There is disclosed heat pump, comprising: an internal heat exchanger configured to transfer heat from refrigerant in a liquid line pathway to refrigerant in a suction line pathway, to superheat the refrigerant upstream of a compressor; and a controller configured to: control an expansion valve to maintain a target superheat of refrigerant at a control location. The target superheat is variable and is determined based on one or more operating conditions of the heat pump. There is also disclosed a method of operating a heat pump and a simulation method to determine a variable superheat.

A refrigerant cycle system includes: a first refrigerant circuit that includes a first heat exchanger, a first compressor, and a first cascade heat exchanger and that is configured as a first vapor compression refrigeration cycle; a second refrigerant circuit that includes the first cascade heat exchanger, a second compressor, and a second heat exchanger and that is configured as a second vapor compression refrigeration cycle; a first unit that accommodates the first heat exchanger and the first compressor; a second unit that accommodates the first cascade heat exchanger and the second compressor; and a third unit that accommodates the second heat exchanger. The first unit, the second unit, and the third unit are disposed apart from each other. The first cascade heat exchanger performs heat exchange between a first refrigerant that flows through the first refrigerant circuit and a second refrigerant that flows through the second refrigerant circuit.

Systems and methods are provided and include first and second case controllers for first and second refrigeration cases. The first case controller receives a first air temperature value of the first refrigeration case and communicates the first air temperature value to the second case controller. The second case controller receives a second air temperature value, determine an evaporator saturated suction temperature (SST) value, controls an evaporator pressure regulator based on a comparison of the evaporator SST value with an evaporator SST setpoint, determines an air temperature control value, determines whether the air temperature control value is within a predetermined range of an air temperature setpoint, and adjusts the evaporator SST setpoint in response to the air temperature control value being outside of the predetermined range of the air temperature setpoint.

A liquid level detector includes: a vertically-mounted accumulator configured to store refrigerant; a heater configured to heat the accumulator; a temperature detector configured to detect a surface temperature of the accumulator; a pressure detector configured to detect a pressure of the refrigerant in the accumulator; and a controller configured to detect a position of a liquid surface of the refrigerant in the accumulator based on a surface temperature of the accumulator detected by the temperature detector when the accumulator is heated by the heater, and a pressure of the refrigerant in the accumulator detected by the pressure detector.

Example implementations relate to a leak mitigation (LM) system. The LM system may include a collection tank, a first valve unit coupled to the collection tank, a second valve unit coupled to a cooling loop carrying a coolant, and an LM pump coupled between the first valve unit and the second valve unit. Moreover, the leak mitigation system may also include a controller operatively coupled to the first valve unit, the second valve unit, and the LM pump to operate, in an event of a leak of the coolant from the cooling loop, the first valve unit, the second valve unit, and the LM pump to transfer at least a portion of the coolant to the collection tank from the cooling loop via the second valve unit and the first valve unit.

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.

An HVAC system includes an evaporator, a condenser, a compressor. A first refrigerant path flows through a first expansion valve, first evaporator inlet, within the evaporator, and out of the evaporator through a first evaporator outlet. A second refrigerant path flows through a second expansion valve, a second evaporator inlet, within the evaporator, and out of the evaporator through a second evaporator outlet. Refrigerant flows from the condenser to the first refrigerant path and the second refrigerant path, and from the first refrigerant path and the second refrigerant path to the compressor.

A refrigerant amount monitoring and charging control system for an electric vehicle and a method thereof include: a controller; a battery management module electrically connected to the controller; a high-speed charging gun connected to the vehicle when the vehicle is charged and configured to generate a high-speed charging signal during performing high-speed charging and to send the high-speed charging signal to the controller; an ambient temperature sensor electrically connected to the controller and configured to obtain an ambient temperature and to send the obtained ambient temperature to the controller; and a chiller including an electronic expansion valve and an evaporator. A situation where a vehicle battery is unable to be cooled by a refrigerant due to an insufficient refrigerant amount may be prevented by controlling charging power based on a monitoring result of a current refrigerant amount.

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.

A refrigeration system configured for controlling operation of a compressor is disclosed. The refrigeration system comprises an electronic expansion device operatively coupled with the compressor. The refrigeration system comprises a controller operatively coupled with the electronic expansion device. The controller is configured to control the electronic expansion valve based on a superheat setpoint range. The controller is further configured to adjust the superheat setpoint range in response to an operating point of the compressor being within a threshold distance from a boundary of an operational envelope for the compressor.