. The controller can be configured to receive sensor data from the sensor indicating a current value associated with the characteristic of the refrigerant line; determine, based at least partially on the sensor data, that the characteristic of the refrigerant line is above a predetermined threshold; and output instructions for the compressor to perform one or more corrective actions.

Thermal management systems are described. These systems include a refrigerant receiver configured to store a refrigerant fluid, an evaporator, a closed-circuit refrigeration system having a closed fluid circuit path, with the refrigerant receiver and evaporator disposed in the closed fluid circuit path, and the closed fluid circuit path including a condenser and compressor. These systems also include a modulation capacity control circuit configured to selectively divert refrigerant vapor flow to the condenser from the compressor by diverting a portion of refrigerant vapor flow (diverted flow) from the compressor to the refrigerant receiver in accordance with cooling capacity demand. These systems also include an open-circuit refrigeration system having an open fluid circuit path with the refrigerant receiver and the evaporator, and an exhaust line that discharges the refrigerant fluid from the exhaust line so that the discharged refrigerant fluid is not returned to the open-circuit and the closed-circuit refrigerant fluid flow paths.

An appliance includes an appliance housing, an interface adapted to receive power information, a plurality of sensors for sensing environmental conditions, a plurality of controls for controlling operations of the appliance, and an intelligent control. The intelligent control is disposed within the appliance housing and operatively connected to the interface and the plurality of sensors and adapted to dynamically select control values associated with the plurality of controls based on at least one of the power information, the environmental conditions, or a combination thereof to increase energy efficiency of the appliance.

An air conditioner unit includes a variable speed compressor for circulating refrigerant through an outdoor heat exchanger and an indoor heat exchanger, an indoor fan, and an outdoor fan. A controller obtains an indoor temperature using an indoor temperature sensor and operates the variable speed compressor, the indoor fan, and the outdoor fan at a first capacity level to adjust the indoor temperature toward a target temperature. The controller determines that a rate of change of the indoor temperature is below a predetermined rate threshold and operates the variable speed compressor, the indoor fan, and the outdoor fan at a second capacity level.

A method and system for improving energy efficiency of a refrigeration system include system components such as a condenser, one or more expansion valves, an evaporator, one or more compressors, and a system controller electrically coupled to the one or more of the system components, according to one embodiment. The system controller is configured to selectively actuate, directly or indirectly, the one or more expansion valves, the condenser, and/or the one or more compressors, at least partially based on temperatures and/or pressures of the system fluid at various points of the system, to control a temperature of a refrigerated area.