A system includes a pressure exchanger (PX) configured to receive a first fluid at a first pressure, receive a second fluid at a second pressure, and exchange pressure between the first fluid and the second fluid. The first fluid is to exit the PX at a third pressure and the second fluid is to exit the PX at a fourth pressure. The system further includes a first heat exchanger configured to provide the first fluid to the PX and provide corresponding thermal energy from the first fluid to a third fluid. The system further includes a turbine configured to receive the third fluid output from the first heat exchanger. The turbine is further configured to convert corresponding thermal energy of the third fluid into kinetic energy.

Provided is a method of determining a loss of charge of refrigerant in a refrigeration system. The method comprises determining at least one performance characteristic of the refrigeration system. The at least one performance characteristic comprises a mass flow rate of the refrigerant in the refrigeration system. The method further comprises, when one or more predetermined criteria are met on the basis of the performance characteristic, determining a loss of charge in the refrigeration system.

In various implementations, an air conditioner may include more than one expansion device. Refrigerant flow through the expansion device(s) may be controlled based at least partially on an operational property of the air conditioner.

A refrigeration apparatus including a compressor (301), a condenser (302), an expansion device (304), and an evaporator (305), fluidly connected to form a refrigeration cycle for a refrigerant, wherein the compressor (301) has a variable working capacity, and wherein the expansion device (304) has a configurable flow resistance with respect to the refrigerant passing through the expansion device. The apparatus further includes a controller (300) which is configured to determine a current working capacity of the compressor (301) and to control the resistance of the expansion device (304) in dependence on the current working capacity of the compressor (301). The controller (300) is further configured to control the resistance of the expansion device (304) in order to achieve a mass flow of the refrigerant through the expansion device (304), which mass flow corresponds to a mass flow of the refrigerant through the compressor (301).

A packaged, pumped liquid, evaporative-condensing recirculating ammonia refrigeration system with charges of 10 lbs or less of refrigerant per ton of refrigeration capacity. The compressor and related components are situated inside the plenum of a standard evaporative condenser unit, and the evaporator is close coupled to the evaporative condenser. Single or dual phase cyclonic separators may also be housed in the plenum of the evaporative condenser.

A refrigeration system includes a heat exchanger including a gas cooler or condenser. The heat exchanger includes a heat exchanger inlet and a heat exchanger outlet. The refrigeration system further includes an evaporator including an evaporator inlet and an evaporator outlet. The refrigeration system further includes a compressor including a compressor inlet fluidly coupled to the evaporator outlet and a compressor outlet fluidly coupled to the heat exchanger inlet. The refrigeration system further includes a pressure exchanger (PX) including a first PX inlet fluidly coupled to the heat exchanger outlet, a first PX outlet fluidly coupled to the heat exchanger inlet, a second PX inlet fluidly coupled to the evaporator outlet, and a second PX outlet fluidly coupled to the evaporator inlet.

A system includes a pressure exchanger (PX) to receive a first fluid at a first pressure, second fluid at a second pressure, and exchange pressure between the first fluid and the second fluid. The first fluid is to exit the PX at a third pressure and the second fluid is to exit the PX at a fourth pressure. A first condenser is to receive the first fluid from a compressor and provide thermal energy from the first fluid to a first environment. A second condenser is to receive the second fluid from the PX and provide thermal energy from the second fluid to a second environment. A heat exchanger is to receive the first fluid from the first condenser and the second fluid from the second condenser, provide thermal energy from the first fluid to the second fluid, and provide the first fluid to the PX.

In various implementations, an air conditioner may include more than one expansion device. Refrigerant flow through the expansion device(s) may be controlled based at least partially on an operational property of the air conditioner.

Systems and methods described herein provide for valve detection and monitoring. A valve detection system includes an activity detector configured to detect flow downstream of a valve in a pipeline and an analyzer assembly. The analyzer assembly stores state detection logic for one or more use cases and receives input to select a use case. The analyzer assembly identifies a flow reading based on a signal from the activity detector and determines a status of the pipeline based on the flow reading and the state detection logic for the selected use case.

Disclosed herein is a method for failure prediction in an Air Cycle Machine (ACM). The method includes calculating a change in energy of an ACM airflow passing from an inlet of the ACM compressor to an outlet of the ACM compressor. The method may also include calculating a kinetic energy of the ACM compressor based on calculating the work of the ACM compressor on the ACM airflow as the ACM airflow passes through the ACM compressor, calculating the work of the ACM compressor based on the inlet temperature of the ACM airflow at the inlet of the ACM compressor, compressor pressure ratio of the ACM compressor, and a fluid property of the ACM airflow at the inlet of the ACM compressor. Additionally, the method can include calculating an ACM compressor efficiency as a ratio of the change in energy of the ACM airflow across the ACM compressor to the kinetic energy of the compressor. The method may further include predicting a failure state of the ACM compressor.